[PATCH] powerpc: Workaround for offb on 64 bits platforms

This fixes a problem with offb not parsing addresses properly on 64 bits
machines, and thus crashing at boot.  The problem is worked around by
locating the matching PCI device and using the properly relocated PCI
base addresses instead of misparsing the Open Firmware properties.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 35 insertions, 5 deletions

diff --git a/drivers/video/offb.c b/drivers/video/offb.c
index 2c856838694e..fe8ba364b3e8 100644
--- a/drivers/video/offb.c
+++ b/drivers/video/offb.c
@@ -325,8 +325,8 @@ static void __init offb_init_nodriver(struct device_node *dp)
         int *pp, i;
         unsigned int len;
         int width = 640, height = 480, depth = 8, pitch;
-        unsigned *up;
-        unsigned long address;
+        unsigned int rsize, *up;
+        unsigned long address = 0;
 
         if ((pp = (int *) get_property(dp, "depth", &len)) != NULL
             && len == sizeof(int))
@@ -344,10 +344,40 @@ static void __init offb_init_nodriver(struct device_node *dp)
                         pitch = 0x1000;
         } else
                 pitch = width;
-        if ((up = (unsigned *) get_property(dp, "address", &len)) != NULL
-            && len == sizeof(unsigned))
+
+       rsize = (unsigned long)pitch * (unsigned long)height *
+               (unsigned long)(depth / 8);
+
+       /* Try to match device to a PCI device in order to get a properly
+        * translated address rather then trying to decode the open firmware
+        * stuff in various incorrect ways
+        */
+#ifdef CONFIG_PCI
+       /* First try to locate the PCI device if any */
+       {
+               struct pci_dev *pdev = NULL;
+
+               for_each_pci_dev(pdev) {
+                       if (dp == pci_device_to_OF_node(pdev))
+                               break;
+               }
+               if (pdev) {
+                       for (i = 0; i < 6 && address == 0; i++) {
+                               if ((pci_resource_flags(pdev, i) &
+                                    IORESOURCE_MEM) &&
+                                   (pci_resource_len(pdev, i) >= rsize))
+                                       address = pci_resource_start(pdev, i);
+                       }
+                       pci_dev_put(pdev);
+               }
+        }
+#endif /* CONFIG_PCI */
+
+        if (address == 0 &&
+            (up = (unsigned *) get_property(dp, "address", &len)) != NULL &&
+            len == sizeof(unsigned))
                 address = (u_long) * up;
-        else {
+        if (address == 0) {
                 for (i = 0; i < dp->n_addrs; ++i)
                         if (dp->addrs[i].size >=
                             pitch * height * depth / 8)