xref: /openbmc/linux/net/mac80211/chan.c (revision 78700c0a)
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 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 || !test_sta_flag(sta, WLAN_STA_ASSOC))
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_STATION:
268 			/*
269 			 * The ap's sta->bandwidth is not set yet at this
270 			 * point, so take the width from the chandef, but
271 			 * account also for TDLS peers
272 			 */
273 			width = max(vif->bss_conf.chandef.width,
274 				    ieee80211_get_max_required_bw(sdata));
275 			break;
276 		case NL80211_IFTYPE_P2P_DEVICE:
277 			continue;
278 		case NL80211_IFTYPE_ADHOC:
279 		case NL80211_IFTYPE_WDS:
280 		case NL80211_IFTYPE_MESH_POINT:
281 		case NL80211_IFTYPE_OCB:
282 			width = vif->bss_conf.chandef.width;
283 			break;
284 		case NL80211_IFTYPE_UNSPECIFIED:
285 		case NUM_NL80211_IFTYPES:
286 		case NL80211_IFTYPE_MONITOR:
287 		case NL80211_IFTYPE_P2P_CLIENT:
288 		case NL80211_IFTYPE_P2P_GO:
289 			WARN_ON_ONCE(1);
290 		}
291 		max_bw = max(max_bw, width);
292 	}
293 
294 	/* use the configured bandwidth in case of monitor interface */
295 	sdata = rcu_dereference(local->monitor_sdata);
296 	if (sdata && rcu_access_pointer(sdata->vif.chanctx_conf) == conf)
297 		max_bw = max(max_bw, conf->def.width);
298 
299 	rcu_read_unlock();
300 
301 	return max_bw;
302 }
303 
304 /*
305  * recalc the min required chan width of the channel context, which is
306  * the max of min required widths of all the interfaces bound to this
307  * channel context.
308  */
309 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
310 				      struct ieee80211_chanctx *ctx)
311 {
312 	enum nl80211_chan_width max_bw;
313 	struct cfg80211_chan_def min_def;
314 
315 	lockdep_assert_held(&local->chanctx_mtx);
316 
317 	/* don't optimize 5MHz, 10MHz, and radar_enabled confs */
318 	if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
319 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
320 	    ctx->conf.radar_enabled) {
321 		ctx->conf.min_def = ctx->conf.def;
322 		return;
323 	}
324 
325 	max_bw = ieee80211_get_chanctx_max_required_bw(local, &ctx->conf);
326 
327 	/* downgrade chandef up to max_bw */
328 	min_def = ctx->conf.def;
329 	while (min_def.width > max_bw)
330 		ieee80211_chandef_downgrade(&min_def);
331 
332 	if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
333 		return;
334 
335 	ctx->conf.min_def = min_def;
336 	if (!ctx->driver_present)
337 		return;
338 
339 	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_MIN_WIDTH);
340 }
341 
342 static void ieee80211_change_chanctx(struct ieee80211_local *local,
343 				     struct ieee80211_chanctx *ctx,
344 				     const struct cfg80211_chan_def *chandef)
345 {
346 	if (cfg80211_chandef_identical(&ctx->conf.def, chandef)) {
347 		ieee80211_recalc_chanctx_min_def(local, ctx);
348 		return;
349 	}
350 
351 	WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
352 
353 	ctx->conf.def = *chandef;
354 	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);
355 	ieee80211_recalc_chanctx_min_def(local, ctx);
356 
357 	if (!local->use_chanctx) {
358 		local->_oper_chandef = *chandef;
359 		ieee80211_hw_config(local, 0);
360 	}
361 }
362 
363 static struct ieee80211_chanctx *
364 ieee80211_find_chanctx(struct ieee80211_local *local,
365 		       const struct cfg80211_chan_def *chandef,
366 		       enum ieee80211_chanctx_mode mode)
367 {
368 	struct ieee80211_chanctx *ctx;
369 
370 	lockdep_assert_held(&local->chanctx_mtx);
371 
372 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
373 		return NULL;
374 
375 	list_for_each_entry(ctx, &local->chanctx_list, list) {
376 		const struct cfg80211_chan_def *compat;
377 
378 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
379 			continue;
380 
381 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
382 			continue;
383 
384 		compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
385 		if (!compat)
386 			continue;
387 
388 		compat = ieee80211_chanctx_reserved_chandef(local, ctx,
