xref: /openbmc/linux/net/mac80211/chan.c (revision 2bc7d3e0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * mac80211 - channel management
4  * Copyright 2020 - 2021 Intel Corporation
5  */
6 
7 #include <linux/nl80211.h>
8 #include <linux/export.h>
9 #include <linux/rtnetlink.h>
10 #include <net/cfg80211.h>
11 #include "ieee80211_i.h"
12 #include "driver-ops.h"
13 #include "rate.h"
14 
15 static int ieee80211_chanctx_num_assigned(struct ieee80211_local *local,
16 					  struct ieee80211_chanctx *ctx)
17 {
18 	struct ieee80211_sub_if_data *sdata;
19 	int num = 0;
20 
21 	lockdep_assert_held(&local->chanctx_mtx);
22 
23 	list_for_each_entry(sdata, &ctx->assigned_vifs, assigned_chanctx_list)
24 		num++;
25 
26 	return num;
27 }
28 
29 static int ieee80211_chanctx_num_reserved(struct ieee80211_local *local,
30 					  struct ieee80211_chanctx *ctx)
31 {
32 	struct ieee80211_sub_if_data *sdata;
33 	int num = 0;
34 
35 	lockdep_assert_held(&local->chanctx_mtx);
36 
37 	list_for_each_entry(sdata, &ctx->reserved_vifs, reserved_chanctx_list)
38 		num++;
39 
40 	return num;
41 }
42 
43 int ieee80211_chanctx_refcount(struct ieee80211_local *local,
44 			       struct ieee80211_chanctx *ctx)
45 {
46 	return ieee80211_chanctx_num_assigned(local, ctx) +
47 	       ieee80211_chanctx_num_reserved(local, ctx);
48 }
49 
50 static int ieee80211_num_chanctx(struct ieee80211_local *local)
51 {
52 	struct ieee80211_chanctx *ctx;
53 	int num = 0;
54 
55 	lockdep_assert_held(&local->chanctx_mtx);
56 
57 	list_for_each_entry(ctx, &local->chanctx_list, list)
58 		num++;
59 
60 	return num;
61 }
62 
63 static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local)
64 {
65 	lockdep_assert_held(&local->chanctx_mtx);
66 	return ieee80211_num_chanctx(local) < ieee80211_max_num_channels(local);
67 }
68 
69 static struct ieee80211_chanctx *
70 ieee80211_vif_get_chanctx(struct ieee80211_sub_if_data *sdata)
71 {
72 	struct ieee80211_local *local __maybe_unused = sdata->local;
73 	struct ieee80211_chanctx_conf *conf;
74 
75 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
76 					 lockdep_is_held(&local->chanctx_mtx));
77 	if (!conf)
78 		return NULL;
79 
80 	return container_of(conf, struct ieee80211_chanctx, conf);
81 }
82 
83 static const struct cfg80211_chan_def *
84 ieee80211_chanctx_reserved_chandef(struct ieee80211_local *local,
85 				   struct ieee80211_chanctx *ctx,
86 				   const struct cfg80211_chan_def *compat)
87 {
88 	struct ieee80211_sub_if_data *sdata;
89 
90 	lockdep_assert_held(&local->chanctx_mtx);
91 
92 	list_for_each_entry(sdata, &ctx->reserved_vifs,
93 			    reserved_chanctx_list) {
94 		if (!compat)
95 			compat = &sdata->reserved_chandef;
96 
97 		compat = cfg80211_chandef_compatible(&sdata->reserved_chandef,
98 						     compat);
99 		if (!compat)
100 			break;
101 	}
102 
103 	return compat;
104 }
105 
106 static const struct cfg80211_chan_def *
107 ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local *local,
108 				       struct ieee80211_chanctx *ctx,
109 				       const struct cfg80211_chan_def *compat)
110 {
111 	struct ieee80211_sub_if_data *sdata;
112 
113 	lockdep_assert_held(&local->chanctx_mtx);
114 
115 	list_for_each_entry(sdata, &ctx->assigned_vifs,
116 			    assigned_chanctx_list) {
117 		if (sdata->reserved_chanctx != NULL)
118 			continue;
119 
120 		if (!compat)
121 			compat = &sdata->vif.bss_conf.chandef;
122 
123 		compat = cfg80211_chandef_compatible(
124 				&sdata->vif.bss_conf.chandef, compat);
125 		if (!compat)
126 			break;
127 	}
128 
129 	return compat;
130 }
131 
132 static const struct cfg80211_chan_def *
133 ieee80211_chanctx_combined_chandef(struct ieee80211_local *local,
134 				   struct ieee80211_chanctx *ctx,
135 				   const struct cfg80211_chan_def *compat)
136 {
137 	lockdep_assert_held(&local->chanctx_mtx);
138 
139 	compat = ieee80211_chanctx_reserved_chandef(local, ctx, compat);
140 	if (!compat)
141 		return NULL;
142 
143 	compat = ieee80211_chanctx_non_reserved_chandef(local, ctx, compat);
144 	if (!compat)
145 		return NULL;
146 
147 	return compat;
148 }
149 
150 static bool
151 ieee80211_chanctx_can_reserve_chandef(struct ieee80211_local *local,
152 				      struct ieee80211_chanctx *ctx,
153 				      const struct cfg80211_chan_def *def)
154 {
155 	lockdep_assert_held(&local->chanctx_mtx);
156 
157 	if (ieee80211_chanctx_combined_chandef(local, ctx, def))
158 		return true;
159 
160 	if (!list_empty(&ctx->reserved_vifs) &&
161 	    ieee80211_chanctx_reserved_chandef(local, ctx, def))
162 		return true;
163 
164 	return false;
165 }
166 
167 static struct ieee80211_chanctx *
168 ieee80211_find_reservation_chanctx(struct ieee80211_local *local,
169 				   const struct cfg80211_chan_def *chandef,
170 				   enum ieee80211_chanctx_mode mode)
171 {
172 	struct ieee80211_chanctx *ctx;
173 
174 	lockdep_assert_held(&local->chanctx_mtx);
175 
176 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
177 		return NULL;
178 
179 	list_for_each_entry(ctx, &local->chanctx_list, list) {
180 		if (ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED)
181 			continue;
182 
183 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
184 			continue;
185 
186 		if (!ieee80211_chanctx_can_reserve_chandef(local, ctx,
187 							   chandef))
188 			continue;
189 
190 		return ctx;
191 	}
192 
193 	return NULL;
194 }
195 
196 static enum nl80211_chan_width ieee80211_get_sta_bw(struct sta_info *sta)
197 {
198 	enum ieee80211_sta_rx_bandwidth width = ieee80211_sta_cap_rx_bw(sta);
199 
200 	switch (width) {
201 	case IEEE80211_STA_RX_BW_20:
202 		if (sta->sta.deflink.ht_cap.ht_supported)
203 			return NL80211_CHAN_WIDTH_20;
204 		else
205 			return NL80211_CHAN_WIDTH_20_NOHT;
206 	case IEEE80211_STA_RX_BW_40:
207 		return NL80211_CHAN_WIDTH_40;
208 	case IEEE80211_STA_RX_BW_80:
209 		return NL80211_CHAN_WIDTH_80;
210 	case IEEE80211_STA_RX_BW_160:
211 		/*
212 		 * This applied for both 160 and 80+80. since we use
213 		 * the returned value to consider degradation of
214 		 * ctx->conf.min_def, we have to make sure to take
215 		 * the bigger one (NL80211_CHAN_WIDTH_160).
216 		 * Otherwise we might try degrading even when not
217 		 * needed, as the max required sta_bw returned (80+80)
218 		 * might be smaller than the configured bw (160).
