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Subject[net-next PATCH 13/27] arch/microblaze: Add option to skip DMA sync as a part of map and unmap
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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 <alexander.h.duyck@intel.com>
---
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
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