389 							    compat);
390 		if (!compat)
391 			continue;
392 
393 		ieee80211_change_chanctx(local, ctx, compat);
394 
395 		return ctx;
396 	}
397 
398 	return NULL;
399 }
400 
401 bool ieee80211_is_radar_required(struct ieee80211_local *local)
402 {
403 	struct ieee80211_sub_if_data *sdata;
404 
405 	lockdep_assert_held(&local->mtx);
406 
407 	rcu_read_lock();
408 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
409 		if (sdata->radar_required) {
410 			rcu_read_unlock();
411 			return true;
412 		}
413 	}
414 	rcu_read_unlock();
415 
416 	return false;
417 }
418 
419 static bool
420 ieee80211_chanctx_radar_required(struct ieee80211_local *local,
421 				 struct ieee80211_chanctx *ctx)
422 {
423 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
424 	struct ieee80211_sub_if_data *sdata;
425 	bool required = false;
426 
427 	lockdep_assert_held(&local->chanctx_mtx);
428 	lockdep_assert_held(&local->mtx);
429 
430 	rcu_read_lock();
431 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
432 		if (!ieee80211_sdata_running(sdata))
433 			continue;
434 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
435 			continue;
436 		if (!sdata->radar_required)
437 			continue;
438 
439 		required = true;
440 		break;
441 	}
442 	rcu_read_unlock();
443 
444 	return required;
445 }
446 
447 static struct ieee80211_chanctx *
448 ieee80211_alloc_chanctx(struct ieee80211_local *local,
449 			const struct cfg80211_chan_def *chandef,
450 			enum ieee80211_chanctx_mode mode)
451 {
452 	struct ieee80211_chanctx *ctx;
453 
454 	lockdep_assert_held(&local->chanctx_mtx);
455 
456 	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
457 	if (!ctx)
458 		return NULL;
459 
460 	INIT_LIST_HEAD(&ctx->assigned_vifs);
461 	INIT_LIST_HEAD(&ctx->reserved_vifs);
462 	ctx->conf.def = *chandef;
463 	ctx->conf.rx_chains_static = 1;
464 	ctx->conf.rx_chains_dynamic = 1;
465 	ctx->mode = mode;
466 	ctx->conf.radar_enabled = false;
467 	ieee80211_recalc_chanctx_min_def(local, ctx);
468 
469 	return ctx;
470 }
471 
472 static int ieee80211_add_chanctx(struct ieee80211_local *local,
473 				 struct ieee80211_chanctx *ctx)
474 {
475 	u32 changed;
476 	int err;
477 
478 	lockdep_assert_held(&local->mtx);
479 	lockdep_assert_held(&local->chanctx_mtx);
480 
481 	if (!local->use_chanctx)
482 		local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
483 
484 	/* turn idle off *before* setting channel -- some drivers need that */
485 	changed = ieee80211_idle_off(local);
486 	if (changed)
487 		ieee80211_hw_config(local, changed);
488 
489 	if (!local->use_chanctx) {
490 		local->_oper_chandef = ctx->conf.def;
491 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
492 	} else {
493 		err = drv_add_chanctx(local, ctx);
494 		if (err) {
495 			ieee80211_recalc_idle(local);
496 			return err;
497 		}
498 	}
499 
500 	return 0;
501 }
502 
503 static struct ieee80211_chanctx *
504 ieee80211_new_chanctx(struct ieee80211_local *local,
505 		      const struct cfg80211_chan_def *chandef,
506 		      enum ieee80211_chanctx_mode mode)
507 {
508 	struct ieee80211_chanctx *ctx;
509 	int err;
510 
511 	lockdep_assert_held(&local->mtx);
512 	lockdep_assert_held(&local->chanctx_mtx);
513 
514 	ctx = ieee80211_alloc_chanctx(local, chandef, mode);
515 	if (!ctx)
516 		return ERR_PTR(-ENOMEM);
517 
518 	err = ieee80211_add_chanctx(local, ctx);
519 	if (err) {
520 		kfree(ctx);
521 		return ERR_PTR(err);
522 	}
523 
524 	list_add_rcu(&ctx->list, &local->chanctx_list);
525 	return ctx;
526 }
527 
528 static void ieee80211_del_chanctx(struct ieee80211_local *local,
529 				  struct ieee80211_chanctx *ctx)
530 {
531 	lockdep_assert_held(&local->chanctx_mtx);
532 
533 	if (!local->use_chanctx) {
534 		struct cfg80211_chan_def *chandef = &local->_oper_chandef;
535 		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
536 		chandef->center_freq1 = chandef->chan->center_freq;
537 		chandef->center_freq2 = 0;
538 
539 		/* NOTE: Disabling radar is only valid here for
540 		 * single channel context. To be sure, check it ...
