[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>

diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index 10cb0f8726e5a72a264e4b62a2cbb9c3e32b65b1..5100996201d189a63c81dcab684e6796b9d00c17 100644 (file)
--- 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);

diff --git a/drivers/s390/cio/qdio_thinint.c b/drivers/s390/cio/qdio_thinint.c
index 8e90e147b746834c6af2c87da10fbdb8c3fc2f93..981044c83864cb3d8024924f78f82567131ecc95 100644 (file)
--- a/drivers/s390/cio/qdio_thinint.c
+++ b/drivers/s390/cio/qdio_thinint.c
@@ -31,6 +31,7 @@
 
 /* list of thin interrupt input queues */
 static LIST_HEAD(tiq_list);
+DEFINE_MUTEX(tiq_list_lock);
 
 /* adapter local summary indicator */
 static unsigned char *tiqdio_alsi;
@@ -95,10 +96,10 @@ void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)
        if (!css_qdio_omit_svs && irq_ptr->siga_flag.sync)
                css_qdio_omit_svs = 1;
 
-       for_each_input_queue(irq_ptr, q, i) {
+       mutex_lock(&tiq_list_lock);
+       for_each_input_queue(irq_ptr, q, i)
                list_add_rcu(&q->entry, &tiq_list);
-               synchronize_rcu();
-       }
+       mutex_unlock(&tiq_list_lock);
        xchg(irq_ptr->dsci, 1);
        tasklet_schedule(&tiqdio_tasklet);
 }
@@ -118,7 +119,10 @@ void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr)
                /* if establish triggered an error */
                if (!q || !q->entry.prev || !q->entry.next)
                        continue;
+
+               mutex_lock(&tiq_list_lock);
                list_del_rcu(&q->entry);
+               mutex_unlock(&tiq_list_lock);
                synchronize_rcu();
        }
 }