PCI: Add pci_last_busno() helper

This is just a handy routine that reports last PCI busno: we walk
down all the hoses and return last hose's last_busno.

Will be used by PCI/PCIe initialization code.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index fffca49..d6d2d6e 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -165,6 +165,19 @@
 	return NULL;
 }
 
+int pci_last_busno(void)
+{
+	struct pci_controller *hose = hose_head;
+
+	if (!hose)
+		return -1;
+
+	while (hose->next)
+		hose = hose->next;
+
+	return hose->last_busno;
+}
+
 #ifndef CONFIG_IXP425
 pci_dev_t pci_find_devices(struct pci_device_id *ids, int index)
 {