cfg80211: vastly simplify locking

Virtually all code paths in cfg80211 already (need to) hold
the RTNL. As such, there's little point in having another
four mutexes for various parts of the code, they just cause
lock ordering issues (and much of the time, the RTNL and a
few of the others need thus be held.)

Simplify all this by getting rid of the extra four mutexes
and just use the RTNL throughout. Only a few code changes
were needed to do this and we can get rid of a work struct
for bonus points.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

13 files changed, 115 insertions, 444 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 9416b8f55f5..5fc642d4071 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -36,12 +36,10 @@ MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("wireless configuration support");
 MODULE_ALIAS_GENL_FAMILY(NL80211_GENL_NAME);
 
-/* RCU-protected (and cfg80211_mutex for writers) */
+/* RCU-protected (and RTNL for writers) */
 LIST_HEAD(cfg80211_rdev_list);
 int cfg80211_rdev_list_generation;
 
-DEFINE_MUTEX(cfg80211_mutex);
-
 /* for debugfs */
 static struct dentry *ieee80211_debugfs_dir;
 
@@ -53,12 +51,11 @@ module_param(cfg80211_disable_40mhz_24ghz, bool, 0644);
 MODULE_PARM_DESC(cfg80211_disable_40mhz_24ghz,
 		 "Disable 40MHz support in the 2.4GHz band");
 
-/* requires cfg80211_mutex to be held! */
 struct cfg80211_registered_device *cfg80211_rdev_by_wiphy_idx(int wiphy_idx)
 {
 	struct cfg80211_registered_device *result = NULL, *rdev;
 
-	assert_cfg80211_lock();
+	ASSERT_RTNL();
 
 	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
 		if (rdev->wiphy_idx == wiphy_idx) {
@@ -77,12 +74,11 @@ int get_wiphy_idx(struct wiphy *wiphy)
 	return rdev->wiphy_idx;
 }
 
-/* requires cfg80211_rdev_mutex to be held! */
 struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx)
 {
 	struct cfg80211_registered_device *rdev;
 
-	assert_cfg80211_lock();
+	ASSERT_RTNL();
 
 	rdev = cfg80211_rdev_by_wiphy_idx(wiphy_idx);
 	if (!rdev)
@@ -90,14 +86,13 @@ struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx)
 	return &rdev->wiphy;
 }
 
-/* requires cfg80211_mutex to be held */
 int cfg80211_dev_rename(struct cfg80211_registered_device *rdev,
 			char *newname)
 {
 	struct cfg80211_registered_device *rdev2;
 	int wiphy_idx, taken = -1, result, digits;
 
-	assert_cfg80211_lock();
+	ASSERT_RTNL();
 
 	/* prohibit calling the thing phy%d when %d is not its number */
 	sscanf(newname, PHY_NAME "%d%n", &wiphy_idx, &taken);
@@ -195,8 +190,7 @@ static void cfg80211_rfkill_poll(struct rfkill *rfkill, void *data)
 void cfg80211_stop_p2p_device(struct cfg80211_registered_device *rdev,
 			      struct wireless_dev *wdev)
 {
-	lockdep_assert_held(&rdev->devlist_mtx);
-	lockdep_assert_held(&rdev->sched_scan_mtx);
+	ASSERT_RTNL();
 
 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_P2P_DEVICE))
 		return;
@@ -235,8 +229,6 @@ static int cfg80211_rfkill_set_block(void *data, bool blocked)
 
 	rtnl_lock();
 
-	/* read-only iteration need not hold the devlist_mtx */
-
 	list_for_each_entry(wdev, &rdev->wdev_list, list) {
 		if (wdev->netdev) {
 			dev_close(wdev->netdev);
@@ -245,12 +237,7 @@ static int cfg80211_rfkill_set_block(void *data, bool blocked)
 		/* otherwise, check iftype */
 		switch (wdev->iftype) {
 		case NL80211_IFTYPE_P2P_DEVICE:
-			/* but this requires it */
-			mutex_lock(&rdev->devlist_mtx);
-			mutex_lock(&rdev->sched_scan_mtx);
 			cfg80211_stop_p2p_device(rdev, wdev);
-			mutex_unlock(&rdev->sched_scan_mtx);
-			mutex_unlock(&rdev->devlist_mtx);
 			break;
 		default:
 			break;
@@ -278,10 +265,7 @@ static void cfg80211_event_work(struct work_struct *work)
 			    event_work);
 
 	rtnl_lock();
-	cfg80211_lock_rdev(rdev);
-
 	cfg80211_process_rdev_events(rdev);
-	cfg80211_unlock_rdev(rdev);
 	rtnl_unlock();
 }
 
@@ -323,9 +307,6 @@ struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
 	/* give it a proper name */
 	dev_set_name(&rdev->wiphy.dev, PHY_NAME "%d", rdev->wiphy_idx);
 
