Messages in this thread Patch in this message | | | From | Christoph Hellwig <> | Subject | [PATCH 2/9] dma-direct: reject highmem pages from dma_alloc_from_contiguous | Date | Mon, 5 Nov 2018 13:19:24 +0100 |
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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 680287779b0a..c49849bcced6 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -162,6 +162,18 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size, if (!page) return NULL; + if (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, "Rejecting highmem page from CMA.\n"); + __dma_direct_free_pages(dev, size, page); + return NULL; + } + ret = page_address(page); if (force_dma_unencrypted()) { set_memory_decrypted((unsigned long)ret, 1 << get_order(size)); -- 2.19.1
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