xref: /linux/net/mac80211/chan.c (revision 90e63d5354951d37fa2b3b91e6f17b95d2bf9bee)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * mac80211 - channel management
4  * Copyright 2020-2026 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 struct ieee80211_chanctx_user_iter {
16 	struct ieee80211_chan_req *chanreq;
17 	struct ieee80211_sub_if_data *sdata;
18 	struct ieee80211_link_data *link;
19 	struct ieee80211_nan_channel *nan_channel;
20 	int nan_channel_next_idx;
21 	enum nl80211_iftype iftype;
22 	bool reserved, radar_required, done;
23 	enum {
24 		CHANCTX_ITER_POS_ASSIGNED,
25 		CHANCTX_ITER_POS_RESERVED,
26 		CHANCTX_ITER_POS_DONE,
27 	} per_link;
28 };
29 
30 enum ieee80211_chanctx_iter_type {
31 	CHANCTX_ITER_ALL,
32 	CHANCTX_ITER_RESERVED,
33 	CHANCTX_ITER_ASSIGNED,
34 };
35 
36 static bool
37 ieee80211_chanctx_user_iter_next_nan_channel(struct ieee80211_chanctx *ctx,
38 					     struct ieee80211_chanctx_user_iter *iter)
39 {
40 	/* Start from the next index after current position */
41 	for (int i = iter->nan_channel_next_idx;
42 	     i < ARRAY_SIZE(iter->sdata->vif.cfg.nan_sched.channels); i++) {
43 		struct ieee80211_nan_channel *nan_channel =
44 			&iter->sdata->vif.cfg.nan_sched.channels[i];
45 
46 		if (!nan_channel->chanreq.oper.chan)
47 			continue;
48 
49 		if (nan_channel->chanctx_conf != &ctx->conf)
50 			continue;
51 
52 		iter->nan_channel = nan_channel;
53 		iter->nan_channel_next_idx = i + 1;
54 		iter->chanreq = &nan_channel->chanreq;
55 		iter->link = NULL;
56 		iter->reserved = false;
57 		iter->radar_required = false;
58 		return true;
59 	}
60 	return false;
61 }
62 
63 static bool
64 ieee80211_chanctx_user_iter_next_link(struct ieee80211_chanctx *ctx,
65 				      struct ieee80211_chanctx_user_iter *iter,
66 				      enum ieee80211_chanctx_iter_type type)
67 {
68 	for (int link_id = iter->link ? iter->link->link_id : 0;
69 	     link_id < ARRAY_SIZE(iter->sdata->link);
70 	     link_id++) {
71 		struct ieee80211_link_data *link;
72 
73 		link = sdata_dereference(iter->sdata->link[link_id],
74 					 iter->sdata);
75 		if (!link)
76 			continue;
77 
78 		switch (iter->per_link) {
79 		case CHANCTX_ITER_POS_ASSIGNED:
80 			iter->per_link = CHANCTX_ITER_POS_RESERVED;
81 			if (type != CHANCTX_ITER_RESERVED &&
82 			    rcu_access_pointer(link->conf->chanctx_conf) == &ctx->conf) {
83 				iter->link = link;
84 				iter->reserved = false;
85 				iter->radar_required = link->radar_required;
86 				iter->chanreq = &link->conf->chanreq;
87 				return true;
88 			}
89 			fallthrough;
90 		case CHANCTX_ITER_POS_RESERVED:
91 			iter->per_link = CHANCTX_ITER_POS_DONE;
92 			if (type != CHANCTX_ITER_ASSIGNED &&
93 			    link->reserved_chanctx == ctx) {
94 				iter->link = link;
95 				iter->reserved = true;
96 				iter->radar_required =
97 					link->reserved_radar_required;
98 
99 				iter->chanreq = &link->reserved;
100 				return true;
101 			}
102 			fallthrough;
103 		case CHANCTX_ITER_POS_DONE:
104 			iter->per_link = CHANCTX_ITER_POS_ASSIGNED;
105 			continue;
106 		}
107 	}
108 	return false;
109 }
110 
111 static void
112 ieee80211_chanctx_user_iter_next(struct ieee80211_local *local,
113 				 struct ieee80211_chanctx *ctx,
114 				 struct ieee80211_chanctx_user_iter *iter,
115 				 enum ieee80211_chanctx_iter_type type,
116 				 bool start)
117 {
118 	bool found;
119 
120 	lockdep_assert_wiphy(local->hw.wiphy);
121 
122 	if (start) {
123 		memset(iter, 0, sizeof(*iter));
124 		goto next_interface;
125 	}
126 
127 next_user:
128 	if (iter->iftype == NL80211_IFTYPE_NAN)
129 		found = ieee80211_chanctx_user_iter_next_nan_channel(ctx, iter);
130 	else
131 		found = ieee80211_chanctx_user_iter_next_link(ctx, iter, type);
132 
133 	if (found)
134 		return;
135 
136 next_interface:
137 	/* next (or first) interface */
138 	iter->sdata = list_prepare_entry(iter->sdata, &local->interfaces, list);
139 	list_for_each_entry_continue(iter->sdata, &local->interfaces, list) {
140 		if (!ieee80211_sdata_running(iter->sdata))
141 			continue;
142 
143 		/* AP_VLAN has a chanctx pointer but follows AP */
144 		if (iter->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
145 			continue;
146 
147 		/* NAN channels don't reserve channel context */
148 		if (iter->sdata->vif.type == NL80211_IFTYPE_NAN &&
149 		    type == CHANCTX_ITER_RESERVED)
150 			continue;
151 
152 		iter->nan_channel = NULL;
153 		iter->link = NULL;
154 		iter->iftype = iter->sdata->vif.type;
155 		iter->chanreq = NULL;
156 		iter->per_link = CHANCTX_ITER_POS_ASSIGNED;
157 		iter->nan_channel_next_idx = 0;
158 		goto next_user;
159 	}
160 
161 	iter->done = true;
162 }
163 
164 #define for_each_chanctx_user_assigned(local, ctx, iter)		\
165 	for (ieee80211_chanctx_user_iter_next(local, ctx, iter,		\
166 					      CHANCTX_ITER_ASSIGNED,	\
167 					      true);			\
168 	     !((iter)->done);						\
169 	     ieee80211_chanctx_user_iter_next(local, ctx, iter,		\
170 					      CHANCTX_ITER_ASSIGNED,	\
171 					      false))
172 
173 #define for_each_chanctx_user_reserved(local, ctx, iter)		\
174 	for (ieee80211_chanctx_user_iter_next(local, ctx, iter,		\
175 					      CHANCTX_ITER_RESERVED,	\
176 					      true);			\
177 	     !((iter)->done);						\
178 	     ieee80211_chanctx_user_iter_next(local, ctx, iter,		\
179 					      CHANCTX_ITER_RESERVED,	\
180 					      false))
181 
182 #define for_each_chanctx_user_all(local, ctx, iter)			\
183 	for (ieee80211_chanctx_user_iter_next(local, ctx, iter,		\
184 					      CHANCTX_ITER_ALL,		\
185 					      true);			\
186 	     !((iter)->done);						\
187 	     ieee80211_chanctx_user_iter_next(local, ctx, iter,		\
188 					      CHANCTX_ITER_ALL,		\
189 					      false))
190 
191 int ieee80211_chanctx_num_assigned(struct ieee80211_local *local,
192 				   struct ieee80211_chanctx *ctx)
193 {
194 	struct ieee80211_chanctx_user_iter iter;
195 	int num = 0;
196 
197 	for_each_chanctx_user_assigned(local, ctx, &iter)
198 		num++;
199 
200 	return num;
201 }
202 
203 static int ieee80211_chanctx_num_reserved(struct ieee80211_local *local,
204 					  struct ieee80211_chanctx *ctx)
205 {
206 	struct ieee80211_chanctx_user_iter iter;
207 	int num = 0;
208 
209 	for_each_chanctx_user_reserved(local, ctx, &iter)
210 		num++;
211 
212 	return num;
213 }
214 
215 int ieee80211_chanctx_refcount(struct ieee80211_local *local,
216 			       struct ieee80211_chanctx *ctx)
217 {
218 	struct ieee80211_chanctx_user_iter iter;
219 	int num = 0;
220 
221 	for_each_chanctx_user_all(local, ctx, &iter)
222 		num++;
223 
224 	/*
225 	 * This ctx is in the process of getting used,
226 	 * take it into consideration
227 	 */
228 	if (ctx->will_be_used)
229 		num++;
230 
231 	return num;
232 }
233 
234 static int ieee80211_num_chanctx(struct ieee80211_local *local, int radio_idx)
235 {
236 	struct ieee80211_chanctx *ctx;
237 	int num = 0;
238 
239 	lockdep_assert_wiphy(local->hw.wiphy);
240 
241 	list_for_each_entry(ctx, &local->chanctx_list, list) {
242 		if (radio_idx >= 0 && ctx->conf.radio_idx != radio_idx)
243 			continue;
244 		num++;
245 	}
246 
247 	return num;
248 }
249 
250 static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local,
251 					     int radio_idx)
252 {
253 	lockdep_assert_wiphy(local->hw.wiphy);
254 
255 	return ieee80211_num_chanctx(local, radio_idx) <
256 	       ieee80211_max_num_channels(local, radio_idx);
257 }
258 
259 static struct ieee80211_chanctx *
260 ieee80211_link_get_chanctx(struct ieee80211_link_data *link)
261 {
262 	struct ieee80211_local *local __maybe_unused = link->sdata->local;
263 	struct ieee80211_chanctx_conf *conf;
264 
265 	conf = rcu_dereference_protected(link->conf->chanctx_conf,
266 					 lockdep_is_held(&local->hw.wiphy->mtx));
267 	if (!conf)
268 		return NULL;
269 
270 	return container_of(conf, struct ieee80211_chanctx, conf);
271 }
272 
273 bool ieee80211_chanreq_identical(const struct ieee80211_chan_req *a,
274 				 const struct ieee80211_chan_req *b)
275 {
276 	if (!cfg80211_chandef_identical(&a->oper, &b->oper))
277 		return false;
278 	if (!a->ap.chan && !b->ap.chan)
279 		return true;
280 	return cfg80211_chandef_identical(&a->ap, &b->ap);
281 }
282 
283 static const struct ieee80211_chan_req *
284 ieee80211_chanreq_compatible(const struct ieee80211_chan_req *a,
285 			     const struct ieee80211_chan_req *b,
286 			     struct ieee80211_chan_req *tmp)
287 {
288 	struct ieee80211_chan_req _a = *a, _b = *b;
289 	const struct cfg80211_chan_def *compat;
290 
291 	if (a->ap.chan && b->ap.chan &&
292 	    !cfg80211_chandef_identical(&a->ap, &b->ap))
293 		return NULL;
294 
295 	/*
296 	 * Remove NPCA if it's not required, so that interfaces
297 	 * sharing a channel context will not use NPCA while the
298 	 * channel context is shared.
299 	 * If both sides are AP interfaces requiring NPC, there's
300 	 * an assumption that userspace will set them up with
301 	 * identical configurations and the same BSS color
302 	 * (if the config is not identical, sharing will fail due
303 	 * to cfg80211_chandef_compatible() failing below.)
304 	 */
305 	if (!_a.require_npca) {
306 		_a.oper.npca_chan = NULL;
307 		_a.oper.npca_punctured = 0;
308 	}
309 
310 	if (!_b.require_npca) {
311 		_b.oper.npca_chan = NULL;
312 		_b.oper.npca_punctured = 0;
313 	}
314 
315 	compat = cfg80211_chandef_compatible(&_a.oper, &_b.oper);
316 	if (!compat)
317 		return NULL;
318 
319 	/* Note: later code assumes this always fills & returns tmp if compat */
320 	tmp->oper = *compat;
321 	tmp->ap = a->ap.chan ? a->ap : b->ap;
322 	tmp->require_npca = a->require_npca && b->require_npca;
323 	return tmp;
324 }
325 
326 /*
327  * When checking for compatible, check against all the links using
328  * the chanctx (except the one passed that might be changing) to
329  * allow changes to the AP's bandwidth for wider bandwidth OFDMA
330  * purposes, which wouldn't be treated as compatible by checking
331  * against the chanctx's oper/ap chandefs.
