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Commit a0812001 authored by Alexander Duyck's avatar Alexander Duyck Committed by Linus Torvalds
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arch/sh: 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/20161110113539.76501.6539.stgit@ahduyck-blue-test.jf.intel.com


Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6f774809

arch/sh/kernel/dma-nommu.c

+5 −2
Original line number Diff line number Diff line
@@ -18,6 +18,8 @@ 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);



	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))

		dma_cache_sync(dev, page_address(page) + offset, size, dir);



	return addr;
@@ -35,6 +37,7 @@ static int nommu_map_sg(struct device *dev, struct scatterlist *sg, 
	for_each_sg(sg, s, nents, i) {

		BUG_ON(!sg_page(s));



		if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))

			dma_cache_sync(dev, sg_virt(s), s->length, dir);



		s->dma_address = sg_phys(s);