xref: /openbmc/linux/net/mac80211/chan.c (revision e1f7c9ee)
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 			width = vif->bss_conf.chandef.width;
274 			break;
275 		case NL80211_IFTYPE_UNSPECIFIED:
276 		case NUM_NL80211_IFTYPES:
277 		case NL80211_IFTYPE_MONITOR:
278 		case NL80211_IFTYPE_P2P_CLIENT:
279 		case NL80211_IFTYPE_P2P_GO:
280 			WARN_ON_ONCE(1);
281 		}
282 		max_bw = max(max_bw, width);
283 	}
284 
285 	/* use the configured bandwidth in case of monitor interface */
286 	sdata = rcu_dereference(local->monitor_sdata);
287 	if (sdata && rcu_access_pointer(sdata->vif.chanctx_conf) == conf)
288 		max_bw = max(max_bw, conf->def.width);
289 
290 	rcu_read_unlock();
291 
292 	return max_bw;
293 }
294 
295 /*
296  * recalc the min required chan width of the channel context, which is
297  * the max of min required widths of all the interfaces bound to this
298  * channel context.
299  */
300 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
301 				      struct ieee80211_chanctx *ctx)
302 {
303 	enum nl80211_chan_width max_bw;
304 	struct cfg80211_chan_def min_def;
305 
306 	lockdep_assert_held(&local->chanctx_mtx);
307 
308 	/* don't optimize 5MHz, 10MHz, and radar_enabled confs */
309 	if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
310 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
311 	    ctx->conf.radar_enabled) {
312 		ctx->conf.min_def = ctx->conf.def;
313 		return;
314 	}
315 
316 	max_bw = ieee80211_get_chanctx_max_required_bw(local, &ctx->conf);
317 
318 	/* downgrade chandef up to max_bw */
319 	min_def = ctx->conf.def;
320 	while (min_def.width > max_bw)
321 		ieee80211_chandef_downgrade(&min_def);
322 
323 	if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
324 		return;
325 
326 	ctx->conf.min_def = min_def;
327 	if (!ctx->driver_present)
328 		return;
329 
330 	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_MIN_WIDTH);
331 }
332 
333 static void ieee80211_change_chanctx(struct ieee80211_local *local,
334 				     struct ieee80211_chanctx *ctx,
335 				     const struct cfg80211_chan_def *chandef)
336 {
337 	if (cfg80211_chandef_identical(&ctx->conf.def, chandef))
338 		return;
339 
340 	WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
341 
342 	ctx->conf.def = *chandef;
343 	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);
344 	ieee80211_recalc_chanctx_min_def(local, ctx);
345 
346 	if (!local->use_chanctx) {
347 		local->_oper_chandef = *chandef;
348 		ieee80211_hw_config(local, 0);
349 	}
350 }
351 
352 static struct ieee80211_chanctx *
353 ieee80211_find_chanctx(struct ieee80211_local *local,
354 		       const struct cfg80211_chan_def *chandef,
355 		       enum ieee80211_chanctx_mode mode)
356 {
357 	struct ieee80211_chanctx *ctx;
358 
359 	lockdep_assert_held(&local->chanctx_mtx);
360 
361 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
362 		return NULL;
363 
364 	list_for_each_entry(ctx, &local->chanctx_list, list) {
365 		const struct cfg80211_chan_def *compat;
366 
367 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
368 			continue;
369 
370 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
371 			continue;
372 
373 		compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
374 		if (!compat)
375 			continue;
376 
377 		compat = ieee80211_chanctx_reserved_chandef(local, ctx,
378 							    compat);
379 		if (!compat)
380 			continue;
381 
382 		ieee80211_change_chanctx(local, ctx, compat);
383 
384 		return ctx;
385 	}
386 
387 	return NULL;
388 }
389 
390 static bool ieee80211_is_radar_required(struct ieee80211_local *local)
391 {
392 	struct ieee80211_sub_if_data *sdata;
393 
394 	lockdep_assert_held(&local->mtx);
395 
396 	rcu_read_lock();
397 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
398 		if (sdata->radar_required) {
399 			rcu_read_unlock();
400 			return true;
401 		}
402 	}
403 	rcu_read_unlock();
404 
405 	return false;
406 }
407 
408 static struct ieee80211_chanctx *
409 ieee80211_alloc_chanctx(struct ieee80211_local *local,
410 			const struct cfg80211_chan_def *chandef,
411 			enum ieee80211_chanctx_mode mode)
412 {
413 	struct ieee80211_chanctx *ctx;
414 
415 	lockdep_assert_held(&local->chanctx_mtx);
416 
417 	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
418 	if (!ctx)
419 		return NULL;
420 
421 	INIT_LIST_HEAD(&ctx->assigned_vifs);
422 	INIT_LIST_HEAD(&ctx->reserved_vifs);
423 	ctx->conf.def = *chandef;
424 	ctx->conf.rx_chains_static = 1;
425 	ctx->conf.rx_chains_dynamic = 1;
426 	ctx->mode = mode;
427 	ctx->conf.radar_enabled = ieee80211_is_radar_required(local);
428 	ieee80211_recalc_chanctx_min_def(local, ctx);
429 
430 	return ctx;
431 }
432 
433 static int ieee80211_add_chanctx(struct ieee80211_local *local,
434 				 struct ieee80211_chanctx *ctx)
435 {
436 	u32 changed;
437 	int err;
438 
439 	lockdep_assert_held(&local->mtx);
440 	lockdep_assert_held(&local->chanctx_mtx);
441 
442 	if (!local->use_chanctx)
443 		local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
444 
445 	/* turn idle off *before* setting channel -- some drivers need that */
446 	changed = ieee80211_idle_off(local);
447 	if (changed)
448 		ieee80211_hw_config(local, changed);
449 
450 	if (!local->use_chanctx) {
451 		local->_oper_chandef = ctx->conf.def;
452 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
453 	} else {
454 		err = drv_add_chanctx(local, ctx);
455 		if (err) {
456 			ieee80211_recalc_idle(local);
457 			return err;
458 		}
459 	}
460 
461 	return 0;
462 }
463 
464 static struct ieee80211_chanctx *
465 ieee80211_new_chanctx(struct ieee80211_local *local,
466 		      const struct cfg80211_chan_def *chandef,
467 		      enum ieee80211_chanctx_mode mode)
468 {
469 	struct ieee80211_chanctx *ctx;
470 	int err;
471 
472 	lockdep_assert_held(&local->mtx);
473 	lockdep_assert_held(&local->chanctx_mtx);
474 
475 	ctx = ieee80211_alloc_chanctx(local, chandef, mode);
476 	if (!ctx)
477 		return ERR_PTR(-ENOMEM);
478 
479 	err = ieee80211_add_chanctx(local, ctx);
480 	if (err) {
481 		kfree(ctx);
482 		return ERR_PTR(err);
483 	}
484 
485 	list_add_rcu(&ctx->list, &local->chanctx_list);
486 	return ctx;
487 }
488 
489 static void ieee80211_del_chanctx(struct ieee80211_local *local,
490 				  struct ieee80211_chanctx *ctx)
491 {
492 	lockdep_assert_held(&local->chanctx_mtx);
493 
494 	if (!local->use_chanctx) {
495 		struct cfg80211_chan_def *chandef = &local->_oper_chandef;
496 		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
497 		chandef->center_freq1 = chandef->chan->center_freq;
498 		chandef->center_freq2 = 0;
499 
500 		/* NOTE: Disabling radar is only valid here for
501 		 * single channel context. To be sure, check it ...
