diff options
Diffstat (limited to 'kernel/dma/swiotlb.c')
| -rw-r--r-- | kernel/dma/swiotlb.c | 23 |
1 files changed, 8 insertions, 15 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 6db1c475ec82..bfc56cb21705 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -627,14 +627,10 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, for (i = 0; i < nr_slots(alloc_size + offset); i++) mem->slots[index + i].orig_addr = slot_addr(orig_addr, i); tlb_addr = slot_addr(mem->start, index) + offset; - /* - * When dir == DMA_FROM_DEVICE we could omit the copy from the orig - * to the tlb buffer, if we knew for sure the device will - * overwirte the entire current content. But we don't. Thus - * unconditional bounce may prevent leaking swiotlb content (i.e. - * kernel memory) to user-space. - */ - swiotlb_bounce(dev, tlb_addr, mapping_size, DMA_TO_DEVICE); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && + (!(attrs & DMA_ATTR_OVERWRITE) || dir == DMA_TO_DEVICE || + dir == DMA_BIDIRECTIONAL)) + swiotlb_bounce(dev, tlb_addr, mapping_size, DMA_TO_DEVICE); return tlb_addr; } @@ -701,13 +697,10 @@ void swiotlb_tbl_unmap_single(struct device *dev, phys_addr_t tlb_addr, void swiotlb_sync_single_for_device(struct device *dev, phys_addr_t tlb_addr, size_t size, enum dma_data_direction dir) { - /* - * Unconditional bounce is necessary to avoid corruption on - * sync_*_for_cpu or dma_ummap_* when the device didn't overwrite - * the whole lengt of the bounce buffer. - */ - swiotlb_bounce(dev, tlb_addr, size, DMA_TO_DEVICE); - BUG_ON(!valid_dma_direction(dir)); + if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) + swiotlb_bounce(dev, tlb_addr, size, DMA_TO_DEVICE); + else + BUG_ON(dir != DMA_FROM_DEVICE); } void swiotlb_sync_single_for_cpu(struct device *dev, phys_addr_t tlb_addr, |