Commit 4bb25789 authored by Will Deacon's avatar Will Deacon
Browse files

arm: dma-mapping: plumb our iommu mapping ops into arch_setup_dma_ops 



This patch plumbs the existing ARM IOMMU DMA infrastructure (which isn't
actually called outside of a few drivers) into arch_setup_dma_ops, so
that we can use IOMMUs for DMA transfers in a more generic fashion.

Since this significantly complicates the arch_setup_dma_ops function,
it is moved out of line into dma-mapping.c. If CONFIG_ARM_DMA_USE_IOMMU
is not set, the iommu parameter is ignored and the normal ops are used
instead.

Acked-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent af4dda73

arch/arm/include/asm/dma-mapping.h

+5 −7
Original line number Diff line number Diff line
@@ -121,14 +121,12 @@ static inline unsigned long dma_max_pfn(struct device *dev) 
}

#define dma_max_pfn(dev) dma_max_pfn(dev)



static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base,

				      u64 size, struct iommu_ops *iommu,

				      bool coherent)

{

	if (coherent)

		set_dma_ops(dev, &arm_coherent_dma_ops);

}

#define arch_setup_dma_ops arch_setup_dma_ops

extern void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,

			       struct iommu_ops *iommu, bool coherent);



#define arch_teardown_dma_ops arch_teardown_dma_ops

extern void arch_teardown_dma_ops(struct device *dev);



static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)

{

arch/arm/mm/dma-mapping.c

+76 −7
Original line number Diff line number Diff line
@@ -1947,9 +1947,8 @@ EXPORT_SYMBOL_GPL(arm_iommu_release_mapping); 
 *	arm_iommu_create_mapping)

 *

 * Attaches specified io address space mapping to the provided device,

 * this replaces the dma operations (dma_map_ops pointer) with the

 * IOMMU aware version. More than one client might be attached to

 * the same io address space mapping.

 * More than one client might be attached to the same io address space

 * mapping.

 */

int arm_iommu_attach_device(struct device *dev,

			    struct dma_iommu_mapping *mapping)
@@ -1962,7 +1961,6 @@ int arm_iommu_attach_device(struct device *dev, 


	kref_get(&mapping->kref);

	dev->archdata.mapping = mapping;

	set_dma_ops(dev, &iommu_ops);



	pr_debug("Attached IOMMU controller to %s device.\n", dev_name(dev));

	return 0;
@@ -1974,7 +1972,6 @@ EXPORT_SYMBOL_GPL(arm_iommu_attach_device); 
 * @dev: valid struct device pointer

 *

 * Detaches the provided device from a previously attached map.

 * This voids the dma operations (dma_map_ops pointer)

 */

void arm_iommu_detach_device(struct device *dev)

{
@@ -1989,10 +1986,82 @@ void arm_iommu_detach_device(struct device *dev) 
	iommu_detach_device(mapping->domain, dev);

	kref_put(&mapping->kref, release_iommu_mapping);

	dev->archdata.mapping = NULL;

	set_dma_ops(dev, NULL);



	pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev));

}

EXPORT_SYMBOL_GPL(arm_iommu_detach_device);



#endif
 
static struct dma_map_ops *arm_get_iommu_dma_map_ops(bool coherent)

{

	return coherent ? &iommu_coherent_ops : &iommu_ops;

}



static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,

				    struct iommu_ops *iommu)

{

	struct dma_iommu_mapping *mapping;



	if (!iommu)

		return false;



	mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);

	if (IS_ERR(mapping)) {

		pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n",

				size, dev_name(dev));

		return false;

	}



	if (arm_iommu_attach_device(dev, mapping)) {

		pr_warn("Failed to attached device %s to IOMMU_mapping\n",

				dev_name(dev));

		arm_iommu_release_mapping(mapping);

		return false;

	}



	return true;

}



static void arm_teardown_iommu_dma_ops(struct device *dev)

{

	struct dma_iommu_mapping *mapping = dev->archdata.mapping;



	arm_iommu_detach_device(dev);

	arm_iommu_release_mapping(mapping);

}



#else



static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,

				    struct iommu_ops *iommu)

{

	return false;

}



static void arm_teardown_iommu_dma_ops(struct device *dev) { }



#define arm_get_iommu_dma_map_ops arm_get_dma_map_ops



#endif	/* CONFIG_ARM_DMA_USE_IOMMU */



static struct dma_map_ops *arm_get_dma_map_ops(bool coherent)

{

	return coherent ? &arm_coherent_dma_ops : &arm_dma_ops;

}



void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,

			struct iommu_ops *iommu, bool coherent)

{

	struct dma_map_ops *dma_ops;



	if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu))

		dma_ops = arm_get_iommu_dma_map_ops(coherent);

	else

		dma_ops = arm_get_dma_map_ops(coherent);



	set_dma_ops(dev, dma_ops);

}



void arch_teardown_dma_ops(struct device *dev)

{

	arm_teardown_iommu_dma_ops(dev);

}

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