219 		 */
220 		return NL80211_CHAN_WIDTH_160;
221 	case IEEE80211_STA_RX_BW_320:
222 		return NL80211_CHAN_WIDTH_320;
223 	default:
224 		WARN_ON(1);
225 		return NL80211_CHAN_WIDTH_20;
226 	}
227 }
228 
229 static enum nl80211_chan_width
230 ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata)
231 {
232 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
233 	struct sta_info *sta;
234 
235 	rcu_read_lock();
236 	list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
237 		if (sdata != sta->sdata &&
238 		    !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
239 			continue;
240 
241 		max_bw = max(max_bw, ieee80211_get_sta_bw(sta));
242 	}
243 	rcu_read_unlock();
244 
245 	return max_bw;
246 }
247 
248 static enum nl80211_chan_width
249 ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
250 				      struct ieee80211_chanctx_conf *conf)
251 {
252 	struct ieee80211_sub_if_data *sdata;
253 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
254 
255 	rcu_read_lock();
256 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
257 		struct ieee80211_vif *vif = &sdata->vif;
258 		enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT;
259 
260 		if (!ieee80211_sdata_running(sdata))
261 			continue;
262 
263 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
264 			continue;
265 
266 		switch (vif->type) {
267 		case NL80211_IFTYPE_AP:
268 		case NL80211_IFTYPE_AP_VLAN:
269 			width = ieee80211_get_max_required_bw(sdata);
270 			break;
271 		case NL80211_IFTYPE_STATION:
272 			/*
273 			 * The ap's sta->bandwidth is not set yet at this
274 			 * point, so take the width from the chandef, but
275 			 * account also for TDLS peers
276 			 */
277 			width = max(vif->bss_conf.chandef.width,
278 				    ieee80211_get_max_required_bw(sdata));
279 			break;
280 		case NL80211_IFTYPE_P2P_DEVICE:
281 		case NL80211_IFTYPE_NAN:
282 			continue;
283 		case NL80211_IFTYPE_ADHOC:
284 		case NL80211_IFTYPE_MESH_POINT:
285 		case NL80211_IFTYPE_OCB:
286 			width = vif->bss_conf.chandef.width;
287 			break;
288 		case NL80211_IFTYPE_WDS:
289 		case NL80211_IFTYPE_UNSPECIFIED:
290 		case NUM_NL80211_IFTYPES:
291 		case NL80211_IFTYPE_MONITOR:
292 		case NL80211_IFTYPE_P2P_CLIENT:
293 		case NL80211_IFTYPE_P2P_GO:
294 			WARN_ON_ONCE(1);
295 		}
296 		max_bw = max(max_bw, width);
297 	}
298 
299 	/* use the configured bandwidth in case of monitor interface */
300 	sdata = rcu_dereference(local->monitor_sdata);
301 	if (sdata && rcu_access_pointer(sdata->vif.chanctx_conf) == conf)
302 		max_bw = max(max_bw, conf->def.width);
303 
304 	rcu_read_unlock();
305 
306 	return max_bw;
307 }
308 
309 /*
310  * recalc the min required chan width of the channel context, which is
311  * the max of min required widths of all the interfaces bound to this
312  * channel context.
313  */
314 static u32 _ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
315 					     struct ieee80211_chanctx *ctx)
316 {
317 	enum nl80211_chan_width max_bw;
318 	struct cfg80211_chan_def min_def;
319 
320 	lockdep_assert_held(&local->chanctx_mtx);
321 
322 	/* don't optimize non-20MHz based and radar_enabled confs */
323 	if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
324 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
325 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_1 ||
326 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_2 ||
327 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_4 ||
328 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_8 ||
329 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_16 ||
330 	    ctx->conf.radar_enabled) {
331 		ctx->conf.min_def = ctx->conf.def;
332 		return 0;
333 	}
334 
335 	max_bw = ieee80211_get_chanctx_max_required_bw(local, &ctx->conf);
336 
337 	/* downgrade chandef up to max_bw */
338 	min_def = ctx->conf.def;
339 	while (min_def.width > max_bw)
340 		ieee80211_chandef_downgrade(&min_def);
341 
342 	if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
343 		return 0;
344 
345 	ctx->conf.min_def = min_def;
346 	if (!ctx->driver_present)
347 		return 0;
348 
349 	return IEEE80211_CHANCTX_CHANGE_MIN_WIDTH;
350 }
351 
352 /* calling this function is assuming that station vif is updated to
353  * lates changes by calling ieee80211_vif_update_chandef
354  */
355 static void ieee80211_chan_bw_change(struct ieee80211_local *local,
356 				     struct ieee80211_chanctx *ctx,
357 				     bool narrowed)
358 {
359 	struct sta_info *sta;
360 	struct ieee80211_supported_band *sband =
361 		local->hw.wiphy->bands[ctx->conf.def.chan->band];
362 
363 	rcu_read_lock();
364 	list_for_each_entry_rcu(sta, &local->sta_list,
365 				list) {
366 		enum ieee80211_sta_rx_bandwidth new_sta_bw;
367 
368 		if (!ieee80211_sdata_running(sta->sdata))
369 			continue;
370 
371 		if (rcu_access_pointer(sta->sdata->vif.chanctx_conf) !=
372 		    &ctx->conf)
373 			continue;
374 
375 		new_sta_bw = ieee80211_sta_cur_vht_bw(sta);
376 
377 		/* nothing change */
378 		if (new_sta_bw == sta->sta.deflink.bandwidth)
379 			continue;
380 
381 		/* vif changed to narrow BW and narrow BW for station wasn't
382 		 * requested or vise versa */
383 		if ((new_sta_bw < sta->sta.deflink.bandwidth) == !narrowed)
384 			continue;
385 
386 		sta->sta.deflink.bandwidth = new_sta_bw;
387 		rate_control_rate_update(local, sband, sta,
388 					 IEEE80211_RC_BW_CHANGED);
389 	}
390 	rcu_read_unlock();
391 }
392 
393 /*
394  * recalc the min required chan width of the channel context, which is
395  * the max of min required widths of all the interfaces bound to this
396  * channel context.
397  */
398 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
399 				      struct ieee80211_chanctx *ctx)
400 {
401 	u32 changed = _ieee80211_recalc_chanctx_min_def(local, ctx);
402 
403 	if (!changed)
404 		return;
405 
406 	/* check is BW narrowed */
407 	ieee80211_chan_bw_change(local, ctx, true);
408 
409 	drv_change_chanctx(local, ctx, changed);
410 
411 	/* check is BW wider */
412 	ieee80211_chan_bw_change(local, ctx, false);
413 }
414 
415 static void ieee80211_change_chanctx(struct ieee80211_local *local,
416 				     struct ieee80211_chanctx *ctx,
417 				     struct ieee80211_chanctx *old_ctx,
418 				     const struct cfg80211_chan_def *chandef)
419 {
420 	u32 changed;
421 
422 	/* expected to handle only 20/40/80/160/320 channel widths */
423 	switch (chandef->width) {
424 	case NL80211_CHAN_WIDTH_20_NOHT:
425 	case NL80211_CHAN_WIDTH_20:
426 	case NL80211_CHAN_WIDTH_40:
427 	case NL80211_CHAN_WIDTH_80:
428 	case NL80211_CHAN_WIDTH_80P80:
429 	case NL80211_CHAN_WIDTH_160:
430 	case NL80211_CHAN_WIDTH_320:
431 		break;
432 	default:
433 		WARN_ON(1);
434 	}
435 
436 	/* Check maybe BW narrowed - we do this _before_ calling recalc_chanctx_min_def
437 	 * due to maybe not returning from it, e.g in case new context was added
438 	 * first time with all parameters up to date.
