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| author |   Andreas Herrmann <andreas.herrmann@calxeda.com> | 2013-09-27 00:36:15 +0200 |
|---|---|---|
| committer |   Marek Szyprowski <m.szyprowski@samsung.com> | 2013-10-02 13:23:11 +0200 |
| commit | c9b24996d5da1bf7d2bebab5770dfcc7834c53b7 (patch) | |
| tree | 986b26dc765c0bfb16ace52b2a7e83e1c1a5a4a8 /arch | |
| parent | Linux 3.12-rc3 (diff) | |
| download | linux-dev-c9b24996d5da1bf7d2bebab5770dfcc7834c53b7.tar.xz linux-dev-c9b24996d5da1bf7d2bebab5770dfcc7834c53b7.zip | |
ARM: dma-mapping: Always pass proper prot flags to iommu_map()
... otherwise it is impossible for the low level iommu driver to
figure out which pte flags should be used.
In __map_sg_chunk we can derive the flags from dma_data_direction.
In __iommu_create_mapping we should treat the memory like
DMA_BIDIRECTIONAL and pass both IOMMU_READ and IOMMU_WRITE to
iommu_map.
__iommu_create_mapping is used during dma_alloc_coherent (via
arm_iommu_alloc_attrs). AFAIK dma_alloc_coherent is responsible for
allocation _and_ mapping. I think this implies that access to the
mapped pages should be allowed.
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andreas Herrmann <andreas.herrmann@calxeda.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/mm/dma-mapping.c | 43 |
1 files changed, 28 insertions, 15 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index f5e1a8471714..1272ed202dde 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1232,7 +1232,8 @@ __iommu_create_mapping(struct device *dev, struct page **pages, size_t size) break; len = (j - i) << PAGE_SHIFT; - ret = iommu_map(mapping->domain, iova, phys, len, 0); + ret = iommu_map(mapping->domain, iova, phys, len, + IOMMU_READ|IOMMU_WRITE); if (ret < 0) goto fail; iova += len; @@ -1431,6 +1432,27 @@ 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 */ @@ -1444,6 +1466,7 @@ static int __map_sg_chunk(struct device *dev, struct scatterlist *sg, int ret = 0; unsigned int count; struct scatterlist *s; + int prot; size = PAGE_ALIGN(size); *handle = DMA_ERROR_CODE; @@ -1460,7 +1483,9 @@ static int __map_sg_chunk(struct device *dev, struct scatterlist *sg, !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir); - ret = iommu_map(mapping->domain, iova, phys, len, 0); + prot = __dma_direction_to_prot(dir); + + ret = iommu_map(mapping->domain, iova, phys, len, prot); if (ret < 0) goto fail; count += len >> PAGE_SHIFT; @@ -1665,19 +1690,7 @@ static dma_addr_t arm_coherent_iommu_map_page(struct device *dev, struct page *p if (dma_addr == DMA_ERROR_CODE) return dma_addr; - 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; - } + prot = __dma_direction_to_prot(dir); ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, prot); if (ret < 0) |