502 		 */
503 		WARN_ON(local->hw.conf.radar_enabled &&
504 			!list_empty(&local->chanctx_list));
505 
506 		local->hw.conf.radar_enabled = false;
507 
508 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
509 	} else {
510 		drv_remove_chanctx(local, ctx);
511 	}
512 
513 	ieee80211_recalc_idle(local);
514 }
515 
516 static void ieee80211_free_chanctx(struct ieee80211_local *local,
517 				   struct ieee80211_chanctx *ctx)
518 {
519 	lockdep_assert_held(&local->chanctx_mtx);
520 
521 	WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
522 
523 	list_del_rcu(&ctx->list);
524 	ieee80211_del_chanctx(local, ctx);
525 	kfree_rcu(ctx, rcu_head);
526 }
527 
528 static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
529 					      struct ieee80211_chanctx *ctx)
530 {
531 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
532 	struct ieee80211_sub_if_data *sdata;
533 	const struct cfg80211_chan_def *compat = NULL;
534 
535 	lockdep_assert_held(&local->chanctx_mtx);
536 
537 	rcu_read_lock();
538 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
539 
540 		if (!ieee80211_sdata_running(sdata))
541 			continue;
542 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
543 			continue;
544 		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
545 			continue;
546 
547 		if (!compat)
548 			compat = &sdata->vif.bss_conf.chandef;
549 
550 		compat = cfg80211_chandef_compatible(
551 				&sdata->vif.bss_conf.chandef, compat);
552 		if (WARN_ON_ONCE(!compat))
553 			break;
554 	}
555 	rcu_read_unlock();
556 
557 	if (!compat)
558 		return;
559 
560 	ieee80211_change_chanctx(local, ctx, compat);
561 }
562 
563 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
564 					   struct ieee80211_chanctx *chanctx)
565 {
566 	bool radar_enabled;
567 
568 	lockdep_assert_held(&local->chanctx_mtx);
569 	/* for setting local->radar_detect_enabled */
570 	lockdep_assert_held(&local->mtx);
571 
572 	radar_enabled = ieee80211_is_radar_required(local);
573 
574 	if (radar_enabled == chanctx->conf.radar_enabled)
575 		return;
576 
577 	chanctx->conf.radar_enabled = radar_enabled;
578 	local->radar_detect_enabled = chanctx->conf.radar_enabled;
579 
580 	if (!local->use_chanctx) {
581 		local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
582 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
583 	}
584 
585 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
586 }
587 
588 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
589 					struct ieee80211_chanctx *new_ctx)
590 {
591 	struct ieee80211_local *local = sdata->local;
592 	struct ieee80211_chanctx_conf *conf;
593 	struct ieee80211_chanctx *curr_ctx = NULL;
594 	int ret = 0;
595 
596 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
597 					 lockdep_is_held(&local->chanctx_mtx));
598 
599 	if (conf) {
600 		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
601 
602 		drv_unassign_vif_chanctx(local, sdata, curr_ctx);
603 		conf = NULL;
604 		list_del(&sdata->assigned_chanctx_list);
605 	}
606 
607 	if (new_ctx) {
608 		ret = drv_assign_vif_chanctx(local, sdata, new_ctx);
609 		if (ret)
610 			goto out;
611 
612 		conf = &new_ctx->conf;
613 		list_add(&sdata->assigned_chanctx_list,
614 			 &new_ctx->assigned_vifs);
615 	}
616 
617 out:
618 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
619 
620 	sdata->vif.bss_conf.idle = !conf;
621 
622 	if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
623 		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
624 		ieee80211_recalc_smps_chanctx(local, curr_ctx);
625 		ieee80211_recalc_radar_chanctx(local, curr_ctx);
626 		ieee80211_recalc_chanctx_min_def(local, curr_ctx);
627 	}
628 
629 	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
630 		ieee80211_recalc_txpower(sdata);
631 		ieee80211_recalc_chanctx_min_def(local, new_ctx);
632 	}
633 
634 	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
635 	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
636 		ieee80211_bss_info_change_notify(sdata,
637 						 BSS_CHANGED_IDLE);
638 
639 	return ret;
640 }
641 
642 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
643 				   struct ieee80211_chanctx *chanctx)
644 {
645 	struct ieee80211_sub_if_data *sdata;
646 	u8 rx_chains_static, rx_chains_dynamic;
647 
648 	lockdep_assert_held(&local->chanctx_mtx);
649 
650 	rx_chains_static = 1;
651 	rx_chains_dynamic = 1;
652 
653 	rcu_read_lock();
654 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
655 		u8 needed_static, needed_dynamic;
656 
657 		if (!ieee80211_sdata_running(sdata))
658 			continue;
659 
660 		if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
661 						&chanctx->conf)
662 			continue;
663 
664 		switch (sdata->vif.type) {
665 		case NL80211_IFTYPE_P2P_DEVICE:
666 			continue;
667 		case NL80211_IFTYPE_STATION:
668 			if (!sdata->u.mgd.associated)
669 				continue;
670 			break;
671 		case NL80211_IFTYPE_AP_VLAN:
672 			continue;
673 		case NL80211_IFTYPE_AP:
674 		case NL80211_IFTYPE_ADHOC:
675 		case NL80211_IFTYPE_WDS:
676 		case NL80211_IFTYPE_MESH_POINT:
677 			break;
678 		default:
