/*
   * mac80211 - channel management
   */

  #include <linux/nl80211.h>

  #include <linux/export.h>

  #include <linux/rtnetlink.h>

  #include <net/cfg80211.h>

  #include "ieee80211_i.h"

  #include "driver-ops.h"

  static int ieee80211_chanctx_num_assigned(struct ieee80211_local *local,
  					  struct ieee80211_chanctx *ctx)
  {
  	struct ieee80211_sub_if_data *sdata;
  	int num = 0;
  
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	list_for_each_entry(sdata, &ctx->assigned_vifs, assigned_chanctx_list)
  		num++;
  
  	return num;
  }
  
  static int ieee80211_chanctx_num_reserved(struct ieee80211_local *local,
  					  struct ieee80211_chanctx *ctx)
  {
  	struct ieee80211_sub_if_data *sdata;
  	int num = 0;
  
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	list_for_each_entry(sdata, &ctx->reserved_vifs, reserved_chanctx_list)
  		num++;
  
  	return num;
  }
  
  int ieee80211_chanctx_refcount(struct ieee80211_local *local,
  			       struct ieee80211_chanctx *ctx)
  {
  	return ieee80211_chanctx_num_assigned(local, ctx) +
  	       ieee80211_chanctx_num_reserved(local, ctx);
  }

  static int ieee80211_num_chanctx(struct ieee80211_local *local)
  {
  	struct ieee80211_chanctx *ctx;
  	int num = 0;
  
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	list_for_each_entry(ctx, &local->chanctx_list, list)
  		num++;
  
  	return num;
  }
  
  static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local)
  {
  	lockdep_assert_held(&local->chanctx_mtx);
  	return ieee80211_num_chanctx(local) < ieee80211_max_num_channels(local);
  }

  static struct ieee80211_chanctx *
  ieee80211_vif_get_chanctx(struct ieee80211_sub_if_data *sdata)
  {

  	struct ieee80211_local *local __maybe_unused = sdata->local;

  	struct ieee80211_chanctx_conf *conf;
  
  	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
  					 lockdep_is_held(&local->chanctx_mtx));
  	if (!conf)
  		return NULL;
  
  	return container_of(conf, struct ieee80211_chanctx, conf);
  }

  static const struct cfg80211_chan_def *
  ieee80211_chanctx_reserved_chandef(struct ieee80211_local *local,
  				   struct ieee80211_chanctx *ctx,
  				   const struct cfg80211_chan_def *compat)
  {
  	struct ieee80211_sub_if_data *sdata;
  
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	list_for_each_entry(sdata, &ctx->reserved_vifs,
  			    reserved_chanctx_list) {
  		if (!compat)
  			compat = &sdata->reserved_chandef;
  
  		compat = cfg80211_chandef_compatible(&sdata->reserved_chandef,
  						     compat);
  		if (!compat)
  			break;
  	}
  
  	return compat;
  }

  static const struct cfg80211_chan_def *
  ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local *local,
  				       struct ieee80211_chanctx *ctx,
  				       const struct cfg80211_chan_def *compat)
  {
  	struct ieee80211_sub_if_data *sdata;
  
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	list_for_each_entry(sdata, &ctx->assigned_vifs,
  			    assigned_chanctx_list) {
  		if (sdata->reserved_chanctx != NULL)
  			continue;
  
  		if (!compat)
  			compat = &sdata->vif.bss_conf.chandef;
  
  		compat = cfg80211_chandef_compatible(
  				&sdata->vif.bss_conf.chandef, compat);
  		if (!compat)
  			break;
  	}
  
  	return compat;
  }
  
  static const struct cfg80211_chan_def *
  ieee80211_chanctx_combined_chandef(struct ieee80211_local *local,
  				   struct ieee80211_chanctx *ctx,
  				   const struct cfg80211_chan_def *compat)
  {
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	compat = ieee80211_chanctx_reserved_chandef(local, ctx, compat);
  	if (!compat)
  		return NULL;
  
  	compat = ieee80211_chanctx_non_reserved_chandef(local, ctx, compat);
  	if (!compat)
  		return NULL;
  
  	return compat;
  }
  
  static bool
  ieee80211_chanctx_can_reserve_chandef(struct ieee80211_local *local,
  				      struct ieee80211_chanctx *ctx,
  				      const struct cfg80211_chan_def *def)
  {
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	if (ieee80211_chanctx_combined_chandef(local, ctx, def))
  		return true;
  
  	if (!list_empty(&ctx->reserved_vifs) &&
  	    ieee80211_chanctx_reserved_chandef(local, ctx, def))
  		return true;
  
  	return false;
  }
  
  static struct ieee80211_chanctx *
  ieee80211_find_reservation_chanctx(struct ieee80211_local *local,
  				   const struct cfg80211_chan_def *chandef,
  				   enum ieee80211_chanctx_mode mode)
  {
  	struct ieee80211_chanctx *ctx;
  
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
  		return NULL;
  
  	list_for_each_entry(ctx, &local->chanctx_list, list) {

  		if (ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED)
  			continue;

  		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
  			continue;
  
  		if (!ieee80211_chanctx_can_reserve_chandef(local, ctx,
  							   chandef))
  			continue;
  
  		return ctx;
  	}
  
  	return NULL;
  }

  enum nl80211_chan_width ieee80211_get_sta_bw(struct ieee80211_sta *sta)

  {
  	switch (sta->bandwidth) {
  	case IEEE80211_STA_RX_BW_20:
  		if (sta->ht_cap.ht_supported)
  			return NL80211_CHAN_WIDTH_20;
  		else
  			return NL80211_CHAN_WIDTH_20_NOHT;
  	case IEEE80211_STA_RX_BW_40:
  		return NL80211_CHAN_WIDTH_40;
  	case IEEE80211_STA_RX_BW_80:
  		return NL80211_CHAN_WIDTH_80;
  	case IEEE80211_STA_RX_BW_160:
  		/*
  		 * This applied for both 160 and 80+80. since we use
  		 * the returned value to consider degradation of
  		 * ctx->conf.min_def, we have to make sure to take
  		 * the bigger one (NL80211_CHAN_WIDTH_160).
  		 * Otherwise we might try degrading even when not
  		 * needed, as the max required sta_bw returned (80+80)
  		 * might be smaller than the configured bw (160).
  		 */
  		return NL80211_CHAN_WIDTH_160;
  	default:
  		WARN_ON(1);
  		return NL80211_CHAN_WIDTH_20;
  	}
  }
  
  static enum nl80211_chan_width
  ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata)
  {
  	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
  	struct sta_info *sta;
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
  		if (sdata != sta->sdata &&
  		    !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
  			continue;

  		max_bw = max(max_bw, ieee80211_get_sta_bw(&sta->sta));
  	}
  	rcu_read_unlock();
  
  	return max_bw;
  }
  
  static enum nl80211_chan_width
  ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
  				      struct ieee80211_chanctx_conf *conf)
  {
  	struct ieee80211_sub_if_data *sdata;
  	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
  		struct ieee80211_vif *vif = &sdata->vif;
  		enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT;
  
  		if (!ieee80211_sdata_running(sdata))
  			continue;
  
