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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>
This commit is contained in:
Andreas Herrmann 2013-09-27 00:36:15 +02:00 committed by Marek Szyprowski
parent 15c03dd485
commit c9b24996d5
1 changed files with 28 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

43
arch/arm/mm/dma-mapping.c
View File

@ -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)