332  */
333 static const struct ieee80211_chan_req *
334 _ieee80211_chanctx_compatible(struct ieee80211_local *local,
335 			      struct ieee80211_link_data *skip_link,
336 			      struct ieee80211_chanctx *ctx,
337 			      const struct ieee80211_chan_req *req,
338 			      struct ieee80211_chan_req *tmp)
339 {
340 	const struct ieee80211_chan_req *ret = req;
341 	struct ieee80211_chanctx_user_iter iter;
342 
343 	lockdep_assert_wiphy(local->hw.wiphy);
344 
345 	for_each_chanctx_user_all(local, ctx, &iter) {
346 		if (iter.link && iter.link == skip_link)
347 			continue;
348 
349 		ret = ieee80211_chanreq_compatible(ret, iter.chanreq, tmp);
350 		if (!ret)
351 			return NULL;
352 	}
353 
354 	*tmp = *ret;
355 	return tmp;
356 }
357 
358 static const struct ieee80211_chan_req *
359 ieee80211_chanctx_compatible(struct ieee80211_local *local,
360 			     struct ieee80211_chanctx *ctx,
361 			     const struct ieee80211_chan_req *req,
362 			     struct ieee80211_chan_req *tmp)
363 {
364 	return _ieee80211_chanctx_compatible(local, NULL, ctx, req, tmp);
365 }
366 
367 static const struct ieee80211_chan_req *
368 ieee80211_chanctx_reserved_chanreq(struct ieee80211_local *local,
369 				   struct ieee80211_chanctx *ctx,
370 				   const struct ieee80211_chan_req *req,
371 				   struct ieee80211_chan_req *tmp)
372 {
373 	struct ieee80211_chanctx_user_iter iter;
374 
375 	lockdep_assert_wiphy(local->hw.wiphy);
376 
377 	if (WARN_ON(!req))
378 		return NULL;
379 
380 	for_each_chanctx_user_reserved(local, ctx, &iter) {
381 		req = ieee80211_chanreq_compatible(iter.chanreq, req, tmp);
382 		if (!req)
383 			break;
384 	}
385 
386 	return req;
387 }
388 
389 static const struct ieee80211_chan_req *
390 ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local *local,
391 				       struct ieee80211_chanctx *ctx,
392 				       const struct ieee80211_chan_req *compat,
393 				       struct ieee80211_chan_req *tmp)
394 {
395 	const struct ieee80211_chan_req *comp_def = compat;
396 	struct ieee80211_chanctx_user_iter iter;
397 
398 	lockdep_assert_wiphy(local->hw.wiphy);
399 
400 	for_each_chanctx_user_assigned(local, ctx, &iter) {
401 		if (iter.link && iter.link->reserved_chanctx)
402 			continue;
403 
404 		comp_def = ieee80211_chanreq_compatible(iter.chanreq,
405 							comp_def, tmp);
406 		if (!comp_def)
407 			break;
408 	}
409 
410 	return comp_def;
411 }
412 
413 static bool
414 ieee80211_chanctx_can_reserve(struct ieee80211_local *local,
415 			      struct ieee80211_chanctx *ctx,
416 			      const struct ieee80211_chan_req *req)
417 {
418 	struct ieee80211_chan_req tmp;
419 
420 	lockdep_assert_wiphy(local->hw.wiphy);
421 
422 	if (!ieee80211_chanctx_reserved_chanreq(local, ctx, req, &tmp))
423 		return false;
424 
425 	if (!ieee80211_chanctx_non_reserved_chandef(local, ctx, req, &tmp))
426 		return false;
427 
428 	if (ieee80211_chanctx_num_reserved(local, ctx) != 0 &&
429 	    ieee80211_chanctx_reserved_chanreq(local, ctx, req, &tmp))
430 		return true;
431 
432 	return false;
433 }
434 
435 static struct ieee80211_chanctx *
436 ieee80211_find_reservation_chanctx(struct ieee80211_local *local,
437 				   const struct ieee80211_chan_req *chanreq,
438 				   enum ieee80211_chanctx_mode mode)
439 {
440 	struct ieee80211_chanctx *ctx;
441 
442 	lockdep_assert_wiphy(local->hw.wiphy);
443 
444 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
445 		return NULL;
446 
447 	list_for_each_entry(ctx, &local->chanctx_list, list) {
448 		if (ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED)
449 			continue;
450 
451 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
452 			continue;
453 
454 		if (!ieee80211_chanctx_can_reserve(local, ctx, chanreq))
455 			continue;
456 
457 		return ctx;
458 	}
459 
460 	return NULL;
461 }
462 
463 static enum nl80211_chan_width
464 ieee80211_get_sta_bw(struct sta_info *sta, struct ieee80211_link_data *link)
465 {
466 	enum ieee80211_sta_rx_bandwidth width;
467 	struct link_sta_info *link_sta;
468 	int link_id = link->link_id;
469 
470 	link_sta = wiphy_dereference(sta->local->hw.wiphy, sta->link[link_id]);
471 
472 	/* no effect if this STA has no presence on this link */
473 	if (!link_sta)
474 		return NL80211_CHAN_WIDTH_20_NOHT;
475 
476 	/*
477 	 * We assume that TX/RX might be asymmetric (so e.g. VHT operating
478 	 * mode notification changes what a STA wants to receive, but not
479 	 * necessarily what it will transmit to us), and therefore use the
480 	 * "from station" bandwidth here.
481 	 */
482 	width = ieee80211_sta_current_bw(link_sta, &link->conf->chanreq.oper,
483 					 IEEE80211_STA_BW_RX_FROM_STA);
484 
485 	if (width == IEEE80211_STA_RX_BW_20 &&
486 	    !link_sta->pub->ht_cap.ht_supported &&
487 	    !link_sta->pub->he_cap.has_he)
488 		return NL80211_CHAN_WIDTH_20_NOHT;
489 
490 	/*
491 	 * This returns 160 for both 160 and 80+80. Since we use
492 	 * the returned value to consider narrowing for
493 	 * ctx->conf.min_def, that's correct and necessary.
494 	 */
495 	return ieee80211_sta_rx_bw_to_chan_width(width);
496 }
497 
498 static enum nl80211_chan_width
499 ieee80211_get_max_required_bw(struct ieee80211_link_data *link)
500 {
501 	struct ieee80211_sub_if_data *sdata = link->sdata;
502 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
503 	struct sta_info *sta;
504 
505 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
506 
507 	list_for_each_entry(sta, &sdata->local->sta_list, list) {
508 		if (sdata != sta->sdata &&
509 		    !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
510 			continue;
511 
512 		max_bw = max(max_bw, ieee80211_get_sta_bw(sta, link));
513 	}
514 
515 	return max_bw;
516 }
517 
518 static enum nl80211_chan_width
519 ieee80211_get_width_of_link(struct ieee80211_link_data *link)
520 {
521 	struct ieee80211_local *local = link->sdata->local;
522 
523 	switch (link->sdata->vif.type) {
524 	case NL80211_IFTYPE_STATION:
525 		if (!link->sdata->vif.cfg.assoc) {
526 			/*
527 			 * The AP's sta->bandwidth may not yet be set
528 			 * at this point (pre-association), so simply
529 			 * take the width from the chandef. We cannot
530 			 * have TDLS peers yet (only after association).
531 			 */
532 			return link->conf->chanreq.oper.width;
533 		}
534 		/*
535 		 * otherwise just use min_def like in AP, depending on what
536 		 * we currently think the AP STA (and possibly TDLS peers)
537 		 * require(s)
538 		 */
539 		fallthrough;
540 	case NL80211_IFTYPE_AP:
541 	case NL80211_IFTYPE_AP_VLAN:
542 		return ieee80211_get_max_required_bw(link);
543 	case NL80211_IFTYPE_P2P_DEVICE:
544 		break;
545 	case NL80211_IFTYPE_MONITOR:
546 		WARN_ON_ONCE(!ieee80211_hw_check(&local->hw,
547 						 NO_VIRTUAL_MONITOR));
548 		fallthrough;
549 	case NL80211_IFTYPE_ADHOC:
550 	case NL80211_IFTYPE_MESH_POINT:
551 	case NL80211_IFTYPE_OCB:
552 		return link->conf->chanreq.oper.width;
553 	case NL80211_IFTYPE_WDS:
554 	case NL80211_IFTYPE_UNSPECIFIED:
555 	case NUM_NL80211_IFTYPES:
556 	case NL80211_IFTYPE_P2P_CLIENT:
557 	case NL80211_IFTYPE_P2P_GO:
558 	case NL80211_IFTYPE_NAN:
559 	case NL80211_IFTYPE_NAN_DATA:
560 	case NL80211_IFTYPE_PD:
561 		WARN_ON_ONCE(1);
562 		break;
563 	}
564 
565 	/* Take the lowest possible, so it won't change the max width */
566 	return NL80211_CHAN_WIDTH_20_NOHT;
567 }
568 
569 static enum nl80211_chan_width
570 ieee80211_get_width_of_chanctx_user(struct ieee80211_chanctx_user_iter *iter)
571 {
572 	if (iter->link)
573 		return ieee80211_get_width_of_link(iter->link);
574 
575 	if (WARN_ON_ONCE(!iter->nan_channel || iter->reserved))
576 		return NL80211_CHAN_WIDTH_20_NOHT;
577 
578 	return iter->nan_channel->chanreq.oper.width;
579 }
580 
581 static enum nl80211_chan_width
582 ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
583 				      struct ieee80211_chanctx *ctx,
584 				      struct ieee80211_link_data *rsvd_for,
585 				      bool check_reserved)
586 {
587 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
588 	struct ieee80211_chanctx_user_iter iter;
589 	struct ieee80211_sub_if_data *sdata;
590 	enum nl80211_chan_width width;
591 
592 	if (WARN_ON(check_reserved && rsvd_for))
593 		return ctx->conf.def.width;
594 
595 	/* When this is true we only care about the reserving links */
596 	if (check_reserved) {
597 		for_each_chanctx_user_reserved(local, ctx, &iter) {
598 			width = ieee80211_get_width_of_chanctx_user(&iter);
599 			max_bw = max(max_bw, width);
600 		}
601 		goto check_monitor;
602 	}
603 
604 	/* Consider all assigned links */
605 	for_each_chanctx_user_assigned(local, ctx, &iter) {
606 		width = ieee80211_get_width_of_chanctx_user(&iter);
607 		max_bw = max(max_bw, width);
608 	}
609 
610 	if (!rsvd_for ||
611 	    rsvd_for->sdata == rcu_access_pointer(local->monitor_sdata))
612 		goto check_monitor;
613 
614 	/* Consider the link for which this chanctx is reserved/going to be assigned */
615 	width = ieee80211_get_width_of_link(rsvd_for);
616 	max_bw = max(max_bw, width);
617 
618 check_monitor:
619 	/* use the configured bandwidth in case of monitor interface */
620 	sdata = wiphy_dereference(local->hw.wiphy, local->monitor_sdata);
621 	if (sdata &&
622 	    rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) == &ctx->conf)
623 		max_bw = max(max_bw, ctx->conf.def.width);
624 
625 	return max_bw;
626 }
627 
628 /*
629  * recalc the min required chan width of the channel context, which is
630  * the max of min required widths of all the interfaces bound to this
631  * channel context.
