xref: /linux/net/mac80211/chan.c (revision 8f8d74ee110c02137f5b78ca0a2bd6c10331f267)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * mac80211 - channel management
4  * Copyright 2020 - 2024 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_link_data *link;
19 	int num = 0;
20 
21 	lockdep_assert_wiphy(local->hw.wiphy);
22 
23 	list_for_each_entry(link, &ctx->assigned_links, 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_link_data *link;
33 	int num = 0;
34 
35 	lockdep_assert_wiphy(local->hw.wiphy);
36 
37 	list_for_each_entry(link, &ctx->reserved_links, 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_wiphy(local->hw.wiphy);
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_wiphy(local->hw.wiphy);
66 
67 	return ieee80211_num_chanctx(local) < ieee80211_max_num_channels(local);
68 }
69 
70 static struct ieee80211_chanctx *
71 ieee80211_link_get_chanctx(struct ieee80211_link_data *link)
72 {
73 	struct ieee80211_local *local __maybe_unused = link->sdata->local;
74 	struct ieee80211_chanctx_conf *conf;
75 
76 	conf = rcu_dereference_protected(link->conf->chanctx_conf,
77 					 lockdep_is_held(&local->hw.wiphy->mtx));
78 	if (!conf)
79 		return NULL;
80 
81 	return container_of(conf, struct ieee80211_chanctx, conf);
82 }
83 
84 bool ieee80211_chanreq_identical(const struct ieee80211_chan_req *a,
85 				 const struct ieee80211_chan_req *b)
86 {
87 	if (!cfg80211_chandef_identical(&a->oper, &b->oper))
88 		return false;
89 	if (!a->ap.chan && !b->ap.chan)
90 		return true;
91 	return cfg80211_chandef_identical(&a->ap, &b->ap);
92 }
93 
94 static const struct ieee80211_chan_req *
95 ieee80211_chanreq_compatible(const struct ieee80211_chan_req *a,
96 			     const struct ieee80211_chan_req *b,
97 			     struct ieee80211_chan_req *tmp)
98 {
99 	const struct cfg80211_chan_def *compat;
100 
101 	if (a->ap.chan && b->ap.chan &&
102 	    !cfg80211_chandef_identical(&a->ap, &b->ap))
103 		return NULL;
104 
105 	compat = cfg80211_chandef_compatible(&a->oper, &b->oper);
106 	if (!compat)
107 		return NULL;
108 
109 	/* Note: later code assumes this always fills & returns tmp if compat */
110 	tmp->oper = *compat;
111 	tmp->ap = a->ap.chan ? a->ap : b->ap;
112 	return tmp;
113 }
114 
115 static const struct ieee80211_chan_req *
116 ieee80211_chanctx_compatible(struct ieee80211_chanctx *ctx,
117 			     const struct ieee80211_chan_req *req,
118 			     struct ieee80211_chan_req *tmp)
119 {
120 	const struct ieee80211_chan_req *ret;
121 	struct ieee80211_chan_req tmp2;
122 
123 	*tmp = (struct ieee80211_chan_req){
124 		.oper = ctx->conf.def,
125 		.ap = ctx->conf.ap,
126 	};
127 
128 	ret = ieee80211_chanreq_compatible(tmp, req, &tmp2);
129 	if (!ret)
130 		return NULL;
131 	*tmp = *ret;
132 	return tmp;
133 }
134 
135 static const struct ieee80211_chan_req *
136 ieee80211_chanctx_reserved_chanreq(struct ieee80211_local *local,
137 				   struct ieee80211_chanctx *ctx,
138 				   const struct ieee80211_chan_req *req,
139 				   struct ieee80211_chan_req *tmp)
140 {
141 	struct ieee80211_link_data *link;
142 
143 	lockdep_assert_wiphy(local->hw.wiphy);
144 
145 	if (WARN_ON(!req))
146 		return NULL;
147 
148 	list_for_each_entry(link, &ctx->reserved_links, reserved_chanctx_list) {
149 		req = ieee80211_chanreq_compatible(&link->reserved, req, tmp);
150 		if (!req)
151 			break;
152 	}
153 
154 	return req;
155 }
156 
157 static const struct ieee80211_chan_req *
158 ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local *local,
159 				       struct ieee80211_chanctx *ctx,
160 				       const struct ieee80211_chan_req *compat,
161 				       struct ieee80211_chan_req *tmp)
162 {
163 	struct ieee80211_link_data *link;
164 	const struct ieee80211_chan_req *comp_def = compat;
165 
166 	lockdep_assert_wiphy(local->hw.wiphy);
167 
168 	list_for_each_entry(link, &ctx->assigned_links, assigned_chanctx_list) {
169 		struct ieee80211_bss_conf *link_conf = link->conf;
170 
171 		if (link->reserved_chanctx)
172 			continue;
173 
174 		comp_def = ieee80211_chanreq_compatible(&link_conf->chanreq,
175 							comp_def, tmp);
176 		if (!comp_def)
177 			break;
178 	}
179 
180 	return comp_def;
181 }
182 
183 static bool
184 ieee80211_chanctx_can_reserve(struct ieee80211_local *local,
185 			      struct ieee80211_chanctx *ctx,
186 			      const struct ieee80211_chan_req *req)
187 {
188 	struct ieee80211_chan_req tmp;
189 
190 	lockdep_assert_wiphy(local->hw.wiphy);
191 
192 	if (!ieee80211_chanctx_reserved_chanreq(local, ctx, req, &tmp))
193 		return false;
194 
195 	if (!ieee80211_chanctx_non_reserved_chandef(local, ctx, req, &tmp))
196 		return false;
197 
198 	if (!list_empty(&ctx->reserved_links) &&
199 	    ieee80211_chanctx_reserved_chanreq(local, ctx, req, &tmp))
200 		return true;
201 
202 	return false;
203 }
204 
205 static struct ieee80211_chanctx *
206 ieee80211_find_reservation_chanctx(struct ieee80211_local *local,
207 				   const struct ieee80211_chan_req *chanreq,
208 				   enum ieee80211_chanctx_mode mode)
209 {
210 	struct ieee80211_chanctx *ctx;
211 
212 	lockdep_assert_wiphy(local->hw.wiphy);
213 
214 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
215 		return NULL;
216 
217 	list_for_each_entry(ctx, &local->chanctx_list, list) {
218 		if (ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED)
219 			continue;
220 
221 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
222 			continue;
223 
224 		if (!ieee80211_chanctx_can_reserve(local, ctx, chanreq))
225 			continue;
226 
227 		return ctx;
228 	}
229 
230 	return NULL;
231 }
232 
233 static enum nl80211_chan_width ieee80211_get_sta_bw(struct sta_info *sta,
234 						    unsigned int link_id)
235 {
236 	enum ieee80211_sta_rx_bandwidth width;
237 	struct link_sta_info *link_sta;
238 
239 	link_sta = wiphy_dereference(sta->local->hw.wiphy, sta->link[link_id]);
240 
241 	/* no effect if this STA has no presence on this link */
242 	if (!link_sta)
243 		return NL80211_CHAN_WIDTH_20_NOHT;
244 
245 	width = ieee80211_sta_cap_rx_bw(link_sta);
246 
247 	switch (width) {
248 	case IEEE80211_STA_RX_BW_20:
249 		if (link_sta->pub->ht_cap.ht_supported)
250 			return NL80211_CHAN_WIDTH_20;
251 		else
252 			return NL80211_CHAN_WIDTH_20_NOHT;
253 	case IEEE80211_STA_RX_BW_40:
254 		return NL80211_CHAN_WIDTH_40;
255 	case IEEE80211_STA_RX_BW_80:
256 		return NL80211_CHAN_WIDTH_80;
257 	case IEEE80211_STA_RX_BW_160:
258 		/*
259 		 * This applied for both 160 and 80+80. since we use
260 		 * the returned value to consider degradation of
261 		 * ctx->conf.min_def, we have to make sure to take
262 		 * the bigger one (NL80211_CHAN_WIDTH_160).
263 		 * Otherwise we might try degrading even when not
264 		 * needed, as the max required sta_bw returned (80+80)
265 		 * might be smaller than the configured bw (160).
