[PATCH 04/11] ia64: make dma_cache_sync a no-op

From: Christoph Hellwig
Date: Tue Oct 03 2017 - 06:46:00 EST


ia64 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@xxxxxx>
---
arch/ia64/include/asm/dma-mapping.h | 5 -----
1 file changed, 5 deletions(-)

diff --git a/arch/ia64/include/asm/dma-mapping.h b/arch/ia64/include/asm/dma-mapping.h
index 3ce5ab4339f3..99dfc1aa9d3c 100644
--- a/arch/ia64/include/asm/dma-mapping.h
+++ b/arch/ia64/include/asm/dma-mapping.h
@@ -48,11 +48,6 @@ static inline void
dma_cache_sync (struct device *dev, void *vaddr, size_t size,
enum dma_data_direction dir)
{
- /*
- * IA-64 is cache-coherent, so this is mostly a no-op. However, we do need to
- * ensure that dma_cache_sync() enforces order, hence the mb().
- */
- mb();
}

#endif /* _ASM_IA64_DMA_MAPPING_H */
--
2.14.1