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[Xen-devel,v2,4/6] xen/iommu: smmu-v3: Add Xen specific code to enable the ported driver

Message ID 20180524004620.23828-5-sameer.goel@linaro.org
State Superseded
Headers show
Series SMMUv3 driver | expand

Commit Message

Sameer Goel May 24, 2018, 12:46 a.m. UTC
This driver follows an approach similar to smmu driver. The intent here
is to reuse as much Linux code as possible.
- Glue code has been introduced to bridge the API calls.
- Called Linux functions from the Xen IOMMU function calls.
- Xen modifications are preceded by /*Xen: comment */
- xen/linux_compat: Add a Linux compat header
  For porting files directly from Linux it is useful to have a function mapping
  definitions from Linux to Xen. This file adds common API functions and
  other defines that are needed for porting arm SMMU drivers.

Signed-off-by: Sameer Goel <sameer.goel@linaro.org>
---
 xen/arch/arm/p2m.c                    |   1 +
 xen/drivers/Kconfig                   |   2 +
 xen/drivers/passthrough/arm/Kconfig   |   8 +
 xen/drivers/passthrough/arm/Makefile  |   1 +
 xen/drivers/passthrough/arm/smmu-v3.c | 934 +++++++++++++++++++++++++-
 xen/include/xen/linux_compat.h        |  84 +++
 6 files changed, 1001 insertions(+), 29 deletions(-)
 create mode 100644 xen/drivers/passthrough/arm/Kconfig
 create mode 100644 xen/include/xen/linux_compat.h

Comments

Manish Jaggi May 24, 2018, 4:48 a.m. UTC | #1
Hi Sameer,

General Comment, please use appropriate variable names for XXX_domain 
structures in code which is xen specific.


On 05/24/2018 06:16 AM, Sameer Goel wrote:
> This driver follows an approach similar to smmu driver. The intent here
> is to reuse as much Linux code as possible.
> - Glue code has been introduced to bridge the API calls.
> - Called Linux functions from the Xen IOMMU function calls.
> - Xen modifications are preceded by /*Xen: comment */
> - xen/linux_compat: Add a Linux compat header
>    For porting files directly from Linux it is useful to have a function mapping
>    definitions from Linux to Xen. This file adds common API functions and
>    other defines that are needed for porting arm SMMU drivers.
>
> Signed-off-by: Sameer Goel <sameer.goel@linaro.org>
> ---
>   xen/arch/arm/p2m.c                    |   1 +
>   xen/drivers/Kconfig                   |   2 +
>   xen/drivers/passthrough/arm/Kconfig   |   8 +
>   xen/drivers/passthrough/arm/Makefile  |   1 +
>   xen/drivers/passthrough/arm/smmu-v3.c | 934 +++++++++++++++++++++++++-
>   xen/include/xen/linux_compat.h        |  84 +++
>   6 files changed, 1001 insertions(+), 29 deletions(-)
>   create mode 100644 xen/drivers/passthrough/arm/Kconfig
>   create mode 100644 xen/include/xen/linux_compat.h
>
> diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
> index d43c3aa896..38aa9f00c1 100644
> --- a/xen/arch/arm/p2m.c
> +++ b/xen/arch/arm/p2m.c
> @@ -1454,6 +1454,7 @@ err:
>   static void __init setup_virt_paging_one(void *data)
>   {
>       unsigned long val = (unsigned long)data;
> +    /* SMMUv3 S2 cfg vtcr reuses the following value */
>       WRITE_SYSREG32(val, VTCR_EL2);
>       isb();
>   }
> diff --git a/xen/drivers/Kconfig b/xen/drivers/Kconfig
> index db94393f47..59ca00f850 100644
> --- a/xen/drivers/Kconfig
> +++ b/xen/drivers/Kconfig
> @@ -15,4 +15,6 @@ source "drivers/video/Kconfig"
>   config HAS_VPCI
>   	bool
>   
> +source "drivers/passthrough/arm/Kconfig"
> +
>   endmenu
> diff --git a/xen/drivers/passthrough/arm/Kconfig b/xen/drivers/passthrough/arm/Kconfig
> new file mode 100644
> index 0000000000..cda899f608
> --- /dev/null
> +++ b/xen/drivers/passthrough/arm/Kconfig
> @@ -0,0 +1,8 @@
> +
> +config ARM_SMMU_v3
> +	bool "ARM SMMUv3 Support"
> +	depends on ARM_64
> +	help
> +	 Support for implementations of the ARM System MMU architecture
> +	 version 3.
> +
> diff --git a/xen/drivers/passthrough/arm/Makefile b/xen/drivers/passthrough/arm/Makefile
> index f4cd26e15d..e14732b55c 100644
> --- a/xen/drivers/passthrough/arm/Makefile
> +++ b/xen/drivers/passthrough/arm/Makefile
> @@ -1,2 +1,3 @@
>   obj-y += iommu.o
>   obj-y += smmu.o
> +obj-$(CONFIG_ARM_SMMU_v3) += smmu-v3.o
> diff --git a/xen/drivers/passthrough/arm/smmu-v3.c b/xen/drivers/passthrough/arm/smmu-v3.c
> index e67ba6c40f..df81626785 100644
> --- a/xen/drivers/passthrough/arm/smmu-v3.c
> +++ b/xen/drivers/passthrough/arm/smmu-v3.c
> @@ -18,28 +18,414 @@
>    * Author: Will Deacon <will.deacon@arm.com>
>    *
>    * This driver is powered by bad coffee and bombay mix.
> + *
> + *
> + * Based on Linux drivers/iommu/arm-smmu-v3.c
> + * => commit 7aa8619a66aea52b145e04cbab4f8d6a4e5f3f3b
> + *
> + * Xen modifications:
> + * Sameer Goel <sameer.goel@linaro.org>
> + * Copyright (C) 2017, The Linux Foundation, All rights reserved.
> + *
>    */
>   
> -#include <linux/acpi.h>
> -#include <linux/acpi_iort.h>
> -#include <linux/delay.h>
> -#include <linux/dma-iommu.h>
> -#include <linux/err.h>
> -#include <linux/interrupt.h>
> -#include <linux/iommu.h>
> -#include <linux/iopoll.h>
> -#include <linux/module.h>
> -#include <linux/msi.h>
> -#include <linux/of.h>
> -#include <linux/of_address.h>
> -#include <linux/of_iommu.h>
> -#include <linux/of_platform.h>
> -#include <linux/pci.h>
> -#include <linux/platform_device.h>
> -
> -#include <linux/amba/bus.h>
> -
> -#include "io-pgtable.h"
> +#include <xen/acpi.h>
> +#include <xen/config.h>
> +#include <xen/delay.h>
> +#include <xen/errno.h>
> +#include <xen/err.h>
> +#include <xen/irq.h>
> +#include <xen/lib.h>
> +#include <xen/linux_compat.h>
> +#include <xen/list.h>
> +#include <xen/mm.h>
> +#include <xen/rbtree.h>
> +#include <xen/sched.h>
> +#include <xen/sizes.h>
> +#include <xen/vmap.h>
> +#include <acpi/acpi_iort.h>
> +#include <asm/atomic.h>
> +#include <asm/device.h>
> +#include <asm/io.h>
> +#include <asm/platform.h>
> +
> +/* Alias to Xen device tree helpers */
> +#define device_node dt_device_node
> +#define of_phandle_args dt_phandle_args
> +#define of_device_id dt_device_match
> +#define of_match_node dt_match_node
> +#define of_property_read_u32(np, pname, out) (!dt_property_read_u32(np, pname, out))
> +#define of_property_read_bool dt_property_read_bool
> +#define of_parse_phandle_with_args dt_parse_phandle_with_args
> +
> +/* Xen: Helpers to get device MMIO and IRQs */
> +struct resource {
> +	u64 addr;
> +	u64 size;
> +	unsigned int type;
> +};
> +
> +#define resource_size(res) ((res)->size)
> +
> +#define platform_device device
> +
> +#define IORESOURCE_MEM 0
> +#define IORESOURCE_IRQ 1
> +
> +static struct resource *platform_get_resource(struct platform_device *pdev,
> +					      unsigned int type,
> +					      unsigned int num)
> +{
> +	/*
> +	 * The resource is only used between 2 calls of platform_get_resource.
> +	 * It's quite ugly but it's avoid to add too much code in the part
> +	 * imported from Linux
> +	 */
> +	static struct resource res;
> +	struct acpi_iort_node *iort_node;
> +	struct acpi_iort_smmu_v3 *node_smmu_data;
> +	int ret = 0;
> +
> +	res.type = type;
> +
> +	switch (type) {
> +	case IORESOURCE_MEM:
> +		if (pdev->type == DEV_ACPI) {
> +			ret = 1;
> +			iort_node = pdev->acpi_node;
> +			node_smmu_data =
> +				(struct acpi_iort_smmu_v3 *)iort_node->node_data;
> +
> +			if (node_smmu_data != NULL) {
> +				res.addr = node_smmu_data->base_address;
> +				res.size = SZ_128K;
> +				ret = 0;
> +			}
> +		} else {
> +			ret = dt_device_get_address(dev_to_dt(pdev), num,
> +						    &res.addr, &res.size);
> +		}
> +
> +		return ((ret) ? NULL : &res);
> +
> +	case IORESOURCE_IRQ:
> +		/* ACPI case not implemented as there is no use case for it */
> +		ret = platform_get_irq(dev_to_dt(pdev), num);
> +
> +		if (ret < 0)
> +			return NULL;
> +
> +		res.addr = ret;
> +		res.size = 1;
> +
> +		return &res;
> +
> +	default:
> +		return NULL;
> +	}
> +}
> +
> +static int platform_get_irq_byname(struct platform_device *pdev, const char *name)
> +{
> +	const struct dt_property *dtprop;
> +	struct acpi_iort_node *iort_node;
> +	struct acpi_iort_smmu_v3 *node_smmu_data;
> +	int ret = 0;
> +
> +	if (pdev->type == DEV_ACPI) {
> +		iort_node = pdev->acpi_node;
> +		node_smmu_data = (struct acpi_iort_smmu_v3 *)iort_node->node_data;
> +
> +		if (node_smmu_data != NULL) {
> +			if (!strcmp(name, "eventq"))
> +				ret = node_smmu_data->event_gsiv;
> +			else if (!strcmp(name, "priq"))
> +				ret = node_smmu_data->pri_gsiv;
> +			else if (!strcmp(name, "cmdq-sync"))
> +				ret = node_smmu_data->sync_gsiv;
> +			else if (!strcmp(name, "gerror"))
> +				ret = node_smmu_data->gerr_gsiv;
> +			else
> +				ret = -EINVAL;
> +		}
> +	} else {
> +		dtprop = dt_find_property(dev_to_dt(pdev), "interrupt-names", NULL);
> +		if (!dtprop)
> +			return -EINVAL;
> +
> +		if (!dtprop->value)
> +			return -ENODATA;
> +	}
> +
> +	return ret;
> +}
> +
> +/*
> + * Xen: Helpers for DMA allocation. Just the function name is reused for
> + * porting code these allocation are not managed allocations
> + */
> +
> +static void *dmam_alloc_coherent(struct device *dev, size_t size,
> +			   dma_addr_t *dma_handle, gfp_t gfp)
I believe the formatting needs to be checked.
> +{
> +	void *vaddr;
> +	unsigned long alignment = size;
> +
> +	/*
> +	 * _xzalloc requires that the (align & (align -1)) = 0. Most of the
> +	 * allocations in SMMU code should send the right value for size. In
> +	 * case this is not true print a warning and align to the size of a
> +	 * (void *)
> +	 */
> +	if (size & (size - 1)) {
> +		dev_warn(dev, "Fixing alignment for the DMA buffer\n");
> +		alignment = sizeof(void *);
> +	}
> +
> +	vaddr = _xzalloc(size, alignment);
> +	if (!vaddr) {
> +		dev_err(dev, "DMA allocation failed\n");
> +		return NULL;
> +	}
> +
> +	*dma_handle = virt_to_maddr(vaddr);
> +
> +	return vaddr;
> +}
> +
> +
> +static void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
> +			dma_addr_t dma_handle)
same
> +{
> +	xfree(vaddr);
> +}
> +
> +/* Xen: Stub out DMA domain related functions */
> +#define iommu_get_dma_cookie(dom) 0
> +#define iommu_put_dma_cookie(dom)
> +
> +/* Xen: Stub out module param related function */
> +#define module_param_named(a, b, c, d)
> +#define MODULE_PARM_DESC(a, b)
> +
> +#define dma_set_mask_and_coherent(d, b) 0
> +
> +#define of_dma_is_coherent(n) 0
> +
> +#define MODULE_DEVICE_TABLE(type, name)
> +
> +static void __iomem *devm_ioremap_resource(struct device *dev,
> +					   struct resource *res)
> +{
> +	void __iomem *ptr;
> +
> +	if (!res || res->type != IORESOURCE_MEM) {
> +		dev_err(dev, "Invalid resource\n");
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	ptr = ioremap_nocache(res->addr, res->size);
> +	if (!ptr) {
> +		dev_err(dev,
> +			"ioremap failed (addr 0x%"PRIx64" size 0x%"PRIx64")\n",
> +			res->addr, res->size);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	return ptr;
> +}
> +
> +/* Xen: Compatibility define for iommu_domain_geometry.*/
> +struct iommu_domain_geometry {
> +	dma_addr_t aperture_start; /* First address that can be mapped    */
> +	dma_addr_t aperture_end;   /* Last address that can be mapped     */
> +	bool force_aperture;       /* DMA only allowed in mappable range? */
> +};
> +
> +
> +/* Xen: Type definitions for iommu_domain */
> +#define IOMMU_DOMAIN_UNMANAGED 0
> +#define IOMMU_DOMAIN_DMA 1
> +#define IOMMU_DOMAIN_IDENTITY 2
> +
> +/* Xen: Dummy iommu_domain */
> +struct iommu_domain {
> +	/* Runtime SMMU configuration for this iommu_domain */
> +	struct arm_smmu_domain		*priv;
> +	unsigned int type;
> +
> +	/* Dummy compatibility defines */
> +	unsigned long pgsize_bitmap;
> +	struct iommu_domain_geometry geometry;
> +
> +	atomic_t ref;
> +	/*
> +	 * Used to link iommu_domain contexts for a same domain.
> +	 * There is at least one per-SMMU to used by the domain.
> +	 */
> +	struct list_head		list;
> +};
> +
> +/* Xen: Describes information required for a Xen domain */
> +struct arm_smmu_xen_domain {
> +	spinlock_t			lock;
> +	/* List of iommu domains associated to this domain */
> +	struct list_head		contexts;
> +};
> +
> +/*
> + * Xen: Information about each device stored in dev->archdata.iommu
> + *
> + * The dev->archdata.iommu stores the iommu_domain (runtime configuration of
> + * the SMMU).
> + */
> +struct arm_smmu_xen_device {
> +	struct iommu_domain *domain;
> +};
> +
As this is a xen specific code, can the variable names be used 
appropriately.
Repeating my comment  from earlier version.
a domain is  usually a VM in Xen. So it is a bit confusing to use domain 
for iommu_domain.
> +/*
> + * Xen: io_pgtable compatibility defines.
> + * Most of these are to port in the S1 translation code as is.
> + */
> +struct io_pgtable_ops {
> +};
> +
> +struct iommu_gather_ops {
> +	void (*tlb_flush_all)(void *cookie);
> +	void (*tlb_add_flush)(unsigned long iova, size_t size, size_t granule,
> +			      bool leaf, void *cookie);
> +	void (*tlb_sync)(void *cookie);
> +};
> +
> +struct io_pgtable_cfg {
> +	/*
> +	 * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE bits in
> +	 *	stage 1 PTEs, for hardware which insists on validating them
> +	 *	even in	non-secure state where they should normally be ignored.
> +	 *
> +	 * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE and
> +	 *	IOMMU_NOEXEC flags and map everything with full access, for
> +	 *	hardware which does not implement the permissions of a given
> +	 *	format, and/or requires some format-specific default value.
> +	 *
> +	 * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching invalid
> +	 *	(unmapped) entries but the hardware might do so anyway, perform
> +	 *	TLB maintenance when mapping as well as when unmapping.
> +	 *
> +	 * IO_PGTABLE_QUIRK_ARM_MTK_4GB: (ARM v7s format) Set bit 9 in all
> +	 *	PTEs, for Mediatek IOMMUs which treat it as a 33rd address bit
> +	 *	when the SoC is in "4GB mode" and they can only access the high
> +	 *	remap of DRAM (0x1_00000000 to 0x1_ffffffff).
> +	 *
> +	 * IO_PGTABLE_QUIRK_NO_DMA: Guarantees that the tables will only ever
> +	 *	be accessed by a fully cache-coherent IOMMU or CPU (e.g. for a
> +	 *	software-emulated IOMMU), such that pagetable updates need not
> +	 *	be treated as explicit DMA data.
> +	 */
> +	#define IO_PGTABLE_QUIRK_ARM_NS		BIT(0)
> +	#define IO_PGTABLE_QUIRK_NO_PERMS	BIT(1)
> +	#define IO_PGTABLE_QUIRK_TLBI_ON_MAP	BIT(2)
> +	#define IO_PGTABLE_QUIRK_ARM_MTK_4GB	BIT(3)
> +	#define IO_PGTABLE_QUIRK_NO_DMA		BIT(4)
> +	unsigned long			quirks;
> +	unsigned long			pgsize_bitmap;
> +	unsigned int			ias;
> +	unsigned int			oas;
> +	const struct iommu_gather_ops	*tlb;
> +	struct device			*iommu_dev;
> +
> +	/* Low-level data specific to the table format */
> +	union {
> +		struct {
> +			u64	ttbr[2];
> +			u64	tcr;
> +			u64	mair[2];
> +		} arm_lpae_s1_cfg;
> +
> +		struct {
> +			u64	vttbr;
> +			u64	vtcr;
> +		} arm_lpae_s2_cfg;
> +
> +		struct {
> +			u32	ttbr[2];
> +			u32	tcr;
> +			u32	nmrr;
> +			u32	prrr;
> +		} arm_v7s_cfg;
> +	};
> +};
> +
> +enum io_pgtable_fmt {
> +	ARM_32_LPAE_S1,
> +	ARM_32_LPAE_S2,
> +	ARM_64_LPAE_S1,
> +	ARM_64_LPAE_S2,
> +	ARM_V7S,
> +	IO_PGTABLE_NUM_FMTS,
> +};
> +
> +/*
> + * Xen: The pgtable_ops are used by the S1 translations, so return the dummy
> + * address.
> + */
> +#define alloc_io_pgtable_ops(f, c, o) ((struct io_pgtable_ops *)0x1)
> +#define free_io_pgtable_ops(o)
> +
> +/* Xen: Define wrapper for requesting IRQs */
> +#define IRQF_ONESHOT 0
> +
> +typedef void (*irq_handler_t)(int, void *, struct cpu_user_regs *);
> +
> +static inline int devm_request_irq(struct device *dev, unsigned int irq,
> +				   irq_handler_t handler, unsigned long irqflags,
> +				   const char *devname, void *dev_id)
> +{
> +	/*
> +	 * SMMUv3 implementation can support wired interrupt outputs that are
> +	 * edge-triggered. Set the irq type as per the spec.
> +	 */
> +	irq_set_type(irq, IRQ_TYPE_EDGE_BOTH);
> +	return request_irq(irq, irqflags, handler, devname, dev_id);
> +}
> +
> +/*
> + * Xen does not have a concept of threaded irq, but we can use tasklets to
> + * achieve the desired functionality as needed.
> + */
> +int devm_request_threaded_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
> +			      irq_handler_t thread_fn, unsigned long irqflags,
> +			      const char *devname, void *dev_id)
> +{
> +	return devm_request_irq(dev, irq, thread_fn, irqflags, devname, dev_id);
> +}
> +
> +/* Xen: The mutex is used only during initialization so the typecast is safe */
> +#define mutex spinlock
> +#define mutex_init spin_lock_init
> +#define mutex_lock spin_lock
> +#define mutex_unlock spin_unlock
> +
> +#define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us) \
> +({ \
> +	s_time_t deadline = NOW() + MICROSECS(timeout_us); \
> +	for (;;) { \
> +		(val) = op(addr); \
> +		if (cond) \
> +			break; \
> +		if (NOW() > deadline) { \
> +			(val) = op(addr); \
> +			break; \
> +		} \
> +	udelay(sleep_us); \
> +	} \
> +	(cond) ? 0 : -ETIMEDOUT; \
> +})
> +
> +#define readl_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
> +	readx_poll_timeout(readl_relaxed, addr, val, cond, delay_us, timeout_us)
> +
> +#define VA_BITS 0 /* Only needed for S1 translations */
>   
>   /* MMIO registers */
>   #define ARM_SMMU_IDR0			0x0
> @@ -433,6 +819,7 @@ enum pri_resp {
>   	PRI_RESP_SUCC,
>   };
>   
> +#if 0 /* Xen: No MSI support in this iteration */
>   enum arm_smmu_msi_index {
>   	EVTQ_MSI_INDEX,
>   	GERROR_MSI_INDEX,
> @@ -457,6 +844,7 @@ static phys_addr_t arm_smmu_msi_cfg[ARM_SMMU_MAX_MSIS][3] = {
>   		ARM_SMMU_PRIQ_IRQ_CFG2,
>   	},
>   };
> +#endif
>   
>   struct arm_smmu_cmdq_ent {
>   	/* Common fields */
> @@ -561,6 +949,8 @@ struct arm_smmu_s2_cfg {
>   	u16				vmid;
>   	u64				vttbr;
>   	u64				vtcr;
> +	/* Xen: Domain associated to this configuration */
> +	struct domain			*domain;
>   };
>   
>   struct arm_smmu_strtab_ent {
> @@ -635,9 +1025,25 @@ struct arm_smmu_device {
>   	struct arm_smmu_strtab_cfg	strtab_cfg;
>   
>   	/* IOMMU core code handle */
> +#if 0 /*Xen: Generic iommu_device ref not needed here */
>   	struct iommu_device		iommu;
> +#endif
Is it clean to put #if 0, can this line be deleted or used with a proper 
macro
> +	/* Xen: Need to keep a list of SMMU devices */
> +	struct list_head                devices;
> +	/* Xen: Tasklets for handling evts/faults and pci page request IRQs*/
> +	struct tasklet			evtq_tasklet;
> +	struct tasklet			priq_tasklet;
> +	struct tasklet			combined_irq_tasklet;
>   };
>   
> +/* Xen: Keep a list of devices associated with this driver */
> +static DEFINE_SPINLOCK(arm_smmu_devices_lock);
> +static LIST_HEAD(arm_smmu_devices);
> +/* Xen: Helper for finding a device using fwnode */
> +static
> +struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode);
> +
> +
>   /* SMMU private data for each master */
>   struct arm_smmu_master_data {
>   	struct arm_smmu_device		*smmu;
> @@ -1232,7 +1638,7 @@ static void arm_smmu_handle_ppr(struct arm_smmu_device *smmu, u64 *evt)
>   
>   	dev_info(smmu->dev, "unexpected PRI request received:\n");
>   	dev_info(smmu->dev,
> -		 "\tsid 0x%08x.0x%05x: [%u%s] %sprivileged %s%s%s access at iova 0x%016llx\n",
> +		 "\tsid 0x%08x.0x%05x: [%u%s] %sprivileged %s%s%s access at iova %#" PRIx64 "\n",
>   		 sid, ssid, grpid, last ? "L" : "",
>   		 evt[0] & PRIQ_0_PERM_PRIV ? "" : "un",
>   		 evt[0] & PRIQ_0_PERM_READ ? "R" : "",
> @@ -1342,10 +1748,20 @@ static irqreturn_t arm_smmu_combined_irq_thread(int irq, void *dev)
>   	return IRQ_HANDLED;
>   }
>   
> +/* Xen: Forward define for combined_irq tasklet */
> +static void arm_smmu_combined_irq_tasklet(unsigned long dev);
> +
>   static irqreturn_t arm_smmu_combined_irq_handler(int irq, void *dev)
>   {
> +	/* Xen: Need an smmu reference to schedule the tasklet */
> +	struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
> +
>   	arm_smmu_gerror_handler(irq, dev);
>   	arm_smmu_cmdq_sync_handler(irq, dev);
> +
> +	/*Xen: No threaded irq. So, schedule the right tasklet*/
> +	tasklet_schedule(&(smmu->combined_irq_tasklet));
> +
>   	return IRQ_WAKE_THREAD;
>   }
>   
> @@ -1358,6 +1774,69 @@ static void __arm_smmu_tlb_sync(struct arm_smmu_device *smmu)
>   	arm_smmu_cmdq_issue_cmd(smmu, &cmd);
>   }
>   
> +/*
> + * Xen: Define the IRQ handlers and tasklets for xen. The linux functions
> + * would be modified to use the functions defined in the following code.
> + */
> +
> +static void arm_smmu_evtq_tasklet(unsigned long dev)
> +{
> +	/* The IRQ number is not relevent for the evtq thread processing */
> +	arm_smmu_evtq_thread(0, (void *)dev);
> +}
> +
> +static void arm_smmu_priq_tasklet(unsigned long dev)
> +{
> +	/* The IRQ number is not relevent for the priq thread processing */
> +	arm_smmu_priq_thread(0, (void *)dev);
> +}
> +
> +static void arm_smmu_combined_irq_tasklet(unsigned long dev)
> +{
> +	/* The IRQ number is not relevent for the combined irq handler.*/
> +	arm_smmu_combined_irq_thread(0, (void *)dev);
> +}
> +
> +static void arm_smmu_evtq_thread_xen(int irq, void *dev,
> +				       struct cpu_user_regs *regs)
> +{
> +	struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
> +
> +	tasklet_schedule(&(smmu->evtq_tasklet));
> +}
> +
> +static void arm_smmu_priq_thread_xen(int irq, void *dev,
> +				       struct cpu_user_regs *regs)
> +{
> +	struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
> +
> +	tasklet_schedule(&(smmu->priq_tasklet));
> +}
> +
> +static void arm_smmu_cmdq_sync_handler_xen(int irq, void *dev,
> +				       struct cpu_user_regs *regs)
> +{
> +	arm_smmu_cmdq_sync_handler(irq, dev);
> +}
> +
> +static void arm_smmu_gerror_handler_xen(int irq, void *dev,
> +				       struct cpu_user_regs *regs)
> +{
> +	arm_smmu_gerror_handler(irq, dev);
> +}
> +
> +static void arm_smmu_combined_irq_handler_xen(int irq, void *dev,
> +				       struct cpu_user_regs *regs)
> +{
> +	arm_smmu_combined_irq_handler(irq, dev);
> +}
> +
> +#define arm_smmu_evtq_thread arm_smmu_evtq_thread_xen
> +#define arm_smmu_priq_thread arm_smmu_priq_thread_xen
> +#define arm_smmu_cmdq_sync_handler arm_smmu_cmdq_sync_handler_xen
> +#define arm_smmu_gerror_handler arm_smmu_gerror_handler_xen
> +#define arm_smmu_combined_irq_handler arm_smmu_combined_irq_handler_xen
> +
>   static void arm_smmu_tlb_sync(void *cookie)
>   {
>   	struct arm_smmu_domain *smmu_domain = cookie;
> @@ -1415,6 +1894,7 @@ static const struct iommu_gather_ops arm_smmu_gather_ops = {
>   	.tlb_sync	= arm_smmu_tlb_sync,
>   };
>   
> +#if 0 /*Xen: Unused functionality */
>   /* IOMMU API */
>   static bool arm_smmu_capable(enum iommu_cap cap)
>   {
> @@ -1427,6 +1907,7 @@ static bool arm_smmu_capable(enum iommu_cap cap)
>   		return false;
>   	}
>   }
> +#endif
>   
>   static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
>   {
> @@ -1546,9 +2027,16 @@ static int arm_smmu_domain_finalise_s2(struct arm_smmu_domain *smmu_domain,
>   	if (vmid < 0)
>   		return vmid;
>   
> -	cfg->vmid	= (u16)vmid;
> -	cfg->vttbr	= pgtbl_cfg->arm_lpae_s2_cfg.vttbr;
> -	cfg->vtcr	= pgtbl_cfg->arm_lpae_s2_cfg.vtcr;
> +	/*
> +	 * Xen: Get the ttbr and vtcr values
> +	 * vttbr: This is a shared value with the domain page table
> +	 * vtcr: The TCR settings are the same as CPU since the page
> +	 * tables are shared
> +	 */
> +
> +	cfg->vmid	= vmid;
> +	cfg->vttbr	= page_to_maddr(cfg->domain->arch.p2m.root);
> +	cfg->vtcr	= READ_SYSREG32(VTCR_EL2) & STRTAB_STE_2_VTCR_MASK;
>   	return 0;
>   }
>   
> @@ -1604,6 +2092,7 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain)
>   	if (smmu->features & ARM_SMMU_FEAT_COHERENCY)
>   		pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_NO_DMA;
>   
> +	/* Xen: pgtbl_ops gets an invalid address */
>   	pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);
>   	if (!pgtbl_ops)
>   		return -ENOMEM;
> @@ -1721,6 +2210,7 @@ out_unlock:
>   	return ret;
>   }
>   
> +#if 0 /* Xen: Unused functionality */
same
>   static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
>   			phys_addr_t paddr, size_t size, int prot)
>   {
> @@ -1772,6 +2262,7 @@ struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
>   	put_device(dev);
>   	return dev ? dev_get_drvdata(dev) : NULL;
>   }
> +#endif
>   
>   static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, u32 sid)
>   {
> @@ -1783,7 +2274,14 @@ static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, u32 sid)
>   	return sid < limit;
>   }
>   
> +/* Xen: Unused */
> +#if 0
>   static struct iommu_ops arm_smmu_ops;
> +#endif
> +
> +/* Xen: Redefine arm_smmu_ops to what fwspec should evaluate */
> +static const struct iommu_ops arm_smmu_iommu_ops;
> +#define arm_smmu_ops arm_smmu_iommu_ops
>   
>   static int arm_smmu_add_device(struct device *dev)
>   {
> @@ -1791,8 +2289,11 @@ static int arm_smmu_add_device(struct device *dev)
>   	struct arm_smmu_device *smmu;
>   	struct arm_smmu_master_data *master;
>   	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
> +#if 0 /*Xen: iommu_group is not needed */
>   	struct iommu_group *group;
> +#endif
>   
> +	/* Xen: fwspec->ops are not needed */
>   	if (!fwspec || fwspec->ops != &arm_smmu_ops)
>   		return -ENODEV;
>   	/*
> @@ -1830,6 +2331,11 @@ static int arm_smmu_add_device(struct device *dev)
>   		}
>   	}
>   
> +/*
> + * Xen: Do not need an iommu group as the stream data is carried by the SMMU
> + * master device object
> + */
> +#if 0
>   	group = iommu_group_get_for_dev(dev);
>   	if (!IS_ERR(group)) {
>   		iommu_group_put(group);
> @@ -1837,8 +2343,16 @@ static int arm_smmu_add_device(struct device *dev)
>   	}
>   
>   	return PTR_ERR_OR_ZERO(group);
> +#endif
> +	return 0;
>   }
>   
> +/*
> + * Xen: We can potentially support this function and destroy a device. This
> + * will be relevant for PCI hotplug. So, will be implemented as needed after
> + * passthrough support is available.
> + */
> +#if 0
>   static void arm_smmu_remove_device(struct device *dev)
>   {
>   	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
> @@ -1974,6 +2488,7 @@ static struct iommu_ops arm_smmu_ops = {
>   	.put_resv_regions	= arm_smmu_put_resv_regions,
>   	.pgsize_bitmap		= -1UL, /* Restricted during device attach */
>   };
> +#endif
>   
>   /* Probing and initialisation functions */
>   static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
> @@ -2182,6 +2697,7 @@ static int arm_smmu_update_gbpa(struct arm_smmu_device *smmu, u32 set, u32 clr)
>   					  1, ARM_SMMU_POLL_TIMEOUT_US);
>   }
>   
> +#if 0 /* Xen: There is no MSI support as yet */
>   static void arm_smmu_free_msis(void *data)
>   {
>   	struct device *dev = data;
> @@ -2247,12 +2763,15 @@ static void arm_smmu_setup_msis(struct arm_smmu_device *smmu)
>   	/* Add callback to free MSIs on teardown */
>   	devm_add_action(dev, arm_smmu_free_msis, dev);
>   }
> +#endif
>   
>   static void arm_smmu_setup_unique_irqs(struct arm_smmu_device *smmu)
>   {
>   	int irq, ret;
>   
> +#if 0 /*Xen: Cannot setup msis for now */
>   	arm_smmu_setup_msis(smmu);
> +#endif
>   
>   	/* Request interrupt lines */
>   	irq = smmu->evtq.q.irq;
> @@ -2316,9 +2835,13 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
>   		 * Cavium ThunderX2 implementation doesn't not support unique
>   		 * irq lines. Use single irq line for all the SMMUv3 interrupts.
>   		 */
> -		ret = devm_request_threaded_irq(smmu->dev, irq,
> +		/*
> +		 * Xen: Does not support threaded irqs, so serialise the setup.
> +		 * This is the same for pris and event interrupt lines on other
> +		 * systems
> +		 */
> +		ret = devm_request_irq(smmu->dev, irq,
>   					arm_smmu_combined_irq_handler,
> -					arm_smmu_combined_irq_thread,
>   					IRQF_ONESHOT,
>   					"arm-smmu-v3-combined-irq", smmu);
>   		if (ret < 0)
> @@ -2452,6 +2975,13 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
>   		return ret;
>   	}
>   
> +	/* Xen: Initialize tasklets */
> +	tasklet_init(&smmu->evtq_tasklet, arm_smmu_evtq_tasklet,
> +			(unsigned long)smmu);
> +	tasklet_init(&smmu->priq_tasklet, arm_smmu_priq_tasklet,
> +			(unsigned long)smmu);
> +	tasklet_init(&smmu->combined_irq_tasklet, arm_smmu_combined_irq_tasklet,
> +			(unsigned long)smmu);
>   
>   	/* Enable the SMMU interface, or ensure bypass */
>   	if (!bypass || disable_bypass) {
> @@ -2542,8 +3072,14 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu)
>   		smmu->features |= ARM_SMMU_FEAT_STALLS;
>   	}
>   
> +/*
> + * Xen: Block stage 1 translations. By doing this here we do not need to set the
> + * domain->stage explicitly.
> + */
> +#if 0
>   	if (reg & IDR0_S1P)
>   		smmu->features |= ARM_SMMU_FEAT_TRANS_S1;
> +#endif
>   
>   	if (reg & IDR0_S2P)
>   		smmu->features |= ARM_SMMU_FEAT_TRANS_S2;
> @@ -2616,10 +3152,12 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu)
>   	if (reg & IDR5_GRAN4K)
>   		smmu->pgsize_bitmap |= SZ_4K | SZ_2M | SZ_1G;
>   
> +#if 0 /* Xen: SMMU ops do not have a pgsize_bitmap member for Xen */
>   	if (arm_smmu_ops.pgsize_bitmap == -1UL)
>   		arm_smmu_ops.pgsize_bitmap = smmu->pgsize_bitmap;
>   	else
>   		arm_smmu_ops.pgsize_bitmap |= smmu->pgsize_bitmap;
> +#endif
>   
>   	/* Output address size */
>   	switch (reg & IDR5_OAS_MASK << IDR5_OAS_SHIFT) {
> @@ -2680,7 +3218,8 @@ static int arm_smmu_device_acpi_probe(struct platform_device *pdev,
>   	struct device *dev = smmu->dev;
>   	struct acpi_iort_node *node;
>   
> -	node = *(struct acpi_iort_node **)dev_get_platdata(dev);
> +	/* Xen: Modification to get iort_node */
> +	node = (struct acpi_iort_node *)dev->acpi_node;
>   
>   	/* Retrieve SMMUv3 specific data */
>   	iort_smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
> @@ -2703,7 +3242,7 @@ static inline int arm_smmu_device_acpi_probe(struct platform_device *pdev,
>   static int arm_smmu_device_dt_probe(struct platform_device *pdev,
>   				    struct arm_smmu_device *smmu)
>   {
> -	struct device *dev = &pdev->dev;
> +	struct device *dev = pdev;
>   	u32 cells;
>   	int ret = -EINVAL;
>   
> @@ -2716,6 +3255,7 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev,
>   
>   	parse_driver_options(smmu);
>   
> +	/* Xen: of_dma_is_coherent is a stub till dt support is introduced */
>   	if (of_dma_is_coherent(dev->of_node))
>   		smmu->features |= ARM_SMMU_FEAT_COHERENCY;
>   
> @@ -2734,9 +3274,11 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>   {
>   	int irq, ret;
>   	struct resource *res;
> +#if 0 /*Xen: Do not need to setup sysfs */
>   	resource_size_t ioaddr;
> +#endif
>   	struct arm_smmu_device *smmu;
> -	struct device *dev = &pdev->dev;
> +	struct device *dev = pdev;/* Xen: dev is ignored */
>   	bool bypass;
>   
>   	smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
> @@ -2763,7 +3305,9 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>   		dev_err(dev, "MMIO region too small (%pr)\n", res);
>   		return -EINVAL;
>   	}
> +#if 0 /*Xen: Do not need to setup sysfs */
>   	ioaddr = res->start;
> +#endif
>   
>   	smmu->base = devm_ioremap_resource(dev, res);
>   	if (IS_ERR(smmu->base))
> @@ -2802,13 +3346,18 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>   		return ret;
>   
>   	/* Record our private device structure */
> +	/* Xen: SMMU is not treated a a platform device*/
> +#if 0
>   	platform_set_drvdata(pdev, smmu);
> +#endif
>   
>   	/* Reset the device */
>   	ret = arm_smmu_device_reset(smmu, bypass);
>   	if (ret)
>   		return ret;
>   
> +/* Xen: Not creating an IOMMU device list for Xen */
> +#if 0
>   	/* And we're up. Go go go! */
>   	ret = iommu_device_sysfs_add(&smmu->iommu, dev, NULL,
>   				     "smmu3.%pa", &ioaddr);
> @@ -2844,9 +3393,20 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>   		if (ret)
>   			return ret;
>   	}
> +#endif
> +	/*
> +	 * Xen: Keep a list of all probed devices. This will be used to query
> +	 * the smmu devices based on the fwnode.
> +	 */
> +	INIT_LIST_HEAD(&smmu->devices);
> +	spin_lock(&arm_smmu_devices_lock);
> +	list_add(&smmu->devices, &arm_smmu_devices);
> +	spin_unlock(&arm_smmu_devices_lock);
>   	return 0;
>   }
>   
> +/* Xen: Unused function */
> +#if 0
>   static int arm_smmu_device_remove(struct platform_device *pdev)
>   {
>   	struct arm_smmu_device *smmu = platform_get_drvdata(pdev);
> @@ -2860,6 +3420,8 @@ static void arm_smmu_device_shutdown(struct platform_device *pdev)
>   {
>   	arm_smmu_device_remove(pdev);
>   }
> +#endif
> +
>   
>   static const struct of_device_id arm_smmu_of_match[] = {
>   	{ .compatible = "arm,smmu-v3", },
> @@ -2867,6 +3429,7 @@ static const struct of_device_id arm_smmu_of_match[] = {
>   };
>   MODULE_DEVICE_TABLE(of, arm_smmu_of_match);
>   
> +#if 0
>   static struct platform_driver arm_smmu_driver = {
>   	.driver	= {
>   		.name		= "arm-smmu-v3",
> @@ -2883,3 +3446,316 @@ IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", NULL);
>   MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 implementations");
>   MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
>   MODULE_LICENSE("GPL v2");
> +#endif
> +
> +/***** Start of Xen specific code *****/
> +
> +static int __must_check arm_smmu_iotlb_flush_all(struct domain *d)
> +{
> +	struct arm_smmu_xen_domain *smmu_domain = dom_iommu(d)->arch.priv;
> +	struct iommu_domain *cfg;
> +
> +	spin_lock(&smmu_domain->lock);
> +	list_for_each_entry(cfg, &smmu_domain->contexts, list) {
> +		/*
> +		 * Only invalidate the context when SMMU is present.
> +		 * This is because the context initialization is delayed
> +		 * until a master has been added.
> +		 */
> +		if (unlikely(!ACCESS_ONCE(cfg->priv->smmu)))
> +			continue;
> +		arm_smmu_tlb_inv_context(cfg->priv);
> +	}
> +	spin_unlock(&smmu_domain->lock);
> +	return 0;
> +}
> +
> +static int __must_check arm_smmu_iotlb_flush(struct domain *d,
> +					     unsigned long gfn,
> +					     unsigned int page_count)
> +{
> +	return arm_smmu_iotlb_flush_all(d);
> +}
> +
> +static struct iommu_domain *arm_smmu_get_domain(struct domain *d,
> +						struct device *dev)
This is returning iommu_domain and not a domain.
Please change the name of function.
> +{
> +	struct iommu_domain *domain;
> +	struct arm_smmu_xen_domain *xen_domain;
A suggestion
1. as you have used in above function smmu_domain variable for 
arm_smmu_xen_domain
Can similar logic be used for iommu_domain.

2. When smmu_domain variable name is used in above function why 
xen_domain is used in this function.
It is quite confusing.
logically xen_domain should mean a VM.
> +	struct arm_smmu_device *smmu;
> +	struct arm_smmu_domain *smmu_domain;
smmu_domain was used for arm_smmu_xen_domain.
consistency of variable names is necessary for code clarity
> +
> +	xen_domain = dom_iommu(d)->arch.priv;
> +
> +	smmu = arm_smmu_get_by_fwnode(dev->iommu_fwspec->iommu_fwnode);
> +	if (!smmu)
> +		return NULL;
> +
> +	/*
> +	 * Loop through the &xen_domain->contexts to locate a context
> +	 * assigned to this SMMU
> +	 */
> +	list_for_each_entry(domain, &xen_domain->contexts, list) {
> +		smmu_domain = to_smmu_domain(domain);
> +		if (smmu_domain->smmu == smmu)
> +			return domain;
> +	}
> +
> +	return NULL;
> +}
> +
> +static void arm_smmu_destroy_iommu_domain(struct iommu_domain *domain)
same
> +{
> +	list_del(&domain->list);
> +	arm_smmu_domain_free(domain);
> +}
> +
> +static int arm_smmu_assign_dev(struct domain *d, u8 devfn,
> +			       struct device *dev, u32 flag)
> +{
> +	int ret = 0;
> +	struct iommu_domain *domain;
> +	struct arm_smmu_xen_domain *xen_domain;
same
> +	struct arm_smmu_domain *arm_smmu;
> +
> +	xen_domain = dom_iommu(d)->arch.priv;
> +
> +	if (!dev->archdata.iommu) {
> +		dev->archdata.iommu = xzalloc(struct arm_smmu_xen_device);
> +		if (!dev->archdata.iommu)
> +			return -ENOMEM;
> +	}
> +
> +	ret = arm_smmu_add_device(dev);
> +	if (ret)
> +		return ret;
> +
> +	spin_lock(&xen_domain->lock);
> +
> +	/*
> +	 * Check to see if an iommu_domain already exists for this xen domain
> +	 * under the same SMMU
> +	 */
> +	domain = arm_smmu_get_domain(d, dev);
> +	if (!domain) {
> +
> +		domain = arm_smmu_domain_alloc(IOMMU_DOMAIN_DMA);
> +		if (!domain) {
> +			ret = -ENOMEM;
> +			goto out;
> +		}
> +
> +		arm_smmu = to_smmu_domain(domain);
> +		arm_smmu->s2_cfg.domain = d;
> +
> +		/* Chain the new context to the domain */
> +		list_add(&domain->list, &xen_domain->contexts);
> +
> +	}
> +
> +	ret = arm_smmu_attach_dev(domain, dev);
> +	if (ret) {
> +		if (domain->ref.counter == 0)
> +			arm_smmu_destroy_iommu_domain(domain);
> +	} else {
> +		atomic_inc(&domain->ref);
> +	}
> +
> +out:
> +	spin_unlock(&xen_domain->lock);
> +	return ret;
> +}
> +
> +static int arm_smmu_deassign_dev(struct domain *d, struct device *dev)
> +{
> +	struct iommu_domain *domain = arm_smmu_get_domain(d, dev);
> +	struct arm_smmu_xen_domain *xen_domain;
> +	struct arm_smmu_domain *arm_smmu = to_smmu_domain(domain);
same
> +
> +	xen_domain = dom_iommu(d)->arch.priv;
> +
> +	if (!arm_smmu || arm_smmu->s2_cfg.domain != d) {
> +		dev_err(dev, " not attached to domain %d\n", d->domain_id);
> +		return -ESRCH;
> +	}
> +
> +	spin_lock(&xen_domain->lock);
> +
> +	arm_smmu_detach_dev(dev);
> +	atomic_dec(&domain->ref);
> +
> +	if (domain->ref.counter == 0)
> +		arm_smmu_destroy_iommu_domain(domain);
> +
> +	spin_unlock(&xen_domain->lock);
> +
> +	return 0;
> +}
> +
> +static int arm_smmu_reassign_dev(struct domain *s, struct domain *t,
> +				 u8 devfn,  struct device *dev)
> +{
> +	int ret = 0;
> +
> +	/* Don't allow remapping on other domain than hwdom */
> +	if (t && t != hardware_domain)
> +		return -EPERM;
> +
> +	if (t == s)
> +		return 0;
> +
> +	ret = arm_smmu_deassign_dev(s, dev);
> +	if (ret)
> +		return ret;
> +
> +	if (t) {
> +		/* No flags are defined for ARM. */
> +		ret = arm_smmu_assign_dev(t, devfn, dev, 0);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int arm_smmu_iommu_domain_init(struct domain *d)
Where is iommu_domain initialized?
The function does not use a iommu_domain * variable
> +{
> +	struct arm_smmu_xen_domain *xen_domain;
> +
> +	xen_domain = xzalloc(struct arm_smmu_xen_domain);
> +	if (!xen_domain)
> +		return -ENOMEM;
> +
> +	spin_lock_init(&xen_domain->lock);
> +	INIT_LIST_HEAD(&xen_domain->contexts);
> +
> +	dom_iommu(d)->arch.priv = xen_domain;
> +
> +	return 0;
> +}
> +
> +static void __hwdom_init arm_smmu_iommu_hwdom_init(struct domain *d)
> +{
> +}
> +
> +static void arm_smmu_iommu_domain_teardown(struct domain *d)
> +{
> +	struct arm_smmu_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
> +
> +	ASSERT(list_empty(&xen_domain->contexts));
> +	xfree(xen_domain);
> +}
> +
> +static int __must_check arm_smmu_map_page(struct domain *d, unsigned long gfn,
> +			unsigned long mfn, unsigned int flags)
> +{
> +	p2m_type_t t;
> +
> +	/*
> +	 * Grant mappings can be used for DMA requests. The dev_bus_addr
> +	 * returned by the hypercall is the MFN (not the IPA). For device
> +	 * protected by an IOMMU, Xen needs to add a 1:1 mapping in the domain
> +	 * p2m to allow DMA request to work.
> +	 * This is only valid when the domain is directed mapped. Hence this
> +	 * function should only be used by gnttab code with gfn == mfn.
> +	 */
> +	BUG_ON(!is_domain_direct_mapped(d));
> +	BUG_ON(mfn != gfn);
> +
> +	/* We only support readable and writable flags */
> +	if (!(flags & (IOMMUF_readable | IOMMUF_writable)))
> +		return -EINVAL;
> +
> +	t = (flags & IOMMUF_writable) ? p2m_iommu_map_rw : p2m_iommu_map_ro;
> +
> +	/*
> +	 * The function guest_physmap_add_entry replaces the current mapping
> +	 * if there is already one...
> +	 */
> +	return guest_physmap_add_entry(d, _gfn(gfn), _mfn(mfn), 0, t);
> +}
> +
> +static int __must_check arm_smmu_unmap_page(struct domain *d, unsigned long gfn)
> +{
> +	/*
> +	 * This function should only be used by gnttab code when the domain
> +	 * is direct mapped
> +	 */
> +	if (!is_domain_direct_mapped(d))
> +		return -EINVAL;
> +
> +	return guest_physmap_remove_page(d, _gfn(gfn), _mfn(gfn), 0);
> +}
> +
> +static const struct iommu_ops arm_smmu_iommu_ops = {
> +	.init = arm_smmu_iommu_domain_init,
> +	.hwdom_init = arm_smmu_iommu_hwdom_init,
> +	.teardown = arm_smmu_iommu_domain_teardown,
> +	.iotlb_flush = arm_smmu_iotlb_flush,
> +	.iotlb_flush_all = arm_smmu_iotlb_flush_all,
> +	.assign_device = arm_smmu_assign_dev,
> +	.reassign_device = arm_smmu_reassign_dev,
> +	.map_page = arm_smmu_map_page,
> +	.unmap_page = arm_smmu_unmap_page,
> +};
> +
> +static
> +struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
> +{
> +	struct arm_smmu_device *smmu = NULL;
> +
> +	spin_lock(&arm_smmu_devices_lock);
> +	list_for_each_entry(smmu, &arm_smmu_devices, devices) {
> +		if (smmu->dev->fwnode == fwnode)
> +			break;
> +	}
> +	spin_unlock(&arm_smmu_devices_lock);
> +
> +	return smmu;
> +}
> +
> +static __init int arm_smmu_dt_init(struct dt_device_node *dev,
> +				   const void *data)
> +{
> +	int rc;
> +
> +	/*
> +	 * Even if the device can't be initialized, we don't want to
> +	 * give the SMMU device to dom0.
> +	 */
> +	dt_device_set_used_by(dev, DOMID_XEN);
> +
> +	rc = arm_smmu_device_probe(dt_to_dev(dev));
> +	if (rc)
> +		return rc;
> +
> +	iommu_set_ops(&arm_smmu_iommu_ops);
> +
> +	return 0;
> +}
> +
> +DT_DEVICE_START(smmuv3, "ARM SMMU V3", DEVICE_IOMMU)
> +	.dt_match = arm_smmu_of_match,
> +	.init = arm_smmu_dt_init,
> +DT_DEVICE_END
> +
> +#ifdef CONFIG_ACPI
> +/* Set up the IOMMU */
> +static int __init arm_smmu_acpi_init(const void *data)
> +{
> +	int rc;
> +
> +	rc = arm_smmu_device_probe((struct device *)data);
> +	if (rc)
> +		return rc;
> +
> +	iommu_set_ops(&arm_smmu_iommu_ops);
> +	return 0;
> +}
> +
> +ACPI_DEVICE_START(asmmuv3, "ARM SMMU V3", DEVICE_IOMMU)
> +	.class_type = ACPI_IORT_NODE_SMMU_V3,
> +	.init = arm_smmu_acpi_init,
> +ACPI_DEVICE_END
> +
> +#endif
> diff --git a/xen/include/xen/linux_compat.h b/xen/include/xen/linux_compat.h
> new file mode 100644
> index 0000000000..8037be0a3e
> --- /dev/null
> +++ b/xen/include/xen/linux_compat.h
> @@ -0,0 +1,84 @@
> +/******************************************************************************
> + * include/xen/linux_compat.h
> + *
> + * Compatibility defines for porting code from Linux to Xen
> + *
> + * Copyright (c) 2017 Linaro Limited
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#ifndef __XEN_LINUX_COMPAT_H__
> +#define __XEN_LINUX_COMPAT_H__
> +
> +#include <asm/types.h>
> +
> +typedef paddr_t phys_addr_t;
> +typedef paddr_t dma_addr_t;
> +
> +typedef unsigned int gfp_t;
> +#define GFP_KERNEL 0
> +#define __GFP_ZERO 0x01U
> +
> +/* Helpers for IRQ functions */
> +#define free_irq release_irq
> +
> +enum irqreturn {
> +    IRQ_NONE,
> +    IRQ_HANDLED,
> +    IRQ_WAKE_THREAD,
> +};
> +
> +typedef enum irqreturn irqreturn_t;
> +
> +/* Device logger functions */
> +#define dev_dbg(dev, fmt, ...) printk(XENLOG_DEBUG fmt, ## __VA_ARGS__)
> +#define dev_notice(dev, fmt, ...) printk(XENLOG_INFO fmt, ## __VA_ARGS__)
> +#define dev_warn(dev, fmt, ...) printk(XENLOG_WARNING fmt, ## __VA_ARGS__)
> +#define dev_err(dev, fmt, ...) printk(XENLOG_ERR fmt, ## __VA_ARGS__)
> +#define dev_info(dev, fmt, ...) printk(XENLOG_INFO fmt, ## __VA_ARGS__)
> +
> +#define dev_err_ratelimited(dev, fmt, ...)                  \
> +     printk(XENLOG_ERR fmt, ## __VA_ARGS__)
> +
> +#define dev_name(dev) dt_node_full_name(dev_to_dt(dev))
> +
> +/* Alias to Xen allocation helpers */
> +#define kfree xfree
> +#define kmalloc(size, flags) ({\
> +	void *__ret_alloc = NULL; \
> +	if (flags & __GFP_ZERO) \
> +		__ret_alloc = _xzalloc(size, sizeof(void *)); \
> +	else \
> +		__ret_alloc = _xmalloc(size, sizeof(void *)); \
> +	__ret_alloc; \
> +})
> +#define kzalloc(size, flags)        _xzalloc(size, sizeof(void *))
> +#define devm_kzalloc(dev, size, flags)  _xzalloc(size, sizeof(void *))
> +#define kmalloc_array(size, n, flags) ({\
> +	void *__ret_alloc = NULL; \
> +	if (flags & __GFP_ZERO) \
> +		__ret_alloc = _xzalloc_array(size, sizeof(void *), n); \
> +	else \
> +		__ret_alloc = _xmalloc_array(size, sizeof(void *), n); \
> +	__ret_alloc; \
> +})
> +
> +/* Alias to Xen time functions */
> +#define ktime_t s_time_t
> +#define ktime_get()             (NOW())
> +#define ktime_add_us(t,i)       (t + MICROSECS(i))
> +#define ktime_compare(t,i)      (t > (i))
> +
> +#endif /* __XEN_LINUX_COMPAT_H__ */
Jan Beulich May 24, 2018, 7:57 a.m. UTC | #2
>>> On 24.05.18 at 02:46, <sameer.goel@linaro.org> wrote:
> --- /dev/null
> +++ b/xen/include/xen/linux_compat.h

I continue to dislike the idea of having a header with these contents in this location.
Independent of that I'd prefer if new files used hyphens instead of underscores
in their names - just like for command line options, other than C identifiers they're
not restricted to a very narrow set of possible delimiters or name components.

Jan
Sameer Goel May 24, 2018, 8:18 p.m. UTC | #3
Can you please point out the specific instances? This patch is no 
different than the last v1 patch. I have just added tasklets to it.


