[S390] cio: call ccw driver notify function with lock held

Calling a ccw driver's notify function without the ccw device lock
held opens up a race window between discovery and handling of a change
in the device operational state. As a result, the device driver may
encounter unexpected device malfunction, leading to out-of-retry
situations or similar.

Remove race by extending the ccw device lock from state change
discovery to the calling of the notify function.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/device.h b/drivers/s390/cio/device.h
index 9800a83..6f5c3f2 100644
--- a/drivers/s390/cio/device.h
+++ b/drivers/s390/cio/device.h
@@ -72,7 +72,6 @@
 }
 
 extern struct workqueue_struct *ccw_device_work;
-extern struct workqueue_struct *ccw_device_notify_work;
 extern wait_queue_head_t ccw_device_init_wq;
 extern atomic_t ccw_device_init_count;
 
@@ -120,6 +119,7 @@
 void ccw_device_trigger_reprobe(struct ccw_device *);
 void ccw_device_kill_io(struct ccw_device *);
 int ccw_device_notify(struct ccw_device *, int);
+void ccw_device_set_notoper(struct ccw_device *cdev);
 
 /* qdio needs this. */
 void ccw_device_set_timeout(struct ccw_device *, int);