xref: /openbmc/linux/net/mac80211/chan.c (revision 1587db11)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * mac80211 - channel management
4  * Copyright 2020 - 2022 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_held(&local->chanctx_mtx);
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_held(&local->chanctx_mtx);
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_held(&local->chanctx_mtx);
56 
57 	list_for_each_entry(ctx, &local->chanctx_list, list)
58 		num++;
59 
60 	return num;
61 }
62 
63 static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local)
64 {
65 	lockdep_assert_held(&local->chanctx_mtx);
66 	return ieee80211_num_chanctx(local) < ieee80211_max_num_channels(local);
67 }
68 
69 static struct ieee80211_chanctx *
70 ieee80211_link_get_chanctx(struct ieee80211_link_data *link)
71 {
72 	struct ieee80211_local *local __maybe_unused = link->sdata->local;
73 	struct ieee80211_chanctx_conf *conf;
74 
75 	conf = rcu_dereference_protected(link->conf->chanctx_conf,
76 					 lockdep_is_held(&local->chanctx_mtx));
77 	if (!conf)
78 		return NULL;
79 
80 	return container_of(conf, struct ieee80211_chanctx, conf);
81 }
82 
83 static const struct cfg80211_chan_def *
84 ieee80211_chanctx_reserved_chandef(struct ieee80211_local *local,
85 				   struct ieee80211_chanctx *ctx,
86 				   const struct cfg80211_chan_def *compat)
87 {
88 	struct ieee80211_link_data *link;
89 
90 	lockdep_assert_held(&local->chanctx_mtx);
91 
92 	list_for_each_entry(link, &ctx->reserved_links,
93 			    reserved_chanctx_list) {
94 		if (!compat)
95 			compat = &link->reserved_chandef;
96 
97 		compat = cfg80211_chandef_compatible(&link->reserved_chandef,
98 						     compat);
99 		if (!compat)
100 			break;
101 	}
102 
103 	return compat;
104 }
105 
106 static const struct cfg80211_chan_def *
107 ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local *local,
108 				       struct ieee80211_chanctx *ctx,
109 				       const struct cfg80211_chan_def *compat)
110 {
111 	struct ieee80211_link_data *link;
112 
113 	lockdep_assert_held(&local->chanctx_mtx);
114 
115 	list_for_each_entry(link, &ctx->assigned_links,
116 			    assigned_chanctx_list) {
117 		struct ieee80211_bss_conf *link_conf = link->conf;
118 
119 		if (link->reserved_chanctx)
120 			continue;
121 
122 		if (!compat)
123 			compat = &link_conf->chandef;
124 
125 		compat = cfg80211_chandef_compatible(
126 				&link_conf->chandef, compat);
127 		if (!compat)
128 			break;
129 	}
130 
131 	return compat;
132 }
133 
134 static const struct cfg80211_chan_def *
135 ieee80211_chanctx_combined_chandef(struct ieee80211_local *local,
136 				   struct ieee80211_chanctx *ctx,
137 				   const struct cfg80211_chan_def *compat)
138 {
139 	lockdep_assert_held(&local->chanctx_mtx);
140 
141 	compat = ieee80211_chanctx_reserved_chandef(local, ctx, compat);
142 	if (!compat)
143 		return NULL;
144 
145 	compat = ieee80211_chanctx_non_reserved_chandef(local, ctx, compat);
146 	if (!compat)
147 		return NULL;
148 
149 	return compat;
150 }
151 
152 static bool
153 ieee80211_chanctx_can_reserve_chandef(struct ieee80211_local *local,
154 				      struct ieee80211_chanctx *ctx,
155 				      const struct cfg80211_chan_def *def)
156 {
157 	lockdep_assert_held(&local->chanctx_mtx);
158 
159 	if (ieee80211_chanctx_combined_chandef(local, ctx, def))
160 		return true;
161 
162 	if (!list_empty(&ctx->reserved_links) &&
163 	    ieee80211_chanctx_reserved_chandef(local, ctx, def))
164 		return true;
165 
166 	return false;
167 }
168 
169 static struct ieee80211_chanctx *
170 ieee80211_find_reservation_chanctx(struct ieee80211_local *local,
171 				   const struct cfg80211_chan_def *chandef,
172 				   enum ieee80211_chanctx_mode mode)
173 {
174 	struct ieee80211_chanctx *ctx;
175 
176 	lockdep_assert_held(&local->chanctx_mtx);
177 
178 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
179 		return NULL;
180 
181 	list_for_each_entry(ctx, &local->chanctx_list, list) {
182 		if (ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED)
183 			continue;
184 
185 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
186 			continue;
187 
188 		if (!ieee80211_chanctx_can_reserve_chandef(local, ctx,
189 							   chandef))
190 			continue;
191 
192 		return ctx;
193 	}
194 
195 	return NULL;
196 }
197 
198 static enum nl80211_chan_width ieee80211_get_sta_bw(struct sta_info *sta,
199 						    unsigned int link_id)
200 {
201 	enum ieee80211_sta_rx_bandwidth width;
202 	struct link_sta_info *link_sta;
203 
204 	link_sta = rcu_dereference(sta->link[link_id]);
205 
206 	/* no effect if this STA has no presence on this link */
207 	if (!link_sta)
208 		return NL80211_CHAN_WIDTH_20_NOHT;
209 
210 	width = ieee80211_sta_cap_rx_bw(link_sta);
211 
212 	switch (width) {
213 	case IEEE80211_STA_RX_BW_20:
214 		if (link_sta->pub->ht_cap.ht_supported)
215 			return NL80211_CHAN_WIDTH_20;
216 		else
217 			return NL80211_CHAN_WIDTH_20_NOHT;
218 	case IEEE80211_STA_RX_BW_40:
219 		return NL80211_CHAN_WIDTH_40;
220 	case IEEE80211_STA_RX_BW_80:
221 		return NL80211_CHAN_WIDTH_80;
222 	case IEEE80211_STA_RX_BW_160:
223 		/*
224 		 * This applied for both 160 and 80+80. since we use
225 		 * the returned value to consider degradation of
226 		 * ctx->conf.min_def, we have to make sure to take
227 		 * the bigger one (NL80211_CHAN_WIDTH_160).
228 		 * Otherwise we might try degrading even when not
229 		 * needed, as the max required sta_bw returned (80+80)
230 		 * might be smaller than the configured bw (160).
231 		 */
232 		return NL80211_CHAN_WIDTH_160;
233 	case IEEE80211_STA_RX_BW_320:
234 		return NL80211_CHAN_WIDTH_320;
235 	default:
236 		WARN_ON(1);
237 		return NL80211_CHAN_WIDTH_20;
238 	}
239 }
240 
241 static enum nl80211_chan_width
242 ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata,
243 			      unsigned int link_id)
244 {
245 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
246 	struct sta_info *sta;
247 
248 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
249 
250 	list_for_each_entry(sta, &sdata->local->sta_list, list) {
251 		if (sdata != sta->sdata &&
252 		    !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
253 			continue;
254 
255 		max_bw = max(max_bw, ieee80211_get_sta_bw(sta, link_id));
256 	}
257 
258 	return max_bw;
259 }
260 
261 static enum nl80211_chan_width
262 ieee80211_get_chanctx_vif_max_required_bw(struct ieee80211_sub_if_data *sdata,
263 					  struct ieee80211_chanctx *ctx,
264 					  struct ieee80211_link_data *rsvd_for)
265 {
266 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
267 	struct ieee80211_vif *vif = &sdata->vif;
268 	int link_id;
269 
270 	rcu_read_lock();
271 	for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
272 		enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT;
273 		struct ieee80211_link_data *link =
274 			rcu_dereference(sdata->link[link_id]);
275 
276 		if (!link)
277 			continue;
278 
279 		if (link != rsvd_for &&
280 		    rcu_access_pointer(link->conf->chanctx_conf) != &ctx->conf)
281 			continue;
282 
283 		switch (vif->type) {
284 		case NL80211_IFTYPE_AP:
285 		case NL80211_IFTYPE_AP_VLAN:
286 			width = ieee80211_get_max_required_bw(sdata, link_id);
287 			break;
288 		case NL80211_IFTYPE_STATION:
289 			/*
290 			 * The ap's sta->bandwidth is not set yet at this
291 			 * point, so take the width from the chandef, but
292 			 * account also for TDLS peers
293 			 */
294 			width = max(link->conf->chandef.width,
295 				    ieee80211_get_max_required_bw(sdata, link_id));
296 			break;
297 		case NL80211_IFTYPE_P2P_DEVICE:
298 		case NL80211_IFTYPE_NAN:
299 			continue;
300 		case NL80211_IFTYPE_ADHOC:
301 		case NL80211_IFTYPE_MESH_POINT:
302 		case NL80211_IFTYPE_OCB:
303 			width = link->conf->chandef.width;
304 			break;
305 		case NL80211_IFTYPE_WDS:
306 		case NL80211_IFTYPE_UNSPECIFIED:
307 		case NUM_NL80211_IFTYPES:
308 		case NL80211_IFTYPE_MONITOR:
309 		case NL80211_IFTYPE_P2P_CLIENT:
310 		case NL80211_IFTYPE_P2P_GO:
311 			WARN_ON_ONCE(1);
312 		}
313 
314 		max_bw = max(max_bw, width);
315 	}
316 	rcu_read_unlock();
317 
318 	return max_bw;
319 }
320 
321 static enum nl80211_chan_width
322 ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
323 				      struct ieee80211_chanctx *ctx,
324 				      struct ieee80211_link_data *rsvd_for)
325 {
326 	struct ieee80211_sub_if_data *sdata;
327 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
328 
329 	rcu_read_lock();
330 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
331 		enum nl80211_chan_width width;
332 
333 		if (!ieee80211_sdata_running(sdata))
334 			continue;
335 
336 		width = ieee80211_get_chanctx_vif_max_required_bw(sdata, ctx,
337 								  rsvd_for);
338 
339 		max_bw = max(max_bw, width);
340 	}
341 
342 	/* use the configured bandwidth in case of monitor interface */
343 	sdata = rcu_dereference(local->monitor_sdata);
344 	if (sdata &&
345 	    rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) == &ctx->conf)
346 		max_bw = max(max_bw, ctx->conf.def.width);
347 
348 	rcu_read_unlock();
349 
350 	return max_bw;
351 }
352 
353 /*
354  * recalc the min required chan width of the channel context, which is
355  * the max of min required widths of all the interfaces bound to this
356  * channel context.
