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>
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 1d158c2..282aacd 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1637,13 +1637,27 @@
{
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;