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arm64: Add support for DMA_ATTR_SKIP_CPU_SYNC attribute to swiotlb

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This patch adds support for DMA_ATTR_SKIP_CPU_SYNC attribute for
dma_{un}map_{page,sg} functions family to swiotlb.

DMA_ATTR_SKIP_CPU_SYNC allows platform code to skip synchronization of
the CPU cache for the given buffer assuming that it has been already
transferred to 'device' domain.

Ported from IOMMU .{un}map_{sg,page} ops.

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Takeshi Kihara 2017-01-11 11:11:17 +01:00 committed by Will Deacon
parent ec6d06efb0
commit 7f332fc1f0
1 changed files with 8 additions and 4 deletions
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12
arch/arm64/mm/dma-mapping.c
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@ -211,7 +211,8 @@ static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page,
dma_addr_t dev_addr;
dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs);
if (!is_device_dma_coherent(dev))
if (!is_device_dma_coherent(dev) &&
(attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
__dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
return dev_addr;
@ -222,7 +223,8 @@ static void __swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr,
size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
if (!is_device_dma_coherent(dev))
if (!is_device_dma_coherent(dev) &&
(attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
__dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
swiotlb_unmap_page(dev, dev_addr, size, dir, attrs);
}
@ -235,7 +237,8 @@ static int __swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
int i, ret;
ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs);
if (!is_device_dma_coherent(dev))
if (!is_device_dma_coherent(dev) &&
(attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
for_each_sg(sgl, sg, ret, i)
__dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
sg->length, dir);
@ -251,7 +254,8 @@ static void __swiotlb_unmap_sg_attrs(struct device *dev,
struct scatterlist *sg;
int i;
if (!is_device_dma_coherent(dev))
if (!is_device_dma_coherent(dev) &&
(attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
for_each_sg(sgl, sg, nelems, i)
__dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
sg->length, dir);