s390/dasd: add support for control unit initiated reconfiguration

Add support for Control Unit Initiated Reconfiguration (CUIR) to
Linux, a storage server interface to reconcile concurrent hardware
changes between storage and host.

Reviewed-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Author: stefan-haberland

drivers/s390/block/dasd.c

@@ -1660,6 +1660,14 @@ void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 		device->discipline->check_for_device_change(device, cqr, irb);
 		dasd_put_device(device);
 	}
+
+	/* check for for attention message */
+	if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
+		device = dasd_device_from_cdev_locked(cdev);
+		device->discipline->check_attention(device, irb->esw.esw1.lpum);
+		dasd_put_device(device);
+	}
+
 	if (!cqr)
 		return;
 

drivers/s390/block/dasd_devmap.c

@@ -1432,6 +1432,29 @@ static ssize_t dasd_reservation_state_store(struct device *dev,
 static DEVICE_ATTR(last_known_reservation_state, 0644,
 		   dasd_reservation_state_show, dasd_reservation_state_store);
 
+static ssize_t dasd_pm_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct dasd_device *device;
+	u8 opm, nppm, cablepm, cuirpm, hpfpm;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return sprintf(buf, "0\n");
+
+	opm = device->path_data.opm;
+	nppm = device->path_data.npm;
+	cablepm = device->path_data.cablepm;
+	cuirpm = device->path_data.cuirpm;
+	hpfpm = device->path_data.hpfpm;
+	dasd_put_device(device);
+
+	return sprintf(buf, "%02x %02x %02x %02x %02x\n", opm, nppm,
+		       cablepm, cuirpm, hpfpm);
+}
+
+static DEVICE_ATTR(path_masks, 0444, dasd_pm_show, NULL);
+
 static struct attribute * dasd_attrs[] = {
 	&dev_attr_readonly.attr,
 	&dev_attr_discipline.attr,
@@ -1450,6 +1473,7 @@ static struct attribute * dasd_attrs[] = {
 	&dev_attr_reservation_policy.attr,
 	&dev_attr_last_known_reservation_state.attr,
 	&dev_attr_safe_offline.attr,
+	&dev_attr_path_masks.attr,
 	NULL,
 };