357  */
358 static u32
359 _ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
360 				  struct ieee80211_chanctx *ctx,
361 				  struct ieee80211_link_data *rsvd_for)
362 {
363 	enum nl80211_chan_width max_bw;
364 	struct cfg80211_chan_def min_def;
365 
366 	lockdep_assert_held(&local->chanctx_mtx);
367 
368 	/* don't optimize non-20MHz based and radar_enabled confs */
369 	if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
370 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
371 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_1 ||
372 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_2 ||
373 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_4 ||
374 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_8 ||
375 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_16 ||
376 	    ctx->conf.radar_enabled) {
377 		ctx->conf.min_def = ctx->conf.def;
378 		return 0;
379 	}
380 
381 	max_bw = ieee80211_get_chanctx_max_required_bw(local, ctx, rsvd_for);
382 
383 	/* downgrade chandef up to max_bw */
384 	min_def = ctx->conf.def;
385 	while (min_def.width > max_bw)
386 		ieee80211_chandef_downgrade(&min_def);
387 
388 	if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
389 		return 0;
390 
391 	ctx->conf.min_def = min_def;
392 	if (!ctx->driver_present)
393 		return 0;
394 
395 	return IEEE80211_CHANCTX_CHANGE_MIN_WIDTH;
396 }
397 
398 /* calling this function is assuming that station vif is updated to
399  * lates changes by calling ieee80211_link_update_chandef
400  */
401 static void ieee80211_chan_bw_change(struct ieee80211_local *local,
402 				     struct ieee80211_chanctx *ctx,
403 				     bool narrowed)
404 {
405 	struct sta_info *sta;
406 	struct ieee80211_supported_band *sband =
407 		local->hw.wiphy->bands[ctx->conf.def.chan->band];
408 
409 	rcu_read_lock();
410 	list_for_each_entry_rcu(sta, &local->sta_list,
411 				list) {
412 		struct ieee80211_sub_if_data *sdata = sta->sdata;
413 		enum ieee80211_sta_rx_bandwidth new_sta_bw;
414 		unsigned int link_id;
415 
416 		if (!ieee80211_sdata_running(sta->sdata))
417 			continue;
418 
419 		for (link_id = 0; link_id < ARRAY_SIZE(sta->sdata->link); link_id++) {
420 			struct ieee80211_bss_conf *link_conf =
421 				rcu_dereference(sdata->vif.link_conf[link_id]);
422 			struct link_sta_info *link_sta;
423 
424 			if (!link_conf)
425 				continue;
426 
427 			if (rcu_access_pointer(link_conf->chanctx_conf) != &ctx->conf)
428 				continue;
429 
430 			link_sta = rcu_dereference(sta->link[link_id]);
431 			if (!link_sta)
432 				continue;
433 
434 			new_sta_bw = ieee80211_sta_cur_vht_bw(link_sta);
435 
436 			/* nothing change */
437 			if (new_sta_bw == link_sta->pub->bandwidth)
438 				continue;
439 
440 			/* vif changed to narrow BW and narrow BW for station wasn't
441 			 * requested or vise versa */
442 			if ((new_sta_bw < link_sta->pub->bandwidth) == !narrowed)
443 				continue;
444 
445 			link_sta->pub->bandwidth = new_sta_bw;
446 			rate_control_rate_update(local, sband, sta, link_id,
447 						 IEEE80211_RC_BW_CHANGED);
448 		}
449 	}
450 	rcu_read_unlock();
451 }
452 
453 /*
454  * recalc the min required chan width of the channel context, which is
455  * the max of min required widths of all the interfaces bound to this
456  * channel context.
457  */
458 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
459 				      struct ieee80211_chanctx *ctx,
460 				      struct ieee80211_link_data *rsvd_for)
461 {
462 	u32 changed = _ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for);
463 
464 	if (!changed)
465 		return;
466 
467 	/* check is BW narrowed */
468 	ieee80211_chan_bw_change(local, ctx, true);
469 
470 	drv_change_chanctx(local, ctx, changed);
471 
472 	/* check is BW wider */
473 	ieee80211_chan_bw_change(local, ctx, false);
474 }
475 
476 static void _ieee80211_change_chanctx(struct ieee80211_local *local,
477 				      struct ieee80211_chanctx *ctx,
478 				      struct ieee80211_chanctx *old_ctx,
479 				      const struct cfg80211_chan_def *chandef,
480 				      struct ieee80211_link_data *rsvd_for)
481 {
482 	u32 changed;
483 
484 	/* expected to handle only 20/40/80/160/320 channel widths */
485 	switch (chandef->width) {
486 	case NL80211_CHAN_WIDTH_20_NOHT:
487 	case NL80211_CHAN_WIDTH_20:
488 	case NL80211_CHAN_WIDTH_40:
489 	case NL80211_CHAN_WIDTH_80:
490 	case NL80211_CHAN_WIDTH_80P80:
491 	case NL80211_CHAN_WIDTH_160:
492 	case NL80211_CHAN_WIDTH_320:
493 		break;
494 	default:
495 		WARN_ON(1);
496 	}
497 
498 	/* Check maybe BW narrowed - we do this _before_ calling recalc_chanctx_min_def
499 	 * due to maybe not returning from it, e.g in case new context was added
500 	 * first time with all parameters up to date.
