[S390] dasd: let device initialization wait for LCU setup

[platform/adaptation/renesas_rcar/renesas_kernel.git] / drivers / s390 / block / dasd_alias.c

diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c
index cdc6c04..fd12317 100644 (file)
--- 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.