439 	 */
440 	ieee80211_chan_bw_change(local, old_ctx, true);
441 
442 	if (cfg80211_chandef_identical(&ctx->conf.def, chandef)) {
443 		ieee80211_recalc_chanctx_min_def(local, ctx);
444 		return;
445 	}
446 
447 	WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
448 
449 	ctx->conf.def = *chandef;
450 
451 	/* check if min chanctx also changed */
452 	changed = IEEE80211_CHANCTX_CHANGE_WIDTH |
453 		  _ieee80211_recalc_chanctx_min_def(local, ctx);
454 	drv_change_chanctx(local, ctx, changed);
455 
456 	if (!local->use_chanctx) {
457 		local->_oper_chandef = *chandef;
458 		ieee80211_hw_config(local, 0);
459 	}
460 
461 	/* check is BW wider */
462 	ieee80211_chan_bw_change(local, old_ctx, false);
463 }
464 
465 static struct ieee80211_chanctx *
466 ieee80211_find_chanctx(struct ieee80211_local *local,
467 		       const struct cfg80211_chan_def *chandef,
468 		       enum ieee80211_chanctx_mode mode)
469 {
470 	struct ieee80211_chanctx *ctx;
471 
472 	lockdep_assert_held(&local->chanctx_mtx);
473 
474 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
475 		return NULL;
476 
477 	list_for_each_entry(ctx, &local->chanctx_list, list) {
478 		const struct cfg80211_chan_def *compat;
479 
480 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
481 			continue;
482 
483 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
484 			continue;
485 
486 		compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
487 		if (!compat)
488 			continue;
489 
490 		compat = ieee80211_chanctx_reserved_chandef(local, ctx,
491 							    compat);
492 		if (!compat)
493 			continue;
494 
495 		ieee80211_change_chanctx(local, ctx, ctx, compat);
496 
497 		return ctx;
498 	}
499 
500 	return NULL;
501 }
502 
503 bool ieee80211_is_radar_required(struct ieee80211_local *local)
504 {
505 	struct ieee80211_sub_if_data *sdata;
506 
507 	lockdep_assert_held(&local->mtx);
508 
509 	rcu_read_lock();
510 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
511 		if (sdata->radar_required) {
512 			rcu_read_unlock();
513 			return true;
514 		}
515 	}
516 	rcu_read_unlock();
517 
518 	return false;
519 }
520 
521 static bool
522 ieee80211_chanctx_radar_required(struct ieee80211_local *local,
523 				 struct ieee80211_chanctx *ctx)
524 {
525 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
526 	struct ieee80211_sub_if_data *sdata;
527 	bool required = false;
528 
529 	lockdep_assert_held(&local->chanctx_mtx);
530 	lockdep_assert_held(&local->mtx);
531 
532 	rcu_read_lock();
533 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
534 		if (!ieee80211_sdata_running(sdata))
535 			continue;
536 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
537 			continue;
538 		if (!sdata->radar_required)
539 			continue;
540 
541 		required = true;
542 		break;
543 	}
544 	rcu_read_unlock();
545 
546 	return required;
547 }
548 
549 static struct ieee80211_chanctx *
550 ieee80211_alloc_chanctx(struct ieee80211_local *local,
551 			const struct cfg80211_chan_def *chandef,
552 			enum ieee80211_chanctx_mode mode)
553 {
554 	struct ieee80211_chanctx *ctx;
555 
556 	lockdep_assert_held(&local->chanctx_mtx);
557 
558 	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
559 	if (!ctx)
560 		return NULL;
561 
562 	INIT_LIST_HEAD(&ctx->assigned_vifs);
563 	INIT_LIST_HEAD(&ctx->reserved_vifs);
564 	ctx->conf.def = *chandef;
565 	ctx->conf.rx_chains_static = 1;
566 	ctx->conf.rx_chains_dynamic = 1;
567 	ctx->mode = mode;
568 	ctx->conf.radar_enabled = false;
569 	ieee80211_recalc_chanctx_min_def(local, ctx);
570 
571 	return ctx;
572 }
573 
574 static int ieee80211_add_chanctx(struct ieee80211_local *local,
575 				 struct ieee80211_chanctx *ctx)
576 {
577 	u32 changed;
578 	int err;
579 
580 	lockdep_assert_held(&local->mtx);
581 	lockdep_assert_held(&local->chanctx_mtx);
582 
583 	if (!local->use_chanctx)
584 		local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
585 
586 	/* turn idle off *before* setting channel -- some drivers need that */
587 	changed = ieee80211_idle_off(local);
588 	if (changed)
589 		ieee80211_hw_config(local, changed);
590 
591 	if (!local->use_chanctx) {
592 		local->_oper_chandef = ctx->conf.def;
593 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
594 	} else {
595 		err = drv_add_chanctx(local, ctx);
596 		if (err) {
597 			ieee80211_recalc_idle(local);
598 			return err;
599 		}
600 	}
601 
602 	return 0;
603 }
604 
605 static struct ieee80211_chanctx *
606 ieee80211_new_chanctx(struct ieee80211_local *local,
607 		      const struct cfg80211_chan_def *chandef,
608 		      enum ieee80211_chanctx_mode mode)
609 {
610 	struct ieee80211_chanctx *ctx;
611 	int err;
612 
613 	lockdep_assert_held(&local->mtx);
614 	lockdep_assert_held(&local->chanctx_mtx);
615 
616 	ctx = ieee80211_alloc_chanctx(local, chandef, mode);
617 	if (!ctx)
618 		return ERR_PTR(-ENOMEM);
619 
620 	err = ieee80211_add_chanctx(local, ctx);
621 	if (err) {
622 		kfree(ctx);
623 		return ERR_PTR(err);
624 	}
625 
626 	list_add_rcu(&ctx->list, &local->chanctx_list);
627 	return ctx;
628 }
629 
630 static void ieee80211_del_chanctx(struct ieee80211_local *local,
631 				  struct ieee80211_chanctx *ctx)
632 {
633 	lockdep_assert_held(&local->chanctx_mtx);
634 
635 	if (!local->use_chanctx) {
636 		struct cfg80211_chan_def *chandef = &local->_oper_chandef;
637 		/* S1G doesn't have 20MHz, so get the correct width for the
638 		 * current channel.
639 		 */
640 		if (chandef->chan->band == NL80211_BAND_S1GHZ)
641 			chandef->width =
642 				ieee80211_s1g_channel_width(chandef->chan);
643 		else
644 			chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
645 		chandef->center_freq1 = chandef->chan->center_freq;
646 		chandef->freq1_offset = chandef->chan->freq_offset;
647 		chandef->center_freq2 = 0;
648 
649 		/* NOTE: Disabling radar is only valid here for
650 		 * single channel context. To be sure, check it ...
