4 files changed, 119 insertions, 127 deletions

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 0dcfc0ee3d8..167446785d1 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -306,47 +306,6 @@ static void ccw_device_unregister(struct ccw_device *cdev)
         }
 }
 
-static void ccw_device_remove_orphan_cb(struct work_struct *work)
-{
-        struct ccw_device_private *priv;
-        struct ccw_device *cdev;
-
-        priv = container_of(work, struct ccw_device_private, kick_work);
-        cdev = priv->cdev;
-        ccw_device_unregister(cdev);
-        /* Release cdev reference for workqueue processing. */
-        put_device(&cdev->dev);
-}
-
-static void
-ccw_device_remove_disconnected(struct ccw_device *cdev)
-{
-        unsigned long flags;
-
-        /*
-         * Forced offline in disconnected state means
-         * 'throw away device'.
-         */
-        if (ccw_device_is_orphan(cdev)) {
-                /*
-                 * Deregister ccw device.
-                 * Unfortunately, we cannot do this directly from the
-                 * attribute method.
-                 */
-                /* Get cdev reference for workqueue processing. */
-                if (!get_device(&cdev->dev))
-                        return;
-                spin_lock_irqsave(cdev->ccwlock, flags);
-                cdev->private->state = DEV_STATE_NOT_OPER;
-                spin_unlock_irqrestore(cdev->ccwlock, flags);
-                PREPARE_WORK(&cdev->private->kick_work,
-                                ccw_device_remove_orphan_cb);
-                queue_work(slow_path_wq, &cdev->private->kick_work);
-        } else
-                /* Deregister subchannel, which will kill the ccw device. */
-                ccw_device_schedule_sch_unregister(cdev);
-}
-
 /**
  * ccw_device_set_offline() - disable a ccw device for I/O
  * @cdev: target ccw device
@@ -494,9 +453,11 @@ error:
 
 static int online_store_handle_offline(struct ccw_device *cdev)
 {
-        if (cdev->private->state == DEV_STATE_DISCONNECTED)
-                ccw_device_remove_disconnected(cdev);
-        else if (cdev->online && cdev->drv && cdev->drv->set_offline)
+        if (cdev->private->state == DEV_STATE_DISCONNECTED) {
+                spin_lock_irq(cdev->ccwlock);
+                ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
+                spin_unlock_irq(cdev->ccwlock);
+        } else if (cdev->online && cdev->drv && cdev->drv->set_offline)
                 return ccw_device_set_offline(cdev);
         return 0;
 }
@@ -690,17 +651,10 @@ static struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
         return dev ? to_ccwdev(dev) : NULL;
 }
 
-void ccw_device_do_unbind_bind(struct work_struct *work)
+static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
 {
-        struct ccw_device_private *priv;
-        struct ccw_device *cdev;
-        struct subchannel *sch;
         int ret;
 
-        priv = container_of(work, struct ccw_device_private, kick_work);
-        cdev = priv->cdev;
-        sch = to_subchannel(cdev->dev.parent);
-
         if (test_bit(1, &cdev->private->registered)) {
                 device_release_driver(&cdev->dev);
                 ret = device_attach(&cdev->dev);
@@ -735,6 +689,8 @@ static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
         return ERR_PTR(-ENOMEM);
 }
 
+static void ccw_device_todo(struct work_struct *work);
+
 static int io_subchannel_initialize_dev(struct subchannel *sch,
                                         struct ccw_device *cdev)
 {
@@ -742,7 +698,7 @@ static int io_subchannel_initialize_dev(struct subchannel *sch,
         atomic_set(&cdev->private->onoff, 0);
         cdev->dev.parent = &sch->dev;
         cdev->dev.release = ccw_device_release;
-        INIT_WORK(&cdev->private->kick_work, NULL);
+        INIT_WORK(&cdev->private->todo_work, ccw_device_todo);
         cdev->dev.groups = ccwdev_attr_groups;
         /* Do first half of device_register. */
         device_initialize(&cdev->dev);
@@ -797,17 +753,12 @@ static void sch_create_and_recog_new_device(struct subchannel *sch)
 /*
  * Register recognized device.
  */
-static void
-io_subchannel_register(struct work_struct *work)
+static void io_subchannel_register(struct ccw_device *cdev)
 {
-        struct ccw_device_private *priv;
-        struct ccw_device *cdev;
         struct subchannel *sch;
         int ret;
         unsigned long flags;
 
