Index: linux/drivers/pci/probe.c
===================================================================
--- linux.orig/drivers/pci/probe.c
+++ linux/drivers/pci/probe.c
@@ -1632,18 +1632,17 @@ unsigned int pci_scan_child_bus(struct p
 	return max;
 }
 
-struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
-		struct pci_ops *ops, void *sysdata, struct list_head *resources)
+/**
+ * pci_alloc_root - Allocate memory for PCI root bus and bridge representations.
+ * @bus: Bus number of the root bus.
+ * @ops: Root bus operations.
+ * @sysdata: Architecture-specific data.
+ */
+struct pci_host_bridge *pci_alloc_root(int bus, struct pci_ops *ops,
+				       void *sysdata)
 {
-	int error;
 	struct pci_host_bridge *bridge;
 	struct pci_bus *b, *b2;
-	struct pci_host_bridge_window *window, *n;
-	struct resource *res;
-	resource_size_t offset;
-	char bus_addr[64];
-	char *fmt;
-
 
 	b = pci_alloc_bus();
 	if (!b)
@@ -1651,16 +1650,43 @@ struct pci_bus *pci_create_root_bus(stru
 
 	b->sysdata = sysdata;
 	b->ops = ops;
+	b->number = bus;
 	b2 = pci_find_bus(pci_domain_nr(b), bus);
 	if (b2) {
-		/* If we already got to this bus through a different bridge, ignore it */
+		/*
+		 * If we already got to this bus through a different bridge,
+		 * ignore it.
+		 */
 		dev_dbg(&b2->dev, "bus already known\n");
-		goto err_out;
+	} else {
+		bridge = pci_alloc_host_bridge(b);
+		if (bridge)
+			return bridge;
 	}
 
-	bridge = pci_alloc_host_bridge(b);
-	if (!bridge)
-		goto err_out;
+	kfree(b);
+	return NULL;
+}
+
+/**
+ * pci_add_root - Register PCI root bridge and root bus.
+ * @bridge: Bridge to register.
+ * @parent: Parent device of the bridge.
+ * @resources: Bridge resources.
+ *
+ * Register PCI root bridge and bus allocated by %pci_alloc_root().
+ */
+struct pci_bus *pci_add_root(struct pci_host_bridge *bridge,
+			     struct device *parent, struct list_head *resources)
+{
+	int error;
+	struct pci_bus *b = bridge->bus;
+	struct pci_host_bridge_window *window, *n;
+	struct resource *res;
+	resource_size_t offset;
+	char bus_addr[64];
+	int bus = b->number;
+	char *fmt;
 
 	bridge->dev.parent = parent;
 	bridge->dev.release = pci_release_bus_bridge_dev;
@@ -1668,6 +1694,7 @@ struct pci_bus *pci_create_root_bus(stru
 	error = device_register(&bridge->dev);
 	if (error)
 		goto bridge_dev_reg_err;
+
 	b->bridge = get_device(&bridge->dev);
 	device_enable_async_suspend(b->bridge);
 	pci_set_bus_of_node(b);
@@ -1685,7 +1712,7 @@ struct pci_bus *pci_create_root_bus(stru
 	/* Create legacy_io and legacy_mem files for this bus */
 	pci_create_legacy_files(b);
 
-	b->number = b->busn_res.start = bus;
+	b->busn_res.start = bus;
 
 	if (parent)
 		dev_info(parent, "PCI host bridge to bus %s\n", dev_name(&b->dev));
@@ -1725,11 +1752,18 @@ class_dev_reg_err:
 	device_unregister(&bridge->dev);
 bridge_dev_reg_err:
 	kfree(bridge);
-err_out:
 	kfree(b);
 	return NULL;
 }
 
+struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
+		struct pci_ops *ops, void *sysdata, struct list_head *resources)
+{
+	struct pci_host_bridge *bridge = pci_alloc_root(bus, ops, sysdata);
+
+	return bridge ? pci_add_root(bridge, parent, resources) : NULL;
+}
+
 int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max)
 {
 	struct resource *res = &b->busn_res;
Index: linux/drivers/pci/pci-acpi.c
===================================================================
--- linux.orig/drivers/pci/pci-acpi.c
+++ linux/drivers/pci/pci-acpi.c
@@ -302,24 +302,6 @@ static int acpi_pci_find_device(struct d
 	return 0;
 }
 
