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authorDavid Stevens <stevensd@chromium.org>2021-09-29 11:32:56 +0900
committerJoerg Roedel <jroedel@suse.de>2021-09-29 12:49:53 +0200
commitee9d4097cc145dcaebedf6b113d17c91c21333a0 (patch)
tree952daa9c0b40bfd664ff18f98e8d7df4f5235266
parent06e620345d544e559b2961cb5a676ec9c80c8950 (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.c11
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.