PCI: Add pci_free_host_bridge() interface

Commit a52d1443bba1 ("PCI: Export host bridge registration interface")
exported the pci_alloc_host_bridge() interface so that PCI host controllers
drivers can make use of it.

Introduce pci_alloc_host_bridge() kernel counterpart to free the host
bridge data structures, pci_free_host_bridge(), export it and update kernel
functions releasing host bridge objects allocated memory to make use of it.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>

drivers/pci/probe.c

@@ -517,9 +517,7 @@ static void pci_release_host_bridge_dev(struct device *dev)
 	if (bridge->release_fn)
 		bridge->release_fn(bridge);
 
-	pci_free_resource_list(&bridge->windows);
-
-	kfree(bridge);
+	pci_free_host_bridge(bridge);
 }
 
 struct pci_host_bridge *pci_alloc_host_bridge(size_t priv)
@@ -537,6 +535,14 @@ struct pci_host_bridge *pci_alloc_host_bridge(size_t priv)
 }
 EXPORT_SYMBOL(pci_alloc_host_bridge);
 
+void pci_free_host_bridge(struct pci_host_bridge *bridge)
+{
+	pci_free_resource_list(&bridge->windows);
+
+	kfree(bridge);
+}
+EXPORT_SYMBOL(pci_free_host_bridge);
+
 static const unsigned char pcix_bus_speed[] = {
 	PCI_SPEED_UNKNOWN,		/* 0 */
 	PCI_SPEED_66MHz_PCIX,		/* 1 */

include/linux/pci.h

@@ -458,6 +458,7 @@ static inline struct pci_host_bridge *pci_host_bridge_from_priv(void *priv)
 }
 
 struct pci_host_bridge *pci_alloc_host_bridge(size_t priv);
+void pci_free_host_bridge(struct pci_host_bridge *bridge);
 int pci_register_host_bridge(struct pci_host_bridge *bridge);
 struct pci_host_bridge *pci_find_host_bridge(struct pci_bus *bus);