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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 /kernel/dma
parent38c38cb73223218f6eedf485280917af1f8a0af2 (diff)
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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 'kernel/dma')
-rw-r--r--kernel/dma/mapping.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 1b96616c9f20..72c825c1788e 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -407,3 +407,14 @@ size_t dma_max_mapping_size(struct device *dev)
return size;
}
EXPORT_SYMBOL_GPL(dma_max_mapping_size);
+
+unsigned long dma_get_merge_boundary(struct device *dev)
+{
+ const struct dma_map_ops *ops = get_dma_ops(dev);
+
+ if (!ops || !ops->get_merge_boundary)
+ return 0; /* can't merge */
+
+ return ops->get_merge_boundary(dev);
+}
+EXPORT_SYMBOL_GPL(dma_get_merge_boundary);