[PATCH v6 12/19] swiotlb: don't assume that io_tlb_start-io_tlb_end is coherent
From: Stefano Stabellini <hidden>
Date: 2013-09-27 16:36:14
Also in:
lkml, xen-devel
Subsystem:
library code, the rest · Maintainers:
Andrew Morton, Linus Torvalds
The swiotlb code has appropriate calls to dma_mark_clean in place for buffers passed to swiotlb_map_page as an argument. However it assumes that the swiotlb bounce buffer (io_tlb_start-io_tlb_end) is already coherent and doesn't need any calls to dma_mark_clean. On ARM the swiotlb bounce buffer is not coherent (the memory is writealloc while it should be bufferable) and therefore we need to call dma_mark_clean appropriately on the bounce buffer code paths too. Note that most architecures have an empty dma_mark_clean implementation anyway. Signed-off-by: Stefano Stabellini <redacted> --- lib/swiotlb.c | 13 ++++++++++--- 1 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 4e8686c..eb45d17 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c@@ -515,6 +515,7 @@ found: io_tlb_orig_addr[index+i] = orig_addr + (i << IO_TLB_SHIFT); if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) swiotlb_bounce(orig_addr, tlb_addr, size, DMA_TO_DEVICE); + dma_mark_clean(phys_to_virt(tlb_addr), size); return tlb_addr; }
@@ -547,7 +548,10 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr, * First, sync the memory before unmapping the entry */ if (orig_addr && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL))) + { + dma_mark_clean(phys_to_virt(tlb_addr), size); swiotlb_bounce(orig_addr, tlb_addr, size, DMA_FROM_DEVICE); + } /* * Return the buffer to the free list by setting the corresponding
@@ -587,17 +591,20 @@ void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr, switch (target) { case SYNC_FOR_CPU: - if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)) + if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)) { + dma_mark_clean(phys_to_virt(tlb_addr), size); swiotlb_bounce(orig_addr, tlb_addr, size, DMA_FROM_DEVICE); + } else BUG_ON(dir != DMA_TO_DEVICE); break; case SYNC_FOR_DEVICE: - if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) + if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) { swiotlb_bounce(orig_addr, tlb_addr, size, DMA_TO_DEVICE); - else + dma_mark_clean(phys_to_virt(tlb_addr), size); + } else BUG_ON(dir != DMA_FROM_DEVICE); break; default:
--
1.7.2.5