xref: /openbmc/linux/net/mac80211/chan.c (revision 94cdda6b)
1 /*
2  * mac80211 - channel management
3  */
4 
5 #include <linux/nl80211.h>
6 #include <linux/export.h>
7 #include <linux/rtnetlink.h>
8 #include <net/cfg80211.h>
9 #include "ieee80211_i.h"
10 #include "driver-ops.h"
11 
12 static int ieee80211_chanctx_num_assigned(struct ieee80211_local *local,
13 					  struct ieee80211_chanctx *ctx)
14 {
15 	struct ieee80211_sub_if_data *sdata;
16 	int num = 0;
17 
18 	lockdep_assert_held(&local->chanctx_mtx);
19 
20 	list_for_each_entry(sdata, &ctx->assigned_vifs, assigned_chanctx_list)
21 		num++;
22 
23 	return num;
24 }
25 
26 static int ieee80211_chanctx_num_reserved(struct ieee80211_local *local,
27 					  struct ieee80211_chanctx *ctx)
28 {
29 	struct ieee80211_sub_if_data *sdata;
30 	int num = 0;
31 
32 	lockdep_assert_held(&local->chanctx_mtx);
33 
34 	list_for_each_entry(sdata, &ctx->reserved_vifs, reserved_chanctx_list)
35 		num++;
36 
37 	return num;
38 }
39 
40 int ieee80211_chanctx_refcount(struct ieee80211_local *local,
41 			       struct ieee80211_chanctx *ctx)
42 {
43 	return ieee80211_chanctx_num_assigned(local, ctx) +
44 	       ieee80211_chanctx_num_reserved(local, ctx);
45 }
46 
47 static int ieee80211_num_chanctx(struct ieee80211_local *local)
48 {
49 	struct ieee80211_chanctx *ctx;
50 	int num = 0;
51 
52 	lockdep_assert_held(&local->chanctx_mtx);
53 
54 	list_for_each_entry(ctx, &local->chanctx_list, list)
55 		num++;
56 
57 	return num;
58 }
59 
60 static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local)
61 {
62 	lockdep_assert_held(&local->chanctx_mtx);
63 	return ieee80211_num_chanctx(local) < ieee80211_max_num_channels(local);
64 }
65 
66 static struct ieee80211_chanctx *
67 ieee80211_vif_get_chanctx(struct ieee80211_sub_if_data *sdata)
68 {
69 	struct ieee80211_local *local __maybe_unused = sdata->local;
70 	struct ieee80211_chanctx_conf *conf;
71 
72 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
73 					 lockdep_is_held(&local->chanctx_mtx));
74 	if (!conf)
75 		return NULL;
76 
77 	return container_of(conf, struct ieee80211_chanctx, conf);
78 }
79 
80 static const struct cfg80211_chan_def *
81 ieee80211_chanctx_reserved_chandef(struct ieee80211_local *local,
82 				   struct ieee80211_chanctx *ctx,
83 				   const struct cfg80211_chan_def *compat)
84 {
85 	struct ieee80211_sub_if_data *sdata;
86 
87 	lockdep_assert_held(&local->chanctx_mtx);
88 
89 	list_for_each_entry(sdata, &ctx->reserved_vifs,
90 			    reserved_chanctx_list) {
91 		if (!compat)
92 			compat = &sdata->reserved_chandef;
93 
94 		compat = cfg80211_chandef_compatible(&sdata->reserved_chandef,
95 						     compat);
96 		if (!compat)
97 			break;
98 	}
99 
100 	return compat;
101 }
102 
103 static const struct cfg80211_chan_def *
104 ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local *local,
105 				       struct ieee80211_chanctx *ctx,
106 				       const struct cfg80211_chan_def *compat)
107 {
108 	struct ieee80211_sub_if_data *sdata;
109 
110 	lockdep_assert_held(&local->chanctx_mtx);
111 
112 	list_for_each_entry(sdata, &ctx->assigned_vifs,
113 			    assigned_chanctx_list) {
114 		if (sdata->reserved_chanctx != NULL)
115 			continue;
116 
117 		if (!compat)
118 			compat = &sdata->vif.bss_conf.chandef;
119 
120 		compat = cfg80211_chandef_compatible(
121 				&sdata->vif.bss_conf.chandef, compat);
122 		if (!compat)
123 			break;
124 	}
125 
126 	return compat;
127 }
128 
129 static const struct cfg80211_chan_def *
130 ieee80211_chanctx_combined_chandef(struct ieee80211_local *local,
131 				   struct ieee80211_chanctx *ctx,
132 				   const struct cfg80211_chan_def *compat)
133 {
134 	lockdep_assert_held(&local->chanctx_mtx);
135 
136 	compat = ieee80211_chanctx_reserved_chandef(local, ctx, compat);
137 	if (!compat)
138 		return NULL;
139 
140 	compat = ieee80211_chanctx_non_reserved_chandef(local, ctx, compat);
141 	if (!compat)
142 		return NULL;
143 
144 	return compat;
145 }
146 
147 static bool
148 ieee80211_chanctx_can_reserve_chandef(struct ieee80211_local *local,
149 				      struct ieee80211_chanctx *ctx,
150 				      const struct cfg80211_chan_def *def)
151 {
152 	lockdep_assert_held(&local->chanctx_mtx);
153 
154 	if (ieee80211_chanctx_combined_chandef(local, ctx, def))
155 		return true;
156 
157 	if (!list_empty(&ctx->reserved_vifs) &&
158 	    ieee80211_chanctx_reserved_chandef(local, ctx, def))
159 		return true;
160 
161 	return false;
162 }
163 
164 static struct ieee80211_chanctx *
165 ieee80211_find_reservation_chanctx(struct ieee80211_local *local,
166 				   const struct cfg80211_chan_def *chandef,
167 				   enum ieee80211_chanctx_mode mode)
168 {
169 	struct ieee80211_chanctx *ctx;
170 
171 	lockdep_assert_held(&local->chanctx_mtx);
172 
173 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
174 		return NULL;
175 
176 	list_for_each_entry(ctx, &local->chanctx_list, list) {
177 		if (ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED)
178 			continue;
179 
180 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
181 			continue;
182 
183 		if (!ieee80211_chanctx_can_reserve_chandef(local, ctx,
184 							   chandef))
185 			continue;
186 
187 		return ctx;
188 	}
189 
190 	return NULL;
191 }
192 
193 static enum nl80211_chan_width ieee80211_get_sta_bw(struct ieee80211_sta *sta)
194 {
195 	switch (sta->bandwidth) {
196 	case IEEE80211_STA_RX_BW_20:
197 		if (sta->ht_cap.ht_supported)
198 			return NL80211_CHAN_WIDTH_20;
199 		else
200 			return NL80211_CHAN_WIDTH_20_NOHT;
201 	case IEEE80211_STA_RX_BW_40:
202 		return NL80211_CHAN_WIDTH_40;
203 	case IEEE80211_STA_RX_BW_80:
204 		return NL80211_CHAN_WIDTH_80;
205 	case IEEE80211_STA_RX_BW_160:
206 		/*
207 		 * This applied for both 160 and 80+80. since we use
208 		 * the returned value to consider degradation of
209 		 * ctx->conf.min_def, we have to make sure to take
210 		 * the bigger one (NL80211_CHAN_WIDTH_160).