266 		 */
267 		return NL80211_CHAN_WIDTH_160;
268 	case IEEE80211_STA_RX_BW_320:
269 		return NL80211_CHAN_WIDTH_320;
270 	default:
271 		WARN_ON(1);
272 		return NL80211_CHAN_WIDTH_20;
273 	}
274 }
275 
276 static enum nl80211_chan_width
277 ieee80211_get_max_required_bw(struct ieee80211_link_data *link)
278 {
279 	struct ieee80211_sub_if_data *sdata = link->sdata;
280 	unsigned int link_id = link->link_id;
281 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
282 	struct sta_info *sta;
283 
284 	list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
285 		if (sdata != sta->sdata &&
286 		    !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
287 			continue;
288 
289 		max_bw = max(max_bw, ieee80211_get_sta_bw(sta, link_id));
290 	}
291 
292 	return max_bw;
293 }
294 
295 static enum nl80211_chan_width
296 ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
297 				      struct ieee80211_chanctx *ctx,
298 				      struct ieee80211_link_data *rsvd_for)
299 {
300 	struct ieee80211_sub_if_data *sdata;
301 	struct ieee80211_link_data *link;
302 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
303 
304 	for_each_sdata_link(local, link) {
305 		enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT;
306 
307 		if (link != rsvd_for &&
308 		    rcu_access_pointer(link->conf->chanctx_conf) != &ctx->conf)
309 			continue;
310 
311 		switch (link->sdata->vif.type) {
312 		case NL80211_IFTYPE_AP:
313 		case NL80211_IFTYPE_AP_VLAN:
314 			width = ieee80211_get_max_required_bw(link);
315 			break;
316 		case NL80211_IFTYPE_STATION:
317 			/*
318 			 * The ap's sta->bandwidth is not set yet at this
319 			 * point, so take the width from the chandef, but
320 			 * account also for TDLS peers
321 			 */
322 			width = max(link->conf->chanreq.oper.width,
323 				    ieee80211_get_max_required_bw(link));
324 			break;
325 		case NL80211_IFTYPE_P2P_DEVICE:
326 		case NL80211_IFTYPE_NAN:
327 			continue;
328 		case NL80211_IFTYPE_ADHOC:
329 		case NL80211_IFTYPE_MESH_POINT:
330 		case NL80211_IFTYPE_OCB:
331 			width = link->conf->chanreq.oper.width;
332 			break;
333 		case NL80211_IFTYPE_WDS:
334 		case NL80211_IFTYPE_UNSPECIFIED:
335 		case NUM_NL80211_IFTYPES:
336 		case NL80211_IFTYPE_MONITOR:
337 		case NL80211_IFTYPE_P2P_CLIENT:
338 		case NL80211_IFTYPE_P2P_GO:
339 			WARN_ON_ONCE(1);
340 		}
341 
342 		max_bw = max(max_bw, width);
343 	}
344 
345 	/* use the configured bandwidth in case of monitor interface */
346 	sdata = wiphy_dereference(local->hw.wiphy, local->monitor_sdata);
347 	if (sdata &&
348 	    rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) == &ctx->conf)
349 		max_bw = max(max_bw, ctx->conf.def.width);
350 
351 	return max_bw;
352 }
353 
354 /*
355  * recalc the min required chan width of the channel context, which is
356  * the max of min required widths of all the interfaces bound to this
357  * channel context.
358  */
359 static u32
360 _ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
361 				  struct ieee80211_chanctx *ctx,
362 				  struct ieee80211_link_data *rsvd_for)
363 {
364 	enum nl80211_chan_width max_bw;
365 	struct cfg80211_chan_def min_def;
366 
367 	lockdep_assert_wiphy(local->hw.wiphy);
368 
369 	/* don't optimize non-20MHz based and radar_enabled confs */
370 	if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
371 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
372 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_1 ||
373 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_2 ||
374 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_4 ||
375 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_8 ||
376 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_16 ||
377 	    ctx->conf.radar_enabled) {
378 		ctx->conf.min_def = ctx->conf.def;
379 		return 0;
380 	}
381 
382 	max_bw = ieee80211_get_chanctx_max_required_bw(local, ctx, rsvd_for);
383 
384 	/* downgrade chandef up to max_bw */
385 	min_def = ctx->conf.def;
386 	while (min_def.width > max_bw)
387 		ieee80211_chandef_downgrade(&min_def, NULL);
388 
389 	if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
390 		return 0;
391 
392 	ctx->conf.min_def = min_def;
393 	if (!ctx->driver_present)
394 		return 0;
395 
396 	return IEEE80211_CHANCTX_CHANGE_MIN_WIDTH;
397 }
398 
399 /* calling this function is assuming that station vif is updated to
400  * lates changes by calling ieee80211_link_update_chanreq
401  */
402 static void ieee80211_chan_bw_change(struct ieee80211_local *local,
403 				     struct ieee80211_chanctx *ctx,
404 				     bool narrowed)
405 {
406 	struct sta_info *sta;
407 	struct ieee80211_supported_band *sband =
408 		local->hw.wiphy->bands[ctx->conf.def.chan->band];
409 
410 	rcu_read_lock();
411 	list_for_each_entry_rcu(sta, &local->sta_list,
412 				list) {
413 		struct ieee80211_sub_if_data *sdata = sta->sdata;
414 		enum ieee80211_sta_rx_bandwidth new_sta_bw;
415 		unsigned int link_id;
416 
417 		if (!ieee80211_sdata_running(sta->sdata))
418 			continue;
419 
420 		for (link_id = 0; link_id < ARRAY_SIZE(sta->sdata->link); link_id++) {
421 			struct ieee80211_bss_conf *link_conf =
422 				rcu_dereference(sdata->vif.link_conf[link_id]);
423 			struct link_sta_info *link_sta;
424 
425 			if (!link_conf)
426 				continue;
427 
428 			if (rcu_access_pointer(link_conf->chanctx_conf) != &ctx->conf)
429 				continue;
430 
431 			link_sta = rcu_dereference(sta->link[link_id]);
432 			if (!link_sta)
433 				continue;
434 
435 			new_sta_bw = ieee80211_sta_cur_vht_bw(link_sta);
436 
437 			/* nothing change */
438 			if (new_sta_bw == link_sta->pub->bandwidth)
439 				continue;
440 
441 			/* vif changed to narrow BW and narrow BW for station wasn't
442 			 * requested or vise versa */
443 			if ((new_sta_bw < link_sta->pub->bandwidth) == !narrowed)
444 				continue;
445 
446 			link_sta->pub->bandwidth = new_sta_bw;
447 			rate_control_rate_update(local, sband, sta, link_id,
448 						 IEEE80211_RC_BW_CHANGED);
449 		}
450 	}
451 	rcu_read_unlock();
452 }
453 
454 /*
455  * recalc the min required chan width of the channel context, which is
456  * the max of min required widths of all the interfaces bound to this
457  * channel context.
458  */
459 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
460 				      struct ieee80211_chanctx *ctx,
461 				      struct ieee80211_link_data *rsvd_for)
462 {
463 	u32 changed = _ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for);
464 
465 	if (!changed)
466 		return;
467 
468 	/* check is BW narrowed */
469 	ieee80211_chan_bw_change(local, ctx, true);
470 
471 	drv_change_chanctx(local, ctx, changed);
472 
473 	/* check is BW wider */
474 	ieee80211_chan_bw_change(local, ctx, false);
475 }
476 
477 static void _ieee80211_change_chanctx(struct ieee80211_local *local,
478 				      struct ieee80211_chanctx *ctx,
479 				      struct ieee80211_chanctx *old_ctx,
480 				      const struct ieee80211_chan_req *chanreq,
481 				      struct ieee80211_link_data *rsvd_for)
482 {
483 	const struct cfg80211_chan_def *chandef = &chanreq->oper;
484 	struct ieee80211_chan_req ctx_req = {
485 		.oper = ctx->conf.def,
486 		.ap = ctx->conf.ap,
487 	};
488 	u32 changed = 0;
489 
490 	/* expected to handle only 20/40/80/160/320 channel widths */
491 	switch (chandef->width) {
492 	case NL80211_CHAN_WIDTH_20_NOHT:
493 	case NL80211_CHAN_WIDTH_20:
494 	case NL80211_CHAN_WIDTH_40:
495 	case NL80211_CHAN_WIDTH_80:
496 	case NL80211_CHAN_WIDTH_80P80:
497 	case NL80211_CHAN_WIDTH_160:
498 	case NL80211_CHAN_WIDTH_320:
499 		break;
500 	default:
501 		WARN_ON(1);
502 	}
503 
504 	/* Check maybe BW narrowed - we do this _before_ calling recalc_chanctx_min_def
505 	 * due to maybe not returning from it, e.g in case new context was added
506 	 * first time with all parameters up to date.
