diff options
| author | Alexander Duyck <alexander.h.duyck@intel.com> | 2016-12-14 15:04:58 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-14 16:04:07 -0800 |
| commit | 9f318d470e37a470d65449f94a06165ea72dbce1 (patch) | |
| tree | 03e6e15a8998785507f793c05500d09554e4e334 /arch/mips/mm | |
| parent | 98ac2fc274e07a22bea43682cf8998f47ffea9d0 (diff) | |
arch/mips: 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/20161110113513.76501.32321.stgit@ahduyck-blue-test.jf.intel.com
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Keguang Zhang <keguang.zhang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/mips/mm')
| -rw-r--r-- | arch/mips/mm/dma-default.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c index 46d5696c4f27..a39c36af97ad 100644 --- a/arch/mips/mm/dma-default.c +++ b/arch/mips/mm/dma-default.c @@ -293,7 +293,7 @@ static inline void __dma_sync(struct page *page, static void mips_dma_unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size, enum dma_data_direction direction, unsigned long attrs) { - if (cpu_needs_post_dma_flush(dev)) + if (cpu_needs_post_dma_flush(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) __dma_sync(dma_addr_to_page(dev, dma_addr), dma_addr & ~PAGE_MASK, size, direction); plat_post_dma_flush(dev); @@ -307,7 +307,8 @@ static int mips_dma_map_sg(struct device *dev, struct scatterlist *sglist, struct scatterlist *sg; for_each_sg(sglist, sg, nents, i) { - if (!plat_device_is_coherent(dev)) + if (!plat_device_is_coherent(dev) && + !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) __dma_sync(sg_page(sg), sg->offset, sg->length, direction); #ifdef CONFIG_NEED_SG_DMA_LENGTH @@ -324,7 +325,7 @@ static dma_addr_t mips_dma_map_page(struct device *dev, struct page *page, unsigned long offset, size_t size, enum dma_data_direction direction, unsigned long attrs) { - if (!plat_device_is_coherent(dev)) + if (!plat_device_is_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) __dma_sync(page, offset, size, direction); return plat_map_dma_mem_page(dev, page) + offset; @@ -339,6 +340,7 @@ static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, for_each_sg(sglist, sg, nhwentries, i) { if (!plat_device_is_coherent(dev) && + !(attrs & DMA_ATTR_SKIP_CPU_SYNC) && direction != DMA_TO_DEVICE) __dma_sync(sg_page(sg), sg->offset, sg->length, direction); |