541 		 */
542 		WARN_ON(local->hw.conf.radar_enabled &&
543 			!list_empty(&local->chanctx_list));
544 
545 		local->hw.conf.radar_enabled = false;
546 
547 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
548 	} else {
549 		drv_remove_chanctx(local, ctx);
550 	}
551 
552 	ieee80211_recalc_idle(local);
553 }
554 
555 static void ieee80211_free_chanctx(struct ieee80211_local *local,
556 				   struct ieee80211_chanctx *ctx)
557 {
558 	lockdep_assert_held(&local->chanctx_mtx);
559 
560 	WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
561 
562 	list_del_rcu(&ctx->list);
563 	ieee80211_del_chanctx(local, ctx);
564 	kfree_rcu(ctx, rcu_head);
565 }
566 
567 void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
568 				       struct ieee80211_chanctx *ctx)
569 {
570 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
571 	struct ieee80211_sub_if_data *sdata;
572 	const struct cfg80211_chan_def *compat = NULL;
573 	struct sta_info *sta;
574 
575 	lockdep_assert_held(&local->chanctx_mtx);
576 
577 	rcu_read_lock();
578 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
579 
580 		if (!ieee80211_sdata_running(sdata))
581 			continue;
582 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
583 			continue;
584 		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
585 			continue;
586 
587 		if (!compat)
588 			compat = &sdata->vif.bss_conf.chandef;
589 
590 		compat = cfg80211_chandef_compatible(
591 				&sdata->vif.bss_conf.chandef, compat);
592 		if (WARN_ON_ONCE(!compat))
593 			break;
594 	}
595 
596 	/* TDLS peers can sometimes affect the chandef width */
597 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
598 		if (!sta->uploaded ||
599 		    !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
600 		    !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
601 		    !sta->tdls_chandef.chan)
602 			continue;
603 
604 		compat = cfg80211_chandef_compatible(&sta->tdls_chandef,
605 						     compat);
606 		if (WARN_ON_ONCE(!compat))
607 			break;
608 	}
609 	rcu_read_unlock();
610 
611 	if (!compat)
612 		return;
613 
614 	ieee80211_change_chanctx(local, ctx, compat);
615 }
616 
617 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
618 					   struct ieee80211_chanctx *chanctx)
619 {
620 	bool radar_enabled;
621 
622 	lockdep_assert_held(&local->chanctx_mtx);
623 	/* for ieee80211_is_radar_required */
624 	lockdep_assert_held(&local->mtx);
625 
626 	radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
627 
628 	if (radar_enabled == chanctx->conf.radar_enabled)
629 		return;
630 
631 	chanctx->conf.radar_enabled = radar_enabled;
632 
633 	if (!local->use_chanctx) {
634 		local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
635 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
636 	}
637 
638 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
639 }
640 
641 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
642 					struct ieee80211_chanctx *new_ctx)
643 {
644 	struct ieee80211_local *local = sdata->local;
645 	struct ieee80211_chanctx_conf *conf;
646 	struct ieee80211_chanctx *curr_ctx = NULL;
647 	int ret = 0;
648 
649 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
650 					 lockdep_is_held(&local->chanctx_mtx));
651 
652 	if (conf) {
653 		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
654 
655 		drv_unassign_vif_chanctx(local, sdata, curr_ctx);
656 		conf = NULL;
657 		list_del(&sdata->assigned_chanctx_list);
658 	}
659 
660 	if (new_ctx) {
661 		ret = drv_assign_vif_chanctx(local, sdata, new_ctx);
662 		if (ret)
663 			goto out;
664 
665 		conf = &new_ctx->conf;
666 		list_add(&sdata->assigned_chanctx_list,
667 			 &new_ctx->assigned_vifs);
668 	}
669 
670 out:
671 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
672 
673 	sdata->vif.bss_conf.idle = !conf;
674 
675 	if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
676 		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
677 		ieee80211_recalc_smps_chanctx(local, curr_ctx);
