xref: /openbmc/linux/net/mac80211/chan.c (revision bcd684aa)
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_MESH_POINT:
279 		case NL80211_IFTYPE_OCB:
280 			width = vif->bss_conf.chandef.width;
281 			break;
282 		case NL80211_IFTYPE_WDS:
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 non-20MHz based 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.def.width == NL80211_CHAN_WIDTH_1 ||
320 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_2 ||
321 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_4 ||
322 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_8 ||
323 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_16 ||
324 	    ctx->conf.radar_enabled) {
325 		ctx->conf.min_def = ctx->conf.def;
326 		return;
327 	}
328 
329 	max_bw = ieee80211_get_chanctx_max_required_bw(local, &ctx->conf);
330 
331 	/* downgrade chandef up to max_bw */
332 	min_def = ctx->conf.def;
333 	while (min_def.width > max_bw)
334 		ieee80211_chandef_downgrade(&min_def);
335 
336 	if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
337 		return;
338 
339 	ctx->conf.min_def = min_def;
340 	if (!ctx->driver_present)
341 		return;
342 
343 	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_MIN_WIDTH);
344 }
345 
346 static void ieee80211_change_chanctx(struct ieee80211_local *local,
347 				     struct ieee80211_chanctx *ctx,
348 				     const struct cfg80211_chan_def *chandef)
349 {
350 	if (cfg80211_chandef_identical(&ctx->conf.def, chandef)) {
351 		ieee80211_recalc_chanctx_min_def(local, ctx);
352 		return;
353 	}
354 
355 	WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
356 
357 	ctx->conf.def = *chandef;
358 	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);
359 	ieee80211_recalc_chanctx_min_def(local, ctx);
360 
361 	if (!local->use_chanctx) {
362 		local->_oper_chandef = *chandef;
363 		ieee80211_hw_config(local, 0);
364 	}
365 }
366 
367 static struct ieee80211_chanctx *
368 ieee80211_find_chanctx(struct ieee80211_local *local,
369 		       const struct cfg80211_chan_def *chandef,
370 		       enum ieee80211_chanctx_mode mode)
371 {
372 	struct ieee80211_chanctx *ctx;
373 
374 	lockdep_assert_held(&local->chanctx_mtx);
375 
376 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
377 		return NULL;
378 
379 	list_for_each_entry(ctx, &local->chanctx_list, list) {
380 		const struct cfg80211_chan_def *compat;
381 
382 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
383 			continue;
384 
385 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
386 			continue;
387 
388 		compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
389 		if (!compat)
390 			continue;
391 
392 		compat = ieee80211_chanctx_reserved_chandef(local, ctx,
393 							    compat);
394 		if (!compat)
395 			continue;
396 
397 		ieee80211_change_chanctx(local, ctx, compat);
398 
399 		return ctx;
400 	}
401 
402 	return NULL;
403 }
404 
405 bool ieee80211_is_radar_required(struct ieee80211_local *local)
406 {
407 	struct ieee80211_sub_if_data *sdata;
408 
409 	lockdep_assert_held(&local->mtx);
410 
411 	rcu_read_lock();
412 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
413 		if (sdata->radar_required) {
414 			rcu_read_unlock();
415 			return true;
416 		}
417 	}
418 	rcu_read_unlock();
419 
420 	return false;
421 }
422 
423 static bool
424 ieee80211_chanctx_radar_required(struct ieee80211_local *local,
425 				 struct ieee80211_chanctx *ctx)
426 {
427 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
428 	struct ieee80211_sub_if_data *sdata;
429 	bool required = false;
430 
431 	lockdep_assert_held(&local->chanctx_mtx);
432 	lockdep_assert_held(&local->mtx);
433 
434 	rcu_read_lock();
435 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
436 		if (!ieee80211_sdata_running(sdata))
437 			continue;
438 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
439 			continue;
440 		if (!sdata->radar_required)
441 			continue;
442 
443 		required = true;
444 		break;
445 	}
446 	rcu_read_unlock();
447 
448 	return required;
449 }
450 
451 static struct ieee80211_chanctx *
452 ieee80211_alloc_chanctx(struct ieee80211_local *local,
453 			const struct cfg80211_chan_def *chandef,
454 			enum ieee80211_chanctx_mode mode)
455 {
456 	struct ieee80211_chanctx *ctx;
457 
458 	lockdep_assert_held(&local->chanctx_mtx);
459 
460 	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
461 	if (!ctx)
462 		return NULL;
463 
464 	INIT_LIST_HEAD(&ctx->assigned_vifs);
465 	INIT_LIST_HEAD(&ctx->reserved_vifs);
466 	ctx->conf.def = *chandef;
467 	ctx->conf.rx_chains_static = 1;
468 	ctx->conf.rx_chains_dynamic = 1;
469 	ctx->mode = mode;
470 	ctx->conf.radar_enabled = false;
471 	ieee80211_recalc_chanctx_min_def(local, ctx);
472 
473 	return ctx;
474 }
475 
476 static int ieee80211_add_chanctx(struct ieee80211_local *local,
477 				 struct ieee80211_chanctx *ctx)
478 {
479 	u32 changed;
480 	int err;
481 
482 	lockdep_assert_held(&local->mtx);
483 	lockdep_assert_held(&local->chanctx_mtx);
484 
485 	if (!local->use_chanctx)
486 		local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
487 
488 	/* turn idle off *before* setting channel -- some drivers need that */
489 	changed = ieee80211_idle_off(local);
490 	if (changed)
491 		ieee80211_hw_config(local, changed);
492 
493 	if (!local->use_chanctx) {
494 		local->_oper_chandef = ctx->conf.def;
495 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
496 	} else {
497 		err = drv_add_chanctx(local, ctx);
498 		if (err) {
499 			ieee80211_recalc_idle(local);
500 			return err;
501 		}
502 	}
503 
504 	return 0;
505 }
506 
507 static struct ieee80211_chanctx *
508 ieee80211_new_chanctx(struct ieee80211_local *local,
509 		      const struct cfg80211_chan_def *chandef,
510 		      enum ieee80211_chanctx_mode mode)
511 {
512 	struct ieee80211_chanctx *ctx;
513 	int err;
514 
515 	lockdep_assert_held(&local->mtx);
516 	lockdep_assert_held(&local->chanctx_mtx);
517 
518 	ctx = ieee80211_alloc_chanctx(local, chandef, mode);
519 	if (!ctx)
520 		return ERR_PTR(-ENOMEM);
521 
522 	err = ieee80211_add_chanctx(local, ctx);
523 	if (err) {
524 		kfree(ctx);
525 		return ERR_PTR(err);
526 	}
527 
528 	list_add_rcu(&ctx->list, &local->chanctx_list);
529 	return ctx;
530 }
531 
532 static void ieee80211_del_chanctx(struct ieee80211_local *local,
533 				  struct ieee80211_chanctx *ctx)
534 {
535 	lockdep_assert_held(&local->chanctx_mtx);
536 
537 	if (!local->use_chanctx) {
538 		struct cfg80211_chan_def *chandef = &local->_oper_chandef;
539 		/* S1G doesn't have 20MHz, so get the correct width for the
540 		 * current channel.
