2 files changed, 16 insertions, 2 deletions

diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index 4a5397bfce27..7f225a4b2a26 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -255,9 +255,11 @@ static inline unsigned long dma_alloc_coherent_mask(struct device *dev,
 
 static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp)
 {
-#ifdef CONFIG_X86_64
         unsigned long dma_mask = dma_alloc_coherent_mask(dev, gfp);
 
+        if (dma_mask <= DMA_24BIT_MASK)
+                gfp |= GFP_DMA;
+#ifdef CONFIG_X86_64
         if (dma_mask <= DMA_32BIT_MASK && !(gfp & GFP_DMA))
                 gfp |= GFP_DMA32;
 #endif
diff --git a/arch/x86/kernel/pci-swiotlb_64.c b/arch/x86/kernel/pci-swiotlb_64.c
index c4ce0332759e..3c539d111abb 100644
--- a/arch/x86/kernel/pci-swiotlb_64.c
+++ b/arch/x86/kernel/pci-swiotlb_64.c
@@ -18,9 +18,21 @@ swiotlb_map_single_phys(struct device *hwdev, phys_addr_t paddr, size_t size,
         return swiotlb_map_single(hwdev, phys_to_virt(paddr), size, direction);
 }
 
+static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
+                                        dma_addr_t *dma_handle, gfp_t flags)
+{
+        void *vaddr;
+
+        vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags);
+        if (vaddr)
+                return vaddr;
+
+        return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
+}
+
 struct dma_mapping_ops swiotlb_dma_ops = {
         .mapping_error = swiotlb_dma_mapping_error,
-        .alloc_coherent = swiotlb_alloc_coherent,
+        .alloc_coherent = x86_swiotlb_alloc_coherent,
         .free_coherent = swiotlb_free_coherent,
         .map_single = swiotlb_map_single_phys,
         .unmap_single = swiotlb_unmap_single,