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authorYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>2019-08-28 21:35:40 +0900
committerChristoph Hellwig <hch@lst.de>2019-09-03 08:33:01 +0200
commit6ba99411b858bd70bae966633561e698cd6de38c (patch)
tree5679bf75e3c4fc1a8bba626da01c2d0ce42f556f /Documentation/DMA-API.txt
parent38c38cb73223218f6eedf485280917af1f8a0af2 (diff)
downloadlinux-6ba99411b858bd70bae966633561e698cd6de38c.tar.bz2
dma-mapping: introduce dma_get_merge_boundary()
This patch adds a new DMA API "dma_get_merge_boundary". This function returns the DMA merge boundary if the DMA layer can merge the segments. This patch also adds the implementation for a new dma_map_ops pointer. Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'Documentation/DMA-API.txt')
-rw-r--r--Documentation/DMA-API.txt8
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index e47c63bd4887..9c4dd3d779ed 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -204,6 +204,14 @@ Returns the maximum size of a mapping for the device. The size parameter
of the mapping functions like dma_map_single(), dma_map_page() and
others should not be larger than the returned value.
+::
+
+ unsigned long
+ dma_get_merge_boundary(struct device *dev);
+
+Returns the DMA merge boundary. If the device cannot merge any the DMA address
+segments, the function returns 0.
+
Part Id - Streaming DMA mappings
--------------------------------