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Commit 38bdbdc7 authored by Alexander Duyck's avatar Alexander Duyck Committed by Linus Torvalds
Browse files

arch/metag: 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/20161110113503.76501.80809.stgit@ahduyck-blue-test.jf.intel.com


Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Cc: James Hogan <james.hogan@imgtec.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5140d234

arch/metag/kernel/dma.c

+13 −3
Original line number Original line Diff line number Diff line
@@ -484,8 +484,9 @@ static dma_addr_t metag_dma_map_page(struct device *dev, struct page *page, 
		unsigned long offset, size_t size,

		unsigned long offset, size_t size,

		enum dma_data_direction direction, unsigned long attrs)

		enum dma_data_direction direction, unsigned long attrs)

{

{

	dma_sync_for_device((void *)(page_to_phys(page) + offset), size,

	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))

			    direction);

		dma_sync_for_device((void *)(page_to_phys(page) + offset),

				    size, direction);

	return page_to_phys(page) + offset;

	return page_to_phys(page) + offset;

}

}
@@ -493,6 +494,7 @@ static void metag_dma_unmap_page(struct device *dev, dma_addr_t dma_address, 
		size_t size, enum dma_data_direction direction,

		size_t size, enum dma_data_direction direction,

		unsigned long attrs)

		unsigned long attrs)

{

{

	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))

		dma_sync_for_cpu(phys_to_virt(dma_address), size, direction);

		dma_sync_for_cpu(phys_to_virt(dma_address), size, direction);

}

}
@@ -507,6 +509,10 @@ static int metag_dma_map_sg(struct device *dev, struct scatterlist *sglist, 
		BUG_ON(!sg_page(sg));

		BUG_ON(!sg_page(sg));





		sg->dma_address = sg_phys(sg);

		sg->dma_address = sg_phys(sg);



		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)

			continue;



		dma_sync_for_device(sg_virt(sg), sg->length, direction);

		dma_sync_for_device(sg_virt(sg), sg->length, direction);

	}

	}
@@ -525,6 +531,10 @@ static void metag_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, 
		BUG_ON(!sg_page(sg));

		BUG_ON(!sg_page(sg));





		sg->dma_address = sg_phys(sg);

		sg->dma_address = sg_phys(sg);



		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)

			continue;



		dma_sync_for_cpu(sg_virt(sg), sg->length, direction);

		dma_sync_for_cpu(sg_virt(sg), sg->length, direction);

	}

	}

}

}