679 			WARN_ON_ONCE(1);
680 		}
681 
682 		switch (sdata->smps_mode) {
683 		default:
684 			WARN_ONCE(1, "Invalid SMPS mode %d\n",
685 				  sdata->smps_mode);
686 			/* fall through */
687 		case IEEE80211_SMPS_OFF:
688 			needed_static = sdata->needed_rx_chains;
689 			needed_dynamic = sdata->needed_rx_chains;
690 			break;
691 		case IEEE80211_SMPS_DYNAMIC:
692 			needed_static = 1;
693 			needed_dynamic = sdata->needed_rx_chains;
694 			break;
695 		case IEEE80211_SMPS_STATIC:
696 			needed_static = 1;
697 			needed_dynamic = 1;
698 			break;
699 		}
700 
701 		rx_chains_static = max(rx_chains_static, needed_static);
702 		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
703 	}
704 
705 	/* Disable SMPS for the monitor interface */
706 	sdata = rcu_dereference(local->monitor_sdata);
707 	if (sdata &&
708 	    rcu_access_pointer(sdata->vif.chanctx_conf) == &chanctx->conf)
709 		rx_chains_dynamic = rx_chains_static = local->rx_chains;
710 
711 	rcu_read_unlock();
712 
713 	if (!local->use_chanctx) {
714 		if (rx_chains_static > 1)
715 			local->smps_mode = IEEE80211_SMPS_OFF;
716 		else if (rx_chains_dynamic > 1)
717 			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
718 		else
719 			local->smps_mode = IEEE80211_SMPS_STATIC;
720 		ieee80211_hw_config(local, 0);
721 	}
722 
723 	if (rx_chains_static == chanctx->conf.rx_chains_static &&
724 	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
725 		return;
726 
727 	chanctx->conf.rx_chains_static = rx_chains_static;
728 	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
729 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
730 }
731 
732 static void
733 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
734 				      bool clear)
735 {
736 	struct ieee80211_local *local __maybe_unused = sdata->local;
737 	struct ieee80211_sub_if_data *vlan;
738 	struct ieee80211_chanctx_conf *conf;
739 
740 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
741 		return;
742 
743 	lockdep_assert_held(&local->mtx);
744 
745 	/* Check that conf exists, even when clearing this function
746 	 * must be called with the AP's channel context still there
747 	 * as it would otherwise cause VLANs to have an invalid
748 	 * channel context pointer for a while, possibly pointing
749 	 * to a channel context that has already been freed.
750 	 */
751 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
752 					 lockdep_is_held(&local->chanctx_mtx));
753 	WARN_ON(!conf);
754 
755 	if (clear)
756 		conf = NULL;
757 
758 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
759 		rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
760 }
761 
762 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
763 					 bool clear)
764 {
765 	struct ieee80211_local *local = sdata->local;
766 
767 	mutex_lock(&local->chanctx_mtx);
768 
769 	__ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
770 
771 	mutex_unlock(&local->chanctx_mtx);
772 }
773 
774 int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
775 {
776 	struct ieee80211_chanctx *ctx = sdata->reserved_chanctx;
777 
778 	lockdep_assert_held(&sdata->local->chanctx_mtx);
779 
780 	if (WARN_ON(!ctx))
781 		return -EINVAL;
782 
783 	list_del(&sdata->reserved_chanctx_list);
784 	sdata->reserved_chanctx = NULL;
785 
786 	if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
787 		if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
788 			if (WARN_ON(!ctx->replace_ctx))
789 				return -EINVAL;
790 
791 			WARN_ON(ctx->replace_ctx->replace_state !=
792 			        IEEE80211_CHANCTX_WILL_BE_REPLACED);
793 			WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
794 
795 			ctx->replace_ctx->replace_ctx = NULL;
796 			ctx->replace_ctx->replace_state =
797 					IEEE80211_CHANCTX_REPLACE_NONE;
798 
799 			list_del_rcu(&ctx->list);
800 			kfree_rcu(ctx, rcu_head);
801 		} else {
802 			ieee80211_free_chanctx(sdata->local, ctx);
803 		}
804 	}
805 
806 	return 0;
807 }
808 
809 int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
810 				  const struct cfg80211_chan_def *chandef,
811 				  enum ieee80211_chanctx_mode mode,
812 				  bool radar_required)
813 {
814 	struct ieee80211_local *local = sdata->local;
815 	struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
816 
817 	lockdep_assert_held(&local->chanctx_mtx);
818 
819 	curr_ctx = ieee80211_vif_get_chanctx(sdata);
820 	if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
821 		return -ENOTSUPP;
822 
823 	new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
824 	if (!new_ctx) {
825 		if (ieee80211_can_create_new_chanctx(local)) {
826 			new_ctx = ieee80211_new_chanctx(local, chandef, mode);
827 			if (IS_ERR(new_ctx))
828 				return PTR_ERR(new_ctx);
829 		} else {
830 			if (!curr_ctx ||
831 			    (curr_ctx->replace_state ==
832 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
833 			    !list_empty(&curr_ctx->reserved_vifs)) {
834 				/*
835 				 * Another vif already requested this context
836 				 * for a reservation. Find another one hoping
837 				 * all vifs assigned to it will also switch
838 				 * soon enough.