678 		ieee80211_recalc_radar_chanctx(local, curr_ctx);
679 		ieee80211_recalc_chanctx_min_def(local, curr_ctx);
680 	}
681 
682 	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
683 		ieee80211_recalc_txpower(sdata, false);
684 		ieee80211_recalc_chanctx_min_def(local, new_ctx);
685 	}
686 
687 	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
688 	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
689 		ieee80211_bss_info_change_notify(sdata,
690 						 BSS_CHANGED_IDLE);
691 
692 	ieee80211_check_fast_xmit_iface(sdata);
693 
694 	return ret;
695 }
696 
697 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
698 				   struct ieee80211_chanctx *chanctx)
699 {
700 	struct ieee80211_sub_if_data *sdata;
701 	u8 rx_chains_static, rx_chains_dynamic;
702 
703 	lockdep_assert_held(&local->chanctx_mtx);
704 
705 	rx_chains_static = 1;
706 	rx_chains_dynamic = 1;
707 
708 	rcu_read_lock();
709 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
710 		u8 needed_static, needed_dynamic;
711 
712 		if (!ieee80211_sdata_running(sdata))
713 			continue;
714 
715 		if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
716 						&chanctx->conf)
717 			continue;
718 
719 		switch (sdata->vif.type) {
720 		case NL80211_IFTYPE_P2P_DEVICE:
721 			continue;
722 		case NL80211_IFTYPE_STATION:
723 			if (!sdata->u.mgd.associated)
724 				continue;
725 			break;
726 		case NL80211_IFTYPE_AP_VLAN:
727 			continue;
728 		case NL80211_IFTYPE_AP:
729 		case NL80211_IFTYPE_ADHOC:
730 		case NL80211_IFTYPE_WDS:
731 		case NL80211_IFTYPE_MESH_POINT:
732 		case NL80211_IFTYPE_OCB:
733 			break;
734 		default:
735 			WARN_ON_ONCE(1);
736 		}
737 
738 		switch (sdata->smps_mode) {
739 		default:
740 			WARN_ONCE(1, "Invalid SMPS mode %d\n",
741 				  sdata->smps_mode);
742 			/* fall through */
743 		case IEEE80211_SMPS_OFF:
744 			needed_static = sdata->needed_rx_chains;
745 			needed_dynamic = sdata->needed_rx_chains;
746 			break;
747 		case IEEE80211_SMPS_DYNAMIC:
748 			needed_static = 1;
749 			needed_dynamic = sdata->needed_rx_chains;
750 			break;
751 		case IEEE80211_SMPS_STATIC:
752 			needed_static = 1;
753 			needed_dynamic = 1;
754 			break;
755 		}
756 
757 		rx_chains_static = max(rx_chains_static, needed_static);
758 		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
759 	}
760 
761 	/* Disable SMPS for the monitor interface */
762 	sdata = rcu_dereference(local->monitor_sdata);
763 	if (sdata &&
764 	    rcu_access_pointer(sdata->vif.chanctx_conf) == &chanctx->conf)
765 		rx_chains_dynamic = rx_chains_static = local->rx_chains;
766 
767 	rcu_read_unlock();
768 
769 	if (!local->use_chanctx) {
770 		if (rx_chains_static > 1)
771 			local->smps_mode = IEEE80211_SMPS_OFF;
772 		else if (rx_chains_dynamic > 1)
773 			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
774 		else
775 			local->smps_mode = IEEE80211_SMPS_STATIC;
776 		ieee80211_hw_config(local, 0);
777 	}
778 
779 	if (rx_chains_static == chanctx->conf.rx_chains_static &&
780 	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
781 		return;
782 
783 	chanctx->conf.rx_chains_static = rx_chains_static;
784 	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
785 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
786 }
787 
788 static void
789 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
790 				      bool clear)
791 {
792 	struct ieee80211_local *local __maybe_unused = sdata->local;
793 	struct ieee80211_sub_if_data *vlan;
794 	struct ieee80211_chanctx_conf *conf;
795 
796 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
797 		return;
798 
799 	lockdep_assert_held(&local->mtx);
800 
801 	/* Check that conf exists, even when clearing this function
802 	 * must be called with the AP's channel context still there
803 	 * as it would otherwise cause VLANs to have an invalid
804 	 * channel context pointer for a while, possibly pointing
805 	 * to a channel context that has already been freed.
