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Commit cb89d730 authored by Chintan Pandya's avatar Chintan Pandya
Browse files

arm: dma-mapping: map sg lists into the SMMU as virtually contiguous 



Following commit implements mapping of sg virtually contiguously.

"arm64: dma-mapping: map sg lists into the SMMU as virtually
contiguous"
a03f74ef16cc73531795176d3ea8b82b66ed0146

This has been left for ARM (32-bit). Implement the same for ARM.

Change-Id: Ibf67f29a60b8d19e526c4719590f2f473ea9dca5
Signed-off-by: default avatarChintan Pandya <cpandya@codeaurora.org>
parent 7e681ea6

arch/arm/mm/dma-mapping.c

+34 −2
Original line number Diff line number Diff line
@@ -1651,7 +1651,31 @@ int arm_coherent_iommu_map_sg(struct device *dev, struct scatterlist *sg, 
int arm_iommu_map_sg(struct device *dev, struct scatterlist *sg,

		int nents, enum dma_data_direction dir, struct dma_attrs *attrs)

{

	return __iommu_map_sg(dev, sg, nents, dir, attrs, false);

	struct scatterlist *s;

	int i;

	size_t ret;

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

	unsigned int total_length = 0, current_offset = 0;

	dma_addr_t iova;

	int prot = __dma_direction_to_prot(dir);



	for_each_sg(sg, s, nents, i)

		total_length += s->length;



	iova = __alloc_iova(mapping, total_length);

	ret = iommu_map_sg(mapping->domain, iova, sg, nents, prot);

	if (ret != total_length) {

		__free_iova(mapping, iova, total_length);

		return 0;

	}



	for_each_sg(sg, s, nents, i) {

		s->dma_address = iova + current_offset;

		s->dma_length = total_length - current_offset;

		current_offset += s->length;

	}



	return nents;

}



static void __iommu_unmap_sg(struct device *dev, struct scatterlist *sg,
@@ -1701,7 +1725,15 @@ void arm_coherent_iommu_unmap_sg(struct device *dev, struct scatterlist *sg, 
void arm_iommu_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,

			enum dma_data_direction dir, struct dma_attrs *attrs)

{

	__iommu_unmap_sg(dev, sg, nents, dir, attrs, false);

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

	unsigned int total_length = sg_dma_len(sg);

	dma_addr_t iova = sg_dma_address(sg);



	total_length = PAGE_ALIGN((iova & ~PAGE_MASK) + total_length);

	iova &= PAGE_MASK;



	iommu_unmap_range(mapping->domain, iova, total_length);

	__free_iova(mapping, iova, total_length);

}



/**