839 				 *
840 				 * TODO: This needs a little more work as some
841 				 * cases (more than 2 chanctx capable devices)
842 				 * may fail which could otherwise succeed
843 				 * provided some channel context juggling was
844 				 * performed.
845 				 *
846 				 * Consider ctx1..3, vif1..6, each ctx has 2
847 				 * vifs. vif1 and vif2 from ctx1 request new
848 				 * different chandefs starting 2 in-place
849 				 * reserations with ctx4 and ctx5 replacing
850 				 * ctx1 and ctx2 respectively. Next vif5 and
851 				 * vif6 from ctx3 reserve ctx4. If vif3 and
852 				 * vif4 remain on ctx2 as they are then this
853 				 * fails unless `replace_ctx` from ctx5 is
854 				 * replaced with ctx3.
855 				 */
856 				list_for_each_entry(ctx, &local->chanctx_list,
857 						    list) {
858 					if (ctx->replace_state !=
859 					    IEEE80211_CHANCTX_REPLACE_NONE)
860 						continue;
861 
862 					if (!list_empty(&ctx->reserved_vifs))
863 						continue;
864 
865 					curr_ctx = ctx;
866 					break;
867 				}
868 			}
869 
870 			/*
871 			 * If that's true then all available contexts already
872 			 * have reservations and cannot be used.
873 			 */
874 			if (!curr_ctx ||
875 			    (curr_ctx->replace_state ==
876 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
877 			    !list_empty(&curr_ctx->reserved_vifs))
878 				return -EBUSY;
879 
880 			new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
881 			if (!new_ctx)
882 				return -ENOMEM;
883 
884 			new_ctx->replace_ctx = curr_ctx;
885 			new_ctx->replace_state =
886 					IEEE80211_CHANCTX_REPLACES_OTHER;
887 
888 			curr_ctx->replace_ctx = new_ctx;
889 			curr_ctx->replace_state =
890 					IEEE80211_CHANCTX_WILL_BE_REPLACED;
891 
892 			list_add_rcu(&new_ctx->list, &local->chanctx_list);
893 		}
894 	}
895 
896 	list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);
897 	sdata->reserved_chanctx = new_ctx;
898 	sdata->reserved_chandef = *chandef;
899 	sdata->reserved_radar_required = radar_required;
900 	sdata->reserved_ready = false;
901 
902 	return 0;
903 }
904 
905 static void
906 ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
907 {
908 	switch (sdata->vif.type) {
909 	case NL80211_IFTYPE_ADHOC:
910 	case NL80211_IFTYPE_AP:
911 	case NL80211_IFTYPE_MESH_POINT:
912 		ieee80211_queue_work(&sdata->local->hw,
913 				     &sdata->csa_finalize_work);
914 		break;
915 	case NL80211_IFTYPE_STATION:
916 		ieee80211_queue_work(&sdata->local->hw,
917 				     &sdata->u.mgd.chswitch_work);
918 		break;
919 	case NL80211_IFTYPE_UNSPECIFIED:
920 	case NL80211_IFTYPE_AP_VLAN:
921 	case NL80211_IFTYPE_WDS:
922 	case NL80211_IFTYPE_MONITOR:
923 	case NL80211_IFTYPE_P2P_CLIENT:
924 	case NL80211_IFTYPE_P2P_GO:
925 	case NL80211_IFTYPE_P2P_DEVICE:
926 	case NUM_NL80211_IFTYPES:
927 		WARN_ON(1);
928 		break;
929 	}
930 }
931 
932 static int
933 ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
934 {
935 	struct ieee80211_local *local = sdata->local;
936 	struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
937 	struct ieee80211_chanctx *old_ctx, *new_ctx;
938 	const struct cfg80211_chan_def *chandef;
939 	u32 changed = 0;
940 	int err;
941 
942 	lockdep_assert_held(&local->mtx);
943 	lockdep_assert_held(&local->chanctx_mtx);
944 
945 	new_ctx = sdata->reserved_chanctx;
946 	old_ctx = ieee80211_vif_get_chanctx(sdata);
947 
948 	if (WARN_ON(!sdata->reserved_ready))
949 		return -EBUSY;
950 
951 	if (WARN_ON(!new_ctx))
952 		return -EINVAL;
953 
954 	if (WARN_ON(!old_ctx))
955 		return -EINVAL;
956 
957 	if (WARN_ON(new_ctx->replace_state ==
958 		    IEEE80211_CHANCTX_REPLACES_OTHER))
959 		return -EINVAL;
960 
961 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
962 				&sdata->reserved_chandef);
963 	if (WARN_ON(!chandef))
964 		return -EINVAL;
965 
966 	vif_chsw[0].vif = &sdata->vif;
967 	vif_chsw[0].old_ctx = &old_ctx->conf;
968 	vif_chsw[0].new_ctx = &new_ctx->conf;
969 
970 	list_del(&sdata->reserved_chanctx_list);
971 	sdata->reserved_chanctx = NULL;
972 
973 	err = drv_switch_vif_chanctx(local, vif_chsw, 1,
974 				     CHANCTX_SWMODE_REASSIGN_VIF);
975 	if (err) {
976 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
977 			ieee80211_free_chanctx(local, new_ctx);
978 
979 		goto out;
980 	}
981 
982 	list_move(&sdata->assigned_chanctx_list, &new_ctx->assigned_vifs);
983 	rcu_assign_pointer(sdata->vif.chanctx_conf, &new_ctx->conf);
984 
985 	if (sdata->vif.type == NL80211_IFTYPE_AP)
986 		__ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
987 
988 	if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
989 		ieee80211_free_chanctx(local, old_ctx);
990 
991 	if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
992 		changed = BSS_CHANGED_BANDWIDTH;
993 
994 	sdata->vif.bss_conf.chandef = sdata->reserved_chandef;
995 
996 	if (changed)
997 		ieee80211_bss_info_change_notify(sdata, changed);
998 
999 out:
1000 	ieee80211_vif_chanctx_reservation_complete(sdata);
1001 	return err;
1002 }
1003 
1004 static int
1005 ieee80211_vif_use_reserved_assign(struct ieee80211_sub_if_data *sdata)
1006 {
1007 	struct ieee80211_local *local = sdata->local;
1008 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1009 	const struct cfg80211_chan_def *chandef;
1010 	int err;