501 	 */
502 	ieee80211_chan_bw_change(local, old_ctx, true);
503 
504 	if (cfg80211_chandef_identical(&ctx->conf.def, chandef)) {
505 		ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for);
506 		return;
507 	}
508 
509 	WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
510 
511 	ctx->conf.def = *chandef;
512 
513 	/* check if min chanctx also changed */
514 	changed = IEEE80211_CHANCTX_CHANGE_WIDTH |
515 		  _ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for);
516 	drv_change_chanctx(local, ctx, changed);
517 
518 	if (!local->use_chanctx) {
519 		local->_oper_chandef = *chandef;
520 		ieee80211_hw_config(local, 0);
521 	}
522 
523 	/* check is BW wider */
524 	ieee80211_chan_bw_change(local, old_ctx, false);
525 }
526 
527 static void ieee80211_change_chanctx(struct ieee80211_local *local,
528 				     struct ieee80211_chanctx *ctx,
529 				     struct ieee80211_chanctx *old_ctx,
530 				     const struct cfg80211_chan_def *chandef)
531 {
532 	_ieee80211_change_chanctx(local, ctx, old_ctx, chandef, NULL);
533 }
534 
535 static struct ieee80211_chanctx *
536 ieee80211_find_chanctx(struct ieee80211_local *local,
537 		       const struct cfg80211_chan_def *chandef,
538 		       enum ieee80211_chanctx_mode mode)
539 {
540 	struct ieee80211_chanctx *ctx;
541 
542 	lockdep_assert_held(&local->chanctx_mtx);
543 
544 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
545 		return NULL;
546 
547 	list_for_each_entry(ctx, &local->chanctx_list, list) {
548 		const struct cfg80211_chan_def *compat;
549 
550 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
551 			continue;
552 
553 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
554 			continue;
555 
556 		compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
557 		if (!compat)
558 			continue;
559 
560 		compat = ieee80211_chanctx_reserved_chandef(local, ctx,
561 							    compat);
562 		if (!compat)
563 			continue;
564 
565 		ieee80211_change_chanctx(local, ctx, ctx, compat);
566 
567 		return ctx;
568 	}
569 
570 	return NULL;
571 }
572 
573 bool ieee80211_is_radar_required(struct ieee80211_local *local)
574 {
575 	struct ieee80211_sub_if_data *sdata;
576 
577 	lockdep_assert_held(&local->mtx);
578 
579 	rcu_read_lock();
580 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
581 		unsigned int link_id;
582 
583 		for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
584 			struct ieee80211_link_data *link;
585 
586 			link = rcu_dereference(sdata->link[link_id]);
587 
588 			if (link && link->radar_required) {
589 				rcu_read_unlock();
590 				return true;
591 			}
592 		}
593 	}
594 	rcu_read_unlock();
595 
596 	return false;
597 }
598 
599 static bool
600 ieee80211_chanctx_radar_required(struct ieee80211_local *local,
601 				 struct ieee80211_chanctx *ctx)
602 {
603 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
604 	struct ieee80211_sub_if_data *sdata;
605 	bool required = false;
606 
607 	lockdep_assert_held(&local->chanctx_mtx);
608 	lockdep_assert_held(&local->mtx);
609 
610 	rcu_read_lock();
611 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
612 		unsigned int link_id;
613 
614 		if (!ieee80211_sdata_running(sdata))
615 			continue;
616 		for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
617 			struct ieee80211_link_data *link;
618 
619 			link = rcu_dereference(sdata->link[link_id]);
620 			if (!link)
621 				continue;
622 
623 			if (rcu_access_pointer(link->conf->chanctx_conf) != conf)
624 				continue;
625 			if (!link->radar_required)
626 				continue;
627 			required = true;
628 			break;
629 		}
630 
631 		if (required)
632 			break;
633 	}
634 	rcu_read_unlock();
635 
636 	return required;
637 }
638 
639 static struct ieee80211_chanctx *
640 ieee80211_alloc_chanctx(struct ieee80211_local *local,
641 			const struct cfg80211_chan_def *chandef,
642 			enum ieee80211_chanctx_mode mode)
643 {
644 	struct ieee80211_chanctx *ctx;
645 
646 	lockdep_assert_held(&local->chanctx_mtx);
647 
648 	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
649 	if (!ctx)
650 		return NULL;
651 
652 	INIT_LIST_HEAD(&ctx->assigned_links);
653 	INIT_LIST_HEAD(&ctx->reserved_links);
654 	ctx->conf.def = *chandef;
655 	ctx->conf.rx_chains_static = 1;
656 	ctx->conf.rx_chains_dynamic = 1;
657 	ctx->mode = mode;
658 	ctx->conf.radar_enabled = false;
659 	_ieee80211_recalc_chanctx_min_def(local, ctx, NULL);
660 
661 	return ctx;
662 }
663 
664 static int ieee80211_add_chanctx(struct ieee80211_local *local,
665 				 struct ieee80211_chanctx *ctx)
666 {
667 	u32 changed;
668 	int err;
669 
670 	lockdep_assert_held(&local->mtx);
671 	lockdep_assert_held(&local->chanctx_mtx);
672 
673 	if (!local->use_chanctx)
674 		local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
675 
676 	/* turn idle off *before* setting channel -- some drivers need that */
677 	changed = ieee80211_idle_off(local);
678 	if (changed)
679 		ieee80211_hw_config(local, changed);
680 
681 	if (!local->use_chanctx) {
682 		local->_oper_chandef = ctx->conf.def;
683 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
684 	} else {
685 		err = drv_add_chanctx(local, ctx);
686 		if (err) {
687 			ieee80211_recalc_idle(local);
688 			return err;
689 		}
690 	}
691 
692 	return 0;
693 }
694 
695 static struct ieee80211_chanctx *
696 ieee80211_new_chanctx(struct ieee80211_local *local,
697 		      const struct cfg80211_chan_def *chandef,
698 		      enum ieee80211_chanctx_mode mode)
699 {
700 	struct ieee80211_chanctx *ctx;
701 	int err;
702 
703 	lockdep_assert_held(&local->mtx);
704 	lockdep_assert_held(&local->chanctx_mtx);
705 
706 	ctx = ieee80211_alloc_chanctx(local, chandef, mode);
707 	if (!ctx)
708 		return ERR_PTR(-ENOMEM);
709 
710 	err = ieee80211_add_chanctx(local, ctx);
711 	if (err) {
712 		kfree(ctx);
713 		return ERR_PTR(err);
714 	}
715 
716 	list_add_rcu(&ctx->list, &local->chanctx_list);
717 	return ctx;
718 }
719 
720 static void ieee80211_del_chanctx(struct ieee80211_local *local,
721 				  struct ieee80211_chanctx *ctx)
722 {
723 	lockdep_assert_held(&local->chanctx_mtx);
724 
725 	if (!local->use_chanctx) {
726 		struct cfg80211_chan_def *chandef = &local->_oper_chandef;
727 		/* S1G doesn't have 20MHz, so get the correct width for the
728 		 * current channel.
729 		 */
730 		if (chandef->chan->band == NL80211_BAND_S1GHZ)
731 			chandef->width =
732 				ieee80211_s1g_channel_width(chandef->chan);
733 		else
734 			chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
735 		chandef->center_freq1 = chandef->chan->center_freq;
736 		chandef->freq1_offset = chandef->chan->freq_offset;
737 		chandef->center_freq2 = 0;
738 
739 		/* NOTE: Disabling radar is only valid here for
740 		 * single channel context. To be sure, check it ...
741 		 */
742 		WARN_ON(local->hw.conf.radar_enabled &&
743 			!list_empty(&local->chanctx_list));
744 
745 		local->hw.conf.radar_enabled = false;
746 
747 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
748 	} else {
749 		drv_remove_chanctx(local, ctx);
750 	}
751 
752 	ieee80211_recalc_idle(local);
753 }
754 
755 static void ieee80211_free_chanctx(struct ieee80211_local *local,
756 				   struct ieee80211_chanctx *ctx)
757 {
758 	lockdep_assert_held(&local->chanctx_mtx);
759 
760 	WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
761 
762 	list_del_rcu(&ctx->list);
763 	ieee80211_del_chanctx(local, ctx);
764 	kfree_rcu(ctx, rcu_head);
765 }
766 
767 void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
768 				       struct ieee80211_chanctx *ctx)
769 {
770 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
771 	struct ieee80211_sub_if_data *sdata;
772 	const struct cfg80211_chan_def *compat = NULL;
773 	struct sta_info *sta;
774 
775 	lockdep_assert_held(&local->chanctx_mtx);
776 
777 	rcu_read_lock();
778 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
779 		int link_id;
780 
781 		if (!ieee80211_sdata_running(sdata))
782 			continue;
783 
784 		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
785 			continue;
786 
787 		for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
788 			struct ieee80211_bss_conf *link_conf =
789 				rcu_dereference(sdata->vif.link_conf[link_id]);
790 
791 			if (!link_conf)
792 				continue;
793 
794 			if (rcu_access_pointer(link_conf->chanctx_conf) != conf)
795 				continue;
796 
797 			if (!compat)
798 				compat = &link_conf->chandef;
799 
800 			compat = cfg80211_chandef_compatible(&link_conf->chandef,
801 							     compat);
802 			if (WARN_ON_ONCE(!compat))
803 				break;
804 		}
805 	}
806 
807 	if (WARN_ON_ONCE(!compat)) {
808 		rcu_read_unlock();
809 		return;
810 	}
811 
812 	/* TDLS peers can sometimes affect the chandef width */
813 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
814 		if (!sta->uploaded ||
815 		    !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
816 		    !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
817 		    !sta->tdls_chandef.chan)
818 			continue;
819 
820 		compat = cfg80211_chandef_compatible(&sta->tdls_chandef,
821 						     compat);
822 		if (WARN_ON_ONCE(!compat))
823 			break;
824 	}
825 	rcu_read_unlock();
826 
827 	if (!compat)
828 		return;
829 
830 	ieee80211_change_chanctx(local, ctx, ctx, compat);
831 }
832 
833 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
834 					   struct ieee80211_chanctx *chanctx)
835 {
836 	bool radar_enabled;
837 
838 	lockdep_assert_held(&local->chanctx_mtx);