806 	 */
807 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
808 					 lockdep_is_held(&local->chanctx_mtx));
809 	WARN_ON(!conf);
810 
811 	if (clear)
812 		conf = NULL;
813 
814 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
815 		rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
816 }
817 
818 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
819 					 bool clear)
820 {
821 	struct ieee80211_local *local = sdata->local;
822 
823 	mutex_lock(&local->chanctx_mtx);
824 
825 	__ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
826 
827 	mutex_unlock(&local->chanctx_mtx);
828 }
829 
830 int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
831 {
832 	struct ieee80211_chanctx *ctx = sdata->reserved_chanctx;
833 
834 	lockdep_assert_held(&sdata->local->chanctx_mtx);
835 
836 	if (WARN_ON(!ctx))
837 		return -EINVAL;
838 
839 	list_del(&sdata->reserved_chanctx_list);
840 	sdata->reserved_chanctx = NULL;
841 
842 	if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
843 		if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
844 			if (WARN_ON(!ctx->replace_ctx))
845 				return -EINVAL;
846 
847 			WARN_ON(ctx->replace_ctx->replace_state !=
848 			        IEEE80211_CHANCTX_WILL_BE_REPLACED);
849 			WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
850 
851 			ctx->replace_ctx->replace_ctx = NULL;
852 			ctx->replace_ctx->replace_state =
853 					IEEE80211_CHANCTX_REPLACE_NONE;
854 
855 			list_del_rcu(&ctx->list);
856 			kfree_rcu(ctx, rcu_head);
857 		} else {
858 			ieee80211_free_chanctx(sdata->local, ctx);
859 		}
860 	}
861 
862 	return 0;
863 }
864 
865 int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
866 				  const struct cfg80211_chan_def *chandef,
867 				  enum ieee80211_chanctx_mode mode,
868 				  bool radar_required)
869 {
870 	struct ieee80211_local *local = sdata->local;
871 	struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
872 
873 	lockdep_assert_held(&local->chanctx_mtx);
874 
875 	curr_ctx = ieee80211_vif_get_chanctx(sdata);
876 	if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
877 		return -ENOTSUPP;
878 
879 	new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
880 	if (!new_ctx) {
881 		if (ieee80211_can_create_new_chanctx(local)) {
882 			new_ctx = ieee80211_new_chanctx(local, chandef, mode);
883 			if (IS_ERR(new_ctx))
884 				return PTR_ERR(new_ctx);
885 		} else {
886 			if (!curr_ctx ||
887 			    (curr_ctx->replace_state ==
888 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
889 			    !list_empty(&curr_ctx->reserved_vifs)) {
890 				/*
891 				 * Another vif already requested this context
892 				 * for a reservation. Find another one hoping
893 				 * all vifs assigned to it will also switch
894 				 * soon enough.
895 				 *
896 				 * TODO: This needs a little more work as some
897 				 * cases (more than 2 chanctx capable devices)
898 				 * may fail which could otherwise succeed
899 				 * provided some channel context juggling was
900 				 * performed.
901 				 *
902 				 * Consider ctx1..3, vif1..6, each ctx has 2
903 				 * vifs. vif1 and vif2 from ctx1 request new
904 				 * different chandefs starting 2 in-place
905 				 * reserations with ctx4 and ctx5 replacing
906 				 * ctx1 and ctx2 respectively. Next vif5 and
907 				 * vif6 from ctx3 reserve ctx4. If vif3 and
908 				 * vif4 remain on ctx2 as they are then this
909 				 * fails unless `replace_ctx` from ctx5 is
910 				 * replaced with ctx3.