211 		 * Otherwise we might try degrading even when not
212 		 * needed, as the max required sta_bw returned (80+80)
213 		 * might be smaller than the configured bw (160).
214 		 */
215 		return NL80211_CHAN_WIDTH_160;
216 	default:
217 		WARN_ON(1);
218 		return NL80211_CHAN_WIDTH_20;
219 	}
220 }
221 
222 static enum nl80211_chan_width
223 ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata)
224 {
225 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
226 	struct sta_info *sta;
227 
228 	rcu_read_lock();
229 	list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
230 		if (sdata != sta->sdata &&
231 		    !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
232 			continue;
233 
234 		if (!sta->uploaded)
235 			continue;
236 
237 		max_bw = max(max_bw, ieee80211_get_sta_bw(&sta->sta));
238 	}
239 	rcu_read_unlock();
240 
241 	return max_bw;
242 }
243 
244 static enum nl80211_chan_width
245 ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
246 				      struct ieee80211_chanctx_conf *conf)
247 {
248 	struct ieee80211_sub_if_data *sdata;
249 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
250 
251 	rcu_read_lock();
252 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
253 		struct ieee80211_vif *vif = &sdata->vif;
254 		enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT;
255 
256 		if (!ieee80211_sdata_running(sdata))
257 			continue;
258 
259 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
260 			continue;
261 
262 		switch (vif->type) {
263 		case NL80211_IFTYPE_AP:
264 		case NL80211_IFTYPE_AP_VLAN:
265 			width = ieee80211_get_max_required_bw(sdata);
266 			break;
267 		case NL80211_IFTYPE_P2P_DEVICE:
268 			continue;
269 		case NL80211_IFTYPE_STATION:
270 		case NL80211_IFTYPE_ADHOC:
271 		case NL80211_IFTYPE_WDS:
272 		case NL80211_IFTYPE_MESH_POINT:
273 		case NL80211_IFTYPE_OCB:
274 			width = vif->bss_conf.chandef.width;
275 			break;
276 		case NL80211_IFTYPE_UNSPECIFIED:
277 		case NUM_NL80211_IFTYPES:
278 		case NL80211_IFTYPE_MONITOR:
279 		case NL80211_IFTYPE_P2P_CLIENT:
280 		case NL80211_IFTYPE_P2P_GO:
281 			WARN_ON_ONCE(1);
282 		}
283 		max_bw = max(max_bw, width);
284 	}
285 
286 	/* use the configured bandwidth in case of monitor interface */
287 	sdata = rcu_dereference(local->monitor_sdata);
288 	if (sdata && rcu_access_pointer(sdata->vif.chanctx_conf) == conf)
289 		max_bw = max(max_bw, conf->def.width);
290 
291 	rcu_read_unlock();
292 
293 	return max_bw;
294 }
295 
296 /*
297  * recalc the min required chan width of the channel context, which is
298  * the max of min required widths of all the interfaces bound to this
299  * channel context.
300  */
301 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
302 				      struct ieee80211_chanctx *ctx)
303 {
304 	enum nl80211_chan_width max_bw;
305 	struct cfg80211_chan_def min_def;
306 
307 	lockdep_assert_held(&local->chanctx_mtx);
308 
309 	/* don't optimize 5MHz, 10MHz, and radar_enabled confs */
310 	if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
311 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
312 	    ctx->conf.radar_enabled) {
313 		ctx->conf.min_def = ctx->conf.def;
314 		return;
315 	}
316 
317 	max_bw = ieee80211_get_chanctx_max_required_bw(local, &ctx->conf);
318 
319 	/* downgrade chandef up to max_bw */
320 	min_def = ctx->conf.def;
321 	while (min_def.width > max_bw)
322 		ieee80211_chandef_downgrade(&min_def);
323 
324 	if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
325 		return;
326 
327 	ctx->conf.min_def = min_def;
328 	if (!ctx->driver_present)
329 		return;
330 
331 	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_MIN_WIDTH);
332 }
333 
334 static void ieee80211_change_chanctx(struct ieee80211_local *local,
335 				     struct ieee80211_chanctx *ctx,
336 				     const struct cfg80211_chan_def *chandef)
337 {
338 	if (cfg80211_chandef_identical(&ctx->conf.def, chandef))
339 		return;
340 
341 	WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
342 
343 	ctx->conf.def = *chandef;
344 	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);
345 	ieee80211_recalc_chanctx_min_def(local, ctx);
346 
347 	if (!local->use_chanctx) {
348 		local->_oper_chandef = *chandef;
349 		ieee80211_hw_config(local, 0);
350 	}
351 }
352 
353 static struct ieee80211_chanctx *
354 ieee80211_find_chanctx(struct ieee80211_local *local,
355 		       const struct cfg80211_chan_def *chandef,
356 		       enum ieee80211_chanctx_mode mode)
357 {
358 	struct ieee80211_chanctx *ctx;
359 
360 	lockdep_assert_held(&local->chanctx_mtx);
361 
362 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
363 		return NULL;
364 
365 	list_for_each_entry(ctx, &local->chanctx_list, list) {
366 		const struct cfg80211_chan_def *compat;
367 
368 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
369 			continue;
370 
371 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
372 			continue;
373 
374 		compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
375 		if (!compat)
376 			continue;
377 
378 		compat = ieee80211_chanctx_reserved_chandef(local, ctx,
379 							    compat);
380 		if (!compat)
381 			continue;
382 
383 		ieee80211_change_chanctx(local, ctx, compat);
384 
385 		return ctx;
386 	}
387 
388 	return NULL;
389 }
390 
391 bool ieee80211_is_radar_required(struct ieee80211_local *local)
392 {
393 	struct ieee80211_sub_if_data *sdata;
394 
395 	lockdep_assert_held(&local->mtx);
396 
397 	rcu_read_lock();
398 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
399 		if (sdata->radar_required) {
400 			rcu_read_unlock();
401 			return true;
402 		}
403 	}
404 	rcu_read_unlock();
405 
406 	return false;
407 }
408 
409 static bool
410 ieee80211_chanctx_radar_required(struct ieee80211_local *local,
411 				 struct ieee80211_chanctx *ctx)
412 {
413 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
414 	struct ieee80211_sub_if_data *sdata;
415 	bool required = false;
416 
417 	lockdep_assert_held(&local->chanctx_mtx);
418 	lockdep_assert_held(&local->mtx);
419 
420 	rcu_read_lock();
421 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
422 		if (!ieee80211_sdata_running(sdata))
423 			continue;
424 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
425 			continue;
426 		if (!sdata->radar_required)
427 			continue;
428 
429 		required = true;
430 		break;
431 	}
432 	rcu_read_unlock();
433 
434 	return required;
435 }
436 
437 static struct ieee80211_chanctx *
438 ieee80211_alloc_chanctx(struct ieee80211_local *local,
439 			const struct cfg80211_chan_def *chandef,
440 			enum ieee80211_chanctx_mode mode)
441 {
442 	struct ieee80211_chanctx *ctx;
443 
444 	lockdep_assert_held(&local->chanctx_mtx);