-	mutex_init(&rdev->mtx);
-	mutex_init(&rdev->devlist_mtx);
-	mutex_init(&rdev->sched_scan_mtx);
 	INIT_LIST_HEAD(&rdev->wdev_list);
 	INIT_LIST_HEAD(&rdev->beacon_registrations);
 	spin_lock_init(&rdev->beacon_registrations_lock);
@@ -573,11 +554,11 @@ int wiphy_register(struct wiphy *wiphy)
 	/* check and set up bitrates */
 	ieee80211_set_bitrate_flags(wiphy);
 
-	mutex_lock(&cfg80211_mutex);
+	rtnl_lock();
 
 	res = device_add(&rdev->wiphy.dev);
 	if (res) {
-		mutex_unlock(&cfg80211_mutex);
+		rtnl_unlock();
 		return res;
 	}
 
@@ -606,25 +587,18 @@ int wiphy_register(struct wiphy *wiphy)
 	}
 
 	cfg80211_debugfs_rdev_add(rdev);
-	mutex_unlock(&cfg80211_mutex);
 
-	/*
-	 * due to a locking dependency this has to be outside of the
-	 * cfg80211_mutex lock
-	 */
 	res = rfkill_register(rdev->rfkill);
 	if (res) {
 		device_del(&rdev->wiphy.dev);
 
-		mutex_lock(&cfg80211_mutex);
 		debugfs_remove_recursive(rdev->wiphy.debugfsdir);
 		list_del_rcu(&rdev->list);
 		wiphy_regulatory_deregister(wiphy);
-		mutex_unlock(&cfg80211_mutex);
+		rtnl_unlock();
 		return res;
 	}
 
-	rtnl_lock();
 	rdev->wiphy.registered = true;
 	rtnl_unlock();
 	return 0;
@@ -654,25 +628,19 @@ void wiphy_unregister(struct wiphy *wiphy)
 {
 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
 
-	rtnl_lock();
-	rdev->wiphy.registered = false;
-	rtnl_unlock();
-
-	rfkill_unregister(rdev->rfkill);
-
-	/* protect the device list */
-	mutex_lock(&cfg80211_mutex);
-
 	wait_event(rdev->dev_wait, ({
 		int __count;
-		mutex_lock(&rdev->devlist_mtx);
+		rtnl_lock();
 		__count = rdev->opencount;
-		mutex_unlock(&rdev->devlist_mtx);
+		rtnl_unlock();
 		__count == 0; }));
 
-	mutex_lock(&rdev->devlist_mtx);
+	rtnl_lock();
+	rdev->wiphy.registered = false;
+
+	rfkill_unregister(rdev->rfkill);
+
 	BUG_ON(!list_empty(&rdev->wdev_list));
-	mutex_unlock(&rdev->devlist_mtx);
 
 	/*
 	 * First remove the hardware from everywhere, this makes
@@ -683,20 +651,6 @@ void wiphy_unregister(struct wiphy *wiphy)
 	synchronize_rcu();
 
 	/*
-	 * Try to grab rdev->mtx. If a command is still in progress,
-	 * hopefully the driver will refuse it since it's tearing
-	 * down the device already. We wait for this command to complete
-	 * before unlinking the item from the list.
-	 * Note: as codified by the BUG_ON above we cannot get here if
-	 * a virtual interface is still present. Hence, we can only get
-	 * to lock contention here if userspace issues a command that
-	 * identified the hardware by wiphy index.
-	 */
-	cfg80211_lock_rdev(rdev);
-	/* nothing */
-	cfg80211_unlock_rdev(rdev);
-
-	/*
 	 * If this device got a regulatory hint tell core its
 	 * free to listen now to a new shiny device regulatory hint
 	 */
@@ -705,7 +659,7 @@ void wiphy_unregister(struct wiphy *wiphy)
 	cfg80211_rdev_list_generation++;
 	device_del(&rdev->wiphy.dev);
 
-	mutex_unlock(&cfg80211_mutex);
+	rtnl_unlock();
 
 	flush_work(&rdev->scan_done_wk);
 	cancel_work_sync(&rdev->conn_work);
@@ -723,9 +677,6 @@ void cfg80211_dev_free(struct cfg80211_registered_device *rdev)
 	struct cfg80211_internal_bss *scan, *tmp;
 	struct cfg80211_beacon_registration *reg, *treg;
 	rfkill_destroy(rdev->rfkill);
-	mutex_destroy(&rdev->mtx);
-	mutex_destroy(&rdev->devlist_mtx);
-	mutex_destroy(&rdev->sched_scan_mtx);
 	list_for_each_entry_safe(reg, treg, &rdev->beacon_registrations, list) {
 		list_del(&reg->list);
 		kfree(reg);
@@ -750,36 +701,6 @@ void wiphy_rfkill_set_hw_state(struct wiphy *wiphy, bool blocked)
 }
 EXPORT_SYMBOL(wiphy_rfkill_set_hw_state);
 
