[PATCH] arm64: Add support for DMA_ATTR_SKIP_CPU_SYNC attribute to swiotlb

[Will Deacon]

On Wed, Jan 11, 2017 at 11:11:17AM +0100, Geert Uytterhoeven wrote:
> From: Takeshi Kihara <takeshi.kihara.df at renesas.com>
> 
> 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.
> 
> Signed-off-by: Takeshi Kihara <takeshi.kihara.df at renesas.com>
> Acked-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Signed-off-by: Geert Uytterhoeven <geert+renesas at glider.be>
> ---
> v2:
>   - Add Acked-by.
> 
> Support for DMA_ATTR_SKIP_CPU_SYNC was included when porting the IOMMU
> ops from arm to arm64 in commit 13b8629f651164d7 ("arm64: Add IOMMU
> dma_ops").
> 
> Presumably it was an oversight that the existing swiotlb based
> implementation didn't have support for DMA_ATTR_SKIP_CPU_SYNC yet?
> ---
>  arch/arm64/mm/dma-mapping.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)

Thanks. Applied for 4.11, with Robin's Reviewed-by.

Will