Messages in this thread Patch in this message | | | From | David Stevens <> | Subject | [PATCH 1/2] dma-iommu: fix swiotlb SKIP_CPU_SYNC and arch sync | Date | Fri, 2 Jul 2021 14:37:41 +0900 |
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From: David Stevens <stevensd@chromium.org>
Make map_swiotlb and unmap_swiotlb only for mapping, and consistently use sync_single_for and sync_sg_for functions for swiotlb sync and arch sync. This ensures that the same code path is responsible for syncing regardless of whether or not SKIP_CPU_SYNC is set. In the process, fix various places where the original physical address and swiotlb tlb_addr are mixed up: - Make sync_sg functions call sync_single functions for untrusted devices, so they use tlb_addr when checking is_swiotlb_buffer and when doing arch sync if necessary. - Use tlb_addr for arch sync in map_page if necessary. - In map_sg, map before syncing so that arch sync can target the bounce buffer if necessary. - Pass SKIP_CPU_SYNC to swiotlb map and unmap to avoid double syncing the swiotlb. This had previously only happened in the unmap_page case, but is now necessary for all swiotlb cases.
Fixes: 82612d66d51d ("iommu: Allow the dma-iommu api to use bounce buffers") Signed-off-by: David Stevens <stevensd@chromium.org> --- drivers/iommu/dma-iommu.c | 82 ++++++++++++++++++++++++--------------- 1 file changed, 51 insertions(+), 31 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 7bcdd1205535..24d1042cd052 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -505,7 +505,8 @@ static void __iommu_dma_unmap_swiotlb(struct device *dev, dma_addr_t dma_addr, __iommu_dma_unmap(dev, dma_addr, size); if (unlikely(is_swiotlb_buffer(phys))) - swiotlb_tbl_unmap_single(dev, phys, size, dir, attrs); + swiotlb_tbl_unmap_single(dev, phys, size, dir, + attrs | DMA_ATTR_SKIP_CPU_SYNC); } static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys, @@ -536,7 +537,8 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys, static dma_addr_t __iommu_dma_map_swiotlb(struct device *dev, phys_addr_t phys, size_t org_size, dma_addr_t dma_mask, bool coherent, - enum dma_data_direction dir, unsigned long attrs) + enum dma_data_direction dir, unsigned long attrs, + phys_addr_t *adj_phys) { int prot = dma_info_to_prot(dir, coherent, attrs); struct iommu_domain *domain = iommu_get_dma_domain(dev); @@ -555,7 +557,8 @@ static dma_addr_t __iommu_dma_map_swiotlb(struct device *dev, phys_addr_t phys, iova_offset(iovad, phys | org_size)) { aligned_size = iova_align(iovad, org_size); phys = swiotlb_tbl_map_single(dev, phys, org_size, - aligned_size, dir, attrs); + aligned_size, dir, + attrs | DMA_ATTR_SKIP_CPU_SYNC); if (phys == DMA_MAPPING_ERROR) return DMA_MAPPING_ERROR; @@ -573,6 +576,8 @@ static dma_addr_t __iommu_dma_map_swiotlb(struct device *dev, phys_addr_t phys, memset(padding_start, 0, padding_size); } + if (adj_phys) + *adj_phys = phys; iova = __iommu_dma_map(dev, phys, aligned_size, prot, dma_mask); if (iova == DMA_MAPPING_ERROR && is_swiotlb_buffer(phys)) @@ -785,15 +790,17 @@ static void iommu_dma_sync_single_for_cpu(struct device *dev, swiotlb_sync_single_for_cpu(dev, phys, size, dir); } -static void iommu_dma_sync_single_for_device(struct device *dev, - dma_addr_t dma_handle, size_t size, enum dma_data_direction dir) +static void __iommu_dma_sync_single_for_device(struct device *dev, + dma_addr_t dma_handle, size_t size, + enum dma_data_direction dir, phys_addr_t phys) { - phys_addr_t phys; - if (dev_is_dma_coherent(dev) && !dev_is_untrusted(dev)) return; - phys = iommu_iova_to_phys(iommu_get_dma_domain(dev), dma_handle); + if (phys == 0) + phys = iommu_iova_to_phys(iommu_get_dma_domain(dev), + dma_handle); + if (is_swiotlb_buffer(phys)) swiotlb_sync_single_for_device(dev, phys, size, dir); @@ -801,6 +808,12 @@ static void iommu_dma_sync_single_for_device(struct device *dev, arch_sync_dma_for_device(phys, size, dir); } +static void iommu_dma_sync_single_for_device(struct device *dev, + dma_addr_t dma_handle, size_t size, enum dma_data_direction dir) +{ + __iommu_dma_sync_single_for_device(dev, dma_handle, size, dir, 0); +} + static void iommu_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sgl, int nelems, enum dma_data_direction dir) @@ -811,14 +824,13 @@ static void iommu_dma_sync_sg_for_cpu(struct device *dev, 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 + for_each_sg(sgl, sg, nelems, i) arch_sync_dma_for_cpu(sg_phys(sg), sg->length, dir); - - if (is_swiotlb_buffer(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, @@ -831,29 +843,30 @@ static void iommu_dma_sync_sg_for_device(struct device *dev, if (dev_is_dma_coherent(dev) && !dev_is_untrusted(dev)) return; - for_each_sg(sgl, sg, nelems, i) { - if (is_swiotlb_buffer(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, 0); + else + 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, unsigned long offset, size_t size, enum dma_data_direction dir, unsigned long attrs) { - phys_addr_t phys = page_to_phys(page) + offset; + phys_addr_t phys = page_to_phys(page) + offset, adj_phys; bool coherent = dev_is_dma_coherent(dev); dma_addr_t dma_handle; - dma_handle = __iommu_dma_map_swiotlb(dev, phys, size, dma_get_mask(dev), - coherent, dir, attrs); - if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) && + dma_handle = __iommu_dma_map_swiotlb(dev, phys, size, + dma_get_mask(dev), coherent, dir, attrs, &adj_phys); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && dma_handle != DMA_MAPPING_ERROR) - arch_sync_dma_for_device(phys, size, dir); + __iommu_dma_sync_single_for_device(dev, dma_handle, size, + dir, adj_phys); return dma_handle; } @@ -960,7 +973,7 @@ static int iommu_dma_map_sg_swiotlb(struct device *dev, struct scatterlist *sg, for_each_sg(sg, s, nents, i) { sg_dma_address(s) = __iommu_dma_map_swiotlb(dev, sg_phys(s), s->length, dma_get_mask(dev), - dev_is_dma_coherent(dev), dir, attrs); + dev_is_dma_coherent(dev), dir, attrs, NULL); if (sg_dma_address(s) == DMA_MAPPING_ERROR) goto out_unmap; sg_dma_len(s) = s->length; @@ -991,17 +1004,24 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, dma_addr_t iova; size_t iova_len = 0; unsigned long mask = dma_get_seg_boundary(dev); - int i; + int i, early_mapped = 0; if (static_branch_unlikely(&iommu_deferred_attach_enabled) && iommu_deferred_attach(dev, domain)) return 0; + if (dev_is_untrusted(dev)) { + early_mapped = iommu_dma_map_sg_swiotlb(dev, sg, nents, + dir, attrs); + if (!early_mapped) + return 0; + } + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) iommu_dma_sync_sg_for_device(dev, sg, nents, dir); - if (dev_is_untrusted(dev)) - return iommu_dma_map_sg_swiotlb(dev, sg, nents, dir, attrs); + if (early_mapped) + return early_mapped; /* * Work out how much IOVA space we need, and align the segments to -- 2.32.0.93.g670b81a890-goog
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