651 		 */
652 		WARN_ON(local->hw.conf.radar_enabled &&
653 			!list_empty(&local->chanctx_list));
654 
655 		local->hw.conf.radar_enabled = false;
656 
657 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
658 	} else {
659 		drv_remove_chanctx(local, ctx);
660 	}
661 
662 	ieee80211_recalc_idle(local);
663 }
664 
665 static void ieee80211_free_chanctx(struct ieee80211_local *local,
666 				   struct ieee80211_chanctx *ctx)
667 {
668 	lockdep_assert_held(&local->chanctx_mtx);
669 
670 	WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
671 
672 	list_del_rcu(&ctx->list);
673 	ieee80211_del_chanctx(local, ctx);
674 	kfree_rcu(ctx, rcu_head);
675 }
676 
677 void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
678 				       struct ieee80211_chanctx *ctx)
679 {
680 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
681 	struct ieee80211_sub_if_data *sdata;
682 	const struct cfg80211_chan_def *compat = NULL;
683 	struct sta_info *sta;
684 
685 	lockdep_assert_held(&local->chanctx_mtx);
686 
687 	rcu_read_lock();
688 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
689 
690 		if (!ieee80211_sdata_running(sdata))
691 			continue;
692 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
693 			continue;
694 		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
695 			continue;
696 
697 		if (!compat)
698 			compat = &sdata->vif.bss_conf.chandef;
699 
700 		compat = cfg80211_chandef_compatible(
701 				&sdata->vif.bss_conf.chandef, compat);
702 		if (WARN_ON_ONCE(!compat))
703 			break;
704 	}
705 
706 	/* TDLS peers can sometimes affect the chandef width */
707 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
708 		if (!sta->uploaded ||
709 		    !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
710 		    !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
711 		    !sta->tdls_chandef.chan)
712 			continue;
713 
714 		compat = cfg80211_chandef_compatible(&sta->tdls_chandef,
715 						     compat);
716 		if (WARN_ON_ONCE(!compat))
717 			break;
718 	}
719 	rcu_read_unlock();
720 
721 	if (!compat)
722 		return;
723 
724 	ieee80211_change_chanctx(local, ctx, ctx, compat);
725 }
726 
727 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
728 					   struct ieee80211_chanctx *chanctx)
729 {
730 	bool radar_enabled;
731 
732 	lockdep_assert_held(&local->chanctx_mtx);
733 	/* for ieee80211_is_radar_required */
734 	lockdep_assert_held(&local->mtx);
735 
736 	radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
737 
738 	if (radar_enabled == chanctx->conf.radar_enabled)
739 		return;
740 
741 	chanctx->conf.radar_enabled = radar_enabled;
742 
743 	if (!local->use_chanctx) {
744 		local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
745 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
746 	}
747 
748 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
749 }
750 
751 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
752 					struct ieee80211_chanctx *new_ctx)
753 {
754 	struct ieee80211_local *local = sdata->local;
755 	struct ieee80211_chanctx_conf *conf;
756 	struct ieee80211_chanctx *curr_ctx = NULL;
757 	int ret = 0;
758 
759 	if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN))
760 		return -ENOTSUPP;
761 
762 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
763 					 lockdep_is_held(&local->chanctx_mtx));
764 
765 	if (conf) {
766 		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
767 
768 		drv_unassign_vif_chanctx(local, sdata, curr_ctx);
769 		conf = NULL;
770 		list_del(&sdata->assigned_chanctx_list);
771 	}
772 
773 	if (new_ctx) {
774 		ret = drv_assign_vif_chanctx(local, sdata, new_ctx);
775 		if (ret)
776 			goto out;
777 
778 		conf = &new_ctx->conf;
779 		list_add(&sdata->assigned_chanctx_list,
780 			 &new_ctx->assigned_vifs);
781 	}
782 
783 out:
784 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
785 
786 	sdata->vif.bss_conf.idle = !conf;
787 
788 	if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
789 		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
790 		ieee80211_recalc_smps_chanctx(local, curr_ctx);
791 		ieee80211_recalc_radar_chanctx(local, curr_ctx);
792 		ieee80211_recalc_chanctx_min_def(local, curr_ctx);
793 	}
794 
795 	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
796 		ieee80211_recalc_txpower(sdata, false);
797 		ieee80211_recalc_chanctx_min_def(local, new_ctx);
798 	}
799 
800 	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
801 	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
802 		ieee80211_bss_info_change_notify(sdata,
803 						 BSS_CHANGED_IDLE);
804 
805 	ieee80211_check_fast_xmit_iface(sdata);
806 
807 	return ret;
808 }
809 
810 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
811 				   struct ieee80211_chanctx *chanctx)
812 {
813 	struct ieee80211_sub_if_data *sdata;
814 	u8 rx_chains_static, rx_chains_dynamic;
815 
816 	lockdep_assert_held(&local->chanctx_mtx);
817 
818 	rx_chains_static = 1;
819 	rx_chains_dynamic = 1;
820 
821 	rcu_read_lock();
822 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
823 		u8 needed_static, needed_dynamic;
824 
825 		if (!ieee80211_sdata_running(sdata))
826 			continue;
827 
828 		if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
829 						&chanctx->conf)
830 			continue;
831 
832 		switch (sdata->vif.type) {
833 		case NL80211_IFTYPE_P2P_DEVICE:
834 		case NL80211_IFTYPE_NAN:
835 			continue;
836 		case NL80211_IFTYPE_STATION:
837 			if (!sdata->u.mgd.associated)
838 				continue;
839 			break;
840 		case NL80211_IFTYPE_AP_VLAN:
841 			continue;
842 		case NL80211_IFTYPE_AP:
843 		case NL80211_IFTYPE_ADHOC:
844 		case NL80211_IFTYPE_MESH_POINT:
845 		case NL80211_IFTYPE_OCB:
846 			break;
847 		default:
848 			WARN_ON_ONCE(1);
849 		}
850 
851 		switch (sdata->smps_mode) {
852 		default:
853 			WARN_ONCE(1, "Invalid SMPS mode %d\n",
854 				  sdata->smps_mode);
855 			fallthrough;
856 		case IEEE80211_SMPS_OFF:
857 			needed_static = sdata->needed_rx_chains;
858 			needed_dynamic = sdata->needed_rx_chains;
859 			break;
860 		case IEEE80211_SMPS_DYNAMIC:
861 			needed_static = 1;
862 			needed_dynamic = sdata->needed_rx_chains;
863 			break;
864 		case IEEE80211_SMPS_STATIC:
865 			needed_static = 1;
866 			needed_dynamic = 1;
867 			break;
868 		}
869 
870 		rx_chains_static = max(rx_chains_static, needed_static);
871 		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
872 	}
873 
874 	/* Disable SMPS for the monitor interface */
875 	sdata = rcu_dereference(local->monitor_sdata);
876 	if (sdata &&
877 	    rcu_access_pointer(sdata->vif.chanctx_conf) == &chanctx->conf)
878 		rx_chains_dynamic = rx_chains_static = local->rx_chains;
879 
880 	rcu_read_unlock();
881 
882 	if (!local->use_chanctx) {
883 		if (rx_chains_static > 1)
884 			local->smps_mode = IEEE80211_SMPS_OFF;
885 		else if (rx_chains_dynamic > 1)
886 			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
887 		else
888 			local->smps_mode = IEEE80211_SMPS_STATIC;
889 		ieee80211_hw_config(local, 0);
890 	}
891 
892 	if (rx_chains_static == chanctx->conf.rx_chains_static &&
893 	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
894 		return;
895 
896 	chanctx->conf.rx_chains_static = rx_chains_static;
897 	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
898 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
899 }
900 
901 static void
902 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
903 				      bool clear)
904 {
905 	struct ieee80211_local *local __maybe_unused = sdata->local;
906 	struct ieee80211_sub_if_data *vlan;
907 	struct ieee80211_chanctx_conf *conf;
908 
909 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
910 		return;
911 
912 	lockdep_assert_held(&local->mtx);
913 
914 	/* Check that conf exists, even when clearing this function
915 	 * must be called with the AP's channel context still there
916 	 * as it would otherwise cause VLANs to have an invalid
917 	 * channel context pointer for a while, possibly pointing
918 	 * to a channel context that has already been freed.