445 
446 	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
447 	if (!ctx)
448 		return NULL;
449 
450 	INIT_LIST_HEAD(&ctx->assigned_vifs);
451 	INIT_LIST_HEAD(&ctx->reserved_vifs);
452 	ctx->conf.def = *chandef;
453 	ctx->conf.rx_chains_static = 1;
454 	ctx->conf.rx_chains_dynamic = 1;
455 	ctx->mode = mode;
456 	ctx->conf.radar_enabled = false;
457 	ieee80211_recalc_chanctx_min_def(local, ctx);
458 
459 	return ctx;
460 }
461 
462 static int ieee80211_add_chanctx(struct ieee80211_local *local,
463 				 struct ieee80211_chanctx *ctx)
464 {
465 	u32 changed;
466 	int err;
467 
468 	lockdep_assert_held(&local->mtx);
469 	lockdep_assert_held(&local->chanctx_mtx);
470 
471 	if (!local->use_chanctx)
472 		local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
473 
474 	/* turn idle off *before* setting channel -- some drivers need that */
475 	changed = ieee80211_idle_off(local);
476 	if (changed)
477 		ieee80211_hw_config(local, changed);
478 
479 	if (!local->use_chanctx) {
480 		local->_oper_chandef = ctx->conf.def;
481 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
482 	} else {
483 		err = drv_add_chanctx(local, ctx);
484 		if (err) {
485 			ieee80211_recalc_idle(local);
486 			return err;
487 		}
488 	}
489 
490 	return 0;
491 }
492 
493 static struct ieee80211_chanctx *
494 ieee80211_new_chanctx(struct ieee80211_local *local,
495 		      const struct cfg80211_chan_def *chandef,
496 		      enum ieee80211_chanctx_mode mode)
497 {
498 	struct ieee80211_chanctx *ctx;
499 	int err;
500 
501 	lockdep_assert_held(&local->mtx);
502 	lockdep_assert_held(&local->chanctx_mtx);
503 
504 	ctx = ieee80211_alloc_chanctx(local, chandef, mode);
505 	if (!ctx)
506 		return ERR_PTR(-ENOMEM);
507 
508 	err = ieee80211_add_chanctx(local, ctx);
509 	if (err) {
510 		kfree(ctx);
511 		return ERR_PTR(err);
512 	}
513 
514 	list_add_rcu(&ctx->list, &local->chanctx_list);
515 	return ctx;
516 }
517 
518 static void ieee80211_del_chanctx(struct ieee80211_local *local,
519 				  struct ieee80211_chanctx *ctx)
520 {
521 	lockdep_assert_held(&local->chanctx_mtx);
522 
523 	if (!local->use_chanctx) {
524 		struct cfg80211_chan_def *chandef = &local->_oper_chandef;
525 		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
526 		chandef->center_freq1 = chandef->chan->center_freq;
527 		chandef->center_freq2 = 0;
528 
529 		/* NOTE: Disabling radar is only valid here for
530 		 * single channel context. To be sure, check it ...
531 		 */
532 		WARN_ON(local->hw.conf.radar_enabled &&
533 			!list_empty(&local->chanctx_list));
534 
535 		local->hw.conf.radar_enabled = false;
536 
537 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
538 	} else {
539 		drv_remove_chanctx(local, ctx);
540 	}
541 
542 	ieee80211_recalc_idle(local);
543 }
544 
545 static void ieee80211_free_chanctx(struct ieee80211_local *local,
546 				   struct ieee80211_chanctx *ctx)
547 {
548 	lockdep_assert_held(&local->chanctx_mtx);
549 
550 	WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
551 
552 	list_del_rcu(&ctx->list);
553 	ieee80211_del_chanctx(local, ctx);
554 	kfree_rcu(ctx, rcu_head);
555 }
556 
557 static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
558 					      struct ieee80211_chanctx *ctx)
559 {
560 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
561 	struct ieee80211_sub_if_data *sdata;
562 	const struct cfg80211_chan_def *compat = NULL;
563 
564 	lockdep_assert_held(&local->chanctx_mtx);
565 
566 	rcu_read_lock();
567 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
568 
569 		if (!ieee80211_sdata_running(sdata))
570 			continue;
571 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
572 			continue;
573 		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
574 			continue;
575 
576 		if (!compat)
577 			compat = &sdata->vif.bss_conf.chandef;
578 
579 		compat = cfg80211_chandef_compatible(
580 				&sdata->vif.bss_conf.chandef, compat);
581 		if (WARN_ON_ONCE(!compat))
582 			break;
583 	}
584 	rcu_read_unlock();
585 
586 	if (!compat)
587 		return;
588 
589 	ieee80211_change_chanctx(local, ctx, compat);
590 }
591 
592 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
593 					   struct ieee80211_chanctx *chanctx)
594 {
595 	bool radar_enabled;
596 
597 	lockdep_assert_held(&local->chanctx_mtx);
598 	/* for ieee80211_is_radar_required */
599 	lockdep_assert_held(&local->mtx);
600 
601 	radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
602 
603 	if (radar_enabled == chanctx->conf.radar_enabled)
604 		return;
605 
606 	chanctx->conf.radar_enabled = radar_enabled;
607 
608 	if (!local->use_chanctx) {
609 		local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
610 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
611 	}
612 
613 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
614 }
615 
616 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
617 					struct ieee80211_chanctx *new_ctx)
618 {
619 	struct ieee80211_local *local = sdata->local;
620 	struct ieee80211_chanctx_conf *conf;
621 	struct ieee80211_chanctx *curr_ctx = NULL;
622 	int ret = 0;
623 
624 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
625 					 lockdep_is_held(&local->chanctx_mtx));
626 
627 	if (conf) {
628 		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
629 
630 		drv_unassign_vif_chanctx(local, sdata, curr_ctx);
631 		conf = NULL;
632 		list_del(&sdata->assigned_chanctx_list);
633 	}
634 
635 	if (new_ctx) {
636 		ret = drv_assign_vif_chanctx(local, sdata, new_ctx);
637 		if (ret)
638 			goto out;
639 
640 		conf = &new_ctx->conf;
641 		list_add(&sdata->assigned_chanctx_list,
642 			 &new_ctx->assigned_vifs);
643 	}
644 
645 out:
646 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
647 
648 	sdata->vif.bss_conf.idle = !conf;
649 
650 	if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
651 		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
652 		ieee80211_recalc_smps_chanctx(local, curr_ctx);
653 		ieee80211_recalc_radar_chanctx(local, curr_ctx);
654 		ieee80211_recalc_chanctx_min_def(local, curr_ctx);
655 	}
656 
657 	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
658 		ieee80211_recalc_txpower(sdata, false);
659 		ieee80211_recalc_chanctx_min_def(local, new_ctx);
660 	}
661 
662 	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
663 	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
664 		ieee80211_bss_info_change_notify(sdata,
665 						 BSS_CHANGED_IDLE);
666 
667 	return ret;
668 }
669 
670 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
671 				   struct ieee80211_chanctx *chanctx)
672 {
673 	struct ieee80211_sub_if_data *sdata;
674 	u8 rx_chains_static, rx_chains_dynamic;
