From: Alexander Duyck <alexander.h.duyck@xxxxxxxxx> Subject: arch/hexagon: 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/20161110113452.76501.45864.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxx> Cc: Richard Kuo <rkuo@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/hexagon/kernel/dma.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff -puN arch/hexagon/kernel/dma.c~arch-hexagon-add-option-to-skip-dma-sync-as-a-part-of-mapping arch/hexagon/kernel/dma.c --- a/arch/hexagon/kernel/dma.c~arch-hexagon-add-option-to-skip-dma-sync-as-a-part-of-mapping +++ a/arch/hexagon/kernel/dma.c @@ -119,6 +119,9 @@ static int hexagon_map_sg(struct device s->dma_length = s->length; + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + continue; + flush_dcache_range(dma_addr_to_virt(s->dma_address), dma_addr_to_virt(s->dma_address + s->length)); } @@ -180,7 +183,8 @@ static dma_addr_t hexagon_map_page(struc if (!check_addr("map_single", dev, bus, size)) return bad_dma_address; - dma_sync(dma_addr_to_virt(bus), size, dir); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + dma_sync(dma_addr_to_virt(bus), size, dir); return bus; } _ -- 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
