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Subject[net-next PATCH 04/27] arch/arc: Add option to skip sync on DMA mapping
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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
later via a sync_for_cpu or sync_for_device call.

Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: linux-snps-arc@lists.infradead.org
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
arch/arc/mm/dma.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index 20afc65..6303c34 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -133,7 +133,10 @@ static dma_addr_t arc_dma_map_page(struct device *dev, struct page *page,
unsigned long attrs)
{
phys_addr_t paddr = page_to_phys(page) + offset;
- _dma_cache_sync(paddr, size, dir);
+
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ _dma_cache_sync(paddr, size, dir);
+
return plat_phys_to_dma(dev, paddr);
}

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