s390/pci: improve handling of hotplug event 0x301

Hypervisors may deliver event 0x301 not only for standby
but also for reserved devices.
Just handle event 0x301 regardless of the device's state.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/pci/pci_event.c

@@ -75,7 +75,13 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
 	zpci_err_hex(ccdf, sizeof(*ccdf));
 
 	switch (ccdf->pec) {
-	case 0x0301: /* Standby -> Configured */
+	case 0x0301: /* Reserved|Standby -> Configured */
+		if (!zdev) {
+			ret = clp_add_pci_device(ccdf->fid, ccdf->fh, 0);
+			if (ret)
+				break;
+			zdev = get_zdev_by_fid(ccdf->fid);
+		}
 		if (!zdev || zdev->state != ZPCI_FN_STATE_STANDBY)
 			break;
 		zdev->state = ZPCI_FN_STATE_CONFIGURED;