xref: /openbmc/linux/net/mac80211/chan.c (revision 37744fee)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * mac80211 - channel management
4  */
5 
6 #include <linux/nl80211.h>
7 #include <linux/export.h>
8 #include <linux/rtnetlink.h>
9 #include <net/cfg80211.h>
10 #include "ieee80211_i.h"
11 #include "driver-ops.h"
12 
13 static int ieee80211_chanctx_num_assigned(struct ieee80211_local *local,
14 					  struct ieee80211_chanctx *ctx)
15 {
16 	struct ieee80211_sub_if_data *sdata;
17 	int num = 0;
18 
19 	lockdep_assert_held(&local->chanctx_mtx);
20 
21 	list_for_each_entry(sdata, &ctx->assigned_vifs, assigned_chanctx_list)
22 		num++;
23 
24 	return num;
25 }
26 
27 static int ieee80211_chanctx_num_reserved(struct ieee80211_local *local,
28 					  struct ieee80211_chanctx *ctx)
29 {
30 	struct ieee80211_sub_if_data *sdata;
31 	int num = 0;
32 
33 	lockdep_assert_held(&local->chanctx_mtx);
34 
35 	list_for_each_entry(sdata, &ctx->reserved_vifs, reserved_chanctx_list)
36 		num++;
37 
38 	return num;
39 }
40 
41 int ieee80211_chanctx_refcount(struct ieee80211_local *local,
42 			       struct ieee80211_chanctx *ctx)
43 {
44 	return ieee80211_chanctx_num_assigned(local, ctx) +
45 	       ieee80211_chanctx_num_reserved(local, ctx);
46 }
47 
48 static int ieee80211_num_chanctx(struct ieee80211_local *local)
49 {
50 	struct ieee80211_chanctx *ctx;
51 	int num = 0;
52 
53 	lockdep_assert_held(&local->chanctx_mtx);
54 
55 	list_for_each_entry(ctx, &local->chanctx_list, list)
56 		num++;
57 
58 	return num;
59 }
60 
61 static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local)
62 {
63 	lockdep_assert_held(&local->chanctx_mtx);
64 	return ieee80211_num_chanctx(local) < ieee80211_max_num_channels(local);
65 }
66 
67 static struct ieee80211_chanctx *
68 ieee80211_vif_get_chanctx(struct ieee80211_sub_if_data *sdata)
69 {
70 	struct ieee80211_local *local __maybe_unused = sdata->local;
71 	struct ieee80211_chanctx_conf *conf;
72 
73 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
74 					 lockdep_is_held(&local->chanctx_mtx));
75 	if (!conf)
76 		return NULL;
77 
78 	return container_of(conf, struct ieee80211_chanctx, conf);
79 }
80 
81 static const struct cfg80211_chan_def *
82 ieee80211_chanctx_reserved_chandef(struct ieee80211_local *local,
83 				   struct ieee80211_chanctx *ctx,
84 				   const struct cfg80211_chan_def *compat)
85 {
86 	struct ieee80211_sub_if_data *sdata;
87 
88 	lockdep_assert_held(&local->chanctx_mtx);
89 
90 	list_for_each_entry(sdata, &ctx->reserved_vifs,
91 			    reserved_chanctx_list) {
92 		if (!compat)
93 			compat = &sdata->reserved_chandef;
94 
95 		compat = cfg80211_chandef_compatible(&sdata->reserved_chandef,
96 						     compat);
97 		if (!compat)
98 			break;
99 	}
100 
101 	return compat;
102 }
103 
104 static const struct cfg80211_chan_def *
105 ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local *local,
106 				       struct ieee80211_chanctx *ctx,
107 				       const struct cfg80211_chan_def *compat)
108 {
109 	struct ieee80211_sub_if_data *sdata;
110 
111 	lockdep_assert_held(&local->chanctx_mtx);
112 
113 	list_for_each_entry(sdata, &ctx->assigned_vifs,
114 			    assigned_chanctx_list) {
115 		if (sdata->reserved_chanctx != NULL)
116 			continue;
117 
118 		if (!compat)
119 			compat = &sdata->vif.bss_conf.chandef;
120 
121 		compat = cfg80211_chandef_compatible(
122 				&sdata->vif.bss_conf.chandef, compat);
123 		if (!compat)
124 			break;
125 	}
126 
127 	return compat;
128 }
129 
130 static const struct cfg80211_chan_def *
131 ieee80211_chanctx_combined_chandef(struct ieee80211_local *local,
132 				   struct ieee80211_chanctx *ctx,
133 				   const struct cfg80211_chan_def *compat)
134 {
135 	lockdep_assert_held(&local->chanctx_mtx);
136 
137 	compat = ieee80211_chanctx_reserved_chandef(local, ctx, compat);
138 	if (!compat)
139 		return NULL;
140 
141 	compat = ieee80211_chanctx_non_reserved_chandef(local, ctx, compat);
142 	if (!compat)
143 		return NULL;
144 
145 	return compat;
146 }
147 
148 static bool
149 ieee80211_chanctx_can_reserve_chandef(struct ieee80211_local *local,
150 				      struct ieee80211_chanctx *ctx,
151 				      const struct cfg80211_chan_def *def)
152 {
153 	lockdep_assert_held(&local->chanctx_mtx);
154 
155 	if (ieee80211_chanctx_combined_chandef(local, ctx, def))
156 		return true;
157 
158 	if (!list_empty(&ctx->reserved_vifs) &&
159 	    ieee80211_chanctx_reserved_chandef(local, ctx, def))
160 		return true;
161 
162 	return false;
163 }
164 
165 static struct ieee80211_chanctx *
166 ieee80211_find_reservation_chanctx(struct ieee80211_local *local,
167 				   const struct cfg80211_chan_def *chandef,
168 				   enum ieee80211_chanctx_mode mode)
169 {
170 	struct ieee80211_chanctx *ctx;
171 
172 	lockdep_assert_held(&local->chanctx_mtx);
173 
174 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
175 		return NULL;
176 
177 	list_for_each_entry(ctx, &local->chanctx_list, list) {
178 		if (ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED)
179 			continue;
180 
181 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
182 			continue;
183 
184 		if (!ieee80211_chanctx_can_reserve_chandef(local, ctx,
185 							   chandef))
186 			continue;
187 
188 		return ctx;
189 	}
190 
191 	return NULL;
192 }
193 
194 enum nl80211_chan_width ieee80211_get_sta_bw(struct ieee80211_sta *sta)
195 {
196 	switch (sta->bandwidth) {
197 	case IEEE80211_STA_RX_BW_20:
198 		if (sta->ht_cap.ht_supported)
199 			return NL80211_CHAN_WIDTH_20;
200 		else
201 			return NL80211_CHAN_WIDTH_20_NOHT;
202 	case IEEE80211_STA_RX_BW_40:
203 		return NL80211_CHAN_WIDTH_40;
204 	case IEEE80211_STA_RX_BW_80:
205 		return NL80211_CHAN_WIDTH_80;
206 	case IEEE80211_STA_RX_BW_160:
207 		/*
208 		 * This applied for both 160 and 80+80. since we use
209 		 * the returned value to consider degradation of
210 		 * ctx->conf.min_def, we have to make sure to take
211 		 * the bigger one (NL80211_CHAN_WIDTH_160).