-static void wdev_cleanup_work(struct work_struct *work)
-{
-	struct wireless_dev *wdev;
-	struct cfg80211_registered_device *rdev;
-
-	wdev = container_of(work, struct wireless_dev, cleanup_work);
-	rdev = wiphy_to_dev(wdev->wiphy);
-
-	mutex_lock(&rdev->sched_scan_mtx);
-
-	if (WARN_ON(rdev->scan_req && rdev->scan_req->wdev == wdev)) {
-		rdev->scan_req->aborted = true;
-		___cfg80211_scan_done(rdev, true);
-	}
-
-	if (WARN_ON(rdev->sched_scan_req &&
-		    rdev->sched_scan_req->dev == wdev->netdev)) {
-		__cfg80211_stop_sched_scan(rdev, false);
-	}
-
-	mutex_unlock(&rdev->sched_scan_mtx);
-
-	mutex_lock(&rdev->devlist_mtx);
-	rdev->opencount--;
-	mutex_unlock(&rdev->devlist_mtx);
-	wake_up(&rdev->dev_wait);
-
-	dev_put(wdev->netdev);
-}
-
 void cfg80211_unregister_wdev(struct wireless_dev *wdev)
 {
 	struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
@@ -789,8 +710,6 @@ void cfg80211_unregister_wdev(struct wireless_dev *wdev)
 	if (WARN_ON(wdev->netdev))
 		return;
 
-	mutex_lock(&rdev->devlist_mtx);
-	mutex_lock(&rdev->sched_scan_mtx);
 	list_del_rcu(&wdev->list);
 	rdev->devlist_generation++;
 
@@ -802,8 +721,6 @@ void cfg80211_unregister_wdev(struct wireless_dev *wdev)
 		WARN_ON_ONCE(1);
 		break;
 	}
-	mutex_unlock(&rdev->sched_scan_mtx);
-	mutex_unlock(&rdev->devlist_mtx);
 }
 EXPORT_SYMBOL(cfg80211_unregister_wdev);
 
@@ -822,7 +739,7 @@ void cfg80211_update_iface_num(struct cfg80211_registered_device *rdev,
 }
 
 void cfg80211_leave(struct cfg80211_registered_device *rdev,
-		   struct wireless_dev *wdev)
+		    struct wireless_dev *wdev)
 {
 	struct net_device *dev = wdev->netdev;
 
@@ -832,9 +749,7 @@ void cfg80211_leave(struct cfg80211_registered_device *rdev,
 		break;
 	case NL80211_IFTYPE_P2P_CLIENT:
 	case NL80211_IFTYPE_STATION:
-		mutex_lock(&rdev->sched_scan_mtx);
 		__cfg80211_stop_sched_scan(rdev, false);
-		mutex_unlock(&rdev->sched_scan_mtx);
 
 		wdev_lock(wdev);
 #ifdef CONFIG_CFG80211_WEXT
@@ -887,13 +802,11 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 		 * are added with nl80211.
 		 */
 		mutex_init(&wdev->mtx);
-		INIT_WORK(&wdev->cleanup_work, wdev_cleanup_work);
 		INIT_LIST_HEAD(&wdev->event_list);
 		spin_lock_init(&wdev->event_lock);
 		INIT_LIST_HEAD(&wdev->mgmt_registrations);
 		spin_lock_init(&wdev->mgmt_registrations_lock);
 
-		mutex_lock(&rdev->devlist_mtx);
 		wdev->identifier = ++rdev->wdev_id;
 		list_add_rcu(&wdev->list, &rdev->wdev_list);
 		rdev->devlist_generation++;
@@ -906,7 +819,6 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 		}
 		wdev->netdev = dev;
 		wdev->sme_state = CFG80211_SME_IDLE;
-		mutex_unlock(&rdev->devlist_mtx);
 #ifdef CONFIG_CFG80211_WEXT
 		wdev->wext.default_key = -1;
 		wdev->wext.default_mgmt_key = -1;
@@ -932,26 +844,22 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 		break;
 	case NETDEV_DOWN:
 		cfg80211_update_iface_num(rdev, wdev->iftype, -1);
-		dev_hold(dev);
-		queue_work(cfg80211_wq, &wdev->cleanup_work);
+		if (rdev->scan_req && rdev->scan_req->wdev == wdev) {
+			if (WARN_ON(!rdev->scan_req->notified))
+				rdev->scan_req->aborted = true;
+			___cfg80211_scan_done(rdev, true);
+		}
+
+		if (WARN_ON(rdev->sched_scan_req &&
+			    rdev->sched_scan_req->dev == wdev->netdev)) {
+			__cfg80211_stop_sched_scan(rdev, false);
+		}
+
+		rdev->opencount--;
+		wake_up(&rdev->dev_wait);
 		break;
 	case NETDEV_UP:
-		/*
-		 * If we have a really quick DOWN/UP succession we may
-		 * have this work still pending ... cancel it and see
-		 * if it was pending, in which case we need to account
-		 * for some of the work it would have done.
-		 */
-		if (cancel_work_sync(&wdev->cleanup_work)) {
-			mutex_lock(&rdev->devlist_mtx);
-			rdev->opencount--;
-			mutex_unlock(&rdev->devlist_mtx);
-			dev_put(dev);
-		}
 		cfg80211_update_iface_num(rdev, wdev->iftype, 1);
-		cfg80211_lock_rdev(rdev);
-		mutex_lock(&rdev->devlist_mtx);
-		mutex_lock(&rdev->sched_scan_mtx);
 		wdev_lock(wdev);
 		switch (wdev->iftype) {
 #ifdef CONFIG_CFG80211_WEXT
@@ -983,10 +891,7 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 			break;
 		}
 		wdev_unlock(wdev);
-		mutex_unlock(&rdev->sched_scan_mtx);
 		rdev->opencount++;
-		mutex_unlock(&rdev->devlist_mtx);
-		cfg80211_unlock_rdev(rdev);
 