-static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle)
-{
-	int num;
-	unsigned int seg, bus;
-
-	/*
-	 * The string should be the same as root bridge's name
-	 * Please look at 'pci_scan_bus_parented'
-	 */
-	num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus);
-	if (num != 2)
-		return -ENODEV;
-	*handle = acpi_get_pci_rootbridge_handle(seg, bus);
-	if (!*handle)
-		return -ENODEV;
-	return 0;
-}
-
 static void pci_acpi_setup(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
@@ -378,7 +360,6 @@ static void pci_acpi_cleanup(struct devi
 static struct acpi_bus_type acpi_pci_bus = {
 	.bus = &pci_bus_type,
 	.find_device = acpi_pci_find_device,
-	.find_bridge = acpi_pci_find_root_bridge,
 	.setup = pci_acpi_setup,
 	.cleanup = pci_acpi_cleanup,
 };
Index: linux/drivers/acpi/pci_root.c
===================================================================
--- linux.orig/drivers/acpi/pci_root.c
+++ linux/drivers/acpi/pci_root.c
@@ -107,24 +107,6 @@ void acpi_pci_unregister_driver(struct a
 }
 EXPORT_SYMBOL(acpi_pci_unregister_driver);
 
-acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
-{
-	struct acpi_pci_root *root;
-	acpi_handle handle = NULL;
-	
-	mutex_lock(&acpi_pci_root_lock);
-	list_for_each_entry(root, &acpi_pci_roots, node)
-		if ((root->segment == (u16) seg) &&
-		    (root->secondary.start == (u16) bus)) {
-			handle = root->device->handle;
-			break;
-		}
-	mutex_unlock(&acpi_pci_root_lock);
-	return handle;
-}
-
-EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
-
 /**
  * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
  * @handle - the ACPI CA node in question.
Index: linux/include/acpi/acpi_bus.h
===================================================================
--- linux.orig/include/acpi/acpi_bus.h
+++ linux/include/acpi/acpi_bus.h
@@ -443,7 +443,6 @@ struct acpi_pci_root {
 /* helper */
 acpi_handle acpi_get_child(acpi_handle, u64);
 int acpi_is_root_bridge(acpi_handle);
-acpi_handle acpi_get_pci_rootbridge_handle(unsigned int, unsigned int);
 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle);
 #define DEVICE_ACPI_HANDLE(dev) ((acpi_handle)ACPI_HANDLE(dev))
 
Index: linux/include/linux/pci.h
===================================================================
--- linux.orig/include/linux/pci.h
+++ linux/include/linux/pci.h
@@ -700,6 +700,11 @@ void pci_bus_add_devices(const struct pc
 struct pci_bus *pci_scan_bus_parented(struct device *parent, int bus,
 				      struct pci_ops *ops, void *sysdata);
 struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops, void *sysdata);
+struct pci_host_bridge *pci_alloc_root(int bus, struct pci_ops *ops,
+				       void *sysdata);
+struct pci_bus *pci_add_root(struct pci_host_bridge *bridge,
+			     struct device *parent,
+			     struct list_head *resources);
 struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 				    struct pci_ops *ops, void *sysdata,
 				    struct list_head *resources);
Index: linux/arch/x86/pci/acpi.c
===================================================================
--- linux.orig/arch/x86/pci/acpi.c
+++ linux/arch/x86/pci/acpi.c
@@ -551,9 +551,15 @@ struct pci_bus * __devinit pci_acpi_scan
 		}
 
 		if (!setup_mcfg_map(info, domain, (u8)root->secondary.start,
-				    (u8)root->secondary.end, root->mcfg_addr))
-			bus = pci_create_root_bus(NULL, busnum, &pci_root_ops,
-						  sd, &resources);
+				    (u8)root->secondary.end, root->mcfg_addr)) {
+			struct pci_host_bridge *bridge;
+
+			bridge = pci_alloc_root(busnum, &pci_root_ops, sd);
+			if (bridge) {
+				ACPI_HANDLE_SET(&bridge->dev, device->handle);
+				bus = pci_add_root(bridge, NULL, &resources);
+			}
+		}
 
 		if (bus) {
 			pci_scan_child_bus(bus);
Index: linux/arch/ia64/pci/pci.c
===================================================================
--- linux.orig/arch/ia64/pci/pci.c
+++ linux/arch/ia64/pci/pci.c
@@ -333,6 +333,7 @@ pci_acpi_scan_root(struct acpi_pci_root
 	struct pci_controller *controller;
 	unsigned int windows = 0;
 	struct pci_root_info info;
+	struct pci_host_bridge *bridge;
 	struct pci_bus *pbus;
 	char *name;
 	int pxm;
@@ -378,8 +379,13 @@ pci_acpi_scan_root(struct acpi_pci_root
 	 * should handle the case here, but it appears that IA64 hasn't
 	 * such quirk. So we just ignore the case now.
 	 */
-	pbus = pci_create_root_bus(NULL, bus, &pci_root_ops, controller,
-				   &info.resources);
+	bridge = pci_alloc_root(bus, &pci_root_ops, controller);
+	if (bridge) {
+		ACPI_HANDLE_SET(&bridge->dev, device->handle);
+		pbus = pci_add_root(bridge, NULL, &info.resources);
+	} else {
+		pbus = NULL;
+	}
 	if (!pbus) {
 		pci_free_resource_list(&info.resources);
 		return NULL;