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authorAlexander Duyck <alexander.h.duyck@intel.com>2016-12-15 00:04:46 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-15 01:04:07 +0100
commitb8a346dd472af45e1ee8cbc77101dad0b836210b (patch)
tree8da5660153e97d6f8094c89fceaafdbfb2c4d9a7
parentarch/frv: add option to skip sync on DMA map (diff)
downloadlinux-b8a346dd472af45e1ee8cbc77101dad0b836210b.tar.xz
linux-b8a346dd472af45e1ee8cbc77101dad0b836210b.zip
arch/hexagon: Add option to skip DMA sync as a part of mapping
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/20161110113452.76501.45864.stgit@ahduyck-blue-test.jf.intel.com Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Cc: Richard Kuo <rkuo@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/hexagon/kernel/dma.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/hexagon/kernel/dma.c b/arch/hexagon/kernel/dma.c
index b9017785fb71..dbc4f1003da4 100644
--- a/arch/hexagon/kernel/dma.c
+++ b/arch/hexagon/kernel/dma.c
@@ -119,6 +119,9 @@ static int hexagon_map_sg(struct device *hwdev, struct scatterlist *sg,
s->dma_length = s->length;
+ if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+ continue;
+
flush_dcache_range(dma_addr_to_virt(s->dma_address),
dma_addr_to_virt(s->dma_address + s->length));
}
@@ -180,7 +183,8 @@ static dma_addr_t hexagon_map_page(struct device *dev, struct page *page,
if (!check_addr("map_single", dev, bus, size))
return bad_dma_address;
- dma_sync(dma_addr_to_virt(bus), size, dir);
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ dma_sync(dma_addr_to_virt(bus), size, dir);
return bus;
}