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| author | David Stevens <stevensd@chromium.org> | 2021-09-29 11:32:59 +0900 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2021-09-29 12:50:34 +0200 |
| commit | e81e99bacc9f9347bda7808a949c1ce9fcc2bbf4 (patch) | |
| tree | a32ae98bfc2d166e2eb38dff191cddee25e72d63 /kernel/dma | |
| parent | 2e727bffbe93750a13d2414f3ce43de2f21600d2 (diff) | |
| download | linux-e81e99bacc9f9347bda7808a949c1ce9fcc2bbf4.tar.gz | |
swiotlb: Support aligned swiotlb buffers
Add an argument to swiotlb_tbl_map_single that specifies the desired alignment of the allocated buffer. This is used by dma-iommu to ensure the buffer is aligned to the iova granule size when using swiotlb with untrusted sub-granule mappings. This addresses an issue where adjacent slots could be exposed to the untrusted device if IO_TLB_SIZE < iova granule < PAGE_SIZE. Signed-off-by: David Stevens <stevensd@chromium.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210929023300.335969-7-stevensd@google.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'kernel/dma')
| -rw-r--r-- | kernel/dma/swiotlb.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 87c40517e822..019672b3da1d 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -459,7 +459,7 @@ static unsigned int wrap_index(struct io_tlb_mem *mem, unsigned int index) * allocate a buffer from that IO TLB pool. */ static int swiotlb_find_slots(struct device *dev, phys_addr_t orig_addr, - size_t alloc_size) + size_t alloc_size, unsigned int alloc_align_mask) { struct io_tlb_mem *mem = dev->dma_io_tlb_mem; unsigned long boundary_mask = dma_get_seg_boundary(dev); @@ -483,6 +483,7 @@ static int swiotlb_find_slots(struct device *dev, phys_addr_t orig_addr, stride = (iotlb_align_mask >> IO_TLB_SHIFT) + 1; if (alloc_size >= PAGE_SIZE) stride = max(stride, stride << (PAGE_SHIFT - IO_TLB_SHIFT)); + stride = max(stride, (alloc_align_mask >> IO_TLB_SHIFT) + 1); spin_lock_irqsave(&mem->lock, flags); if (unlikely(nslots > mem->nslabs - mem->used)) @@ -541,7 +542,8 @@ found: phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, size_t mapping_size, size_t alloc_size, - enum dma_data_direction dir, unsigned long attrs) + unsigned int alloc_align_mask, enum dma_data_direction dir, + unsigned long attrs) { struct io_tlb_mem *mem = dev->dma_io_tlb_mem; unsigned int offset = swiotlb_align_offset(dev, orig_addr); @@ -561,7 +563,8 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, return (phys_addr_t)DMA_MAPPING_ERROR; } - index = swiotlb_find_slots(dev, orig_addr, alloc_size + offset); + index = swiotlb_find_slots(dev, orig_addr, + alloc_size + offset, alloc_align_mask); if (index == -1) { if (!(attrs & DMA_ATTR_NO_WARN)) dev_warn_ratelimited(dev, @@ -675,7 +678,7 @@ dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size, trace_swiotlb_bounced(dev, phys_to_dma(dev, paddr), size, swiotlb_force); - swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, size, dir, + swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, size, 0, dir, attrs); if (swiotlb_addr == (phys_addr_t)DMA_MAPPING_ERROR) return DMA_MAPPING_ERROR; @@ -759,7 +762,7 @@ struct page *swiotlb_alloc(struct device *dev, size_t size) if (!mem) return NULL; - index = swiotlb_find_slots(dev, 0, size); + index = swiotlb_find_slots(dev, 0, size, 0); if (index == -1) return NULL; |