x86: return conditional to mmu

Just return our allocation if we don't have an mmu. For i386, where this patch
is being applied, we never have. So our goal is just to have the code to look like
x86_64's.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/pci-dma_32.c b/arch/x86/kernel/pci-dma_32.c
index 5450bd142cb0a568ba0df5e9ff832f834bfb8b9f..f134de3833a2552c1e0a6fa0a31fe477aaa4cb94 100644 (file)
--- 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);