541 		 */
542 		if (chandef->chan->band == NL80211_BAND_S1GHZ)
543 			chandef->width =
544 				ieee80211_s1g_channel_width(chandef->chan);
545 		else
546 			chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
547 		chandef->center_freq1 = chandef->chan->center_freq;
548 		chandef->freq1_offset = chandef->chan->freq_offset;
549 		chandef->center_freq2 = 0;
550 
551 		/* NOTE: Disabling radar is only valid here for
552 		 * single channel context. To be sure, check it ...
553 		 */
554 		WARN_ON(local->hw.conf.radar_enabled &&
555 			!list_empty(&local->chanctx_list));
556 
557 		local->hw.conf.radar_enabled = false;
558 
559 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
560 	} else {
561 		drv_remove_chanctx(local, ctx);
562 	}
563 
564 	ieee80211_recalc_idle(local);
565 }
566 
567 static void ieee80211_free_chanctx(struct ieee80211_local *local,
568 				   struct ieee80211_chanctx *ctx)
569 {
570 	lockdep_assert_held(&local->chanctx_mtx);
571 
572 	WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
573 
574 	list_del_rcu(&ctx->list);
575 	ieee80211_del_chanctx(local, ctx);
576 	kfree_rcu(ctx, rcu_head);
577 }
578 
579 void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
580 				       struct ieee80211_chanctx *ctx)
581 {
582 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
583 	struct ieee80211_sub_if_data *sdata;
584 	const struct cfg80211_chan_def *compat = NULL;
585 	struct sta_info *sta;
586 
587 	lockdep_assert_held(&local->chanctx_mtx);
588 
589 	rcu_read_lock();
590 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
591 
592 		if (!ieee80211_sdata_running(sdata))
593 			continue;
594 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
595 			continue;
596 		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
597 			continue;
598 
599 		if (!compat)
600 			compat = &sdata->vif.bss_conf.chandef;
601 
602 		compat = cfg80211_chandef_compatible(
603 				&sdata->vif.bss_conf.chandef, compat);
604 		if (WARN_ON_ONCE(!compat))
605 			break;
606 	}
607 
608 	/* TDLS peers can sometimes affect the chandef width */
609 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
610 		if (!sta->uploaded ||
611 		    !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
612 		    !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
613 		    !sta->tdls_chandef.chan)
614 			continue;
615 
616 		compat = cfg80211_chandef_compatible(&sta->tdls_chandef,
617 						     compat);
618 		if (WARN_ON_ONCE(!compat))
619 			break;
620 	}
621 	rcu_read_unlock();
622 
623 	if (!compat)
624 		return;
625 
626 	ieee80211_change_chanctx(local, ctx, compat);
627 }
628 
629 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
630 					   struct ieee80211_chanctx *chanctx)
631 {
632 	bool radar_enabled;
633 
634 	lockdep_assert_held(&local->chanctx_mtx);
635 	/* for ieee80211_is_radar_required */
636 	lockdep_assert_held(&local->mtx);
637 
638 	radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
639 
640 	if (radar_enabled == chanctx->conf.radar_enabled)
641 		return;
642 
643 	chanctx->conf.radar_enabled = radar_enabled;
644 
645 	if (!local->use_chanctx) {
646 		local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
647 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
648 	}
649 
650 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
651 }
652 
653 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
654 					struct ieee80211_chanctx *new_ctx)
655 {
656 	struct ieee80211_local *local = sdata->local;
657 	struct ieee80211_chanctx_conf *conf;
658 	struct ieee80211_chanctx *curr_ctx = NULL;
659 	int ret = 0;
660 
661 	if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN))
662 		return -ENOTSUPP;
663 
664 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
665 					 lockdep_is_held(&local->chanctx_mtx));
666 
667 	if (conf) {
668 		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
669 
670 		drv_unassign_vif_chanctx(local, sdata, curr_ctx);
671 		conf = NULL;
672 		list_del(&sdata->assigned_chanctx_list);
673 	}
674 
675 	if (new_ctx) {
676 		ret = drv_assign_vif_chanctx(local, sdata, new_ctx);
677 		if (ret)
678 			goto out;
679 
680 		conf = &new_ctx->conf;
681 		list_add(&sdata->assigned_chanctx_list,
682 			 &new_ctx->assigned_vifs);
683 	}
684 
685 out:
686 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
687 
688 	sdata->vif.bss_conf.idle = !conf;
689 
690 	if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
691 		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
692 		ieee80211_recalc_smps_chanctx(local, curr_ctx);
693 		ieee80211_recalc_radar_chanctx(local, curr_ctx);
694 		ieee80211_recalc_chanctx_min_def(local, curr_ctx);
695 	}
696 
697 	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
698 		ieee80211_recalc_txpower(sdata, false);
699 		ieee80211_recalc_chanctx_min_def(local, new_ctx);
700 	}
701 
702 	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
703 	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
704 		ieee80211_bss_info_change_notify(sdata,
705 						 BSS_CHANGED_IDLE);
706 
707 	ieee80211_check_fast_xmit_iface(sdata);
708 
709 	return ret;
710 }
711 
712 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
713 				   struct ieee80211_chanctx *chanctx)
714 {
715 	struct ieee80211_sub_if_data *sdata;
716 	u8 rx_chains_static, rx_chains_dynamic;
717 
718 	lockdep_assert_held(&local->chanctx_mtx);
719 
720 	rx_chains_static = 1;
721 	rx_chains_dynamic = 1;
722 
723 	rcu_read_lock();
724 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
725 		u8 needed_static, needed_dynamic;
726 
727 		if (!ieee80211_sdata_running(sdata))
728 			continue;
729 
