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Commit 7d2822df authored by Sricharan R's avatar Sricharan R Committed by Will Deacon
Browse files

arm/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.  Adding it to the
arm dma-mapping.c so that the ARM32 DMA IOMMU mapper can make use of it.

Signed-off-by: default avatarSricharan R <sricharan@codeaurora.org>
Reviewed-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 737c85ca

arch/arm/mm/dma-mapping.c

+30 −30
Original line number Diff line number Diff line
@@ -1171,6 +1171,25 @@ core_initcall(dma_debug_do_init); 


#ifdef CONFIG_ARM_DMA_USE_IOMMU



static int __dma_info_to_prot(enum dma_data_direction dir, unsigned long attrs)

{

	int prot = 0;



	if (attrs & DMA_ATTR_PRIVILEGED)

		prot |= IOMMU_PRIV;



	switch (dir) {

	case DMA_BIDIRECTIONAL:

		return prot | IOMMU_READ | IOMMU_WRITE;

	case DMA_TO_DEVICE:

		return prot | IOMMU_READ;

	case DMA_FROM_DEVICE:

		return prot | IOMMU_WRITE;

	default:

		return prot;

	}

}



/* IOMMU */



static int extend_iommu_mapping(struct dma_iommu_mapping *mapping);
@@ -1394,7 +1413,8 @@ __iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot, 
 * Create a mapping in device IO address space for specified pages

 */

static dma_addr_t

__iommu_create_mapping(struct device *dev, struct page **pages, size_t size)

__iommu_create_mapping(struct device *dev, struct page **pages, size_t size,

		       unsigned long attrs)

{

	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);

	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
@@ -1419,7 +1439,7 @@ __iommu_create_mapping(struct device *dev, struct page **pages, size_t size) 


		len = (j - i) << PAGE_SHIFT;

		ret = iommu_map(mapping->domain, iova, phys, len,

				IOMMU_READ|IOMMU_WRITE);

				__dma_info_to_prot(DMA_BIDIRECTIONAL, attrs));

		if (ret < 0)

			goto fail;

		iova += len;
@@ -1476,7 +1496,8 @@ static struct page **__iommu_get_pages(void *cpu_addr, unsigned long attrs) 
}



static void *__iommu_alloc_simple(struct device *dev, size_t size, gfp_t gfp,

				  dma_addr_t *handle, int coherent_flag)

				  dma_addr_t *handle, int coherent_flag,

				  unsigned long attrs)

{

	struct page *page;

	void *addr;
@@ -1488,7 +1509,7 @@ static void *__iommu_alloc_simple(struct device *dev, size_t size, gfp_t gfp, 
	if (!addr)

		return NULL;



	*handle = __iommu_create_mapping(dev, &page, size);

	*handle = __iommu_create_mapping(dev, &page, size, attrs);

	if (*handle == DMA_ERROR_CODE)

		goto err_mapping;
@@ -1522,7 +1543,7 @@ static void *__arm_iommu_alloc_attrs(struct device *dev, size_t size, 


	if (coherent_flag  == COHERENT || !gfpflags_allow_blocking(gfp))

		return __iommu_alloc_simple(dev, size, gfp, handle,

					    coherent_flag);

					    coherent_flag, attrs);



	/*

	 * Following is a work-around (a.k.a. hack) to prevent pages
@@ -1537,7 +1558,7 @@ static void *__arm_iommu_alloc_attrs(struct device *dev, size_t size, 
	if (!pages)

		return NULL;



	*handle = __iommu_create_mapping(dev, pages, size);

	*handle = __iommu_create_mapping(dev, pages, size, attrs);

	if (*handle == DMA_ERROR_CODE)

		goto err_buffer;
@@ -1672,27 +1693,6 @@ static int arm_iommu_get_sgtable(struct device *dev, struct sg_table *sgt, 
					 GFP_KERNEL);

}



static int __dma_direction_to_prot(enum dma_data_direction dir)

{

	int prot;



	switch (dir) {

	case DMA_BIDIRECTIONAL:

		prot = IOMMU_READ | IOMMU_WRITE;

		break;

	case DMA_TO_DEVICE:

		prot = IOMMU_READ;

		break;

	case DMA_FROM_DEVICE:

		prot = IOMMU_WRITE;

		break;

	default:

		prot = 0;

	}



	return prot;

}



/*

 * Map a part of the scatter-gather list into contiguous io address space

 */
@@ -1722,7 +1722,7 @@ static int __map_sg_chunk(struct device *dev, struct scatterlist *sg, 
		if (!is_coherent && (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)

			__dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);



		prot = __dma_direction_to_prot(dir);

		prot = __dma_info_to_prot(dir, attrs);



		ret = iommu_map(mapping->domain, iova, phys, len, prot);

		if (ret < 0)
@@ -1930,7 +1930,7 @@ static dma_addr_t arm_coherent_iommu_map_page(struct device *dev, struct page *p 
	if (dma_addr == DMA_ERROR_CODE)

		return dma_addr;



	prot = __dma_direction_to_prot(dir);

	prot = __dma_info_to_prot(dir, attrs);



	ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, prot);

	if (ret < 0)
@@ -2036,7 +2036,7 @@ static dma_addr_t arm_iommu_map_resource(struct device *dev, 
	if (dma_addr == DMA_ERROR_CODE)

		return dma_addr;



	prot = __dma_direction_to_prot(dir) | IOMMU_MMIO;

	prot = __dma_info_to_prot(dir, attrs) | IOMMU_MMIO;



	ret = iommu_map(mapping->domain, dma_addr, addr, len, prot);

	if (ret < 0)