| Message ID | 20210603085003.50465-4-sven@svenpeter.dev |
|---|---|
| State | New |
| Headers | show |
| Series | Apple M1 DART IOMMU driver | expand |
Hi Sven, just a small comment, see inline. On Thu, 2021-06-03 at 10:50 +0200, Sven Peter wrote: > Apple's new SoCs use iommus for almost all peripherals. These Device > Address Resolution Tables must be setup before these peripherals can > act as DMA masters. > > Signed-off-by: Sven Peter <sven@svenpeter.dev> > --- > MAINTAINERS | 1 + > drivers/iommu/Kconfig | 15 + > drivers/iommu/Makefile | 1 + > drivers/iommu/apple-dart-iommu.c | 966 +++++++++++++++++++++++++++++++ > 4 files changed, 983 insertions(+) > create mode 100644 drivers/iommu/apple-dart-iommu.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 4373d63f9ccf..cb9200ad05fe 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -1245,6 +1245,7 @@ M: Sven Peter <sven@svenpeter.dev> > L: iommu@lists.linux-foundation.org > S: Maintained > F: Documentation/devicetree/bindings/iommu/apple,dart.yaml > +F: drivers/iommu/apple-dart-iommu.c > > APPLE SMC DRIVER > M: Henrik Rydberg <rydberg@bitmath.org> > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig > index 1f111b399bca..87882c628b46 100644 > --- a/drivers/iommu/Kconfig > +++ b/drivers/iommu/Kconfig > @@ -249,6 +249,21 @@ config SPAPR_TCE_IOMMU > Enables bits of IOMMU API required by VFIO. The iommu_ops > is not implemented as it is not necessary for VFIO. > > +config IOMMU_APPLE_DART > + tristate "Apple DART IOMMU Support" > + depends on ARM64 || (COMPILE_TEST && !GENERIC_ATOMIC64) > + select IOMMU_API > + select IOMMU_IO_PGTABLE > + select IOMMU_IO_PGTABLE_LPAE > + default ARCH_APPLE > + help > + Support for Apple DART (Device Address Resolution Table) IOMMUs > + found in Apple ARM SoCs like the M1. > + This IOMMU is required for most peripherals using DMA to access > + the main memory. > + > + Say Y here if you are using an Apple SoC with a DART IOMMU. > + > # ARM IOMMU support > config ARM_SMMU > tristate "ARM Ltd. System MMU (SMMU) Support" > diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile > index c0fb0ba88143..8c813f0ebc54 100644 > --- a/drivers/iommu/Makefile > +++ b/drivers/iommu/Makefile > @@ -29,3 +29,4 @@ obj-$(CONFIG_HYPERV_IOMMU) += hyperv-iommu.o > obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o > obj-$(CONFIG_IOMMU_SVA_LIB) += iommu-sva-lib.o io-pgfault.o > obj-$(CONFIG_SPRD_IOMMU) += sprd-iommu.o > +obj-$(CONFIG_IOMMU_APPLE_DART) += apple-dart-iommu.o > diff --git a/drivers/iommu/apple-dart-iommu.c b/drivers/iommu/apple-dart-iommu.c > new file mode 100644 > index 000000000000..2777852498de > --- /dev/null > +++ b/drivers/iommu/apple-dart-iommu.c > @@ -0,0 +1,966 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Apple DART (Device Address Resolution Table) IOMMU driver > + * > + * Copyright (C) 2021 The Asahi Linux Contributors > + * > + * Based on arm/arm-smmu/arm-ssmu.c and arm/arm-smmu-v3/arm-smmu-v3.c > + * Copyright (C) 2013 ARM Limited > + * Copyright (C) 2015 ARM Limited > + * and on exynos-iommu.c > + * Copyright (c) 2011,2016 Samsung Electronics Co., Ltd. > + */ > + > +#include <linux/bitfield.h> > +#include <linux/clk.h> > +#include <linux/dma-iommu.h> > +#include <linux/dma-mapping.h> > +#include <linux/err.h> > +#include <linux/interrupt.h> > +#include <linux/io-pgtable.h> > +#include <linux/iopoll.h> > +#include <linux/list.h> > +#include <linux/module.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/ratelimit.h> > +#include <linux/slab.h> > +#include <linux/pci.h> > + > +#define DART_MAX_STREAMS 16 > +#define DART_MAX_TTBR 4 > + > +#define DART_STREAM_ALL 0xffff > + > +#define DART_PARAMS1 0x00 > +#define DART_PARAMS_PAGE_SHIFT GENMASK(27, 24) > + > +#define DART_PARAMS2 0x04 > +#define DART_PARAMS_BYPASS_SUPPORT BIT(0) > + > +#define DART_STREAM_COMMAND 0x20 > +#define DART_STREAM_COMMAND_BUSY BIT(2) > +#define DART_STREAM_COMMAND_INVALIDATE BIT(20) > + > +#define DART_STREAM_SELECT 0x34 > + > +#define DART_ERROR 0x40 > +#define DART_ERROR_STREAM GENMASK(27, 24) > +#define DART_ERROR_CODE GENMASK(23, 0) > +#define DART_ERROR_FLAG BIT(31) > +#define DART_ERROR_READ_FAULT BIT(4) > +#define DART_ERROR_WRITE_FAULT BIT(3) > +#define DART_ERROR_NO_PTE BIT(2) > +#define DART_ERROR_NO_PMD BIT(1) > +#define DART_ERROR_NO_TTBR BIT(0) > + > +#define DART_CONFIG 0x60 > +#define DART_CONFIG_LOCK BIT(15) > + > +#define DART_STREAM_COMMAND_BUSY_TIMEOUT 100 > + > +#define DART_STREAM_REMAP 0x80 > + > +#define DART_ERROR_ADDR_HI 0x54 > +#define DART_ERROR_ADDR_LO 0x50 > + > +#define DART_TCR(sid) (0x100 + 4 * (sid)) > +#define DART_TCR_TRANSLATE_ENABLE BIT(7) > +#define DART_TCR_BYPASS0_ENABLE BIT(8) > +#define DART_TCR_BYPASS1_ENABLE BIT(12) > + > +#define DART_TTBR(sid, idx) (0x200 + 16 * (sid) + 4 * (idx)) > +#define DART_TTBR_VALID BIT(31) > +#define DART_TTBR_SHIFT 12 > + > +/* > + * Private structure associated with each DART device. > + * > + * @dev: device struct > + * @regs: mapped MMIO region > + * @irq: interrupt number, can be shared with other DARTs > + * @clks: clocks associated with this DART > + * @num_clks: number of @clks > + * @lock: lock for @used_sids and hardware operations involving this dart > + * @used_sids: bitmap of streams attached to a domain > + * @pgsize: pagesize supported by this DART > + * @supports_bypass: indicates if this DART supports bypass mode > + * @force_bypass: force bypass mode due to pagesize mismatch? > + * @iommu: iommu core device > + */ > +struct apple_dart { > + struct device *dev; > + > + void __iomem *regs; > + > + int irq; > + struct clk_bulk_data *clks; > + int num_clks; > + > + spinlock_t lock; > + > + u32 used_sids; > + u32 pgsize; > + > + u32 supports_bypass : 1; > + u32 force_bypass : 1; > + u64 force_bypass_offset; > + u64 force_bypass_len; > + > + struct iommu_device iommu; > +}; > + > +/* > + * This structure is used to identify a single stream attached to a domain. > + * It's used as a list inside that domain to be able to attach multiple > + * streams to a single domain. Since multiple devices can use a single stream > + * it additionally keeps track of how many devices are represented by this > + * stream. Once that number reaches zero it is detached from the IOMMU domain > + * and all translations from this stream are disabled. > + * > + * @dart: DART instance to which this stream belongs > + * @sid: stream id within the DART instance > + * @num_devices: count of devices attached to this stream > + * @stream_head: list head for the next stream > + */ > +struct apple_dart_stream { > + struct apple_dart *dart; > + u32 sid; > + > + u32 num_devices; > + > + struct list_head stream_head; > +}; > + > +/* > + * This structure is attached to each iommu domain handled by a DART. > + * A single domain is used to represent a single virtual address spaces. > + * It is always allocated together with a page table. > + * > + * Streams are the smallest units the DART hardware can differentiate. > + * These are pointed to the page table of a domain whenever a device is > + * attached to it. A single stream can only be assigned to a single domain. > + * > + * Devices are assigned to at least a single and sometimes multiple individual > + * streams (using the iommus property in the device tree). Multiple devices > + * can theoretically be represented by the same stream, though this is usually > + * not the case. > + * > + * We only keep track of streams here and just count how many devices are > + * represented by each stream. When the last device is removed the whole stream > + * is removed from the domain. > + * > + * @dart: pointer