507 	 */
508 	ieee80211_chan_bw_change(local, old_ctx, true);
509 
510 	if (ieee80211_chanreq_identical(&ctx_req, chanreq)) {
511 		ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for);
512 		return;
513 	}
514 
515 	WARN_ON(ieee80211_chanctx_refcount(local, ctx) > 1 &&
516 		!cfg80211_chandef_compatible(&ctx->conf.def, &chanreq->oper));
517 
518 	ieee80211_remove_wbrf(local, &ctx->conf.def);
519 
520 	if (!cfg80211_chandef_identical(&ctx->conf.def, &chanreq->oper)) {
521 		if (ctx->conf.def.width != chanreq->oper.width)
522 			changed |= IEEE80211_CHANCTX_CHANGE_WIDTH;
523 		if (ctx->conf.def.punctured != chanreq->oper.punctured)
524 			changed |= IEEE80211_CHANCTX_CHANGE_PUNCTURING;
525 	}
526 	if (!cfg80211_chandef_identical(&ctx->conf.ap, &chanreq->ap))
527 		changed |= IEEE80211_CHANCTX_CHANGE_AP;
528 	ctx->conf.def = *chandef;
529 	ctx->conf.ap = chanreq->ap;
530 
531 	/* check if min chanctx also changed */
532 	changed |= _ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for);
533 
534 	ieee80211_add_wbrf(local, &ctx->conf.def);
535 
536 	drv_change_chanctx(local, ctx, changed);
537 
538 	/* check if BW is wider */
539 	ieee80211_chan_bw_change(local, old_ctx, false);
540 }
541 
542 static void ieee80211_change_chanctx(struct ieee80211_local *local,
543 				     struct ieee80211_chanctx *ctx,
544 				     struct ieee80211_chanctx *old_ctx,
545 				     const struct ieee80211_chan_req *chanreq)
546 {
547 	_ieee80211_change_chanctx(local, ctx, old_ctx, chanreq, NULL);
548 }
549 
550 static struct ieee80211_chanctx *
551 ieee80211_find_chanctx(struct ieee80211_local *local,
552 		       const struct ieee80211_chan_req *chanreq,
553 		       enum ieee80211_chanctx_mode mode)
554 {
555 	struct ieee80211_chan_req tmp;
556 	struct ieee80211_chanctx *ctx;
557 
558 	lockdep_assert_wiphy(local->hw.wiphy);
559 
560 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
561 		return NULL;
562 
563 	list_for_each_entry(ctx, &local->chanctx_list, list) {
564 		const struct ieee80211_chan_req *compat;
565 
566 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
567 			continue;
568 
569 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
570 			continue;
571 
572 		compat = ieee80211_chanctx_compatible(ctx, chanreq, &tmp);
573 		if (!compat)
574 			continue;
575 
576 		compat = ieee80211_chanctx_reserved_chanreq(local, ctx,
577 							    compat, &tmp);
578 		if (!compat)
579 			continue;
580 
581 		ieee80211_change_chanctx(local, ctx, ctx, compat);
582 
583 		return ctx;
584 	}
585 
586 	return NULL;
587 }
588 
589 bool ieee80211_is_radar_required(struct ieee80211_local *local)
590 {
591 	struct ieee80211_link_data *link;
592 
593 	lockdep_assert_wiphy(local->hw.wiphy);
594 
595 	for_each_sdata_link(local, link) {
596 		if (link->radar_required)
597 			return true;
598 	}
599 
600 	return false;
601 }
602 
603 static bool
604 ieee80211_chanctx_radar_required(struct ieee80211_local *local,
605 				 struct ieee80211_chanctx *ctx)
606 {
607 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
608 	struct ieee80211_link_data *link;
609 
610 	lockdep_assert_wiphy(local->hw.wiphy);
611 
612 	for_each_sdata_link(local, link) {
613 		if (rcu_access_pointer(link->conf->chanctx_conf) != conf)
614 			continue;
615 		if (!link->radar_required)
616 			continue;
617 		return true;
618 	}
619 
620 	return false;
621 }
622 
623 static struct ieee80211_chanctx *
624 ieee80211_alloc_chanctx(struct ieee80211_local *local,
625 			const struct ieee80211_chan_req *chanreq,
626 			enum ieee80211_chanctx_mode mode)
627 {
628 	struct ieee80211_chanctx *ctx;
629 
630 	lockdep_assert_wiphy(local->hw.wiphy);
631 
632 	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
633 	if (!ctx)
634 		return NULL;
635 
636 	INIT_LIST_HEAD(&ctx->assigned_links);
637 	INIT_LIST_HEAD(&ctx->reserved_links);
638 	ctx->conf.def = chanreq->oper;
639 	ctx->conf.ap = chanreq->ap;
640 	ctx->conf.rx_chains_static = 1;
641 	ctx->conf.rx_chains_dynamic = 1;
642 	ctx->mode = mode;
643 	ctx->conf.radar_enabled = false;
644 	_ieee80211_recalc_chanctx_min_def(local, ctx, NULL);
645 
646 	return ctx;
647 }
648 
649 static int ieee80211_add_chanctx(struct ieee80211_local *local,
650 				 struct ieee80211_chanctx *ctx)
651 {
652 	u32 changed;
653 	int err;
654 
655 	lockdep_assert_wiphy(local->hw.wiphy);
656 
657 	ieee80211_add_wbrf(local, &ctx->conf.def);
658 
659 	/* turn idle off *before* setting channel -- some drivers need that */
660 	changed = ieee80211_idle_off(local);
661 	if (changed)
662 		ieee80211_hw_config(local, changed);
663 
664 	err = drv_add_chanctx(local, ctx);
665 	if (err) {
666 		ieee80211_recalc_idle(local);
667 		return err;
668 	}
669 
670 	return 0;
671 }
672 
673 static struct ieee80211_chanctx *
674 ieee80211_new_chanctx(struct ieee80211_local *local,
675 		      const struct ieee80211_chan_req *chanreq,
676 		      enum ieee80211_chanctx_mode mode)
677 {
678 	struct ieee80211_chanctx *ctx;
679 	int err;
680 
681 	lockdep_assert_wiphy(local->hw.wiphy);
682 
683 	ctx = ieee80211_alloc_chanctx(local, chanreq, mode);
684 	if (!ctx)
685 		return ERR_PTR(-ENOMEM);
686 
687 	err = ieee80211_add_chanctx(local, ctx);
688 	if (err) {
689 		kfree(ctx);
690 		return ERR_PTR(err);
691 	}
692 
693 	list_add_rcu(&ctx->list, &local->chanctx_list);
694 	return ctx;
695 }
696 
697 static void ieee80211_del_chanctx(struct ieee80211_local *local,
698 				  struct ieee80211_chanctx *ctx)
699 {
700 	lockdep_assert_wiphy(local->hw.wiphy);
701 
702 	drv_remove_chanctx(local, ctx);
703 
704 	ieee80211_recalc_idle(local);
705 
706 	ieee80211_remove_wbrf(local, &ctx->conf.def);
707 }
708 
709 static void ieee80211_free_chanctx(struct ieee80211_local *local,
710 				   struct ieee80211_chanctx *ctx)
711 {
712 	lockdep_assert_wiphy(local->hw.wiphy);
713 
714 	WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
715 
716 	list_del_rcu(&ctx->list);
717 	ieee80211_del_chanctx(local, ctx);
718 	kfree_rcu(ctx, rcu_head);
719 }
720 
721 void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
722 				       struct ieee80211_chanctx *ctx)
723 {
724 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
725 	const struct ieee80211_chan_req *compat = NULL;
726 	struct ieee80211_link_data *link;
727 	struct ieee80211_chan_req tmp;
728 	struct sta_info *sta;
729 
730 	lockdep_assert_wiphy(local->hw.wiphy);
731 
732 	for_each_sdata_link(local, link) {
733 		struct ieee80211_bss_conf *link_conf;
734 
735 		if (link->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
736 			continue;
737 
738 		link_conf = link->conf;
739 
740 		if (rcu_access_pointer(link_conf->chanctx_conf) != conf)
741 			continue;
742 
743 		if (!compat)
744 			compat = &link_conf->chanreq;
745 
746 		compat = ieee80211_chanreq_compatible(&link_conf->chanreq,
747 						      compat, &tmp);
748 		if (WARN_ON_ONCE(!compat))
749 			return;
750 	}
751 
752 	if (WARN_ON_ONCE(!compat))
753 		return;
754 
755 	/* TDLS peers can sometimes affect the chandef width */
756 	list_for_each_entry(sta, &local->sta_list, list) {
757 		struct ieee80211_chan_req tdls_chanreq = {};
758 		if (!sta->uploaded ||
759 		    !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
760 		    !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
761 		    !sta->tdls_chandef.chan)
762 			continue;
763 
764 		tdls_chanreq.oper = sta->tdls_chandef;
765 
766 		/* note this always fills and returns &tmp if compat */
767 		compat = ieee80211_chanreq_compatible(&tdls_chanreq,
768 						      compat, &tmp);
769 		if (WARN_ON_ONCE(!compat))
770 			return;
771 	}
772 
773 	ieee80211_change_chanctx(local, ctx, ctx, compat);
774 }
775 
776 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
777 					   struct ieee80211_chanctx *chanctx)
778 {
779 	bool radar_enabled;
780 
781 	lockdep_assert_wiphy(local->hw.wiphy);
782 
783 	radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
784 
785 	if (radar_enabled == chanctx->conf.radar_enabled)
786 		return;
787 
788 	chanctx->conf.radar_enabled = radar_enabled;
789 
790 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
791 }
792 
793 static int ieee80211_assign_link_chanctx(struct ieee80211_link_data *link,
794 					 struct ieee80211_chanctx *new_ctx)
795 {
796 	struct ieee80211_sub_if_data *sdata = link->sdata;
797 	struct ieee80211_local *local = sdata->local;