On 05/23/2018 10:48 PM, Manish Jaggi wrote:
> Hi Sameer,
>
> General Comment, please use appropriate variable names for XXX_domain 
> structures in code which is xen specific.
>
>
> On 05/24/2018 06:16 AM, Sameer Goel wrote:
>> This driver follows an approach similar to smmu driver. The intent here
>> is to reuse as much Linux code as possible.
>> - Glue code has been introduced to bridge the API calls.
>> - Called Linux functions from the Xen IOMMU function calls.
>> - Xen modifications are preceded by /*Xen: comment */
>> - xen/linux_compat: Add a Linux compat header
>>    For porting files directly from Linux it is useful to have a 
>> function mapping
>>    definitions from Linux to Xen. This file adds common API functions 
>> and
>>    other defines that are needed for porting arm SMMU drivers.
>>
>> Signed-off-by: Sameer Goel <sameer.goel@linaro.org>
>> ---
>>   xen/arch/arm/p2m.c                    |   1 +
>>   xen/drivers/Kconfig                   |   2 +
>>   xen/drivers/passthrough/arm/Kconfig   |   8 +
>>   xen/drivers/passthrough/arm/Makefile  |   1 +
>>   xen/drivers/passthrough/arm/smmu-v3.c | 934 +++++++++++++++++++++++++-
>>   xen/include/xen/linux_compat.h        |  84 +++
>>   6 files changed, 1001 insertions(+), 29 deletions(-)
>>   create mode 100644 xen/drivers/passthrough/arm/Kconfig
>>   create mode 100644 xen/include/xen/linux_compat.h
>>
>> diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
>> index d43c3aa896..38aa9f00c1 100644
>> --- a/xen/arch/arm/p2m.c
>> +++ b/xen/arch/arm/p2m.c
>> @@ -1454,6 +1454,7 @@ err:
>>   static void __init setup_virt_paging_one(void *data)
>>   {
>>       unsigned long val = (unsigned long)data;
>> +    /* SMMUv3 S2 cfg vtcr reuses the following value */
>>       WRITE_SYSREG32(val, VTCR_EL2);
>>       isb();
>>   }
>> diff --git a/xen/drivers/Kconfig b/xen/drivers/Kconfig
>> index db94393f47..59ca00f850 100644
>> --- a/xen/drivers/Kconfig
>> +++ b/xen/drivers/Kconfig
>> @@ -15,4 +15,6 @@ source "drivers/video/Kconfig"
>>   config HAS_VPCI
>>       bool
>>   +source "drivers/passthrough/arm/Kconfig"
>> +
>>   endmenu
>> diff --git a/xen/drivers/passthrough/arm/Kconfig 
>> b/xen/drivers/passthrough/arm/Kconfig
>> new file mode 100644
>> index 0000000000..cda899f608
>> --- /dev/null
>> +++ b/xen/drivers/passthrough/arm/Kconfig
>> @@ -0,0 +1,8 @@
>> +
>> +config ARM_SMMU_v3
>> +    bool "ARM SMMUv3 Support"
>> +    depends on ARM_64
>> +    help
>> +     Support for implementations of the ARM System MMU architecture
>> +     version 3.
>> +
>> diff --git a/xen/drivers/passthrough/arm/Makefile 
>> b/xen/drivers/passthrough/arm/Makefile
>> index f4cd26e15d..e14732b55c 100644
>> --- a/xen/drivers/passthrough/arm/Makefile
>> +++ b/xen/drivers/passthrough/arm/Makefile
>> @@ -1,2 +1,3 @@
>>   obj-y += iommu.o
>>   obj-y += smmu.o
>> +obj-$(CONFIG_ARM_SMMU_v3) += smmu-v3.o
>> diff --git a/xen/drivers/passthrough/arm/smmu-v3.c 
>> b/xen/drivers/passthrough/arm/smmu-v3.c
>> index e67ba6c40f..df81626785 100644
>> --- a/xen/drivers/passthrough/arm/smmu-v3.c
>> +++ b/xen/drivers/passthrough/arm/smmu-v3.c
>> @@ -18,28 +18,414 @@
>>    * Author: Will Deacon <will.deacon@arm.com>
>>    *
>>    * This driver is powered by bad coffee and bombay mix.
>> + *
>> + *
>> + * Based on Linux drivers/iommu/arm-smmu-v3.c
>> + * => commit 7aa8619a66aea52b145e04cbab4f8d6a4e5f3f3b
>> + *
>> + * Xen modifications:
>> + * Sameer Goel <sameer.goel@linaro.org>
>> + * Copyright (C) 2017, The Linux Foundation, All rights reserved.
>> + *
>>    */
>>   -#include <linux/acpi.h>
>> -#include <linux/acpi_iort.h>
>> -#include <linux/delay.h>
>> -#include <linux/dma-iommu.h>
>> -#include <linux/err.h>
>> -#include <linux/interrupt.h>
>> -#include <linux/iommu.h>
>> -#include <linux/iopoll.h>
>> -#include <linux/module.h>
>> -#include <linux/msi.h>
>> -#include <linux/of.h>
>> -#include <linux/of_address.h>
>> -#include <linux/of_iommu.h>
>> -#include <linux/of_platform.h>
>> -#include <linux/pci.h>
>> -#include <linux/platform_device.h>
>> -
>> -#include <linux/amba/bus.h>
>> -
>> -#include "io-pgtable.h"
>> +#include <xen/acpi.h>
>> +#include <xen/config.h>
>> +#include <xen/delay.h>
>> +#include <xen/errno.h>
>> +#include <xen/err.h>
>> +#include <xen/irq.h>
>> +#include <xen/lib.h>
>> +#include <xen/linux_compat.h>
>> +#include <xen/list.h>
>> +#include <xen/mm.h>
>> +#include <xen/rbtree.h>
>> +#include <xen/sched.h>
>> +#include <xen/sizes.h>
>> +#include <xen/vmap.h>
>> +#include <acpi/acpi_iort.h>
>> +#include <asm/atomic.h>
>> +#include <asm/device.h>
>> +#include <asm/io.h>
>> +#include <asm/platform.h>
>> +
>> +/* Alias to Xen device tree helpers */
>> +#define device_node dt_device_node
>> +#define of_phandle_args dt_phandle_args
>> +#define of_device_id dt_device_match
>> +#define of_match_node dt_match_node
>> +#define of_property_read_u32(np, pname, out) 
>> (!dt_property_read_u32(np, pname, out))
>> +#define of_property_read_bool dt_property_read_bool
>> +#define of_parse_phandle_with_args dt_parse_phandle_with_args
>> +
>> +/* Xen: Helpers to get device MMIO and IRQs */
>> +struct resource {
>> +    u64 addr;
>> +    u64 size;
>> +    unsigned int type;
>> +};
>> +
>> +#define resource_size(res) ((res)->size)
>> +
>> +#define platform_device device
>> +
>> +#define IORESOURCE_MEM 0
>> +#define IORESOURCE_IRQ 1
>> +
>> +static struct resource *platform_get_resource(struct platform_device 
>> *pdev,
>> +                          unsigned int type,
>> +                          unsigned int num)
>> +{
>> +    /*
>> +     * The resource is only used between 2 calls of 
>> platform_get_resource.
>> +     * It's quite ugly but it's avoid to add too much code in the part
>> +     * imported from Linux
>> +     */
>> +    static struct resource res;
>> +    struct acpi_iort_node *iort_node;
>> +    struct acpi_iort_smmu_v3 *node_smmu_data;
>> +    int ret = 0;
>> +
>> +    res.type = type;
>> +
>> +    switch (type) {
>> +    case IORESOURCE_MEM:
>> +        if (pdev->type == DEV_ACPI) {
>> +            ret = 1;
>> +            iort_node = pdev->acpi_node;
>> +            node_smmu_data =
>> +                (struct acpi_iort_smmu_v3 *)iort_node->node_data;
>> +
>> +            if (node_smmu_data != NULL) {
>> +                res.addr = node_smmu_data->base_address;
>> +                res.size = SZ_128K;
>> +                ret = 0;
>> +            }
>> +        } else {
>> +            ret = dt_device_get_address(dev_to_dt(pdev), num,
>> +                            &res.addr, &res.size);
>> +        }
>> +
>> +        return ((ret) ? NULL : &res);
>> +
>> +    case IORESOURCE_IRQ:
>> +        /* ACPI case not implemented as there is no use case for it */
>> +        ret = platform_get_irq(dev_to_dt(pdev), num);
>> +
>> +        if (ret < 0)
>> +            return NULL;
>> +
>> +        res.addr = ret;
>> +        res.size = 1;
>> +
>> +        return &res;
>> +
>> +    default:
>> +        return NULL;
>> +    }
>> +}
>> +
>> +static int platform_get_irq_byname(struct platform_device *pdev, 
>> const char *name)
>> +{
>> +    const struct dt_property *dtprop;
>> +    struct acpi_iort_node *iort_node;
>> +    struct acpi_iort_smmu_v3 *node_smmu_data;
>> +    int ret = 0;
>> +
>> +    if (pdev->type == DEV_ACPI) {
>> +        iort_node = pdev->acpi_node;
>> +        node_smmu_data = (struct acpi_iort_smmu_v3 
>> *)iort_node->node_data;
>> +
>> +        if (node_smmu_data != NULL) {
>> +            if (!strcmp(name, "eventq"))
>> +                ret = node_smmu_data->event_gsiv;
>> +            else if (!strcmp(name, "priq"))
>> +                ret = node_smmu_data->pri_gsiv;
>> +            else if (!strcmp(name, "cmdq-sync"))
>> +                ret = node_smmu_data->sync_gsiv;
>> +            else if (!strcmp(name, "gerror"))
>> +                ret = node_smmu_data->gerr_gsiv;
>> +            else
>> +                ret = -EINVAL;
>> +        }
>> +    } else {
>> +        dtprop = dt_find_property(dev_to_dt(pdev), 
>> "interrupt-names", NULL);
>> +        if (!dtprop)
>> +            return -EINVAL;
>> +
>> +        if (!dtprop->value)
>> +            return -ENODATA;
>> +    }
>> +
>> +    return ret;
>> +}
>> +
>> +/*
>> + * Xen: Helpers for DMA allocation. Just the function name is reused 
>> for
>> + * porting code these allocation are not managed allocations
>> + */
>> +
>> +static void *dmam_alloc_coherent(struct device *dev, size_t size,
>> +               dma_addr_t *dma_handle, gfp_t gfp)
> I believe the formatting needs to be checked.
>> +{
>> +    void *vaddr;
>> +    unsigned long alignment = size;
>> +
>> +    /*
>> +     * _xzalloc requires that the (align & (align -1)) = 0. Most of the
>> +     * allocations in SMMU code should send the right value for 
>> size. In
>> +     * case this is not true print a warning and align to the size of a
>> +     * (void *)
>> +     */
>> +    if (size & (size - 1)) {
>> +        dev_warn(dev, "Fixing alignment for the DMA buffer\n");
>> +        alignment = sizeof(void *);
>> +    }
>> +
>> +    vaddr = _xzalloc(size, alignment);
>> +    if (!vaddr) {
>> +        dev_err(dev, "DMA allocation failed\n");
>> +        return NULL;
>> +    }
>> +
>> +    *dma_handle = virt_to_maddr(vaddr);
>> +
>> +    return vaddr;
>> +}
>> +
>> +
>> +static void dmam_free_coherent(struct device *dev, size_t size, void 
>> *vaddr,
>> +            dma_addr_t dma_handle)
> same
>> +{
>> +    xfree(vaddr);
>> +}
>> +
>> +/* Xen: Stub out DMA domain related functions */
>> +#define iommu_get_dma_cookie(dom) 0
>> +#define iommu_put_dma_cookie(dom)
>> +
>> +/* Xen: Stub out module param related function */
>> +#define module_param_named(a, b, c, d)
>> +#define MODULE_PARM_DESC(a, b)
>> +
>> +#define dma_set_mask_and_coherent(d, b) 0
>> +
>> +#define of_dma_is_coherent(n) 0
>> +
>> +#define MODULE_DEVICE_TABLE(type, name)
>> +
>> +static void __iomem *devm_ioremap_resource(struct device *dev,
>> +                       struct resource *res)
>> +{
>> +    void __iomem *ptr;
>> +
>> +    if (!res || res->type != IORESOURCE_MEM) {
>> +        dev_err(dev, "Invalid resource\n");
>> +        return ERR_PTR(-EINVAL);
>> +    }
>> +
>> +    ptr = ioremap_nocache(res->addr, res->size);
>> +    if (!ptr) {
>> +        dev_err(dev,
>> +            "ioremap failed (addr 0x%"PRIx64" size 0x%"PRIx64")\n",
>> +            res->addr, res->size);
>> +        return ERR_PTR(-ENOMEM);
>> +    }
>> +
>> +    return ptr;
>> +}
>> +
>> +/* Xen: Compatibility define for iommu_domain_geometry.*/
>> +struct iommu_domain_geometry {
>> +    dma_addr_t aperture_start; /* First address that can be 
>> mapped    */
>> +    dma_addr_t aperture_end;   /* Last address that can be 
>> mapped     */
>> +    bool force_aperture;       /* DMA only allowed in mappable 
>> range? */
>> +};
>> +
>> +
>> +/* Xen: Type definitions for iommu_domain */
>> +#define IOMMU_DOMAIN_UNMANAGED 0
>> +#define IOMMU_DOMAIN_DMA 1
>> +#define IOMMU_DOMAIN_IDENTITY 2
>> +
>> +/* Xen: Dummy iommu_domain */
>> +struct iommu_domain {
>> +    /* Runtime SMMU configuration for this iommu_domain */
>> +    struct arm_smmu_domain        *priv;
>> +    unsigned int type;
>> +
>> +    /* Dummy compatibility defines */
>> +    unsigned long pgsize_bitmap;
>> +    struct iommu_domain_geometry geometry;
>> +
>> +    atomic_t ref;
>> +    /*
>> +     * Used to link iommu_domain contexts for a same domain.
>> +     * There is at least one per-SMMU to used by the domain.
>> +     */
>> +    struct list_head        list;
>> +};
>> +
>> +/* Xen: Describes information required for a Xen domain */
>> +struct arm_smmu_xen_domain {
>> +    spinlock_t            lock;
>> +    /* List of iommu domains associated to this domain */
>> +    struct list_head        contexts;
>> +};
>> +
>> +/*
>> + * Xen: Information about each device stored in dev->archdata.iommu
>> + *
>> + * The dev->archdata.iommu stores the iommu_domain (runtime 
>> configuration of
>> + * the SMMU).
>> + */
>> +struct arm_smmu_xen_device {
>> +    struct iommu_domain *domain;
>> +};
>> +
> As this is a xen specific code, can the variable names be used 
> appropriately.
> Repeating my comment  from earlier version.
> a domain is  usually a VM in Xen. So it is a bit confusing to use 
> domain for iommu_domain.
>> +/*
>> + * Xen: io_pgtable compatibility defines.
>> + * Most of these are to port in the S1 translation code as is.
>> + */
>> +struct io_pgtable_ops {
>> +};
>> +
>> +struct iommu_gather_ops {
>> +    void (*tlb_flush_all)(void *cookie);
>> +    void (*tlb_add_flush)(unsigned long iova, size_t size, size_t 
>> granule,
>> +                  bool leaf, void *cookie);
>> +    void (*tlb_sync)(void *cookie);
>> +};
>> +
>> +struct io_pgtable_cfg {
>> +    /*
>> +     * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE 
>> bits in
>> +     *    stage 1 PTEs, for hardware which insists on validating them
>> +     *    even in    non-secure state where they should normally be 
>> ignored.
>> +     *
>> +     * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE 
>> and
>> +     *    IOMMU_NOEXEC flags and map everything with full access, for
>> +     *    hardware which does not implement the permissions of a given
>> +     *    format, and/or requires some format-specific default value.
>> +     *
>> +     * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching 
>> invalid
>> +     *    (unmapped) entries but the hardware might do so anyway, 
>> perform
>> +     *    TLB maintenance when mapping as well as when unmapping.
>> +     *
>> +     * IO_PGTABLE_QUIRK_ARM_MTK_4GB: (ARM v7s format) Set bit 9 in all
>> +     *    PTEs, for Mediatek IOMMUs which treat it as a 33rd address 
>> bit
>> +     *    when the SoC is in "4GB mode" and they can only access the 
>> high
>> +     *    remap of DRAM (0x1_00000000 to 0x1_ffffffff).
>> +     *
>> +     * IO_PGTABLE_QUIRK_NO_DMA: Guarantees that the tables will only 
>> ever
>> +     *    be accessed by a fully cache-coherent IOMMU or CPU (e.g. 
>> for a
>> +     *    software-emulated IOMMU), such that pagetable updates need 
>> not
>> +     *    be treated as explicit DMA data.
>> +     */
>> +    #define IO_PGTABLE_QUIRK_ARM_NS        BIT(0)
>> +    #define IO_PGTABLE_QUIRK_NO_PERMS    BIT(1)
>> +    #define IO_PGTABLE_QUIRK_TLBI_ON_MAP    BIT(2)
>> +    #define IO_PGTABLE_QUIRK_ARM_MTK_4GB    BIT(3)
>> +    #define IO_PGTABLE_QUIRK_NO_DMA        BIT(4)
>> +    unsigned long            quirks;
>> +    unsigned long            pgsize_bitmap;
>> +    unsigned int            ias;
>> +    unsigned int            oas;
>> +    const struct iommu_gather_ops    *tlb;
>> +    struct device            *iommu_dev;
>> +
>> +    /* Low-level data specific to the table format */
>> +    union {
>> +        struct {
>> +            u64    ttbr[2];
>> +            u64    tcr;
>> +            u64    mair[2];
>> +        } arm_lpae_s1_cfg;
>> +
>> +        struct {
>> +            u64    vttbr;
>> +            u64    vtcr;
>> +        } arm_lpae_s2_cfg;
>> +
>> +        struct {
>> +            u32    ttbr[2];
>> +            u32    tcr;
>> +            u32    nmrr;
>> +            u32    prrr;
>> +        } arm_v7s_cfg;
>> +    };
>> +};
>> +
>> +enum io_pgtable_fmt {
>> +    ARM_32_LPAE_S1,
>> +    ARM_32_LPAE_S2,
>> +    ARM_64_LPAE_S1,
>> +    ARM_64_LPAE_S2,
>> +    ARM_V7S,
>> +    IO_PGTABLE_NUM_FMTS,
>> +};
>> +
>> +/*
>> + * Xen: The pgtable_ops are used by the S1 translations, so return 
>> the dummy
>> + * address.
>> + */
>> +#define alloc_io_pgtable_ops(f, c, o) ((struct io_pgtable_ops *)0x1)
>> +#define free_io_pgtable_ops(o)
>> +
>> +/* Xen: Define wrapper for requesting IRQs */
>> +#define IRQF_ONESHOT 0
>> +
>> +typedef void (*irq_handler_t)(int, void *, struct cpu_user_regs *);
>> +
>> +static inline int devm_request_irq(struct device *dev, unsigned int 
>> irq,
>> +                   irq_handler_t handler, unsigned long irqflags,
>> +                   const char *devname, void *dev_id)
>> +{
>> +    /*
>> +     * SMMUv3 implementation can support wired interrupt outputs 
>> that are
>> +     * edge-triggered. Set the irq type as per the spec.
>> +     */
>> +    irq_set_type(irq, IRQ_TYPE_EDGE_BOTH);
>> +    return request_irq(irq, irqflags, handler, devname, dev_id);
>> +}
>> +
>> +/*
>> + * Xen does not have a concept of threaded irq, but we can use 
>> tasklets to
>> + * achieve the desired functionality as needed.
>> + */
>> +int devm_request_threaded_irq(struct device *dev, unsigned int irq, 
>> irq_handler_t handler,
>> +                  irq_handler_t thread_fn, unsigned long irqflags,
>> +                  const char *devname, void *dev_id)
>> +{
>> +    return devm_request_irq(dev, irq, thread_fn, irqflags, devname, 
>> dev_id);
>> +}
>> +
>> +/* Xen: The mutex is used only during initialization so the typecast 
>> is safe */
>> +#define mutex spinlock
>> +#define mutex_init spin_lock_init
>> +#define mutex_lock spin_lock
>> +#define mutex_unlock spin_unlock
>> +
>> +#define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us) \
>> +({ \
>> +    s_time_t deadline = NOW() + MICROSECS(timeout_us); \
>> +    for (;;) { \
>> +        (val) = op(addr); \
>> +        if (cond) \
>> +            break; \
>> +        if (NOW() > deadline) { \
>> +            (val) = op(addr); \
>> +            break; \
>> +        } \
>> +    udelay(sleep_us); \
>> +    } \
>> +    (cond) ? 0 : -ETIMEDOUT; \
>> +})
>> +
>> +#define readl_relaxed_poll_timeout(addr, val, cond, delay_us, 
>> timeout_us) \
>> +    readx_poll_timeout(readl_relaxed, addr, val, cond, delay_us, 
>> timeout_us)
>> +
>> +#define VA_BITS 0 /* Only needed for S1 translations */
>>     /* MMIO registers */
>>   #define ARM_SMMU_IDR0            0x0
>> @@ -433,6 +819,7 @@ enum pri_resp {
>>       PRI_RESP_SUCC,
>>   };
>>   +#if 0 /* Xen: No MSI support in this iteration */
>>   enum arm_smmu_msi_index {
>>       EVTQ_MSI_INDEX,
>>       GERROR_MSI_INDEX,
>> @@ -457,6 +844,7 @@ static phys_addr_t 
>> arm_smmu_msi_cfg[ARM_SMMU_MAX_MSIS][3] = {
>>           ARM_SMMU_PRIQ_IRQ_CFG2,
>>       },
>>   };
>> +#endif
>>     struct arm_smmu_cmdq_ent {
>>       /* Common fields */
>> @@ -561,6 +949,8 @@ struct arm_smmu_s2_cfg {
>>       u16                vmid;
>>       u64                vttbr;
>>       u64                vtcr;
>> +    /* Xen: Domain associated to this configuration */
>> +    struct domain            *domain;
>>   };
>>     struct arm_smmu_strtab_ent {
>> @@ -635,9 +1025,25 @@ struct arm_smmu_device {
>>       struct arm_smmu_strtab_cfg    strtab_cfg;
>>         /* IOMMU core code handle */
>> +#if 0 /*Xen: Generic iommu_device ref not needed here */
>>       struct iommu_device        iommu;
>> +#endif
> Is it clean to put #if 0, can this line be deleted or used with a 
> proper macro
>> +    /* Xen: Need to keep a list of SMMU devices */
>> +    struct list_head                devices;
>> +    /* Xen: Tasklets for handling evts/faults and pci page request 
>> IRQs*/
>> +    struct tasklet            evtq_tasklet;
>> +    struct tasklet            priq_tasklet;
>> +    struct tasklet            combined_irq_tasklet;
>>   };
>>   +/* Xen: Keep a list of devices associated with this driver */
>> +static DEFINE_SPINLOCK(arm_smmu_devices_lock);
>> +static LIST_HEAD(arm_smmu_devices);
>> +/* Xen: Helper for finding a device using fwnode */
>> +static
>> +struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle 
>> *fwnode);
>> +
>> +
>>   /* SMMU private data for each master */
>>   struct arm_smmu_master_data {
>>       struct arm_smmu_device        *smmu;
>> @@ -1232,7 +1638,7 @@ static void arm_smmu_handle_ppr(struct 
>> arm_smmu_device *smmu, u64 *evt)
>>         dev_info(smmu->dev, "unexpected PRI request received:\n");
>>       dev_info(smmu->dev,
>> -         "\tsid 0x%08x.0x%05x: [%u%s] %sprivileged %s%s%s access at 
>> iova 0x%016llx\n",
>> +         "\tsid 0x%08x.0x%05x: [%u%s] %sprivileged %s%s%s access at 
>> iova %#" PRIx64 "\n",
>>            sid, ssid, grpid, last ? "L" : "",
>>            evt[0] & PRIQ_0_PERM_PRIV ? "" : "un",
>>            evt[0] & PRIQ_0_PERM_READ ? "R" : "",
>> @@ -1342,10 +1748,20 @@ static irqreturn_t 
>> arm_smmu_combined_irq_thread(int irq, void *dev)
>>       return IRQ_HANDLED;
>>   }
>>   +/* Xen: Forward define for combined_irq tasklet */
>> +static void arm_smmu_combined_irq_tasklet(unsigned long dev);
>> +
>>   static irqreturn_t arm_smmu_combined_irq_handler(int irq, void *dev)
>>   {
>> +    /* Xen: Need an smmu reference to schedule the tasklet */
>> +    struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
>> +
>>       arm_smmu_gerror_handler(irq, dev);
>>       arm_smmu_cmdq_sync_handler(irq, dev);
>> +
>> +    /*Xen: No threaded irq. So, schedule the right tasklet*/
>> +    tasklet_schedule(&(smmu->combined_irq_tasklet));
>> +
>>       return IRQ_WAKE_THREAD;
>>   }
>>   @@ -1358,6 +1774,69 @@ static void __arm_smmu_tlb_sync(struct 
>> arm_smmu_device *smmu)
>>       arm_smmu_cmdq_issue_cmd(smmu, &cmd);
>>   }
>>   +/*
>> + * Xen: Define the IRQ handlers and tasklets for xen. The linux 
>> functions
>> + * would be modified to use the functions defined in the following 
>> code.
>> + */
>> +
>> +static void arm_smmu_evtq_tasklet(unsigned long dev)
>> +{
>> +    /* The IRQ number is not relevent for the evtq thread processing */
>> +    arm_smmu_evtq_thread(0, (void *)dev);
>> +}
>> +
>> +static void arm_smmu_priq_tasklet(unsigned long dev)
>> +{
>> +    /* The IRQ number is not relevent for the priq thread processing */
>> +    arm_smmu_priq_thread(0, (void *)dev);
>> +}
>> +
>> +static void arm_smmu_combined_irq_tasklet(unsigned long dev)
>> +{
>> +    /* The IRQ number is not relevent for the combined irq handler.*/
>> +    arm_smmu_combined_irq_thread(0, (void *)dev);
>> +}
>> +
>> +static void arm_smmu_evtq_thread_xen(int irq, void *dev,
>> +                       struct cpu_user_regs *regs)
>> +{
>> +    struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
>> +
>> +    tasklet_schedule(&(smmu->evtq_tasklet));
>> +}
>> +
>> +static void arm_smmu_priq_thread_xen(int irq, void *dev,
>> +                       struct cpu_user_regs *regs)
>> +{
>> +    struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
>> +
>> +    tasklet_schedule(&(smmu->priq_tasklet));
>> +}
>> +
>> +static void arm_smmu_cmdq_sync_handler_xen(int irq, void *dev,
>> +                       struct cpu_user_regs *regs)
>> +{
>> +    arm_smmu_cmdq_sync_handler(irq, dev);
>> +}
>> +
>> +static void arm_smmu_gerror_handler_xen(int irq, void *dev,
>> +                       struct cpu_user_regs *regs)
>> +{
>> +    arm_smmu_gerror_handler(irq, dev);
>> +}
>> +
>> +static void arm_smmu_combined_irq_handler_xen(int irq, void *dev,
>> +                       struct cpu_user_regs *regs)
>> +{
>> +    arm_smmu_combined_irq_handler(irq, dev);
>> +}
>> +
>> +#define arm_smmu_evtq_thread arm_smmu_evtq_thread_xen
>> +#define arm_smmu_priq_thread arm_smmu_priq_thread_xen
>> +#define arm_smmu_cmdq_sync_handler arm_smmu_cmdq_sync_handler_xen
>> +#define arm_smmu_gerror_handler arm_smmu_gerror_handler_xen
>> +#define arm_smmu_combined_irq_handler arm_smmu_combined_irq_handler_xen
>> +
>>   static void arm_smmu_tlb_sync(void *cookie)
>>   {
>>       struct arm_smmu_domain *smmu_domain = cookie;
>> @@ -1415,6 +1894,7 @@ static const struct iommu_gather_ops 
>> arm_smmu_gather_ops = {
>>       .tlb_sync    = arm_smmu_tlb_sync,
>>   };
>>   +#if 0 /*Xen: Unused functionality */
>>   /* IOMMU API */
>>   static bool arm_smmu_capable(enum iommu_cap cap)
>>   {
>> @@ -1427,6 +1907,7 @@ static bool arm_smmu_capable(enum iommu_cap cap)
>>           return false;
>>       }
>>   }
>> +#endif
>>     static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
>>   {
>> @@ -1546,9 +2027,16 @@ static int arm_smmu_domain_finalise_s2(struct 
>> arm_smmu_domain *smmu_domain,
>>       if (vmid < 0)
>>           return vmid;
>>   -    cfg->vmid    = (u16)vmid;
>> -    cfg->vttbr    = pgtbl_cfg->arm_lpae_s2_cfg.vttbr;
>> -    cfg->vtcr    = pgtbl_cfg->arm_lpae_s2_cfg.vtcr;
>> +    /*
>> +     * Xen: Get the ttbr and vtcr values
>> +     * vttbr: This is a shared value with the domain page table
>> +     * vtcr: The TCR settings are the same as CPU since the page
>> +     * tables are shared
>> +     */
>> +
>> +    cfg->vmid    = vmid;
>> +    cfg->vttbr    = page_to_maddr(cfg->domain->arch.p2m.root);
>> +    cfg->vtcr    = READ_SYSREG32(VTCR_EL2) & STRTAB_STE_2_VTCR_MASK;
>>       return 0;
>>   }
>>   @@ -1604,6 +2092,7 @@ static int arm_smmu_domain_finalise(struct 
>> iommu_domain *domain)
>>       if (smmu->features & ARM_SMMU_FEAT_COHERENCY)
>>           pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_NO_DMA;
>>   +    /* Xen: pgtbl_ops gets an invalid address */
>>       pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);
>>       if (!pgtbl_ops)
>>           return -ENOMEM;
>> @@ -1721,6 +2210,7 @@ out_unlock:
>>       return ret;
>>   }
>>   +#if 0 /* Xen: Unused functionality */
> same
>>   static int arm_smmu_map(struct iommu_domain *domain, unsigned long 
>> iova,
>>               phys_addr_t paddr, size_t size, int prot)
>>   {
>> @@ -1772,6 +2262,7 @@ struct arm_smmu_device 
>> *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
>>       put_device(dev);
>>       return dev ? dev_get_drvdata(dev) : NULL;
>>   }
>> +#endif
>>     static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, 
>> u32 sid)
>>   {
>> @@ -1783,7 +2274,14 @@ static bool arm_smmu_sid_in_range(struct 
>> arm_smmu_device *smmu, u32 sid)
>>       return sid < limit;
>>   }
>>   +/* Xen: Unused */
>> +#if 0
>>   static struct iommu_ops arm_smmu_ops;
>> +#endif
>> +
>> +/* Xen: Redefine arm_smmu_ops to what fwspec should evaluate */
>> +static const struct iommu_ops arm_smmu_iommu_ops;
>> +#define arm_smmu_ops arm_smmu_iommu_ops
>>     static int arm_smmu_add_device(struct device *dev)
>>   {
>> @@ -1791,8 +2289,11 @@ static int arm_smmu_add_device(struct device 
>> *dev)
>>       struct arm_smmu_device *smmu;
>>       struct arm_smmu_master_data *master;
>>       struct iommu_fwspec *fwspec = dev->iommu_fwspec;
>> +#if 0 /*Xen: iommu_group is not needed */
>>       struct iommu_group *group;
>> +#endif
>>   +    /* Xen: fwspec->ops are not needed */
>>       if (!fwspec || fwspec->ops != &arm_smmu_ops)
>>           return -ENODEV;
>>       /*
>> @@ -1830,6 +2331,11 @@ static int arm_smmu_add_device(struct device 
>> *dev)
>>           }
>>       }
>>   +/*
>> + * Xen: Do not need an iommu group as the stream data is carried by 
>> the SMMU
>> + * master device object
>> + */
>> +#if 0
>>       group = iommu_group_get_for_dev(dev);
>>       if (!IS_ERR(group)) {
>>           iommu_group_put(group);
>> @@ -1837,8 +2343,16 @@ static int arm_smmu_add_device(struct device 
>> *dev)
>>       }
>>         return PTR_ERR_OR_ZERO(group);
>> +#endif
>> +    return 0;
>>   }
>>   +/*
>> + * Xen: We can potentially support this function and destroy a 
>> device. This
>> + * will be relevant for PCI hotplug. So, will be implemented as 
>> needed after
>> + * passthrough support is available.
>> + */
>> +#if 0
>>   static void arm_smmu_remove_device(struct device *dev)
>>   {
>>       struct iommu_fwspec *fwspec = dev->iommu_fwspec;
>> @@ -1974,6 +2488,7 @@ static struct iommu_ops arm_smmu_ops = {
>>       .put_resv_regions    = arm_smmu_put_resv_regions,
>>       .pgsize_bitmap        = -1UL, /* Restricted during device 
>> attach */
>>   };
>> +#endif
>>     /* Probing and initialisation functions */
>>   static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
>> @@ -2182,6 +2697,7 @@ static int arm_smmu_update_gbpa(struct 
>> arm_smmu_device *smmu, u32 set, u32 clr)
>>                         1, ARM_SMMU_POLL_TIMEOUT_US);
>>   }
>>   +#if 0 /* Xen: There is no MSI support as yet */
>>   static void arm_smmu_free_msis(void *data)
>>   {
>>       struct device *dev = data;
>> @@ -2247,12 +2763,15 @@ static void arm_smmu_setup_msis(struct 
>> arm_smmu_device *smmu)
>>       /* Add callback to free MSIs on teardown */
>>       devm_add_action(dev, arm_smmu_free_msis, dev);
>>   }
>> +#endif
>>     static void arm_smmu_setup_unique_irqs(struct arm_smmu_device *smmu)
>>   {
>>       int irq, ret;
>>   +#if 0 /*Xen: Cannot setup msis for now */
>>       arm_smmu_setup_msis(smmu);
>> +#endif
>>         /* Request interrupt lines */
>>       irq = smmu->evtq.q.irq;
>> @@ -2316,9 +2835,13 @@ static int arm_smmu_setup_irqs(struct 
>> arm_smmu_device *smmu)
>>            * Cavium ThunderX2 implementation doesn't not support unique
>>            * irq lines. Use single irq line for all the SMMUv3 
>> interrupts.
>>            */
>> -        ret = devm_request_threaded_irq(smmu->dev, irq,
>> +        /*
>> +         * Xen: Does not support threaded irqs, so serialise the setup.
>> +         * This is the same for pris and event interrupt lines on other
>> +         * systems
>> +         */
>> +        ret = devm_request_irq(smmu->dev, irq,
>>                       arm_smmu_combined_irq_handler,
>> -                    arm_smmu_combined_irq_thread,
>>                       IRQF_ONESHOT,
>>                       "arm-smmu-v3-combined-irq", smmu);
>>           if (ret < 0)
>> @@ -2452,6 +2975,13 @@ static int arm_smmu_device_reset(struct 
>> arm_smmu_device *smmu, bool bypass)
>>           return ret;
>>       }
>>   +    /* Xen: Initialize tasklets */
>> +    tasklet_init(&smmu->evtq_tasklet, arm_smmu_evtq_tasklet,
>> +            (unsigned long)smmu);
>> +    tasklet_init(&smmu->priq_tasklet, arm_smmu_priq_tasklet,
>> +            (unsigned long)smmu);
>> +    tasklet_init(&smmu->combined_irq_tasklet, 
>> arm_smmu_combined_irq_tasklet,
>> +            (unsigned long)smmu);
>>         /* Enable the SMMU interface, or ensure bypass */
>>       if (!bypass || disable_bypass) {
>> @@ -2542,8 +3072,14 @@ static int arm_smmu_device_hw_probe(struct 
>> arm_smmu_device *smmu)
>>           smmu->features |= ARM_SMMU_FEAT_STALLS;
>>       }
>>   +/*
>> + * Xen: Block stage 1 translations. By doing this here we do not 
>> need to set the
>> + * domain->stage explicitly.
>> + */
>> +#if 0
>>       if (reg & IDR0_S1P)
>>           smmu->features |= ARM_SMMU_FEAT_TRANS_S1;
>> +#endif
>>         if (reg & IDR0_S2P)
>>           smmu->features |= ARM_SMMU_FEAT_TRANS_S2;
>> @@ -2616,10 +3152,12 @@ static int arm_smmu_device_hw_probe(struct 
>> arm_smmu_device *smmu)
>>       if (reg & IDR5_GRAN4K)
>>           smmu->pgsize_bitmap |= SZ_4K | SZ_2M | SZ_1G;
>>   +#if 0 /* Xen: SMMU ops do not have a pgsize_bitmap member for Xen */
>>       if (arm_smmu_ops.pgsize_bitmap == -1UL)
>>           arm_smmu_ops.pgsize_bitmap = smmu->pgsize_bitmap;
>>       else
>>           arm_smmu_ops.pgsize_bitmap |= smmu->pgsize_bitmap;
>> +#endif
>>         /* Output address size */
>>       switch (reg & IDR5_OAS_MASK << IDR5_OAS_SHIFT) {
>> @@ -2680,7 +3218,8 @@ static int arm_smmu_device_acpi_probe(struct 
>> platform_device *pdev,
>>       struct device *dev = smmu->dev;
>>       struct acpi_iort_node *node;
>>   -    node = *(struct acpi_iort_node **)dev_get_platdata(dev);
>> +    /* Xen: Modification to get iort_node */
>> +    node = (struct acpi_iort_node *)dev->acpi_node;
>>         /* Retrieve SMMUv3 specific data */
>>       iort_smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
>> @@ -2703,7 +3242,7 @@ static inline int 
>> arm_smmu_device_acpi_probe(struct platform_device *pdev,
>>   static int arm_smmu_device_dt_probe(struct platform_device *pdev,
>>                       struct arm_smmu_device *smmu)
>>   {
>> -    struct device *dev = &pdev->dev;
>> +    struct device *dev = pdev;
>>       u32 cells;
>>       int ret = -EINVAL;
>>   @@ -2716,6 +3255,7 @@ static int arm_smmu_device_dt_probe(struct 
>> platform_device *pdev,
>>         parse_driver_options(smmu);
>>   +    /* Xen: of_dma_is_coherent is a stub till dt support is 
>> introduced */
>>       if (of_dma_is_coherent(dev->of_node))
>>           smmu->features |= ARM_SMMU_FEAT_COHERENCY;
>>   @@ -2734,9 +3274,11 @@ static int arm_smmu_device_probe(struct 
>> platform_device *pdev)
>>   {
>>       int irq, ret;
>>       struct resource *res;
>> +#if 0 /*Xen: Do not need to setup sysfs */
>>       resource_size_t ioaddr;
>> +#endif
>>       struct arm_smmu_device *smmu;
>> -    struct device *dev = &pdev->dev;
>> +    struct device *dev = pdev;/* Xen: dev is ignored */
>>       bool bypass;
>>         smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
>> @@ -2763,7 +3305,9 @@ static int arm_smmu_device_probe(struct 
>> platform_device *pdev)
>>           dev_err(dev, "MMIO region too small (%pr)\n", res);
>>           return -EINVAL;
>>       }
>> +#if 0 /*Xen: Do not need to setup sysfs */
>>       ioaddr = res->start;
>> +#endif
>>         smmu->base = devm_ioremap_resource(dev, res);
>>       if (IS_ERR(smmu->base))
>> @@ -2802,13 +3346,18 @@ static int arm_smmu_device_probe(struct 
>> platform_device *pdev)
>>           return ret;
>>         /* Record our private device structure */
>> +    /* Xen: SMMU is not treated a a platform device*/
>> +#if 0
>>       platform_set_drvdata(pdev, smmu);
>> +#endif
>>         /* Reset the device */
>>       ret = arm_smmu_device_reset(smmu, bypass);
>>       if (ret)
>>           return ret;
>>   +/* Xen: Not creating an IOMMU device list for Xen */
>> +#if 0
>>       /* And we're up. Go go go! */
>>       ret = iommu_device_sysfs_add(&smmu->iommu, dev, NULL,
>>                        "smmu3.%pa", &ioaddr);
>> @@ -2844,9 +3393,20 @@ static int arm_smmu_device_probe(struct 
>> platform_device *pdev)
>>           if (ret)
>>               return ret;
>>       }
>> +#endif
>> +    /*
>> +     * Xen: Keep a list of all probed devices. This will be used to 
>> query
>> +     * the smmu devices based on the fwnode.
>> +     */
>> +    INIT_LIST_HEAD(&smmu->devices);
>> +    spin_lock(&arm_smmu_devices_lock);
>> +    list_add(&smmu->devices, &arm_smmu_devices);
>> +    spin_unlock(&arm_smmu_devices_lock);
>>       return 0;
>>   }
>>   +/* Xen: Unused function */
>> +#if 0
>>   static int arm_smmu_device_remove(struct platform_device *pdev)
>>   {
>>       struct arm_smmu_device *smmu = platform_get_drvdata(pdev);
>> @@ -2860,6 +3420,8 @@ static void arm_smmu_device_shutdown(struct 
>> platform_device *pdev)
>>   {
>>       arm_smmu_device_remove(pdev);
>>   }
>> +#endif
>> +
>>     static const struct of_device_id arm_smmu_of_match[] = {
>>       { .compatible = "arm,smmu-v3", },
>> @@ -2867,6 +3429,7 @@ static const struct of_device_id 
>> arm_smmu_of_match[] = {
>>   };
>>   MODULE_DEVICE_TABLE(of, arm_smmu_of_match);
>>   +#if 0
>>   static struct platform_driver arm_smmu_driver = {
>>       .driver    = {
>>           .name        = "arm-smmu-v3",
>> @@ -2883,3 +3446,316 @@ IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", 
>> NULL);
>>   MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 
>> implementations");
>>   MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
>>   MODULE_LICENSE("GPL v2");
>> +#endif
>> +
>> +/***** Start of Xen specific code *****/
>> +
>> +static int __must_check arm_smmu_iotlb_flush_all(struct domain *d)
>> +{
>> +    struct arm_smmu_xen_domain *smmu_domain = dom_iommu(d)->arch.priv;
>> +    struct iommu_domain *cfg;
>> +
>> +    spin_lock(&smmu_domain->lock);
>> +    list_for_each_entry(cfg, &smmu_domain->contexts, list) {
>> +        /*
>> +         * Only invalidate the context when SMMU is present.
>> +         * This is because the context initialization is delayed
>> +         * until a master has been added.
>> +         */
>> +        if (unlikely(!ACCESS_ONCE(cfg->priv->smmu)))
>> +            continue;
>> +        arm_smmu_tlb_inv_context(cfg->priv);
>> +    }
>> +    spin_unlock(&smmu_domain->lock);
>> +    return 0;
>> +}
>> +
>> +static int __must_check arm_smmu_iotlb_flush(struct domain *d,
>> +                         unsigned long gfn,
>> +                         unsigned int page_count)
>> +{
>> +    return arm_smmu_iotlb_flush_all(d);
>> +}
>> +
>> +static struct iommu_domain *arm_smmu_get_domain(struct domain *d,
>> +                        struct device *dev)
> This is returning iommu_domain and not a domain.
> Please change the name of function.
>> +{
>> +    struct iommu_domain *domain;
>> +    struct arm_smmu_xen_domain *xen_domain;
> A suggestion
> 1. as you have used in above function smmu_domain variable for 
> arm_smmu_xen_domain
> Can similar logic be used for iommu_domain.
>
> 2. When smmu_domain variable name is used in above function why 
> xen_domain is used in this function.
> It is quite confusing.
> logically xen_domain should mean a VM.
>> +    struct arm_smmu_device *smmu;
>> +    struct arm_smmu_domain *smmu_domain;
> smmu_domain was used for arm_smmu_xen_domain.
> consistency of variable names is necessary for code clarity
>> +
>> +    xen_domain = dom_iommu(d)->arch.priv;
>> +
>> +    smmu = arm_smmu_get_by_fwnode(dev->iommu_fwspec->iommu_fwnode);
>> +    if (!smmu)
>> +        return NULL;
>> +
>> +    /*
>> +     * Loop through the &xen_domain->contexts to locate a context
>> +     * assigned to this SMMU
>> +     */
>> +    list_for_each_entry(domain, &xen_domain->contexts, list) {
>> +        smmu_domain = to_smmu_domain(domain);
>> +        if (smmu_domain->smmu == smmu)
>> +            return domain;
>> +    }
>> +
>> +    return NULL;
>> +}
>> +
>> +static void arm_smmu_destroy_iommu_domain(struct iommu_domain *domain)
> same
>> +{
>> +    list_del(&domain->list);
>> +    arm_smmu_domain_free(domain);
>> +}
>> +
>> +static int arm_smmu_assign_dev(struct domain *d, u8 devfn,
>> +                   struct device *dev, u32 flag)
>> +{
>> +    int ret = 0;
>> +    struct iommu_domain *domain;
>> +    struct arm_smmu_xen_domain *xen_domain;
> same
>> +    struct arm_smmu_domain *arm_smmu;
>> +
>> +    xen_domain = dom_iommu(d)->arch.priv;
>> +
>> +    if (!dev->archdata.iommu) {
>> +        dev->archdata.iommu = xzalloc(struct arm_smmu_xen_device);
>> +        if (!dev->archdata.iommu)
>> +            return -ENOMEM;
>> +    }
>> +
>> +    ret = arm_smmu_add_device(dev);
>> +    if (ret)
>> +        return ret;
>> +
>> +    spin_lock(&xen_domain->lock);
>> +
>> +    /*
>> +     * Check to see if an iommu_domain already exists for this xen 
>> domain
>> +     * under the same SMMU
>> +     */
>> +    domain = arm_smmu_get_domain(d, dev);
>> +    if (!domain) {
>> +
>> +        domain = arm_smmu_domain_alloc(IOMMU_DOMAIN_DMA);
>> +        if (!domain) {
>> +            ret = -ENOMEM;
>> +            goto out;
>> +        }
>> +
>> +        arm_smmu = to_smmu_domain(domain);
>> +        arm_smmu->s2_cfg.domain = d;
>> +
>> +        /* Chain the new context to the domain */
>> +        list_add(&domain->list, &xen_domain->contexts);
>> +
>> +    }
>> +
>> +    ret = arm_smmu_attach_dev(domain, dev);
>> +    if (ret) {
>> +        if (domain->ref.counter == 0)
>> +            arm_smmu_destroy_iommu_domain(domain);
>> +    } else {
>> +        atomic_inc(&domain->ref);
>> +    }
>> +
>> +out:
>> +    spin_unlock(&xen_domain->lock);
>> +    return ret;
>> +}
>> +
>> +static int arm_smmu_deassign_dev(struct domain *d, struct device *dev)
>> +{
>> +    struct iommu_domain *domain = arm_smmu_get_domain(d, dev);
>> +    struct arm_smmu_xen_domain *xen_domain;
>> +    struct arm_smmu_domain *arm_smmu = to_smmu_domain(domain);
> same
>> +
>> +    xen_domain = dom_iommu(d)->arch.priv;
>> +
>> +    if (!arm_smmu || arm_smmu->s2_cfg.domain != d) {
>> +        dev_err(dev, " not attached to domain %d\n", d->domain_id);
>> +        return -ESRCH;
>> +    }
>> +
>> +    spin_lock(&xen_domain->lock);
>> +
>> +    arm_smmu_detach_dev(dev);
>> +    atomic_dec(&domain->ref);
>> +
>> +    if (domain->ref.counter == 0)
>> +        arm_smmu_destroy_iommu_domain(domain);
>> +
>> +    spin_unlock(&xen_domain->lock);
>> +
>> +    return 0;
>> +}
>> +
>> +static int arm_smmu_reassign_dev(struct domain *s, struct domain *t,
>> +                 u8 devfn,  struct device *dev)
>> +{
>> +    int ret = 0;
>> +
>> +    /* Don't allow remapping on other domain than hwdom */
>> +    if (t && t != hardware_domain)
>> +        return -EPERM;
>> +
>> +    if (t == s)
>> +        return 0;
>> +
>> +    ret = arm_smmu_deassign_dev(s, dev);
>> +    if (ret)
>> +        return ret;
>> +
>> +    if (t) {
>> +        /* No flags are defined for ARM. */
>> +        ret = arm_smmu_assign_dev(t, devfn, dev, 0);
>> +        if (ret)
>> +            return ret;
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>> +static int arm_smmu_iommu_domain_init(struct domain *d)
> Where is iommu_domain initialized?
> The function does not use a iommu_domain * variable
>> +{
>> +    struct arm_smmu_xen_domain *xen_domain;
>> +
>> +    xen_domain = xzalloc(struct arm_smmu_xen_domain);
>> +    if (!xen_domain)
>> +        return -ENOMEM;
>> +
>> +    spin_lock_init(&xen_domain->lock);
>> +    INIT_LIST_HEAD(&xen_domain->contexts);
>> +
>> +    dom_iommu(d)->arch.priv = xen_domain;
>> +
>> +    return 0;
>> +}
>> +
>> +static void __hwdom_init arm_smmu_iommu_hwdom_init(struct domain *d)
>> +{
>> +}
>> +
>> +static void arm_smmu_iommu_domain_teardown(struct domain *d)
>> +{
>> +    struct arm_smmu_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
>> +
>> +    ASSERT(list_empty(&xen_domain->contexts));
>> +    xfree(xen_domain);
>> +}
>> +
>> +static int __must_check arm_smmu_map_page(struct domain *d, unsigned 
>> long gfn,
>> +            unsigned long mfn, unsigned int flags)
>> +{
>> +    p2m_type_t t;
>> +
>> +    /*
>> +     * Grant mappings can be used for DMA requests. The dev_bus_addr
>> +     * returned by the hypercall is the MFN (not the IPA). For device
>> +     * protected by an IOMMU, Xen needs to add a 1:1 mapping in the 
>> domain
>> +     * p2m to allow DMA request to work.
>> +     * This is only valid when the domain is directed mapped. Hence 
>> this
>> +     * function should only be used by gnttab code with gfn == mfn.
>> +     */
>> +    BUG_ON(!is_domain_direct_mapped(d));
>> +    BUG_ON(mfn != gfn);
>> +
>> +    /* We only support readable and writable flags */
>> +    if (!(flags & (IOMMUF_readable | IOMMUF_writable)))
>> +        return -EINVAL;
>> +
>> +    t = (flags & IOMMUF_writable) ? p2m_iommu_map_rw : 
>> p2m_iommu_map_ro;
>> +
>> +    /*
>> +     * The function guest_physmap_add_entry replaces the current 
>> mapping
>> +     * if there is already one...
>> +     */
>> +    return guest_physmap_add_entry(d, _gfn(gfn), _mfn(mfn), 0, t);
>> +}
>> +
>> +static int __must_check arm_smmu_unmap_page(struct domain *d, 
>> unsigned long gfn)
>> +{
>> +    /*
>> +     * This function should only be used by gnttab code when the domain
>> +     * is direct mapped
>> +     */
>> +    if (!is_domain_direct_mapped(d))
>> +        return -EINVAL;
>> +
>> +    return guest_physmap_remove_page(d, _gfn(gfn), _mfn(gfn), 0);
>> +}
>> +
>> +static const struct iommu_ops arm_smmu_iommu_ops = {
>> +    .init = arm_smmu_iommu_domain_init,
>> +    .hwdom_init = arm_smmu_iommu_hwdom_init,
>> +    .teardown = arm_smmu_iommu_domain_teardown,
>> +    .iotlb_flush = arm_smmu_iotlb_flush,
>> +    .iotlb_flush_all = arm_smmu_iotlb_flush_all,
>> +    .assign_device = arm_smmu_assign_dev,
>> +    .reassign_device = arm_smmu_reassign_dev,
>> +    .map_page = arm_smmu_map_page,
>> +    .unmap_page = arm_smmu_unmap_page,
>> +};
>> +
>> +static
>> +struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle 
>> *fwnode)
>> +{
>> +    struct arm_smmu_device *smmu = NULL;
>> +
>> +    spin_lock(&arm_smmu_devices_lock);
>> +    list_for_each_entry(smmu, &arm_smmu_devices, devices) {
>> +        if (smmu->dev->fwnode == fwnode)
>> +            break;
>> +    }
>> +    spin_unlock(&arm_smmu_devices_lock);
>> +
>> +    return smmu;
>> +}
>> +
>> +static __init int arm_smmu_dt_init(struct dt_device_node *dev,
>> +                   const void *data)
>> +{
>> +    int rc;
>> +
>> +    /*
>> +     * Even if the device can't be initialized, we don't want to
>> +     * give the SMMU device to dom0.
>> +     */
>> +    dt_device_set_used_by(dev, DOMID_XEN);
>> +
>> +    rc = arm_smmu_device_probe(dt_to_dev(dev));
>> +    if (rc)
>> +        return rc;
>> +
>> +    iommu_set_ops(&arm_smmu_iommu_ops);
>> +
>> +    return 0;
>> +}
>> +
>> +DT_DEVICE_START(smmuv3, "ARM SMMU V3", DEVICE_IOMMU)
>> +    .dt_match = arm_smmu_of_match,
>> +    .init = arm_smmu_dt_init,
>> +DT_DEVICE_END
>> +
>> +#ifdef CONFIG_ACPI
>> +/* Set up the IOMMU */
>> +static int __init arm_smmu_acpi_init(const void *data)
>> +{
>> +    int rc;
>> +
>> +    rc = arm_smmu_device_probe((struct device *)data);
>> +    if (rc)
>> +        return rc;
>> +
>> +    iommu_set_ops(&arm_smmu_iommu_ops);
>> +    return 0;
>> +}
>> +
>> +ACPI_DEVICE_START(asmmuv3, "ARM SMMU V3", DEVICE_IOMMU)
>> +    .class_type = ACPI_IORT_NODE_SMMU_V3,
>> +    .init = arm_smmu_acpi_init,
>> +ACPI_DEVICE_END
>> +
>> +#endif
>> diff --git a/xen/include/xen/linux_compat.h 
>> b/xen/include/xen/linux_compat.h
>> new file mode 100644
>> index 0000000000..8037be0a3e
>> --- /dev/null
>> +++ b/xen/include/xen/linux_compat.h
>> @@ -0,0 +1,84 @@
>> +/****************************************************************************** 
>>
>> + * include/xen/linux_compat.h
>> + *
>> + * Compatibility defines for porting code from Linux to Xen
>> + *
>> + * Copyright (c) 2017 Linaro Limited
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program; If not, see <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#ifndef __XEN_LINUX_COMPAT_H__
>> +#define __XEN_LINUX_COMPAT_H__
>> +
>> +#include <asm/types.h>
>> +
>> +typedef paddr_t phys_addr_t;
>> +typedef paddr_t dma_addr_t;
>> +
>> +typedef unsigned int gfp_t;
>> +#define GFP_KERNEL 0
>> +#define __GFP_ZERO 0x01U
>> +
>> +/* Helpers for IRQ functions */
>> +#define free_irq release_irq
>> +
>> +enum irqreturn {
>> +    IRQ_NONE,
>> +    IRQ_HANDLED,
>> +    IRQ_WAKE_THREAD,
>> +};
>> +
>> +typedef enum irqreturn irqreturn_t;
>> +
>> +/* Device logger functions */
>> +#define dev_dbg(dev, fmt, ...) printk(XENLOG_DEBUG fmt, ## __VA_ARGS__)
>> +#define dev_notice(dev, fmt, ...) printk(XENLOG_INFO fmt, ## 
>> __VA_ARGS__)
>> +#define dev_warn(dev, fmt, ...) printk(XENLOG_WARNING fmt, ## 
>> __VA_ARGS__)
>> +#define dev_err(dev, fmt, ...) printk(XENLOG_ERR fmt, ## __VA_ARGS__)
>> +#define dev_info(dev, fmt, ...) printk(XENLOG_INFO fmt, ## __VA_ARGS__)
>> +
>> +#define dev_err_ratelimited(dev, fmt, ...)                  \
>> +     printk(XENLOG_ERR fmt, ## __VA_ARGS__)
>> +
>> +#define dev_name(dev) dt_node_full_name(dev_to_dt(dev))
>> +
>> +/* Alias to Xen allocation helpers */
>> +#define kfree xfree
>> +#define kmalloc(size, flags) ({\
>> +    void *__ret_alloc = NULL; \
>> +    if (flags & __GFP_ZERO) \
>> +        __ret_alloc = _xzalloc(size, sizeof(void *)); \
>> +    else \
>> +        __ret_alloc = _xmalloc(size, sizeof(void *)); \
>> +    __ret_alloc; \
>> +})
>> +#define kzalloc(size, flags)        _xzalloc(size, sizeof(void *))
>> +#define devm_kzalloc(dev, size, flags)  _xzalloc(size, sizeof(void *))
>> +#define kmalloc_array(size, n, flags) ({\
>> +    void *__ret_alloc = NULL; \
>> +    if (flags & __GFP_ZERO) \
>> +        __ret_alloc = _xzalloc_array(size, sizeof(void *), n); \
>> +    else \
>> +        __ret_alloc = _xmalloc_array(size, sizeof(void *), n); \
>> +    __ret_alloc; \
>> +})
>> +
>> +/* Alias to Xen time functions */
>> +#define ktime_t s_time_t
>> +#define ktime_get()             (NOW())
>> +#define ktime_add_us(t,i)       (t + MICROSECS(i))
>> +#define ktime_compare(t,i)      (t > (i))
>> +
>> +#endif /* __XEN_LINUX_COMPAT_H__ */
>
Sameer Goel May 24, 2018, 8:26 p.m. UTC | #4
On 05/24/2018 01:57 AM, Jan Beulich wrote:
>>>> On 24.05.18 at 02:46, <sameer.goel@linaro.org> wrote:
>> --- /dev/null
>> +++ b/xen/include/xen/linux_compat.h
> I continue to dislike the idea of having a header with these contents in this location.
As explained previously this header can be used for the any driver that 
we want to port from Linux. This is not arm specific. This seemed like 
the best location for the file. Which other common location should I pick?
> Independent of that I'd prefer if new files used hyphens instead of underscores
I'll change the name of the file.
> in their names - just like for command line options, other than C identifiers they're
> not restricted to a very narrow set of possible delimiters or name components.
>
> Jan
>
>
Sameer Goel May 24, 2018, 8:29 p.m. UTC | #5
On 05/23/2018 10:48 PM, Manish Jaggi wrote:
> Hi Sameer,
>
> General Comment, please use appropriate variable names for XXX_domain 
> structures in code which is xen specific.
I thought that we had discussed this before on one of the RFCs. At this 
point we are just using the format used for smmu-v2. I don't think that 
the variable names are inappropriate. Unless there is a very specific 
issue with the variable names, I think we should stick with the current 
version.