1011 
1012 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1013 	new_ctx = sdata->reserved_chanctx;
1014 
1015 	if (WARN_ON(!sdata->reserved_ready))
1016 		return -EINVAL;
1017 
1018 	if (WARN_ON(old_ctx))
1019 		return -EINVAL;
1020 
1021 	if (WARN_ON(!new_ctx))
1022 		return -EINVAL;
1023 
1024 	if (WARN_ON(new_ctx->replace_state ==
1025 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1026 		return -EINVAL;
1027 
1028 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1029 				&sdata->reserved_chandef);
1030 	if (WARN_ON(!chandef))
1031 		return -EINVAL;
1032 
1033 	list_del(&sdata->reserved_chanctx_list);
1034 	sdata->reserved_chanctx = NULL;
1035 
1036 	err = ieee80211_assign_vif_chanctx(sdata, new_ctx);
1037 	if (err) {
1038 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1039 			ieee80211_free_chanctx(local, new_ctx);
1040 
1041 		goto out;
1042 	}
1043 
1044 out:
1045 	ieee80211_vif_chanctx_reservation_complete(sdata);
1046 	return err;
1047 }
1048 
1049 static bool
1050 ieee80211_vif_has_in_place_reservation(struct ieee80211_sub_if_data *sdata)
1051 {
1052 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1053 
1054 	lockdep_assert_held(&sdata->local->chanctx_mtx);
1055 
1056 	new_ctx = sdata->reserved_chanctx;
1057 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1058 
1059 	if (!old_ctx)
1060 		return false;
1061 
1062 	if (WARN_ON(!new_ctx))
1063 		return false;
1064 
1065 	if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1066 		return false;
1067 
1068 	if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1069 		return false;
1070 
1071 	return true;
1072 }
1073 
1074 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1075 					struct ieee80211_chanctx *new_ctx)
1076 {
1077 	const struct cfg80211_chan_def *chandef;
1078 
1079 	lockdep_assert_held(&local->mtx);
1080 	lockdep_assert_held(&local->chanctx_mtx);
1081 
1082 	chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1083 	if (WARN_ON(!chandef))
1084 		return -EINVAL;
1085 
1086 	local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1087 	local->_oper_chandef = *chandef;
1088 	ieee80211_hw_config(local, 0);
1089 
1090 	return 0;
1091 }
1092 
1093 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1094 				      int n_vifs)
1095 {
1096 	struct ieee80211_vif_chanctx_switch *vif_chsw;
1097 	struct ieee80211_sub_if_data *sdata;
1098 	struct ieee80211_chanctx *ctx, *old_ctx;
1099 	int i, err;
1100 
1101 	lockdep_assert_held(&local->mtx);
1102 	lockdep_assert_held(&local->chanctx_mtx);
1103 
1104 	vif_chsw = kzalloc(sizeof(vif_chsw[0]) * n_vifs, GFP_KERNEL);
1105 	if (!vif_chsw)
1106 		return -ENOMEM;
1107 
1108 	i = 0;
1109 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1110 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1111 			continue;
1112 
1113 		if (WARN_ON(!ctx->replace_ctx)) {
1114 			err = -EINVAL;
1115 			goto out;
1116 		}
1117 
1118 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1119 				    reserved_chanctx_list) {
1120 			if (!ieee80211_vif_has_in_place_reservation(
1121 					sdata))
1122 				continue;
1123 
1124 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1125 			vif_chsw[i].vif = &sdata->vif;
1126 			vif_chsw[i].old_ctx = &old_ctx->conf;
1127 			vif_chsw[i].new_ctx = &ctx->conf;
1128 
1129 			i++;
1130 		}
1131 	}
1132 
1133 	err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1134 				     CHANCTX_SWMODE_SWAP_CONTEXTS);
1135 
1136 out:
1137 	kfree(vif_chsw);
1138 	return err;
1139 }
1140 
1141 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1142 {
1143 	struct ieee80211_chanctx *ctx;
1144 	int err;
1145 
1146 	lockdep_assert_held(&local->mtx);
1147 	lockdep_assert_held(&local->chanctx_mtx);
1148 
1149 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1150 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1151 			continue;
1152 
1153 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1154 			continue;
1155 
1156 		ieee80211_del_chanctx(local, ctx->replace_ctx);
1157 		err = ieee80211_add_chanctx(local, ctx);
1158 		if (err)
1159 			goto err;
1160 	}
1161 
1162 	return 0;
1163 
1164 err:
1165 	WARN_ON(ieee80211_add_chanctx(local, ctx));
1166 	list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1167 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1168 			continue;
1169 
1170 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1171 			continue;
1172 
1173 		ieee80211_del_chanctx(local, ctx);
1174 		WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1175 	}
1176 
1177 	return err;
1178 }
1179 
1180 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1181 {
1182 	struct ieee80211_sub_if_data *sdata, *sdata_tmp;
1183 	struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1184 	struct ieee80211_chanctx *new_ctx = NULL;
1185 	int i, err, n_assigned, n_reserved, n_ready;
1186 	int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1187 
1188 	lockdep_assert_held(&local->mtx);
1189 	lockdep_assert_held(&local->chanctx_mtx);
1190 
1191 	/*
1192 	 * If there are 2 independent pairs of channel contexts performing
1193 	 * cross-switch of their vifs this code will still wait until both are
1194 	 * ready even though it could be possible to switch one before the
1195 	 * other is ready.
