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| author | Marek Szyprowski | 2012-06-13 10:01:15 +0200 |
|---|---|---|
| committer | Marek Szyprowski | 2012-07-30 12:25:47 +0200 |
| commit | dc2832e1e7db3f9ad465d2fe894bd69ef05d1e4b (patch) | |
| tree | 67b74751c0d7ee64c6ab9702a56041ab0f3df092 /arch/arm/mm/dma-mapping.c | |
| parent | common: dma-mapping: introduce dma_get_sgtable() function (diff) | |
| download | kernel-qcow2-linux-dc2832e1e7db3f9ad465d2fe894bd69ef05d1e4b.tar.gz kernel-qcow2-linux-dc2832e1e7db3f9ad465d2fe894bd69ef05d1e4b.tar.xz kernel-qcow2-linux-dc2832e1e7db3f9ad465d2fe894bd69ef05d1e4b.zip | |
ARM: dma-mapping: add support for dma_get_sgtable()
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>
Diffstat (limited to 'arch/arm/mm/dma-mapping.c')
| -rw-r--r-- | arch/arm/mm/dma-mapping.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 8e505b9df5c7..51278ede2028 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -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, |