 		/*
 		 * Configure power management to the driver here so that its
@@ -1003,12 +908,6 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 		break;
 	case NETDEV_UNREGISTER:
 		/*
-		 * NB: cannot take rdev->mtx here because this may be
-		 * called within code protected by it when interfaces
-		 * are removed with nl80211.
-		 */
-		mutex_lock(&rdev->devlist_mtx);
-		/*
 		 * It is possible to get NETDEV_UNREGISTER
 		 * multiple times. To detect that, check
 		 * that the interface is still on the list
@@ -1024,7 +923,6 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 			kfree(wdev->wext.keys);
 #endif
 		}
-		mutex_unlock(&rdev->devlist_mtx);
 		/*
 		 * synchronise (so that we won't find this netdev
 		 * from other code any more) and then clear the list
@@ -1044,9 +942,7 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 			return notifier_from_errno(-EOPNOTSUPP);
 		if (rfkill_blocked(rdev->rfkill))
 			return notifier_from_errno(-ERFKILL);
-		mutex_lock(&rdev->devlist_mtx);
 		ret = cfg80211_can_add_interface(rdev, wdev->iftype);
-		mutex_unlock(&rdev->devlist_mtx);
 		if (ret)
 			return notifier_from_errno(ret);
 		break;
@@ -1064,12 +960,10 @@ static void __net_exit cfg80211_pernet_exit(struct net *net)
 	struct cfg80211_registered_device *rdev;
 
 	rtnl_lock();
-	mutex_lock(&cfg80211_mutex);
 	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
 		if (net_eq(wiphy_net(&rdev->wiphy), net))
 			WARN_ON(cfg80211_switch_netns(rdev, &init_net));
 	}
-	mutex_unlock(&cfg80211_mutex);
 	rtnl_unlock();
 }
 
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 95b29075a9c..d21a0fc0140 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -5,7 +5,6 @@
  */
 #ifndef __NET_WIRELESS_CORE_H
 #define __NET_WIRELESS_CORE_H
-#include <linux/mutex.h>
 #include <linux/list.h>
 #include <linux/netdevice.h>
 #include <linux/rbtree.h>
@@ -23,11 +22,6 @@
 struct cfg80211_registered_device {
 	const struct cfg80211_ops *ops;
 	struct list_head list;
-	/* we hold this mutex during any call so that
-	 * we cannot do multiple calls at once, and also
-	 * to avoid the deregister call to proceed while
-	 * any call is in progress */
-	struct mutex mtx;
 
 	/* rfkill support */
 	struct rfkill_ops rfkill_ops;
@@ -49,9 +43,7 @@ struct cfg80211_registered_device {
 	/* wiphy index, internal only */
 	int wiphy_idx;
 
-	/* associated wireless interfaces */
-	struct mutex devlist_mtx;
-	/* protected by devlist_mtx or RCU */
+	/* associated wireless interfaces, protected by rtnl or RCU */
 	struct list_head wdev_list;
 	int devlist_generation, wdev_id;
 	int opencount; /* also protected by devlist_mtx */
@@ -75,8 +67,6 @@ struct cfg80211_registered_device {
 	struct work_struct scan_done_wk;
 	struct work_struct sched_scan_results_wk;
 
-	struct mutex sched_scan_mtx;
-
 #ifdef CONFIG_NL80211_TESTMODE
 	struct genl_info *testmode_info;
 #endif
@@ -120,15 +110,9 @@ cfg80211_rdev_free_wowlan(struct cfg80211_registered_device *rdev)
 }
 
 extern struct workqueue_struct *cfg80211_wq;
-extern struct mutex cfg80211_mutex;
 extern struct list_head cfg80211_rdev_list;
 extern int cfg80211_rdev_list_generation;
 