911 				 */
912 				list_for_each_entry(ctx, &local->chanctx_list,
913 						    list) {
914 					if (ctx->replace_state !=
915 					    IEEE80211_CHANCTX_REPLACE_NONE)
916 						continue;
917 
918 					if (!list_empty(&ctx->reserved_vifs))
919 						continue;
920 
921 					curr_ctx = ctx;
922 					break;
923 				}
924 			}
925 
926 			/*
927 			 * If that's true then all available contexts already
928 			 * have reservations and cannot be used.
929 			 */
930 			if (!curr_ctx ||
931 			    (curr_ctx->replace_state ==
932 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
933 			    !list_empty(&curr_ctx->reserved_vifs))
934 				return -EBUSY;
935 
936 			new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
937 			if (!new_ctx)
938 				return -ENOMEM;
939 
940 			new_ctx->replace_ctx = curr_ctx;
941 			new_ctx->replace_state =
942 					IEEE80211_CHANCTX_REPLACES_OTHER;
943 
944 			curr_ctx->replace_ctx = new_ctx;
945 			curr_ctx->replace_state =
946 					IEEE80211_CHANCTX_WILL_BE_REPLACED;
947 
948 			list_add_rcu(&new_ctx->list, &local->chanctx_list);
949 		}
950 	}
951 
952 	list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);
953 	sdata->reserved_chanctx = new_ctx;
954 	sdata->reserved_chandef = *chandef;
955 	sdata->reserved_radar_required = radar_required;
956 	sdata->reserved_ready = false;
957 
958 	return 0;
959 }
960 
961 static void
962 ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
963 {
964 	switch (sdata->vif.type) {
965 	case NL80211_IFTYPE_ADHOC:
966 	case NL80211_IFTYPE_AP:
967 	case NL80211_IFTYPE_MESH_POINT:
968 	case NL80211_IFTYPE_OCB:
969 		ieee80211_queue_work(&sdata->local->hw,
970 				     &sdata->csa_finalize_work);
971 		break;
972 	case NL80211_IFTYPE_STATION:
973 		ieee80211_queue_work(&sdata->local->hw,
974 				     &sdata->u.mgd.chswitch_work);
975 		break;
976 	case NL80211_IFTYPE_UNSPECIFIED:
977 	case NL80211_IFTYPE_AP_VLAN:
978 	case NL80211_IFTYPE_WDS:
979 	case NL80211_IFTYPE_MONITOR:
980 	case NL80211_IFTYPE_P2P_CLIENT:
981 	case NL80211_IFTYPE_P2P_GO:
982 	case NL80211_IFTYPE_P2P_DEVICE:
983 	case NUM_NL80211_IFTYPES:
984 		WARN_ON(1);
985 		break;
986 	}
987 }
988 
989 static void
990 ieee80211_vif_update_chandef(struct ieee80211_sub_if_data *sdata,
991 			     const struct cfg80211_chan_def *chandef)
992 {
993 	struct ieee80211_sub_if_data *vlan;
994 
995 	sdata->vif.bss_conf.chandef = *chandef;
996 
997 	if (sdata->vif.type != NL80211_IFTYPE_AP)
998 		return;
999 
1000 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
1001 		vlan->vif.bss_conf.chandef = *chandef;
1002 }
1003 
1004 static int
1005 ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
1006 {
1007 	struct ieee80211_local *local = sdata->local;
1008 	struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1009 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1010 	const struct cfg80211_chan_def *chandef;
1011 	u32 changed = 0;
1012 	int err;
1013 
1014 	lockdep_assert_held(&local->mtx);
1015 	lockdep_assert_held(&local->chanctx_mtx);
1016 
1017 	new_ctx = sdata->reserved_chanctx;
1018 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1019 
1020 	if (WARN_ON(!sdata->reserved_ready))
1021 		return -EBUSY;
1022 
1023 	if (WARN_ON(!new_ctx))
1024 		return -EINVAL;
1025 
1026 	if (WARN_ON(!old_ctx))
1027 		return -EINVAL;
1028 
1029 	if (WARN_ON(new_ctx->replace_state ==
1030 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1031 		return -EINVAL;
1032 
1033 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1034 				&sdata->reserved_chandef);
1035 	if (WARN_ON(!chandef))
1036 		return -EINVAL;
1037 
1038 	ieee80211_change_chanctx(local, new_ctx, chandef);
1039 
1040 	vif_chsw[0].vif = &sdata->vif;
1041 	vif_chsw[0].old_ctx = &old_ctx->conf;
1042 	vif_chsw[0].new_ctx = &new_ctx->conf;
1043 
1044 	list_del(&sdata->reserved_chanctx_list);