212 		 * Otherwise we might try degrading even when not
213 		 * needed, as the max required sta_bw returned (80+80)
214 		 * might be smaller than the configured bw (160).
215 		 */
216 		return NL80211_CHAN_WIDTH_160;
217 	default:
218 		WARN_ON(1);
219 		return NL80211_CHAN_WIDTH_20;
220 	}
221 }
222 
223 static enum nl80211_chan_width
224 ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata)
225 {
226 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
227 	struct sta_info *sta;
228 
229 	rcu_read_lock();
230 	list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
231 		if (sdata != sta->sdata &&
232 		    !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
233 			continue;
234 
235 		max_bw = max(max_bw, ieee80211_get_sta_bw(&sta->sta));
236 	}
237 	rcu_read_unlock();
238 
239 	return max_bw;
240 }
241 
242 static enum nl80211_chan_width
243 ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
244 				      struct ieee80211_chanctx_conf *conf)
245 {
246 	struct ieee80211_sub_if_data *sdata;
247 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
248 
249 	rcu_read_lock();
250 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
251 		struct ieee80211_vif *vif = &sdata->vif;
252 		enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT;
253 
254 		if (!ieee80211_sdata_running(sdata))
255 			continue;
256 
257 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
258 			continue;
259 
260 		switch (vif->type) {
261 		case NL80211_IFTYPE_AP:
262 		case NL80211_IFTYPE_AP_VLAN:
263 			width = ieee80211_get_max_required_bw(sdata);
264 			break;
265 		case NL80211_IFTYPE_STATION:
266 			/*
267 			 * The ap's sta->bandwidth is not set yet at this
268 			 * point, so take the width from the chandef, but
269 			 * account also for TDLS peers
270 			 */
271 			width = max(vif->bss_conf.chandef.width,
272 				    ieee80211_get_max_required_bw(sdata));
273 			break;
274 		case NL80211_IFTYPE_P2P_DEVICE:
275 		case NL80211_IFTYPE_NAN:
276 			continue;
277 		case NL80211_IFTYPE_ADHOC:
278 		case NL80211_IFTYPE_WDS:
279 		case NL80211_IFTYPE_MESH_POINT:
280 		case NL80211_IFTYPE_OCB:
281 			width = vif->bss_conf.chandef.width;
282 			break;
283 		case NL80211_IFTYPE_UNSPECIFIED:
284 		case NUM_NL80211_IFTYPES:
285 		case NL80211_IFTYPE_MONITOR:
286 		case NL80211_IFTYPE_P2P_CLIENT:
287 		case NL80211_IFTYPE_P2P_GO:
288 			WARN_ON_ONCE(1);
289 		}
290 		max_bw = max(max_bw, width);
291 	}
292 
293 	/* use the configured bandwidth in case of monitor interface */
294 	sdata = rcu_dereference(local->monitor_sdata);
295 	if (sdata && rcu_access_pointer(sdata->vif.chanctx_conf) == conf)
296 		max_bw = max(max_bw, conf->def.width);
297 
298 	rcu_read_unlock();
299 
300 	return max_bw;
301 }
302 
303 /*
304  * recalc the min required chan width of the channel context, which is
305  * the max of min required widths of all the interfaces bound to this
306  * channel context.
307  */
308 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
309 				      struct ieee80211_chanctx *ctx)
310 {
311 	enum nl80211_chan_width max_bw;
312 	struct cfg80211_chan_def min_def;
313 
314 	lockdep_assert_held(&local->chanctx_mtx);
315 
316 	/* don't optimize 5MHz, 10MHz, and radar_enabled confs */
317 	if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
318 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
319 	    ctx->conf.radar_enabled) {
320 		ctx->conf.min_def = ctx->conf.def;
321 		return;
322 	}
323 
324 	max_bw = ieee80211_get_chanctx_max_required_bw(local, &ctx->conf);
325 
326 	/* downgrade chandef up to max_bw */
327 	min_def = ctx->conf.def;
328 	while (min_def.width > max_bw)
329 		ieee80211_chandef_downgrade(&min_def);
330 
331 	if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
332 		return;
333 
334 	ctx->conf.min_def = min_def;
335 	if (!ctx->driver_present)
336 		return;
337 
338 	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_MIN_WIDTH);
339 }
340 
341 static void ieee80211_change_chanctx(struct ieee80211_local *local,
342 				     struct ieee80211_chanctx *ctx,
343 				     const struct cfg80211_chan_def *chandef)
344 {
345 	if (cfg80211_chandef_identical(&ctx->conf.def, chandef)) {
346 		ieee80211_recalc_chanctx_min_def(local, ctx);
347 		return;
348 	}
349 
350 	WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
351 
352 	ctx->conf.def = *chandef;
353 	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);
354 	ieee80211_recalc_chanctx_min_def(local, ctx);
355 
356 	if (!local->use_chanctx) {
357 		local->_oper_chandef = *chandef;
358 		ieee80211_hw_config(local, 0);
359 	}
360 }
361 
362 static struct ieee80211_chanctx *
363 ieee80211_find_chanctx(struct ieee80211_local *local,
364 		       const struct cfg80211_chan_def *chandef,
365 		       enum ieee80211_chanctx_mode mode)
366 {
367 	struct ieee80211_chanctx *ctx;
368 
369 	lockdep_assert_held(&local->chanctx_mtx);
370 
371 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
372 		return NULL;
373 
374 	list_for_each_entry(ctx, &local->chanctx_list, list) {
375 		const struct cfg80211_chan_def *compat;
376 
377 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
378 			continue;
379 
380 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
381 			continue;
382 
383 		compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
384 		if (!compat)
385 			continue;
386 
387 		compat = ieee80211_chanctx_reserved_chandef(local, ctx,
388 							    compat);
389 		if (!compat)
390 			continue;
391 
392 		ieee80211_change_chanctx(local, ctx, compat);
393 
394 		return ctx;
395 	}
396 
397 	return NULL;
398 }
399 
400 bool ieee80211_is_radar_required(struct ieee80211_local *local)
401 {
402 	struct ieee80211_sub_if_data *sdata;
403 
404 	lockdep_assert_held(&local->mtx);
405 
406 	rcu_read_lock();
407 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
408 		if (sdata->radar_required) {
409 			rcu_read_unlock();
410 			return true;
411 		}
412 	}
413 	rcu_read_unlock();
414 
415 	return false;
416 }
417 
418 static bool
419 ieee80211_chanctx_radar_required(struct ieee80211_local *local,
420 				 struct ieee80211_chanctx *ctx)
421 {
422 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
423 	struct ieee80211_sub_if_data *sdata;
424 	bool required = false;
425 
426 	lockdep_assert_held(&local->chanctx_mtx);
427 	lockdep_assert_held(&local->mtx);
428 
429 	rcu_read_lock();
430 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
431 		if (!ieee80211_sdata_running(sdata))
432 			continue;
433 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
434 			continue;
435 		if (!sdata->radar_required)
436 			continue;
437 
438 		required = true;
439 		break;
440 	}
441 	rcu_read_unlock();
442 
443 	return required;
444 }
445 
446 static struct ieee80211_chanctx *
447 ieee80211_alloc_chanctx(struct ieee80211_local *local,