  		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
  			continue;
  
  		switch (vif->type) {
  		case NL80211_IFTYPE_AP:
  		case NL80211_IFTYPE_AP_VLAN:
  			width = ieee80211_get_max_required_bw(sdata);
  			break;

  		case NL80211_IFTYPE_STATION:
  			/*
  			 * The ap's sta->bandwidth is not set yet at this
  			 * point, so take the width from the chandef, but
  			 * account also for TDLS peers
  			 */
  			width = max(vif->bss_conf.chandef.width,
  				    ieee80211_get_max_required_bw(sdata));
  			break;

  		case NL80211_IFTYPE_P2P_DEVICE:

  		case NL80211_IFTYPE_NAN:

  			continue;

  		case NL80211_IFTYPE_ADHOC:
  		case NL80211_IFTYPE_WDS:
  		case NL80211_IFTYPE_MESH_POINT:

  		case NL80211_IFTYPE_OCB:

  			width = vif->bss_conf.chandef.width;
  			break;
  		case NL80211_IFTYPE_UNSPECIFIED:
  		case NUM_NL80211_IFTYPES:
  		case NL80211_IFTYPE_MONITOR:
  		case NL80211_IFTYPE_P2P_CLIENT:
  		case NL80211_IFTYPE_P2P_GO:
  			WARN_ON_ONCE(1);
  		}
  		max_bw = max(max_bw, width);
  	}

  
  	/* use the configured bandwidth in case of monitor interface */
  	sdata = rcu_dereference(local->monitor_sdata);
  	if (sdata && rcu_access_pointer(sdata->vif.chanctx_conf) == conf)
  		max_bw = max(max_bw, conf->def.width);

  	rcu_read_unlock();
  
  	return max_bw;
  }
  
  /*
   * recalc the min required chan width of the channel context, which is
   * the max of min required widths of all the interfaces bound to this
   * channel context.
   */
  void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
  				      struct ieee80211_chanctx *ctx)
  {
  	enum nl80211_chan_width max_bw;
  	struct cfg80211_chan_def min_def;
  
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	/* don't optimize 5MHz, 10MHz, and radar_enabled confs */
  	if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
  	    ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
  	    ctx->conf.radar_enabled) {
  		ctx->conf.min_def = ctx->conf.def;
  		return;
  	}
  
  	max_bw = ieee80211_get_chanctx_max_required_bw(local, &ctx->conf);
  
  	/* downgrade chandef up to max_bw */
  	min_def = ctx->conf.def;
  	while (min_def.width > max_bw)
  		ieee80211_chandef_downgrade(&min_def);
  
  	if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
  		return;
  
  	ctx->conf.min_def = min_def;
  	if (!ctx->driver_present)
  		return;
  
  	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_MIN_WIDTH);
  }

  static void ieee80211_change_chanctx(struct ieee80211_local *local,

  				     struct ieee80211_chanctx *ctx,
  				     const struct cfg80211_chan_def *chandef)

  {

  	if (cfg80211_chandef_identical(&ctx->conf.def, chandef)) {
  		ieee80211_recalc_chanctx_min_def(local, ctx);

  		return;

  	}

  	WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
  
  	ctx->conf.def = *chandef;
  	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);

  	ieee80211_recalc_chanctx_min_def(local, ctx);

  
  	if (!local->use_chanctx) {

  		local->_oper_chandef = *chandef;

  		ieee80211_hw_config(local, 0);
  	}

  }

  
  static struct ieee80211_chanctx *
  ieee80211_find_chanctx(struct ieee80211_local *local,

  		       const struct cfg80211_chan_def *chandef,

  		       enum ieee80211_chanctx_mode mode)
  {
  	struct ieee80211_chanctx *ctx;
  
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
  		return NULL;

  
  	list_for_each_entry(ctx, &local->chanctx_list, list) {

  		const struct cfg80211_chan_def *compat;

  		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
  			continue;

  		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
  			continue;

  
  		compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
  		if (!compat)

  			continue;

  		compat = ieee80211_chanctx_reserved_chandef(local, ctx,
  							    compat);
  		if (!compat)
  			continue;

  		ieee80211_change_chanctx(local, ctx, compat);

  		return ctx;
  	}
  
  	return NULL;
  }

  bool ieee80211_is_radar_required(struct ieee80211_local *local)

  {
  	struct ieee80211_sub_if_data *sdata;

  	lockdep_assert_held(&local->mtx);

  	rcu_read_lock();
  	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
  		if (sdata->radar_required) {
  			rcu_read_unlock();
  			return true;
  		}
  	}
  	rcu_read_unlock();
  
  	return false;
  }

  static bool
  ieee80211_chanctx_radar_required(struct ieee80211_local *local,
  				 struct ieee80211_chanctx *ctx)
  {
  	struct ieee80211_chanctx_conf *conf = &ctx->conf;
  	struct ieee80211_sub_if_data *sdata;
  	bool required = false;
  
  	lockdep_assert_held(&local->chanctx_mtx);
  	lockdep_assert_held(&local->mtx);
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
  		if (!ieee80211_sdata_running(sdata))
  			continue;
  		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
  			continue;
  		if (!sdata->radar_required)
  			continue;
  
  		required = true;
  		break;
  	}
  	rcu_read_unlock();
  
  	return required;
  }

  static struct ieee80211_chanctx *

  ieee80211_alloc_chanctx(struct ieee80211_local *local,
  			const struct cfg80211_chan_def *chandef,
  			enum ieee80211_chanctx_mode mode)

  {
  	struct ieee80211_chanctx *ctx;
  
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
  	if (!ctx)

  		return NULL;

  	INIT_LIST_HEAD(&ctx->assigned_vifs);