730 		if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
731 						&chanctx->conf)
732 			continue;
733 
734 		switch (sdata->vif.type) {
735 		case NL80211_IFTYPE_P2P_DEVICE:
736 		case NL80211_IFTYPE_NAN:
737 			continue;
738 		case NL80211_IFTYPE_STATION:
739 			if (!sdata->u.mgd.associated)
740 				continue;
741 			break;
742 		case NL80211_IFTYPE_AP_VLAN:
743 			continue;
744 		case NL80211_IFTYPE_AP:
745 		case NL80211_IFTYPE_ADHOC:
746 		case NL80211_IFTYPE_MESH_POINT:
747 		case NL80211_IFTYPE_OCB:
748 			break;
749 		default:
750 			WARN_ON_ONCE(1);
751 		}
752 
753 		switch (sdata->smps_mode) {
754 		default:
755 			WARN_ONCE(1, "Invalid SMPS mode %d\n",
756 				  sdata->smps_mode);
757 			fallthrough;
758 		case IEEE80211_SMPS_OFF:
759 			needed_static = sdata->needed_rx_chains;
760 			needed_dynamic = sdata->needed_rx_chains;
761 			break;
762 		case IEEE80211_SMPS_DYNAMIC:
763 			needed_static = 1;
764 			needed_dynamic = sdata->needed_rx_chains;
765 			break;
766 		case IEEE80211_SMPS_STATIC:
767 			needed_static = 1;
768 			needed_dynamic = 1;
769 			break;
770 		}
771 
772 		rx_chains_static = max(rx_chains_static, needed_static);
773 		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
774 	}
775 
776 	/* Disable SMPS for the monitor interface */
777 	sdata = rcu_dereference(local->monitor_sdata);
778 	if (sdata &&
779 	    rcu_access_pointer(sdata->vif.chanctx_conf) == &chanctx->conf)
780 		rx_chains_dynamic = rx_chains_static = local->rx_chains;
781 
782 	rcu_read_unlock();
783 
784 	if (!local->use_chanctx) {
785 		if (rx_chains_static > 1)
786 			local->smps_mode = IEEE80211_SMPS_OFF;
787 		else if (rx_chains_dynamic > 1)
788 			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
789 		else
790 			local->smps_mode = IEEE80211_SMPS_STATIC;
791 		ieee80211_hw_config(local, 0);
792 	}
793 
794 	if (rx_chains_static == chanctx->conf.rx_chains_static &&
795 	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
796 		return;
797 
798 	chanctx->conf.rx_chains_static = rx_chains_static;
799 	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
800 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
801 }
802 
803 static void
804 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
805 				      bool clear)
806 {
807 	struct ieee80211_local *local __maybe_unused = sdata->local;
808 	struct ieee80211_sub_if_data *vlan;
809 	struct ieee80211_chanctx_conf *conf;
810 
811 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
812 		return;
813 
814 	lockdep_assert_held(&local->mtx);
815 
816 	/* Check that conf exists, even when clearing this function
817 	 * must be called with the AP's channel context still there
818 	 * as it would otherwise cause VLANs to have an invalid
819 	 * channel context pointer for a while, possibly pointing
820 	 * to a channel context that has already been freed.
821 	 */
822 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
823 					 lockdep_is_held(&local->chanctx_mtx));
824 	WARN_ON(!conf);
825 
826 	if (clear)
827 		conf = NULL;
828 
829 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
830 		rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
831 }
832 
833 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
834 					 bool clear)
835 {
836 	struct ieee80211_local *local = sdata->local;
837 
838 	mutex_lock(&local->chanctx_mtx);
839 
840 	__ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
841 
842 	mutex_unlock(&local->chanctx_mtx);
843 }
844 
845 int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
846 {
847 	struct ieee80211_chanctx *ctx = sdata->reserved_chanctx;
848 
849 	lockdep_assert_held(&sdata->local->chanctx_mtx);
850 
851 	if (WARN_ON(!ctx))
852 		return -EINVAL;
853 
854 	list_del(&sdata->reserved_chanctx_list);
855 	sdata->reserved_chanctx = NULL;
856 
857 	if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
858 		if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
859 			if (WARN_ON(!ctx->replace_ctx))
860 				return -EINVAL;
861 
862 			WARN_ON(ctx->replace_ctx->replace_state !=
863 			        IEEE80211_CHANCTX_WILL_BE_REPLACED);
864 			WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
865 
866 			ctx->replace_ctx->replace_ctx = NULL;
867 			ctx->replace_ctx->replace_state =
868 					IEEE80211_CHANCTX_REPLACE_NONE;
869 
870 			list_del_rcu(&ctx->list);
871 			kfree_rcu(ctx, rcu_head);
872 		} else {
873 			ieee80211_free_chanctx(sdata->local, ctx);
874 		}
875 	}
876 
877 	return 0;
878 }
879 
880 int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
881 				  const struct cfg80211_chan_def *chandef,
882 				  enum ieee80211_chanctx_mode mode,
883 				  bool radar_required)
884 {
885 	struct ieee80211_local *local = sdata->local;
886 	struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
887 
888 	lockdep_assert_held(&local->chanctx_mtx);
889 
890 	curr_ctx = ieee80211_vif_get_chanctx(sdata);
891 	if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
892 		return -ENOTSUPP;
893 
894 	new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
895 	if (!new_ctx) {
896 		if (ieee80211_can_create_new_chanctx(local)) {
897 			new_ctx = ieee80211_new_chanctx(local, chandef, mode);
898 			if (IS_ERR(new_ctx))
899 				return PTR_ERR(new_ctx);
900 		} else {
901 			if (!curr_ctx ||
902 			    (curr_ctx->replace_state ==
903 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
904 			    !list_empty(&curr_ctx->reserved_vifs)) {
905 				/*
906 				 * Another vif already requested this context
907 				 * for a reservation. Find another one hoping
908 				 * all vifs assigned to it will also switch
909 				 * soon enough.