675 
676 	lockdep_assert_held(&local->chanctx_mtx);
677 
678 	rx_chains_static = 1;
679 	rx_chains_dynamic = 1;
680 
681 	rcu_read_lock();
682 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
683 		u8 needed_static, needed_dynamic;
684 
685 		if (!ieee80211_sdata_running(sdata))
686 			continue;
687 
688 		if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
689 						&chanctx->conf)
690 			continue;
691 
692 		switch (sdata->vif.type) {
693 		case NL80211_IFTYPE_P2P_DEVICE:
694 			continue;
695 		case NL80211_IFTYPE_STATION:
696 			if (!sdata->u.mgd.associated)
697 				continue;
698 			break;
699 		case NL80211_IFTYPE_AP_VLAN:
700 			continue;
701 		case NL80211_IFTYPE_AP:
702 		case NL80211_IFTYPE_ADHOC:
703 		case NL80211_IFTYPE_WDS:
704 		case NL80211_IFTYPE_MESH_POINT:
705 		case NL80211_IFTYPE_OCB:
706 			break;
707 		default:
708 			WARN_ON_ONCE(1);
709 		}
710 
711 		switch (sdata->smps_mode) {
712 		default:
713 			WARN_ONCE(1, "Invalid SMPS mode %d\n",
714 				  sdata->smps_mode);
715 			/* fall through */
716 		case IEEE80211_SMPS_OFF:
717 			needed_static = sdata->needed_rx_chains;
718 			needed_dynamic = sdata->needed_rx_chains;
719 			break;
720 		case IEEE80211_SMPS_DYNAMIC:
721 			needed_static = 1;
722 			needed_dynamic = sdata->needed_rx_chains;
723 			break;
724 		case IEEE80211_SMPS_STATIC:
725 			needed_static = 1;
726 			needed_dynamic = 1;
727 			break;
728 		}
729 
730 		rx_chains_static = max(rx_chains_static, needed_static);
731 		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
732 	}
733 
734 	/* Disable SMPS for the monitor interface */
735 	sdata = rcu_dereference(local->monitor_sdata);
736 	if (sdata &&
737 	    rcu_access_pointer(sdata->vif.chanctx_conf) == &chanctx->conf)
738 		rx_chains_dynamic = rx_chains_static = local->rx_chains;
739 
740 	rcu_read_unlock();
741 
742 	if (!local->use_chanctx) {
743 		if (rx_chains_static > 1)
744 			local->smps_mode = IEEE80211_SMPS_OFF;
745 		else if (rx_chains_dynamic > 1)
746 			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
747 		else
748 			local->smps_mode = IEEE80211_SMPS_STATIC;
749 		ieee80211_hw_config(local, 0);
750 	}
751 
752 	if (rx_chains_static == chanctx->conf.rx_chains_static &&
753 	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
754 		return;
755 
756 	chanctx->conf.rx_chains_static = rx_chains_static;
757 	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
758 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
759 }
760 
761 static void
762 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
763 				      bool clear)
764 {
765 	struct ieee80211_local *local __maybe_unused = sdata->local;
766 	struct ieee80211_sub_if_data *vlan;
767 	struct ieee80211_chanctx_conf *conf;
768 
769 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
770 		return;
771 
772 	lockdep_assert_held(&local->mtx);
773 
774 	/* Check that conf exists, even when clearing this function
775 	 * must be called with the AP's channel context still there
776 	 * as it would otherwise cause VLANs to have an invalid
777 	 * channel context pointer for a while, possibly pointing
778 	 * to a channel context that has already been freed.
779 	 */
780 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
781 					 lockdep_is_held(&local->chanctx_mtx));
782 	WARN_ON(!conf);
783 
784 	if (clear)
785 		conf = NULL;
786 
787 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
788 		rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
789 }
790 
791 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
792 					 bool clear)
793 {
794 	struct ieee80211_local *local = sdata->local;
795 
796 	mutex_lock(&local->chanctx_mtx);
797 
798 	__ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
799 
800 	mutex_unlock(&local->chanctx_mtx);
801 }
802 
803 int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
804 {
805 	struct ieee80211_chanctx *ctx = sdata->reserved_chanctx;
806 
807 	lockdep_assert_held(&sdata->local->chanctx_mtx);
808 
809 	if (WARN_ON(!ctx))
810 		return -EINVAL;
811 
812 	list_del(&sdata->reserved_chanctx_list);
813 	sdata->reserved_chanctx = NULL;
814 
815 	if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
816 		if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
817 			if (WARN_ON(!ctx->replace_ctx))
818 				return -EINVAL;
819 
820 			WARN_ON(ctx->replace_ctx->replace_state !=
821 			        IEEE80211_CHANCTX_WILL_BE_REPLACED);
822 			WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
823 
824 			ctx->replace_ctx->replace_ctx = NULL;
825 			ctx->replace_ctx->replace_state =
826 					IEEE80211_CHANCTX_REPLACE_NONE;
827 
828 			list_del_rcu(&ctx->list);
829 			kfree_rcu(ctx, rcu_head);
830 		} else {
831 			ieee80211_free_chanctx(sdata->local, ctx);
832 		}
833 	}
834 
835 	return 0;
836 }
837 
838 int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
839 				  const struct cfg80211_chan_def *chandef,
840 				  enum ieee80211_chanctx_mode mode,
841 				  bool radar_required)
842 {
843 	struct ieee80211_local *local = sdata->local;
844 	struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
845 
846 	lockdep_assert_held(&local->chanctx_mtx);
847 
848 	curr_ctx = ieee80211_vif_get_chanctx(sdata);
849 	if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
850 		return -ENOTSUPP;
851 
852 	new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
853 	if (!new_ctx) {
854 		if (ieee80211_can_create_new_chanctx(local)) {
855 			new_ctx = ieee80211_new_chanctx(local, chandef, mode);
856 			if (IS_ERR(new_ctx))
857 				return PTR_ERR(new_ctx);
858 		} else {
859 			if (!curr_ctx ||
860 			    (curr_ctx->replace_state ==
861 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
862 			    !list_empty(&curr_ctx->reserved_vifs)) {
863 				/*
864 				 * Another vif already requested this context
865 				 * for a reservation. Find another one hoping
866 				 * all vifs assigned to it will also switch
867 				 * soon enough.
868 				 *
869 				 * TODO: This needs a little more work as some
870 				 * cases (more than 2 chanctx capable devices)
871 				 * may fail which could otherwise succeed
872 				 * provided some channel context juggling was
873 				 * performed.
874 				 *
875 				 * Consider ctx1..3, vif1..6, each ctx has 2
876 				 * vifs. vif1 and vif2 from ctx1 request new
877 				 * different chandefs starting 2 in-place
878 				 * reserations with ctx4 and ctx5 replacing
879 				 * ctx1 and ctx2 respectively. Next vif5 and
880 				 * vif6 from ctx3 reserve ctx4. If vif3 and
881 				 * vif4 remain on ctx2 as they are then this
882 				 * fails unless `replace_ctx` from ctx5 is
883 				 * replaced with ctx3.
