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ARM: dma-mapping: convert DMA direction into IOMMU protection attributes 

IOMMU mappings take a prot parameter, identifying the protection bits
to enforce on the newly created mapping (READ or WRITE). The ARM
dma-mapping framework currently just passes 0 as the prot argument,
resulting in faulting mappings.

This patch infers the protection attributes based on the direction of
the DMA transfer.

Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
This commit is contained in:
Will Deacon 2013-06-10 19:34:39 +01:00 committed by Marek Szyprowski
parent 836bfa0d29
commit 13987d68bc
1 changed files with 16 additions and 2 deletions
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18
arch/arm/mm/dma-mapping.c
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@ -1637,13 +1637,27 @@ static dma_addr_t arm_coherent_iommu_map_page(struct device *dev, struct page *p
{
struct dma_iommu_mapping *mapping = dev->archdata.mapping;
dma_addr_t dma_addr;
int ret, len = PAGE_ALIGN(size + offset);
int ret, prot, len = PAGE_ALIGN(size + offset);
dma_addr = __alloc_iova(mapping, len);
if (dma_addr == DMA_ERROR_CODE)
return dma_addr;
ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, 0);
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;
}
ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, prot);
if (ret < 0)
goto fail;