res->flags |= pci_calc_resource_flags(l) | IORESOURCE_SIZEALIGN;
                if (type == pci_bar_io) {
                        l &= PCI_BASE_ADDRESS_IO_MASK;
-                       mask = PCI_BASE_ADDRESS_IO_MASK & 0xffff;
+                       mask = PCI_BASE_ADDRESS_IO_MASK & IO_SPACE_LIMIT;
                } else {
                        l &= PCI_BASE_ADDRESS_MEM_MASK;
                        mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
                        dev_printk(KERN_DEBUG, &dev->dev,
                                "reg %x 64bit mmio: %pR\n", pos, res);
                }
+
+               res->flags |= IORESOURCE_MEM_64;
        } else {
                sz = pci_size(l, sz, mask);
 
                }
        }
        if (base <= limit) {
-               res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM | IORESOURCE_PREFETCH;
+               res->flags = (mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) |
+                                        IORESOURCE_MEM | IORESOURCE_PREFETCH;
+               if (res->flags & PCI_PREF_RANGE_TYPE_64)
+                       res->flags |= IORESOURCE_MEM_64;
                res->start = base;
                res->end = limit + 0xfffff;
                dev_printk(KERN_DEBUG, &dev->dev, "bridge %sbit mmio pref: %pR\n",
 
        struct pci_dev *bridge = bus->self;
        struct pci_bus_region region;
        u32 l, bu, lu, io_upper16;
+       int pref_mem64;
 
        if (pci_is_enabled(bridge))
                return;
        pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, 0);
 
        /* Set up PREF base/limit. */
+       pref_mem64 = 0;
        bu = lu = 0;
        pcibios_resource_to_bus(bridge, ®ion, bus->resource[2]);
        if (bus->resource[2]->flags & IORESOURCE_PREFETCH) {
+               int width = 8;
                l = (region.start >> 16) & 0xfff0;
                l |= region.end & 0xfff00000;
-               bu = upper_32_bits(region.start);
-               lu = upper_32_bits(region.end);
-               dev_info(&bridge->dev, "  PREFETCH window: %#016llx-%#016llx\n",
-                   (unsigned long long)region.start,
-                   (unsigned long long)region.end);
+               if (bus->resource[2]->flags & IORESOURCE_MEM_64) {
+                       pref_mem64 = 1;
+                       bu = upper_32_bits(region.start);
+                       lu = upper_32_bits(region.end);
+                       width = 16;
+               }
+               dev_info(&bridge->dev, "  PREFETCH window: %#0*llx-%#0*llx\n",
+                               width, (unsigned long long)region.start,
+                               width, (unsigned long long)region.end);
        }
        else {
                l = 0x0000fff0;
        }
        pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l);
 
-       /* Set the upper 32 bits of PREF base & limit. */
-       pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, bu);
-       pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, lu);
+       if (pref_mem64) {
+               /* Set the upper 32 bits of PREF base & limit. */
+               pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, bu);
+               pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, lu);
+       }
 
        pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, bus->bridge_ctl);
 }
                pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
                pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0);
        }
-       if (pmem)
+       if (pmem) {
                b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
+               if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64)
+                       b_res[2].flags |= IORESOURCE_MEM_64;
+       }
+
+       /* double check if bridge does support 64 bit pref */
+       if (b_res[2].flags & IORESOURCE_MEM_64) {
+               u32 mem_base_hi, tmp;
+               pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32,
+                                        &mem_base_hi);
+               pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
+                                              0xffffffff);
+               pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp);
+               if (!tmp)
+                       b_res[2].flags &= ~IORESOURCE_MEM_64;
+               pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
+                                      mem_base_hi);
+       }
 }
 
 /* Helper function for sizing routines: find first available
        resource_size_t aligns[12];     /* Alignments from 1Mb to 2Gb */
        int order, max_order;
        struct resource *b_res = find_free_bus_resource(bus, type);
+       unsigned int mem64_mask = 0;
 
        if (!b_res)
                return 0;
        max_order = 0;
        size = 0;
 
+       mem64_mask = b_res->flags & IORESOURCE_MEM_64;
+       b_res->flags &= ~IORESOURCE_MEM_64;
+
        list_for_each_entry(dev, &bus->devices, bus_list) {
                int i;
-               
+
                for (i = 0; i < PCI_NUM_RESOURCES; i++) {
                        struct resource *r = &dev->resource[i];
                        resource_size_t r_size;
                                aligns[order] += align;
                        if (order > max_order)
                                max_order = order;
+                       mem64_mask &= r->flags & IORESOURCE_MEM_64;
                }
        }
 
        b_res->start = min_align;
        b_res->end = size + min_align - 1;
        b_res->flags |= IORESOURCE_STARTALIGN;
+       b_res->flags |= mem64_mask;
        return 1;
 }