  	INIT_LIST_HEAD(&ctx->reserved_vifs);

  	ctx->conf.def = *chandef;

  	ctx->conf.rx_chains_static = 1;
  	ctx->conf.rx_chains_dynamic = 1;

  	ctx->mode = mode;

  	ctx->conf.radar_enabled = false;

  	ieee80211_recalc_chanctx_min_def(local, ctx);

  
  	return ctx;
  }
  
  static int ieee80211_add_chanctx(struct ieee80211_local *local,
  				 struct ieee80211_chanctx *ctx)
  {
  	u32 changed;
  	int err;
  
  	lockdep_assert_held(&local->mtx);
  	lockdep_assert_held(&local->chanctx_mtx);

  	if (!local->use_chanctx)
  		local->hw.conf.radar_enabled = ctx->conf.radar_enabled;

  	/* turn idle off *before* setting channel -- some drivers need that */
  	changed = ieee80211_idle_off(local);
  	if (changed)
  		ieee80211_hw_config(local, changed);

  	if (!local->use_chanctx) {

  		local->_oper_chandef = ctx->conf.def;

  		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);

  	} else {
  		err = drv_add_chanctx(local, ctx);
  		if (err) {

  			ieee80211_recalc_idle(local);

  			return err;

  		}

  	}

  	return 0;
  }
  
  static struct ieee80211_chanctx *
  ieee80211_new_chanctx(struct ieee80211_local *local,
  		      const struct cfg80211_chan_def *chandef,
  		      enum ieee80211_chanctx_mode mode)
  {
  	struct ieee80211_chanctx *ctx;
  	int err;

  	lockdep_assert_held(&local->mtx);
  	lockdep_assert_held(&local->chanctx_mtx);

  	ctx = ieee80211_alloc_chanctx(local, chandef, mode);
  	if (!ctx)
  		return ERR_PTR(-ENOMEM);
  
  	err = ieee80211_add_chanctx(local, ctx);
  	if (err) {
  		kfree(ctx);
  		return ERR_PTR(err);
  	}
  
  	list_add_rcu(&ctx->list, &local->chanctx_list);

  	return ctx;
  }

  static void ieee80211_del_chanctx(struct ieee80211_local *local,
  				  struct ieee80211_chanctx *ctx)

  {
  	lockdep_assert_held(&local->chanctx_mtx);

  	if (!local->use_chanctx) {

  		struct cfg80211_chan_def *chandef = &local->_oper_chandef;
  		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
  		chandef->center_freq1 = chandef->chan->center_freq;
  		chandef->center_freq2 = 0;

  
  		/* NOTE: Disabling radar is only valid here for
  		 * single channel context. To be sure, check it ...
  		 */

  		WARN_ON(local->hw.conf.radar_enabled &&
  			!list_empty(&local->chanctx_list));

  		local->hw.conf.radar_enabled = false;

  		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);

  	} else {
  		drv_remove_chanctx(local, ctx);
  	}

  	ieee80211_recalc_idle(local);

  }

  static void ieee80211_free_chanctx(struct ieee80211_local *local,
  				   struct ieee80211_chanctx *ctx)

  {

  	lockdep_assert_held(&local->chanctx_mtx);

  	WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);

  	list_del_rcu(&ctx->list);
  	ieee80211_del_chanctx(local, ctx);
  	kfree_rcu(ctx, rcu_head);

  }

  void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
  				       struct ieee80211_chanctx *ctx)

  {
  	struct ieee80211_chanctx_conf *conf = &ctx->conf;
  	struct ieee80211_sub_if_data *sdata;

  	const struct cfg80211_chan_def *compat = NULL;

  	struct sta_info *sta;

  
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(sdata, &local->interfaces, list) {

  		if (!ieee80211_sdata_running(sdata))
  			continue;
  		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
  			continue;

  		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
  			continue;

  		if (!compat)
  			compat = &sdata->vif.bss_conf.chandef;
  
  		compat = cfg80211_chandef_compatible(
  				&sdata->vif.bss_conf.chandef, compat);

  		if (WARN_ON_ONCE(!compat))

  			break;

  	}

  
  	/* TDLS peers can sometimes affect the chandef width */
  	list_for_each_entry_rcu(sta, &local->sta_list, list) {
  		if (!sta->uploaded ||
  		    !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
  		    !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
  		    !sta->tdls_chandef.chan)
  			continue;
  
  		compat = cfg80211_chandef_compatible(&sta->tdls_chandef,
  						     compat);
  		if (WARN_ON_ONCE(!compat))
  			break;
  	}

  	rcu_read_unlock();

  	if (!compat)

  		return;

  	ieee80211_change_chanctx(local, ctx, compat);

  }

  static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
  					   struct ieee80211_chanctx *chanctx)
  {
  	bool radar_enabled;
  
  	lockdep_assert_held(&local->chanctx_mtx);

  	/* for ieee80211_is_radar_required */

  	lockdep_assert_held(&local->mtx);

  	radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);

  
  	if (radar_enabled == chanctx->conf.radar_enabled)
  		return;
  
  	chanctx->conf.radar_enabled = radar_enabled;

  
  	if (!local->use_chanctx) {
  		local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
  		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
  	}
  
  	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
  }

  static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
  					struct ieee80211_chanctx *new_ctx)

  {

  	struct ieee80211_local *local = sdata->local;

  	struct ieee80211_chanctx_conf *conf;
  	struct ieee80211_chanctx *curr_ctx = NULL;
  	int ret = 0;

  	if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN))
  		return -ENOTSUPP;

  	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
  					 lockdep_is_held(&local->chanctx_mtx));

  	if (conf) {
  		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);

  		drv_unassign_vif_chanctx(local, sdata, curr_ctx);
  		conf = NULL;

  		list_del(&sdata->assigned_chanctx_list);

  	}

  	if (new_ctx) {
  		ret = drv_assign_vif_chanctx(local, sdata, new_ctx);
  		if (ret)
  			goto out;

  		conf = &new_ctx->conf;

  		list_add(&sdata->assigned_chanctx_list,
  			 &new_ctx->assigned_vifs);

  	}

  out:
  	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);

  	sdata->vif.bss_conf.idle = !conf;

  	if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {

  		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
  		ieee80211_recalc_smps_chanctx(local, curr_ctx);
  		ieee80211_recalc_radar_chanctx(local, curr_ctx);
  		ieee80211_recalc_chanctx_min_def(local, curr_ctx);

  	}

  	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {

  		ieee80211_recalc_txpower(sdata, false);

  		ieee80211_recalc_chanctx_min_def(local, new_ctx);

  	}

  
  	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
  	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
  		ieee80211_bss_info_change_notify(sdata,
  						 BSS_CHANGED_IDLE);

  	ieee80211_check_fast_xmit_iface(sdata);

  	return ret;

