Move pci device address assignment to a separate function.

Index: trunk/hw/pci.c
===================================================================
--- trunk.orig/hw/pci.c
+++ trunk/hw/pci.c
@@ -121,6 +121,16 @@ int pci_bus_num(PCIBus *s)
     return s->bus_num;
 }
 
+int pci_bus_assign_dev_addr(PCIBus *bus)
+{
+    int devfn;
+
+    for(devfn = bus->devfn_min ; devfn < 256; devfn += 8)
+        if (!bus->devices[devfn])
+                return devfn;
+    return -1;
+}
+
 void pci_device_save(PCIDevice *s, QEMUFile *f)
 {
     int i;
@@ -246,14 +256,6 @@ PCIDevice *pci_register_device(PCIBus *b
     if (pci_irq_index >= PCI_DEVICES_MAX)
         return NULL;
 
-    if (devfn < 0) {
-        for(devfn = bus->devfn_min ; devfn < 256; devfn += 8) {
-            if (!bus->devices[devfn])
-                goto found;
-        }
-        return NULL;
-    found: ;
-    }
     pci_dev = qemu_mallocz(instance_size);
     pci_dev->bus = bus;
     pci_dev->devfn = devfn;
Index: trunk/hw/pci.h
===================================================================
--- trunk.orig/hw/pci.h
+++ trunk/hw/pci.h
@@ -184,6 +184,7 @@ PCIDevice *pci_nic_init(PCIBus *bus, NIC
 void pci_data_write(void *opaque, uint32_t addr, uint32_t val, int len);
 uint32_t pci_data_read(void *opaque, uint32_t addr, int len);
 int pci_bus_num(PCIBus *s);
+int pci_bus_assign_dev_addr(PCIBus *bus);
 void pci_for_each_device(int bus_num, void (*fn)(PCIDevice *d));
 PCIBus *pci_find_bus(int bus_num);
 PCIDevice *pci_find_device(int bus_num, int slot, int function);