448 			const struct cfg80211_chan_def *chandef,
449 			enum ieee80211_chanctx_mode mode)
450 {
451 	struct ieee80211_chanctx *ctx;
452 
453 	lockdep_assert_held(&local->chanctx_mtx);
454 
455 	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
456 	if (!ctx)
457 		return NULL;
458 
459 	INIT_LIST_HEAD(&ctx->assigned_vifs);
460 	INIT_LIST_HEAD(&ctx->reserved_vifs);
461 	ctx->conf.def = *chandef;
462 	ctx->conf.rx_chains_static = 1;
463 	ctx->conf.rx_chains_dynamic = 1;
464 	ctx->mode = mode;
465 	ctx->conf.radar_enabled = false;
466 	ieee80211_recalc_chanctx_min_def(local, ctx);
467 
468 	return ctx;
469 }
470 
471 static int ieee80211_add_chanctx(struct ieee80211_local *local,
472 				 struct ieee80211_chanctx *ctx)
473 {
474 	u32 changed;
475 	int err;
476 
477 	lockdep_assert_held(&local->mtx);
478 	lockdep_assert_held(&local->chanctx_mtx);
479 
480 	if (!local->use_chanctx)
481 		local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
482 
483 	/* turn idle off *before* setting channel -- some drivers need that */
484 	changed = ieee80211_idle_off(local);
485 	if (changed)
486 		ieee80211_hw_config(local, changed);
487 
488 	if (!local->use_chanctx) {
489 		local->_oper_chandef = ctx->conf.def;
490 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
491 	} else {
492 		err = drv_add_chanctx(local, ctx);
493 		if (err) {
494 			ieee80211_recalc_idle(local);
495 			return err;
496 		}
497 	}
498 
499 	return 0;
500 }
501 
502 static struct ieee80211_chanctx *
503 ieee80211_new_chanctx(struct ieee80211_local *local,
504 		      const struct cfg80211_chan_def *chandef,
505 		      enum ieee80211_chanctx_mode mode)
506 {
507 	struct ieee80211_chanctx *ctx;
508 	int err;
509 
510 	lockdep_assert_held(&local->mtx);
511 	lockdep_assert_held(&local->chanctx_mtx);
512 
513 	ctx = ieee80211_alloc_chanctx(local, chandef, mode);
514 	if (!ctx)
515 		return ERR_PTR(-ENOMEM);
516 
517 	err = ieee80211_add_chanctx(local, ctx);
518 	if (err) {
519 		kfree(ctx);
520 		return ERR_PTR(err);
521 	}
522 
523 	list_add_rcu(&ctx->list, &local->chanctx_list);
524 	return ctx;
525 }
526 
527 static void ieee80211_del_chanctx(struct ieee80211_local *local,
528 				  struct ieee80211_chanctx *ctx)
529 {
530 	lockdep_assert_held(&local->chanctx_mtx);
531 
532 	if (!local->use_chanctx) {
533 		struct cfg80211_chan_def *chandef = &local->_oper_chandef;
534 		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
535 		chandef->center_freq1 = chandef->chan->center_freq;
536 		chandef->center_freq2 = 0;
537 
538 		/* NOTE: Disabling radar is only valid here for
539 		 * single channel context. To be sure, check it ...
540 		 */
541 		WARN_ON(local->hw.conf.radar_enabled &&
542 			!list_empty(&local->chanctx_list));
543 
544 		local->hw.conf.radar_enabled = false;
545 
546 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
547 	} else {
548 		drv_remove_chanctx(local, ctx);
549 	}
550 
551 	ieee80211_recalc_idle(local);
552 }
553 
554 static void ieee80211_free_chanctx(struct ieee80211_local *local,
555 				   struct ieee80211_chanctx *ctx)
556 {
557 	lockdep_assert_held(&local->chanctx_mtx);
558 
559 	WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
560 
561 	list_del_rcu(&ctx->list);
562 	ieee80211_del_chanctx(local, ctx);
563 	kfree_rcu(ctx, rcu_head);
564 }
565 
566 void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
567 				       struct ieee80211_chanctx *ctx)
568 {
569 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
570 	struct ieee80211_sub_if_data *sdata;
571 	const struct cfg80211_chan_def *compat = NULL;
572 	struct sta_info *sta;
573 
574 	lockdep_assert_held(&local->chanctx_mtx);
575 
576 	rcu_read_lock();
577 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
578 
579 		if (!ieee80211_sdata_running(sdata))
580 			continue;
581 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
582 			continue;
583 		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
584 			continue;
585 
586 		if (!compat)
587 			compat = &sdata->vif.bss_conf.chandef;
588 
589 		compat = cfg80211_chandef_compatible(
590 				&sdata->vif.bss_conf.chandef, compat);
591 		if (WARN_ON_ONCE(!compat))
592 			break;
593 	}
594 
595 	/* TDLS peers can sometimes affect the chandef width */
596 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
597 		if (!sta->uploaded ||
598 		    !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
599 		    !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
600 		    !sta->tdls_chandef.chan)
601 			continue;
602 
603 		compat = cfg80211_chandef_compatible(&sta->tdls_chandef,
604 						     compat);
605 		if (WARN_ON_ONCE(!compat))
606 			break;
607 	}
608 	rcu_read_unlock();
609 
610 	if (!compat)
611 		return;
612 
613 	ieee80211_change_chanctx(local, ctx, compat);
614 }
615 
616 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
617 					   struct ieee80211_chanctx *chanctx)
618 {
619 	bool radar_enabled;
620 
621 	lockdep_assert_held(&local->chanctx_mtx);
622 	/* for ieee80211_is_radar_required */
623 	lockdep_assert_held(&local->mtx);
624 
625 	radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
626 
627 	if (radar_enabled == chanctx->conf.radar_enabled)
628 		return;
629 
630 	chanctx->conf.radar_enabled = radar_enabled;
631 
632 	if (!local->use_chanctx) {
633 		local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
634 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
635 	}
636 
637 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
638 }
639 
640 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
641 					struct ieee80211_chanctx *new_ctx)
642 {
643 	struct ieee80211_local *local = sdata->local;
644 	struct ieee80211_chanctx_conf *conf;
645 	struct ieee80211_chanctx *curr_ctx = NULL;
646 	int ret = 0;
647 
648 	if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN))
649 		return -ENOTSUPP;
650 
651 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
652 					 lockdep_is_held(&local->chanctx_mtx));
653 
654 	if (conf) {
655 		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
656 
657 		drv_unassign_vif_chanctx(local, sdata, curr_ctx);
658 		conf = NULL;
659 		list_del(&sdata->assigned_chanctx_list);
660 	}
661 
662 	if (new_ctx) {
663 		ret = drv_assign_vif_chanctx(local, sdata, new_ctx);
664 		if (ret)
665 			goto out;
666 
667 		conf = &new_ctx->conf;
668 		list_add(&sdata->assigned_chanctx_list,
669 			 &new_ctx->assigned_vifs);
670 	}
671 
672 out:
673 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
674 
675 	sdata->vif.bss_conf.idle = !conf;
676 
677 	if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
678 		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
679 		ieee80211_recalc_smps_chanctx(local, curr_ctx);
680 		ieee80211_recalc_radar_chanctx(local, curr_ctx);
681 		ieee80211_recalc_chanctx_min_def(local, curr_ctx);
682 	}
683 