  }

  void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
  				   struct ieee80211_chanctx *chanctx)
  {
  	struct ieee80211_sub_if_data *sdata;
  	u8 rx_chains_static, rx_chains_dynamic;
  
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	rx_chains_static = 1;
  	rx_chains_dynamic = 1;
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
  		u8 needed_static, needed_dynamic;
  
  		if (!ieee80211_sdata_running(sdata))
  			continue;
  
  		if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
  						&chanctx->conf)
  			continue;
  
  		switch (sdata->vif.type) {
  		case NL80211_IFTYPE_P2P_DEVICE:

  		case NL80211_IFTYPE_NAN:

  			continue;
  		case NL80211_IFTYPE_STATION:
  			if (!sdata->u.mgd.associated)
  				continue;
  			break;
  		case NL80211_IFTYPE_AP_VLAN:
  			continue;
  		case NL80211_IFTYPE_AP:
  		case NL80211_IFTYPE_ADHOC:
  		case NL80211_IFTYPE_WDS:
  		case NL80211_IFTYPE_MESH_POINT:

  		case NL80211_IFTYPE_OCB:

  			break;
  		default:
  			WARN_ON_ONCE(1);
  		}
  
  		switch (sdata->smps_mode) {
  		default:
  			WARN_ONCE(1, "Invalid SMPS mode %d
  ",
  				  sdata->smps_mode);
  			/* fall through */
  		case IEEE80211_SMPS_OFF:
  			needed_static = sdata->needed_rx_chains;
  			needed_dynamic = sdata->needed_rx_chains;
  			break;
  		case IEEE80211_SMPS_DYNAMIC:
  			needed_static = 1;
  			needed_dynamic = sdata->needed_rx_chains;
  			break;
  		case IEEE80211_SMPS_STATIC:
  			needed_static = 1;
  			needed_dynamic = 1;
  			break;
  		}
  
  		rx_chains_static = max(rx_chains_static, needed_static);
  		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
  	}

  
  	/* Disable SMPS for the monitor interface */
  	sdata = rcu_dereference(local->monitor_sdata);
  	if (sdata &&
  	    rcu_access_pointer(sdata->vif.chanctx_conf) == &chanctx->conf)
  		rx_chains_dynamic = rx_chains_static = local->rx_chains;

  	rcu_read_unlock();
  
  	if (!local->use_chanctx) {
  		if (rx_chains_static > 1)
  			local->smps_mode = IEEE80211_SMPS_OFF;
  		else if (rx_chains_dynamic > 1)
  			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
  		else
  			local->smps_mode = IEEE80211_SMPS_STATIC;
  		ieee80211_hw_config(local, 0);
  	}
  
  	if (rx_chains_static == chanctx->conf.rx_chains_static &&
  	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
  		return;
  
  	chanctx->conf.rx_chains_static = rx_chains_static;
  	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
  	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
  }

  static void
  __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
  				      bool clear)
  {

  	struct ieee80211_local *local __maybe_unused = sdata->local;

  	struct ieee80211_sub_if_data *vlan;
  	struct ieee80211_chanctx_conf *conf;
  
  	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
  		return;
  
  	lockdep_assert_held(&local->mtx);
  
  	/* Check that conf exists, even when clearing this function
  	 * must be called with the AP's channel context still there
  	 * as it would otherwise cause VLANs to have an invalid
  	 * channel context pointer for a while, possibly pointing
  	 * to a channel context that has already been freed.
  	 */
  	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,

  					 lockdep_is_held(&local->chanctx_mtx));

  	WARN_ON(!conf);
  
  	if (clear)
  		conf = NULL;
  
  	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
  		rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
  }
  
  void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
  					 bool clear)
  {
  	struct ieee80211_local *local = sdata->local;
  
  	mutex_lock(&local->chanctx_mtx);
  
  	__ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
  
  	mutex_unlock(&local->chanctx_mtx);
  }
  
  int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
  {

  	struct ieee80211_chanctx *ctx = sdata->reserved_chanctx;

  	lockdep_assert_held(&sdata->local->chanctx_mtx);

  	if (WARN_ON(!ctx))

  		return -EINVAL;

  	list_del(&sdata->reserved_chanctx_list);

  	sdata->reserved_chanctx = NULL;

  	if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
  		if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
  			if (WARN_ON(!ctx->replace_ctx))
  				return -EINVAL;
  
  			WARN_ON(ctx->replace_ctx->replace_state !=
  			        IEEE80211_CHANCTX_WILL_BE_REPLACED);
  			WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
  
  			ctx->replace_ctx->replace_ctx = NULL;
  			ctx->replace_ctx->replace_state =
  					IEEE80211_CHANCTX_REPLACE_NONE;
  
  			list_del_rcu(&ctx->list);
  			kfree_rcu(ctx, rcu_head);
  		} else {
  			ieee80211_free_chanctx(sdata->local, ctx);
  		}
  	}

  	return 0;
  }
  
  int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
  				  const struct cfg80211_chan_def *chandef,

  				  enum ieee80211_chanctx_mode mode,
  				  bool radar_required)

  {
  	struct ieee80211_local *local = sdata->local;

  	struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;

  	lockdep_assert_held(&local->chanctx_mtx);

  	curr_ctx = ieee80211_vif_get_chanctx(sdata);
  	if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
  		return -ENOTSUPP;

  	new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);

  	if (!new_ctx) {

  		if (ieee80211_can_create_new_chanctx(local)) {

  			new_ctx = ieee80211_new_chanctx(local, chandef, mode);

  			if (IS_ERR(new_ctx))
  				return PTR_ERR(new_ctx);

  		} else {

  			if (!curr_ctx ||
  			    (curr_ctx->replace_state ==
  			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
  			    !list_empty(&curr_ctx->reserved_vifs)) {
  				/*
  				 * Another vif already requested this context
  				 * for a reservation. Find another one hoping
  				 * all vifs assigned to it will also switch
  				 * soon enough.
  				 *
  				 * TODO: This needs a little more work as some
  				 * cases (more than 2 chanctx capable devices)
  				 * may fail which could otherwise succeed
  				 * provided some channel context juggling was
  				 * performed.
  				 *
  				 * Consider ctx1..3, vif1..6, each ctx has 2
  				 * vifs. vif1 and vif2 from ctx1 request new
  				 * different chandefs starting 2 in-place
  				 * reserations with ctx4 and ctx5 replacing
  				 * ctx1 and ctx2 respectively. Next vif5 and
  				 * vif6 from ctx3 reserve ctx4. If vif3 and
  				 * vif4 remain on ctx2 as they are then this
  				 * fails unless `replace_ctx` from ctx5 is
  				 * replaced with ctx3.
  				 */
  				list_for_each_entry(ctx, &local->chanctx_list,
  						    list) {
  					if (ctx->replace_state !=
  					    IEEE80211_CHANCTX_REPLACE_NONE)
  						continue;
  