632  */
633 static u32
634 __ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
635 				   struct ieee80211_chanctx *ctx,
636 				   struct ieee80211_link_data *rsvd_for,
637 				   bool check_reserved)
638 {
639 	enum nl80211_chan_width max_bw;
640 	struct cfg80211_chan_def min_def;
641 
642 	lockdep_assert_wiphy(local->hw.wiphy);
643 
644 	/* don't optimize non-20MHz based and radar_enabled confs */
645 	if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
646 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
647 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_1 ||
648 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_2 ||
649 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_4 ||
650 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_8 ||
651 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_16 ||
652 	    ctx->conf.radar_enabled) {
653 		ctx->conf.min_def = ctx->conf.def;
654 		return 0;
655 	}
656 
657 	max_bw = ieee80211_get_chanctx_max_required_bw(local, ctx, rsvd_for,
658 						       check_reserved);
659 
660 	/* downgrade chandef up to max_bw */
661 	min_def = ctx->conf.def;
662 	while (min_def.width > max_bw)
663 		ieee80211_chandef_downgrade(&min_def, NULL);
664 
665 	if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
666 		return 0;
667 
668 	ctx->conf.min_def = min_def;
669 	if (!ctx->driver_present)
670 		return 0;
671 
672 	return IEEE80211_CHANCTX_CHANGE_MIN_DEF;
673 }
674 
675 static void ieee80211_chan_bw_change(struct ieee80211_local *local,
676 				     struct ieee80211_chanctx *ctx,
677 				     bool reserved, bool narrowed)
678 {
679 	struct sta_info *sta;
680 	struct ieee80211_supported_band *sband =
681 		local->hw.wiphy->bands[ctx->conf.def.chan->band];
682 
683 	rcu_read_lock();
684 	list_for_each_entry_rcu(sta, &local->sta_list,
685 				list) {
686 		struct ieee80211_sub_if_data *sdata;
687 		enum ieee80211_sta_rx_bandwidth new_sta_bw;
688 		unsigned int link_id;
689 
690 		if (!ieee80211_sdata_running(sta->sdata))
691 			continue;
692 
693 		sdata = get_bss_sdata(sta->sdata);
694 
695 		for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
696 			struct ieee80211_link_data *link =
697 				rcu_dereference(sdata->link[link_id]);
698 			struct ieee80211_bss_conf *link_conf;
699 			struct cfg80211_chan_def *new_chandef;
700 			struct link_sta_info *link_sta;
701 
702 			if (!link)
703 				continue;
704 
705 			link_conf = link->conf;
706 
707 			if (rcu_access_pointer(link_conf->chanctx_conf) != &ctx->conf)
708 				continue;
709 
710 			link_sta = rcu_dereference(sta->link[link_id]);
711 			if (!link_sta)
712 				continue;
713 
714 			if (reserved)
715 				new_chandef = &link->reserved.oper;
716 			else
717 				new_chandef = &link_conf->chanreq.oper;
718 
719 			new_sta_bw = ieee80211_sta_current_bw(link_sta,
720 							      new_chandef,
721 							      IEEE80211_STA_BW_TX_TO_STA);
722 
723 			/* nothing change */
724 			if (new_sta_bw == link_sta->pub->bandwidth)
725 				continue;
726 
727 			/* vif changed to narrow BW and narrow BW for station wasn't
728 			 * requested or vice versa */
729 			if ((new_sta_bw < link_sta->pub->bandwidth) == !narrowed)
730 				continue;
731 
732 			link_sta->pub->bandwidth = new_sta_bw;
733 			rate_control_rate_update(local, sband, link_sta,
734 						 IEEE80211_RC_BW_CHANGED);
735 		}
736 	}
737 	rcu_read_unlock();
738 }
739 
740 /*
741  * recalc the min required chan width of the channel context, which is
742  * the max of min required widths of all the interfaces bound to this
743  * channel context.
744  *
745  * Note: ieee80211_update_ap_bandwidth() relies on this iterating all
746  *	 affected stations, even if min_def didn't change.
747  */
748 static void
749 _ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
750 				  struct ieee80211_chanctx *ctx,
751 				  struct ieee80211_link_data *rsvd_for,
752 				  bool check_reserved)
753 {
754 	u32 changed;
755 
756 	/* No recalc for S1G chan ctx's */
757 	if (cfg80211_chandef_is_s1g(&ctx->conf.def))
758 		return;
759 
760 	changed = __ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for,
761 						     check_reserved);
762 
763 	/* check is BW narrowed */
764 	ieee80211_chan_bw_change(local, ctx, false, true);
765 
766 	if (changed)
767 		drv_change_chanctx(local, ctx, changed);
768 
769 	/* check is BW wider */
770 	ieee80211_chan_bw_change(local, ctx, false, false);
771 }
772 
773 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
774 				      struct ieee80211_chanctx *ctx)
775 {
776 	_ieee80211_recalc_chanctx_min_def(local, ctx, NULL, false);
777 }
778 
779 static void
780 ieee80211_chanctx_update_npca_links(struct ieee80211_local *local,
781 				    struct ieee80211_chanctx *ctx,
782 				    bool enable)
783 {
784 	struct ieee80211_chanctx_user_iter iter;
785 
786 	if (!!ctx->conf.def.npca_chan != enable)
787 		return;
788 
789 	for_each_chanctx_user_assigned(local, ctx, &iter) {
790 		if (!iter.link)
791 			continue;
792 		if (!iter.sdata->vif.cfg.assoc)
793 			continue;
794 
795 		if (enable) {
796 			if (!iter.link->conf->chanreq.oper.npca_chan)
797 				continue;
798 		} else {
799 			if (!iter.link->conf->npca.enabled)
800 				continue;
801 		}
802 
803 		iter.link->conf->npca.enabled = enable;
804 		drv_link_info_changed(local, iter.sdata,
805 				      iter.link->conf,
806 				      iter.link->link_id,
807 				      BSS_CHANGED_NPCA);
808 	}
809 }
810 
811 static void _ieee80211_change_chanctx(struct ieee80211_local *local,
812 				      struct ieee80211_chanctx *ctx,
813 				      struct ieee80211_chanctx *old_ctx,
814 				      const struct ieee80211_chan_req *chanreq,
815 				      struct ieee80211_link_data *rsvd_for)
816 {
817 	struct ieee80211_chan_req ctx_req = {
818 		.oper = ctx->conf.def,
819 		.ap = ctx->conf.ap,
820 	};
821 	u32 changed = 0;
822 
823 	/* 5/10 MHz not handled here */
824 	switch (chanreq->oper.width) {
825 	case NL80211_CHAN_WIDTH_1:
826 	case NL80211_CHAN_WIDTH_2:
827 	case NL80211_CHAN_WIDTH_4:
828 	case NL80211_CHAN_WIDTH_8:
829 	case NL80211_CHAN_WIDTH_16:
830 		/*
831 		 * mac80211 currently only supports sharing identical
832 		 * chanctx's for S1G interfaces.
833 		 */
834 		WARN_ON(!ieee80211_chanreq_identical(&ctx_req, chanreq));
835 		return;
836 	case NL80211_CHAN_WIDTH_20_NOHT:
837 	case NL80211_CHAN_WIDTH_20:
838 	case NL80211_CHAN_WIDTH_40:
839 	case NL80211_CHAN_WIDTH_80:
840 	case NL80211_CHAN_WIDTH_80P80:
841 	case NL80211_CHAN_WIDTH_160:
842 	case NL80211_CHAN_WIDTH_320:
843 		break;
844 	default:
845 		WARN_ON(1);
846 	}
847 
848 	/* Check maybe BW narrowed - we do this _before_ calling recalc_chanctx_min_def
849 	 * due to maybe not returning from it, e.g in case new context was added
850 	 * first time with all parameters up to date.
851 	 */
852 	ieee80211_chan_bw_change(local, old_ctx, false, true);
853 
854 	if (ieee80211_chanreq_identical(&ctx_req, chanreq)) {
855 		_ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for, false);
856 		return;
857 	}
858 
859 	WARN_ON(ieee80211_chanctx_refcount(local, ctx) > 1 &&
860 		!cfg80211_chandef_compatible(&ctx->conf.def, &chanreq->oper));
861 
862 	ieee80211_remove_wbrf(local, &ctx->conf.def);
863 
864 	if (!cfg80211_chandef_identical(&ctx->conf.def, &chanreq->oper)) {
865 		if (ctx->conf.def.width != chanreq->oper.width)
866 			changed |= IEEE80211_CHANCTX_CHANGE_WIDTH;
867 		if (ctx->conf.def.punctured != chanreq->oper.punctured)
868 			changed |= IEEE80211_CHANCTX_CHANGE_PUNCTURING;
869 		if (ctx->conf.def.npca_chan != chanreq->oper.npca_chan)
870 			changed |= IEEE80211_CHANCTX_CHANGE_NPCA;
871 		if (chanreq->oper.npca_chan &&
872 		    ctx->conf.def.npca_punctured != chanreq->oper.npca_punctured)
873 			changed |= IEEE80211_CHANCTX_CHANGE_NPCA_PUNCT;
874 	}
875 	if (!cfg80211_chandef_identical(&ctx->conf.ap, &chanreq->ap))
876 		changed |= IEEE80211_CHANCTX_CHANGE_AP;
877 	ctx->conf.def = chanreq->oper;
878 	ctx->conf.ap = chanreq->ap;
879 
880 	/* check if min chanctx also changed */
881 	changed |= __ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for,
882 						      false);
883 
884 	ieee80211_add_wbrf(local, &ctx->conf.def);
885 
886 	/* disable NPCA on the link using it */
887 	ieee80211_chanctx_update_npca_links(local, ctx, false);
888 
889 	drv_change_chanctx(local, ctx, changed);
890 
891 	/* check if BW is wider */
892 	ieee80211_chan_bw_change(local, old_ctx, false, false);
893 
894 	/* enable NPCA on the link that requested it */
895 	ieee80211_chanctx_update_npca_links(local, ctx, true);
896 }
897 
898 static void ieee80211_change_chanctx(struct ieee80211_local *local,
899 				     struct ieee80211_chanctx *ctx,
900 				     struct ieee80211_chanctx *old_ctx,
901 				     const struct ieee80211_chan_req *chanreq)
902 {
903 	_ieee80211_change_chanctx(local, ctx, old_ctx, chanreq, NULL);
904 }
905 
906 /* Note: if successful, the returned chanctx will_be_used flag is set */
907 static struct ieee80211_chanctx *
908 ieee80211_find_chanctx(struct ieee80211_local *local,
909 		       const struct ieee80211_chan_req *chanreq,
910 		       enum ieee80211_chanctx_mode mode)
911 {
912 	struct ieee80211_chan_req tmp;
913 	struct ieee80211_chanctx *ctx;
914 
915 	lockdep_assert_wiphy(local->hw.wiphy);
916 
917 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
918 		return NULL;
919 
920 	list_for_each_entry(ctx, &local->chanctx_list, list) {
921 		const struct ieee80211_chan_req *compat;
922 
923 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
924 			continue;
925 
926 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
927 			continue;
928 
929 		compat = ieee80211_chanctx_compatible(local, ctx, chanreq,
930 						      &tmp);
931 		if (!compat)
932 			continue;
933 
934 		compat = ieee80211_chanctx_reserved_chanreq(local, ctx,
935 							    compat, &tmp);
936 		if (!compat)
937 			continue;
938 
939 		/*
940 		 * Mark the chanctx as will be used, as the driver might change
941 		 * active links during callbacks we make into it below and/or
942 		 * later during assignment, which could (otherwise) cause the
943 		 * context to actually be removed.
