--- setup-bus.c 2007-02-19 22:34:32.000000000 -0800
+++ setup-bus.c.new     2007-09-05 10:02:34.000000000 -0700
@@ -156,6 +156,7 @@
        struct pci_dev *bridge = bus->self;
        struct pci_bus_region region;
        u32 l, io_upper16;
+       u32 pref_upper32, pref_limit_upper32;

        DBG(KERN_INFO "PCI: Bridge: %s\n", pci_name(bridge));

@@ -209,17 +210,21 @@
        if (bus->resource[2]->flags & IORESOURCE_PREFETCH) {
                l = (region.start >> 16) & 0xfff0;
                l |= region.end & 0xfff00000;
+               pref_upper32 = region.start >> 32;
+               pref_limit_upper32 = region.end >> 32;
                DBG(KERN_INFO "  PREFETCH window: %08lx-%08lx\n",
                                region.start, region.end);
        }
        else {
                l = 0x0000fff0;
+               pref_upper32 = pref_limit_upper32 = 0;
                DBG(KERN_INFO "  PREFETCH window: disabled.\n");
        }
        pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l);

-       /* Clear out the upper 32 bits of PREF base. */
-       pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, 0);
+       pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, pref_upper32);
+
+       pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, pref_limit_upper32);

        pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, bus->bridge_ctl);
 }