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Commit 9f318d47 authored by Alexander Duyck's avatar Alexander Duyck Committed by Linus Torvalds
Browse files

arch/mips: add option to skip DMA sync as a part of map and unmap 

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/20161110113513.76501.32321.stgit@ahduyck-blue-test.jf.intel.com


Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Keguang Zhang <keguang.zhang@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 98ac2fc2

arch/mips/loongson64/common/dma-swiotlb.c

+1 −1
Original line number Diff line number Diff line
@@ -61,7 +61,7 @@ static int loongson_dma_map_sg(struct device *dev, struct scatterlist *sg, 
				int nents, enum dma_data_direction dir,

				unsigned long attrs)

{

	int r = swiotlb_map_sg_attrs(dev, sg, nents, dir, 0);

	int r = swiotlb_map_sg_attrs(dev, sg, nents, dir, attrs);

	mb();



	return r;

arch/mips/mm/dma-default.c

+5 −3
Original line number Diff line number Diff line
@@ -293,7 +293,7 @@ static inline void __dma_sync(struct page *page, 
static void mips_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,

	size_t size, enum dma_data_direction direction, unsigned long attrs)

{

	if (cpu_needs_post_dma_flush(dev))

	if (cpu_needs_post_dma_flush(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))

		__dma_sync(dma_addr_to_page(dev, dma_addr),

			   dma_addr & ~PAGE_MASK, size, direction);

	plat_post_dma_flush(dev);
@@ -307,7 +307,8 @@ static int mips_dma_map_sg(struct device *dev, struct scatterlist *sglist, 
	struct scatterlist *sg;



	for_each_sg(sglist, sg, nents, i) {

		if (!plat_device_is_coherent(dev))

		if (!plat_device_is_coherent(dev) &&

		    !(attrs & DMA_ATTR_SKIP_CPU_SYNC))

			__dma_sync(sg_page(sg), sg->offset, sg->length,

				   direction);

#ifdef CONFIG_NEED_SG_DMA_LENGTH
@@ -324,7 +325,7 @@ static dma_addr_t mips_dma_map_page(struct device *dev, struct page *page, 
	unsigned long offset, size_t size, enum dma_data_direction direction,

	unsigned long attrs)

{

	if (!plat_device_is_coherent(dev))

	if (!plat_device_is_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))

		__dma_sync(page, offset, size, direction);



	return plat_map_dma_mem_page(dev, page) + offset;
@@ -339,6 +340,7 @@ static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, 


	for_each_sg(sglist, sg, nhwentries, i) {

		if (!plat_device_is_coherent(dev) &&

		    !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&

		    direction != DMA_TO_DEVICE)

			__dma_sync(sg_page(sg), sg->offset, sg->length,

				   direction);