684 	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
685 		ieee80211_recalc_txpower(sdata, false);
686 		ieee80211_recalc_chanctx_min_def(local, new_ctx);
687 	}
688 
689 	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
690 	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
691 		ieee80211_bss_info_change_notify(sdata,
692 						 BSS_CHANGED_IDLE);
693 
694 	ieee80211_check_fast_xmit_iface(sdata);
695 
696 	return ret;
697 }
698 
699 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
700 				   struct ieee80211_chanctx *chanctx)
701 {
702 	struct ieee80211_sub_if_data *sdata;
703 	u8 rx_chains_static, rx_chains_dynamic;
704 
705 	lockdep_assert_held(&local->chanctx_mtx);
706 
707 	rx_chains_static = 1;
708 	rx_chains_dynamic = 1;
709 
710 	rcu_read_lock();
711 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
712 		u8 needed_static, needed_dynamic;
713 
714 		if (!ieee80211_sdata_running(sdata))
715 			continue;
716 
717 		if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
718 						&chanctx->conf)
719 			continue;
720 
721 		switch (sdata->vif.type) {
722 		case NL80211_IFTYPE_P2P_DEVICE:
723 		case NL80211_IFTYPE_NAN:
724 			continue;
725 		case NL80211_IFTYPE_STATION:
726 			if (!sdata->u.mgd.associated)
727 				continue;
728 			break;
729 		case NL80211_IFTYPE_AP_VLAN:
730 			continue;
731 		case NL80211_IFTYPE_AP:
732 		case NL80211_IFTYPE_ADHOC:
733 		case NL80211_IFTYPE_WDS:
734 		case NL80211_IFTYPE_MESH_POINT:
735 		case NL80211_IFTYPE_OCB:
736 			break;
737 		default:
738 			WARN_ON_ONCE(1);
739 		}
740 
741 		switch (sdata->smps_mode) {
742 		default:
743 			WARN_ONCE(1, "Invalid SMPS mode %d\n",
744 				  sdata->smps_mode);
745 			/* fall through */
746 		case IEEE80211_SMPS_OFF:
747 			needed_static = sdata->needed_rx_chains;
748 			needed_dynamic = sdata->needed_rx_chains;
749 			break;
750 		case IEEE80211_SMPS_DYNAMIC:
751 			needed_static = 1;
752 			needed_dynamic = sdata->needed_rx_chains;
753 			break;
754 		case IEEE80211_SMPS_STATIC:
755 			needed_static = 1;
756 			needed_dynamic = 1;
757 			break;
758 		}
759 
760 		rx_chains_static = max(rx_chains_static, needed_static);
761 		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
762 	}
763 
764 	/* Disable SMPS for the monitor interface */
765 	sdata = rcu_dereference(local->monitor_sdata);
766 	if (sdata &&
767 	    rcu_access_pointer(sdata->vif.chanctx_conf) == &chanctx->conf)
768 		rx_chains_dynamic = rx_chains_static = local->rx_chains;
769 
770 	rcu_read_unlock();
771 
772 	if (!local->use_chanctx) {
773 		if (rx_chains_static > 1)
774 			local->smps_mode = IEEE80211_SMPS_OFF;
775 		else if (rx_chains_dynamic > 1)
776 			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
777 		else
778 			local->smps_mode = IEEE80211_SMPS_STATIC;
779 		ieee80211_hw_config(local, 0);
780 	}
781 
782 	if (rx_chains_static == chanctx->conf.rx_chains_static &&
783 	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
784 		return;
785 
786 	chanctx->conf.rx_chains_static = rx_chains_static;
787 	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
788 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
789 }
790 
791 static void
792 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
793 				      bool clear)
794 {
795 	struct ieee80211_local *local __maybe_unused = sdata->local;
796 	struct ieee80211_sub_if_data *vlan;
797 	struct ieee80211_chanctx_conf *conf;
798 
799 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
800 		return;
801 
802 	lockdep_assert_held(&local->mtx);
803 
804 	/* Check that conf exists, even when clearing this function
805 	 * must be called with the AP's channel context still there
806 	 * as it would otherwise cause VLANs to have an invalid
807 	 * channel context pointer for a while, possibly pointing
808 	 * to a channel context that has already been freed.
809 	 */
810 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
811 					 lockdep_is_held(&local->chanctx_mtx));
812 	WARN_ON(!conf);
813 
814 	if (clear)
815 		conf = NULL;
816 
817 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
818 		rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
819 }
820 
821 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
822 					 bool clear)
823 {
824 	struct ieee80211_local *local = sdata->local;
825 
826 	mutex_lock(&local->chanctx_mtx);
827 
828 	__ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
829 
830 	mutex_unlock(&local->chanctx_mtx);
831 }
832 
833 int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
834 {
835 	struct ieee80211_chanctx *ctx = sdata->reserved_chanctx;
836 
837 	lockdep_assert_held(&sdata->local->chanctx_mtx);
838 
839 	if (WARN_ON(!ctx))
840 		return -EINVAL;
841 
842 	list_del(&sdata->reserved_chanctx_list);
843 	sdata->reserved_chanctx = NULL;
844 
845 	if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
846 		if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
847 			if (WARN_ON(!ctx->replace_ctx))
848 				return -EINVAL;
849 
850 			WARN_ON(ctx->replace_ctx->replace_state !=
851 			        IEEE80211_CHANCTX_WILL_BE_REPLACED);
852 			WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
853 
854 			ctx->replace_ctx->replace_ctx = NULL;
855 			ctx->replace_ctx->replace_state =
856 					IEEE80211_CHANCTX_REPLACE_NONE;
857 
858 			list_del_rcu(&ctx->list);
859 			kfree_rcu(ctx, rcu_head);
860 		} else {
861 			ieee80211_free_chanctx(sdata->local, ctx);
862 		}
863 	}
864 
865 	return 0;
866 }
867 
868 int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
869 				  const struct cfg80211_chan_def *chandef,
870 				  enum ieee80211_chanctx_mode mode,
871 				  bool radar_required)
872 {
873 	struct ieee80211_local *local = sdata->local;
874 	struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
875 
876 	lockdep_assert_held(&local->chanctx_mtx);
877 
878 	curr_ctx = ieee80211_vif_get_chanctx(sdata);
879 	if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
880 		return -ENOTSUPP;
881 
882 	new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
883 	if (!new_ctx) {
884 		if (ieee80211_can_create_new_chanctx(local)) {
885 			new_ctx = ieee80211_new_chanctx(local, chandef, mode);
886 			if (IS_ERR(new_ctx))
887 				return PTR_ERR(new_ctx);
888 		} else {
889 			if (!curr_ctx ||
890 			    (curr_ctx->replace_state ==
891 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
892 			    !list_empty(&curr_ctx->reserved_vifs)) {
893 				/*
894 				 * Another vif already requested this context
895 				 * for a reservation. Find another one hoping
896 				 * all vifs assigned to it will also switch
897 				 * soon enough.
898 				 *
899 				 * TODO: This needs a little more work as some
900 				 * cases (more than 2 chanctx capable devices)
901 				 * may fail which could otherwise succeed
902 				 * provided some channel context juggling was
903 				 * performed.