910 				 *
911 				 * TODO: This needs a little more work as some
912 				 * cases (more than 2 chanctx capable devices)
913 				 * may fail which could otherwise succeed
914 				 * provided some channel context juggling was
915 				 * performed.
916 				 *
917 				 * Consider ctx1..3, vif1..6, each ctx has 2
918 				 * vifs. vif1 and vif2 from ctx1 request new
919 				 * different chandefs starting 2 in-place
920 				 * reserations with ctx4 and ctx5 replacing
921 				 * ctx1 and ctx2 respectively. Next vif5 and
922 				 * vif6 from ctx3 reserve ctx4. If vif3 and
923 				 * vif4 remain on ctx2 as they are then this
924 				 * fails unless `replace_ctx` from ctx5 is
925 				 * replaced with ctx3.
926 				 */
927 				list_for_each_entry(ctx, &local->chanctx_list,
928 						    list) {
929 					if (ctx->replace_state !=
930 					    IEEE80211_CHANCTX_REPLACE_NONE)
931 						continue;
932 
933 					if (!list_empty(&ctx->reserved_vifs))
934 						continue;
935 
936 					curr_ctx = ctx;
937 					break;
938 				}
939 			}
940 
941 			/*
942 			 * If that's true then all available contexts already
943 			 * have reservations and cannot be used.
944 			 */
945 			if (!curr_ctx ||
946 			    (curr_ctx->replace_state ==
947 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
948 			    !list_empty(&curr_ctx->reserved_vifs))
949 				return -EBUSY;
950 
951 			new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
952 			if (!new_ctx)
953 				return -ENOMEM;
954 
955 			new_ctx->replace_ctx = curr_ctx;
956 			new_ctx->replace_state =
957 					IEEE80211_CHANCTX_REPLACES_OTHER;
958 
959 			curr_ctx->replace_ctx = new_ctx;
960 			curr_ctx->replace_state =
961 					IEEE80211_CHANCTX_WILL_BE_REPLACED;
962 
963 			list_add_rcu(&new_ctx->list, &local->chanctx_list);
964 		}
965 	}
966 
967 	list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);
968 	sdata->reserved_chanctx = new_ctx;
969 	sdata->reserved_chandef = *chandef;
970 	sdata->reserved_radar_required = radar_required;
971 	sdata->reserved_ready = false;
972 
973 	return 0;
974 }
975 
976 static void
977 ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
978 {
979 	switch (sdata->vif.type) {
980 	case NL80211_IFTYPE_ADHOC:
981 	case NL80211_IFTYPE_AP:
982 	case NL80211_IFTYPE_MESH_POINT:
983 	case NL80211_IFTYPE_OCB:
984 		ieee80211_queue_work(&sdata->local->hw,
985 				     &sdata->csa_finalize_work);
986 		break;
987 	case NL80211_IFTYPE_STATION:
988 		ieee80211_queue_work(&sdata->local->hw,
989 				     &sdata->u.mgd.chswitch_work);
990 		break;
991 	case NL80211_IFTYPE_UNSPECIFIED:
992 	case NL80211_IFTYPE_AP_VLAN:
993 	case NL80211_IFTYPE_WDS:
994 	case NL80211_IFTYPE_MONITOR:
995 	case NL80211_IFTYPE_P2P_CLIENT:
996 	case NL80211_IFTYPE_P2P_GO:
997 	case NL80211_IFTYPE_P2P_DEVICE:
998 	case NL80211_IFTYPE_NAN:
999 	case NUM_NL80211_IFTYPES:
1000 		WARN_ON(1);
1001 		break;
1002 	}
1003 }
1004 
1005 static void
1006 ieee80211_vif_update_chandef(struct ieee80211_sub_if_data *sdata,
1007 			     const struct cfg80211_chan_def *chandef)
1008 {
1009 	struct ieee80211_sub_if_data *vlan;
1010 
1011 	sdata->vif.bss_conf.chandef = *chandef;
1012 
1013 	if (sdata->vif.type != NL80211_IFTYPE_AP)
1014 		return;
1015 
1016 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
1017 		vlan->vif.bss_conf.chandef = *chandef;
1018 }
1019 
1020 static int
1021 ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
1022 {
1023 	struct ieee80211_local *local = sdata->local;
1024 	struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1025 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1026 	const struct cfg80211_chan_def *chandef;
1027 	u32 changed = 0;
1028 	int err;
1029 
1030 	lockdep_assert_held(&local->mtx);
1031 	lockdep_assert_held(&local->chanctx_mtx);
1032 
1033 	new_ctx = sdata->reserved_chanctx;
1034 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1035 
1036 	if (WARN_ON(!sdata->reserved_ready))
1037 		return -EBUSY;
1038 
1039 	if (WARN_ON(!new_ctx))
1040 		return -EINVAL;
1041 
1042 	if (WARN_ON(!old_ctx))
1043 		return -EINVAL;
1044 
1045 	if (WARN_ON(new_ctx->replace_state ==
1046 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1047 		return -EINVAL;
1048 
1049 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1050 				&sdata->reserved_chandef);
1051 	if (WARN_ON(!chandef))
1052 		return -EINVAL;
1053 
1054 	ieee80211_change_chanctx(local, new_ctx, chandef);
1055 
1056 	vif_chsw[0].vif = &sdata->vif;
1057 	vif_chsw[0].old_ctx = &old_ctx->conf;
1058 	vif_chsw[0].new_ctx = &new_ctx->conf;
1059 
1060 	list_del(&sdata->reserved_chanctx_list);
1061 	sdata->reserved_chanctx = NULL;
1062 
1063 	err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1064 				     CHANCTX_SWMODE_REASSIGN_VIF);
1065 	if (err) {
1066 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1067 			ieee80211_free_chanctx(local, new_ctx);
1068 
1069 		goto out;
1070 	}
1071 
1072 	list_move(&sdata->assigned_chanctx_list, &new_ctx->assigned_vifs);
1073 	rcu_assign_pointer(sdata->vif.chanctx_conf, &new_ctx->conf);
1074 
1075 	if (sdata->vif.type == NL80211_IFTYPE_AP)
1076 		__ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
1077 
1078 	ieee80211_check_fast_xmit_iface(sdata);
1079 
1080 	if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1081 		ieee80211_free_chanctx(local, old_ctx);
1082 
1083 	if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
1084 		changed = BSS_CHANGED_BANDWIDTH;
1085 
1086 	ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1087 
1088 	ieee80211_recalc_smps_chanctx(local, new_ctx);
1089 	ieee80211_recalc_radar_chanctx(local, new_ctx);
1090 	ieee80211_recalc_chanctx_min_def(local, new_ctx);
1091 
1092 	if (changed)
