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authorAlexander Duyck <alexander.h.duyck@intel.com>2016-12-14 15:04:41 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-14 16:04:07 -0800
commit64c596b59c726514f548e15f13a87010efbff40d (patch)
tree22131f32f19ea044111641b7211ee6242fed8c8b /arch/c6x/kernel
parent8c16a2e209d563a1909451c769417a6f953e5b2c (diff)
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arch/c6x: add option to skip sync on DMA map and unmap
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. Link: http://lkml.kernel.org/r/20161110113442.76501.7673.stgit@ahduyck-blue-test.jf.intel.com Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Acked-by: Mark Salter <msalter@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/c6x/kernel')
-rw-r--r--arch/c6x/kernel/dma.c14
1 files changed, 10 insertions, 4 deletions
diff --git a/arch/c6x/kernel/dma.c b/arch/c6x/kernel/dma.c
index db4a6a301f5e..6752df32ef06 100644
--- a/arch/c6x/kernel/dma.c
+++ b/arch/c6x/kernel/dma.c
@@ -42,14 +42,17 @@ static dma_addr_t c6x_dma_map_page(struct device *dev, struct page *page,
{
dma_addr_t handle = virt_to_phys(page_address(page) + offset);
- c6x_dma_sync(handle, size, dir);
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ c6x_dma_sync(handle, size, dir);
+
return handle;
}
static void c6x_dma_unmap_page(struct device *dev, dma_addr_t handle,
size_t size, enum dma_data_direction dir, unsigned long attrs)
{
- c6x_dma_sync(handle, size, dir);
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ c6x_dma_sync(handle, size, dir);
}
static int c6x_dma_map_sg(struct device *dev, struct scatterlist *sglist,
@@ -60,7 +63,8 @@ static int c6x_dma_map_sg(struct device *dev, struct scatterlist *sglist,
for_each_sg(sglist, sg, nents, i) {
sg->dma_address = sg_phys(sg);
- c6x_dma_sync(sg->dma_address, sg->length, dir);
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ c6x_dma_sync(sg->dma_address, sg->length, dir);
}
return nents;
@@ -72,9 +76,11 @@ static void c6x_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
struct scatterlist *sg;
int i;
+ if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+ return;
+
for_each_sg(sglist, sg, nents, i)
c6x_dma_sync(sg_dma_address(sg), sg->length, dir);
-
}
static void c6x_dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle,