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 <[email protected]>
---
 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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