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[net-next,04/27] arch/arc: Add option to skip sync on DMA mapping

Message ID 20161025153709.4815.82720.stgit@ahduyck-blue-test.jf.intel.com
State New
Headers show

Commit Message

Duyck, Alexander H Oct. 25, 2016, 3:37 p.m. UTC
This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to
avoid invoking cache line invalidation if the driver will just handle it
later via a sync_for_cpu or sync_for_device call.

Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: linux-snps-arc@lists.infradead.org
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
 arch/arc/mm/dma.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Vineet Gupta Oct. 25, 2016, 10 p.m. UTC | #1
On 10/25/2016 02:38 PM, Alexander Duyck wrote:
> This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to
> avoid invoking cache line invalidation if the driver will just handle it
> later via a sync_for_cpu or sync_for_device call.
>
> Cc: Vineet Gupta <vgupta@synopsys.com>
> Cc: linux-snps-arc@lists.infradead.org
> Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
> ---
>  arch/arc/mm/dma.c |    5 ++++-

Acked-by: Vineet Gupta <vgupta@synopsys.com>

>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
> index 20afc65..6303c34 100644
> --- a/arch/arc/mm/dma.c
> +++ b/arch/arc/mm/dma.c
> @@ -133,7 +133,10 @@ static dma_addr_t arc_dma_map_page(struct device *dev, struct page *page,
>  		unsigned long attrs)
>  {
>  	phys_addr_t paddr = page_to_phys(page) + offset;
> -	_dma_cache_sync(paddr, size, dir);
> +
> +	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
> +		_dma_cache_sync(paddr, size, dir);
> +
>  	return plat_phys_to_dma(dev, paddr);
>  }
>  
>
>
diff mbox

Patch

diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index 20afc65..6303c34 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -133,7 +133,10 @@  static dma_addr_t arc_dma_map_page(struct device *dev, struct page *page,
 		unsigned long attrs)
 {
 	phys_addr_t paddr = page_to_phys(page) + offset;
-	_dma_cache_sync(paddr, size, dir);
+
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		_dma_cache_sync(paddr, size, dir);
+
 	return plat_phys_to_dma(dev, paddr);
 }