powerpc/PCI: register busn_res for root buses

Add the host bridge bus number aperture to the resource list.
Like the MMIO and I/O port apertures, this is used when assigning
resources to hot-added devices or in the case of conflicts.

[bhelgaas: changelog]
CC: Paul Mackerras <paulus@samba.org>
CC: linuxppc-dev@lists.ozlabs.org
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

arch/powerpc/include/asm/pci-bridge.h

@@ -30,6 +30,7 @@ struct pci_controller {
 	int first_busno;
 	int last_busno;
 	int self_busno;
+	struct resource busn;
 
 	void __iomem *io_base_virt;
 #ifdef CONFIG_PPC64

arch/powerpc/kernel/pci-common.c

@@ -1637,6 +1637,11 @@ void __devinit pcibios_scan_phb(struct pci_controller *hose)
 	/* Wire up PHB bus resources */
 	pcibios_setup_phb_resources(hose, &resources);
 
+	hose->busn.start = hose->first_busno;
+	hose->busn.end	 = hose->last_busno;
+	hose->busn.flags = IORESOURCE_BUS;
+	pci_add_resource(&resources, &hose->busn);
+
 	/* Create an empty bus for the toplevel */
 	bus = pci_create_root_bus(hose->parent, hose->first_busno,
 				  hose->ops, hose, &resources);
@@ -1646,21 +1651,21 @@ void __devinit pcibios_scan_phb(struct pci_controller *hose)
 		pci_free_resource_list(&resources);
 		return;
 	}
-	bus->busn_res.start = hose->first_busno;
 	hose->bus = bus;
 
 	/* Get probe mode and perform scan */
 	mode = PCI_PROBE_NORMAL;
 	if (node && ppc_md.pci_probe_mode)
 		mode = ppc_md.pci_probe_mode(bus);
 	pr_debug("    probe mode: %d\n", mode);
-	if (mode == PCI_PROBE_DEVTREE) {
-		bus->busn_res.end = hose->last_busno;
+	if (mode == PCI_PROBE_DEVTREE)
 		of_scan_bus(node, bus);
-	}
 
-	if (mode == PCI_PROBE_NORMAL)
-		hose->last_busno = bus->busn_res.end = pci_scan_child_bus(bus);
+	if (mode == PCI_PROBE_NORMAL) {
+		pci_bus_update_busn_res_end(bus, 255);
+		hose->last_busno = pci_scan_child_bus(bus);
+		pci_bus_update_busn_res_end(bus, hose->last_busno);
+	}
 
 	/* Platform gets a chance to do some global fixups before
 	 * we proceed to resource allocation

arch/powerpc/kernel/pci_of_scan.c

@@ -240,7 +240,7 @@ void __devinit of_scan_pci_bridge(struct pci_dev *dev)
 	}
 
 	bus->primary = dev->bus->number;
-	bus->busn_res.end = busrange[1];
+	pci_bus_insert_busn_res(bus, busrange[0], busrange[1]);
 	bus->bridge_ctl = 0;
 
 	/* parse ranges property */