From: Alexander Duyck <alexander.h.duyck@xxxxxxxxx> Subject: arch/xtensa: 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/20161110113555.76501.52536.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxx> Cc: Max Filippov <jcmvbkbc@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/xtensa/kernel/pci-dma.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff -puN arch/xtensa/kernel/pci-dma.c~arch-xtensa-add-option-to-skip-dma-sync-as-a-part-of-mapping arch/xtensa/kernel/pci-dma.c --- a/arch/xtensa/kernel/pci-dma.c~arch-xtensa-add-option-to-skip-dma-sync-as-a-part-of-mapping +++ a/arch/xtensa/kernel/pci-dma.c @@ -189,7 +189,9 @@ static dma_addr_t xtensa_map_page(struct { dma_addr_t dma_handle = page_to_phys(page) + offset; - xtensa_sync_single_for_device(dev, dma_handle, size, dir); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + xtensa_sync_single_for_device(dev, dma_handle, size, dir); + return dma_handle; } @@ -197,7 +199,8 @@ static void xtensa_unmap_page(struct dev size_t size, enum dma_data_direction dir, unsigned long attrs) { - xtensa_sync_single_for_cpu(dev, dma_handle, size, dir); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + xtensa_sync_single_for_cpu(dev, dma_handle, size, dir); } static int xtensa_map_sg(struct device *dev, struct scatterlist *sg, _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