944 		 */
945 		ctx->will_be_used = true;
946 
947 		ieee80211_change_chanctx(local, ctx, ctx, compat);
948 
949 		return ctx;
950 	}
951 
952 	return NULL;
953 }
954 
955 bool ieee80211_is_radar_required(struct ieee80211_local *local,
956 				 struct cfg80211_scan_request *req)
957 {
958 	struct wiphy *wiphy = local->hw.wiphy;
959 	struct ieee80211_link_data *link;
960 	struct ieee80211_channel *chan;
961 	int radio_idx;
962 
963 	lockdep_assert_wiphy(local->hw.wiphy);
964 
965 	if (!req)
966 		return false;
967 
968 	for_each_sdata_link(local, link) {
969 		if (link->radar_required) {
970 			chan = link->conf->chanreq.oper.chan;
971 			radio_idx = cfg80211_get_radio_idx_by_chan(wiphy, chan);
972 
973 			if (ieee80211_is_radio_idx_in_scan_req(wiphy, req,
974 							       radio_idx))
975 				return true;
976 		}
977 	}
978 
979 	return false;
980 }
981 
982 static bool
983 ieee80211_chanctx_radar_required(struct ieee80211_local *local,
984 				 struct ieee80211_chanctx *ctx)
985 {
986 	struct ieee80211_chanctx_user_iter iter;
987 
988 	lockdep_assert_wiphy(local->hw.wiphy);
989 
990 	for_each_chanctx_user_assigned(local, ctx, &iter) {
991 		if (iter.radar_required)
992 			return true;
993 	}
994 
995 	return false;
996 }
997 
998 static struct ieee80211_chanctx *
999 ieee80211_alloc_chanctx(struct ieee80211_local *local,
1000 			const struct ieee80211_chan_req *chanreq,
1001 			enum ieee80211_chanctx_mode mode,
1002 			int radio_idx)
1003 {
1004 	struct ieee80211_chanctx *ctx;
1005 
1006 	lockdep_assert_wiphy(local->hw.wiphy);
1007 
1008 	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
1009 	if (!ctx)
1010 		return NULL;
1011 
1012 	ctx->conf.def = chanreq->oper;
1013 	ctx->conf.ap = chanreq->ap;
1014 	ctx->conf.rx_chains_static = 1;
1015 	ctx->conf.rx_chains_dynamic = 1;
1016 	ctx->mode = mode;
1017 	ctx->conf.radar_enabled = false;
1018 	ctx->conf.radio_idx = radio_idx;
1019 	ctx->radar_detected = false;
1020 	__ieee80211_recalc_chanctx_min_def(local, ctx, NULL, false);
1021 
1022 	return ctx;
1023 }
1024 
1025 static int ieee80211_add_chanctx(struct ieee80211_local *local,
1026 				 struct ieee80211_chanctx *ctx)
1027 {
1028 	u32 changed;
1029 	int err;
1030 
1031 	lockdep_assert_wiphy(local->hw.wiphy);
1032 
1033 	ieee80211_add_wbrf(local, &ctx->conf.def);
1034 
1035 	/* turn idle off *before* setting channel -- some drivers need that */
1036 	changed = ieee80211_idle_off(local);
1037 	if (changed)
1038 		ieee80211_hw_config(local, -1, changed);
1039 
1040 	err = drv_add_chanctx(local, ctx);
1041 	if (err) {
1042 		ieee80211_recalc_idle(local);
1043 		return err;
1044 	}
1045 
1046 	return 0;
1047 }
1048 
1049 static struct ieee80211_chanctx *
1050 ieee80211_new_chanctx(struct ieee80211_local *local,
1051 		      const struct ieee80211_chan_req *chanreq,
1052 		      enum ieee80211_chanctx_mode mode,
1053 		      bool assign_on_failure,
1054 		      int radio_idx)
1055 {
1056 	struct ieee80211_chanctx *ctx;
1057 	int err;
1058 
1059 	lockdep_assert_wiphy(local->hw.wiphy);
1060 
1061 	ctx = ieee80211_alloc_chanctx(local, chanreq, mode, radio_idx);
1062 	if (!ctx)
1063 		return ERR_PTR(-ENOMEM);
1064 
1065 	err = ieee80211_add_chanctx(local, ctx);
1066 	if (!assign_on_failure && err) {
1067 		kfree(ctx);
1068 		return ERR_PTR(err);
1069 	}
1070 	/*
1071 	 * We ignored a driver error, see _ieee80211_set_active_links and/or
1072 	 * ieee80211_nan_set_local_sched
1073 	 */
1074 	WARN_ON_ONCE(err && !local->in_reconfig);
1075 
1076 	list_add_rcu(&ctx->list, &local->chanctx_list);
1077 	return ctx;
1078 }
1079 
1080 static void ieee80211_del_chanctx(struct ieee80211_local *local,
1081 				  struct ieee80211_chanctx *ctx,
1082 				  bool skip_idle_recalc)
1083 {
1084 	lockdep_assert_wiphy(local->hw.wiphy);
1085 
1086 	drv_remove_chanctx(local, ctx);
1087 
1088 	if (!skip_idle_recalc)
1089 		ieee80211_recalc_idle(local);
1090 
1091 	ieee80211_remove_wbrf(local, &ctx->conf.def);
1092 }
1093 
1094 void ieee80211_free_chanctx(struct ieee80211_local *local,
1095 			    struct ieee80211_chanctx *ctx,
1096 			    bool skip_idle_recalc)
1097 {
1098 	lockdep_assert_wiphy(local->hw.wiphy);
1099 
1100 	WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
1101 
1102 	list_del_rcu(&ctx->list);
1103 	ieee80211_del_chanctx(local, ctx, skip_idle_recalc);
1104 	kfree_rcu(ctx, rcu_head);
1105 }
1106 
1107 void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
1108 				       struct ieee80211_chanctx *ctx)
1109 {
1110 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
1111 	const struct ieee80211_chan_req *compat = NULL;
1112 	struct ieee80211_chanctx_user_iter iter;
1113 	struct ieee80211_chan_req tmp;
1114 	struct sta_info *sta;
1115 
1116 	lockdep_assert_wiphy(local->hw.wiphy);
1117 
1118 	for_each_chanctx_user_assigned(local, ctx, &iter) {
1119 		if (!compat)
1120 			compat = iter.chanreq;
1121 
1122 		compat = ieee80211_chanreq_compatible(iter.chanreq,
1123 						      compat, &tmp);
1124 		if (WARN_ON_ONCE(!compat))
1125 			return;
1126 	}
1127 
1128 	if (WARN_ON_ONCE(!compat))
1129 		return;
1130 
1131 	/* TDLS peers can sometimes affect the chandef width */
1132 	list_for_each_entry(sta, &local->sta_list, list) {
1133 		struct ieee80211_sub_if_data *sdata = sta->sdata;
1134 		struct ieee80211_chan_req tdls_chanreq = {};
1135 		struct ieee80211_link_data *link;
1136 		int tdls_link_id;
1137 
1138 		if (!sta->uploaded ||
1139 		    !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
1140 		    !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
1141 		    !sta->tdls_chandef.chan)
1142 			continue;
1143 
1144 		tdls_link_id = ieee80211_tdls_sta_link_id(sta);
1145 		link = sdata_dereference(sdata->link[tdls_link_id], sdata);
1146 		if (!link)
1147 			continue;
1148 
1149 		if (rcu_access_pointer(link->conf->chanctx_conf) != conf)
1150 			continue;
1151 
1152 		tdls_chanreq.oper = sta->tdls_chandef;
1153 
1154 		/* note this always fills and returns &tmp if compat */
1155 		compat = ieee80211_chanreq_compatible(&tdls_chanreq,
1156 						      compat, &tmp);
1157 		if (WARN_ON_ONCE(!compat))
1158 			return;
1159 	}
1160 
1161 	ieee80211_change_chanctx(local, ctx, ctx, compat);
1162 }
1163 
1164 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
1165 					   struct ieee80211_chanctx *chanctx)
1166 {
1167 	bool radar_enabled;
1168 
1169 	lockdep_assert_wiphy(local->hw.wiphy);
1170 
1171 	radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
1172 
1173 	if (radar_enabled == chanctx->conf.radar_enabled)
1174 		return;
1175 
1176 	chanctx->conf.radar_enabled = radar_enabled;
1177 
1178 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
1179 }
1180 
1181 static int ieee80211_assign_link_chanctx(struct ieee80211_link_data *link,
1182 					 struct ieee80211_chanctx *new_ctx,
1183 					 bool assign_on_failure)
1184 {
1185 	struct ieee80211_sub_if_data *sdata = link->sdata;
1186 	struct ieee80211_local *local = sdata->local;
1187 	struct ieee80211_chanctx_conf *conf;
1188 	struct ieee80211_chanctx *curr_ctx = NULL;
1189 	bool new_idle;
1190 	int ret;
1191 
1192 	if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN))
1193 		return -EOPNOTSUPP;
1194 
1195 	conf = rcu_dereference_protected(link->conf->chanctx_conf,
1196 					 lockdep_is_held(&local->hw.wiphy->mtx));
1197 
1198 	if (conf && !local->in_reconfig) {
1199 		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
1200 
1201 		drv_unassign_vif_chanctx(local, sdata, link->conf, curr_ctx);
1202 		conf = NULL;
1203 	}
1204 
1205 	if (new_ctx) {
1206 		/* recalc considering the link we'll use it for now */
1207 		_ieee80211_recalc_chanctx_min_def(local, new_ctx, link, false);
1208 
1209 		ret = drv_assign_vif_chanctx(local, sdata, link->conf, new_ctx);
1210 		if (assign_on_failure || !ret) {
1211 			/* Need to continue, see _ieee80211_set_active_links */
1212 			WARN_ON_ONCE(ret && !local->in_reconfig);
1213 			ret = 0;
1214 
1215 			/* succeeded, so commit it to the data structures */
1216 			conf = &new_ctx->conf;
1217 		}
1218 	} else {
1219 		ret = 0;
1220 	}
1221 
1222 	rcu_assign_pointer(link->conf->chanctx_conf, conf);
1223 
1224 	if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
1225 		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
1226 		ieee80211_recalc_smps_chanctx(local, curr_ctx);
1227 		ieee80211_recalc_radar_chanctx(local, curr_ctx);
1228 		ieee80211_recalc_chanctx_min_def(local, curr_ctx);
1229 	}
1230 
1231 	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
1232 		ieee80211_recalc_txpower(link, false);
1233 		ieee80211_recalc_chanctx_min_def(local, new_ctx);
1234 	}
1235 
1236 	if (conf) {
1237 		new_idle = false;
1238 	} else {
1239 		struct ieee80211_link_data *tmp;
1240 
1241 		new_idle = true;
1242 		for_each_sdata_link(local, tmp) {
1243 			if (rcu_access_pointer(tmp->conf->chanctx_conf)) {
1244 				new_idle = false;
1245 				break;
1246 			}
1247 		}
1248 	}
1249 
1250 	if (new_idle != sdata->vif.cfg.idle) {
1251 		sdata->vif.cfg.idle = new_idle;
1252 
1253 		if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
1254 		    sdata->vif.type != NL80211_IFTYPE_MONITOR)
1255 			ieee80211_vif_cfg_change_notify(sdata, BSS_CHANGED_IDLE);
1256 	}
1257 
1258 	ieee80211_check_fast_xmit_iface(sdata);
1259 
1260 	return ret;
1261 }
1262 
1263 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
1264 				   struct ieee80211_chanctx *chanctx)
1265 {
1266 	struct ieee80211_chanctx_user_iter iter;
1267 	struct ieee80211_sub_if_data *sdata;
1268 	u8 rx_chains_static, rx_chains_dynamic;
1269 
1270 	lockdep_assert_wiphy(local->hw.wiphy);
1271 
1272 	rx_chains_static = 1;
1273 	rx_chains_dynamic = 1;
1274 
1275 	for_each_chanctx_user_assigned(local, chanctx, &iter) {
1276 		u8 needed_static, needed_dynamic;
1277 
1278 		switch (iter.iftype) {
1279 		case NL80211_IFTYPE_STATION:
1280 			if (!iter.sdata->u.mgd.associated)
1281 				continue;
1282 			break;
1283 		case NL80211_IFTYPE_MONITOR:
1284 			if (!ieee80211_hw_check(&local->hw, NO_VIRTUAL_MONITOR))
1285 				continue;
1286 			break;
1287 		case NL80211_IFTYPE_AP:
1288 		case NL80211_IFTYPE_ADHOC:
1289 		case NL80211_IFTYPE_MESH_POINT:
1290 		case NL80211_IFTYPE_OCB:
1291 		case NL80211_IFTYPE_NAN:
1292 			break;
1293 		default:
1294 			continue;
1295 		}
1296 
1297 		if (iter.iftype == NL80211_IFTYPE_MONITOR) {
1298 			rx_chains_dynamic = rx_chains_static = local->rx_chains;
1299 			break;
1300 		}
1301 
1302 		if (iter.nan_channel) {
1303 			rx_chains_dynamic = rx_chains_static =
1304 				iter.nan_channel->needed_rx_chains;
1305 			break;
1306 		}
1307 
1308 		if (!iter.link)
1309 			continue;
1310 
1311 		switch (iter.link->smps_mode) {
1312 		default:
1313 			WARN_ONCE(1, "Invalid SMPS mode %d\n",
1314 				  iter.link->smps_mode);
1315 			fallthrough;
1316 		case IEEE80211_SMPS_OFF:
1317 			needed_static = iter.link->needed_rx_chains;
1318 			needed_dynamic = iter.link->needed_rx_chains;
1319 			break;
1320 		case IEEE80211_SMPS_DYNAMIC:
1321 			needed_static = 1;
1322 			needed_dynamic = iter.link->needed_rx_chains;
1323 			break;
1324 		case IEEE80211_SMPS_STATIC:
1325 			needed_static = 1;
1326 			needed_dynamic = 1;
1327 			break;
1328 		}
1329 
1330 		rx_chains_static = max(rx_chains_static, needed_static);
1331 		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
1332 	}
1333 
1334 	/* Disable SMPS for the monitor interface */
1335 	sdata = wiphy_dereference(local->hw.wiphy, local->monitor_sdata);
1336 	if (sdata &&
1337 	    rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) == &chanctx->conf)
1338 		rx_chains_dynamic = rx_chains_static = local->rx_chains;
1339 
1340 	if (rx_chains_static == chanctx->conf.rx_chains_static &&
1341 	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
1342 		return;
1343 
1344 	chanctx->conf.rx_chains_static = rx_chains_static;
1345 	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
1346 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
1347 }
1348 
1349 static void
1350 __ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link,
1351 				       bool clear)
1352 {
1353 	struct ieee80211_sub_if_data *sdata = link->sdata;
1354 	unsigned int link_id = link->link_id;
1355 	struct ieee80211_bss_conf *link_conf = link->conf;
1356 	struct ieee80211_local *local __maybe_unused = sdata->local;
1357 	struct ieee80211_sub_if_data *vlan;
1358 	struct ieee80211_chanctx_conf *conf;
1359 
1360 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
1361 		return;
1362 
1363 	lockdep_assert_wiphy(local->hw.wiphy);
1364 
1365 	/* Check that conf exists, even when clearing this function
1366 	 * must be called with the AP's channel context still there
1367 	 * as it would otherwise cause VLANs to have an invalid
1368 	 * channel context pointer for a while, possibly pointing
1369 	 * to a channel context that has already been freed.
