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authorMarek Szyprowski <m.szyprowski@samsung.com>2012-06-13 10:01:15 +0200
committerMarek Szyprowski <m.szyprowski@samsung.com>2012-07-30 12:25:47 +0200
commitdc2832e1e7db3f9ad465d2fe894bd69ef05d1e4b (patch)
tree67b74751c0d7ee64c6ab9702a56041ab0f3df092
parentd2b7428eb0caa7c66e34b6ac869a43915b294123 (diff)
downloadop-kernel-dev-dc2832e1e7db3f9ad465d2fe894bd69ef05d1e4b.zip
op-kernel-dev-dc2832e1e7db3f9ad465d2fe894bd69ef05d1e4b.tar.gz
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>
-rw-r--r--arch/arm/common/dmabounce.c1
-rw-r--r--arch/arm/include/asm/dma-mapping.h3
-rw-r--r--arch/arm/mm/dma-mapping.c31
3 files changed, 35 insertions, 0 deletions
diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c
index aa07f59..1143c4d 100644
--- a/arch/arm/common/dmabounce.c
+++ b/arch/arm/common/dmabounce.c
@@ -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,
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index a048033..2ae842d 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -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
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 8e505b9..51278ed 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,
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