  					if (!list_empty(&ctx->reserved_vifs))
  						continue;
  
  					curr_ctx = ctx;
  					break;
  				}
  			}
  
  			/*
  			 * If that's true then all available contexts already
  			 * have reservations and cannot be used.
  			 */
  			if (!curr_ctx ||
  			    (curr_ctx->replace_state ==
  			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
  			    !list_empty(&curr_ctx->reserved_vifs))
  				return -EBUSY;
  
  			new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
  			if (!new_ctx)
  				return -ENOMEM;
  
  			new_ctx->replace_ctx = curr_ctx;
  			new_ctx->replace_state =
  					IEEE80211_CHANCTX_REPLACES_OTHER;
  
  			curr_ctx->replace_ctx = new_ctx;
  			curr_ctx->replace_state =
  					IEEE80211_CHANCTX_WILL_BE_REPLACED;
  
  			list_add_rcu(&new_ctx->list, &local->chanctx_list);

  		}
  	}

  	list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);

  	sdata->reserved_chanctx = new_ctx;
  	sdata->reserved_chandef = *chandef;

  	sdata->reserved_radar_required = radar_required;

  	sdata->reserved_ready = false;
  
  	return 0;

  }

  static void
  ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
  {
  	switch (sdata->vif.type) {
  	case NL80211_IFTYPE_ADHOC:
  	case NL80211_IFTYPE_AP:
  	case NL80211_IFTYPE_MESH_POINT:

  	case NL80211_IFTYPE_OCB:

  		ieee80211_queue_work(&sdata->local->hw,
  				     &sdata->csa_finalize_work);
  		break;

  	case NL80211_IFTYPE_STATION:

  		ieee80211_queue_work(&sdata->local->hw,
  				     &sdata->u.mgd.chswitch_work);
  		break;
  	case NL80211_IFTYPE_UNSPECIFIED:

  	case NL80211_IFTYPE_AP_VLAN:
  	case NL80211_IFTYPE_WDS:
  	case NL80211_IFTYPE_MONITOR:
  	case NL80211_IFTYPE_P2P_CLIENT:
  	case NL80211_IFTYPE_P2P_GO:
  	case NL80211_IFTYPE_P2P_DEVICE:

  	case NL80211_IFTYPE_NAN:

  	case NUM_NL80211_IFTYPES:
  		WARN_ON(1);
  		break;
  	}
  }

  static void
  ieee80211_vif_update_chandef(struct ieee80211_sub_if_data *sdata,
  			     const struct cfg80211_chan_def *chandef)
  {
  	struct ieee80211_sub_if_data *vlan;
  
  	sdata->vif.bss_conf.chandef = *chandef;
  
  	if (sdata->vif.type != NL80211_IFTYPE_AP)
  		return;
  
  	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
  		vlan->vif.bss_conf.chandef = *chandef;
  }

  static int
  ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)

  {
  	struct ieee80211_local *local = sdata->local;

  	struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
  	struct ieee80211_chanctx *old_ctx, *new_ctx;
  	const struct cfg80211_chan_def *chandef;
  	u32 changed = 0;
  	int err;

  
  	lockdep_assert_held(&local->mtx);

  	lockdep_assert_held(&local->chanctx_mtx);

  	new_ctx = sdata->reserved_chanctx;
  	old_ctx = ieee80211_vif_get_chanctx(sdata);

  	if (WARN_ON(!sdata->reserved_ready))
  		return -EBUSY;

  	if (WARN_ON(!new_ctx))
  		return -EINVAL;
  
  	if (WARN_ON(!old_ctx))
  		return -EINVAL;
  
  	if (WARN_ON(new_ctx->replace_state ==
  		    IEEE80211_CHANCTX_REPLACES_OTHER))
  		return -EINVAL;
  
  	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
  				&sdata->reserved_chandef);
  	if (WARN_ON(!chandef))
  		return -EINVAL;

  	ieee80211_change_chanctx(local, new_ctx, chandef);

  	vif_chsw[0].vif = &sdata->vif;
  	vif_chsw[0].old_ctx = &old_ctx->conf;
  	vif_chsw[0].new_ctx = &new_ctx->conf;
  
  	list_del(&sdata->reserved_chanctx_list);
  	sdata->reserved_chanctx = NULL;
  
  	err = drv_switch_vif_chanctx(local, vif_chsw, 1,
  				     CHANCTX_SWMODE_REASSIGN_VIF);
  	if (err) {
  		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
  			ieee80211_free_chanctx(local, new_ctx);

  		goto out;

  	}

  	list_move(&sdata->assigned_chanctx_list, &new_ctx->assigned_vifs);
  	rcu_assign_pointer(sdata->vif.chanctx_conf, &new_ctx->conf);
  
  	if (sdata->vif.type == NL80211_IFTYPE_AP)
  		__ieee80211_vif_copy_chanctx_to_vlans(sdata, false);

  	ieee80211_check_fast_xmit_iface(sdata);

  	if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
  		ieee80211_free_chanctx(local, old_ctx);

  	if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)

  		changed = BSS_CHANGED_BANDWIDTH;

  	ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);

  	ieee80211_recalc_smps_chanctx(local, new_ctx);
  	ieee80211_recalc_radar_chanctx(local, new_ctx);
  	ieee80211_recalc_chanctx_min_def(local, new_ctx);

  	if (changed)
  		ieee80211_bss_info_change_notify(sdata, changed);

  out:
  	ieee80211_vif_chanctx_reservation_complete(sdata);

  	return err;
  }
  
  static int
  ieee80211_vif_use_reserved_assign(struct ieee80211_sub_if_data *sdata)
  {
  	struct ieee80211_local *local = sdata->local;
  	struct ieee80211_chanctx *old_ctx, *new_ctx;
  	const struct cfg80211_chan_def *chandef;
  	int err;
  
  	old_ctx = ieee80211_vif_get_chanctx(sdata);
  	new_ctx = sdata->reserved_chanctx;
  
  	if (WARN_ON(!sdata->reserved_ready))
  		return -EINVAL;
  
  	if (WARN_ON(old_ctx))
  		return -EINVAL;
  
  	if (WARN_ON(!new_ctx))
  		return -EINVAL;
  
  	if (WARN_ON(new_ctx->replace_state ==
  		    IEEE80211_CHANCTX_REPLACES_OTHER))
  		return -EINVAL;
  