1370 	 */
1371 	conf = rcu_dereference_protected(link_conf->chanctx_conf,
1372 					 lockdep_is_held(&local->hw.wiphy->mtx));
1373 	WARN_ON(!conf);
1374 
1375 	if (clear)
1376 		conf = NULL;
1377 
1378 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
1379 		struct ieee80211_bss_conf *vlan_conf;
1380 
1381 		if (vlan->vif.valid_links &&
1382 		    !(vlan->vif.valid_links & BIT(link_id)))
1383 			continue;
1384 
1385 		vlan_conf = wiphy_dereference(local->hw.wiphy,
1386 					      vlan->vif.link_conf[link_id]);
1387 		if (WARN_ON(!vlan_conf))
1388 			continue;
1389 
1390 		rcu_assign_pointer(vlan_conf->chanctx_conf, conf);
1391 	}
1392 }
1393 
1394 void ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link,
1395 					  bool clear)
1396 {
1397 	struct ieee80211_local *local = link->sdata->local;
1398 
1399 	lockdep_assert_wiphy(local->hw.wiphy);
1400 
1401 	__ieee80211_link_copy_chanctx_to_vlans(link, clear);
1402 }
1403 
1404 void ieee80211_link_unreserve_chanctx(struct ieee80211_link_data *link)
1405 {
1406 	struct ieee80211_sub_if_data *sdata = link->sdata;
1407 	struct ieee80211_chanctx *ctx = link->reserved_chanctx;
1408 
1409 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
1410 
1411 	if (WARN_ON(!ctx))
1412 		return;
1413 
1414 	link->reserved_chanctx = NULL;
1415 
1416 	if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
1417 		if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1418 			if (WARN_ON(!ctx->replace_ctx))
1419 				return;
1420 
1421 			WARN_ON(ctx->replace_ctx->replace_state !=
1422 			        IEEE80211_CHANCTX_WILL_BE_REPLACED);
1423 			WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
1424 
1425 			ctx->replace_ctx->replace_ctx = NULL;
1426 			ctx->replace_ctx->replace_state =
1427 					IEEE80211_CHANCTX_REPLACE_NONE;
1428 
1429 			list_del_rcu(&ctx->list);
1430 			kfree_rcu(ctx, rcu_head);
1431 		} else {
1432 			ieee80211_free_chanctx(sdata->local, ctx, false);
1433 		}
1434 	}
1435 }
1436 
1437 static struct ieee80211_chanctx *
1438 ieee80211_replace_chanctx(struct ieee80211_local *local,
1439 			  const struct ieee80211_chan_req *chanreq,
1440 			  enum ieee80211_chanctx_mode mode,
1441 			  struct ieee80211_chanctx *curr_ctx)
1442 {
1443 	struct ieee80211_chanctx *new_ctx, *ctx;
1444 	struct wiphy *wiphy = local->hw.wiphy;
1445 	const struct wiphy_radio *radio;
1446 
1447 	if (!curr_ctx ||
1448 	    curr_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED ||
1449 	    ieee80211_chanctx_num_reserved(local, curr_ctx) != 0) {
1450 		/*
1451 		 * Another link already requested this context for a
1452 		 * reservation. Find another one hoping all links assigned
1453 		 * to it will also switch soon enough.
1454 		 *
1455 		 * TODO: This needs a little more work as some cases
1456 		 * (more than 2 chanctx capable devices) may fail which could
1457 		 * otherwise succeed provided some channel context juggling was
1458 		 * performed.
1459 		 *
1460 		 * Consider ctx1..3, link1..6, each ctx has 2 links. link1 and
1461 		 * link2 from ctx1 request new different chandefs starting 2
1462 		 * in-place reservations with ctx4 and ctx5 replacing ctx1 and
1463 		 * ctx2 respectively. Next link5 and link6 from ctx3 reserve
1464 		 * ctx4. If link3 and link4 remain on ctx2 as they are then this
1465 		 * fails unless `replace_ctx` from ctx5 is replaced with ctx3.
1466 		 */
1467 		list_for_each_entry(ctx, &local->chanctx_list, list) {
1468 			if (ctx->replace_state !=
1469 			    IEEE80211_CHANCTX_REPLACE_NONE)
1470 				continue;
1471 
1472 			if (ieee80211_chanctx_num_reserved(local, ctx) != 0)
1473 				continue;
1474 
1475 			if (ctx->conf.radio_idx >= 0) {
1476 				radio = &wiphy->radio[ctx->conf.radio_idx];
1477 				if (!cfg80211_radio_chandef_valid(radio, &chanreq->oper))
1478 					continue;
1479 			}
1480 
1481 			curr_ctx = ctx;
1482 			break;
1483 		}
1484 	}
1485 
1486 	/*
1487 	 * If that's true then all available contexts already have reservations
1488 	 * and cannot be used.
1489 	 */
1490 	if (!curr_ctx ||
1491 	    curr_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED ||
1492 	    ieee80211_chanctx_num_reserved(local, curr_ctx) != 0)
1493 		return ERR_PTR(-EBUSY);
1494 
1495 	new_ctx = ieee80211_alloc_chanctx(local, chanreq, mode, -1);
1496 	if (!new_ctx)
1497 		return ERR_PTR(-ENOMEM);
1498 
1499 	new_ctx->replace_ctx = curr_ctx;
1500 	new_ctx->replace_state = IEEE80211_CHANCTX_REPLACES_OTHER;
1501 
1502 	curr_ctx->replace_ctx = new_ctx;
1503 	curr_ctx->replace_state = IEEE80211_CHANCTX_WILL_BE_REPLACED;
1504 
1505 	list_add_rcu(&new_ctx->list, &local->chanctx_list);
1506 
1507 	return new_ctx;
1508 }
1509 
1510 static bool
1511 ieee80211_find_available_radio(struct ieee80211_local *local,
1512 			       const struct ieee80211_chan_req *chanreq,
1513 			       u32 radio_mask, int *radio_idx)
1514 {
1515 	struct wiphy *wiphy = local->hw.wiphy;
1516 	const struct wiphy_radio *radio;
1517 	int i;
1518 
1519 	*radio_idx = -1;
1520 	if (!wiphy->n_radio)
1521 		return true;
1522 
1523 	for (i = 0; i < wiphy->n_radio; i++) {
1524 		if (!(radio_mask & BIT(i)))
1525 			continue;
1526 
1527 		radio = &wiphy->radio[i];
1528 		if (!cfg80211_radio_chandef_valid(radio, &chanreq->oper))
1529 			continue;
1530 
1531 		if (!ieee80211_can_create_new_chanctx(local, i))
1532 			continue;
1533 
1534 		*radio_idx = i;
1535 		return true;
1536 	}
1537 
1538 	return false;
1539 }
1540 
1541 int ieee80211_link_reserve_chanctx(struct ieee80211_link_data *link,
1542 				   const struct ieee80211_chan_req *chanreq,
1543 				   enum ieee80211_chanctx_mode mode,
1544 				   bool radar_required)
1545 {
1546 	struct ieee80211_sub_if_data *sdata = link->sdata;
1547 	struct ieee80211_local *local = sdata->local;
1548 	struct ieee80211_chanctx *new_ctx, *curr_ctx;
1549 	int radio_idx;
1550 
1551 	lockdep_assert_wiphy(local->hw.wiphy);
1552 
1553 	curr_ctx = ieee80211_link_get_chanctx(link);
1554 	if (curr_ctx && !local->ops->switch_vif_chanctx)
1555 		return -EOPNOTSUPP;
1556 
1557 	new_ctx = ieee80211_find_reservation_chanctx(local, chanreq, mode);
1558 	if (!new_ctx) {
1559 		if (ieee80211_can_create_new_chanctx(local, -1) &&
1560 		    ieee80211_find_available_radio(local, chanreq,
1561 						   sdata->wdev.radio_mask,
1562 						   &radio_idx))
1563 			new_ctx = ieee80211_new_chanctx(local, chanreq, mode,
1564 							false, radio_idx);
1565 		else
1566 			new_ctx = ieee80211_replace_chanctx(local, chanreq,
1567 							    mode, curr_ctx);
1568 		if (IS_ERR(new_ctx))
1569 			return PTR_ERR(new_ctx);
1570 	}
1571 
1572 	link->reserved_chanctx = new_ctx;
1573 	link->reserved = *chanreq;
1574 	link->reserved_radar_required = radar_required;
1575 	link->reserved_ready = false;
1576 
1577 	return 0;
1578 }
1579 
1580 static void
1581 ieee80211_link_chanctx_reservation_complete(struct ieee80211_link_data *link)
1582 {
1583 	struct ieee80211_sub_if_data *sdata = link->sdata;
1584 
1585 	switch (sdata->vif.type) {
1586 	case NL80211_IFTYPE_ADHOC:
1587 	case NL80211_IFTYPE_AP:
1588 	case NL80211_IFTYPE_MESH_POINT:
1589 	case NL80211_IFTYPE_OCB:
1590 		wiphy_work_queue(sdata->local->hw.wiphy,
1591 				 &link->csa.finalize_work);
1592 		break;
1593 	case NL80211_IFTYPE_STATION:
1594 		wiphy_hrtimer_work_queue(sdata->local->hw.wiphy,
1595 					 &link->u.mgd.csa.switch_work, 0);
1596 		break;
1597 	case NL80211_IFTYPE_UNSPECIFIED:
1598 	case NL80211_IFTYPE_AP_VLAN:
1599 	case NL80211_IFTYPE_WDS:
1600 	case NL80211_IFTYPE_MONITOR:
1601 	case NL80211_IFTYPE_P2P_CLIENT:
1602 	case NL80211_IFTYPE_P2P_GO:
1603 	case NL80211_IFTYPE_P2P_DEVICE:
1604 	case NL80211_IFTYPE_NAN:
1605 	case NL80211_IFTYPE_NAN_DATA:
1606 	case NL80211_IFTYPE_PD:
1607 	case NUM_NL80211_IFTYPES:
1608 		WARN_ON(1);
1609 		break;
1610 	}
1611 }
1612 
1613 static void
1614 ieee80211_link_update_chanreq(struct ieee80211_link_data *link,
1615 			      const struct ieee80211_chan_req *chanreq)
1616 {
1617 	struct ieee80211_sub_if_data *sdata = link->sdata;
1618 	unsigned int link_id = link->link_id;
1619 	struct ieee80211_sub_if_data *vlan;
1620 
1621 	link->conf->chanreq = *chanreq;
1622 
1623 	if (sdata->vif.type != NL80211_IFTYPE_AP)
1624 		return;
1625 
1626 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
