Commit 6f774809 authored by Alexander Duyck's avatar Alexander Duyck Committed by Linus Torvalds

arch/powerpc: 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/20161110113534.76501.86492.stgit@ahduyck-blue-test.jf.intel.comSigned-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Acked-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f50a2bd2
......@@ -203,6 +203,10 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
for_each_sg(sgl, sg, nents, i) {
sg->dma_address = sg_phys(sg) + get_dma_offset(dev);
sg->dma_length = sg->length;
if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
continue;
__dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
}
......@@ -235,7 +239,10 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev,
unsigned long attrs)
{
BUG_ON(dir == DMA_NONE);
__dma_sync_page(page, offset, size, dir);
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
__dma_sync_page(page, offset, size, dir);
return page_to_phys(page) + offset + get_dma_offset(dev);
}
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment