wifi: cfg80211: remove wdev mutex

Since we're now protecting everything with the wiphy mutex
(and were really using it for almost everything before),
there's no longer any real reason to have a separate wdev
mutex. It may feel better, but really has no value.

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

drivers/net/wireless/ath/ath6kl/cfg80211.c

@@ -1118,9 +1118,9 @@ void ath6kl_cfg80211_ch_switch_notify(struct ath6kl_vif *vif, int freq,
 				 ath6kl_band_2ghz.ht_cap.ht_supported) ?
 					NL80211_CHAN_HT20 : NL80211_CHAN_NO_HT);
 
-	mutex_lock(&vif->wdev.mtx);
+	wiphy_lock(vif->ar->wiphy);
 	cfg80211_ch_switch_notify(vif->ndev, &chandef, 0, 0);
-	mutex_unlock(&vif->wdev.mtx);
+	wiphy_unlock(vif->ar->wiphy);
 }
 
 static int ath6kl_cfg80211_add_key(struct wiphy *wiphy, struct net_device *ndev,

drivers/net/wireless/marvell/mwifiex/11h.c

@@ -287,7 +287,7 @@ void mwifiex_dfs_chan_sw_work_queue(struct work_struct *work)
 
 	mwifiex_dbg(priv->adapter, MSG,
 		    "indicating channel switch completion to kernel\n");
-	mutex_lock(&priv->wdev.mtx);
+	wiphy_lock(priv->wdev.wiphy);
 	cfg80211_ch_switch_notify(priv->netdev, &priv->dfs_chandef, 0, 0);
-	mutex_unlock(&priv->wdev.mtx);
+	wiphy_unlock(priv->wdev.wiphy);
 }

drivers/net/wireless/quantenna/qtnfmac/event.c

@@ -477,9 +477,9 @@ qtnf_event_handle_freq_change(struct qtnf_wmac *mac,
 		if (!vif->netdev)
 			continue;
 
-		mutex_lock(&vif->wdev.mtx);
+		wiphy_lock(priv_to_wiphy(vif->mac));
 		cfg80211_ch_switch_notify(vif->netdev, &chandef, 0, 0);
-		mutex_unlock(&vif->wdev.mtx);
+		wiphy_unlock(priv_to_wiphy(vif->mac));
 	}
 
 	return 0;

include/net/cfg80211.h

@@ -5938,8 +5938,6 @@ void wiphy_delayed_work_flush(struct wiphy *wiphy,
  * @mgmt_registrations: list of registrations for management frames
  * @mgmt_registrations_need_update: mgmt registrations were updated,
  *	need to propagate the update to the driver
- * @mtx: mutex used to lock data in this struct, may be used by drivers
- *	and some API functions require it held
  * @beacon_interval: beacon interval used on this device for transmitting
  *	beacons, 0 when not valid
  * @address: The address for this device, valid only if @netdev is %NULL
@@ -5985,8 +5983,6 @@ struct wireless_dev {
 	struct list_head mgmt_registrations;
 	u8 mgmt_registrations_need_update:1;
 
-	struct mutex mtx;
-
 	bool use_4addr, is_running, registered, registering;
 
 	u8 address[ETH_ALEN] __aligned(sizeof(u16));
@@ -8589,7 +8585,7 @@ bool cfg80211_reg_can_beacon_relax(struct wiphy *wiphy,
  * @link_id: the link ID for MLO, must be 0 for non-MLO
  * @punct_bitmap: the new puncturing bitmap
  *
- * Caller must acquire wdev_lock, therefore must only be called from sleepable
+ * Caller must hold wiphy mutex, therefore must only be called from sleepable
  * driver context!
  */
 void cfg80211_ch_switch_notify(struct net_device *dev,

include/net/mac80211.h

@@ -643,19 +643,15 @@ struct ieee80211_fils_discovery {
  * @pwr_reduction: power constraint of BSS.
  * @eht_support: does this BSS support EHT
  * @eht_puncturing: bitmap to indicate which channels are punctured in this BSS
- * @csa_active: marks whether a channel switch is going on. Internally it is
- *	write-protected by sdata_lock and local->mtx so holding either is fine
- *	for read access.
+ * @csa_active: marks whether a channel switch is going on.
  * @csa_punct_bitmap: new puncturing bitmap for channel switch
  * @mu_mimo_owner: indicates interface owns MU-MIMO capability
  * @chanctx_conf: The channel context this interface is assigned to, or %NULL
  *	when it is not assigned. This pointer is RCU-protected due to the TX
  *	path needing to access it; even though the netdev carrier will always
  *	be off when it is %NULL there can still be races and packets could be
  *	processed after it switches back to %NULL.
- * @color_change_active: marks whether a color change is ongoing. Internally it is
- *	write-protected by sdata_lock and local->mtx so holding either is fine
- *	for read access.
+ * @color_change_active: marks whether a color change is ongoing.
  * @color_change_color: the bss color that will be used after the change.
  * @ht_ldpc: in AP mode, indicates interface has HT LDPC capability.
  * @vht_ldpc: in AP mode, indicates interface has VHT LDPC capability.
@@ -1974,22 +1970,18 @@ struct ieee80211_vif *wdev_to_ieee80211_vif(struct wireless_dev *wdev);
  */
 struct wireless_dev *ieee80211_vif_to_wdev(struct ieee80211_vif *vif);
 
-/**
- * lockdep_vif_mutex_held - for lockdep checks on link poiners
- * @vif: the interface to check
- */
-static inline bool lockdep_vif_mutex_held(struct ieee80211_vif *vif)
+static inline bool lockdep_vif_wiphy_mutex_held(struct ieee80211_vif *vif)
 {
-	return lockdep_is_held(&ieee80211_vif_to_wdev(vif)->mtx);
+	return lockdep_is_held(&ieee80211_vif_to_wdev(vif)->wiphy->mtx);
 }
 
 #define link_conf_dereference_protected(vif, link_id)		\
 	rcu_dereference_protected((vif)->link_conf[link_id],	\
-				  lockdep_vif_mutex_held(vif))
+				  lockdep_vif_wiphy_mutex_held(vif))
 
 #define link_conf_dereference_check(vif, link_id)		\
 	rcu_dereference_check((vif)->link_conf[link_id],	\
-			      lockdep_vif_mutex_held(vif))
+			      lockdep_vif_wiphy_mutex_held(vif))
 
 /**
  * enum ieee80211_key_flags - key flags

net/mac80211/cfg.c

@@ -573,8 +573,7 @@ ieee80211_lookup_key(struct ieee80211_sub_if_data *sdata, int link_id,
 	struct ieee80211_key *key;
 
 	if (link_id >= 0) {
-		link = rcu_dereference_check(sdata->link[link_id],
-					     lockdep_is_held(&sdata->wdev.mtx));
+		link = sdata_dereference(sdata->link[link_id], sdata);
 		if (!link)
 			return NULL;
 	}
@@ -896,12 +895,10 @@ static int ieee80211_set_monitor_channel(struct wiphy *wiphy,
 		sdata = wiphy_dereference(local->hw.wiphy,
 					  local->monitor_sdata);
 		if (sdata) {
-			sdata_lock(sdata);
 			ieee80211_link_release_channel(&sdata->deflink);
 			ret = ieee80211_link_use_channel(&sdata->deflink,
 							 chandef,
 							 IEEE80211_CHANCTX_EXCLUSIVE);
-			sdata_unlock(sdata);
 		}
 	} else {
 		if (local->open_count == local->monitors) {
@@ -1490,7 +1487,7 @@ static int ieee80211_change_beacon(struct wiphy *wiphy, struct net_device *dev,
 	struct ieee80211_bss_conf *link_conf;
 	u64 changed = 0;
 
-	sdata_assert_lock(sdata);
+	lockdep_assert_wiphy(wiphy);
 
 	link = sdata_dereference(sdata->link[params->link_id], sdata);
 	if (!link)
@@ -1549,7 +1546,6 @@ static int ieee80211_stop_ap(struct wiphy *wiphy, struct net_device *dev,
 		sdata_dereference(sdata->link[link_id], sdata);
 	struct ieee80211_bss_conf *link_conf = link->conf;
 
-	sdata_assert_lock(sdata);
 	lockdep_assert_wiphy(local->hw.wiphy);
 
 	old_beacon = sdata_dereference(link->u.ap.beacon, sdata);
@@ -2163,14 +2159,7 @@ static int ieee80211_change_station(struct wiphy *wiphy,
 		}
 	}
 
