mac80211: use channel contexts

Instead of operating on a single channel only,
use the new channel context infrastructure in
all mac80211 code.

This enables drivers that want to use the new
channel context infrastructure to use multiple
channels, while nothing should change for all
the other drivers that don't support it.

Right now this disables both TX power settings
and spatial multiplexing powersave. Both need
to be re-enabled on a channel context basis.

Additionally, when channel contexts are used
drop the connection when channel switch is
received rather than trying to handle it. This
will have to be improved later.

[With fixes from Eliad and Emmanuel incorporated]
Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 70a5d26..09c9062 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -372,10 +372,11 @@
 
 static void rate_idx_to_bitrate(struct rate_info *rate, struct sta_info *sta, int idx)
 {
+	enum ieee80211_band band = ieee80211_get_sdata_band(sta->sdata);
+
 	if (!(rate->flags & RATE_INFO_FLAGS_MCS)) {
 		struct ieee80211_supported_band *sband;
-		sband = sta->local->hw.wiphy->bands[
-				sta->local->oper_channel->band];
+		sband = sta->local->hw.wiphy->bands[band];
 		rate->legacy = sband->bitrates[idx].bitrate;
 	} else
 		rate->mcs = idx;
@@ -532,6 +533,8 @@
 				   u64 *data)
 {
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_channel *channel;
 	struct sta_info *sta;
 	struct ieee80211_local *local = sdata->local;
 	struct station_info sinfo;
@@ -607,19 +610,26 @@
 do_survey:
 	i = STA_STATS_LEN - STA_STATS_SURVEY_LEN;
 	/* Get survey stats for current channel */
-	q = 0;
-	while (true) {
-		survey.filled = 0;
-		if (drv_get_survey(local, q, &survey) != 0) {
-			survey.filled = 0;
-			break;
-		}
+	survey.filled = 0;
 
-		if (survey.channel &&
-		    (local->oper_channel->center_freq ==
-		     survey.channel->center_freq))
-			break;
-		q++;
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (chanctx_conf)
+		channel = chanctx_conf->channel;
+	else
+		channel = NULL;
+	rcu_read_unlock();
+
+	if (channel) {
+		q = 0;
+		do {
+			survey.filled = 0;
+			if (drv_get_survey(local, q, &survey) != 0) {
+				survey.filled = 0;
+				break;
+			}
+			q++;
+		} while (channel != survey.channel);
 	}
 
 	if (survey.filled)
@@ -724,47 +734,42 @@
 	return ret;
 }
 
-static int ieee80211_set_channel(struct wiphy *wiphy,
-				 struct net_device *netdev,
-				 struct ieee80211_channel *chan,
-				 enum nl80211_channel_type channel_type)
-{
-	struct ieee80211_local *local = wiphy_priv(wiphy);
-	struct ieee80211_sub_if_data *sdata = NULL;
-
-	if (netdev)
-		sdata = IEEE80211_DEV_TO_SUB_IF(netdev);
-
-	switch (ieee80211_get_channel_mode(local, NULL)) {
-	case CHAN_MODE_HOPPING:
-		return -EBUSY;
-	case CHAN_MODE_FIXED:
-		if (local->oper_channel != chan ||
-		    (!sdata && local->_oper_channel_type != channel_type))
-			return -EBUSY;
-		if (!sdata && local->_oper_channel_type == channel_type)
-			return 0;
-		break;
-	case CHAN_MODE_UNDEFINED:
-		break;
-	}
-
-	if (!ieee80211_set_channel_type(local, sdata, channel_type))
-		return -EBUSY;
-
-	local->oper_channel = chan;
-
-	/* auto-detects changes */
-	ieee80211_hw_config(local, 0);
-
-	return 0;
-}
-
 static int ieee80211_set_monitor_channel(struct wiphy *wiphy,
 					 struct ieee80211_channel *chan,
 					 enum nl80211_channel_type channel_type)
 {
-	return ieee80211_set_channel(wiphy, NULL, chan, channel_type);
+	struct ieee80211_local *local = wiphy_priv(wiphy);
+	struct ieee80211_sub_if_data *sdata;
+	int ret = 0;
+
+	if (local->monitor_channel == chan &&
+	    local->monitor_channel_type == channel_type)
+		return 0;
+
+	mutex_lock(&local->iflist_mtx);
+	if (local->use_chanctx) {
+		sdata = rcu_dereference_protected(
+				local->monitor_sdata,
+				lockdep_is_held(&local->iflist_mtx));
+		if (sdata) {
+			ieee80211_vif_release_channel(sdata);
+			ret = ieee80211_vif_use_channel(
+					sdata, chan, channel_type,
+					IEEE80211_CHANCTX_EXCLUSIVE);
+		}
+	} else if (local->open_count == local->monitors) {
+		local->_oper_channel = chan;
+		local->_oper_channel_type = channel_type;
+		ieee80211_hw_config(local, 0);
+	}
+
+	if (ret == 0) {
+		local->monitor_channel = chan;
+		local->monitor_channel_type = channel_type;
+	}
+	mutex_unlock(&local->iflist_mtx);
+
+	return ret;
 }
 
 static int ieee80211_set_probe_resp(struct ieee80211_sub_if_data *sdata,
@@ -879,8 +884,9 @@
 	if (old)
 		return -EALREADY;
 
-	err = ieee80211_set_channel(wiphy, dev, params->channel,
-				    params->channel_type);
+	err = ieee80211_vif_use_channel(sdata, params->channel,
+					params->channel_type,
+					IEEE80211_CHANCTX_SHARED);
 	if (err)
 		return err;
 
@@ -963,6 +969,8 @@
 	sta_info_flush(sdata->local, sdata);
 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
 
+	ieee80211_vif_release_channel(sdata);
+
 	return 0;
 }
 
@@ -1019,9 +1027,10 @@
 	int i, j;
 	struct ieee80211_supported_band *sband;
 	struct ieee80211_sub_if_data *sdata = sta->sdata;
+	enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 	u32 mask, set;
 
-	sband = local->hw.wiphy->bands[local->oper_channel->band];
+	sband = local->hw.wiphy->bands[band];
 
 	mask = params->sta_flags_mask;
 	set = params->sta_flags_set;
@@ -1136,7 +1145,7 @@
 					rates |= BIT(j);
 			}
 		}
-		sta->sta.supp_rates[local->oper_channel->band] = rates;
+		sta->sta.supp_rates[band] = rates;
 	}
 
 	if (params->ht_capa)
@@ -1664,8 +1673,9 @@
 	if (err)
 		return err;
 
-	err = ieee80211_set_channel(wiphy, dev, setup->channel,
-				    setup->channel_type);
+	err = ieee80211_vif_use_channel(sdata, setup->channel,
+					setup->channel_type,
+					IEEE80211_CHANCTX_SHARED);
 	if (err)
 		return err;
 
@@ -1679,6 +1689,7 @@
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 
 	ieee80211_stop_mesh(sdata);
+	ieee80211_vif_release_channel(sdata);
 
 	return 0;
 }
@@ -1688,10 +1699,14 @@
 				struct net_device *dev,
 				struct bss_parameters *params)
 {
-	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	enum ieee80211_band band;
 	u32 changed = 0;
 
-	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	if (!rtnl_dereference(sdata->u.ap.beacon))
+		return -ENOENT;
+
+	band = ieee80211_get_sdata_band(sdata);
 
 	if (params->use_cts_prot >= 0) {
 		sdata->vif.bss_conf.use_cts_prot = params->use_cts_prot;
@@ -1704,7 +1719,7 @@
 	}
 
 	if (!sdata->vif.bss_conf.use_short_slot &&
-	    sdata->local->oper_channel->band == IEEE80211_BAND_5GHZ) {
+	    band == IEEE80211_BAND_5GHZ) {
 		sdata->vif.bss_conf.use_short_slot = true;
 		changed |= BSS_CHANGED_ERP_SLOT;
 	}
@@ -1718,9 +1733,7 @@
 	if (params->basic_rates) {
 		int i, j;
 		u32 rates = 0;
-		struct ieee80211_local *local = wiphy_priv(wiphy);
-		struct ieee80211_supported_band *sband =
-			wiphy->bands[local->oper_channel->band];
+		struct ieee80211_supported_band *sband = wiphy->bands[band];
 
 		for (i = 0; i < params->basic_rates_len; i++) {
 			int rate = (params->basic_rates[i] & 0x7f) * 5;
@@ -1872,20 +1885,6 @@
 static int ieee80211_assoc(struct wiphy *wiphy, struct net_device *dev,
 			   struct cfg80211_assoc_request *req)
 {
-	struct ieee80211_local *local = wiphy_priv(wiphy);
-	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-
-	switch (ieee80211_get_channel_mode(local, sdata)) {
-	case CHAN_MODE_HOPPING:
-		return -EBUSY;
-	case CHAN_MODE_FIXED:
-		if (local->oper_channel == req->bss->channel)
-			break;
-		return -EBUSY;
-	case CHAN_MODE_UNDEFINED:
-		break;
-	}
-
 	return ieee80211_mgd_assoc(IEEE80211_DEV_TO_SUB_IF(dev), req);
 }
 