-        priv = container_of(work, struct ccw_device_private, kick_work);
-        cdev = priv->cdev;
         sch = to_subchannel(cdev->dev.parent);
         /*
          * Check if subchannel is still registered. It may have become
@@ -859,41 +810,23 @@ out:
         cdev->private->flags.recog_done = 1;
         wake_up(&cdev->private->wait_q);
 out_err:
-        /* Release reference for workqueue processing. */
-        put_device(&cdev->dev);
         if (atomic_dec_and_test(&ccw_device_init_count))
                 wake_up(&ccw_device_init_wq);
 }
 
-static void ccw_device_call_sch_unregister(struct work_struct *work)
+static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
 {
-        struct ccw_device_private *priv;
-        struct ccw_device *cdev;
         struct subchannel *sch;
 
-        priv = container_of(work, struct ccw_device_private, kick_work);
-        cdev = priv->cdev;
         /* Get subchannel reference for local processing. */
         if (!get_device(cdev->dev.parent))
                 return;
         sch = to_subchannel(cdev->dev.parent);
         css_sch_device_unregister(sch);
-        /* Release cdev reference for workqueue processing.*/
-        put_device(&cdev->dev);
         /* Release subchannel reference for local processing. */
         put_device(&sch->dev);
 }
 
-void ccw_device_schedule_sch_unregister(struct ccw_device *cdev)
-{
-        /* Get cdev reference for workqueue processing. */
-        if (!get_device(&cdev->dev))
-                return;
-        PREPARE_WORK(&cdev->private->kick_work,
-                     ccw_device_call_sch_unregister);
-        queue_work(slow_path_wq, &cdev->private->kick_work);
-}
-
 /*
  * subchannel recognition done. Called from the state machine.
  */
@@ -909,7 +842,8 @@ io_subchannel_recog_done(struct ccw_device *cdev)
                 /* Device did not respond in time. */
         case DEV_STATE_NOT_OPER:
                 cdev->private->flags.recog_done = 1;
-                ccw_device_schedule_sch_unregister(cdev);
+                /* Remove device found not operational. */
+                ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
                 if (atomic_dec_and_test(&ccw_device_init_count))
                         wake_up(&ccw_device_init_wq);
                 break;
@@ -918,11 +852,7 @@ io_subchannel_recog_done(struct ccw_device *cdev)
                  * We can't register the device in interrupt context so
                  * we schedule a work item.
                  */
-                if (!get_device(&cdev->dev))
-                        break;
-                PREPARE_WORK(&cdev->private->kick_work,
-                             io_subchannel_register);
-                queue_work(slow_path_wq, &cdev->private->kick_work);
+                ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
                 break;
         }
 }
@@ -1333,20 +1263,16 @@ static void ccw_device_schedule_recovery(void)
 static int purge_fn(struct device *dev, void *data)
 {
         struct ccw_device *cdev = to_ccwdev(dev);
-        struct ccw_device_private *priv = cdev->private;
-        int unreg;
+        struct ccw_dev_id *id = &cdev->private->dev_id;
 