1627 		struct ieee80211_bss_conf *vlan_conf;
1628 
1629 		if (vlan->vif.valid_links &&
1630 		    !(vlan->vif.valid_links & BIT(link_id)))
1631 			continue;
1632 
1633 		vlan_conf = wiphy_dereference(sdata->local->hw.wiphy,
1634 					      vlan->vif.link_conf[link_id]);
1635 		if (WARN_ON(!vlan_conf))
1636 			continue;
1637 
1638 		vlan_conf->chanreq = *chanreq;
1639 	}
1640 }
1641 
1642 static int
1643 ieee80211_link_use_reserved_reassign(struct ieee80211_link_data *link)
1644 {
1645 	struct ieee80211_sub_if_data *sdata = link->sdata;
1646 	struct ieee80211_bss_conf *link_conf = link->conf;
1647 	struct ieee80211_local *local = sdata->local;
1648 	struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1649 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1650 	const struct ieee80211_chan_req *chanreq;
1651 	struct ieee80211_chan_req tmp;
1652 	u64 changed = 0;
1653 	int err;
1654 
1655 	lockdep_assert_wiphy(local->hw.wiphy);
1656 
1657 	new_ctx = link->reserved_chanctx;
1658 	old_ctx = ieee80211_link_get_chanctx(link);
1659 
1660 	if (WARN_ON(!link->reserved_ready))
1661 		return -EBUSY;
1662 
1663 	if (WARN_ON(!new_ctx))
1664 		return -EINVAL;
1665 
1666 	if (WARN_ON(!old_ctx))
1667 		return -EINVAL;
1668 
1669 	if (WARN_ON(new_ctx->replace_state ==
1670 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1671 		return -EINVAL;
1672 
1673 	chanreq = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1674 							 &link->reserved,
1675 							 &tmp);
1676 	if (WARN_ON(!chanreq))
1677 		return -EINVAL;
1678 
1679 	if (link_conf->chanreq.oper.width != link->reserved.oper.width)
1680 		changed = BSS_CHANGED_BANDWIDTH;
1681 
1682 	ieee80211_link_update_chanreq(link, &link->reserved);
1683 
1684 	_ieee80211_change_chanctx(local, new_ctx, old_ctx, chanreq, link);
1685 
1686 	vif_chsw[0].vif = &sdata->vif;
1687 	vif_chsw[0].old_ctx = &old_ctx->conf;
1688 	vif_chsw[0].new_ctx = &new_ctx->conf;
1689 	vif_chsw[0].link_conf = link->conf;
1690 
1691 	link->reserved_chanctx = NULL;
1692 
1693 	err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1694 				     CHANCTX_SWMODE_REASSIGN_VIF);
1695 	if (err) {
1696 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1697 			ieee80211_free_chanctx(local, new_ctx, false);
1698 
1699 		goto out;
1700 	}
1701 
1702 	link->radar_required = link->reserved_radar_required;
1703 	rcu_assign_pointer(link_conf->chanctx_conf, &new_ctx->conf);
1704 
1705 	if (sdata->vif.type == NL80211_IFTYPE_AP)
1706 		__ieee80211_link_copy_chanctx_to_vlans(link, false);
1707 
1708 	ieee80211_check_fast_xmit_iface(sdata);
1709 
1710 	if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1711 		ieee80211_free_chanctx(local, old_ctx, false);
1712 
1713 	ieee80211_recalc_chanctx_min_def(local, new_ctx);
1714 	ieee80211_recalc_smps_chanctx(local, new_ctx);
1715 	ieee80211_recalc_radar_chanctx(local, new_ctx);
1716 
1717 	if (changed)
1718 		ieee80211_link_info_change_notify(sdata, link, changed);
1719 
1720 out:
1721 	ieee80211_link_chanctx_reservation_complete(link);
1722 	return err;
1723 }
1724 
1725 static int
1726 ieee80211_link_use_reserved_assign(struct ieee80211_link_data *link)
1727 {
1728 	struct ieee80211_sub_if_data *sdata = link->sdata;
1729 	struct ieee80211_local *local = sdata->local;
1730 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1731 	const struct ieee80211_chan_req *chanreq;
1732 	struct ieee80211_chan_req tmp;
1733 	int err;
1734 
1735 	old_ctx = ieee80211_link_get_chanctx(link);
1736 	new_ctx = link->reserved_chanctx;
1737 
1738 	if (WARN_ON(!link->reserved_ready))
1739 		return -EINVAL;
1740 
1741 	if (WARN_ON(old_ctx))
1742 		return -EINVAL;
1743 
1744 	if (WARN_ON(!new_ctx))
1745 		return -EINVAL;
1746 
1747 	if (WARN_ON(new_ctx->replace_state ==
1748 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1749 		return -EINVAL;
1750 
1751 	chanreq = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1752 							 &link->reserved,
1753 							 &tmp);
1754 	if (WARN_ON(!chanreq))
1755 		return -EINVAL;
1756 
1757 	ieee80211_change_chanctx(local, new_ctx, new_ctx, chanreq);
1758 
1759 	link->reserved_chanctx = NULL;
1760 
1761 	err = ieee80211_assign_link_chanctx(link, new_ctx, false);
1762 	if (err) {
1763 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1764 			ieee80211_free_chanctx(local, new_ctx, false);
1765 
1766 		goto out;
1767 	}
1768 
1769 out:
1770 	ieee80211_link_chanctx_reservation_complete(link);
1771 	return err;
1772 }
1773 
1774 static bool
1775 ieee80211_link_has_in_place_reservation(struct ieee80211_link_data *link)
1776 {
1777 	struct ieee80211_sub_if_data *sdata = link->sdata;
1778 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1779 
1780 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
1781 
1782 	new_ctx = link->reserved_chanctx;
1783 	old_ctx = ieee80211_link_get_chanctx(link);
1784 
1785 	if (!old_ctx)
1786 		return false;
1787 
1788 	if (WARN_ON(!new_ctx))
1789 		return false;
1790 
1791 	if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1792 		return false;
1793 
1794 	if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1795 		return false;
1796 
1797 	return true;
1798 }
1799 
1800 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1801 				      int n_vifs)
1802 {
1803 	struct ieee80211_vif_chanctx_switch *vif_chsw;
1804 	struct ieee80211_chanctx *ctx, *old_ctx;
1805 	int i, err;
1806 
1807 	lockdep_assert_wiphy(local->hw.wiphy);
1808 
1809 	vif_chsw = kzalloc_objs(vif_chsw[0], n_vifs);
1810 	if (!vif_chsw)
1811 		return -ENOMEM;
1812 
1813 	i = 0;
1814 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1815 		struct ieee80211_chanctx_user_iter iter;
1816 
1817 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1818 			continue;
1819 
1820 		if (WARN_ON(!ctx->replace_ctx)) {
1821 			err = -EINVAL;
1822 			goto out;
1823 		}
1824 
1825 		for_each_chanctx_user_reserved(local, ctx, &iter) {
1826 			if (!ieee80211_link_has_in_place_reservation(iter.link))
1827 				continue;
1828 
1829 			old_ctx = ieee80211_link_get_chanctx(iter.link);
1830 			vif_chsw[i].vif = &iter.sdata->vif;
1831 			vif_chsw[i].old_ctx = &old_ctx->conf;
1832 			vif_chsw[i].new_ctx = &ctx->conf;
1833 			vif_chsw[i].link_conf = iter.link->conf;
1834 
1835 			i++;
1836 		}
1837 	}
1838 
1839 	err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1840 				     CHANCTX_SWMODE_SWAP_CONTEXTS);
1841 
1842 out:
1843 	kfree(vif_chsw);
1844 	return err;
1845 }
1846 
1847 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1848 {
1849 	struct ieee80211_chanctx *ctx;
1850 	int err;
1851 
1852 	lockdep_assert_wiphy(local->hw.wiphy);
1853 
1854 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1855 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1856 			continue;
1857 
1858 		if (ieee80211_chanctx_num_assigned(local, ctx) != 0)
1859 			continue;
1860 
1861 		ieee80211_del_chanctx(local, ctx->replace_ctx, false);
1862 		err = ieee80211_add_chanctx(local, ctx);
1863 		if (err)
1864 			goto err;
1865 	}
1866 
1867 	return 0;
1868 
1869 err:
1870 	WARN_ON(ieee80211_add_chanctx(local, ctx));
1871 	list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1872 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1873 			continue;
1874 
1875 		if (ieee80211_chanctx_num_assigned(local, ctx) != 0)
1876 			continue;
1877 
1878 		ieee80211_del_chanctx(local, ctx, false);
1879 		WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1880 	}
1881 
1882 	return err;
1883 }
1884 
1885 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1886 {
1887 	struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1888 	int err, n_assigned, n_reserved, n_ready;
1889 	int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1890 
1891 	lockdep_assert_wiphy(local->hw.wiphy);
1892 
1893 	/*
1894 	 * If there are 2 independent pairs of channel contexts performing
1895 	 * cross-switch of their vifs this code will still wait until both are
1896 	 * ready even though it could be possible to switch one before the
1897 	 * other is ready.
1898 	 *
1899 	 * For practical reasons and code simplicity just do a single huge
1900 	 * switch.
1901 	 */
1902 
1903 	/*
1904 	 * Verify if the reservation is still feasible.