798 	struct ieee80211_chanctx_conf *conf;
799 	struct ieee80211_chanctx *curr_ctx = NULL;
800 	bool new_idle;
801 	int ret = 0;
802 
803 	if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN))
804 		return -EOPNOTSUPP;
805 
806 	conf = rcu_dereference_protected(link->conf->chanctx_conf,
807 					 lockdep_is_held(&local->hw.wiphy->mtx));
808 
809 	if (conf) {
810 		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
811 
812 		drv_unassign_vif_chanctx(local, sdata, link->conf, curr_ctx);
813 		conf = NULL;
814 		list_del(&link->assigned_chanctx_list);
815 	}
816 
817 	if (new_ctx) {
818 		/* recalc considering the link we'll use it for now */
819 		ieee80211_recalc_chanctx_min_def(local, new_ctx, link);
820 
821 		ret = drv_assign_vif_chanctx(local, sdata, link->conf, new_ctx);
822 		if (ret)
823 			goto out;
824 
825 		conf = &new_ctx->conf;
826 		list_add(&link->assigned_chanctx_list,
827 			 &new_ctx->assigned_links);
828 	}
829 
830 out:
831 	rcu_assign_pointer(link->conf->chanctx_conf, conf);
832 
833 	if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
834 		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
835 		ieee80211_recalc_smps_chanctx(local, curr_ctx);
836 		ieee80211_recalc_radar_chanctx(local, curr_ctx);
837 		ieee80211_recalc_chanctx_min_def(local, curr_ctx, NULL);
838 	}
839 
840 	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
841 		ieee80211_recalc_txpower(sdata, false);
842 		ieee80211_recalc_chanctx_min_def(local, new_ctx, NULL);
843 	}
844 
845 	if (conf) {
846 		new_idle = false;
847 	} else {
848 		struct ieee80211_link_data *tmp;
849 
850 		new_idle = true;
851 		for_each_sdata_link(local, tmp) {
852 			if (rcu_access_pointer(tmp->conf->chanctx_conf)) {
853 				new_idle = false;
854 				break;
855 			}
856 		}
857 	}
858 
859 	if (new_idle != sdata->vif.cfg.idle) {
860 		sdata->vif.cfg.idle = new_idle;
861 
862 		if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
863 		    sdata->vif.type != NL80211_IFTYPE_MONITOR)
864 			ieee80211_vif_cfg_change_notify(sdata, BSS_CHANGED_IDLE);
865 	}
866 
867 	ieee80211_check_fast_xmit_iface(sdata);
868 
869 	return ret;
870 }
871 
872 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
873 				   struct ieee80211_chanctx *chanctx)
874 {
875 	struct ieee80211_sub_if_data *sdata;
876 	u8 rx_chains_static, rx_chains_dynamic;
877 	struct ieee80211_link_data *link;
878 
879 	lockdep_assert_wiphy(local->hw.wiphy);
880 
881 	rx_chains_static = 1;
882 	rx_chains_dynamic = 1;
883 
884 	for_each_sdata_link(local, link) {
885 		u8 needed_static, needed_dynamic;
886 
887 		switch (link->sdata->vif.type) {
888 		case NL80211_IFTYPE_STATION:
889 			if (!link->sdata->u.mgd.associated)
890 				continue;
891 			break;
892 		case NL80211_IFTYPE_AP:
893 		case NL80211_IFTYPE_ADHOC:
894 		case NL80211_IFTYPE_MESH_POINT:
895 		case NL80211_IFTYPE_OCB:
896 			break;
897 		default:
898 			continue;
899 		}
900 
901 		if (rcu_access_pointer(link->conf->chanctx_conf) != &chanctx->conf)
902 			continue;
903 
904 		switch (link->smps_mode) {
905 		default:
906 			WARN_ONCE(1, "Invalid SMPS mode %d\n",
907 				  link->smps_mode);
908 			fallthrough;
909 		case IEEE80211_SMPS_OFF:
910 			needed_static = link->needed_rx_chains;
911 			needed_dynamic = link->needed_rx_chains;
912 			break;
913 		case IEEE80211_SMPS_DYNAMIC:
914 			needed_static = 1;
915 			needed_dynamic = link->needed_rx_chains;
916 			break;
917 		case IEEE80211_SMPS_STATIC:
918 			needed_static = 1;
919 			needed_dynamic = 1;
920 			break;
921 		}
922 
923 		rx_chains_static = max(rx_chains_static, needed_static);
924 		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
925 	}
926 
927 	/* Disable SMPS for the monitor interface */
928 	sdata = wiphy_dereference(local->hw.wiphy, local->monitor_sdata);
929 	if (sdata &&
930 	    rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) == &chanctx->conf)
931 		rx_chains_dynamic = rx_chains_static = local->rx_chains;
932 
933 	if (rx_chains_static == chanctx->conf.rx_chains_static &&
934 	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
935 		return;
936 
937 	chanctx->conf.rx_chains_static = rx_chains_static;
938 	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
939 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
940 }
941 
942 static void
943 __ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link,
944 				       bool clear)
945 {
946 	struct ieee80211_sub_if_data *sdata = link->sdata;
947 	unsigned int link_id = link->link_id;
948 	struct ieee80211_bss_conf *link_conf = link->conf;
949 	struct ieee80211_local *local __maybe_unused = sdata->local;
950 	struct ieee80211_sub_if_data *vlan;
951 	struct ieee80211_chanctx_conf *conf;
952 
953 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
954 		return;
955 
956 	lockdep_assert_wiphy(local->hw.wiphy);
957 
958 	/* Check that conf exists, even when clearing this function
959 	 * must be called with the AP's channel context still there
960 	 * as it would otherwise cause VLANs to have an invalid
961 	 * channel context pointer for a while, possibly pointing
962 	 * to a channel context that has already been freed.
963 	 */
964 	conf = rcu_dereference_protected(link_conf->chanctx_conf,
965 					 lockdep_is_held(&local->hw.wiphy->mtx));
966 	WARN_ON(!conf);
967 
968 	if (clear)
969 		conf = NULL;
970 
971 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
972 		struct ieee80211_bss_conf *vlan_conf;
973 
974 		vlan_conf = wiphy_dereference(local->hw.wiphy,
975 					      vlan->vif.link_conf[link_id]);
976 		if (WARN_ON(!vlan_conf))
977 			continue;
978 
979 		rcu_assign_pointer(vlan_conf->chanctx_conf, conf);
980 	}
981 }
982 
983 void ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link,
984 					  bool clear)
985 {
986 	struct ieee80211_local *local = link->sdata->local;
987 
988 	lockdep_assert_wiphy(local->hw.wiphy);
989 
990 	__ieee80211_link_copy_chanctx_to_vlans(link, clear);
991 }
992 
993 int ieee80211_link_unreserve_chanctx(struct ieee80211_link_data *link)
994 {
995 	struct ieee80211_sub_if_data *sdata = link->sdata;
996 	struct ieee80211_chanctx *ctx = link->reserved_chanctx;
997 
998 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
999 
1000 	if (WARN_ON(!ctx))
1001 		return -EINVAL;
1002 
1003 	list_del(&link->reserved_chanctx_list);
1004 	link->reserved_chanctx = NULL;
1005 
1006 	if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
1007 		if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1008 			if (WARN_ON(!ctx->replace_ctx))
1009 				return -EINVAL;
1010 
1011 			WARN_ON(ctx->replace_ctx->replace_state !=
1012 			        IEEE80211_CHANCTX_WILL_BE_REPLACED);
1013 			WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
1014 
1015 			ctx->replace_ctx->replace_ctx = NULL;
1016 			ctx->replace_ctx->replace_state =
1017 					IEEE80211_CHANCTX_REPLACE_NONE;
1018 
1019 			list_del_rcu(&ctx->list);
1020 			kfree_rcu(ctx, rcu_head);
1021 		} else {
1022 			ieee80211_free_chanctx(sdata->local, ctx);
1023 		}
1024 	}
1025 
1026 	return 0;
1027 }
1028 
1029 int ieee80211_link_reserve_chanctx(struct ieee80211_link_data *link,
1030 				   const struct ieee80211_chan_req *chanreq,
1031 				   enum ieee80211_chanctx_mode mode,
1032 				   bool radar_required)
1033 {
1034 	struct ieee80211_sub_if_data *sdata = link->sdata;
1035 	struct ieee80211_local *local = sdata->local;
1036 	struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
1037 
1038 	lockdep_assert_wiphy(local->hw.wiphy);
1039 
1040 	curr_ctx = ieee80211_link_get_chanctx(link);
1041 	if (curr_ctx && !local->ops->switch_vif_chanctx)
1042 		return -EOPNOTSUPP;
1043 
1044 	new_ctx = ieee80211_find_reservation_chanctx(local, chanreq, mode);
1045 	if (!new_ctx) {
1046 		if (ieee80211_can_create_new_chanctx(local)) {
1047 			new_ctx = ieee80211_new_chanctx(local, chanreq, mode);
1048 			if (IS_ERR(new_ctx))
1049 				return PTR_ERR(new_ctx);
1050 		} else {
1051 			if (!curr_ctx ||
1052 			    (curr_ctx->replace_state ==
1053 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1054 			    !list_empty(&curr_ctx->reserved_links)) {
1055 				/*
1056 				 * Another link already requested this context
1057 				 * for a reservation. Find another one hoping
1058 				 * all links assigned to it will also switch
1059 				 * soon enough.