904 				 *
905 				 * Consider ctx1..3, vif1..6, each ctx has 2
906 				 * vifs. vif1 and vif2 from ctx1 request new
907 				 * different chandefs starting 2 in-place
908 				 * reserations with ctx4 and ctx5 replacing
909 				 * ctx1 and ctx2 respectively. Next vif5 and
910 				 * vif6 from ctx3 reserve ctx4. If vif3 and
911 				 * vif4 remain on ctx2 as they are then this
912 				 * fails unless `replace_ctx` from ctx5 is
913 				 * replaced with ctx3.
914 				 */
915 				list_for_each_entry(ctx, &local->chanctx_list,
916 						    list) {
917 					if (ctx->replace_state !=
918 					    IEEE80211_CHANCTX_REPLACE_NONE)
919 						continue;
920 
921 					if (!list_empty(&ctx->reserved_vifs))
922 						continue;
923 
924 					curr_ctx = ctx;
925 					break;
926 				}
927 			}
928 
929 			/*
930 			 * If that's true then all available contexts already
931 			 * have reservations and cannot be used.
932 			 */
933 			if (!curr_ctx ||
934 			    (curr_ctx->replace_state ==
935 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
936 			    !list_empty(&curr_ctx->reserved_vifs))
937 				return -EBUSY;
938 
939 			new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
940 			if (!new_ctx)
941 				return -ENOMEM;
942 
943 			new_ctx->replace_ctx = curr_ctx;
944 			new_ctx->replace_state =
945 					IEEE80211_CHANCTX_REPLACES_OTHER;
946 
947 			curr_ctx->replace_ctx = new_ctx;
948 			curr_ctx->replace_state =
949 					IEEE80211_CHANCTX_WILL_BE_REPLACED;
950 
951 			list_add_rcu(&new_ctx->list, &local->chanctx_list);
952 		}
953 	}
954 
955 	list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);
956 	sdata->reserved_chanctx = new_ctx;
957 	sdata->reserved_chandef = *chandef;
958 	sdata->reserved_radar_required = radar_required;
959 	sdata->reserved_ready = false;
960 
961 	return 0;
962 }
963 
964 static void
965 ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
966 {
967 	switch (sdata->vif.type) {
968 	case NL80211_IFTYPE_ADHOC:
969 	case NL80211_IFTYPE_AP:
970 	case NL80211_IFTYPE_MESH_POINT:
971 	case NL80211_IFTYPE_OCB:
972 		ieee80211_queue_work(&sdata->local->hw,
973 				     &sdata->csa_finalize_work);
974 		break;
975 	case NL80211_IFTYPE_STATION:
976 		ieee80211_queue_work(&sdata->local->hw,
977 				     &sdata->u.mgd.chswitch_work);
978 		break;
979 	case NL80211_IFTYPE_UNSPECIFIED:
980 	case NL80211_IFTYPE_AP_VLAN:
981 	case NL80211_IFTYPE_WDS:
982 	case NL80211_IFTYPE_MONITOR:
983 	case NL80211_IFTYPE_P2P_CLIENT:
984 	case NL80211_IFTYPE_P2P_GO:
985 	case NL80211_IFTYPE_P2P_DEVICE:
986 	case NL80211_IFTYPE_NAN:
987 	case NUM_NL80211_IFTYPES:
988 		WARN_ON(1);
989 		break;
990 	}
991 }
992 
993 static void
994 ieee80211_vif_update_chandef(struct ieee80211_sub_if_data *sdata,
995 			     const struct cfg80211_chan_def *chandef)
996 {
997 	struct ieee80211_sub_if_data *vlan;
998 
999 	sdata->vif.bss_conf.chandef = *chandef;
1000 
1001 	if (sdata->vif.type != NL80211_IFTYPE_AP)
1002 		return;
1003 
1004 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
1005 		vlan->vif.bss_conf.chandef = *chandef;
1006 }
1007 
1008 static int
1009 ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
1010 {
1011 	struct ieee80211_local *local = sdata->local;
1012 	struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1013 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1014 	const struct cfg80211_chan_def *chandef;
1015 	u32 changed = 0;
1016 	int err;
1017 
1018 	lockdep_assert_held(&local->mtx);
1019 	lockdep_assert_held(&local->chanctx_mtx);
1020 
1021 	new_ctx = sdata->reserved_chanctx;
1022 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1023 
1024 	if (WARN_ON(!sdata->reserved_ready))
1025 		return -EBUSY;
1026 
1027 	if (WARN_ON(!new_ctx))
1028 		return -EINVAL;
1029 
1030 	if (WARN_ON(!old_ctx))
1031 		return -EINVAL;
1032 
1033 	if (WARN_ON(new_ctx->replace_state ==
1034 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1035 		return -EINVAL;
1036 
1037 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1038 				&sdata->reserved_chandef);
1039 	if (WARN_ON(!chandef))
1040 		return -EINVAL;
1041 
1042 	ieee80211_change_chanctx(local, new_ctx, chandef);
1043 
1044 	vif_chsw[0].vif = &sdata->vif;
1045 	vif_chsw[0].old_ctx = &old_ctx->conf;
1046 	vif_chsw[0].new_ctx = &new_ctx->conf;
1047 
1048 	list_del(&sdata->reserved_chanctx_list);
1049 	sdata->reserved_chanctx = NULL;
1050 
1051 	err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1052 				     CHANCTX_SWMODE_REASSIGN_VIF);
1053 	if (err) {
1054 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1055 			ieee80211_free_chanctx(local, new_ctx);
1056 
1057 		goto out;
1058 	}
1059 
1060 	list_move(&sdata->assigned_chanctx_list, &new_ctx->assigned_vifs);
1061 	rcu_assign_pointer(sdata->vif.chanctx_conf, &new_ctx->conf);
1062 
1063 	if (sdata->vif.type == NL80211_IFTYPE_AP)
1064 		__ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
1065 
1066 	ieee80211_check_fast_xmit_iface(sdata);
1067 
1068 	if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1069 		ieee80211_free_chanctx(local, old_ctx);
1070 
1071 	if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
1072 		changed = BSS_CHANGED_BANDWIDTH;
1073 
1074 	ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1075 
1076 	ieee80211_recalc_smps_chanctx(local, new_ctx);
1077 	ieee80211_recalc_radar_chanctx(local, new_ctx);
1078 	ieee80211_recalc_chanctx_min_def(local, new_ctx);
1079 
1080 	if (changed)
1081 		ieee80211_bss_info_change_notify(sdata, changed);
1082 
1083 out:
1084 	ieee80211_vif_chanctx_reservation_complete(sdata);
1085 	return err;
1086 }
1087 
1088 static int
1089 ieee80211_vif_use_reserved_assign(struct ieee80211_sub_if_data *sdata)
1090 {
1091 	struct ieee80211_local *local = sdata->local;
1092 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1093 	const struct cfg80211_chan_def *chandef;
1094 	int err;
1095 
1096 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1097 	new_ctx = sdata->reserved_chanctx;
1098 
1099 	if (WARN_ON(!sdata->reserved_ready))
1100 		return -EINVAL;
1101 
1102 	if (WARN_ON(old_ctx))
1103 		return -EINVAL;
1104 
1105 	if (WARN_ON(!new_ctx))
1106 		return -EINVAL;
1107 
1108 	if (WARN_ON(new_ctx->replace_state ==
1109 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1110 		return -EINVAL;
1111 
1112 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1113 				&sdata->reserved_chandef);
1114 	if (WARN_ON(!chandef))
1115 		return -EINVAL;
1116 
1117 	ieee80211_change_chanctx(local, new_ctx, chandef);
1118 
1119 	list_del(&sdata->reserved_chanctx_list);
1120 	sdata->reserved_chanctx = NULL;
1121 
1122 	err = ieee80211_assign_vif_chanctx(sdata, new_ctx);
1123 	if (err) {
1124 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1125 			ieee80211_free_chanctx(local, new_ctx);
