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author | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-10-31 16:52:16 (GMT) |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-02-15 15:21:43 (GMT) |
commit | 18eabe2347ae7a11b3db768695913724166dfb0e (patch) | |
tree | 2f6a9bb654d01e07a62be75adc1282e97b5c16d4 /arch/arm/mm | |
parent | bf32eb85492af197ea5ff20e0be56f667a80584d (diff) | |
download | linux-18eabe2347ae7a11b3db768695913724166dfb0e.tar.xz |
ARM: dma-mapping: introduce the idea of buffer ownership
The DMA API has the notion of buffer ownership; make it explicit in the
ARM implementation of this API. This gives us a set of hooks to allow
us to deal with CPU cache issues arising from non-cache coherent DMA.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-By: Jamie Iles <jamie@jamieiles.com>
Diffstat (limited to 'arch/arm/mm')
-rw-r--r-- | arch/arm/mm/dma-mapping.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 26325cb..a316c94 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -573,8 +573,12 @@ void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int i; for_each_sg(sg, s, nents, i) { - dmabounce_sync_for_cpu(dev, sg_dma_address(s), 0, - sg_dma_len(s), dir); + if (!dmabounce_sync_for_cpu(dev, sg_dma_address(s), 0, + sg_dma_len(s), dir)) + continue; + + __dma_page_dev_to_cpu(sg_page(s), s->offset, + s->length, dir); } } EXPORT_SYMBOL(dma_sync_sg_for_cpu); @@ -597,9 +601,8 @@ void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, sg_dma_len(s), dir)) continue; - if (!arch_is_coherent()) - dma_cache_maint_page(sg_page(s), s->offset, - s->length, dir); + __dma_page_cpu_to_dev(sg_page(s), s->offset, + s->length, dir); } } EXPORT_SYMBOL(dma_sync_sg_for_device); |