1060 				 *
1061 				 * TODO: This needs a little more work as some
1062 				 * cases (more than 2 chanctx capable devices)
1063 				 * may fail which could otherwise succeed
1064 				 * provided some channel context juggling was
1065 				 * performed.
1066 				 *
1067 				 * Consider ctx1..3, link1..6, each ctx has 2
1068 				 * links. link1 and link2 from ctx1 request new
1069 				 * different chandefs starting 2 in-place
1070 				 * reserations with ctx4 and ctx5 replacing
1071 				 * ctx1 and ctx2 respectively. Next link5 and
1072 				 * link6 from ctx3 reserve ctx4. If link3 and
1073 				 * link4 remain on ctx2 as they are then this
1074 				 * fails unless `replace_ctx` from ctx5 is
1075 				 * replaced with ctx3.
1076 				 */
1077 				list_for_each_entry(ctx, &local->chanctx_list,
1078 						    list) {
1079 					if (ctx->replace_state !=
1080 					    IEEE80211_CHANCTX_REPLACE_NONE)
1081 						continue;
1082 
1083 					if (!list_empty(&ctx->reserved_links))
1084 						continue;
1085 
1086 					curr_ctx = ctx;
1087 					break;
1088 				}
1089 			}
1090 
1091 			/*
1092 			 * If that's true then all available contexts already
1093 			 * have reservations and cannot be used.
1094 			 */
1095 			if (!curr_ctx ||
1096 			    (curr_ctx->replace_state ==
1097 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1098 			    !list_empty(&curr_ctx->reserved_links))
1099 				return -EBUSY;
1100 
1101 			new_ctx = ieee80211_alloc_chanctx(local, chanreq, mode);
1102 			if (!new_ctx)
1103 				return -ENOMEM;
1104 
1105 			new_ctx->replace_ctx = curr_ctx;
1106 			new_ctx->replace_state =
1107 					IEEE80211_CHANCTX_REPLACES_OTHER;
1108 
1109 			curr_ctx->replace_ctx = new_ctx;
1110 			curr_ctx->replace_state =
1111 					IEEE80211_CHANCTX_WILL_BE_REPLACED;
1112 
1113 			list_add_rcu(&new_ctx->list, &local->chanctx_list);
1114 		}
1115 	}
1116 
1117 	list_add(&link->reserved_chanctx_list, &new_ctx->reserved_links);
1118 	link->reserved_chanctx = new_ctx;
1119 	link->reserved = *chanreq;
1120 	link->reserved_radar_required = radar_required;
1121 	link->reserved_ready = false;
1122 
1123 	return 0;
1124 }
1125 
1126 static void
1127 ieee80211_link_chanctx_reservation_complete(struct ieee80211_link_data *link)
1128 {
1129 	struct ieee80211_sub_if_data *sdata = link->sdata;
1130 
1131 	switch (sdata->vif.type) {
1132 	case NL80211_IFTYPE_ADHOC:
1133 	case NL80211_IFTYPE_AP:
1134 	case NL80211_IFTYPE_MESH_POINT:
1135 	case NL80211_IFTYPE_OCB:
1136 		wiphy_work_queue(sdata->local->hw.wiphy,
1137 				 &link->csa_finalize_work);
1138 		break;
1139 	case NL80211_IFTYPE_STATION:
1140 		wiphy_delayed_work_queue(sdata->local->hw.wiphy,
1141 					 &link->u.mgd.chswitch_work, 0);
1142 		break;
1143 	case NL80211_IFTYPE_UNSPECIFIED:
1144 	case NL80211_IFTYPE_AP_VLAN:
1145 	case NL80211_IFTYPE_WDS:
1146 	case NL80211_IFTYPE_MONITOR:
1147 	case NL80211_IFTYPE_P2P_CLIENT:
1148 	case NL80211_IFTYPE_P2P_GO:
1149 	case NL80211_IFTYPE_P2P_DEVICE:
1150 	case NL80211_IFTYPE_NAN:
1151 	case NUM_NL80211_IFTYPES:
1152 		WARN_ON(1);
1153 		break;
1154 	}
1155 }
1156 
1157 static void
1158 ieee80211_link_update_chanreq(struct ieee80211_link_data *link,
1159 			      const struct ieee80211_chan_req *chanreq)
1160 {
1161 	struct ieee80211_sub_if_data *sdata = link->sdata;
1162 	unsigned int link_id = link->link_id;
1163 	struct ieee80211_sub_if_data *vlan;
1164 
1165 	link->conf->chanreq = *chanreq;
1166 
1167 	if (sdata->vif.type != NL80211_IFTYPE_AP)
1168 		return;
1169 
1170 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
1171 		struct ieee80211_bss_conf *vlan_conf;
1172 
1173 		vlan_conf = wiphy_dereference(sdata->local->hw.wiphy,
1174 					      vlan->vif.link_conf[link_id]);
1175 		if (WARN_ON(!vlan_conf))
1176 			continue;
1177 
1178 		vlan_conf->chanreq = *chanreq;
1179 	}
1180 }
1181 
1182 static int
1183 ieee80211_link_use_reserved_reassign(struct ieee80211_link_data *link)
1184 {
1185 	struct ieee80211_sub_if_data *sdata = link->sdata;
1186 	struct ieee80211_bss_conf *link_conf = link->conf;
1187 	struct ieee80211_local *local = sdata->local;
1188 	struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1189 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1190 	const struct ieee80211_chan_req *chanreq;
1191 	struct ieee80211_chan_req tmp;
1192 	u64 changed = 0;
1193 	int err;
1194 
1195 	lockdep_assert_wiphy(local->hw.wiphy);
1196 
1197 	new_ctx = link->reserved_chanctx;
1198 	old_ctx = ieee80211_link_get_chanctx(link);
1199 
1200 	if (WARN_ON(!link->reserved_ready))
1201 		return -EBUSY;
1202 
1203 	if (WARN_ON(!new_ctx))
1204 		return -EINVAL;
1205 
1206 	if (WARN_ON(!old_ctx))
1207 		return -EINVAL;
1208 
1209 	if (WARN_ON(new_ctx->replace_state ==
1210 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1211 		return -EINVAL;
1212 
1213 	chanreq = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1214 							 &link->reserved,
1215 							 &tmp);
1216 	if (WARN_ON(!chanreq))
1217 		return -EINVAL;
1218 
1219 	if (link_conf->chanreq.oper.width != link->reserved.oper.width)
1220 		changed = BSS_CHANGED_BANDWIDTH;
1221 
1222 	ieee80211_link_update_chanreq(link, &link->reserved);
1223 
1224 	_ieee80211_change_chanctx(local, new_ctx, old_ctx, chanreq, link);
1225 
1226 	vif_chsw[0].vif = &sdata->vif;
1227 	vif_chsw[0].old_ctx = &old_ctx->conf;
1228 	vif_chsw[0].new_ctx = &new_ctx->conf;
1229 	vif_chsw[0].link_conf = link->conf;
1230 
1231 	list_del(&link->reserved_chanctx_list);
1232 	link->reserved_chanctx = NULL;
1233 
1234 	err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1235 				     CHANCTX_SWMODE_REASSIGN_VIF);
1236 	if (err) {
1237 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1238 			ieee80211_free_chanctx(local, new_ctx);
1239 
1240 		goto out;
1241 	}
1242 
1243 	list_move(&link->assigned_chanctx_list, &new_ctx->assigned_links);
1244 	rcu_assign_pointer(link_conf->chanctx_conf, &new_ctx->conf);
1245 
1246 	if (sdata->vif.type == NL80211_IFTYPE_AP)
1247 		__ieee80211_link_copy_chanctx_to_vlans(link, false);
1248 
1249 	ieee80211_check_fast_xmit_iface(sdata);
1250 
1251 	if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1252 		ieee80211_free_chanctx(local, old_ctx);
1253 
1254 	ieee80211_recalc_chanctx_min_def(local, new_ctx, NULL);
1255 	ieee80211_recalc_smps_chanctx(local, new_ctx);
1256 	ieee80211_recalc_radar_chanctx(local, new_ctx);
1257 
1258 	if (changed)
1259 		ieee80211_link_info_change_notify(sdata, link, changed);
1260 
1261 out:
1262 	ieee80211_link_chanctx_reservation_complete(link);
1263 	return err;
1264 }
1265 
1266 static int
1267 ieee80211_link_use_reserved_assign(struct ieee80211_link_data *link)
1268 {
1269 	struct ieee80211_sub_if_data *sdata = link->sdata;
1270 	struct ieee80211_local *local = sdata->local;
1271 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1272 	const struct ieee80211_chan_req *chanreq;
1273 	struct ieee80211_chan_req tmp;
1274 	int err;
1275 
1276 	old_ctx = ieee80211_link_get_chanctx(link);
1277 	new_ctx = link->reserved_chanctx;
1278 
1279 	if (WARN_ON(!link->reserved_ready))
1280 		return -EINVAL;