to the DART instance > + * @pgtbl_ops: pagetable ops allocated by io-pgtable > + * @type: domain type IOMMU_DOMAIN_IDENTITY_{IDENTITY,DMA,UNMANAGED,BLOCKED} > + * @streams: list of streams attached to this domain > + * @lock: spinlock for operations involving the list of streams > + * @domain: core iommu domain pointer > + */ > +struct apple_dart_domain { > + struct apple_dart *dart; > + struct io_pgtable_ops *pgtbl_ops; > + > + unsigned int type; > + > + struct list_head streams; > + > + spinlock_t lock; > + > + struct iommu_domain domain; > +}; > + > +/* > + * This structure is attached to devices with dev_iommu_priv_set() on of_xlate > + * and contains a list of streams bound to this device as defined in the > + * device tree. Multiple DART instances can be attached to a single device > + * and each stream is identified by its stream id. > + * It's usually reference by a pointer called *cfg. > + * > + * A dynamic array instead of a linked list is used here since in almost > + * all cases a device will just be attached to a single stream and streams > + * are never removed after they have been added. > + * > + * @num_streams: number of streams attached > + * @streams: array of structs to identify attached streams and the device link > + * to the iommu > + */ > +struct apple_dart_master_cfg { > + int num_streams; > + struct { > + struct apple_dart *dart; > + u32 sid; > + > + struct device_link *link; > + } streams[]; > +}; > + > +static struct platform_driver apple_dart_driver; > +static const struct iommu_ops apple_dart_iommu_ops; > +static const struct iommu_flush_ops apple_dart_tlb_ops; > + > +static struct apple_dart_domain *to_dart_domain(struct iommu_domain *dom) > +{ > + return container_of(dom, struct apple_dart_domain, domain); > +} > + > +static void apple_dart_hw_enable_translation(struct apple_dart *dart, u16 sid) > +{ > + writel(DART_TCR_TRANSLATE_ENABLE, dart->regs + DART_TCR(sid)); > +} > + > +static void apple_dart_hw_disable_dma(struct apple_dart *dart, u16 sid) > +{ > + writel(0, dart->regs + DART_TCR(sid)); > +} > + > +static void apple_dart_hw_enable_bypass(struct apple_dart *dart, u16 sid) > +{ > + WARN_ON(!dart->supports_bypass); > + writel(DART_TCR_BYPASS0_ENABLE | DART_TCR_BYPASS1_ENABLE, > + dart->regs + DART_TCR(sid)); > +} > + > +static void apple_dart_hw_set_ttbr(struct apple_dart *dart, u16 sid, u16 idx, > + phys_addr_t paddr) > +{ > + writel(DART_TTBR_VALID | (paddr >> DART_TTBR_SHIFT), > + dart->regs + DART_TTBR(sid, idx)); > +} > + > +static void apple_dart_hw_clear_ttbr(struct apple_dart *dart, u16 sid, u16 idx) > +{ > + writel(0, dart->regs + DART_TTBR(sid, idx)); > +} > + > +static void apple_dart_hw_clear_all_ttbrs(struct apple_dart *dart, u16 sid) > +{ > + int i; > + > + for (i = 0; i < 4; ++i) > + apple_dart_hw_clear_ttbr(dart, sid, i); > +} > + > +static int apple_dart_hw_stream_command(struct apple_dart *dart, u16 sid_bitmap, > + u32 command) > +{ > + unsigned long flags; > + int ret; > + u32 command_reg; > + > + spin_lock_irqsave(&dart->lock, flags); > + > + writel(sid_bitmap, dart->regs + DART_STREAM_SELECT); > + writel(command, dart->regs + DART_STREAM_COMMAND); > + > + ret = readl_poll_timeout_atomic( > + dart->regs + DART_STREAM_COMMAND, command_reg, > + !(command_reg & DART_STREAM_COMMAND_BUSY), 1, > + DART_STREAM_COMMAND_BUSY_TIMEOUT); > + > + spin_unlock_irqrestore(&dart->lock, flags); > + > + if (ret) { > + dev_err(dart->dev, > + "busy bit did not clear after command %x for streams %x\n", > + command, sid_bitmap); > + return ret; > + } > + > + return 0; > +} > + > +static int apple_dart_hw_invalidate_tlb_global(struct apple_dart *dart) > +{ > + return apple_dart_hw_stream_command(dart, DART_STREAM_ALL, > + DART_STREAM_COMMAND_INVALIDATE); > +} > + > +static int apple_dart_hw_invalidate_tlb_stream(struct apple_dart *dart, u16 sid) > +{ > + return apple_dart_hw_stream_command(dart, 1 << sid, > + DART_STREAM_COMMAND_INVALIDATE); > +} > + > +static int apple_dart_hw_reset(struct apple_dart *dart) > +{ > + int sid; > + u32 config; > + > + config = readl(dart->regs + DART_CONFIG); > + if (config & DART_CONFIG_LOCK) { > + dev_err(dart->dev, "DART is locked down until reboot: %08x\n", > + config); > + return -EINVAL; > + } > + > + for (sid = 0; sid < DART_MAX_STREAMS; ++sid) { > + apple_dart_hw_disable_dma(dart, sid); > + apple_dart_hw_clear_all_ttbrs(dart, sid); > + apple_dart_hw_enable_translation(dart, sid); > + } > + > + /* restore stream identity map */ > + writel(0x03020100, dart->regs + DART_STREAM_REMAP); > + writel(0x07060504, dart->regs + DART_STREAM_REMAP + 4); > + writel(0x0b0a0908, dart->regs + DART_STREAM_REMAP + 8); > + writel(0x0f0e0d0c, dart->regs + DART_STREAM_REMAP + 12); > + > + /* clear any pending errors before the interrupt is unmasked */ > + writel(readl(dart->regs + DART_ERROR), dart->regs + DART_ERROR); > + > + return apple_dart_hw_invalidate_tlb_global(dart); > +} > + > +static void apple_dart_domain_flush_tlb(struct apple_dart_domain *domain) > +{ > + unsigned long flags; > + struct apple_dart_stream *stream; > + struct apple_dart *dart = domain->dart; > + > + if (!dart) > + return; > + > + spin_lock_irqsave(&domain->lock, flags); > + list_for_each_entry(stream, &domain->streams, stream_head) { > + apple_dart_hw_invalidate_tlb_stream(stream->dart, stream->sid); > + } > + spin_unlock_irqrestore(&domain->lock, flags); > +} > + > +static void apple_dart_flush_iotlb_all(struct iommu_domain *domain) > +{ > + struct apple_dart_domain *dart_domain = to_dart_domain(domain); > + > + apple_dart_domain_flush_tlb(dart_domain); > +} > + > +static void apple_dart_iotlb_sync(struct iommu_domain *domain, > + struct iommu_iotlb_gather *gather) > +{ > + struct apple_dart_domain *dart_domain = to_dart_domain(domain); > + > + apple_dart_domain_flush_tlb(dart_domain); > +} > + > +static void apple_dart_iotlb_sync_map(struct iommu_domain *domain, > + unsigned long iova, size_t size) > +{ > + struct apple_dart_domain *dart_domain = to_dart_domain(domain); > + > + apple_dart_domain_flush_tlb(dart_domain); > +} > + > +static void apple_dart_tlb_flush_all(void *cookie) > +{ > + struct apple_dart_domain *domain = cookie; > + > + apple_dart_domain_flush_tlb(domain); > +} > + > +static void apple_dart_tlb_flush_walk(unsigned long iova, size_t size, > + size_t granule, void *cookie) > +{ > + struct apple_dart_domain *domain = cookie; > + > + apple_dart_domain_flush_tlb(domain); > +} > + > +static const struct iommu_flush_ops apple_dart_tlb_ops = { > + .tlb_flush_all = apple_dart_tlb_flush_all, > + .tlb_flush_walk = apple_dart_tlb_flush_walk, > + .tlb_add_page = NULL, > +}; > + > +static phys_addr_t apple_dart_iova_to_phys(struct iommu_domain *domain, > + dma_addr_t iova) > +{ > + struct apple_dart_domain *dart_domain = to_dart_domain(domain); > + struct io_pgtable_ops *ops = dart_domain->pgtbl_ops; > + > + if (domain->type == IOMMU_DOMAIN_IDENTITY) > + return iova; > + if (!ops) > + return -ENODEV; > + > + return ops->iova_to_phys(ops, iova); > +} > + > +static int apple_dart_map(struct iommu_domain *domain, unsigned long iova, > + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) > +{ > + struct apple_dart_domain *dart_domain = to_dart_domain(domain); > + struct io_pgtable_ops *ops = dart_domain->pgtbl_ops; > + > + if (!ops) > + return -ENODEV; > + if (prot & IOMMU_MMIO) > + return -EINVAL; > + if (prot & IOMMU_NOEXEC) > + return -EINVAL; > + > + return ops->map(ops, iova, paddr, size, prot, gfp); > +} > + > +static size_t apple_dart_unmap(struct iommu_domain *domain, unsigned long iova, > + size_t size, struct iommu_iotlb_gather *gather) > +{ > + struct apple_dart_domain *dart_domain = to_dart_domain(domain); > + struct io_pgtable_ops *ops = dart_domain->pgtbl_ops; > + > + if (!ops) > + return 0; > + > + return ops->unmap(ops, iova, size, gather); > +} > + > +static int apple_dart_domain_needs_pgtbl_ops(struct apple_dart *dart, > + struct iommu_domain *domain) > +{ > + if (domain->type == IOMMU_DOMAIN_DMA) > + return 1; > + if (domain->type == IOMMU_DOMAIN_UNMANAGED) > + return 1; > + if (!dart->supports_bypass && domain->type == IOMMU_DOMAIN_IDENTITY) > + return 1; > + return 0; > +} > + > +/* must be called with held dart_domain->lock */ You can remove this comment, include lockdep.h and… > +static int apple_dart_finalize_domain(struct iommu_domain *domain) > +{ > + struct apple_dart_domain *dart_domain = to_dart_domain(domain); > + struct apple_dart *dart = dart_domain->dart; > + struct io_pgtable_cfg pgtbl_cfg; > + lockdep_assert_held(&dart_domain->lock); A lockdep enabled kernel will warn if this function is called without the lock held, otherwise this gets optimized out. Same for the similar comments below. > + if (dart_domain->pgtbl_ops) > + return 0; > + if (!apple_dart_domain_needs_pgtbl_ops(dart, domain)) > + return 0; > + > + pgtbl_cfg = (struct io_pgtable_cfg){ > + .pgsize_bitmap = dart->pgsize, > + .ias = 32, > + .oas = 36, > + .coherent_walk = 1, > + .tlb = &apple_dart_tlb_ops, > + .iommu_dev = dart->dev, > + }; > + > + dart_domain->pgtbl_ops = > + alloc_io_pgtable_ops(ARM_APPLE_DART, &pgtbl_cfg, domain); > + if (!dart_domain->pgtbl_ops) > + return -ENOMEM; > + > + domain->pgsize_bitmap = pgtbl_cfg.pgsize_bitmap; > + domain->geometry.aperture_start = 0; > + domain->geometry.aperture_end = DMA_BIT_MASK(32); > + domain->geometry.force_aperture = true; > + > + // HACK: create a static pagetable to fake bypass mode > + if (domain->type == IOMMU_DOMAIN_IDENTITY) { > + u64 addr; > + > + for (addr = 0; addr < dart->force_bypass_len; > + addr += dart->pgsize) > + dart_domain->pgtbl_ops->map( > + dart_domain->pgtbl_ops, addr, > + dart->force_bypass_offset + addr, dart->pgsize, > + IOMMU_READ | IOMMU_WRITE, GFP_ATOMIC); > + } > + > + return 0; > +} > + > +static void apple_dart_stream_setup_ttbrs(struct apple_dart_domain *domain, > + struct apple_dart *dart, u32 sid) > +{ > + int i; > + struct io_pgtable_cfg *pgtbl_cfg = > + &io_pgtable_ops_to_pgtable(domain->pgtbl_ops)->cfg; > + > + for (i = 0; i < pgtbl_cfg->apple_dart_cfg.n_ttbrs; ++i) > + apple_dart_hw_set_ttbr(dart, sid, i, > + pgtbl_cfg->apple_dart_cfg.ttbr[i]); > + for (; i < DART_MAX_TTBR; ++i) > + apple_dart_hw_clear_ttbr(dart, sid, i); > +} > + > +/* must be called with held domain->lock */ > +static int apple_dart_attach_stream(struct apple_dart_domain *domain, > + struct apple_dart *dart, u32 sid) > +{ > + unsigned long flags; > + struct apple_dart_stream *stream; > + int ret; > + > + if (WARN_ON(dart->force_bypass && > + domain->type != IOMMU_DOMAIN_IDENTITY)) > + return -EINVAL; > + > + /* > + * we can't mix and match DARTs that support bypass mode with those who don't > + * because the iova space in fake bypass mode generally has an offset > + */ > + if (WARN_ON(domain->type == IOMMU_DOMAIN_IDENTITY && > + (domain->dart->supports_bypass != dart->supports_bypass))) > + return -EINVAL; > + > + list_for_each_entry(stream, &domain->streams, stream_head) { > + if (stream->dart == dart && stream->sid == sid) { > + stream->num_devices++; > + return 0; > + } > + } > + > + spin_lock_irqsave(&dart->lock, flags); > + > + if (WARN_ON(dart->used_sids & BIT(sid))) { > + ret = -EINVAL; > + goto error; > + } > + > + stream = kzalloc(sizeof(*stream), GFP_ATOMIC); > + if (!stream) { > + ret = -ENOMEM; > + goto error; > + } > + > + stream->dart = dart; > + stream->sid = sid; > + stream->num_devices = 1; > + list_add(&stream->stream_head, &domain->streams); > + > + dart->used_sids |= BIT(sid); > + spin_unlock_irqrestore(&dart->lock, flags); > + > + apple_dart_hw_clear_all_ttbrs(stream->dart, stream->sid); > + > + switch (domain->type) { > + case IOMMU_DOMAIN_IDENTITY: > + if (stream->dart->supports_bypass) { > + apple_dart_hw_enable_bypass(stream->dart, stream->sid); > + } else { > + apple_dart_stream_setup_ttbrs(domain, stream->dart, > + stream->sid); > + apple_dart_hw_enable_translation(stream->dart, > + stream->sid); > + apple_dart_hw_invalidate_tlb_stream(stream->dart, > + stream->sid); > + } > + break; > + case IOMMU_DOMAIN_BLOCKED: > + apple_dart_hw_disable_dma(stream->dart, stream->sid); > + break; > + case IOMMU_DOMAIN_UNMANAGED: > + case IOMMU_DOMAIN_DMA: > + apple_dart_stream_setup_ttbrs(domain, stream->dart, > + stream->sid); > + apple_dart_hw_enable_translation(stream->dart, stream->sid); > + apple_dart_hw_invalidate_tlb_stream(stream->dart, stream->sid); > + break; > + } > + > + return 0; > + > +error: > + spin_unlock_irqrestore(&dart->lock, flags); > + return ret; > +} > + > +static void apple_dart_disable_stream(struct apple_dart *dart, u32 sid) > +{ > + unsigned long flags; > + > + apple_dart_hw_disable_dma(dart, sid); > + apple_dart_hw_clear_all_ttbrs(dart, sid); > + apple_dart_hw_invalidate_tlb_stream(dart, sid); > + > + spin_lock_irqsave(&dart->lock, flags); > + dart->used_sids &= ~BIT(sid); > + spin_unlock_irqrestore(&dart->lock, flags); > +} > + > +/* must be called with held domain->lock */ > +static void apple_dart_detach_stream(struct apple_dart_domain *domain, > + struct apple_dart *dart, u32 sid) > +{ > + struct apple_dart_stream *stream; > + > + list_for_each_entry(stream, &domain->streams, stream_head) { > + if (stream->dart == dart && stream->sid == sid) { > + stream->num_devices--; > + > + if (stream->num_devices == 0) { > + apple_dart_disable_stream(dart, sid); > + list_del(&stream->stream_head); > + kfree(stream); > + } > + return; > + } > + } > +} > + > +static int apple_dart_attach_dev(struct iommu_domain *domain, > + struct device *dev) > +{ > + int ret; > + int i, j; > + unsigned long flags; > + struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev); > + struct apple_dart_domain *dart_domain = to_dart_domain(domain); > + struct apple_dart *dart = cfg->streams[0].dart; > + > + spin_lock_irqsave(&dart_domain->lock, flags); > + > + if (!dart_domain->dart) > + dart_domain->dart = dart; > + > + if (WARN_ON(dart->force_bypass && > + dart_domain->type != IOMMU_DOMAIN_IDENTITY)) { > + dev_warn( > + dev, > + "IOMMU must be in bypass mode but trying to attach to translated domain.\n"); > + ret = -EINVAL; > + goto out; > + } > + > + ret = apple_dart_finalize_domain(domain); > + if (ret) > + goto out; > + > + for (i = 0; i < cfg->num_streams; ++i) { > + ret = apple_dart_attach_stream( > + dart_domain, cfg->streams[i].dart, cfg->streams[i].sid); > + if (ret) { > + /* try to undo what we did before returning */ > + for (j = 0; j < i; ++j) > + apple_dart_detach_stream(dart_domain, > + cfg->streams[j].dart, > + cfg->streams[j].sid); > + > + goto out; > + } > + } > + > + ret = 0; > + > +out: > + spin_unlock_irqrestore(&dart_domain->lock, flags); > + return ret; > +} > + > +static void apple_dart_detach_dev(struct iommu_domain *domain, > + struct device *dev) > +{ > + int i; > + unsigned long flags; > + struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev); > + struct apple_dart_domain *dart_domain = to_dart_domain(domain); > + > + spin_lock_irqsave(&dart_domain->lock, flags); > + > + for (i = 0; i < cfg->num_streams; ++i) > + apple_dart_detach_stream(dart_domain, cfg->streams[i].dart, > + cfg->streams[i].sid); > + > + spin_unlock_irqrestore(&dart_domain->lock, flags); > +} > + > +static struct iommu_device *apple_dart_probe_device(struct