1093 		ieee80211_bss_info_change_notify(sdata, changed);
1094 
1095 out:
1096 	ieee80211_vif_chanctx_reservation_complete(sdata);
1097 	return err;
1098 }
1099 
1100 static int
1101 ieee80211_vif_use_reserved_assign(struct ieee80211_sub_if_data *sdata)
1102 {
1103 	struct ieee80211_local *local = sdata->local;
1104 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1105 	const struct cfg80211_chan_def *chandef;
1106 	int err;
1107 
1108 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1109 	new_ctx = sdata->reserved_chanctx;
1110 
1111 	if (WARN_ON(!sdata->reserved_ready))
1112 		return -EINVAL;
1113 
1114 	if (WARN_ON(old_ctx))
1115 		return -EINVAL;
1116 
1117 	if (WARN_ON(!new_ctx))
1118 		return -EINVAL;
1119 
1120 	if (WARN_ON(new_ctx->replace_state ==
1121 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1122 		return -EINVAL;
1123 
1124 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1125 				&sdata->reserved_chandef);
1126 	if (WARN_ON(!chandef))
1127 		return -EINVAL;
1128 
1129 	ieee80211_change_chanctx(local, new_ctx, chandef);
1130 
1131 	list_del(&sdata->reserved_chanctx_list);
1132 	sdata->reserved_chanctx = NULL;
1133 
1134 	err = ieee80211_assign_vif_chanctx(sdata, new_ctx);
1135 	if (err) {
1136 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1137 			ieee80211_free_chanctx(local, new_ctx);
1138 
1139 		goto out;
1140 	}
1141 
1142 out:
1143 	ieee80211_vif_chanctx_reservation_complete(sdata);
1144 	return err;
1145 }
1146 
1147 static bool
1148 ieee80211_vif_has_in_place_reservation(struct ieee80211_sub_if_data *sdata)
1149 {
1150 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1151 
1152 	lockdep_assert_held(&sdata->local->chanctx_mtx);
1153 
1154 	new_ctx = sdata->reserved_chanctx;
1155 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1156 
1157 	if (!old_ctx)
1158 		return false;
1159 
1160 	if (WARN_ON(!new_ctx))
1161 		return false;
1162 
1163 	if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1164 		return false;
1165 
1166 	if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1167 		return false;
1168 
1169 	return true;
1170 }
1171 
1172 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1173 					struct ieee80211_chanctx *new_ctx)
1174 {
1175 	const struct cfg80211_chan_def *chandef;
1176 
1177 	lockdep_assert_held(&local->mtx);
1178 	lockdep_assert_held(&local->chanctx_mtx);
1179 
1180 	chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1181 	if (WARN_ON(!chandef))
1182 		return -EINVAL;
1183 
1184 	local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1185 	local->_oper_chandef = *chandef;
1186 	ieee80211_hw_config(local, 0);
1187 
1188 	return 0;
1189 }
1190 
1191 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1192 				      int n_vifs)
1193 {
1194 	struct ieee80211_vif_chanctx_switch *vif_chsw;
1195 	struct ieee80211_sub_if_data *sdata;
1196 	struct ieee80211_chanctx *ctx, *old_ctx;
1197 	int i, err;
1198 
1199 	lockdep_assert_held(&local->mtx);
1200 	lockdep_assert_held(&local->chanctx_mtx);
1201 
1202 	vif_chsw = kcalloc(n_vifs, sizeof(vif_chsw[0]), GFP_KERNEL);
1203 	if (!vif_chsw)
1204 		return -ENOMEM;
1205 
1206 	i = 0;
1207 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1208 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1209 			continue;
1210 
1211 		if (WARN_ON(!ctx->replace_ctx)) {
1212 			err = -EINVAL;
1213 			goto out;
1214 		}
1215 
1216 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1217 				    reserved_chanctx_list) {
1218 			if (!ieee80211_vif_has_in_place_reservation(
1219 					sdata))
1220 				continue;
1221 
1222 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1223 			vif_chsw[i].vif = &sdata->vif;
1224 			vif_chsw[i].old_ctx = &old_ctx->conf;
1225 			vif_chsw[i].new_ctx = &ctx->conf;
1226 
1227 			i++;
1228 		}
1229 	}
1230 
1231 	err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1232 				     CHANCTX_SWMODE_SWAP_CONTEXTS);
1233 
1234 out:
1235 	kfree(vif_chsw);
1236 	return err;
1237 }
1238 
1239 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1240 {
1241 	struct ieee80211_chanctx *ctx;
1242 	int err;
1243 
1244 	lockdep_assert_held(&local->mtx);
1245 	lockdep_assert_held(&local->chanctx_mtx);
1246 
1247 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1248 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1249 			continue;
1250 
1251 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1252 			continue;
1253 
1254 		ieee80211_del_chanctx(local, ctx->replace_ctx);
1255 		err = ieee80211_add_chanctx(local, ctx);
1256 		if (err)
1257 			goto err;
1258 	}
1259 
1260 	return 0;
1261 
1262 err:
1263 	WARN_ON(ieee80211_add_chanctx(local, ctx));
1264 	list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1265 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1266 			continue;
1267 
1268 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1269 			continue;
1270 
1271 		ieee80211_del_chanctx(local, ctx);
1272 		WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1273 	}
1274 
1275 	return err;
1276 }
1277 
1278 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1279 {
1280 	struct ieee80211_sub_if_data *sdata, *sdata_tmp;
1281 	struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1282 	struct ieee80211_chanctx *new_ctx = NULL;
1283 	int err, n_assigned, n_reserved, n_ready;
1284 	int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1285 
1286 	lockdep_assert_held(&local->mtx);
1287 	lockdep_assert_held(&local->chanctx_mtx);
1288 
1289 	/*
1290 	 * If there are 2 independent pairs of channel contexts performing
1291 	 * cross-switch of their vifs this code will still wait until both are
1292 	 * ready even though it could be possible to switch one before the
1293 	 * other is ready.