919 	 */
920 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
921 					 lockdep_is_held(&local->chanctx_mtx));
922 	WARN_ON(!conf);
923 
924 	if (clear)
925 		conf = NULL;
926 
927 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
928 		rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
929 }
930 
931 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
932 					 bool clear)
933 {
934 	struct ieee80211_local *local = sdata->local;
935 
936 	mutex_lock(&local->chanctx_mtx);
937 
938 	__ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
939 
940 	mutex_unlock(&local->chanctx_mtx);
941 }
942 
943 int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
944 {
945 	struct ieee80211_chanctx *ctx = sdata->reserved_chanctx;
946 
947 	lockdep_assert_held(&sdata->local->chanctx_mtx);
948 
949 	if (WARN_ON(!ctx))
950 		return -EINVAL;
951 
952 	list_del(&sdata->reserved_chanctx_list);
953 	sdata->reserved_chanctx = NULL;
954 
955 	if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
956 		if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
957 			if (WARN_ON(!ctx->replace_ctx))
958 				return -EINVAL;
959 
960 			WARN_ON(ctx->replace_ctx->replace_state !=
961 			        IEEE80211_CHANCTX_WILL_BE_REPLACED);
962 			WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
963 
964 			ctx->replace_ctx->replace_ctx = NULL;
965 			ctx->replace_ctx->replace_state =
966 					IEEE80211_CHANCTX_REPLACE_NONE;
967 
968 			list_del_rcu(&ctx->list);
969 			kfree_rcu(ctx, rcu_head);
970 		} else {
971 			ieee80211_free_chanctx(sdata->local, ctx);
972 		}
973 	}
974 
975 	return 0;
976 }
977 
978 int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
979 				  const struct cfg80211_chan_def *chandef,
980 				  enum ieee80211_chanctx_mode mode,
981 				  bool radar_required)
982 {
983 	struct ieee80211_local *local = sdata->local;
984 	struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
985 
986 	lockdep_assert_held(&local->chanctx_mtx);
987 
988 	curr_ctx = ieee80211_vif_get_chanctx(sdata);
989 	if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
990 		return -ENOTSUPP;
991 
992 	new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
993 	if (!new_ctx) {
994 		if (ieee80211_can_create_new_chanctx(local)) {
995 			new_ctx = ieee80211_new_chanctx(local, chandef, mode);
996 			if (IS_ERR(new_ctx))
997 				return PTR_ERR(new_ctx);
998 		} else {
999 			if (!curr_ctx ||
1000 			    (curr_ctx->replace_state ==
1001 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1002 			    !list_empty(&curr_ctx->reserved_vifs)) {
1003 				/*
1004 				 * Another vif already requested this context
1005 				 * for a reservation. Find another one hoping
1006 				 * all vifs assigned to it will also switch
1007 				 * soon enough.
1008 				 *
1009 				 * TODO: This needs a little more work as some
1010 				 * cases (more than 2 chanctx capable devices)
1011 				 * may fail which could otherwise succeed
1012 				 * provided some channel context juggling was
1013 				 * performed.
1014 				 *
1015 				 * Consider ctx1..3, vif1..6, each ctx has 2
1016 				 * vifs. vif1 and vif2 from ctx1 request new
1017 				 * different chandefs starting 2 in-place
1018 				 * reserations with ctx4 and ctx5 replacing
1019 				 * ctx1 and ctx2 respectively. Next vif5 and
1020 				 * vif6 from ctx3 reserve ctx4. If vif3 and
1021 				 * vif4 remain on ctx2 as they are then this
1022 				 * fails unless `replace_ctx` from ctx5 is
1023 				 * replaced with ctx3.
1024 				 */
1025 				list_for_each_entry(ctx, &local->chanctx_list,
1026 						    list) {
1027 					if (ctx->replace_state !=
1028 					    IEEE80211_CHANCTX_REPLACE_NONE)
1029 						continue;
1030 
1031 					if (!list_empty(&ctx->reserved_vifs))
1032 						continue;
1033 
1034 					curr_ctx = ctx;
1035 					break;
1036 				}
1037 			}
1038 
1039 			/*
1040 			 * If that's true then all available contexts already
1041 			 * have reservations and cannot be used.
1042 			 */
1043 			if (!curr_ctx ||
1044 			    (curr_ctx->replace_state ==
1045 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1046 			    !list_empty(&curr_ctx->reserved_vifs))
1047 				return -EBUSY;
1048 
1049 			new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
1050 			if (!new_ctx)
1051 				return -ENOMEM;
1052 
1053 			new_ctx->replace_ctx = curr_ctx;
1054 			new_ctx->replace_state =
1055 					IEEE80211_CHANCTX_REPLACES_OTHER;
1056 
1057 			curr_ctx->replace_ctx = new_ctx;
1058 			curr_ctx->replace_state =
1059 					IEEE80211_CHANCTX_WILL_BE_REPLACED;
1060 
1061 			list_add_rcu(&new_ctx->list, &local->chanctx_list);
1062 		}
1063 	}
1064 
1065 	list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);
1066 	sdata->reserved_chanctx = new_ctx;
1067 	sdata->reserved_chandef = *chandef;
1068 	sdata->reserved_radar_required = radar_required;
1069 	sdata->reserved_ready = false;
1070 
1071 	return 0;
1072 }
1073 
1074 static void
1075 ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
1076 {
1077 	switch (sdata->vif.type) {
1078 	case NL80211_IFTYPE_ADHOC:
1079 	case NL80211_IFTYPE_AP:
1080 	case NL80211_IFTYPE_MESH_POINT:
1081 	case NL80211_IFTYPE_OCB:
1082 		ieee80211_queue_work(&sdata->local->hw,
1083 				     &sdata->csa_finalize_work);
1084 		break;
1085 	case NL80211_IFTYPE_STATION:
1086 		ieee80211_queue_work(&sdata->local->hw,
1087 				     &sdata->u.mgd.chswitch_work);
1088 		break;
1089 	case NL80211_IFTYPE_UNSPECIFIED:
1090 	case NL80211_IFTYPE_AP_VLAN:
1091 	case NL80211_IFTYPE_WDS:
1092 	case NL80211_IFTYPE_MONITOR:
1093 	case NL80211_IFTYPE_P2P_CLIENT:
1094 	case NL80211_IFTYPE_P2P_GO:
1095 	case NL80211_IFTYPE_P2P_DEVICE:
1096 	case NL80211_IFTYPE_NAN:
1097 	case NUM_NL80211_IFTYPES:
1098 		WARN_ON(1);
1099 		break;
1100 	}
1101 }
1102 
1103 static void
1104 ieee80211_vif_update_chandef(struct ieee80211_sub_if_data *sdata,
1105 			     const struct cfg80211_chan_def *chandef)
1106 {
1107 	struct ieee80211_sub_if_data *vlan;
1108 
1109 	sdata->vif.bss_conf.chandef = *chandef;
1110 
1111 	if (sdata->vif.type != NL80211_IFTYPE_AP)
1112 		return;
1113 
1114 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
1115 		vlan->vif.bss_conf.chandef = *chandef;
1116 }
1117 
1118 static int
1119 ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
1120 {
1121 	struct ieee80211_local *local = sdata->local;
1122 	struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1123 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1124 	const struct cfg80211_chan_def *chandef;
1125 	u32 changed = 0;
1126 	int err;
1127 
1128 	lockdep_assert_held(&local->mtx);
1129 	lockdep_assert_held(&local->chanctx_mtx);
1130 
1131 	new_ctx = sdata->reserved_chanctx;
1132 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1133 
1134 	if (WARN_ON(!sdata->reserved_ready))
1135 		return -EBUSY;
1136 
1137 	if (WARN_ON(!new_ctx))
1138 		return -EINVAL;
1139 
1140 	if (WARN_ON(!old_ctx))
1141 		return -EINVAL;
1142 
1143 	if (WARN_ON(new_ctx->replace_state ==
1144 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1145 		return -EINVAL;
1146 
1147 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1148 				&sdata->reserved_chandef);
1149 	if (WARN_ON(!chandef))
1150 		return -EINVAL;
1151 
1152 	if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
