[v9,4/8] iommu/msi-iommu: initialization

iommu_get/put_msi_cookie allocates/frees the resource used to store
and ref count the MSI doorbell mappings. iommu_msi_set_aperture
initializes the iova domain used for MSI IOVA allocation and sets the
iommu domain's msi geometry.

The implementation relies on dma-iommu API and iova API.

New msi functions are fully implemented if CONFIG_IOMMU_MSI is set.

Signed-off-by: Eric Auger <eric.auger@linaro.org>


---
v9:
- remove is_aperture_set and use iommu_domain_msi_aperture_valid helper
  instead
- set iommu domain's msi geometry

v8:
- new design where msi-iommu relies on dma-iommu
- remove the iommu_domain * from the doorbell_mapping struct
- added is_aperture_set

v7:
- fix locking
- add iova_cache_get/put
- static inline functions when CONFIG_IOMMU_DMA_RESERVED is not set
- introduce struct reserved_iova_domain to encapsulate prot info &
  add prot parameter in alloc_reserved_iova_domain

v5 -> v6:
- use spin lock instead of mutex

v3 -> v4:
- formerly in "iommu/arm-smmu: implement alloc/free_reserved_iova_domain" &
  "iommu: add alloc/free_reserved_iova_domain"

v2 -> v3:
- remove iommu_alloc_reserved_iova_domain & iommu_free_reserved_iova_domain
  static implementation in case CONFIG_IOMMU_API is not set

v1 -> v2:
- moved from vfio API to IOMMU API
---
 drivers/iommu/Kconfig     |  7 ++++
 drivers/iommu/Makefile    |  1 +
 drivers/iommu/msi-iommu.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/msi-iommu.h | 65 +++++++++++++++++++++++++++++++
 4 files changed, 170 insertions(+)
 create mode 100644 drivers/iommu/msi-iommu.c
 create mode 100644 include/linux/msi-iommu.h

-- 
1.9.1

Hi Alex,
On 05/09/2016 10:57 PM, Alex Williamson wrote:
> On Wed,  4 May 2016 11:40:03 +0000

> Eric Auger <eric.auger@linaro.org> wrote:

> 

>> iommu_get/put_msi_cookie allocates/frees the resource used to store

>> and ref count the MSI doorbell mappings. iommu_msi_set_aperture

>> initializes the iova domain used for MSI IOVA allocation and sets the

>> iommu domain's msi geometry.

>>

>> The implementation relies on dma-iommu API and iova API.

>>

>> New msi functions are fully implemented if CONFIG_IOMMU_MSI is set.

>>

>> Signed-off-by: Eric Auger <eric.auger@linaro.org>

>>

>> ---

>> v9:

>> - remove is_aperture_set and use iommu_domain_msi_aperture_valid helper

>>   instead

>> - set iommu domain's msi geometry

>>

>> v8:

>> - new design where msi-iommu relies on dma-iommu

>> - remove the iommu_domain * from the doorbell_mapping struct

>> - added is_aperture_set

>>

>> v7:

>> - fix locking

>> - add iova_cache_get/put

>> - static inline functions when CONFIG_IOMMU_DMA_RESERVED is not set

>> - introduce struct reserved_iova_domain to encapsulate prot info &

>>   add prot parameter in alloc_reserved_iova_domain

>>

>> v5 -> v6:

>> - use spin lock instead of mutex

>>

>> v3 -> v4:

>> - formerly in "iommu/arm-smmu: implement alloc/free_reserved_iova_domain" &

>>   "iommu: add alloc/free_reserved_iova_domain"

>>

>> v2 -> v3:

>> - remove iommu_alloc_reserved_iova_domain & iommu_free_reserved_iova_domain

>>   static implementation in case CONFIG_IOMMU_API is not set

>>

>> v1 -> v2:

>> - moved from vfio API to IOMMU API

>> ---

>>  drivers/iommu/Kconfig     |  7 ++++

>>  drivers/iommu/Makefile    |  1 +

>>  drivers/iommu/msi-iommu.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++

>>  include/linux/msi-iommu.h | 65 +++++++++++++++++++++++++++++++

>>  4 files changed, 170 insertions(+)

>>  create mode 100644 drivers/iommu/msi-iommu.c

>>  create mode 100644 include/linux/msi-iommu.h

>>

>> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig

>> index dd1dc39..0078b72 100644

>> --- a/drivers/iommu/Kconfig

>> +++ b/drivers/iommu/Kconfig

>> @@ -74,6 +74,11 @@ config IOMMU_DMA

>>  	select IOMMU_IOVA

>>  	select NEED_SG_DMA_LENGTH

>>  

>> +# IOMMU MSI mapping

>> +config IOMMU_MSI

>> +	bool

>> +	select IOMMU_DMA

>> +

>>  config FSL_PAMU

>>  	bool "Freescale IOMMU support"

>>  	depends on PPC32

>> @@ -307,6 +312,7 @@ config SPAPR_TCE_IOMMU

>>  config ARM_SMMU

>>  	bool "ARM Ltd. System MMU (SMMU) Support"

>>  	depends on (ARM64 || ARM) && MMU

>> +	select IOMMU_MSI

>>  	select IOMMU_API

>>  	select IOMMU_IO_PGTABLE_LPAE

>>  	select ARM_DMA_USE_IOMMU if ARM

>> @@ -320,6 +326,7 @@ config ARM_SMMU

>>  config ARM_SMMU_V3

>>  	bool "ARM Ltd. System MMU Version 3 (SMMUv3) Support"

>>  	depends on ARM64 && PCI

>> +	select IOMMU_MSI

>>  	select IOMMU_API

>>  	select IOMMU_IO_PGTABLE_LPAE

>>  	select GENERIC_MSI_IRQ_DOMAIN

>> diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile

>> index c6edb31..a381e66 100644

>> --- a/drivers/iommu/Makefile

>> +++ b/drivers/iommu/Makefile

>> @@ -2,6 +2,7 @@ obj-$(CONFIG_IOMMU_API) += iommu.o

>>  obj-$(CONFIG_IOMMU_API) += iommu-traces.o

>>  obj-$(CONFIG_IOMMU_API) += iommu-sysfs.o

>>  obj-$(CONFIG_IOMMU_DMA) += dma-iommu.o

>> +obj-$(CONFIG_IOMMU_MSI) += msi-iommu.o

>>  obj-$(CONFIG_IOMMU_IO_PGTABLE) += io-pgtable.o

>>  obj-$(CONFIG_IOMMU_IO_PGTABLE_ARMV7S) += io-pgtable-arm-v7s.o

>>  obj-$(CONFIG_IOMMU_IO_PGTABLE_LPAE) += io-pgtable-arm.o

>> diff --git a/drivers/iommu/msi-iommu.c b/drivers/iommu/msi-iommu.c

>> new file mode 100644

>> index 0000000..4292957

>> --- /dev/null

>> +++ b/drivers/iommu/msi-iommu.c

>> @@ -0,0 +1,97 @@

>> +/*

>> + * Reserved IOVA Management

>> + *

>> + * Copyright (c) 2015 Linaro Ltd.

>> + *              www.linaro.org

>> + *

>> + * This program is free software; you can redistribute it and/or modify

>> + * it under the terms of the GNU General Public License version 2 as

>> + * published by the Free Software Foundation.

>> + *

>> + * 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.

>> + *

>> + */

>> +

>> +#include <linux/iommu.h>

>> +#include <linux/dma-iommu.h>

>> +#include <linux/msi-iommu.h>

>> +#include <linux/spinlock.h>

>> +#include <linux/iova.h>

>> +

>> +struct doorbell_mapping {

>> +	struct kref		kref;

>> +	struct list_head	next;

>> +	phys_addr_t		addr;

>> +	dma_addr_t		iova;

>> +	size_t			size;

>> +};

>> +

>> +struct doorbell_mapping_info {

>> +	struct list_head list; /* list of doorbell mapping entries */

>> +	spinlock_t lock;

>> +};

>> +

>> +int iommu_get_msi_cookie(struct iommu_domain *domain)

>> +{

>> +	struct doorbell_mapping_info *dmi;

>> +	int ret;

>> +

>> +	if (domain->msi_cookie || domain->iova_cookie)

>> +		return -EINVAL;

>> +

>> +	ret = iommu_get_dma_cookie(domain);

>> +	if (ret)

>> +		return ret;

>> +

>> +	dmi = kzalloc(sizeof(*dmi), GFP_KERNEL);

>> +

>> +	INIT_LIST_HEAD(&dmi->list);

>> +	spin_lock_init(&dmi->lock);