@@ -1904,30 +1903,12 @@
 static int ieee80211_join_ibss(struct wiphy *wiphy, struct net_device *dev,
 			       struct cfg80211_ibss_params *params)
 {
-	struct ieee80211_local *local = wiphy_priv(wiphy);
-	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-
-	switch (ieee80211_get_channel_mode(local, sdata)) {
-	case CHAN_MODE_HOPPING:
-		return -EBUSY;
-	case CHAN_MODE_FIXED:
-		if (!params->channel_fixed)
-			return -EBUSY;
-		if (local->oper_channel == params->channel)
-			break;
-		return -EBUSY;
-	case CHAN_MODE_UNDEFINED:
-		break;
-	}
-
-	return ieee80211_ibss_join(sdata, params);
+	return ieee80211_ibss_join(IEEE80211_DEV_TO_SUB_IF(dev), params);
 }
 
 static int ieee80211_leave_ibss(struct wiphy *wiphy, struct net_device *dev)
 {
-	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-
-	return ieee80211_ibss_leave(sdata);
+	return ieee80211_ibss_leave(IEEE80211_DEV_TO_SUB_IF(dev));
 }
 
 static int ieee80211_set_wiphy_params(struct wiphy *wiphy, u32 changed)
@@ -1971,9 +1952,13 @@
 				  enum nl80211_tx_power_setting type, int mbm)
 {
 	struct ieee80211_local *local = wiphy_priv(wiphy);
-	struct ieee80211_channel *chan = local->oper_channel;
+	struct ieee80211_channel *chan = local->_oper_channel;
 	u32 changes = 0;
 
+	/* FIXME */
+	if (local->use_chanctx)
+		return -EOPNOTSUPP;
+
 	switch (type) {
 	case NL80211_TX_POWER_AUTOMATIC:
 		local->user_power_level = -1;
@@ -2518,10 +2503,20 @@
 
 	/* Check if the operating channel is the requested channel */
 	if (!need_offchan) {
-		need_offchan = chan != local->oper_channel;
-		if (channel_type_valid &&
-		    channel_type != local->_oper_channel_type)
+		struct ieee80211_chanctx_conf *chanctx_conf;
+
+		rcu_read_lock();
+		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+
+		if (chanctx_conf) {
+			need_offchan = chan != chanctx_conf->channel;
+			if (channel_type_valid &&
+			    channel_type != chanctx_conf->channel_type)
+				need_offchan = true;
+		} else {
 			need_offchan = true;
+		}
+		rcu_read_unlock();
 	}
 
 	if (need_offchan && !offchan) {
@@ -2670,7 +2665,7 @@
 	u16 capab;
 
 	capab = 0;
-	if (local->oper_channel->band != IEEE80211_BAND_2GHZ)
+	if (ieee80211_get_sdata_band(sdata) != IEEE80211_BAND_2GHZ)
 		return capab;
 
 	if (!(local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE))
@@ -2702,7 +2697,7 @@
 			       u16 status_code, struct sk_buff *skb)
 {
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-	struct ieee80211_local *local = sdata->local;
+	enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 	struct ieee80211_tdls_data *tf;
 
 	tf = (void *)skb_put(skb, offsetof(struct ieee80211_tdls_data, u));
@@ -2722,10 +2717,8 @@
 		tf->u.setup_req.capability =
 			cpu_to_le16(ieee80211_get_tdls_sta_capab(sdata));
 
-		ieee80211_add_srates_ie(sdata, skb, false,
-					local->oper_channel->band);
-		ieee80211_add_ext_srates_ie(sdata, skb, false,
-					    local->oper_channel->band);
+		ieee80211_add_srates_ie(sdata, skb, false, band);
+		ieee80211_add_ext_srates_ie(sdata, skb, false, band);
 		ieee80211_tdls_add_ext_capab(skb);
 		break;
 	case WLAN_TDLS_SETUP_RESPONSE:
@@ -2738,10 +2731,8 @@
 		tf->u.setup_resp.capability =
 			cpu_to_le16(ieee80211_get_tdls_sta_capab(sdata));
 
-		ieee80211_add_srates_ie(sdata, skb, false,
-					local->oper_channel->band);
-		ieee80211_add_ext_srates_ie(sdata, skb, false,
-					    local->oper_channel->band);
+		ieee80211_add_srates_ie(sdata, skb, false, band);
+		ieee80211_add_ext_srates_ie(sdata, skb, false, band);
 		ieee80211_tdls_add_ext_capab(skb);
 		break;
 	case WLAN_TDLS_SETUP_CONFIRM:
@@ -2779,7 +2770,7 @@
 			   u16 status_code, struct sk_buff *skb)
 {
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-	struct ieee80211_local *local = sdata->local;
+	enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 	struct ieee80211_mgmt *mgmt;
 
 	mgmt = (void *)skb_put(skb, 24);
@@ -2802,10 +2793,8 @@
 		mgmt->u.action.u.tdls_discover_resp.capability =
 			cpu_to_le16(ieee80211_get_tdls_sta_capab(sdata));
 
-		ieee80211_add_srates_ie(sdata, skb, false,
-					local->oper_channel->band);
-		ieee80211_add_ext_srates_ie(sdata, skb, false,
-					    local->oper_channel->band);
+		ieee80211_add_srates_ie(sdata, skb, false, band);
+		ieee80211_add_ext_srates_ie(sdata, skb, false, band);
 		ieee80211_tdls_add_ext_capab(skb);
 		break;
 	default:
@@ -2985,12 +2974,19 @@
 	bool qos;
 	struct ieee80211_tx_info *info;
 	struct sta_info *sta;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	enum ieee80211_band band;
 
 	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (WARN_ON(!chanctx_conf)) {
+		rcu_read_unlock();
+		return -EINVAL;
+	}
+	band = chanctx_conf->channel->band;
 	sta = sta_info_get(sdata, peer);
 	if (sta) {
 		qos = test_sta_flag(sta, WLAN_STA_WME);
-		rcu_read_unlock();
 	} else {
 		rcu_read_unlock();
 		return -ENOLINK;
@@ -3008,8 +3004,10 @@
 	}
 
 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + size);
-	if (!skb)
+	if (!skb) {
+		rcu_read_unlock();
 		return -ENOMEM;
+	}
 
 	skb->dev = dev;
 
@@ -3034,8 +3032,9 @@
 		nullfunc->qos_ctrl = cpu_to_le16(7);
 
 	local_bh_disable();
-	ieee80211_xmit(sdata, skb);
+	ieee80211_xmit(sdata, skb, band);
 	local_bh_enable();
+	rcu_read_unlock();
 
 	*cookie = (unsigned long) skb;
 	return 0;
@@ -3045,10 +3044,19 @@
 ieee80211_cfg_get_channel(struct wiphy *wiphy, struct wireless_dev *wdev,
 			  enum nl80211_channel_type *type)
 {
-	struct ieee80211_local *local = wiphy_priv(wiphy);
+	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_channel *chan = NULL;
 
-	*type = local->_oper_channel_type;
-	return local->oper_channel;
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (chanctx_conf) {
+		*type = chanctx_conf->channel_type;
+		chan = chanctx_conf->channel;
+	}
+	rcu_read_unlock();
+
+	return chan;
 }
 
 #ifdef CONFIG_PM
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 1a8dee4..41e1aa6 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -7,106 +7,6 @@
 #include "ieee80211_i.h"
 #include "driver-ops.h"
 
-static enum ieee80211_chan_mode
-__ieee80211_get_channel_mode(struct ieee80211_local *local,
-			     struct ieee80211_sub_if_data *ignore)
-{
-	struct ieee80211_sub_if_data *sdata;
-
-	lockdep_assert_held(&local->iflist_mtx);
-
-	list_for_each_entry(sdata, &local->interfaces, list) {
-		if (sdata == ignore)
-			continue;
-
-		if (!ieee80211_sdata_running(sdata))
-			continue;
-
-		switch (sdata->vif.type) {
-		case NL80211_IFTYPE_MONITOR:
-			continue;
-		case NL80211_IFTYPE_STATION:
-			if (!sdata->u.mgd.associated)
-				continue;
-			break;
-		case NL80211_IFTYPE_ADHOC:
-			if (!sdata->u.ibss.ssid_len)
-				continue;
-			if (!sdata->u.ibss.fixed_channel)
-				return CHAN_MODE_HOPPING;
-			break;
-		case NL80211_IFTYPE_AP_VLAN:
-			/* will also have _AP interface */
-			continue;
-		case NL80211_IFTYPE_AP:
-			if (!sdata->u.ap.beacon)
-				continue;
-			break;
-		case NL80211_IFTYPE_MESH_POINT:
-			if (!sdata->wdev.mesh_id_len)
-				continue;
-			break;
-		default:
-			break;
-		}
-
-		return CHAN_MODE_FIXED;
-	}
-
-	return CHAN_MODE_UNDEFINED;
-}
-
-enum ieee80211_chan_mode
-ieee80211_get_channel_mode(struct ieee80211_local *local,
-			   struct ieee80211_sub_if_data *ignore)
-{
-	enum ieee80211_chan_mode mode;
-
-	mutex_lock(&local->iflist_mtx);
-	mode = __ieee80211_get_channel_mode(local, ignore);
-	mutex_unlock(&local->iflist_mtx);
-
-	return mode;
-}
-
-static enum nl80211_channel_type
-ieee80211_get_superchan(struct ieee80211_local *local,
-			struct ieee80211_sub_if_data *sdata)
-{
-	enum nl80211_channel_type superchan = NL80211_CHAN_NO_HT;
-	struct ieee80211_sub_if_data *tmp;
-
-	mutex_lock(&local->iflist_mtx);
-	list_for_each_entry(tmp, &local->interfaces, list) {
-		if (tmp == sdata)
-			continue;
-
-		if (!ieee80211_sdata_running(tmp))
-			continue;
-
-		switch (tmp->vif.bss_conf.channel_type) {
-		case NL80211_CHAN_NO_HT:
-		case NL80211_CHAN_HT20:
-			if (superchan > tmp->vif.bss_conf.channel_type)
-				break;
-
-			superchan = tmp->vif.bss_conf.channel_type;
-			break;
-		case NL80211_CHAN_HT40PLUS:
-			WARN_ON(superchan == NL80211_CHAN_HT40MINUS);
-			superchan = NL80211_CHAN_HT40PLUS;
-			break;
-		case NL80211_CHAN_HT40MINUS:
-			WARN_ON(superchan == NL80211_CHAN_HT40PLUS);
-			superchan = NL80211_CHAN_HT40MINUS;
-			break;
-		}
-	}
-	mutex_unlock(&local->iflist_mtx);
-
-	return superchan;
-}
-
 static bool
 ieee80211_channel_types_are_compatible(enum nl80211_channel_type chantype1,
 				       enum nl80211_channel_type chantype2,
@@ -149,26 +49,6 @@
 	return true;
 }
 