-static inline void assert_cfg80211_lock(void)
-{
-	lockdep_assert_held(&cfg80211_mutex);
-}
-
 struct cfg80211_internal_bss {
 	struct list_head list;
 	struct list_head hidden_list;
@@ -161,23 +145,11 @@ static inline void cfg80211_unhold_bss(struct cfg80211_internal_bss *bss)
 struct cfg80211_registered_device *cfg80211_rdev_by_wiphy_idx(int wiphy_idx);
 int get_wiphy_idx(struct wiphy *wiphy);
 
-/* requires cfg80211_rdev_mutex to be held! */
 struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx);
 
 int cfg80211_switch_netns(struct cfg80211_registered_device *rdev,
 			  struct net *net);
 
-static inline void cfg80211_lock_rdev(struct cfg80211_registered_device *rdev)
-{
-	mutex_lock(&rdev->mtx);
-}
-
-static inline void cfg80211_unlock_rdev(struct cfg80211_registered_device *rdev)
-{
-	BUG_ON(IS_ERR(rdev) || !rdev);
-	mutex_unlock(&rdev->mtx);
-}
-
 static inline void wdev_lock(struct wireless_dev *wdev)
 	__acquires(wdev)
 {
@@ -192,7 +164,7 @@ static inline void wdev_unlock(struct wireless_dev *wdev)
 	mutex_unlock(&wdev->mtx);
 }
 
-#define ASSERT_RDEV_LOCK(rdev) lockdep_assert_held(&(rdev)->mtx)
+#define ASSERT_RDEV_LOCK(rdev) ASSERT_RTNL()
 #define ASSERT_WDEV_LOCK(wdev) lockdep_assert_held(&(wdev)->mtx)
 
 static inline bool cfg80211_has_monitors_only(struct cfg80211_registered_device *rdev)
diff --git a/net/wireless/debugfs.c b/net/wireless/debugfs.c
index 920cabe0461..90d05003662 100644
--- a/net/wireless/debugfs.c
+++ b/net/wireless/debugfs.c
@@ -74,7 +74,7 @@ static ssize_t ht40allow_map_read(struct file *file,
 	if (!buf)
 		return -ENOMEM;
 
-	mutex_lock(&cfg80211_mutex);
+	rtnl_lock();
 
 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 		sband = wiphy->bands[band];
@@ -85,7 +85,7 @@ static ssize_t ht40allow_map_read(struct file *file,
 						buf, buf_size, offset);
 	}
 
-	mutex_unlock(&cfg80211_mutex);
+	rtnl_unlock();
 
 	r = simple_read_from_buffer(user_buf, count, ppos, buf, offset);
 
diff --git a/net/wireless/ibss.c b/net/wireless/ibss.c
index d80e47194d4..5449c5a6de8 100644
--- a/net/wireless/ibss.c
+++ b/net/wireless/ibss.c
@@ -152,11 +152,11 @@ int cfg80211_join_ibss(struct cfg80211_registered_device *rdev,
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	int err;
 
-	mutex_lock(&rdev->devlist_mtx);
+	ASSERT_RTNL();
+
 	wdev_lock(wdev);
 	err = __cfg80211_join_ibss(rdev, dev, params, connkeys);
 	wdev_unlock(wdev);
-	mutex_unlock(&rdev->devlist_mtx);
 
 	return err;
 }
@@ -359,11 +359,9 @@ int cfg80211_ibss_wext_siwfreq(struct net_device *dev,
 		wdev->wext.ibss.channel_fixed = false;
 	}
 
-	mutex_lock(&rdev->devlist_mtx);
 	wdev_lock(wdev);
 	err = cfg80211_ibss_wext_join(rdev, wdev);
 	wdev_unlock(wdev);
-	mutex_unlock(&rdev->devlist_mtx);
 
 	return err;
 }
@@ -429,11 +427,9 @@ int cfg80211_ibss_wext_siwessid(struct net_device *dev,
 	memcpy(wdev->wext.ibss.ssid, ssid, len);
 	wdev->wext.ibss.ssid_len = len;
 
-	mutex_lock(&rdev->devlist_mtx);
 	wdev_lock(wdev);
 	err = cfg80211_ibss_wext_join(rdev, wdev);
 	wdev_unlock(wdev);
-	mutex_unlock(&rdev->devlist_mtx);
 
 	return err;
 }
@@ -512,11 +508,9 @@ int cfg80211_ibss_wext_siwap(struct net_device *dev,
 	} else
 		wdev->wext.ibss.bssid = NULL;
 
-	mutex_lock(&rdev->devlist_mtx);
 	wdev_lock(wdev);
 	err = cfg80211_ibss_wext_join(rdev, wdev);
 	wdev_unlock(wdev);
-	mutex_unlock(&rdev->devlist_mtx);
 
 	return err;
 }
diff --git a/net/wireless/mesh.c b/net/wireless/mesh.c
index 9546ad21055..5dfb289ab76 100644
--- a/net/wireless/mesh.c
+++ b/net/wireless/mesh.c
@@ -186,11 +186,9 @@ int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	int err;
 
