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arch/xtensa: add option to skip DMA sync as a part of mapping 

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/20161110113555.76501.52536.stgit@ahduyck-blue-test.jf.intel.com
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alexander Duyck 2016-12-14 15:05:21 -08:00 committed by Linus Torvalds
parent 33c77e53d8
commit 4bfa135abe
1 changed files with 5 additions and 2 deletions
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7
arch/xtensa/kernel/pci-dma.c
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@ -189,7 +189,9 @@ static dma_addr_t xtensa_map_page(struct device *dev, struct page *page,
{
dma_addr_t dma_handle = page_to_phys(page) + offset;
xtensa_sync_single_for_device(dev, dma_handle, size, dir);
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
xtensa_sync_single_for_device(dev, dma_handle, size, dir);
return dma_handle;
}
@ -197,7 +199,8 @@ static void xtensa_unmap_page(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
xtensa_sync_single_for_cpu(dev, dma_handle, size, dir);
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
xtensa_sync_single_for_cpu(dev, dma_handle, size, dir);
}
static int xtensa_map_sg(struct device *dev, struct scatterlist *sg,