From 18eabe2347ae7a11b3db768695913724166dfb0e Mon Sep 17 00:00:00 2001 From: Russell King Date: Sat, 31 Oct 2009 16:52:16 +0000 Subject: 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 Tested-By: Santosh Shilimkar Tested-By: Jamie Iles --- arch/arm/mm/dma-mapping.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'arch/arm/mm/dma-mapping.c') diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 26325cb5d36..a316c945952 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); -- cgit v1.2.3-70-g09d2