提交 64c596b5 编写于 作者: A Alexander Duyck 提交者: Linus Torvalds

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.comSigned-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Acked-by: NMark Salter <msalter@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 8c16a2e2
......@@ -42,14 +42,17 @@ 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);
c6x_dma_sync(handle, size, dir);
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)
{
c6x_dma_sync(handle, size, dir);
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
c6x_dma_sync(handle, size, dir);
}
static int c6x_dma_map_sg(struct device *dev, struct scatterlist *sglist,
......@@ -60,7 +63,8 @@ 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);
c6x_dma_sync(sg->dma_address, sg->length, dir);
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
c6x_dma_sync(sg->dma_address, sg->length, dir);
}
return nents;
......@@ -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,
......
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