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| author | Alexander Duyck <alexander.h.duyck@intel.com> | 2016-12-14 15:04:41 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-14 16:04:07 -0800 |
| commit | 64c596b59c726514f548e15f13a87010efbff40d (patch) | |
| tree | 22131f32f19ea044111641b7211ee6242fed8c8b /arch/c6x/kernel | |
| parent | 8c16a2e209d563a1909451c769417a6f953e5b2c (diff) | |
| download | linux-stable-64c596b59c726514f548e15f13a87010efbff40d.tar.gz linux-stable-64c596b59c726514f548e15f13a87010efbff40d.tar.bz2 linux-stable-64c596b59c726514f548e15f13a87010efbff40d.zip | |
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.c | 14 |
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, |