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Message-Id: <20170827161032.22772-6-hch@lst.de>
Date: Sun, 27 Aug 2017 18:10:25 +0200
From: Christoph Hellwig <hch@....de>
To: iommu@...ts.linux-foundation.org
Cc: Marek Szyprowski <m.szyprowski@...sung.com>,
Robin Murphy <robin.murphy@....com>,
Michal Simek <monstr@...str.eu>,
David Howells <dhowells@...hat.com>,
Guan Xuetao <gxt@...c.pku.edu.cn>,
Chris Zankel <chris@...kel.net>,
Max Filippov <jcmvbkbc@...il.com>, x86@...nel.org,
linux-mips@...ux-mips.org, linux-ia64@...r.kernel.org,
linuxppc-dev@...ts.ozlabs.org, linux-xtensa@...ux-xtensa.org,
linux-sh@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 05/12] ia64: make dma_cache_sync a no-op
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@....de>
---
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 */
--
2.11.0
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