1 files changed, 62 insertions, 0 deletions

diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c
index cdc6c049c353..fd1231738ef4 100644
--- a/drivers/s390/block/dasd_alias.c
+++ b/drivers/s390/block/dasd_alias.c
@@ -152,6 +152,7 @@ static struct alias_lcu *_allocate_lcu(struct dasd_uid *uid)
         INIT_WORK(&lcu->suc_data.worker, summary_unit_check_handling_work);
         INIT_DELAYED_WORK(&lcu->ruac_data.dwork, lcu_update_work);
         spin_lock_init(&lcu->lock);
+        init_completion(&lcu->lcu_setup);
         return lcu;
 
 out_err4:
@@ -240,6 +241,67 @@ int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
 }
 
 /*
+ * 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)
+{
+        struct dasd_eckd_private *private;
+        unsigned long flags;
+        struct alias_server *server;
+        struct alias_lcu *lcu;
+        struct dasd_uid *uid;
+
+        private = (struct dasd_eckd_private *) device->private;
+        uid = &private->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)
+{
+        struct dasd_eckd_private *private;
+        unsigned long flags;
+        struct alias_server *server;
+        struct alias_lcu *lcu;
+        struct dasd_uid *uid;
+
+        private = (struct dasd_eckd_private *) device->private;
+        uid = &private->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);
+}
+
+/*
  * This function removes a device from the scope of alias management.
  * The complicated part is to make sure that it is not in use by
  * any of the workers. If necessary cancel the work.