839 	/* for ieee80211_is_radar_required */
840 	lockdep_assert_held(&local->mtx);
841 
842 	radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
843 
844 	if (radar_enabled == chanctx->conf.radar_enabled)
845 		return;
846 
847 	chanctx->conf.radar_enabled = radar_enabled;
848 
849 	if (!local->use_chanctx) {
850 		local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
851 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
852 	}
853 
854 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
855 }
856 
857 static int ieee80211_assign_link_chanctx(struct ieee80211_link_data *link,
858 					 struct ieee80211_chanctx *new_ctx)
859 {
860 	struct ieee80211_sub_if_data *sdata = link->sdata;
861 	struct ieee80211_local *local = sdata->local;
862 	struct ieee80211_chanctx_conf *conf;
863 	struct ieee80211_chanctx *curr_ctx = NULL;
864 	int ret = 0;
865 
866 	if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN))
867 		return -ENOTSUPP;
868 
869 	conf = rcu_dereference_protected(link->conf->chanctx_conf,
870 					 lockdep_is_held(&local->chanctx_mtx));
871 
872 	if (conf) {
873 		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
874 
875 		drv_unassign_vif_chanctx(local, sdata, link->conf, curr_ctx);
876 		conf = NULL;
877 		list_del(&link->assigned_chanctx_list);
878 	}
879 
880 	if (new_ctx) {
881 		/* recalc considering the link we'll use it for now */
882 		ieee80211_recalc_chanctx_min_def(local, new_ctx, link);
883 
884 		ret = drv_assign_vif_chanctx(local, sdata, link->conf, new_ctx);
885 		if (ret)
886 			goto out;
887 
888 		conf = &new_ctx->conf;
889 		list_add(&link->assigned_chanctx_list,
890 			 &new_ctx->assigned_links);
891 	}
892 
893 out:
894 	rcu_assign_pointer(link->conf->chanctx_conf, conf);
895 
896 	sdata->vif.cfg.idle = !conf;
897 
898 	if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
899 		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
900 		ieee80211_recalc_smps_chanctx(local, curr_ctx);
901 		ieee80211_recalc_radar_chanctx(local, curr_ctx);
902 		ieee80211_recalc_chanctx_min_def(local, curr_ctx, NULL);
903 	}
904 
905 	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
906 		ieee80211_recalc_txpower(sdata, false);
907 		ieee80211_recalc_chanctx_min_def(local, new_ctx, NULL);
908 	}
909 
910 	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
911 	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
912 		ieee80211_vif_cfg_change_notify(sdata, BSS_CHANGED_IDLE);
913 
914 	ieee80211_check_fast_xmit_iface(sdata);
915 
916 	return ret;
917 }
918 
919 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
920 				   struct ieee80211_chanctx *chanctx)
921 {
922 	struct ieee80211_sub_if_data *sdata;
923 	u8 rx_chains_static, rx_chains_dynamic;
924 
925 	lockdep_assert_held(&local->chanctx_mtx);
926 
927 	rx_chains_static = 1;
928 	rx_chains_dynamic = 1;
929 
930 	rcu_read_lock();
931 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
932 		u8 needed_static, needed_dynamic;
933 		unsigned int link_id;
934 
935 		if (!ieee80211_sdata_running(sdata))
936 			continue;
937 
938 		switch (sdata->vif.type) {
939 		case NL80211_IFTYPE_STATION:
940 			if (!sdata->u.mgd.associated)
941 				continue;
942 			break;
943 		case NL80211_IFTYPE_AP:
944 		case NL80211_IFTYPE_ADHOC:
945 		case NL80211_IFTYPE_MESH_POINT:
946 		case NL80211_IFTYPE_OCB:
947 			break;
948 		default:
949 			continue;
950 		}
951 
952 		for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
953 			struct ieee80211_link_data *link;
954 
955 			link = rcu_dereference(sdata->link[link_id]);
956 
957 			if (!link)
958 				continue;
959 
960 			if (rcu_access_pointer(link->conf->chanctx_conf) != &chanctx->conf)
961 				continue;
962 
963 			switch (link->smps_mode) {
964 			default:
965 				WARN_ONCE(1, "Invalid SMPS mode %d\n",
966 					  link->smps_mode);
967 				fallthrough;
968 			case IEEE80211_SMPS_OFF:
969 				needed_static = link->needed_rx_chains;
970 				needed_dynamic = link->needed_rx_chains;
971 				break;
972 			case IEEE80211_SMPS_DYNAMIC:
973 				needed_static = 1;
974 				needed_dynamic = link->needed_rx_chains;
975 				break;
976 			case IEEE80211_SMPS_STATIC:
977 				needed_static = 1;
978 				needed_dynamic = 1;
979 				break;
980 			}
981 
982 			rx_chains_static = max(rx_chains_static, needed_static);
983 			rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
984 		}
985 	}
986 
987 	/* Disable SMPS for the monitor interface */
988 	sdata = rcu_dereference(local->monitor_sdata);
989 	if (sdata &&
990 	    rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) == &chanctx->conf)
991 		rx_chains_dynamic = rx_chains_static = local->rx_chains;
992 
993 	rcu_read_unlock();
994 
995 	if (!local->use_chanctx) {
996 		if (rx_chains_static > 1)
997 			local->smps_mode = IEEE80211_SMPS_OFF;
998 		else if (rx_chains_dynamic > 1)
999 			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
1000 		else
1001 			local->smps_mode = IEEE80211_SMPS_STATIC;
1002 		ieee80211_hw_config(local, 0);
1003 	}
1004 
1005 	if (rx_chains_static == chanctx->conf.rx_chains_static &&
1006 	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
1007 		return;
1008 
1009 	chanctx->conf.rx_chains_static = rx_chains_static;
1010 	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
1011 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
1012 }
1013 
1014 static void
1015 __ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link,
1016 				       bool clear)
1017 {
1018 	struct ieee80211_sub_if_data *sdata = link->sdata;
1019 	unsigned int link_id = link->link_id;
1020 	struct ieee80211_bss_conf *link_conf = link->conf;
1021 	struct ieee80211_local *local __maybe_unused = sdata->local;
1022 	struct ieee80211_sub_if_data *vlan;
1023 	struct ieee80211_chanctx_conf *conf;
1024 
1025 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
1026 		return;
1027 
1028 	lockdep_assert_held(&local->mtx);
1029 
1030 	/* Check that conf exists, even when clearing this function
1031 	 * must be called with the AP's channel context still there
1032 	 * as it would otherwise cause VLANs to have an invalid
1033 	 * channel context pointer for a while, possibly pointing
1034 	 * to a channel context that has already been freed.
1035 	 */
1036 	conf = rcu_dereference_protected(link_conf->chanctx_conf,
1037 					 lockdep_is_held(&local->chanctx_mtx));
1038 	WARN_ON(!conf);
1039 
1040 	if (clear)
1041 		conf = NULL;
1042 
1043 	rcu_read_lock();
1044 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
1045 		struct ieee80211_bss_conf *vlan_conf;
1046 
1047 		vlan_conf = rcu_dereference(vlan->vif.link_conf[link_id]);
1048 		if (WARN_ON(!vlan_conf))
1049 			continue;
1050 
1051 		rcu_assign_pointer(vlan_conf->chanctx_conf, conf);
1052 	}
1053 	rcu_read_unlock();
1054 }
1055 
1056 void ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link,
1057 					  bool clear)
1058 {
1059 	struct ieee80211_local *local = link->sdata->local;
1060 
1061 	mutex_lock(&local->chanctx_mtx);
1062 
1063 	__ieee80211_link_copy_chanctx_to_vlans(link, clear);
1064 
1065 	mutex_unlock(&local->chanctx_mtx);
1066 }
1067 
1068 int ieee80211_link_unreserve_chanctx(struct ieee80211_link_data *link)
1069 {
1070 	struct ieee80211_sub_if_data *sdata = link->sdata;
1071 	struct ieee80211_chanctx *ctx = link->reserved_chanctx;
1072 
1073 	lockdep_assert_held(&sdata->local->chanctx_mtx);
1074 
1075 	if (WARN_ON(!ctx))
1076 		return -EINVAL;
1077 
1078 	list_del(&link->reserved_chanctx_list);
1079 	link->reserved_chanctx = NULL;
1080 
1081 	if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
1082 		if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1083 			if (WARN_ON(!ctx->replace_ctx))
1084 				return -EINVAL;
1085 
1086 			WARN_ON(ctx->replace_ctx->replace_state !=
1087 			        IEEE80211_CHANCTX_WILL_BE_REPLACED);
1088 			WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
1089 
1090 			ctx->replace_ctx->replace_ctx = NULL;
1091 			ctx->replace_ctx->replace_state =
1092 					IEEE80211_CHANCTX_REPLACE_NONE;
1093 
1094 			list_del_rcu(&ctx->list);
1095 			kfree_rcu(ctx, rcu_head);
1096 		} else {
1097 			ieee80211_free_chanctx(sdata->local, ctx);
1098 		}
1099 	}
1100 
1101 	return 0;
1102 }
1103 
1104 int ieee80211_link_reserve_chanctx(struct ieee80211_link_data *link,
1105 				   const struct cfg80211_chan_def *chandef,
1106 				   enum ieee80211_chanctx_mode mode,
1107 				   bool radar_required)
1108 {
1109 	struct ieee80211_sub_if_data *sdata = link->sdata;
1110 	struct ieee80211_local *local = sdata->local;
1111 	struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
1112 
1113 	lockdep_assert_held(&local->chanctx_mtx);
1114 
1115 	curr_ctx = ieee80211_link_get_chanctx(link);
1116 	if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
1117 		return -ENOTSUPP;
1118 
1119 	new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
1120 	if (!new_ctx) {
1121 		if (ieee80211_can_create_new_chanctx(local)) {
1122 			new_ctx = ieee80211_new_chanctx(local, chandef, mode);
1123 			if (IS_ERR(new_ctx))
1124 				return PTR_ERR(new_ctx);
1125 		} else {
1126 			if (!curr_ctx ||
1127 			    (curr_ctx->replace_state ==
1128 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1129 			    !list_empty(&curr_ctx->reserved_links)) {
1130 				/*
1131 				 * Another link already requested this context
1132 				 * for a reservation. Find another one hoping
1133 				 * all links assigned to it will also switch
1134 				 * soon enough.