884 				 */
885 				list_for_each_entry(ctx, &local->chanctx_list,
886 						    list) {
887 					if (ctx->replace_state !=
888 					    IEEE80211_CHANCTX_REPLACE_NONE)
889 						continue;
890 
891 					if (!list_empty(&ctx->reserved_vifs))
892 						continue;
893 
894 					curr_ctx = ctx;
895 					break;
896 				}
897 			}
898 
899 			/*
900 			 * If that's true then all available contexts already
901 			 * have reservations and cannot be used.
902 			 */
903 			if (!curr_ctx ||
904 			    (curr_ctx->replace_state ==
905 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
906 			    !list_empty(&curr_ctx->reserved_vifs))
907 				return -EBUSY;
908 
909 			new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
910 			if (!new_ctx)
911 				return -ENOMEM;
912 
913 			new_ctx->replace_ctx = curr_ctx;
914 			new_ctx->replace_state =
915 					IEEE80211_CHANCTX_REPLACES_OTHER;
916 
917 			curr_ctx->replace_ctx = new_ctx;
918 			curr_ctx->replace_state =
919 					IEEE80211_CHANCTX_WILL_BE_REPLACED;
920 
921 			list_add_rcu(&new_ctx->list, &local->chanctx_list);
922 		}
923 	}
924 
925 	list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);
926 	sdata->reserved_chanctx = new_ctx;
927 	sdata->reserved_chandef = *chandef;
928 	sdata->reserved_radar_required = radar_required;
929 	sdata->reserved_ready = false;
930 
931 	return 0;
932 }
933 
934 static void
935 ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
936 {
937 	switch (sdata->vif.type) {
938 	case NL80211_IFTYPE_ADHOC:
939 	case NL80211_IFTYPE_AP:
940 	case NL80211_IFTYPE_MESH_POINT:
941 	case NL80211_IFTYPE_OCB:
942 		ieee80211_queue_work(&sdata->local->hw,
943 				     &sdata->csa_finalize_work);
944 		break;
945 	case NL80211_IFTYPE_STATION:
946 		ieee80211_queue_work(&sdata->local->hw,
947 				     &sdata->u.mgd.chswitch_work);
948 		break;
949 	case NL80211_IFTYPE_UNSPECIFIED:
950 	case NL80211_IFTYPE_AP_VLAN:
951 	case NL80211_IFTYPE_WDS:
952 	case NL80211_IFTYPE_MONITOR:
953 	case NL80211_IFTYPE_P2P_CLIENT:
954 	case NL80211_IFTYPE_P2P_GO:
955 	case NL80211_IFTYPE_P2P_DEVICE:
956 	case NUM_NL80211_IFTYPES:
957 		WARN_ON(1);
958 		break;
959 	}
960 }
961 
962 static void
963 ieee80211_vif_update_chandef(struct ieee80211_sub_if_data *sdata,
964 			     const struct cfg80211_chan_def *chandef)
965 {
966 	struct ieee80211_sub_if_data *vlan;
967 
968 	sdata->vif.bss_conf.chandef = *chandef;
969 
970 	if (sdata->vif.type != NL80211_IFTYPE_AP)
971 		return;
972 
973 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
974 		vlan->vif.bss_conf.chandef = *chandef;
975 }
976 
977 static int
978 ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
979 {
980 	struct ieee80211_local *local = sdata->local;
981 	struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
982 	struct ieee80211_chanctx *old_ctx, *new_ctx;
983 	const struct cfg80211_chan_def *chandef;
984 	u32 changed = 0;
985 	int err;
986 
987 	lockdep_assert_held(&local->mtx);
988 	lockdep_assert_held(&local->chanctx_mtx);
989 
990 	new_ctx = sdata->reserved_chanctx;
991 	old_ctx = ieee80211_vif_get_chanctx(sdata);
992 
993 	if (WARN_ON(!sdata->reserved_ready))
994 		return -EBUSY;
995 
996 	if (WARN_ON(!new_ctx))
997 		return -EINVAL;
998 
999 	if (WARN_ON(!old_ctx))
1000 		return -EINVAL;
1001 
1002 	if (WARN_ON(new_ctx->replace_state ==
1003 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1004 		return -EINVAL;
1005 
1006 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1007 				&sdata->reserved_chandef);
1008 	if (WARN_ON(!chandef))
1009 		return -EINVAL;
1010 
1011 	vif_chsw[0].vif = &sdata->vif;
1012 	vif_chsw[0].old_ctx = &old_ctx->conf;
1013 	vif_chsw[0].new_ctx = &new_ctx->conf;
1014 
1015 	list_del(&sdata->reserved_chanctx_list);
1016 	sdata->reserved_chanctx = NULL;
1017 
1018 	err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1019 				     CHANCTX_SWMODE_REASSIGN_VIF);
1020 	if (err) {
1021 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1022 			ieee80211_free_chanctx(local, new_ctx);
1023 
1024 		goto out;
1025 	}
1026 
1027 	list_move(&sdata->assigned_chanctx_list, &new_ctx->assigned_vifs);
1028 	rcu_assign_pointer(sdata->vif.chanctx_conf, &new_ctx->conf);
1029 
1030 	if (sdata->vif.type == NL80211_IFTYPE_AP)
1031 		__ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
1032 
1033 	if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1034 		ieee80211_free_chanctx(local, old_ctx);
1035 
1036 	if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
1037 		changed = BSS_CHANGED_BANDWIDTH;
1038 
1039 	ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1040 
1041 	ieee80211_recalc_smps_chanctx(local, new_ctx);
1042 	ieee80211_recalc_radar_chanctx(local, new_ctx);
1043 	ieee80211_recalc_chanctx_min_def(local, new_ctx);
1044 
1045 	if (changed)
1046 		ieee80211_bss_info_change_notify(sdata, changed);
1047 
1048 out:
1049 	ieee80211_vif_chanctx_reservation_complete(sdata);
1050 	return err;
1051 }
1052 
1053 static int
1054 ieee80211_vif_use_reserved_assign(struct ieee80211_sub_if_data *sdata)
1055 {
1056 	struct ieee80211_local *local = sdata->local;
1057 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1058 	const struct cfg80211_chan_def *chandef;
1059 	int err;
1060 
1061 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1062 	new_ctx = sdata->reserved_chanctx;
1063 
1064 	if (WARN_ON(!sdata->reserved_ready))
1065 		return -EINVAL;
1066 
1067 	if (WARN_ON(old_ctx))
1068 		return -EINVAL;
1069 
1070 	if (WARN_ON(!new_ctx))
1071 		return -EINVAL;
1072 
1073 	if (WARN_ON(new_ctx->replace_state ==
1074 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1075 		return -EINVAL;
1076 
1077 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1078 				&sdata->reserved_chandef);
1079 	if (WARN_ON(!chandef))
1080 		return -EINVAL;
1081 
1082 	list_del(&sdata->reserved_chanctx_list);
1083 	sdata->reserved_chanctx = NULL;
1084 
1085 	err = ieee80211_assign_vif_chanctx(sdata, new_ctx);
1086 	if (err) {
1087 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1088 			ieee80211_free_chanctx(local, new_ctx);
1089 
1090 		goto out;
1091 	}
1092 
1093 out:
1094 	ieee80211_vif_chanctx_reservation_complete(sdata);
1095 	return err;
1096 }
1097 
1098 static bool
1099 ieee80211_vif_has_in_place_reservation(struct ieee80211_sub_if_data *sdata)
1100 {
1101 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1102 
1103 	lockdep_assert_held(&sdata->local->chanctx_mtx);
