[S390] cio: trigger subchannel event at resume time

ccw_device_pm_restore: trigger subchannel event to better handle
changes to the subchannel device.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

3 files changed, 63 insertions, 51 deletions

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 169a27723c4f..2769da54f2b9 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -1020,7 +1020,7 @@ static int css_settle(struct device_driver *drv, void *unused)
         return 0;
 }
 
-static inline int css_complete_work(void)
+int css_complete_work(void)
 {
         int ret;
 
diff --git a/drivers/s390/cio/css.h b/drivers/s390/cio/css.h
index 325d813bb8e0..7e37886de231 100644
--- a/drivers/s390/cio/css.h
+++ b/drivers/s390/cio/css.h
@@ -146,6 +146,7 @@ extern struct channel_subsystem *channel_subsystems[];
 /* Helper functions to build lists for the slow path. */
 void css_schedule_eval(struct subchannel_id schid);
 void css_schedule_eval_all(void);
+int css_complete_work(void);
 
 int sch_is_pseudo_sch(struct subchannel *);
 struct schib;
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index c7b2b7b26b8b..c6abb75c4615 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1400,6 +1400,12 @@ static int io_subchannel_sch_event(struct subchannel *sch, int process)
                 rc = 0;
                 goto out_unlock;
         case IO_SCH_VERIFY:
+                if (cdev->private->flags.resuming == 1) {
+                        if (cio_enable_subchannel(sch, (u32)(addr_t)sch)) {
+                                ccw_device_set_notoper(cdev);
+                                break;
+                        }
+                }
                 /* Trigger path verification. */
                 io_subchannel_verify(sch);
                 rc = 0;
@@ -1438,7 +1444,8 @@ static int io_subchannel_sch_event(struct subchannel *sch, int process)
                 break;
         case IO_SCH_UNREG_ATTACH:
                 /* Unregister ccw device. */
-                ccw_device_unregister(cdev);
+                if (!cdev->private->flags.resuming)
+                        ccw_device_unregister(cdev);
                 break;
         default:
                 break;
@@ -1447,7 +1454,8 @@ static int io_subchannel_sch_event(struct subchannel *sch, int process)
         switch (action) {
         case IO_SCH_ORPH_UNREG:
         case IO_SCH_UNREG:
-                css_sch_device_unregister(sch);
+                if (!cdev || !cdev->private->flags.resuming)
+                        css_sch_device_unregister(sch);
                 break;
         case IO_SCH_ORPH_ATTACH:
         case IO_SCH_UNREG_ATTACH:
@@ -1769,20 +1777,36 @@ static void __ccw_device_pm_restore(struct ccw_device *cdev)
 {
         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 
-        if (cio_is_console(sch->schid))
-                goto out;
+        spin_lock_irq(sch->lock);
+        if (cio_is_console(sch->schid)) {
+                cio_enable_subchannel(sch, (u32)(addr_t)sch);
+                goto out_unlock;
+        }
         /*
          * While we were sleeping, devices may have gone or become
          * available again. Kick re-detection.
          */
-        spin_lock_irq(sch->lock);
         cdev->private->flags.resuming = 1;
+        css_schedule_eval(sch->schid);
+        spin_unlock_irq(sch->lock);
+        css_complete_work();
+
+        /* cdev may have been moved to a different subchannel. */
+        sch = to_subchannel(cdev->dev.parent);
+        spin_lock_irq(sch->lock);
+        if (cdev->private->state != DEV_STATE_ONLINE &&
+            cdev->private->state != DEV_STATE_OFFLINE)
+                goto out_unlock;
+
         ccw_device_recognition(cdev);
         spin_unlock_irq(sch->lock);
         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
                    cdev->private->state == DEV_STATE_DISCONNECTED);
-out:
+        spin_lock_irq(sch->lock);
+
+out_unlock:
         cdev->private->flags.resuming = 0;
+        spin_unlock_irq(sch->lock);
 }
 
 static int resume_handle_boxed(struct ccw_device *cdev)
@@ -1806,40 +1830,31 @@ static int resume_handle_disc(struct ccw_device *cdev)
 static int ccw_device_pm_restore(struct device *dev)
 {
         struct ccw_device *cdev = to_ccwdev(dev);
-        struct subchannel *sch = to_subchannel(cdev->dev.parent);
-        int ret = 0, cm_enabled;
+        struct subchannel *sch;
+        int ret = 0;
 
