diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ab002671fa60..4853c8fbd701 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -521,7 +521,7 @@ static void pci_release_host_bridge_dev(struct device *dev)
 	kfree(bridge);
 }
 
-static struct pci_host_bridge *pci_alloc_host_bridge(struct pci_bus *b)
+static struct pci_host_bridge *pci_alloc_host_bridge(void)
 {
 	struct pci_host_bridge *bridge;
 
@@ -530,7 +530,7 @@ static struct pci_host_bridge *pci_alloc_host_bridge(struct pci_bus *b)
 		return NULL;
 
 	INIT_LIST_HEAD(&bridge->windows);
-	bridge->bus = b;
+
 	return bridge;
 }
 
@@ -717,6 +717,122 @@ static void pci_set_bus_msi_domain(struct pci_bus *bus)
 	dev_set_msi_domain(&bus->dev, d);
 }
 
+static int pci_register_host_bridge(struct pci_host_bridge *bridge)
+{
+	struct device *parent = bridge->dev.parent;
+	struct resource_entry *window, *n;
+	struct pci_bus *bus, *b;
+	resource_size_t offset;
+	LIST_HEAD(resources);
+	struct resource *res;
+	char addr[64], *fmt;
+	const char *name;
+	int err;
+
+	bus = pci_alloc_bus(NULL);
+	if (!bus)
+		return -ENOMEM;
+
+	bridge->bus = bus;
+
+	/* temporarily move resources off the list */
+	list_splice_init(&bridge->windows, &resources);
+	bus->sysdata = bridge->sysdata;
+	bus->msi = bridge->msi;
+	bus->ops = bridge->ops;
+	bus->number = bus->busn_res.start = bridge->busnr;
+#ifdef CONFIG_PCI_DOMAINS_GENERIC
+	bus->domain_nr = pci_bus_find_domain_nr(bus, parent);
+#endif
+
+	b = pci_find_bus(pci_domain_nr(bus), bridge->busnr);
+	if (b) {
+		/* If we already got to this bus through a different bridge, ignore it */
+		dev_dbg(&b->dev, "bus already known\n");
+		err = -EEXIST;
+		goto free;
+	}
+
+	dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(bus),
+		     bridge->busnr);
+
+	err = pcibios_root_bridge_prepare(bridge);
+	if (err)
+		goto free;
+
+	err = device_register(&bridge->dev);
+	if (err)
+		put_device(&bridge->dev);
+
+	bus->bridge = get_device(&bridge->dev);
+	device_enable_async_suspend(bus->bridge);
+	pci_set_bus_of_node(bus);
+	pci_set_bus_msi_domain(bus);
+
+	if (!parent)
+		set_dev_node(bus->bridge, pcibus_to_node(bus));
+
+	bus->dev.class = &pcibus_class;
+	bus->dev.parent = bus->bridge;
+
+	dev_set_name(&bus->dev, "%04x:%02x", pci_domain_nr(bus), bus->number);
+	name = dev_name(&bus->dev);
+
+	err = device_register(&bus->dev);
+	if (err)
+		goto unregister;
+
+	pcibios_add_bus(bus);
+
+	/* Create legacy_io and legacy_mem files for this bus */
+	pci_create_legacy_files(bus);
+
+	if (parent)
+		dev_info(parent, "PCI host bridge to bus %s\n", name);
+	else
+		pr_info("PCI host bridge to bus %s\n", name);
+
+	/* Add initial resources to the bus */
+	resource_list_for_each_entry_safe(window, n, &resources) {
+		list_move_tail(&window->node, &bridge->windows);
+		offset = window->offset;
+		res = window->res;
+
+		if (res->flags & IORESOURCE_BUS)
+			pci_bus_insert_busn_res(bus, bus->number, res->end);
+		else
+			pci_bus_add_resource(bus, res, 0);
+
+		if (offset) {
+			if (resource_type(res) == IORESOURCE_IO)
+				fmt = " (bus address [%#06llx-%#06llx])";
+			else
+				fmt = " (bus address [%#010llx-%#010llx])";
+
+			snprintf(addr, sizeof(addr), fmt,
+				 (unsigned long long)(res->start - offset),
+				 (unsigned long long)(res->end - offset));
+		} else
+			addr[0] = '\0';
+
+		dev_info(&bus->dev, "root bus resource %pR%s\n", res, addr);
+	}
+
+	down_write(&pci_bus_sem);
+	list_add_tail(&bus->node, &pci_root_buses);
+	up_write(&pci_bus_sem);
+
+	return 0;
+
+unregister:
+	put_device(&bridge->dev);
+	device_unregister(&bridge->dev);
+
+free:
+	kfree(bus);
+	return err;
+}
+
 static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
 					   struct pci_dev *bridge, int busnr)
 {
@@ -2130,113 +2246,43 @@ void __weak pcibios_remove_bus(struct pci_bus *bus)
 {
 }
 
-struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
-		struct pci_ops *ops, void *sysdata, struct list_head *resources)
+static struct pci_bus *pci_create_root_bus_msi(struct device *parent,
+		int bus, struct pci_ops *ops, void *sysdata,
+		struct list_head *resources, struct msi_controller *msi)
 {
 	int error;
 	struct pci_host_bridge *bridge;
-	struct pci_bus *b, *b2;
-	struct resource_entry *window, *n;
-	struct resource *res;
-	resource_size_t offset;
-	char bus_addr[64];
-	char *fmt;
 
