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Commit 64c596b5 authored by Alexander Duyck's avatar Alexander Duyck Committed by Linus Torvalds
Browse files

arch/c6x: add option to skip sync on DMA 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
later via a sync_for_cpu or sync_for_device call.

Link: http://lkml.kernel.org/r/20161110113442.76501.7673.stgit@ahduyck-blue-test.jf.intel.com


Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Acked-by: default avatarMark Salter <msalter@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8c16a2e2

arch/c6x/kernel/dma.c

+10 −4
Original line number Diff line number Diff line
@@ -42,13 +42,16 @@ static dma_addr_t c6x_dma_map_page(struct device *dev, struct page *page, 
{

	dma_addr_t handle = virt_to_phys(page_address(page) + offset);



	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))

		c6x_dma_sync(handle, size, dir);



	return handle;

}



static void c6x_dma_unmap_page(struct device *dev, dma_addr_t handle,

		size_t size, enum dma_data_direction dir, unsigned long attrs)

{

	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))

		c6x_dma_sync(handle, size, dir);

}
@@ -60,6 +63,7 @@ static int c6x_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))

			c6x_dma_sync(sg->dma_address, sg->length, dir);

	}
@@ -72,9 +76,11 @@ static void c6x_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, 
	struct scatterlist *sg;

	int i;



	if (attrs & DMA_ATTR_SKIP_CPU_SYNC)

		return;



	for_each_sg(sglist, sg, nents, i)

		c6x_dma_sync(sg_dma_address(sg), sg->length, dir);



}



static void c6x_dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle,