Messages in this thread Patch in this message | | | From | Sanjeev Sharma <> | Subject | [PATCH] ARM:dma-mapping: Handle DMA_BIDIRECTIONAL in _dma_page_cpu_to_dev() | Date | Wed, 4 Nov 2015 15:26:48 +0530 |
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_dma_page_cpu_to_dev() treat DMA_BIDIRECTIONAL similar to DMA_TO_DEVICE which means that destination buffer is device memory,means cpu may have written some data to source buffer and data may be in cache line.For cleaner operation we need to call outer_flush_range() which will clean and invalidate outer cache lines.
Signed-off-by: Sanjeev Sharma <sanjeev_sharma@mentor.com> --- arch/arm/mm/dma-mapping.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index e62400e..e195235 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -850,12 +850,20 @@ static void __dma_page_cpu_to_dev(struct page *page, unsigned long off, dma_cache_maint_page(page, off, size, dir, dmac_map_area); paddr = page_to_phys(page) + off; - if (dir == DMA_FROM_DEVICE) { - outer_inv_range(paddr, paddr + size); - } else { - outer_clean_range(paddr, paddr + size); + + switch (dir) { + case DMA_FROM_DEVICE: + outer_inv_range(paddr, paddr + size); + break; + case DMA_TO_DEVICE: + outer_clean_range(paddr, paddr + size); + break; + case DMA_BIDIRECTIONAL: + outer_flush_range(paddr, paddr + size); + break; + default: + break; } - /* FIXME: non-speculating: flush on bidirectional mappings? */ } static void __dma_page_dev_to_cpu(struct page *page, unsigned long off, -- 1.7.11.7
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