1153 		changed = BSS_CHANGED_BANDWIDTH;
1154 
1155 	ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1156 
1157 	ieee80211_change_chanctx(local, new_ctx, old_ctx, chandef);
1158 
1159 	vif_chsw[0].vif = &sdata->vif;
1160 	vif_chsw[0].old_ctx = &old_ctx->conf;
1161 	vif_chsw[0].new_ctx = &new_ctx->conf;
1162 
1163 	list_del(&sdata->reserved_chanctx_list);
1164 	sdata->reserved_chanctx = NULL;
1165 
1166 	err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1167 				     CHANCTX_SWMODE_REASSIGN_VIF);
1168 	if (err) {
1169 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1170 			ieee80211_free_chanctx(local, new_ctx);
1171 
1172 		goto out;
1173 	}
1174 
1175 	list_move(&sdata->assigned_chanctx_list, &new_ctx->assigned_vifs);
1176 	rcu_assign_pointer(sdata->vif.chanctx_conf, &new_ctx->conf);
1177 
1178 	if (sdata->vif.type == NL80211_IFTYPE_AP)
1179 		__ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
1180 
1181 	ieee80211_check_fast_xmit_iface(sdata);
1182 
1183 	if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1184 		ieee80211_free_chanctx(local, old_ctx);
1185 
1186 	ieee80211_recalc_chanctx_min_def(local, new_ctx);
1187 	ieee80211_recalc_smps_chanctx(local, new_ctx);
1188 	ieee80211_recalc_radar_chanctx(local, new_ctx);
1189 
1190 	if (changed)
1191 		ieee80211_bss_info_change_notify(sdata, changed);
1192 
1193 out:
1194 	ieee80211_vif_chanctx_reservation_complete(sdata);
1195 	return err;
1196 }
1197 
1198 static int
1199 ieee80211_vif_use_reserved_assign(struct ieee80211_sub_if_data *sdata)
1200 {
1201 	struct ieee80211_local *local = sdata->local;
1202 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1203 	const struct cfg80211_chan_def *chandef;
1204 	int err;
1205 
1206 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1207 	new_ctx = sdata->reserved_chanctx;
1208 
1209 	if (WARN_ON(!sdata->reserved_ready))
1210 		return -EINVAL;
1211 
1212 	if (WARN_ON(old_ctx))
1213 		return -EINVAL;
1214 
1215 	if (WARN_ON(!new_ctx))
1216 		return -EINVAL;
1217 
1218 	if (WARN_ON(new_ctx->replace_state ==
1219 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1220 		return -EINVAL;
1221 
1222 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1223 				&sdata->reserved_chandef);
1224 	if (WARN_ON(!chandef))
1225 		return -EINVAL;
1226 
1227 	ieee80211_change_chanctx(local, new_ctx, new_ctx, chandef);
1228 
1229 	list_del(&sdata->reserved_chanctx_list);
1230 	sdata->reserved_chanctx = NULL;
1231 
1232 	err = ieee80211_assign_vif_chanctx(sdata, new_ctx);
1233 	if (err) {
1234 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1235 			ieee80211_free_chanctx(local, new_ctx);
1236 
1237 		goto out;
1238 	}
1239 
1240 out:
1241 	ieee80211_vif_chanctx_reservation_complete(sdata);
1242 	return err;
1243 }
1244 
1245 static bool
1246 ieee80211_vif_has_in_place_reservation(struct ieee80211_sub_if_data *sdata)
1247 {
1248 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1249 
1250 	lockdep_assert_held(&sdata->local->chanctx_mtx);
1251 
1252 	new_ctx = sdata->reserved_chanctx;
1253 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1254 
1255 	if (!old_ctx)
1256 		return false;
1257 
1258 	if (WARN_ON(!new_ctx))
1259 		return false;
1260 
1261 	if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1262 		return false;
1263 
1264 	if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1265 		return false;
1266 
1267 	return true;
1268 }
1269 
1270 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1271 					struct ieee80211_chanctx *new_ctx)
1272 {
1273 	const struct cfg80211_chan_def *chandef;
1274 
1275 	lockdep_assert_held(&local->mtx);
1276 	lockdep_assert_held(&local->chanctx_mtx);
1277 
1278 	chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1279 	if (WARN_ON(!chandef))
1280 		return -EINVAL;
1281 
1282 	local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1283 	local->_oper_chandef = *chandef;
1284 	ieee80211_hw_config(local, 0);
1285 
1286 	return 0;
1287 }
1288 
1289 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1290 				      int n_vifs)
1291 {
1292 	struct ieee80211_vif_chanctx_switch *vif_chsw;
1293 	struct ieee80211_sub_if_data *sdata;
1294 	struct ieee80211_chanctx *ctx, *old_ctx;
1295 	int i, err;
1296 
1297 	lockdep_assert_held(&local->mtx);
1298 	lockdep_assert_held(&local->chanctx_mtx);
1299 
1300 	vif_chsw = kcalloc(n_vifs, sizeof(vif_chsw[0]), GFP_KERNEL);
1301 	if (!vif_chsw)
1302 		return -ENOMEM;
1303 
1304 	i = 0;
1305 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1306 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1307 			continue;
1308 
1309 		if (WARN_ON(!ctx->replace_ctx)) {
1310 			err = -EINVAL;
1311 			goto out;
1312 		}
1313 
1314 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1315 				    reserved_chanctx_list) {
1316 			if (!ieee80211_vif_has_in_place_reservation(
1317 					sdata))
1318 				continue;
1319 
1320 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1321 			vif_chsw[i].vif = &sdata->vif;
1322 			vif_chsw[i].old_ctx = &old_ctx->conf;
1323 			vif_chsw[i].new_ctx = &ctx->conf;
1324 
1325 			i++;
1326 		}
1327 	}
1328 
1329 	err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1330 				     CHANCTX_SWMODE_SWAP_CONTEXTS);
1331 
1332 out:
1333 	kfree(vif_chsw);
1334 	return err;
1335 }
1336 
1337 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1338 {
1339 	struct ieee80211_chanctx *ctx;
1340 	int err;
1341 
1342 	lockdep_assert_held(&local->mtx);
1343 	lockdep_assert_held(&local->chanctx_mtx);
1344 
1345 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1346 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1347 			continue;
1348 
1349 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1350 			continue;
1351 
1352 		ieee80211_del_chanctx(local, ctx->replace_ctx);
1353 		err = ieee80211_add_chanctx(local, ctx);
1354 		if (err)
1355 			goto err;
1356 	}
1357 
1358 	return 0;
1359 
1360 err:
1361 	WARN_ON(ieee80211_add_chanctx(local, ctx));
1362 	list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1363 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1364 			continue;
1365 
1366 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1367 			continue;
1368 
1369 		ieee80211_del_chanctx(local, ctx);
1370 		WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1371 	}
1372 
1373 	return err;
1374 }
1375 
1376 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1377 {
1378 	struct ieee80211_sub_if_data *sdata, *sdata_tmp;
1379 	struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1380 	struct ieee80211_chanctx *new_ctx = NULL;
1381 	int err, n_assigned, n_reserved, n_ready;
1382 	int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1383 
1384 	lockdep_assert_held(&local->mtx);
1385 	lockdep_assert_held(&local->chanctx_mtx);
1386 
1387 	/*
1388 	 * If there are 2 independent pairs of channel contexts performing
1389 	 * cross-switch of their vifs this code will still wait until both are
1390 	 * ready even though it could be possible to switch one before the
1391 	 * other is ready.
1392 	 *
1393 	 * For practical reasons and code simplicity just do a single huge
1394 	 * switch.
1395 	 */
1396 
1397 	/*
1398 	 * Verify if the reservation is still feasible.
