diff options
| author | David Stevens <stevensd@chromium.org> | 2021-09-29 11:32:56 +0900 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2021-09-29 12:49:53 +0200 |
| commit | ee9d4097cc145dcaebedf6b113d17c91c21333a0 (patch) | |
| tree | 952daa9c0b40bfd664ff18f98e8d7df4f5235266 | |
| parent | 06e620345d544e559b2961cb5a676ec9c80c8950 (diff) | |
iommu/dma: Skip extra sync during unmap w/swiotlb
Calling the iommu_dma_sync_*_for_cpu functions during unmap can cause
two copies out of the swiotlb buffer. Do the arch sync directly in
__iommu_dma_unmap_swiotlb instead to avoid this. This makes the call to
iommu_dma_sync_sg_for_cpu for untrusted devices in iommu_dma_unmap_sg no
longer necessary, so move that invocation later in the function.
Signed-off-by: David Stevens <stevensd@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20210929023300.335969-4-stevensd@google.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
| -rw-r--r-- | drivers/iommu/dma-iommu.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 19bebacbf178..027b489714b7 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -521,6 +521,9 @@ static void __iommu_dma_unmap_swiotlb(struct device *dev, dma_addr_t dma_addr, if (WARN_ON(!phys)) return; + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && !dev_is_dma_coherent(dev)) + arch_sync_dma_for_cpu(phys, size, dir); + __iommu_dma_unmap(dev, dma_addr, size); if (unlikely(is_swiotlb_buffer(dev, phys))) @@ -871,8 +874,6 @@ static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page, static void iommu_dma_unmap_page(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction dir, unsigned long attrs) { - if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) - iommu_dma_sync_single_for_cpu(dev, dma_handle, size, dir); __iommu_dma_unmap_swiotlb(dev, dma_handle, size, dir, attrs); } @@ -1088,14 +1089,14 @@ static void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, struct scatterlist *tmp; int i; - if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) - iommu_dma_sync_sg_for_cpu(dev, sg, nents, dir); - if (dev_is_untrusted(dev)) { iommu_dma_unmap_sg_swiotlb(dev, sg, nents, dir, attrs); return; } + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + iommu_dma_sync_sg_for_cpu(dev, sg, nents, dir); + /* * The scatterlist segments are mapped into a single * contiguous IOVA allocation, so this is incredibly easy. |