1104 
1105 	new_ctx = sdata->reserved_chanctx;
1106 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1107 
1108 	if (!old_ctx)
1109 		return false;
1110 
1111 	if (WARN_ON(!new_ctx))
1112 		return false;
1113 
1114 	if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1115 		return false;
1116 
1117 	if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1118 		return false;
1119 
1120 	return true;
1121 }
1122 
1123 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1124 					struct ieee80211_chanctx *new_ctx)
1125 {
1126 	const struct cfg80211_chan_def *chandef;
1127 
1128 	lockdep_assert_held(&local->mtx);
1129 	lockdep_assert_held(&local->chanctx_mtx);
1130 
1131 	chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1132 	if (WARN_ON(!chandef))
1133 		return -EINVAL;
1134 
1135 	local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1136 	local->_oper_chandef = *chandef;
1137 	ieee80211_hw_config(local, 0);
1138 
1139 	return 0;
1140 }
1141 
1142 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1143 				      int n_vifs)
1144 {
1145 	struct ieee80211_vif_chanctx_switch *vif_chsw;
1146 	struct ieee80211_sub_if_data *sdata;
1147 	struct ieee80211_chanctx *ctx, *old_ctx;
1148 	int i, err;
1149 
1150 	lockdep_assert_held(&local->mtx);
1151 	lockdep_assert_held(&local->chanctx_mtx);
1152 
1153 	vif_chsw = kzalloc(sizeof(vif_chsw[0]) * n_vifs, GFP_KERNEL);
1154 	if (!vif_chsw)
1155 		return -ENOMEM;
1156 
1157 	i = 0;
1158 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1159 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1160 			continue;
1161 
1162 		if (WARN_ON(!ctx->replace_ctx)) {
1163 			err = -EINVAL;
1164 			goto out;
1165 		}
1166 
1167 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1168 				    reserved_chanctx_list) {
1169 			if (!ieee80211_vif_has_in_place_reservation(
1170 					sdata))
1171 				continue;
1172 
1173 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1174 			vif_chsw[i].vif = &sdata->vif;
1175 			vif_chsw[i].old_ctx = &old_ctx->conf;
1176 			vif_chsw[i].new_ctx = &ctx->conf;
1177 
1178 			i++;
1179 		}
1180 	}
1181 
1182 	err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1183 				     CHANCTX_SWMODE_SWAP_CONTEXTS);
1184 
1185 out:
1186 	kfree(vif_chsw);
1187 	return err;
1188 }
1189 
1190 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1191 {
1192 	struct ieee80211_chanctx *ctx;
1193 	int err;
1194 
1195 	lockdep_assert_held(&local->mtx);
1196 	lockdep_assert_held(&local->chanctx_mtx);
1197 
1198 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1199 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1200 			continue;
1201 
1202 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1203 			continue;
1204 
1205 		ieee80211_del_chanctx(local, ctx->replace_ctx);
1206 		err = ieee80211_add_chanctx(local, ctx);
1207 		if (err)
1208 			goto err;
1209 	}
1210 
1211 	return 0;
1212 
1213 err:
1214 	WARN_ON(ieee80211_add_chanctx(local, ctx));
1215 	list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1216 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1217 			continue;
1218 
1219 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1220 			continue;
1221 
1222 		ieee80211_del_chanctx(local, ctx);
1223 		WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1224 	}
1225 
1226 	return err;
1227 }
1228 
1229 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1230 {
1231 	struct ieee80211_sub_if_data *sdata, *sdata_tmp;
1232 	struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1233 	struct ieee80211_chanctx *new_ctx = NULL;
1234 	int i, err, n_assigned, n_reserved, n_ready;
1235 	int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1236 
1237 	lockdep_assert_held(&local->mtx);
1238 	lockdep_assert_held(&local->chanctx_mtx);
1239 
1240 	/*
1241 	 * If there are 2 independent pairs of channel contexts performing
1242 	 * cross-switch of their vifs this code will still wait until both are
1243 	 * ready even though it could be possible to switch one before the
1244 	 * other is ready.
1245 	 *
1246 	 * For practical reasons and code simplicity just do a single huge
1247 	 * switch.
1248 	 */
1249 
1250 	/*
1251 	 * Verify if the reservation is still feasible.
1252 	 *  - if it's not then disconnect
1253 	 *  - if it is but not all vifs necessary are ready then defer
1254 	 */
1255 
1256 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1257 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1258 			continue;
1259 
1260 		if (WARN_ON(!ctx->replace_ctx)) {
1261 			err = -EINVAL;
1262 			goto err;
1263 		}
1264 
1265 		if (!local->use_chanctx)
1266 			new_ctx = ctx;
1267 
1268 		n_ctx++;
1269 
1270 		n_assigned = 0;
1271 		n_reserved = 0;
1272 		n_ready = 0;
1273 
1274 		list_for_each_entry(sdata, &ctx->replace_ctx->assigned_vifs,
1275 				    assigned_chanctx_list) {
1276 			n_assigned++;
1277 			if (sdata->reserved_chanctx) {
1278 				n_reserved++;
1279 				if (sdata->reserved_ready)
1280 					n_ready++;
1281 			}
1282 		}
1283 
1284 		if (n_assigned != n_reserved) {
1285 			if (n_ready == n_reserved) {
1286 				wiphy_info(local->hw.wiphy,
1287 					   "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1288 				err = -EBUSY;
1289 				goto err;
1290 			}
1291 
1292 			return -EAGAIN;
1293 		}
1294 
1295 		ctx->conf.radar_enabled = false;
1296 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1297 				    reserved_chanctx_list) {
1298 			if (ieee80211_vif_has_in_place_reservation(sdata) &&
1299 			    !sdata->reserved_ready)
1300 				return -EAGAIN;
1301 
1302 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1303 			if (old_ctx) {
1304 				if (old_ctx->replace_state ==
1305 				    IEEE80211_CHANCTX_WILL_BE_REPLACED)
1306 					n_vifs_switch++;
1307 				else
1308 					n_vifs_assign++;
1309 			} else {
1310 				n_vifs_ctxless++;
1311 			}
1312 
1313 			if (sdata->reserved_radar_required)
1314 				ctx->conf.radar_enabled = true;
1315 		}
1316 	}
1317 
1318 	if (WARN_ON(n_ctx == 0) ||
1319 	    WARN_ON(n_vifs_switch == 0 &&
1320 		    n_vifs_assign == 0 &&
1321 		    n_vifs_ctxless == 0) ||
1322 	    WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1323 	    WARN_ON(!new_ctx && !local->use_chanctx)) {
1324 		err = -EINVAL;
1325 		goto err;
1326 	}
1327 
1328 	/*
1329 	 * All necessary vifs are ready. Perform the switch now depending on
1330 	 * reservations and driver capabilities.
