From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefano Stabellini Subject: [PATCH v5 13/13] swiotlb: don't assume that io_tlb_start-io_tlb_end is coherent Date: Thu, 29 Aug 2013 19:32:34 +0100 Message-ID: <1377801154-29215-13-git-send-email-stefano.stabellini@eu.citrix.com> References: Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: xen-devel@lists.xensource.com Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, konrad.wilk@oracle.com, Stefano.Stabellini@eu.citrix.com, Ian.Campbell@citrix.com, Stefano Stabellini List-Id: xen-devel@lists.xenproject.org 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 --- lib/swiotlb.c | 12 +++++++++--- 1 files changed, 9 insertions(+), 3 deletions(-) diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 4e8686c..b1f43f6 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -547,7 +547,10 @@ 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 +590,20 @@ 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