1294 	 *
1295 	 * For practical reasons and code simplicity just do a single huge
1296 	 * switch.
1297 	 */
1298 
1299 	/*
1300 	 * Verify if the reservation is still feasible.
1301 	 *  - if it's not then disconnect
1302 	 *  - if it is but not all vifs necessary are ready then defer
1303 	 */
1304 
1305 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1306 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1307 			continue;
1308 
1309 		if (WARN_ON(!ctx->replace_ctx)) {
1310 			err = -EINVAL;
1311 			goto err;
1312 		}
1313 
1314 		if (!local->use_chanctx)
1315 			new_ctx = ctx;
1316 
1317 		n_ctx++;
1318 
1319 		n_assigned = 0;
1320 		n_reserved = 0;
1321 		n_ready = 0;
1322 
1323 		list_for_each_entry(sdata, &ctx->replace_ctx->assigned_vifs,
1324 				    assigned_chanctx_list) {
1325 			n_assigned++;
1326 			if (sdata->reserved_chanctx) {
1327 				n_reserved++;
1328 				if (sdata->reserved_ready)
1329 					n_ready++;
1330 			}
1331 		}
1332 
1333 		if (n_assigned != n_reserved) {
1334 			if (n_ready == n_reserved) {
1335 				wiphy_info(local->hw.wiphy,
1336 					   "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1337 				err = -EBUSY;
1338 				goto err;
1339 			}
1340 
1341 			return -EAGAIN;
1342 		}
1343 
1344 		ctx->conf.radar_enabled = false;
1345 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1346 				    reserved_chanctx_list) {
1347 			if (ieee80211_vif_has_in_place_reservation(sdata) &&
1348 			    !sdata->reserved_ready)
1349 				return -EAGAIN;
1350 
1351 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1352 			if (old_ctx) {
1353 				if (old_ctx->replace_state ==
1354 				    IEEE80211_CHANCTX_WILL_BE_REPLACED)
1355 					n_vifs_switch++;
1356 				else
1357 					n_vifs_assign++;
1358 			} else {
1359 				n_vifs_ctxless++;
1360 			}
1361 
1362 			if (sdata->reserved_radar_required)
1363 				ctx->conf.radar_enabled = true;
1364 		}
1365 	}
1366 
1367 	if (WARN_ON(n_ctx == 0) ||
1368 	    WARN_ON(n_vifs_switch == 0 &&
1369 		    n_vifs_assign == 0 &&
1370 		    n_vifs_ctxless == 0) ||
1371 	    WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1372 	    WARN_ON(!new_ctx && !local->use_chanctx)) {
1373 		err = -EINVAL;
1374 		goto err;
1375 	}
1376 
1377 	/*
1378 	 * All necessary vifs are ready. Perform the switch now depending on
1379 	 * reservations and driver capabilities.
1380 	 */
1381 
1382 	if (local->use_chanctx) {
1383 		if (n_vifs_switch > 0) {
1384 			err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1385 			if (err)
1386 				goto err;
1387 		}
1388 
1389 		if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1390 			err = ieee80211_chsw_switch_ctxs(local);
1391 			if (err)
1392 				goto err;
1393 		}
1394 	} else {
1395 		err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1396 		if (err)
1397 			goto err;
1398 	}
1399 
1400 	/*
1401 	 * Update all structures, values and pointers to point to new channel
1402 	 * context(s).
1403 	 */
1404 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1405 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1406 			continue;
1407 
1408 		if (WARN_ON(!ctx->replace_ctx)) {
1409 			err = -EINVAL;
1410 			goto err;
1411 		}
1412 
1413 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1414 				    reserved_chanctx_list) {
1415 			u32 changed = 0;
1416 
1417 			if (!ieee80211_vif_has_in_place_reservation(sdata))
1418 				continue;
1419 
1420 			rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
1421 
1422 			if (sdata->vif.type == NL80211_IFTYPE_AP)
1423 				__ieee80211_vif_copy_chanctx_to_vlans(sdata,
1424 								      false);
1425 
1426 			ieee80211_check_fast_xmit_iface(sdata);
1427 
1428 			sdata->radar_required = sdata->reserved_radar_required;
1429 
1430 			if (sdata->vif.bss_conf.chandef.width !=
1431 			    sdata->reserved_chandef.width)
1432 				changed = BSS_CHANGED_BANDWIDTH;
1433 
1434 			ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1435 			if (changed)
1436 				ieee80211_bss_info_change_notify(sdata,
1437 								 changed);
1438 
1439 			ieee80211_recalc_txpower(sdata, false);
1440 		}
1441 
1442 		ieee80211_recalc_chanctx_chantype(local, ctx);
1443 		ieee80211_recalc_smps_chanctx(local, ctx);
1444 		ieee80211_recalc_radar_chanctx(local, ctx);
1445 		ieee80211_recalc_chanctx_min_def(local, ctx);
1446 
1447 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1448 					 reserved_chanctx_list) {
1449 			if (ieee80211_vif_get_chanctx(sdata) != ctx)
1450 				continue;
1451 
1452 			list_del(&sdata->reserved_chanctx_list);
1453 			list_move(&sdata->assigned_chanctx_list,
1454 				  &ctx->assigned_vifs);
1455 			sdata->reserved_chanctx = NULL;
1456 
1457 			ieee80211_vif_chanctx_reservation_complete(sdata);
1458 		}
1459 
1460 		/*
1461 		 * This context might have been a dependency for an already
1462 		 * ready re-assign reservation interface that was deferred. Do
1463 		 * not propagate error to the caller though. The in-place
1464 		 * reservation for originally requested interface has already
1465 		 * succeeded at this point.