>
>
> On 05/24/2018 06:16 AM, Sameer Goel wrote:
>> This driver follows an approach similar to smmu driver. The intent here
>> is to reuse as much Linux code as possible.
>> - Glue code has been introduced to bridge the API calls.
>> - Called Linux functions from the Xen IOMMU function calls.
>> - Xen modifications are preceded by /*Xen: comment */
>> - xen/linux_compat: Add a Linux compat header
>>    For porting files directly from Linux it is useful to have a 
>> function mapping
>>    definitions from Linux to Xen. This file adds common API functions 
>> and
>>    other defines that are needed for porting arm SMMU drivers.
>>
>> Signed-off-by: Sameer Goel <sameer.goel@linaro.org>
>> ---
>>   xen/arch/arm/p2m.c                    |   1 +
>>   xen/drivers/Kconfig                   |   2 +
>>   xen/drivers/passthrough/arm/Kconfig   |   8 +
>>   xen/drivers/passthrough/arm/Makefile  |   1 +
>>   xen/drivers/passthrough/arm/smmu-v3.c | 934 +++++++++++++++++++++++++-
>>   xen/include/xen/linux_compat.h        |  84 +++
>>   6 files changed, 1001 insertions(+), 29 deletions(-)
>>   create mode 100644 xen/drivers/passthrough/arm/Kconfig
>>   create mode 100644 xen/include/xen/linux_compat.h
>>
>> diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
>> index d43c3aa896..38aa9f00c1 100644
>> --- a/xen/arch/arm/p2m.c
>> +++ b/xen/arch/arm/p2m.c
>> @@ -1454,6 +1454,7 @@ err:
>>   static void __init setup_virt_paging_one(void *data)
>>   {
>>       unsigned long val = (unsigned long)data;
>> +    /* SMMUv3 S2 cfg vtcr reuses the following value */
>>       WRITE_SYSREG32(val, VTCR_EL2);
>>       isb();
>>   }
>> diff --git a/xen/drivers/Kconfig b/xen/drivers/Kconfig
>> index db94393f47..59ca00f850 100644
>> --- a/xen/drivers/Kconfig
>> +++ b/xen/drivers/Kconfig
>> @@ -15,4 +15,6 @@ source "drivers/video/Kconfig"
>>   config HAS_VPCI
>>       bool
>>   +source "drivers/passthrough/arm/Kconfig"
>> +
>>   endmenu
>> diff --git a/xen/drivers/passthrough/arm/Kconfig 
>> b/xen/drivers/passthrough/arm/Kconfig
>> new file mode 100644
>> index 0000000000..cda899f608
>> --- /dev/null
>> +++ b/xen/drivers/passthrough/arm/Kconfig
>> @@ -0,0 +1,8 @@
>> +
>> +config ARM_SMMU_v3
>> +    bool "ARM SMMUv3 Support"
>> +    depends on ARM_64
>> +    help
>> +     Support for implementations of the ARM System MMU architecture
>> +     version 3.
>> +
>> diff --git a/xen/drivers/passthrough/arm/Makefile 
>> b/xen/drivers/passthrough/arm/Makefile
>> index f4cd26e15d..e14732b55c 100644
>> --- a/xen/drivers/passthrough/arm/Makefile
>> +++ b/xen/drivers/passthrough/arm/Makefile
>> @@ -1,2 +1,3 @@
>>   obj-y += iommu.o
>>   obj-y += smmu.o
>> +obj-$(CONFIG_ARM_SMMU_v3) += smmu-v3.o
>> diff --git a/xen/drivers/passthrough/arm/smmu-v3.c 
>> b/xen/drivers/passthrough/arm/smmu-v3.c
>> index e67ba6c40f..df81626785 100644
>> --- a/xen/drivers/passthrough/arm/smmu-v3.c
>> +++ b/xen/drivers/passthrough/arm/smmu-v3.c
>> @@ -18,28 +18,414 @@
>>    * Author: Will Deacon <will.deacon@arm.com>
>>    *
>>    * This driver is powered by bad coffee and bombay mix.
>> + *
>> + *
>> + * Based on Linux drivers/iommu/arm-smmu-v3.c
>> + * => commit 7aa8619a66aea52b145e04cbab4f8d6a4e5f3f3b
>> + *
>> + * Xen modifications:
>> + * Sameer Goel <sameer.goel@linaro.org>
>> + * Copyright (C) 2017, The Linux Foundation, All rights reserved.
>> + *
>>    */
>>   -#include <linux/acpi.h>
>> -#include <linux/acpi_iort.h>
>> -#include <linux/delay.h>
>> -#include <linux/dma-iommu.h>
>> -#include <linux/err.h>
>> -#include <linux/interrupt.h>
>> -#include <linux/iommu.h>
>> -#include <linux/iopoll.h>
>> -#include <linux/module.h>
>> -#include <linux/msi.h>
>> -#include <linux/of.h>
>> -#include <linux/of_address.h>
>> -#include <linux/of_iommu.h>
>> -#include <linux/of_platform.h>
>> -#include <linux/pci.h>
>> -#include <linux/platform_device.h>
>> -
>> -#include <linux/amba/bus.h>
>> -
>> -#include "io-pgtable.h"
>> +#include <xen/acpi.h>
>> +#include <xen/config.h>
>> +#include <xen/delay.h>
>> +#include <xen/errno.h>
>> +#include <xen/err.h>
>> +#include <xen/irq.h>
>> +#include <xen/lib.h>
>> +#include <xen/linux_compat.h>
>> +#include <xen/list.h>
>> +#include <xen/mm.h>
>> +#include <xen/rbtree.h>
>> +#include <xen/sched.h>
>> +#include <xen/sizes.h>
>> +#include <xen/vmap.h>
>> +#include <acpi/acpi_iort.h>
>> +#include <asm/atomic.h>
>> +#include <asm/device.h>
>> +#include <asm/io.h>
>> +#include <asm/platform.h>
>> +
>> +/* Alias to Xen device tree helpers */
>> +#define device_node dt_device_node
>> +#define of_phandle_args dt_phandle_args
>> +#define of_device_id dt_device_match
>> +#define of_match_node dt_match_node
>> +#define of_property_read_u32(np, pname, out) 
>> (!dt_property_read_u32(np, pname, out))
>> +#define of_property_read_bool dt_property_read_bool
>> +#define of_parse_phandle_with_args dt_parse_phandle_with_args
>> +
>> +/* Xen: Helpers to get device MMIO and IRQs */
>> +struct resource {
>> +    u64 addr;
>> +    u64 size;
>> +    unsigned int type;
>> +};
>> +
>> +#define resource_size(res) ((res)->size)
>> +
>> +#define platform_device device
>> +
>> +#define IORESOURCE_MEM 0
>> +#define IORESOURCE_IRQ 1
>> +
>> +static struct resource *platform_get_resource(struct platform_device 
>> *pdev,
>> +                          unsigned int type,
>> +                          unsigned int num)
>> +{
>> +    /*
>> +     * The resource is only used between 2 calls of 
>> platform_get_resource.
>> +     * It's quite ugly but it's avoid to add too much code in the part
>> +     * imported from Linux
>> +     */
>> +    static struct resource res;
>> +    struct acpi_iort_node *iort_node;
>> +    struct acpi_iort_smmu_v3 *node_smmu_data;
>> +    int ret = 0;
>> +
>> +    res.type = type;
>> +
>> +    switch (type) {
>> +    case IORESOURCE_MEM:
>> +        if (pdev->type == DEV_ACPI) {
>> +            ret = 1;
>> +            iort_node = pdev->acpi_node;
>> +            node_smmu_data =
>> +                (struct acpi_iort_smmu_v3 *)iort_node->node_data;
>> +
>> +            if (node_smmu_data != NULL) {
>> +                res.addr = node_smmu_data->base_address;
>> +                res.size = SZ_128K;
>> +                ret = 0;
>> +            }
>> +        } else {
>> +            ret = dt_device_get_address(dev_to_dt(pdev), num,
>> +                            &res.addr, &res.size);
>> +        }
>> +
>> +        return ((ret) ? NULL : &res);
>> +
>> +    case IORESOURCE_IRQ:
>> +        /* ACPI case not implemented as there is no use case for it */
>> +        ret = platform_get_irq(dev_to_dt(pdev), num);
>> +
>> +        if (ret < 0)
>> +            return NULL;
>> +
>> +        res.addr = ret;
>> +        res.size = 1;
>> +
>> +        return &res;
>> +
>> +    default:
>> +        return NULL;
>> +    }
>> +}
>> +
>> +static int platform_get_irq_byname(struct platform_device *pdev, 
>> const char *name)
>> +{
>> +    const struct dt_property *dtprop;
>> +    struct acpi_iort_node *iort_node;
>> +    struct acpi_iort_smmu_v3 *node_smmu_data;
>> +    int ret = 0;
>> +
>> +    if (pdev->type == DEV_ACPI) {
>> +        iort_node = pdev->acpi_node;
>> +        node_smmu_data = (struct acpi_iort_smmu_v3 
>> *)iort_node->node_data;
>> +
>> +        if (node_smmu_data != NULL) {
>> +            if (!strcmp(name, "eventq"))
>> +                ret = node_smmu_data->event_gsiv;
>> +            else if (!strcmp(name, "priq"))
>> +                ret = node_smmu_data->pri_gsiv;
>> +            else if (!strcmp(name, "cmdq-sync"))
>> +                ret = node_smmu_data->sync_gsiv;
>> +            else if (!strcmp(name, "gerror"))
>> +                ret = node_smmu_data->gerr_gsiv;
>> +            else
>> +                ret = -EINVAL;
>> +        }
>> +    } else {
>> +        dtprop = dt_find_property(dev_to_dt(pdev), 
>> "interrupt-names", NULL);
>> +        if (!dtprop)
>> +            return -EINVAL;
>> +
>> +        if (!dtprop->value)
>> +            return -ENODATA;
>> +    }
>> +
>> +    return ret;
>> +}
>> +
>> +/*
>> + * Xen: Helpers for DMA allocation. Just the function name is reused 
>> for
>> + * porting code these allocation are not managed allocations
>> + */
>> +
>> +static void *dmam_alloc_coherent(struct device *dev, size_t size,
>> +               dma_addr_t *dma_handle, gfp_t gfp)
> I believe the formatting needs to be checked.
>> +{
>> +    void *vaddr;
>> +    unsigned long alignment = size;
>> +
>> +    /*
>> +     * _xzalloc requires that the (align & (align -1)) = 0. Most of the
>> +     * allocations in SMMU code should send the right value for 
>> size. In
>> +     * case this is not true print a warning and align to the size of a
>> +     * (void *)
>> +     */
>> +    if (size & (size - 1)) {
>> +        dev_warn(dev, "Fixing alignment for the DMA buffer\n");
>> +        alignment = sizeof(void *);
>> +    }
>> +
>> +    vaddr = _xzalloc(size, alignment);
>> +    if (!vaddr) {
>> +        dev_err(dev, "DMA allocation failed\n");
>> +        return NULL;
>> +    }
>> +
>> +    *dma_handle = virt_to_maddr(vaddr);
>> +
>> +    return vaddr;
>> +}
>> +
>> +
>> +static void dmam_free_coherent(struct device *dev, size_t size, void 
>> *vaddr,
>> +            dma_addr_t dma_handle)
> same
>> +{
>> +    xfree(vaddr);
>> +}
>> +
>> +/* Xen: Stub out DMA domain related functions */
>> +#define iommu_get_dma_cookie(dom) 0
>> +#define iommu_put_dma_cookie(dom)
>> +
>> +/* Xen: Stub out module param related function */
>> +#define module_param_named(a, b, c, d)
>> +#define MODULE_PARM_DESC(a, b)
>> +
>> +#define dma_set_mask_and_coherent(d, b) 0
>> +
>> +#define of_dma_is_coherent(n) 0
>> +
>> +#define MODULE_DEVICE_TABLE(type, name)
>> +
>> +static void __iomem *devm_ioremap_resource(struct device *dev,
>> +                       struct resource *res)
>> +{
>> +    void __iomem *ptr;
>> +
>> +    if (!res || res->type != IORESOURCE_MEM) {
>> +        dev_err(dev, "Invalid resource\n");
>> +        return ERR_PTR(-EINVAL);
>> +    }
>> +
>> +    ptr = ioremap_nocache(res->addr, res->size);
>> +    if (!ptr) {
>> +        dev_err(dev,
>> +            "ioremap failed (addr 0x%"PRIx64" size 0x%"PRIx64")\n",
>> +            res->addr, res->size);
>> +        return ERR_PTR(-ENOMEM);
>> +    }
>> +
>> +    return ptr;
>> +}
>> +
>> +/* Xen: Compatibility define for iommu_domain_geometry.*/
>> +struct iommu_domain_geometry {
>> +    dma_addr_t aperture_start; /* First address that can be 
>> mapped    */
>> +    dma_addr_t aperture_end;   /* Last address that can be 
>> mapped     */
>> +    bool force_aperture;       /* DMA only allowed in mappable 
>> range? */
>> +};
>> +
>> +
>> +/* Xen: Type definitions for iommu_domain */
>> +#define IOMMU_DOMAIN_UNMANAGED 0
>> +#define IOMMU_DOMAIN_DMA 1
>> +#define IOMMU_DOMAIN_IDENTITY 2
>> +
>> +/* Xen: Dummy iommu_domain */
>> +struct iommu_domain {
>> +    /* Runtime SMMU configuration for this iommu_domain */
>> +    struct arm_smmu_domain        *priv;
>> +    unsigned int type;
>> +
>> +    /* Dummy compatibility defines */
>> +    unsigned long pgsize_bitmap;
>> +    struct iommu_domain_geometry geometry;
>> +
>> +    atomic_t ref;
>> +    /*
>> +     * Used to link iommu_domain contexts for a same domain.
>> +     * There is at least one per-SMMU to used by the domain.
>> +     */
>> +    struct list_head        list;
>> +};
>> +
>> +/* Xen: Describes information required for a Xen domain */
>> +struct arm_smmu_xen_domain {
>> +    spinlock_t            lock;
>> +    /* List of iommu domains associated to this domain */
>> +    struct list_head        contexts;
>> +};
>> +
>> +/*
>> + * Xen: Information about each device stored in dev->archdata.iommu
>> + *
>> + * The dev->archdata.iommu stores the iommu_domain (runtime 
>> configuration of
>> + * the SMMU).
>> + */
>> +struct arm_smmu_xen_device {
>> +    struct iommu_domain *domain;
>> +};
>> +
> As this is a xen specific code, can the variable names be used 
> appropriately.
> Repeating my comment  from earlier version.
> a domain is  usually a VM in Xen. So it is a bit confusing to use 
> domain for iommu_domain.
>> +/*
>> + * Xen: io_pgtable compatibility defines.
>> + * Most of these are to port in the S1 translation code as is.
>> + */
>> +struct io_pgtable_ops {
>> +};
>> +
>> +struct iommu_gather_ops {
>> +    void (*tlb_flush_all)(void *cookie);
>> +    void (*tlb_add_flush)(unsigned long iova, size_t size, size_t 
>> granule,
>> +                  bool leaf, void *cookie);
>> +    void (*tlb_sync)(void *cookie);
>> +};
>> +
>> +struct io_pgtable_cfg {
>> +    /*
>> +     * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE 
>> bits in
>> +     *    stage 1 PTEs, for hardware which insists on validating them
>> +     *    even in    non-secure state where they should normally be 
>> ignored.
>> +     *
>> +     * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE 
>> and
>> +     *    IOMMU_NOEXEC flags and map everything with full access, for
>> +     *    hardware which does not implement the permissions of a given
>> +     *    format, and/or requires some format-specific default value.
>> +     *
>> +     * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching 
>> invalid
>> +     *    (unmapped) entries but the hardware might do so anyway, 
>> perform
>> +     *    TLB maintenance when mapping as well as when unmapping.
>> +     *
>> +     * IO_PGTABLE_QUIRK_ARM_MTK_4GB: (ARM v7s format) Set bit 9 in all
>> +     *    PTEs, for Mediatek IOMMUs which treat it as a 33rd address 
>> bit
>> +     *    when the SoC is in "4GB mode" and they can only access the 
>> high
>> +     *    remap of DRAM (0x1_00000000 to 0x1_ffffffff).
>> +     *
>> +     * IO_PGTABLE_QUIRK_NO_DMA: Guarantees that the tables will only 
>> ever
>> +     *    be accessed by a fully cache-coherent IOMMU or CPU (e.g. 
>> for a
>> +     *    software-emulated IOMMU), such that pagetable updates need 
>> not
>> +     *    be treated as explicit DMA data.
>> +     */
>> +    #define IO_PGTABLE_QUIRK_ARM_NS        BIT(0)
>> +    #define IO_PGTABLE_QUIRK_NO_PERMS    BIT(1)
>> +    #define IO_PGTABLE_QUIRK_TLBI_ON_MAP    BIT(2)
>> +    #define IO_PGTABLE_QUIRK_ARM_MTK_4GB    BIT(3)
>> +    #define IO_PGTABLE_QUIRK_NO_DMA        BIT(4)
>> +    unsigned long            quirks;
>> +    unsigned long            pgsize_bitmap;
>> +    unsigned int            ias;
>> +    unsigned int            oas;
>> +    const struct iommu_gather_ops    *tlb;
>> +    struct device            *iommu_dev;
>> +
>> +    /* Low-level data specific to the table format */
>> +    union {
>> +        struct {
>> +            u64    ttbr[2];
>> +            u64    tcr;
>> +            u64    mair[2];
>> +        } arm_lpae_s1_cfg;
>> +
>> +        struct {
>> +            u64    vttbr;
>> +            u64    vtcr;
>> +        } arm_lpae_s2_cfg;
>> +
>> +        struct {
>> +            u32    ttbr[2];
>> +            u32    tcr;
>> +            u32    nmrr;
>> +            u32    prrr;
>> +        } arm_v7s_cfg;
>> +    };
>> +};
>> +
>> +enum io_pgtable_fmt {
>> +    ARM_32_LPAE_S1,
>> +    ARM_32_LPAE_S2,
>> +    ARM_64_LPAE_S1,
>> +    ARM_64_LPAE_S2,
>> +    ARM_V7S,
>> +    IO_PGTABLE_NUM_FMTS,
>> +};
>> +
>> +/*
>> + * Xen: The pgtable_ops are used by the S1 translations, so return 
>> the dummy
>> + * address.
>> + */
>> +#define alloc_io_pgtable_ops(f, c, o) ((struct io_pgtable_ops *)0x1)
>> +#define free_io_pgtable_ops(o)
>> +
>> +/* Xen: Define wrapper for requesting IRQs */
>> +#define IRQF_ONESHOT 0
>> +
>> +typedef void (*irq_handler_t)(int, void *, struct cpu_user_regs *);
>> +
>> +static inline int devm_request_irq(struct device *dev, unsigned int 
>> irq,
>> +                   irq_handler_t handler, unsigned long irqflags,
>> +                   const char *devname, void *dev_id)
>> +{
>> +    /*
>> +     * SMMUv3 implementation can support wired interrupt outputs 
>> that are
>> +     * edge-triggered. Set the irq type as per the spec.
>> +     */
>> +    irq_set_type(irq, IRQ_TYPE_EDGE_BOTH);
>> +    return request_irq(irq, irqflags, handler, devname, dev_id);
>> +}
>> +
>> +/*
>> + * Xen does not have a concept of threaded irq, but we can use 
>> tasklets to
>> + * achieve the desired functionality as needed.
>> + */
>> +int devm_request_threaded_irq(struct device *dev, unsigned int irq, 
>> irq_handler_t handler,
>> +                  irq_handler_t thread_fn, unsigned long irqflags,
>> +                  const char *devname, void *dev_id)
>> +{
>> +    return devm_request_irq(dev, irq, thread_fn, irqflags, devname, 
>> dev_id);
>> +}
>> +
>> +/* Xen: The mutex is used only during initialization so the typecast 
>> is safe */
>> +#define mutex spinlock
>> +#define mutex_init spin_lock_init
>> +#define mutex_lock spin_lock
>> +#define mutex_unlock spin_unlock
>> +
>> +#define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us) \
>> +({ \
>> +    s_time_t deadline = NOW() + MICROSECS(timeout_us); \
>> +    for (;;) { \
>> +        (val) = op(addr); \
>> +        if (cond) \
>> +            break; \
>> +        if (NOW() > deadline) { \
>> +            (val) = op(addr); \
>> +            break; \
>> +        } \
>> +    udelay(sleep_us); \
>> +    } \
>> +    (cond) ? 0 : -ETIMEDOUT; \
>> +})
>> +
>> +#define readl_relaxed_poll_timeout(addr, val, cond, delay_us, 
>> timeout_us) \
>> +    readx_poll_timeout(readl_relaxed, addr, val, cond, delay_us, 
>> timeout_us)
>> +
>> +#define VA_BITS 0 /* Only needed for S1 translations */
>>     /* MMIO registers */
>>   #define ARM_SMMU_IDR0            0x0
>> @@ -433,6 +819,7 @@ enum pri_resp {
>>       PRI_RESP_SUCC,
>>   };
>>   +#if 0 /* Xen: No MSI support in this iteration */
>>   enum arm_smmu_msi_index {
>>       EVTQ_MSI_INDEX,
>>       GERROR_MSI_INDEX,
>> @@ -457,6 +844,7 @@ static phys_addr_t 
>> arm_smmu_msi_cfg[ARM_SMMU_MAX_MSIS][3] = {
>>           ARM_SMMU_PRIQ_IRQ_CFG2,
>>       },
>>   };
>> +#endif
>>     struct arm_smmu_cmdq_ent {
>>       /* Common fields */
>> @@ -561,6 +949,8 @@ struct arm_smmu_s2_cfg {
>>       u16                vmid;
>>       u64                vttbr;
>>       u64                vtcr;
>> +    /* Xen: Domain associated to this configuration */
>> +    struct domain            *domain;
>>   };
>>     struct arm_smmu_strtab_ent {
>> @@ -635,9 +1025,25 @@ struct arm_smmu_device {
>>       struct arm_smmu_strtab_cfg    strtab_cfg;
>>         /* IOMMU core code handle */
>> +#if 0 /*Xen: Generic iommu_device ref not needed here */
>>       struct iommu_device        iommu;
>> +#endif
> Is it clean to put #if 0, can this line be deleted or used with a 
> proper macro
>> +    /* Xen: Need to keep a list of SMMU devices */
>> +    struct list_head                devices;
>> +    /* Xen: Tasklets for handling evts/faults and pci page request 
>> IRQs*/
>> +    struct tasklet            evtq_tasklet;
>> +    struct tasklet            priq_tasklet;
>> +    struct tasklet            combined_irq_tasklet;
>>   };
>>   +/* Xen: Keep a list of devices associated with this driver */
>> +static DEFINE_SPINLOCK(arm_smmu_devices_lock);
>> +static LIST_HEAD(arm_smmu_devices);
>> +/* Xen: Helper for finding a device using fwnode */
>> +static
>> +struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle 
>> *fwnode);
>> +
>> +
>>   /* SMMU private data for each master */
>>   struct arm_smmu_master_data {
>>       struct arm_smmu_device        *smmu;
>> @@ -1232,7 +1638,7 @@ static void arm_smmu_handle_ppr(struct 
>> arm_smmu_device *smmu, u64 *evt)
>>         dev_info(smmu->dev, "unexpected PRI request received:\n");
>>       dev_info(smmu->dev,
>> -         "\tsid 0x%08x.0x%05x: [%u%s] %sprivileged %s%s%s access at 
>> iova 0x%016llx\n",
>> +         "\tsid 0x%08x.0x%05x: [%u%s] %sprivileged %s%s%s access at 
>> iova %#" PRIx64 "\n",
>>            sid, ssid, grpid, last ? "L" : "",
>>            evt[0] & PRIQ_0_PERM_PRIV ? "" : "un",
>>            evt[0] & PRIQ_0_PERM_READ ? "R" : "",
>> @@ -1342,10 +1748,20 @@ static irqreturn_t 
>> arm_smmu_combined_irq_thread(int irq, void *dev)
>>       return IRQ_HANDLED;
>>   }
>>   +/* Xen: Forward define for combined_irq tasklet */
>> +static void arm_smmu_combined_irq_tasklet(unsigned long dev);
>> +
>>   static irqreturn_t arm_smmu_combined_irq_handler(int irq, void *dev)
>>   {
>> +    /* Xen: Need an smmu reference to schedule the tasklet */
>> +    struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
>> +
>>       arm_smmu_gerror_handler(irq, dev);
>>       arm_smmu_cmdq_sync_handler(irq, dev);
>> +
>> +    /*Xen: No threaded irq. So, schedule the right tasklet*/
>> +    tasklet_schedule(&(smmu->combined_irq_tasklet));
>> +
>>       return IRQ_WAKE_THREAD;
>>   }
>>   @@ -1358,6 +1774,69 @@ static void __arm_smmu_tlb_sync(struct 
>> arm_smmu_device *smmu)
>>       arm_smmu_cmdq_issue_cmd(smmu, &cmd);
>>   }
>>   +/*
>> + * Xen: Define the IRQ handlers and tasklets for xen. The linux 
>> functions
>> + * would be modified to use the functions defined in the following 
>> code.
>> + */
>> +
>> +static void arm_smmu_evtq_tasklet(unsigned long dev)
>> +{
>> +    /* The IRQ number is not relevent for the evtq thread processing */
>> +    arm_smmu_evtq_thread(0, (void *)dev);
>> +}
>> +
>> +static void arm_smmu_priq_tasklet(unsigned long dev)
>> +{
>> +    /* The IRQ number is not relevent for the priq thread processing */
>> +    arm_smmu_priq_thread(0, (void *)dev);
>> +}
>> +
>> +static void arm_smmu_combined_irq_tasklet(unsigned long dev)
>> +{
>> +    /* The IRQ number is not relevent for the combined irq handler.*/
>> +    arm_smmu_combined_irq_thread(0, (void *)dev);
>> +}
>> +
>> +static void arm_smmu_evtq_thread_xen(int irq, void *dev,
>> +                       struct cpu_user_regs *regs)
>> +{
>> +    struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
>> +
>> +    tasklet_schedule(&(smmu->evtq_tasklet));
>> +}
>> +
>> +static void arm_smmu_priq_thread_xen(int irq, void *dev,
>> +                       struct cpu_user_regs *regs)
>> +{
>> +    struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
>> +
>> +    tasklet_schedule(&(smmu->priq_tasklet));
>> +}
>> +
>> +static void arm_smmu_cmdq_sync_handler_xen(int irq, void *dev,
>> +                       struct cpu_user_regs *regs)
>> +{
>> +    arm_smmu_cmdq_sync_handler(irq, dev);
>> +}
>> +
>> +static void arm_smmu_gerror_handler_xen(int irq, void *dev,
>> +                       struct cpu_user_regs *regs)
>> +{
>> +    arm_smmu_gerror_handler(irq, dev);
>> +}
>> +
>> +static void arm_smmu_combined_irq_handler_xen(int irq, void *dev,
>> +                       struct cpu_user_regs *regs)
>> +{
>> +    arm_smmu_combined_irq_handler(irq, dev);
>> +}
>> +
>> +#define arm_smmu_evtq_thread arm_smmu_evtq_thread_xen
>> +#define arm_smmu_priq_thread arm_smmu_priq_thread_xen
>> +#define arm_smmu_cmdq_sync_handler arm_smmu_cmdq_sync_handler_xen
>> +#define arm_smmu_gerror_handler arm_smmu_gerror_handler_xen
>> +#define arm_smmu_combined_irq_handler arm_smmu_combined_irq_handler_xen
>> +
>>   static void arm_smmu_tlb_sync(void *cookie)
>>   {
>>       struct arm_smmu_domain *smmu_domain = cookie;
>> @@ -1415,6 +1894,7 @@ static const struct iommu_gather_ops 
>> arm_smmu_gather_ops = {
>>       .tlb_sync    = arm_smmu_tlb_sync,
>>   };
>>   +#if 0 /*Xen: Unused functionality */
>>   /* IOMMU API */
>>   static bool arm_smmu_capable(enum iommu_cap cap)
>>   {
>> @@ -1427,6 +1907,7 @@ static bool arm_smmu_capable(enum iommu_cap cap)
>>           return false;
>>       }
>>   }
>> +#endif
>>     static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
>>   {
>> @@ -1546,9 +2027,16 @@ static int arm_smmu_domain_finalise_s2(struct 
>> arm_smmu_domain *smmu_domain,
>>       if (vmid < 0)
>>           return vmid;
>>   -    cfg->vmid    = (u16)vmid;
>> -    cfg->vttbr    = pgtbl_cfg->arm_lpae_s2_cfg.vttbr;
>> -    cfg->vtcr    = pgtbl_cfg->arm_lpae_s2_cfg.vtcr;
>> +    /*
>> +     * Xen: Get the ttbr and vtcr values
>> +     * vttbr: This is a shared value with the domain page table
>> +     * vtcr: The TCR settings are the same as CPU since the page
>> +     * tables are shared
>> +     */
>> +
>> +    cfg->vmid    = vmid;
>> +    cfg->vttbr    = page_to_maddr(cfg->domain->arch.p2m.root);
>> +    cfg->vtcr    = READ_SYSREG32(VTCR_EL2) & STRTAB_STE_2_VTCR_MASK;
>>       return 0;
>>   }
>>   @@ -1604,6 +2092,7 @@ static int arm_smmu_domain_finalise(struct 
>> iommu_domain *domain)
>>       if (smmu->features & ARM_SMMU_FEAT_COHERENCY)
>>           pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_NO_DMA;
>>   +    /* Xen: pgtbl_ops gets an invalid address */
>>       pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);
>>       if (!pgtbl_ops)
>>           return -ENOMEM;
>> @@ -1721,6 +2210,7 @@ out_unlock:
>>       return ret;
>>   }
>>   +#if 0 /* Xen: Unused functionality */
> same
>>   static int arm_smmu_map(struct iommu_domain *domain, unsigned long 
>> iova,
>>               phys_addr_t paddr, size_t size, int prot)
>>   {
>> @@ -1772,6 +2262,7 @@ struct arm_smmu_device 
>> *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
>>       put_device(dev);
>>       return dev ? dev_get_drvdata(dev) : NULL;
>>   }
>> +#endif
>>     static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, 
>> u32 sid)
>>   {
>> @@ -1783,7 +2274,14 @@ static bool arm_smmu_sid_in_range(struct 
>> arm_smmu_device *smmu, u32 sid)
>>       return sid < limit;
>>   }
>>   +/* Xen: Unused */
>> +#if 0
>>   static struct iommu_ops arm_smmu_ops;
>> +#endif
>> +
>> +/* Xen: Redefine arm_smmu_ops to what fwspec should evaluate */
>> +static const struct iommu_ops arm_smmu_iommu_ops;
>> +#define arm_smmu_ops arm_smmu_iommu_ops
>>     static int arm_smmu_add_device(struct device *dev)
>>   {
>> @@ -1791,8 +2289,11 @@ static int arm_smmu_add_device(struct device 
>> *dev)
>>       struct arm_smmu_device *smmu;
>>       struct arm_smmu_master_data *master;
>>       struct iommu_fwspec *fwspec = dev->iommu_fwspec;
>> +#if 0 /*Xen: iommu_group is not needed */
>>       struct iommu_group *group;
>> +#endif
>>   +    /* Xen: fwspec->ops are not needed */
>>       if (!fwspec || fwspec->ops != &arm_smmu_ops)
>>           return -ENODEV;
>>       /*
>> @@ -1830,6 +2331,11 @@ static int arm_smmu_add_device(struct device 
>> *dev)
>>           }
>>       }
>>   +/*
>> + * Xen: Do not need an iommu group as the stream data is carried by 
>> the SMMU
>> + * master device object
>> + */
>> +#if 0
>>       group = iommu_group_get_for_dev(dev);
>>       if (!IS_ERR(group)) {
>>           iommu_group_put(group);
>> @@ -1837,8 +2343,16 @@ static int arm_smmu_add_device(struct device 
>> *dev)
>>       }
>>         return PTR_ERR_OR_ZERO(group);
>> +#endif
>> +    return 0;
>>   }
>>   +/*
>> + * Xen: We can potentially support this function and destroy a 
>> device. This
>> + * will be relevant for PCI hotplug. So, will be implemented as 
>> needed after
>> + * passthrough support is available.
>> + */
>> +#if 0
>>   static void arm_smmu_remove_device(struct device *dev)
>>   {
>>       struct iommu_fwspec *fwspec = dev->iommu_fwspec;
>> @@ -1974,6 +2488,7 @@ static struct iommu_ops arm_smmu_ops = {
>>       .put_resv_regions    = arm_smmu_put_resv_regions,
>>       .pgsize_bitmap        = -1UL, /* Restricted during device 
>> attach */
>>   };
>> +#endif
>>     /* Probing and initialisation functions */
>>   static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
>> @@ -2182,6 +2697,7 @@ static int arm_smmu_update_gbpa(struct 
>> arm_smmu_device *smmu, u32 set, u32 clr)
>>                         1, ARM_SMMU_POLL_TIMEOUT_US);
>>   }
>>   +#if 0 /* Xen: There is no MSI support as yet */
>>   static void arm_smmu_free_msis(void *data)
>>   {
>>       struct device *dev = data;
>> @@ -2247,12 +2763,15 @@ static void arm_smmu_setup_msis(struct 
>> arm_smmu_device *smmu)
>>       /* Add callback to free MSIs on teardown */
>>       devm_add_action(dev, arm_smmu_free_msis, dev);
>>   }
>> +#endif
>>     static void arm_smmu_setup_unique_irqs(struct arm_smmu_device *smmu)
>>   {
>>       int irq, ret;
>>   +#if 0 /*Xen: Cannot setup msis for now */
>>       arm_smmu_setup_msis(smmu);
>> +#endif
>>         /* Request interrupt lines */
>>       irq = smmu->evtq.q.irq;
>> @@ -2316,9 +2835,13 @@ static int arm_smmu_setup_irqs(struct 
>> arm_smmu_device *smmu)
>>            * Cavium ThunderX2 implementation doesn't not support unique
>>            * irq lines. Use single irq line for all the SMMUv3 
>> interrupts.
>>            */
>> -        ret = devm_request_threaded_irq(smmu->dev, irq,
>> +        /*
>> +         * Xen: Does not support threaded irqs, so serialise the setup.
>> +         * This is the same for pris and event interrupt lines on other
>> +         * systems
>> +         */
>> +        ret = devm_request_irq(smmu->dev, irq,
>>                       arm_smmu_combined_irq_handler,
>> -                    arm_smmu_combined_irq_thread,
>>                       IRQF_ONESHOT,
>>                       "arm-smmu-v3-combined-irq", smmu);
>>           if (ret < 0)
>> @@ -2452,6 +2975,13 @@ static int arm_smmu_device_reset(struct 
>> arm_smmu_device *smmu, bool bypass)
>>           return ret;
>>       }
>>   +    /* Xen: Initialize tasklets */
>> +    tasklet_init(&smmu->evtq_tasklet, arm_smmu_evtq_tasklet,
>> +            (unsigned long)smmu);
>> +    tasklet_init(&smmu->priq_tasklet, arm_smmu_priq_tasklet,
>> +            (unsigned long)smmu);
>> +    tasklet_init(&smmu->combined_irq_tasklet, 
>> arm_smmu_combined_irq_tasklet,
>> +            (unsigned long)smmu);
>>         /* Enable the SMMU interface, or ensure bypass */
>>       if (!bypass || disable_bypass) {
>> @@ -2542,8 +3072,14 @@ static int arm_smmu_device_hw_probe(struct 
>> arm_smmu_device *smmu)
>>           smmu->features |= ARM_SMMU_FEAT_STALLS;
>>       }
>>   +/*
>> + * Xen: Block stage 1 translations. By doing this here we do not 
>> need to set the
>> + * domain->stage explicitly.
>> + */
>> +#if 0
>>       if (reg & IDR0_S1P)
>>           smmu->features |= ARM_SMMU_FEAT_TRANS_S1;
>> +#endif
>>         if (reg & IDR0_S2P)
>>           smmu->features |= ARM_SMMU_FEAT_TRANS_S2;
>> @@ -2616,10 +3152,12 @@ static int arm_smmu_device_hw_probe(struct 
>> arm_smmu_device *smmu)
>>       if (reg & IDR5_GRAN4K)
>>           smmu->pgsize_bitmap |= SZ_4K | SZ_2M | SZ_1G;
>>   +#if 0 /* Xen: SMMU ops do not have a pgsize_bitmap member for Xen */
>>       if (arm_smmu_ops.pgsize_bitmap == -1UL)
>>           arm_smmu_ops.pgsize_bitmap = smmu->pgsize_bitmap;
>>       else
>>           arm_smmu_ops.pgsize_bitmap |= smmu->pgsize_bitmap;
>> +#endif
>>         /* Output address size */
>>       switch (reg & IDR5_OAS_MASK << IDR5_OAS_SHIFT) {
>> @@ -2680,7 +3218,8 @@ static int arm_smmu_device_acpi_probe(struct 
>> platform_device *pdev,
>>       struct device *dev = smmu->dev;
>>       struct acpi_iort_node *node;
>>   -    node = *(struct acpi_iort_node **)dev_get_platdata(dev);
>> +    /* Xen: Modification to get iort_node */
>> +    node = (struct acpi_iort_node *)dev->acpi_node;
>>         /* Retrieve SMMUv3 specific data */
>>       iort_smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
>> @@ -2703,7 +3242,7 @@ static inline int 
>> arm_smmu_device_acpi_probe(struct platform_device *pdev,
>>   static int arm_smmu_device_dt_probe(struct platform_device *pdev,
>>                       struct arm_smmu_device *smmu)
>>   {
>> -    struct device *dev = &pdev->dev;
>> +    struct device *dev = pdev;
>>       u32 cells;
>>       int ret = -EINVAL;
>>   @@ -2716,6 +3255,7 @@ static int arm_smmu_device_dt_probe(struct 
>> platform_device *pdev,
>>         parse_driver_options(smmu);
>>   +    /* Xen: of_dma_is_coherent is a stub till dt support is 
>> introduced */
>>       if (of_dma_is_coherent(dev->of_node))
>>           smmu->features |= ARM_SMMU_FEAT_COHERENCY;
>>   @@ -2734,9 +3274,11 @@ static int arm_smmu_device_probe(struct 
>> platform_device *pdev)
>>   {
>>       int irq, ret;
>>       struct resource *res;
>> +#if 0 /*Xen: Do not need to setup sysfs */
>>       resource_size_t ioaddr;
>> +#endif
>>       struct arm_smmu_device *smmu;
>> -    struct device *dev = &pdev->dev;
>> +    struct device *dev = pdev;/* Xen: dev is ignored */
>>       bool bypass;
>>         smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
>> @@ -2763,7 +3305,9 @@ static int arm_smmu_device_probe(struct 
>> platform_device *pdev)
>>           dev_err(dev, "MMIO region too small (%pr)\n", res);
>>           return -EINVAL;
>>       }
>> +#if 0 /*Xen: Do not need to setup sysfs */
>>       ioaddr = res->start;
>> +#endif
>>         smmu->base = devm_ioremap_resource(dev, res);
>>       if (IS_ERR(smmu->base))
>> @@ -2802,13 +3346,18 @@ static int arm_smmu_device_probe(struct 
>> platform_device *pdev)
>>           return ret;
>>         /* Record our private device structure */
>> +    /* Xen: SMMU is not treated a a platform device*/
>> +#if 0
>>       platform_set_drvdata(pdev, smmu);
>> +#endif
>>         /* Reset the device */
>>       ret = arm_smmu_device_reset(smmu, bypass);
>>       if (ret)
>>           return ret;
>>   +/* Xen: Not creating an IOMMU device list for Xen */
>> +#if 0
>>       /* And we're up. Go go go! */
>>       ret = iommu_device_sysfs_add(&smmu->iommu, dev, NULL,
>>                        "smmu3.%pa", &ioaddr);
>> @@ -2844,9 +3393,20 @@ static int arm_smmu_device_probe(struct 
>> platform_device *pdev)
>>           if (ret)
>>               return ret;
>>       }
>> +#endif
>> +    /*
>> +     * Xen: Keep a list of all probed devices. This will be used to 
>> query
>> +     * the smmu devices based on the fwnode.
>> +     */
>> +    INIT_LIST_HEAD(&smmu->devices);
>> +    spin_lock(&arm_smmu_devices_lock);
>> +    list_add(&smmu->devices, &arm_smmu_devices);
>> +    spin_unlock(&arm_smmu_devices_lock);
>>       return 0;
>>   }
>>   +/* Xen: Unused function */
>> +#if 0
>>   static int arm_smmu_device_remove(struct platform_device *pdev)
>>   {
>>       struct arm_smmu_device *smmu = platform_get_drvdata(pdev);
>> @@ -2860,6 +3420,8 @@ static void arm_smmu_device_shutdown(struct 
>> platform_device *pdev)
>>   {
>>       arm_smmu_device_remove(pdev);
>>   }
>> +#endif
>> +
>>     static const struct of_device_id arm_smmu_of_match[] = {
>>       { .compatible = "arm,smmu-v3", },
>> @@ -2867,6 +3429,7 @@ static const struct of_device_id 
>> arm_smmu_of_match[] = {
>>   };
>>   MODULE_DEVICE_TABLE(of, arm_smmu_of_match);
>>   +#if 0
>>   static struct platform_driver arm_smmu_driver = {
>>       .driver    = {
>>           .name        = "arm-smmu-v3",
>> @@ -2883,3 +3446,316 @@ IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", 
>> NULL);
>>   MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 
>> implementations");
>>   MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
>>   MODULE_LICENSE("GPL v2");
>> +#endif
>> +
>> +/***** Start of Xen specific code *****/
>> +
>> +static int __must_check arm_smmu_iotlb_flush_all(struct domain *d)
>> +{
>> +    struct arm_smmu_xen_domain *smmu_domain = dom_iommu(d)->arch.priv;
>> +    struct iommu_domain *cfg;
>> +
>> +    spin_lock(&smmu_domain->lock);
>> +    list_for_each_entry(cfg, &smmu_domain->contexts, list) {
>> +        /*
>> +         * Only invalidate the context when SMMU is present.
>> +         * This is because the context initialization is delayed
>> +         * until a master has been added.
>> +         */
>> +        if (unlikely(!ACCESS_ONCE(cfg->priv->smmu)))
>> +            continue;
>> +        arm_smmu_tlb_inv_context(cfg->priv);
>> +    }
>> +    spin_unlock(&smmu_domain->lock);
>> +    return 0;
>> +}
>> +
>> +static int __must_check arm_smmu_iotlb_flush(struct domain *d,
>> +                         unsigned long gfn,
>> +                         unsigned int page_count)
>> +{
>> +    return arm_smmu_iotlb_flush_all(d);
>> +}
>> +
>> +static struct iommu_domain *arm_smmu_get_domain(struct domain *d,
>> +                        struct device *dev)
> This is returning iommu_domain and not a domain.
> Please change the name of function.
>> +{
>> +    struct iommu_domain *domain;
>> +    struct arm_smmu_xen_domain *xen_domain;
> A suggestion
> 1. as you have used in above function smmu_domain variable for 
> arm_smmu_xen_domain
> Can similar logic be used for iommu_domain.
>
> 2. When smmu_domain variable name is used in above function why 
> xen_domain is used in this function.
> It is quite confusing.
> logically xen_domain should mean a VM.
>> +    struct arm_smmu_device *smmu;
>> +    struct arm_smmu_domain *smmu_domain;
> smmu_domain was used for arm_smmu_xen_domain.
> consistency of variable names is necessary for code clarity
>> +
>> +    xen_domain = dom_iommu(d)->arch.priv;
>> +
>> +    smmu = arm_smmu_get_by_fwnode(dev->iommu_fwspec->iommu_fwnode);
>> +    if (!smmu)
>> +        return NULL;
>> +
>> +    /*
>> +     * Loop through the &xen_domain->contexts to locate a context
>> +     * assigned to this SMMU
>> +     */
>> +    list_for_each_entry(domain, &xen_domain->contexts, list) {
>> +        smmu_domain = to_smmu_domain(domain);
>> +        if (smmu_domain->smmu == smmu)
>> +            return domain;
>> +    }
>> +
>> +    return NULL;
>> +}
>> +
>> +static void arm_smmu_destroy_iommu_domain(struct iommu_domain *domain)
> same
>> +{
>> +    list_del(&domain->list);
>> +    arm_smmu_domain_free(domain);
>> +}
>> +
>> +static int arm_smmu_assign_dev(struct domain *d, u8 devfn,
>> +                   struct device *dev, u32 flag)
>> +{
>> +    int ret = 0;
>> +    struct iommu_domain *domain;
>> +    struct arm_smmu_xen_domain *xen_domain;
> same
>> +    struct arm_smmu_domain *arm_smmu;
>> +
>> +    xen_domain = dom_iommu(d)->arch.priv;
>> +
>> +    if (!dev->archdata.iommu) {
>> +        dev->archdata.iommu = xzalloc(struct arm_smmu_xen_device);
>> +        if (!dev->archdata.iommu)
>> +            return -ENOMEM;
>> +    }
>> +
>> +    ret = arm_smmu_add_device(dev);
>> +    if (ret)
>> +        return ret;
>> +
>> +    spin_lock(&xen_domain->lock);
>> +
>> +    /*
>> +     * Check to see if an iommu_domain already exists for this xen 
>> domain
>> +     * under the same SMMU
>> +     */
>> +    domain = arm_smmu_get_domain(d, dev);
>> +    if (!domain) {
>> +
>> +        domain = arm_smmu_domain_alloc(IOMMU_DOMAIN_DMA);
>> +        if (!domain) {
>> +            ret = -ENOMEM;
>> +            goto out;
>> +        }
>> +
>> +        arm_smmu = to_smmu_domain(domain);
>> +        arm_smmu->s2_cfg.domain = d;
>> +
>> +        /* Chain the new context to the domain */
>> +        list_add(&domain->list, &xen_domain->contexts);
>> +
>> +    }
>> +
>> +    ret = arm_smmu_attach_dev(domain, dev);
>> +    if (ret) {
>> +        if (domain->ref.counter == 0)
>> +            arm_smmu_destroy_iommu_domain(domain);
>> +    } else {
>> +        atomic_inc(&domain->ref);
>> +    }
>> +
>> +out:
>> +    spin_unlock(&xen_domain->lock);
>> +    return ret;
>> +}
>> +
>> +static int arm_smmu_deassign_dev(struct domain *d, struct device *dev)
>> +{
>> +    struct iommu_domain *domain = arm_smmu_get_domain(d, dev);
>> +    struct arm_smmu_xen_domain *xen_domain;
>> +    struct arm_smmu_domain *arm_smmu = to_smmu_domain(domain);
> same
>> +
>> +    xen_domain = dom_iommu(d)->arch.priv;
>> +
>> +    if (!arm_smmu || arm_smmu->s2_cfg.domain != d) {
>> +        dev_err(dev, " not attached to domain %d\n", d->domain_id);
>> +        return -ESRCH;
>> +    }
>> +
>> +    spin_lock(&xen_domain->lock);
>> +
>> +    arm_smmu_detach_dev(dev);
>> +    atomic_dec(&domain->ref);
>> +
>> +    if (domain->ref.counter == 0)
>> +        arm_smmu_destroy_iommu_domain(domain);
>> +
>> +    spin_unlock(&xen_domain->lock);
>> +
>> +    return 0;
>> +}
>> +
>> +static int arm_smmu_reassign_dev(struct domain *s, struct domain *t,
>> +                 u8 devfn,  struct device *dev)
>> +{
>> +    int ret = 0;
>> +
>> +    /* Don't allow remapping on other domain than hwdom */
>> +    if (t && t != hardware_domain)
>> +        return -EPERM;
>> +
>> +    if (t == s)
>> +        return 0;
>> +
>> +    ret = arm_smmu_deassign_dev(s, dev);
>> +    if (ret)
>> +        return ret;
>> +
>> +    if (t) {
>> +        /* No flags are defined for ARM. */
>> +        ret = arm_smmu_assign_dev(t, devfn, dev, 0);
>> +        if (ret)
>> +            return ret;
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>> +static int arm_smmu_iommu_domain_init(struct domain *d)
> Where is iommu_domain initialized?
> The function does not use a iommu_domain * variable
>> +{
>> +    struct arm_smmu_xen_domain *xen_domain;
>> +
>> +    xen_domain = xzalloc(struct arm_smmu_xen_domain);
>> +    if (!xen_domain)
>> +        return -ENOMEM;
>> +
>> +    spin_lock_init(&xen_domain->lock);
>> +    INIT_LIST_HEAD(&xen_domain->contexts);
>> +
>> +    dom_iommu(d)->arch.priv = xen_domain;
>> +
>> +    return 0;
>> +}
>> +
>> +static void __hwdom_init arm_smmu_iommu_hwdom_init(struct domain *d)
>> +{
>> +}
>> +
>> +static void arm_smmu_iommu_domain_teardown(struct domain *d)
>> +{
>> +    struct arm_smmu_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
>> +
>> +    ASSERT(list_empty(&xen_domain->contexts));
>> +    xfree(xen_domain);
>> +}
>> +
>> +static int __must_check arm_smmu_map_page(struct domain *d, unsigned 
>> long gfn,
>> +            unsigned long mfn, unsigned int flags)
>> +{
>> +    p2m_type_t t;
>> +
>> +    /*
>> +     * Grant mappings can be used for DMA requests. The dev_bus_addr
>> +     * returned by the hypercall is the MFN (not the IPA). For device
>> +     * protected by an IOMMU, Xen needs to add a 1:1 mapping in the 
>> domain
>> +     * p2m to allow DMA request to work.
>> +     * This is only valid when the domain is directed mapped. Hence 
>> this
>> +     * function should only be used by gnttab code with gfn == mfn.
>> +     */
>> +    BUG_ON(!is_domain_direct_mapped(d));
>> +    BUG_ON(mfn != gfn);
>> +
>> +    /* We only support readable and writable flags */
>> +    if (!(flags & (IOMMUF_readable | IOMMUF_writable)))
>> +        return -EINVAL;
>> +
>> +    t = (flags & IOMMUF_writable) ? p2m_iommu_map_rw : 
>> p2m_iommu_map_ro;
>> +
>> +    /*
>> +     * The function guest_physmap_add_entry replaces the current 
>> mapping
>> +     * if there is already one...
>> +     */
>> +    return guest_physmap_add_entry(d, _gfn(gfn), _mfn(mfn), 0, t);
>> +}
>> +
>> +static int __must_check arm_smmu_unmap_page(struct domain *d, 
>> unsigned long gfn)
>> +{
>> +    /*
>> +     * This function should only be used by gnttab code when the domain
>> +     * is direct mapped
>> +     */
>> +    if (!is_domain_direct_mapped(d))
>> +        return -EINVAL;
>> +
>> +    return guest_physmap_remove_page(d, _gfn(gfn), _mfn(gfn), 0);
>> +}
>> +
>> +static const struct iommu_ops arm_smmu_iommu_ops = {
>> +    .init = arm_smmu_iommu_domain_init,
>> +    .hwdom_init = arm_smmu_iommu_hwdom_init,
>> +    .teardown = arm_smmu_iommu_domain_teardown,
>> +    .iotlb_flush = arm_smmu_iotlb_flush,
>> +    .iotlb_flush_all = arm_smmu_iotlb_flush_all,
>> +    .assign_device = arm_smmu_assign_dev,
>> +    .reassign_device = arm_smmu_reassign_dev,
>> +    .map_page = arm_smmu_map_page,
>> +    .unmap_page = arm_smmu_unmap_page,
>> +};
>> +
>> +static
>> +struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle 
>> *fwnode)
>> +{
>> +    struct arm_smmu_device *smmu = NULL;
>> +
>> +    spin_lock(&arm_smmu_devices_lock);
>> +    list_for_each_entry(smmu, &arm_smmu_devices, devices) {
>> +        if (smmu->dev->fwnode == fwnode)
>> +            break;
>> +    }
>> +    spin_unlock(&arm_smmu_devices_lock);
>> +
>> +    return smmu;
>> +}
>> +
>> +static __init int arm_smmu_dt_init(struct dt_device_node *dev,
>> +                   const void *data)
>> +{
>> +    int rc;
>> +
>> +    /*
>> +     * Even if the device can't be initialized, we don't want to
>> +     * give the SMMU device to dom0.
>> +     */
>> +    dt_device_set_used_by(dev, DOMID_XEN);
>> +
>> +    rc = arm_smmu_device_probe(dt_to_dev(dev));
>> +    if (rc)
>> +        return rc;
>> +
>> +    iommu_set_ops(&arm_smmu_iommu_ops);
>> +
>> +    return 0;
>> +}
>> +
>> +DT_DEVICE_START(smmuv3, "ARM SMMU V3", DEVICE_IOMMU)
>> +    .dt_match = arm_smmu_of_match,
>> +    .init = arm_smmu_dt_init,
>> +DT_DEVICE_END
>> +
>> +#ifdef CONFIG_ACPI
>> +/* Set up the IOMMU */
>> +static int __init arm_smmu_acpi_init(const void *data)
>> +{
>> +    int rc;
>> +
>> +    rc = arm_smmu_device_probe((struct device *)data);
>> +    if (rc)
>> +        return rc;
>> +
>> +    iommu_set_ops(&arm_smmu_iommu_ops);
>> +    return 0;
>> +}
>> +
>> +ACPI_DEVICE_START(asmmuv3, "ARM SMMU V3", DEVICE_IOMMU)
>> +    .class_type = ACPI_IORT_NODE_SMMU_V3,
>> +    .init = arm_smmu_acpi_init,
>> +ACPI_DEVICE_END
>> +
>> +#endif
>> diff --git a/xen/include/xen/linux_compat.h 
>> b/xen/include/xen/linux_compat.h
>> new file mode 100644
>> index 0000000000..8037be0a3e
>> --- /dev/null
>> +++ b/xen/include/xen/linux_compat.h
>> @@ -0,0 +1,84 @@
>> +/****************************************************************************** 
>>
>> + * include/xen/linux_compat.h
>> + *
>> + * Compatibility defines for porting code from Linux to Xen
>> + *
>> + * Copyright (c) 2017 Linaro Limited
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program; If not, see <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#ifndef __XEN_LINUX_COMPAT_H__
>> +#define __XEN_LINUX_COMPAT_H__
>> +
>> +#include <asm/types.h>
>> +
>> +typedef paddr_t phys_addr_t;
>> +typedef paddr_t dma_addr_t;
>> +
>> +typedef unsigned int gfp_t;
>> +#define GFP_KERNEL 0
>> +#define __GFP_ZERO 0x01U
>> +
>> +/* Helpers for IRQ functions */
>> +#define free_irq release_irq
>> +
>> +enum irqreturn {
>> +    IRQ_NONE,
>> +    IRQ_HANDLED,
>> +    IRQ_WAKE_THREAD,
>> +};
>> +
>> +typedef enum irqreturn irqreturn_t;
>> +
>> +/* Device logger functions */
>> +#define dev_dbg(dev, fmt, ...) printk(XENLOG_DEBUG fmt, ## __VA_ARGS__)
>> +#define dev_notice(dev, fmt, ...) printk(XENLOG_INFO fmt, ## 
>> __VA_ARGS__)
>> +#define dev_warn(dev, fmt, ...) printk(XENLOG_WARNING fmt, ## 
>> __VA_ARGS__)
>> +#define dev_err(dev, fmt, ...) printk(XENLOG_ERR fmt, ## __VA_ARGS__)
>> +#define dev_info(dev, fmt, ...) printk(XENLOG_INFO fmt, ## __VA_ARGS__)
>> +
>> +#define dev_err_ratelimited(dev, fmt, ...)                  \
>> +     printk(XENLOG_ERR fmt, ## __VA_ARGS__)
>> +
>> +#define dev_name(dev) dt_node_full_name(dev_to_dt(dev))
>> +
>> +/* Alias to Xen allocation helpers */
>> +#define kfree xfree
>> +#define kmalloc(size, flags) ({\
>> +    void *__ret_alloc = NULL; \
>> +    if (flags & __GFP_ZERO) \
>> +        __ret_alloc = _xzalloc(size, sizeof(void *)); \
>> +    else \
>> +        __ret_alloc = _xmalloc(size, sizeof(void *)); \
>> +    __ret_alloc; \
>> +})
>> +#define kzalloc(size, flags)        _xzalloc(size, sizeof(void *))
>> +#define devm_kzalloc(dev, size, flags)  _xzalloc(size, sizeof(void *))
>> +#define kmalloc_array(size, n, flags) ({\
>> +    void *__ret_alloc = NULL; \
>> +    if (flags & __GFP_ZERO) \
>> +        __ret_alloc = _xzalloc_array(size, sizeof(void *), n); \
>> +    else \
>> +        __ret_alloc = _xmalloc_array(size, sizeof(void *), n); \
>> +    __ret_alloc; \
>> +})
>> +
>> +/* Alias to Xen time functions */
>> +#define ktime_t s_time_t
>> +#define ktime_get()             (NOW())
>> +#define ktime_add_us(t,i)       (t + MICROSECS(i))
>> +#define ktime_compare(t,i)      (t > (i))
>> +
>> +#endif /* __XEN_LINUX_COMPAT_H__ */
>
Manish Jaggi May 25, 2018, 4:41 a.m. UTC | #6
On 05/25/2018 01:59 AM, Sameer Goel wrote:
>
>
> On 05/23/2018 10:48 PM, Manish Jaggi wrote:
>> Hi Sameer,
>>
>> General Comment, please use appropriate variable names for XXX_domain 
>> structures in code which is xen specific.
> I thought that we had discussed this before on one of the RFCs.
Yes and no one replied to my last comment that the var names have to be 
non confusing in Xen specific code.
> At this point we are just using the format used for smmu-v2.
smmu-v2 has a lot of confusing variable names with _domain.
I believe that file needs to be fixed as well.
> I don't think that the variable names are inappropriate. Unless there 
> is a very specific issue with the variable names,
The issue is in code readability and understanding the flow.
It is confusing so many _domain variable names are used which are not 
verbose.

