From 8a4134322bd429d24f71147eb59a47a981e8f63a Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Fri, 23 Dec 2011 09:30:47 +0100 Subject: common: DMA-mapping: add WRITE_COMBINE attribute DMA_ATTR_WRITE_COMBINE specifies that writes to the mapping may be buffered to improve performance. It will be used by the replacement for ARM/ARV32 specific dma_alloc_writecombine() function. Signed-off-by: Marek Szyprowski Acked-by: Kyungmin Park Reviewed-by: Arnd Bergmann --- Documentation/DMA-attributes.txt | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'Documentation') diff --git a/Documentation/DMA-attributes.txt b/Documentation/DMA-attributes.txt index b768cc0e402b..811a5d458dae 100644 --- a/Documentation/DMA-attributes.txt +++ b/Documentation/DMA-attributes.txt @@ -31,3 +31,13 @@ may be weakly ordered, that is that reads and writes may pass each other. Since it is optional for platforms to implement DMA_ATTR_WEAK_ORDERING, those that do not will simply ignore the attribute and exhibit default behavior. + +DMA_ATTR_WRITE_COMBINE +---------------------- + +DMA_ATTR_WRITE_COMBINE specifies that writes to the mapping may be +buffered to improve performance. + +Since it is optional for platforms to implement DMA_ATTR_WRITE_COMBINE, +those that do not will simply ignore the attribute and exhibit default +behavior. -- cgit v1.2.3 From 64d70fe5d3640e1a89790ed21120921278f8cb86 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Wed, 28 Mar 2012 07:55:56 +0200 Subject: common: DMA-mapping: add NON-CONSISTENT attribute DMA_ATTR_NON_CONSISTENT lets the platform to choose to return either consistent or non-consistent memory as it sees fit. By using this API, you are guaranteeing to the platform that you have all the correct and necessary sync points for this memory in the driver. Signed-off-by: Marek Szyprowski Acked-by: Kyungmin Park Reviewed-by: Arnd Bergmann --- Documentation/DMA-attributes.txt | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'Documentation') diff --git a/Documentation/DMA-attributes.txt b/Documentation/DMA-attributes.txt index 811a5d458dae..5c72eed89563 100644 --- a/Documentation/DMA-attributes.txt +++ b/Documentation/DMA-attributes.txt @@ -41,3 +41,11 @@ buffered to improve performance. Since it is optional for platforms to implement DMA_ATTR_WRITE_COMBINE, those that do not will simply ignore the attribute and exhibit default behavior. + +DMA_ATTR_NON_CONSISTENT +----------------------- + +DMA_ATTR_NON_CONSISTENT lets the platform to choose to return either +consistent or non-consistent memory as it sees fit. By using this API, +you are guaranteeing to the platform that you have all the correct and +necessary sync points for this memory in the driver. -- cgit v1.2.3