On 2021-08-11 03:42, David Stevens wrote:
From: David Stevens
After syncing in map/unmap, add the DMA_ATTR_SKIP_CPU_SYNC flag so
anything that uses attrs later on will skip any sync work that has
already been completed. In particular, this skips copying from the
swiotlb twice during unmap.
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index 4f0cc4a0a61f..be0214b1455c 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -859,8 +859,11 @@ static dma_addr_t iommu_dma_map_page(struct device *dev,
> struct page *page,
> static void
From: David Stevens
After syncing in map/unmap, add the DMA_ATTR_SKIP_CPU_SYNC flag so
anything that uses attrs later on will skip any sync work that has
already been completed. In particular, this skips copying from the
swiotlb twice during unmap.
Signed-off-by: David Stevens
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