1135 				 *
1136 				 * TODO: This needs a little more work as some
1137 				 * cases (more than 2 chanctx capable devices)
1138 				 * may fail which could otherwise succeed
1139 				 * provided some channel context juggling was
1140 				 * performed.
1141 				 *
1142 				 * Consider ctx1..3, link1..6, each ctx has 2
1143 				 * links. link1 and link2 from ctx1 request new
1144 				 * different chandefs starting 2 in-place
1145 				 * reserations with ctx4 and ctx5 replacing
1146 				 * ctx1 and ctx2 respectively. Next link5 and
1147 				 * link6 from ctx3 reserve ctx4. If link3 and
1148 				 * link4 remain on ctx2 as they are then this
1149 				 * fails unless `replace_ctx` from ctx5 is
1150 				 * replaced with ctx3.
1151 				 */
1152 				list_for_each_entry(ctx, &local->chanctx_list,
1153 						    list) {
1154 					if (ctx->replace_state !=
1155 					    IEEE80211_CHANCTX_REPLACE_NONE)
1156 						continue;
1157 
1158 					if (!list_empty(&ctx->reserved_links))
1159 						continue;
1160 
1161 					curr_ctx = ctx;
1162 					break;
1163 				}
1164 			}
1165 
1166 			/*
1167 			 * If that's true then all available contexts already
1168 			 * have reservations and cannot be used.
1169 			 */
1170 			if (!curr_ctx ||
1171 			    (curr_ctx->replace_state ==
1172 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1173 			    !list_empty(&curr_ctx->reserved_links))
1174 				return -EBUSY;
1175 
1176 			new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
1177 			if (!new_ctx)
1178 				return -ENOMEM;
1179 
1180 			new_ctx->replace_ctx = curr_ctx;
1181 			new_ctx->replace_state =
1182 					IEEE80211_CHANCTX_REPLACES_OTHER;
1183 
1184 			curr_ctx->replace_ctx = new_ctx;
1185 			curr_ctx->replace_state =
1186 					IEEE80211_CHANCTX_WILL_BE_REPLACED;
1187 
1188 			list_add_rcu(&new_ctx->list, &local->chanctx_list);
1189 		}
1190 	}
1191 
1192 	list_add(&link->reserved_chanctx_list, &new_ctx->reserved_links);
1193 	link->reserved_chanctx = new_ctx;
1194 	link->reserved_chandef = *chandef;
1195 	link->reserved_radar_required = radar_required;
1196 	link->reserved_ready = false;
1197 
1198 	return 0;
1199 }
1200 
1201 static void
1202 ieee80211_link_chanctx_reservation_complete(struct ieee80211_link_data *link)
1203 {
1204 	struct ieee80211_sub_if_data *sdata = link->sdata;
1205 
1206 	switch (sdata->vif.type) {
1207 	case NL80211_IFTYPE_ADHOC:
1208 	case NL80211_IFTYPE_AP:
1209 	case NL80211_IFTYPE_MESH_POINT:
1210 	case NL80211_IFTYPE_OCB:
1211 		ieee80211_queue_work(&sdata->local->hw,
1212 				     &link->csa_finalize_work);
1213 		break;
1214 	case NL80211_IFTYPE_STATION:
1215 		wiphy_delayed_work_queue(sdata->local->hw.wiphy,
1216 					 &link->u.mgd.chswitch_work, 0);
1217 		break;
1218 	case NL80211_IFTYPE_UNSPECIFIED:
1219 	case NL80211_IFTYPE_AP_VLAN:
1220 	case NL80211_IFTYPE_WDS:
1221 	case NL80211_IFTYPE_MONITOR:
1222 	case NL80211_IFTYPE_P2P_CLIENT:
1223 	case NL80211_IFTYPE_P2P_GO:
1224 	case NL80211_IFTYPE_P2P_DEVICE:
1225 	case NL80211_IFTYPE_NAN:
1226 	case NUM_NL80211_IFTYPES:
1227 		WARN_ON(1);
1228 		break;
1229 	}
1230 }
1231 
1232 static void
1233 ieee80211_link_update_chandef(struct ieee80211_link_data *link,
1234 			      const struct cfg80211_chan_def *chandef)
1235 {
1236 	struct ieee80211_sub_if_data *sdata = link->sdata;
1237 	unsigned int link_id = link->link_id;
1238 	struct ieee80211_sub_if_data *vlan;
1239 
1240 	link->conf->chandef = *chandef;
1241 
1242 	if (sdata->vif.type != NL80211_IFTYPE_AP)
1243 		return;
1244 
1245 	rcu_read_lock();
1246 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
1247 		struct ieee80211_bss_conf *vlan_conf;
1248 
1249 		vlan_conf = rcu_dereference(vlan->vif.link_conf[link_id]);
1250 		if (WARN_ON(!vlan_conf))
1251 			continue;
1252 
1253 		vlan_conf->chandef = *chandef;
1254 	}
1255 	rcu_read_unlock();
1256 }
1257 
1258 static int
1259 ieee80211_link_use_reserved_reassign(struct ieee80211_link_data *link)
1260 {
1261 	struct ieee80211_sub_if_data *sdata = link->sdata;
1262 	struct ieee80211_bss_conf *link_conf = link->conf;
1263 	struct ieee80211_local *local = sdata->local;
1264 	struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1265 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1266 	const struct cfg80211_chan_def *chandef;
1267 	u64 changed = 0;
1268 	int err;
1269 
1270 	lockdep_assert_held(&local->mtx);
1271 	lockdep_assert_held(&local->chanctx_mtx);
1272 
1273 	new_ctx = link->reserved_chanctx;
1274 	old_ctx = ieee80211_link_get_chanctx(link);
1275 
1276 	if (WARN_ON(!link->reserved_ready))
1277 		return -EBUSY;
1278 
1279 	if (WARN_ON(!new_ctx))
1280 		return -EINVAL;
1281 
1282 	if (WARN_ON(!old_ctx))
1283 		return -EINVAL;
1284 
1285 	if (WARN_ON(new_ctx->replace_state ==
1286 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1287 		return -EINVAL;
1288 
1289 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1290 				&link->reserved_chandef);
1291 	if (WARN_ON(!chandef))
1292 		return -EINVAL;
1293 
1294 	if (link_conf->chandef.width != link->reserved_chandef.width)
1295 		changed = BSS_CHANGED_BANDWIDTH;
1296 
1297 	ieee80211_link_update_chandef(link, &link->reserved_chandef);
1298 
1299 	_ieee80211_change_chanctx(local, new_ctx, old_ctx, chandef, link);
1300 
1301 	vif_chsw[0].vif = &sdata->vif;
1302 	vif_chsw[0].old_ctx = &old_ctx->conf;
1303 	vif_chsw[0].new_ctx = &new_ctx->conf;
1304 	vif_chsw[0].link_conf = link->conf;
1305 
1306 	list_del(&link->reserved_chanctx_list);
1307 	link->reserved_chanctx = NULL;
1308 
1309 	err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1310 				     CHANCTX_SWMODE_REASSIGN_VIF);
1311 	if (err) {
1312 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1313 			ieee80211_free_chanctx(local, new_ctx);
1314 
1315 		goto out;
1316 	}
1317 
1318 	list_move(&link->assigned_chanctx_list, &new_ctx->assigned_links);
1319 	rcu_assign_pointer(link_conf->chanctx_conf, &new_ctx->conf);
1320 
1321 	if (sdata->vif.type == NL80211_IFTYPE_AP)
1322 		__ieee80211_link_copy_chanctx_to_vlans(link, false);
1323 
1324 	ieee80211_check_fast_xmit_iface(sdata);
1325 
1326 	if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1327 		ieee80211_free_chanctx(local, old_ctx);
1328 
1329 	ieee80211_recalc_chanctx_min_def(local, new_ctx, NULL);
1330 	ieee80211_recalc_smps_chanctx(local, new_ctx);
1331 	ieee80211_recalc_radar_chanctx(local, new_ctx);
1332 
1333 	if (changed)
1334 		ieee80211_link_info_change_notify(sdata, link, changed);
1335 
1336 out:
1337 	ieee80211_link_chanctx_reservation_complete(link);
1338 	return err;
1339 }
1340 
1341 static int
1342 ieee80211_link_use_reserved_assign(struct ieee80211_link_data *link)
1343 {
1344 	struct ieee80211_sub_if_data *sdata = link->sdata;
1345 	struct ieee80211_local *local = sdata->local;
1346 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1347 	const struct cfg80211_chan_def *chandef;
1348 	int err;
1349 
1350 	old_ctx = ieee80211_link_get_chanctx(link);
1351 	new_ctx = link->reserved_chanctx;
1352 
1353 	if (WARN_ON(!link->reserved_ready))
1354 		return -EINVAL;
1355 
1356 	if (WARN_ON(old_ctx))
1357 		return -EINVAL;
1358 
1359 	if (WARN_ON(!new_ctx))
1360 		return -EINVAL;
1361 
1362 	if (WARN_ON(new_ctx->replace_state ==
1363 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1364 		return -EINVAL;