Two functions different and confusing variable names

+static int __must_check arm_smmu_iotlb_flush_all(struct domain *d)
+{
+    struct arm_smmu_xen_domain *smmu_domain;

+static struct iommu_domain *arm_smmu_get_domain(struct domain *d,
+                        struct device *dev)
+{
+    struct iommu_domain *domain;
+    struct arm_smmu_xen_domain *xen_domain;

Why use smmu_domain at one place and xen_domain at another ?
Intuitively xen_domain should mean a VM.

Doesn't is look confusing?

Please take a look, I have pointed out the other specific ones below.
> I think we should stick with the current version.
>
>>
>>
>> On 05/24/2018 06:16 AM, Sameer Goel wrote:
>>> This driver follows an approach similar to smmu driver. The intent here
>>> is to reuse as much Linux code as possible.
>>> - Glue code has been introduced to bridge the API calls.
>>> - Called Linux functions from the Xen IOMMU function calls.
>>> - Xen modifications are preceded by /*Xen: comment */
>>> - xen/linux_compat: Add a Linux compat header
>>>    For porting files directly from Linux it is useful to have a 
>>> function mapping
>>>    definitions from Linux to Xen. This file adds common API 
>>> functions and
>>>    other defines that are needed for porting arm SMMU drivers.
>>>
>>> Signed-off-by: Sameer Goel <sameer.goel@linaro.org>
>>> ---
>>>   xen/arch/arm/p2m.c                    |   1 +
>>>   xen/drivers/Kconfig                   |   2 +
>>>   xen/drivers/passthrough/arm/Kconfig   |   8 +
>>>   xen/drivers/passthrough/arm/Makefile  |   1 +
>>>   xen/drivers/passthrough/arm/smmu-v3.c | 934 
>>> +++++++++++++++++++++++++-
>>>   xen/include/xen/linux_compat.h        |  84 +++
>>>   6 files changed, 1001 insertions(+), 29 deletions(-)
>>>   create mode 100644 xen/drivers/passthrough/arm/Kconfig
>>>   create mode 100644 xen/include/xen/linux_compat.h
>>>
>>> diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
>>> index d43c3aa896..38aa9f00c1 100644
>>> --- a/xen/arch/arm/p2m.c
>>> +++ b/xen/arch/arm/p2m.c
>>> @@ -1454,6 +1454,7 @@ err:
>>>   static void __init setup_virt_paging_one(void *data)
>>>   {
>>>       unsigned long val = (unsigned long)data;
>>> +    /* SMMUv3 S2 cfg vtcr reuses the following value */
>>>       WRITE_SYSREG32(val, VTCR_EL2);
>>>       isb();
>>>   }
>>> diff --git a/xen/drivers/Kconfig b/xen/drivers/Kconfig
>>> index db94393f47..59ca00f850 100644
>>> --- a/xen/drivers/Kconfig
>>> +++ b/xen/drivers/Kconfig
>>> @@ -15,4 +15,6 @@ source "drivers/video/Kconfig"
>>>   config HAS_VPCI
>>>       bool
>>>   +source "drivers/passthrough/arm/Kconfig"
>>> +
>>>   endmenu
>>> diff --git a/xen/drivers/passthrough/arm/Kconfig 
>>> b/xen/drivers/passthrough/arm/Kconfig
>>> new file mode 100644
>>> index 0000000000..cda899f608
>>> --- /dev/null
>>> +++ b/xen/drivers/passthrough/arm/Kconfig
>>> @@ -0,0 +1,8 @@
>>> +
>>> +config ARM_SMMU_v3
>>> +    bool "ARM SMMUv3 Support"
>>> +    depends on ARM_64
>>> +    help
>>> +     Support for implementations of the ARM System MMU architecture
>>> +     version 3.
>>> +
>>> diff --git a/xen/drivers/passthrough/arm/Makefile 
>>> b/xen/drivers/passthrough/arm/Makefile
>>> index f4cd26e15d..e14732b55c 100644
>>> --- a/xen/drivers/passthrough/arm/Makefile
>>> +++ b/xen/drivers/passthrough/arm/Makefile
>>> @@ -1,2 +1,3 @@
>>>   obj-y += iommu.o
>>>   obj-y += smmu.o
>>> +obj-$(CONFIG_ARM_SMMU_v3) += smmu-v3.o
>>> diff --git a/xen/drivers/passthrough/arm/smmu-v3.c 
>>> b/xen/drivers/passthrough/arm/smmu-v3.c
>>> index e67ba6c40f..df81626785 100644
>>> --- a/xen/drivers/passthrough/arm/smmu-v3.c
>>> +++ b/xen/drivers/passthrough/arm/smmu-v3.c
>>> @@ -18,28 +18,414 @@
>>>    * Author: Will Deacon <will.deacon@arm.com>
>>>    *
>>>    * This driver is powered by bad coffee and bombay mix.
>>> + *
>>> + *
>>> + * Based on Linux drivers/iommu/arm-smmu-v3.c
>>> + * => commit 7aa8619a66aea52b145e04cbab4f8d6a4e5f3f3b
>>> + *
>>> + * Xen modifications:
>>> + * Sameer Goel <sameer.goel@linaro.org>
>>> + * Copyright (C) 2017, The Linux Foundation, All rights reserved.
>>> + *
>>>    */
>>>   -#include <linux/acpi.h>
>>> -#include <linux/acpi_iort.h>
>>> -#include <linux/delay.h>
>>> -#include <linux/dma-iommu.h>
>>> -#include <linux/err.h>
>>> -#include <linux/interrupt.h>
>>> -#include <linux/iommu.h>
>>> -#include <linux/iopoll.h>
>>> -#include <linux/module.h>
>>> -#include <linux/msi.h>
>>> -#include <linux/of.h>
>>> -#include <linux/of_address.h>
>>> -#include <linux/of_iommu.h>
>>> -#include <linux/of_platform.h>
>>> -#include <linux/pci.h>
>>> -#include <linux/platform_device.h>
>>> -
>>> -#include <linux/amba/bus.h>
>>> -
>>> -#include "io-pgtable.h"
>>> +#include <xen/acpi.h>
>>> +#include <xen/config.h>
>>> +#include <xen/delay.h>
>>> +#include <xen/errno.h>
>>> +#include <xen/err.h>
>>> +#include <xen/irq.h>
>>> +#include <xen/lib.h>
>>> +#include <xen/linux_compat.h>
>>> +#include <xen/list.h>
>>> +#include <xen/mm.h>
>>> +#include <xen/rbtree.h>
>>> +#include <xen/sched.h>
>>> +#include <xen/sizes.h>
>>> +#include <xen/vmap.h>
>>> +#include <acpi/acpi_iort.h>
>>> +#include <asm/atomic.h>
>>> +#include <asm/device.h>
>>> +#include <asm/io.h>
>>> +#include <asm/platform.h>
>>> +
>>> +/* Alias to Xen device tree helpers */
>>> +#define device_node dt_device_node
>>> +#define of_phandle_args dt_phandle_args
>>> +#define of_device_id dt_device_match
>>> +#define of_match_node dt_match_node
>>> +#define of_property_read_u32(np, pname, out) 
>>> (!dt_property_read_u32(np, pname, out))
>>> +#define of_property_read_bool dt_property_read_bool
>>> +#define of_parse_phandle_with_args dt_parse_phandle_with_args
>>> +
>>> +/* Xen: Helpers to get device MMIO and IRQs */
>>> +struct resource {
>>> +    u64 addr;
>>> +    u64 size;
>>> +    unsigned int type;
>>> +};
>>> +
>>> +#define resource_size(res) ((res)->size)
>>> +
>>> +#define platform_device device
>>> +
>>> +#define IORESOURCE_MEM 0
>>> +#define IORESOURCE_IRQ 1
>>> +
>>> +static struct resource *platform_get_resource(struct 
>>> platform_device *pdev,
>>> +                          unsigned int type,
>>> +                          unsigned int num)
>>> +{
>>> +    /*
>>> +     * The resource is only used between 2 calls of 
>>> platform_get_resource.
>>> +     * It's quite ugly but it's avoid to add too much code in the part
>>> +     * imported from Linux
>>> +     */
>>> +    static struct resource res;
>>> +    struct acpi_iort_node *iort_node;
>>> +    struct acpi_iort_smmu_v3 *node_smmu_data;
>>> +    int ret = 0;
>>> +
>>> +    res.type = type;
>>> +
>>> +    switch (type) {
>>> +    case IORESOURCE_MEM:
>>> +        if (pdev->type == DEV_ACPI) {
>>> +            ret = 1;
>>> +            iort_node = pdev->acpi_node;
>>> +            node_smmu_data =
>>> +                (struct acpi_iort_smmu_v3 *)iort_node->node_data;
>>> +
>>> +            if (node_smmu_data != NULL) {
>>> +                res.addr = node_smmu_data->base_address;
>>> +                res.size = SZ_128K;
>>> +                ret = 0;
>>> +            }
>>> +        } else {
>>> +            ret = dt_device_get_address(dev_to_dt(pdev), num,
>>> +                            &res.addr, &res.size);
>>> +        }
>>> +
>>> +        return ((ret) ? NULL : &res);
>>> +
>>> +    case IORESOURCE_IRQ:
>>> +        /* ACPI case not implemented as there is no use case for it */
>>> +        ret = platform_get_irq(dev_to_dt(pdev), num);
>>> +
>>> +        if (ret < 0)
>>> +            return NULL;
>>> +
>>> +        res.addr = ret;
>>> +        res.size = 1;
>>> +
>>> +        return &res;
>>> +
>>> +    default:
>>> +        return NULL;
>>> +    }
>>> +}
>>> +
>>> +static int platform_get_irq_byname(struct platform_device *pdev, 
>>> const char *name)
>>> +{
>>> +    const struct dt_property *dtprop;
>>> +    struct acpi_iort_node *iort_node;
>>> +    struct acpi_iort_smmu_v3 *node_smmu_data;
>>> +    int ret = 0;
>>> +
>>> +    if (pdev->type == DEV_ACPI) {
>>> +        iort_node = pdev->acpi_node;
>>> +        node_smmu_data = (struct acpi_iort_smmu_v3 
>>> *)iort_node->node_data;
>>> +
>>> +        if (node_smmu_data != NULL) {
>>> +            if (!strcmp(name, "eventq"))
>>> +                ret = node_smmu_data->event_gsiv;
>>> +            else if (!strcmp(name, "priq"))
>>> +                ret = node_smmu_data->pri_gsiv;
>>> +            else if (!strcmp(name, "cmdq-sync"))
>>> +                ret = node_smmu_data->sync_gsiv;
>>> +            else if (!strcmp(name, "gerror"))
>>> +                ret = node_smmu_data->gerr_gsiv;
>>> +            else
>>> +                ret = -EINVAL;
>>> +        }
>>> +    } else {
>>> +        dtprop = dt_find_property(dev_to_dt(pdev), 
>>> "interrupt-names", NULL);
>>> +        if (!dtprop)
>>> +            return -EINVAL;
>>> +
>>> +        if (!dtprop->value)
>>> +            return -ENODATA;
>>> +    }
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +/*
>>> + * Xen: Helpers for DMA allocation. Just the function name is 
>>> reused for
>>> + * porting code these allocation are not managed allocations
>>> + */
>>> +
>>> +static void *dmam_alloc_coherent(struct device *dev, size_t size,
>>> +               dma_addr_t *dma_handle, gfp_t gfp)
>> I believe the formatting needs to be checked.
>>> +{
>>> +    void *vaddr;
>>> +    unsigned long alignment = size;
>>> +
>>> +    /*
>>> +     * _xzalloc requires that the (align & (align -1)) = 0. Most of 
>>> the
>>> +     * allocations in SMMU code should send the right value for 
>>> size. In
>>> +     * case this is not true print a warning and align to the size 
>>> of a
>>> +     * (void *)
>>> +     */
>>> +    if (size & (size - 1)) {
>>> +        dev_warn(dev, "Fixing alignment for the DMA buffer\n");
>>> +        alignment = sizeof(void *);
>>> +    }
>>> +
>>> +    vaddr = _xzalloc(size, alignment);
>>> +    if (!vaddr) {
>>> +        dev_err(dev, "DMA allocation failed\n");
>>> +        return NULL;
>>> +    }
>>> +
>>> +    *dma_handle = virt_to_maddr(vaddr);
>>> +
>>> +    return vaddr;
>>> +}
>>> +
>>> +
>>> +static void dmam_free_coherent(struct device *dev, size_t size, 
>>> void *vaddr,
>>> +            dma_addr_t dma_handle)
>> same
>>> +{
>>> +    xfree(vaddr);
>>> +}
>>> +
>>> +/* Xen: Stub out DMA domain related functions */
>>> +#define iommu_get_dma_cookie(dom) 0
>>> +#define iommu_put_dma_cookie(dom)
>>> +
>>> +/* Xen: Stub out module param related function */
>>> +#define module_param_named(a, b, c, d)
>>> +#define MODULE_PARM_DESC(a, b)
>>> +
>>> +#define dma_set_mask_and_coherent(d, b) 0
>>> +
>>> +#define of_dma_is_coherent(n) 0
>>> +
>>> +#define MODULE_DEVICE_TABLE(type, name)
>>> +
>>> +static void __iomem *devm_ioremap_resource(struct device *dev,
>>> +                       struct resource *res)
>>> +{
>>> +    void __iomem *ptr;
>>> +
>>> +    if (!res || res->type != IORESOURCE_MEM) {
>>> +        dev_err(dev, "Invalid resource\n");
>>> +        return ERR_PTR(-EINVAL);
>>> +    }
>>> +
>>> +    ptr = ioremap_nocache(res->addr, res->size);
>>> +    if (!ptr) {
>>> +        dev_err(dev,
>>> +            "ioremap failed (addr 0x%"PRIx64" size 0x%"PRIx64")\n",
>>> +            res->addr, res->size);
>>> +        return ERR_PTR(-ENOMEM);
>>> +    }
>>> +
>>> +    return ptr;
>>> +}
>>> +
>>> +/* Xen: Compatibility define for iommu_domain_geometry.*/
>>> +struct iommu_domain_geometry {
>>> +    dma_addr_t aperture_start; /* First address that can be 
>>> mapped    */
>>> +    dma_addr_t aperture_end;   /* Last address that can be 
>>> mapped     */
>>> +    bool force_aperture;       /* DMA only allowed in mappable 
>>> range? */
>>> +};
>>> +
>>> +
>>> +/* Xen: Type definitions for iommu_domain */
>>> +#define IOMMU_DOMAIN_UNMANAGED 0
>>> +#define IOMMU_DOMAIN_DMA 1
>>> +#define IOMMU_DOMAIN_IDENTITY 2
>>> +
>>> +/* Xen: Dummy iommu_domain */
>>> +struct iommu_domain {
>>> +    /* Runtime SMMU configuration for this iommu_domain */
>>> +    struct arm_smmu_domain        *priv;
>>> +    unsigned int type;
>>> +
>>> +    /* Dummy compatibility defines */
>>> +    unsigned long pgsize_bitmap;
>>> +    struct iommu_domain_geometry geometry;
>>> +
>>> +    atomic_t ref;
>>> +    /*
>>> +     * Used to link iommu_domain contexts for a same domain.
>>> +     * There is at least one per-SMMU to used by the domain.
>>> +     */
>>> +    struct list_head        list;
>>> +};
>>> +
>>> +/* Xen: Describes information required for a Xen domain */
>>> +struct arm_smmu_xen_domain {
>>> +    spinlock_t            lock;
>>> +    /* List of iommu domains associated to this domain */
>>> +    struct list_head        contexts;
>>> +};
>>> +
>>> +/*
>>> + * Xen: Information about each device stored in dev->archdata.iommu
>>> + *
>>> + * The dev->archdata.iommu stores the iommu_domain (runtime 
>>> configuration of
>>> + * the SMMU).
>>> + */
>>> +struct arm_smmu_xen_device {
>>> +    struct iommu_domain *domain;
>>> +};
>>> +
>> As this is a xen specific code, can the variable names be used 
>> appropriately.
>> Repeating my comment  from earlier version.
>> a domain is  usually a VM in Xen. So it is a bit confusing to use 
>> domain for iommu_domain.
>>> +/*
>>> + * Xen: io_pgtable compatibility defines.
>>> + * Most of these are to port in the S1 translation code as is.
>>> + */
>>> +struct io_pgtable_ops {
>>> +};
>>> +
>>> +struct iommu_gather_ops {
>>> +    void (*tlb_flush_all)(void *cookie);
>>> +    void (*tlb_add_flush)(unsigned long iova, size_t size, size_t 
>>> granule,
>>> +                  bool leaf, void *cookie);
>>> +    void (*tlb_sync)(void *cookie);
>>> +};
>>> +
>>> +struct io_pgtable_cfg {
>>> +    /*
>>> +     * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE 
>>> bits in
>>> +     *    stage 1 PTEs, for hardware which insists on validating them
>>> +     *    even in    non-secure state where they should normally be 
>>> ignored.
>>> +     *
>>> +     * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, 
>>> IOMMU_WRITE and
>>> +     *    IOMMU_NOEXEC flags and map everything with full access, for
>>> +     *    hardware which does not implement the permissions of a given
>>> +     *    format, and/or requires some format-specific default value.
>>> +     *
>>> +     * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching 
>>> invalid
>>> +     *    (unmapped) entries but the hardware might do so anyway, 
>>> perform
>>> +     *    TLB maintenance when mapping as well as when unmapping.
>>> +     *
>>> +     * IO_PGTABLE_QUIRK_ARM_MTK_4GB: (ARM v7s format) Set bit 9 in all
>>> +     *    PTEs, for Mediatek IOMMUs which treat it as a 33rd 
>>> address bit
>>> +     *    when the SoC is in "4GB mode" and they can only access 
>>> the high
>>> +     *    remap of DRAM (0x1_00000000 to 0x1_ffffffff).
>>> +     *
>>> +     * IO_PGTABLE_QUIRK_NO_DMA: Guarantees that the tables will 
>>> only ever
>>> +     *    be accessed by a fully cache-coherent IOMMU or CPU (e.g. 
>>> for a
>>> +     *    software-emulated IOMMU), such that pagetable updates 
>>> need not
>>> +     *    be treated as explicit DMA data.
>>> +     */
>>> +    #define IO_PGTABLE_QUIRK_ARM_NS        BIT(0)
>>> +    #define IO_PGTABLE_QUIRK_NO_PERMS    BIT(1)
>>> +    #define IO_PGTABLE_QUIRK_TLBI_ON_MAP    BIT(2)
>>> +    #define IO_PGTABLE_QUIRK_ARM_MTK_4GB    BIT(3)
>>> +    #define IO_PGTABLE_QUIRK_NO_DMA        BIT(4)
>>> +    unsigned long            quirks;
>>> +    unsigned long            pgsize_bitmap;
>>> +    unsigned int            ias;
>>> +    unsigned int            oas;
>>> +    const struct iommu_gather_ops    *tlb;
>>> +    struct device            *iommu_dev;
>>> +
>>> +    /* Low-level data specific to the table format */
>>> +    union {
>>> +        struct {
>>> +            u64    ttbr[2];
>>> +            u64    tcr;
>>> +            u64    mair[2];
>>> +        } arm_lpae_s1_cfg;
>>> +
>>> +        struct {
>>> +            u64    vttbr;
>>> +            u64    vtcr;
>>> +        } arm_lpae_s2_cfg;
>>> +
>>> +        struct {
>>> +            u32    ttbr[2];
>>> +            u32    tcr;
>>> +            u32    nmrr;
>>> +            u32    prrr;
>>> +        } arm_v7s_cfg;
>>> +    };
>>> +};
>>> +
>>> +enum io_pgtable_fmt {
>>> +    ARM_32_LPAE_S1,
>>> +    ARM_32_LPAE_S2,
>>> +    ARM_64_LPAE_S1,
>>> +    ARM_64_LPAE_S2,
>>> +    ARM_V7S,
>>> +    IO_PGTABLE_NUM_FMTS,
>>> +};
>>> +
>>> +/*
>>> + * Xen: The pgtable_ops are used by the S1 translations, so return 
>>> the dummy
>>> + * address.
>>> + */
>>> +#define alloc_io_pgtable_ops(f, c, o) ((struct io_pgtable_ops *)0x1)
>>> +#define free_io_pgtable_ops(o)
>>> +
>>> +/* Xen: Define wrapper for requesting IRQs */
>>> +#define IRQF_ONESHOT 0
>>> +
>>> +typedef void (*irq_handler_t)(int, void *, struct cpu_user_regs *);
>>> +
>>> +static inline int devm_request_irq(struct device *dev, unsigned int 
>>> irq,
>>> +                   irq_handler_t handler, unsigned long irqflags,
>>> +                   const char *devname, void *dev_id)
>>> +{
>>> +    /*
>>> +     * SMMUv3 implementation can support wired interrupt outputs 
>>> that are
>>> +     * edge-triggered. Set the irq type as per the spec.
>>> +     */
>>> +    irq_set_type(irq, IRQ_TYPE_EDGE_BOTH);
>>> +    return request_irq(irq, irqflags, handler, devname, dev_id);
>>> +}
>>> +
>>> +/*
>>> + * Xen does not have a concept of threaded irq, but we can use 
>>> tasklets to
>>> + * achieve the desired functionality as needed.
>>> + */
>>> +int devm_request_threaded_irq(struct device *dev, unsigned int irq, 
>>> irq_handler_t handler,
>>> +                  irq_handler_t thread_fn, unsigned long irqflags,
>>> +                  const char *devname, void *dev_id)
>>> +{
>>> +    return devm_request_irq(dev, irq, thread_fn, irqflags, devname, 
>>> dev_id);
>>> +}
>>> +
>>> +/* Xen: The mutex is used only during initialization so the 
>>> typecast is safe */
>>> +#define mutex spinlock
>>> +#define mutex_init spin_lock_init
>>> +#define mutex_lock spin_lock
>>> +#define mutex_unlock spin_unlock
>>> +
>>> +#define readx_poll_timeout(op, addr, val, cond, sleep_us, 
>>> timeout_us) \
>>> +({ \
>>> +    s_time_t deadline = NOW() + MICROSECS(timeout_us); \
>>> +    for (;;) { \
>>> +        (val) = op(addr); \
>>> +        if (cond) \
>>> +            break; \
>>> +        if (NOW() > deadline) { \
>>> +            (val) = op(addr); \
>>> +            break; \
>>> +        } \
>>> +    udelay(sleep_us); \
>>> +    } \
>>> +    (cond) ? 0 : -ETIMEDOUT; \
>>> +})
>>> +
>>> +#define readl_relaxed_poll_timeout(addr, val, cond, delay_us, 
>>> timeout_us) \
>>> +    readx_poll_timeout(readl_relaxed, addr, val, cond, delay_us, 
>>> timeout_us)
>>> +
>>> +#define VA_BITS 0 /* Only needed for S1 translations */
>>>     /* MMIO registers */
>>>   #define ARM_SMMU_IDR0            0x0
>>> @@ -433,6 +819,7 @@ enum pri_resp {
>>>       PRI_RESP_SUCC,
>>>   };
>>>   +#if 0 /* Xen: No MSI support in this iteration */
>>>   enum arm_smmu_msi_index {
>>>       EVTQ_MSI_INDEX,
>>>       GERROR_MSI_INDEX,
>>> @@ -457,6 +844,7 @@ static phys_addr_t 
>>> arm_smmu_msi_cfg[ARM_SMMU_MAX_MSIS][3] = {
>>>           ARM_SMMU_PRIQ_IRQ_CFG2,
>>>       },
>>>   };
>>> +#endif
>>>     struct arm_smmu_cmdq_ent {
>>>       /* Common fields */
>>> @@ -561,6 +949,8 @@ struct arm_smmu_s2_cfg {
>>>       u16                vmid;
>>>       u64                vttbr;
>>>       u64                vtcr;
>>> +    /* Xen: Domain associated to this configuration */
>>> +    struct domain            *domain;
>>>   };
>>>     struct arm_smmu_strtab_ent {
>>> @@ -635,9 +1025,25 @@ struct arm_smmu_device {
>>>       struct arm_smmu_strtab_cfg    strtab_cfg;
>>>         /* IOMMU core code handle */
>>> +#if 0 /*Xen: Generic iommu_device ref not needed here */
>>>       struct iommu_device        iommu;
>>> +#endif
>> Is it clean to put #if 0, can this line be deleted or used with a 
>> proper macro
>>> +    /* Xen: Need to keep a list of SMMU devices */
>>> +    struct list_head                devices;
>>> +    /* Xen: Tasklets for handling evts/faults and pci page request 
>>> IRQs*/
>>> +    struct tasklet            evtq_tasklet;
>>> +    struct tasklet            priq_tasklet;
>>> +    struct tasklet            combined_irq_tasklet;
>>>   };
>>>   +/* Xen: Keep a list of devices associated with this driver */
>>> +static DEFINE_SPINLOCK(arm_smmu_devices_lock);
>>> +static LIST_HEAD(arm_smmu_devices);
>>> +/* Xen: Helper for finding a device using fwnode */
>>> +static
>>> +struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle 
>>> *fwnode);
>>> +
>>> +
>>>   /* SMMU private data for each master */
>>>   struct arm_smmu_master_data {
>>>       struct arm_smmu_device        *smmu;
>>> @@ -1232,7 +1638,7 @@ static void arm_smmu_handle_ppr(struct 
>>> arm_smmu_device *smmu, u64 *evt)
>>>         dev_info(smmu->dev, "unexpected PRI request received:\n");
>>>       dev_info(smmu->dev,
>>> -         "\tsid 0x%08x.0x%05x: [%u%s] %sprivileged %s%s%s access at 
>>> iova 0x%016llx\n",
>>> +         "\tsid 0x%08x.0x%05x: [%u%s] %sprivileged %s%s%s access at 
>>> iova %#" PRIx64 "\n",
>>>            sid, ssid, grpid, last ? "L" : "",
>>>            evt[0] & PRIQ_0_PERM_PRIV ? "" : "un",
>>>            evt[0] & PRIQ_0_PERM_READ ? "R" : "",
>>> @@ -1342,10 +1748,20 @@ static irqreturn_t 
>>> arm_smmu_combined_irq_thread(int irq, void *dev)
>>>       return IRQ_HANDLED;
>>>   }
>>>   +/* Xen: Forward define for combined_irq tasklet */
>>> +static void arm_smmu_combined_irq_tasklet(unsigned long dev);
>>> +
>>>   static irqreturn_t arm_smmu_combined_irq_handler(int irq, void *dev)
>>>   {
>>> +    /* Xen: Need an smmu reference to schedule the tasklet */
>>> +    struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
>>> +
>>>       arm_smmu_gerror_handler(irq, dev);
>>>       arm_smmu_cmdq_sync_handler(irq, dev);
>>> +
>>> +    /*Xen: No threaded irq. So, schedule the right tasklet*/
>>> +    tasklet_schedule(&(smmu->combined_irq_tasklet));
>>> +
>>>       return IRQ_WAKE_THREAD;
>>>   }
>>>   @@ -1358,6 +1774,69 @@ static void __arm_smmu_tlb_sync(struct 
>>> arm_smmu_device *smmu)
>>>       arm_smmu_cmdq_issue_cmd(smmu, &cmd);
>>>   }
>>>   +/*
>>> + * Xen: Define the IRQ handlers and tasklets for xen. The linux 
>>> functions
>>> + * would be modified to use the functions defined in the following 
>>> code.
>>> + */
>>> +
>>> +static void arm_smmu_evtq_tasklet(unsigned long dev)
>>> +{
>>> +    /* The IRQ number is not relevent for the evtq thread 
>>> processing */
>>> +    arm_smmu_evtq_thread(0, (void *)dev);
>>> +}
>>> +
>>> +static void arm_smmu_priq_tasklet(unsigned long dev)
>>> +{
>>> +    /* The IRQ number is not relevent for the priq thread 
>>> processing */
>>> +    arm_smmu_priq_thread(0, (void *)dev);
>>> +}
>>> +
>>> +static void arm_smmu_combined_irq_tasklet(unsigned long dev)
>>> +{
>>> +    /* The IRQ number is not relevent for the combined irq handler.*/
>>> +    arm_smmu_combined_irq_thread(0, (void *)dev);
>>> +}
>>> +
>>> +static void arm_smmu_evtq_thread_xen(int irq, void *dev,
>>> +                       struct cpu_user_regs *regs)
>>> +{
>>> +    struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
>>> +
>>> +    tasklet_schedule(&(smmu->evtq_tasklet));
>>> +}
>>> +
>>> +static void arm_smmu_priq_thread_xen(int irq, void *dev,
>>> +                       struct cpu_user_regs *regs)
>>> +{
>>> +    struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
>>> +
>>> +    tasklet_schedule(&(smmu->priq_tasklet));
>>> +}
>>> +
>>> +static void arm_smmu_cmdq_sync_handler_xen(int irq, void *dev,
>>> +                       struct cpu_user_regs *regs)
>>> +{
>>> +    arm_smmu_cmdq_sync_handler(irq, dev);
>>> +}
>>> +
>>> +static void arm_smmu_gerror_handler_xen(int irq, void *dev,
>>> +                       struct cpu_user_regs *regs)
>>> +{
>>> +    arm_smmu_gerror_handler(irq, dev);
>>> +}
>>> +
>>> +static void arm_smmu_combined_irq_handler_xen(int irq, void *dev,
>>> +                       struct cpu_user_regs *regs)
>>> +{
>>> +    arm_smmu_combined_irq_handler(irq, dev);
>>> +}
>>> +
>>> +#define arm_smmu_evtq_thread arm_smmu_evtq_thread_xen
>>> +#define arm_smmu_priq_thread arm_smmu_priq_thread_xen
>>> +#define arm_smmu_cmdq_sync_handler arm_smmu_cmdq_sync_handler_xen
>>> +#define arm_smmu_gerror_handler arm_smmu_gerror_handler_xen
>>> +#define arm_smmu_combined_irq_handler 
>>> arm_smmu_combined_irq_handler_xen
>>> +
>>>   static void arm_smmu_tlb_sync(void *cookie)
>>>   {
>>>       struct arm_smmu_domain *smmu_domain = cookie;
>>> @@ -1415,6 +1894,7 @@ static const struct iommu_gather_ops 
>>> arm_smmu_gather_ops = {
>>>       .tlb_sync    = arm_smmu_tlb_sync,
>>>   };
>>>   +#if 0 /*Xen: Unused functionality */
>>>   /* IOMMU API */
>>>   static bool arm_smmu_capable(enum iommu_cap cap)
>>>   {
>>> @@ -1427,6 +1907,7 @@ static bool arm_smmu_capable(enum iommu_cap cap)
>>>           return false;
>>>       }
>>>   }
>>> +#endif
>>>     static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
>>>   {
>>> @@ -1546,9 +2027,16 @@ static int arm_smmu_domain_finalise_s2(struct 
>>> arm_smmu_domain *smmu_domain,
>>>       if (vmid < 0)
>>>           return vmid;
>>>   -    cfg->vmid    = (u16)vmid;
>>> -    cfg->vttbr    = pgtbl_cfg->arm_lpae_s2_cfg.vttbr;
>>> -    cfg->vtcr    = pgtbl_cfg->arm_lpae_s2_cfg.vtcr;
>>> +    /*
>>> +     * Xen: Get the ttbr and vtcr values
>>> +     * vttbr: This is a shared value with the domain page table
>>> +     * vtcr: The TCR settings are the same as CPU since the page
>>> +     * tables are shared
>>> +     */
>>> +
>>> +    cfg->vmid    = vmid;
>>> +    cfg->vttbr    = page_to_maddr(cfg->domain->arch.p2m.root);
>>> +    cfg->vtcr    = READ_SYSREG32(VTCR_EL2) & STRTAB_STE_2_VTCR_MASK;
>>>       return 0;
>>>   }
>>>   @@ -1604,6 +2092,7 @@ static int arm_smmu_domain_finalise(struct 
>>> iommu_domain *domain)
>>>       if (smmu->features & ARM_SMMU_FEAT_COHERENCY)
>>>           pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_NO_DMA;
>>>   +    /* Xen: pgtbl_ops gets an invalid address */
>>>       pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);
>>>       if (!pgtbl_ops)
>>>           return -ENOMEM;
>>> @@ -1721,6 +2210,7 @@ out_unlock:
>>>       return ret;
>>>   }
>>>   +#if 0 /* Xen: Unused functionality */
>> same
>>>   static int arm_smmu_map(struct iommu_domain *domain, unsigned long 
>>> iova,
>>>               phys_addr_t paddr, size_t size, int prot)
>>>   {
>>> @@ -1772,6 +2262,7 @@ struct arm_smmu_device 
>>> *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
>>>       put_device(dev);
>>>       return dev ? dev_get_drvdata(dev) : NULL;
>>>   }
>>> +#endif
>>>     static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, 
>>> u32 sid)
>>>   {
>>> @@ -1783,7 +2274,14 @@ static bool arm_smmu_sid_in_range(struct 
>>> arm_smmu_device *smmu, u32 sid)
>>>       return sid < limit;
>>>   }
>>>   +/* Xen: Unused */
>>> +#if 0
>>>   static struct iommu_ops arm_smmu_ops;
>>> +#endif
>>> +
>>> +/* Xen: Redefine arm_smmu_ops to what fwspec should evaluate */
>>> +static const struct iommu_ops arm_smmu_iommu_ops;
>>> +#define arm_smmu_ops arm_smmu_iommu_ops
>>>     static int arm_smmu_add_device(struct device *dev)
>>>   {
>>> @@ -1791,8 +2289,11 @@ static int arm_smmu_add_device(struct device 
>>> *dev)
>>>       struct arm_smmu_device *smmu;
>>>       struct arm_smmu_master_data *master;
>>>       struct iommu_fwspec *fwspec = dev->iommu_fwspec;
>>> +#if 0 /*Xen: iommu_group is not needed */
>>>       struct iommu_group *group;
>>> +#endif
>>>   +    /* Xen: fwspec->ops are not needed */
>>>       if (!fwspec || fwspec->ops != &arm_smmu_ops)
>>>           return -ENODEV;
>>>       /*
>>> @@ -1830,6 +2331,11 @@ static int arm_smmu_add_device(struct device 
>>> *dev)
>>>           }
>>>       }
>>>   +/*
>>> + * Xen: Do not need an iommu group as the stream data is carried by 
>>> the SMMU
>>> + * master device object
>>> + */
>>> +#if 0
>>>       group = iommu_group_get_for_dev(dev);
>>>       if (!IS_ERR(group)) {
>>>           iommu_group_put(group);
>>> @@ -1837,8 +2343,16 @@ static int arm_smmu_add_device(struct device 
>>> *dev)
>>>       }
>>>         return PTR_ERR_OR_ZERO(group);
>>> +#endif
>>> +    return 0;
>>>   }
>>>   +/*
>>> + * Xen: We can potentially support this function and destroy a 
>>> device. This
>>> + * will be relevant for PCI hotplug. So, will be implemented as 
>>> needed after
>>> + * passthrough support is available.
>>> + */
>>> +#if 0
>>>   static void arm_smmu_remove_device(struct device *dev)
>>>   {
>>>       struct iommu_fwspec *fwspec = dev->iommu_fwspec;
>>> @@ -1974,6 +2488,7 @@ static struct iommu_ops arm_smmu_ops = {
>>>       .put_resv_regions    = arm_smmu_put_resv_regions,
>>>       .pgsize_bitmap        = -1UL, /* Restricted during device 
>>> attach */
>>>   };
>>> +#endif
>>>     /* Probing and initialisation functions */
>>>   static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
>>> @@ -2182,6 +2697,7 @@ static int arm_smmu_update_gbpa(struct 
>>> arm_smmu_device *smmu, u32 set, u32 clr)
>>>                         1, ARM_SMMU_POLL_TIMEOUT_US);
>>>   }
>>>   +#if 0 /* Xen: There is no MSI support as yet */
>>>   static void arm_smmu_free_msis(void *data)
>>>   {
>>>       struct device *dev = data;
>>> @@ -2247,12 +2763,15 @@ static void arm_smmu_setup_msis(struct 
>>> arm_smmu_device *smmu)
>>>       /* Add callback to free MSIs on teardown */
>>>       devm_add_action(dev, arm_smmu_free_msis, dev);
>>>   }
>>> +#endif
>>>     static void arm_smmu_setup_unique_irqs(struct arm_smmu_device 
>>> *smmu)
>>>   {
>>>       int irq, ret;
>>>   +#if 0 /*Xen: Cannot setup msis for now */
>>>       arm_smmu_setup_msis(smmu);
>>> +#endif
>>>         /* Request interrupt lines */
>>>       irq = smmu->evtq.q.irq;
>>> @@ -2316,9 +2835,13 @@ static int arm_smmu_setup_irqs(struct 
>>> arm_smmu_device *smmu)
>>>            * Cavium ThunderX2 implementation doesn't not support unique
>>>            * irq lines. Use single irq line for all the SMMUv3 
>>> interrupts.
>>>            */
>>> -        ret = devm_request_threaded_irq(smmu->dev, irq,
>>> +        /*
>>> +         * Xen: Does not support threaded irqs, so serialise the 
>>> setup.
>>> +         * This is the same for pris and event interrupt lines on 
>>> other
>>> +         * systems
>>> +         */
>>> +        ret = devm_request_irq(smmu->dev, irq,
>>>                       arm_smmu_combined_irq_handler,
>>> -                    arm_smmu_combined_irq_thread,
>>>                       IRQF_ONESHOT,
>>>                       "arm-smmu-v3-combined-irq", smmu);
>>>           if (ret < 0)
>>> @@ -2452,6 +2975,13 @@ static int arm_smmu_device_reset(struct 
>>> arm_smmu_device *smmu, bool bypass)
>>>           return ret;
>>>       }
>>>   +    /* Xen: Initialize tasklets */
>>> +    tasklet_init(&smmu->evtq_tasklet, arm_smmu_evtq_tasklet,
>>> +            (unsigned long)smmu);
>>> +    tasklet_init(&smmu->priq_tasklet, arm_smmu_priq_tasklet,
>>> +            (unsigned long)smmu);
>>> +    tasklet_init(&smmu->combined_irq_tasklet, 
>>> arm_smmu_combined_irq_tasklet,
>>> +            (unsigned long)smmu);
>>>         /* Enable the SMMU interface, or ensure bypass */
>>>       if (!bypass || disable_bypass) {
>>> @@ -2542,8 +3072,14 @@ static int arm_smmu_device_hw_probe(struct 
>>> arm_smmu_device *smmu)
>>>           smmu->features |= ARM_SMMU_FEAT_STALLS;
>>>       }
>>>   +/*
>>> + * Xen: Block stage 1 translations. By doing this here we do not 
>>> need to set the
>>> + * domain->stage explicitly.
>>> + */
>>> +#if 0
>>>       if (reg & IDR0_S1P)
>>>           smmu->features |= ARM_SMMU_FEAT_TRANS_S1;
>>> +#endif
>>>         if (reg & IDR0_S2P)
>>>           smmu->features |= ARM_SMMU_FEAT_TRANS_S2;
>>> @@ -2616,10 +3152,12 @@ static int arm_smmu_device_hw_probe(struct 
>>> arm_smmu_device *smmu)
>>>       if (reg & IDR5_GRAN4K)
>>>           smmu->pgsize_bitmap |= SZ_4K | SZ_2M | SZ_1G;
>>>   +#if 0 /* Xen: SMMU ops do not have a pgsize_bitmap member for Xen */
>>>       if (arm_smmu_ops.pgsize_bitmap == -1UL)
>>>           arm_smmu_ops.pgsize_bitmap = smmu->pgsize_bitmap;
>>>       else
>>>           arm_smmu_ops.pgsize_bitmap |= smmu->pgsize_bitmap;
>>> +#endif
>>>         /* Output address size */
>>>       switch (reg & IDR5_OAS_MASK << IDR5_OAS_SHIFT) {
>>> @@ -2680,7 +3218,8 @@ static int arm_smmu_device_acpi_probe(struct 
>>> platform_device *pdev,
>>>       struct device *dev = smmu->dev;
>>>       struct acpi_iort_node *node;
>>>   -    node = *(struct acpi_iort_node **)dev_get_platdata(dev);
>>> +    /* Xen: Modification to get iort_node */
>>> +    node = (struct acpi_iort_node *)dev->acpi_node;
>>>         /* Retrieve SMMUv3 specific data */
>>>       iort_smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
>>> @@ -2703,7 +3242,7 @@ static inline int 
>>> arm_smmu_device_acpi_probe(struct platform_device *pdev,
>>>   static int arm_smmu_device_dt_probe(struct platform_device *pdev,
>>>                       struct arm_smmu_device *smmu)
>>>   {
>>> -    struct device *dev = &pdev->dev;
>>> +    struct device *dev = pdev;
>>>       u32 cells;
>>>       int ret = -EINVAL;
>>>   @@ -2716,6 +3255,7 @@ static int arm_smmu_device_dt_probe(struct 
>>> platform_device *pdev,
>>>         parse_driver_options(smmu);
>>>   +    /* Xen: of_dma_is_coherent is a stub till dt support is 
>>> introduced */
>>>       if (of_dma_is_coherent(dev->of_node))
>>>           smmu->features |= ARM_SMMU_FEAT_COHERENCY;
>>>   @@ -2734,9 +3274,11 @@ static int arm_smmu_device_probe(struct 
>>> platform_device *pdev)
>>>   {
>>>       int irq, ret;
>>>       struct resource *res;
>>> +#if 0 /*Xen: Do not need to setup sysfs */
>>>       resource_size_t ioaddr;
>>> +#endif
>>>       struct arm_smmu_device *smmu;
>>> -    struct device *dev = &pdev->dev;
>>> +    struct device *dev = pdev;/* Xen: dev is ignored */
>>>       bool bypass;
>>>         smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
>>> @@ -2763,7 +3305,9 @@ static int arm_smmu_device_probe(struct 
>>> platform_device *pdev)
>>>           dev_err(dev, "MMIO region too small (%pr)\n", res);
>>>           return -EINVAL;
>>>       }
>>> +#if 0 /*Xen: Do not need to setup sysfs */
>>>       ioaddr = res->start;
>>> +#endif
>>>         smmu->base = devm_ioremap_resource(dev, res);
>>>       if (IS_ERR(smmu->base))
>>> @@ -2802,13 +3346,18 @@ static int arm_smmu_device_probe(struct 
>>> platform_device *pdev)
>>>           return ret;
>>>         /* Record our private device structure */
>>> +    /* Xen: SMMU is not treated a a platform device*/
>>> +#if 0
>>>       platform_set_drvdata(pdev, smmu);
>>> +#endif
>>>         /* Reset the device */
>>>       ret = arm_smmu_device_reset(smmu, bypass);
>>>       if (ret)
>>>           return ret;
>>>   +/* Xen: Not creating an IOMMU device list for Xen */
>>> +#if 0
>>>       /* And we're up. Go go go! */
>>>       ret = iommu_device_sysfs_add(&smmu->iommu, dev, NULL,
>>>                        "smmu3.%pa", &ioaddr);
>>> @@ -2844,9 +3393,20 @@ static int arm_smmu_device_probe(struct 
>>> platform_device *pdev)
>>>           if (ret)
>>>               return ret;
>>>       }
>>> +#endif
>>> +    /*
>>> +     * Xen: Keep a list of all probed devices. This will be used to 
>>> query
>>> +     * the smmu devices based on the fwnode.
>>> +     */
>>> +    INIT_LIST_HEAD(&smmu->devices);
>>> +    spin_lock(&arm_smmu_devices_lock);
>>> +    list_add(&smmu->devices, &arm_smmu_devices);
>>> +    spin_unlock(&arm_smmu_devices_lock);
>>>       return 0;
>>>   }
>>>   +/* Xen: Unused function */
>>> +#if 0
>>>   static int arm_smmu_device_remove(struct platform_device *pdev)
>>>   {
>>>       struct arm_smmu_device *smmu = platform_get_drvdata(pdev);
>>> @@ -2860,6 +3420,8 @@ static void arm_smmu_device_shutdown(struct 
>>> platform_device *pdev)
>>>   {
>>>       arm_smmu_device_remove(pdev);
>>>   }
>>> +#endif
>>> +
>>>     static const struct of_device_id arm_smmu_of_match[] = {
>>>       { .compatible = "arm,smmu-v3", },
>>> @@ -2867,6 +3429,7 @@ static const struct of_device_id 
>>> arm_smmu_of_match[] = {
>>>   };
>>>   MODULE_DEVICE_TABLE(of, arm_smmu_of_match);
>>>   +#if 0
>>>   static struct platform_driver arm_smmu_driver = {
>>>       .driver    = {
>>>           .name        = "arm-smmu-v3",
>>> @@ -2883,3 +3446,316 @@ IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", 
>>> NULL);
>>>   MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 
>>> implementations");
>>>   MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
>>>   MODULE_LICENSE("GPL v2");
>>> +#endif
>>> +
>>> +/***** Start of Xen specific code *****/
>>> +
>>> +static int __must_check arm_smmu_iotlb_flush_all(struct domain *d)
>>> +{
>>> +    struct arm_smmu_xen_domain *smmu_domain = dom_iommu(d)->arch.priv;
>>> +    struct iommu_domain *cfg;
>>> +
>>> +    spin_lock(&smmu_domain->lock);
>>> +    list_for_each_entry(cfg, &smmu_domain->contexts, list) {
>>> +        /*
>>> +         * Only invalidate the context when SMMU is present.
>>> +         * This is because the context initialization is delayed
>>> +         * until a master has been added.
>>> +         */
>>> +        if (unlikely(!ACCESS_ONCE(cfg->priv->smmu)))
>>> +            continue;
>>> +        arm_smmu_tlb_inv_context(cfg->priv);
>>> +    }
>>> +    spin_unlock(&smmu_domain->lock);
>>> +    return 0;
>>> +}
>>> +
>>> +static int __must_check arm_smmu_iotlb_flush(struct domain *d,
>>> +                         unsigned long gfn,
>>> +                         unsigned int page_count)
>>> +{
>>> +    return arm_smmu_iotlb_flush_all(d);
>>> +}
>>> +
>>> +static struct iommu_domain *arm_smmu_get_domain(struct domain *d,
>>> +                        struct device *dev)
>> This is returning iommu_domain and not a domain.
>> Please change the name of function.
>>> +{
>>> +    struct iommu_domain *domain;
>>> +    struct arm_smmu_xen_domain *xen_domain;
>> A suggestion
>> 1. as you have used in above function smmu_domain variable for 
>> arm_smmu_xen_domain
>> Can similar logic be used for iommu_domain.
>>
>> 2. When smmu_domain variable name is used in above function why 
>> xen_domain is used in this function.
>> It is quite confusing.
>> logically xen_domain should mean a VM.
>>> +    struct arm_smmu_device *smmu;
>>> +    struct arm_smmu_domain *smmu_domain;
>> smmu_domain was used for arm_smmu_xen_domain.
>> consistency of variable names is necessary for code clarity
>>> +
>>> +    xen_domain = dom_iommu(d)->arch.priv;
>>> +
>>> +    smmu = arm_smmu_get_by_fwnode(dev->iommu_fwspec->iommu_fwnode);
>>> +    if (!smmu)
>>> +        return NULL;
>>> +
>>> +    /*
>>> +     * Loop through the &xen_domain->contexts to locate a context
>>> +     * assigned to this SMMU
>>> +     */
>>> +    list_for_each_entry(domain, &xen_domain->contexts, list) {
>>> +        smmu_domain = to_smmu_domain(domain);
>>> +        if (smmu_domain->smmu == smmu)
>>> +            return domain;
>>> +    }
>>> +
>>> +    return NULL;
>>> +}
>>> +
>>> +static void arm_smmu_destroy_iommu_domain(struct iommu_domain *domain)
>> same
>>> +{
>>> +    list_del(&domain->list);
>>> +    arm_smmu_domain_free(domain);
>>> +}
>>> +
>>> +static int arm_smmu_assign_dev(struct domain *d, u8 devfn,
>>> +                   struct device *dev, u32 flag)
>>> +{
>>> +    int ret = 0;
>>> +    struct iommu_domain *domain;
>>> +    struct arm_smmu_xen_domain *xen_domain;
>> same
>>> +    struct arm_smmu_domain *arm_smmu;
>>> +
>>> +    xen_domain = dom_iommu(d)->arch.priv;
>>> +
>>> +    if (!dev->archdata.iommu) {
>>> +        dev->archdata.iommu = xzalloc(struct arm_smmu_xen_device);
>>> +        if (!dev->archdata.iommu)
>>> +            return -ENOMEM;
>>> +    }
>>> +
>>> +    ret = arm_smmu_add_device(dev);
>>> +    if (ret)
>>> +        return ret;
>>> +
>>> +    spin_lock(&xen_domain->lock);
>>> +
>>> +    /*
>>> +     * Check to see if an iommu_domain already exists for this xen 
>>> domain
>>> +     * under the same SMMU
>>> +     */
>>> +    domain = arm_smmu_get_domain(d, dev);
>>> +    if (!domain) {
>>> +
>>> +        domain = arm_smmu_domain_alloc(IOMMU_DOMAIN_DMA);
>>> +        if (!domain) {
>>> +            ret = -ENOMEM;
>>> +            goto out;
>>> +        }
>>> +
>>> +        arm_smmu = to_smmu_domain(domain);
>>> +        arm_smmu->s2_cfg.domain = d;
>>> +
>>> +        /* Chain the new context to the domain */
>>> +        list_add(&domain->list, &xen_domain->contexts);
>>> +
>>> +    }
>>> +
>>> +    ret = arm_smmu_attach_dev(domain, dev);
>>> +    if (ret) {
>>> +        if (domain->ref.counter == 0)
>>> +            arm_smmu_destroy_iommu_domain(domain);
>>> +    } else {
>>> +        atomic_inc(&domain->ref);
>>> +    }
>>> +
>>> +out:
>>> +    spin_unlock(&xen_domain->lock);
>>> +    return ret;
>>> +}
>>> +
>>> +static int arm_smmu_deassign_dev(struct domain *d, struct device *dev)
>>> +{
>>> +    struct iommu_domain *domain = arm_smmu_get_domain(d, dev);
>>> +    struct arm_smmu_xen_domain *xen_domain;
>>> +    struct arm_smmu_domain *arm_smmu = to_smmu_domain(domain);
>> same
>>> +
>>> +    xen_domain = dom_iommu(d)->arch.priv;
>>> +
>>> +    if (!arm_smmu || arm_smmu->s2_cfg.domain != d) {
>>> +        dev_err(dev, " not attached to domain %d\n", d->domain_id);
>>> +        return -ESRCH;
>>> +    }
>>> +
>>> +    spin_lock(&xen_domain->lock);
>>> +
>>> +    arm_smmu_detach_dev(dev);
>>> +    atomic_dec(&domain->ref);
>>> +
>>> +    if (domain->ref.counter == 0)
>>> +        arm_smmu_destroy_iommu_domain(domain);
>>> +
>>> +    spin_unlock(&xen_domain->lock);
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int arm_smmu_reassign_dev(struct domain *s, struct domain *t,
>>> +                 u8 devfn,  struct device *dev)
>>> +{
>>> +    int ret = 0;
>>> +
>>> +    /* Don't allow remapping on other domain than hwdom */
>>> +    if (t && t != hardware_domain)
>>> +        return -EPERM;
>>> +
>>> +    if (t == s)
>>> +        return 0;
>>> +
>>> +    ret = arm_smmu_deassign_dev(s, dev);
>>> +    if (ret)
>>> +        return ret;
>>> +
>>> +    if (t) {
>>> +        /* No flags are defined for ARM. */
>>> +        ret = arm_smmu_assign_dev(t, devfn, dev, 0);
>>> +        if (ret)
>>> +            return ret;
>>> +    }
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int arm_smmu_iommu_domain_init(struct domain *d)
>> Where is iommu_domain initialized?
>> The function does not use a iommu_domain * variable
>>> +{
>>> +    struct arm_smmu_xen_domain *xen_domain;
>>> +
>>> +    xen_domain = xzalloc(struct arm_smmu_xen_domain);
>>> +    if (!xen_domain)
>>> +        return -ENOMEM;
>>> +
>>> +    spin_lock_init(&xen_domain->lock);
>>> +    INIT_LIST_HEAD(&xen_domain->contexts);
>>> +
>>> +    dom_iommu(d)->arch.priv = xen_domain;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static void __hwdom_init arm_smmu_iommu_hwdom_init(struct domain *d)
>>> +{
>>> +}
>>> +
>>> +static void arm_smmu_iommu_domain_teardown(struct domain *d)
>>> +{
>>> +    struct arm_smmu_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
>>> +
>>> +    ASSERT(list_empty(&xen_domain->contexts));
>>> +    xfree(xen_domain);
>>> +}
>>> +
>>> +static int __must_check arm_smmu_map_page(struct domain *d, 
>>> unsigned long gfn,
>>> +            unsigned long mfn, unsigned int flags)
>>> +{
>>> +    p2m_type_t t;
>>> +
>>> +    /*
>>> +     * Grant mappings can be used for DMA requests. The dev_bus_addr
>>> +     * returned by the hypercall is the MFN (not the IPA). For device
>>> +     * protected by an IOMMU, Xen needs to add a 1:1 mapping in the 
>>> domain
>>> +     * p2m to allow DMA request to work.
>>> +     * This is only valid when the domain is directed mapped. Hence 
>>> this
>>> +     * function should only be used by gnttab code with gfn == mfn.
>>> +     */
>>> +    BUG_ON(!is_domain_direct_mapped(d));
>>> +    BUG_ON(mfn != gfn);
>>> +
>>> +    /* We only support readable and writable flags */
>>> +    if (!(flags & (IOMMUF_readable | IOMMUF_writable)))
>>> +        return -EINVAL;
>>> +
>>> +    t = (flags & IOMMUF_writable) ? p2m_iommu_map_rw : 
>>> p2m_iommu_map_ro;
>>> +
>>> +    /*
>>> +     * The function guest_physmap_add_entry replaces the current 
>>> mapping
>>> +     * if there is already one...
>>> +     */
>>> +    return guest_physmap_add_entry(d, _gfn(gfn), _mfn(mfn), 0, t);
>>> +}
>>> +
>>> +static int __must_check arm_smmu_unmap_page(struct domain *d, 
>>> unsigned long gfn)
>>> +{
>>> +    /*
>>> +     * This function should only be used by gnttab code when the 
>>> domain
>>> +     * is direct mapped
>>> +     */
>>> +    if (!is_domain_direct_mapped(d))
>>> +        return -EINVAL;
>>> +
>>> +    return guest_physmap_remove_page(d, _gfn(gfn), _mfn(gfn), 0);
>>> +}
>>> +
>>> +static const struct iommu_ops arm_smmu_iommu_ops = {
>>> +    .init = arm_smmu_iommu_domain_init,
>>> +    .hwdom_init = arm_smmu_iommu_hwdom_init,
>>> +    .teardown = arm_smmu_iommu_domain_teardown,
>>> +    .iotlb_flush = arm_smmu_iotlb_flush,
>>> +    .iotlb_flush_all = arm_smmu_iotlb_flush_all,
>>> +    .assign_device = arm_smmu_assign_dev,
>>> +    .reassign_device = arm_smmu_reassign_dev,
>>> +    .map_page = arm_smmu_map_page,
>>> +    .unmap_page = arm_smmu_unmap_page,
>>> +};
>>> +
>>> +static
>>> +struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle 
>>> *fwnode)
>>> +{
>>> +    struct arm_smmu_device *smmu = NULL;
>>> +
>>> +    spin_lock(&arm_smmu_devices_lock);
>>> +    list_for_each_entry(smmu, &arm_smmu_devices, devices) {
>>> +        if (smmu->dev->fwnode == fwnode)
>>> +            break;
>>> +    }
>>> +    spin_unlock(&arm_smmu_devices_lock);
>>> +
>>> +    return smmu;
>>> +}
>>> +
>>> +static __init int arm_smmu_dt_init(struct dt_device_node *dev,
>>> +                   const void *data)
>>> +{
>>> +    int rc;
>>> +
>>> +    /*
>>> +     * Even if the device can't be initialized, we don't want to
>>> +     * give the SMMU device to dom0.
>>> +     */
>>> +    dt_device_set_used_by(dev, DOMID_XEN);
>>> +
>>> +    rc = arm_smmu_device_probe(dt_to_dev(dev));
>>> +    if (rc)
>>> +        return rc;
>>> +
>>> +    iommu_set_ops(&arm_smmu_iommu_ops);
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +DT_DEVICE_START(smmuv3, "ARM SMMU V3", DEVICE_IOMMU)
>>> +    .dt_match = arm_smmu_of_match,
>>> +    .init = arm_smmu_dt_init,
>>> +DT_DEVICE_END
>>> +
>>> +#ifdef CONFIG_ACPI
>>> +/* Set up the IOMMU */
>>> +static int __init arm_smmu_acpi_init(const void *data)
>>> +{
>>> +    int rc;
>>> +
>>> +    rc = arm_smmu_device_probe((struct device *)data);
>>> +    if (rc)
>>> +        return rc;
>>> +
>>> +    iommu_set_ops(&arm_smmu_iommu_ops);
>>> +    return 0;
>>> +}
>>> +
>>> +ACPI_DEVICE_START(asmmuv3, "ARM SMMU V3", DEVICE_IOMMU)
>>> +    .class_type = ACPI_IORT_NODE_SMMU_V3,
>>> +    .init = arm_smmu_acpi_init,
>>> +ACPI_DEVICE_END
>>> +
>>> +#endif
>>> diff --git a/xen/include/xen/linux_compat.h 
>>> b/xen/include/xen/linux_compat.h
>>> new file mode 100644
>>> index 0000000000..8037be0a3e
>>> --- /dev/null
>>> +++ b/xen/include/xen/linux_compat.h
>>> @@ -0,0 +1,84 @@
>>> +/****************************************************************************** 
>>>
>>> + * include/xen/linux_compat.h
>>> + *
>>> + * Compatibility defines for porting code from Linux to Xen
>>> + *
>>> + * Copyright (c) 2017 Linaro Limited
>>> + *
>>> + * This program is free software; you can redistribute it and/or 
>>> modify
>>> + * it under the terms of the GNU General Public License as 
>>> published by
>>> + * the Free Software Foundation; either version 2 of the License, or
>>> + * (at your option) any later version.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>> + * GNU General Public License for more details.
>>> + *
>>> + * You should have received a copy of the GNU General Public License
>>> + * along with this program; If not, see 
>>> <http://www.gnu.org/licenses/>.
>>> + */
>>> +
>>> +#ifndef __XEN_LINUX_COMPAT_H__
>>> +#define __XEN_LINUX_COMPAT_H__
>>> +
>>> +#include <asm/types.h>
>>> +
>>> +typedef paddr_t phys_addr_t;
>>> +typedef paddr_t dma_addr_t;
>>> +
>>> +typedef unsigned int gfp_t;
>>> +#define GFP_KERNEL 0
>>> +#define __GFP_ZERO 0x01U
>>> +
>>> +/* Helpers for IRQ functions */
>>> +#define free_irq release_irq
>>> +
>>> +enum irqreturn {
>>> +    IRQ_NONE,
>>> +    IRQ_HANDLED,
>>> +    IRQ_WAKE_THREAD,
>>> +};
>>> +
>>> +typedef enum irqreturn irqreturn_t;
>>> +
>>> +/* Device logger functions */
>>> +#define dev_dbg(dev, fmt, ...) printk(XENLOG_DEBUG fmt, ## 
>>> __VA_ARGS__)
>>> +#define dev_notice(dev, fmt, ...) printk(XENLOG_INFO fmt, ## 
>>> __VA_ARGS__)
>>> +#define dev_warn(dev, fmt, ...) printk(XENLOG_WARNING fmt, ## 
>>> __VA_ARGS__)
>>> +#define dev_err(dev, fmt, ...) printk(XENLOG_ERR fmt, ## __VA_ARGS__)
>>> +#define dev_info(dev, fmt, ...) printk(XENLOG_INFO fmt, ## 
>>> __VA_ARGS__)
>>> +
>>> +#define dev_err_ratelimited(dev, fmt, ...)                  \
>>> +     printk(XENLOG_ERR fmt, ## __VA_ARGS__)
>>> +
>>> +#define dev_name(dev) dt_node_full_name(dev_to_dt(dev))
>>> +
>>> +/* Alias to Xen allocation helpers */
>>> +#define kfree xfree
>>> +#define kmalloc(size, flags) ({\
>>> +    void *__ret_alloc = NULL; \
>>> +    if (flags & __GFP_ZERO) \
>>> +        __ret_alloc = _xzalloc(size, sizeof(void *)); \
>>> +    else \
>>> +        __ret_alloc = _xmalloc(size, sizeof(void *)); \
>>> +    __ret_alloc; \
>>> +})
>>> +#define kzalloc(size, flags)        _xzalloc(size, sizeof(void *))
>>> +#define devm_kzalloc(dev, size, flags)  _xzalloc(size, sizeof(void *))
>>> +#define kmalloc_array(size, n, flags) ({\
>>> +    void *__ret_alloc = NULL; \
>>> +    if (flags & __GFP_ZERO) \
>>> +        __ret_alloc = _xzalloc_array(size, sizeof(void *), n); \
>>> +    else \
>>> +        __ret_alloc = _xmalloc_array(size, sizeof(void *), n); \
>>> +    __ret_alloc; \
>>> +})
>>> +
>>> +/* Alias to Xen time functions */
>>> +#define ktime_t s_time_t
>>> +#define ktime_get()             (NOW())
>>> +#define ktime_add_us(t,i)       (t + MICROSECS(i))
>>> +#define ktime_compare(t,i)      (t > (i))
>>> +
>>> +#endif /* __XEN_LINUX_COMPAT_H__ */
>>
>
Jan Beulich May 25, 2018, 7:10 a.m. UTC | #7
>>> On 24.05.18 at 22:26, <sameer.goel@linaro.org> wrote:
> On 05/24/2018 01:57 AM, Jan Beulich wrote:
>>>>> On 24.05.18 at 02:46, <sameer.goel@linaro.org> wrote:
>>> --- /dev/null
>>> +++ b/xen/include/xen/linux_compat.h
>> I continue to dislike the idea of having a header with these contents in 
> this location.
> As explained previously this header can be used for the any driver that 
> we want to port from Linux. This is not arm specific. This seemed like 
> the best location for the file.