-bool ieee80211_set_channel_type(struct ieee80211_local *local,
-				struct ieee80211_sub_if_data *sdata,
-				enum nl80211_channel_type chantype)
-{
-	enum nl80211_channel_type superchan;
-	enum nl80211_channel_type compatchan;
-
-	superchan = ieee80211_get_superchan(local, sdata);
-	if (!ieee80211_channel_types_are_compatible(superchan, chantype,
-						    &compatchan))
-		return false;
-
-	local->_oper_channel_type = compatchan;
-
-	if (sdata)
-		sdata->vif.bss_conf.channel_type = chantype;
-
-	return true;
-}
-
 static void ieee80211_change_chantype(struct ieee80211_local *local,
 				      struct ieee80211_chanctx *ctx,
 				      enum nl80211_channel_type chantype)
@@ -178,6 +58,11 @@
 
 	ctx->conf.channel_type = chantype;
 	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_CHANNEL_TYPE);
+
+	if (!local->use_chanctx) {
+		local->_oper_channel_type = chantype;
+		ieee80211_hw_config(local, 0);
+	}
 }
 
 static struct ieee80211_chanctx *
@@ -235,10 +120,16 @@
 	ctx->conf.channel_type = channel_type;
 	ctx->mode = mode;
 
-	err = drv_add_chanctx(local, ctx);
-	if (err) {
-		kfree(ctx);
-		return ERR_PTR(err);
+	if (!local->use_chanctx) {
+		local->_oper_channel_type = channel_type;
+		local->_oper_channel = channel;
+		ieee80211_hw_config(local, 0);
+	} else {
+		err = drv_add_chanctx(local, ctx);
+		if (err) {
+			kfree(ctx);
+			return ERR_PTR(err);
+		}
 	}
 
 	list_add(&ctx->list, &local->chanctx_list);
@@ -253,7 +144,12 @@
 
 	WARN_ON_ONCE(ctx->refcount != 0);
 
-	drv_remove_chanctx(local, ctx);
+	if (!local->use_chanctx) {
+		local->_oper_channel_type = NL80211_CHAN_NO_HT;
+		ieee80211_hw_config(local, 0);
+	} else {
+		drv_remove_chanctx(local, ctx);
+	}
 
 	list_del(&ctx->list);
 	kfree_rcu(ctx, rcu_head);
@@ -359,6 +255,8 @@
 	struct ieee80211_chanctx *ctx;
 	int ret;
 
+	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
+
 	mutex_lock(&local->chanctx_mtx);
 	__ieee80211_vif_release_channel(sdata);
 
@@ -370,6 +268,8 @@
 		goto out;
 	}
 
+	sdata->vif.bss_conf.channel_type = channel_type;
+
 	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
 	if (ret) {
 		/* if assign fails refcount stays the same */
@@ -385,6 +285,8 @@
 
 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 {
+	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
+
 	mutex_lock(&sdata->local->chanctx_mtx);
 	__ieee80211_vif_release_channel(sdata);
 	mutex_unlock(&sdata->local->chanctx_mtx);
diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 5f3620f..34d9235 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -26,7 +26,6 @@
 #include "rate.h"
 
 #define IEEE80211_SCAN_INTERVAL (2 * HZ)
-#define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ)
 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
 
 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
@@ -76,21 +75,22 @@
 		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS);
 	}
 
-	memcpy(ifibss->bssid, bssid, ETH_ALEN);
-
 	sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
 
-	local->oper_channel = chan;
 	channel_type = ifibss->channel_type;
 	if (!cfg80211_can_beacon_sec_chan(local->hw.wiphy, chan, channel_type))
 		channel_type = NL80211_CHAN_HT20;
-	if (!ieee80211_set_channel_type(local, sdata, channel_type)) {
-		/* can only fail due to HT40+/- mismatch */
-		channel_type = NL80211_CHAN_HT20;
-		WARN_ON(!ieee80211_set_channel_type(local, sdata,
-						    NL80211_CHAN_HT20));
+
+	ieee80211_vif_release_channel(sdata);
+	if (ieee80211_vif_use_channel(sdata, chan, channel_type,
+				      ifibss->fixed_channel ?
+					IEEE80211_CHANCTX_SHARED :
+					IEEE80211_CHANCTX_EXCLUSIVE)) {
+		sdata_info(sdata, "Failed to join IBSS, no channel context\n");
+		return;
 	}
-	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
+
+	memcpy(ifibss->bssid, bssid, ETH_ALEN);
 
 	sband = local->hw.wiphy->bands[chan->band];
 
@@ -294,7 +294,8 @@
 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 	struct ieee80211_local *local = sdata->local;
 	struct sta_info *sta;
-	int band = local->oper_channel->band;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	int band;
 
 	/*
 	 * XXX: Consider removing the least recently used entry and
@@ -317,6 +318,13 @@
 		return NULL;
 	}
 
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (WARN_ON_ONCE(!chanctx_conf))
+		return NULL;
+	band = chanctx_conf->channel->band;
+	rcu_read_unlock();
+
 	sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
 	if (!sta) {
 		rcu_read_lock();
@@ -517,7 +525,8 @@
 		goto put_bss;
 
 	/* different channel */
-	if (cbss->channel != local->oper_channel)
+	if (sdata->u.ibss.fixed_channel &&
+	    sdata->u.ibss.channel != cbss->channel)
 		goto put_bss;
 
 	/* different SSID */
@@ -592,7 +601,8 @@
 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 	struct ieee80211_local *local = sdata->local;
 	struct sta_info *sta;
-	int band = local->oper_channel->band;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	int band;
 
 	/*
 	 * XXX: Consider removing the least recently used entry and
@@ -610,6 +620,15 @@
 	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
 		return;
 
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (WARN_ON_ONCE(!chanctx_conf)) {
+		rcu_read_unlock();
+		return;
+	}
+	band = chanctx_conf->channel->band;
+	rcu_read_unlock();
+
 	sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
 	if (!sta)
 		return;
@@ -784,18 +803,8 @@
 		int interval = IEEE80211_SCAN_INTERVAL;
 
 		if (time_after(jiffies, ifibss->ibss_join_req +
-			       IEEE80211_IBSS_JOIN_TIMEOUT)) {
-			if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
-				ieee80211_sta_create_ibss(sdata);
-				return;
-			}
-			sdata_info(sdata, "IBSS not allowed on %d MHz\n",
-				   local->oper_channel->center_freq);
-
-			/* No IBSS found - decrease scan interval and continue
-			 * scanning. */
-			interval = IEEE80211_SCAN_INTERVAL_SLOW;
-		}
+			       IEEE80211_IBSS_JOIN_TIMEOUT))
+			ieee80211_sta_create_ibss(sdata);
 
 		mod_timer(&ifibss->timer,
 			  round_jiffies(jiffies + interval));
@@ -1086,17 +1095,6 @@
 	sdata->u.ibss.channel_type = params->channel_type;
 	sdata->u.ibss.fixed_channel = params->channel_fixed;
 
-	/* fix ourselves to that channel now already */
-	if (params->channel_fixed) {
-		sdata->local->oper_channel = params->channel;
-		if (!ieee80211_set_channel_type(sdata->local, sdata,
-					       params->channel_type)) {
-			mutex_unlock(&sdata->u.ibss.mtx);
-			kfree_skb(skb);
-			return -EINVAL;
-		}
-	}
-
 	if (params->ie) {
 		sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
 					   GFP_KERNEL);
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 8fa00ad..6660118 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -773,6 +773,21 @@
 	return container_of(p, struct ieee80211_sub_if_data, vif);
 }
 
+static inline enum ieee80211_band
+ieee80211_get_sdata_band(struct ieee80211_sub_if_data *sdata)
+{
+	enum ieee80211_band band = IEEE80211_BAND_2GHZ;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (!WARN_ON(!chanctx_conf))
+		band = chanctx_conf->channel->band;
+	rcu_read_unlock();
+
+	return band;
+}
+
 enum sdata_queue_type {
 	IEEE80211_SDATA_QUEUE_TYPE_FRAME	= 0,
 	IEEE80211_SDATA_QUEUE_AGG_START		= 1,
@@ -1006,8 +1021,10 @@
 	enum mac80211_scan_state next_scan_state;
 	struct delayed_work scan_work;
 	struct ieee80211_sub_if_data __rcu *scan_sdata;
+	struct ieee80211_channel *csa_channel;
+	/* For backward compatibility only -- do not use */
+	struct ieee80211_channel *_oper_channel;
 	enum nl80211_channel_type _oper_channel_type;
-	struct ieee80211_channel *oper_channel, *csa_channel;
 
 	/* Temporary remain-on-channel for off-channel operations */
 	struct ieee80211_channel *tmp_channel;
@@ -1121,6 +1138,8 @@
 
 	/* virtual monitor interface */
 	struct ieee80211_sub_if_data __rcu *monitor_sdata;
+	struct ieee80211_channel *monitor_channel;
+	enum nl80211_channel_type monitor_channel_type;
 };
 
 static inline struct ieee80211_sub_if_data *
@@ -1423,11 +1442,42 @@
 				     gfp_t gfp);
 void ieee80211_set_wmm_default(struct ieee80211_sub_if_data *sdata,
 			       bool bss_notify);
-void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb);
+void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
+		    enum ieee80211_band band);
 