1281 
1282 	if (WARN_ON(old_ctx))
1283 		return -EINVAL;
1284 
1285 	if (WARN_ON(!new_ctx))
1286 		return -EINVAL;
1287 
1288 	if (WARN_ON(new_ctx->replace_state ==
1289 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1290 		return -EINVAL;
1291 
1292 	chanreq = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1293 							 &link->reserved,
1294 							 &tmp);
1295 	if (WARN_ON(!chanreq))
1296 		return -EINVAL;
1297 
1298 	ieee80211_change_chanctx(local, new_ctx, new_ctx, chanreq);
1299 
1300 	list_del(&link->reserved_chanctx_list);
1301 	link->reserved_chanctx = NULL;
1302 
1303 	err = ieee80211_assign_link_chanctx(link, new_ctx);
1304 	if (err) {
1305 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1306 			ieee80211_free_chanctx(local, new_ctx);
1307 
1308 		goto out;
1309 	}
1310 
1311 out:
1312 	ieee80211_link_chanctx_reservation_complete(link);
1313 	return err;
1314 }
1315 
1316 static bool
1317 ieee80211_link_has_in_place_reservation(struct ieee80211_link_data *link)
1318 {
1319 	struct ieee80211_sub_if_data *sdata = link->sdata;
1320 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1321 
1322 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
1323 
1324 	new_ctx = link->reserved_chanctx;
1325 	old_ctx = ieee80211_link_get_chanctx(link);
1326 
1327 	if (!old_ctx)
1328 		return false;
1329 
1330 	if (WARN_ON(!new_ctx))
1331 		return false;
1332 
1333 	if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1334 		return false;
1335 
1336 	if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1337 		return false;
1338 
1339 	return true;
1340 }
1341 
1342 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1343 				      int n_vifs)
1344 {
1345 	struct ieee80211_vif_chanctx_switch *vif_chsw;
1346 	struct ieee80211_link_data *link;
1347 	struct ieee80211_chanctx *ctx, *old_ctx;
1348 	int i, err;
1349 
1350 	lockdep_assert_wiphy(local->hw.wiphy);
1351 
1352 	vif_chsw = kcalloc(n_vifs, sizeof(vif_chsw[0]), GFP_KERNEL);
1353 	if (!vif_chsw)
1354 		return -ENOMEM;
1355 
1356 	i = 0;
1357 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1358 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1359 			continue;
1360 
1361 		if (WARN_ON(!ctx->replace_ctx)) {
1362 			err = -EINVAL;
1363 			goto out;
1364 		}
1365 
1366 		list_for_each_entry(link, &ctx->reserved_links,
1367 				    reserved_chanctx_list) {
1368 			if (!ieee80211_link_has_in_place_reservation(link))
1369 				continue;
1370 
1371 			old_ctx = ieee80211_link_get_chanctx(link);
1372 			vif_chsw[i].vif = &link->sdata->vif;
1373 			vif_chsw[i].old_ctx = &old_ctx->conf;
1374 			vif_chsw[i].new_ctx = &ctx->conf;
1375 			vif_chsw[i].link_conf = link->conf;
1376 
1377 			i++;
1378 		}
1379 	}
1380 
1381 	err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1382 				     CHANCTX_SWMODE_SWAP_CONTEXTS);
1383 
1384 out:
1385 	kfree(vif_chsw);
1386 	return err;
1387 }
1388 
1389 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1390 {
1391 	struct ieee80211_chanctx *ctx;
1392 	int err;
1393 
1394 	lockdep_assert_wiphy(local->hw.wiphy);
1395 
1396 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1397 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1398 			continue;
1399 
1400 		if (!list_empty(&ctx->replace_ctx->assigned_links))
1401 			continue;
1402 
1403 		ieee80211_del_chanctx(local, ctx->replace_ctx);
1404 		err = ieee80211_add_chanctx(local, ctx);
1405 		if (err)
1406 			goto err;
1407 	}
1408 
1409 	return 0;
1410 
1411 err:
1412 	WARN_ON(ieee80211_add_chanctx(local, ctx));
1413 	list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1414 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1415 			continue;
1416 
1417 		if (!list_empty(&ctx->replace_ctx->assigned_links))
1418 			continue;
1419 
1420 		ieee80211_del_chanctx(local, ctx);
1421 		WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1422 	}
1423 
1424 	return err;
1425 }
1426 
1427 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1428 {
1429 	struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1430 	int err, n_assigned, n_reserved, n_ready;
1431 	int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1432 
1433 	lockdep_assert_wiphy(local->hw.wiphy);
1434 
1435 	/*
1436 	 * If there are 2 independent pairs of channel contexts performing
1437 	 * cross-switch of their vifs this code will still wait until both are
1438 	 * ready even though it could be possible to switch one before the
1439 	 * other is ready.
1440 	 *
1441 	 * For practical reasons and code simplicity just do a single huge
1442 	 * switch.
1443 	 */
1444 
1445 	/*
1446 	 * Verify if the reservation is still feasible.
1447 	 *  - if it's not then disconnect
1448 	 *  - if it is but not all vifs necessary are ready then defer
1449 	 */
1450 
1451 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1452 		struct ieee80211_link_data *link;
1453 
1454 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1455 			continue;
1456 
1457 		if (WARN_ON(!ctx->replace_ctx)) {
1458 			err = -EINVAL;
1459 			goto err;
1460 		}
1461 
1462 		n_ctx++;
1463 
1464 		n_assigned = 0;
1465 		n_reserved = 0;
1466 		n_ready = 0;
1467 
1468 		list_for_each_entry(link, &ctx->replace_ctx->assigned_links,
1469 				    assigned_chanctx_list) {
1470 			n_assigned++;
1471 			if (link->reserved_chanctx) {
1472 				n_reserved++;
1473 				if (link->reserved_ready)
1474 					n_ready++;
1475 			}
1476 		}
1477 
1478 		if (n_assigned != n_reserved) {
1479 			if (n_ready == n_reserved) {
1480 				wiphy_info(local->hw.wiphy,
1481 					   "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1482 				err = -EBUSY;
1483 				goto err;
1484 			}
1485 
1486 			return -EAGAIN;
1487 		}
1488 
1489 		ctx->conf.radar_enabled = false;
1490 		list_for_each_entry(link, &ctx->reserved_links,
1491 				    reserved_chanctx_list) {
1492 			if (ieee80211_link_has_in_place_reservation(link) &&
1493 			    !link->reserved_ready)
1494 				return -EAGAIN;
1495 
1496 			old_ctx = ieee80211_link_get_chanctx(link);
1497 			if (old_ctx) {
1498 				if (old_ctx->replace_state ==
1499 				    IEEE80211_CHANCTX_WILL_BE_REPLACED)
1500 					n_vifs_switch++;
1501 				else
1502 					n_vifs_assign++;
1503 			} else {
1504 				n_vifs_ctxless++;
1505 			}
1506 
1507 			if (link->reserved_radar_required)
1508 				ctx->conf.radar_enabled = true;
1509 		}
1510 	}
1511 
1512 	if (WARN_ON(n_ctx == 0) ||
1513 	    WARN_ON(n_vifs_switch == 0 &&
1514 		    n_vifs_assign == 0 &&
1515 		    n_vifs_ctxless == 0)) {
1516 		err = -EINVAL;
1517 		goto err;
1518 	}
1519 
1520 	/*
1521 	 * All necessary vifs are ready. Perform the switch now depending on
1522 	 * reservations and driver capabilities.
1523 	 */
1524 
1525 	if (n_vifs_switch > 0) {
1526 		err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1527 		if (err)
1528 			goto err;
1529 	}
1530 
1531 	if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1532 		err = ieee80211_chsw_switch_ctxs(local);
1533 		if (err)
1534 			goto err;
1535 	}
1536 
1537 	/*
1538 	 * Update all structures, values and pointers to point to new channel
1539 	 * context(s).