1399 	 *  - if it's not then disconnect
1400 	 *  - if it is but not all vifs necessary are ready then defer
1401 	 */
1402 
1403 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1404 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1405 			continue;
1406 
1407 		if (WARN_ON(!ctx->replace_ctx)) {
1408 			err = -EINVAL;
1409 			goto err;
1410 		}
1411 
1412 		if (!local->use_chanctx)
1413 			new_ctx = ctx;
1414 
1415 		n_ctx++;
1416 
1417 		n_assigned = 0;
1418 		n_reserved = 0;
1419 		n_ready = 0;
1420 
1421 		list_for_each_entry(sdata, &ctx->replace_ctx->assigned_vifs,
1422 				    assigned_chanctx_list) {
1423 			n_assigned++;
1424 			if (sdata->reserved_chanctx) {
1425 				n_reserved++;
1426 				if (sdata->reserved_ready)
1427 					n_ready++;
1428 			}
1429 		}
1430 
1431 		if (n_assigned != n_reserved) {
1432 			if (n_ready == n_reserved) {
1433 				wiphy_info(local->hw.wiphy,
1434 					   "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1435 				err = -EBUSY;
1436 				goto err;
1437 			}
1438 
1439 			return -EAGAIN;
1440 		}
1441 
1442 		ctx->conf.radar_enabled = false;
1443 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1444 				    reserved_chanctx_list) {
1445 			if (ieee80211_vif_has_in_place_reservation(sdata) &&
1446 			    !sdata->reserved_ready)
1447 				return -EAGAIN;
1448 
1449 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1450 			if (old_ctx) {
1451 				if (old_ctx->replace_state ==
1452 				    IEEE80211_CHANCTX_WILL_BE_REPLACED)
1453 					n_vifs_switch++;
1454 				else
1455 					n_vifs_assign++;
1456 			} else {
1457 				n_vifs_ctxless++;
1458 			}
1459 
1460 			if (sdata->reserved_radar_required)
1461 				ctx->conf.radar_enabled = true;
1462 		}
1463 	}
1464 
1465 	if (WARN_ON(n_ctx == 0) ||
1466 	    WARN_ON(n_vifs_switch == 0 &&
1467 		    n_vifs_assign == 0 &&
1468 		    n_vifs_ctxless == 0) ||
1469 	    WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1470 	    WARN_ON(!new_ctx && !local->use_chanctx)) {
1471 		err = -EINVAL;
1472 		goto err;
1473 	}
1474 
1475 	/*
1476 	 * All necessary vifs are ready. Perform the switch now depending on
1477 	 * reservations and driver capabilities.
1478 	 */
1479 
1480 	if (local->use_chanctx) {
1481 		if (n_vifs_switch > 0) {
1482 			err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1483 			if (err)
1484 				goto err;
1485 		}
1486 
1487 		if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1488 			err = ieee80211_chsw_switch_ctxs(local);
1489 			if (err)
1490 				goto err;
1491 		}
1492 	} else {
1493 		err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1494 		if (err)
1495 			goto err;
1496 	}
1497 
1498 	/*
1499 	 * Update all structures, values and pointers to point to new channel
1500 	 * context(s).
1501 	 */
1502 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1503 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1504 			continue;
1505 
1506 		if (WARN_ON(!ctx->replace_ctx)) {
1507 			err = -EINVAL;
1508 			goto err;
1509 		}
1510 
1511 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1512 				    reserved_chanctx_list) {
1513 			u32 changed = 0;
1514 
1515 			if (!ieee80211_vif_has_in_place_reservation(sdata))
1516 				continue;
1517 
1518 			rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
1519 
1520 			if (sdata->vif.type == NL80211_IFTYPE_AP)
1521 				__ieee80211_vif_copy_chanctx_to_vlans(sdata,
1522 								      false);
1523 
1524 			ieee80211_check_fast_xmit_iface(sdata);
1525 
1526 			sdata->radar_required = sdata->reserved_radar_required;
1527 
1528 			if (sdata->vif.bss_conf.chandef.width !=
1529 			    sdata->reserved_chandef.width)
1530 				changed = BSS_CHANGED_BANDWIDTH;
1531 
1532 			ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1533 			if (changed)
1534 				ieee80211_bss_info_change_notify(sdata,
1535 								 changed);
1536 
1537 			ieee80211_recalc_txpower(sdata, false);
1538 		}
1539 
1540 		ieee80211_recalc_chanctx_chantype(local, ctx);
1541 		ieee80211_recalc_smps_chanctx(local, ctx);
1542 		ieee80211_recalc_radar_chanctx(local, ctx);
1543 		ieee80211_recalc_chanctx_min_def(local, ctx);
1544 
1545 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1546 					 reserved_chanctx_list) {
1547 			if (ieee80211_vif_get_chanctx(sdata) != ctx)
1548 				continue;
1549 
1550 			list_del(&sdata->reserved_chanctx_list);
1551 			list_move(&sdata->assigned_chanctx_list,
1552 				  &ctx->assigned_vifs);
1553 			sdata->reserved_chanctx = NULL;
1554 
1555 			ieee80211_vif_chanctx_reservation_complete(sdata);
1556 		}
1557 
1558 		/*
1559 		 * This context might have been a dependency for an already
1560 		 * ready re-assign reservation interface that was deferred. Do
1561 		 * not propagate error to the caller though. The in-place
1562 		 * reservation for originally requested interface has already
1563 		 * succeeded at this point.
1564 		 */
1565 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1566 					 reserved_chanctx_list) {
1567 			if (WARN_ON(ieee80211_vif_has_in_place_reservation(
1568 					sdata)))
1569 				continue;
1570 
1571 			if (WARN_ON(sdata->reserved_chanctx != ctx))
1572 				continue;
1573 
1574 			if (!sdata->reserved_ready)
1575 				continue;
1576 
1577 			if (ieee80211_vif_get_chanctx(sdata))
1578 				err = ieee80211_vif_use_reserved_reassign(
1579 						sdata);
1580 			else
1581 				err = ieee80211_vif_use_reserved_assign(sdata);
1582 
1583 			if (err) {
1584 				sdata_info(sdata,
1585 					   "failed to finalize (re-)assign reservation (err=%d)\n",
1586 					   err);
1587 				ieee80211_vif_unreserve_chanctx(sdata);
1588 				cfg80211_stop_iface(local->hw.wiphy,
1589 						    &sdata->wdev,
1590 						    GFP_KERNEL);
1591 			}
1592 		}
1593 	}
1594 
1595 	/*
1596 	 * Finally free old contexts
1597 	 */
1598 
1599 	list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1600 		if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1601 			continue;
1602 
1603 		ctx->replace_ctx->replace_ctx = NULL;
1604 		ctx->replace_ctx->replace_state =
1605 				IEEE80211_CHANCTX_REPLACE_NONE;
1606 
1607 		list_del_rcu(&ctx->list);
1608 		kfree_rcu(ctx, rcu_head);
1609 	}
1610 
1611 	return 0;
1612 
1613 err:
1614 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1615 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1616 			continue;
1617 
1618 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1619 					 reserved_chanctx_list) {
1620 			ieee80211_vif_unreserve_chanctx(sdata);
1621 			ieee80211_vif_chanctx_reservation_complete(sdata);
1622 		}
1623 	}
1624 
1625 	return err;
1626 }
1627 
1628 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1629 {
1630 	struct ieee80211_local *local = sdata->local;
1631 	struct ieee80211_chanctx_conf *conf;
1632 	struct ieee80211_chanctx *ctx;
1633 	bool use_reserved_switch = false;
1634 
1635 	lockdep_assert_held(&local->chanctx_mtx);
1636 
1637 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1638 					 lockdep_is_held(&local->chanctx_mtx));
1639 	if (!conf)
1640 		return;
1641 
1642 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1643 
1644 	if (sdata->reserved_chanctx) {
1645 		if (sdata->reserved_chanctx->replace_state ==
1646 		    IEEE80211_CHANCTX_REPLACES_OTHER &&
1647 		    ieee80211_chanctx_num_reserved(local,
1648 						   sdata->reserved_chanctx) > 1)
1649 			use_reserved_switch = true;
1650 
1651 		ieee80211_vif_unreserve_chanctx(sdata);
1652 	}
1653 
1654 	ieee80211_assign_vif_chanctx(sdata, NULL);
1655 	if (ieee80211_chanctx_refcount(local, ctx) == 0)
1656 		ieee80211_free_chanctx(local, ctx);