1196 	 *
1197 	 * For practical reasons and code simplicity just do a single huge
1198 	 * switch.
1199 	 */
1200 
1201 	/*
1202 	 * Verify if the reservation is still feasible.
1203 	 *  - if it's not then disconnect
1204 	 *  - if it is but not all vifs necessary are ready then defer
1205 	 */
1206 
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 err;
1214 		}
1215 
1216 		if (!local->use_chanctx)
1217 			new_ctx = ctx;
1218 
1219 		n_ctx++;
1220 
1221 		n_assigned = 0;
1222 		n_reserved = 0;
1223 		n_ready = 0;
1224 
1225 		list_for_each_entry(sdata, &ctx->replace_ctx->assigned_vifs,
1226 				    assigned_chanctx_list) {
1227 			n_assigned++;
1228 			if (sdata->reserved_chanctx) {
1229 				n_reserved++;
1230 				if (sdata->reserved_ready)
1231 					n_ready++;
1232 			}
1233 		}
1234 
1235 		if (n_assigned != n_reserved) {
1236 			if (n_ready == n_reserved) {
1237 				wiphy_info(local->hw.wiphy,
1238 					   "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1239 				err = -EBUSY;
1240 				goto err;
1241 			}
1242 
1243 			return -EAGAIN;
1244 		}
1245 
1246 		ctx->conf.radar_enabled = false;
1247 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1248 				    reserved_chanctx_list) {
1249 			if (ieee80211_vif_has_in_place_reservation(sdata) &&
1250 			    !sdata->reserved_ready)
1251 				return -EAGAIN;
1252 
1253 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1254 			if (old_ctx) {
1255 				if (old_ctx->replace_state ==
1256 				    IEEE80211_CHANCTX_WILL_BE_REPLACED)
1257 					n_vifs_switch++;
1258 				else
1259 					n_vifs_assign++;
1260 			} else {
1261 				n_vifs_ctxless++;
1262 			}
1263 
1264 			if (sdata->reserved_radar_required)
1265 				ctx->conf.radar_enabled = true;
1266 		}
1267 	}
1268 
1269 	if (WARN_ON(n_ctx == 0) ||
1270 	    WARN_ON(n_vifs_switch == 0 &&
1271 		    n_vifs_assign == 0 &&
1272 		    n_vifs_ctxless == 0) ||
1273 	    WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1274 	    WARN_ON(!new_ctx && !local->use_chanctx)) {
1275 		err = -EINVAL;
1276 		goto err;
1277 	}
1278 
1279 	/*
1280 	 * All necessary vifs are ready. Perform the switch now depending on
1281 	 * reservations and driver capabilities.
1282 	 */
1283 
1284 	if (local->use_chanctx) {
1285 		if (n_vifs_switch > 0) {
1286 			err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1287 			if (err)
1288 				goto err;
1289 		}
1290 
1291 		if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1292 			err = ieee80211_chsw_switch_ctxs(local);
1293 			if (err)
1294 				goto err;
1295 		}
1296 	} else {
1297 		err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1298 		if (err)
1299 			goto err;
1300 	}
1301 
1302 	/*
1303 	 * Update all structures, values and pointers to point to new channel
1304 	 * context(s).
1305 	 */
1306 
1307 	i = 0;
1308 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1309 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1310 			continue;
1311 
1312 		if (WARN_ON(!ctx->replace_ctx)) {
1313 			err = -EINVAL;
1314 			goto err;
1315 		}
1316 
1317 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1318 				    reserved_chanctx_list) {
1319 			u32 changed = 0;
1320 
1321 			if (!ieee80211_vif_has_in_place_reservation(sdata))
1322 				continue;
1323 
1324 			rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
1325 
1326 			if (sdata->vif.type == NL80211_IFTYPE_AP)
1327 				__ieee80211_vif_copy_chanctx_to_vlans(sdata,
1328 								      false);
1329 
1330 			sdata->radar_required = sdata->reserved_radar_required;
1331 
1332 			if (sdata->vif.bss_conf.chandef.width !=
1333 			    sdata->reserved_chandef.width)
1334 				changed = BSS_CHANGED_BANDWIDTH;
1335 
1336 			sdata->vif.bss_conf.chandef = sdata->reserved_chandef;
1337 			if (changed)
1338 				ieee80211_bss_info_change_notify(sdata,
1339 								 changed);
1340 
1341 			ieee80211_recalc_txpower(sdata);
1342 		}
1343 
1344 		ieee80211_recalc_chanctx_chantype(local, ctx);
1345 		ieee80211_recalc_smps_chanctx(local, ctx);
1346 		ieee80211_recalc_radar_chanctx(local, ctx);
1347 		ieee80211_recalc_chanctx_min_def(local, ctx);
1348 
1349 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1350 					 reserved_chanctx_list) {
1351 			if (ieee80211_vif_get_chanctx(sdata) != ctx)
1352 				continue;
1353 
1354 			list_del(&sdata->reserved_chanctx_list);
1355 			list_move(&sdata->assigned_chanctx_list,
1356 				  &ctx->assigned_vifs);
1357 			sdata->reserved_chanctx = NULL;
1358 
1359 			ieee80211_vif_chanctx_reservation_complete(sdata);
1360 		}
1361 
1362 		/*
1363 		 * This context might have been a dependency for an already
1364 		 * ready re-assign reservation interface that was deferred. Do
1365 		 * not propagate error to the caller though. The in-place
1366 		 * reservation for originally requested interface has already
1367 		 * succeeded at this point.