1331 	 */
1332 
1333 	if (local->use_chanctx) {
1334 		if (n_vifs_switch > 0) {
1335 			err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1336 			if (err)
1337 				goto err;
1338 		}
1339 
1340 		if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1341 			err = ieee80211_chsw_switch_ctxs(local);
1342 			if (err)
1343 				goto err;
1344 		}
1345 	} else {
1346 		err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1347 		if (err)
1348 			goto err;
1349 	}
1350 
1351 	/*
1352 	 * Update all structures, values and pointers to point to new channel
1353 	 * context(s).
1354 	 */
1355 
1356 	i = 0;
1357 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1358 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1359 			continue;
1360 
1361 		if (WARN_ON(!ctx->replace_ctx)) {
1362 			err = -EINVAL;
1363 			goto err;
1364 		}
1365 
1366 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1367 				    reserved_chanctx_list) {
1368 			u32 changed = 0;
1369 
1370 			if (!ieee80211_vif_has_in_place_reservation(sdata))
1371 				continue;
1372 
1373 			rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
1374 
1375 			if (sdata->vif.type == NL80211_IFTYPE_AP)
1376 				__ieee80211_vif_copy_chanctx_to_vlans(sdata,
1377 								      false);
1378 
1379 			sdata->radar_required = sdata->reserved_radar_required;
1380 
1381 			if (sdata->vif.bss_conf.chandef.width !=
1382 			    sdata->reserved_chandef.width)
1383 				changed = BSS_CHANGED_BANDWIDTH;
1384 
1385 			ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1386 			if (changed)
1387 				ieee80211_bss_info_change_notify(sdata,
1388 								 changed);
1389 
1390 			ieee80211_recalc_txpower(sdata, false);
1391 		}
1392 
1393 		ieee80211_recalc_chanctx_chantype(local, ctx);
1394 		ieee80211_recalc_smps_chanctx(local, ctx);
1395 		ieee80211_recalc_radar_chanctx(local, ctx);
1396 		ieee80211_recalc_chanctx_min_def(local, ctx);
1397 
1398 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1399 					 reserved_chanctx_list) {
1400 			if (ieee80211_vif_get_chanctx(sdata) != ctx)
1401 				continue;
1402 
1403 			list_del(&sdata->reserved_chanctx_list);
1404 			list_move(&sdata->assigned_chanctx_list,
1405 				  &ctx->assigned_vifs);
1406 			sdata->reserved_chanctx = NULL;
1407 
1408 			ieee80211_vif_chanctx_reservation_complete(sdata);
1409 		}
1410 
1411 		/*
1412 		 * This context might have been a dependency for an already
1413 		 * ready re-assign reservation interface that was deferred. Do
1414 		 * not propagate error to the caller though. The in-place
1415 		 * reservation for originally requested interface has already
1416 		 * succeeded at this point.
1417 		 */
1418 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1419 					 reserved_chanctx_list) {
1420 			if (WARN_ON(ieee80211_vif_has_in_place_reservation(
1421 					sdata)))
1422 				continue;
1423 
1424 			if (WARN_ON(sdata->reserved_chanctx != ctx))
1425 				continue;
1426 
1427 			if (!sdata->reserved_ready)
1428 				continue;
1429 
1430 			if (ieee80211_vif_get_chanctx(sdata))
1431 				err = ieee80211_vif_use_reserved_reassign(
1432 						sdata);
1433 			else
1434 				err = ieee80211_vif_use_reserved_assign(sdata);
1435 
1436 			if (err) {
1437 				sdata_info(sdata,
1438 					   "failed to finalize (re-)assign reservation (err=%d)\n",
1439 					   err);
1440 				ieee80211_vif_unreserve_chanctx(sdata);
1441 				cfg80211_stop_iface(local->hw.wiphy,
1442 						    &sdata->wdev,
1443 						    GFP_KERNEL);
1444 			}
1445 		}
1446 	}
1447 
1448 	/*
1449 	 * Finally free old contexts
1450 	 */
1451 
1452 	list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1453 		if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1454 			continue;
1455 
1456 		ctx->replace_ctx->replace_ctx = NULL;
1457 		ctx->replace_ctx->replace_state =
1458 				IEEE80211_CHANCTX_REPLACE_NONE;
1459 
1460 		list_del_rcu(&ctx->list);
1461 		kfree_rcu(ctx, rcu_head);
1462 	}
1463 
1464 	return 0;
1465 
1466 err:
1467 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1468 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1469 			continue;
1470 
1471 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1472 					 reserved_chanctx_list) {
1473 			ieee80211_vif_unreserve_chanctx(sdata);
1474 			ieee80211_vif_chanctx_reservation_complete(sdata);
1475 		}
1476 	}
1477 
1478 	return err;
1479 }
1480 
1481 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1482 {
1483 	struct ieee80211_local *local = sdata->local;
1484 	struct ieee80211_chanctx_conf *conf;
1485 	struct ieee80211_chanctx *ctx;
1486 	bool use_reserved_switch = false;
1487 
1488 	lockdep_assert_held(&local->chanctx_mtx);
1489 
1490 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1491 					 lockdep_is_held(&local->chanctx_mtx));
1492 	if (!conf)
1493 		return;
1494 
1495 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1496 
1497 	if (sdata->reserved_chanctx) {
1498 		if (sdata->reserved_chanctx->replace_state ==
1499 		    IEEE80211_CHANCTX_REPLACES_OTHER &&
1500 		    ieee80211_chanctx_num_reserved(local,
1501 						   sdata->reserved_chanctx) > 1)
1502 			use_reserved_switch = true;
1503 
1504 		ieee80211_vif_unreserve_chanctx(sdata);
1505 	}
1506 
1507 	ieee80211_assign_vif_chanctx(sdata, NULL);
1508 	if (ieee80211_chanctx_refcount(local, ctx) == 0)
1509 		ieee80211_free_chanctx(local, ctx);
1510 
1511 	sdata->radar_required = false;
1512 
1513 	/* Unreserving may ready an in-place reservation. */
1514 	if (use_reserved_switch)
1515 		ieee80211_vif_use_reserved_switch(local);
1516 }
1517 
1518 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
1519 			      const struct cfg80211_chan_def *chandef,
1520 			      enum ieee80211_chanctx_mode mode)
1521 {
1522 	struct ieee80211_local *local = sdata->local;
1523 	struct ieee80211_chanctx *ctx;
1524 	u8 radar_detect_width = 0;
1525 	int ret;
1526 
1527 	lockdep_assert_held(&local->mtx);
1528 
1529 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1530 
1531 	mutex_lock(&local->chanctx_mtx);
1532 
1533 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1534 					    chandef,
1535 					    sdata->wdev.iftype);
1536 	if (ret < 0)
1537 		goto out;
1538 	if (ret > 0)
1539 		radar_detect_width = BIT(chandef->width);
1540 
1541 	sdata->radar_required = ret;
1542 
1543 	ret = ieee80211_check_combinations(sdata, chandef, mode,
1544 					   radar_detect_width);
1545 	if (ret < 0)
1546 		goto out;
1547 
1548 	__ieee80211_vif_release_channel(sdata);
1549 