-void ieee80211_tx_skb_tid(struct ieee80211_sub_if_data *sdata,
-			  struct sk_buff *skb, int tid);
-static void inline ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata,
+void __ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
+				 struct sk_buff *skb, int tid,
+				 enum ieee80211_band band);
+
+static inline void
+ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
+			  struct sk_buff *skb, int tid,
+			  enum ieee80211_band band)
+{
+	rcu_read_lock();
+	__ieee80211_tx_skb_tid_band(sdata, skb, tid, band);
+	rcu_read_unlock();
+}
+
+static inline void ieee80211_tx_skb_tid(struct ieee80211_sub_if_data *sdata,
+					struct sk_buff *skb, int tid)
+{
+	struct ieee80211_chanctx_conf *chanctx_conf;
+
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (WARN_ON(!chanctx_conf)) {
+		rcu_read_unlock();
+		kfree_skb(skb);
+		return;
+	}
+
+	__ieee80211_tx_skb_tid_band(sdata, skb, tid,
+				    chanctx_conf->channel->band);
+	rcu_read_unlock();
+}
+
+static inline void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata,
 				    struct sk_buff *skb)
 {
 	/* Send all internal mgmt frames on VO. Accordingly set TID to 7. */
@@ -1494,7 +1544,7 @@
 			      const u8 *ssid, size_t ssid_len,
 			      const u8 *ie, size_t ie_len,
 			      u32 ratemask, bool directed, bool no_cck,
-			      struct ieee80211_channel *channel);
+			      struct ieee80211_channel *channel, bool scan);
 
 void ieee80211_sta_def_wmm_params(struct ieee80211_sub_if_data *sdata,
 				  const size_t supp_rates_len,
@@ -1525,18 +1575,6 @@
 				enum ieee80211_band band);
 
 /* channel management */
-enum ieee80211_chan_mode {
-	CHAN_MODE_UNDEFINED,
-	CHAN_MODE_HOPPING,
-	CHAN_MODE_FIXED,
-};
-
-enum ieee80211_chan_mode
-ieee80211_get_channel_mode(struct ieee80211_local *local,
-			   struct ieee80211_sub_if_data *ignore);
-bool ieee80211_set_channel_type(struct ieee80211_local *local,
-				struct ieee80211_sub_if_data *sdata,
-				enum nl80211_channel_type chantype);
 enum nl80211_channel_type
 ieee80211_ht_oper_to_channel_type(struct ieee80211_ht_operation *ht_oper);
 
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 6f8a73c..7cb8382 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -380,6 +380,15 @@
 		goto out_unlock;
 	}
 
+	ret = ieee80211_vif_use_channel(sdata, local->monitor_channel,
+					local->monitor_channel_type,
+					IEEE80211_CHANCTX_EXCLUSIVE);
+	if (ret) {
+		drv_remove_interface(local, sdata);
+		kfree(sdata);
+		goto out_unlock;
+	}
+
 	rcu_assign_pointer(local->monitor_sdata, sdata);
  out_unlock:
 	mutex_unlock(&local->iflist_mtx);
@@ -403,6 +412,8 @@
 	rcu_assign_pointer(local->monitor_sdata, NULL);
 	synchronize_net();
 
+	ieee80211_vif_release_channel(sdata);
+
 	drv_remove_interface(local, sdata);
 
 	kfree(sdata);
@@ -665,7 +676,6 @@
 	struct sk_buff *skb, *tmp;
 	u32 hw_reconf_flags = 0;
 	int i;
-	enum nl80211_channel_type orig_ct;
 
 	clear_bit(SDATA_STATE_RUNNING, &sdata->state);
 
@@ -837,14 +847,8 @@
 		hw_reconf_flags = 0;
 	}
 
-	/* Re-calculate channel-type, in case there are multiple vifs
-	 * on different channel types.
-	 */
-	orig_ct = local->_oper_channel_type;
-	ieee80211_set_channel_type(local, NULL, NL80211_CHAN_NO_HT);
-
 	/* do after stop to avoid reconfiguring when we stop anyway */
-	if (hw_reconf_flags || (orig_ct != local->_oper_channel_type))
+	if (hw_reconf_flags)
 		ieee80211_hw_config(local, hw_reconf_flags);
 
 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
@@ -1282,11 +1286,6 @@
 	if (type == ieee80211_vif_type_p2p(&sdata->vif))
 		return 0;
 
-	/* Setting ad-hoc mode on non-IBSS channel is not supported. */
-	if (sdata->local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS &&
-	    type == NL80211_IFTYPE_ADHOC)
-		return -EOPNOTSUPP;
-
 	if (ieee80211_sdata_running(sdata)) {
 		ret = ieee80211_runtime_change_iftype(sdata, type);
 		if (ret)
@@ -1298,9 +1297,6 @@
 	}
 
 	/* reset some values that shouldn't be kept across type changes */
-	sdata->vif.bss_conf.basic_rates =
-		ieee80211_mandatory_rates(sdata->local,
-			sdata->local->oper_channel->band);
 	sdata->drop_unencrypted = 0;
 	if (type == NL80211_IFTYPE_STATION)
 		sdata->u.mgd.use_4addr = false;
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 0dd1ea2..9cb6280 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -93,23 +93,21 @@
 	ieee80211_configure_filter(local);
 }
 
-int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
+static u32 ieee80211_hw_conf_chan(struct ieee80211_local *local)
 {
 	struct ieee80211_channel *chan;
-	int ret = 0;
+	u32 changed = 0;
 	int power;
 	enum nl80211_channel_type channel_type;
 	u32 offchannel_flag;
 
-	might_sleep();
-
 	offchannel_flag = local->hw.conf.flags & IEEE80211_CONF_OFFCHANNEL;
 	if (local->scan_channel) {
 		chan = local->scan_channel;
 		/* If scanning on oper channel, use whatever channel-type
 		 * is currently in use.
 		 */
-		if (chan == local->oper_channel)
+		if (chan == local->_oper_channel)
 			channel_type = local->_oper_channel_type;
 		else
 			channel_type = NL80211_CHAN_NO_HT;
@@ -117,11 +115,11 @@
 		chan = local->tmp_channel;
 		channel_type = local->tmp_channel_type;
 	} else {
-		chan = local->oper_channel;
+		chan = local->_oper_channel;
 		channel_type = local->_oper_channel_type;
 	}
 
-	if (chan != local->oper_channel ||
+	if (chan != local->_oper_channel ||
 	    channel_type != local->_oper_channel_type)
 		local->hw.conf.flags |= IEEE80211_CONF_OFFCHANNEL;
 	else
@@ -164,6 +162,21 @@
 		local->hw.conf.power_level = power;
 	}
 
+	return changed;
+}
+
+int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
+{
+	int ret = 0;
+
+	might_sleep();
+
+	if (!local->use_chanctx)
+		changed |= ieee80211_hw_conf_chan(local);
+	else
+		changed &= ~(IEEE80211_CONF_CHANGE_CHANNEL |
+			     IEEE80211_CONF_CHANGE_POWER);
+
 	if (changed && local->open_count) {
 		ret = drv_config(local, changed);
 		/*
@@ -775,12 +788,16 @@
 		sband = local->hw.wiphy->bands[band];
 		if (!sband)
 			continue;
-		if (!local->oper_channel) {
+		if (!local->use_chanctx && !local->_oper_channel) {
 			/* init channel we're on */
 			local->hw.conf.channel =
-			local->oper_channel = &sband->channels[0];
+			local->_oper_channel = &sband->channels[0];
 			local->hw.conf.channel_type = NL80211_CHAN_NO_HT;
 		}
+		if (!local->monitor_channel) {
+			local->monitor_channel = &sband->channels[0];
+			local->monitor_channel_type = NL80211_CHAN_NO_HT;
+		}
 		channels += sband->n_channels;
 
 		if (max_bitrates < sband->n_bitrates)
@@ -810,19 +827,13 @@
 	hw->wiphy->interface_modes |= BIT(NL80211_IFTYPE_MONITOR);
 	hw->wiphy->software_iftypes |= BIT(NL80211_IFTYPE_MONITOR);
 
-	/*
-	 * mac80211 doesn't support more than 1 channel, and also not more
-	 * than one IBSS interface
-	 */
+	/* mac80211 doesn't support more than one IBSS interface right now */
 	for (i = 0; i < hw->wiphy->n_iface_combinations; i++) {
 		const struct ieee80211_iface_combination *c;
 		int j;
 
 		c = &hw->wiphy->iface_combinations[i];
 
-		if (c->num_different_channels > 1)
-			return -EINVAL;
-
 		for (j = 0; j < c->n_limits; j++)
 			if ((c->limits[j].types & BIT(NL80211_IFTYPE_ADHOC)) &&
 			    c->limits[j].max > 1)
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index ff0296c..19725e0 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -97,7 +97,7 @@
 	     (ifmsh->mesh_auth_id == ie->mesh_config->meshconf_auth)))
 		goto mismatch;
 
-	ieee80211_sta_get_rates(local, ie, local->oper_channel->band,
+	ieee80211_sta_get_rates(local, ie, ieee80211_get_sdata_band(sdata),
 				&basic_rates);
 
 	if (sdata->vif.bss_conf.basic_rates != basic_rates)
@@ -355,12 +355,22 @@
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_supported_band *sband;
-	struct ieee80211_channel *chan = local->oper_channel;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_channel *chan;
 	u8 *pos;
 
 	if (skb_tailroom(skb) < 3)
 		return -ENOMEM;
 