1126 
1127 		goto out;
1128 	}
1129 
1130 out:
1131 	ieee80211_vif_chanctx_reservation_complete(sdata);
1132 	return err;
1133 }
1134 
1135 static bool
1136 ieee80211_vif_has_in_place_reservation(struct ieee80211_sub_if_data *sdata)
1137 {
1138 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1139 
1140 	lockdep_assert_held(&sdata->local->chanctx_mtx);
1141 
1142 	new_ctx = sdata->reserved_chanctx;
1143 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1144 
1145 	if (!old_ctx)
1146 		return false;
1147 
1148 	if (WARN_ON(!new_ctx))
1149 		return false;
1150 
1151 	if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1152 		return false;
1153 
1154 	if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1155 		return false;
1156 
1157 	return true;
1158 }
1159 
1160 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1161 					struct ieee80211_chanctx *new_ctx)
1162 {
1163 	const struct cfg80211_chan_def *chandef;
1164 
1165 	lockdep_assert_held(&local->mtx);
1166 	lockdep_assert_held(&local->chanctx_mtx);
1167 
1168 	chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1169 	if (WARN_ON(!chandef))
1170 		return -EINVAL;
1171 
1172 	local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1173 	local->_oper_chandef = *chandef;
1174 	ieee80211_hw_config(local, 0);
1175 
1176 	return 0;
1177 }
1178 
1179 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1180 				      int n_vifs)
1181 {
1182 	struct ieee80211_vif_chanctx_switch *vif_chsw;
1183 	struct ieee80211_sub_if_data *sdata;
1184 	struct ieee80211_chanctx *ctx, *old_ctx;
1185 	int i, err;
1186 
1187 	lockdep_assert_held(&local->mtx);
1188 	lockdep_assert_held(&local->chanctx_mtx);
1189 
1190 	vif_chsw = kcalloc(n_vifs, sizeof(vif_chsw[0]), GFP_KERNEL);
1191 	if (!vif_chsw)
1192 		return -ENOMEM;
1193 
1194 	i = 0;
1195 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1196 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1197 			continue;
1198 
1199 		if (WARN_ON(!ctx->replace_ctx)) {
1200 			err = -EINVAL;
1201 			goto out;
1202 		}
1203 
1204 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1205 				    reserved_chanctx_list) {
1206 			if (!ieee80211_vif_has_in_place_reservation(
1207 					sdata))
1208 				continue;
1209 
1210 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1211 			vif_chsw[i].vif = &sdata->vif;
1212 			vif_chsw[i].old_ctx = &old_ctx->conf;
1213 			vif_chsw[i].new_ctx = &ctx->conf;
1214 
1215 			i++;
1216 		}
1217 	}
1218 
1219 	err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1220 				     CHANCTX_SWMODE_SWAP_CONTEXTS);
1221 
1222 out:
1223 	kfree(vif_chsw);
1224 	return err;
1225 }
1226 
1227 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1228 {
1229 	struct ieee80211_chanctx *ctx;
1230 	int err;
1231 
1232 	lockdep_assert_held(&local->mtx);
1233 	lockdep_assert_held(&local->chanctx_mtx);
1234 
1235 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1236 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1237 			continue;
1238 
1239 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1240 			continue;
1241 
1242 		ieee80211_del_chanctx(local, ctx->replace_ctx);
1243 		err = ieee80211_add_chanctx(local, ctx);
1244 		if (err)
1245 			goto err;
1246 	}
1247 
1248 	return 0;
1249 
1250 err:
1251 	WARN_ON(ieee80211_add_chanctx(local, ctx));
1252 	list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1253 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1254 			continue;
1255 
1256 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1257 			continue;
1258 
1259 		ieee80211_del_chanctx(local, ctx);
1260 		WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1261 	}
1262 
1263 	return err;
1264 }
1265 
1266 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1267 {
1268 	struct ieee80211_sub_if_data *sdata, *sdata_tmp;
1269 	struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1270 	struct ieee80211_chanctx *new_ctx = NULL;
1271 	int err, n_assigned, n_reserved, n_ready;
1272 	int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1273 
1274 	lockdep_assert_held(&local->mtx);
1275 	lockdep_assert_held(&local->chanctx_mtx);
1276 
1277 	/*
1278 	 * If there are 2 independent pairs of channel contexts performing
1279 	 * cross-switch of their vifs this code will still wait until both are
1280 	 * ready even though it could be possible to switch one before the
1281 	 * other is ready.
1282 	 *
1283 	 * For practical reasons and code simplicity just do a single huge
1284 	 * switch.
1285 	 */
1286 
1287 	/*
1288 	 * Verify if the reservation is still feasible.
1289 	 *  - if it's not then disconnect
1290 	 *  - if it is but not all vifs necessary are ready then defer
1291 	 */
1292 
1293 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1294 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1295 			continue;
1296 
1297 		if (WARN_ON(!ctx->replace_ctx)) {
1298 			err = -EINVAL;
1299 			goto err;
1300 		}
1301 
1302 		if (!local->use_chanctx)
1303 			new_ctx = ctx;
1304 
1305 		n_ctx++;
1306 
1307 		n_assigned = 0;
1308 		n_reserved = 0;
1309 		n_ready = 0;
1310 
1311 		list_for_each_entry(sdata, &ctx->replace_ctx->assigned_vifs,
1312 				    assigned_chanctx_list) {
1313 			n_assigned++;
1314 			if (sdata->reserved_chanctx) {
1315 				n_reserved++;
1316 				if (sdata->reserved_ready)
1317 					n_ready++;
1318 			}
1319 		}
1320 
1321 		if (n_assigned != n_reserved) {
1322 			if (n_ready == n_reserved) {
1323 				wiphy_info(local->hw.wiphy,
1324 					   "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1325 				err = -EBUSY;
1326 				goto err;
1327 			}
1328 
1329 			return -EAGAIN;
1330 		}
1331 
1332 		ctx->conf.radar_enabled = false;
1333 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1334 				    reserved_chanctx_list) {
1335 			if (ieee80211_vif_has_in_place_reservation(sdata) &&
1336 			    !sdata->reserved_ready)
1337 				return -EAGAIN;
1338 
1339 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1340 			if (old_ctx) {
1341 				if (old_ctx->replace_state ==
1342 				    IEEE80211_CHANCTX_WILL_BE_REPLACED)
1343 					n_vifs_switch++;
1344 				else
1345 					n_vifs_assign++;
1346 			} else {
1347 				n_vifs_ctxless++;
1348 			}
1349 
1350 			if (sdata->reserved_radar_required)
1351 				ctx->conf.radar_enabled = true;
1352 		}
1353 	}
1354 
1355 	if (WARN_ON(n_ctx == 0) ||
1356 	    WARN_ON(n_vifs_switch == 0 &&
1357 		    n_vifs_assign == 0 &&
1358 		    n_vifs_ctxless == 0) ||
1359 	    WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1360 	    WARN_ON(!new_ctx && !local->use_chanctx)) {
1361 		err = -EINVAL;
1362 		goto err;
1363 	}
1364 
1365 	/*
1366 	 * All necessary vifs are ready. Perform the switch now depending on
1367 	 * reservations and driver capabilities.