1045 	sdata->reserved_chanctx = NULL;
1046 
1047 	err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1048 				     CHANCTX_SWMODE_REASSIGN_VIF);
1049 	if (err) {
1050 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1051 			ieee80211_free_chanctx(local, new_ctx);
1052 
1053 		goto out;
1054 	}
1055 
1056 	list_move(&sdata->assigned_chanctx_list, &new_ctx->assigned_vifs);
1057 	rcu_assign_pointer(sdata->vif.chanctx_conf, &new_ctx->conf);
1058 
1059 	if (sdata->vif.type == NL80211_IFTYPE_AP)
1060 		__ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
1061 
1062 	ieee80211_check_fast_xmit_iface(sdata);
1063 
1064 	if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1065 		ieee80211_free_chanctx(local, old_ctx);
1066 
1067 	if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
1068 		changed = BSS_CHANGED_BANDWIDTH;
1069 
1070 	ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1071 
1072 	ieee80211_recalc_smps_chanctx(local, new_ctx);
1073 	ieee80211_recalc_radar_chanctx(local, new_ctx);
1074 	ieee80211_recalc_chanctx_min_def(local, new_ctx);
1075 
1076 	if (changed)
1077 		ieee80211_bss_info_change_notify(sdata, changed);
1078 
1079 out:
1080 	ieee80211_vif_chanctx_reservation_complete(sdata);
1081 	return err;
1082 }
1083 
1084 static int
1085 ieee80211_vif_use_reserved_assign(struct ieee80211_sub_if_data *sdata)
1086 {
1087 	struct ieee80211_local *local = sdata->local;
1088 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1089 	const struct cfg80211_chan_def *chandef;
1090 	int err;
1091 
1092 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1093 	new_ctx = sdata->reserved_chanctx;
1094 
1095 	if (WARN_ON(!sdata->reserved_ready))
1096 		return -EINVAL;
1097 
1098 	if (WARN_ON(old_ctx))
1099 		return -EINVAL;
1100 
1101 	if (WARN_ON(!new_ctx))
1102 		return -EINVAL;
1103 
1104 	if (WARN_ON(new_ctx->replace_state ==
1105 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1106 		return -EINVAL;
1107 
1108 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1109 				&sdata->reserved_chandef);
1110 	if (WARN_ON(!chandef))
1111 		return -EINVAL;
1112 
1113 	ieee80211_change_chanctx(local, new_ctx, chandef);
1114 
1115 	list_del(&sdata->reserved_chanctx_list);
1116 	sdata->reserved_chanctx = NULL;
1117 
1118 	err = ieee80211_assign_vif_chanctx(sdata, new_ctx);
1119 	if (err) {
1120 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1121 			ieee80211_free_chanctx(local, new_ctx);
1122 
1123 		goto out;
1124 	}
1125 
1126 out:
1127 	ieee80211_vif_chanctx_reservation_complete(sdata);
1128 	return err;
1129 }
1130 
1131 static bool
1132 ieee80211_vif_has_in_place_reservation(struct ieee80211_sub_if_data *sdata)
1133 {
1134 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1135 
1136 	lockdep_assert_held(&sdata->local->chanctx_mtx);
1137 
1138 	new_ctx = sdata->reserved_chanctx;
1139 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1140 
1141 	if (!old_ctx)
1142 		return false;
1143 
1144 	if (WARN_ON(!new_ctx))
1145 		return false;
1146 
1147 	if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1148 		return false;
1149 
1150 	if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1151 		return false;
1152 
1153 	return true;
1154 }
1155 
1156 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1157 					struct ieee80211_chanctx *new_ctx)
1158 {
1159 	const struct cfg80211_chan_def *chandef;
1160 
1161 	lockdep_assert_held(&local->mtx);
1162 	lockdep_assert_held(&local->chanctx_mtx);
1163 
1164 	chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1165 	if (WARN_ON(!chandef))
1166 		return -EINVAL;
1167 
1168 	local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1169 	local->_oper_chandef = *chandef;
1170 	ieee80211_hw_config(local, 0);
1171 
1172 	return 0;
1173 }
1174 
