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Subject[net-next PATCH 10/27] arch/hexagon: Add option to skip DMA sync as a part of 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: Richard Kuo <rkuo@codeaurora.org>
Cc: linux-hexagon@vger.kernel.org
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
arch/hexagon/kernel/dma.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/hexagon/kernel/dma.c b/arch/hexagon/kernel/dma.c
index b901778..dbc4f10 100644
--- a/arch/hexagon/kernel/dma.c
+++ b/arch/hexagon/kernel/dma.c
@@ -119,6 +119,9 @@ static int hexagon_map_sg(struct device *hwdev, struct scatterlist *sg,

s->dma_length = s->length;

+ if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+ continue;
+
flush_dcache_range(dma_addr_to_virt(s->dma_address),
dma_addr_to_virt(s->dma_address + s->length));
}
@@ -180,7 +183,8 @@ static dma_addr_t hexagon_map_page(struct device *dev, struct page *page,
if (!check_addr("map_single", dev, bus, size))
return bad_dma_address;

- dma_sync(dma_addr_to_virt(bus), size, dir);
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ dma_sync(dma_addr_to_virt(bus), size, dir);

return bus;
}
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