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| author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2008-09-29 22:50:59 +0400 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2008-09-30 14:01:36 +0400 |
| commit | 309dbbabee7b19e003e1ba4b98f43d28f390a84e (patch) | |
| tree | ba748b84c0573f5eb151a581e333b95010576521 /arch/arm | |
| parent | 0e18b5d7c6339311f1e32e7b186ae3556c5b6d33 (diff) | |
| download | linux-309dbbabee7b19e003e1ba4b98f43d28f390a84e.tar.xz | |
[ARM] dma: don't touch cache on dma_*_for_cpu()
As per the dma_unmap_* calls, we don't touch the cache when a DMA
buffer transitions from device to CPU ownership. Presently, no
problems have been identified with speculative cache prefetching
which in itself is a new feature in later architectures. We may
have to revisit the DMA API later for these architectures anyway.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/include/asm/dma-mapping.h | 6 | ||||
| -rw-r--r-- | arch/arm/mm/dma-mapping.c | 8 |
2 files changed, 3 insertions, 11 deletions
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index 2544a087c213..ad62020763f1 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -376,11 +376,7 @@ static inline void dma_sync_single_range_for_cpu(struct device *dev, { BUG_ON(!valid_dma_direction(dir)); - if (!dmabounce_sync_for_cpu(dev, handle, offset, size, dir)) - return; - - if (!arch_is_coherent()) - dma_cache_maint(dma_to_virt(dev, handle) + offset, size, dir); + dmabounce_sync_for_cpu(dev, handle, offset, size, dir); } static inline void dma_sync_single_range_for_device(struct device *dev, diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 0e28cf33f7dd..67960017dc8f 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -585,12 +585,8 @@ void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int i; for_each_sg(sg, s, nents, i) { - if (!dmabounce_sync_for_cpu(dev, sg_dma_address(s), 0, - sg_dma_len(s), dir)) - continue; - - if (!arch_is_coherent()) - dma_cache_maint(sg_virt(s), s->length, dir); + dmabounce_sync_for_cpu(dev, sg_dma_address(s), 0, + sg_dma_len(s), dir); } } EXPORT_SYMBOL(dma_sync_sg_for_cpu); |