PCI: add generic pci_hp_add_bridge()

This creates a generic pci_hp_add_bridge() that can be used by several
hotplug drivers.

[bhelgaas: split out from pciehp patch]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/hotplug-pci.c

@@ -4,6 +4,29 @@
 #include <linux/export.h>
 #include "pci.h"
 
+int __ref pci_hp_add_bridge(struct pci_dev *dev)
+{
+	struct pci_bus *parent = dev->bus;
+	int pass, busnr, start = parent->busn_res.start;
+	int end = parent->busn_res.end;
+
+	for (busnr = start; busnr <= end; busnr++) {
+		if (!pci_find_bus(pci_domain_nr(parent), busnr))
+			break;
+	}
+	if (busnr-- > end) {
+		printk(KERN_ERR "No bus number available for hot-added bridge %s\n",
+				pci_name(dev));
+		return -1;
+	}
+	for (pass = 0; pass < 2; pass++)
+		busnr = pci_scan_bridge(parent, dev, busnr, pass);
+	if (!dev->subordinate)
+		return -1;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pci_hp_add_bridge);
 
 unsigned int __devinit pci_do_scan_bus(struct pci_bus *bus)
 {

drivers/pci/pci.h

@@ -124,6 +124,7 @@ static inline int pci_proc_detach_bus(struct pci_bus *bus) { return 0; }
 #endif
 
 /* Functions for PCI Hotplug drivers to use */
+int pci_hp_add_bridge(struct pci_dev *dev);
 extern unsigned int pci_do_scan_bus(struct pci_bus *bus);
 
 #ifdef HAVE_PCI_LEGACY