1368 		 */
1369 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1370 					 reserved_chanctx_list) {
1371 			if (WARN_ON(ieee80211_vif_has_in_place_reservation(
1372 					sdata)))
1373 				continue;
1374 
1375 			if (WARN_ON(sdata->reserved_chanctx != ctx))
1376 				continue;
1377 
1378 			if (!sdata->reserved_ready)
1379 				continue;
1380 
1381 			if (ieee80211_vif_get_chanctx(sdata))
1382 				err = ieee80211_vif_use_reserved_reassign(
1383 						sdata);
1384 			else
1385 				err = ieee80211_vif_use_reserved_assign(sdata);
1386 
1387 			if (err) {
1388 				sdata_info(sdata,
1389 					   "failed to finalize (re-)assign reservation (err=%d)\n",
1390 					   err);
1391 				ieee80211_vif_unreserve_chanctx(sdata);
1392 				cfg80211_stop_iface(local->hw.wiphy,
1393 						    &sdata->wdev,
1394 						    GFP_KERNEL);
1395 			}
1396 		}
1397 	}
1398 
1399 	/*
1400 	 * Finally free old contexts
1401 	 */
1402 
1403 	list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1404 		if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1405 			continue;
1406 
1407 		ctx->replace_ctx->replace_ctx = NULL;
1408 		ctx->replace_ctx->replace_state =
1409 				IEEE80211_CHANCTX_REPLACE_NONE;
1410 
1411 		list_del_rcu(&ctx->list);
1412 		kfree_rcu(ctx, rcu_head);
1413 	}
1414 
1415 	return 0;
1416 
1417 err:
1418 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1419 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1420 			continue;
1421 
1422 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1423 					 reserved_chanctx_list) {
1424 			ieee80211_vif_unreserve_chanctx(sdata);
1425 			ieee80211_vif_chanctx_reservation_complete(sdata);
1426 		}
1427 	}
1428 
1429 	return err;
1430 }
1431 
1432 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1433 {
1434 	struct ieee80211_local *local = sdata->local;
1435 	struct ieee80211_chanctx_conf *conf;
1436 	struct ieee80211_chanctx *ctx;
1437 	bool use_reserved_switch = false;
1438 
1439 	lockdep_assert_held(&local->chanctx_mtx);
1440 
1441 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1442 					 lockdep_is_held(&local->chanctx_mtx));
1443 	if (!conf)
1444 		return;
1445 
1446 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1447 
1448 	if (sdata->reserved_chanctx) {
1449 		if (sdata->reserved_chanctx->replace_state ==
1450 		    IEEE80211_CHANCTX_REPLACES_OTHER &&
1451 		    ieee80211_chanctx_num_reserved(local,
1452 						   sdata->reserved_chanctx) > 1)
1453 			use_reserved_switch = true;
1454 
1455 		ieee80211_vif_unreserve_chanctx(sdata);
1456 	}
1457 
1458 	ieee80211_assign_vif_chanctx(sdata, NULL);
1459 	if (ieee80211_chanctx_refcount(local, ctx) == 0)
1460 		ieee80211_free_chanctx(local, ctx);
1461 
1462 	/* Unreserving may ready an in-place reservation. */
1463 	if (use_reserved_switch)
1464 		ieee80211_vif_use_reserved_switch(local);
1465 }
1466 
1467 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
1468 			      const struct cfg80211_chan_def *chandef,
1469 			      enum ieee80211_chanctx_mode mode)
1470 {
1471 	struct ieee80211_local *local = sdata->local;
1472 	struct ieee80211_chanctx *ctx;
1473 	u8 radar_detect_width = 0;
1474 	int ret;
1475 
1476 	lockdep_assert_held(&local->mtx);
1477 
1478 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1479 
1480 	mutex_lock(&local->chanctx_mtx);
1481 
1482 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1483 					    chandef,
1484 					    sdata->wdev.iftype);
1485 	if (ret < 0)
1486 		goto out;
1487 	if (ret > 0)
1488 		radar_detect_width = BIT(chandef->width);
1489 
1490 	sdata->radar_required = ret;
1491 
1492 	ret = ieee80211_check_combinations(sdata, chandef, mode,
1493 					   radar_detect_width);
1494 	if (ret < 0)
1495 		goto out;
1496 
1497 	__ieee80211_vif_release_channel(sdata);
1498 
1499 	ctx = ieee80211_find_chanctx(local, chandef, mode);
1500 	if (!ctx)
1501 		ctx = ieee80211_new_chanctx(local, chandef, mode);
1502 	if (IS_ERR(ctx)) {
1503 		ret = PTR_ERR(ctx);
1504 		goto out;
1505 	}
1506 
1507 	sdata->vif.bss_conf.chandef = *chandef;
1508 
1509 	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
1510 	if (ret) {
1511 		/* if assign fails refcount stays the same */
1512 		if (ieee80211_chanctx_refcount(local, ctx) == 0)
1513 			ieee80211_free_chanctx(local, ctx);
1514 		goto out;
1515 	}
1516 
1517 	ieee80211_recalc_smps_chanctx(local, ctx);
1518 	ieee80211_recalc_radar_chanctx(local, ctx);
1519  out:
1520 	mutex_unlock(&local->chanctx_mtx);
1521 	return ret;
1522 }
1523 
1524 int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata)
1525 {
1526 	struct ieee80211_local *local = sdata->local;
1527 	struct ieee80211_chanctx *new_ctx;
1528 	struct ieee80211_chanctx *old_ctx;
1529 	int err;
1530 
1531 	lockdep_assert_held(&local->mtx);
1532 	lockdep_assert_held(&local->chanctx_mtx);
1533 
1534 	new_ctx = sdata->reserved_chanctx;
1535 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1536 
1537 	if (WARN_ON(!new_ctx))
1538 		return -EINVAL;
1539 
1540 	if (WARN_ON(new_ctx->replace_state ==
1541 		    IEEE80211_CHANCTX_WILL_BE_REPLACED))
1542 		return -EINVAL;
1543 
1544 	if (WARN_ON(sdata->reserved_ready))
1545 		return -EINVAL;
1546 
1547 	sdata->reserved_ready = true;
1548 
1549 	if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1550 		if (old_ctx)
1551 			err = ieee80211_vif_use_reserved_reassign(sdata);
1552 		else
1553 			err = ieee80211_vif_use_reserved_assign(sdata);
1554 
1555 		if (err)
1556 			return err;
1557 	}
1558 
1559 	/*
1560 	 * In-place reservation may need to be finalized now either if:
1561 	 *  a) sdata is taking part in the swapping itself and is the last one
1562 	 *  b) sdata has switched with a re-assign reservation to an existing
1563 	 *     context readying in-place switching of old_ctx
1564 	 *
1565 	 * In case of (b) do not propagate the error up because the requested
1566 	 * sdata already switched successfully. Just spill an extra warning.