1905 	 *  - if it's not then disconnect
1906 	 *  - if it is but not all vifs necessary are ready then defer
1907 	 */
1908 
1909 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1910 		struct ieee80211_chanctx_user_iter iter;
1911 
1912 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1913 			continue;
1914 
1915 		if (WARN_ON(!ctx->replace_ctx)) {
1916 			err = -EINVAL;
1917 			goto err;
1918 		}
1919 
1920 		n_ctx++;
1921 
1922 		n_assigned = 0;
1923 		n_reserved = 0;
1924 		n_ready = 0;
1925 
1926 		for_each_chanctx_user_assigned(local, ctx->replace_ctx, &iter) {
1927 			n_assigned++;
1928 			if (iter.link && iter.link->reserved_chanctx) {
1929 				n_reserved++;
1930 				if (iter.link->reserved_ready)
1931 					n_ready++;
1932 			}
1933 		}
1934 
1935 		if (n_assigned != n_reserved) {
1936 			if (n_ready != n_reserved)
1937 				return -EAGAIN;
1938 
1939 			if (n_assigned == n_reserved + 1 &&
1940 			    ieee80211_nan_try_evacuate(&local->hw,
1941 						       &ctx->replace_ctx->conf))
1942 				goto use_reserved;
1943 
1944 			wiphy_info(local->hw.wiphy,
1945 				   "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1946 			err = -EBUSY;
1947 			goto err;
1948 		}
1949 
1950 use_reserved:
1951 		ctx->conf.radar_enabled = false;
1952 		for_each_chanctx_user_reserved(local, ctx, &iter) {
1953 			if (ieee80211_link_has_in_place_reservation(iter.link) &&
1954 			    !iter.link->reserved_ready)
1955 				return -EAGAIN;
1956 
1957 			old_ctx = ieee80211_link_get_chanctx(iter.link);
1958 			if (old_ctx) {
1959 				if (old_ctx->replace_state ==
1960 				    IEEE80211_CHANCTX_WILL_BE_REPLACED)
1961 					n_vifs_switch++;
1962 				else
1963 					n_vifs_assign++;
1964 			} else {
1965 				n_vifs_ctxless++;
1966 			}
1967 
1968 			if (iter.radar_required)
1969 				ctx->conf.radar_enabled = true;
1970 		}
1971 	}
1972 
1973 	if (WARN_ON(n_ctx == 0) ||
1974 	    WARN_ON(n_vifs_switch == 0 &&
1975 		    n_vifs_assign == 0 &&
1976 		    n_vifs_ctxless == 0)) {
1977 		err = -EINVAL;
1978 		goto err;
1979 	}
1980 
1981 	/* update station rate control and min width before switch */
1982 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1983 		struct ieee80211_chanctx_user_iter iter;
1984 
1985 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1986 			continue;
1987 
1988 		if (WARN_ON(!ctx->replace_ctx)) {
1989 			err = -EINVAL;
1990 			goto err;
1991 		}
1992 
1993 		for_each_chanctx_user_reserved(local, ctx, &iter) {
1994 			if (!ieee80211_link_has_in_place_reservation(iter.link))
1995 				continue;
1996 
1997 			ieee80211_chan_bw_change(local,
1998 						 ieee80211_link_get_chanctx(iter.link),
1999 						 true, true);
2000 		}
2001 
2002 		_ieee80211_recalc_chanctx_min_def(local, ctx, NULL, true);
2003 	}
2004 
2005 	/*
2006 	 * All necessary vifs are ready. Perform the switch now depending on
2007 	 * reservations and driver capabilities.
2008 	 */
2009 
2010 	if (n_vifs_switch > 0) {
2011 		err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
2012 		if (err)
2013 			goto err;
2014 	}
2015 
2016 	if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
2017 		err = ieee80211_chsw_switch_ctxs(local);
2018 		if (err)
2019 			goto err;
2020 	}
2021 
2022 	/*
2023 	 * Update all structures, values and pointers to point to new channel
2024 	 * context(s).
2025 	 */
2026 	list_for_each_entry(ctx, &local->chanctx_list, list) {
2027 		struct ieee80211_chanctx_user_iter iter;
2028 
2029 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
2030 			continue;
2031 
2032 		if (WARN_ON(!ctx->replace_ctx)) {
2033 			err = -EINVAL;
2034 			goto err;
2035 		}
2036 
2037 		for_each_chanctx_user_reserved(local, ctx, &iter) {
2038 			struct ieee80211_link_data *link = iter.link;
2039 			struct ieee80211_sub_if_data *sdata = iter.sdata;
2040 			struct ieee80211_bss_conf *link_conf = link->conf;
2041 			u64 changed = 0;
2042 
2043 			if (!ieee80211_link_has_in_place_reservation(link))
2044 				continue;
2045 
2046 			rcu_assign_pointer(link_conf->chanctx_conf,
2047 					   &ctx->conf);
2048 
2049 			if (sdata->vif.type == NL80211_IFTYPE_AP)
2050 				__ieee80211_link_copy_chanctx_to_vlans(link,
2051 								       false);
2052 
2053 			ieee80211_check_fast_xmit_iface(sdata);
2054 
2055 			link->radar_required = iter.radar_required;
2056 
2057 			if (link_conf->chanreq.oper.width != iter.chanreq->oper.width)
2058 				changed = BSS_CHANGED_BANDWIDTH;
2059 
2060 			ieee80211_link_update_chanreq(link, &link->reserved);
2061 			if (changed)
2062 				ieee80211_link_info_change_notify(sdata,
2063 								  link,
2064 								  changed);
2065 
2066 			ieee80211_recalc_txpower(link, false);
2067 		}
2068 
2069 		ieee80211_recalc_chanctx_chantype(local, ctx);
2070 		ieee80211_recalc_smps_chanctx(local, ctx);
2071 		ieee80211_recalc_radar_chanctx(local, ctx);
2072 		ieee80211_recalc_chanctx_min_def(local, ctx);
2073 
2074 		for_each_chanctx_user_reserved(local, ctx, &iter) {
2075 			if (ieee80211_link_get_chanctx(iter.link) != ctx)
2076 				continue;
2077 
2078 			iter.link->reserved_chanctx = NULL;
2079 
2080 			ieee80211_link_chanctx_reservation_complete(iter.link);
2081 			ieee80211_chan_bw_change(local, ctx, false, false);
2082 		}
2083 
2084 		/*
2085 		 * This context might have been a dependency for an already
2086 		 * ready re-assign reservation interface that was deferred. Do
2087 		 * not propagate error to the caller though. The in-place
2088 		 * reservation for originally requested interface has already
2089 		 * succeeded at this point.
2090 		 */
2091 		for_each_chanctx_user_reserved(local, ctx, &iter) {
2092 			struct ieee80211_link_data *link = iter.link;
2093 
2094 			if (WARN_ON(ieee80211_link_has_in_place_reservation(link)))
2095 				continue;
2096 
2097 			if (!link->reserved_ready)
2098 				continue;
2099 
2100 			if (ieee80211_link_get_chanctx(link))
2101 				err = ieee80211_link_use_reserved_reassign(link);
2102 			else
2103 				err = ieee80211_link_use_reserved_assign(link);
2104 
2105 			if (err) {
2106 				link_info(link,
2107 					  "failed to finalize (re-)assign reservation (err=%d)\n",
2108 					  err);
2109 				ieee80211_link_unreserve_chanctx(link);
2110 				cfg80211_stop_iface(local->hw.wiphy,
2111 						    &link->sdata->wdev,
2112 						    GFP_KERNEL);
2113 			}
2114 		}
2115 	}
2116 
2117 	/*
2118 	 * Finally free old contexts
2119 	 */
2120 
2121 	list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
2122 		if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
2123 			continue;
2124 
2125 		ctx->replace_ctx->replace_ctx = NULL;
2126 		ctx->replace_ctx->replace_state =
2127 				IEEE80211_CHANCTX_REPLACE_NONE;
2128 
2129 		list_del_rcu(&ctx->list);
2130 		kfree_rcu(ctx, rcu_head);
2131 	}
2132 
2133 	return 0;
2134 
2135 err:
2136 	list_for_each_entry(ctx, &local->chanctx_list, list) {
2137 		struct ieee80211_chanctx_user_iter iter;
2138 
2139 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
2140 			continue;
2141 
2142 		for_each_chanctx_user_reserved(local, ctx, &iter) {
2143 			ieee80211_link_unreserve_chanctx(iter.link);
2144 			ieee80211_link_chanctx_reservation_complete(iter.link);
2145 		}
2146 	}
2147 
2148 	return err;
2149 }
2150 
2151 void __ieee80211_link_release_channel(struct ieee80211_link_data *link,
2152 				      bool skip_idle_recalc)
2153 {
2154 	struct ieee80211_sub_if_data *sdata = link->sdata;
2155 	struct ieee80211_bss_conf *link_conf = link->conf;
2156 	struct ieee80211_local *local = sdata->local;
2157 	struct ieee80211_chanctx_conf *conf;
2158 	struct ieee80211_chanctx *ctx;
2159 	bool use_reserved_switch = false;
2160 
2161 	lockdep_assert_wiphy(local->hw.wiphy);
2162 
2163 	conf = rcu_dereference_protected(link_conf->chanctx_conf,
2164 					 lockdep_is_held(&local->hw.wiphy->mtx));
2165 	if (!conf)
2166 		return;
2167 
2168 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
2169 
2170 	if (link->reserved_chanctx) {
2171 		if (link->reserved_chanctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER &&
2172 		    ieee80211_chanctx_num_reserved(local, link->reserved_chanctx) > 1)
2173 			use_reserved_switch = true;
2174 
2175 		ieee80211_link_unreserve_chanctx(link);
2176 	}
2177 
2178 	ieee80211_assign_link_chanctx(link, NULL, false);
2179 	if (ieee80211_chanctx_refcount(local, ctx) == 0)
2180 		ieee80211_free_chanctx(local, ctx, skip_idle_recalc);
2181 
2182 	link->radar_required = false;
2183 
2184 	/* Unreserving may ready an in-place reservation. */
2185 	if (use_reserved_switch)
2186 		ieee80211_vif_use_reserved_switch(local);
2187 }
2188 
2189 struct ieee80211_chanctx *
2190 ieee80211_find_or_create_chanctx(struct ieee80211_sub_if_data *sdata,
2191 				 const struct ieee80211_chan_req *chanreq,
2192 				 enum ieee80211_chanctx_mode mode,
2193 				 bool assign_on_failure,
2194 				 bool *reused_ctx)
2195 {
2196 	struct ieee80211_local *local = sdata->local;
2197 	struct ieee80211_chanctx *ctx;
2198 	int radio_idx;
2199 
2200 	lockdep_assert_wiphy(local->hw.wiphy);
2201 
2202 	ctx = ieee80211_find_chanctx(local, chanreq, mode);
2203 	if (ctx) {
2204 		*reused_ctx = true;
2205 		return ctx;
2206 	}
2207 
2208 	*reused_ctx = false;
2209 
2210 	if (!ieee80211_find_available_radio(local, chanreq,
2211 					    sdata->wdev.radio_mask,
2212 					    &radio_idx))
2213 		return ERR_PTR(-EBUSY);
2214 
2215 	return ieee80211_new_chanctx(local, chanreq, mode,
2216 				     assign_on_failure, radio_idx);
2217 }
2218 
2219 static bool
2220 ieee80211_nan_evac_chanctx_filter(struct ieee80211_chanctx *ctx,
2221 				  void *filter_data)
2222 {
2223 	return ctx == filter_data;
2224 }
2225 
2226 static int
2227 ieee80211_try_nan_chan_evacuation(struct ieee80211_local *local,
2228 				  struct ieee80211_sub_if_data *sdata,
2229 				  const struct cfg80211_chan_def *chandef,
2230 				  enum ieee80211_chanctx_mode mode,
2231 				  u8 radar_detect_width)
2232 {
2233 	struct ieee80211_sub_if_data *nan_sdata = ieee80211_find_nan_sdata(local);
2234 	struct ieee80211_check_combinations_data comb_data = {
2235 		.chandef = chandef,
2236 		.chanmode = mode,
2237 		.radar_detect = radar_detect_width,
2238 		.radio_idx = -1,
2239 		.chanctx_filter = ieee80211_nan_evac_chanctx_filter,
2240 	};
2241 	struct ieee80211_nan_channel *evac_chan;