1368 	 */
1369 
1370 	if (local->use_chanctx) {
1371 		if (n_vifs_switch > 0) {
1372 			err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1373 			if (err)
1374 				goto err;
1375 		}
1376 
1377 		if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1378 			err = ieee80211_chsw_switch_ctxs(local);
1379 			if (err)
1380 				goto err;
1381 		}
1382 	} else {
1383 		err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1384 		if (err)
1385 			goto err;
1386 	}
1387 
1388 	/*
1389 	 * Update all structures, values and pointers to point to new channel
1390 	 * context(s).
1391 	 */
1392 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1393 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1394 			continue;
1395 
1396 		if (WARN_ON(!ctx->replace_ctx)) {
1397 			err = -EINVAL;
1398 			goto err;
1399 		}
1400 
1401 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1402 				    reserved_chanctx_list) {
1403 			u32 changed = 0;
1404 
1405 			if (!ieee80211_vif_has_in_place_reservation(sdata))
1406 				continue;
1407 
1408 			rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
1409 
1410 			if (sdata->vif.type == NL80211_IFTYPE_AP)
1411 				__ieee80211_vif_copy_chanctx_to_vlans(sdata,
1412 								      false);
1413 
1414 			ieee80211_check_fast_xmit_iface(sdata);
1415 
1416 			sdata->radar_required = sdata->reserved_radar_required;
1417 
1418 			if (sdata->vif.bss_conf.chandef.width !=
1419 			    sdata->reserved_chandef.width)
1420 				changed = BSS_CHANGED_BANDWIDTH;
1421 
1422 			ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1423 			if (changed)
1424 				ieee80211_bss_info_change_notify(sdata,
1425 								 changed);
1426 
1427 			ieee80211_recalc_txpower(sdata, false);
1428 		}
1429 
1430 		ieee80211_recalc_chanctx_chantype(local, ctx);
1431 		ieee80211_recalc_smps_chanctx(local, ctx);
1432 		ieee80211_recalc_radar_chanctx(local, ctx);
1433 		ieee80211_recalc_chanctx_min_def(local, ctx);
1434 
1435 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1436 					 reserved_chanctx_list) {
1437 			if (ieee80211_vif_get_chanctx(sdata) != ctx)
1438 				continue;
1439 
1440 			list_del(&sdata->reserved_chanctx_list);
1441 			list_move(&sdata->assigned_chanctx_list,
1442 				  &ctx->assigned_vifs);
1443 			sdata->reserved_chanctx = NULL;
1444 
1445 			ieee80211_vif_chanctx_reservation_complete(sdata);
1446 		}
1447 
1448 		/*
1449 		 * This context might have been a dependency for an already
1450 		 * ready re-assign reservation interface that was deferred. Do
1451 		 * not propagate error to the caller though. The in-place
1452 		 * reservation for originally requested interface has already
1453 		 * succeeded at this point.
1454 		 */
1455 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1456 					 reserved_chanctx_list) {
1457 			if (WARN_ON(ieee80211_vif_has_in_place_reservation(
1458 					sdata)))
1459 				continue;
1460 
1461 			if (WARN_ON(sdata->reserved_chanctx != ctx))
1462 				continue;
1463 
1464 			if (!sdata->reserved_ready)
1465 				continue;
1466 
1467 			if (ieee80211_vif_get_chanctx(sdata))
1468 				err = ieee80211_vif_use_reserved_reassign(
1469 						sdata);
1470 			else
1471 				err = ieee80211_vif_use_reserved_assign(sdata);
1472 
1473 			if (err) {
1474 				sdata_info(sdata,
1475 					   "failed to finalize (re-)assign reservation (err=%d)\n",
1476 					   err);
1477 				ieee80211_vif_unreserve_chanctx(sdata);
1478 				cfg80211_stop_iface(local->hw.wiphy,
1479 						    &sdata->wdev,
1480 						    GFP_KERNEL);
1481 			}
1482 		}
1483 	}
1484 
1485 	/*
1486 	 * Finally free old contexts
1487 	 */
1488 
1489 	list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1490 		if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1491 			continue;
1492 
1493 		ctx->replace_ctx->replace_ctx = NULL;
1494 		ctx->replace_ctx->replace_state =
1495 				IEEE80211_CHANCTX_REPLACE_NONE;
1496 
1497 		list_del_rcu(&ctx->list);
1498 		kfree_rcu(ctx, rcu_head);
1499 	}
1500 
1501 	return 0;
1502 
1503 err:
1504 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1505 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1506 			continue;
1507 
1508 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1509 					 reserved_chanctx_list) {
1510 			ieee80211_vif_unreserve_chanctx(sdata);
1511 			ieee80211_vif_chanctx_reservation_complete(sdata);
1512 		}
1513 	}
1514 
1515 	return err;
1516 }
1517 
1518 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1519 {
1520 	struct ieee80211_local *local = sdata->local;
1521 	struct ieee80211_chanctx_conf *conf;
1522 	struct ieee80211_chanctx *ctx;
1523 	bool use_reserved_switch = false;
1524 
1525 	lockdep_assert_held(&local->chanctx_mtx);
1526 
1527 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1528 					 lockdep_is_held(&local->chanctx_mtx));
1529 	if (!conf)
1530 		return;
1531 
1532 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1533 
1534 	if (sdata->reserved_chanctx) {
1535 		if (sdata->reserved_chanctx->replace_state ==
1536 		    IEEE80211_CHANCTX_REPLACES_OTHER &&
1537 		    ieee80211_chanctx_num_reserved(local,
1538 						   sdata->reserved_chanctx) > 1)
1539 			use_reserved_switch = true;
1540 
1541 		ieee80211_vif_unreserve_chanctx(sdata);
1542 	}
1543 
1544 	ieee80211_assign_vif_chanctx(sdata, NULL);
1545 	if (ieee80211_chanctx_refcount(local, ctx) == 0)
1546 		ieee80211_free_chanctx(local, ctx);
1547 
1548 	sdata->radar_required = false;
1549 
1550 	/* Unreserving may ready an in-place reservation. */
1551 	if (use_reserved_switch)
1552 		ieee80211_vif_use_reserved_switch(local);
1553 }
1554 
1555 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
1556 			      const struct cfg80211_chan_def *chandef,
1557 			      enum ieee80211_chanctx_mode mode)
1558 {
1559 	struct ieee80211_local *local = sdata->local;
1560 	struct ieee80211_chanctx *ctx;
1561 	u8 radar_detect_width = 0;
1562 	int ret;
1563 
1564 	lockdep_assert_held(&local->mtx);
1565 
1566 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1567 
1568 	mutex_lock(&local->chanctx_mtx);
1569 
1570 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1571 					    chandef,
1572 					    sdata->wdev.iftype);
1573 	if (ret < 0)
1574 		goto out;
1575 	if (ret > 0)
1576 		radar_detect_width = BIT(chandef->width);
1577 
1578 	sdata->radar_required = ret;
1579 
1580 	ret = ieee80211_check_combinations(sdata, chandef, mode,
1581 					   radar_detect_width);
1582 	if (ret < 0)
1583 		goto out;
1584 
1585 	__ieee80211_vif_release_channel(sdata);