device *dev) > +{ > + struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev); > + int i; > + > + if (!cfg) > + return ERR_PTR(-ENODEV); > + > + for (i = 0; i < cfg->num_streams; ++i) { > + cfg->streams[i].link = > + device_link_add(dev, cfg->streams[i].dart->dev, > + DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); > + } > + > + return &cfg->streams[0].dart->iommu; > +} > + > +static void apple_dart_release_device(struct device *dev) > +{ > + struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev); > + int i; > + > + if (!cfg) > + return; > + > + for (i = 0; i < cfg->num_streams; ++i) > + device_link_del(cfg->streams[i].link); > + > + dev_iommu_priv_set(dev, NULL); > + kfree(cfg); > +} > + > +static struct iommu_domain *apple_dart_domain_alloc(unsigned int type) > +{ > + struct apple_dart_domain *dart_domain; > + > + if (type != IOMMU_DOMAIN_DMA && type != IOMMU_DOMAIN_UNMANAGED && > + type != IOMMU_DOMAIN_IDENTITY && type != IOMMU_DOMAIN_BLOCKED) > + return NULL; > + > + dart_domain = kzalloc(sizeof(*dart_domain), GFP_KERNEL); > + if (!dart_domain) > + return NULL; > + > + INIT_LIST_HEAD(&dart_domain->streams); > + spin_lock_init(&dart_domain->lock); > + iommu_get_dma_cookie(&dart_domain->domain); > + dart_domain->type = type; > + > + return &dart_domain->domain; > +} > + > +static void apple_dart_domain_free(struct iommu_domain *domain) > +{ > + struct apple_dart_domain *dart_domain = to_dart_domain(domain); > + > + WARN_ON(!list_empty(&dart_domain->streams)); > + > + kfree(dart_domain); > +} > + > +static int apple_dart_of_xlate(struct device *dev, struct of_phandle_args *args) > +{ > + struct platform_device *iommu_pdev = of_find_device_by_node(args->np); > + struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev); > + unsigned int num_streams = cfg ? cfg->num_streams : 0; > + struct apple_dart_master_cfg *cfg_new; > + struct apple_dart *dart = platform_get_drvdata(iommu_pdev); > + > + if (args->args_count != 1) > + return -EINVAL; > + > + cfg_new = krealloc(cfg, struct_size(cfg, streams, num_streams + 1), > + GFP_KERNEL); > + if (!cfg_new) > + return -ENOMEM; > + > + cfg = cfg_new; > + dev_iommu_priv_set(dev, cfg); > + > + cfg->num_streams = num_streams; > + cfg->streams[cfg->num_streams].dart = dart; > + cfg->streams[cfg->num_streams].sid = args->args[0]; > + cfg->num_streams++; > + > + return 0; > +} > + > +static struct iommu_group *apple_dart_device_group(struct device *dev) > +{ > +#ifdef CONFIG_PCI > + struct iommu_group *group; > + > + if (dev_is_pci(dev)) > + group = pci_device_group(dev); > + else > + group = generic_device_group(dev); > + > + return group; > +#else > + return generic_device_group(dev); > +#endif > +} > + > +static const struct iommu_ops apple_dart_iommu_ops = { > + .domain_alloc = apple_dart_domain_alloc, > + .domain_free = apple_dart_domain_free, > + .attach_dev = apple_dart_attach_dev, > + .detach_dev = apple_dart_detach_dev, > + .map = apple_dart_map, > + .unmap = apple_dart_unmap, > + .flush_iotlb_all = apple_dart_flush_iotlb_all, > + .iotlb_sync = apple_dart_iotlb_sync, > + .iotlb_sync_map = apple_dart_iotlb_sync_map, > + .iova_to_phys = apple_dart_iova_to_phys, > + .probe_device = apple_dart_probe_device, > + .release_device = apple_dart_release_device, > + .device_group = apple_dart_device_group, > + .of_xlate = apple_dart_of_xlate, > + .pgsize_bitmap = -1UL, /* Restricted during dart probe */ > +}; > + > +static irqreturn_t apple_dart_irq(int irq, void *dev) > +{ > + struct apple_dart *dart = dev; > + static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, > + DEFAULT_RATELIMIT_BURST); > + const char *fault_name = NULL; > + u32 error = readl(dart->regs + DART_ERROR); > + u32 error_code = FIELD_GET(DART_ERROR_CODE, error); > + u32 addr_lo = readl(dart->regs + DART_ERROR_ADDR_LO); > + u32 addr_hi = readl(dart->regs + DART_ERROR_ADDR_HI); > + u64 addr = addr_lo | (((u64)addr_hi) << 32); > + u8 stream_idx = FIELD_GET(DART_ERROR_STREAM, error); > + > + if (!(error & DART_ERROR_FLAG)) > + return IRQ_NONE; > + > + if (error_code & DART_ERROR_READ_FAULT) > + fault_name = "READ FAULT"; > + else if (error_code & DART_ERROR_WRITE_FAULT) > + fault_name = "WRITE FAULT"; > + else if (error_code & DART_ERROR_NO_PTE) > + fault_name = "NO PTE FOR IOVA"; > + else if (error_code & DART_ERROR_NO_PMD) > + fault_name = "NO PMD FOR IOVA"; > + else if (error_code & DART_ERROR_NO_TTBR) > + fault_name = "NO TTBR FOR IOVA"; > + > + if (WARN_ON(fault_name == NULL)) > + fault_name = "unknown"; > + > + if (__ratelimit(&rs)) { > + dev_err(dart->dev, > + "translation fault: status:0x%x stream:%d code:0x%x (%s) at 0x%llx", > + error, stream_idx, error_code, fault_name, addr); > + } > + > + writel(error, dart->regs + DART_ERROR); > + return IRQ_HANDLED; > +} > + > +static int apple_dart_probe(struct platform_device *pdev) > +{ > + int ret; > + u32 dart_params[2]; > + struct resource *res; > + struct apple_dart *dart; > + struct device *dev = &pdev->dev; > + > + dart = devm_kzalloc(dev, sizeof(*dart), GFP_KERNEL); > + if (!dart) > + return -ENOMEM; > + > + dart->dev = dev; > + spin_lock_init(&dart->lock); > + > + if (pdev->num_resources < 1) > + return -ENODEV; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (resource_size(res) < 0x4000) { > + dev_err(dev, "MMIO region too small (%pr)\n", res); > + return -EINVAL; > + } > + > + dart->regs = devm_ioremap_resource(dev, res); > + if (IS_ERR(dart->regs)) > + return PTR_ERR(dart->regs); > + > + ret = devm_clk_bulk_get_all(dev, &dart->clks); > + if (ret < 0) > + return ret; > + dart->num_clks = ret; > + > + ret = clk_bulk_prepare_enable(dart->num_clks, dart->clks); > + if (ret) > + return ret; > + > + ret = apple_dart_hw_reset(dart); > + if (ret) > + return ret; > + > + dart_params[0] = readl(dart->regs + DART_PARAMS1); > + dart_params[1] = readl(dart->regs + DART_PARAMS2); > + dart->pgsize = 1 << FIELD_GET(DART_PARAMS_PAGE_SHIFT, dart_params[0]); > + dart->supports_bypass = dart_params[1] & DART_PARAMS_BYPASS_SUPPORT; > + dart->force_bypass = dart->pgsize > PAGE_SIZE; > + > + // HACK: these shouldn't be hardcoded here but come from the device tree > + dart->force_bypass_offset = 0x0800000000; > + dart->force_bypass_len = 0x0100000000; > + > + dart->irq = platform_get_irq(pdev, 0); > + if (dart->irq < 0) > + return -ENODEV; > + > + ret = devm_request_irq(dart->dev, dart->irq, apple_dart_irq, > + IRQF_SHARED, "apple-dart fault handler", dart); > + if (ret) > + return ret; > + > + platform_set_drvdata(pdev, dart); > + > + ret = iommu_device_sysfs_add(&dart->iommu, dev, NULL, "apple-dart.%s", > + dev_name(&pdev->dev)); > + if (ret) > + return ret; > + > + ret = iommu_device_register(&dart->iommu, &apple_dart_iommu_ops, dev); > + if (ret) > + return ret; > + > + if (dev->bus->iommu_ops != &apple_dart_iommu_ops) { > + ret = bus_set_iommu(dev->bus, &apple_dart_iommu_ops); > + if (ret) > + return ret; > + } > +#ifdef CONFIG_PCI > + if (dev->bus->iommu_ops != pci_bus_type.iommu_ops) { > + ret = bus_set_iommu(&pci_bus_type, &apple_dart_iommu_ops); > + if (ret) > + return ret; > + } > +#endif > + > + dev_info( > + &pdev->dev, > + "DART [pagesize %x, bypass support: %d, bypass forced: %d] initialized\n", > + dart->pgsize, dart->supports_bypass, dart->force_bypass); > + return 0; > +} > + > +static int apple_dart_remove(struct platform_device *pdev) > +{ > + struct apple_dart *dart = platform_get_drvdata(pdev); > + > + devm_free_irq(dart->dev, dart->irq, dart); > + > + iommu_device_unregister(&dart->iommu); > + iommu_device_sysfs_remove(&dart->iommu); > + > + clk_bulk_disable(dart->num_clks, dart->clks); > + clk_bulk_unprepare(dart->num_clks, dart->clks); > + > + return 0; > +} > + > +static void apple_dart_shutdown(struct platform_device *pdev) > +{ > + apple_dart_remove(pdev); > +} > + > +static const struct of_device_id apple_dart_of_match[] = { > + { .compatible = "apple,t8103-dart", .data = NULL }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, apple_dart_of_match); > + > +static struct platform_driver apple_dart_driver = { > + .driver = { > + .name = "apple-dart", > + .of_match_table = apple_dart_of_match, > + }, > + .probe = apple_dart_probe, > + .remove = apple_dart_remove, > + .shutdown = apple_dart_shutdown, > +}; > +module_platform_driver(apple_dart_driver); > + > +MODULE_DESCRIPTION("IOMMU API for Apple's DART"); > +MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>"); > +MODULE_LICENSE("GPL v2"); Regards, Rouven
