cfg80211: export interface stopping function

This exports a new cfg80211_stop_iface() function.

This is intended for driver internal interface
combination management and channel switching.

Due to locking issues (it re-enters driver) the
call is asynchronous and uses cfg80211 event
list/worker.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/core.c b/net/wireless/core.c
index f509da4..7e023b7 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -792,23 +792,23 @@
 		rdev->num_running_monitor_ifaces += num;
 }
 
-void cfg80211_leave(struct cfg80211_registered_device *rdev,
-		    struct wireless_dev *wdev)
+void __cfg80211_leave(struct cfg80211_registered_device *rdev,
+		      struct wireless_dev *wdev)
 {
 	struct net_device *dev = wdev->netdev;
 
 	ASSERT_RTNL();
+	ASSERT_WDEV_LOCK(wdev);
 
 	switch (wdev->iftype) {
 	case NL80211_IFTYPE_ADHOC:
-		cfg80211_leave_ibss(rdev, dev, true);
+		__cfg80211_leave_ibss(rdev, dev, true);
 		break;
 	case NL80211_IFTYPE_P2P_CLIENT:
 	case NL80211_IFTYPE_STATION:
 		if (rdev->sched_scan_req && dev == rdev->sched_scan_req->dev)
 			__cfg80211_stop_sched_scan(rdev, false);
 
-		wdev_lock(wdev);
 #ifdef CONFIG_CFG80211_WEXT
 		kfree(wdev->wext.ie);
 		wdev->wext.ie = NULL;
@@ -817,20 +817,49 @@
 #endif
 		cfg80211_disconnect(rdev, dev,
 				    WLAN_REASON_DEAUTH_LEAVING, true);
-		wdev_unlock(wdev);
 		break;
 	case NL80211_IFTYPE_MESH_POINT:
-		cfg80211_leave_mesh(rdev, dev);
+		__cfg80211_leave_mesh(rdev, dev);
 		break;
 	case NL80211_IFTYPE_AP:
 	case NL80211_IFTYPE_P2P_GO:
-		cfg80211_stop_ap(rdev, dev, true);
+		__cfg80211_stop_ap(rdev, dev, true);
 		break;
 	default:
 		break;
 	}
 }
 
+void cfg80211_leave(struct cfg80211_registered_device *rdev,
+		    struct wireless_dev *wdev)
+{
+	wdev_lock(wdev);
+	__cfg80211_leave(rdev, wdev);
+	wdev_unlock(wdev);
+}
+
+void cfg80211_stop_iface(struct wiphy *wiphy, struct wireless_dev *wdev,
+			 gfp_t gfp)
+{
+	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
+	struct cfg80211_event *ev;
+	unsigned long flags;
+
+	trace_cfg80211_stop_iface(wiphy, wdev);
+
+	ev = kzalloc(sizeof(*ev), gfp);
+	if (!ev)
+		return;
+
+	ev->type = EVENT_STOPPED;
+
+	spin_lock_irqsave(&wdev->event_lock, flags);
+	list_add_tail(&ev->list, &wdev->event_list);
+	spin_unlock_irqrestore(&wdev->event_lock, flags);
+	queue_work(cfg80211_wq, &rdev->event_work);
+}
+EXPORT_SYMBOL(cfg80211_stop_iface);
+
 static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 					 unsigned long state, void *ptr)
 {