         spin_lock_irq(cdev->ccwlock);
-        unreg = is_blacklisted(priv->dev_id.ssid, priv->dev_id.devno) &&
-                (priv->state == DEV_STATE_OFFLINE);
+        if (is_blacklisted(id->ssid, id->devno) &&
+            (cdev->private->state == DEV_STATE_OFFLINE)) {
+                CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
+                              id->devno);
+                ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
+        }
         spin_unlock_irq(cdev->ccwlock);
-        if (!unreg)
-                goto out;
-        CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", priv->dev_id.ssid,
-                      priv->dev_id.devno);
-        ccw_device_schedule_sch_unregister(cdev);
-
-out:
         /* Abort loop in case of pending signal. */
         if (signal_pending(current))
                 return -EINTR;
@@ -1456,12 +1382,14 @@ static int io_subchannel_sch_event(struct subchannel *sch, int process)
                 goto out_unlock;
         if (work_pending(&sch->todo_work))
                 goto out_unlock;
+        cdev = sch_get_cdev(sch);
+        if (cdev && work_pending(&cdev->private->todo_work))
+                goto out_unlock;
         action = sch_get_action(sch);
         CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
                       sch->schid.ssid, sch->schid.sch_no, process,
                       action);
         /* Perform immediate actions while holding the lock. */
-        cdev = sch_get_cdev(sch);
         switch (action) {
         case IO_SCH_REPROBE:
                 /* Trigger device recognition. */
@@ -1753,7 +1681,7 @@ static int ccw_device_pm_prepare(struct device *dev)
 {
         struct ccw_device *cdev = to_ccwdev(dev);
 
-        if (work_pending(&cdev->private->kick_work))
+        if (work_pending(&cdev->private->todo_work))
                 return -EAGAIN;
         /* Fail while device is being set online/offline. */
         if (atomic_read(&cdev->private->onoff))
@@ -1874,7 +1802,7 @@ static int resume_handle_boxed(struct ccw_device *cdev)
         cdev->private->state = DEV_STATE_BOXED;
         if (ccw_device_notify(cdev, CIO_BOXED))
                 return 0;
-        ccw_device_schedule_sch_unregister(cdev);
+        ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
         return -ENODEV;
 }
 
@@ -1883,7 +1811,7 @@ static int resume_handle_disc(struct ccw_device *cdev)
         cdev->private->state = DEV_STATE_DISCONNECTED;
         if (ccw_device_notify(cdev, CIO_GONE))
                 return 0;
-        ccw_device_schedule_sch_unregister(cdev);
+        ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
         return -ENODEV;
 }
 
@@ -1928,9 +1856,7 @@ static int ccw_device_pm_restore(struct device *dev)
         /* check if the device type has changed */
         if (!ccw_device_test_sense_data(cdev)) {
                 ccw_device_update_sense_data(cdev);
-                PREPARE_WORK(&cdev->private->kick_work,
-                             ccw_device_do_unbind_bind);
-                queue_work(ccw_device_work, &cdev->private->kick_work);
+                ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
                 ret = -ENODEV;
                 goto out_unlock;
         }
@@ -1974,7 +1900,7 @@ out_disc_unlock:
         goto out_restore;
 
 out_unreg_unlock:
-        ccw_device_schedule_sch_unregister(cdev);
+        ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
         ret = -ENODEV;
 out_unlock:
         spin_unlock_irq(sch->lock);
@@ -2039,6 +1965,77 @@ ccw_device_get_subchannel_id(struct ccw_device *cdev)
         return sch->schid;
 }
 
