From: David Stevens <stevensd@chromium.org> To: Robin Murphy <robin.murphy@arm.com>, Christoph Hellwig <hch@lst.de> Cc: Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>, Lu Baolu <baolu.lu@linux.intel.com>, Tom Murphy <murphyt7@tcd.ie>, Rajat Jain <rajatja@google.com>, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, David Stevens <stevensd@chromium.org> Subject: [PATCH v8 1/7] dma-iommu: fix sync_sg with swiotlb Date: Wed, 29 Sep 2021 11:32:54 +0900 [thread overview] Message-ID: <20210929023300.335969-2-stevensd@google.com> (raw) In-Reply-To: <20210929023300.335969-1-stevensd@google.com> From: David Stevens <stevensd@chromium.org> The is_swiotlb_buffer function takes the physical address of the swiotlb buffer, not the physical address of the original buffer. The sglist contains the physical addresses of the original buffer, so for the sync_sg functions to work properly when a bounce buffer might have been used, we need to use iommu_iova_to_phys to look up the physical address. This is what sync_single does, so call that function on each sglist segment. The previous code mostly worked because swiotlb does the transfer on map and unmap. However, any callers which use DMA_ATTR_SKIP_CPU_SYNC with sglists or which call sync_sg would not have had anything copied to the bounce buffer. Fixes: 82612d66d51d ("iommu: Allow the dma-iommu api to use bounce buffers") Signed-off-by: David Stevens <stevensd@chromium.org> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> --- drivers/iommu/dma-iommu.c | 33 +++++++++++++-------------------- 1 file changed, 13 insertions(+), 20 deletions(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 896bea04c347..c4d205b63c58 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -828,17 +828,13 @@ static void iommu_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg; int i; - if (dev_is_dma_coherent(dev) && !dev_is_untrusted(dev)) - return; - - for_each_sg(sgl, sg, nelems, i) { - if (!dev_is_dma_coherent(dev)) + if (dev_is_untrusted(dev)) + for_each_sg(sgl, sg, nelems, i) + iommu_dma_sync_single_for_cpu(dev, sg_dma_address(sg), + sg->length, dir); + else if (!dev_is_dma_coherent(dev)) + for_each_sg(sgl, sg, nelems, i) arch_sync_dma_for_cpu(sg_phys(sg), sg->length, dir); - - if (is_swiotlb_buffer(dev, sg_phys(sg))) - swiotlb_sync_single_for_cpu(dev, sg_phys(sg), - sg->length, dir); - } } static void iommu_dma_sync_sg_for_device(struct device *dev, @@ -848,17 +844,14 @@ static void iommu_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg; int i; - if (dev_is_dma_coherent(dev) && !dev_is_untrusted(dev)) - return; - - for_each_sg(sgl, sg, nelems, i) { - if (is_swiotlb_buffer(dev, sg_phys(sg))) - swiotlb_sync_single_for_device(dev, sg_phys(sg), - sg->length, dir); - - if (!dev_is_dma_coherent(dev)) + if (dev_is_untrusted(dev)) + for_each_sg(sgl, sg, nelems, i) + iommu_dma_sync_single_for_device(dev, + sg_dma_address(sg), + sg->length, dir); + else if (!dev_is_dma_coherent(dev)) + for_each_sg(sgl, sg, nelems, i) arch_sync_dma_for_device(sg_phys(sg), sg->length, dir); - } } static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page, -- 2.33.0.685.g46640cef36-goog
WARNING: multiple messages have this Message-ID (diff)
