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 <[email protected]> Acked-by: Kyungmin Park <[email protected]> Reviewed-by: Arnd Bergmann <[email protected]>
goeke · Mar 28, 2012 · 64d70fe · 64d70fe
1 parent 8a41343
commit 64d70fe
Show file tree

Hide file tree

Showing 2 changed files with 9 additions and 0 deletions.
diff --git 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.
diff --git a/include/linux/dma-attrs.h b/include/linux/dma-attrs.h
@@ -14,6 +14,7 @@ enum dma_attr {
 	DMA_ATTR_WRITE_BARRIER,
 	DMA_ATTR_WEAK_ORDERING,
 	DMA_ATTR_WRITE_COMBINE,
+	DMA_ATTR_NON_CONSISTENT,
 	DMA_ATTR_MAX,
 };