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| author | Alexander Duyck <alexander.h.duyck@intel.com> | 2016-12-14 15:04:52 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-14 16:04:07 -0800 |
| commit | 38bdbdc7e391f5326a9f27f0bc8be0c175a73567 (patch) | |
| tree | 79cd65c08e31dced3a65d0f0d46ab6e91a36e99a /arch | |
| parent | 5140d2344f1036dadffbb949a60af971b6dde0d3 (diff) | |
| download | linux-38bdbdc7e391f5326a9f27f0bc8be0c175a73567.tar.bz2 | |
arch/metag: add option to skip DMA sync as a part of 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
via a sync_for_cpu or sync_for_device call.
Link: http://lkml.kernel.org/r/20161110113503.76501.80809.stgit@ahduyck-blue-test.jf.intel.com
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: James Hogan <james.hogan@imgtec.com>
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/metag/kernel/dma.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/arch/metag/kernel/dma.c b/arch/metag/kernel/dma.c index 0db31e24c541..91968d92652b 100644 --- a/arch/metag/kernel/dma.c +++ b/arch/metag/kernel/dma.c @@ -484,8 +484,9 @@ static dma_addr_t metag_dma_map_page(struct device *dev, struct page *page, unsigned long offset, size_t size, enum dma_data_direction direction, unsigned long attrs) { - dma_sync_for_device((void *)(page_to_phys(page) + offset), size, - direction); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + dma_sync_for_device((void *)(page_to_phys(page) + offset), + size, direction); return page_to_phys(page) + offset; } @@ -493,7 +494,8 @@ static void metag_dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size, enum dma_data_direction direction, unsigned long attrs) { - dma_sync_for_cpu(phys_to_virt(dma_address), size, direction); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + dma_sync_for_cpu(phys_to_virt(dma_address), size, direction); } static int metag_dma_map_sg(struct device *dev, struct scatterlist *sglist, @@ -507,6 +509,10 @@ static int metag_dma_map_sg(struct device *dev, struct scatterlist *sglist, BUG_ON(!sg_page(sg)); sg->dma_address = sg_phys(sg); + + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + continue; + dma_sync_for_device(sg_virt(sg), sg->length, direction); } @@ -525,6 +531,10 @@ static void metag_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, BUG_ON(!sg_page(sg)); sg->dma_address = sg_phys(sg); + + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + continue; + dma_sync_for_cpu(sg_virt(sg), sg->length, direction); } } |