1 files changed, 32 insertions, 2 deletions

diff --git a/arch/x86/kernel/pci-dma_32.c b/arch/x86/kernel/pci-dma_32.c
index 5450bd142cb0..f134de3833a2 100644
--- a/arch/x86/kernel/pci-dma_32.c
+++ b/arch/x86/kernel/pci-dma_32.c
@@ -116,12 +116,42 @@ again:
                                 gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
                                 goto again;
                         }
+
+                        /* Let low level make its own zone decisions */
+                        gfp &= ~(GFP_DMA32|GFP_DMA);
+
+                        if (dma_ops->alloc_coherent)
+                                return dma_ops->alloc_coherent(dev, size,
+                                                           dma_handle, gfp);
+                        return NULL;
+
                 }
                 memset(ret, 0, size);
-                *dma_handle = bus;
+                if (!mmu) {
+                        *dma_handle = bus;
+                        return ret;
+                }
+        }
+
+        if (dma_ops->alloc_coherent) {
+                free_pages((unsigned long)ret, get_order(size));
+                gfp &= ~(GFP_DMA|GFP_DMA32);
+                return dma_ops->alloc_coherent(dev, size, dma_handle, gfp);
+        }
+
+        if (dma_ops->map_simple) {
+                *dma_handle = dma_ops->map_simple(dev, virt_to_phys(ret),
+                                              size,
+                                              PCI_DMA_BIDIRECTIONAL);
+                if (*dma_handle != bad_dma_address)
+                        return ret;
         }
 
-        return ret;
+        if (panic_on_overflow)
+                panic("dma_alloc_coherent: IOMMU overflow by %lu bytes\n",
+                      (unsigned long)size);
+        free_pages((unsigned long)ret, get_order(size));
+        return NULL;
 }
 EXPORT_SYMBOL(dma_alloc_coherent);