  	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
  				&sdata->reserved_chandef);
  	if (WARN_ON(!chandef))
  		return -EINVAL;

  	ieee80211_change_chanctx(local, new_ctx, chandef);

  	list_del(&sdata->reserved_chanctx_list);

  	sdata->reserved_chanctx = NULL;

  	err = ieee80211_assign_vif_chanctx(sdata, new_ctx);
  	if (err) {
  		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
  			ieee80211_free_chanctx(local, new_ctx);
  
  		goto out;
  	}
  
  out:

  	ieee80211_vif_chanctx_reservation_complete(sdata);

  	return err;
  }
  
  static bool
  ieee80211_vif_has_in_place_reservation(struct ieee80211_sub_if_data *sdata)
  {
  	struct ieee80211_chanctx *old_ctx, *new_ctx;
  
  	lockdep_assert_held(&sdata->local->chanctx_mtx);
  
  	new_ctx = sdata->reserved_chanctx;
  	old_ctx = ieee80211_vif_get_chanctx(sdata);
  
  	if (!old_ctx)
  		return false;
  
  	if (WARN_ON(!new_ctx))
  		return false;
  
  	if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
  		return false;
  
  	if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
  		return false;
  
  	return true;
  }
  
  static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
  					struct ieee80211_chanctx *new_ctx)
  {
  	const struct cfg80211_chan_def *chandef;
  
  	lockdep_assert_held(&local->mtx);
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
  	if (WARN_ON(!chandef))
  		return -EINVAL;
  
  	local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
  	local->_oper_chandef = *chandef;
  	ieee80211_hw_config(local, 0);
  
  	return 0;
  }
  
  static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
  				      int n_vifs)
  {
  	struct ieee80211_vif_chanctx_switch *vif_chsw;
  	struct ieee80211_sub_if_data *sdata;
  	struct ieee80211_chanctx *ctx, *old_ctx;
  	int i, err;
  
  	lockdep_assert_held(&local->mtx);
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	vif_chsw = kzalloc(sizeof(vif_chsw[0]) * n_vifs, GFP_KERNEL);
  	if (!vif_chsw)
  		return -ENOMEM;
  
  	i = 0;
  	list_for_each_entry(ctx, &local->chanctx_list, list) {
  		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
  			continue;
  
  		if (WARN_ON(!ctx->replace_ctx)) {
  			err = -EINVAL;

  			goto out;
  		}

  		list_for_each_entry(sdata, &ctx->reserved_vifs,
  				    reserved_chanctx_list) {
  			if (!ieee80211_vif_has_in_place_reservation(
  					sdata))
  				continue;
  
  			old_ctx = ieee80211_vif_get_chanctx(sdata);
  			vif_chsw[i].vif = &sdata->vif;
  			vif_chsw[i].old_ctx = &old_ctx->conf;
  			vif_chsw[i].new_ctx = &ctx->conf;
  
  			i++;
  		}

  	}

  	err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
  				     CHANCTX_SWMODE_SWAP_CONTEXTS);

  out:

  	kfree(vif_chsw);
  	return err;
  }
  
  static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
  {
  	struct ieee80211_chanctx *ctx;
  	int err;
  
  	lockdep_assert_held(&local->mtx);
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	list_for_each_entry(ctx, &local->chanctx_list, list) {
  		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
  			continue;
  
  		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
  			continue;
  
  		ieee80211_del_chanctx(local, ctx->replace_ctx);
  		err = ieee80211_add_chanctx(local, ctx);
  		if (err)
  			goto err;
  	}
  
  	return 0;
  
  err:
  	WARN_ON(ieee80211_add_chanctx(local, ctx));
  	list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
  		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
  			continue;
  
  		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
  			continue;
  
  		ieee80211_del_chanctx(local, ctx);
  		WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
  	}
  
  	return err;
  }

  static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)

  {
  	struct ieee80211_sub_if_data *sdata, *sdata_tmp;
  	struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
  	struct ieee80211_chanctx *new_ctx = NULL;

  	int err, n_assigned, n_reserved, n_ready;

  	int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
  
  	lockdep_assert_held(&local->mtx);
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	/*
  	 * If there are 2 independent pairs of channel contexts performing
  	 * cross-switch of their vifs this code will still wait until both are
  	 * ready even though it could be possible to switch one before the
  	 * other is ready.
  	 *
  	 * For practical reasons and code simplicity just do a single huge
  	 * switch.
  	 */
  
  	/*
  	 * Verify if the reservation is still feasible.
  	 *  - if it's not then disconnect
  	 *  - if it is but not all vifs necessary are ready then defer
  	 */
  
  	list_for_each_entry(ctx, &local->chanctx_list, list) {
  		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
  			continue;
  
  		if (WARN_ON(!ctx->replace_ctx)) {
  			err = -EINVAL;
  			goto err;
  		}
  
  		if (!local->use_chanctx)
  			new_ctx = ctx;
  
  		n_ctx++;
  
  		n_assigned = 0;
  		n_reserved = 0;
  		n_ready = 0;
  
  		list_for_each_entry(sdata, &ctx->replace_ctx->assigned_vifs,
  				    assigned_chanctx_list) {
  			n_assigned++;
  			if (sdata->reserved_chanctx) {
  				n_reserved++;
  				if (sdata->reserved_ready)
  					n_ready++;
  			}
  		}
  
  		if (n_assigned != n_reserved) {
  			if (n_ready == n_reserved) {
  				wiphy_info(local->hw.wiphy,
  					   "channel context reservation cannot be finalized because some interfaces aren't switching
  ");
  				err = -EBUSY;
  				goto err;
  			}
  
  			return -EAGAIN;
  		}
  
  		ctx->conf.radar_enabled = false;
  		list_for_each_entry(sdata, &ctx->reserved_vifs,
  				    reserved_chanctx_list) {
  			if (ieee80211_vif_has_in_place_reservation(sdata) &&
  			    !sdata->reserved_ready)
  				return -EAGAIN;
  
  			old_ctx = ieee80211_vif_get_chanctx(sdata);
  			if (old_ctx) {
  				if (old_ctx->replace_state ==
  				    IEEE80211_CHANCTX_WILL_BE_REPLACED)
  					n_vifs_switch++;
  				else
  					n_vifs_assign++;
  			} else {
  				n_vifs_ctxless++;
  			}
  
  			if (sdata->reserved_radar_required)
  				ctx->conf.radar_enabled = true;
  		}
  	}
  
  	if (WARN_ON(n_ctx == 0) ||
  	    WARN_ON(n_vifs_switch == 0 &&
  		    n_vifs_assign == 0 &&
  		    n_vifs_ctxless == 0) ||
  	    WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
  	    WARN_ON(!new_ctx && !local->use_chanctx)) {
  		err = -EINVAL;
  		goto err;
  	}
  
