Messages in this thread Patch in this message | | | From | Zhen Lei <> | Subject | [PATCH v2 1/1] arm64/dma-mapping: reduce an unnecessary conversion for coherent DMA | Date | Fri, 18 Mar 2016 10:26:07 +0800 |
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1.For coherent DMA In swiotlb_alloc_coherent, it directly return vaddr on success, and pass vaddr to free_pages on failure. So, we can directly transparent pass vaddr from __dma_free to swiotlb_free_coherent.
2.Keep no change for non-coherent DMA.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> --- arch/arm64/mm/dma-mapping.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index a6e757c..ceb2018 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -187,16 +187,22 @@ static void __dma_free(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle, struct dma_attrs *attrs) { - void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle)); - size = PAGE_ALIGN(size);
if (!is_device_dma_coherent(dev)) { if (__free_from_pool(vaddr, size)) return; vunmap(vaddr); + + /* + * For non-coherent DMA, the vaddr is not part of the linear + * mapping as it has been remapped by __dma_alloc() via + * dma_common_contiguous_remap(), hence for swiotlb freeing we + * need the actual linear map address. + */ + vaddr = phys_to_virt(dma_to_phys(dev, dma_handle)); } - __dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs); + __dma_free_coherent(dev, size, vaddr, dma_handle, attrs); }
static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page, -- 2.5.0
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