s390/pci: prevent inadvertently triggered bus scans

Initialization and scanning of the pci bus is omitted on older
machines without pci support or if pci=off was specified. Remember
the fact that we ran without pci support and prevent further bus
scans during resume from hibernate or after receiving hotplug
notifications.

Reported-by: Stefan Haberland <stefan.haberland@de.ibm.com>
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>
diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c
index 800f064..228787a 100644
--- a/arch/s390/pci/pci_event.c
+++ b/arch/s390/pci/pci_event.c
@@ -43,9 +43,8 @@
 	u16 pec;			/* PCI event code */
 } __packed;
 
-void zpci_event_error(void *data)
+static void __zpci_event_error(struct zpci_ccdf_err *ccdf)
 {
-	struct zpci_ccdf_err *ccdf = data;
 	struct zpci_dev *zdev = get_zdev_by_fid(ccdf->fid);
 
 	zpci_err("error CCDF:\n");
@@ -58,9 +57,14 @@
 	       pci_name(zdev->pdev), ccdf->pec, ccdf->fid);
 }
 
-void zpci_event_availability(void *data)
+void zpci_event_error(void *data)
 {
-	struct zpci_ccdf_avail *ccdf = data;
+	if (zpci_is_enabled())
+		__zpci_event_error(data);
+}
+
+static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
+{
 	struct zpci_dev *zdev = get_zdev_by_fid(ccdf->fid);
 	struct pci_dev *pdev = zdev ? zdev->pdev : NULL;
 	int ret;
@@ -115,3 +119,9 @@
 		break;
 	}
 }
+
+void zpci_event_availability(void *data)
+{
+	if (zpci_is_enabled())
+		__zpci_event_availability(data);
+}