diff options
| author | Alexander Duyck <alexander.h.duyck@intel.com> | 2016-12-14 15:05:18 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-14 16:04:08 -0800 |
| commit | 33c77e53d838dc27e9d2edec5b6ab6a11861fb32 (patch) | |
| tree | c41c4e8c2d2c058ced9db32f5b71ba0b25dceab6 /arch/tile | |
| parent | 68bbc28f616c18b695a13e59adefb9a1fc0c46a0 (diff) | |
arch/tile: 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/20161110113550.76501.73060.stgit@ahduyck-blue-test.jf.intel.com
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/tile')
| -rw-r--r-- | arch/tile/kernel/pci-dma.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/tile/kernel/pci-dma.c b/arch/tile/kernel/pci-dma.c index 09bb774b39cd..24e0f8c21f2f 100644 --- a/arch/tile/kernel/pci-dma.c +++ b/arch/tile/kernel/pci-dma.c @@ -213,10 +213,12 @@ static int tile_dma_map_sg(struct device *dev, struct scatterlist *sglist, for_each_sg(sglist, sg, nents, i) { sg->dma_address = sg_phys(sg); - __dma_prep_pa_range(sg->dma_address, sg->length, direction); #ifdef CONFIG_NEED_SG_DMA_LENGTH sg->dma_length = sg->length; #endif + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + continue; + __dma_prep_pa_range(sg->dma_address, sg->length, direction); } return nents; @@ -232,6 +234,8 @@ static void tile_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, BUG_ON(!valid_dma_direction(direction)); for_each_sg(sglist, sg, nents, i) { sg->dma_address = sg_phys(sg); + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + continue; __dma_complete_pa_range(sg->dma_address, sg->length, direction); } @@ -245,7 +249,8 @@ static dma_addr_t tile_dma_map_page(struct device *dev, struct page *page, BUG_ON(!valid_dma_direction(direction)); BUG_ON(offset + size > PAGE_SIZE); - __dma_prep_page(page, offset, size, direction); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + __dma_prep_page(page, offset, size, direction); return page_to_pa(page) + offset; } @@ -256,6 +261,9 @@ static void tile_dma_unmap_page(struct device *dev, dma_addr_t dma_address, { BUG_ON(!valid_dma_direction(direction)); + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + return; + __dma_complete_page(pfn_to_page(PFN_DOWN(dma_address)), dma_address & (PAGE_SIZE - 1), size, direction); } |