  	/*
  	 * All necessary vifs are ready. Perform the switch now depending on
  	 * reservations and driver capabilities.
  	 */
  
  	if (local->use_chanctx) {
  		if (n_vifs_switch > 0) {
  			err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
  			if (err)
  				goto err;
  		}
  
  		if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
  			err = ieee80211_chsw_switch_ctxs(local);
  			if (err)
  				goto err;
  		}
  	} else {
  		err = ieee80211_chsw_switch_hwconf(local, new_ctx);
  		if (err)
  			goto err;
  	}
  
  	/*
  	 * Update all structures, values and pointers to point to new channel
  	 * context(s).
  	 */

  	list_for_each_entry(ctx, &local->chanctx_list, list) {
  		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
  			continue;
  
  		if (WARN_ON(!ctx->replace_ctx)) {
  			err = -EINVAL;
  			goto err;
  		}
  
  		list_for_each_entry(sdata, &ctx->reserved_vifs,
  				    reserved_chanctx_list) {
  			u32 changed = 0;
  
  			if (!ieee80211_vif_has_in_place_reservation(sdata))
  				continue;
  
  			rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
  
  			if (sdata->vif.type == NL80211_IFTYPE_AP)
  				__ieee80211_vif_copy_chanctx_to_vlans(sdata,
  								      false);

  			ieee80211_check_fast_xmit_iface(sdata);

  			sdata->radar_required = sdata->reserved_radar_required;
  
  			if (sdata->vif.bss_conf.chandef.width !=
  			    sdata->reserved_chandef.width)
  				changed = BSS_CHANGED_BANDWIDTH;

  			ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);

  			if (changed)
  				ieee80211_bss_info_change_notify(sdata,
  								 changed);

  			ieee80211_recalc_txpower(sdata, false);

  		}
  
  		ieee80211_recalc_chanctx_chantype(local, ctx);
  		ieee80211_recalc_smps_chanctx(local, ctx);
  		ieee80211_recalc_radar_chanctx(local, ctx);
  		ieee80211_recalc_chanctx_min_def(local, ctx);
  
  		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
  					 reserved_chanctx_list) {
  			if (ieee80211_vif_get_chanctx(sdata) != ctx)
  				continue;
  
  			list_del(&sdata->reserved_chanctx_list);
  			list_move(&sdata->assigned_chanctx_list,

  				  &ctx->assigned_vifs);

  			sdata->reserved_chanctx = NULL;

  
  			ieee80211_vif_chanctx_reservation_complete(sdata);

  		}
  
  		/*
  		 * This context might have been a dependency for an already
  		 * ready re-assign reservation interface that was deferred. Do
  		 * not propagate error to the caller though. The in-place
  		 * reservation for originally requested interface has already
  		 * succeeded at this point.
  		 */
  		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
  					 reserved_chanctx_list) {
  			if (WARN_ON(ieee80211_vif_has_in_place_reservation(
  					sdata)))
  				continue;
  
  			if (WARN_ON(sdata->reserved_chanctx != ctx))
  				continue;
  
  			if (!sdata->reserved_ready)
  				continue;
  
  			if (ieee80211_vif_get_chanctx(sdata))
  				err = ieee80211_vif_use_reserved_reassign(
  						sdata);
  			else
  				err = ieee80211_vif_use_reserved_assign(sdata);
  
  			if (err) {
  				sdata_info(sdata,
  					   "failed to finalize (re-)assign reservation (err=%d)
  ",
  					   err);
  				ieee80211_vif_unreserve_chanctx(sdata);
  				cfg80211_stop_iface(local->hw.wiphy,
  						    &sdata->wdev,
  						    GFP_KERNEL);
  			}
  		}
  	}
  
  	/*
  	 * Finally free old contexts
  	 */
  
  	list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
  		if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
  			continue;
  
  		ctx->replace_ctx->replace_ctx = NULL;
  		ctx->replace_ctx->replace_state =
  				IEEE80211_CHANCTX_REPLACE_NONE;
  
  		list_del_rcu(&ctx->list);
  		kfree_rcu(ctx, rcu_head);
  	}
  
  	return 0;
  
  err:
  	list_for_each_entry(ctx, &local->chanctx_list, list) {
  		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
  			continue;
  
  		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,

  					 reserved_chanctx_list) {

  			ieee80211_vif_unreserve_chanctx(sdata);

  			ieee80211_vif_chanctx_reservation_complete(sdata);
  		}

  	}
  
  	return err;
  }

  static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
  {
  	struct ieee80211_local *local = sdata->local;
  	struct ieee80211_chanctx_conf *conf;
  	struct ieee80211_chanctx *ctx;
  	bool use_reserved_switch = false;
  
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
  					 lockdep_is_held(&local->chanctx_mtx));
  	if (!conf)
  		return;
  
  	ctx = container_of(conf, struct ieee80211_chanctx, conf);
  
  	if (sdata->reserved_chanctx) {
  		if (sdata->reserved_chanctx->replace_state ==
  		    IEEE80211_CHANCTX_REPLACES_OTHER &&
  		    ieee80211_chanctx_num_reserved(local,
  						   sdata->reserved_chanctx) > 1)
  			use_reserved_switch = true;
  
  		ieee80211_vif_unreserve_chanctx(sdata);
  	}
  
  	ieee80211_assign_vif_chanctx(sdata, NULL);
  	if (ieee80211_chanctx_refcount(local, ctx) == 0)
  		ieee80211_free_chanctx(local, ctx);

  	sdata->radar_required = false;

  	/* Unreserving may ready an in-place reservation. */
  	if (use_reserved_switch)
  		ieee80211_vif_use_reserved_switch(local);
  }
  
  int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
  			      const struct cfg80211_chan_def *chandef,
  			      enum ieee80211_chanctx_mode mode)
  {
  	struct ieee80211_local *local = sdata->local;
  	struct ieee80211_chanctx *ctx;
  	u8 radar_detect_width = 0;
  	int ret;
  
  	lockdep_assert_held(&local->mtx);
  
  	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
  
  	mutex_lock(&local->chanctx_mtx);
  
  	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
  					    chandef,
  					    sdata->wdev.iftype);
  	if (ret < 0)
  		goto out;
  	if (ret > 0)
  		radar_detect_width = BIT(chandef->width);
  
  	sdata->radar_required = ret;
  
  	ret = ieee80211_check_combinations(sdata, chandef, mode,
  					   radar_detect_width);
  	if (ret < 0)
  		goto out;
  
