[S390] dasd: revert LCU optimization

Remove the optimization that validate server is only called once per
LCU. If a device is set online we only know that we already know the
LCU. But if the pathgroup was lost in between we have to do a
validate server again to activate some features.
Since we have no indication when a pathgroup gets lost we have to do
a validate server every time a device is set online.

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

drivers/s390/block/dasd_alias.c

@@ -189,14 +189,12 @@ int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
 	unsigned long flags;
 	struct alias_server *server, *newserver;
 	struct alias_lcu *lcu, *newlcu;
-	int is_lcu_known;
 	struct dasd_uid uid;
 
 	private = (struct dasd_eckd_private *) device->private;
 
 	device->discipline->get_uid(device, &uid);
 	spin_lock_irqsave(&aliastree.lock, flags);
-	is_lcu_known = 1;
 	server = _find_server(&uid);
 	if (!server) {
 		spin_unlock_irqrestore(&aliastree.lock, flags);
@@ -208,7 +206,6 @@ int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
 		if (!server) {
 			list_add(&newserver->server, &aliastree.serverlist);
 			server = newserver;
-			is_lcu_known = 0;
 		} else {
 			/* someone was faster */
 			_free_server(newserver);
@@ -226,12 +223,10 @@ int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
 		if (!lcu) {
 			list_add(&newlcu->lcu, &server->lculist);
 			lcu = newlcu;
-			is_lcu_known = 0;
 		} else {
 			/* someone was faster */
 			_free_lcu(newlcu);
 		}
-		is_lcu_known = 0;
 	}
 	spin_lock(&lcu->lock);
 	list_add(&device->alias_list, &lcu->inactive_devices);
@@ -239,64 +234,7 @@ int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
 	spin_unlock(&lcu->lock);
 	spin_unlock_irqrestore(&aliastree.lock, flags);
 
-	return is_lcu_known;
-}
-
-/*
- * The first device to be registered on an LCU will have to do
- * some additional setup steps to configure that LCU on the
- * storage server. All further devices should wait with their
- * initialization until the first device is done.
- * To synchronize this work, the first device will call
- * dasd_alias_lcu_setup_complete when it is done, and all
- * other devices will wait for it with dasd_alias_wait_for_lcu_setup.
- */
-void dasd_alias_lcu_setup_complete(struct dasd_device *device)
-{
-	unsigned long flags;
-	struct alias_server *server;
-	struct alias_lcu *lcu;
-	struct dasd_uid uid;
-
-	device->discipline->get_uid(device, &uid);
-	lcu = NULL;
-	spin_lock_irqsave(&aliastree.lock, flags);
-	server = _find_server(&uid);
-	if (server)
-		lcu = _find_lcu(server, &uid);
-	spin_unlock_irqrestore(&aliastree.lock, flags);
-	if (!lcu) {
-		DBF_EVENT_DEVID(DBF_ERR, device->cdev,
-				"could not find lcu for %04x %02x",
-				uid.ssid, uid.real_unit_addr);
-		WARN_ON(1);
-		return;
-	}
-	complete_all(&lcu->lcu_setup);
-}
-
-void dasd_alias_wait_for_lcu_setup(struct dasd_device *device)
-{
-	unsigned long flags;
-	struct alias_server *server;
-	struct alias_lcu *lcu;
-	struct dasd_uid uid;
-
-	device->discipline->get_uid(device, &uid);
-	lcu = NULL;
-	spin_lock_irqsave(&aliastree.lock, flags);
-	server = _find_server(&uid);
-	if (server)
-		lcu = _find_lcu(server, &uid);
-	spin_unlock_irqrestore(&aliastree.lock, flags);
-	if (!lcu) {
-		DBF_EVENT_DEVID(DBF_ERR, device->cdev,
-				"could not find lcu for %04x %02x",
-				uid.ssid, uid.real_unit_addr);
-		WARN_ON(1);
-		return;
-	}
-	wait_for_completion(&lcu->lcu_setup);
+	return 0;
 }
 
 /*

drivers/s390/block/dasd_eckd.c

@@ -1534,6 +1534,10 @@ static void dasd_eckd_validate_server(struct dasd_device *device)
 	struct dasd_eckd_private *private;
 	int enable_pav;
 
+	private = (struct dasd_eckd_private *) device->private;
+	if (private->uid.type == UA_BASE_PAV_ALIAS ||
+	    private->uid.type == UA_HYPER_PAV_ALIAS)
+		return;
 	if (dasd_nopav || MACHINE_IS_VM)
 		enable_pav = 0;
 	else
@@ -1542,7 +1546,6 @@ static void dasd_eckd_validate_server(struct dasd_device *device)
 
 	/* may be requested feature is not available on server,
 	 * therefore just report error and go ahead */
-	private = (struct dasd_eckd_private *) device->private;
 	DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "PSF-SSC for SSID %04x "
 			"returned rc=%d", private->uid.ssid, rc);
 }
@@ -1588,7 +1591,7 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
 	struct dasd_eckd_private *private;
 	struct dasd_block *block;
 	struct dasd_uid temp_uid;
-	int is_known, rc, i;
+	int rc, i;
 	int readonly;
 	unsigned long value;
 
@@ -1651,22 +1654,12 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
 		block->base = device;
 	}
 
-	/* 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) {
-		rc = is_known;
+	/* register lcu with alias handling, enable PAV */
+	rc = dasd_alias_make_device_known_to_lcu(device);
+	if (rc)
 		goto out_err2;
-	}
-	/*
-	 * dasd_eckd_validate_server is done on the first device that
-	 * is found for an LCU. All later other devices have to wait
-	 * for it, so they will read the correct feature codes.
-	 */
-	if (!is_known) {
-		dasd_eckd_validate_server(device);
-		dasd_alias_lcu_setup_complete(device);
-	} else
-		dasd_alias_wait_for_lcu_setup(device);
+
+	dasd_eckd_validate_server(device);
 
 	/* device may report different configuration data after LCU setup */
 	rc = dasd_eckd_read_conf(device);
@@ -4098,7 +4091,7 @@ static int dasd_eckd_restore_device(struct dasd_device *device)
 {
 	struct dasd_eckd_private *private;
 	struct dasd_eckd_characteristics temp_rdc_data;
-	int is_known, rc;
+	int rc;
 	struct dasd_uid temp_uid;
 	unsigned long flags;
 
@@ -4121,14 +4114,10 @@ static int dasd_eckd_restore_device(struct dasd_device *device)
 		goto out_err;
 
 	/* 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) {
-		dasd_eckd_validate_server(device);
-		dasd_alias_lcu_setup_complete(device);
-	} else
-		dasd_alias_wait_for_lcu_setup(device);
+	rc = dasd_alias_make_device_known_to_lcu(device);
+	if (rc)
+		return rc;
+	dasd_eckd_validate_server(device);
 
 	/* RE-Read Configuration Data */
 	rc = dasd_eckd_read_conf(device);