dma-direct: don't fail on highmem CMA pages in dma_direct_alloc_pages

[ Upstream commit 92826e967535db2eb117db227b1191aaf98e4bb3 ]

When dma_direct_alloc_pages encounters a highmem page it just gives up
currently.  But what we really should do is to try memory using the
page allocator instead - without this platforms with a global highmem
CMA pool will fail all dma_alloc_pages allocations.

Fixes: efa70f2fdc84 ("dma-mapping: add a new dma_alloc_pages API")
Reported-by: Mark O'Neill <mao@tumblingdice.co.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index ddaac01..a1573ed 100644 (file)
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -85,7 +85,7 @@ static void __dma_direct_free_pages(struct device *dev, struct page *page,
 }
 
 static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
-               gfp_t gfp)
+               gfp_t gfp, bool allow_highmem)
 {
        int node = dev_to_node(dev);
        struct page *page = NULL;
@@ -106,9 +106,12 @@ static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
        }
 
        page = dma_alloc_contiguous(dev, size, gfp);
-       if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {
-               dma_free_contiguous(dev, page, size);
-               page = NULL;
+       if (page) {
+               if (!dma_coherent_ok(dev, page_to_phys(page), size) ||
+                   (!allow_highmem && PageHighMem(page))) {
+                       dma_free_contiguous(dev, page, size);
+                       page = NULL;
+               }
        }
 again:
        if (!page)
@@ -154,7 +157,7 @@ static void *dma_direct_alloc_no_mapping(struct device *dev, size_t size,
 {
        struct page *page;
 
-       page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO);
+       page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO, true);
        if (!page)
                return NULL;
 
@@ -209,7 +212,7 @@ void *dma_direct_alloc(struct device *dev, size_t size,
                return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
 
        /* we always manually zero the memory once we are done */
-       page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO);
+       page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO, true);
        if (!page)
                return NULL;
 
@@ -335,19 +338,9 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size,
            !is_swiotlb_for_alloc(dev))
                return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
 
-       page = __dma_direct_alloc_pages(dev, size, gfp);
+       page = __dma_direct_alloc_pages(dev, size, gfp, false);
        if (!page)
                return NULL;
-       if (PageHighMem(page)) {
-               /*
-                * Depending on the cma= arguments and per-arch setup
-                * dma_alloc_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");
-               goto out_free_pages;
-       }
 
        ret = page_address(page);
        if (force_dma_unencrypted(dev)) {