1550 	ctx = ieee80211_find_chanctx(local, chandef, mode);
1551 	if (!ctx)
1552 		ctx = ieee80211_new_chanctx(local, chandef, mode);
1553 	if (IS_ERR(ctx)) {
1554 		ret = PTR_ERR(ctx);
1555 		goto out;
1556 	}
1557 
1558 	ieee80211_vif_update_chandef(sdata, chandef);
1559 
1560 	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
1561 	if (ret) {
1562 		/* if assign fails refcount stays the same */
1563 		if (ieee80211_chanctx_refcount(local, ctx) == 0)
1564 			ieee80211_free_chanctx(local, ctx);
1565 		goto out;
1566 	}
1567 
1568 	ieee80211_recalc_smps_chanctx(local, ctx);
1569 	ieee80211_recalc_radar_chanctx(local, ctx);
1570  out:
1571 	if (ret)
1572 		sdata->radar_required = false;
1573 
1574 	mutex_unlock(&local->chanctx_mtx);
1575 	return ret;
1576 }
1577 
1578 int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata)
1579 {
1580 	struct ieee80211_local *local = sdata->local;
1581 	struct ieee80211_chanctx *new_ctx;
1582 	struct ieee80211_chanctx *old_ctx;
1583 	int err;
1584 
1585 	lockdep_assert_held(&local->mtx);
1586 	lockdep_assert_held(&local->chanctx_mtx);
1587 
1588 	new_ctx = sdata->reserved_chanctx;
1589 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1590 
1591 	if (WARN_ON(!new_ctx))
1592 		return -EINVAL;
1593 
1594 	if (WARN_ON(new_ctx->replace_state ==
1595 		    IEEE80211_CHANCTX_WILL_BE_REPLACED))
1596 		return -EINVAL;
1597 
1598 	if (WARN_ON(sdata->reserved_ready))
1599 		return -EINVAL;
1600 
1601 	sdata->reserved_ready = true;
1602 
1603 	if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1604 		if (old_ctx)
1605 			err = ieee80211_vif_use_reserved_reassign(sdata);
1606 		else
1607 			err = ieee80211_vif_use_reserved_assign(sdata);
1608 
1609 		if (err)
1610 			return err;
1611 	}
1612 
1613 	/*
1614 	 * In-place reservation may need to be finalized now either if:
1615 	 *  a) sdata is taking part in the swapping itself and is the last one
1616 	 *  b) sdata has switched with a re-assign reservation to an existing
1617 	 *     context readying in-place switching of old_ctx
1618 	 *
1619 	 * In case of (b) do not propagate the error up because the requested
1620 	 * sdata already switched successfully. Just spill an extra warning.
1621 	 * The ieee80211_vif_use_reserved_switch() already stops all necessary
1622 	 * interfaces upon failure.
1623 	 */
1624 	if ((old_ctx &&
1625 	     old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1626 	    new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1627 		err = ieee80211_vif_use_reserved_switch(local);
1628 		if (err && err != -EAGAIN) {
1629 			if (new_ctx->replace_state ==
1630 			    IEEE80211_CHANCTX_REPLACES_OTHER)
1631 				return err;
1632 
1633 			wiphy_info(local->hw.wiphy,
1634 				   "depending in-place reservation failed (err=%d)\n",
1635 				   err);
1636 		}
1637 	}
1638 
1639 	return 0;
1640 }
1641 
1642 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
1643 				   const struct cfg80211_chan_def *chandef,
1644 				   u32 *changed)
1645 {
1646 	struct ieee80211_local *local = sdata->local;
1647 	struct ieee80211_chanctx_conf *conf;
1648 	struct ieee80211_chanctx *ctx;
1649 	const struct cfg80211_chan_def *compat;
1650 	int ret;
1651 
1652 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1653 				     IEEE80211_CHAN_DISABLED))
1654 		return -EINVAL;
1655 
1656 	mutex_lock(&local->chanctx_mtx);
1657 	if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
1658 		ret = 0;
1659 		goto out;
1660 	}
1661 
1662 	if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1663 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1664 		ret = -EINVAL;
1665 		goto out;
1666 	}
1667 
1668 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1669 					 lockdep_is_held(&local->chanctx_mtx));
1670 	if (!conf) {
1671 		ret = -EINVAL;
1672 		goto out;
1673 	}
1674 
1675 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1676 
1677 	compat = cfg80211_chandef_compatible(&conf->def, chandef);
1678 	if (!compat) {
1679 		ret = -EINVAL;
1680 		goto out;
1681 	}
1682 
1683 	switch (ctx->replace_state) {
1684 	case IEEE80211_CHANCTX_REPLACE_NONE:
1685 		if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1686 			ret = -EBUSY;
1687 			goto out;
1688 		}
1689 		break;
1690 	case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1691 		/* TODO: Perhaps the bandwidth change could be treated as a
1692 		 * reservation itself? */
1693 		ret = -EBUSY;
1694 		goto out;
1695 	case IEEE80211_CHANCTX_REPLACES_OTHER:
1696 		/* channel context that is going to replace another channel
1697 		 * context doesn't really exist and shouldn't be assigned
1698 		 * anywhere yet */
1699 		WARN_ON(1);
1700 		break;
1701 	}
1702 
1703 	ieee80211_vif_update_chandef(sdata, chandef);
1704 
1705 	ieee80211_recalc_chanctx_chantype(local, ctx);
1706 
1707 	*changed |= BSS_CHANGED_BANDWIDTH;
1708 	ret = 0;
1709  out:
1710 	mutex_unlock(&local->chanctx_mtx);
1711 	return ret;
1712 }
1713 
1714 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1715 {
1716 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1717 
1718 	lockdep_assert_held(&sdata->local->mtx);
1719 
1720 	mutex_lock(&sdata->local->chanctx_mtx);
1721 	__ieee80211_vif_release_channel(sdata);
1722 	mutex_unlock(&sdata->local->chanctx_mtx);
1723 }
1724 
1725 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
1726 {
1727 	struct ieee80211_local *local = sdata->local;
1728 	struct ieee80211_sub_if_data *ap;
1729 	struct ieee80211_chanctx_conf *conf;
1730 
1731 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
1732 		return;
1733 
1734 	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
1735 
1736 	mutex_lock(&local->chanctx_mtx);
1737 
1738 	conf = rcu_dereference_protected(ap->vif.chanctx_conf,
1739 					 lockdep_is_held(&local->chanctx_mtx));
1740 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
1741 	mutex_unlock(&local->chanctx_mtx);
1742 }
1743 
1744 void ieee80211_iter_chan_contexts_atomic(
1745 	struct ieee80211_hw *hw,
1746 	void (*iter)(struct ieee80211_hw *hw,
1747 		     struct ieee80211_chanctx_conf *chanctx_conf,
1748 		     void *data),
1749 	void *iter_data)
1750 {
1751 	struct ieee80211_local *local = hw_to_local(hw);
1752 	struct ieee80211_chanctx *ctx;
1753 
1754 	rcu_read_lock();
1755 	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
1756 		if (ctx->driver_present)
1757 			iter(hw, &ctx->conf, iter_data);
1758 	rcu_read_unlock();
1759 }
1760 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);
1761