+static void ccw_device_todo(struct work_struct *work)
+{
+        struct ccw_device_private *priv;
+        struct ccw_device *cdev;
+        struct subchannel *sch;
+        enum cdev_todo todo;
+
+        priv = container_of(work, struct ccw_device_private, todo_work);
+        cdev = priv->cdev;
+        sch = to_subchannel(cdev->dev.parent);
+        /* Find out todo. */
+        spin_lock_irq(cdev->ccwlock);
+        todo = priv->todo;
+        priv->todo = CDEV_TODO_NOTHING;
+        CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
+                      priv->dev_id.ssid, priv->dev_id.devno, todo);
+        spin_unlock_irq(cdev->ccwlock);
+        /* Perform todo. */
+        switch (todo) {
+        case CDEV_TODO_ENABLE_CMF:
+                cmf_reenable(cdev);
+                break;
+        case CDEV_TODO_REBIND:
+                ccw_device_do_unbind_bind(cdev);
+                break;
+        case CDEV_TODO_REGISTER:
+                io_subchannel_register(cdev);
+                break;
+        case CDEV_TODO_UNREG_EVAL:
+                if (!sch_is_pseudo_sch(sch))
+                        css_schedule_eval(sch->schid);
+                /* fall-through */
+        case CDEV_TODO_UNREG:
+                if (sch_is_pseudo_sch(sch))
+                        ccw_device_unregister(cdev);
+                else
+                        ccw_device_call_sch_unregister(cdev);
+                break;
+        default:
+                break;
+        }
+        /* Release workqueue ref. */
+        put_device(&cdev->dev);
+}
+
+/**
+ * ccw_device_sched_todo - schedule ccw device operation
+ * @cdev: ccw device
+ * @todo: todo
+ *
+ * Schedule the operation identified by @todo to be performed on the slow path
+ * workqueue. Do nothing if another operation with higher priority is already
+ * scheduled. Needs to be called with ccwdev lock held.
+ */
+void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
+{
+        CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
+                      cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
+                      todo);
+        if (cdev->private->todo >= todo)
+                return;
+        cdev->private->todo = todo;
+        /* Get workqueue ref. */
+        if (!get_device(&cdev->dev))
+                return;
+        if (!queue_work(slow_path_wq, &cdev->private->todo_work)) {
+                /* Already queued, release workqueue ref. */
+                put_device(&cdev->dev);
+        }
+}
+
 MODULE_LICENSE("GPL");
 EXPORT_SYMBOL(ccw_device_set_online);
 EXPORT_SYMBOL(ccw_device_set_offline);
diff --git a/drivers/s390/cio/device.h b/drivers/s390/cio/device.h
index 246c6482842..adaa27efc59 100644
--- a/drivers/s390/cio/device.h
+++ b/drivers/s390/cio/device.h
@@ -81,8 +81,6 @@ void io_subchannel_init_config(struct subchannel *sch);
 
 int ccw_device_cancel_halt_clear(struct ccw_device *);
 
-void ccw_device_do_unbind_bind(struct work_struct *);
-void ccw_device_move_to_orphanage(struct work_struct *);
 int ccw_device_is_orphan(struct ccw_device *);
 
 int ccw_device_recognition(struct ccw_device *);
@@ -92,6 +90,7 @@ void ccw_device_update_sense_data(struct ccw_device *);
 int ccw_device_test_sense_data(struct ccw_device *);
 void ccw_device_schedule_sch_unregister(struct ccw_device *);
 int ccw_purge_blacklisted(void);
+void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo);
 
 /* Function prototypes for device status and basic sense stuff. */
 void ccw_device_accumulate_irb(struct ccw_device *, struct irb *);
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index d1e05f44fb6..b163743bf58 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -289,9 +289,7 @@ ccw_device_recog_done(struct ccw_device *cdev, int state)
                         wake_up(&cdev->private->wait_q);
                 } else {
                         ccw_device_update_sense_data(cdev);
-                        PREPARE_WORK(&cdev->private->kick_work,
-                                     ccw_device_do_unbind_bind);
-                        queue_work(ccw_device_work, &cdev->private->kick_work);
+                        ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
                 }
                 return;
         case DEV_STATE_BOXED:
@@ -343,28 +341,16 @@ int ccw_device_notify(struct ccw_device *cdev, int event)
         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
 }
 
