[S390] pm: dasd power management callbacks.

Introduce the power management callbacks to the dasd driver. On suspend
the dasd devices are stopped and removed from the focus of alias
management.
On resume they are reinitialized by rereading the device characteristics
and adding the device to the alias management.
In case the device has gone away during suspend it will caught in the
suspend state with stopped flag set to UNRESUMED. After it appears again
the restore function is called again.

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

1 files changed, 95 insertions, 13 deletions

diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index cf0cfdb..1c28ec3 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -5,10 +5,9 @@
  *		    Carsten Otte <Cotte@de.ibm.com>
  *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
  * Bugreports.to..: <Linux390@de.ibm.com>
- * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
+ * Copyright IBM Corp. 1999, 2009
  * EMC Symmetrix ioctl Copyright EMC Corporation, 2008
  * Author.........: Nigel Hislop <hislop_nigel@emc.com>
- *
  */
 
 #define KMSG_COMPONENT "dasd"
@@ -104,17 +103,6 @@ dasd_eckd_set_online(struct ccw_device *cdev)
 	return dasd_generic_set_online(cdev, &dasd_eckd_discipline);
 }
 
-static struct ccw_driver dasd_eckd_driver = {
-	.name        = "dasd-eckd",
-	.owner       = THIS_MODULE,
-	.ids         = dasd_eckd_ids,
-	.probe       = dasd_eckd_probe,
-	.remove      = dasd_generic_remove,
-	.set_offline = dasd_generic_set_offline,
-	.set_online  = dasd_eckd_set_online,
-	.notify      = dasd_generic_notify,
-};
-
 static const int sizes_trk0[] = { 28, 148, 84 };
 #define LABEL_SIZE 140
 
@@ -3236,6 +3224,98 @@ static void dasd_eckd_dump_sense(struct dasd_device *device,
 		dasd_eckd_dump_sense_ccw(device, req, irb);
 }
 
+int dasd_eckd_pm_freeze(struct dasd_device *device)
+{
+	/*
+	 * the device should be disconnected from our LCU structure
+	 * on restore we will reconnect it and reread LCU specific
+	 * information like PAV support that might have changed
+	 */
+	dasd_alias_remove_device(device);
+	dasd_alias_disconnect_device_from_lcu(device);
+
+	return 0;
+}
+
+int dasd_eckd_restore_device(struct dasd_device *device)
+{
+	struct dasd_eckd_private *private;
+	int is_known, rc;
+	struct dasd_uid temp_uid;
+
+	/* allow new IO again */
+	device->stopped &= ~DASD_STOPPED_PM;
+
+	private = (struct dasd_eckd_private *) device->private;
+
+	/* Read Configuration Data */
+	rc = dasd_eckd_read_conf(device);
+	if (rc)
+		goto out_err;
+
+	/* Generate device unique id and register in devmap */
+	rc = dasd_eckd_generate_uid(device, &private->uid);
+	dasd_get_uid(device->cdev, &temp_uid);
+	if (memcmp(&private->uid, &temp_uid, sizeof(struct dasd_uid)) != 0)
+		dev_err(&device->cdev->dev, "The UID of the DASD has changed\n");
+	if (rc)
+		goto out_err;
+	dasd_set_uid(device->cdev, &private->uid);
+
+	/* register lcu with alias handling, enable PAV if this is a new lcu */
+	is_known = dasd_alias_make_device_known_to_lcu(device);
+	if (is_known < 0)
+		return is_known;
+	if (!is_known) {
+		/* new lcu found */
+		rc = dasd_eckd_validate_server(device); /* will switch pav on */
+		if (rc)
+			goto out_err;
+	}
+
+	/* Read Feature Codes */
+	rc = dasd_eckd_read_features(device);
+	if (rc)
+		goto out_err;
+
+	/* Read Device Characteristics */
+	memset(&private->rdc_data, 0, sizeof(private->rdc_data));
+	rc = dasd_generic_read_dev_chars(device, "ECKD",
+					 &private->rdc_data, 64);
+	if (rc) {
+		DBF_EVENT(DBF_WARNING,
+			  "Read device characteristics failed, rc=%d for "
+			  "device: %s", rc, dev_name(&device->cdev->dev));
+		goto out_err;
+	}
+
+	/* add device to alias management */
+	dasd_alias_add_device(device);
+
+	return 0;
+
+out_err:
+	/*
+	 * if the resume failed for the DASD we put it in
+	 * an UNRESUMED stop state
+	 */
+	device->stopped |= DASD_UNRESUMED_PM;
+	return 0;
+}
+
+static struct ccw_driver dasd_eckd_driver = {
+	.name	     = "dasd-eckd",
+	.owner	     = THIS_MODULE,
+	.ids	     = dasd_eckd_ids,
+	.probe	     = dasd_eckd_probe,
+	.remove      = dasd_generic_remove,
+	.set_offline = dasd_generic_set_offline,
+	.set_online  = dasd_eckd_set_online,
+	.notify      = dasd_generic_notify,
+	.freeze      = dasd_generic_pm_freeze,
+	.thaw	     = dasd_generic_restore_device,
+	.restore     = dasd_generic_restore_device,
+};
 
 /*
  * max_blocks is dependent on the amount of storage that is available
@@ -3274,6 +3354,8 @@ static struct dasd_discipline dasd_eckd_discipline = {
 	.dump_sense_dbf = dasd_eckd_dump_sense_dbf,
 	.fill_info = dasd_eckd_fill_info,
 	.ioctl = dasd_eckd_ioctl,
+	.freeze = dasd_eckd_pm_freeze,
+	.restore = dasd_eckd_restore_device,
 };
 
 static int __init