Please take into consideration that with lots of code originally having come
from Linux, in all the years we've never had a need to have such a header.
With that history, it needs good reasoning to introduce one now in such a
global fashion.

> Which other common location should I pick?

None - that's the whole point of my comment: I don't see this as something
that should go in a common location.

Jan
Julien Grall May 25, 2018, 8:45 a.m. UTC | #8
Hi,

On 25/05/18 05:41, Manish Jaggi wrote:
> 
> 
> On 05/25/2018 01:59 AM, Sameer Goel wrote:
>>
>>
>> On 05/23/2018 10:48 PM, Manish Jaggi wrote:
>>> Hi Sameer,
>>>
>>> General Comment, please use appropriate variable names for XXX_domain 
>>> structures in code which is xen specific.
>> I thought that we had discussed this before on one of the RFCs.
> Yes and no one replied to my last comment that the var names have to be 
> non confusing in Xen specific code.

Rather than just saying "you haven't replied to my last comment", how 
about giving a pointer to that e-mail?

AFAICT, the last answer was a reply from me to your e-mail. As I wrote 
there if it is used by Xen only code, then it should be alright. But 
Linux code *should not* be changed.

Cheers,
Sameer Goel May 30, 2018, 7:30 p.m. UTC | #9
On 5/25/2018 1:10 AM, Jan Beulich wrote:
>>>> On 24.05.18 at 22:26, <sameer.goel@linaro.org> wrote:
>> On 05/24/2018 01:57 AM, Jan Beulich wrote:
>>>>>> On 24.05.18 at 02:46, <sameer.goel@linaro.org> wrote:
>>>> --- /dev/null
>>>> +++ b/xen/include/xen/linux_compat.h
>>> I continue to dislike the idea of having a header with these contents in 
>> this location.
>> As explained previously this header can be used for the any driver that 
>> we want to port from Linux. This is not arm specific. This seemed like 
>> the best location for the file.
This code was added to every source file that was being ported. I found this explicitly in smmu-v2.c. Eventually this might be needed for the iort code that Manish might pull in.

The function signatures in the header file are consistent and should not change.

So, if we plan on porting a lot of Linux code, I would argue that this file is a necessity so that we do not define these functions in every ported source file.  (If we want to port Linux code with minimal changes.) The only example I found in the code base is arm smmu driver and the iort code that is being pulled in. So, we can move it to an arm specific location if needed, but this header is needed.

Thanks,
Sameer
> Please take into consideration that with lots of code originally having come
> from Linux, in all the years we've never had a need to have such a header.
> With that history, it needs good reasoning to introduce one now in such a
> global fashion.
>
>> Which other common location should I pick?
> None - that's the whole point of my comment: I don't see this as something
> that should go in a common location.
>
> Jan
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xenproject.org
> https://lists.xenproject.org/mailman/listinfo/xen-devel
Sameer Goel May 30, 2018, 7:46 p.m. UTC | #10
Manish, I'll take another look at the variable names. I might not have enough time :).
>>
>>
>> On 05/23/2018 10:48 PM, Manish Jaggi wrote:
>>> Hi Sameer,
>>>
>>> General Comment, please use appropriate variable names for XXX_domain structures in code which is xen specific.
>> I thought that we had discussed this before on one of the RFCs.
> Yes and no one replied to my last comment that the var names have to be non confusing in Xen specific code.
I'm sorry about that. I just assumed that since the policy on ported variable names was consistent we so not nee to change the names.

>> At this point we are just using the format used for smmu-v2.
> smmu-v2 has a lot of confusing variable names with _domain.
> I believe that file needs to be fixed as well.
>> I don't think that the variable names are inappropriate. Unless there is a very specific issue with the variable names,
> The issue is in code readability and understanding the flow.
> It is confusing so many _domain variable names are used which are not verbose.
These names are coming from the original Linux code. So, we do not change them as per the policy. That being said I can add a comment section to explain the confusing variables in the Xen specific code? Please let me know if this will help us resolve this issue?
 
>
> Two functions different and confusing variable names
>
> +static int __must_check arm_smmu_iotlb_flush_all(struct domain *d)
> +{
> +    struct arm_smmu_xen_domain *smmu_domain;
>
> +static struct iommu_domain *arm_smmu_get_domain(struct domain *d,
> +                        struct device *dev)
> +{
> +    struct iommu_domain *domain;
> +    struct arm_smmu_xen_domain *xen_domain;
>
> Why use smmu_domain at one place and xen_domain at another ?
> Intuitively xen_domain should mean a VM.
>
> Doesn't is look confusing?
>
> Please take a look, I have pointed out the other specific ones below.
>> I think we should stick with the current version.
>>
>>>
>>>
>>> On 05/24/2018 06:16 AM, Sameer Goel wrote:
>>>> This driver follows an approach similar to smmu driver. The intent here
>>>> is to reuse as much Linux code as possible.
>>>> - Glue code has been introduced to bridge the API calls.
>>>> - Called Linux functions from the Xen IOMMU function calls.
>>>> - Xen modifications are preceded by /*Xen: comment */
>>>> - xen/linux_compat: Add a Linux compat header
>>>>    For porting files directly from Linux it is useful to have a function mapping
>>>>    definitions from Linux to Xen. This file adds common API functions and
>>>>    other defines that are needed for porting arm SMMU drivers.
>>>>
>>>> Signed-off-by: Sameer Goel <sameer.goel@linaro.org>
>>>> ---
>>>>   xen/arch/arm/p2m.c                    |   1 +
>>>>   xen/drivers/Kconfig                   |   2 +
>>>>   xen/drivers/passthrough/arm/Kconfig   |   8 +
>>>>   xen/drivers/passthrough/arm/Makefile  |   1 +
>>>>   xen/drivers/passthrough/arm/smmu-v3.c | 934 +++++++++++++++++++++++++-
>>>>   xen/include/xen/linux_compat.h        |  84 +++
>>>>   6 files changed, 1001 insertions(+), 29 deletions(-)
>>>>   create mode 100644 xen/drivers/passthrough/arm/Kconfig
>>>>   create mode 100644 xen/include/xen/linux_compat.h
>>>>
>>>> diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
>>>> index d43c3aa896..38aa9f00c1 100644
>>>> --- a/xen/arch/arm/p2m.c
>>>> +++ b/xen/arch/arm/p2m.c
>>>> @@ -1454,6 +1454,7 @@ err:
>>>>   static void __init setup_virt_paging_one(void *data)
>>>>   {
>>>>       unsigned long val = (unsigned long)data;
>>>> +    /* SMMUv3 S2 cfg vtcr reuses the following value */
>>>>       WRITE_SYSREG32(val, VTCR_EL2);
>>>>       isb();
>>>>   }
>>>> diff --git a/xen/drivers/Kconfig b/xen/drivers/Kconfig
>>>> index db94393f47..59ca00f850 100644
>>>> --- a/xen/drivers/Kconfig
>>>> +++ b/xen/drivers/Kconfig
>>>> @@ -15,4 +15,6 @@ source "drivers/video/Kconfig"
>>>>   config HAS_VPCI
>>>>       bool
>>>>   +source "drivers/passthrough/arm/Kconfig"
>>>> +
>>>>   endmenu
>>>> diff --git a/xen/drivers/passthrough/arm/Kconfig b/xen/drivers/passthrough/arm/Kconfig
>>>> new file mode 100644
>>>> index 0000000000..cda899f608
>>>> --- /dev/null
>>>> +++ b/xen/drivers/passthrough/arm/Kconfig
>>>> @@ -0,0 +1,8 @@
>>>> +
>>>> +config ARM_SMMU_v3
>>>> +    bool "ARM SMMUv3 Support"
>>>> +    depends on ARM_64
>>>> +    help
>>>> +     Support for implementations of the ARM System MMU architecture
>>>> +     version 3.
>>>> +
>>>> diff --git a/xen/drivers/passthrough/arm/Makefile b/xen/drivers/passthrough/arm/Makefile
>>>> index f4cd26e15d..e14732b55c 100644
>>>> --- a/xen/drivers/passthrough/arm/Makefile
>>>> +++ b/xen/drivers/passthrough/arm/Makefile
>>>> @@ -1,2 +1,3 @@
>>>>   obj-y += iommu.o
>>>>   obj-y += smmu.o
>>>> +obj-$(CONFIG_ARM_SMMU_v3) += smmu-v3.o
>>>> diff --git a/xen/drivers/passthrough/arm/smmu-v3.c b/xen/drivers/passthrough/arm/smmu-v3.c
>>>> index e67ba6c40f..df81626785 100644
>>>> --- a/xen/drivers/passthrough/arm/smmu-v3.c
>>>> +++ b/xen/drivers/passthrough/arm/smmu-v3.c
>>>> @@ -18,28 +18,414 @@
>>>>    * Author: Will Deacon <will.deacon@arm.com>
>>>>    *
>>>>    * This driver is powered by bad coffee and bombay mix.
>>>> + *
>>>> + *
>>>> + * Based on Linux drivers/iommu/arm-smmu-v3.c
>>>> + * => commit 7aa8619a66aea52b145e04cbab4f8d6a4e5f3f3b
>>>> + *
>>>> + * Xen modifications:
>>>> + * Sameer Goel <sameer.goel@linaro.org>
>>>> + * Copyright (C) 2017, The Linux Foundation, All rights reserved.
>>>> + *
>>>>    */
>>>>   -#include <linux/acpi.h>
>>>> -#include <linux/acpi_iort.h>
>>>> -#include <linux/delay.h>
>>>> -#include <linux/dma-iommu.h>
>>>> -#include <linux/err.h>
>>>> -#include <linux/interrupt.h>
>>>> -#include <linux/iommu.h>
>>>> -#include <linux/iopoll.h>
>>>> -#include <linux/module.h>
>>>> -#include <linux/msi.h>
>>>> -#include <linux/of.h>
>>>> -#include <linux/of_address.h>
>>>> -#include <linux/of_iommu.h>
>>>> -#include <linux/of_platform.h>
>>>> -#include <linux/pci.h>
>>>> -#include <linux/platform_device.h>
>>>> -
>>>> -#include <linux/amba/bus.h>
>>>> -
>>>> -#include "io-pgtable.h"
>>>> +#include <xen/acpi.h>
>>>> +#include <xen/config.h>
>>>> +#include <xen/delay.h>
>>>> +#include <xen/errno.h>
>>>> +#include <xen/err.h>
>>>> +#include <xen/irq.h>
>>>> +#include <xen/lib.h>
>>>> +#include <xen/linux_compat.h>
>>>> +#include <xen/list.h>
>>>> +#include <xen/mm.h>
>>>> +#include <xen/rbtree.h>
>>>> +#include <xen/sched.h>
>>>> +#include <xen/sizes.h>
>>>> +#include <xen/vmap.h>
>>>> +#include <acpi/acpi_iort.h>
>>>> +#include <asm/atomic.h>
>>>> +#include <asm/device.h>
>>>> +#include <asm/io.h>
>>>> +#include <asm/platform.h>
>>>> +
>>>> +/* Alias to Xen device tree helpers */
>>>> +#define device_node dt_device_node
>>>> +#define of_phandle_args dt_phandle_args
>>>> +#define of_device_id dt_device_match
>>>> +#define of_match_node dt_match_node
>>>> +#define of_property_read_u32(np, pname, out) (!dt_property_read_u32(np, pname, out))
>>>> +#define of_property_read_bool dt_property_read_bool
>>>> +#define of_parse_phandle_with_args dt_parse_phandle_with_args
>>>> +
>>>> +/* Xen: Helpers to get device MMIO and IRQs */
>>>> +struct resource {
>>>> +    u64 addr;
>>>> +    u64 size;
>>>> +    unsigned int type;
>>>> +};
>>>> +
>>>> +#define resource_size(res) ((res)->size)
>>>> +
>>>> +#define platform_device device
>>>> +
>>>> +#define IORESOURCE_MEM 0
>>>> +#define IORESOURCE_IRQ 1
>>>> +
>>>> +static struct resource *platform_get_resource(struct platform_device *pdev,
>>>> +                          unsigned int type,
>>>> +                          unsigned int num)
>>>> +{
>>>> +    /*
>>>> +     * The resource is only used between 2 calls of platform_get_resource.
>>>> +     * It's quite ugly but it's avoid to add too much code in the part
>>>> +     * imported from Linux
>>>> +     */
>>>> +    static struct resource res;
>>>> +    struct acpi_iort_node *iort_node;
>>>> +    struct acpi_iort_smmu_v3 *node_smmu_data;
>>>> +    int ret = 0;
>>>> +
>>>> +    res.type = type;
>>>> +
>>>> +    switch (type) {
>>>> +    case IORESOURCE_MEM:
>>>> +        if (pdev->type == DEV_ACPI) {
>>>> +            ret = 1;
>>>> +            iort_node = pdev->acpi_node;
>>>> +            node_smmu_data =
>>>> +                (struct acpi_iort_smmu_v3 *)iort_node->node_data;
>>>> +
>>>> +            if (node_smmu_data != NULL) {
>>>> +                res.addr = node_smmu_data->base_address;
>>>> +                res.size = SZ_128K;
>>>> +                ret = 0;
>>>> +            }
>>>> +        } else {
>>>> +            ret = dt_device_get_address(dev_to_dt(pdev), num,
>>>> +                            &res.addr, &res.size);
>>>> +        }
>>>> +
>>>> +        return ((ret) ? NULL : &res);
>>>> +
>>>> +    case IORESOURCE_IRQ:
>>>> +        /* ACPI case not implemented as there is no use case for it */
>>>> +        ret = platform_get_irq(dev_to_dt(pdev), num);
>>>> +
>>>> +        if (ret < 0)
>>>> +            return NULL;
>>>> +
>>>> +        res.addr = ret;
>>>> +        res.size = 1;
>>>> +
>>>> +        return &res;
>>>> +
>>>> +    default:
>>>> +        return NULL;
>>>> +    }
>>>> +}
>>>> +
>>>> +static int platform_get_irq_byname(struct platform_device *pdev, const char *name)
>>>> +{
>>>> +    const struct dt_property *dtprop;
>>>> +    struct acpi_iort_node *iort_node;
>>>> +    struct acpi_iort_smmu_v3 *node_smmu_data;
>>>> +    int ret = 0;
>>>> +
>>>> +    if (pdev->type == DEV_ACPI) {
>>>> +        iort_node = pdev->acpi_node;
>>>> +        node_smmu_data = (struct acpi_iort_smmu_v3 *)iort_node->node_data;
>>>> +
>>>> +        if (node_smmu_data != NULL) {
>>>> +            if (!strcmp(name, "eventq"))
>>>> +                ret = node_smmu_data->event_gsiv;
>>>> +            else if (!strcmp(name, "priq"))
>>>> +                ret = node_smmu_data->pri_gsiv;
>>>> +            else if (!strcmp(name, "cmdq-sync"))
>>>> +                ret = node_smmu_data->sync_gsiv;
>>>> +            else if (!strcmp(name, "gerror"))
>>>> +                ret = node_smmu_data->gerr_gsiv;
>>>> +            else
>>>> +                ret = -EINVAL;
>>>> +        }
>>>> +    } else {
>>>> +        dtprop = dt_find_property(dev_to_dt(pdev), "interrupt-names", NULL);
>>>> +        if (!dtprop)
>>>> +            return -EINVAL;
>>>> +
>>>> +        if (!dtprop->value)
>>>> +            return -ENODATA;
>>>> +    }
>>>> +
>>>> +    return ret;
>>>> +}
>>>> +
>>>> +/*
>>>> + * Xen: Helpers for DMA allocation. Just the function name is reused for
>>>> + * porting code these allocation are not managed allocations
>>>> + */
>>>> +
>>>> +static void *dmam_alloc_coherent(struct device *dev, size_t size,
>>>> +               dma_addr_t *dma_handle, gfp_t gfp)
>>> I believe the formatting needs to be checked.
>>>> +{
>>>> +    void *vaddr;
>>>> +    unsigned long alignment = size;
>>>> +
>>>> +    /*
>>>> +     * _xzalloc requires that the (align & (align -1)) = 0. Most of the
>>>> +     * allocations in SMMU code should send the right value for size. In
>>>> +     * case this is not true print a warning and align to the size of a
>>>> +     * (void *)
>>>> +     */
>>>> +    if (size & (size - 1)) {
>>>> +        dev_warn(dev, "Fixing alignment for the DMA buffer\n");
>>>> +        alignment = sizeof(void *);
>>>> +    }
>>>> +
>>>> +    vaddr = _xzalloc(size, alignment);
>>>> +    if (!vaddr) {
>>>> +        dev_err(dev, "DMA allocation failed\n");
>>>> +        return NULL;
>>>> +    }
>>>> +
>>>> +    *dma_handle = virt_to_maddr(vaddr);
>>>> +
>>>> +    return vaddr;
>>>> +}
>>>> +
>>>> +
>>>> +static void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
>>>> +            dma_addr_t dma_handle)
>>> same
>>>> +{
>>>> +    xfree(vaddr);
>>>> +}
>>>> +
>>>> +/* Xen: Stub out DMA domain related functions */
>>>> +#define iommu_get_dma_cookie(dom) 0
>>>> +#define iommu_put_dma_cookie(dom)
>>>> +
>>>> +/* Xen: Stub out module param related function */
>>>> +#define module_param_named(a, b, c, d)
>>>> +#define MODULE_PARM_DESC(a, b)
>>>> +
>>>> +#define dma_set_mask_and_coherent(d, b) 0
>>>> +
>>>> +#define of_dma_is_coherent(n) 0
>>>> +
>>>> +#define MODULE_DEVICE_TABLE(type, name)
>>>> +
>>>> +static void __iomem *devm_ioremap_resource(struct device *dev,
>>>> +                       struct resource *res)
>>>> +{
>>>> +    void __iomem *ptr;
>>>> +
>>>> +    if (!res || res->type != IORESOURCE_MEM) {
>>>> +        dev_err(dev, "Invalid resource\n");
>>>> +        return ERR_PTR(-EINVAL);
>>>> +    }
>>>> +
>>>> +    ptr = ioremap_nocache(res->addr, res->size);
>>>> +    if (!ptr) {
>>>> +        dev_err(dev,
>>>> +            "ioremap failed (addr 0x%"PRIx64" size 0x%"PRIx64")\n",
>>>> +            res->addr, res->size);
>>>> +        return ERR_PTR(-ENOMEM);
>>>> +    }
>>>> +
>>>> +    return ptr;
>>>> +}
>>>> +
>>>> +/* Xen: Compatibility define for iommu_domain_geometry.*/
>>>> +struct iommu_domain_geometry {
>>>> +    dma_addr_t aperture_start; /* First address that can be mapped    */
>>>> +    dma_addr_t aperture_end;   /* Last address that can be mapped     */
>>>> +    bool force_aperture;       /* DMA only allowed in mappable range? */
>>>> +};
>>>> +
>>>> +
>>>> +/* Xen: Type definitions for iommu_domain */
>>>> +#define IOMMU_DOMAIN_UNMANAGED 0
>>>> +#define IOMMU_DOMAIN_DMA 1
>>>> +#define IOMMU_DOMAIN_IDENTITY 2
>>>> +
>>>> +/* Xen: Dummy iommu_domain */
>>>> +struct iommu_domain {
>>>> +    /* Runtime SMMU configuration for this iommu_domain */
>>>> +    struct arm_smmu_domain        *priv;
>>>> +    unsigned int type;
>>>> +
>>>> +    /* Dummy compatibility defines */
>>>> +    unsigned long pgsize_bitmap;
>>>> +    struct iommu_domain_geometry geometry;
>>>> +
>>>> +    atomic_t ref;
>>>> +    /*
>>>> +     * Used to link iommu_domain contexts for a same domain.
>>>> +     * There is at least one per-SMMU to used by the domain.
>>>> +     */
>>>> +    struct list_head        list;
>>>> +};
>>>> +
>>>> +/* Xen: Describes information required for a Xen domain */
>>>> +struct arm_smmu_xen_domain {
>>>> +    spinlock_t            lock;
>>>> +    /* List of iommu domains associated to this domain */
>>>> +    struct list_head        contexts;
>>>> +};
>>>> +
>>>> +/*
>>>> + * Xen: Information about each device stored in dev->archdata.iommu
>>>> + *
>>>> + * The dev->archdata.iommu stores the iommu_domain (runtime configuration of
>>>> + * the SMMU).
>>>> + */
>>>> +struct arm_smmu_xen_device {
>>>> +    struct iommu_domain *domain;
>>>> +};
>>>> +
>>> As this is a xen specific code, can the variable names be used appropriately.
>>> Repeating my comment  from earlier version.
>>> a domain is  usually a VM in Xen. So it is a bit confusing to use domain for iommu_domain.
The struct is fine but you have an issue with the var name right?

>>>> +/*
>>>> + * Xen: io_pgtable compatibility defines.
>>>> + * Most of these are to port in the S1 translation code as is.
>>>> + */
>>>> +struct io_pgtable_ops {
>>>> +};
>>>> +
>>>> +struct iommu_gather_ops {
>>>> +    void (*tlb_flush_all)(void *cookie);
>>>> +    void (*tlb_add_flush)(unsigned long iova, size_t size, size_t granule,
>>>> +                  bool leaf, void *cookie);
>>>> +    void (*tlb_sync)(void *cookie);
>>>> +};
>>>> +
>>>> +struct io_pgtable_cfg {
>>>> +    /*
>>>> +     * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE bits in
>>>> +     *    stage 1 PTEs, for hardware which insists on validating them
>>>> +     *    even in    non-secure state where they should normally be ignored.
>>>> +     *
>>>> +     * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE and
>>>> +     *    IOMMU_NOEXEC flags and map everything with full access, for
>>>> +     *    hardware which does not implement the permissions of a given
>>>> +     *    format, and/or requires some format-specific default value.
>>>> +     *
>>>> +     * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching invalid
>>>> +     *    (unmapped) entries but the hardware might do so anyway, perform
>>>> +     *    TLB maintenance when mapping as well as when unmapping.
>>>> +     *
>>>> +     * IO_PGTABLE_QUIRK_ARM_MTK_4GB: (ARM v7s format) Set bit 9 in all
>>>> +     *    PTEs, for Mediatek IOMMUs which treat it as a 33rd address bit
>>>> +     *    when the SoC is in "4GB mode" and they can only access the high
>>>> +     *    remap of DRAM (0x1_00000000 to 0x1_ffffffff).
>>>> +     *
>>>> +     * IO_PGTABLE_QUIRK_NO_DMA: Guarantees that the tables will only ever
>>>> +     *    be accessed by a fully cache-coherent IOMMU or CPU (e.g. for a
>>>> +     *    software-emulated IOMMU), such that pagetable updates need not
>>>> +     *    be treated as explicit DMA data.
>>>> +     */
>>>> +    #define IO_PGTABLE_QUIRK_ARM_NS        BIT(0)
>>>> +    #define IO_PGTABLE_QUIRK_NO_PERMS    BIT(1)
>>>> +    #define IO_PGTABLE_QUIRK_TLBI_ON_MAP    BIT(2)
>>>> +    #define IO_PGTABLE_QUIRK_ARM_MTK_4GB    BIT(3)
>>>> +    #define IO_PGTABLE_QUIRK_NO_DMA        BIT(4)
>>>> +    unsigned long            quirks;
>>>> +    unsigned long            pgsize_bitmap;
>>>> +    unsigned int            ias;
>>>> +    unsigned int            oas;
>>>> +    const struct iommu_gather_ops    *tlb;
>>>> +    struct device            *iommu_dev;
>>>> +
>>>> +    /* Low-level data specific to the table format */
>>>> +    union {
>>>> +        struct {
>>>> +            u64    ttbr[2];
>>>> +            u64    tcr;
>>>> +            u64    mair[2];
>>>> +        } arm_lpae_s1_cfg;
>>>> +
>>>> +        struct {
>>>> +            u64    vttbr;
>>>> +            u64    vtcr;
>>>> +        } arm_lpae_s2_cfg;
>>>> +
>>>> +        struct {
>>>> +            u32    ttbr[2];
>>>> +            u32    tcr;
>>>> +            u32    nmrr;
>>>> +            u32    prrr;
>>>> +        } arm_v7s_cfg;
>>>> +    };
>>>> +};
>>>> +
>>>> +enum io_pgtable_fmt {
>>>> +    ARM_32_LPAE_S1,
>>>> +    ARM_32_LPAE_S2,
>>>> +    ARM_64_LPAE_S1,
>>>> +    ARM_64_LPAE_S2,
>>>> +    ARM_V7S,
>>>> +    IO_PGTABLE_NUM_FMTS,
>>>> +};
>>>> +
>>>> +/*
>>>> + * Xen: The pgtable_ops are used by the S1 translations, so return the dummy
>>>> + * address.
>>>> + */
>>>> +#define alloc_io_pgtable_ops(f, c, o) ((struct io_pgtable_ops *)0x1)
>>>> +#define free_io_pgtable_ops(o)
>>>> +
>>>> +/* Xen: Define wrapper for requesting IRQs */
>>>> +#define IRQF_ONESHOT 0
>>>> +
>>>> +typedef void (*irq_handler_t)(int, void *, struct cpu_user_regs *);
>>>> +
>>>> +static inline int devm_request_irq(struct device *dev, unsigned int irq,
>>>> +                   irq_handler_t handler, unsigned long irqflags,
>>>> +                   const char *devname, void *dev_id)
>>>> +{
>>>> +    /*
>>>> +     * SMMUv3 implementation can support wired interrupt outputs that are
>>>> +     * edge-triggered. Set the irq type as per the spec.
>>>> +     */
>>>> +    irq_set_type(irq, IRQ_TYPE_EDGE_BOTH);
>>>> +    return request_irq(irq, irqflags, handler, devname, dev_id);
>>>> +}
>>>> +
>>>> +/*
>>>> + * Xen does not have a concept of threaded irq, but we can use tasklets to
>>>> + * achieve the desired functionality as needed.
>>>> + */
>>>> +int devm_request_threaded_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
>>>> +                  irq_handler_t thread_fn, unsigned long irqflags,
>>>> +                  const char *devname, void *dev_id)
>>>> +{
>>>> +    return devm_request_irq(dev, irq, thread_fn, irqflags, devname, dev_id);
>>>> +}
>>>> +
>>>> +/* Xen: The mutex is used only during initialization so the typecast is safe */
>>>> +#define mutex spinlock
>>>> +#define mutex_init spin_lock_init
>>>> +#define mutex_lock spin_lock
>>>> +#define mutex_unlock spin_unlock
>>>> +
>>>> +#define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us) \
>>>> +({ \
>>>> +    s_time_t deadline = NOW() + MICROSECS(timeout_us); \
>>>> +    for (;;) { \
>>>> +        (val) = op(addr); \
>>>> +        if (cond) \
>>>> +            break; \
>>>> +        if (NOW() > deadline) { \
>>>> +            (val) = op(addr); \
>>>> +            break; \
>>>> +        } \
>>>> +    udelay(sleep_us); \
>>>> +    } \
>>>> +    (cond) ? 0 : -ETIMEDOUT; \
>>>> +})
>>>> +
>>>> +#define readl_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
>>>> +    readx_poll_timeout(readl_relaxed, addr, val, cond, delay_us, timeout_us)
>>>> +
>>>> +#define VA_BITS 0 /* Only needed for S1 translations */
>>>>     /* MMIO registers */
>>>>   #define ARM_SMMU_IDR0            0x0
>>>> @@ -433,6 +819,7 @@ enum pri_resp {
>>>>       PRI_RESP_SUCC,
>>>>   };
>>>>   +#if 0 /* Xen: No MSI support in this iteration */
>>>>   enum arm_smmu_msi_index {
>>>>       EVTQ_MSI_INDEX,
>>>>       GERROR_MSI_INDEX,
>>>> @@ -457,6 +844,7 @@ static phys_addr_t arm_smmu_msi_cfg[ARM_SMMU_MAX_MSIS][3] = {
>>>>           ARM_SMMU_PRIQ_IRQ_CFG2,
>>>>       },
>>>>   };
>>>> +#endif
>>>>     struct arm_smmu_cmdq_ent {
>>>>       /* Common fields */
>>>> @@ -561,6 +949,8 @@ struct arm_smmu_s2_cfg {
>>>>       u16                vmid;
>>>>       u64                vttbr;
>>>>       u64                vtcr;
>>>> +    /* Xen: Domain associated to this configuration */
>>>> +    struct domain            *domain;
>>>>   };
>>>>     struct arm_smmu_strtab_ent {
>>>> @@ -635,9 +1025,25 @@ struct arm_smmu_device {
>>>>       struct arm_smmu_strtab_cfg    strtab_cfg;
>>>>         /* IOMMU core code handle */
>>>> +#if 0 /*Xen: Generic iommu_device ref not needed here */
>>>>       struct iommu_device        iommu;
>>>> +#endif
>>> Is it clean to put #if 0, can this line be deleted or used with a proper macro
Manish this is a var name from original struct from Linux. I have just followed the prior standard of adding #if 0.
>>>> +    /* Xen: Need to keep a list of SMMU devices */
>>>> +    struct list_head                devices;
>>>> +    /* Xen: Tasklets for handling evts/faults and pci page request IRQs*/
>>>> +    struct tasklet            evtq_tasklet;
>>>> +    struct tasklet            priq_tasklet;
>>>> +    struct tasklet            combined_irq_tasklet;
>>>>   };
>>>>   +/* Xen: Keep a list of devices associated with this driver */
>>>> +static DEFINE_SPINLOCK(arm_smmu_devices_lock);
>>>> +static LIST_HEAD(arm_smmu_devices);
>>>> +/* Xen: Helper for finding a device using fwnode */
>>>> +static
>>>> +struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode);
>>>> +
>>>> +
>>>>   /* SMMU private data for each master */
>>>>   struct arm_smmu_master_data {
>>>>       struct arm_smmu_device        *smmu;
>>>> @@ -1232,7 +1638,7 @@ static void arm_smmu_handle_ppr(struct arm_smmu_device *smmu, u64 *evt)
>>>>         dev_info(smmu->dev, "unexpected PRI request received:\n");
>>>>       dev_info(smmu->dev,
>>>> -         "\tsid 0x%08x.0x%05x: [%u%s] %sprivileged %s%s%s access at iova 0x%016llx\n",
>>>> +         "\tsid 0x%08x.0x%05x: [%u%s] %sprivileged %s%s%s access at iova %#" PRIx64 "\n",
>>>>            sid, ssid, grpid, last ? "L" : "",
>>>>            evt[0] & PRIQ_0_PERM_PRIV ? "" : "un",
>>>>            evt[0] & PRIQ_0_PERM_READ ? "R" : "",
>>>> @@ -1342,10 +1748,20 @@ static irqreturn_t arm_smmu_combined_irq_thread(int irq, void *dev)
>>>>       return IRQ_HANDLED;
>>>>   }
>>>>   +/* Xen: Forward define for combined_irq tasklet */
>>>> +static void arm_smmu_combined_irq_tasklet(unsigned long dev);
>>>> +
>>>>   static irqreturn_t arm_smmu_combined_irq_handler(int irq, void *dev)
>>>>   {
>>>> +    /* Xen: Need an smmu reference to schedule the tasklet */
>>>> +    struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
>>>> +
>>>>       arm_smmu_gerror_handler(irq, dev);
>>>>       arm_smmu_cmdq_sync_handler(irq, dev);
>>>> +
>>>> +    /*Xen: No threaded irq. So, schedule the right tasklet*/
>>>> +    tasklet_schedule(&(smmu->combined_irq_tasklet));
>>>> +
>>>>       return IRQ_WAKE_THREAD;
>>>>   }
>>>>   @@ -1358,6 +1774,69 @@ static void __arm_smmu_tlb_sync(struct arm_smmu_device *smmu)
>>>>       arm_smmu_cmdq_issue_cmd(smmu, &cmd);
>>>>   }
>>>>   +/*
>>>> + * Xen: Define the IRQ handlers and tasklets for xen. The linux functions
>>>> + * would be modified to use the functions defined in the following code.
>>>> + */
>>>> +
>>>> +static void arm_smmu_evtq_tasklet(unsigned long dev)
>>>> +{
>>>> +    /* The IRQ number is not relevent for the evtq thread processing */
>>>> +    arm_smmu_evtq_thread(0, (void *)dev);
>>>> +}
>>>> +
>>>> +static void arm_smmu_priq_tasklet(unsigned long dev)
>>>> +{
>>>> +    /* The IRQ number is not relevent for the priq thread processing */
>>>> +    arm_smmu_priq_thread(0, (void *)dev);
>>>> +}
>>>> +
>>>> +static void arm_smmu_combined_irq_tasklet(unsigned long dev)
>>>> +{
>>>> +    /* The IRQ number is not relevent for the combined irq handler.*/
>>>> +    arm_smmu_combined_irq_thread(0, (void *)dev);
>>>> +}
>>>> +
>>>> +static void arm_smmu_evtq_thread_xen(int irq, void *dev,
>>>> +                       struct cpu_user_regs *regs)
>>>> +{
>>>> +    struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
>>>> +
>>>> +    tasklet_schedule(&(smmu->evtq_tasklet));
>>>> +}
>>>> +
>>>> +static void arm_smmu_priq_thread_xen(int irq, void *dev,
>>>> +                       struct cpu_user_regs *regs)
>>>> +{
>>>> +    struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
>>>> +
>>>> +    tasklet_schedule(&(smmu->priq_tasklet));
>>>> +}
>>>> +
>>>> +static void arm_smmu_cmdq_sync_handler_xen(int irq, void *dev,
>>>> +                       struct cpu_user_regs *regs)
>>>> +{
>>>> +    arm_smmu_cmdq_sync_handler(irq, dev);
>>>> +}
>>>> +
>>>> +static void arm_smmu_gerror_handler_xen(int irq, void *dev,
>>>> +                       struct cpu_user_regs *regs)
>>>> +{
>>>> +    arm_smmu_gerror_handler(irq, dev);
>>>> +}
>>>> +
>>>> +static void arm_smmu_combined_irq_handler_xen(int irq, void *dev,
>>>> +                       struct cpu_user_regs *regs)
>>>> +{
>>>> +    arm_smmu_combined_irq_handler(irq, dev);
>>>> +}
>>>> +
>>>> +#define arm_smmu_evtq_thread arm_smmu_evtq_thread_xen
>>>> +#define arm_smmu_priq_thread arm_smmu_priq_thread_xen
>>>> +#define arm_smmu_cmdq_sync_handler arm_smmu_cmdq_sync_handler_xen
>>>> +#define arm_smmu_gerror_handler arm_smmu_gerror_handler_xen
>>>> +#define arm_smmu_combined_irq_handler arm_smmu_combined_irq_handler_xen
>>>> +
>>>>   static void arm_smmu_tlb_sync(void *cookie)
>>>>   {
>>>>       struct arm_smmu_domain *smmu_domain = cookie;
>>>> @@ -1415,6 +1894,7 @@ static const struct iommu_gather_ops arm_smmu_gather_ops = {
>>>>       .tlb_sync    = arm_smmu_tlb_sync,
>>>>   };
>>>>   +#if 0 /*Xen: Unused functionality */
>>>>   /* IOMMU API */
>>>>   static bool arm_smmu_capable(enum iommu_cap cap)
>>>>   {
>>>> @@ -1427,6 +1907,7 @@ static bool arm_smmu_capable(enum iommu_cap cap)
>>>>           return false;
>>>>       }
>>>>   }
>>>> +#endif
>>>>     static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
>>>>   {
>>>> @@ -1546,9 +2027,16 @@ static int arm_smmu_domain_finalise_s2(struct arm_smmu_domain *smmu_domain,
>>>>       if (vmid < 0)
>>>>           return vmid;
>>>>   -    cfg->vmid    = (u16)vmid;
>>>> -    cfg->vttbr    = pgtbl_cfg->arm_lpae_s2_cfg.vttbr;
>>>> -    cfg->vtcr    = pgtbl_cfg->arm_lpae_s2_cfg.vtcr;
>>>> +    /*
>>>> +     * Xen: Get the ttbr and vtcr values
>>>> +     * vttbr: This is a shared value with the domain page table
>>>> +     * vtcr: The TCR settings are the same as CPU since the page
>>>> +     * tables are shared
>>>> +     */
>>>> +
>>>> +    cfg->vmid    = vmid;
>>>> +    cfg->vttbr    = page_to_maddr(cfg->domain->arch.p2m.root);
>>>> +    cfg->vtcr    = READ_SYSREG32(VTCR_EL2) & STRTAB_STE_2_VTCR_MASK;
>>>>       return 0;
>>>>   }
>>>>   @@ -1604,6 +2092,7 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain)
>>>>       if (smmu->features & ARM_SMMU_FEAT_COHERENCY)
>>>>           pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_NO_DMA;
>>>>   +    /* Xen: pgtbl_ops gets an invalid address */
>>>>       pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);
>>>>       if (!pgtbl_ops)
>>>>           return -ENOMEM;
>>>> @@ -1721,6 +2210,7 @@ out_unlock:
>>>>       return ret;
>>>>   }
>>>>   +#if 0 /* Xen: Unused functionality */
>>> same
Same as above.
>>>>   static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
>>>>               phys_addr_t paddr, size_t size, int prot)
>>>>   {
>>>> @@ -1772,6 +2262,7 @@ struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
>>>>       put_device(dev);
>>>>       return dev ? dev_get_drvdata(dev) : NULL;
>>>>   }
>>>> +#endif
>>>>     static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, u32 sid)
>>>>   {
>>>> @@ -1783,7 +2274,14 @@ static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, u32 sid)
>>>>       return sid < limit;
>>>>   }
>>>>   +/* Xen: Unused */
>>>> +#if 0
>>>>   static struct iommu_ops arm_smmu_ops;
>>>> +#endif
>>>> +
>>>> +/* Xen: Redefine arm_smmu_ops to what fwspec should evaluate */
>>>> +static const struct iommu_ops arm_smmu_iommu_ops;
>>>> +#define arm_smmu_ops arm_smmu_iommu_ops
>>>>     static int arm_smmu_add_device(struct device *dev)
>>>>   {
>>>> @@ -1791,8 +2289,11 @@ static int arm_smmu_add_device(struct device *dev)
>>>>       struct arm_smmu_device *smmu;
>>>>       struct arm_smmu_master_data *master;
>>>>       struct iommu_fwspec *fwspec = dev->iommu_fwspec;
>>>> +#if 0 /*Xen: iommu_group is not needed */
>>>>       struct iommu_group *group;
>>>> +#endif
>>>>   +    /* Xen: fwspec->ops are not needed */
>>>>       if (!fwspec || fwspec->ops != &arm_smmu_ops)
>>>>           return -ENODEV;
>>>>       /*
>>>> @@ -1830,6 +2331,11 @@ static int arm_smmu_add_device(struct device *dev)
>>>>           }
>>>>       }
>>>>   +/*
>>>> + * Xen: Do not need an iommu group as the stream data is carried by the SMMU
>>>> + * master device object
>>>> + */
>>>> +#if 0
>>>>       group = iommu_group_get_for_dev(dev);
>>>>       if (!IS_ERR(group)) {
>>>>           iommu_group_put(group);
>>>> @@ -1837,8 +2343,16 @@ static int arm_smmu_add_device(struct device *dev)
>>>>       }
>>>>         return PTR_ERR_OR_ZERO(group);
>>>> +#endif
>>>> +    return 0;
>>>>   }
>>>>   +/*
>>>> + * Xen: We can potentially support this function and destroy a device. This
>>>> + * will be relevant for PCI hotplug. So, will be implemented as needed after
>>>> + * passthrough support is available.
>>>> + */
>>>> +#if 0
>>>>   static void arm_smmu_remove_device(struct device *dev)
>>>>   {
>>>>       struct iommu_fwspec *fwspec = dev->iommu_fwspec;
>>>> @@ -1974,6 +2488,7 @@ static struct iommu_ops arm_smmu_ops = {
>>>>       .put_resv_regions    = arm_smmu_put_resv_regions,
>>>>       .pgsize_bitmap        = -1UL, /* Restricted during device attach */
>>>>   };
>>>> +#endif
>>>>     /* Probing and initialisation functions */
>>>>   static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
>>>> @@ -2182,6 +2697,7 @@ static int arm_smmu_update_gbpa(struct arm_smmu_device *smmu, u32 set, u32 clr)
>>>>                         1, ARM_SMMU_POLL_TIMEOUT_US);
>>>>   }
>>>>   +#if 0 /* Xen: There is no MSI support as yet */
>>>>   static void arm_smmu_free_msis(void *data)
>>>>   {
>>>>       struct device *dev = data;
>>>> @@ -2247,12 +2763,15 @@ static void arm_smmu_setup_msis(struct arm_smmu_device *smmu)
>>>>       /* Add callback to free MSIs on teardown */
>>>>       devm_add_action(dev, arm_smmu_free_msis, dev);
>>>>   }
>>>> +#endif
>>>>     static void arm_smmu_setup_unique_irqs(struct arm_smmu_device *smmu)
>>>>   {
>>>>       int irq, ret;
>>>>   +#if 0 /*Xen: Cannot setup msis for now */
>>>>       arm_smmu_setup_msis(smmu);
>>>> +#endif
>>>>         /* Request interrupt lines */
>>>>       irq = smmu->evtq.q.irq;
>>>> @@ -2316,9 +2835,13 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
>>>>            * Cavium ThunderX2 implementation doesn't not support unique
>>>>            * irq lines. Use single irq line for all the SMMUv3 interrupts.
>>>>            */
>>>> -        ret = devm_request_threaded_irq(smmu->dev, irq,
>>>> +        /*
>>>> +         * Xen: Does not support threaded irqs, so serialise the setup.
>>>> +         * This is the same for pris and event interrupt lines on other
>>>> +         * systems
>>>> +         */
>>>> +        ret = devm_request_irq(smmu->dev, irq,
>>>>                       arm_smmu_combined_irq_handler,
>>>> -                    arm_smmu_combined_irq_thread,
>>>>                       IRQF_ONESHOT,
>>>>                       "arm-smmu-v3-combined-irq", smmu);
>>>>           if (ret < 0)
>>>> @@ -2452,6 +2975,13 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
>>>>           return ret;
>>>>       }
>>>>   +    /* Xen: Initialize tasklets */
>>>> +    tasklet_init(&smmu->evtq_tasklet, arm_smmu_evtq_tasklet,
>>>> +            (unsigned long)smmu);
>>>> +    tasklet_init(&smmu->priq_tasklet, arm_smmu_priq_tasklet,
>>>> +            (unsigned long)smmu);
>>>> +    tasklet_init(&smmu->combined_irq_tasklet, arm_smmu_combined_irq_tasklet,
>>>> +            (unsigned long)smmu);
>>>>         /* Enable the SMMU interface, or ensure bypass */
>>>>       if (!bypass || disable_bypass) {
>>>> @@ -2542,8 +3072,14 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu)
>>>>           smmu->features |= ARM_SMMU_FEAT_STALLS;
>>>>       }
>>>>   +/*
>>>> + * Xen: Block stage 1 translations. By doing this here we do not need to set the
>>>> + * domain->stage explicitly.
>>>> + */
>>>> +#if 0
>>>>       if (reg & IDR0_S1P)
>>>>           smmu->features |= ARM_SMMU_FEAT_TRANS_S1;
>>>> +#endif
>>>>         if (reg & IDR0_S2P)
>>>>           smmu->features |= ARM_SMMU_FEAT_TRANS_S2;
>>>> @@ -2616,10 +3152,12 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu)
>>>>       if (reg & IDR5_GRAN4K)
>>>>           smmu->pgsize_bitmap |= SZ_4K | SZ_2M | SZ_1G;
>>>>   +#if 0 /* Xen: SMMU ops do not have a pgsize_bitmap member for Xen */
>>>>       if (arm_smmu_ops.pgsize_bitmap == -1UL)
>>>>           arm_smmu_ops.pgsize_bitmap = smmu->pgsize_bitmap;
>>>>       else
>>>>           arm_smmu_ops.pgsize_bitmap |= smmu->pgsize_bitmap;
>>>> +#endif
>>>>         /* Output address size */
>>>>       switch (reg & IDR5_OAS_MASK << IDR5_OAS_SHIFT) {
>>>> @@ -2680,7 +3218,8 @@ static int arm_smmu_device_acpi_probe(struct platform_device *pdev,
>>>>       struct device *dev = smmu->dev;
>>>>       struct acpi_iort_node *node;
>>>>   -    node = *(struct acpi_iort_node **)dev_get_platdata(dev);
>>>> +    /* Xen: Modification to get iort_node */
>>>> +    node = (struct acpi_iort_node *)dev->acpi_node;
>>>>         /* Retrieve SMMUv3 specific data */
>>>>       iort_smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
>>>> @@ -2703,7 +3242,7 @@ static inline int arm_smmu_device_acpi_probe(struct platform_device *pdev,
>>>>   static int arm_smmu_device_dt_probe(struct platform_device *pdev,
>>>>                       struct arm_smmu_device *smmu)
>>>>   {
>>>> -    struct device *dev = &pdev->dev;
>>>> +    struct device *dev = pdev;
>>>>       u32 cells;
>>>>       int ret = -EINVAL;
>>>>   @@ -2716,6 +3255,7 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev,
>>>>         parse_driver_options(smmu);
>>>>   +    /* Xen: of_dma_is_coherent is a stub till dt support is introduced */
>>>>       if (of_dma_is_coherent(dev->of_node))
>>>>           smmu->features |= ARM_SMMU_FEAT_COHERENCY;
>>>>   @@ -2734,9 +3274,11 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>>>>   {
>>>>       int irq, ret;
>>>>       struct resource *res;
>>>> +#if 0 /*Xen: Do not need to setup sysfs */
>>>>       resource_size_t ioaddr;
>>>> +#endif
>>>>       struct arm_smmu_device *smmu;
>>>> -    struct device *dev = &pdev->dev;
>>>> +    struct device *dev = pdev;/* Xen: dev is ignored */
>>>>       bool bypass;
>>>>         smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
>>>> @@ -2763,7 +3305,9 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>>>>           dev_err(dev, "MMIO region too small (%pr)\n", res);
>>>>           return -EINVAL;
>>>>       }
>>>> +#if 0 /*Xen: Do not need to setup sysfs */
>>>>       ioaddr = res->start;
>>>> +#endif
>>>>         smmu->base = devm_ioremap_resource(dev, res);
>>>>       if (IS_ERR(smmu->base))
>>>> @@ -2802,13 +3346,18 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>>>>           return ret;
>>>>         /* Record our private device structure */
>>>> +    /* Xen: SMMU is not treated a a platform device*/
>>>> +#if 0
>>>>       platform_set_drvdata(pdev, smmu);
>>>> +#endif
>>>>         /* Reset the device */
>>>>       ret = arm_smmu_device_reset(smmu, bypass);
>>>>       if (ret)
>>>>           return ret;
>>>>   +/* Xen: Not creating an IOMMU device list for Xen */
>>>> +#if 0
>>>>       /* And we're up. Go go go! */
>>>>       ret = iommu_device_sysfs_add(&smmu->iommu, dev, NULL,
>>>>                        "smmu3.%pa", &ioaddr);
>>>> @@ -2844,9 +3393,20 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>>>>           if (ret)
>>>>               return ret;
>>>>       }
>>>> +#endif
>>>> +    /*
>>>> +     * Xen: Keep a list of all probed devices. This will be used to query
>>>> +     * the smmu devices based on the fwnode.
>>>> +     */
>>>> +    INIT_LIST_HEAD(&smmu->devices);
>>>> +    spin_lock(&arm_smmu_devices_lock);
>>>> +    list_add(&smmu->devices, &arm_smmu_devices);
>>>> +    spin_unlock(&arm_smmu_devices_lock);
>>>>       return 0;
>>>>   }
>>>>   +/* Xen: Unused function */
>>>> +#if 0
>>>>   static int arm_smmu_device_remove(struct platform_device *pdev)
>>>>   {
>>>>       struct arm_smmu_device *smmu = platform_get_drvdata(pdev);
>>>> @@ -2860,6 +3420,8 @@ static void arm_smmu_device_shutdown(struct platform_device *pdev)
>>>>   {
>>>>       arm_smmu_device_remove(pdev);
>>>>   }
>>>> +#endif
>>>> +
>>>>     static const struct of_device_id arm_smmu_of_match[] = {
>>>>       { .compatible = "arm,smmu-v3", },
>>>> @@ -2867,6 +3429,7 @@ static const struct of_device_id arm_smmu_of_match[] = {
>>>>   };
>>>>   MODULE_DEVICE_TABLE(of, arm_smmu_of_match);
>>>>   +#if 0
>>>>   static struct platform_driver arm_smmu_driver = {
>>>>       .driver    = {
>>>>           .name        = "arm-smmu-v3",
>>>> @@ -2883,3 +3446,316 @@ IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", NULL);
>>>>   MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 implementations");
>>>>   MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
>>>>   MODULE_LICENSE("GPL v2");
>>>> +#endif
>>>> +
>>>> +/***** Start of Xen specific code *****/
>>>> +
>>>> +static int __must_check arm_smmu_iotlb_flush_all(struct domain *d)
>>>> +{
>>>> +    struct arm_smmu_xen_domain *smmu_domain = dom_iommu(d)->arch.priv;
>>>> +    struct iommu_domain *cfg;
>>>> +
>>>> +    spin_lock(&smmu_domain->lock);
>>>> +    list_for_each_entry(cfg, &smmu_domain->contexts, list) {
>>>> +        /*
>>>> +         * Only invalidate the context when SMMU is present.
>>>> +         * This is because the context initialization is delayed
>>>> +         * until a master has been added.
>>>> +         */
>>>> +        if (unlikely(!ACCESS_ONCE(cfg->priv->smmu)))
>>>> +            continue;
>>>> +        arm_smmu_tlb_inv_context(cfg->priv);
>>>> +    }
>>>> +    spin_unlock(&smmu_domain->lock);
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +static int __must_check arm_smmu_iotlb_flush(struct domain *d,
>>>> +                         unsigned long gfn,
>>>> +                         unsigned int page_count)
>>>> +{
>>>> +    return arm_smmu_iotlb_flush_all(d);
>>>> +}
>>>> +
>>>> +static struct iommu_domain *arm_smmu_get_domain(struct domain *d,
>>>> +                        struct device *dev)
>>> This is returning iommu_domain and not a domain.
>>> Please change the name of function.
Same as smmu-v2.c. I think with the complexity of the code we should try to get this in as the prior code. Once the set that has been pending for some time is in. We can start on the variable cleanup activity. I say this so that we can make the names consistent across the drivers and this will be a lot easier to do when the majority of the other code is in.
>>>> +{
>>>> +    struct iommu_domain *domain;
>>>> +    struct arm_smmu_xen_domain *xen_domain;
>>> A suggestion
>>> 1. as you have used in above function smmu_domain variable for arm_smmu_xen_domain
>>> Can similar logic be used for iommu_domain.
I am fine changing the var name.
>>>
>>> 2. When smmu_domain variable name is used in above function why xen_domain is used in this function.
>>> It is quite confusing.
>>> logically xen_domain should mean a VM.
You lost me man. xen_domain is referring to the page tables of the the VM currently using the SMMU. What is the concern?
>>>> +    struct arm_smmu_device *smmu;
>>>> +    struct arm_smmu_domain *smmu_domain;
>>> smmu_domain was used for arm_smmu_xen_domain.
Failed to see it. But, I'll have another look.