1365 
1366 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1367 				&link->reserved_chandef);
1368 	if (WARN_ON(!chandef))
1369 		return -EINVAL;
1370 
1371 	ieee80211_change_chanctx(local, new_ctx, new_ctx, chandef);
1372 
1373 	list_del(&link->reserved_chanctx_list);
1374 	link->reserved_chanctx = NULL;
1375 
1376 	err = ieee80211_assign_link_chanctx(link, new_ctx);
1377 	if (err) {
1378 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1379 			ieee80211_free_chanctx(local, new_ctx);
1380 
1381 		goto out;
1382 	}
1383 
1384 out:
1385 	ieee80211_link_chanctx_reservation_complete(link);
1386 	return err;
1387 }
1388 
1389 static bool
1390 ieee80211_link_has_in_place_reservation(struct ieee80211_link_data *link)
1391 {
1392 	struct ieee80211_sub_if_data *sdata = link->sdata;
1393 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1394 
1395 	lockdep_assert_held(&sdata->local->chanctx_mtx);
1396 
1397 	new_ctx = link->reserved_chanctx;
1398 	old_ctx = ieee80211_link_get_chanctx(link);
1399 
1400 	if (!old_ctx)
1401 		return false;
1402 
1403 	if (WARN_ON(!new_ctx))
1404 		return false;
1405 
1406 	if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1407 		return false;
1408 
1409 	if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1410 		return false;
1411 
1412 	return true;
1413 }
1414 
1415 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1416 					struct ieee80211_chanctx *new_ctx)
1417 {
1418 	const struct cfg80211_chan_def *chandef;
1419 
1420 	lockdep_assert_held(&local->mtx);
1421 	lockdep_assert_held(&local->chanctx_mtx);
1422 
1423 	chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1424 	if (WARN_ON(!chandef))
1425 		return -EINVAL;
1426 
1427 	local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1428 	local->_oper_chandef = *chandef;
1429 	ieee80211_hw_config(local, 0);
1430 
1431 	return 0;
1432 }
1433 
1434 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1435 				      int n_vifs)
1436 {
1437 	struct ieee80211_vif_chanctx_switch *vif_chsw;
1438 	struct ieee80211_link_data *link;
1439 	struct ieee80211_chanctx *ctx, *old_ctx;
1440 	int i, err;
1441 
1442 	lockdep_assert_held(&local->mtx);
1443 	lockdep_assert_held(&local->chanctx_mtx);
1444 
1445 	vif_chsw = kcalloc(n_vifs, sizeof(vif_chsw[0]), GFP_KERNEL);
1446 	if (!vif_chsw)
1447 		return -ENOMEM;
1448 
1449 	i = 0;
1450 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1451 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1452 			continue;
1453 
1454 		if (WARN_ON(!ctx->replace_ctx)) {
1455 			err = -EINVAL;
1456 			goto out;
1457 		}
1458 
1459 		list_for_each_entry(link, &ctx->reserved_links,
1460 				    reserved_chanctx_list) {
1461 			if (!ieee80211_link_has_in_place_reservation(link))
1462 				continue;
1463 
1464 			old_ctx = ieee80211_link_get_chanctx(link);
1465 			vif_chsw[i].vif = &link->sdata->vif;
1466 			vif_chsw[i].old_ctx = &old_ctx->conf;
1467 			vif_chsw[i].new_ctx = &ctx->conf;
1468 			vif_chsw[i].link_conf = link->conf;
1469 
1470 			i++;
1471 		}
1472 	}
1473 
1474 	err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1475 				     CHANCTX_SWMODE_SWAP_CONTEXTS);
1476 
1477 out:
1478 	kfree(vif_chsw);
1479 	return err;
1480 }
1481 
1482 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1483 {
1484 	struct ieee80211_chanctx *ctx;
1485 	int err;
1486 
1487 	lockdep_assert_held(&local->mtx);
1488 	lockdep_assert_held(&local->chanctx_mtx);
1489 
1490 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1491 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1492 			continue;
1493 
1494 		if (!list_empty(&ctx->replace_ctx->assigned_links))
1495 			continue;
1496 
1497 		ieee80211_del_chanctx(local, ctx->replace_ctx);
1498 		err = ieee80211_add_chanctx(local, ctx);
1499 		if (err)
1500 			goto err;
1501 	}
1502 
1503 	return 0;
1504 
1505 err:
1506 	WARN_ON(ieee80211_add_chanctx(local, ctx));
1507 	list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1508 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1509 			continue;
1510 
1511 		if (!list_empty(&ctx->replace_ctx->assigned_links))
1512 			continue;
1513 
1514 		ieee80211_del_chanctx(local, ctx);
1515 		WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1516 	}
1517 
1518 	return err;
1519 }
1520 
1521 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1522 {
1523 	struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1524 	struct ieee80211_chanctx *new_ctx = NULL;
1525 	int err, n_assigned, n_reserved, n_ready;
1526 	int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1527 
1528 	lockdep_assert_held(&local->mtx);
1529 	lockdep_assert_held(&local->chanctx_mtx);
1530 
1531 	/*
1532 	 * If there are 2 independent pairs of channel contexts performing
1533 	 * cross-switch of their vifs this code will still wait until both are
1534 	 * ready even though it could be possible to switch one before the
1535 	 * other is ready.
1536 	 *
1537 	 * For practical reasons and code simplicity just do a single huge
1538 	 * switch.
1539 	 */
1540 
1541 	/*
1542 	 * Verify if the reservation is still feasible.
1543 	 *  - if it's not then disconnect
1544 	 *  - if it is but not all vifs necessary are ready then defer
1545 	 */
1546 
1547 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1548 		struct ieee80211_link_data *link;
1549 
1550 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1551 			continue;
1552 
1553 		if (WARN_ON(!ctx->replace_ctx)) {
1554 			err = -EINVAL;
1555 			goto err;
1556 		}
1557 
1558 		if (!local->use_chanctx)
1559 			new_ctx = ctx;
1560 
1561 		n_ctx++;
1562 
1563 		n_assigned = 0;
1564 		n_reserved = 0;
1565 		n_ready = 0;
1566 
1567 		list_for_each_entry(link, &ctx->replace_ctx->assigned_links,
1568 				    assigned_chanctx_list) {
1569 			n_assigned++;
1570 			if (link->reserved_chanctx) {
1571 				n_reserved++;
1572 				if (link->reserved_ready)
1573 					n_ready++;
1574 			}
1575 		}
1576 
1577 		if (n_assigned != n_reserved) {
1578 			if (n_ready == n_reserved) {
1579 				wiphy_info(local->hw.wiphy,
1580 					   "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1581 				err = -EBUSY;
1582 				goto err;
1583 			}
1584 
1585 			return -EAGAIN;
1586 		}
1587 
1588 		ctx->conf.radar_enabled = false;
1589 		list_for_each_entry(link, &ctx->reserved_links,
1590 				    reserved_chanctx_list) {
1591 			if (ieee80211_link_has_in_place_reservation(link) &&
1592 			    !link->reserved_ready)
1593 				return -EAGAIN;
1594 
1595 			old_ctx = ieee80211_link_get_chanctx(link);
1596 			if (old_ctx) {
1597 				if (old_ctx->replace_state ==
1598 				    IEEE80211_CHANCTX_WILL_BE_REPLACED)
1599 					n_vifs_switch++;
1600 				else
1601 					n_vifs_assign++;
1602 			} else {
1603 				n_vifs_ctxless++;
1604 			}
1605 
1606 			if (link->reserved_radar_required)
1607 				ctx->conf.radar_enabled = true;
1608 		}
1609 	}
1610 
1611 	if (WARN_ON(n_ctx == 0) ||
1612 	    WARN_ON(n_vifs_switch == 0 &&
1613 		    n_vifs_assign == 0 &&
1614 		    n_vifs_ctxless == 0) ||
1615 	    WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1616 	    WARN_ON(!new_ctx && !local->use_chanctx)) {
1617 		err = -EINVAL;
1618 		goto err;
1619 	}
1620 
1621 	/*
1622 	 * All necessary vifs are ready. Perform the switch now depending on
1623 	 * reservations and driver capabilities.