-	/* we use sta_info_get_bss() so this might be different */
-	if (sdata != sta->sdata) {
-		mutex_lock_nested(&sta->sdata->wdev.mtx, 1);
-		err = sta_apply_parameters(local, sta, params);
-		mutex_unlock(&sta->sdata->wdev.mtx);
-	} else {
-		err = sta_apply_parameters(local, sta, params);
-	}
+	err = sta_apply_parameters(local, sta, params);
 	if (err)
 		return err;
 
@@ -3132,7 +3121,7 @@ int __ieee80211_request_smps_mgd(struct ieee80211_sub_if_data *sdata,
 	struct sta_info *sta;
 	bool tdls_peer_found = false;
 
-	lockdep_assert_held(&sdata->wdev.mtx);
+	lockdep_assert_wiphy(sdata->local->hw.wiphy);
 
 	if (WARN_ON_ONCE(sdata->vif.type != NL80211_IFTYPE_STATION))
 		return -EINVAL;
@@ -3211,7 +3200,6 @@ static int ieee80211_set_power_mgmt(struct wiphy *wiphy, struct net_device *dev,
 	local->dynamic_ps_forced_timeout = timeout;
 
 	/* no change, but if automatic follow powersave */
-	sdata_lock(sdata);
 	for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
 		struct ieee80211_link_data *link;
 
@@ -3222,7 +3210,6 @@ static int ieee80211_set_power_mgmt(struct wiphy *wiphy, struct net_device *dev,
 		__ieee80211_request_smps_mgd(sdata, link,
 					     link->u.mgd.req_smps);
 	}
-	sdata_unlock(sdata);
 
 	if (ieee80211_hw_check(&local->hw, SUPPORTS_DYNAMIC_PS))
 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
@@ -3609,7 +3596,6 @@ static int __ieee80211_csa_finalize(struct ieee80211_sub_if_data *sdata)
 	u64 changed = 0;
 	int err;
 
-	sdata_assert_lock(sdata);
 	lockdep_assert_wiphy(local->hw.wiphy);
 
 	/*
@@ -3681,20 +3667,16 @@ void ieee80211_csa_finalize_work(struct wiphy *wiphy, struct wiphy_work *work)
 			     deflink.csa_finalize_work);
 	struct ieee80211_local *local = sdata->local;
 
-	sdata_lock(sdata);
 	lockdep_assert_wiphy(local->hw.wiphy);
 
 	/* AP might have been stopped while waiting for the lock. */
 	if (!sdata->vif.bss_conf.csa_active)
-		goto unlock;
+		return;
 
 	if (!ieee80211_sdata_running(sdata))
-		goto unlock;
+		return;
 
 	ieee80211_csa_finalize(sdata);
-
-unlock:
-	sdata_unlock(sdata);
 }
 
 static int ieee80211_set_csa_beacon(struct ieee80211_sub_if_data *sdata,
@@ -3850,7 +3832,6 @@ __ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
 	u64 changed = 0;
 	int err;
 
-	sdata_assert_lock(sdata);
 	lockdep_assert_wiphy(local->hw.wiphy);
 
 	if (!list_empty(&local->roc_list) || local->scanning)
@@ -4665,7 +4646,6 @@ static int ieee80211_color_change_finalize(struct ieee80211_sub_if_data *sdata)
 	u64 changed = 0;
 	int err;
 
-	sdata_assert_lock(sdata);
 	lockdep_assert_wiphy(local->hw.wiphy);
 
 	sdata->vif.bss_conf.color_change_active = false;
@@ -4692,20 +4672,16 @@ void ieee80211_color_change_finalize_work(struct wiphy *wiphy,
 			     deflink.color_change_finalize_work);
 	struct ieee80211_local *local = sdata->local;
 
-	sdata_lock(sdata);
 	lockdep_assert_wiphy(local->hw.wiphy);
 
 	/* AP might have been stopped while waiting for the lock. */
 	if (!sdata->vif.bss_conf.color_change_active)
-		goto unlock;
+		return;
 
 	if (!ieee80211_sdata_running(sdata))
-		goto unlock;
+		return;
 
 	ieee80211_color_change_finalize(sdata);
-
-unlock:
-	sdata_unlock(sdata);
 }
 
 void ieee80211_color_collision_detection_work(struct work_struct *work)
@@ -4716,9 +4692,7 @@ void ieee80211_color_collision_detection_work(struct work_struct *work)
 			     color_collision_detect_work);
 	struct ieee80211_sub_if_data *sdata = link->sdata;
 
