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| author | Alexander Duyck <alexander.h.duyck@intel.com> | 2016-12-14 15:05:12 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-14 16:04:07 -0800 |
| commit | a08120017d7d659719d446fb036d500fa9b1e6f9 (patch) | |
| tree | 6b3f1b964478e1c8f70a0b85cb4b557c762da219 /arch | |
| parent | 6f774809612d1f1fc800b452ee1ef447a277ec9d (diff) | |
| download | linux-a08120017d7d659719d446fb036d500fa9b1e6f9.tar.gz linux-a08120017d7d659719d446fb036d500fa9b1e6f9.tar.bz2 linux-a08120017d7d659719d446fb036d500fa9b1e6f9.zip | |
arch/sh: 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
via a sync_for_cpu or sync_for_device call.
Link: http://lkml.kernel.org/r/20161110113539.76501.6539.stgit@ahduyck-blue-test.jf.intel.com
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/sh/kernel/dma-nommu.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/sh/kernel/dma-nommu.c b/arch/sh/kernel/dma-nommu.c index eadb669a7329..47fee3b6e29c 100644 --- a/arch/sh/kernel/dma-nommu.c +++ b/arch/sh/kernel/dma-nommu.c @@ -18,7 +18,9 @@ static dma_addr_t nommu_map_page(struct device *dev, struct page *page, dma_addr_t addr = page_to_phys(page) + offset; WARN_ON(size == 0); - dma_cache_sync(dev, page_address(page) + offset, size, dir); + + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + dma_cache_sync(dev, page_address(page) + offset, size, dir); return addr; } @@ -35,7 +37,8 @@ static int nommu_map_sg(struct device *dev, struct scatterlist *sg, for_each_sg(sg, s, nents, i) { BUG_ON(!sg_page(s)); - dma_cache_sync(dev, sg_virt(s), s->length, dir); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + dma_cache_sync(dev, sg_virt(s), s->length, dir); s->dma_address = sg_phys(s); s->dma_length = s->length; |