1 files changed, 47 insertions, 3 deletions

diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index 9208c0e56c33..45e792f6afd0 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -27,6 +27,9 @@ struct workqueue_struct *vfio_ccw_work_q;
 static struct kmem_cache *vfio_ccw_io_region;
 static struct kmem_cache *vfio_ccw_cmd_region;
 
+debug_info_t *vfio_ccw_debug_msg_id;
+debug_info_t *vfio_ccw_debug_trace_id;
+
 /*
  * Helpers
  */
@@ -164,6 +167,9 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
 	if (ret)
 		goto out_disable;
 
+	VFIO_CCW_MSG_EVENT(4, "bound to subchannel %x.%x.%04x\n",
+			   sch->schid.cssid, sch->schid.ssid,
+			   sch->schid.sch_no);
 	return 0;
 
 out_disable:
@@ -194,6 +200,9 @@ static int vfio_ccw_sch_remove(struct subchannel *sch)
 	kfree(private->cp.guest_cp);
 	kfree(private);
 
+	VFIO_CCW_MSG_EVENT(4, "unbound from subchannel %x.%x.%04x\n",
+			   sch->schid.cssid, sch->schid.ssid,
+			   sch->schid.sch_no);
 	return 0;
 }
 
@@ -263,13 +272,46 @@ static struct css_driver vfio_ccw_sch_driver = {
 	.sch_event = vfio_ccw_sch_event,
 };
 
+static int __init vfio_ccw_debug_init(void)
+{
+	vfio_ccw_debug_msg_id = debug_register("vfio_ccw_msg", 16, 1,
+					       11 * sizeof(long));
+	if (!vfio_ccw_debug_msg_id)
+		goto out_unregister;
+	debug_register_view(vfio_ccw_debug_msg_id, &debug_sprintf_view);
+	debug_set_level(vfio_ccw_debug_msg_id, 2);
+	vfio_ccw_debug_trace_id = debug_register("vfio_ccw_trace", 16, 1, 16);
+	if (!vfio_ccw_debug_trace_id)
+		goto out_unregister;
+	debug_register_view(vfio_ccw_debug_trace_id, &debug_hex_ascii_view);
+	debug_set_level(vfio_ccw_debug_trace_id, 2);
+	return 0;
+
+out_unregister:
+	debug_unregister(vfio_ccw_debug_msg_id);
+	debug_unregister(vfio_ccw_debug_trace_id);
+	return -1;
+}
+
+static void vfio_ccw_debug_exit(void)
+{
+	debug_unregister(vfio_ccw_debug_msg_id);
+	debug_unregister(vfio_ccw_debug_trace_id);
+}
+
 static int __init vfio_ccw_sch_init(void)
 {
-	int ret = -ENOMEM;
+	int ret;
+
+	ret = vfio_ccw_debug_init();
+	if (ret)
+		return ret;
 
 	vfio_ccw_work_q = create_singlethread_workqueue("vfio-ccw");
-	if (!vfio_ccw_work_q)
-		return -ENOMEM;
+	if (!vfio_ccw_work_q) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
 
 	vfio_ccw_io_region = kmem_cache_create_usercopy("vfio_ccw_io_region",
 					sizeof(struct ccw_io_region), 0,
@@ -298,6 +340,7 @@ out_err:
 	kmem_cache_destroy(vfio_ccw_cmd_region);
 	kmem_cache_destroy(vfio_ccw_io_region);
 	destroy_workqueue(vfio_ccw_work_q);
+	vfio_ccw_debug_exit();
 	return ret;
 }
 
@@ -308,6 +351,7 @@ static void __exit vfio_ccw_sch_exit(void)
 	kmem_cache_destroy(vfio_ccw_io_region);
 	kmem_cache_destroy(vfio_ccw_cmd_region);
 	destroy_workqueue(vfio_ccw_work_q);
+	vfio_ccw_debug_exit();
 }
 module_init(vfio_ccw_sch_init);
 module_exit(vfio_ccw_sch_exit);