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Commit 0495c3d3 authored by Alexander Duyck's avatar Alexander Duyck Committed by Linus Torvalds
Browse files

dma: add calls for dma_map_page_attrs and dma_unmap_page_attrs 

Add support for mapping and unmapping a page with attributes.

The primary use for this is currently to allow for us to pass the
DMA_ATTR_SKIP_CPU_SYNC attribute when mapping and unmapping a page.  On
some architectures such as ARM the synchronization has significant
overhead and if we are already taking care of the sync_for_cpu and
sync_for_device from the driver there isn't much need to handle this in
the map/unmap calls as well.

Link: http://lkml.kernel.org/r/20161110113601.76501.46095.stgit@ahduyck-blue-test.jf.intel.com


Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4bfa135a

include/linux/dma-mapping.h

+13 −7
Original line number Diff line number Diff line
@@ -243,29 +243,33 @@ static inline void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg 
		ops->unmap_sg(dev, sg, nents, dir, attrs);

}



static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,

static inline dma_addr_t dma_map_page_attrs(struct device *dev,

					    struct page *page,

					    size_t offset, size_t size,

				      enum dma_data_direction dir)

					    enum dma_data_direction dir,

					    unsigned long attrs)

{

	struct dma_map_ops *ops = get_dma_ops(dev);

	dma_addr_t addr;



	kmemcheck_mark_initialized(page_address(page) + offset, size);

	BUG_ON(!valid_dma_direction(dir));

	addr = ops->map_page(dev, page, offset, size, dir, 0);

	addr = ops->map_page(dev, page, offset, size, dir, attrs);

	debug_dma_map_page(dev, page, offset, size, dir, addr, false);



	return addr;

}



static inline void dma_unmap_page(struct device *dev, dma_addr_t addr,

				  size_t size, enum dma_data_direction dir)

static inline void dma_unmap_page_attrs(struct device *dev,

					dma_addr_t addr, size_t size,

					enum dma_data_direction dir,

					unsigned long attrs)

{

	struct dma_map_ops *ops = get_dma_ops(dev);



	BUG_ON(!valid_dma_direction(dir));

	if (ops->unmap_page)

		ops->unmap_page(dev, addr, size, dir, 0);

		ops->unmap_page(dev, addr, size, dir, attrs);

	debug_dma_unmap_page(dev, addr, size, dir, false);

}
@@ -385,6 +389,8 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, 
#define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, 0)

#define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, 0)

#define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, 0)

#define dma_map_page(d, p, o, s, r) dma_map_page_attrs(d, p, o, s, r, 0)

#define dma_unmap_page(d, a, s, r) dma_unmap_page_attrs(d, a, s, r, 0)



extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,

			   void *cpu_addr, dma_addr_t dma_addr, size_t size);