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Commit 737c85ca authored by Mitchel Humpherys's avatar Mitchel Humpherys Committed by Will Deacon
Browse files

arm64/dma-mapping: Implement DMA_ATTR_PRIVILEGED 



The newly added DMA_ATTR_PRIVILEGED is useful for creating mappings that
are only accessible to privileged DMA engines.  Implement it in
dma-iommu.c so that the ARM64 DMA IOMMU mapper can make use of it.

Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
Tested-by: default avatarRobin Murphy <robin.murphy@arm.com>
Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarMitchel Humpherys <mitchelh@codeaurora.org>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent b2fb3664

arch/arm64/mm/dma-mapping.c

+3 −3
Original line number Diff line number Diff line
@@ -558,7 +558,7 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size, 
				 unsigned long attrs)

{

	bool coherent = is_device_dma_coherent(dev);

	int ioprot = dma_direction_to_prot(DMA_BIDIRECTIONAL, coherent);

	int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);

	size_t iosize = size;

	void *addr;
@@ -712,7 +712,7 @@ static dma_addr_t __iommu_map_page(struct device *dev, struct page *page, 
				   unsigned long attrs)

{

	bool coherent = is_device_dma_coherent(dev);

	int prot = dma_direction_to_prot(dir, coherent);

	int prot = dma_info_to_prot(dir, coherent, attrs);

	dma_addr_t dev_addr = iommu_dma_map_page(dev, page, offset, size, prot);



	if (!iommu_dma_mapping_error(dev, dev_addr) &&
@@ -770,7 +770,7 @@ static int __iommu_map_sg_attrs(struct device *dev, struct scatterlist *sgl, 
		__iommu_sync_sg_for_device(dev, sgl, nelems, dir);



	return iommu_dma_map_sg(dev, sgl, nelems,

			dma_direction_to_prot(dir, coherent));

				dma_info_to_prot(dir, coherent, attrs));

}



static void __iommu_unmap_sg_attrs(struct device *dev,

drivers/iommu/dma-iommu.c

+9 −3
Original line number Diff line number Diff line
@@ -181,16 +181,22 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, 
EXPORT_SYMBOL(iommu_dma_init_domain);



/**

 * dma_direction_to_prot - Translate DMA API directions to IOMMU API page flags

 * dma_info_to_prot - Translate DMA API directions and attributes to IOMMU API

 *                    page flags.

 * @dir: Direction of DMA transfer

 * @coherent: Is the DMA master cache-coherent?

 * @attrs: DMA attributes for the mapping

 *

 * Return: corresponding IOMMU API page protection flags

 */

int dma_direction_to_prot(enum dma_data_direction dir, bool coherent)

int dma_info_to_prot(enum dma_data_direction dir, bool coherent,

		     unsigned long attrs)

{

	int prot = coherent ? IOMMU_CACHE : 0;



	if (attrs & DMA_ATTR_PRIVILEGED)

		prot |= IOMMU_PRIV;



	switch (dir) {

	case DMA_BIDIRECTIONAL:

		return prot | IOMMU_READ | IOMMU_WRITE;
@@ -633,7 +639,7 @@ dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys, 
		size_t size, enum dma_data_direction dir, unsigned long attrs)

{

	return __iommu_dma_map(dev, phys, size,

			dma_direction_to_prot(dir, false) | IOMMU_MMIO);

			dma_info_to_prot(dir, false, attrs) | IOMMU_MMIO);

}



void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,

include/linux/dma-iommu.h

+2 −1
Original line number Diff line number Diff line
@@ -34,7 +34,8 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, 
		u64 size, struct device *dev);



/* General helpers for DMA-API <-> IOMMU-API interaction */

int dma_direction_to_prot(enum dma_data_direction dir, bool coherent);

int dma_info_to_prot(enum dma_data_direction dir, bool coherent,

		     unsigned long attrs);



/*

 * These implement the bulk of the relevant DMA mapping callbacks, but require