1567 	 * The ieee80211_vif_use_reserved_switch() already stops all necessary
1568 	 * interfaces upon failure.
1569 	 */
1570 	if ((old_ctx &&
1571 	     old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1572 	    new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1573 		err = ieee80211_vif_use_reserved_switch(local);
1574 		if (err && err != -EAGAIN) {
1575 			if (new_ctx->replace_state ==
1576 			    IEEE80211_CHANCTX_REPLACES_OTHER)
1577 				return err;
1578 
1579 			wiphy_info(local->hw.wiphy,
1580 				   "depending in-place reservation failed (err=%d)\n",
1581 				   err);
1582 		}
1583 	}
1584 
1585 	return 0;
1586 }
1587 
1588 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
1589 				   const struct cfg80211_chan_def *chandef,
1590 				   u32 *changed)
1591 {
1592 	struct ieee80211_local *local = sdata->local;
1593 	struct ieee80211_chanctx_conf *conf;
1594 	struct ieee80211_chanctx *ctx;
1595 	const struct cfg80211_chan_def *compat;
1596 	int ret;
1597 
1598 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1599 				     IEEE80211_CHAN_DISABLED))
1600 		return -EINVAL;
1601 
1602 	mutex_lock(&local->chanctx_mtx);
1603 	if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
1604 		ret = 0;
1605 		goto out;
1606 	}
1607 
1608 	if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1609 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1610 		ret = -EINVAL;
1611 		goto out;
1612 	}
1613 
1614 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1615 					 lockdep_is_held(&local->chanctx_mtx));
1616 	if (!conf) {
1617 		ret = -EINVAL;
1618 		goto out;
1619 	}
1620 
1621 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1622 
1623 	compat = cfg80211_chandef_compatible(&conf->def, chandef);
1624 	if (!compat) {
1625 		ret = -EINVAL;
1626 		goto out;
1627 	}
1628 
1629 	switch (ctx->replace_state) {
1630 	case IEEE80211_CHANCTX_REPLACE_NONE:
1631 		if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1632 			ret = -EBUSY;
1633 			goto out;
1634 		}
1635 		break;
1636 	case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1637 		/* TODO: Perhaps the bandwith change could be treated as a
1638 		 * reservation itself? */
1639 		ret = -EBUSY;
1640 		goto out;
1641 	case IEEE80211_CHANCTX_REPLACES_OTHER:
1642 		/* channel context that is going to replace another channel
1643 		 * context doesn't really exist and shouldn't be assigned
1644 		 * anywhere yet */
1645 		WARN_ON(1);
1646 		break;
1647 	}
1648 
1649 	sdata->vif.bss_conf.chandef = *chandef;
1650 
1651 	ieee80211_recalc_chanctx_chantype(local, ctx);
1652 
1653 	*changed |= BSS_CHANGED_BANDWIDTH;
1654 	ret = 0;
1655  out:
1656 	mutex_unlock(&local->chanctx_mtx);
1657 	return ret;
1658 }
1659 
1660 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1661 {
1662 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1663 
1664 	lockdep_assert_held(&sdata->local->mtx);
1665 
1666 	mutex_lock(&sdata->local->chanctx_mtx);
1667 	__ieee80211_vif_release_channel(sdata);
1668 	mutex_unlock(&sdata->local->chanctx_mtx);
1669 }
1670 
1671 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
1672 {
1673 	struct ieee80211_local *local = sdata->local;
1674 	struct ieee80211_sub_if_data *ap;
1675 	struct ieee80211_chanctx_conf *conf;
1676 
1677 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
1678 		return;
1679 
1680 	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
1681 
1682 	mutex_lock(&local->chanctx_mtx);
1683 
1684 	conf = rcu_dereference_protected(ap->vif.chanctx_conf,
1685 					 lockdep_is_held(&local->chanctx_mtx));
1686 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
1687 	mutex_unlock(&local->chanctx_mtx);
1688 }
1689 
1690 void ieee80211_iter_chan_contexts_atomic(
1691 	struct ieee80211_hw *hw,
1692 	void (*iter)(struct ieee80211_hw *hw,
1693 		     struct ieee80211_chanctx_conf *chanctx_conf,
1694 		     void *data),
1695 	void *iter_data)
1696 {
1697 	struct ieee80211_local *local = hw_to_local(hw);
1698 	struct ieee80211_chanctx *ctx;
1699 
1700 	rcu_read_lock();
1701 	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
1702 		if (ctx->driver_present)
1703 			iter(hw, &ctx->conf, iter_data);
1704 	rcu_read_unlock();
1705 }
1706 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);
1707