1624 	 */
1625 
1626 	if (local->use_chanctx) {
1627 		if (n_vifs_switch > 0) {
1628 			err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1629 			if (err)
1630 				goto err;
1631 		}
1632 
1633 		if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1634 			err = ieee80211_chsw_switch_ctxs(local);
1635 			if (err)
1636 				goto err;
1637 		}
1638 	} else {
1639 		err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1640 		if (err)
1641 			goto err;
1642 	}
1643 
1644 	/*
1645 	 * Update all structures, values and pointers to point to new channel
1646 	 * context(s).
1647 	 */
1648 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1649 		struct ieee80211_link_data *link, *link_tmp;
1650 
1651 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1652 			continue;
1653 
1654 		if (WARN_ON(!ctx->replace_ctx)) {
1655 			err = -EINVAL;
1656 			goto err;
1657 		}
1658 
1659 		list_for_each_entry(link, &ctx->reserved_links,
1660 				    reserved_chanctx_list) {
1661 			struct ieee80211_sub_if_data *sdata = link->sdata;
1662 			struct ieee80211_bss_conf *link_conf = link->conf;
1663 			u64 changed = 0;
1664 
1665 			if (!ieee80211_link_has_in_place_reservation(link))
1666 				continue;
1667 
1668 			rcu_assign_pointer(link_conf->chanctx_conf,
1669 					   &ctx->conf);
1670 
1671 			if (sdata->vif.type == NL80211_IFTYPE_AP)
1672 				__ieee80211_link_copy_chanctx_to_vlans(link,
1673 								       false);
1674 
1675 			ieee80211_check_fast_xmit_iface(sdata);
1676 
1677 			link->radar_required = link->reserved_radar_required;
1678 
1679 			if (link_conf->chandef.width != link->reserved_chandef.width)
1680 				changed = BSS_CHANGED_BANDWIDTH;
1681 
1682 			ieee80211_link_update_chandef(link, &link->reserved_chandef);
1683 			if (changed)
1684 				ieee80211_link_info_change_notify(sdata,
1685 								  link,
1686 								  changed);
1687 
1688 			ieee80211_recalc_txpower(sdata, false);
1689 		}
1690 
1691 		ieee80211_recalc_chanctx_chantype(local, ctx);
1692 		ieee80211_recalc_smps_chanctx(local, ctx);
1693 		ieee80211_recalc_radar_chanctx(local, ctx);
1694 		ieee80211_recalc_chanctx_min_def(local, ctx, NULL);
1695 
1696 		list_for_each_entry_safe(link, link_tmp, &ctx->reserved_links,
1697 					 reserved_chanctx_list) {
1698 			if (ieee80211_link_get_chanctx(link) != ctx)
1699 				continue;
1700 
1701 			list_del(&link->reserved_chanctx_list);
1702 			list_move(&link->assigned_chanctx_list,
1703 				  &ctx->assigned_links);
1704 			link->reserved_chanctx = NULL;
1705 
1706 			ieee80211_link_chanctx_reservation_complete(link);
1707 		}
1708 
1709 		/*
1710 		 * This context might have been a dependency for an already
1711 		 * ready re-assign reservation interface that was deferred. Do
1712 		 * not propagate error to the caller though. The in-place
1713 		 * reservation for originally requested interface has already
1714 		 * succeeded at this point.
1715 		 */
1716 		list_for_each_entry_safe(link, link_tmp, &ctx->reserved_links,
1717 					 reserved_chanctx_list) {
1718 			if (WARN_ON(ieee80211_link_has_in_place_reservation(link)))
1719 				continue;
1720 
1721 			if (WARN_ON(link->reserved_chanctx != ctx))
1722 				continue;
1723 
1724 			if (!link->reserved_ready)
1725 				continue;
1726 
1727 			if (ieee80211_link_get_chanctx(link))
1728 				err = ieee80211_link_use_reserved_reassign(link);
1729 			else
1730 				err = ieee80211_link_use_reserved_assign(link);
1731 
1732 			if (err) {
1733 				link_info(link,
1734 					  "failed to finalize (re-)assign reservation (err=%d)\n",
1735 					  err);
1736 				ieee80211_link_unreserve_chanctx(link);
1737 				cfg80211_stop_iface(local->hw.wiphy,
1738 						    &link->sdata->wdev,
1739 						    GFP_KERNEL);
1740 			}
1741 		}
1742 	}
1743 
1744 	/*
1745 	 * Finally free old contexts
1746 	 */
1747 
1748 	list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1749 		if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1750 			continue;
1751 
1752 		ctx->replace_ctx->replace_ctx = NULL;
1753 		ctx->replace_ctx->replace_state =
1754 				IEEE80211_CHANCTX_REPLACE_NONE;
1755 
1756 		list_del_rcu(&ctx->list);
1757 		kfree_rcu(ctx, rcu_head);
1758 	}
1759 
1760 	return 0;
1761 
1762 err:
1763 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1764 		struct ieee80211_link_data *link, *link_tmp;
1765 
1766 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1767 			continue;
1768 
1769 		list_for_each_entry_safe(link, link_tmp, &ctx->reserved_links,
1770 					 reserved_chanctx_list) {
1771 			ieee80211_link_unreserve_chanctx(link);
1772 			ieee80211_link_chanctx_reservation_complete(link);
1773 		}
1774 	}
1775 
1776 	return err;
1777 }
1778 
1779 static void __ieee80211_link_release_channel(struct ieee80211_link_data *link)
1780 {
1781 	struct ieee80211_sub_if_data *sdata = link->sdata;
1782 	struct ieee80211_bss_conf *link_conf = link->conf;
1783 	struct ieee80211_local *local = sdata->local;
1784 	struct ieee80211_chanctx_conf *conf;
1785 	struct ieee80211_chanctx *ctx;
1786 	bool use_reserved_switch = false;
1787 
1788 	lockdep_assert_held(&local->chanctx_mtx);
1789 
1790 	conf = rcu_dereference_protected(link_conf->chanctx_conf,
1791 					 lockdep_is_held(&local->chanctx_mtx));
1792 	if (!conf)
1793 		return;
1794 
1795 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1796 
1797 	if (link->reserved_chanctx) {
1798 		if (link->reserved_chanctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER &&
1799 		    ieee80211_chanctx_num_reserved(local, link->reserved_chanctx) > 1)
1800 			use_reserved_switch = true;
1801 
1802 		ieee80211_link_unreserve_chanctx(link);
1803 	}
1804 
1805 	ieee80211_assign_link_chanctx(link, NULL);
1806 	if (ieee80211_chanctx_refcount(local, ctx) == 0)
1807 		ieee80211_free_chanctx(local, ctx);
1808 
1809 	link->radar_required = false;
1810 
1811 	/* Unreserving may ready an in-place reservation. */
1812 	if (use_reserved_switch)
1813 		ieee80211_vif_use_reserved_switch(local);
1814 }
1815 
1816 int ieee80211_link_use_channel(struct ieee80211_link_data *link,
1817 			       const struct cfg80211_chan_def *chandef,
1818 			       enum ieee80211_chanctx_mode mode)
1819 {
1820 	struct ieee80211_sub_if_data *sdata = link->sdata;
1821 	struct ieee80211_local *local = sdata->local;
1822 	struct ieee80211_chanctx *ctx;
1823 	u8 radar_detect_width = 0;
1824 	int ret;
1825 
1826 	lockdep_assert_held(&local->mtx);
1827 
1828 	if (sdata->vif.active_links &&
1829 	    !(sdata->vif.active_links & BIT(link->link_id))) {
1830 		ieee80211_link_update_chandef(link, chandef);
1831 		return 0;
1832 	}
1833 
1834 	mutex_lock(&local->chanctx_mtx);
1835 
1836 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1837 					    chandef,
1838 					    sdata->wdev.iftype);
1839 	if (ret < 0)
1840 		goto out;
1841 	if (ret > 0)
1842 		radar_detect_width = BIT(chandef->width);
1843 
1844 	link->radar_required = ret;
1845 
1846 	ret = ieee80211_check_combinations(sdata, chandef, mode,
1847 					   radar_detect_width);
1848 	if (ret < 0)
1849 		goto out;
1850 
1851 	__ieee80211_link_release_channel(link);
