[PATCH 1/3] hexagon: remove the sync_single_for_cpu DMA operation

From: Christoph Hellwig
Date: Thu Jul 19 2018 - 08:56:38 EST


hexagon does all the required cache maintainance at dma map time, and none
at unmap time. It thus has to implement sync_single_for_device to match
the map cace for buffer reuse, but there is no point in doing another
invalidation in the sync_single_cpu_case, which in terms of cache
maintainance is equivalent to the unmap case.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
arch/hexagon/kernel/dma.c | 8 --------
1 file changed, 8 deletions(-)

diff --git a/arch/hexagon/kernel/dma.c b/arch/hexagon/kernel/dma.c
index 77459df34e2e..d2b717f352f4 100644
--- a/arch/hexagon/kernel/dma.c
+++ b/arch/hexagon/kernel/dma.c
@@ -181,13 +181,6 @@ static dma_addr_t hexagon_map_page(struct device *dev, struct page *page,
return bus;
}

-static void hexagon_sync_single_for_cpu(struct device *dev,
- dma_addr_t dma_handle, size_t size,
- enum dma_data_direction dir)
-{
- dma_sync(dma_addr_to_virt(dma_handle), size, dir);
-}
-
static void hexagon_sync_single_for_device(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction dir)
@@ -205,7 +198,6 @@ const struct dma_map_ops hexagon_dma_ops = {
.free = hexagon_free_coherent,
.map_sg = hexagon_map_sg,
.map_page = hexagon_map_page,
- .sync_single_for_cpu = hexagon_sync_single_for_cpu,
.sync_single_for_device = hexagon_sync_single_for_device,
.mapping_error = hexagon_mapping_error,
};
--
2.18.0