[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>

2 files changed, 16 insertions, 89 deletions

diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c
index 553b3c5abb0a..b3beed5434e4 100644
--- a/drivers/s390/block/dasd_alias.c
+++ b/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;
 }
 
 /*
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index bbcd5e9206ee..1b6e7ea9347f 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/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);