Commit 5140d234 authored Dec 14, 2016 by Alexander Duyck Committed by Linus Torvalds Dec 14, 2016

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@ahduyck-blue-test.jf.intel.com

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent b8a346dd

arch/m68k/kernel/dma.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -134,7 +134,9 @@ static dma_addr_t m68k_dma_map_page(struct device dev, struct page page,
		{
		dma_addr_t handle = page_to_phys(page) + offset;

		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 dev, struct scatterlist sglist,

		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);
		}