From: David Stevens <stevensd@chromium.org> To: Robin Murphy <robin.murphy@arm.com>, Christoph Hellwig <hch@lst.de> Cc: linux-kernel@vger.kernel.org, Tom Murphy <murphyt7@tcd.ie>, iommu@lists.linux-foundation.org, David Stevens <stevensd@chromium.org>, Rajat Jain <rajatja@google.com>, Will Deacon <will@kernel.org> Subject: [PATCH v8 1/7] dma-iommu: fix sync_sg with swiotlb Date: Wed, 29 Sep 2021 11:32:54 +0900 [thread overview] Message-ID: <20210929023300.335969-2-stevensd@google.com> (raw) In-Reply-To: <20210929023300.335969-1-stevensd@google.com> From: David Stevens <stevensd@chromium.org> The is_swiotlb_buffer function takes the physical address of the swiotlb buffer, not the physical address of the original buffer. The sglist contains the physical addresses of the original buffer, so for the sync_sg functions to work properly when a bounce buffer might have been used, we need to use iommu_iova_to_phys to look up the physical address. This is what sync_single does, so call that function on each sglist segment. The previous code mostly worked because swiotlb does the transfer on map and unmap. However, any callers which use DMA_ATTR_SKIP_CPU_SYNC with sglists or which call sync_sg would not have had anything copied to the bounce buffer. Fixes: 82612d66d51d ("iommu: Allow the dma-iommu api to use bounce buffers") Signed-off-by: David Stevens <stevensd@chromium.org> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> --- drivers/iommu/dma-iommu.c | 33 +++++++++++++-------------------- 1 file changed, 13 insertions(+), 20 deletions(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 896bea04c347..c4d205b63c58 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -828,17 +828,13 @@ static void iommu_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg; int i; - if (dev_is_dma_coherent(dev) && !dev_is_untrusted(dev)) - return; - - for_each_sg(sgl, sg, nelems, i) { - if (!dev_is_dma_coherent(dev)) + if (dev_is_untrusted(dev)) + for_each_sg(sgl, sg, nelems, i) + iommu_dma_sync_single_for_cpu(dev, sg_dma_address(sg), + sg->length, dir); + else if (!dev_is_dma_coherent(dev)) + for_each_sg(sgl, sg, nelems, i) arch_sync_dma_for_cpu(sg_phys(sg), sg->length, dir); - - if (is_swiotlb_buffer(dev, sg_phys(sg))) - swiotlb_sync_single_for_cpu(dev, sg_phys(sg), - sg->length, dir); - } } static void iommu_dma_sync_sg_for_device(struct device *dev, @@ -848,17 +844,14 @@ static void iommu_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg; int i; - if (dev_is_dma_coherent(dev) && !dev_is_untrusted(dev)) - return; - - for_each_sg(sgl, sg, nelems, i) { - if (is_swiotlb_buffer(dev, sg_phys(sg))) - swiotlb_sync_single_for_device(dev, sg_phys(sg), - sg->length, dir); - - if (!dev_is_dma_coherent(dev)) + if (dev_is_untrusted(dev)) + for_each_sg(sgl, sg, nelems, i) + iommu_dma_sync_single_for_device(dev, + sg_dma_address(sg), + sg->length, dir); + else if (!dev_is_dma_coherent(dev)) + for_each_sg(sgl, sg, nelems, i) arch_sync_dma_for_device(sg_phys(sg), sg->length, dir); - } } static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page, -- 2.33.0.685.g46640cef36-goog _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2021-09-29 2:33 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-29 2:32 [PATCH v8 0/7] Fixes for dma-iommu swiotlb bounce buffers David Stevens 2021-09-29 2:32 ` David Stevens 2021-09-29 2:32 ` David Stevens [this message] 2021-09-29 2:32 ` [PATCH v8 1/7] dma-iommu: fix sync_sg with swiotlb David Stevens 2021-09-29 2:32 ` [PATCH v8 2/7] dma-iommu: fix arch_sync_dma for map David Stevens 2021-09-29 2:32 ` David Stevens 2021-09-29 2:32 ` [PATCH v8 3/7] dma-iommu: skip extra sync during unmap w/swiotlb David Stevens 2021-09-29 2:32 ` David Stevens 2021-09-29 2:32 ` [PATCH v8 4/7] dma-iommu: fold _swiotlb helpers into callers David Stevens 2021-09-29 2:32 ` David Stevens 2021-09-29 2:32 ` [PATCH v8 5/7] dma-iommu: Check CONFIG_SWIOTLB more broadly David Stevens 2021-09-29 2:32 ` David Stevens 2021-09-29 2:32 ` [PATCH v8 6/7] swiotlb: support aligned swiotlb buffers David Stevens 2021-09-29 2:32 ` David Stevens 2021-09-29 2:33 ` [PATCH v8 7/7] dma-iommu: account for min_align_mask w/swiotlb David Stevens 2021-09-29 2:33 ` David Stevens
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