  	__ieee80211_vif_release_channel(sdata);
  
  	ctx = ieee80211_find_chanctx(local, chandef, mode);
  	if (!ctx)
  		ctx = ieee80211_new_chanctx(local, chandef, mode);
  	if (IS_ERR(ctx)) {
  		ret = PTR_ERR(ctx);
  		goto out;
  	}

  	ieee80211_vif_update_chandef(sdata, chandef);

  
  	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
  	if (ret) {
  		/* if assign fails refcount stays the same */
  		if (ieee80211_chanctx_refcount(local, ctx) == 0)
  			ieee80211_free_chanctx(local, ctx);
  		goto out;
  	}
  
  	ieee80211_recalc_smps_chanctx(local, ctx);
  	ieee80211_recalc_radar_chanctx(local, ctx);
   out:

  	if (ret)
  		sdata->radar_required = false;

  	mutex_unlock(&local->chanctx_mtx);
  	return ret;
  }

  int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata)
  {
  	struct ieee80211_local *local = sdata->local;
  	struct ieee80211_chanctx *new_ctx;
  	struct ieee80211_chanctx *old_ctx;
  	int err;
  
  	lockdep_assert_held(&local->mtx);
  	lockdep_assert_held(&local->chanctx_mtx);
  
  	new_ctx = sdata->reserved_chanctx;
  	old_ctx = ieee80211_vif_get_chanctx(sdata);
  
  	if (WARN_ON(!new_ctx))
  		return -EINVAL;
  
  	if (WARN_ON(new_ctx->replace_state ==
  		    IEEE80211_CHANCTX_WILL_BE_REPLACED))
  		return -EINVAL;
  
  	if (WARN_ON(sdata->reserved_ready))
  		return -EINVAL;
  
  	sdata->reserved_ready = true;
  
  	if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
  		if (old_ctx)
  			err = ieee80211_vif_use_reserved_reassign(sdata);
  		else
  			err = ieee80211_vif_use_reserved_assign(sdata);
  
  		if (err)
  			return err;
  	}
  
  	/*
  	 * In-place reservation may need to be finalized now either if:
  	 *  a) sdata is taking part in the swapping itself and is the last one
  	 *  b) sdata has switched with a re-assign reservation to an existing
  	 *     context readying in-place switching of old_ctx
  	 *
  	 * In case of (b) do not propagate the error up because the requested
  	 * sdata already switched successfully. Just spill an extra warning.
  	 * The ieee80211_vif_use_reserved_switch() already stops all necessary
  	 * interfaces upon failure.
  	 */
  	if ((old_ctx &&
  	     old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
  	    new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
  		err = ieee80211_vif_use_reserved_switch(local);
  		if (err && err != -EAGAIN) {
  			if (new_ctx->replace_state ==
  			    IEEE80211_CHANCTX_REPLACES_OTHER)
  				return err;
  
  			wiphy_info(local->hw.wiphy,
  				   "depending in-place reservation failed (err=%d)
  ",
  				   err);
  		}
  	}
  
  	return 0;

  }

  int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
  				   const struct cfg80211_chan_def *chandef,
  				   u32 *changed)
  {
  	struct ieee80211_local *local = sdata->local;
  	struct ieee80211_chanctx_conf *conf;
  	struct ieee80211_chanctx *ctx;

  	const struct cfg80211_chan_def *compat;

  	int ret;
  
  	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
  				     IEEE80211_CHAN_DISABLED))
  		return -EINVAL;
  
  	mutex_lock(&local->chanctx_mtx);
  	if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
  		ret = 0;
  		goto out;
  	}
  
  	if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
  	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
  		ret = -EINVAL;
  		goto out;
  	}
  
  	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
  					 lockdep_is_held(&local->chanctx_mtx));
  	if (!conf) {
  		ret = -EINVAL;
  		goto out;
  	}
  
  	ctx = container_of(conf, struct ieee80211_chanctx, conf);

  
  	compat = cfg80211_chandef_compatible(&conf->def, chandef);
  	if (!compat) {

  		ret = -EINVAL;
  		goto out;
  	}

  	switch (ctx->replace_state) {
  	case IEEE80211_CHANCTX_REPLACE_NONE:
  		if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
  			ret = -EBUSY;
  			goto out;
  		}
  		break;
  	case IEEE80211_CHANCTX_WILL_BE_REPLACED:

  		/* TODO: Perhaps the bandwidth change could be treated as a

  		 * reservation itself? */
  		ret = -EBUSY;
  		goto out;
  	case IEEE80211_CHANCTX_REPLACES_OTHER:
  		/* channel context that is going to replace another channel
  		 * context doesn't really exist and shouldn't be assigned
  		 * anywhere yet */
  		WARN_ON(1);
  		break;
  	}

  	ieee80211_vif_update_chandef(sdata, chandef);

  
  	ieee80211_recalc_chanctx_chantype(local, ctx);
  
  	*changed |= BSS_CHANGED_BANDWIDTH;
  	ret = 0;
   out:
  	mutex_unlock(&local->chanctx_mtx);
  	return ret;
  }

  void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
  {

  	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));

  	lockdep_assert_held(&sdata->local->mtx);

  	mutex_lock(&sdata->local->chanctx_mtx);
  	__ieee80211_vif_release_channel(sdata);
  	mutex_unlock(&sdata->local->chanctx_mtx);
  }

  void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
  {
  	struct ieee80211_local *local = sdata->local;
  	struct ieee80211_sub_if_data *ap;
  	struct ieee80211_chanctx_conf *conf;
  
  	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
  		return;
  
  	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
  
  	mutex_lock(&local->chanctx_mtx);
  
  	conf = rcu_dereference_protected(ap->vif.chanctx_conf,
  					 lockdep_is_held(&local->chanctx_mtx));
  	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
  	mutex_unlock(&local->chanctx_mtx);
  }

  void ieee80211_iter_chan_contexts_atomic(
  	struct ieee80211_hw *hw,
  	void (*iter)(struct ieee80211_hw *hw,
  		     struct ieee80211_chanctx_conf *chanctx_conf,
  		     void *data),
  	void *iter_data)
  {
  	struct ieee80211_local *local = hw_to_local(hw);
  	struct ieee80211_chanctx *ctx;
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)

  		if (ctx->driver_present)
  			iter(hw, &ctx->conf, iter_data);

  	rcu_read_unlock();
  }
  EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);