Split all functionality related to non-coherent devices into a separate helper, and make the decision flow more obvious.
Signed-off-by: Christoph Hellwig <h...@lst.de> --- drivers/iommu/dma-iommu.c | 51 +++++++++++++++++++-------------------- 1 file changed, 25 insertions(+), 26 deletions(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 09b29f6093bb..f65dd19b0953 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -767,6 +767,22 @@ static void *iommu_dma_alloc_pool(struct device *dev, size_t size, return vaddr; } +static void *iommu_dma_alloc_noncoherent(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) +{ + /* + * In atomic context we can't remap anything, so we'll only get the + * virtually contiguous buffer we need by way of a physically + * contiguous allocation. + */ + if (!gfpflags_allow_blocking(gfp)) + return iommu_dma_alloc_pool(dev, size, dma_handle, gfp, attrs); + if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) + return iommu_dma_alloc_contiguous_remap(dev, size, dma_handle, + gfp, attrs); + return iommu_dma_alloc_remap(dev, size, dma_handle, gfp, attrs); +} + static void iommu_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction dir) { @@ -1040,40 +1056,23 @@ static void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle, } static void *iommu_dma_alloc(struct device *dev, size_t size, - dma_addr_t *handle, gfp_t gfp, unsigned long attrs) + dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) { - bool coherent = dev_is_dma_coherent(dev); - size_t iosize = size; - void *addr; - /* * Some drivers rely on this, and we probably don't want the * possibility of stale kernel data being read by devices anyway. */ gfp |= __GFP_ZERO; - if (!gfpflags_allow_blocking(gfp)) { - /* - * In atomic context we can't remap anything, so we'll only - * get the virtually contiguous buffer we need by way of a - * physically contiguous allocation. - */ - if (!coherent) - return iommu_dma_alloc_pool(dev, iosize, handle, gfp, - attrs); - return iommu_dma_alloc_contiguous(dev, iosize, handle, gfp, + if (!dev_is_dma_coherent(dev)) + return iommu_dma_alloc_noncoherent(dev, size, dma_handle, gfp, attrs); - } else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) { - if (coherent) - addr = iommu_dma_alloc_contiguous(dev, iosize, handle, - gfp, attrs); - else - addr = iommu_dma_alloc_contiguous_remap(dev, iosize, - handle, gfp, attrs); - } else { - addr = iommu_dma_alloc_remap(dev, iosize, handle, gfp, attrs); - } - return addr; + + if (gfpflags_allow_blocking(gfp) && + !(attrs & DMA_ATTR_FORCE_CONTIGUOUS)) + return iommu_dma_alloc_remap(dev, size, dma_handle, gfp, attrs); + + return iommu_dma_alloc_contiguous(dev, size, dma_handle, gfp, attrs); } static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr, -- 2.20.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu