powerpc: make dma_cache_sync a no-op

powerpc does not implement DMA_ATTR_NON_CONSISTENT allocations, so it
doesn't make any sense to do any work in dma_cache_sync given that it
must be a no-op when dma_alloc_attrs returns coherent memory.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>

diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
index eaece3d3e2254bd2f8a46043db92239eb7aa9025..320846442bfb0cb311f0b125880d6b844c0f1287 100644 (file)
--- a/arch/powerpc/include/asm/dma-mapping.h
+++ b/arch/powerpc/include/asm/dma-mapping.h
@@ -144,8 +144,6 @@ static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
 static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
                enum dma_data_direction direction)
 {
-       BUG_ON(direction == DMA_NONE);
-       __dma_sync(vaddr, size, (int)direction);
 }
 
 #endif /* __KERNEL__ */