>>>
>>> consistency of variable names is necessary for code clarity
>>>> +
>>>> +    xen_domain = dom_iommu(d)->arch.priv;
>>>> +
>>>> +    smmu = arm_smmu_get_by_fwnode(dev->iommu_fwspec->iommu_fwnode);
>>>> +    if (!smmu)
>>>> +        return NULL;
>>>> +
>>>> +    /*
>>>> +     * Loop through the &xen_domain->contexts to locate a context
>>>> +     * assigned to this SMMU
>>>> +     */
>>>> +    list_for_each_entry(domain, &xen_domain->contexts, list) {
>>>> +        smmu_domain = to_smmu_domain(domain);
>>>> +        if (smmu_domain->smmu == smmu)
>>>> +            return domain;
>>>> +    }
>>>> +
>>>> +    return NULL;
>>>> +}
>>>> +
>>>> +static void arm_smmu_destroy_iommu_domain(struct iommu_domain *domain)
>>> same
Ok
>>>> +{
>>>> +    list_del(&domain->list);
>>>> +    arm_smmu_domain_free(domain);
>>>> +}
>>>> +
>>>> +static int arm_smmu_assign_dev(struct domain *d, u8 devfn,
>>>> +                   struct device *dev, u32 flag)
>>>> +{
>>>> +    int ret = 0;
>>>> +    struct iommu_domain *domain;
>>>> +    struct arm_smmu_xen_domain *xen_domain;
>>> same
xen_domain is fine. You have an issue with the iommu_domioan here?
>>>> +    struct arm_smmu_domain *arm_smmu;
>>>> +
>>>> +    xen_domain = dom_iommu(d)->arch.priv;
>>>> +
>>>> +    if (!dev->archdata.iommu) {
>>>> +        dev->archdata.iommu = xzalloc(struct arm_smmu_xen_device);
>>>> +        if (!dev->archdata.iommu)
>>>> +            return -ENOMEM;
>>>> +    }
>>>> +
>>>> +    ret = arm_smmu_add_device(dev);
>>>> +    if (ret)
>>>> +        return ret;
>>>> +
>>>> +    spin_lock(&xen_domain->lock);
>>>> +
>>>> +    /*
>>>> +     * Check to see if an iommu_domain already exists for this xen domain
>>>> +     * under the same SMMU
>>>> +     */
>>>> +    domain = arm_smmu_get_domain(d, dev);
>>>> +    if (!domain) {
>>>> +
>>>> +        domain = arm_smmu_domain_alloc(IOMMU_DOMAIN_DMA);
>>>> +        if (!domain) {
>>>> +            ret = -ENOMEM;
>>>> +            goto out;
>>>> +        }
>>>> +
>>>> +        arm_smmu = to_smmu_domain(domain);
>>>> +        arm_smmu->s2_cfg.domain = d;
>>>> +
>>>> +        /* Chain the new context to the domain */
>>>> +        list_add(&domain->list, &xen_domain->contexts);
>>>> +
>>>> +    }
>>>> +
>>>> +    ret = arm_smmu_attach_dev(domain, dev);
>>>> +    if (ret) {
>>>> +        if (domain->ref.counter == 0)
>>>> +            arm_smmu_destroy_iommu_domain(domain);
>>>> +    } else {
>>>> +        atomic_inc(&domain->ref);
>>>> +    }
>>>> +
>>>> +out:
>>>> +    spin_unlock(&xen_domain->lock);
>>>> +    return ret;
>>>> +}
>>>> +
>>>> +static int arm_smmu_deassign_dev(struct domain *d, struct device *dev)
>>>> +{
>>>> +    struct iommu_domain *domain = arm_smmu_get_domain(d, dev);
>>>> +    struct arm_smmu_xen_domain *xen_domain;
>>>> +    struct arm_smmu_domain *arm_smmu = to_smmu_domain(domain);
>>> same
>>>> +
>>>> +    xen_domain = dom_iommu(d)->arch.priv;
>>>> +
>>>> +    if (!arm_smmu || arm_smmu->s2_cfg.domain != d) {
>>>> +        dev_err(dev, " not attached to domain %d\n", d->domain_id);
>>>> +        return -ESRCH;
>>>> +    }
>>>> +
>>>> +    spin_lock(&xen_domain->lock);
>>>> +
>>>> +    arm_smmu_detach_dev(dev);
>>>> +    atomic_dec(&domain->ref);
>>>> +
>>>> +    if (domain->ref.counter == 0)
>>>> +        arm_smmu_destroy_iommu_domain(domain);
>>>> +
>>>> +    spin_unlock(&xen_domain->lock);
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +static int arm_smmu_reassign_dev(struct domain *s, struct domain *t,
>>>> +                 u8 devfn,  struct device *dev)
>>>> +{
>>>> +    int ret = 0;
>>>> +
>>>> +    /* Don't allow remapping on other domain than hwdom */
>>>> +    if (t && t != hardware_domain)
>>>> +        return -EPERM;
>>>> +
>>>> +    if (t == s)
>>>> +        return 0;
>>>> +
>>>> +    ret = arm_smmu_deassign_dev(s, dev);
>>>> +    if (ret)
>>>> +        return ret;
>>>> +
>>>> +    if (t) {
>>>> +        /* No flags are defined for ARM. */
>>>> +        ret = arm_smmu_assign_dev(t, devfn, dev, 0);
>>>> +        if (ret)
>>>> +            return ret;
>>>> +    }
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +static int arm_smmu_iommu_domain_init(struct domain *d)
>>> Where is iommu_domain initialized?
>>> The function does not use a iommu_domain * variable
>>>> +{
>>>> +    struct arm_smmu_xen_domain *xen_domain;
>>>> +
>>>> +    xen_domain = xzalloc(struct arm_smmu_xen_domain);
>>>> +    if (!xen_domain)
>>>> +        return -ENOMEM;
>>>> +
>>>> +    spin_lock_init(&xen_domain->lock);
>>>> +    INIT_LIST_HEAD(&xen_domain->contexts);
>>>> +
>>>> +    dom_iommu(d)->arch.priv = xen_domain;
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +static void __hwdom_init arm_smmu_iommu_hwdom_init(struct domain *d)
>>>> +{
>>>> +}
>>>> +
>>>> +static void arm_smmu_iommu_domain_teardown(struct domain *d)
>>>> +{
>>>> +    struct arm_smmu_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
>>>> +
>>>> +    ASSERT(list_empty(&xen_domain->contexts));
>>>> +    xfree(xen_domain);
>>>> +}
>>>> +
>>>> +static int __must_check arm_smmu_map_page(struct domain *d, unsigned long gfn,
>>>> +            unsigned long mfn, unsigned int flags)
>>>> +{
>>>> +    p2m_type_t t;
>>>> +
>>>> +    /*
>>>> +     * Grant mappings can be used for DMA requests. The dev_bus_addr
>>>> +     * returned by the hypercall is the MFN (not the IPA). For device
>>>> +     * protected by an IOMMU, Xen needs to add a 1:1 mapping in the domain
>>>> +     * p2m to allow DMA request to work.
>>>> +     * This is only valid when the domain is directed mapped. Hence this
>>>> +     * function should only be used by gnttab code with gfn == mfn.
>>>> +     */
>>>> +    BUG_ON(!is_domain_direct_mapped(d));
>>>> +    BUG_ON(mfn != gfn);
>>>> +
>>>> +    /* We only support readable and writable flags */
>>>> +    if (!(flags & (IOMMUF_readable | IOMMUF_writable)))
>>>> +        return -EINVAL;
>>>> +
>>>> +    t = (flags & IOMMUF_writable) ? p2m_iommu_map_rw : p2m_iommu_map_ro;
>>>> +
>>>> +    /*
>>>> +     * The function guest_physmap_add_entry replaces the current mapping
>>>> +     * if there is already one...
>>>> +     */
>>>> +    return guest_physmap_add_entry(d, _gfn(gfn), _mfn(mfn), 0, t);
>>>> +}
>>>> +
>>>> +static int __must_check arm_smmu_unmap_page(struct domain *d, unsigned long gfn)
>>>> +{
>>>> +    /*
>>>> +     * This function should only be used by gnttab code when the domain
>>>> +     * is direct mapped
>>>> +     */
>>>> +    if (!is_domain_direct_mapped(d))
>>>> +        return -EINVAL;
>>>> +
>>>> +    return guest_physmap_remove_page(d, _gfn(gfn), _mfn(gfn), 0);
>>>> +}
>>>> +
>>>> +static const struct iommu_ops arm_smmu_iommu_ops = {
>>>> +    .init = arm_smmu_iommu_domain_init,
>>>> +    .hwdom_init = arm_smmu_iommu_hwdom_init,
>>>> +    .teardown = arm_smmu_iommu_domain_teardown,
>>>> +    .iotlb_flush = arm_smmu_iotlb_flush,
>>>> +    .iotlb_flush_all = arm_smmu_iotlb_flush_all,
>>>> +    .assign_device = arm_smmu_assign_dev,
>>>> +    .reassign_device = arm_smmu_reassign_dev,
>>>> +    .map_page = arm_smmu_map_page,
>>>> +    .unmap_page = arm_smmu_unmap_page,
>>>> +};
>>>> +
>>>> +static
>>>> +struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
>>>> +{
>>>> +    struct arm_smmu_device *smmu = NULL;
>>>> +
>>>> +    spin_lock(&arm_smmu_devices_lock);
>>>> +    list_for_each_entry(smmu, &arm_smmu_devices, devices) {
>>>> +        if (smmu->dev->fwnode == fwnode)
>>>> +            break;
>>>> +    }
>>>> +    spin_unlock(&arm_smmu_devices_lock);
>>>> +
>>>> +    return smmu;
>>>> +}
>>>> +
>>>> +static __init int arm_smmu_dt_init(struct dt_device_node *dev,
>>>> +                   const void *data)
>>>> +{
>>>> +    int rc;
>>>> +
>>>> +    /*
>>>> +     * Even if the device can't be initialized, we don't want to
>>>> +     * give the SMMU device to dom0.
>>>> +     */
>>>> +    dt_device_set_used_by(dev, DOMID_XEN);
>>>> +
>>>> +    rc = arm_smmu_device_probe(dt_to_dev(dev));
>>>> +    if (rc)
>>>> +        return rc;
>>>> +
>>>> +    iommu_set_ops(&arm_smmu_iommu_ops);
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +DT_DEVICE_START(smmuv3, "ARM SMMU V3", DEVICE_IOMMU)
>>>> +    .dt_match = arm_smmu_of_match,
>>>> +    .init = arm_smmu_dt_init,
>>>> +DT_DEVICE_END
>>>> +
>>>> +#ifdef CONFIG_ACPI
>>>> +/* Set up the IOMMU */
>>>> +static int __init arm_smmu_acpi_init(const void *data)
>>>> +{
>>>> +    int rc;
>>>> +
>>>> +    rc = arm_smmu_device_probe((struct device *)data);
>>>> +    if (rc)
>>>> +        return rc;
>>>> +
>>>> +    iommu_set_ops(&arm_smmu_iommu_ops);
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +ACPI_DEVICE_START(asmmuv3, "ARM SMMU V3", DEVICE_IOMMU)
>>>> +    .class_type = ACPI_IORT_NODE_SMMU_V3,
>>>> +    .init = arm_smmu_acpi_init,
>>>> +ACPI_DEVICE_END
>>>> +
>>>> +#endif
>>>> diff --git a/xen/include/xen/linux_compat.h b/xen/include/xen/linux_compat.h
>>>> new file mode 100644
>>>> index 0000000000..8037be0a3e
>>>> --- /dev/null
>>>> +++ b/xen/include/xen/linux_compat.h
>>>> @@ -0,0 +1,84 @@
>>>> +/******************************************************************************
>>>> + * include/xen/linux_compat.h
>>>> + *
>>>> + * Compatibility defines for porting code from Linux to Xen
>>>> + *
>>>> + * Copyright (c) 2017 Linaro Limited
>>>> + *
>>>> + * This program is free software; you can redistribute it and/or modify
>>>> + * it under the terms of the GNU General Public License as published by
>>>> + * the Free Software Foundation; either version 2 of the License, or
>>>> + * (at your option) any later version.
>>>> + *
>>>> + * This program is distributed in the hope that it will be useful,
>>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>>> + * GNU General Public License for more details.
>>>> + *
>>>> + * You should have received a copy of the GNU General Public License
>>>> + * along with this program; If not, see <http://www.gnu.org/licenses/>.
>>>> + */
>>>> +
>>>> +#ifndef __XEN_LINUX_COMPAT_H__
>>>> +#define __XEN_LINUX_COMPAT_H__
>>>> +
>>>> +#include <asm/types.h>
>>>> +
>>>> +typedef paddr_t phys_addr_t;
>>>> +typedef paddr_t dma_addr_t;
>>>> +
>>>> +typedef unsigned int gfp_t;
>>>> +#define GFP_KERNEL 0
>>>> +#define __GFP_ZERO 0x01U
>>>> +
>>>> +/* Helpers for IRQ functions */
>>>> +#define free_irq release_irq
>>>> +
>>>> +enum irqreturn {
>>>> +    IRQ_NONE,
>>>> +    IRQ_HANDLED,
>>>> +    IRQ_WAKE_THREAD,
>>>> +};
>>>> +
>>>> +typedef enum irqreturn irqreturn_t;
>>>> +
>>>> +/* Device logger functions */
>>>> +#define dev_dbg(dev, fmt, ...) printk(XENLOG_DEBUG fmt, ## __VA_ARGS__)
>>>> +#define dev_notice(dev, fmt, ...) printk(XENLOG_INFO fmt, ## __VA_ARGS__)
>>>> +#define dev_warn(dev, fmt, ...) printk(XENLOG_WARNING fmt, ## __VA_ARGS__)
>>>> +#define dev_err(dev, fmt, ...) printk(XENLOG_ERR fmt, ## __VA_ARGS__)
>>>> +#define dev_info(dev, fmt, ...) printk(XENLOG_INFO fmt, ## __VA_ARGS__)
>>>> +
>>>> +#define dev_err_ratelimited(dev, fmt, ...)                  \
>>>> +     printk(XENLOG_ERR fmt, ## __VA_ARGS__)
>>>> +
>>>> +#define dev_name(dev) dt_node_full_name(dev_to_dt(dev))
>>>> +
>>>> +/* Alias to Xen allocation helpers */
>>>> +#define kfree xfree
>>>> +#define kmalloc(size, flags) ({\
>>>> +    void *__ret_alloc = NULL; \
>>>> +    if (flags & __GFP_ZERO) \
>>>> +        __ret_alloc = _xzalloc(size, sizeof(void *)); \
>>>> +    else \
>>>> +        __ret_alloc = _xmalloc(size, sizeof(void *)); \
>>>> +    __ret_alloc; \
>>>> +})
>>>> +#define kzalloc(size, flags)        _xzalloc(size, sizeof(void *))
>>>> +#define devm_kzalloc(dev, size, flags)  _xzalloc(size, sizeof(void *))
>>>> +#define kmalloc_array(size, n, flags) ({\
>>>> +    void *__ret_alloc = NULL; \
>>>> +    if (flags & __GFP_ZERO) \
>>>> +        __ret_alloc = _xzalloc_array(size, sizeof(void *), n); \
>>>> +    else \
>>>> +        __ret_alloc = _xmalloc_array(size, sizeof(void *), n); \
>>>> +    __ret_alloc; \
>>>> +})
>>>> +
>>>> +/* Alias to Xen time functions */
>>>> +#define ktime_t s_time_t
>>>> +#define ktime_get()             (NOW())
>>>> +#define ktime_add_us(t,i)       (t + MICROSECS(i))
>>>> +#define ktime_compare(t,i)      (t > (i))
>>>> +
>>>> +#endif /* __XEN_LINUX_COMPAT_H__ */
>>>
>>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xenproject.org
> https://lists.xenproject.org/mailman/listinfo/xen-devel
Sameer Goel May 30, 2018, 11:01 p.m. UTC | #11
>>>> +
>>>> +static int arm_smmu_iommu_domain_init(struct domain *d)
>>> Where is iommu_domain initialized?
>>> The function does not use a iommu_domain * variable
Please check iommu.c 2 levels up.
Thanks,
Sameer
>>>>
>>>
>>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xenproject.org
> https://lists.xenproject.org/mailman/listinfo/xen-devel
Manish Jaggi May 31, 2018, 4:10 a.m. UTC | #12
On 05/31/2018 01:16 AM, Sameer Goel wrote:
> Manish, I'll take another look at the variable names. I might not have enough time :).
>>>
>>> On 05/23/2018 10:48 PM, Manish Jaggi wrote:
>>>> Hi Sameer,
>>>>
>>>> General Comment, please use appropriate variable names for XXX_domain structures in code which is xen specific.
>>> I thought that we had discussed this before on one of the RFCs.
>> Yes and no one replied to my last comment that the var names have to be non confusing in Xen specific code.
> I'm sorry about that. I just assumed that since the policy on ported variable names was consistent we so not nee to change the names.
>
>>> At this point we are just using the format used for smmu-v2.
>> smmu-v2 has a lot of confusing variable names with _domain.
>> I believe that file needs to be fixed as well.
>>> I don't think that the variable names are inappropriate. Unless there is a very specific issue with the variable names,
>> The issue is in code readability and understanding the flow.
>> It is confusing so many _domain variable names are used which are not verbose.
> These names are coming from the original Linux code. So, we do not change them as per the policy. That being said I can add a comment section to explain the confusing variables in the Xen specific code? Please let me know if this will help us resolve this issue?
>   
If it is in Xen specific functions, then it can be changed, this is what 
julien also confirmed.

>> Two functions different and confusing variable names
>>
>> +static int __must_check arm_smmu_iotlb_flush_all(struct domain *d)
>> +{
>> +    struct arm_smmu_xen_domain *smmu_domain;
>>
>> +static struct iommu_domain *arm_smmu_get_domain(struct domain *d,
>> +                        struct device *dev)
>> +{
>> +    struct iommu_domain *domain;
>> +    struct arm_smmu_xen_domain *xen_domain;
>>
>> Why use smmu_domain at one place and xen_domain at another ?
>> Intuitively xen_domain should mean a VM.
>>
>> Doesn't is look confusing?
>>
>> Please take a look, I have pointed out the other specific ones below.
>>> I think we should stick with the current version.
>>>
>>>>
>>>> On 05/24/2018 06:16 AM, Sameer Goel wrote:
>>>>> This driver follows an approach similar to smmu driver. The intent here
>>>>> is to reuse as much Linux code as possible.
>>>>> - Glue code has been introduced to bridge the API calls.
>>>>> - Called Linux functions from the Xen IOMMU function calls.
>>>>> - Xen modifications are preceded by /*Xen: comment */
>>>>> - xen/linux_compat: Add a Linux compat header
>>>>>     For porting files directly from Linux it is useful to have a function mapping
>>>>>     definitions from Linux to Xen. This file adds common API functions and
>>>>>     other defines that are needed for porting arm SMMU drivers.
>>>>>
>>>>> Signed-off-by: Sameer Goel <sameer.goel@linaro.org>
>>>>> ---
>>>>>    xen/arch/arm/p2m.c                    |   1 +
>>>>>    xen/drivers/Kconfig                   |   2 +
>>>>>    xen/drivers/passthrough/arm/Kconfig   |   8 +
>>>>>    xen/drivers/passthrough/arm/Makefile  |   1 +
>>>>>    xen/drivers/passthrough/arm/smmu-v3.c | 934 +++++++++++++++++++++++++-
>>>>>    xen/include/xen/linux_compat.h        |  84 +++
>>>>>    6 files changed, 1001 insertions(+), 29 deletions(-)
>>>>>    create mode 100644 xen/drivers/passthrough/arm/Kconfig
>>>>>    create mode 100644 xen/include/xen/linux_compat.h
>>>>>
>>>>> diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
>>>>> index d43c3aa896..38aa9f00c1 100644
>>>>> --- a/xen/arch/arm/p2m.c
>>>>> +++ b/xen/arch/arm/p2m.c
>>>>> @@ -1454,6 +1454,7 @@ err:
>>>>>    static void __init setup_virt_paging_one(void *data)
>>>>>    {
>>>>>        unsigned long val = (unsigned long)data;
>>>>> +    /* SMMUv3 S2 cfg vtcr reuses the following value */
>>>>>        WRITE_SYSREG32(val, VTCR_EL2);
>>>>>        isb();
>>>>>    }
>>>>> diff --git a/xen/drivers/Kconfig b/xen/drivers/Kconfig
>>>>> index db94393f47..59ca00f850 100644
>>>>> --- a/xen/drivers/Kconfig
>>>>> +++ b/xen/drivers/Kconfig
>>>>> @@ -15,4 +15,6 @@ source "drivers/video/Kconfig"
>>>>>    config HAS_VPCI
>>>>>        bool
>>>>>    +source "drivers/passthrough/arm/Kconfig"
>>>>> +
>>>>>    endmenu
>>>>> diff --git a/xen/drivers/passthrough/arm/Kconfig b/xen/drivers/passthrough/arm/Kconfig
>>>>> new file mode 100644
>>>>> index 0000000000..cda899f608
>>>>> --- /dev/null
>>>>> +++ b/xen/drivers/passthrough/arm/Kconfig
>>>>> @@ -0,0 +1,8 @@
>>>>> +
>>>>> +config ARM_SMMU_v3
>>>>> +    bool "ARM SMMUv3 Support"
>>>>> +    depends on ARM_64
>>>>> +    help
>>>>> +     Support for implementations of the ARM System MMU architecture
>>>>> +     version 3.
>>>>> +
>>>>> diff --git a/xen/drivers/passthrough/arm/Makefile b/xen/drivers/passthrough/arm/Makefile
>>>>> index f4cd26e15d..e14732b55c 100644
>>>>> --- a/xen/drivers/passthrough/arm/Makefile
>>>>> +++ b/xen/drivers/passthrough/arm/Makefile
>>>>> @@ -1,2 +1,3 @@
>>>>>    obj-y += iommu.o
>>>>>    obj-y += smmu.o
>>>>> +obj-$(CONFIG_ARM_SMMU_v3) += smmu-v3.o
>>>>> diff --git a/xen/drivers/passthrough/arm/smmu-v3.c b/xen/drivers/passthrough/arm/smmu-v3.c
>>>>> index e67ba6c40f..df81626785 100644
>>>>> --- a/xen/drivers/passthrough/arm/smmu-v3.c
>>>>> +++ b/xen/drivers/passthrough/arm/smmu-v3.c
>>>>> @@ -18,28 +18,414 @@
>>>>>     * Author: Will Deacon <will.deacon@arm.com>
>>>>>     *
>>>>>     * This driver is powered by bad coffee and bombay mix.
>>>>> + *
>>>>> + *
>>>>> + * Based on Linux drivers/iommu/arm-smmu-v3.c
>>>>> + * => commit 7aa8619a66aea52b145e04cbab4f8d6a4e5f3f3b
>>>>> + *
>>>>> + * Xen modifications:
>>>>> + * Sameer Goel <sameer.goel@linaro.org>
>>>>> + * Copyright (C) 2017, The Linux Foundation, All rights reserved.
>>>>> + *
>>>>>     */
>>>>>    -#include <linux/acpi.h>
>>>>> -#include <linux/acpi_iort.h>
>>>>> -#include <linux/delay.h>
>>>>> -#include <linux/dma-iommu.h>
>>>>> -#include <linux/err.h>
>>>>> -#include <linux/interrupt.h>
>>>>> -#include <linux/iommu.h>
>>>>> -#include <linux/iopoll.h>
>>>>> -#include <linux/module.h>
>>>>> -#include <linux/msi.h>
>>>>> -#include <linux/of.h>
>>>>> -#include <linux/of_address.h>
>>>>> -#include <linux/of_iommu.h>
>>>>> -#include <linux/of_platform.h>
>>>>> -#include <linux/pci.h>
>>>>> -#include <linux/platform_device.h>
>>>>> -
>>>>> -#include <linux/amba/bus.h>
>>>>> -
>>>>> -#include "io-pgtable.h"
>>>>> +#include <xen/acpi.h>
>>>>> +#include <xen/config.h>
>>>>> +#include <xen/delay.h>
>>>>> +#include <xen/errno.h>
>>>>> +#include <xen/err.h>
>>>>> +#include <xen/irq.h>
>>>>> +#include <xen/lib.h>
>>>>> +#include <xen/linux_compat.h>
>>>>> +#include <xen/list.h>
>>>>> +#include <xen/mm.h>
>>>>> +#include <xen/rbtree.h>
>>>>> +#include <xen/sched.h>
>>>>> +#include <xen/sizes.h>
>>>>> +#include <xen/vmap.h>
>>>>> +#include <acpi/acpi_iort.h>
>>>>> +#include <asm/atomic.h>
>>>>> +#include <asm/device.h>
>>>>> +#include <asm/io.h>
>>>>> +#include <asm/platform.h>
>>>>> +
>>>>> +/* Alias to Xen device tree helpers */
>>>>> +#define device_node dt_device_node
>>>>> +#define of_phandle_args dt_phandle_args
>>>>> +#define of_device_id dt_device_match
>>>>> +#define of_match_node dt_match_node
>>>>> +#define of_property_read_u32(np, pname, out) (!dt_property_read_u32(np, pname, out))
>>>>> +#define of_property_read_bool dt_property_read_bool
>>>>> +#define of_parse_phandle_with_args dt_parse_phandle_with_args
>>>>> +
>>>>> +/* Xen: Helpers to get device MMIO and IRQs */
>>>>> +struct resource {
>>>>> +    u64 addr;
>>>>> +    u64 size;
>>>>> +    unsigned int type;
>>>>> +};
>>>>> +
>>>>> +#define resource_size(res) ((res)->size)
>>>>> +
>>>>> +#define platform_device device
>>>>> +
>>>>> +#define IORESOURCE_MEM 0
>>>>> +#define IORESOURCE_IRQ 1
>>>>> +
>>>>> +static struct resource *platform_get_resource(struct platform_device *pdev,
>>>>> +                          unsigned int type,
>>>>> +                          unsigned int num)
>>>>> +{
>>>>> +    /*
>>>>> +     * The resource is only used between 2 calls of platform_get_resource.
>>>>> +     * It's quite ugly but it's avoid to add too much code in the part
>>>>> +     * imported from Linux
>>>>> +     */
>>>>> +    static struct resource res;
>>>>> +    struct acpi_iort_node *iort_node;
>>>>> +    struct acpi_iort_smmu_v3 *node_smmu_data;
>>>>> +    int ret = 0;
>>>>> +
>>>>> +    res.type = type;
>>>>> +
>>>>> +    switch (type) {
>>>>> +    case IORESOURCE_MEM:
>>>>> +        if (pdev->type == DEV_ACPI) {
>>>>> +            ret = 1;
>>>>> +            iort_node = pdev->acpi_node;
>>>>> +            node_smmu_data =
>>>>> +                (struct acpi_iort_smmu_v3 *)iort_node->node_data;
>>>>> +
>>>>> +            if (node_smmu_data != NULL) {
>>>>> +                res.addr = node_smmu_data->base_address;
>>>>> +                res.size = SZ_128K;
>>>>> +                ret = 0;
>>>>> +            }
>>>>> +        } else {
>>>>> +            ret = dt_device_get_address(dev_to_dt(pdev), num,
>>>>> +                            &res.addr, &res.size);
>>>>> +        }
>>>>> +
>>>>> +        return ((ret) ? NULL : &res);
>>>>> +
>>>>> +    case IORESOURCE_IRQ:
>>>>> +        /* ACPI case not implemented as there is no use case for it */
>>>>> +        ret = platform_get_irq(dev_to_dt(pdev), num);
>>>>> +
>>>>> +        if (ret < 0)
>>>>> +            return NULL;
>>>>> +
>>>>> +        res.addr = ret;
>>>>> +        res.size = 1;
>>>>> +
>>>>> +        return &res;
>>>>> +
>>>>> +    default:
>>>>> +        return NULL;
>>>>> +    }
>>>>> +}
>>>>> +
>>>>> +static int platform_get_irq_byname(struct platform_device *pdev, const char *name)
>>>>> +{
>>>>> +    const struct dt_property *dtprop;
>>>>> +    struct acpi_iort_node *iort_node;
>>>>> +    struct acpi_iort_smmu_v3 *node_smmu_data;
>>>>> +    int ret = 0;
>>>>> +
>>>>> +    if (pdev->type == DEV_ACPI) {
>>>>> +        iort_node = pdev->acpi_node;
>>>>> +        node_smmu_data = (struct acpi_iort_smmu_v3 *)iort_node->node_data;
>>>>> +
>>>>> +        if (node_smmu_data != NULL) {
>>>>> +            if (!strcmp(name, "eventq"))
>>>>> +                ret = node_smmu_data->event_gsiv;
>>>>> +            else if (!strcmp(name, "priq"))
>>>>> +                ret = node_smmu_data->pri_gsiv;
>>>>> +            else if (!strcmp(name, "cmdq-sync"))
>>>>> +                ret = node_smmu_data->sync_gsiv;
>>>>> +            else if (!strcmp(name, "gerror"))
>>>>> +                ret = node_smmu_data->gerr_gsiv;
>>>>> +            else
>>>>> +                ret = -EINVAL;
>>>>> +        }
>>>>> +    } else {
>>>>> +        dtprop = dt_find_property(dev_to_dt(pdev), "interrupt-names", NULL);
>>>>> +        if (!dtprop)
>>>>> +            return -EINVAL;
>>>>> +
>>>>> +        if (!dtprop->value)
>>>>> +            return -ENODATA;
>>>>> +    }
>>>>> +
>>>>> +    return ret;
>>>>> +}
>>>>> +
>>>>> +/*
>>>>> + * Xen: Helpers for DMA allocation. Just the function name is reused for
>>>>> + * porting code these allocation are not managed allocations
>>>>> + */
>>>>> +
>>>>> +static void *dmam_alloc_coherent(struct device *dev, size_t size,
>>>>> +               dma_addr_t *dma_handle, gfp_t gfp)
>>>> I believe the formatting needs to be checked.
>>>>> +{
>>>>> +    void *vaddr;
>>>>> +    unsigned long alignment = size;
>>>>> +
>>>>> +    /*
>>>>> +     * _xzalloc requires that the (align & (align -1)) = 0. Most of the
>>>>> +     * allocations in SMMU code should send the right value for size. In
>>>>> +     * case this is not true print a warning and align to the size of a
>>>>> +     * (void *)
>>>>> +     */
>>>>> +    if (size & (size - 1)) {
>>>>> +        dev_warn(dev, "Fixing alignment for the DMA buffer\n");
>>>>> +        alignment = sizeof(void *);
>>>>> +    }
>>>>> +
>>>>> +    vaddr = _xzalloc(size, alignment);
>>>>> +    if (!vaddr) {
>>>>> +        dev_err(dev, "DMA allocation failed\n");
>>>>> +        return NULL;
>>>>> +    }
>>>>> +
>>>>> +    *dma_handle = virt_to_maddr(vaddr);
>>>>> +
>>>>> +    return vaddr;
>>>>> +}
>>>>> +
>>>>> +
>>>>> +static void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
>>>>> +            dma_addr_t dma_handle)
>>>> same
>>>>> +{
>>>>> +    xfree(vaddr);
>>>>> +}
>>>>> +
>>>>> +/* Xen: Stub out DMA domain related functions */
>>>>> +#define iommu_get_dma_cookie(dom) 0
>>>>> +#define iommu_put_dma_cookie(dom)
>>>>> +
>>>>> +/* Xen: Stub out module param related function */
>>>>> +#define module_param_named(a, b, c, d)
>>>>> +#define MODULE_PARM_DESC(a, b)
>>>>> +
>>>>> +#define dma_set_mask_and_coherent(d, b) 0
>>>>> +
>>>>> +#define of_dma_is_coherent(n) 0
>>>>> +
>>>>> +#define MODULE_DEVICE_TABLE(type, name)
>>>>> +
>>>>> +static void __iomem *devm_ioremap_resource(struct device *dev,
>>>>> +                       struct resource *res)
>>>>> +{
>>>>> +    void __iomem *ptr;
>>>>> +
>>>>> +    if (!res || res->type != IORESOURCE_MEM) {
>>>>> +        dev_err(dev, "Invalid resource\n");
>>>>> +        return ERR_PTR(-EINVAL);
>>>>> +    }
>>>>> +
>>>>> +    ptr = ioremap_nocache(res->addr, res->size);
>>>>> +    if (!ptr) {
>>>>> +        dev_err(dev,
>>>>> +            "ioremap failed (addr 0x%"PRIx64" size 0x%"PRIx64")\n",
>>>>> +            res->addr, res->size);
>>>>> +        return ERR_PTR(-ENOMEM);
>>>>> +    }
>>>>> +
>>>>> +    return ptr;
>>>>> +}
>>>>> +
>>>>> +/* Xen: Compatibility define for iommu_domain_geometry.*/
>>>>> +struct iommu_domain_geometry {
>>>>> +    dma_addr_t aperture_start; /* First address that can be mapped    */
>>>>> +    dma_addr_t aperture_end;   /* Last address that can be mapped     */
>>>>> +    bool force_aperture;       /* DMA only allowed in mappable range? */
>>>>> +};
>>>>> +
>>>>> +
>>>>> +/* Xen: Type definitions for iommu_domain */
>>>>> +#define IOMMU_DOMAIN_UNMANAGED 0
>>>>> +#define IOMMU_DOMAIN_DMA 1
>>>>> +#define IOMMU_DOMAIN_IDENTITY 2
>>>>> +
>>>>> +/* Xen: Dummy iommu_domain */
>>>>> +struct iommu_domain {
>>>>> +    /* Runtime SMMU configuration for this iommu_domain */
>>>>> +    struct arm_smmu_domain        *priv;
>>>>> +    unsigned int type;
>>>>> +
>>>>> +    /* Dummy compatibility defines */
>>>>> +    unsigned long pgsize_bitmap;
>>>>> +    struct iommu_domain_geometry geometry;
>>>>> +
>>>>> +    atomic_t ref;
>>>>> +    /*
>>>>> +     * Used to link iommu_domain contexts for a same domain.
>>>>> +     * There is at least one per-SMMU to used by the domain.
>>>>> +     */
>>>>> +    struct list_head        list;
>>>>> +};
>>>>> +
>>>>> +/* Xen: Describes information required for a Xen domain */
>>>>> +struct arm_smmu_xen_domain {
>>>>> +    spinlock_t            lock;
>>>>> +    /* List of iommu domains associated to this domain */
>>>>> +    struct list_head        contexts;
>>>>> +};
>>>>> +
>>>>> +/*
>>>>> + * Xen: Information about each device stored in dev->archdata.iommu
>>>>> + *
>>>>> + * The dev->archdata.iommu stores the iommu_domain (runtime configuration of
>>>>> + * the SMMU).
>>>>> + */
>>>>> +struct arm_smmu_xen_device {
>>>>> +    struct iommu_domain *domain;
>>>>> +};
>>>>> +
>>>> As this is a xen specific code, can the variable names be used appropriately.
>>>> Repeating my comment  from earlier version.
>>>> a domain is  usually a VM in Xen. So it is a bit confusing to use domain for iommu_domain.
> The struct is fine but you have an issue with the var name right?
Yes.
>
>>>>> +/*
>>>>> + * Xen: io_pgtable compatibility defines.
>>>>> + * Most of these are to port in the S1 translation code as is.
>>>>> + */
>>>>> +struct io_pgtable_ops {
>>>>> +};
>>>>> +
>>>>> +struct iommu_gather_ops {
>>>>> +    void (*tlb_flush_all)(void *cookie);
>>>>> +    void (*tlb_add_flush)(unsigned long iova, size_t size, size_t granule,
>>>>> +                  bool leaf, void *cookie);
>>>>> +    void (*tlb_sync)(void *cookie);
>>>>> +};
>>>>> +
>>>>> +struct io_pgtable_cfg {
>>>>> +    /*
>>>>> +     * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE bits in
>>>>> +     *    stage 1 PTEs, for hardware which insists on validating them
>>>>> +     *    even in    non-secure state where they should normally be ignored.
>>>>> +     *
>>>>> +     * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE and
>>>>> +     *    IOMMU_NOEXEC flags and map everything with full access, for
>>>>> +     *    hardware which does not implement the permissions of a given
>>>>> +     *    format, and/or requires some format-specific default value.
>>>>> +     *
>>>>> +     * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching invalid
>>>>> +     *    (unmapped) entries but the hardware might do so anyway, perform
>>>>> +     *    TLB maintenance when mapping as well as when unmapping.
>>>>> +     *
>>>>> +     * IO_PGTABLE_QUIRK_ARM_MTK_4GB: (ARM v7s format) Set bit 9 in all
>>>>> +     *    PTEs, for Mediatek IOMMUs which treat it as a 33rd address bit
>>>>> +     *    when the SoC is in "4GB mode" and they can only access the high
>>>>> +     *    remap of DRAM (0x1_00000000 to 0x1_ffffffff).
>>>>> +     *
>>>>> +     * IO_PGTABLE_QUIRK_NO_DMA: Guarantees that the tables will only ever
>>>>> +     *    be accessed by a fully cache-coherent IOMMU or CPU (e.g. for a
>>>>> +     *    software-emulated IOMMU), such that pagetable updates need not
>>>>> +     *    be treated as explicit DMA data.
>>>>> +     */
>>>>> +    #define IO_PGTABLE_QUIRK_ARM_NS        BIT(0)
>>>>> +    #define IO_PGTABLE_QUIRK_NO_PERMS    BIT(1)
>>>>> +    #define IO_PGTABLE_QUIRK_TLBI_ON_MAP    BIT(2)
>>>>> +    #define IO_PGTABLE_QUIRK_ARM_MTK_4GB    BIT(3)
>>>>> +    #define IO_PGTABLE_QUIRK_NO_DMA        BIT(4)
>>>>> +    unsigned long            quirks;
>>>>> +    unsigned long            pgsize_bitmap;
>>>>> +    unsigned int            ias;
>>>>> +    unsigned int            oas;
>>>>> +    const struct iommu_gather_ops    *tlb;
>>>>> +    struct device            *iommu_dev;
>>>>> +
>>>>> +    /* Low-level data specific to the table format */
>>>>> +    union {
>>>>> +        struct {
>>>>> +            u64    ttbr[2];
>>>>> +            u64    tcr;
>>>>> +            u64    mair[2];
>>>>> +        } arm_lpae_s1_cfg;
>>>>> +
>>>>> +        struct {
>>>>> +            u64    vttbr;
>>>>> +            u64    vtcr;
>>>>> +        } arm_lpae_s2_cfg;
>>>>> +
>>>>> +        struct {
>>>>> +            u32    ttbr[2];
>>>>> +            u32    tcr;
>>>>> +            u32    nmrr;
>>>>> +            u32    prrr;
>>>>> +        } arm_v7s_cfg;
>>>>> +    };
>>>>> +};
>>>>> +
>>>>> +enum io_pgtable_fmt {
>>>>> +    ARM_32_LPAE_S1,
>>>>> +    ARM_32_LPAE_S2,
>>>>> +    ARM_64_LPAE_S1,
>>>>> +    ARM_64_LPAE_S2,
>>>>> +    ARM_V7S,
>>>>> +    IO_PGTABLE_NUM_FMTS,
>>>>> +};
>>>>> +
>>>>> +/*
>>>>> + * Xen: The pgtable_ops are used by the S1 translations, so return the dummy
>>>>> + * address.
>>>>> + */
>>>>> +#define alloc_io_pgtable_ops(f, c, o) ((struct io_pgtable_ops *)0x1)
>>>>> +#define free_io_pgtable_ops(o)
>>>>> +
>>>>> +/* Xen: Define wrapper for requesting IRQs */
>>>>> +#define IRQF_ONESHOT 0
>>>>> +
>>>>> +typedef void (*irq_handler_t)(int, void *, struct cpu_user_regs *);
>>>>> +
>>>>> +static inline int devm_request_irq(struct device *dev, unsigned int irq,
>>>>> +                   irq_handler_t handler, unsigned long irqflags,
>>>>> +                   const char *devname, void *dev_id)
>>>>> +{
>>>>> +    /*
>>>>> +     * SMMUv3 implementation can support wired interrupt outputs that are
>>>>> +     * edge-triggered. Set the irq type as per the spec.
>>>>> +     */
>>>>> +    irq_set_type(irq, IRQ_TYPE_EDGE_BOTH);
>>>>> +    return request_irq(irq, irqflags, handler, devname, dev_id);
>>>>> +}
>>>>> +
>>>>> +/*
>>>>> + * Xen does not have a concept of threaded irq, but we can use tasklets to
>>>>> + * achieve the desired functionality as needed.
>>>>> + */
>>>>> +int devm_request_threaded_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
>>>>> +                  irq_handler_t thread_fn, unsigned long irqflags,
>>>>> +                  const char *devname, void *dev_id)
>>>>> +{
>>>>> +    return devm_request_irq(dev, irq, thread_fn, irqflags, devname, dev_id);
>>>>> +}
>>>>> +
>>>>> +/* Xen: The mutex is used only during initialization so the typecast is safe */
>>>>> +#define mutex spinlock
>>>>> +#define mutex_init spin_lock_init
>>>>> +#define mutex_lock spin_lock
>>>>> +#define mutex_unlock spin_unlock
>>>>> +
>>>>> +#define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us) \
>>>>> +({ \
>>>>> +    s_time_t deadline = NOW() + MICROSECS(timeout_us); \
>>>>> +    for (;;) { \
>>>>> +        (val) = op(addr); \
>>>>> +        if (cond) \
>>>>> +            break; \
>>>>> +        if (NOW() > deadline) { \
>>>>> +            (val) = op(addr); \
>>>>> +            break; \
>>>>> +        } \
>>>>> +    udelay(sleep_us); \
>>>>> +    } \
>>>>> +    (cond) ? 0 : -ETIMEDOUT; \
>>>>> +})
>>>>> +
>>>>> +#define readl_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
>>>>> +    readx_poll_timeout(readl_relaxed, addr, val, cond, delay_us, timeout_us)
>>>>> +
>>>>> +#define VA_BITS 0 /* Only needed for S1 translations */
>>>>>      /* MMIO registers */
>>>>>    #define ARM_SMMU_IDR0            0x0
>>>>> @@ -433,6 +819,7 @@ enum pri_resp {
>>>>>        PRI_RESP_SUCC,
>>>>>    };
>>>>>    +#if 0 /* Xen: No MSI support in this iteration */
>>>>>    enum arm_smmu_msi_index {
>>>>>        EVTQ_MSI_INDEX,
>>>>>        GERROR_MSI_INDEX,
>>>>> @@ -457,6 +844,7 @@ static phys_addr_t arm_smmu_msi_cfg[ARM_SMMU_MAX_MSIS][3] = {
>>>>>            ARM_SMMU_PRIQ_IRQ_CFG2,
>>>>>        },
>>>>>    };
>>>>> +#endif
>>>>>      struct arm_smmu_cmdq_ent {
>>>>>        /* Common fields */
>>>>> @@ -561,6 +949,8 @@ struct arm_smmu_s2_cfg {
>>>>>        u16                vmid;
>>>>>        u64                vttbr;
>>>>>        u64                vtcr;
>>>>> +    /* Xen: Domain associated to this configuration */
>>>>> +    struct domain            *domain;
>>>>>    };
>>>>>      struct arm_smmu_strtab_ent {
>>>>> @@ -635,9 +1025,25 @@ struct arm_smmu_device {
>>>>>        struct arm_smmu_strtab_cfg    strtab_cfg;
>>>>>          /* IOMMU core code handle */
>>>>> +#if 0 /*Xen: Generic iommu_device ref not needed here */
>>>>>        struct iommu_device        iommu;
>>>>> +#endif
>>>> Is it clean to put #if 0, can this line be deleted or used with a proper macro
> Manish this is a var name from original struct from Linux. I have just followed the prior standard of adding #if 0.
It does not look clean, can we use something other than 0, say a macro 
NA_CODE ...
>>>>> +    /* Xen: Need to keep a list of SMMU devices */
>>>>> +    struct list_head                devices;
>>>>> +    /* Xen: Tasklets for handling evts/faults and pci page request IRQs*/
>>>>> +    struct tasklet            evtq_tasklet;
>>>>> +    struct tasklet            priq_tasklet;
>>>>> +    struct tasklet            combined_irq_tasklet;
>>>>>    };
>>>>>    +/* Xen: Keep a list of devices associated with this driver */
>>>>> +static DEFINE_SPINLOCK(arm_smmu_devices_lock);
>>>>> +static LIST_HEAD(arm_smmu_devices);
>>>>> +/* Xen: Helper for finding a device using fwnode */
>>>>> +static
>>>>> +struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode);
>>>>> +
>>>>> +
>>>>>    /* SMMU private data for each master */
>>>>>    struct arm_smmu_master_data {
>>>>>        struct arm_smmu_device        *smmu;
>>>>> @@ -1232,7 +1638,7 @@ static void arm_smmu_handle_ppr(struct arm_smmu_device *smmu, u64 *evt)
>>>>>          dev_info(smmu->dev, "unexpected PRI request received:\n");
>>>>>        dev_info(smmu->dev,
>>>>> -         "\tsid 0x%08x.0x%05x: [%u%s] %sprivileged %s%s%s access at iova 0x%016llx\n",
>>>>> +         "\tsid 0x%08x.0x%05x: [%u%s] %sprivileged %s%s%s access at iova %#" PRIx64 "\n",
>>>>>             sid, ssid, grpid, last ? "L" : "",
>>>>>             evt[0] & PRIQ_0_PERM_PRIV ? "" : "un",
>>>>>             evt[0] & PRIQ_0_PERM_READ ? "R" : "",
>>>>> @@ -1342,10 +1748,20 @@ static irqreturn_t arm_smmu_combined_irq_thread(int irq, void *dev)
>>>>>        return IRQ_HANDLED;
>>>>>    }
>>>>>    +/* Xen: Forward define for combined_irq tasklet */
>>>>> +static void arm_smmu_combined_irq_tasklet(unsigned long dev);
>>>>> +
>>>>>    static irqreturn_t arm_smmu_combined_irq_handler(int irq, void *dev)
>>>>>    {
>>>>> +    /* Xen: Need an smmu reference to schedule the tasklet */
>>>>> +    struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
>>>>> +
>>>>>        arm_smmu_gerror_handler(irq, dev);
>>>>>        arm_smmu_cmdq_sync_handler(irq, dev);
>>>>> +
>>>>> +    /*Xen: No threaded irq. So, schedule the right tasklet*/
>>>>> +    tasklet_schedule(&(smmu->combined_irq_tasklet));
>>>>> +
>>>>>        return IRQ_WAKE_THREAD;
>>>>>    }
>>>>>    @@ -1358,6 +1774,69 @@ static void __arm_smmu_tlb_sync(struct arm_smmu_device *smmu)
>>>>>        arm_smmu_cmdq_issue_cmd(smmu, &cmd);
>>>>>    }
>>>>>    +/*
>>>>> + * Xen: Define the IRQ handlers and tasklets for xen. The linux functions
>>>>> + * would be modified to use the functions defined in the following code.
>>>>> + */
>>>>> +
>>>>> +static void arm_smmu_evtq_tasklet(unsigned long dev)
>>>>> +{
>>>>> +    /* The IRQ number is not relevent for the evtq thread processing */
>>>>> +    arm_smmu_evtq_thread(0, (void *)dev);
>>>>> +}
>>>>> +
>>>>> +static void arm_smmu_priq_tasklet(unsigned long dev)
>>>>> +{
>>>>> +    /* The IRQ number is not relevent for the priq thread processing */
>>>>> +    arm_smmu_priq_thread(0, (void *)dev);
>>>>> +}
>>>>> +
>>>>> +static void arm_smmu_combined_irq_tasklet(unsigned long dev)
>>>>> +{
>>>>> +    /* The IRQ number is not relevent for the combined irq handler.*/
>>>>> +    arm_smmu_combined_irq_thread(0, (void *)dev);
>>>>> +}
>>>>> +
>>>>> +static void arm_smmu_evtq_thread_xen(int irq, void *dev,
>>>>> +                       struct cpu_user_regs *regs)
>>>>> +{
>>>>> +    struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
>>>>> +
>>>>> +    tasklet_schedule(&(smmu->evtq_tasklet));
>>>>> +}
>>>>> +
>>>>> +static void arm_smmu_priq_thread_xen(int irq, void *dev,
>>>>> +                       struct cpu_user_regs *regs)
>>>>> +{
>>>>> +    struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
>>>>> +
>>>>> +    tasklet_schedule(&(smmu->priq_tasklet));
>>>>> +}
>>>>> +
>>>>> +static void arm_smmu_cmdq_sync_handler_xen(int irq, void *dev,
>>>>> +                       struct cpu_user_regs *regs)
>>>>> +{
>>>>> +    arm_smmu_cmdq_sync_handler(irq, dev);
>>>>> +}
>>>>> +
>>>>> +static void arm_smmu_gerror_handler_xen(int irq, void *dev,
>>>>> +                       struct cpu_user_regs *regs)
>>>>> +{
>>>>> +    arm_smmu_gerror_handler(irq, dev);
>>>>> +}
>>>>> +
>>>>> +static void arm_smmu_combined_irq_handler_xen(int irq, void *dev,
>>>>> +                       struct cpu_user_regs *regs)
>>>>> +{
>>>>> +    arm_smmu_combined_irq_handler(irq, dev);
>>>>> +}
>>>>> +
>>>>> +#define arm_smmu_evtq_thread arm_smmu_evtq_thread_xen
>>>>> +#define arm_smmu_priq_thread arm_smmu_priq_thread_xen
>>>>> +#define arm_smmu_cmdq_sync_handler arm_smmu_cmdq_sync_handler_xen
>>>>> +#define arm_smmu_gerror_handler arm_smmu_gerror_handler_xen
>>>>> +#define arm_smmu_combined_irq_handler arm_smmu_combined_irq_handler_xen
>>>>> +
>>>>>    static void arm_smmu_tlb_sync(void *cookie)
>>>>>    {
>>>>>        struct arm_smmu_domain *smmu_domain = cookie;
>>>>> @@ -1415,6 +1894,7 @@ static const struct iommu_gather_ops arm_smmu_gather_ops = {
>>>>>        .tlb_sync    = arm_smmu_tlb_sync,
>>>>>    };
>>>>>    +#if 0 /*Xen: Unused functionality */
>>>>>    /* IOMMU API */
>>>>>    static bool arm_smmu_capable(enum iommu_cap cap)
>>>>>    {
>>>>> @@ -1427,6 +1907,7 @@ static bool arm_smmu_capable(enum iommu_cap cap)
>>>>>            return false;
>>>>>        }
>>>>>    }
>>>>> +#endif
>>>>>      static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
>>>>>    {
>>>>> @@ -1546,9 +2027,16 @@ static int arm_smmu_domain_finalise_s2(struct arm_smmu_domain *smmu_domain,
>>>>>        if (vmid < 0)
>>>>>            return vmid;
>>>>>    -    cfg->vmid    = (u16)vmid;
>>>>> -    cfg->vttbr    = pgtbl_cfg->arm_lpae_s2_cfg.vttbr;
>>>>> -    cfg->vtcr    = pgtbl_cfg->arm_lpae_s2_cfg.vtcr;
>>>>> +    /*
>>>>> +     * Xen: Get the ttbr and vtcr values
>>>>> +     * vttbr: This is a shared value with the domain page table
>>>>> +     * vtcr: The TCR settings are the same as CPU since the page
>>>>> +     * tables are shared
>>>>> +     */
>>>>> +
>>>>> +    cfg->vmid    = vmid;
>>>>> +    cfg->vttbr    = page_to_maddr(cfg->domain->arch.p2m.root);
>>>>> +    cfg->vtcr    = READ_SYSREG32(VTCR_EL2) & STRTAB_STE_2_VTCR_MASK;
>>>>>        return 0;
>>>>>    }
>>>>>    @@ -1604,6 +2092,7 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain)
>>>>>        if (smmu->features & ARM_SMMU_FEAT_COHERENCY)
>>>>>            pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_NO_DMA;
>>>>>    +    /* Xen: pgtbl_ops gets an invalid address */
>>>>>        pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);
>>>>>        if (!pgtbl_ops)
>>>>>            return -ENOMEM;
>>>>> @@ -1721,6 +2210,7 @@ out_unlock:
>>>>>        return ret;
>>>>>    }
>>>>>    +#if 0 /* Xen: Unused functionality */
>>>> same
> Same as above.
>>>>>    static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
>>>>>                phys_addr_t paddr, size_t size, int prot)
>>>>>    {
>>>>> @@ -1772,6 +2262,7 @@ struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
>>>>>        put_device(dev);
>>>>>        return dev ? dev_get_drvdata(dev) : NULL;
>>>>>    }
>>>>> +#endif
>>>>>      static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, u32 sid)
>>>>>    {
>>>>> @@ -1783,7 +2274,14 @@ static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, u32 sid)
>>>>>        return sid < limit;
>>>>>    }
>>>>>    +/* Xen: Unused */
>>>>> +#if 0
>>>>>    static struct iommu_ops arm_smmu_ops;
>>>>> +#endif
>>>>> +
>>>>> +/* Xen: Redefine arm_smmu_ops to what fwspec should evaluate */
>>>>> +static const struct iommu_ops arm_smmu_iommu_ops;
>>>>> +#define arm_smmu_ops arm_smmu_iommu_ops
>>>>>      static int arm_smmu_add_device(struct device *dev)
>>>>>    {
>>>>> @@ -1791,8 +2289,11 @@ static int arm_smmu_add_device(struct device *dev)
>>>>>        struct arm_smmu_device *smmu;
>>>>>        struct arm_smmu_master_data *master;
>>>>>        struct iommu_fwspec *fwspec = dev->iommu_fwspec;
>>>>> +#if 0 /*Xen: iommu_group is not needed */
>>>>>        struct iommu_group *group;
>>>>> +#endif
>>>>>    +    /* Xen: fwspec->ops are not needed */
>>>>>        if (!fwspec || fwspec->ops != &arm_smmu_ops)
>>>>>            return -ENODEV;
>>>>>        /*
>>>>> @@ -1830,6 +2331,11 @@ static int arm_smmu_add_device(struct device *dev)
>>>>>            }
>>>>>        }
>>>>>    +/*
>>>>> + * Xen: Do not need an iommu group as the stream data is carried by the SMMU
>>>>> + * master device object
>>>>> + */
>>>>> +#if 0
>>>>>        group = iommu_group_get_for_dev(dev);
>>>>>        if (!IS_ERR(group)) {
>>>>>            iommu_group_put(group);
>>>>> @@ -1837,8 +2343,16 @@ static int arm_smmu_add_device(struct device *dev)
>>>>>        }
>>>>>          return PTR_ERR_OR_ZERO(group);
>>>>> +#endif
>>>>> +    return 0;
>>>>>    }
>>>>>    +/*
>>>>> + * Xen: We can potentially support this function and destroy a device. This
>>>>> + * will be relevant for PCI hotplug. So, will be implemented as needed after
>>>>> + * passthrough support is available.
>>>>> + */
>>>>> +#if 0
>>>>>    static void arm_smmu_remove_device(struct device *dev)
>>>>>    {
>>>>>        struct iommu_fwspec *fwspec = dev->iommu_fwspec;
>>>>> @@ -1974,6 +2488,7 @@ static struct iommu_ops arm_smmu_ops = {
>>>>>        .put_resv_regions    = arm_smmu_put_resv_regions,
>>>>>        .pgsize_bitmap        = -1UL, /* Restricted during device attach */
>>>>>    };
>>>>> +#endif
>>>>>      /* Probing and initialisation functions */
>>>>>    static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
>>>>> @@ -2182,6 +2697,7 @@ static int arm_smmu_update_gbpa(struct arm_smmu_device *smmu, u32 set, u32 clr)
>>>>>                          1, ARM_SMMU_POLL_TIMEOUT_US);
>>>>>    }
>>>>>    +#if 0 /* Xen: There is no MSI support as yet */
>>>>>    static void arm_smmu_free_msis(void *data)
>>>>>    {
>>>>>        struct device *dev = data;
>>>>> @@ -2247,12 +2763,15 @@ static void arm_smmu_setup_msis(struct arm_smmu_device *smmu)
>>>>>        /* Add callback to free MSIs on teardown */
>>>>>        devm_add_action(dev, arm_smmu_free_msis, dev);
>>>>>    }
>>>>> +#endif
>>>>>      static void arm_smmu_setup_unique_irqs(struct arm_smmu_device *smmu)
>>>>>    {
>>>>>        int irq, ret;
>>>>>    +#if 0 /*Xen: Cannot setup msis for now */
>>>>>        arm_smmu_setup_msis(smmu);
>>>>> +#endif
>>>>>          /* Request interrupt lines */
>>>>>        irq = smmu->evtq.q.irq;
>>>>> @@ -2316,9 +2835,13 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
>>>>>             * Cavium ThunderX2 implementation doesn't not support unique
>>>>>             * irq lines. Use single irq line for all the SMMUv3 interrupts.
>>>>>             */
>>>>> -        ret = devm_request_threaded_irq(smmu->dev, irq,
>>>>> +        /*
>>>>> +         * Xen: Does not support threaded irqs, so serialise the setup.
>>>>> +         * This is the same for pris and event interrupt lines on other
>>>>> +         * systems
>>>>> +         */
>>>>> +        ret = devm_request_irq(smmu->dev, irq,
>>>>>                        arm_smmu_combined_irq_handler,
>>>>> -                    arm_smmu_combined_irq_thread,
>>>>>                        IRQF_ONESHOT,
>>>>>                        "arm-smmu-v3-combined-irq", smmu);
>>>>>            if (ret < 0)
>>>>> @@ -2452,6 +2975,13 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
>>>>>            return ret;
>>>>>        }
>>>>>    +    /* Xen: Initialize tasklets */
>>>>> +    tasklet_init(&smmu->evtq_tasklet, arm_smmu_evtq_tasklet,
>>>>> +            (unsigned long)smmu);
>>>>> +    tasklet_init(&smmu->priq_tasklet, arm_smmu_priq_tasklet,
>>>>> +            (unsigned long)smmu);
>>>>> +    tasklet_init(&smmu->combined_irq_tasklet, arm_smmu_combined_irq_tasklet,
>>>>> +            (unsigned long)smmu);
>>>>>          /* Enable the SMMU interface, or ensure bypass */
>>>>>        if (!bypass || disable_bypass) {
>>>>> @@ -2542,8 +3072,14 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu)
>>>>>            smmu->features |= ARM_SMMU_FEAT_STALLS;
>>>>>        }
>>>>>    +/*
>>>>> + * Xen: Block stage 1 translations. By doing this here we do not need to set the
>>>>> + * domain->stage explicitly.
>>>>> + */
>>>>> +#if 0
>>>>>        if (reg & IDR0_S1P)
>>>>>            smmu->features |= ARM_SMMU_FEAT_TRANS_S1;
>>>>> +#endif
>>>>>          if (reg & IDR0_S2P)
>>>>>            smmu->features |= ARM_SMMU_FEAT_TRANS_S2;
>>>>> @@ -2616,10 +3152,12 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu)
>>>>>        if (reg & IDR5_GRAN4K)
>>>>>            smmu->pgsize_bitmap |= SZ_4K | SZ_2M | SZ_1G;
>>>>>    +#if 0 /* Xen: SMMU ops do not have a pgsize_bitmap member for Xen */
>>>>>        if (arm_smmu_ops.pgsize_bitmap == -1UL)
>>>>>            arm_smmu_ops.pgsize_bitmap = smmu->pgsize_bitmap;
>>>>>        else
>>>>>            arm_smmu_ops.pgsize_bitmap |= smmu->pgsize_bitmap;
>>>>> +#endif
>>>>>          /* Output address size */
>>>>>        switch (reg & IDR5_OAS_MASK << IDR5_OAS_SHIFT) {
>>>>> @@ -2680,7 +3218,8 @@ static int arm_smmu_device_acpi_probe(struct platform_device *pdev,
>>>>>        struct device *dev = smmu->dev;
>>>>>        struct acpi_iort_node *node;
>>>>>    -    node = *(struct acpi_iort_node **)dev_get_platdata(dev);
>>>>> +    /* Xen: Modification to get iort_node */
>>>>> +    node = (struct acpi_iort_node *)dev->acpi_node;
>>>>>          /* Retrieve SMMUv3 specific data */
>>>>>        iort_smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
>>>>> @@ -2703,7 +3242,7 @@ static inline int arm_smmu_device_acpi_probe(struct platform_device *pdev,
>>>>>    static int arm_smmu_device_dt_probe(struct platform_device *pdev,
>>>>>                        struct arm_smmu_device *smmu)
>>>>>    {
>>>>> -    struct device *dev = &pdev->dev;
>>>>> +    struct device *dev = pdev;
>>>>>        u32 cells;
>>>>>        int ret = -EINVAL;
>>>>>    @@ -2716,6 +3255,7 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev,
>>>>>          parse_driver_options(smmu);
>>>>>    +    /* Xen: of_dma_is_coherent is a stub till dt support is introduced */
>>>>>        if (of_dma_is_coherent(dev->of_node))
>>>>>            smmu->features |= ARM_SMMU_FEAT_COHERENCY;
>>>>>    @@ -2734,9 +3274,11 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>>>>>    {
>>>>>        int irq, ret;
>>>>>        struct resource *res;
>>>>> +#if 0 /*Xen: Do not need to setup sysfs */
>>>>>        resource_size_t ioaddr;
>>>>> +#endif
>>>>>        struct arm_smmu_device *smmu;
>>>>> -    struct device *dev = &pdev->dev;
>>>>> +    struct device *dev = pdev;/* Xen: dev is ignored */
>>>>>        bool bypass;
>>>>>          smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
>>>>> @@ -2763,7 +3305,9 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>>>>>            dev_err(dev, "MMIO region too small (%pr)\n", res);
>>>>>            return -EINVAL;
>>>>>        }
>>>>> +#if 0 /*Xen: Do not need to setup sysfs */
>>>>>        ioaddr = res->start;
>>>>> +#endif
>>>>>          smmu->base = devm_ioremap_resource(dev, res);
>>>>>        if (IS_ERR(smmu->base))
>>>>> @@ -2802,13 +3346,18 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>>>>>            return ret;
>>>>>          /* Record our private device structure */
>>>>> +    /* Xen: SMMU is not treated a a platform device*/
>>>>> +#if 0
>>>>>        platform_set_drvdata(pdev, smmu);
>>>>> +#endif
>>>>>          /* Reset the device */
>>>>>        ret = arm_smmu_device_reset(smmu, bypass);
>>>>>        if (ret)
>>>>>            return ret;
>>>>>    +/* Xen: Not creating an IOMMU device list for Xen */
>>>>> +#if 0
>>>>>        /* And we're up. Go go go! */
>>>>>        ret = iommu_device_sysfs_add(&smmu->iommu, dev, NULL,
>>>>>                         "smmu3.%pa", &ioaddr);
>>>>> @@ -2844,9 +3393,20 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>>>>>            if (ret)
>>>>>                return ret;
>>>>>        }
>>>>> +#endif
>>>>> +    /*
>>>>> +     * Xen: Keep a list of all probed devices. This will be used to query
>>>>> +     * the smmu devices based on the fwnode.
>>>>> +     */
>>>>> +    INIT_LIST_HEAD(&smmu->devices);
>>>>> +    spin_lock(&arm_smmu_devices_lock);
>>>>> +    list_add(&smmu->devices, &arm_smmu_devices);
>>>>> +    spin_unlock(&arm_smmu_devices_lock);
>>>>>        return 0;
>>>>>    }
>>>>>    +/* Xen: Unused function */
>>>>> +#if 0
>>>>>    static int arm_smmu_device_remove(struct platform_device *pdev)
>>>>>    {
>>>>>        struct arm_smmu_device *smmu = platform_get_drvdata(pdev);
>>>>> @@ -2860,6 +3420,8 @@ static void arm_smmu_device_shutdown(struct platform_device *pdev)
>>>>>    {
>>>>>        arm_smmu_device_remove(pdev);
>>>>>    }
>>>>> +#endif
>>>>> +
>>>>>      static const struct of_device_id arm_smmu_of_match[] = {
>>>>>        { .compatible = "arm,smmu-v3", },
>>>>> @@ -2867,6 +3429,7 @@ static const struct of_device_id arm_smmu_of_match[] = {
>>>>>    };
>>>>>    MODULE_DEVICE_TABLE(of, arm_smmu_of_match);
>>>>>    +#if 0
>>>>>    static struct platform_driver arm_smmu_driver = {
>>>>>        .driver    = {
>>>>>            .name        = "arm-smmu-v3",
>>>>> @@ -2883,3 +3446,316 @@ IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", NULL);
>>>>>    MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 implementations");
>>>>>    MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
>>>>>    MODULE_LICENSE("GPL v2");
>>>>> +#endif
>>>>> +
>>>>> +/***** Start of Xen specific code *****/
>>>>> +
>>>>> +static int __must_check arm_smmu_iotlb_flush_all(struct domain *d)
>>>>> +{
>>>>> +    struct arm_smmu_xen_domain *smmu_domain = dom_iommu(d)->arch.priv;
>>>>> +    struct iommu_domain *cfg;
>>>>> +
>>>>> +    spin_lock(&smmu_domain->lock);
>>>>> +    list_for_each_entry(cfg, &smmu_domain->contexts, list) {
>>>>> +        /*
>>>>> +         * Only invalidate the context when SMMU is present.
>>>>> +         * This is because the context initialization is delayed
>>>>> +         * until a master has been added.
>>>>> +         */
>>>>> +        if (unlikely(!ACCESS_ONCE(cfg->priv->smmu)))
>>>>> +            continue;
>>>>> +        arm_smmu_tlb_inv_context(cfg->priv);
>>>>> +    }
>>>>> +    spin_unlock(&smmu_domain->lock);
>>>>> +    return 0;
>>>>> +}
>>>>> +
>>>>> +static int __must_check arm_smmu_iotlb_flush(struct domain *d,
>>>>> +                         unsigned long gfn,
>>>>> +                         unsigned int page_count)
>>>>> +{
>>>>> +    return arm_smmu_iotlb_flush_all(d);
>>>>> +}
>>>>> +
>>>>> +static struct iommu_domain *arm_smmu_get_domain(struct domain *d,
>>>>> +                        struct device *dev)
>>>> This is returning iommu_domain and not a domain.
>>>> Please change the name of function.
> Same as smmu-v2.c. I think with the complexity of the code we should try to get this in as the prior code. Once the set that has been pending for some time is in. We can start on the variable cleanup activity. I say this so that we can make the names consistent across the drivers and this will be a lot easier to do when the majority of the other code is in.
smmu-v2.c had this issue and I had hard time understanding the code, the 
confusing variable names break the understanding flow, especially when 
you are debugging something and have lost touch of code.
So let not do same mistake as in smmu-v2.c
>>>>> +{
>>>>> +    struct iommu_domain *domain;
>>>>> +    struct arm_smmu_xen_domain *xen_domain;
>>>> A suggestion
>>>> 1. as you have used in above function smmu_domain variable for arm_smmu_xen_domain
>>>> Can similar logic be used for iommu_domain.
> I am fine changing the var name.
>>>> 2. When smmu_domain variable name is used in above function why xen_domain is used in this function.
>>>> It is quite confusing.
>>>> logically xen_domain should mean a VM.
> You lost me man. xen_domain is referring to the page tables of the the VM currently using the SMMU. What is the concern?
in xen when you read basic documentation a domain is a VM, right?
Now what would xen_domain variable should mean.
How would you know it has something to do with SMMU.

