[net-next PATCH RFC 12/26] arch/microblaze: Add option to skip DMA sync as a part of map and unmap
From: Alexander Duyck <hidden>
Date: 2016-10-24 18:06:12
Also in:
linux-mm, lkml
Subsystem:
microblaze architecture, the rest · Maintainers:
Michal Simek, Linus Torvalds
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: Michal Simek <monstr@monstr.eu> Signed-off-by: Alexander Duyck <redacted> --- arch/microblaze/kernel/dma.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/microblaze/kernel/dma.c b/arch/microblaze/kernel/dma.c
index ec04dc1..818daf2 100644
--- a/arch/microblaze/kernel/dma.c
+++ b/arch/microblaze/kernel/dma.c@@ -61,6 +61,10 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, /* FIXME this part of code is untested */ for_each_sg(sgl, sg, nents, i) { sg->dma_address = sg_phys(sg); + + if (attrs & DMA_ATTR_SKIP_CPU_SYNC) + continue; + __dma_sync(page_to_phys(sg_page(sg)) + sg->offset, sg->length, direction); }
@@ -80,7 +84,8 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev, enum dma_data_direction direction, unsigned long attrs) { - __dma_sync(page_to_phys(page) + offset, size, direction); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + __dma_sync(page_to_phys(page) + offset, size, direction); return page_to_phys(page) + offset; }
@@ -95,7 +100,8 @@ static inline void dma_direct_unmap_page(struct device *dev, * phys_to_virt is here because in __dma_sync_page is __virt_to_phys and * dma_address is physical address */ - __dma_sync(dma_address, size, direction); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + __dma_sync(dma_address, size, direction); } static inline void