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (WARN_ON(!chanctx_conf)) {
+		rcu_read_unlock();
+		return -EINVAL;
+	}
+	chan = chanctx_conf->channel;
+	rcu_read_unlock();
+
 	sband = local->hw.wiphy->bands[chan->band];
 	if (sband->band == IEEE80211_BAND_2GHZ) {
 		pos = skb_put(skb, 2 + 1);
@@ -376,10 +386,11 @@
 		       struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_local *local = sdata->local;
+	enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 	struct ieee80211_supported_band *sband;
 	u8 *pos;
 
-	sband = local->hw.wiphy->bands[local->oper_channel->band];
+	sband = local->hw.wiphy->bands[band];
 	if (!sband->ht_cap.ht_supported ||
 	    sdata->vif.bss_conf.channel_type == NL80211_CHAN_NO_HT)
 		return 0;
@@ -397,14 +408,26 @@
 			struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_local *local = sdata->local;
-	struct ieee80211_channel *channel = local->oper_channel;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_channel *channel;
 	enum nl80211_channel_type channel_type =
-				sdata->vif.bss_conf.channel_type;
-	struct ieee80211_supported_band *sband =
-				local->hw.wiphy->bands[channel->band];
-	struct ieee80211_sta_ht_cap *ht_cap = &sband->ht_cap;
+		sdata->vif.bss_conf.channel_type;
+	struct ieee80211_supported_band *sband;
+	struct ieee80211_sta_ht_cap *ht_cap;
 	u8 *pos;
 
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (WARN_ON(!chanctx_conf)) {
+		rcu_read_unlock();
+		return -EINVAL;
+	}
+	channel = chanctx_conf->channel;
+	rcu_read_unlock();
+
+	sband = local->hw.wiphy->bands[channel->band];
+	ht_cap = &sband->ht_cap;
+
 	if (!ht_cap->ht_supported || channel_type == NL80211_CHAN_NO_HT)
 		return 0;
 
@@ -610,7 +633,7 @@
 	sdata->vif.bss_conf.beacon_int = MESH_DEFAULT_BEACON_INTERVAL;
 	sdata->vif.bss_conf.basic_rates =
 		ieee80211_mandatory_rates(sdata->local,
-					  sdata->local->oper_channel->band);
+					  ieee80211_get_sdata_band(sdata));
 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON |
 						BSS_CHANGED_BEACON_ENABLED |
 						BSS_CHANGED_HT |
diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
index 3ab34d8..8a8b459 100644
--- a/net/mac80211/mesh_plink.c
+++ b/net/mac80211/mesh_plink.c
@@ -252,6 +252,8 @@
 	mgmt->u.action.u.self_prot.action_code = action;
 
 	if (action != WLAN_SP_MESH_PEERING_CLOSE) {
+		enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
+
 		/* capability info */
 		pos = skb_put(skb, 2);
 		memset(pos, 0, 2);
@@ -260,10 +262,8 @@
 			pos = skb_put(skb, 2);
 			memcpy(pos + 2, &plid, 2);
 		}
-		if (ieee80211_add_srates_ie(sdata, skb, true,
-					    local->oper_channel->band) ||
-		    ieee80211_add_ext_srates_ie(sdata, skb, true,
-						local->oper_channel->band) ||
+		if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
+		    ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
 		    mesh_add_rsn_ie(skb, sdata) ||
 		    mesh_add_meshid_ie(skb, sdata) ||
 		    mesh_add_meshconf_ie(skb, sdata))
@@ -343,7 +343,7 @@
 				       struct ieee802_11_elems *elems)
 {
 	struct ieee80211_local *local = sdata->local;
-	enum ieee80211_band band = local->oper_channel->band;
+	enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 	struct ieee80211_supported_band *sband;
 	u32 rates, basic_rates = 0;
 	struct sta_info *sta;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index e714ed8..4add500 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -178,20 +178,30 @@
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_supported_band *sband;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_channel *chan;
 	struct sta_info *sta;
 	u32 changed = 0;
 	u16 ht_opmode;
 	bool disable_40 = false;
 
-	sband = local->hw.wiphy->bands[local->oper_channel->band];
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (WARN_ON(!chanctx_conf)) {
+		rcu_read_unlock();
+		return 0;
+	}
+	chan = chanctx_conf->channel;
+	rcu_read_unlock();
+	sband = local->hw.wiphy->bands[chan->band];
 
 	switch (sdata->vif.bss_conf.channel_type) {
 	case NL80211_CHAN_HT40PLUS:
-		if (local->oper_channel->flags & IEEE80211_CHAN_NO_HT40PLUS)
+		if (chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
 			disable_40 = true;
 		break;
 	case NL80211_CHAN_HT40MINUS:
-		if (local->oper_channel->flags & IEEE80211_CHAN_NO_HT40MINUS)
+		if (chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
 			disable_40 = true;
 		break;
 	default:
@@ -359,11 +369,21 @@
 	int i, count, rates_len, supp_rates_len;
 	u16 capab;
 	struct ieee80211_supported_band *sband;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_channel *chan;
 	u32 rates = 0;
 
 	lockdep_assert_held(&ifmgd->mtx);
 
-	sband = local->hw.wiphy->bands[local->oper_channel->band];
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (WARN_ON(!chanctx_conf)) {
+		rcu_read_unlock();
+		return;
+	}
+	chan = chanctx_conf->channel;
+	rcu_read_unlock();
+	sband = local->hw.wiphy->bands[chan->band];
 
 	if (assoc_data->supp_rates_len) {
 		/*
@@ -485,7 +505,7 @@
 		*pos++ = WLAN_EID_PWR_CAPABILITY;
 		*pos++ = 2;
 		*pos++ = 0; /* min tx power */
-		*pos++ = local->oper_channel->max_power; /* max tx power */
+		*pos++ = chan->max_power; /* max tx power */
 
 		/* 2. supported channels */
 		/* TODO: get this in reg domain format */
@@ -523,7 +543,7 @@
 
 	if (!(ifmgd->flags & IEEE80211_STA_DISABLE_11N))
 		ieee80211_add_ht_ie(sdata, skb, assoc_data->ap_ht_param,
-				    sband, local->oper_channel, ifmgd->ap_smps);
+				    sband, chan, ifmgd->ap_smps);
 
 	if (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT))
 		ieee80211_add_vht_ie(sdata, skb, sband);
@@ -657,18 +677,18 @@
 	if (!ifmgd->associated)
 		goto out;
 
-	sdata->local->oper_channel = sdata->local->csa_channel;
+	sdata->local->_oper_channel = sdata->local->csa_channel;
 	if (!sdata->local->ops->channel_switch) {
 		/* call "hw_config" only if doing sw channel switch */
 		ieee80211_hw_config(sdata->local,
 			IEEE80211_CONF_CHANGE_CHANNEL);
 	} else {
 		/* update the device channel directly */
-		sdata->local->hw.conf.channel = sdata->local->oper_channel;
+		sdata->local->hw.conf.channel = sdata->local->_oper_channel;
 	}
 
 	/* XXX: shouldn't really modify cfg80211-owned data! */
-	ifmgd->associated->channel = sdata->local->oper_channel;
+	ifmgd->associated->channel = sdata->local->_oper_channel;
 
 	/* XXX: wait for a beacon first? */
 	ieee80211_wake_queues_by_reason(&sdata->local->hw,
@@ -680,11 +700,8 @@
 
 void ieee80211_chswitch_done(struct ieee80211_vif *vif, bool success)
 {
-	struct ieee80211_sub_if_data *sdata;
-	struct ieee80211_if_managed *ifmgd;
-
-	sdata = vif_to_sdata(vif);
-	ifmgd = &sdata->u.mgd;
+	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 
 	trace_api_chswitch_done(sdata, success);
 	if (!success) {
@@ -723,6 +740,7 @@
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 	int new_freq = ieee80211_channel_to_frequency(sw_elem->new_ch_num,
 						      cbss->channel->band);
+	struct ieee80211_chanctx *chanctx;
 
 	ASSERT_MGD_MTX(ifmgd);
 
@@ -748,10 +766,34 @@
 		return;
 	}
 
-	sdata->local->csa_channel = new_ch;
-
 	ifmgd->flags |= IEEE80211_STA_CSA_RECEIVED;
 
+	if (sdata->local->use_chanctx) {
+		sdata_info(sdata,
+			   "not handling channel switch with channel contexts\n");
+		ieee80211_queue_work(&sdata->local->hw,
+				     &ifmgd->csa_connection_drop_work);
+	}
+
+	mutex_lock(&sdata->local->chanctx_mtx);
+	if (WARN_ON(!rcu_access_pointer(sdata->vif.chanctx_conf))) {
+		mutex_unlock(&sdata->local->chanctx_mtx);
+		return;
+	}
+	chanctx = container_of(rcu_access_pointer(sdata->vif.chanctx_conf),
+			       struct ieee80211_chanctx, conf);
+	if (chanctx->refcount > 1) {
+		sdata_info(sdata,
+			   "channel switch with multiple interfaces on the same channel, disconnecting\n");
+		ieee80211_queue_work(&sdata->local->hw,
+				     &ifmgd->csa_connection_drop_work);
+		mutex_unlock(&sdata->local->chanctx_mtx);
+		return;
+	}
+	mutex_unlock(&sdata->local->chanctx_mtx);
+
+	sdata->local->csa_channel = new_ch;
+
 	if (sw_elem->mode)
 		ieee80211_stop_queues_by_reason(&sdata->local->hw,
 				IEEE80211_QUEUE_STOP_REASON_CSA);
@@ -1280,7 +1322,7 @@
 	}
 
 	use_short_slot = !!(capab & WLAN_CAPABILITY_SHORT_SLOT_TIME);
-	if (sdata->local->oper_channel->band == IEEE80211_BAND_5GHZ)
+	if (ieee80211_get_sdata_band(sdata) == IEEE80211_BAND_5GHZ)
 		use_short_slot = true;
 
 	if (use_protection != bss_conf->use_cts_prot) {
@@ -1465,9 +1507,7 @@
 	changed |= BSS_CHANGED_BSSID | BSS_CHANGED_HT;
 	ieee80211_bss_info_change_notify(sdata, changed);
 
-	/* channel(_type) changes are handled by ieee80211_hw_config */
-	WARN_ON(!ieee80211_set_channel_type(local, sdata, NL80211_CHAN_NO_HT));
-	ieee80211_hw_config(local, 0);
+	ieee80211_vif_release_channel(sdata);
 
 	/* disassociated - set to defaults now */
 	ieee80211_set_wmm_default(sdata, false);
@@ -1589,7 +1629,7 @@
 
 		ieee80211_send_probe_req(sdata, dst, ssid + 2, ssid_len, NULL,
 					 0, (u32) -1, true, false,
-					 ifmgd->associated->channel);
+					 ifmgd->associated->channel, false);
 	}
 
 	ifmgd->probe_timeout = jiffies + msecs_to_jiffies(probe_wait_ms);
@@ -1692,8 +1732,7 @@
 		ssid_len = ssid[1];
 
 	skb = ieee80211_build_probe_req(sdata, cbss->bssid,
-					(u32) -1,
-					sdata->local->oper_channel,
+					(u32) -1, cbss->channel,
 					ssid + 2, ssid_len,
 					NULL, 0, true);
 
@@ -1804,6 +1843,7 @@
 
 		memset(sdata->u.mgd.bssid, 0, ETH_ALEN);
 		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BSSID);
+		ieee80211_vif_release_channel(sdata);
 	}
 
 	cfg80211_put_bss(auth_data->bss);
@@ -2030,6 +2070,7 @@
 
 		memset(sdata->u.mgd.bssid, 0, ETH_ALEN);
 		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BSSID);
+		ieee80211_vif_release_channel(sdata);
 	}
 
 	kfree(assoc_data);
@@ -2091,7 +2132,7 @@
 		return false;
 	}
 
-	sband = local->hw.wiphy->bands[local->oper_channel->band];
+	sband = local->hw.wiphy->bands[ieee80211_get_sdata_band(sdata)];
 
 	if (elems.ht_cap_elem && !(ifmgd->flags & IEEE80211_STA_DISABLE_11N))
 		ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
@@ -2369,6 +2410,8 @@
 	size_t baselen;
 	struct ieee802_11_elems elems;
 	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_channel *chan;
 	u32 changed = 0;
 	bool erp_valid, directed_tim = false;
 	u8 erp_value = 0;
@@ -2382,8 +2425,19 @@
 	if (baselen > len)
 		return;
 
-	if (rx_status->freq != local->oper_channel->center_freq)
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (!chanctx_conf) {
+		rcu_read_unlock();
 		return;
+	}
+
+	if (rx_status->freq != chanctx_conf->channel->center_freq) {
+		rcu_read_unlock();
+		return;
+	}
+	chan = chanctx_conf->channel;
+	rcu_read_unlock();
 
 	if (ifmgd->assoc_data && !ifmgd->assoc_data->have_beacon &&
 	    ether_addr_equal(mgmt->bssid, ifmgd->assoc_data->bss->bssid)) {
@@ -2546,7 +2600,7 @@
 	    !(ifmgd->flags & IEEE80211_STA_DISABLE_11N)) {
 		struct ieee80211_supported_band *sband;
 
-		sband = local->hw.wiphy->bands[local->oper_channel->band];
+		sband = local->hw.wiphy->bands[chan->band];
 
 		changed |= ieee80211_config_ht_tx(sdata, elems.ht_operation,
 						  bssid, true);
@@ -2555,7 +2609,7 @@
 	if (elems.country_elem && elems.pwr_constr_elem &&
 	    mgmt->u.probe_resp.capab_info &
 				cpu_to_le16(WLAN_CAPABILITY_SPECTRUM_MGMT))
-		ieee80211_handle_pwr_constr(sdata, local->oper_channel,
+		ieee80211_handle_pwr_constr(sdata, chan,
 					    elems.country_elem,
 					    elems.country_elem_len,
 					    elems.pwr_constr_elem);
@@ -2728,7 +2782,7 @@
 		 */
 		ieee80211_send_probe_req(sdata, NULL, ssidie + 2, ssidie[1],
 					 NULL, 0, (u32) -1, true, false,
-					 auth_data->bss->channel);
+					 auth_data->bss->channel, false);
 	}
 
 	auth_data->timeout = jiffies + IEEE80211_AUTH_TIMEOUT;
@@ -3118,20 +3172,9 @@
 		}
 	}
 
-	if (!ieee80211_set_channel_type(local, sdata, channel_type)) {
-		/* can only fail due to HT40+/- mismatch */
-		channel_type = NL80211_CHAN_HT20;
-		sdata_info(sdata,
-			   "disabling 40 MHz due to multi-vif mismatch\n");
-		ifmgd->flags |= IEEE80211_STA_DISABLE_40MHZ;
-		WARN_ON(!ieee80211_set_channel_type(local, sdata,
-						    channel_type));
-	}
-
-	local->oper_channel = cbss->channel;
-	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
-
-	return 0;
+	ieee80211_vif_release_channel(sdata);
+	return ieee80211_vif_use_channel(sdata, cbss->channel, channel_type,
+					 IEEE80211_CHANCTX_SHARED);
 }
 
 static int ieee80211_prep_connection(struct ieee80211_sub_if_data *sdata,
@@ -3201,7 +3244,7 @@
 		sdata->vif.bss_conf.basic_rates = basic_rates;
 
 		/* cf. IEEE 802.11 9.2.12 */
-		if (local->oper_channel->band == IEEE80211_BAND_2GHZ &&
+		if (cbss->channel->band == IEEE80211_BAND_2GHZ &&
 		    have_higher_than_11mbit)
 			sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
 		else
diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
index 9c52fc4..c349f3a 100644
--- a/net/mac80211/offchannel.c
+++ b/net/mac80211/offchannel.c
@@ -199,7 +199,8 @@
 
 	if (roc->mgmt_tx_cookie) {
 		if (!WARN_ON(!roc->frame)) {
-			ieee80211_tx_skb(roc->sdata, roc->frame);
+			ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7,
+						  roc->chan->band);
 			roc->frame = NULL;
 		}
 	} else {
diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c
index 5c572e7..9f404ac 100644
--- a/net/mac80211/pm.c
+++ b/net/mac80211/pm.c
@@ -135,6 +135,8 @@
 		ieee80211_bss_info_change_notify(sdata,
 			BSS_CHANGED_BEACON_ENABLED);
 
+		/* the interface is leaving the channel and is removed */
+		ieee80211_vif_release_channel(sdata);
 		drv_remove_interface(local, sdata);
 	}
 
diff --git a/net/mac80211/rate.h b/net/mac80211/rate.h
index 10de668..ec198ef 100644
--- a/net/mac80211/rate.h
+++ b/net/mac80211/rate.h
@@ -52,11 +52,21 @@
 	struct ieee80211_sta *ista = &sta->sta;
 	void *priv_sta = sta->rate_ctrl_priv;
 	struct ieee80211_supported_band *sband;
+	struct ieee80211_chanctx_conf *chanctx_conf;
 
 	if (!ref)
 		return;
 
-	sband = local->hw.wiphy->bands[local->oper_channel->band];
+	rcu_read_lock();
+
+	chanctx_conf = rcu_dereference(sta->sdata->vif.chanctx_conf);
+	if (WARN_ON(!chanctx_conf)) {
+		rcu_read_unlock();
+		return;
+	}
+
+	sband = local->hw.wiphy->bands[chanctx_conf->channel->band];
+	rcu_read_unlock();
 
 	ref->ops->rate_init(ref->priv, sband, ista, priv_sta);
 	set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index fdaa505..987c75d4 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -421,7 +421,7 @@
 			local->scan_req->ie, local->scan_req->ie_len,
 			local->scan_req->rates[band], false,
 			local->scan_req->no_cck,
-			local->hw.conf.channel);
+			local->hw.conf.channel, true);
 
 	/*
 	 * After sending probe requests, wait for probe responses
@@ -484,7 +484,7 @@
 	if (local->ops->hw_scan) {
 		__set_bit(SCAN_HW_SCANNING, &local->scanning);
 	} else if ((req->n_channels == 1) &&
-		   (req->channels[0] == local->oper_channel)) {
+		   (req->channels[0] == local->_oper_channel)) {
 		/*
 		 * If we are scanning only on the operating channel
 		 * then we do not need to stop normal activities
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 797dd36..fa639f4 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -1008,6 +1008,7 @@
 	__le16 fc;
 	bool qos = test_sta_flag(sta, WLAN_STA_WME);
 	struct ieee80211_tx_info *info;
+	struct ieee80211_chanctx_conf *chanctx_conf;
 
 	if (qos) {
 		fc = cpu_to_le16(IEEE80211_FTYPE_DATA |
@@ -1057,7 +1058,16 @@
 
 	drv_allow_buffered_frames(local, sta, BIT(tid), 1, reason, false);
 
-	ieee80211_xmit(sdata, skb);
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (WARN_ON(!chanctx_conf)) {
+		rcu_read_unlock();
+		kfree_skb(skb);
+		return;
+	}
+
+	ieee80211_xmit(sdata, skb, chanctx_conf->channel->band);
+	rcu_read_unlock();
 }
 
 static void
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index c9bf83f..eee448a 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -324,11 +324,6 @@
 	struct ieee80211_sub_if_data *sdata;
 	struct sta_info *sta;
 
