Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Christoph Hellwig <> | Subject | [PATCH] dma-direct: reject highmem pages from dma_alloc_from_contiguous | Date | Sun, 14 Oct 2018 20:14:47 +0200 |
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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
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