1852 
1853 	ctx = ieee80211_find_chanctx(local, chandef, mode);
1854 	if (!ctx)
1855 		ctx = ieee80211_new_chanctx(local, chandef, mode);
1856 	if (IS_ERR(ctx)) {
1857 		ret = PTR_ERR(ctx);
1858 		goto out;
1859 	}
1860 
1861 	ieee80211_link_update_chandef(link, chandef);
1862 
1863 	ret = ieee80211_assign_link_chanctx(link, ctx);
1864 	if (ret) {
1865 		/* if assign fails refcount stays the same */
1866 		if (ieee80211_chanctx_refcount(local, ctx) == 0)
1867 			ieee80211_free_chanctx(local, ctx);
1868 		goto out;
1869 	}
1870 
1871 	ieee80211_recalc_smps_chanctx(local, ctx);
1872 	ieee80211_recalc_radar_chanctx(local, ctx);
1873  out:
1874 	if (ret)
1875 		link->radar_required = false;
1876 
1877 	mutex_unlock(&local->chanctx_mtx);
1878 	return ret;
1879 }
1880 
1881 int ieee80211_link_use_reserved_context(struct ieee80211_link_data *link)
1882 {
1883 	struct ieee80211_sub_if_data *sdata = link->sdata;
1884 	struct ieee80211_local *local = sdata->local;
1885 	struct ieee80211_chanctx *new_ctx;
1886 	struct ieee80211_chanctx *old_ctx;
1887 	int err;
1888 
1889 	lockdep_assert_held(&local->mtx);
1890 	lockdep_assert_held(&local->chanctx_mtx);
1891 
1892 	new_ctx = link->reserved_chanctx;
1893 	old_ctx = ieee80211_link_get_chanctx(link);
1894 
1895 	if (WARN_ON(!new_ctx))
1896 		return -EINVAL;
1897 
1898 	if (WARN_ON(new_ctx->replace_state ==
1899 		    IEEE80211_CHANCTX_WILL_BE_REPLACED))
1900 		return -EINVAL;
1901 
1902 	if (WARN_ON(link->reserved_ready))
1903 		return -EINVAL;
1904 
1905 	link->reserved_ready = true;
1906 
1907 	if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1908 		if (old_ctx)
1909 			return ieee80211_link_use_reserved_reassign(link);
1910 
1911 		return ieee80211_link_use_reserved_assign(link);
1912 	}
1913 
1914 	/*
1915 	 * In-place reservation may need to be finalized now either if:
1916 	 *  a) sdata is taking part in the swapping itself and is the last one
1917 	 *  b) sdata has switched with a re-assign reservation to an existing
1918 	 *     context readying in-place switching of old_ctx
1919 	 *
1920 	 * In case of (b) do not propagate the error up because the requested
1921 	 * sdata already switched successfully. Just spill an extra warning.
1922 	 * The ieee80211_vif_use_reserved_switch() already stops all necessary
1923 	 * interfaces upon failure.
1924 	 */
1925 	if ((old_ctx &&
1926 	     old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1927 	    new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1928 		err = ieee80211_vif_use_reserved_switch(local);
1929 		if (err && err != -EAGAIN) {
1930 			if (new_ctx->replace_state ==
1931 			    IEEE80211_CHANCTX_REPLACES_OTHER)
1932 				return err;
1933 
1934 			wiphy_info(local->hw.wiphy,
1935 				   "depending in-place reservation failed (err=%d)\n",
1936 				   err);
1937 		}
1938 	}
1939 
1940 	return 0;
1941 }
1942 
1943 int ieee80211_link_change_bandwidth(struct ieee80211_link_data *link,
1944 				    const struct cfg80211_chan_def *chandef,
1945 				    u64 *changed)
1946 {
1947 	struct ieee80211_sub_if_data *sdata = link->sdata;
1948 	struct ieee80211_bss_conf *link_conf = link->conf;
1949 	struct ieee80211_local *local = sdata->local;
1950 	struct ieee80211_chanctx_conf *conf;
1951 	struct ieee80211_chanctx *ctx;
1952 	const struct cfg80211_chan_def *compat;
1953 	int ret;
1954 
1955 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1956 				     IEEE80211_CHAN_DISABLED))
1957 		return -EINVAL;
1958 
1959 	mutex_lock(&local->chanctx_mtx);
1960 	if (cfg80211_chandef_identical(chandef, &link_conf->chandef)) {
1961 		ret = 0;
1962 		goto out;
1963 	}
1964 
1965 	if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1966 	    link_conf->chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1967 		ret = -EINVAL;
1968 		goto out;
1969 	}
1970 
1971 	conf = rcu_dereference_protected(link_conf->chanctx_conf,
1972 					 lockdep_is_held(&local->chanctx_mtx));
1973 	if (!conf) {
1974 		ret = -EINVAL;
1975 		goto out;
1976 	}
1977 
1978 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1979 
1980 	compat = cfg80211_chandef_compatible(&conf->def, chandef);
1981 	if (!compat) {
1982 		ret = -EINVAL;
1983 		goto out;
1984 	}
1985 
1986 	switch (ctx->replace_state) {
1987 	case IEEE80211_CHANCTX_REPLACE_NONE:
1988 		if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1989 			ret = -EBUSY;
1990 			goto out;
1991 		}
1992 		break;
1993 	case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1994 		/* TODO: Perhaps the bandwidth change could be treated as a
1995 		 * reservation itself? */
1996 		ret = -EBUSY;
1997 		goto out;
1998 	case IEEE80211_CHANCTX_REPLACES_OTHER:
1999 		/* channel context that is going to replace another channel
2000 		 * context doesn't really exist and shouldn't be assigned
2001 		 * anywhere yet */
2002 		WARN_ON(1);
2003 		break;
2004 	}
2005 
2006 	ieee80211_link_update_chandef(link, chandef);
2007 
2008 	ieee80211_recalc_chanctx_chantype(local, ctx);
2009 
2010 	*changed |= BSS_CHANGED_BANDWIDTH;
2011 	ret = 0;
2012  out:
2013 	mutex_unlock(&local->chanctx_mtx);
2014 	return ret;
2015 }
2016 
2017 void ieee80211_link_release_channel(struct ieee80211_link_data *link)
2018 {
2019 	struct ieee80211_sub_if_data *sdata = link->sdata;
2020 
2021 	mutex_lock(&sdata->local->chanctx_mtx);
2022 	if (rcu_access_pointer(link->conf->chanctx_conf)) {
2023 		lockdep_assert_held(&sdata->local->mtx);
2024 		__ieee80211_link_release_channel(link);
2025 	}
2026 	mutex_unlock(&sdata->local->chanctx_mtx);
2027 }
2028 
2029 void ieee80211_link_vlan_copy_chanctx(struct ieee80211_link_data *link)
2030 {
2031 	struct ieee80211_sub_if_data *sdata = link->sdata;
2032 	unsigned int link_id = link->link_id;
2033 	struct ieee80211_bss_conf *link_conf = link->conf;
2034 	struct ieee80211_bss_conf *ap_conf;
2035 	struct ieee80211_local *local = sdata->local;
2036 	struct ieee80211_sub_if_data *ap;
2037 	struct ieee80211_chanctx_conf *conf;
2038 
2039 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
2040 		return;
2041 
2042 	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
2043 
2044 	mutex_lock(&local->chanctx_mtx);
2045 
2046 	rcu_read_lock();
2047 	ap_conf = rcu_dereference(ap->vif.link_conf[link_id]);
2048 	conf = rcu_dereference_protected(ap_conf->chanctx_conf,
2049 					 lockdep_is_held(&local->chanctx_mtx));
2050 	rcu_assign_pointer(link_conf->chanctx_conf, conf);
2051 	rcu_read_unlock();
2052 	mutex_unlock(&local->chanctx_mtx);
2053 }
2054 
2055 void ieee80211_iter_chan_contexts_atomic(
2056 	struct ieee80211_hw *hw,
2057 	void (*iter)(struct ieee80211_hw *hw,
2058 		     struct ieee80211_chanctx_conf *chanctx_conf,
2059 		     void *data),
2060 	void *iter_data)
2061 {
2062 	struct ieee80211_local *local = hw_to_local(hw);
2063 	struct ieee80211_chanctx *ctx;
2064 
2065 	rcu_read_lock();
2066 	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
2067 		if (ctx->driver_present)
2068 			iter(hw, &ctx->conf, iter_data);
2069 	rcu_read_unlock();
2070 }
2071 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);
2072