-	/*
-	 * virtual interfaces are protected by RCU
-	 */
-	rcu_read_lock();
-
 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 		struct ieee80211_if_ap *ap;
 		if (sdata->vif.type != NL80211_IFTYPE_AP)
@@ -360,8 +355,6 @@
 		}
 	}
 
-	rcu_read_unlock();
-
 	local->total_ps_buffered = total;
 	ps_dbg_hw(&local->hw, "PS buffers full - purged %d frames\n", purged);
 }
@@ -1372,7 +1365,8 @@
  * Returns false if the frame couldn't be transmitted but was queued instead.
  */
 static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
-			 struct sk_buff *skb, bool txpending)
+			 struct sk_buff *skb, bool txpending,
+			 enum ieee80211_band band)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_tx_data tx;
@@ -1386,20 +1380,18 @@
 		return true;
 	}
 
-	rcu_read_lock();
-
 	/* initialises tx */
 	led_len = skb->len;
 	res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);
 
 	if (unlikely(res_prepare == TX_DROP)) {
 		ieee80211_free_txskb(&local->hw, skb);
-		goto out;
+		return true;
 	} else if (unlikely(res_prepare == TX_QUEUED)) {
-		goto out;
+		return true;
 	}
 
-	info->band = local->hw.conf.channel->band;
+	info->band = band;
 
 	/* set up hw_queue value early */
 	if (!(info->flags & IEEE80211_TX_CTL_TX_OFFCHAN) ||
@@ -1410,8 +1402,7 @@
 	if (!invoke_tx_handlers(&tx))
 		result = __ieee80211_tx(local, &tx.skbs, led_len,
 					tx.sta, txpending);
- out:
-	rcu_read_unlock();
+
 	return result;
 }
 
@@ -1446,7 +1437,8 @@
 	return 0;
 }
 
-void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
+void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
+		    enum ieee80211_band band)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
@@ -1454,8 +1446,6 @@
 	int headroom;
 	bool may_encrypt;
 
-	rcu_read_lock();
-
 	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
 
 	headroom = local->tx_headroom;
@@ -1466,7 +1456,6 @@
 
 	if (ieee80211_skb_resize(sdata, skb, headroom, may_encrypt)) {
 		ieee80211_free_txskb(&local->hw, skb);
-		rcu_read_unlock();
 		return;
 	}
 
@@ -1478,13 +1467,11 @@
 	    !is_multicast_ether_addr(hdr->addr1) &&
 	    mesh_nexthop_resolve(skb, sdata)) {
 		/* skb queued: don't free */
-		rcu_read_unlock();
 		return;
 	}
 
 	ieee80211_set_qos_hdr(sdata, skb);
-	ieee80211_tx(sdata, skb, false);
-	rcu_read_unlock();
+	ieee80211_tx(sdata, skb, false, band);
 }
 
 static bool ieee80211_parse_tx_radiotap(struct sk_buff *skb)
@@ -1574,7 +1561,8 @@
 					 struct net_device *dev)
 {
 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
-	struct ieee80211_channel *chan = local->hw.conf.channel;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_channel *chan;
 	struct ieee80211_radiotap_header *prthdr =
 		(struct ieee80211_radiotap_header *)skb->data;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
@@ -1583,26 +1571,6 @@
 	u16 len_rthdr;
 	int hdrlen;
 
-	/*
-	 * Frame injection is not allowed if beaconing is not allowed
-	 * or if we need radar detection. Beaconing is usually not allowed when
-	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
-	 * Passive scan is also used in world regulatory domains where
-	 * your country is not known and as such it should be treated as
-	 * NO TX unless the channel is explicitly allowed in which case
-	 * your current regulatory domain would not have the passive scan
-	 * flag.
-	 *
-	 * Since AP mode uses monitor interfaces to inject/TX management
-	 * frames we can make AP mode the exception to this rule once it
-	 * supports radar detection as its implementation can deal with
-	 * radar detection by itself. We can do that later by adding a
-	 * monitor flag interfaces used for AP support.
-	 */
-	if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
-	     IEEE80211_CHAN_PASSIVE_SCAN)))
-		goto fail;
-
 	/* check for not even having the fixed radiotap header part */
 	if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
 		goto fail; /* too short to be possibly valid */
@@ -1688,11 +1656,45 @@
 		}
 	}
 
-	ieee80211_xmit(sdata, skb);
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (!chanctx_conf) {
+		tmp_sdata = rcu_dereference(local->monitor_sdata);
+		if (tmp_sdata)
+			chanctx_conf =
+				rcu_dereference(tmp_sdata->vif.chanctx_conf);
+	}
+	if (!chanctx_conf)
+		goto fail_rcu;
+
+	chan = chanctx_conf->channel;
+
+	/*
+	 * Frame injection is not allowed if beaconing is not allowed
+	 * or if we need radar detection. Beaconing is usually not allowed when
+	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
+	 * Passive scan is also used in world regulatory domains where
+	 * your country is not known and as such it should be treated as
+	 * NO TX unless the channel is explicitly allowed in which case
+	 * your current regulatory domain would not have the passive scan
+	 * flag.
+	 *
+	 * Since AP mode uses monitor interfaces to inject/TX management
+	 * frames we can make AP mode the exception to this rule once it
+	 * supports radar detection as its implementation can deal with
+	 * radar detection by itself. We can do that later by adding a
+	 * monitor flag interfaces used for AP support.
+	 */
+	if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
+			    IEEE80211_CHAN_PASSIVE_SCAN)))
+		goto fail_rcu;
+
+	ieee80211_xmit(sdata, skb, chan->band);
 	rcu_read_unlock();
 
 	return NETDEV_TX_OK;
 
+fail_rcu:
+	rcu_read_unlock();
 fail:
 	dev_kfree_skb(skb);
 	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
@@ -1734,6 +1736,9 @@
 	bool multicast;
 	u32 info_flags = 0;
 	u16 info_id = 0;
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	struct ieee80211_sub_if_data *ap_sdata;
+	enum ieee80211_band band;
 
 	if (unlikely(skb->len < ETH_HLEN))
 		goto fail;
@@ -1743,9 +1748,10 @@
 	ethertype = (skb->data[12] << 8) | skb->data[13];
 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
 
+	rcu_read_lock();
+
 	switch (sdata->vif.type) {
 	case NL80211_IFTYPE_AP_VLAN:
-		rcu_read_lock();
 		sta = rcu_dereference(sdata->u.vlan.sta);
 		if (sta) {
 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
@@ -1758,7 +1764,12 @@
 			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
 			wme_sta = test_sta_flag(sta, WLAN_STA_WME);
 		}
-		rcu_read_unlock();
+		ap_sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
+					u.ap);
+		chanctx_conf = rcu_dereference(ap_sdata->vif.chanctx_conf);
+		if (!chanctx_conf)
+			goto fail_rcu;
+		band = chanctx_conf->channel->band;
 		if (sta)
 			break;
 		/* fall through */
@@ -1769,6 +1780,11 @@
 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
 		hdrlen = 24;
+		if (sdata->vif.type == NL80211_IFTYPE_AP)
+			chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+		if (!chanctx_conf)
+			goto fail_rcu;
+		band = chanctx_conf->channel->band;
 		break;
 	case NL80211_IFTYPE_WDS:
 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
@@ -1778,15 +1794,20 @@
 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
 		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
 		hdrlen = 30;
+		/*
+		 * This is the exception! WDS style interfaces are prohibited
+		 * when channel contexts are in used so this must be valid
+		 */
+		band = local->hw.conf.channel->band;
 		break;
 #ifdef CONFIG_MAC80211_MESH
 	case NL80211_IFTYPE_MESH_POINT:
 		if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
 			/* Do not send frames with mesh_ttl == 0 */
 			sdata->u.mesh.mshstats.dropped_frames_ttl++;
-			goto fail;
+			goto fail_rcu;
 		}
-		rcu_read_lock();
+
 		if (!is_multicast_ether_addr(skb->data)) {
 			mpath = mesh_path_lookup(skb->data, sdata);
 			if (!mpath)
@@ -1803,7 +1824,6 @@
 		    !(mppath && !ether_addr_equal(mppath->mpp, skb->data))) {
 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
 					skb->data, skb->data + ETH_ALEN);
-			rcu_read_unlock();
 			meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,
 					sdata, NULL, NULL);
 		} else {
@@ -1819,7 +1839,6 @@
 				mesh_da = mppath->mpp;
 			else if (mpath)
 				mesh_da = mpath->dst;
-			rcu_read_unlock();
 
 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
 					mesh_da, sdata->vif.addr);
@@ -1839,13 +1858,16 @@
 							skb->data + ETH_ALEN);
 
 		}
+		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+		if (!chanctx_conf)
+			goto fail_rcu;
+		band = chanctx_conf->channel->band;
 		break;
 #endif
 	case NL80211_IFTYPE_STATION:
 		if (sdata->wdev.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS) {
 			bool tdls_peer = false;
 
-			rcu_read_lock();
 			sta = sta_info_get(sdata, skb->data);
 			if (sta) {
 				authorized = test_sta_flag(sta,
@@ -1856,7 +1878,6 @@
 				tdls_auth = test_sta_flag(sta,
 						WLAN_STA_TDLS_PEER_AUTH);
 			}
-			rcu_read_unlock();
 
 			/*
 			 * If the TDLS link is enabled, send everything
@@ -1871,7 +1892,7 @@
 		if (tdls_direct) {
 			/* link during setup - throw out frames to peer */
 			if (!tdls_auth)
-				goto fail;
+				goto fail_rcu;
 