1586 
1587 	ctx = ieee80211_find_chanctx(local, chandef, mode);
1588 	if (!ctx)
1589 		ctx = ieee80211_new_chanctx(local, chandef, mode);
1590 	if (IS_ERR(ctx)) {
1591 		ret = PTR_ERR(ctx);
1592 		goto out;
1593 	}
1594 
1595 	ieee80211_vif_update_chandef(sdata, chandef);
1596 
1597 	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
1598 	if (ret) {
1599 		/* if assign fails refcount stays the same */
1600 		if (ieee80211_chanctx_refcount(local, ctx) == 0)
1601 			ieee80211_free_chanctx(local, ctx);
1602 		goto out;
1603 	}
1604 
1605 	ieee80211_recalc_smps_chanctx(local, ctx);
1606 	ieee80211_recalc_radar_chanctx(local, ctx);
1607  out:
1608 	if (ret)
1609 		sdata->radar_required = false;
1610 
1611 	mutex_unlock(&local->chanctx_mtx);
1612 	return ret;
1613 }
1614 
1615 int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata)
1616 {
1617 	struct ieee80211_local *local = sdata->local;
1618 	struct ieee80211_chanctx *new_ctx;
1619 	struct ieee80211_chanctx *old_ctx;
1620 	int err;
1621 
1622 	lockdep_assert_held(&local->mtx);
1623 	lockdep_assert_held(&local->chanctx_mtx);
1624 
1625 	new_ctx = sdata->reserved_chanctx;
1626 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1627 
1628 	if (WARN_ON(!new_ctx))
1629 		return -EINVAL;
1630 
1631 	if (WARN_ON(new_ctx->replace_state ==
1632 		    IEEE80211_CHANCTX_WILL_BE_REPLACED))
1633 		return -EINVAL;
1634 
1635 	if (WARN_ON(sdata->reserved_ready))
1636 		return -EINVAL;
1637 
1638 	sdata->reserved_ready = true;
1639 
1640 	if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1641 		if (old_ctx)
1642 			err = ieee80211_vif_use_reserved_reassign(sdata);
1643 		else
1644 			err = ieee80211_vif_use_reserved_assign(sdata);
1645 
1646 		if (err)
1647 			return err;
1648 	}
1649 
1650 	/*
1651 	 * In-place reservation may need to be finalized now either if:
1652 	 *  a) sdata is taking part in the swapping itself and is the last one
1653 	 *  b) sdata has switched with a re-assign reservation to an existing
1654 	 *     context readying in-place switching of old_ctx
1655 	 *
1656 	 * In case of (b) do not propagate the error up because the requested
1657 	 * sdata already switched successfully. Just spill an extra warning.
1658 	 * The ieee80211_vif_use_reserved_switch() already stops all necessary
1659 	 * interfaces upon failure.
1660 	 */
1661 	if ((old_ctx &&
1662 	     old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1663 	    new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1664 		err = ieee80211_vif_use_reserved_switch(local);
1665 		if (err && err != -EAGAIN) {
1666 			if (new_ctx->replace_state ==
1667 			    IEEE80211_CHANCTX_REPLACES_OTHER)
1668 				return err;
1669 
1670 			wiphy_info(local->hw.wiphy,
1671 				   "depending in-place reservation failed (err=%d)\n",
1672 				   err);
1673 		}
1674 	}
1675 
1676 	return 0;
1677 }
1678 
1679 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
1680 				   const struct cfg80211_chan_def *chandef,
1681 				   u32 *changed)
1682 {
1683 	struct ieee80211_local *local = sdata->local;
1684 	struct ieee80211_chanctx_conf *conf;
1685 	struct ieee80211_chanctx *ctx;
1686 	const struct cfg80211_chan_def *compat;
1687 	int ret;
1688 
1689 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1690 				     IEEE80211_CHAN_DISABLED))
1691 		return -EINVAL;
1692 
1693 	mutex_lock(&local->chanctx_mtx);
1694 	if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
1695 		ret = 0;
1696 		goto out;
1697 	}
1698 
1699 	if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1700 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1701 		ret = -EINVAL;
1702 		goto out;
1703 	}
1704 
1705 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1706 					 lockdep_is_held(&local->chanctx_mtx));
1707 	if (!conf) {
1708 		ret = -EINVAL;
1709 		goto out;
1710 	}
1711 
1712 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1713 
1714 	compat = cfg80211_chandef_compatible(&conf->def, chandef);
1715 	if (!compat) {
1716 		ret = -EINVAL;
1717 		goto out;
1718 	}
1719 
1720 	switch (ctx->replace_state) {
1721 	case IEEE80211_CHANCTX_REPLACE_NONE:
1722 		if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1723 			ret = -EBUSY;
1724 			goto out;
1725 		}
1726 		break;
1727 	case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1728 		/* TODO: Perhaps the bandwidth change could be treated as a
1729 		 * reservation itself? */
1730 		ret = -EBUSY;
1731 		goto out;
1732 	case IEEE80211_CHANCTX_REPLACES_OTHER:
1733 		/* channel context that is going to replace another channel
1734 		 * context doesn't really exist and shouldn't be assigned
1735 		 * anywhere yet */
1736 		WARN_ON(1);
1737 		break;
1738 	}
1739 
1740 	ieee80211_vif_update_chandef(sdata, chandef);
1741 
1742 	ieee80211_recalc_chanctx_chantype(local, ctx);
1743 
1744 	*changed |= BSS_CHANGED_BANDWIDTH;
1745 	ret = 0;
1746  out:
1747 	mutex_unlock(&local->chanctx_mtx);
1748 	return ret;
1749 }
1750 
1751 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1752 {
1753 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1754 
1755 	lockdep_assert_held(&sdata->local->mtx);
1756 
1757 	mutex_lock(&sdata->local->chanctx_mtx);
1758 	__ieee80211_vif_release_channel(sdata);
1759 	mutex_unlock(&sdata->local->chanctx_mtx);
1760 }
1761 
1762 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
1763 {
1764 	struct ieee80211_local *local = sdata->local;
1765 	struct ieee80211_sub_if_data *ap;
1766 	struct ieee80211_chanctx_conf *conf;
1767 
1768 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
1769 		return;
1770 
1771 	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
1772 
1773 	mutex_lock(&local->chanctx_mtx);
1774 
1775 	conf = rcu_dereference_protected(ap->vif.chanctx_conf,
1776 					 lockdep_is_held(&local->chanctx_mtx));
1777 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
1778 	mutex_unlock(&local->chanctx_mtx);
1779 }
1780 
1781 void ieee80211_iter_chan_contexts_atomic(
1782 	struct ieee80211_hw *hw,
1783 	void (*iter)(struct ieee80211_hw *hw,
1784 		     struct ieee80211_chanctx_conf *chanctx_conf,
1785 		     void *data),
1786 	void *iter_data)
1787 {
1788 	struct ieee80211_local *local = hw_to_local(hw);
1789 	struct ieee80211_chanctx *ctx;
1790 
1791 	rcu_read_lock();
1792 	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
1793 		if (ctx->driver_present)
1794 			iter(hw, &ctx->conf, iter_data);
1795 	rcu_read_unlock();
1796 }
1797 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);
1798