[net-next PATCH 10/27] arch/hexagon: Add option to skip DMA sync as a part of mapping

[Alexander Duyck]

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 <r...@codeaurora.org>
Cc: linux-hexa...@vger.kernel.org
Signed-off-by: Alexander Duyck <alexander.h.du...@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;
 }