>> +	iova_cache_get();

>> +

>> +	domain->msi_cookie = dmi;

>> +

>> +	return dmi ? 0 : -ENOMEM;

>> +}

>> +EXPORT_SYMBOL(iommu_get_msi_cookie);

>> +

>> +void iommu_put_msi_cookie(struct iommu_domain *domain)

>> +{

>> +	struct doorbell_mapping_info *dmi = domain->msi_cookie;

>> +

>> +	if (!dmi)

>> +		return;

>> +

>> +	domain->msi_cookie = NULL;

>> +

>> +	WARN_ON(!list_empty(&dmi->list));

>> +

>> +	kfree(dmi);

>> +	iommu_put_dma_cookie(domain);

>> +	iova_cache_put();

>> +}

>> +EXPORT_SYMBOL(iommu_put_msi_cookie);

>> +

>> +int iommu_msi_set_aperture(struct iommu_domain *domain,

>> +			   dma_addr_t start, dma_addr_t end)

>> +{

>> +	struct doorbell_mapping_info *dmi = domain->msi_cookie;

>> +	int ret;

>> +

>> +	if (!dmi || iommu_domain_msi_aperture_valid(domain))

>> +		return -ENODEV;

> 

> 

> nit, the next patch splits to use different errnos for each issue,

> which seems preferable.


sure

Eric
> 

> 

>> +

>> +	ret = iommu_dma_init_domain(domain, start, end - start + 1);

>> +

>> +	if (!ret) {

>> +		domain->msi_geometry.aperture_start = start;

>> +		domain->msi_geometry.aperture_end = end;

>> +	}

>> +

>> +	return ret;

>> +}

>> +EXPORT_SYMBOL_GPL(iommu_msi_set_aperture);

>> +

>> diff --git a/include/linux/msi-iommu.h b/include/linux/msi-iommu.h

>> new file mode 100644

>> index 0000000..392aa6f

>> --- /dev/null

>> +++ b/include/linux/msi-iommu.h

>> @@ -0,0 +1,65 @@

>> +/*

>> + * Copyright (c) 2015 Linaro Ltd.

>> + *              www.linaro.org

>> + *

>> + * This program is free software; you can redistribute it and/or modify

>> + * it under the terms of the GNU General Public License version 2 as

>> + * published by the Free Software Foundation.

>> + *

>> + * 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.

>> + *

>> + */

>> +#ifndef __MSI_IOMMU_H

>> +#define __MSI_IOMMU_H

>> +

>> +#include <linux/types.h>

>> +#include <linux/kernel.h>

>> +

>> +struct iommu_domain;

>> +

>> +#ifdef CONFIG_IOMMU_MSI

>> +

>> +/**

>> + * iommu_get_msi_cookie - Acquire MSI mapping resources for a domain

>> + * @domain: IOMMU domain to prepare for MSI mapping

>> + *

>> + * IOMMU drivers which require MSI mapping should normally call this

>> + * from their domain_alloc callback when domain->type ==

>> + * IOMMU_DOMAIN_UNMANAGED.

>> + */

>> +int iommu_get_msi_cookie(struct iommu_domain *domain);

>> +

>> +/**

>> + * iommu_put_msi_cookie - Release a domain's MSI mapping resources

>> + * @domain: IOMMU domain previously prepared by iommu_get_msi_cookie()

>> + *

>> + * IOMMU drivers requesting MSI mapping should normally call this from

>> + * their domain_free callback.

>> + */

>> +void iommu_put_msi_cookie(struct iommu_domain *domain);

>> +

>> +/**

>> + * iommu_msi_set_aperture: allocate the msi iova domain

>> + * according to the specified start/end IOVAs

>> + *

>> + * @domain: iommu domain handle

>> + * @start: MSI iova start address

>> + * @end: MSI iova end address

>> + */

>> +int iommu_msi_set_aperture(struct iommu_domain *domain,

>> +			   dma_addr_t start, dma_addr_t end);

>> +

>> +#else

>> +

>> +static inline int

>> +iommu_msi_set_aperture(struct iommu_domain *domain,

>> +		       dma_addr_t start, dma_addr_t end)

>> +{

>> +	return -ENOENT;

>> +}

>> +

>> +#endif	/* CONFIG_IOMMU_MSI */

>> +#endif	/* __MSI_IOMMU_H */

>