-	mutex_lock(&rdev->devlist_mtx);
 	wdev_lock(wdev);
 	err = __cfg80211_join_mesh(rdev, dev, setup, conf);
 	wdev_unlock(wdev);
-	mutex_unlock(&rdev->devlist_mtx);
 
 	return err;
 }
diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index c21e32f9549..68b40f21bc3 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -313,14 +313,14 @@ int cfg80211_mlme_auth(struct cfg80211_registered_device *rdev,
 {
 	int err;
 
-	mutex_lock(&rdev->devlist_mtx);
+	ASSERT_RTNL();
+
 	wdev_lock(dev->ieee80211_ptr);
 	err = __cfg80211_mlme_auth(rdev, dev, chan, auth_type, bssid,
 				   ssid, ssid_len, ie, ie_len,
 				   key, key_len, key_idx,
 				   sae_data, sae_data_len);
 	wdev_unlock(dev->ieee80211_ptr);
-	mutex_unlock(&rdev->devlist_mtx);
 
 	return err;
 }
@@ -424,12 +424,12 @@ int cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	int err;
 
-	mutex_lock(&rdev->devlist_mtx);
+	ASSERT_RTNL();
+
 	wdev_lock(wdev);
 	err = __cfg80211_mlme_assoc(rdev, dev, chan, bssid,
 				    ssid, ssid_len, req);
 	wdev_unlock(wdev);
-	mutex_unlock(&rdev->devlist_mtx);
 
 	return err;
 }
@@ -844,7 +844,7 @@ void cfg80211_dfs_channels_update_work(struct work_struct *work)
 			    dfs_update_channels_wk);
 	wiphy = &rdev->wiphy;
 
-	mutex_lock(&cfg80211_mutex);
+	rtnl_lock();
 	for (bandid = 0; bandid < IEEE80211_NUM_BANDS; bandid++) {
 		sband = wiphy->bands[bandid];
 		if (!sband)
@@ -877,7 +877,7 @@ void cfg80211_dfs_channels_update_work(struct work_struct *work)
 			check_again = true;
 		}
 	}
-	mutex_unlock(&cfg80211_mutex);
+	rtnl_unlock();
 
 	/* reschedule if there are other channels waiting to be cleared again */
 	if (check_again)
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 5bcf3a5b646..74cdb1a0cf3 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -59,7 +59,7 @@ __cfg80211_wdev_from_attrs(struct net *netns, struct nlattr **attrs)
 	int wiphy_idx = -1;
 	int ifidx = -1;
 
-	assert_cfg80211_lock();
+	ASSERT_RTNL();
 
 	if (!have_ifidx && !have_wdev_id)
 		return ERR_PTR(-EINVAL);
@@ -80,7 +80,6 @@ __cfg80211_wdev_from_attrs(struct net *netns, struct nlattr **attrs)
 		if (have_wdev_id && rdev->wiphy_idx != wiphy_idx)
 			continue;
 
-		mutex_lock(&rdev->devlist_mtx);
 		list_for_each_entry(wdev, &rdev->wdev_list, list) {
 			if (have_ifidx && wdev->netdev &&
 			    wdev->netdev->ifindex == ifidx) {
@@ -92,7 +91,6 @@ __cfg80211_wdev_from_attrs(struct net *netns, struct nlattr **attrs)
 				break;
 			}
 		}
-		mutex_unlock(&rdev->devlist_mtx);
 
 		if (result)
 			break;
@@ -109,7 +107,7 @@ __cfg80211_rdev_from_attrs(struct net *netns, struct nlattr **attrs)
 	struct cfg80211_registered_device *rdev = NULL, *tmp;
 	struct net_device *netdev;
 
-	assert_cfg80211_lock();
+	ASSERT_RTNL();
 
 	if (!attrs[NL80211_ATTR_WIPHY] &&
 	    !attrs[NL80211_ATTR_IFINDEX] &&
@@ -128,14 +126,12 @@ __cfg80211_rdev_from_attrs(struct net *netns, struct nlattr **attrs)
 		tmp = cfg80211_rdev_by_wiphy_idx(wdev_id >> 32);
 		if (tmp) {
 			/* make sure wdev exists */
-			mutex_lock(&tmp->devlist_mtx);
 			list_for_each_entry(wdev, &tmp->wdev_list, list) {
 				if (wdev->identifier != (u32)wdev_id)
 					continue;
 				found = true;
 				break;
 			}
-			mutex_unlock(&tmp->devlist_mtx);
 