Hi Rouven, On Sat, Jun 5, 2021, at 13:50, Rouven Czerwinski wrote: > Hi Sven, > > just a small comment, see inline. > > On Thu, 2021-06-03 at 10:50 +0200, Sven Peter wrote: > > + > > +/* must be called with held dart_domain->lock */ > > You can remove this comment, include lockdep.h and… > > > +static int apple_dart_finalize_domain(struct iommu_domain *domain) > > +{ > > + struct apple_dart_domain *dart_domain = to_dart_domain(domain); > > + struct apple_dart *dart = dart_domain->dart; > > + struct io_pgtable_cfg pgtbl_cfg; > > + > > lockdep_assert_held(&dart_domain->lock); > > A lockdep enabled kernel will warn if this function is called without > the lock held, otherwise this gets optimized out. Same for the similar > comments below. > That looks very useful, thanks! Will use it for v4. I only found assert_spin_locked originally but didn't want to have that performance overhead for code that (I hope :-)) correctly uses these functions with a held lock right now. Thanks, Sven
diff --git a/MAINTAINERS b/MAINTAINERS index 4373d63f9ccf..cb9200ad05fe 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1245,6 +1245,7 @@ M: Sven Peter <sven@svenpeter.dev> L: iommu@lists.linux-foundation.org S: Maintained F: Documentation/devicetree/bindings/iommu/apple,dart.yaml +F: drivers/iommu/apple-dart-iommu.c APPLE SMC DRIVER M: Henrik Rydberg <rydberg@bitmath.org> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 1f111b399bca..87882c628b46 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -249,6 +249,21 @@ config SPAPR_TCE_IOMMU Enables bits of IOMMU API required by VFIO. The iommu_ops is not implemented as it is not necessary for VFIO. +config IOMMU_APPLE_DART + tristate "Apple DART IOMMU Support" + depends on ARM64 || (COMPILE_TEST && !GENERIC_ATOMIC64) + select IOMMU_API + select IOMMU_IO_PGTABLE + select IOMMU_IO_PGTABLE_LPAE + default ARCH_APPLE + help + Support for Apple DART (Device Address Resolution Table) IOMMUs + found in Apple ARM SoCs like the M1. + This IOMMU is required for most peripherals using DMA to access + the main memory. + + Say Y here if you are using an Apple SoC with a DART IOMMU. + # ARM IOMMU support config ARM_SMMU tristate "ARM Ltd. System MMU (SMMU) Support" diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile index c0fb0ba88143..8c813f0ebc54 100644 --- a/drivers/iommu/Makefile +++ b/drivers/iommu/Makefile @@ -29,3 +29,4 @@ obj-$(CONFIG_HYPERV_IOMMU) += hyperv-iommu.o obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o obj-$(CONFIG_IOMMU_SVA_LIB) += iommu-sva-lib.o io-pgfault.o obj-$(CONFIG_SPRD_IOMMU) += sprd-iommu.o +obj-$(CONFIG_IOMMU_APPLE_DART) += apple-dart-iommu.o diff --git a/drivers/iommu/apple-dart-iommu.c b/drivers/iommu/apple-dart-iommu.c new file mode 100644 index 000000000000..2777852498de --- /dev/null +++ b/drivers/iommu/apple-dart-iommu.c @@ -0,0 +1,966 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Apple DART (Device Address Resolution Table) IOMMU driver + * + * Copyright (C) 2021 The Asahi Linux Contributors + * + * Based on arm/arm-smmu/arm-ssmu.c and arm/arm-smmu-v3/arm-smmu-v3.c + * Copyright (C) 2013 ARM Limited + * Copyright (C) 2015 ARM Limited + * and on exynos-iommu.c + * Copyright (c) 2011,2016 Samsung Electronics Co., Ltd. + */ + +#include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/dma-iommu.h> +#include <linux/dma-mapping.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/io-pgtable.h> +#include <linux/iopoll.h> +#include <linux/list.h> +#include <linux/module.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/ratelimit.h> +#include <linux/slab.h> +#include <linux/pci.h> + +#define DART_MAX_STREAMS 16 +#define DART_MAX_TTBR 4 + +#define DART_STREAM_ALL 0xffff + +#define DART_PARAMS1 0x00 +#define DART_PARAMS_PAGE_SHIFT GENMASK(27, 24) + +#define DART_PARAMS2 0x04 +#define DART_PARAMS_BYPASS_SUPPORT BIT(0) + +#define DART_STREAM_COMMAND 0x20 +#define DART_STREAM_COMMAND_BUSY BIT(2) +#define DART_STREAM_COMMAND_INVALIDATE BIT(20) + +#define DART_STREAM_SELECT 0x34 + +#define DART_ERROR 0x40 +#define DART_ERROR_STREAM GENMASK(27, 24) +#define DART_ERROR_CODE GENMASK(23, 0) +#define DART_ERROR_FLAG BIT(31) +#define DART_ERROR_READ_FAULT BIT(4) +#define DART_ERROR_WRITE_FAULT BIT(3) +#define DART_ERROR_NO_PTE BIT(2) +#define DART_ERROR_NO_PMD BIT(1) +#define DART_ERROR_NO_TTBR BIT(0) + +#define DART_CONFIG 0x60 +#define DART_CONFIG_LOCK BIT(15) + +#define DART_STREAM_COMMAND_BUSY_TIMEOUT 100 + +#define DART_STREAM_REMAP 0x80 + +#define DART_ERROR_ADDR_HI 0x54 +#define DART_ERROR_ADDR_LO 0x50 + +#define DART_TCR(sid) (0x100 + 4 * (sid)) +#define DART_TCR_TRANSLATE_ENABLE BIT(7) +#define DART_TCR_BYPASS0_ENABLE BIT(8) +#define DART_TCR_BYPASS1_ENABLE BIT(12) + +#define DART_TTBR(sid, idx) (0x200 + 16 * (sid) + 4 * (idx)) +#define DART_TTBR_VALID BIT(31) +#define DART_TTBR_SHIFT 12 + +/* + * Private structure associated with each DART device. + * + * @dev: device struct + * @regs: mapped MMIO region + * @irq: interrupt number, can be shared with other DARTs + * @clks: clocks associated with this DART + * @num_clks: number of @clks + * @lock: lock for @used_sids and hardware operations involving this dart + * @used_sids: bitmap of streams attached to a domain + * @pgsize: pagesize supported by this DART + * @supports_bypass: indicates if this DART supports bypass mode + * @force_bypass: force bypass mode due to pagesize mismatch? + * @iommu: iommu core device + */ +struct apple_dart { + struct device *dev; + + void __iomem *regs; + + int irq; + struct clk_bulk_data *clks; + int num_clks; + + spinlock_t lock; + + u32 used_sids; + u32 pgsize; + + u32 supports_bypass : 1; + u32 force_bypass : 1; + u64 force_bypass_offset; + u64 force_bypass_len; + + struct iommu_device iommu; +}; + +/* + * This structure is used to identify a single stream attached to a domain. + * It's used as a list inside that domain to be able to attach multiple + * streams to a single domain. Since multiple devices can use a single stream + * it additionally keeps track of how many devices are represented by this + * stream. Once that number reaches zero it is detached from the IOMMU domain + * and all translations from this stream are disabled. + * + * @dart: DART instance to which this stream belongs + * @sid: stream id within the DART instance + * @num_devices: count of devices attached to this stream + * @stream_head: list head for the next stream + */ +struct apple_dart_stream { + struct apple_dart *dart; + u32 sid; + + u32 num_devices; + + struct list_head stream_head; +}; + +/* + * This structure is attached to each iommu domain handled by a DART. + * A single domain is used to represent a single virtual address spaces. + * It is always allocated together with a page table. + * + * Streams are