[S390] qdio: add missing tiq_list locking

Add a mutex to protect the tiq_list. Although reading the list is done
using RCU adding and removing elements from the list must still
happen locked since multiple qdio devices may change the list in parallel
otherwise.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index 10cb0f8726e5..5100996201d1 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -1112,6 +1112,7 @@ int qdio_shutdown(struct ccw_device *cdev, int how)
         if (!irq_ptr)
                 return -ENODEV;
 
+        BUG_ON(irqs_disabled());
         DBF_EVENT("qshutdown:%4x", cdev->private->schid.sch_no);
 
         mutex_lock(&irq_ptr->setup_mutex);