2242 	struct ieee80211_chanctx *evac_ctx;
2243 	int ret;
2244 
2245 	if (!nan_sdata)
2246 		return -ENOENT;
2247 
2248 	/* Find an evacuation candidate... */
2249 	evac_chan = ieee80211_nan_find_evac_chan(local, nan_sdata, NULL);
2250 	if (!evac_chan || WARN_ON(!evac_chan->chanctx_conf))
2251 		return -ENOENT;
2252 
2253 	evac_ctx = container_of(evac_chan->chanctx_conf,
2254 				struct ieee80211_chanctx, conf);
2255 
2256 	/*
2257 	 * ... check combinations assuming to-be-evacuated ctx is already
2258 	 * released
2259 	 */
2260 	comb_data.filter_data = evac_ctx;
2261 	ret = ieee80211_check_combinations_ext(sdata, &comb_data);
2262 	if (ret < 0)
2263 		return ret;
2264 
2265 	/* That helped! Let's evacuate the channel */
2266 	ieee80211_nan_evacuate_channel(nan_sdata, evac_chan);
2267 
2268 	/* Re-check, just to be on the safe-side */
2269 	ret = ieee80211_check_combinations(sdata, chandef, mode,
2270 					   radar_detect_width, -1);
2271 
2272 	/* That shouldn't happen, we checked before! */
2273 	WARN_ON(ret);
2274 	return ret;
2275 }
2276 
2277 int _ieee80211_link_use_channel(struct ieee80211_link_data *link,
2278 				const struct ieee80211_chan_req *chanreq,
2279 				enum ieee80211_chanctx_mode mode,
2280 				bool assign_on_failure)
2281 {
2282 	struct ieee80211_sub_if_data *sdata = link->sdata;
2283 	struct ieee80211_local *local = sdata->local;
2284 	struct ieee80211_chanctx *ctx;
2285 	u8 radar_detect_width = 0;
2286 	bool reused_ctx = false;
2287 	int ret;
2288 
2289 	lockdep_assert_wiphy(local->hw.wiphy);
2290 
2291 	if (!ieee80211_vif_link_active(&sdata->vif, link->link_id)) {
2292 		ieee80211_link_update_chanreq(link, chanreq);
2293 		return 0;
2294 	}
2295 
2296 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
2297 					    &chanreq->oper,
2298 					    sdata->wdev.iftype);
2299 	if (ret < 0)
2300 		goto out;
2301 	if (ret > 0)
2302 		radar_detect_width = BIT(chanreq->oper.width);
2303 
2304 	link->radar_required = ret;
2305 
2306 	ret = ieee80211_check_combinations(sdata, &chanreq->oper, mode,
2307 					   radar_detect_width, -1);
2308 	if (ret < 0) {
2309 		/* Let's check if evacuating a NAN channel will help */
2310 		ret = ieee80211_try_nan_chan_evacuation(local, sdata,
2311 							&chanreq->oper,
2312 							mode,
2313 							radar_detect_width);
2314 		if (ret < 0)
2315 			goto out;
2316 	}
2317 
2318 	if (!local->in_reconfig)
2319 		__ieee80211_link_release_channel(link, false);
2320 
2321 	ctx = ieee80211_find_or_create_chanctx(sdata, chanreq, mode,
2322 					       assign_on_failure, &reused_ctx);
2323 	if (IS_ERR(ctx)) {
2324 		ret = PTR_ERR(ctx);
2325 		goto out;
2326 	}
2327 
2328 	ieee80211_link_update_chanreq(link, chanreq);
2329 
2330 	ret = ieee80211_assign_link_chanctx(link, ctx, assign_on_failure);
2331 
2332 	/*
2333 	 * In case an existing channel context is being used, we marked it as
2334 	 * will_be_used, now that it is assigned - clear this indication
2335 	 */
2336 	if (reused_ctx) {
2337 		WARN_ON(!ctx->will_be_used);
2338 		ctx->will_be_used = false;
2339 	}
2340 
2341 	if (ret) {
2342 		/* if assign fails refcount stays the same */
2343 		if (ieee80211_chanctx_refcount(local, ctx) == 0)
2344 			ieee80211_free_chanctx(local, ctx, false);
2345 		goto out;
2346 	}
2347 
2348 	ieee80211_recalc_smps_chanctx(local, ctx);
2349 	ieee80211_recalc_radar_chanctx(local, ctx);
2350  out:
2351 	if (ret)
2352 		link->radar_required = false;
2353 
2354 	return ret;
2355 }
2356 
2357 int ieee80211_link_use_reserved_context(struct ieee80211_link_data *link)
2358 {
2359 	struct ieee80211_sub_if_data *sdata = link->sdata;
2360 	struct ieee80211_local *local = sdata->local;
2361 	struct ieee80211_chanctx *new_ctx;
2362 	struct ieee80211_chanctx *old_ctx;
2363 	int err;
2364 
2365 	lockdep_assert_wiphy(local->hw.wiphy);
2366 
2367 	new_ctx = link->reserved_chanctx;
2368 	old_ctx = ieee80211_link_get_chanctx(link);
2369 
2370 	if (WARN_ON(!new_ctx))
2371 		return -EINVAL;
2372 
2373 	if (WARN_ON(new_ctx->replace_state ==
2374 		    IEEE80211_CHANCTX_WILL_BE_REPLACED))
2375 		return -EINVAL;
2376 
2377 	if (WARN_ON(link->reserved_ready))
2378 		return -EINVAL;
2379 
2380 	link->reserved_ready = true;
2381 
2382 	if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
2383 		if (old_ctx)
2384 			return ieee80211_link_use_reserved_reassign(link);
2385 
2386 		return ieee80211_link_use_reserved_assign(link);
2387 	}
2388 
2389 	/*
2390 	 * In-place reservation may need to be finalized now either if:
2391 	 *  a) sdata is taking part in the swapping itself and is the last one
2392 	 *  b) sdata has switched with a re-assign reservation to an existing
2393 	 *     context readying in-place switching of old_ctx
2394 	 *
2395 	 * In case of (b) do not propagate the error up because the requested
2396 	 * sdata already switched successfully. Just spill an extra warning.
2397 	 * The ieee80211_vif_use_reserved_switch() already stops all necessary
2398 	 * interfaces upon failure.
2399 	 */
2400 	if ((old_ctx &&
2401 	     old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
2402 	    new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
2403 		err = ieee80211_vif_use_reserved_switch(local);
2404 		if (err && err != -EAGAIN) {
2405 			if (new_ctx->replace_state ==
2406 			    IEEE80211_CHANCTX_REPLACES_OTHER)
2407 				return err;
2408 
2409 			wiphy_info(local->hw.wiphy,
2410 				   "depending in-place reservation failed (err=%d)\n",
2411 				   err);
2412 		}
2413 	}
2414 
2415 	return 0;
2416 }
2417 
2418 int ieee80211_link_change_chanreq(struct ieee80211_link_data *link,
2419 				  const struct ieee80211_chan_req *chanreq,
2420 				  u64 *changed)
2421 {
2422 	struct ieee80211_sub_if_data *sdata = link->sdata;
2423 	struct ieee80211_bss_conf *link_conf = link->conf;
2424 	struct ieee80211_local *local = sdata->local;
2425 	struct ieee80211_chanctx_conf *conf;
2426 	struct ieee80211_chanctx *ctx;
2427 	const struct ieee80211_chan_req *compat;
2428 	struct ieee80211_chan_req tmp;
2429 
2430 	lockdep_assert_wiphy(local->hw.wiphy);
2431 
2432 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy,
2433 				     &chanreq->oper,
2434 				     IEEE80211_CHAN_DISABLED))
2435 		return -EINVAL;
2436 
2437 	/* for non-HT 20 MHz the rest doesn't matter */
2438 	if (chanreq->oper.width == NL80211_CHAN_WIDTH_20_NOHT &&
2439 	    cfg80211_chandef_identical(&chanreq->oper, &link_conf->chanreq.oper))
2440 		return 0;
2441 
2442 	/* but you cannot switch to/from it */
2443 	if (chanreq->oper.width == NL80211_CHAN_WIDTH_20_NOHT ||
2444 	    link_conf->chanreq.oper.width == NL80211_CHAN_WIDTH_20_NOHT)
2445 		return -EINVAL;
2446 
2447 	conf = rcu_dereference_protected(link_conf->chanctx_conf,
2448 					 lockdep_is_held(&local->hw.wiphy->mtx));
2449 	if (!conf)
2450 		return -EINVAL;
2451 
2452 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
2453 
2454 	compat = _ieee80211_chanctx_compatible(local, link, ctx, chanreq, &tmp);
2455 	if (!compat)
2456 		return -EINVAL;
2457 
2458 	switch (ctx->replace_state) {
2459 	case IEEE80211_CHANCTX_REPLACE_NONE:
2460 		if (!ieee80211_chanctx_reserved_chanreq(local, ctx, compat,
2461 							&tmp))
2462 			return -EBUSY;
2463 		break;
2464 	case IEEE80211_CHANCTX_WILL_BE_REPLACED:
2465 		/* TODO: Perhaps the bandwidth change could be treated as a
2466 		 * reservation itself? */
2467 		return -EBUSY;
2468 	case IEEE80211_CHANCTX_REPLACES_OTHER:
2469 		/* channel context that is going to replace another channel
2470 		 * context doesn't really exist and shouldn't be assigned
2471 		 * anywhere yet */
2472 		WARN_ON(1);
2473 		break;
2474 	}
2475 
2476 	ieee80211_link_update_chanreq(link, chanreq);
2477 
2478 	ieee80211_recalc_chanctx_chantype(local, ctx);
2479 
2480 	*changed |= BSS_CHANGED_BANDWIDTH;
2481 	return 0;
2482 }
2483 
2484 void ieee80211_link_release_channel(struct ieee80211_link_data *link)
2485 {
2486 	struct ieee80211_sub_if_data *sdata = link->sdata;
2487 
2488 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2489 		return;
2490 
2491 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
2492 
2493 	if (rcu_access_pointer(link->conf->chanctx_conf))
2494 		__ieee80211_link_release_channel(link, false);
2495 }
2496 
2497 void ieee80211_link_vlan_copy_chanctx(struct ieee80211_link_data *link)
2498 {
2499 	struct ieee80211_sub_if_data *sdata = link->sdata;
2500 	unsigned int link_id = link->link_id;
2501 	struct ieee80211_bss_conf *link_conf = link->conf;
2502 	struct ieee80211_bss_conf *ap_conf;
2503 	struct ieee80211_local *local = sdata->local;
2504 	struct ieee80211_sub_if_data *ap;
2505 	struct ieee80211_chanctx_conf *conf;
2506 
2507 	lockdep_assert_wiphy(local->hw.wiphy);
2508 
2509 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
2510 		return;
2511 
2512 	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
2513 
2514 	ap_conf = wiphy_dereference(local->hw.wiphy,
2515 				    ap->vif.link_conf[link_id]);
2516 	conf = wiphy_dereference(local->hw.wiphy,
2517 				 ap_conf->chanctx_conf);
2518 	rcu_assign_pointer(link_conf->chanctx_conf, conf);
2519 }
2520 
2521 void ieee80211_iter_chan_contexts_atomic(
2522 	struct ieee80211_hw *hw,
2523 	void (*iter)(struct ieee80211_hw *hw,
2524 		     struct ieee80211_chanctx_conf *chanctx_conf,
2525 		     void *data),
2526 	void *iter_data)
2527 {
2528 	struct ieee80211_local *local = hw_to_local(hw);
2529 	struct ieee80211_chanctx *ctx;
2530 
2531 	rcu_read_lock();
2532 	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
2533 		if (ctx->driver_present)
2534 			iter(hw, &ctx->conf, iter_data);
2535 	rcu_read_unlock();
2536 }
2537 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);
2538 
2539 void ieee80211_iter_chan_contexts_mtx(
2540 	struct ieee80211_hw *hw,
2541 	void (*iter)(struct ieee80211_hw *hw,
2542 		     struct ieee80211_chanctx_conf *chanctx_conf,
2543 		     void *data),
2544 	void *iter_data)
2545 {
2546 	struct ieee80211_local *local = hw_to_local(hw);
2547 	struct ieee80211_chanctx *ctx;
2548 
2549 	lockdep_assert_wiphy(hw->wiphy);
2550 
2551 	list_for_each_entry(ctx, &local->chanctx_list, list)
2552 		if (ctx->driver_present)
2553 			iter(hw, &ctx->conf, iter_data);
2554 }
2555 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_mtx);
2556