the smallest units the DART hardware can differentiate. + * These are pointed to the page table of a domain whenever a device is + * attached to it. A single stream can only be assigned to a single domain. + * + * Devices are assigned to at least a single and sometimes multiple individual + * streams (using the iommus property in the device tree). Multiple devices + * can theoretically be represented by the same stream, though this is usually + * not the case. + * + * We only keep track of streams here and just count how many devices are + * represented by each stream. When the last device is removed the whole stream + * is removed from the domain. + * + * @dart: pointer to the DART instance + * @pgtbl_ops: pagetable ops allocated by io-pgtable + * @type: domain type IOMMU_DOMAIN_IDENTITY_{IDENTITY,DMA,UNMANAGED,BLOCKED} + * @streams: list of streams attached to this domain + * @lock: spinlock for operations involving the list of streams + * @domain: core iommu domain pointer + */ +struct apple_dart_domain { + struct apple_dart *dart; + struct io_pgtable_ops *pgtbl_ops; + + unsigned int type; + + struct list_head streams; + + spinlock_t lock; + + struct iommu_domain domain; +}; + +/* + * This structure is attached to devices with dev_iommu_priv_set() on of_xlate + * and contains a list of streams bound to this device as defined in the + * device tree. Multiple DART instances can be attached to a single device + * and each stream is identified by its stream id. + * It's usually reference by a pointer called *cfg. + * + * A dynamic array instead of a linked list is used here since in almost + * all cases a device will just be attached to a single stream and streams + * are never removed after they have been added. + * + * @num_streams: number of streams attached + * @streams: array of structs to identify attached streams and the device link + * to the iommu + */ +struct apple_dart_master_cfg { + int num_streams; + struct { + struct apple_dart *dart; + u32 sid; + + struct device_link *link; + } streams[]; +}; + +static struct platform_driver apple_dart_driver; +static const struct iommu_ops apple_dart_iommu_ops; +static const struct iommu_flush_ops apple_dart_tlb_ops; + +static struct apple_dart_domain *to_dart_domain(struct iommu_domain *dom) +{ + return container_of(dom, struct apple_dart_domain, domain); +} + +static void apple_dart_hw_enable_translation(struct apple_dart *dart, u16 sid) +{ + writel(DART_TCR_TRANSLATE_ENABLE, dart->regs + DART_TCR(sid)); +} + +static void apple_dart_hw_disable_dma(struct apple_dart *dart, u16 sid) +{ + writel(0, dart->regs + DART_TCR(sid)); +} + +static void apple_dart_hw_enable_bypass(struct apple_dart *dart, u16 sid) +{ + WARN_ON(!dart->supports_bypass); + writel(DART_TCR_BYPASS0_ENABLE | DART_TCR_BYPASS1_ENABLE, + dart->regs + DART_TCR(sid)); +} + +static void apple_dart_hw_set_ttbr(struct apple_dart *dart, u16 sid, u16 idx, + phys_addr_t paddr) +{ + writel(DART_TTBR_VALID | (paddr >> DART_TTBR_SHIFT), + dart->regs + DART_TTBR(sid, idx)); +} + +static void apple_dart_hw_clear_ttbr(struct apple_dart *dart, u16 sid, u16 idx) +{ + writel(0, dart->regs + DART_TTBR(sid, idx)); +} + +static void apple_dart_hw_clear_all_ttbrs(struct apple_dart *dart, u16 sid) +{ + int i; + + for (i = 0; i < 4; ++i) + apple_dart_hw_clear_ttbr(dart, sid, i); +} + +static int apple_dart_hw_stream_command(struct apple_dart *dart, u16 sid_bitmap, + u32 command) +{ + unsigned long flags; + int ret; + u32 command_reg; + + spin_lock_irqsave(&dart->lock, flags); + + writel(sid_bitmap, dart->regs + DART_STREAM_SELECT); + writel(command, dart->regs + DART_STREAM_COMMAND); + + ret = readl_poll_timeout_atomic( + dart->regs + DART_STREAM_COMMAND, command_reg, + !(command_reg & DART_STREAM_COMMAND_BUSY), 1, + DART_STREAM_COMMAND_BUSY_TIMEOUT); + + spin_unlock_irqrestore(&dart->lock, flags); + + if (ret) { + dev_err(dart->dev, + "busy bit did not clear after command %x for streams %x\n", + command, sid_bitmap); + return ret; + } + + return 0; +} + +static int apple_dart_hw_invalidate_tlb_global(struct apple_dart *dart) +{ + return apple_dart_hw_stream_command(dart, DART_STREAM_ALL, + DART_STREAM_COMMAND_INVALIDATE); +} + +static int apple_dart_hw_invalidate_tlb_stream(struct apple_dart *dart, u16 sid) +{ + return apple_dart_hw_stream_command(dart, 1 << sid, + DART_STREAM_COMMAND_INVALIDATE); +} + +static int apple_dart_hw_reset(struct apple_dart *dart) +{ + int sid; + u32 config; + + config = readl(dart->regs + DART_CONFIG); + if (config & DART_CONFIG_LOCK) { + dev_err(dart->dev, "DART is locked down until reboot: %08x\n", + config); + return -EINVAL; + } + + for (sid = 0; sid < DART_MAX_STREAMS; ++sid) { + apple_dart_hw_disable_dma(dart, sid); + apple_dart_hw_clear_all_ttbrs(dart, sid); + apple_dart_hw_enable_translation(dart, sid); + } + + /* restore stream identity map */ + writel(0x03020100, dart->regs + DART_STREAM_REMAP); + writel(0x07060504, dart->regs + DART_STREAM_REMAP + 4); + writel(0x0b0a0908, dart->regs + DART_STREAM_REMAP + 8); + writel(0x0f0e0d0c, dart->regs + DART_STREAM_REMAP + 12); + + /* clear any pending errors before the interrupt is unmasked */ + writel(readl(dart->regs + DART_ERROR), dart->regs + DART_ERROR); + + return apple_dart_hw_invalidate_tlb_global(dart); +} + +static void apple_dart_domain_flush_tlb(struct apple_dart_domain *domain) +{ + unsigned long flags; + struct apple_dart_stream *stream; + struct apple_dart *dart = domain->dart; + + if (!dart) + return; + + spin_lock_irqsave(&domain->lock, flags); + list_for_each_entry(stream, &domain->streams, stream_head) { + apple_dart_hw_invalidate_tlb_stream(stream->dart, stream->sid); + } + spin_unlock_irqrestore(&domain->lock, flags); +} + +static void apple_dart_flush_iotlb_all(struct iommu_domain *domain) +{ + struct apple_dart_domain *dart_domain = to_dart_domain(domain); + + apple_dart_domain_flush_tlb(dart_domain); +} + +static void apple_dart_iotlb_sync(struct iommu_domain *domain, + struct iommu_iotlb_gather *gather) +{ + struct apple_dart_domain *dart_domain = to_dart_domain(domain); + + apple_dart_domain_flush_tlb(dart_domain); +} + +static void apple_dart_iotlb_sync_map(struct iommu_domain *domain, + unsigned long iova, size_t size) +{ + struct apple_dart_domain *dart_domain = to_dart_domain(domain); + + apple_dart_domain_flush_tlb(dart_domain); +} + +static void apple_dart_tlb_flush_all(void *cookie) +{ + struct apple_dart_domain *domain = cookie; + + apple_dart_domain_flush_tlb(domain); +} + +static void apple_dart_tlb_flush_walk(unsigned long iova, size_t size, + size_t granule, void *cookie) +{ + struct apple_dart_domain *domain = cookie; + + apple_dart_domain_flush_tlb(domain); +} + +static const struct iommu_flush_ops apple_dart_tlb_ops = { + .tlb_flush_all = apple_dart_tlb_flush_all, + .tlb_flush_walk = apple_dart_tlb_flush_walk, + .tlb_add_page = NULL, +}; + +static phys_addr_t apple_dart_iova_to_phys(struct iommu_domain *domain, + dma_addr_t iova) +{ + struct apple_dart_domain *dart_domain = to_dart_domain(domain); + struct io_pgtable_ops *ops = dart_domain->pgtbl_ops; + + if (domain->type == IOMMU_DOMAIN_IDENTITY) + return iova; + if (!ops) + return -ENODEV; + + return ops->iova_to_phys(ops, iova); +} + +static int apple_dart_map(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) +{ + struct apple_dart_domain *dart_domain = to_dart_domain(domain); + struct io_pgtable_ops *ops = dart_domain->pgtbl_ops; + + if (!ops) + return -ENODEV; + if (prot & IOMMU_MMIO) + return -EINVAL; + if (prot & IOMMU_NOEXEC) + return -EINVAL; + + return ops->map(ops, iova, paddr, size, prot, gfp); +} + +static