 			if (!found)
 				tmp = NULL;
@@ -182,19 +178,6 @@ __cfg80211_rdev_from_attrs(struct net *netns, struct nlattr **attrs)
 /*
  * This function returns a pointer to the driver
  * that the genl_info item that is passed refers to.
- * If successful, it returns non-NULL and also locks
- * the driver's mutex!
- *
- * This means that you need to call cfg80211_unlock_rdev()
- * before being allowed to acquire &cfg80211_mutex!
- *
- * This is necessary because we need to lock the global
- * mutex to get an item off the list safely, and then
- * we lock the rdev mutex so it doesn't go away under us.
- *
- * We don't want to keep cfg80211_mutex locked
- * for all the time in order to allow requests on
- * other interfaces to go through at the same time.
  *
  * The result of this can be a PTR_ERR and hence must
  * be checked with IS_ERR() for errors.
@@ -202,20 +185,7 @@ __cfg80211_rdev_from_attrs(struct net *netns, struct nlattr **attrs)
 static struct cfg80211_registered_device *
 cfg80211_get_dev_from_info(struct net *netns, struct genl_info *info)
 {
-	struct cfg80211_registered_device *rdev;
-
-	mutex_lock(&cfg80211_mutex);
-	rdev = __cfg80211_rdev_from_attrs(netns, info->attrs);
-
-	/* if it is not an error we grab the lock on
-	 * it to assure it won't be going away while
-	 * we operate on it */
-	if (!IS_ERR(rdev))
-		mutex_lock(&rdev->mtx);
-
-	mutex_unlock(&cfg80211_mutex);
-
-	return rdev;
+	return __cfg80211_rdev_from_attrs(netns, info->attrs);
 }
 
 /* policy for the attributes */
@@ -456,7 +426,6 @@ static int nl80211_prepare_wdev_dump(struct sk_buff *skb,
 	int err;
 
 	rtnl_lock();
-	mutex_lock(&cfg80211_mutex);
 
 	if (!cb->args[0]) {
 		err = nlmsg_parse(cb->nlh, GENL_HDRLEN + nl80211_fam.hdrsize,
@@ -485,14 +454,12 @@ static int nl80211_prepare_wdev_dump(struct sk_buff *skb,
 		*rdev = wiphy_to_dev(wiphy);
 		*wdev = NULL;
 
-		mutex_lock(&(*rdev)->devlist_mtx);
 		list_for_each_entry(tmp, &(*rdev)->wdev_list, list) {
 			if (tmp->identifier == cb->args[1]) {
 				*wdev = tmp;
 				break;
 			}
 		}
-		mutex_unlock(&(*rdev)->devlist_mtx);
 
 		if (!*wdev) {
 			err = -ENODEV;
@@ -500,19 +467,14 @@ static int nl80211_prepare_wdev_dump(struct sk_buff *skb,
 		}
 	}
 
-	cfg80211_lock_rdev(*rdev);
-
-	mutex_unlock(&cfg80211_mutex);
 	return 0;
  out_unlock:
-	mutex_unlock(&cfg80211_mutex);
 	rtnl_unlock();
 	return err;
 }
 
 static void nl80211_finish_wdev_dump(struct cfg80211_registered_device *rdev)
 {
-	cfg80211_unlock_rdev(rdev);
 	rtnl_unlock();
 }
 
@@ -1568,7 +1530,7 @@ static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb)
 	struct nlattr **tb = nl80211_fam.attrbuf;
 	int res;
 
-	mutex_lock(&cfg80211_mutex);
+	rtnl_lock();
 	res = nlmsg_parse(cb->nlh, GENL_HDRLEN + nl80211_fam.hdrsize,
 			  tb, nl80211_fam.maxattr, nl80211_policy);
 	if (res == 0) {
@@ -1582,10 +1544,8 @@ static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb)
 			int ifidx = nla_get_u32(tb[NL80211_ATTR_IFINDEX]);
 
 			netdev = dev_get_by_index(sock_net(skb->sk), ifidx);
-			if (!netdev) {
-				mutex_unlock(&cfg80211_mutex);
+			if (!netdev)
 				return -ENODEV;
-			}
 			if (netdev->ieee80211_ptr) {
 				dev = wiphy_to_dev(
 					netdev->ieee80211_ptr->wiphy);
@@ -1629,7 +1589,6 @@ static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb)
 				    !skb->len &&
 				    cb->min_dump_alloc < 4096) {
 					cb->min_dump_alloc = 4096;
-					mutex_unlock(&cfg80211_mutex);
 					return 1;
 				}
 				idx--;
@@ -1638,7 +1597,7 @@ static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb)
 		} while (cb->args[1] > 0);
 		break;
 	}
-	mutex_unlock(&cfg80211_mutex);
+	rtnl_unlock();
 
 	cb->args[0] = idx;
 
@@ -1793,7 +1752,6 @@ static int __nl80211_set_channel(struct cfg80211_registered_device *rdev,
 	if (result)
 		return result;
 
-	mutex_lock(&rdev->devlist_mtx);
 	switch (iftype) {
 	case NL80211_IFTYPE_AP:
 	case NL80211_IFTYPE_P2P_GO:
@@ -1817,7 +1775,6 @@ static int __nl80211_set_channel(struct cfg80211_registered_device *rdev,
 	default:
 		result = -EINVAL;
 	}
-	mutex_unlock(&rdev->devlist_mtx);
 
 	return result;
 }
@@ -1866,6 +1823,8 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 	u32 frag_threshold = 0, rts_threshold = 0;
 	u8 coverage_class = 0;
 