1466 		 */
1467 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1468 					 reserved_chanctx_list) {
1469 			if (WARN_ON(ieee80211_vif_has_in_place_reservation(
1470 					sdata)))
1471 				continue;
1472 
1473 			if (WARN_ON(sdata->reserved_chanctx != ctx))
1474 				continue;
1475 
1476 			if (!sdata->reserved_ready)
1477 				continue;
1478 
1479 			if (ieee80211_vif_get_chanctx(sdata))
1480 				err = ieee80211_vif_use_reserved_reassign(
1481 						sdata);
1482 			else
1483 				err = ieee80211_vif_use_reserved_assign(sdata);
1484 
1485 			if (err) {
1486 				sdata_info(sdata,
1487 					   "failed to finalize (re-)assign reservation (err=%d)\n",
1488 					   err);
1489 				ieee80211_vif_unreserve_chanctx(sdata);
1490 				cfg80211_stop_iface(local->hw.wiphy,
1491 						    &sdata->wdev,
1492 						    GFP_KERNEL);
1493 			}
1494 		}
1495 	}
1496 
1497 	/*
1498 	 * Finally free old contexts
1499 	 */
1500 
1501 	list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1502 		if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1503 			continue;
1504 
1505 		ctx->replace_ctx->replace_ctx = NULL;
1506 		ctx->replace_ctx->replace_state =
1507 				IEEE80211_CHANCTX_REPLACE_NONE;
1508 
1509 		list_del_rcu(&ctx->list);
1510 		kfree_rcu(ctx, rcu_head);
1511 	}
1512 
1513 	return 0;
1514 
1515 err:
1516 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1517 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1518 			continue;
1519 
1520 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1521 					 reserved_chanctx_list) {
1522 			ieee80211_vif_unreserve_chanctx(sdata);
1523 			ieee80211_vif_chanctx_reservation_complete(sdata);
1524 		}
1525 	}
1526 
1527 	return err;
1528 }
1529 
1530 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1531 {
1532 	struct ieee80211_local *local = sdata->local;
1533 	struct ieee80211_chanctx_conf *conf;
1534 	struct ieee80211_chanctx *ctx;
1535 	bool use_reserved_switch = false;
1536 
1537 	lockdep_assert_held(&local->chanctx_mtx);
1538 
1539 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1540 					 lockdep_is_held(&local->chanctx_mtx));
1541 	if (!conf)
1542 		return;
1543 
1544 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1545 
1546 	if (sdata->reserved_chanctx) {
1547 		if (sdata->reserved_chanctx->replace_state ==
1548 		    IEEE80211_CHANCTX_REPLACES_OTHER &&
1549 		    ieee80211_chanctx_num_reserved(local,
1550 						   sdata->reserved_chanctx) > 1)
1551 			use_reserved_switch = true;
1552 
1553 		ieee80211_vif_unreserve_chanctx(sdata);
1554 	}
1555 
1556 	ieee80211_assign_vif_chanctx(sdata, NULL);
1557 	if (ieee80211_chanctx_refcount(local, ctx) == 0)
1558 		ieee80211_free_chanctx(local, ctx);
1559 
1560 	sdata->radar_required = false;
1561 
1562 	/* Unreserving may ready an in-place reservation. */
1563 	if (use_reserved_switch)
1564 		ieee80211_vif_use_reserved_switch(local);
1565 }
1566 
1567 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
1568 			      const struct cfg80211_chan_def *chandef,
1569 			      enum ieee80211_chanctx_mode mode)
1570 {
1571 	struct ieee80211_local *local = sdata->local;
1572 	struct ieee80211_chanctx *ctx;
1573 	u8 radar_detect_width = 0;
1574 	int ret;
1575 
1576 	lockdep_assert_held(&local->mtx);
1577 
1578 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1579 
1580 	mutex_lock(&local->chanctx_mtx);
1581 
1582 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1583 					    chandef,
1584 					    sdata->wdev.iftype);
1585 	if (ret < 0)
1586 		goto out;
1587 	if (ret > 0)
1588 		radar_detect_width = BIT(chandef->width);
1589 
1590 	sdata->radar_required = ret;
1591 
1592 	ret = ieee80211_check_combinations(sdata, chandef, mode,
1593 					   radar_detect_width);
1594 	if (ret < 0)
1595 		goto out;
1596 
1597 	__ieee80211_vif_release_channel(sdata);
1598 
1599 	ctx = ieee80211_find_chanctx(local, chandef, mode);
1600 	if (!ctx)
1601 		ctx = ieee80211_new_chanctx(local, chandef, mode);
1602 	if (IS_ERR(ctx)) {
1603 		ret = PTR_ERR(ctx);
1604 		goto out;
1605 	}
1606 
1607 	ieee80211_vif_update_chandef(sdata, chandef);
1608 
1609 	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
1610 	if (ret) {
1611 		/* if assign fails refcount stays the same */
1612 		if (ieee80211_chanctx_refcount(local, ctx) == 0)
1613 			ieee80211_free_chanctx(local, ctx);
1614 		goto out;
1615 	}
1616 
1617 	ieee80211_recalc_smps_chanctx(local, ctx);
1618 	ieee80211_recalc_radar_chanctx(local, ctx);
1619  out:
1620 	if (ret)
1621 		sdata->radar_required = false;
1622 
1623 	mutex_unlock(&local->chanctx_mtx);
1624 	return ret;
1625 }
1626 
1627 int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata)
1628 {
1629 	struct ieee80211_local *local = sdata->local;
1630 	struct ieee80211_chanctx *new_ctx;
1631 	struct ieee80211_chanctx *old_ctx;
1632 	int err;
1633 
1634 	lockdep_assert_held(&local->mtx);
1635 	lockdep_assert_held(&local->chanctx_mtx);
1636 
1637 	new_ctx = sdata->reserved_chanctx;
1638 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1639 
1640 	if (WARN_ON(!new_ctx))
1641 		return -EINVAL;
1642 
1643 	if (WARN_ON(new_ctx->replace_state ==
1644 		    IEEE80211_CHANCTX_WILL_BE_REPLACED))
1645 		return -EINVAL;
1646 
1647 	if (WARN_ON(sdata->reserved_ready))
1648 		return -EINVAL;
1649 
1650 	sdata->reserved_ready = true;
1651 
1652 	if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1653 		if (old_ctx)
1654 			err = ieee80211_vif_use_reserved_reassign(sdata);
1655 		else
1656 			err = ieee80211_vif_use_reserved_assign(sdata);
1657 
1658 		if (err)
1659 			return err;
1660 	}
1661 
1662 	/*
1663 	 * In-place reservation may need to be finalized now either if:
1664 	 *  a) sdata is taking part in the swapping itself and is the last one
1665 	 *  b) sdata has switched with a re-assign reservation to an existing
1666 	 *     context readying in-place switching of old_ctx
1667 	 *
1668 	 * In case of (b) do not propagate the error up because the requested
1669 	 * sdata already switched successfully. Just spill an extra warning.
