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ARM: dma-mapping: add support for dma_get_sgtable()

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This patch adds support for dma_get_sgtable() function which is required
to let drivers to share the buffers allocated by DMA-mapping subsystem.

Generic implementation based on virt_to_page() is not suitable for ARM
dma-mapping subsystem.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
This commit is contained in:
Marek Szyprowski 2012-06-13 10:01:15 +02:00
parent d2b7428eb0
commit dc2832e1e7
3 changed files with 35 additions and 0 deletions
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1
arch/arm/common/dmabounce.c
View file

@ -452,6 +452,7 @@ static struct dma_map_ops dmabounce_ops = {
.alloc = arm_dma_alloc,
.free = arm_dma_free,
.mmap = arm_dma_mmap,
.get_sgtable = arm_dma_get_sgtable,
.map_page = dmabounce_map_page,
.unmap_page = dmabounce_unmap_page,
.sync_single_for_cpu = dmabounce_sync_for_cpu,

3
arch/arm/include/asm/dma-mapping.h
View file

@ -261,6 +261,9 @@ extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
enum dma_data_direction);
extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
enum dma_data_direction);
extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
struct dma_attrs *attrs);
#endif /* __KERNEL__ */
#endif

31
arch/arm/mm/dma-mapping.c
View file

@ -125,6 +125,7 @@ struct dma_map_ops arm_dma_ops = {
.alloc = arm_dma_alloc,
.free = arm_dma_free,
.mmap = arm_dma_mmap,
.get_sgtable = arm_dma_get_sgtable,
.map_page = arm_dma_map_page,
.unmap_page = arm_dma_unmap_page,
.map_sg = arm_dma_map_sg,
@ -661,6 +662,21 @@ void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
}
}
int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t handle, size_t size,
struct dma_attrs *attrs)
{
struct page *page = pfn_to_page(dma_to_pfn(dev, handle));
int ret;
ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
if (unlikely(ret))
return ret;
sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
return 0;
}
static void dma_cache_maint_page(struct page *page, unsigned long offset,
size_t size, enum dma_data_direction dir,
void (*op)(const void *, size_t, int))
@ -1172,6 +1188,20 @@ void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
__iommu_free_buffer(dev, pages, size);
}
static int arm_iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t dma_addr,
size_t size, struct dma_attrs *attrs)
{
unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
struct page **pages = __iommu_get_pages(cpu_addr, attrs);
if (!pages)
return -ENXIO;
return sg_alloc_table_from_pages(sgt, pages, count, 0, size,
GFP_KERNEL);
}
/*
* Map a part of the scatter-gather list into contiguous io address space
*/
@ -1431,6 +1461,7 @@ struct dma_map_ops iommu_ops = {
.alloc = arm_iommu_alloc_attrs,
.free = arm_iommu_free_attrs,
.mmap = arm_iommu_mmap_attrs,
.get_sgtable = arm_iommu_get_sgtable,
.map_page = arm_iommu_map_page,
.unmap_page = arm_iommu_unmap_page,