From: Alexander Duyck <alexander.h.duyck@xxxxxxxxx> Subject: arch/m68k: 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 later via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113457.76501.77603.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxx> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/m68k/kernel/dma.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff -puN arch/m68k/kernel/dma.c~arch-m68k-add-option-to-skip-dma-sync-as-a-part-of-mapping arch/m68k/kernel/dma.c --- a/arch/m68k/kernel/dma.c~arch-m68k-add-option-to-skip-dma-sync-as-a-part-of-mapping +++ a/arch/m68k/kernel/dma.c @@ -134,7 +134,9 @@ static dma_addr_t m68k_dma_map_page(stru { dma_addr_t handle = page_to_phys(page) + offset; - dma_sync_single_for_device(dev, handle, size, dir); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + dma_sync_single_for_device(dev, handle, size, dir); + return handle; } @@ -146,6 +148,10 @@ static int m68k_dma_map_sg(struct device for_each_sg(sglist, sg, nents, i) { sg->dma_address = sg_phys(sg); + + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + continue; + dma_sync_single_for_device(dev, sg->dma_address, sg->length, dir); } _ -- 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
