diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
index 28b24a5..c49a1c4 100644
--- a/drivers/pci/host-bridge.c
+++ b/drivers/pci/host-bridge.c
@@ -16,15 +16,22 @@
 	list_add_tail(&bridge->list, &pci_host_bridges);
 }
 
-static struct pci_host_bridge *pci_host_bridge(struct pci_dev *dev)
+static struct pci_bus *find_pci_root_bus(struct pci_dev *dev)
 {
 	struct pci_bus *bus;
-	struct pci_host_bridge *bridge;
 
 	bus = dev->bus;
 	while (bus->parent)
 		bus = bus->parent;
 
+	return bus;
+}
+
+static struct pci_host_bridge *find_pci_host_bridge(struct pci_dev *dev)
+{
+	struct pci_bus *bus = find_pci_root_bus(dev);
+	struct pci_host_bridge *bridge;
+
 	list_for_each_entry(bridge, &pci_host_bridges, list) {
 		if (bridge->bus == bus)
 			return bridge;
@@ -41,7 +48,7 @@
 void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
 			     struct resource *res)
 {
-	struct pci_host_bridge *bridge = pci_host_bridge(dev);
+	struct pci_host_bridge *bridge = find_pci_host_bridge(dev);
 	struct pci_host_bridge_window *window;
 	resource_size_t offset = 0;
 
@@ -69,12 +76,13 @@
 void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
 			     struct pci_bus_region *region)
 {
-	struct pci_host_bridge *bridge = pci_host_bridge(dev);
+	struct pci_host_bridge *bridge = find_pci_host_bridge(dev);
 	struct pci_host_bridge_window *window;
-	struct pci_bus_region bus_region;
 	resource_size_t offset = 0;
 
 	list_for_each_entry(window, &bridge->windows, list) {
+		struct pci_bus_region bus_region;
+
 		if (resource_type(res) != resource_type(window->res))
 			continue;