size_t apple_dart_unmap(struct iommu_domain *domain, unsigned long iova, + size_t size, struct iommu_iotlb_gather *gather) +{ + struct apple_dart_domain *dart_domain = to_dart_domain(domain); + struct io_pgtable_ops *ops = dart_domain->pgtbl_ops; + + if (!ops) + return 0; + + return ops->unmap(ops, iova, size, gather); +} + +static int apple_dart_domain_needs_pgtbl_ops(struct apple_dart *dart, + struct iommu_domain *domain) +{ + if (domain->type == IOMMU_DOMAIN_DMA) + return 1; + if (domain->type == IOMMU_DOMAIN_UNMANAGED) + return 1; + if (!dart->supports_bypass && domain->type == IOMMU_DOMAIN_IDENTITY) + return 1; + return 0; +} + +/* must be called with held dart_domain->lock */ +static int apple_dart_finalize_domain(struct iommu_domain *domain) +{ + struct apple_dart_domain *dart_domain = to_dart_domain(domain); + struct apple_dart *dart = dart_domain->dart; + struct io_pgtable_cfg pgtbl_cfg; + + if (dart_domain->pgtbl_ops) + return 0; + if (!apple_dart_domain_needs_pgtbl_ops(dart, domain)) + return 0; + + pgtbl_cfg = (struct io_pgtable_cfg){ + .pgsize_bitmap = dart->pgsize, + .ias = 32, + .oas = 36, + .coherent_walk = 1, + .tlb = &apple_dart_tlb_ops, + .iommu_dev = dart->dev, + }; + + dart_domain->pgtbl_ops = + alloc_io_pgtable_ops(ARM_APPLE_DART, &pgtbl_cfg, domain); + if (!dart_domain->pgtbl_ops) + return -ENOMEM; + + domain->pgsize_bitmap = pgtbl_cfg.pgsize_bitmap; + domain->geometry.aperture_start = 0; + domain->geometry.aperture_end = DMA_BIT_MASK(32); + domain->geometry.force_aperture = true; + + // HACK: create a static pagetable to fake bypass mode + if (domain->type == IOMMU_DOMAIN_IDENTITY) { + u64 addr; + + for (addr = 0; addr < dart->force_bypass_len; + addr += dart->pgsize) + dart_domain->pgtbl_ops->map( + dart_domain->pgtbl_ops, addr, + dart->force_bypass_offset + addr, dart->pgsize, + IOMMU_READ | IOMMU_WRITE, GFP_ATOMIC); + } + + return 0; +} + +static void apple_dart_stream_setup_ttbrs(struct apple_dart_domain *domain, + struct apple_dart *dart, u32 sid) +{ + int i; + struct io_pgtable_cfg *pgtbl_cfg = + &io_pgtable_ops_to_pgtable(domain->pgtbl_ops)->cfg; + + for (i = 0; i < pgtbl_cfg->apple_dart_cfg.n_ttbrs; ++i) + apple_dart_hw_set_ttbr(dart, sid, i, + pgtbl_cfg->apple_dart_cfg.ttbr[i]); + for (; i < DART_MAX_TTBR; ++i) + apple_dart_hw_clear_ttbr(dart, sid, i); +} + +/* must be called with held domain->lock */ +static int apple_dart_attach_stream(struct apple_dart_domain *domain, + struct apple_dart *dart, u32 sid) +{ + unsigned long flags; + struct apple_dart_stream *stream; + int ret; + + if (WARN_ON(dart->force_bypass && + domain->type != IOMMU_DOMAIN_IDENTITY)) + return -EINVAL; + + /* + * we can't mix and match DARTs that support bypass mode with those who don't + * because the iova space in fake bypass mode generally has an offset + */ + if (WARN_ON(domain->type == IOMMU_DOMAIN_IDENTITY && + (domain->dart->supports_bypass != dart->supports_bypass))) + return -EINVAL; + + list_for_each_entry(stream, &domain->streams, stream_head) { + if (stream->dart == dart && stream->sid == sid) { + stream->num_devices++; + return 0; + } + } + + spin_lock_irqsave(&dart->lock, flags); + + if (WARN_ON(dart->used_sids & BIT(sid))) { + ret = -EINVAL; + goto error; + } + + stream = kzalloc(sizeof(*stream), GFP_ATOMIC); + if (!stream) { + ret = -ENOMEM; + goto error; + } + + stream->dart = dart; + stream->sid = sid; + stream->num_devices = 1; + list_add(&stream->stream_head, &domain->streams); + + dart->used_sids |= BIT(sid); + spin_unlock_irqrestore(&dart->lock, flags); + + apple_dart_hw_clear_all_ttbrs(stream->dart, stream->sid); + + switch (domain->type) { + case IOMMU_DOMAIN_IDENTITY: + if (stream->dart->supports_bypass) { + apple_dart_hw_enable_bypass(stream->dart, stream->sid); + } else { + apple_dart_stream_setup_ttbrs(domain, stream->dart, + stream->sid); + apple_dart_hw_enable_translation(stream->dart, + stream->sid); + apple_dart_hw_invalidate_tlb_stream(stream->dart, + stream->sid); + } + break; + case IOMMU_DOMAIN_BLOCKED: + apple_dart_hw_disable_dma(stream->dart, stream->sid); + break; + case IOMMU_DOMAIN_UNMANAGED: + case IOMMU_DOMAIN_DMA: + apple_dart_stream_setup_ttbrs(domain, stream->dart, + stream->sid); + apple_dart_hw_enable_translation(stream->dart, stream->sid); + apple_dart_hw_invalidate_tlb_stream(stream->dart, stream->sid); + break; + } + + return 0; + +error: + spin_unlock_irqrestore(&dart->lock, flags); + return ret; +} + +static void apple_dart_disable_stream(struct apple_dart *dart, u32 sid) +{ + unsigned long flags; + + apple_dart_hw_disable_dma(dart, sid); + apple_dart_hw_clear_all_ttbrs(dart, sid); + apple_dart_hw_invalidate_tlb_stream(dart, sid); + + spin_lock_irqsave(&dart->lock, flags); + dart->used_sids &= ~BIT(sid); + spin_unlock_irqrestore(&dart->lock, flags); +} + +/* must be called with held domain->lock */ +static void apple_dart_detach_stream(struct apple_dart_domain *domain, + struct apple_dart *dart, u32 sid) +{ + struct apple_dart_stream *stream; + + list_for_each_entry(stream, &domain->streams, stream_head) { + if (stream->dart == dart && stream->sid == sid) { + stream->num_devices--; + + if (stream->num_devices == 0) { + apple_dart_disable_stream(dart, sid); + list_del(&stream->stream_head); + kfree(stream); + } + return; + } + } +} + +static int apple_dart_attach_dev(struct iommu_domain *domain, + struct device *dev) +{ + int ret; + int i, j; + unsigned long flags; + struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev); + struct apple_dart_domain *dart_domain = to_dart_domain(domain); + struct apple_dart *dart = cfg->streams[0].dart; + + spin_lock_irqsave(&dart_domain->lock, flags); + + if (!dart_domain->dart) + dart_domain->dart = dart; + + if (WARN_ON(dart->force_bypass && + dart_domain->type != IOMMU_DOMAIN_IDENTITY)) { + dev_warn( + dev, + "IOMMU must be in bypass mode but trying to attach to translated domain.\n"); + ret = -EINVAL; + goto out; + } + + ret = apple_dart_finalize_domain(domain); + if (ret) + goto out; + + for (i = 0; i < cfg->num_streams; ++i) { + ret = apple_dart_attach_stream( + dart_domain, cfg->streams[i].dart, cfg->streams[i].sid); + if (ret) { + /* try to undo what we did before returning */ + for (j = 0; j < i; ++j) + apple_dart_detach_stream(dart_domain, + cfg->streams[j].dart, + cfg->streams[j].sid); + + goto out; + } + } + + ret = 0; + +out: + spin_unlock_irqrestore(&dart_domain->lock, flags); + return ret; +} + +static void apple_dart_detach_dev(struct iommu_domain *domain, + struct device *dev) +{ + int i; + unsigned long flags; + struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev); + struct apple_dart_domain *dart_domain = to_dart_domain(domain); + + spin_lock_irqsave(&dart_domain->lock, flags); + + for (i = 0; i < cfg->num_streams; ++i) + apple_dart_detach_stream(dart_domain, cfg->streams[i].dart, + cfg->streams[i].sid); + + spin_unlock_irqrestore(&dart_domain->lock, flags); +} + +static struct iommu_device *apple_dart_probe_device(struct device *dev) +{ + struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev); + int i; + + if (!cfg) + return ERR_PTR(-ENODEV); + + for (i = 0; i < cfg->num_streams; ++i) { + cfg->streams[i].link = + device_link_add(dev, cfg->streams[i].dart->dev, + DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); + } + + return &cfg->streams[0].dart->iommu; +} + +static void apple_dart_release_device(struct device *dev) +{ + struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev); + int i; + + if (!cfg) + return; + + for (i = 0; i < cfg->num_streams; ++i) + device_link_del(cfg->streams[i].link); + + dev_iommu_priv_set(dev, NULL); + kfree(cfg); +} + +static