 			/* DA SA BSSID */
 			memcpy(hdr.addr1, skb->data, ETH_ALEN);
@@ -1896,6 +1917,10 @@
 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
 			hdrlen = 24;
 		}
+		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+		if (!chanctx_conf)
+			goto fail_rcu;
+		band = chanctx_conf->channel->band;
 		break;
 	case NL80211_IFTYPE_ADHOC:
 		/* DA SA BSSID */
@@ -1903,9 +1928,13 @@
 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
 		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
 		hdrlen = 24;
+		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+		if (!chanctx_conf)
+			goto fail_rcu;
+		band = chanctx_conf->channel->band;
 		break;
 	default:
-		goto fail;
+		goto fail_rcu;
 	}
 
 	/*
@@ -1915,13 +1944,11 @@
 	 */
 	multicast = is_multicast_ether_addr(hdr.addr1);
 	if (!multicast) {
-		rcu_read_lock();
 		sta = sta_info_get(sdata, hdr.addr1);
 		if (sta) {
 			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
 			wme_sta = test_sta_flag(sta, WLAN_STA_WME);
 		}
-		rcu_read_unlock();
 	}
 
 	/* For mesh, the use of the QoS header is mandatory */
@@ -1949,7 +1976,7 @@
 
 		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
 
-		goto fail;
+		goto fail_rcu;
 	}
 
 	if (unlikely(!multicast && skb->sk &&
@@ -2004,7 +2031,7 @@
 		kfree_skb(tmp_skb);
 
 		if (!skb)
-			goto fail;
+			goto fail_rcu;
 	}
 
 	hdr.frame_control = fc;
@@ -2052,7 +2079,7 @@
 		head_need = max_t(int, 0, head_need);
 		if (ieee80211_skb_resize(sdata, skb, head_need, true)) {
 			ieee80211_free_txskb(&local->hw, skb);
-			return NETDEV_TX_OK;
+			goto fail_rcu;
 		}
 	}
 
@@ -2104,10 +2131,13 @@
 	info->flags = info_flags;
 	info->ack_frame_id = info_id;
 
-	ieee80211_xmit(sdata, skb);
+	ieee80211_xmit(sdata, skb, band);
+	rcu_read_unlock();
 
 	return NETDEV_TX_OK;
 
+ fail_rcu:
+	rcu_read_unlock();
  fail:
 	dev_kfree_skb(skb);
 	return NETDEV_TX_OK;
@@ -2139,11 +2169,18 @@
 	struct sta_info *sta;
 	struct ieee80211_hdr *hdr;
 	bool result;
+	struct ieee80211_chanctx_conf *chanctx_conf;
 
 	sdata = vif_to_sdata(info->control.vif);
 
 	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
-		result = ieee80211_tx(sdata, skb, true);
+		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+		if (unlikely(!chanctx_conf)) {
+			dev_kfree_skb(skb);
+			return true;
+		}
+		result = ieee80211_tx(sdata, skb, true,
+				      chanctx_conf->channel->band);
 	} else {
 		struct sk_buff_head skbs;
 
@@ -2285,14 +2322,16 @@
 	struct ieee80211_sub_if_data *sdata = NULL;
 	struct ieee80211_if_ap *ap = NULL;
 	struct beacon_data *beacon;
-	enum ieee80211_band band = local->oper_channel->band;
+	enum ieee80211_band band;
 	struct ieee80211_tx_rate_control txrc;
+	struct ieee80211_chanctx_conf *chanctx_conf;
 
 	rcu_read_lock();
 
 	sdata = vif_to_sdata(vif);
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 
-	if (!ieee80211_sdata_running(sdata))
+	if (!ieee80211_sdata_running(sdata) || !chanctx_conf)
 		goto out;
 
 	if (tim_offset)
@@ -2409,6 +2448,8 @@
 		*pos++ = WLAN_EID_SSID;
 		*pos++ = 0x0;
 
+		band = chanctx_conf->channel->band;
+
 		if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
 		    mesh_add_ds_params_ie(skb, sdata) ||
 		    ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
@@ -2426,6 +2467,8 @@
 		goto out;
 	}
 
+	band = chanctx_conf->channel->band;
+
 	info = IEEE80211_SKB_CB(skb);
 
 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
@@ -2656,14 +2699,17 @@
 	struct ieee80211_if_ap *bss = NULL;
 	struct beacon_data *beacon;
 	struct ieee80211_tx_info *info;
+	struct ieee80211_chanctx_conf *chanctx_conf;
 
 	sdata = vif_to_sdata(vif);
 	bss = &sdata->u.ap;
 
 	rcu_read_lock();
 	beacon = rcu_dereference(bss->beacon);
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 
-	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
+	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head ||
+	    !chanctx_conf)
 		goto out;
 
 	if (bss->dtim_count != 0 || !bss->dtim_bc_mc)
@@ -2693,7 +2739,7 @@
 	info = IEEE80211_SKB_CB(skb);
 
 	tx.flags |= IEEE80211_TX_PS_BUFFERED;
-	info->band = local->oper_channel->band;
+	info->band = chanctx_conf->channel->band;
 
 	if (invoke_tx_handlers(&tx))
 		skb = NULL;
@@ -2704,8 +2750,9 @@
 }
 EXPORT_SYMBOL(ieee80211_get_buffered_bc);
 
-void ieee80211_tx_skb_tid(struct ieee80211_sub_if_data *sdata,
-			  struct sk_buff *skb, int tid)
+void __ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
+				 struct sk_buff *skb, int tid,
+				 enum ieee80211_band band)
 {
 	int ac = ieee802_1d_to_ac[tid & 7];
 
@@ -2722,6 +2769,6 @@
 	 * requirements are that we do not come into tx with bhs on.
 	 */
 	local_bh_disable();
-	ieee80211_xmit(sdata, skb);
+	ieee80211_xmit(sdata, skb, band);
 	local_bh_enable();
 }
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 22ca350..7d73707 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -832,6 +832,7 @@
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_tx_queue_params qparam;
+	struct ieee80211_chanctx_conf *chanctx_conf;
 	int ac;
 	bool use_11b, enable_qos;
 	int aCWmin, aCWmax;
@@ -844,8 +845,12 @@
 
 	memset(&qparam, 0, sizeof(qparam));
 
-	use_11b = (local->oper_channel->band == IEEE80211_BAND_2GHZ) &&
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	use_11b = (chanctx_conf &&
+		   chanctx_conf->channel->band == IEEE80211_BAND_2GHZ) &&
 		 !(sdata->flags & IEEE80211_SDATA_OPERATING_GMODE);
+	rcu_read_unlock();
 
 	/*
 	 * By default disable QoS in STA mode for old access points, which do
@@ -924,7 +929,7 @@
 				  const size_t supp_rates_len,
 				  const u8 *supp_rates)
 {
-	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_chanctx_conf *chanctx_conf;
 	int i, have_higher_than_11mbit = 0;
 
 	/* cf. IEEE 802.11 9.2.12 */
@@ -932,11 +937,16 @@
 		if ((supp_rates[i] & 0x7f) * 5 > 110)
 			have_higher_than_11mbit = 1;
 
-	if (local->oper_channel->band == IEEE80211_BAND_2GHZ &&
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+
+	if (chanctx_conf &&
+	    chanctx_conf->channel->band == IEEE80211_BAND_2GHZ &&
 	    have_higher_than_11mbit)
 		sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
 	else
 		sdata->flags &= ~IEEE80211_SDATA_OPERATING_GMODE;
+	rcu_read_unlock();
 
 	ieee80211_set_wmm_default(sdata, true);
 }
@@ -1206,7 +1216,7 @@
 			      const u8 *ssid, size_t ssid_len,
 			      const u8 *ie, size_t ie_len,
 			      u32 ratemask, bool directed, bool no_cck,
-			      struct ieee80211_channel *channel)
+			      struct ieee80211_channel *channel, bool scan)
 {
 	struct sk_buff *skb;
 
@@ -1217,7 +1227,10 @@
 		if (no_cck)
 			IEEE80211_SKB_CB(skb)->flags |=
 				IEEE80211_TX_CTL_NO_CCK_RATE;
-		ieee80211_tx_skb(sdata, skb);
+		if (scan)
+			ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
+		else
+			ieee80211_tx_skb(sdata, skb);
 	}
 }
 
@@ -1280,6 +1293,7 @@
 {
 	struct ieee80211_hw *hw = &local->hw;
 	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_chanctx *ctx;
 	struct sta_info *sta;
 	int res, i;
 
@@ -1352,6 +1366,12 @@
 			res = drv_add_interface(local, sdata);
 	}
 
+	/* add channel contexts */
+	mutex_lock(&local->chanctx_mtx);
+	list_for_each_entry(ctx, &local->chanctx_list, list)
+		WARN_ON(drv_add_chanctx(local, ctx));
+	mutex_unlock(&local->chanctx_mtx);
+
 	/* add STAs back */
 	mutex_lock(&local->sta_mtx);
 	list_for_each_entry(sta, &local->sta_list, list) {
@@ -1392,11 +1412,22 @@
 
 	/* Finally also reconfigure all the BSS information */
 	list_for_each_entry(sdata, &local->interfaces, list) {
+		struct ieee80211_chanctx_conf *ctx_conf;
 		u32 changed;
 
 		if (!ieee80211_sdata_running(sdata))
 			continue;
 
+		mutex_lock(&local->chanctx_mtx);
+		ctx_conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
+				lockdep_is_held(&local->chanctx_mtx));
+		if (ctx_conf) {
+			ctx = container_of(ctx_conf, struct ieee80211_chanctx,
+					   conf);
+			drv_assign_vif_chanctx(local, sdata, ctx);
+		}
+		mutex_unlock(&local->chanctx_mtx);
+
 		/* common change flags for all interface types */
 		changed = BSS_CHANGED_ERP_CTS_PROT |
 			  BSS_CHANGED_ERP_PREAMBLE |