+	ASSERT_RTNL();
+
 	/*
 	 * Try to find the wiphy and netdev. Normally this
 	 * function shouldn't need the netdev, but this is
@@ -1875,31 +1834,25 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 	 * also passed a netdev to set_wiphy, so that it is
 	 * possible to let that go to the right netdev!
 	 */
-	mutex_lock(&cfg80211_mutex);
 
 	if (info->attrs[NL80211_ATTR_IFINDEX]) {
 		int ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
 
 		netdev = dev_get_by_index(genl_info_net(info), ifindex);
-		if (netdev && netdev->ieee80211_ptr) {
+		if (netdev && netdev->ieee80211_ptr)
 			rdev = wiphy_to_dev(netdev->ieee80211_ptr->wiphy);
-			mutex_lock(&rdev->mtx);
-		} else
+		else
 			netdev = NULL;
 	}
 
 	if (!netdev) {
 		rdev = __cfg80211_rdev_from_attrs(genl_info_net(info),
 						  info->attrs);
-		if (IS_ERR(rdev)) {
-			mutex_unlock(&cfg80211_mutex);
+		if (IS_ERR(rdev))
 			return PTR_ERR(rdev);
-		}
 		wdev = NULL;
 		netdev = NULL;
 		result = 0;
-
-		mutex_lock(&rdev->mtx);
 	} else
 		wdev = netdev->ieee80211_ptr;
 
@@ -1912,8 +1865,6 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 		result = cfg80211_dev_rename(
 			rdev, nla_data(info->attrs[NL80211_ATTR_WIPHY_NAME]));
 
-	mutex_unlock(&cfg80211_mutex);
-
 	if (result)
 		goto bad_res;
 
@@ -2120,7 +2071,6 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 	}
 
  bad_res:
-	mutex_unlock(&rdev->mtx);
 	if (netdev)
 		dev_put(netdev);
 	return result;
@@ -2218,7 +2168,7 @@ static int nl80211_dump_interface(struct sk_buff *skb, struct netlink_callback *
 	struct cfg80211_registered_device *rdev;
 	struct wireless_dev *wdev;
 
-	mutex_lock(&cfg80211_mutex);
+	rtnl_lock();
 	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
 		if (!net_eq(wiphy_net(&rdev->wiphy), sock_net(skb->sk)))
 			continue;
@@ -2228,7 +2178,6 @@ static int nl80211_dump_interface(struct sk_buff *skb, struct netlink_callback *
 		}
 		if_idx = 0;
 
-		mutex_lock(&rdev->devlist_mtx);
 		list_for_each_entry(wdev, &rdev->wdev_list, list) {
 			if (if_idx < if_start) {
 				if_idx++;
@@ -2237,17 +2186,15 @@ static int nl80211_dump_interface(struct sk_buff *skb, struct netlink_callback *
 			if (nl80211_send_iface(skb, NETLINK_CB(cb->skb).portid,
 					       cb->nlh->nlmsg_seq, NLM_F_MULTI,
 					       rdev, wdev) < 0) {
-				mutex_unlock(&rdev->devlist_mtx);
 				goto out;
 			}
 			if_idx++;
 		}
-		mutex_unlock(&rdev->devlist_mtx);
 
 		wp_idx++;
 	}
  out:
-	mutex_unlock(&cfg80211_mutex);
+	rtnl_unlock();
 
 	cb->args[0] = wp_idx;
 	cb->args[1] = if_idx;
@@ -2480,11 +2427,9 @@ static int nl80211_new_interface(struct sk_buff *skb, struct genl_info *info)
 		INIT_LIST_HEAD(&wdev->mgmt_registrations);
 		spin_lock_init(&wdev->mgmt_registrations_lock);
 
-		mutex_lock(&rdev->devlist_mtx);
 		wdev->identifier = ++rdev->wdev_id;
 		list_add_rcu(&wdev->list, &rdev->wdev_list);
 		rdev->devlist_generation++;
-		mutex_unlock(&rdev->devlist_mtx);
 		break;
 	default:
 		break;
@@ -2993,8 +2938,6 @@ static bool nl80211_get_ap_channel(struct cfg80211_registered_device *rdev,
 	struct wireless_dev *wdev;
 	bool ret = false;
 
-	mutex_lock(&rdev->devlist_mtx);
-
 	list_for_each_entry(wdev, &rdev->wdev_list, list) {
 		if (wdev->iftype != NL80211_IFTYPE_AP &&
 		    wdev->iftype != NL80211_IFTYPE_P2P_GO)
@@ -3008,8 +2951,6 @@ static bool nl80211_get_ap_channel(struct cfg80211_registered_device *rdev,
 		break;
 	}
 
-	mutex_unlock(&rdev->devlist_mtx);
-
 	return ret;
 }
 
@@ -3171,13 +3112,10 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 		params.radar_require