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Commit 33c77e53 authored by Alexander Duyck's avatar Alexander Duyck Committed by Linus Torvalds
Browse files

arch/tile: 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/20161110113550.76501.73060.stgit@ahduyck-blue-test.jf.intel.com


Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 68bbc28f

arch/tile/kernel/pci-dma.c

+10 −2
Original line number Diff line number Diff line
@@ -213,10 +213,12 @@ static int tile_dma_map_sg(struct device *dev, struct scatterlist *sglist, 


	for_each_sg(sglist, sg, nents, i) {

		sg->dma_address = sg_phys(sg);

		__dma_prep_pa_range(sg->dma_address, sg->length, direction);

#ifdef CONFIG_NEED_SG_DMA_LENGTH

		sg->dma_length = sg->length;

#endif

		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)

			continue;

		__dma_prep_pa_range(sg->dma_address, sg->length, direction);

	}



	return nents;
@@ -232,6 +234,8 @@ static void tile_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, 
	BUG_ON(!valid_dma_direction(direction));

	for_each_sg(sglist, sg, nents, i) {

		sg->dma_address = sg_phys(sg);

		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)

			continue;

		__dma_complete_pa_range(sg->dma_address, sg->length,

					direction);

	}
@@ -245,6 +249,7 @@ static dma_addr_t tile_dma_map_page(struct device *dev, struct page *page, 
	BUG_ON(!valid_dma_direction(direction));



	BUG_ON(offset + size > PAGE_SIZE);

	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))

		__dma_prep_page(page, offset, size, direction);



	return page_to_pa(page) + offset;
@@ -256,6 +261,9 @@ static void tile_dma_unmap_page(struct device *dev, dma_addr_t dma_address, 
{

	BUG_ON(!valid_dma_direction(direction));



	if (attrs & DMA_ATTR_SKIP_CPU_SYNC)

		return;



	__dma_complete_page(pfn_to_page(PFN_DOWN(dma_address)),

			    dma_address & (PAGE_SIZE - 1), size, direction);

}