-static void cmf_reenable_delayed(struct work_struct *work)
-{
-        struct ccw_device_private *priv;
-        struct ccw_device *cdev;
-
-        priv = container_of(work, struct ccw_device_private, kick_work);
-        cdev = priv->cdev;
-        cmf_reenable(cdev);
-}
-
 static void ccw_device_oper_notify(struct ccw_device *cdev)
 {
         if (ccw_device_notify(cdev, CIO_OPER)) {
                 /* Reenable channel measurements, if needed. */
-                PREPARE_WORK(&cdev->private->kick_work, cmf_reenable_delayed);
-                queue_work(ccw_device_work, &cdev->private->kick_work);
+                ccw_device_sched_todo(cdev, CDEV_TODO_ENABLE_CMF);
                 return;
         }
         /* Driver doesn't want device back. */
         ccw_device_set_notoper(cdev);
-        PREPARE_WORK(&cdev->private->kick_work, ccw_device_do_unbind_bind);
-        queue_work(ccw_device_work, &cdev->private->kick_work);
+        ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
 }
 
 /*
@@ -392,14 +378,14 @@ ccw_device_done(struct ccw_device *cdev, int state)
                 CIO_MSG_EVENT(0, "Boxed device %04x on subchannel %04x\n",
                               cdev->private->dev_id.devno, sch->schid.sch_no);
                 if (cdev->online && !ccw_device_notify(cdev, CIO_BOXED))
-                        ccw_device_schedule_sch_unregister(cdev);
+                        ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
                 cdev->private->flags.donotify = 0;
                 break;
         case DEV_STATE_NOT_OPER:
                 CIO_MSG_EVENT(0, "Device %04x gone on subchannel %04x\n",
                               cdev->private->dev_id.devno, sch->schid.sch_no);
                 if (!ccw_device_notify(cdev, CIO_GONE))
-                        ccw_device_schedule_sch_unregister(cdev);
+                        ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
                 else
                         ccw_device_set_disconnected(cdev);
                 cdev->private->flags.donotify = 0;
@@ -409,7 +395,7 @@ ccw_device_done(struct ccw_device *cdev, int state)
                               "%04x\n", cdev->private->dev_id.devno,
                               sch->schid.sch_no);
                 if (!ccw_device_notify(cdev, CIO_NO_PATH))
-                        ccw_device_schedule_sch_unregister(cdev);
+                        ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
                 else
                         ccw_device_set_disconnected(cdev);
                 cdev->private->flags.donotify = 0;
@@ -751,7 +737,7 @@ static void ccw_device_generic_notoper(struct ccw_device *cdev,
                                        enum dev_event dev_event)
 {
         if (!ccw_device_notify(cdev, CIO_GONE))
-                ccw_device_schedule_sch_unregister(cdev);
+                ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
         else
                 ccw_device_set_disconnected(cdev);
 }
diff --git a/drivers/s390/cio/io_sch.h b/drivers/s390/cio/io_sch.h
index 0b8f381bd20..b770e420213 100644
--- a/drivers/s390/cio/io_sch.h
+++ b/drivers/s390/cio/io_sch.h
@@ -82,6 +82,15 @@ struct senseid {
         struct ciw ciw[MAX_CIWS];       /* variable # of CIWs */
 }  __attribute__ ((packed, aligned(4)));
 
+enum cdev_todo {
+        CDEV_TODO_NOTHING,
+        CDEV_TODO_ENABLE_CMF,
+        CDEV_TODO_REBIND,
+        CDEV_TODO_REGISTER,
+        CDEV_TODO_UNREG,
+        CDEV_TODO_UNREG_EVAL,
+};
+
 struct ccw_device_private {
         struct ccw_device *cdev;
         struct subchannel *sch;
@@ -115,7 +124,8 @@ struct ccw_device_private {
         struct senseid senseid; /* SenseID info */
         struct pgid pgid[8];    /* path group IDs per chpid*/
         struct ccw1 iccws[2];   /* ccws for SNID/SID/SPGID commands */
-        struct work_struct kick_work;
+        struct work_struct todo_work;
+        enum cdev_todo todo;
         wait_queue_head_t wait_q;
         struct timer_list timer;
         void *cmb;                      /* measurement information */