1670 	 * The ieee80211_vif_use_reserved_switch() already stops all necessary
1671 	 * interfaces upon failure.
1672 	 */
1673 	if ((old_ctx &&
1674 	     old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1675 	    new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1676 		err = ieee80211_vif_use_reserved_switch(local);
1677 		if (err && err != -EAGAIN) {
1678 			if (new_ctx->replace_state ==
1679 			    IEEE80211_CHANCTX_REPLACES_OTHER)
1680 				return err;
1681 
1682 			wiphy_info(local->hw.wiphy,
1683 				   "depending in-place reservation failed (err=%d)\n",
1684 				   err);
1685 		}
1686 	}
1687 
1688 	return 0;
1689 }
1690 
1691 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
1692 				   const struct cfg80211_chan_def *chandef,
1693 				   u32 *changed)
1694 {
1695 	struct ieee80211_local *local = sdata->local;
1696 	struct ieee80211_chanctx_conf *conf;
1697 	struct ieee80211_chanctx *ctx;
1698 	const struct cfg80211_chan_def *compat;
1699 	int ret;
1700 
1701 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1702 				     IEEE80211_CHAN_DISABLED))
1703 		return -EINVAL;
1704 
1705 	mutex_lock(&local->chanctx_mtx);
1706 	if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
1707 		ret = 0;
1708 		goto out;
1709 	}
1710 
1711 	if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1712 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1713 		ret = -EINVAL;
1714 		goto out;
1715 	}
1716 
1717 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1718 					 lockdep_is_held(&local->chanctx_mtx));
1719 	if (!conf) {
1720 		ret = -EINVAL;
1721 		goto out;
1722 	}
1723 
1724 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1725 
1726 	compat = cfg80211_chandef_compatible(&conf->def, chandef);
1727 	if (!compat) {
1728 		ret = -EINVAL;
1729 		goto out;
1730 	}
1731 
1732 	switch (ctx->replace_state) {
1733 	case IEEE80211_CHANCTX_REPLACE_NONE:
1734 		if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1735 			ret = -EBUSY;
1736 			goto out;
1737 		}
1738 		break;
1739 	case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1740 		/* TODO: Perhaps the bandwidth change could be treated as a
1741 		 * reservation itself? */
1742 		ret = -EBUSY;
1743 		goto out;
1744 	case IEEE80211_CHANCTX_REPLACES_OTHER:
1745 		/* channel context that is going to replace another channel
1746 		 * context doesn't really exist and shouldn't be assigned
1747 		 * anywhere yet */
1748 		WARN_ON(1);
1749 		break;
1750 	}
1751 
1752 	ieee80211_vif_update_chandef(sdata, chandef);
1753 
1754 	ieee80211_recalc_chanctx_chantype(local, ctx);
1755 
1756 	*changed |= BSS_CHANGED_BANDWIDTH;
1757 	ret = 0;
1758  out:
1759 	mutex_unlock(&local->chanctx_mtx);
1760 	return ret;
1761 }
1762 
1763 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1764 {
1765 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1766 
1767 	lockdep_assert_held(&sdata->local->mtx);
1768 
1769 	mutex_lock(&sdata->local->chanctx_mtx);
1770 	__ieee80211_vif_release_channel(sdata);
1771 	mutex_unlock(&sdata->local->chanctx_mtx);
1772 }
1773 
1774 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
1775 {
1776 	struct ieee80211_local *local = sdata->local;
1777 	struct ieee80211_sub_if_data *ap;
1778 	struct ieee80211_chanctx_conf *conf;
1779 
1780 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
1781 		return;
1782 
1783 	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
1784 
1785 	mutex_lock(&local->chanctx_mtx);
1786 
1787 	conf = rcu_dereference_protected(ap->vif.chanctx_conf,
1788 					 lockdep_is_held(&local->chanctx_mtx));
1789 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
1790 	mutex_unlock(&local->chanctx_mtx);
1791 }
1792 
1793 void ieee80211_iter_chan_contexts_atomic(
1794 	struct ieee80211_hw *hw,
1795 	void (*iter)(struct ieee80211_hw *hw,
1796 		     struct ieee80211_chanctx_conf *chanctx_conf,
1797 		     void *data),
1798 	void *iter_data)
1799 {
1800 	struct ieee80211_local *local = hw_to_local(hw);
1801 	struct ieee80211_chanctx *ctx;
1802 
1803 	rcu_read_lock();
1804 	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
1805 		if (ctx->driver_present)
1806 			iter(hw, &ctx->conf, iter_data);
1807 	rcu_read_unlock();
1808 }
1809 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);
1810