1540 	 */
1541 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1542 		struct ieee80211_link_data *link, *link_tmp;
1543 
1544 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1545 			continue;
1546 
1547 		if (WARN_ON(!ctx->replace_ctx)) {
1548 			err = -EINVAL;
1549 			goto err;
1550 		}
1551 
1552 		list_for_each_entry(link, &ctx->reserved_links,
1553 				    reserved_chanctx_list) {
1554 			struct ieee80211_sub_if_data *sdata = link->sdata;
1555 			struct ieee80211_bss_conf *link_conf = link->conf;
1556 			u64 changed = 0;
1557 
1558 			if (!ieee80211_link_has_in_place_reservation(link))
1559 				continue;
1560 
1561 			rcu_assign_pointer(link_conf->chanctx_conf,
1562 					   &ctx->conf);
1563 
1564 			if (sdata->vif.type == NL80211_IFTYPE_AP)
1565 				__ieee80211_link_copy_chanctx_to_vlans(link,
1566 								       false);
1567 
1568 			ieee80211_check_fast_xmit_iface(sdata);
1569 
1570 			link->radar_required = link->reserved_radar_required;
1571 
1572 			if (link_conf->chanreq.oper.width != link->reserved.oper.width)
1573 				changed = BSS_CHANGED_BANDWIDTH;
1574 
1575 			ieee80211_link_update_chanreq(link, &link->reserved);
1576 			if (changed)
1577 				ieee80211_link_info_change_notify(sdata,
1578 								  link,
1579 								  changed);
1580 
1581 			ieee80211_recalc_txpower(sdata, false);
1582 		}
1583 
1584 		ieee80211_recalc_chanctx_chantype(local, ctx);
1585 		ieee80211_recalc_smps_chanctx(local, ctx);
1586 		ieee80211_recalc_radar_chanctx(local, ctx);
1587 		ieee80211_recalc_chanctx_min_def(local, ctx, NULL);
1588 
1589 		list_for_each_entry_safe(link, link_tmp, &ctx->reserved_links,
1590 					 reserved_chanctx_list) {
1591 			if (ieee80211_link_get_chanctx(link) != ctx)
1592 				continue;
1593 
1594 			list_del(&link->reserved_chanctx_list);
1595 			list_move(&link->assigned_chanctx_list,
1596 				  &ctx->assigned_links);
1597 			link->reserved_chanctx = NULL;
1598 
1599 			ieee80211_link_chanctx_reservation_complete(link);
1600 		}
1601 
1602 		/*
1603 		 * This context might have been a dependency for an already
1604 		 * ready re-assign reservation interface that was deferred. Do
1605 		 * not propagate error to the caller though. The in-place
1606 		 * reservation for originally requested interface has already
1607 		 * succeeded at this point.
1608 		 */
1609 		list_for_each_entry_safe(link, link_tmp, &ctx->reserved_links,
1610 					 reserved_chanctx_list) {
1611 			if (WARN_ON(ieee80211_link_has_in_place_reservation(link)))
1612 				continue;
1613 
1614 			if (WARN_ON(link->reserved_chanctx != ctx))
1615 				continue;
1616 
1617 			if (!link->reserved_ready)
1618 				continue;
1619 
1620 			if (ieee80211_link_get_chanctx(link))
1621 				err = ieee80211_link_use_reserved_reassign(link);
1622 			else
1623 				err = ieee80211_link_use_reserved_assign(link);
1624 
1625 			if (err) {
1626 				link_info(link,
1627 					  "failed to finalize (re-)assign reservation (err=%d)\n",
1628 					  err);
1629 				ieee80211_link_unreserve_chanctx(link);
1630 				cfg80211_stop_iface(local->hw.wiphy,
1631 						    &link->sdata->wdev,
1632 						    GFP_KERNEL);
1633 			}
1634 		}
1635 	}
1636 
1637 	/*
1638 	 * Finally free old contexts
1639 	 */
1640 
1641 	list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1642 		if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1643 			continue;
1644 
1645 		ctx->replace_ctx->replace_ctx = NULL;
1646 		ctx->replace_ctx->replace_state =
1647 				IEEE80211_CHANCTX_REPLACE_NONE;
1648 
1649 		list_del_rcu(&ctx->list);
1650 		kfree_rcu(ctx, rcu_head);
1651 	}
1652 
1653 	return 0;
1654 
1655 err:
1656 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1657 		struct ieee80211_link_data *link, *link_tmp;
1658 
1659 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1660 			continue;
1661 
1662 		list_for_each_entry_safe(link, link_tmp, &ctx->reserved_links,
1663 					 reserved_chanctx_list) {
1664 			ieee80211_link_unreserve_chanctx(link);
1665 			ieee80211_link_chanctx_reservation_complete(link);
1666 		}
1667 	}
1668 
1669 	return err;
1670 }
1671 
1672 static void __ieee80211_link_release_channel(struct ieee80211_link_data *link)
1673 {
1674 	struct ieee80211_sub_if_data *sdata = link->sdata;
1675 	struct ieee80211_bss_conf *link_conf = link->conf;
1676 	struct ieee80211_local *local = sdata->local;
1677 	struct ieee80211_chanctx_conf *conf;
1678 	struct ieee80211_chanctx *ctx;
1679 	bool use_reserved_switch = false;
1680 
1681 	lockdep_assert_wiphy(local->hw.wiphy);
1682 
1683 	conf = rcu_dereference_protected(link_conf->chanctx_conf,
1684 					 lockdep_is_held(&local->hw.wiphy->mtx));
1685 	if (!conf)
1686 		return;
1687 
1688 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1689 
1690 	if (link->reserved_chanctx) {
1691 		if (link->reserved_chanctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER &&
1692 		    ieee80211_chanctx_num_reserved(local, link->reserved_chanctx) > 1)
1693 			use_reserved_switch = true;
1694 
1695 		ieee80211_link_unreserve_chanctx(link);
1696 	}
1697 
1698 	ieee80211_assign_link_chanctx(link, NULL);
1699 	if (ieee80211_chanctx_refcount(local, ctx) == 0)
1700 		ieee80211_free_chanctx(local, ctx);
1701 
1702 	link->radar_required = false;
1703 
1704 	/* Unreserving may ready an in-place reservation. */
1705 	if (use_reserved_switch)
1706 		ieee80211_vif_use_reserved_switch(local);
1707 }
1708 
1709 int ieee80211_link_use_channel(struct ieee80211_link_data *link,
1710 			       const struct ieee80211_chan_req *chanreq,
1711 			       enum ieee80211_chanctx_mode mode)
1712 {
1713 	struct ieee80211_sub_if_data *sdata = link->sdata;
1714 	struct ieee80211_local *local = sdata->local;
1715 	struct ieee80211_chanctx *ctx;
1716 	u8 radar_detect_width = 0;
1717 	int ret;
1718 
1719 	lockdep_assert_wiphy(local->hw.wiphy);
1720 
1721 	if (!ieee80211_vif_link_active(&sdata->vif, link->link_id)) {
1722 		ieee80211_link_update_chanreq(link, chanreq);
1723 		return 0;
1724 	}
1725 
1726 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1727 					    &chanreq->oper,
1728 					    sdata->wdev.iftype);
1729 	if (ret < 0)
1730 		goto out;
1731 	if (ret > 0)
1732 		radar_detect_width = BIT(chanreq->oper.width);
1733 
1734 	link->radar_required = ret;
1735 
1736 	ret = ieee80211_check_combinations(sdata, &chanreq->oper, mode,
1737 					   radar_detect_width);
1738 	if (ret < 0)
1739 		goto out;
1740 
1741 	__ieee80211_link_release_channel(link);
1742 
1743 	ctx = ieee80211_find_chanctx(local, chanreq, mode);
1744 	if (!ctx)
1745 		ctx = ieee80211_new_chanctx(local, chanreq, mode);
1746 	if (IS_ERR(ctx)) {
1747 		ret = PTR_ERR(ctx);
1748 		goto out;
1749 	}
1750 
1751 	ieee80211_link_update_chanreq(link, chanreq);
1752 
1753 	ret = ieee80211_assign_link_chanctx(link, ctx);
1754 	if (ret) {
1755 		/* if assign fails refcount stays the same */
1756 		if (ieee80211_chanctx_refcount(local, ctx) == 0)
1757 			ieee80211_free_chanctx(local, ctx);
1758 		goto out;
1759 	}
1760 
1761 	ieee80211_recalc_smps_chanctx(local, ctx);
1762 	ieee80211_recalc_radar_chanctx(local, ctx);
1763  out:
1764 	if (ret)
1765 		link->radar_required = false;
1766 
1767 	return ret;
1768 }
1769 
1770 int ieee80211_link_use_reserved_context(struct ieee80211_link_data *link)
1771 {
1772 	struct ieee80211_sub_if_data *sdata = link->sdata;
1773 	struct ieee80211_local *local = sdata->local;
1774 	struct ieee80211_chanctx *new_ctx;
1775 	struct ieee80211_chanctx *old_ctx;
1776 	int err;
1777 
1778 	lockdep_assert_wiphy(local->hw.wiphy);
1779 
1780 	new_ctx = link->reserved_chanctx;
1781 	old_ctx = ieee80211_link_get_chanctx(link);
1782 
1783 	if (WARN_ON(!new_ctx))
1784 		return -EINVAL;
1785 
1786 	if (WARN_ON(new_ctx->replace_state ==
1787 		    IEEE80211_CHANCTX_WILL_BE_REPLACED))
1788 		return -EINVAL;
1789 
1790 	if (WARN_ON(link->reserved_ready))
1791 		return -EINVAL;
1792 
1793 	link->reserved_ready = true;
1794 
1795 	if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1796 		if (old_ctx)
1797 			return ieee80211_link_use_reserved_reassign(link);
1798 
1799 		return ieee80211_link_use_reserved_assign(link);
1800 	}
1801 
1802 	/*
1803 	 * In-place reservation may need to be finalized now either if:
1804 	 *  a) sdata is taking part in the swapping itself and is the last one
1805 	 *  b) sdata has switched with a re-assign reservation to an existing
1806 	 *     context readying in-place switching of old_ctx
1807 	 *
1808 	 * In case of (b) do not propagate the error up because the requested
1809 	 * sdata already switched successfully. Just spill an extra warning.
