PCI: limit pci_get_bus_and_slot to domain 0

Limit pci_get_bus_and_slot() to domain (segment) 0 since domain is not
specified in the function call and defaulting to domain 0 is the only
reasonable thing to do (rather than returning a device from some other
unknown domain).

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/pci/search.c

@@ -139,12 +139,14 @@ struct pci_dev * pci_get_slot(struct pci_bus *bus, unsigned int devfn)
 }
 
 /**
- * pci_get_bus_and_slot - locate PCI device from a given PCI slot
+ * pci_get_bus_and_slot - locate PCI device from a given PCI bus & slot
  * @bus: number of PCI bus on which desired PCI device resides
  * @devfn: encodes number of PCI slot in which the desired PCI
  * device resides and the logical device number within that slot
  * in case of multi-function devices.
  *
+ * Note: the bus/slot search is limited to PCI domain (segment) 0.
+ *
  * Given a PCI bus and slot/function number, the desired PCI device
  * is located in system global list of PCI devices.  If the device
  * is found, a pointer to its data structure is returned.  If no
@@ -157,7 +159,8 @@ struct pci_dev * pci_get_bus_and_slot(unsigned int bus, unsigned int devfn)
 	struct pci_dev *dev = NULL;
 
 	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
-		if (dev->bus->number == bus && dev->devfn == devfn)
+		if (pci_domain_nr(dev->bus) == 0 &&
+		   (dev->bus->number == bus && dev->devfn == devfn))
 			return dev;
 	}
 	return NULL;