         __ccw_device_pm_restore(cdev);
+        sch = to_subchannel(cdev->dev.parent);
         spin_lock_irq(sch->lock);
-        if (cio_is_console(sch->schid)) {
-                cio_enable_subchannel(sch, (u32)(addr_t)sch);
-                spin_unlock_irq(sch->lock);
+        if (cio_is_console(sch->schid))
                 goto out_restore;
-        }
-        cdev->private->flags.donotify = 0;
+
         /* check recognition results */
         switch (cdev->private->state) {
         case DEV_STATE_OFFLINE:
+        case DEV_STATE_ONLINE:
+                cdev->private->flags.donotify = 0;
                 break;
         case DEV_STATE_BOXED:
                 ret = resume_handle_boxed(cdev);
-                spin_unlock_irq(sch->lock);
                 if (ret)
-                        goto out;
+                        goto out_unlock;
                 goto out_restore;
-        case DEV_STATE_DISCONNECTED:
-                goto out_disc_unlock;
         default:
-                goto out_unreg_unlock;
-        }
-        /* check if the device id has changed */
-        if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
-                CIO_MSG_EVENT(0, "resume: sch 0.%x.%04x: failed (devno "
-                              "changed from %04x to %04x)\n",
-                              sch->schid.ssid, sch->schid.sch_no,
-                              cdev->private->dev_id.devno,
-                              sch->schib.pmcw.dev);
-                goto out_unreg_unlock;
+                ret = resume_handle_disc(cdev);
+                if (ret)
+                        goto out_unlock;
+                goto out_restore;
         }
         /* check if the device type has changed */
         if (!ccw_device_test_sense_data(cdev)) {
@@ -1848,24 +1863,30 @@ static int ccw_device_pm_restore(struct device *dev)
                 ret = -ENODEV;
                 goto out_unlock;
         }
-        if (!cdev->online) {
-                ret = 0;
+        if (!cdev->online)
                 goto out_unlock;
-        }
-        ret = ccw_device_online(cdev);
-        if (ret)
-                goto out_disc_unlock;
 
-        cm_enabled = cdev->private->cmb != NULL;
+        if (ccw_device_online(cdev)) {
+                ret = resume_handle_disc(cdev);
+                if (ret)
+                        goto out_unlock;
+                goto out_restore;
+        }
         spin_unlock_irq(sch->lock);
-
         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
-        if (cdev->private->state != DEV_STATE_ONLINE) {
-                spin_lock_irq(sch->lock);
-                goto out_disc_unlock;
+        spin_lock_irq(sch->lock);
+
+        if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_BAD) {
+                ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
+                ret = -ENODEV;
+                goto out_unlock;
         }
-        if (cm_enabled) {
+
+        /* reenable cmf, if needed */
+        if (cdev->private->cmb) {
+                spin_unlock_irq(sch->lock);
                 ret = ccw_set_cmf(cdev, 1);
+                spin_lock_irq(sch->lock);
                 if (ret) {
                         CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
                                       "(rc=%d)\n", cdev->private->dev_id.ssid,
@@ -1875,21 +1896,11 @@ static int ccw_device_pm_restore(struct device *dev)
         }
 
 out_restore:
+        spin_unlock_irq(sch->lock);
         if (cdev->online && cdev->drv && cdev->drv->restore)
                 ret = cdev->drv->restore(cdev);
-out:
         return ret;
 
-out_disc_unlock:
-        ret = resume_handle_disc(cdev);
-        spin_unlock_irq(sch->lock);
-        if (ret)
-                return ret;
-        goto out_restore;
-
-out_unreg_unlock:
-        ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
-        ret = -ENODEV;
 out_unlock:
         spin_unlock_irq(sch->lock);
         return ret;