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.szyprow...@samsung.com>
Signed-off-by: Will Deacon <will.dea...@arm.com>
---
arch/arm/mm/dma-mapping.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 6fb80cf..d119de7 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1636,13 +1636,27 @@ 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;
--
1.8.2.2
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