| Message ID | 20161102111513.79519.65315.stgit@ahduyck-blue-test.jf.intel.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
Alexander Duyck <alexander.h.duyck@intel.com> writes: > 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. > > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> > Cc: Paul Mackerras <paulus@samba.org> > Cc: Michael Ellerman <mpe@ellerman.id.au> > Cc: linuxppc-dev@lists.ozlabs.org > Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> > --- > arch/powerpc/kernel/dma.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) LGTM. Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) cheers
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c index e64a601..6877e3f 100644 --- a/arch/powerpc/kernel/dma.c +++ b/arch/powerpc/kernel/dma.c @@ -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); }
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. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> --- arch/powerpc/kernel/dma.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)