So it is confusing to someone looking at the code.
>>>>> +    struct arm_smmu_device *smmu;
>>>>> +    struct arm_smmu_domain *smmu_domain;
>>>> smmu_domain was used for arm_smmu_xen_domain.
> Failed to see it. But, I'll have another look.
>
>>>> consistency of variable names is necessary for code clarity
>>>>> +
>>>>> +    xen_domain = dom_iommu(d)->arch.priv;
>>>>> +
>>>>> +    smmu = arm_smmu_get_by_fwnode(dev->iommu_fwspec->iommu_fwnode);
>>>>> +    if (!smmu)
>>>>> +        return NULL;
>>>>> +
>>>>> +    /*
>>>>> +     * Loop through the &xen_domain->contexts to locate a context
>>>>> +     * assigned to this SMMU
>>>>> +     */
>>>>> +    list_for_each_entry(domain, &xen_domain->contexts, list) {
>>>>> +        smmu_domain = to_smmu_domain(domain);
>>>>> +        if (smmu_domain->smmu == smmu)
>>>>> +            return domain;
>>>>> +    }
>>>>> +
>>>>> +    return NULL;
>>>>> +}
>>>>> +
>>>>> +static void arm_smmu_destroy_iommu_domain(struct iommu_domain *domain)
>>>> same
> Ok
>>>>> +{
>>>>> +    list_del(&domain->list);
>>>>> +    arm_smmu_domain_free(domain);
>>>>> +}
>>>>> +
>>>>> +static int arm_smmu_assign_dev(struct domain *d, u8 devfn,
>>>>> +                   struct device *dev, u32 flag)
>>>>> +{
>>>>> +    int ret = 0;
>>>>> +    struct iommu_domain *domain;
>>>>> +    struct arm_smmu_xen_domain *xen_domain;
>>>> same
> xen_domain is fine. You have an issue with the iommu_domioan here?
domain has a variable name d, and iommu_domain has a variable name domain.
Isnt it confusing.
Why cant we use
struct iommu_domain *io_domain ...

>>>>> +    struct arm_smmu_domain *arm_smmu;
>>>>> +
>>>>> +    xen_domain = dom_iommu(d)->arch.priv;
>>>>> +
>>>>> +    if (!dev->archdata.iommu) {
>>>>> +        dev->archdata.iommu = xzalloc(struct arm_smmu_xen_device);
>>>>> +        if (!dev->archdata.iommu)
>>>>> +            return -ENOMEM;
>>>>> +    }
>>>>> +
>>>>> +    ret = arm_smmu_add_device(dev);
>>>>> +    if (ret)
>>>>> +        return ret;
>>>>> +
>>>>> +    spin_lock(&xen_domain->lock);
>>>>> +
>>>>> +    /*
>>>>> +     * Check to see if an iommu_domain already exists for this xen domain
>>>>> +     * under the same SMMU
>>>>> +     */
>>>>> +    domain = arm_smmu_get_domain(d, dev);
>>>>> +    if (!domain) {
>>>>> +
>>>>> +        domain = arm_smmu_domain_alloc(IOMMU_DOMAIN_DMA);
>>>>> +        if (!domain) {
>>>>> +            ret = -ENOMEM;
>>>>> +            goto out;
>>>>> +        }
>>>>> +
>>>>> +        arm_smmu = to_smmu_domain(domain);
>>>>> +        arm_smmu->s2_cfg.domain = d;
>>>>> +
>>>>> +        /* Chain the new context to the domain */
>>>>> +        list_add(&domain->list, &xen_domain->contexts);
>>>>> +
>>>>> +    }
>>>>> +
>>>>> +    ret = arm_smmu_attach_dev(domain, dev);
>>>>> +    if (ret) {
>>>>> +        if (domain->ref.counter == 0)
>>>>> +            arm_smmu_destroy_iommu_domain(domain);
>>>>> +    } else {
>>>>> +        atomic_inc(&domain->ref);
>>>>> +    }
>>>>> +
>>>>> +out:
>>>>> +    spin_unlock(&xen_domain->lock);
>>>>> +    return ret;
>>>>> +}
>>>>> +
>>>>> +static int arm_smmu_deassign_dev(struct domain *d, struct device *dev)
>>>>> +{
>>>>> +    struct iommu_domain *domain = arm_smmu_get_domain(d, dev);
>>>>> +    struct arm_smmu_xen_domain *xen_domain;
>>>>> +    struct arm_smmu_domain *arm_smmu = to_smmu_domain(domain);
>>>> same
>>>>> +
>>>>> +    xen_domain = dom_iommu(d)->arch.priv;
>>>>> +
>>>>> +    if (!arm_smmu || arm_smmu->s2_cfg.domain != d) {
>>>>> +        dev_err(dev, " not attached to domain %d\n", d->domain_id);
>>>>> +        return -ESRCH;
>>>>> +    }
>>>>> +
>>>>> +    spin_lock(&xen_domain->lock);
>>>>> +
>>>>> +    arm_smmu_detach_dev(dev);
>>>>> +    atomic_dec(&domain->ref);
>>>>> +
>>>>> +    if (domain->ref.counter == 0)
>>>>> +        arm_smmu_destroy_iommu_domain(domain);
>>>>> +
>>>>> +    spin_unlock(&xen_domain->lock);
>>>>> +
>>>>> +    return 0;
>>>>> +}
>>>>> +
>>>>> +static int arm_smmu_reassign_dev(struct domain *s, struct domain *t,
>>>>> +                 u8 devfn,  struct device *dev)
>>>>> +{
>>>>> +    int ret = 0;
>>>>> +
>>>>> +    /* Don't allow remapping on other domain than hwdom */
>>>>> +    if (t && t != hardware_domain)
>>>>> +        return -EPERM;
>>>>> +
>>>>> +    if (t == s)
>>>>> +        return 0;
>>>>> +
>>>>> +    ret = arm_smmu_deassign_dev(s, dev);
>>>>> +    if (ret)
>>>>> +        return ret;
>>>>> +
>>>>> +    if (t) {
>>>>> +        /* No flags are defined for ARM. */
>>>>> +        ret = arm_smmu_assign_dev(t, devfn, dev, 0);
>>>>> +        if (ret)
>>>>> +            return ret;
>>>>> +    }
>>>>> +
>>>>> +    return 0;
>>>>> +}
>>>>> +
>>>>> +static int arm_smmu_iommu_domain_init(struct domain *d)
>>>> Where is iommu_domain initialized?
>>>> The function does not use a iommu_domain * variable
>>>>> +{
>>>>> +    struct arm_smmu_xen_domain *xen_domain;
>>>>> +
>>>>> +    xen_domain = xzalloc(struct arm_smmu_xen_domain);
>>>>> +    if (!xen_domain)
>>>>> +        return -ENOMEM;
>>>>> +
>>>>> +    spin_lock_init(&xen_domain->lock);
>>>>> +    INIT_LIST_HEAD(&xen_domain->contexts);
>>>>> +
>>>>> +    dom_iommu(d)->arch.priv = xen_domain;
>>>>> +
>>>>> +    return 0;
>>>>> +}
>>>>> +
>>>>> +static void __hwdom_init arm_smmu_iommu_hwdom_init(struct domain *d)
>>>>> +{
>>>>> +}
>>>>> +
>>>>> +static void arm_smmu_iommu_domain_teardown(struct domain *d)
>>>>> +{
>>>>> +    struct arm_smmu_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
>>>>> +
>>>>> +    ASSERT(list_empty(&xen_domain->contexts));
>>>>> +    xfree(xen_domain);
>>>>> +}
>>>>> +
>>>>> +static int __must_check arm_smmu_map_page(struct domain *d, unsigned long gfn,
>>>>> +            unsigned long mfn, unsigned int flags)
>>>>> +{
>>>>> +    p2m_type_t t;
>>>>> +
>>>>> +    /*
>>>>> +     * Grant mappings can be used for DMA requests. The dev_bus_addr
>>>>> +     * returned by the hypercall is the MFN (not the IPA). For device
>>>>> +     * protected by an IOMMU, Xen needs to add a 1:1 mapping in the domain
>>>>> +     * p2m to allow DMA request to work.
>>>>> +     * This is only valid when the domain is directed mapped. Hence this
>>>>> +     * function should only be used by gnttab code with gfn == mfn.
>>>>> +     */
>>>>> +    BUG_ON(!is_domain_direct_mapped(d));
>>>>> +    BUG_ON(mfn != gfn);
>>>>> +
>>>>> +    /* We only support readable and writable flags */
>>>>> +    if (!(flags & (IOMMUF_readable | IOMMUF_writable)))
>>>>> +        return -EINVAL;
>>>>> +
>>>>> +    t = (flags & IOMMUF_writable) ? p2m_iommu_map_rw : p2m_iommu_map_ro;
>>>>> +
>>>>> +    /*
>>>>> +     * The function guest_physmap_add_entry replaces the current mapping
>>>>> +     * if there is already one...
>>>>> +     */
>>>>> +    return guest_physmap_add_entry(d, _gfn(gfn), _mfn(mfn), 0, t);
>>>>> +}
>>>>> +
>>>>> +static int __must_check arm_smmu_unmap_page(struct domain *d, unsigned long gfn)
>>>>> +{
>>>>> +    /*
>>>>> +     * This function should only be used by gnttab code when the domain
>>>>> +     * is direct mapped
>>>>> +     */
>>>>> +    if (!is_domain_direct_mapped(d))
>>>>> +        return -EINVAL;
>>>>> +
>>>>> +    return guest_physmap_remove_page(d, _gfn(gfn), _mfn(gfn), 0);
>>>>> +}
>>>>> +
>>>>> +static const struct iommu_ops arm_smmu_iommu_ops = {
>>>>> +    .init = arm_smmu_iommu_domain_init,
>>>>> +    .hwdom_init = arm_smmu_iommu_hwdom_init,
>>>>> +    .teardown = arm_smmu_iommu_domain_teardown,
>>>>> +    .iotlb_flush = arm_smmu_iotlb_flush,
>>>>> +    .iotlb_flush_all = arm_smmu_iotlb_flush_all,
>>>>> +    .assign_device = arm_smmu_assign_dev,
>>>>> +    .reassign_device = arm_smmu_reassign_dev,
>>>>> +    .map_page = arm_smmu_map_page,
>>>>> +    .unmap_page = arm_smmu_unmap_page,
>>>>> +};
>>>>> +
>>>>> +static
>>>>> +struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
>>>>> +{
>>>>> +    struct arm_smmu_device *smmu = NULL;
>>>>> +
>>>>> +    spin_lock(&arm_smmu_devices_lock);
>>>>> +    list_for_each_entry(smmu, &arm_smmu_devices, devices) {
>>>>> +        if (smmu->dev->fwnode == fwnode)
>>>>> +            break;
>>>>> +    }
>>>>> +    spin_unlock(&arm_smmu_devices_lock);
>>>>> +
>>>>> +    return smmu;
>>>>> +}
>>>>> +
>>>>> +static __init int arm_smmu_dt_init(struct dt_device_node *dev,
>>>>> +                   const void *data)
>>>>> +{
>>>>> +    int rc;
>>>>> +
>>>>> +    /*
>>>>> +     * Even if the device can't be initialized, we don't want to
>>>>> +     * give the SMMU device to dom0.
>>>>> +     */
>>>>> +    dt_device_set_used_by(dev, DOMID_XEN);
>>>>> +
>>>>> +    rc = arm_smmu_device_probe(dt_to_dev(dev));
>>>>> +    if (rc)
>>>>> +        return rc;
>>>>> +
>>>>> +    iommu_set_ops(&arm_smmu_iommu_ops);
>>>>> +
>>>>> +    return 0;
>>>>> +}
>>>>> +
>>>>> +DT_DEVICE_START(smmuv3, "ARM SMMU V3", DEVICE_IOMMU)
>>>>> +    .dt_match = arm_smmu_of_match,
>>>>> +    .init = arm_smmu_dt_init,
>>>>> +DT_DEVICE_END
>>>>> +
>>>>> +#ifdef CONFIG_ACPI
>>>>> +/* Set up the IOMMU */
>>>>> +static int __init arm_smmu_acpi_init(const void *data)
>>>>> +{
>>>>> +    int rc;
>>>>> +
>>>>> +    rc = arm_smmu_device_probe((struct device *)data);
>>>>> +    if (rc)
>>>>> +        return rc;
>>>>> +
>>>>> +    iommu_set_ops(&arm_smmu_iommu_ops);
>>>>> +    return 0;
>>>>> +}
>>>>> +
>>>>> +ACPI_DEVICE_START(asmmuv3, "ARM SMMU V3", DEVICE_IOMMU)
>>>>> +    .class_type = ACPI_IORT_NODE_SMMU_V3,
>>>>> +    .init = arm_smmu_acpi_init,
>>>>> +ACPI_DEVICE_END
>>>>> +
>>>>> +#endif
>>>>> diff --git a/xen/include/xen/linux_compat.h b/xen/include/xen/linux_compat.h
>>>>> new file mode 100644
>>>>> index 0000000000..8037be0a3e
>>>>> --- /dev/null
>>>>> +++ b/xen/include/xen/linux_compat.h
>>>>> @@ -0,0 +1,84 @@
>>>>> +/******************************************************************************
>>>>> + * include/xen/linux_compat.h
>>>>> + *
>>>>> + * Compatibility defines for porting code from Linux to Xen
>>>>> + *
>>>>> + * Copyright (c) 2017 Linaro Limited
>>>>> + *
>>>>> + * This program is free software; you can redistribute it and/or modify
>>>>> + * it under the terms of the GNU General Public License as published by
>>>>> + * the Free Software Foundation; either version 2 of the License, or
>>>>> + * (at your option) any later version.
>>>>> + *
>>>>> + * This program is distributed in the hope that it will be useful,
>>>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>>>> + * GNU General Public License for more details.
>>>>> + *
>>>>> + * You should have received a copy of the GNU General Public License
>>>>> + * along with this program; If not, see <http://www.gnu.org/licenses/>.
>>>>> + */
>>>>> +
>>>>> +#ifndef __XEN_LINUX_COMPAT_H__
>>>>> +#define __XEN_LINUX_COMPAT_H__
>>>>> +
>>>>> +#include <asm/types.h>
>>>>> +
>>>>> +typedef paddr_t phys_addr_t;
>>>>> +typedef paddr_t dma_addr_t;
>>>>> +
>>>>> +typedef unsigned int gfp_t;
>>>>> +#define GFP_KERNEL 0
>>>>> +#define __GFP_ZERO 0x01U
>>>>> +
>>>>> +/* Helpers for IRQ functions */
>>>>> +#define free_irq release_irq
>>>>> +
>>>>> +enum irqreturn {
>>>>> +    IRQ_NONE,
>>>>> +    IRQ_HANDLED,
>>>>> +    IRQ_WAKE_THREAD,
>>>>> +};
>>>>> +
>>>>> +typedef enum irqreturn irqreturn_t;
>>>>> +
>>>>> +/* Device logger functions */
>>>>> +#define dev_dbg(dev, fmt, ...) printk(XENLOG_DEBUG fmt, ## __VA_ARGS__)
>>>>> +#define dev_notice(dev, fmt, ...) printk(XENLOG_INFO fmt, ## __VA_ARGS__)
>>>>> +#define dev_warn(dev, fmt, ...) printk(XENLOG_WARNING fmt, ## __VA_ARGS__)
>>>>> +#define dev_err(dev, fmt, ...) printk(XENLOG_ERR fmt, ## __VA_ARGS__)
>>>>> +#define dev_info(dev, fmt, ...) printk(XENLOG_INFO fmt, ## __VA_ARGS__)
>>>>> +
>>>>> +#define dev_err_ratelimited(dev, fmt, ...)                  \
>>>>> +     printk(XENLOG_ERR fmt, ## __VA_ARGS__)
>>>>> +
>>>>> +#define dev_name(dev) dt_node_full_name(dev_to_dt(dev))
>>>>> +
>>>>> +/* Alias to Xen allocation helpers */
>>>>> +#define kfree xfree
>>>>> +#define kmalloc(size, flags) ({\
>>>>> +    void *__ret_alloc = NULL; \
>>>>> +    if (flags & __GFP_ZERO) \
>>>>> +        __ret_alloc = _xzalloc(size, sizeof(void *)); \
>>>>> +    else \
>>>>> +        __ret_alloc = _xmalloc(size, sizeof(void *)); \
>>>>> +    __ret_alloc; \
>>>>> +})
>>>>> +#define kzalloc(size, flags)        _xzalloc(size, sizeof(void *))
>>>>> +#define devm_kzalloc(dev, size, flags)  _xzalloc(size, sizeof(void *))
>>>>> +#define kmalloc_array(size, n, flags) ({\
>>>>> +    void *__ret_alloc = NULL; \
>>>>> +    if (flags & __GFP_ZERO) \
>>>>> +        __ret_alloc = _xzalloc_array(size, sizeof(void *), n); \
>>>>> +    else \
>>>>> +        __ret_alloc = _xmalloc_array(size, sizeof(void *), n); \
>>>>> +    __ret_alloc; \
>>>>> +})
>>>>> +
>>>>> +/* Alias to Xen time functions */
>>>>> +#define ktime_t s_time_t
>>>>> +#define ktime_get()             (NOW())
>>>>> +#define ktime_add_us(t,i)       (t + MICROSECS(i))
>>>>> +#define ktime_compare(t,i)      (t > (i))
>>>>> +
>>>>> +#endif /* __XEN_LINUX_COMPAT_H__ */
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xenproject.org
>> https://lists.xenproject.org/mailman/listinfo/xen-devel
Manish Jaggi May 31, 2018, 4:13 a.m. UTC | #13
On 05/31/2018 04:31 AM, Sameer Goel wrote:
>>>>> +
>>>>> +static int arm_smmu_iommu_domain_init(struct domain *d)
>>>> Where is iommu_domain initialized?
>>>> The function does not use a iommu_domain * variable
> Please check iommu.c 2 levels up.
In this function do you see iommu_domain getting allocated or initialized?
As per the name of function arm_smmu iommu_domain_init.
Where is init of iommu_domain in this function?

+static int arm_smmu_iommu_domain_init(struct domain *d)
+{
+	struct arm_smmu_xen_domain *xen_domain;
+
+	xen_domain = xzalloc(struct arm_smmu_xen_domain);
+	if (!xen_domain)
+		return -ENOMEM;
+
+	spin_lock_init(&xen_domain->lock);
+	INIT_LIST_HEAD(&xen_domain->contexts);
+
+	dom_iommu(d)->arch.priv = xen_domain;
+
+	return 0;
+}
+



> Thanks,
> Sameer
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xenproject.org
>> https://lists.xenproject.org/mailman/listinfo/xen-devel
Sameer Goel May 31, 2018, 3:57 p.m. UTC | #14
On 5/30/2018 10:13 PM, Manish Jaggi wrote:
>
>
> On 05/31/2018 04:31 AM, Sameer Goel wrote:
>>>>>> +
>>>>>> +static int arm_smmu_iommu_domain_init(struct domain *d)
>>>>> Where is iommu_domain initialized?
>>>>> The function does not use a iommu_domain * variable
>> Please check iommu.c 2 levels up.
> In this function do you see iommu_domain getting allocated or initialized?
> As per the name of function arm_smmu iommu_domain_init.
> Where is init of iommu_domain in this function?
Well without the xen_domain the iommu_domain is not initialized. It is just the default value. This generic iommu code makes an .init call to our code for whatever initialization is needed. So the name here seemed absolutely fine to me.

Initialization does not always refer to allocation. In this case this is driver specific initialization. Since, the iommu code is making an init call to the smmu code hence the name arm_smmu_iommu_domain_init. So, again I agree with your comments on the domain variable names and I'm making these changes as they would make the code cleaner. This function name change probably will not do much but the move along the discussion, let me know what you were thinking.
>
> +static int arm_smmu_iommu_domain_init(struct domain *d)
> +{
> +    struct arm_smmu_xen_domain *xen_domain;
> +
> +    xen_domain = xzalloc(struct arm_smmu_xen_domain);
> +    if (!xen_domain)
> +        return -ENOMEM;
> +
> +    spin_lock_init(&xen_domain->lock);
> +    INIT_LIST_HEAD(&xen_domain->contexts);
> +
> +    dom_iommu(d)->arch.priv = xen_domain;
> +
> +    return 0;
> +}
> +
>
>
>
>> Thanks,
>> Sameer
>>>
>>> _______________________________________________
>>> Xen-devel mailing list
>>> Xen-devel@lists.xenproject.org
>>> https://lists.xenproject.org/mailman/listinfo/xen-devel
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xenproject.org
> https://lists.xenproject.org/mailman/listinfo/xen-devel
Goel, Sameer May 31, 2018, 4:06 p.m. UTC | #15
On 5/30/2018 10:10 PM, Manish Jaggi wrote:
> 
> 
> On 05/31/2018 01:16 AM, Sameer Goel wrote:
>> Manish, I'll take another look at the variable names. I might not have enough time :).
>>>>
>>>> On 05/23/2018 10:48 PM, Manish Jaggi wrote:
>>>>> Hi Sameer,
>>>>>
>>>>> General Comment, please use appropriate variable names for XXX_domain structures in code which is xen specific.
>>>> I thought that we had discussed this before on one of the RFCs.
>>> Yes and no one replied to my last comment that the var names have to be non confusing in Xen specific code.
>> I'm sorry about that. I just assumed that since the policy on ported variable names was consistent we so not nee to change the names.
>>
>>>> At this point we are just using the format used for smmu-v2.
>>> smmu-v2 has a lot of confusing variable names with _domain.
>>> I believe that file needs to be fixed as well.
>>>> I don't think that the variable names are inappropriate. Unless there is a very specific issue with the variable names,
>>> The issue is in code readability and understanding the flow.
>>> It is confusing so many _domain variable names are used which are not verbose.
>> These names are coming from the original Linux code. So, we do not change them as per the policy. That being said I can add a comment section to explain the confusing variables in the Xen specific code? Please let me know if this will help us resolve this issue?
>>   
> If it is in Xen specific functions, then it can be changed, this is what julien also confirmed.

Agreed. Changing the var names.
> 
>>> Two functions different and confusing variable names
>>>>>> +    struct iommu_domain *domain;
>>>>>> +};
>>>>>> +
>>>>> As this is a xen specific code, can the variable names be used appropriately.
>>>>> Repeating my comment  from earlier version.
>>>>> a domain is  usually a VM in Xen. So it is a bit confusing to use domain for iommu_domain.
>> The struct is fine but you have an issue with the var name right?
> Yes.
>>
>>>>>> +/*
>>>>>> + * Xen: io_pgtable compatibility defines.
>>>>>> + * Most of these are to port in the S1 translation code as is.
>>>>>> + */
>>>>>> +struct io_pgtable_ops {
>>>>>> +};
>>>>>> +
>>>>>> +struct iommu_gather_ops {
>>>>>> +    void (*tlb_flush_all)(void *cookie);
>>>>>> +    void (*tlb_add_flush)(unsigned long iova, size_t size, size_t granule,
>>>>>> +                  bool leaf, void *cookie);
>>>>>> +    void (*tlb_sync)(void *cookie);
>>>>>> +};
>>>>>> +
>>>>>> +struct io_pgtable_cfg {
>>>>>> +    /*
>>>>>> +     * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE bits in
>>>>>> +     *    stage 1 PTEs, for hardware which insists on validating them
>>>>>> +     *    even in    non-secure state where they should normally be ignored.
>>>>>> +     *
>>>>>> +     * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE and
>>>>>> +     *    IOMMU_NOEXEC flags and map everything with full access, for
>>>>>> +     *    hardware which does not implement the permissions of a given
>>>>>> +     *    format, and/or requires some format-specific default value.
>>>>>> +     *
>>>>>> +     * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching invalid
>>>>>> +     *    (unmapped) entries but the hardware might do so anyway, perform
>>>>>> +     *    TLB maintenance when mapping as well as when unmapping.
>>>>>> +     *
>>>>>> +     * IO_PGTABLE_QUIRK_ARM_MTK_4GB: (ARM v7s format) Set bit 9 in all
>>>>>> +     *    PTEs, for Mediatek IOMMUs which treat it as a 33rd address bit
>>>>>> +     *    when the SoC is in "4GB mode" and they can only access the high
>>>>>> +     *    remap of DRAM (0x1_00000000 to 0x1_ffffffff).
>>>>>> +     *
>>>>>> +     * IO_PGTABLE_QUIRK_NO_DMA: Guarantees that the tables will only ever
>>>>>> +     *    be accessed by a fully cache-coherent IOMMU or CPU (e.g. for a
>>>>>> +     *    software-emulated IOMMU), such that pagetable updates need not
>>>>>> +     *    be treated as explicit DMA data.
>>>>>> +     */
>>>>>> +    #define IO_PGTABLE_QUIRK_ARM_NS        BIT(0)
>>>>>> +    #define IO_PGTABLE_QUIRK_NO_PERMS    BIT(1)
>>>>>> +    #define IO_PGTABLE_QUIRK_TLBI_ON_MAP    BIT(2)
>>>>>> +    #define IO_PGTABLE_QUIRK_ARM_MTK_4GB    BIT(3)
>>>>>> +    #define IO_PGTABLE_QUIRK_NO_DMA        BIT(4)
>>>>>> +    unsigned long            quirks;
>>>>>> +    unsigned long            pgsize_bitmap;
>>>>>> +    unsigned int            ias;
>>>>>> +    unsigned int            oas;
>>>>>> +    const struct iommu_gather_ops    *tlb;
>>>>>> +    struct device            *iommu_dev;
>>>>>> +
>>>>>> +    /* Low-level data specific to the table format */
>>>>>> +    union {
>>>>>> +        struct {
>>>>>> +            u64    ttbr[2];
>>>>>> +            u64    tcr;
>>>>>> +            u64    mair[2];
>>>>>> +        } arm_lpae_s1_cfg;
>>>>>> +
>>>>>> +        struct {
>>>>>> +            u64    vttbr;
>>>>>> +            u64    vtcr;
>>>>>> +        } arm_lpae_s2_cfg;
>>>>>> +
>>>>>> +        struct {
>>>>>> +            u32    ttbr[2];
>>>>>> +            u32    tcr;
>>>>>> +            u32    nmrr;
>>>>>> +            u32    prrr;
>>>>>> +        } arm_v7s_cfg;
>>>>>> +    };
>>>>>> +};
>>>>>> +
>>>>>> +enum io_pgtable_fmt {
>>>>>> +    ARM_32_LPAE_S1,
>>>>>> +    ARM_32_LPAE_S2,
>>>>>> +    ARM_64_LPAE_S1,
>>>>>> +    ARM_64_LPAE_S2,
>>>>>> +    ARM_V7S,
>>>>>> +    IO_PGTABLE_NUM_FMTS,
>>>>>> +};
>>>>>> +
>>>>>> +/*
>>>>>> + * Xen: The pgtable_ops are used by the S1 translations, so return the dummy
>>>>>> + * address.
>>>>>> + */
>>>>>> +#define alloc_io_pgtable_ops(f, c, o) ((struct io_pgtable_ops *)0x1)
>>>>>> +#define free_io_pgtable_ops(o)
>>>>>> +
>>>>>> +/* Xen: Define wrapper for requesting IRQs */
>>>>>> +#define IRQF_ONESHOT 0
>>>>>> +
>>>>>> +typedef void (*irq_handler_t)(int, void *, struct cpu_user_regs *);
>>>>>> +
>>>>>> +static inline int devm_request_irq(struct device *dev, unsigned int irq,
>>>>>> +                   irq_handler_t handler, unsigned long irqflags,
>>>>>> +                   const char *devname, void *dev_id)
>>>>>> +{
>>>>>> +    /*
>>>>>> +     * SMMUv3 implementation can support wired interrupt outputs that are
>>>>>> +     * edge-triggered. Set the irq type as per the spec.
>>>>>> +     */
>>>>>> +    irq_set_type(irq, IRQ_TYPE_EDGE_BOTH);
>>>>>> +    return request_irq(irq, irqflags, handler, devname, dev_id);
>>>>>> +}
>>>>>> +
>>>>>> +/*
>>>>>> + * Xen does not have a concept of threaded irq, but we can use tasklets to
>>>>>> + * achieve the desired functionality as needed.
>>>>>> + */
>>>>>> +int devm_request_threaded_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
>>>>>> +                  irq_handler_t thread_fn, unsigned long irqflags,
>>>>>> +                  const char *devname, void *dev_id)
>>>>>> +{
>>>>>> +    return devm_request_irq(dev, irq, thread_fn, irqflags, devname, dev_id);
>>>>>> +}
>>>>>> +
>>>>>> +/* Xen: The mutex is used only during initialization so the typecast is safe */
>>>>>> +#define mutex spinlock
>>>>>> +#define mutex_init spin_lock_init
>>>>>> +#define mutex_lock spin_lock
>>>>>> +#define mutex_unlock spin_unlock
>>>>>> +
>>>>>> +#define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us) \
>>>>>> +({ \
>>>>>> +    s_time_t deadline = NOW() + MICROSECS(timeout_us); \
>>>>>> +    for (;;) { \
>>>>>> +        (val) = op(addr); \
>>>>>> +        if (cond) \
>>>>>> +            break; \
>>>>>> +        if (NOW() > deadline) { \
>>>>>> +            (val) = op(addr); \
>>>>>> +            break; \
>>>>>> +        } \
>>>>>> +    udelay(sleep_us); \
>>>>>> +    } \
>>>>>> +    (cond) ? 0 : -ETIMEDOUT; \
>>>>>> +})
>>>>>> +
>>>>>> +#define readl_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
>>>>>> +    readx_poll_timeout(readl_relaxed, addr, val, cond, delay_us, timeout_us)
>>>>>> +
>>>>>> +#define VA_BITS 0 /* Only needed for S1 translations */
>>>>>>      /* MMIO registers */
>>>>>>    #define ARM_SMMU_IDR0            0x0
>>>>>> @@ -433,6 +819,7 @@ enum pri_resp {
>>>>>>        PRI_RESP_SUCC,
>>>>>>    };
>>>>>>    +#if 0 /* Xen: No MSI support in this iteration */
>>>>>>    enum arm_smmu_msi_index {
>>>>>>        EVTQ_MSI_INDEX,
>>>>>>        GERROR_MSI_INDEX,
>>>>>> @@ -457,6 +844,7 @@ static phys_addr_t arm_smmu_msi_cfg[ARM_SMMU_MAX_MSIS][3] = {
>>>>>>            ARM_SMMU_PRIQ_IRQ_CFG2,
>>>>>>        },
>>>>>>    };
>>>>>> +#endif
>>>>>>      struct arm_smmu_cmdq_ent {
>>>>>>        /* Common fields */
>>>>>> @@ -561,6 +949,8 @@ struct arm_smmu_s2_cfg {
>>>>>>        u16                vmid;
>>>>>>        u64                vttbr;
>>>>>>        u64                vtcr;
>>>>>> +    /* Xen: Domain associated to this configuration */
>>>>>> +    struct domain            *domain;
>>>>>>    };
>>>>>>      struct arm_smmu_strtab_ent {
>>>>>> @@ -635,9 +1025,25 @@ struct arm_smmu_device {
>>>>>>        struct arm_smmu_strtab_cfg    strtab_cfg;
>>>>>>          /* IOMMU core code handle */
>>>>>> +#if 0 /*Xen: Generic iommu_device ref not needed here */
>>>>>>        struct iommu_device        iommu;
>>>>>> +#endif
>>>>> Is it clean to put #if 0, can this line be deleted or used with a proper macro
>> Manish this is a var name from original struct from Linux. I have just followed the prior standard of adding #if 0.
> It does not look clean, can we use something other than 0, say a macro NA_CODE ...
That's true. Adding NA_CODE will probably make things clearer. I'll incorporate the change.

>>>>>> +    /* Xen: Need to keep a list of SMMU devices */
>>>>>> +    struct list_head                devices;
>>>>>> +    /* Xen: Tasklets for handling evts/faults and pci page request IRQs*/
>>>>>> +    struct tasklet            evtq_tasklet;
>>>>>> +    struct tasklet            priq_tasklet;
>>>>>> +    struct tasklet            combined_irq_tasklet;
.....
>>>>>> +                        struct device *dev)
>>>>> This is returning iommu_domain and not a domain.
>>>>> Please change the name of function.
>> Same as smmu-v2.c. I think with the complexity of the code we should try to get this in as the prior code. Once the set that has been pending for some time is in. We can start on the variable cleanup activity. I say this so that we can make the names consistent across the drivers and this will be a lot easier to do when the majority of the other code is in.
> smmu-v2.c had this issue and I had hard time understanding the code, the confusing variable names break the understanding flow, especially when you are debugging something and have lost touch of code.
> So let not do same mistake as in smmu-v2.c
Agreed. Will change the variable name.
>>>>>> +{
>>>>>> +    struct iommu_domain *domain;
>>>>>> +    struct arm_smmu_xen_domain *xen_domain;
>>>>> A suggestion
>>>>> 1. as you have used in above function smmu_domain variable for arm_smmu_xen_domain
>>>>> Can similar logic be used for iommu_domain.
>> I am fine changing the var name.
>>>>> 2. When smmu_domain variable name is used in above function why xen_domain is used in this function.
>>>>> It is quite confusing.
>>>>> logically xen_domain should mean a VM.
>> You lost me man. xen_domain is referring to the page tables of the the VM currently using the SMMU. What is the concern?
> in xen when you read basic documentation a domain is a VM, right?
> Now what would xen_domain variable should mean.
> How would you know it has something to do with SMMU.
> 
> So it is confusing to someone looking at the code.
I agree that you would think about the VMs when you see xen_domain. In this case the xen_domain variable has a 1:1 correspondence with the SMMU. If I call this smmu_xen_domain will it be easier to read?
>>>>>> +    struct arm_smmu_device *smmu;
>>>>>> +    struct arm_smmu_domain *smmu_domain;
>>>>> smmu_domain was used for arm_smmu_xen_domain.
>> Failed to see it. But, I'll have another look.
>>
>>>>> consistency of variable names is necessary for code clarity
>>>>>> +
>>>>>> +    xen_domain = dom_iommu(d)->arch.priv;
>>>>>> +
>>>>>> +    smmu = arm_smmu_get_by_fwnode(dev->iommu_fwspec->iommu_fwnode);
>>>>>> +    if (!smmu)
>>>>>> +        return NULL;
>>>>>> +
>>>>>> +    /*
>>>>>> +     * Loop through the &xen_domain->contexts to locate a context
>>>>>> +     * assigned to this SMMU
>>>>>> +     */
>>>>>> +    list_for_each_entry(domain, &xen_domain->contexts, list) {
>>>>>> +        smmu_domain = to_smmu_domain(domain);
>>>>>> +        if (smmu_domain->smmu == smmu)
>>>>>> +            return domain;
>>>>>> +    }
>>>>>> +
>>>>>> +    return NULL;
>>>>>> +}
>>>>>> +
>>>>>> +static void arm_smmu_destroy_iommu_domain(struct iommu_domain *domain)
>>>>> same
>> Ok
>>>>>> +{
>>>>>> +    list_del(&domain->list);
>>>>>> +    arm_smmu_domain_free(domain);
>>>>>> +}
>>>>>> +
>>>>>> +static int arm_smmu_assign_dev(struct domain *d, u8 devfn,
>>>>>> +                   struct device *dev, u32 flag)
>>>>>> +{
>>>>>> +    int ret = 0;
>>>>>> +    struct iommu_domain *domain;
>>>>>> +    struct arm_smmu_xen_domain *xen_domain;
>>>>> same
>> xen_domain is fine. You have an issue with the iommu_domioan here?
> domain has a variable name d, and iommu_domain has a variable name domain.
> Isnt it confusing.
> Why cant we use
> struct iommu_domain *io_domain ...
I agree. I am changing this all to iommu_domain. io_domain is fine too. What do you prefer?
> 
>>>>>> +    struct arm_smmu_domain *arm_smmu;
>>>>>> +
>>>>>> +    xen_domain = dom_iommu(d)->arch.priv;
>>>>>> +
>>>>>> +    if (!dev->archdata.iommu) {
>>>>>> +        dev->archdata.iommu = xzalloc(struct arm_smmu_xen_device);
>>>>>> +        if (!dev->archdata.iommu)
>>>>>> +            return -ENOMEM;
>>>>>> +    }
>>>>>> +
>>>>>> +    ret = arm_smmu_add_device(dev);
>>>>>> +    if (ret)
>>>>>> +        return ret;
>>>>>> +
>>>>>> +    spin_lock(&xen_domain->lock);
>>>>>> +
>>>>>> +    /*
>>>>>> +     * Check to see if an iommu_domain already exists for this xen domain
>>>>>> +     * under the same SMMU
>>>>>> +     */
>>>>>> +    domain = arm_smmu_get_domain(d, dev);
>>>>>> +    if (!domain) {
>>>>>> +
>>>>>> +        domain = arm_smmu_domain_alloc(IOMMU_DOMAIN_DMA);
>>>>>> +        if (!domain) {
>>>>>> +            ret = -ENOMEM;
>>>>>> +            goto out;
>>>>>> +        }
>>>>>> +
>>>>>> +        arm_smmu = to_smmu_domain(domain);
>>>>>> +        arm_smmu->s2_cfg.domain = d;
>>>>>> +
>>>>>> +        /* Chain the new context to the domain */
>>>>>> +        list_add(&domain->list, &xen_domain->contexts);
>>>>>> +
>>>>>> +    }
>>>>>> +
>>>>>> +    ret = arm_smmu_attach_dev(domain, dev);
>>>>>> +    if (ret) {
>>>>>> +        if (domain->ref.counter == 0)
>>>>>> +            arm_smmu_destroy_iommu_domain(domain);
>>>>>> +    } else {
>>>>>> +        atomic_inc(&domain->ref);
>>>>>> +    }
>>>>>> +
>>>>>> +out:
>>>>>> +    spin_unlock(&xen_domain->lock);
>>>>>> +    return ret;
>>>>>> +}
>>>>>> +
>>>>>> +static int arm_smmu_deassign_dev(struct domain *d, struct device *dev)
>>>>>> +{
>>>>>> +    struct iommu_domain *domain = arm_smmu_get_domain(d, dev);
>>>>>> +    struct arm_smmu_xen_domain *xen_domain;
>>>>>> +    struct arm_smmu_domain *arm_smmu = to_smmu_domain(domain);
>>>>> same
>>>>>> +
>>>>>> +    xen_domain = dom_iommu(d)->arch.priv;
>>>>>> +
>>>>>> +    if (!arm_smmu || arm_smmu->s2_cfg.domain != d) {
>>>>>> +        dev_err(dev, " not attached to domain %d\n", d->domain_id);
>>>>>> +        return -ESRCH;
>>>>>> +    }
>>>>>> +
>>>>>> +    spin_lock(&xen_domain->lock);
>>>>>> +
>>>>>> +    arm_smmu_detach_dev(dev);
>>>>>> +    atomic_dec(&domain->ref);
>>>>>> +
>>>>>> +    if (domain->ref.counter == 0)
>>>>>> +        arm_smmu_destroy_iommu_domain(domain);
>>>>>> +
>>>>>> +    spin_unlock(&xen_domain->lock);
>>>>>> +
>>>>>> +    return 0;
>>>>>> +}
>>>>>> +
>>>>>> +static int arm_smmu_reassign_dev(struct domain *s, struct domain *t,
>>>>>> +                 u8 devfn,  struct device *dev)
>>>>>> +{
>>>>>> +    int ret = 0;
>>>>>> +
>>>>>> +    /* Don't allow remapping on other domain than hwdom */
>>>>>> +    if (t && t != hardware_domain)
>>>>>> +        return -EPERM;
>>>>>> +
>>>>>> +    if (t == s)
>>>>>> +        return 0;
>>>>>> +
>>>>>> +    ret = arm_smmu_deassign_dev(s, dev);
>>>>>> +    if (ret)
>>>>>> +        return ret;
>>>>>> +
>>>>>> +    if (t) {
>>>>>> +        /* No flags are defined for ARM. */
>>>>>> +        ret = arm_smmu_assign_dev(t, devfn, dev, 0);
>>>>>> +        if (ret)
>>>>>> +            return ret;
>>>>>> +    }
>>>>>> +
>>>>>> +    return 0;
>>>>>> +}
>>>>>> +
>>>>>> +static int arm_smmu_iommu_domain_init(struct domain *d)
>>>>> Where is iommu_domain initialized?
>>>>> The function does not use a iommu_domain * variable
>>>>>> +{
>>>>>> +    struct arm_smmu_xen_domain *xen_domain;
>>>>>> +
>>>>>> +    xen_domain = xzalloc(struct arm_smmu_xen_domain);
>>>>>> +    if (!xen_domain)
>>>>>> +        return -ENOMEM;
>>>>>> +
>>>>>> +    spin_lock_init(&xen_domain->lock);
>>>>>> +    INIT_LIST_HEAD(&xen_domain->contexts);
>>>>>> +
>>>>>> +    dom_iommu(d)->arch.priv = xen_domain;
>>>>>> +
>>>>>> +    return 0;
>>>>>> +}
>>>>>> +
>>>>>> +static void __hwdom_init arm_smmu_iommu_hwdom_init(struct domain *d)
>>>>>> +{
>>>>>> +}
>>>>>> +
>>>>>> +static void arm_smmu_iommu_domain_teardown(struct domain *d)
>>>>>> +{
>>>>>> +    struct arm_smmu_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
>>>>>> +
>>>>>> +    ASSERT(list_empty(&xen_domain->contexts));
>>>>>> +    xfree(xen_domain);
>>>>>> +}
>>>>>> +
>>>>>> +static int __must_check arm_smmu_map_page(struct domain *d, unsigned long gfn,
>>>>>> +            unsigned long mfn, unsigned int flags)
>>>>>> +{
>>>>>> +    p2m_type_t t;
>>>>>> +
>>>>>> +    /*
>>>>>> +     * Grant mappings can be used for DMA requests. The dev_bus_addr
>>>>>> +     * returned by the hypercall is the MFN (not the IPA). For device

>>> https://lists.xenproject.org/mailman/listinfo/xen-devel
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xenproject.org
> https://lists.xenproject.org/mailman/listinfo/xen-devel
Manish Jaggi June 1, 2018, 5:16 a.m. UTC | #16
On 05/31/2018 09:27 PM, Sameer Goel wrote:
>
> On 5/30/2018 10:13 PM, Manish Jaggi wrote:
>>
>> On 05/31/2018 04:31 AM, Sameer Goel wrote:
>>>>>>> +
>>>>>>> +static int arm_smmu_iommu_domain_init(struct domain *d)
>>>>>> Where is iommu_domain initialized?
>>>>>> The function does not use a iommu_domain * variable
>>> Please check iommu.c 2 levels up.
>> In this function do you see iommu_domain getting allocated or initialized?
>> As per the name of function arm_smmu iommu_domain_init.
>> Where is init of iommu_domain in this function?
> Well without the xen_domain the iommu_domain is not initialized. It is just the default value. This generic iommu code makes an .init call to our code for whatever initialization is needed. So the name here seemed absolutely fine to me.
>
> Initialization does not always refer to allocation. In this case this is driver specific initialization. Since, the iommu code is making an init call to the smmu code hence the name arm_smmu_iommu_domain_init. So, again I agree with your comments on the domain variable names and I'm making these changes as they would make the code cleaner. This function name change probably will not do much but the move along the discussion, let me know what you were thinking.
Sameer, few points
a. all the functions are prefixed with arm_smmu_ , so what the function 
is doing can be understood by the rest part of the name
In this case it is iommu_domain_init.

b. By the name it seems to suggest that you are  doing some kind of init 
for iommu_domain

c. But in this complete function, iommu_domain pointer is never used.