1810 	 * The ieee80211_vif_use_reserved_switch() already stops all necessary
1811 	 * interfaces upon failure.
1812 	 */
1813 	if ((old_ctx &&
1814 	     old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1815 	    new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1816 		err = ieee80211_vif_use_reserved_switch(local);
1817 		if (err && err != -EAGAIN) {
1818 			if (new_ctx->replace_state ==
1819 			    IEEE80211_CHANCTX_REPLACES_OTHER)
1820 				return err;
1821 
1822 			wiphy_info(local->hw.wiphy,
1823 				   "depending in-place reservation failed (err=%d)\n",
1824 				   err);
1825 		}
1826 	}
1827 
1828 	return 0;
1829 }
1830 
1831 /*
1832  * This is similar to ieee80211_chanctx_compatible(), but rechecks
1833  * against all the links actually using it (except the one that's
1834  * passed, since that one is changing).
1835  * This is done in order to allow changes to the AP's bandwidth for
1836  * wider bandwidth OFDMA purposes, which wouldn't be treated as
1837  * compatible by ieee80211_chanctx_recheck() but is OK if the link
1838  * requesting the update is the only one using it.
1839  */
1840 static const struct ieee80211_chan_req *
1841 ieee80211_chanctx_recheck(struct ieee80211_local *local,
1842 			  struct ieee80211_link_data *skip_link,
1843 			  struct ieee80211_chanctx *ctx,
1844 			  const struct ieee80211_chan_req *req,
1845 			  struct ieee80211_chan_req *tmp)
1846 {
1847 	const struct ieee80211_chan_req *ret = req;
1848 	struct ieee80211_link_data *link;
1849 
1850 	lockdep_assert_wiphy(local->hw.wiphy);
1851 
1852 	for_each_sdata_link(local, link) {
1853 		if (link == skip_link)
1854 			continue;
1855 
1856 		if (rcu_access_pointer(link->conf->chanctx_conf) == &ctx->conf) {
1857 			ret = ieee80211_chanreq_compatible(ret,
1858 							   &link->conf->chanreq,
1859 							   tmp);
1860 			if (!ret)
1861 				return NULL;
1862 		}
1863 
1864 		if (link->reserved_chanctx == ctx) {
1865 			ret = ieee80211_chanreq_compatible(ret,
1866 							   &link->reserved,
1867 							   tmp);
1868 			if (!ret)
1869 				return NULL;
1870 		}
1871 	}
1872 
1873 	*tmp = *ret;
1874 	return tmp;
1875 }
1876 
1877 int ieee80211_link_change_chanreq(struct ieee80211_link_data *link,
1878 				  const struct ieee80211_chan_req *chanreq,
1879 				  u64 *changed)
1880 {
1881 	struct ieee80211_sub_if_data *sdata = link->sdata;
1882 	struct ieee80211_bss_conf *link_conf = link->conf;
1883 	struct ieee80211_local *local = sdata->local;
1884 	struct ieee80211_chanctx_conf *conf;
1885 	struct ieee80211_chanctx *ctx;
1886 	const struct ieee80211_chan_req *compat;
1887 	struct ieee80211_chan_req tmp;
1888 
1889 	lockdep_assert_wiphy(local->hw.wiphy);
1890 
1891 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy,
1892 				     &chanreq->oper,
1893 				     IEEE80211_CHAN_DISABLED))
1894 		return -EINVAL;
1895 
1896 	/* for non-HT 20 MHz the rest doesn't matter */
1897 	if (chanreq->oper.width == NL80211_CHAN_WIDTH_20_NOHT &&
1898 	    cfg80211_chandef_identical(&chanreq->oper, &link_conf->chanreq.oper))
1899 		return 0;
1900 
1901 	/* but you cannot switch to/from it */
1902 	if (chanreq->oper.width == NL80211_CHAN_WIDTH_20_NOHT ||
1903 	    link_conf->chanreq.oper.width == NL80211_CHAN_WIDTH_20_NOHT)
1904 		return -EINVAL;
1905 
1906 	conf = rcu_dereference_protected(link_conf->chanctx_conf,
1907 					 lockdep_is_held(&local->hw.wiphy->mtx));
1908 	if (!conf)
1909 		return -EINVAL;
1910 
1911 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1912 
1913 	compat = ieee80211_chanctx_recheck(local, link, ctx, chanreq, &tmp);
1914 	if (!compat)
1915 		return -EINVAL;
1916 
1917 	switch (ctx->replace_state) {
1918 	case IEEE80211_CHANCTX_REPLACE_NONE:
1919 		if (!ieee80211_chanctx_reserved_chanreq(local, ctx, compat,
1920 							&tmp))
1921 			return -EBUSY;
1922 		break;
1923 	case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1924 		/* TODO: Perhaps the bandwidth change could be treated as a
1925 		 * reservation itself? */
1926 		return -EBUSY;
1927 	case IEEE80211_CHANCTX_REPLACES_OTHER:
1928 		/* channel context that is going to replace another channel
1929 		 * context doesn't really exist and shouldn't be assigned
1930 		 * anywhere yet */
1931 		WARN_ON(1);
1932 		break;
1933 	}
1934 
1935 	ieee80211_link_update_chanreq(link, chanreq);
1936 
1937 	ieee80211_recalc_chanctx_chantype(local, ctx);
1938 
1939 	*changed |= BSS_CHANGED_BANDWIDTH;
1940 	return 0;
1941 }
1942 
1943 void ieee80211_link_release_channel(struct ieee80211_link_data *link)
1944 {
1945 	struct ieee80211_sub_if_data *sdata = link->sdata;
1946 
1947 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
1948 
1949 	if (rcu_access_pointer(link->conf->chanctx_conf))
1950 		__ieee80211_link_release_channel(link);
1951 }
1952 
1953 void ieee80211_link_vlan_copy_chanctx(struct ieee80211_link_data *link)
1954 {
1955 	struct ieee80211_sub_if_data *sdata = link->sdata;
1956 	unsigned int link_id = link->link_id;
1957 	struct ieee80211_bss_conf *link_conf = link->conf;
1958 	struct ieee80211_bss_conf *ap_conf;
1959 	struct ieee80211_local *local = sdata->local;
1960 	struct ieee80211_sub_if_data *ap;
1961 	struct ieee80211_chanctx_conf *conf;
1962 
1963 	lockdep_assert_wiphy(local->hw.wiphy);
1964 
1965 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
1966 		return;
1967 
1968 	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
1969 
1970 	ap_conf = wiphy_dereference(local->hw.wiphy,
1971 				    ap->vif.link_conf[link_id]);
1972 	conf = wiphy_dereference(local->hw.wiphy,
1973 				 ap_conf->chanctx_conf);
1974 	rcu_assign_pointer(link_conf->chanctx_conf, conf);
1975 }
1976 
1977 void ieee80211_iter_chan_contexts_atomic(
1978 	struct ieee80211_hw *hw,
1979 	void (*iter)(struct ieee80211_hw *hw,
1980 		     struct ieee80211_chanctx_conf *chanctx_conf,
1981 		     void *data),
1982 	void *iter_data)
1983 {
1984 	struct ieee80211_local *local = hw_to_local(hw);
1985 	struct ieee80211_chanctx *ctx;
1986 
1987 	rcu_read_lock();
1988 	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
1989 		if (ctx->driver_present)
1990 			iter(hw, &ctx->conf, iter_data);
1991 	rcu_read_unlock();
1992 }
1993 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);
1994