x86/PCI: Factor out pcibios_allocate_dev_rom_resource()

Factor pcibios_allocate_rom_resources() and
pcibios_allocate_dev_rom_resource() out of pcibios_assign_resources().
This will allow us to allocate ROM resources for hot-added root buses.

[bhelgaas: changelog]
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

arch/x86/pci/i386.c

@@ -298,27 +298,45 @@ static void __init pcibios_allocate_resources(struct pci_bus *bus, int pass)
 	}
 }
 
-static int __init pcibios_assign_resources(void)
+static void __init pcibios_allocate_dev_rom_resource(struct pci_dev *dev)
 {
-	struct pci_dev *dev = NULL;
 	struct resource *r;
 
-	if (!(pci_probe & PCI_ASSIGN_ROMS)) {
 	/*
 	 * Try to use BIOS settings for ROMs, otherwise let
 	 * pci_assign_unassigned_resources() allocate the new
 	 * addresses.
 	 */
-		for_each_pci_dev(dev) {
 	r = &dev->resource[PCI_ROM_RESOURCE];
 	if (!r->flags || !r->start)
-				continue;
+		return;
+
 	if (pci_claim_resource(dev, PCI_ROM_RESOURCE) < 0) {
 		r->end -= r->start;
 		r->start = 0;
 	}
+}
+static void __init pcibios_allocate_rom_resources(struct pci_bus *bus)
+{
+	struct pci_dev *dev;
+	struct pci_bus *child;
+
+	list_for_each_entry(dev, &bus->devices, bus_list) {
+		pcibios_allocate_dev_rom_resource(dev);
+
+		child = dev->subordinate;
+		if (child)
+			pcibios_allocate_rom_resources(child);
 	}
-	}
+}
+
+static int __init pcibios_assign_resources(void)
+{
+	struct pci_bus *bus;
+
+	if (!(pci_probe & PCI_ASSIGN_ROMS))
+		list_for_each_entry(bus, &pci_root_buses, node)
+			pcibios_allocate_rom_resources(bus);
 
 	pci_assign_unassigned_resources();
 	pcibios_fw_addr_list_del();