Messages in this thread | | | Date | Mon, 22 Oct 2018 11:41:48 +0200 | From | Christoph Hellwig <> | Subject | Re: [PATCH] dma-direct: reject highmem pages from dma_alloc_from_contiguous |
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Any comments?
On Sun, Oct 14, 2018 at 08:14:47PM +0200, Christoph Hellwig wrote: > dma_alloc_from_contiguous can return highmem pages depending on the > setup, which a plain non-remapping DMA allocator can't handle. Detect > this case and try the normal page allocator instead. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > kernel/dma/direct.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c > index 87a6bc2a96c0..46fbaa49125b 100644 > --- a/kernel/dma/direct.c > +++ b/kernel/dma/direct.c > @@ -126,6 +126,18 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size, > if (gfpflags_allow_blocking(gfp)) { > page = dma_alloc_from_contiguous(dev, count, page_order, > gfp & __GFP_NOWARN); > + if (page && PageHighMem(page)) { > + /* > + * Depending on the cma= arguments and per-arch setup > + * dma_alloc_from_contiguous could return highmem > + * pages. Without remapping there is no way to return > + * them here, so log an error and fail. > + */ > + dev_info(dev, "Ignoring highmem page from CMA.\n"); > + dma_release_from_contiguous(dev, page, count); > + page = NULL; > + } > + > if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) { > dma_release_from_contiguous(dev, page, count); > page = NULL; > -- > 2.19.1 > > _______________________________________________ > iommu mailing list > iommu@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu ---end quoted text---
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