1657 
1658 	sdata->radar_required = false;
1659 
1660 	/* Unreserving may ready an in-place reservation. */
1661 	if (use_reserved_switch)
1662 		ieee80211_vif_use_reserved_switch(local);
1663 }
1664 
1665 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
1666 			      const struct cfg80211_chan_def *chandef,
1667 			      enum ieee80211_chanctx_mode mode)
1668 {
1669 	struct ieee80211_local *local = sdata->local;
1670 	struct ieee80211_chanctx *ctx;
1671 	u8 radar_detect_width = 0;
1672 	int ret;
1673 
1674 	lockdep_assert_held(&local->mtx);
1675 
1676 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1677 
1678 	mutex_lock(&local->chanctx_mtx);
1679 
1680 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1681 					    chandef,
1682 					    sdata->wdev.iftype);
1683 	if (ret < 0)
1684 		goto out;
1685 	if (ret > 0)
1686 		radar_detect_width = BIT(chandef->width);
1687 
1688 	sdata->radar_required = ret;
1689 
1690 	ret = ieee80211_check_combinations(sdata, chandef, mode,
1691 					   radar_detect_width);
1692 	if (ret < 0)
1693 		goto out;
1694 
1695 	__ieee80211_vif_release_channel(sdata);
1696 
1697 	ctx = ieee80211_find_chanctx(local, chandef, mode);
1698 	if (!ctx)
1699 		ctx = ieee80211_new_chanctx(local, chandef, mode);
1700 	if (IS_ERR(ctx)) {
1701 		ret = PTR_ERR(ctx);
1702 		goto out;
1703 	}
1704 
1705 	ieee80211_vif_update_chandef(sdata, chandef);
1706 
1707 	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
1708 	if (ret) {
1709 		/* if assign fails refcount stays the same */
1710 		if (ieee80211_chanctx_refcount(local, ctx) == 0)
1711 			ieee80211_free_chanctx(local, ctx);
1712 		goto out;
1713 	}
1714 
1715 	ieee80211_recalc_smps_chanctx(local, ctx);
1716 	ieee80211_recalc_radar_chanctx(local, ctx);
1717  out:
1718 	if (ret)
1719 		sdata->radar_required = false;
1720 
1721 	mutex_unlock(&local->chanctx_mtx);
1722 	return ret;
1723 }
1724 
1725 int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata)
1726 {
1727 	struct ieee80211_local *local = sdata->local;
1728 	struct ieee80211_chanctx *new_ctx;
1729 	struct ieee80211_chanctx *old_ctx;
1730 	int err;
1731 
1732 	lockdep_assert_held(&local->mtx);
1733 	lockdep_assert_held(&local->chanctx_mtx);
1734 
1735 	new_ctx = sdata->reserved_chanctx;
1736 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1737 
1738 	if (WARN_ON(!new_ctx))
1739 		return -EINVAL;
1740 
1741 	if (WARN_ON(new_ctx->replace_state ==
1742 		    IEEE80211_CHANCTX_WILL_BE_REPLACED))
1743 		return -EINVAL;
1744 
1745 	if (WARN_ON(sdata->reserved_ready))
1746 		return -EINVAL;
1747 
1748 	sdata->reserved_ready = true;
1749 
1750 	if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1751 		if (old_ctx)
1752 			return ieee80211_vif_use_reserved_reassign(sdata);
1753 
1754 		return ieee80211_vif_use_reserved_assign(sdata);
1755 	}
1756 
1757 	/*
1758 	 * In-place reservation may need to be finalized now either if:
1759 	 *  a) sdata is taking part in the swapping itself and is the last one
1760 	 *  b) sdata has switched with a re-assign reservation to an existing
1761 	 *     context readying in-place switching of old_ctx
1762 	 *
1763 	 * In case of (b) do not propagate the error up because the requested
1764 	 * sdata already switched successfully. Just spill an extra warning.
1765 	 * The ieee80211_vif_use_reserved_switch() already stops all necessary
1766 	 * interfaces upon failure.
1767 	 */
1768 	if ((old_ctx &&
1769 	     old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1770 	    new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1771 		err = ieee80211_vif_use_reserved_switch(local);
1772 		if (err && err != -EAGAIN) {
1773 			if (new_ctx->replace_state ==
1774 			    IEEE80211_CHANCTX_REPLACES_OTHER)
1775 				return err;
1776 
1777 			wiphy_info(local->hw.wiphy,
1778 				   "depending in-place reservation failed (err=%d)\n",
1779 				   err);
1780 		}
1781 	}
1782 
1783 	return 0;
1784 }
1785 
1786 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
1787 				   const struct cfg80211_chan_def *chandef,
1788 				   u32 *changed)
1789 {
1790 	struct ieee80211_local *local = sdata->local;
1791 	struct ieee80211_chanctx_conf *conf;
1792 	struct ieee80211_chanctx *ctx;
1793 	const struct cfg80211_chan_def *compat;
1794 	int ret;
1795 
1796 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1797 				     IEEE80211_CHAN_DISABLED))
1798 		return -EINVAL;
1799 
1800 	mutex_lock(&local->chanctx_mtx);
1801 	if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
1802 		ret = 0;
1803 		goto out;
1804 	}
1805 
1806 	if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1807 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1808 		ret = -EINVAL;
1809 		goto out;
1810 	}
1811 
1812 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1813 					 lockdep_is_held(&local->chanctx_mtx));
1814 	if (!conf) {
1815 		ret = -EINVAL;
1816 		goto out;
1817 	}
1818 
1819 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1820 
1821 	compat = cfg80211_chandef_compatible(&conf->def, chandef);
1822 	if (!compat) {
1823 		ret = -EINVAL;
1824 		goto out;
1825 	}
1826 
1827 	switch (ctx->replace_state) {
1828 	case IEEE80211_CHANCTX_REPLACE_NONE:
1829 		if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1830 			ret = -EBUSY;
1831 			goto out;
1832 		}
1833 		break;
1834 	case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1835 		/* TODO: Perhaps the bandwidth change could be treated as a
1836 		 * reservation itself? */
1837 		ret = -EBUSY;
1838 		goto out;
1839 	case IEEE80211_CHANCTX_REPLACES_OTHER:
1840 		/* channel context that is going to replace another channel
1841 		 * context doesn't really exist and shouldn't be assigned
1842 		 * anywhere yet */
1843 		WARN_ON(1);
1844 		break;
1845 	}
1846 
1847 	ieee80211_vif_update_chandef(sdata, chandef);
1848 
1849 	ieee80211_recalc_chanctx_chantype(local, ctx);
1850 
1851 	*changed |= BSS_CHANGED_BANDWIDTH;
1852 	ret = 0;
1853  out:
1854 	mutex_unlock(&local->chanctx_mtx);
1855 	return ret;
1856 }
1857 
1858 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1859 {
1860 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1861 
1862 	lockdep_assert_held(&sdata->local->mtx);
1863 
1864 	mutex_lock(&sdata->local->chanctx_mtx);
1865 	__ieee80211_vif_release_channel(sdata);
1866 	mutex_unlock(&sdata->local->chanctx_mtx);
1867 }
1868 
1869 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
1870 {
1871 	struct ieee80211_local *local = sdata->local;
1872 	struct ieee80211_sub_if_data *ap;
1873 	struct ieee80211_chanctx_conf *conf;
1874 
1875 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
1876 		return;
1877 
1878 	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
1879 
1880 	mutex_lock(&local->chanctx_mtx);
1881 
1882 	conf = rcu_dereference_protected(ap->vif.chanctx_conf,
1883 					 lockdep_is_held(&local->chanctx_mtx));
1884 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
1885 	mutex_unlock(&local->chanctx_mtx);
1886 }
1887 
1888 void ieee80211_iter_chan_contexts_atomic(
1889 	struct ieee80211_hw *hw,
1890 	void (*iter)(struct ieee80211_hw *hw,
1891 		     struct ieee80211_chanctx_conf *chanctx_conf,
1892 		     void *data),
1893 	void *iter_data)
1894 {
1895 	struct ieee80211_local *local = hw_to_local(hw);
1896 	struct ieee80211_chanctx *ctx;
1897 
1898 	rcu_read_lock();
1899 	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
1900 		if (ctx->driver_present)
1901 			iter(hw, &ctx->conf, iter_data);
1902 	rcu_read_unlock();
1903 }
1904 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);
1905