提交 abdf4799 编写于 作者: A Alexander Duyck 提交者: Linus Torvalds

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.comSigned-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Reviewed-by: NTobias Klauser <tklauser@distanz.ch>
Cc: Ley Foon Tan <lftan@altera.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 9f318d47
......@@ -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);
addr = sg_virt(sg);
if (addr) {
__dma_sync_for_device(addr, sg->length, direction);
sg->dma_address = sg_phys(sg);
}
if (!addr)
continue;
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;
__dma_sync_for_device(addr, size, direction);
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
__dma_sync_for_device(addr, size, direction);
return page_to_phys(page) + offset;
}
......@@ -125,7 +131,8 @@ 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)
{
__dma_sync_for_cpu(phys_to_virt(dma_address), size, direction);
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
__dma_sync_for_cpu(phys_to_virt(dma_address), size, direction);
}
static void nios2_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
......@@ -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)
......
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