From 7f332fc1f0f053799aeda587cefbc67b5ecd72c5 Mon Sep 17 00:00:00 2001 From: Takeshi Kihara Date: Wed, 11 Jan 2017 11:11:17 +0100 Subject: [PATCH] arm64: Add support for DMA_ATTR_SKIP_CPU_SYNC attribute to swiotlb 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 Reviewed-by: Robin Murphy Signed-off-by: Takeshi Kihara Signed-off-by: Geert Uytterhoeven Signed-off-by: Will Deacon --- arch/arm64/mm/dma-mapping.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index e04082700bb1..1d7d5d2881db 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -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); -- 2.20.1