If I take your point, the appropriate name of the function should be 
arm_smmu_xen_domain_init().

-Manish
>> +static int arm_smmu_iommu_domain_init(struct domain *d)
>> +{
>> +    struct arm_smmu_xen_domain *xen_domain;
>> +
>> +    xen_domain = xzalloc(struct arm_smmu_xen_domain);
>> +    if (!xen_domain)
>> +        return -ENOMEM;
>> +
>> +    spin_lock_init(&xen_domain->lock);
>> +    INIT_LIST_HEAD(&xen_domain->contexts);
>> +
>> +    dom_iommu(d)->arch.priv = xen_domain;
>> +
>> +    return 0;
>> +}
>> +
>>
>>
>>
>>> Thanks,
>>> Sameer
>>>> _______________________________________________
>>>> Xen-devel mailing list
>>>> Xen-devel@lists.xenproject.org
>>>> https://lists.xenproject.org/mailman/listinfo/xen-devel
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xenproject.org
>> https://lists.xenproject.org/mailman/listinfo/xen-devel
Sameer Goel June 1, 2018, 6:58 p.m. UTC | #17
On 5/31/2018 11:16 PM, Manish Jaggi wrote:
>
>
> On 05/31/2018 09:27 PM, Sameer Goel wrote:
>>
>> On 5/30/2018 10:13 PM, Manish Jaggi wrote:
>>>
>>> On 05/31/2018 04:31 AM, Sameer Goel wrote:
>>>>>>>> +
>>>>>>>> +static int arm_smmu_iommu_domain_init(struct domain *d)
>>>>>>> Where is iommu_domain initialized?
>>>>>>> The function does not use a iommu_domain * variable
>>>> Please check iommu.c 2 levels up.
>>> In this function do you see iommu_domain getting allocated or initialized?
>>> As per the name of function arm_smmu iommu_domain_init.
>>> Where is init of iommu_domain in this function?
>> Well without the xen_domain the iommu_domain is not initialized. It is just the default value. This generic iommu code makes an .init call to our code for whatever initialization is needed. So the name here seemed absolutely fine to me.
>>
>> Initialization does not always refer to allocation. In this case this is driver specific initialization. Since, the iommu code is making an init call to the smmu code hence the name arm_smmu_iommu_domain_init. So, again I agree with your comments on the domain variable names and I'm making these changes as they would make the code cleaner. This function name change probably will not do much but the move along the discussion, let me know what you were thinking.
> Sameer, few points
> a. all the functions are prefixed with arm_smmu_ , so what the function is doing can be understood by the rest part of the name
> In this case it is iommu_domain_init.
>
> b. By the name it seems to suggest that you are  doing some kind of init for iommu_domain
>
> c. But in this complete function, iommu_domain pointer is never used.
>
> If I take your point, the appropriate name of the function should be arm_smmu_xen_domain_init().
Its not the iommu domain defined within the current driver.  I'll change the name to arm_smmu_xen_iommu_init().

arm_smmu for just keeping the prefixes as needed. Sounds good?

Thanks,
Sameer
>
> -Manish
>>> +static int arm_smmu_iommu_domain_init(struct domain *d)
>>> +{
>>> +    struct arm_smmu_xen_domain *xen_domain;
>>> +
>>> +    xen_domain = xzalloc(struct arm_smmu_xen_domain);
>>> +    if (!xen_domain)
>>> +        return -ENOMEM;
>>> +
>>> +    spin_lock_init(&xen_domain->lock);
>>> +    INIT_LIST_HEAD(&xen_domain->contexts);
>>> +
>>> +    dom_iommu(d)->arch.priv = xen_domain;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>>
>>>
>>>
>>>> Thanks,
>>>> Sameer
>>>>> _______________________________________________
>>>>> Xen-devel mailing list
>>>>> Xen-devel@lists.xenproject.org
>>>>> https://lists.xenproject.org/mailman/listinfo/xen-devel
>>>
>>> _______________________________________________
>>> Xen-devel mailing list
>>> Xen-devel@lists.xenproject.org
>>> https://lists.xenproject.org/mailman/listinfo/xen-devel
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xenproject.org
> https://lists.xenproject.org/mailman/listinfo/xen-devel
Manish Jaggi June 2, 2018, 9:26 p.m. UTC | #18
On 06/02/2018 12:28 AM, Sameer Goel wrote:
>
> On 5/31/2018 11:16 PM, Manish Jaggi wrote:
>>
>> On 05/31/2018 09:27 PM, Sameer Goel wrote:
>>> On 5/30/2018 10:13 PM, Manish Jaggi wrote:
>>>> On 05/31/2018 04:31 AM, Sameer Goel wrote:
>>>>>>>>> +
>>>>>>>>> +static int arm_smmu_iommu_domain_init(struct domain *d)
>>>>>>>> Where is iommu_domain initialized?
>>>>>>>> The function does not use a iommu_domain * variable
>>>>> Please check iommu.c 2 levels up.
>>>> In this function do you see iommu_domain getting allocated or initialized?
>>>> As per the name of function arm_smmu iommu_domain_init.
>>>> Where is init of iommu_domain in this function?
>>> Well without the xen_domain the iommu_domain is not initialized. It is just the default value. This generic iommu code makes an .init call to our code for whatever initialization is needed. So the name here seemed absolutely fine to me.
>>>
>>> Initialization does not always refer to allocation. In this case this is driver specific initialization. Since, the iommu code is making an init call to the smmu code hence the name arm_smmu_iommu_domain_init. So, again I agree with your comments on the domain variable names and I'm making these changes as they would make the code cleaner. This function name change probably will not do much but the move along the discussion, let me know what you were thinking.
>> Sameer, few points
>> a. all the functions are prefixed with arm_smmu_ , so what the function is doing can be understood by the rest part of the name
>> In this case it is iommu_domain_init.
>>
>> b. By the name it seems to suggest that you are  doing some kind of init for iommu_domain
>>
>> c. But in this complete function, iommu_domain pointer is never used.
>>
>> If I take your point, the appropriate name of the function should be arm_smmu_xen_domain_init().
> Its not the iommu domain defined within the current driver.  I'll change the name to arm_smmu_xen_iommu_init().
>
> arm_smmu for just keeping the prefixes as needed. Sounds good?
yes. thanks.
>
> Thanks,
> Sameer
>> -Manish
>>>> +static int arm_smmu_iommu_domain_init(struct domain *d)
>>>> +{
>>>> +    struct arm_smmu_xen_domain *xen_domain;
>>>> +
>>>> +    xen_domain = xzalloc(struct arm_smmu_xen_domain);
>>>> +    if (!xen_domain)
>>>> +        return -ENOMEM;
>>>> +
>>>> +    spin_lock_init(&xen_domain->lock);
>>>> +    INIT_LIST_HEAD(&xen_domain->contexts);
>>>> +
>>>> +    dom_iommu(d)->arch.priv = xen_domain;
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>>
>>>>
>>>>
>>>>> Thanks,
>>>>> Sameer
>>>>>> _______________________________________________
>>>>>> Xen-devel mailing list
>>>>>> Xen-devel@lists.xenproject.org
>>>>>> https://lists.xenproject.org/mailman/listinfo/xen-devel
>>>> _______________________________________________
>>>> Xen-devel mailing list
>>>> Xen-devel@lists.xenproject.org
>>>> https://lists.xenproject.org/mailman/listinfo/xen-devel
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xenproject.org
>> https://lists.xenproject.org/mailman/listinfo/xen-devel
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xenproject.org
> https://lists.xenproject.org/mailman/listinfo/xen-devel
diff mbox series

Patch

diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index d43c3aa896..38aa9f00c1 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -1454,6 +1454,7 @@  err:
 static void __init setup_virt_paging_one(void *data)
 {
     unsigned long val = (unsigned long)data;
+    /* SMMUv3 S2 cfg vtcr reuses the following value */
     WRITE_SYSREG32(val, VTCR_EL2);
     isb();
 }
diff --git a/xen/drivers/Kconfig b/xen/drivers/Kconfig
index db94393f47..59ca00f850 100644
--- a/xen/drivers/Kconfig
+++ b/xen/drivers/Kconfig
@@ -15,4 +15,6 @@  source "drivers/video/Kconfig"
 config HAS_VPCI
 	bool
 
+source "drivers/passthrough/arm/Kconfig"
+
 endmenu
diff --git a/xen/drivers/passthrough/arm/Kconfig b/xen/drivers/passthrough/arm/Kconfig
new file mode 100644
index 0000000000..cda899f608
--- /dev/null
+++ b/xen/drivers/passthrough/arm/Kconfig
@@ -0,0 +1,8 @@ 
+
+config ARM_SMMU_v3
+	bool "ARM SMMUv3 Support"
+	depends on ARM_64
+	help
+	 Support for implementations of the ARM System MMU architecture
+	 version 3.
+
diff --git a/xen/drivers/passthrough/arm/Makefile b/xen/drivers/passthrough/arm/Makefile
index f4cd26e15d..e14732b55c 100644
--- a/xen/drivers/passthrough/arm/Makefile
+++ b/xen/drivers/passthrough/arm/Makefile
@@ -1,2 +1,3 @@ 
 obj-y += iommu.o
 obj-y += smmu.o
+obj-$(CONFIG_ARM_SMMU_v3) += smmu-v3.o
diff --git a/xen/drivers/passthrough/arm/smmu-v3.c b/xen/drivers/passthrough/arm/smmu-v3.c
index e67ba6c40f..df81626785 100644
--- a/xen/drivers/passthrough/arm/smmu-v3.c
+++ b/xen/drivers/passthrough/arm/smmu-v3.c
@@ -18,28 +18,414 @@ 
  * Author: Will Deacon <will.deacon@arm.com>
  *
  * This driver is powered by bad coffee and bombay mix.
+ *
+ *
+ * Based on Linux drivers/iommu/arm-smmu-v3.c
+ * => commit 7aa8619a66aea52b145e04cbab4f8d6a4e5f3f3b
+ *
+ * Xen modifications:
+ * Sameer Goel <sameer.goel@linaro.org>
+ * Copyright (C) 2017, The Linux Foundation, All rights reserved.
+ *
  */
 
-#include <linux/acpi.h>
-#include <linux/acpi_iort.h>
-#include <linux/delay.h>
-#include <linux/dma-iommu.h>
-#include <linux/err.h>
-#include <linux/interrupt.h>
-#include <linux/iommu.h>
-#include <linux/iopoll.h>
-#include <linux/module.h>
-#include <linux/msi.h>
-#include <linux/of.h>
-#include <linux/of_address.h>
-#include <linux/of_iommu.h>
-#include <linux/of_platform.h>
-#include <linux/pci.h>
-#include <linux/platform_device.h>
-
-#include <linux/amba/bus.h>
-
-#include "io-pgtable.h"
+#include <xen/acpi.h>
+#include <xen/config.h>
+#include <xen/delay.h>
+#include <xen/errno.h>
+#include <xen/err.h>
+#include <xen/irq.h>
+#include <xen/lib.h>
+#include <xen/linux_compat.h>
+#include <xen/list.h>
+#include <xen/mm.h>
+#include <xen/rbtree.h>
+#include <xen/sched.h>
+#include <xen/sizes.h>
+#include <xen/vmap.h>
+#include <acpi/acpi_iort.h>
+#include <asm/atomic.h>
+#include <asm/device.h>
+#include <asm/io.h>
+#include <asm/platform.h>
+
+/* Alias to Xen device tree helpers */
+#define device_node dt_device_node
+#define of_phandle_args dt_phandle_args
+#define of_device_id dt_device_match
+#define of_match_node dt_match_node
+#define of_property_read_u32(np, pname, out) (!dt_property_read_u32(np, pname, out))
+#define of_property_read_bool dt_property_read_bool
+#define of_parse_phandle_with_args dt_parse_phandle_with_args
+
+/* Xen: Helpers to get device MMIO and IRQs */
+struct resource {
+	u64 addr;
+	u64 size;
+	unsigned int type;
+};
+
+#define resource_size(res) ((res)->size)
+
+#define platform_device device
+
+#define IORESOURCE_MEM 0
+#define IORESOURCE_IRQ 1
+
+static struct resource *platform_get_resource(struct platform_device *pdev,
+					      unsigned int type,
+					      unsigned int num)
+{
+	/*
+	 * The resource is only used between 2 calls of platform_get_resource.
+	 * It's quite ugly but it's avoid to add too much code in the part
+	 * imported from Linux
+	 */
+	static struct resource res;
+	struct acpi_iort_node *iort_node;
+	struct acpi_iort_smmu_v3 *node_smmu_data;
+	int ret = 0;
+
+	res.type = type;
+
+	switch (type) {
+	case IORESOURCE_MEM:
+		if (pdev->type == DEV_ACPI) {
+			ret = 1;
+			iort_node = pdev->acpi_node;
+			node_smmu_data =
+				(struct acpi_iort_smmu_v3 *)iort_node->node_data;
+
+			if (node_smmu_data != NULL) {
+				res.addr = node_smmu_data->base_address;
+				res.size = SZ_128K;
+				ret = 0;
+			}
+		} else {
+			ret = dt_device_get_address(dev_to_dt(pdev), num,
+						    &res.addr, &res.size);
+		}
+
+		return ((ret) ? NULL : &res);
+
+	case IORESOURCE_IRQ:
+		/* ACPI case not implemented as there is no use case for it */
+		ret = platform_get_irq(dev_to_dt(pdev), num);
+
+		if (ret < 0)
+			return NULL;
+
+		res.addr = ret;
+		res.size = 1;
+
+		return &res;
+
+	default:
+		return NULL;
+	}
+}
+
+static int platform_get_irq_byname(struct platform_device *pdev, const char *name)
+{
+	const struct dt_property *dtprop;
+	struct acpi_iort_node *iort_node;
+	struct acpi_iort_smmu_v3 *node_smmu_data;
+	int ret = 0;
+
+	if (pdev->type == DEV_ACPI) {
+		iort_node = pdev->acpi_node;
+		node_smmu_data = (struct acpi_iort_smmu_v3 *)iort_node->node_data;
+
+		if (node_smmu_data != NULL) {
+			if (!strcmp(name, "eventq"))
+				ret = node_smmu_data->event_gsiv;
+			else if (!strcmp(name, "priq"))
+				ret = node_smmu_data->pri_gsiv;
+			else if (!strcmp(name, "cmdq-sync"))
+				ret = node_smmu_data->sync_gsiv;
+			else if (!strcmp(name, "gerror"))
+				ret = node_smmu_data->gerr_gsiv;
+			else
+				ret = -EINVAL;
+		}
+	} else {
+		dtprop = dt_find_property(dev_to_dt(pdev), "interrupt-names", NULL);
+		if (!dtprop)
+			return -EINVAL;
+
+		if (!dtprop->value)
+			return -ENODATA;
+	}
+
+	return ret;
+}
+
+/*
+ * Xen: Helpers for DMA allocation. Just the function name is reused for
+ * porting code these allocation are not managed allocations
+ */
+
+static void *dmam_alloc_coherent(struct device *dev, size_t size,
+			   dma_addr_t *dma_handle, gfp_t gfp)
+{
+	void *vaddr;
+	unsigned long alignment = size;
+
+	/*
+	 * _xzalloc requires that the (align & (align -1)) = 0. Most of the
+	 * allocations in SMMU code should send the right value for size. In
+	 * case this is not true print a warning and align to the size of a
+	 * (void *)
+	 */
+	if (size & (size - 1)) {
+		dev_warn(dev, "Fixing alignment for the DMA buffer\n");
+		alignment = sizeof(void *);
+	}
+
+	vaddr = _xzalloc(size, alignment);
+	if (!vaddr) {
+		dev_err(dev, "DMA allocation failed\n");
+		return NULL;
+	}
+
+	*dma_handle = virt_to_maddr(vaddr);
+
+	return vaddr;
+}
+
+
+static void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
+			dma_addr_t dma_handle)
+{
+	xfree(vaddr);
+}
+
+/* Xen: Stub out DMA domain related functions */
+#define iommu_get_dma_cookie(dom) 0
+#define iommu_put_dma_cookie(dom)
+
+/* Xen: Stub out module param related function */
+#define module_param_named(a, b, c, d)
+#define MODULE_PARM_DESC(a, b)
+
+#define dma_set_mask_and_coherent(d, b) 0
+
+#define of_dma_is_coherent(n) 0
+
+#define MODULE_DEVICE_TABLE(type, name)
+
+static void __iomem *devm_ioremap_resource(struct device *dev,
+					   struct resource *res)
+{
+	void __iomem *ptr;
+
+	if (!res || res->type != IORESOURCE_MEM) {
+		dev_err(dev, "Invalid resource\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	ptr = ioremap_nocache(res->addr, res->size);
+	if (!ptr) {
+		dev_err(dev,
+			"ioremap failed (addr 0x%"PRIx64" size 0x%"PRIx64")\n",
+			res->addr, res->size);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	return ptr;
+}
+
+/* Xen: Compatibility define for iommu_domain_geometry.*/
+struct iommu_domain_geometry {
+	dma_addr_t aperture_start; /* First address that can be mapped    */
+	dma_addr_t aperture_end;   /* Last address that can be mapped     */
+	bool force_aperture;       /* DMA only allowed in mappable range? */
+};
+
+
+/* Xen: Type definitions for iommu_domain */
+#define IOMMU_DOMAIN_UNMANAGED 0
+#define IOMMU_DOMAIN_DMA 1
+#define IOMMU_DOMAIN_IDENTITY 2
+
+/* Xen: Dummy iommu_domain */
+struct iommu_domain {
+	/* Runtime SMMU configuration for this iommu_domain */
+	struct arm_smmu_domain		*priv;
+	unsigned int type;
+
+	/* Dummy compatibility defines */
+	unsigned long pgsize_bitmap;
+	struct iommu_domain_geometry geometry;
+
+	atomic_t ref;
+	/*
+	 * Used to link iommu_domain contexts for a same domain.
+	 * There is at least one per-SMMU to used by the domain.
+	 */
+	struct list_head		list;
+};
+
+/* Xen: Describes information required for a Xen domain */
+struct arm_smmu_xen_domain {
+	spinlock_t			lock;
+	/* List of iommu domains associated to this domain */
+	struct list_head		contexts;
+};
+
+/*
+ * Xen: Information about each device stored in dev->archdata.iommu
+ *
+ * The dev->archdata.iommu stores the iommu_domain (runtime configuration of
+ * the SMMU).
+ */
+struct arm_smmu_xen_device {
+	struct iommu_domain *domain;
+};
+
+/*
+ * Xen: io_pgtable compatibility defines.
+ * Most of these are to port in the S1 translation code as is.
+ */
+struct io_pgtable_ops {
+};
+
+struct iommu_gather_ops {
+	void (*tlb_flush_all)(void *cookie);
+	void (*tlb_add_flush)(unsigned long iova, size_t size, size_t granule,
+			      bool leaf, void *cookie);
+	void (*tlb_sync)(void *cookie);
+};
+
+struct io_pgtable_cfg {
+	/*
+	 * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE bits in
+	 *	stage 1 PTEs, for hardware which insists on validating them
+	 *	even in	non-secure state where they should normally be ignored.
+	 *
+	 * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE and
+	 *	IOMMU_NOEXEC flags and map everything with full access, for
+	 *	hardware which does not implement the permissions of a given
+	 *	format, and/or requires some format-specific default value.
+	 *
+	 * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching invalid
+	 *	(unmapped) entries but the hardware might do so anyway, perform
+	 *	TLB maintenance when mapping as well as when unmapping.
+	 *
+	 * IO_PGTABLE_QUIRK_ARM_MTK_4GB: (ARM v7s format) Set bit 9 in all
+	 *	PTEs, for Mediatek IOMMUs which treat it as a 33rd address bit
+	 *	when the SoC is in "4GB mode" and they can only access the high
+	 *	remap of DRAM (0x1_00000000 to 0x1_ffffffff).
+	 *
+	 * IO_PGTABLE_QUIRK_NO_DMA: Guarantees that the tables will only ever
+	 *	be accessed by a fully cache-coherent IOMMU or CPU (e.g. for a
+	 *	software-emulated IOMMU), such that pagetable updates need not
+	 *	be treated as explicit DMA data.
+	 */
+	#define IO_PGTABLE_QUIRK_ARM_NS		BIT(0)
+	#define IO_PGTABLE_QUIRK_NO_PERMS	BIT(1)
+	#define IO_PGTABLE_QUIRK_TLBI_ON_MAP	BIT(2)
+	#define IO_PGTABLE_QUIRK_ARM_MTK_4GB	BIT(3)
+	#define IO_PGTABLE_QUIRK_NO_DMA		BIT(4)
+	unsigned long			quirks;
+	unsigned long			pgsize_bitmap;
+	unsigned int			ias;
+	unsigned int			oas;
+	const struct iommu_gather_ops	*tlb;
+	struct device			*iommu_dev;
+
+	/* Low-level data specific to the table format */
+	union {
+		struct {
+			u64	ttbr[2];
+			u64	tcr;
+			u64	mair[2];
+		} arm_lpae_s1_cfg;
+
+		struct {
+			u64	vttbr;
+			u64	vtcr;
+		} arm_lpae_s2_cfg;
+
+		struct {
+			u32	ttbr[2];
+			u32	tcr;
+			u32	nmrr;
+			u32	prrr;
+		} arm_v7s_cfg;
+	};
+};
+
+enum io_pgtable_fmt {
+	ARM_32_LPAE_S1,
+	ARM_32_LPAE_S2,
+	ARM_64_LPAE_S1,
+	ARM_64_LPAE_S2,
+	ARM_V7S,
+	IO_PGTABLE_NUM_FMTS,
+};
+
+/*
+ * Xen: The pgtable_ops are used by the S1 translations, so return the dummy
+ * address.
+ */
+#define alloc_io_pgtable_ops(f, c, o) ((struct io_pgtable_ops *)0x1)
+#define free_io_pgtable_ops(o)
+
+/* Xen: Define wrapper for requesting IRQs */
+#define IRQF_ONESHOT 0
+
+typedef void (*irq_handler_t)(int, void *, struct cpu_user_regs *);
+
+static inline int devm_request_irq(struct device *dev, unsigned int irq,
+				   irq_handler_t handler, unsigned long irqflags,
+				   const char *devname, void *dev_id)
+{
+	/*
+	 * SMMUv3 implementation can support wired interrupt outputs that are
+	 * edge-triggered. Set the irq type as per the spec.
+	 */
+	irq_set_type(irq, IRQ_TYPE_EDGE_BOTH);
+	return request_irq(irq, irqflags, handler, devname, dev_id);
+}
+
+/*
+ * Xen does not have a concept of threaded irq, but we can use tasklets to
+ * achieve the desired functionality as needed.
+ */
+int devm_request_threaded_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
+			      irq_handler_t thread_fn, unsigned long irqflags,
+			      const char *devname, void *dev_id)
+{
+	return devm_request_irq(dev, irq, thread_fn, irqflags, devname, dev_id);
+}
+
+/* Xen: The mutex is used only during initialization so the typecast is safe */
+#define mutex spinlock
+#define mutex_init spin_lock_init
+#define mutex_lock spin_lock
+#define mutex_unlock spin_unlock
+
+#define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us) \
+({ \
+	s_time_t deadline = NOW() + MICROSECS(timeout_us); \
+	for (;;) { \
+		(val) = op(addr); \
+		if (cond) \
+			break; \
+		if (NOW() > deadline) { \
+			(val) = op(addr); \
+			break; \
+		} \
+	udelay(sleep_us); \
+	} \
+	(cond) ? 0 : -ETIMEDOUT; \
+})
+
+#define readl_relaxed_poll_timeout(addr, val, cond, delay_us, timeout_us) \
+	readx_poll_timeout(readl_relaxed, addr, val, cond, delay_us, timeout_us)
+
+#define VA_BITS 0 /* Only needed for S1 translations */
 
 /* MMIO registers */
 #define ARM_SMMU_IDR0			0x0
@@ -433,6 +819,7 @@  enum pri_resp {
 	PRI_RESP_SUCC,
 };
 
+#if 0 /* Xen: No MSI support in this iteration */
 enum arm_smmu_msi_index {
 	EVTQ_MSI_INDEX,
 	GERROR_MSI_INDEX,
@@ -457,6 +844,7 @@  static phys_addr_t arm_smmu_msi_cfg[ARM_SMMU_MAX_MSIS][3] = {
 		ARM_SMMU_PRIQ_IRQ_CFG2,
 	},
 };
+#endif
 
 struct arm_smmu_cmdq_ent {
 	/* Common fields */
@@ -561,6 +949,8 @@  struct arm_smmu_s2_cfg {
 	u16				vmid;
 	u64				vttbr;
 	u64				vtcr;
+	/* Xen: Domain associated to this configuration */
+	struct domain			*domain;
 };
 
 struct arm_smmu_strtab_ent {
@@ -635,9 +1025,25 @@  struct arm_smmu_device {
 	struct arm_smmu_strtab_cfg	strtab_cfg;
 
 	/* IOMMU core code handle */
+#if 0 /*Xen: Generic iommu_device ref not needed here */
 	struct iommu_device		iommu;
+#endif
+	/* Xen: Need to keep a list of SMMU devices */
+	struct list_head                devices;
+	/* Xen: Tasklets for handling evts/faults and pci page request IRQs*/
+	struct tasklet			evtq_tasklet;
+	struct tasklet			priq_tasklet;
+	struct tasklet			combined_irq_tasklet;
 };
 
+/* Xen: Keep a list of devices associated with this driver */
+static DEFINE_SPINLOCK(arm_smmu_devices_lock);
+static LIST_HEAD(arm_smmu_devices);
+/* Xen: Helper for finding a device using fwnode */
+static
+struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode);
+
+
 /* SMMU private data for each master */
 struct arm_smmu_master_data {
 	struct arm_smmu_device		*smmu;
@@ -1232,7 +1638,7 @@  static void arm_smmu_handle_ppr(struct arm_smmu_device *smmu, u64 *evt)
 
 	dev_info(smmu->dev, "unexpected PRI request received:\n");
 	dev_info(smmu->dev,
-		 "\tsid 0x%08x.0x%05x: [%u%s] %sprivileged %s%s%s access at iova 0x%016llx\n",
+		 "\tsid 0x%08x.0x%05x: [%u%s] %sprivileged %s%s%s access at iova %#" PRIx64 "\n",
 		 sid, ssid, grpid, last ? "L" : "",
 		 evt[0] & PRIQ_0_PERM_PRIV ? "" : "un",
 		 evt[0] & PRIQ_0_PERM_READ ? "R" : "",
@@ -1342,10 +1748,20 @@  static irqreturn_t arm_smmu_combined_irq_thread(int irq, void *dev)
 	return IRQ_HANDLED;
 }
 
+/* Xen: Forward define for combined_irq tasklet */
+static void arm_smmu_combined_irq_tasklet(unsigned long dev);
+
 static irqreturn_t arm_smmu_combined_irq_handler(int irq, void *dev)
 {
+	/* Xen: Need an smmu reference to schedule the tasklet */
+	struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
+
 	arm_smmu_gerror_handler(irq, dev);
 	arm_smmu_cmdq_sync_handler(irq, dev);
+
+	/*Xen: No threaded irq. So, schedule the right tasklet*/
+	tasklet_schedule(&(smmu->combined_irq_tasklet));
+
 	return IRQ_WAKE_THREAD;
 }
 
@@ -1358,6 +1774,69 @@  static void __arm_smmu_tlb_sync(struct arm_smmu_device *smmu)
 	arm_smmu_cmdq_issue_cmd(smmu, &cmd);
 }
 
+/*
+ * Xen: Define the IRQ handlers and tasklets for xen. The linux functions
+ * would be modified to use the functions defined in the following code.
+ */
+
+static void arm_smmu_evtq_tasklet(unsigned long dev)
+{
+	/* The IRQ number is not relevent for the evtq thread processing */
+	arm_smmu_evtq_thread(0, (void *)dev);
+}
+
+static void arm_smmu_priq_tasklet(unsigned long dev)
+{
+	/* The IRQ number is not relevent for the priq thread processing */
+	arm_smmu_priq_thread(0, (void *)dev);
+}
+
+static void arm_smmu_combined_irq_tasklet(unsigned long dev)
+{
+	/* The IRQ number is not relevent for the combined irq handler.*/
+	arm_smmu_combined_irq_thread(0, (void *)dev);
+}
+
+static void arm_smmu_evtq_thread_xen(int irq, void *dev,
+				       struct cpu_user_regs *regs)
+{
+	struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
+
+	tasklet_schedule(&(smmu->evtq_tasklet));
+}
+
+static void arm_smmu_priq_thread_xen(int irq, void *dev,
+				       struct cpu_user_regs *regs)
+{
+	struct arm_smmu_device *smmu = (struct arm_smmu_device *)dev;
+
+	tasklet_schedule(&(smmu->priq_tasklet));
+}
+
+static void arm_smmu_cmdq_sync_handler_xen(int irq, void *dev,
+				       struct cpu_user_regs *regs)
+{
+	arm_smmu_cmdq_sync_handler(irq, dev);
+}
+
+static void arm_smmu_gerror_handler_xen(int irq, void *dev,
+				       struct cpu_user_regs *regs)
+{
+	arm_smmu_gerror_handler(irq, dev);
+}
+
+static void arm_smmu_combined_irq_handler_xen(int irq, void *dev,
+				       struct cpu_user_regs *regs)
+{
+	arm_smmu_combined_irq_handler(irq, dev);
+}
+
+#define arm_smmu_evtq_thread arm_smmu_evtq_thread_xen
+#define arm_smmu_priq_thread arm_smmu_priq_thread_xen
+#define arm_smmu_cmdq_sync_handler arm_smmu_cmdq_sync_handler_xen
+#define arm_smmu_gerror_handler arm_smmu_gerror_handler_xen
+#define arm_smmu_combined_irq_handler arm_smmu_combined_irq_handler_xen
+
 static void arm_smmu_tlb_sync(void *cookie)
 {
 	struct arm_smmu_domain *smmu_domain = cookie;
@@ -1415,6 +1894,7 @@  static const struct iommu_gather_ops arm_smmu_gather_ops = {
 	.tlb_sync	= arm_smmu_tlb_sync,
 };
 
+#if 0 /*Xen: Unused functionality */
 /* IOMMU API */
 static bool arm_smmu_capable(enum iommu_cap cap)
 {
@@ -1427,6 +1907,7 @@  static bool arm_smmu_capable(enum iommu_cap cap)
 		return false;
 	}
 }
+#endif
 
 static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
 {
@@ -1546,9 +2027,16 @@  static int arm_smmu_domain_finalise_s2(struct arm_smmu_domain *smmu_domain,
 	if (vmid < 0)
 		return vmid;
 
-	cfg->vmid	= (u16)vmid;
-	cfg->vttbr	= pgtbl_cfg->arm_lpae_s2_cfg.vttbr;
-	cfg->vtcr	= pgtbl_cfg->arm_lpae_s2_cfg.vtcr;
+	/*
+	 * Xen: Get the ttbr and vtcr values
+	 * vttbr: This is a shared value with the domain page table
+	 * vtcr: The TCR settings are the same as CPU since the page
+	 * tables are shared
+	 */
+
+	cfg->vmid	= vmid;
+	cfg->vttbr	= page_to_maddr(cfg->domain->arch.p2m.root);
+	cfg->vtcr	= READ_SYSREG32(VTCR_EL2) & STRTAB_STE_2_VTCR_MASK;
 	return 0;
 }
 
@@ -1604,6 +2092,7 @@  static int arm_smmu_domain_finalise(struct iommu_domain *domain)
 	if (smmu->features & ARM_SMMU_FEAT_COHERENCY)
 		pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_NO_DMA;
 
+	/* Xen: pgtbl_ops gets an invalid address */
 	pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);
 	if (!pgtbl_ops)
 		return -ENOMEM;
@@ -1721,6 +2210,7 @@  out_unlock:
 	return ret;
 }
 
+#if 0 /* Xen: Unused functionality */
 static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
 			phys_addr_t paddr, size_t size, int prot)
 {
@@ -1772,6 +2262,7 @@  struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
 	put_device(dev);
 	return dev ? dev_get_drvdata(dev) : NULL;
 }
+#endif
 
 static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, u32 sid)
 {
@@ -1783,7 +2274,14 @@  static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, u32 sid)
 	return sid < limit;
 }
 
+/* Xen: Unused */
+#if 0
 static struct iommu_ops arm_smmu_ops;
+#endif
+
+/* Xen: Redefine arm_smmu_ops to what fwspec should evaluate */
+static const struct iommu_ops arm_smmu_iommu_ops;
+#define arm_smmu_ops arm_smmu_iommu_ops
 
 static int arm_smmu_add_device(struct device *dev)
 {
@@ -1791,8 +2289,11 @@  static int arm_smmu_add_device(struct device *dev)
 	struct arm_smmu_device *smmu;
 	struct arm_smmu_master_data *master;
 	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
+#if 0 /*Xen: iommu_group is not needed */
 	struct iommu_group *group;
+#endif
 
+	/* Xen: fwspec->ops are not needed */
 	if (!fwspec || fwspec->ops != &arm_smmu_ops)
 		return -ENODEV;
 	/*
@@ -1830,6 +2331,11 @@  static int arm_smmu_add_device(struct device *dev)
 		}
 	}
 
+/*
+ * Xen: Do not need an iommu group as the stream data is carried by the SMMU
+ * master device object
+ */
+#if 0
 	group = iommu_group_get_for_dev(dev);
 	if (!IS_ERR(group)) {
 		iommu_group_put(group);
@@ -1837,8 +2343,16 @@  static int arm_smmu_add_device(struct device *dev)
 	}
 
 	return PTR_ERR_OR_ZERO(group);
+#endif
+	return 0;
 }
 
+/*
+ * Xen: We can potentially support this function and destroy a device. This
+ * will be relevant for PCI hotplug. So, will be implemented as needed after
+ * passthrough support is available.
+ */
+#if 0
 static void arm_smmu_remove_device(struct device *dev)
 {
 	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
@@ -1974,6 +2488,7 @@  static struct iommu_ops arm_smmu_ops = {
 	.put_resv_regions	= arm_smmu_put_resv_regions,
 	.pgsize_bitmap		= -1UL, /* Restricted during device attach */
 };
+#endif
 
 /* Probing and initialisation functions */
 static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
@@ -2182,6 +2697,7 @@  static int arm_smmu_update_gbpa(struct arm_smmu_device *smmu, u32 set, u32 clr)
 					  1, ARM_SMMU_POLL_TIMEOUT_US);
 }
 
+#if 0 /* Xen: There is no MSI support as yet */
 static void arm_smmu_free_msis(void *data)
 {
 	struct device *dev = data;
@@ -2247,12 +2763,15 @@  static void arm_smmu_setup_msis(struct arm_smmu_device *smmu)
 	/* Add callback to free MSIs on teardown */
 	devm_add_action(dev, arm_smmu_free_msis, dev);
 }
+#endif
 
 static void arm_smmu_setup_unique_irqs(struct arm_smmu_device *smmu)
 {
 	int irq, ret;
 
+#if 0 /*Xen: Cannot setup msis for now */
 	arm_smmu_setup_msis(smmu);
+#endif
 
 	/* Request interrupt lines */
 	irq = smmu->evtq.q.irq;
@@ -2316,9 +2835,13 @@  static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
 		 * Cavium ThunderX2 implementation doesn't not support unique
 		 * irq lines. Use single irq line for all the SMMUv3 interrupts.
 		 */
-		ret = devm_request_threaded_irq(smmu->dev, irq,
+		/*
+		 * Xen: Does not support threaded irqs, so serialise the setup.
+		 * This is the same for pris and event interrupt lines on other
+		 * systems
+		 */
+		ret = devm_request_irq(smmu->dev, irq,
 					arm_smmu_combined_irq_handler,
-					arm_smmu_combined_irq_thread,
 					IRQF_ONESHOT,
 					"arm-smmu-v3-combined-irq", smmu);
 		if (ret < 0)
@@ -2452,6 +2975,13 @@  static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
 		return ret;
 	}
 
+	/* Xen: Initialize tasklets */
+	tasklet_init(&smmu->evtq_tasklet, arm_smmu_evtq_tasklet,
+			(unsigned long)smmu);
+	tasklet_init(&smmu->priq_tasklet, arm_smmu_priq_tasklet,
+			(unsigned long)smmu);
+	tasklet_init(&smmu->combined_irq_tasklet, arm_smmu_combined_irq_tasklet,
+			(unsigned long)smmu);
 
 	/* Enable the SMMU interface, or ensure bypass */
 	if (!bypass || disable_bypass) {
@@ -2542,8 +3072,14 @@  static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu)
 		smmu->features |= ARM_SMMU_FEAT_STALLS;
 	}
 
+/*
+ * Xen: Block stage 1 translations. By doing this here we do not need to set the
+ * domain->stage explicitly.
+ */
+#if 0
 	if (reg & IDR0_S1P)
 		smmu->features |= ARM_SMMU_FEAT_TRANS_S1;
+#endif
 
 	if (reg & IDR0_S2P)
 		smmu->features |= ARM_SMMU_FEAT_TRANS_S2;
@@ -2616,10 +3152,12 @@  static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu)
 	if (reg & IDR5_GRAN4K)
 		smmu->pgsize_bitmap |= SZ_4K | SZ_2M | SZ_1G;
 
+#if 0 /* Xen: SMMU ops do not have a pgsize_bitmap member for Xen */
 	if (arm_smmu_ops.pgsize_bitmap == -1UL)
 		arm_smmu_ops.pgsize_bitmap = smmu->pgsize_bitmap;
 	else
 		arm_smmu_ops.pgsize_bitmap |= smmu->pgsize_bitmap;
+#endif
 
 	/* Output address size */
 	switch (reg & IDR5_OAS_MASK << IDR5_OAS_SHIFT) {
@@ -2680,7 +3218,8 @@  static int arm_smmu_device_acpi_probe(struct platform_device *pdev,
 	struct device *dev = smmu->dev;
 	struct acpi_iort_node *node;
 
-	node = *(struct acpi_iort_node **)dev_get_platdata(dev);
+	/* Xen: Modification to get iort_node */
+	node = (struct acpi_iort_node *)dev->acpi_node;
 
 	/* Retrieve SMMUv3 specific data */
 	iort_smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
@@ -2703,7 +3242,7 @@  static inline int arm_smmu_device_acpi_probe(struct platform_device *pdev,
 static int arm_smmu_device_dt_probe(struct platform_device *pdev,
 				    struct arm_smmu_device *smmu)
 {
-	struct device *dev = &pdev->dev;
+	struct device *dev = pdev;
 	u32 cells;
 	int ret = -EINVAL;
 
@@ -2716,6 +3255,7 @@  static int arm_smmu_device_dt_probe(struct platform_device *pdev,
 
 	parse_driver_options(smmu);
 
+	/* Xen: of_dma_is_coherent is a stub till dt support is introduced */
 	if (of_dma_is_coherent(dev->of_node))
 		smmu->features |= ARM_SMMU_FEAT_COHERENCY;
 
@@ -2734,9 +3274,11 @@  static int arm_smmu_device_probe(struct platform_device *pdev)
 {
 	int irq, ret;
 	struct resource *res;
+#if 0 /*Xen: Do not need to setup sysfs */
 	resource_size_t ioaddr;
+#endif
 	struct arm_smmu_device *smmu;
-	struct device *dev = &pdev->dev;
+	struct device *dev = pdev;/* Xen: dev is ignored */
 	bool bypass;
 
 	smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
@@ -2763,7 +3305,9 @@  static int arm_smmu_device_probe(struct platform_device *pdev)
 		dev_err(dev, "MMIO region too small (%pr)\n", res);
 		return -EINVAL;
 	}
+#if 0 /*Xen: Do not need to setup sysfs */
 	ioaddr = res->start;
+#endif
 
 	smmu->base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(smmu->base))
@@ -2802,13 +3346,18 @@  static int arm_smmu_device_probe(struct platform_device *pdev)
 		return ret;
 
 	/* Record our private device structure */
+	/* Xen: SMMU is not treated a a platform device*/
+#if 0
 	platform_set_drvdata(pdev, smmu);
+#endif
 
 	/* Reset the device */
 	ret = arm_smmu_device_reset(smmu, bypass);
 	if (ret)
 		return ret;
 
+/* Xen: Not creating an IOMMU device list for Xen */
+#if 0
 	/* And we're up. Go go go! */
 	ret = iommu_device_sysfs_add(&smmu->iommu, dev, NULL,
 				     "smmu3.%pa", &ioaddr);
@@ -2844,9 +3393,20 @@  static int arm_smmu_device_probe(struct platform_device *pdev)
 		if (ret)
 			return ret;
 	}
+#endif
+	/*
+	 * Xen: Keep a list of all probed devices. This will be used to query
+	 * the smmu devices based on the fwnode.
+	 */
+	INIT_LIST_HEAD(&smmu->devices);
+	spin_lock(&arm_smmu_devices_lock);
+	list_add(&smmu->devices, &arm_smmu_devices);
+	spin_unlock(&arm_smmu_devices_lock);
 	return 0;
 }
 
+/* Xen: Unused function */
+#if 0
 static int arm_smmu_device_remove(struct platform_device *pdev)
 {
 	struct arm_smmu_device *smmu = platform_get_drvdata(pdev);
@@ -2860,6 +3420,8 @@  static void arm_smmu_device_shutdown(struct platform_device *pdev)
 {
 	arm_smmu_device_remove(pdev);
 }
+#endif
+
 
 static const struct of_device_id arm_smmu_of_match[] = {
 	{ .compatible = "arm,smmu-v3", },
@@ -2867,6 +3429,7 @@  static const struct of_device_id arm_smmu_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, arm_smmu_of_match);
 
+#if 0
 static struct platform_driver arm_smmu_driver = {
 	.driver	= {
 		.name		= "arm-smmu-v3",
@@ -2883,3 +3446,316 @@  IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", NULL);
 MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 implementations");
 MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
 MODULE_LICENSE("GPL v2");
+#endif
+
+/***** Start of Xen specific code *****/
+
+static int __must_check arm_smmu_iotlb_flush_all(struct domain *d)
+{
+	struct arm_smmu_xen_domain *smmu_domain = dom_iommu(d)->arch.priv;
+	struct iommu_domain *cfg;
+
+	spin_lock(&smmu_domain->lock);
+	list_for_each_entry(cfg, &smmu_domain->contexts, list) {
+		/*
+		 * Only invalidate the context when SMMU is present.
+		 * This is because the context initialization is delayed
+		 * until a master has been added.
+		 */
+		if (unlikely(!ACCESS_ONCE(cfg->priv->smmu)))
+			continue;
+		arm_smmu_tlb_inv_context(cfg->priv);
+	}
+	spin_unlock(&smmu_domain->lock);
+	return 0;
+}
+
+static int __must_check arm_smmu_iotlb_flush(struct domain *d,
+					     unsigned long gfn,
+					     unsigned int page_count)
+{
+	return arm_smmu_iotlb_flush_all(d);
+}
+
+static struct iommu_domain *arm_smmu_get_domain(struct domain *d,
+						struct device *dev)
+{
+	struct iommu_domain *domain;
+	struct arm_smmu_xen_domain *xen_domain;
+	struct arm_smmu_device *smmu;
+	struct arm_smmu_domain *smmu_domain;
+
+	xen_domain = dom_iommu(d)->arch.priv;
+
+	smmu = arm_smmu_get_by_fwnode(dev->iommu_fwspec->iommu_fwnode);
+	if (!smmu)
+		return NULL;
+
+	/*
+	 * Loop through the &xen_domain->contexts to locate a context
+	 * assigned to this SMMU
+	 */
+	list_for_each_entry(domain, &xen_domain->contexts, list) {
+		smmu_domain = to_smmu_domain(domain);
+		if (smmu_domain->smmu == smmu)
+			return domain;
+	}
+
+	return NULL;
+}
+
+static void arm_smmu_destroy_iommu_domain(struct iommu_domain *domain)
+{
+	list_del(&domain->list);
+	arm_smmu_domain_free(domain);
+}
+
+static int arm_smmu_assign_dev(struct domain *d, u8 devfn,
+			       struct device *dev, u32 flag)
+{
+	int ret = 0;
+	struct iommu_domain *domain;
+	struct arm_smmu_xen_domain *xen_domain;
+	struct arm_smmu_domain *arm_smmu;
+
+	xen_domain = dom_iommu(d)->arch.priv;
+
+	if (!dev->archdata.iommu) {
+		dev->archdata.iommu = xzalloc(struct arm_smmu_xen_device);
+		if (!dev->archdata.iommu)
+			return -ENOMEM;
+	}
+
+	ret = arm_smmu_add_device(dev);
+	if (ret)
+		return ret;
+
+	spin_lock(&xen_domain->lock);
+
+	/*
+	 * Check to see if an iommu_domain already exists for this xen domain
+	 * under the same SMMU
+	 */
+	domain = arm_smmu_get_domain(d, dev);
+	if (!domain) {
+
+		domain = arm_smmu_domain_alloc(IOMMU_DOMAIN_DMA);
+		if (!domain) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		arm_smmu = to_smmu_domain(domain);
+		arm_smmu->s2_cfg.domain = d;
+
+		/* Chain the new context to the domain */
+		list_add(&domain->list, &xen_domain->contexts);
+
+	}
+
+	ret = arm_smmu_attach_dev(domain, dev);
+	if (ret) {
+		if (domain->ref.counter == 0)
+			arm_smmu_destroy_iommu_domain(domain);
+	} else {
+		atomic_inc(&domain->ref);
+	}
+
+out:
+	spin_unlock(&xen_domain->lock);
+	return ret;
+}
+
+static int arm_smmu_deassign_dev(struct domain *d, struct device *dev)
+{
+	struct iommu_domain *domain = arm_smmu_get_domain(d, dev);
+	struct arm_smmu_xen_domain *xen_domain;
+	struct arm_smmu_domain *arm_smmu = to_smmu_domain(domain);
+
+	xen_domain = dom_iommu(d)->arch.priv;
+
+	if (!arm_smmu || arm_smmu->s2_cfg.domain != d) {
+		dev_err(dev, " not attached to domain %d\n", d->domain_id);
+		return -ESRCH;
+	}
+
+	spin_lock(&xen_domain->lock);
+
+	arm_smmu_detach_dev(dev);
+	atomic_dec(&domain->ref);
+
+	if (domain->ref.counter == 0)
+		arm_smmu_destroy_iommu_domain(domain);
+
+	spin_unlock(&xen_domain->lock);
+
+	return 0;
+}
+
+static int arm_smmu_reassign_dev(struct domain *s, struct domain *t,
+				 u8 devfn,  struct device *dev)
+{
+	int ret = 0;
+
+	/* Don't allow remapping on other domain than hwdom */
+	if (t && t != hardware_domain)
+		return -EPERM;
+
+	if (t == s)
+		return 0;
+
+	ret = arm_smmu_deassign_dev(s, dev);
+	if (ret)
+		return ret;
+
+	if (t) {
+		/* No flags are defined for ARM. */
+		ret = arm_smmu_assign_dev(t, devfn, dev, 0);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int arm_smmu_iommu_domain_init(struct domain *d)
+{
+	struct arm_smmu_xen_domain *xen_domain;
+
+	xen_domain = xzalloc(struct arm_smmu_xen_domain);
+	if (!xen_domain)
+		return -ENOMEM;
+
+	spin_lock_init(&xen_domain->lock);
+	INIT_LIST_HEAD(&xen_domain->contexts);
+
+	dom_iommu(d)->arch.priv = xen_domain;
+
+	return 0;
+}
+
+static void __hwdom_init arm_smmu_iommu_hwdom_init(struct domain *d)
+{
+}
+
+static void arm_smmu_iommu_domain_teardown(struct domain *d)
+{
+	struct arm_smmu_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
+
+	ASSERT(list_empty(&xen_domain->contexts));
+	xfree(xen_domain);
+}
+
+static int __must_check arm_smmu_map_page(struct domain *d, unsigned long gfn,
+			unsigned long mfn, unsigned int flags)
+{
+	p2m_type_t t;
+
+	/*
+	 * Grant mappings can be used for DMA requests. The dev_bus_addr
+	 * returned by the hypercall is the MFN (not the IPA). For device
+	 * protected by an IOMMU, Xen needs to add a 1:1 mapping in the domain
+	 * p2m to allow DMA request to work.
+	 * This is only valid when the domain is directed mapped. Hence this
+	 * function should only be used by gnttab code with gfn == mfn.
+	 */
+	BUG_ON(!is_domain_direct_mapped(d));
+	BUG_ON(mfn != gfn);
+
+	/* We only support readable and writable flags */
+	if (!(flags & (IOMMUF_readable | IOMMUF_writable)))
+		return -EINVAL;
+
+	t = (flags & IOMMUF_writable) ? p2m_iommu_map_rw : p2m_iommu_map_ro;
+
+	/*
+	 * The function guest_physmap_add_entry replaces the current mapping
+	 * if there is already one...
+	 */
+	return guest_physmap_add_entry(d, _gfn(gfn), _mfn(mfn), 0, t);
+}
+
+static int __must_check arm_smmu_unmap_page(struct domain *d, unsigned long gfn)
+{
+	/*
+	 * This function should only be used by gnttab code when the domain
+	 * is direct mapped
+	 */
+	if (!is_domain_direct_mapped(d))
+		return -EINVAL;
+
+	return guest_physmap_remove_page(d, _gfn(gfn), _mfn(gfn), 0);
+}
+
+static const struct iommu_ops arm_smmu_iommu_ops = {
+	.init = arm_smmu_iommu_domain_init,
+	.hwdom_init = arm_smmu_iommu_hwdom_init,
+	.teardown = arm_smmu_iommu_domain_teardown,
+	.iotlb_flush = arm_smmu_iotlb_flush,
+	.iotlb_flush_all = arm_smmu_iotlb_flush_all,
+	.assign_device = arm_smmu_assign_dev,
+	.reassign_device = arm_smmu_reassign_dev,
+	.map_page = arm_smmu_map_page,
+	.unmap_page = arm_smmu_unmap_page,
+};
+
+static
+struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
+{
+	struct arm_smmu_device *smmu = NULL;
+
+	spin_lock(&arm_smmu_devices_lock);
+	list_for_each_entry(smmu, &arm_smmu_devices, devices) {
+		if (smmu->dev->fwnode == fwnode)
+			break;
+	}
+	spin_unlock(&arm_smmu_devices_lock);
+
+	return smmu;
+}
+
+static __init int arm_smmu_dt_init(struct dt_device_node *dev,
+				   const void *data)
+{
+	int rc;
+
+	/*
+	 * Even if the device can't be initialized, we don't want to
+	 * give the SMMU device to dom0.
+	 */
+	dt_device_set_used_by(dev, DOMID_XEN);
+
+	rc = arm_smmu_device_probe(dt_to_dev(dev));
+	if (rc)
+		return rc;
+
+	iommu_set_ops(&arm_smmu_iommu_ops);
+
+	return 0;
+}
+
+DT_DEVICE_START(smmuv3, "ARM SMMU V3", DEVICE_IOMMU)
+	.dt_match = arm_smmu_of_match,
+	.init = arm_smmu_dt_init,
+DT_DEVICE_END
+
+#ifdef CONFIG_ACPI
+/* Set up the IOMMU */
+static int __init arm_smmu_acpi_init(const void *data)
+{
+	int rc;
+
+	rc = arm_smmu_device_probe((struct device *)data);
+	if (rc)
+		return rc;
+
+	iommu_set_ops(&arm_smmu_iommu_ops);
+	return 0;
+}
+
+ACPI_DEVICE_START(asmmuv3, "ARM SMMU V3", DEVICE_IOMMU)
+	.class_type = ACPI_IORT_NODE_SMMU_V3,
+	.init = arm_smmu_acpi_init,
+ACPI_DEVICE_END
+
+#endif
diff --git a/xen/include/xen/linux_compat.h b/xen/include/xen/linux_compat.h
new file mode 100644
index 0000000000..8037be0a3e
--- /dev/null
+++ b/xen/include/xen/linux_compat.h
@@ -0,0 +1,84 @@ 
+/******************************************************************************
+ * include/xen/linux_compat.h
+ *
+ * Compatibility defines for porting code from Linux to Xen
+ *
+ * Copyright (c) 2017 Linaro Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __XEN_LINUX_COMPAT_H__
+#define __XEN_LINUX_COMPAT_H__
+
+#include <asm/types.h>
+
+typedef paddr_t phys_addr_t;
+typedef paddr_t dma_addr_t;
+
+typedef unsigned int gfp_t;
+#define GFP_KERNEL 0
+#define __GFP_ZERO 0x01U
+
+/* Helpers for IRQ functions */
+#define free_irq release_irq
+
+enum irqreturn {
+    IRQ_NONE,
+    IRQ_HANDLED,
+    IRQ_WAKE_THREAD,
+};
+
+typedef enum irqreturn irqreturn_t;
+
+/* Device logger functions */
+#define dev_dbg(dev, fmt, ...) printk(XENLOG_DEBUG fmt, ## __VA_ARGS__)
+#define dev_notice(dev, fmt, ...) printk(XENLOG_INFO fmt, ## __VA_ARGS__)
+#define dev_warn(dev, fmt, ...) printk(XENLOG_WARNING fmt, ## __VA_ARGS__)
+#define dev_err(dev, fmt, ...) printk(XENLOG_ERR fmt, ## __VA_ARGS__)
+#define dev_info(dev, fmt, ...) printk(XENLOG_INFO fmt, ## __VA_ARGS__)
+
+#define dev_err_ratelimited(dev, fmt, ...)                  \
+     printk(XENLOG_ERR fmt, ## __VA_ARGS__)
+
+#define dev_name(dev) dt_node_full_name(dev_to_dt(dev))
+
+/* Alias to Xen allocation helpers */
+#define kfree xfree
+#define kmalloc(size, flags) ({\
+	void *__ret_alloc = NULL; \
+	if (flags & __GFP_ZERO) \
+		__ret_alloc = _xzalloc(size, sizeof(void *)); \
+	else \
+		__ret_alloc = _xmalloc(size, sizeof(void *)); \
+	__ret_alloc; \
+})
+#define kzalloc(size, flags)        _xzalloc(size, sizeof(void *))
+#define devm_kzalloc(dev, size, flags)  _xzalloc(size, sizeof(void *))
+#define kmalloc_array(size, n, flags) ({\
+	void *__ret_alloc = NULL; \
+	if (flags & __GFP_ZERO) \
+		__ret_alloc = _xzalloc_array(size, sizeof(void *), n); \
+	else \
+		__ret_alloc = _xmalloc_array(size, sizeof(void *), n); \
+	__ret_alloc; \
+})
+
+/* Alias to Xen time functions */
+#define ktime_t s_time_t
+#define ktime_get()             (NOW())
+#define ktime_add_us(t,i)       (t + MICROSECS(i))
+#define ktime_compare(t,i)      (t > (i))
+
+#endif /* __XEN_LINUX_COMPAT_H__ */