-	sdata_lock(sdata);
 	cfg80211_obss_color_collision_notify(sdata->dev, link->color_bitmap);
-	sdata_unlock(sdata);
 }
 
 void ieee80211_color_change_finish(struct ieee80211_vif *vif)
@@ -4762,7 +4736,6 @@ ieee80211_color_change(struct wiphy *wiphy, struct net_device *dev,
 	u64 changed = 0;
 	int err;
 
-	sdata_assert_lock(sdata);
 	lockdep_assert_wiphy(local->hw.wiphy);
 
 	if (sdata->vif.bss_conf.nontransmitted)

net/mac80211/debugfs_netdev.c

@@ -322,7 +322,6 @@ static int ieee80211_set_smps(struct ieee80211_link_data *link,
 {
 	struct ieee80211_sub_if_data *sdata = link->sdata;
 	struct ieee80211_local *local = sdata->local;
-	int err;
 
 	if (sdata->vif.driver_flags & IEEE80211_VIF_DISABLE_SMPS_OVERRIDE)
 		return -EOPNOTSUPP;
@@ -340,11 +339,7 @@ static int ieee80211_set_smps(struct ieee80211_link_data *link,
 	if (sdata->vif.type != NL80211_IFTYPE_STATION)
 		return -EOPNOTSUPP;
 
-	sdata_lock(sdata);
-	err = __ieee80211_request_smps_mgd(link->sdata, link, smps_mode);
-	sdata_unlock(sdata);
-
-	return err;
+	return __ieee80211_request_smps_mgd(link->sdata, link, smps_mode);
 }
 
 static const char *smps_modes[IEEE80211_SMPS_NUM_MODES] = {
@@ -416,16 +411,13 @@ static ssize_t ieee80211_if_parse_tkip_mic_test(
 	case NL80211_IFTYPE_STATION:
 		fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
 		/* BSSID SA DA */
-		sdata_lock(sdata);
 		if (!sdata->u.mgd.associated) {
-			sdata_unlock(sdata);
 			dev_kfree_skb(skb);
 			return -ENOTCONN;
 		}
 		memcpy(hdr->addr1, sdata->deflink.u.mgd.bssid, ETH_ALEN);
 		memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
 		memcpy(hdr->addr3, addr, ETH_ALEN);
-		sdata_unlock(sdata);
 		break;
 	default:
 		dev_kfree_skb(skb);

net/mac80211/driver-ops.c

@@ -300,7 +300,6 @@ int drv_assign_vif_chanctx(struct ieee80211_local *local,
 	might_sleep();
 	lockdep_assert_wiphy(local->hw.wiphy);
 
-	drv_verify_link_exists(sdata, link_conf);
 	if (!check_sdata_in_driver(sdata))
 		return -EIO;
 
@@ -329,7 +328,6 @@ void drv_unassign_vif_chanctx(struct ieee80211_local *local,
 	might_sleep();
 	lockdep_assert_wiphy(local->hw.wiphy);
 
-	drv_verify_link_exists(sdata, link_conf);
 	if (!check_sdata_in_driver(sdata))
 		return;
 

net/mac80211/driver-ops.h

@@ -996,14 +996,6 @@ static inline void drv_change_chanctx(struct ieee80211_local *local,
 	trace_drv_return_void(local);
 }
 
-static inline void drv_verify_link_exists(struct ieee80211_sub_if_data *sdata,
-					  struct ieee80211_bss_conf *link_conf)
-{
-	/* deflink always exists, so need to check only for other links */
-	if (sdata->deflink.conf != link_conf)
-		sdata_assert_lock(sdata);
-}
-
 int drv_assign_vif_chanctx(struct ieee80211_local *local,
 			   struct ieee80211_sub_if_data *sdata,
 			   struct ieee80211_bss_conf *link_conf,
@@ -1022,9 +1014,6 @@ static inline int drv_start_ap(struct ieee80211_local *local,
 {
 	int ret = 0;
 
-	/* make sure link_conf is protected */
-	drv_verify_link_exists(sdata, link_conf);
-
 	might_sleep();
 	lockdep_assert_wiphy(local->hw.wiphy);
 
@@ -1045,9 +1034,6 @@ static inline void drv_stop_ap(struct ieee80211_local *local,
 	might_sleep();
 	lockdep_assert_wiphy(local->hw.wiphy);
 
-	/* make sure link_conf is protected */
-	drv_verify_link_exists(sdata, link_conf);
-
 	if (!check_sdata_in_driver(sdata))
 		return;