1 files changed, 27 insertions, 14 deletions

diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c
index f82710a8694d..098360d7ff81 100644
--- a/drivers/pci/proc.c
+++ b/drivers/pci/proc.c
@@ -202,6 +202,8 @@ static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd,
 
 #ifdef HAVE_PCI_MMAP
         case PCIIOC_MMAP_IS_IO:
+                if (!arch_can_pci_mmap_io())
+                        return -EINVAL;
                 fpriv->mmap_state = pci_mmap_io;
                 break;
 
@@ -210,14 +212,15 @@ static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd,
                 break;
 
         case PCIIOC_WRITE_COMBINE:
-                if (arg)
-                        fpriv->write_combine = 1;
-                else
-                        fpriv->write_combine = 0;
-                break;
-
+                if (arch_can_pci_mmap_wc()) {
+                        if (arg)
+                                fpriv->write_combine = 1;
+                        else
+                                fpriv->write_combine = 0;
+                        break;
+                }
+                /* If arch decided it can't, fall through... */
 #endif /* HAVE_PCI_MMAP */
-
         default:
                 ret = -EINVAL;
                 break;
@@ -231,25 +234,35 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma)
 {
         struct pci_dev *dev = PDE_DATA(file_inode(file));
         struct pci_filp_private *fpriv = file->private_data;
-        int i, ret, write_combine;
+        int i, ret, write_combine = 0, res_bit = IORESOURCE_MEM;
 
         if (!capable(CAP_SYS_RAWIO))
                 return -EPERM;
 
+        if (fpriv->mmap_state == pci_mmap_io) {
+                if (!arch_can_pci_mmap_io())
+                        return -EINVAL;
+                res_bit = IORESOURCE_IO;
+        }
+
         /* Make sure the caller is mapping a real resource for this device */
         for (i = 0; i < PCI_ROM_RESOURCE; i++) {
-                if (pci_mmap_fits(dev, i, vma,  PCI_MMAP_PROCFS))
+                if (dev->resource[i].flags & res_bit &&
+                    pci_mmap_fits(dev, i, vma,  PCI_MMAP_PROCFS))
                         break;
         }
 
         if (i >= PCI_ROM_RESOURCE)
                 return -ENODEV;
 
-        if (fpriv->mmap_state == pci_mmap_mem)
-                write_combine = fpriv->write_combine;
-        else
-                write_combine = 0;
-        ret = pci_mmap_page_range(dev, vma,
+        if (fpriv->mmap_state == pci_mmap_mem &&
+            fpriv->write_combine) {
+                if (dev->resource[i].flags & IORESOURCE_PREFETCH)
+                        write_combine = 1;
+                else
+                        return -EINVAL;
+        }
+        ret = pci_mmap_page_range(dev, i, vma,
                                   fpriv->mmap_state, write_combine);
         if (ret < 0)
                 return ret;