-	b = pci_alloc_bus(NULL);
-	if (!b)
-		return NULL;
-
-	b->sysdata = sysdata;
-	b->ops = ops;
-	b->number = b->busn_res.start = bus;
-#ifdef CONFIG_PCI_DOMAINS_GENERIC
-	b->domain_nr = pci_bus_find_domain_nr(b, parent);
-#endif
-	b2 = pci_find_bus(pci_domain_nr(b), bus);
-	if (b2) {
-		/* If we already got to this bus through a different bridge, ignore it */
-		dev_dbg(&b2->dev, "bus already known\n");
-		goto err_out;
-	}
-
-	bridge = pci_alloc_host_bridge(b);
+	bridge = pci_alloc_host_bridge();
 	if (!bridge)
-		goto err_out;
+		return NULL;
 
 	bridge->dev.parent = parent;
 	bridge->dev.release = pci_release_host_bridge_dev;
-	dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus);
-	error = pcibios_root_bridge_prepare(bridge);
-	if (error) {
-		kfree(bridge);
+
+	list_splice_init(resources, &bridge->windows);
+	bridge->sysdata = sysdata;
+	bridge->busnr = bus;
+	bridge->ops = ops;
+	bridge->msi = msi;
+
+	error = pci_register_host_bridge(bridge);
+	if (error < 0)
 		goto err_out;
-	}
 
-	error = device_register(&bridge->dev);
-	if (error) {
-		put_device(&bridge->dev);
-		goto err_out;
-	}
-	b->bridge = get_device(&bridge->dev);
-	device_enable_async_suspend(b->bridge);
-	pci_set_bus_of_node(b);
-	pci_set_bus_msi_domain(b);
+	return bridge->bus;
 
-	if (!parent)
-		set_dev_node(b->bridge, pcibus_to_node(b));
-
-	b->dev.class = &pcibus_class;
-	b->dev.parent = b->bridge;
-	dev_set_name(&b->dev, "%04x:%02x", pci_domain_nr(b), bus);
-	error = device_register(&b->dev);
-	if (error)
-		goto class_dev_reg_err;
-
-	pcibios_add_bus(b);
-
-	/* Create legacy_io and legacy_mem files for this bus */
-	pci_create_legacy_files(b);
-
-	if (parent)
-		dev_info(parent, "PCI host bridge to bus %s\n", dev_name(&b->dev));
-	else
-		printk(KERN_INFO "PCI host bridge to bus %s\n", dev_name(&b->dev));
-
-	/* Add initial resources to the bus */
-	resource_list_for_each_entry_safe(window, n, resources) {
-		list_move_tail(&window->node, &bridge->windows);
-		res = window->res;
-		offset = window->offset;
-		if (res->flags & IORESOURCE_BUS)
-			pci_bus_insert_busn_res(b, bus, res->end);
-		else
-			pci_bus_add_resource(b, res, 0);
-		if (offset) {
-			if (resource_type(res) == IORESOURCE_IO)
-				fmt = " (bus address [%#06llx-%#06llx])";
-			else
-				fmt = " (bus address [%#010llx-%#010llx])";
-			snprintf(bus_addr, sizeof(bus_addr), fmt,
-				 (unsigned long long) (res->start - offset),
-				 (unsigned long long) (res->end - offset));
-		} else
-			bus_addr[0] = '\0';
-		dev_info(&b->dev, "root bus resource %pR%s\n", res, bus_addr);
-	}
-
-	down_write(&pci_bus_sem);
-	list_add_tail(&b->node, &pci_root_buses);
-	up_write(&pci_bus_sem);
-
-	return b;
-
-class_dev_reg_err:
-	put_device(&bridge->dev);
-	device_unregister(&bridge->dev);
 err_out:
-	kfree(b);
+	kfree(bridge);
 	return NULL;
 }
+
+struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
+		struct pci_ops *ops, void *sysdata, struct list_head *resources)
+{
+	return pci_create_root_bus_msi(parent, bus, ops, sysdata, resources,
+				       NULL);
+}
 EXPORT_SYMBOL_GPL(pci_create_root_bus);
 
 int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max)
@@ -2317,12 +2363,10 @@ struct pci_bus *pci_scan_root_bus_msi(struct device *parent, int bus,
 			break;
 		}
 
-	b = pci_create_root_bus(parent, bus, ops, sysdata, resources);
+	b = pci_create_root_bus_msi(parent, bus, ops, sysdata, resources, msi);
 	if (!b)
 		return NULL;
 
-	b->msi = msi;
-
 	if (!found) {
 		dev_info(&b->dev,
 		 "No busn resource found for root bus, will use [bus %02x-ff]\n",
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 0e49f70dbd9b..f79634612fbf 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -420,9 +420,13 @@ static inline int pci_channel_offline(struct pci_dev *pdev)
 struct pci_host_bridge {
 	struct device dev;
 	struct pci_bus *bus;		/* root bus */
+	struct pci_ops *ops;
+	void *sysdata;
+	int busnr;
 	struct list_head windows;	/* resource_entry */
 	void (*release_fn)(struct pci_host_bridge *);
 	void *release_data;
+	struct msi_controller *msi;
 	unsigned int ignore_reset_delay:1;	/* for entire hierarchy */
 	/* Resource alignment requirements */
 	resource_size_t (*align_resource)(struct pci_dev *dev,