struct iommu_domain *apple_dart_domain_alloc(unsigned int type) +{ + struct apple_dart_domain *dart_domain; + + if (type != IOMMU_DOMAIN_DMA && type != IOMMU_DOMAIN_UNMANAGED && + type != IOMMU_DOMAIN_IDENTITY && type != IOMMU_DOMAIN_BLOCKED) + return NULL; + + dart_domain = kzalloc(sizeof(*dart_domain), GFP_KERNEL); + if (!dart_domain) + return NULL; + + INIT_LIST_HEAD(&dart_domain->streams); + spin_lock_init(&dart_domain->lock); + iommu_get_dma_cookie(&dart_domain->domain); + dart_domain->type = type; + + return &dart_domain->domain; +} + +static void apple_dart_domain_free(struct iommu_domain *domain) +{ + struct apple_dart_domain *dart_domain = to_dart_domain(domain); + + WARN_ON(!list_empty(&dart_domain->streams)); + + kfree(dart_domain); +} + +static int apple_dart_of_xlate(struct device *dev, struct of_phandle_args *args) +{ + struct platform_device *iommu_pdev = of_find_device_by_node(args->np); + struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev); + unsigned int num_streams = cfg ? cfg->num_streams : 0; + struct apple_dart_master_cfg *cfg_new; + struct apple_dart *dart = platform_get_drvdata(iommu_pdev); + + if (args->args_count != 1) + return -EINVAL; + + cfg_new = krealloc(cfg, struct_size(cfg, streams, num_streams + 1), + GFP_KERNEL); + if (!cfg_new) + return -ENOMEM; + + cfg = cfg_new; + dev_iommu_priv_set(dev, cfg); + + cfg->num_streams = num_streams; + cfg->streams[cfg->num_streams].dart = dart; + cfg->streams[cfg->num_streams].sid = args->args[0]; + cfg->num_streams++; + + return 0; +} + +static struct iommu_group *apple_dart_device_group(struct device *dev) +{ +#ifdef CONFIG_PCI + struct iommu_group *group; + + if (dev_is_pci(dev)) + group = pci_device_group(dev); + else + group = generic_device_group(dev); + + return group; +#else + return generic_device_group(dev); +#endif +} + +static const struct iommu_ops apple_dart_iommu_ops = { + .domain_alloc = apple_dart_domain_alloc, + .domain_free = apple_dart_domain_free, + .attach_dev = apple_dart_attach_dev, + .detach_dev = apple_dart_detach_dev, + .map = apple_dart_map, + .unmap = apple_dart_unmap, + .flush_iotlb_all = apple_dart_flush_iotlb_all, + .iotlb_sync = apple_dart_iotlb_sync, + .iotlb_sync_map = apple_dart_iotlb_sync_map, + .iova_to_phys = apple_dart_iova_to_phys, + .probe_device = apple_dart_probe_device, + .release_device = apple_dart_release_device, + .device_group = apple_dart_device_group, + .of_xlate = apple_dart_of_xlate, + .pgsize_bitmap = -1UL, /* Restricted during dart probe */ +}; + +static irqreturn_t apple_dart_irq(int irq, void *dev) +{ + struct apple_dart *dart = dev; + static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + const char *fault_name = NULL; + u32 error = readl(dart->regs + DART_ERROR); + u32 error_code = FIELD_GET(DART_ERROR_CODE, error); + u32 addr_lo = readl(dart->regs + DART_ERROR_ADDR_LO); + u32 addr_hi = readl(dart->regs + DART_ERROR_ADDR_HI); + u64 addr = addr_lo | (((u64)addr_hi) << 32); + u8 stream_idx = FIELD_GET(DART_ERROR_STREAM, error); + + if (!(error & DART_ERROR_FLAG)) + return IRQ_NONE; + + if (error_code & DART_ERROR_READ_FAULT) + fault_name = "READ FAULT"; + else if (error_code & DART_ERROR_WRITE_FAULT) + fault_name = "WRITE FAULT"; + else if (error_code & DART_ERROR_NO_PTE) + fault_name = "NO PTE FOR IOVA"; + else if (error_code & DART_ERROR_NO_PMD) + fault_name = "NO PMD FOR IOVA"; + else if (error_code & DART_ERROR_NO_TTBR) + fault_name = "NO TTBR FOR IOVA"; + + if (WARN_ON(fault_name == NULL)) + fault_name = "unknown"; + + if (__ratelimit(&rs)) { + dev_err(dart->dev, + "translation fault: status:0x%x stream:%d code:0x%x (%s) at 0x%llx", + error, stream_idx, error_code, fault_name, addr); + } + + writel(error, dart->regs + DART_ERROR); + return IRQ_HANDLED; +} + +static int apple_dart_probe(struct platform_device *pdev) +{ + int ret; + u32 dart_params[2]; + struct resource *res; + struct apple_dart *dart; + struct device *dev = &pdev->dev; + + dart = devm_kzalloc(dev, sizeof(*dart), GFP_KERNEL); + if (!dart) + return -ENOMEM; + + dart->dev = dev; + spin_lock_init(&dart->lock); + + if (pdev->num_resources < 1) + return -ENODEV; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (resource_size(res) < 0x4000) { + dev_err(dev, "MMIO region too small (%pr)\n", res); + return -EINVAL; + } + + dart->regs = devm_ioremap_resource(dev, res); + if (IS_ERR(dart->regs)) + return PTR_ERR(dart->regs); + + ret = devm_clk_bulk_get_all(dev, &dart->clks); + if (ret < 0) + return ret; + dart->num_clks = ret; + + ret = clk_bulk_prepare_enable(dart->num_clks, dart->clks); + if (ret) + return ret; + + ret = apple_dart_hw_reset(dart); + if (ret) + return ret; + + dart_params[0] = readl(dart->regs + DART_PARAMS1); + dart_params[1] = readl(dart->regs + DART_PARAMS2); + dart->pgsize = 1 << FIELD_GET(DART_PARAMS_PAGE_SHIFT, dart_params[0]); + dart->supports_bypass = dart_params[1] & DART_PARAMS_BYPASS_SUPPORT; + dart->force_bypass = dart->pgsize > PAGE_SIZE; + + // HACK: these shouldn't be hardcoded here but come from the device tree + dart->force_bypass_offset = 0x0800000000; + dart->force_bypass_len = 0x0100000000; + + dart->irq = platform_get_irq(pdev, 0); + if (dart->irq < 0) + return -ENODEV; + + ret = devm_request_irq(dart->dev, dart->irq, apple_dart_irq, + IRQF_SHARED, "apple-dart fault handler", dart); + if (ret) + return ret; + + platform_set_drvdata(pdev, dart); + + ret = iommu_device_sysfs_add(&dart->iommu, dev, NULL, "apple-dart.%s", + dev_name(&pdev->dev)); + if (ret) + return ret; + + ret = iommu_device_register(&dart->iommu, &apple_dart_iommu_ops, dev); + if (ret) + return ret; + + if (dev->bus->iommu_ops != &apple_dart_iommu_ops) { + ret = bus_set_iommu(dev->bus, &apple_dart_iommu_ops); + if (ret) + return ret; + } +#ifdef CONFIG_PCI + if (dev->bus->iommu_ops != pci_bus_type.iommu_ops) { + ret = bus_set_iommu(&pci_bus_type, &apple_dart_iommu_ops); + if (ret) + return ret; + } +#endif + + dev_info( + &pdev->dev, + "DART [pagesize %x, bypass support: %d, bypass forced: %d] initialized\n", + dart->pgsize, dart->supports_bypass, dart->force_bypass); + return 0; +} + +static int apple_dart_remove(struct platform_device *pdev) +{ + struct apple_dart *dart = platform_get_drvdata(pdev); + + devm_free_irq(dart->dev, dart->irq, dart); + + iommu_device_unregister(&dart->iommu); + iommu_device_sysfs_remove(&dart->iommu); + + clk_bulk_disable(dart->num_clks, dart->clks); + clk_bulk_unprepare(dart->num_clks, dart->clks); + + return 0; +} + +static void apple_dart_shutdown(struct platform_device *pdev) +{ + apple_dart_remove(pdev); +} + +static const struct of_device_id apple_dart_of_match[] = { + { .compatible = "apple,t8103-dart", .data = NULL }, + {}, +}; +MODULE_DEVICE_TABLE(of, apple_dart_of_match); + +static struct platform_driver apple_dart_driver = { + .driver = { + .name = "apple-dart", + .of_match_table = apple_dart_of_match, + }, + .probe = apple_dart_probe, + .remove = apple_dart_remove, + .shutdown = apple_dart_shutdown, +}; +module_platform_driver(apple_dart_driver); + +MODULE_DESCRIPTION("IOMMU API for Apple's DART"); +MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>"); +MODULE_LICENSE("GPL v2");
Apple's new SoCs use iommus for almost all peripherals. These Device Address Resolution Tables must be setup before these peripherals can act as DMA masters. Signed-off-by: Sven Peter <sven@svenpeter.dev> --- MAINTAINERS | 1 + drivers/iommu/Kconfig | 15 + drivers/iommu/Makefile | 1 + drivers/iommu/apple-dart-iommu.c | 966 +++++++++++++++++++++++++++++++ 4 files changed, 983 insertions(+) create mode 100644 drivers/iommu/apple-dart-iommu.c