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Commit abdf4799 authored by Alexander Duyck's avatar Alexander Duyck Committed by Linus Torvalds
Browse files

arch/nios2: 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/20161110113518.76501.52225.stgit@ahduyck-blue-test.jf.intel.com


Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Reviewed-by: default avatarTobias Klauser <tklauser@distanz.ch>
Cc: Ley Foon Tan <lftan@altera.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9f318d47

arch/nios2/mm/dma-mapping.c

+18 −8
Original line number Diff line number Diff line
@@ -98,13 +98,17 @@ static int nios2_dma_map_sg(struct device *dev, struct scatterlist *sg, 
	int i;



	for_each_sg(sg, sg, nents, i) {

		void *addr;

		void *addr = sg_virt(sg);



		if (!addr)

			continue;



		addr = sg_virt(sg);

		if (addr) {

			__dma_sync_for_device(addr, sg->length, direction);

		sg->dma_address = sg_phys(sg);

		}



		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)

			continue;



		__dma_sync_for_device(addr, sg->length, direction);

	}



	return nents;
@@ -117,7 +121,9 @@ static dma_addr_t nios2_dma_map_page(struct device *dev, struct page *page, 
{

	void *addr = page_address(page) + offset;



	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))

		__dma_sync_for_device(addr, size, direction);



	return page_to_phys(page) + offset;

}
@@ -125,6 +131,7 @@ static void nios2_dma_unmap_page(struct device *dev, dma_addr_t dma_address, 
		size_t size, enum dma_data_direction direction,

		unsigned long attrs)

{

	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))

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

}
@@ -138,6 +145,9 @@ static void nios2_dma_unmap_sg(struct device *dev, struct scatterlist *sg, 
	if (direction == DMA_TO_DEVICE)

		return;



	if (attrs & DMA_ATTR_SKIP_CPU_SYNC)

		return;



	for_each_sg(sg, sg, nhwentries, i) {

		addr = sg_virt(sg);

		if (addr)