[net-next PATCH 19/27] arch/sh: Add option to skip DMA sync as a part of mapping
From: Alexander Duyck <hidden>
Date: 2016-10-25 21:39:11
Also in:
intel-wired-lan, linux-mm, linux-sh, lkml
Subsystem:
superh, the rest · Maintainers:
Yoshinori Sato, Rich Felker, John Paul Adrian Glaubitz, Linus Torvalds
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. Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: linux-sh@vger.kernel.org Signed-off-by: Alexander Duyck <redacted> --- arch/sh/kernel/dma-nommu.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/sh/kernel/dma-nommu.c b/arch/sh/kernel/dma-nommu.c
index eadb669..47fee3b 100644
--- a/arch/sh/kernel/dma-nommu.c
+++ b/arch/sh/kernel/dma-nommu.c@@ -18,7 +18,9 @@ static dma_addr_t nommu_map_page(struct device *dev, struct page *page, dma_addr_t addr = page_to_phys(page) + offset; WARN_ON(size == 0); - dma_cache_sync(dev, page_address(page) + offset, size, dir); + + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + dma_cache_sync(dev, page_address(page) + offset, size, dir); return addr; }
@@ -35,7 +37,8 @@ static int nommu_map_sg(struct device *dev, struct scatterlist *sg, for_each_sg(sg, s, nents, i) { BUG_ON(!sg_page(s)); - dma_cache_sync(dev, sg_virt(s), s->length, dir); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + dma_cache_sync(dev, sg_virt(s), s->length, dir); s->dma_address = sg_phys(s); s->dma_length = s->length; --
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