1175 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1176 				      int n_vifs)
1177 {
1178 	struct ieee80211_vif_chanctx_switch *vif_chsw;
1179 	struct ieee80211_sub_if_data *sdata;
1180 	struct ieee80211_chanctx *ctx, *old_ctx;
1181 	int i, err;
1182 
1183 	lockdep_assert_held(&local->mtx);
1184 	lockdep_assert_held(&local->chanctx_mtx);
1185 
1186 	vif_chsw = kzalloc(sizeof(vif_chsw[0]) * n_vifs, GFP_KERNEL);
1187 	if (!vif_chsw)
1188 		return -ENOMEM;
1189 
1190 	i = 0;
1191 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1192 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1193 			continue;
1194 
1195 		if (WARN_ON(!ctx->replace_ctx)) {
1196 			err = -EINVAL;
1197 			goto out;
1198 		}
1199 
1200 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1201 				    reserved_chanctx_list) {
1202 			if (!ieee80211_vif_has_in_place_reservation(
1203 					sdata))
1204 				continue;
1205 
1206 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1207 			vif_chsw[i].vif = &sdata->vif;
1208 			vif_chsw[i].old_ctx = &old_ctx->conf;
1209 			vif_chsw[i].new_ctx = &ctx->conf;
1210 
1211 			i++;
1212 		}
1213 	}
1214 
1215 	err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1216 				     CHANCTX_SWMODE_SWAP_CONTEXTS);
1217 
1218 out:
1219 	kfree(vif_chsw);
1220 	return err;
1221 }
1222 
1223 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1224 {
1225 	struct ieee80211_chanctx *ctx;
1226 	int err;
1227 
1228 	lockdep_assert_held(&local->mtx);
1229 	lockdep_assert_held(&local->chanctx_mtx);
1230 
1231 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1232 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1233 			continue;
1234 
1235 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1236 			continue;
1237 
1238 		ieee80211_del_chanctx(local, ctx->replace_ctx);
1239 		err = ieee80211_add_chanctx(local, ctx);
1240 		if (err)
1241 			goto err;
1242 	}
1243 
1244 	return 0;
1245 
1246 err:
1247 	WARN_ON(ieee80211_add_chanctx(local, ctx));
1248 	list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1249 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1250 			continue;
1251 
1252 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1253 			continue;
1254 
1255 		ieee80211_del_chanctx(local, ctx);
1256 		WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1257 	}
1258 
1259 	return err;
1260 }
1261 
1262 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1263 {
1264 	struct ieee80211_sub_if_data *sdata, *sdata_tmp;
1265 	struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1266 	struct ieee80211_chanctx *new_ctx = NULL;
1267 	int i, err, n_assigned, n_reserved, n_ready;
1268 	int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1269 
1270 	lockdep_assert_held(&local->mtx);
1271 	lockdep_assert_held(&local->chanctx_mtx);
1272 
1273 	/*
1274 	 * If there are 2 independent pairs of channel contexts performing
1275 	 * cross-switch of their vifs this code will still wait until both are
1276 	 * ready even though it could be possible to switch one before the
1277 	 * other is ready.
1278 	 *
1279 	 * For practical reasons and code simplicity just do a single huge
1280 	 * switch.
1281 	 */
1282 
1283 	/*
1284 	 * Verify if the reservation is still feasible.
1285 	 *  - if it's not then disconnect
1286 	 *  - if it is but not all vifs necessary are ready then defer
1287 	 */
1288 
1289 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1290 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1291 			continue;
1292 
1293 		if (WARN_ON(!ctx->replace_ctx)) {
1294 			err = -EINVAL;
1295 			goto err;
1296 		}
1297 
1298 		if (!local->use_chanctx)
1299 			new_ctx = ctx;
1300 
1301 		n_ctx++;
1302 
1303 		n_assigned = 0;
1304 		n_reserved = 0;
1305 		n_ready = 0;
1306 
1307 		list_for_each_entry(sdata, &ctx->replace_ctx->assigned_vifs,
1308 				    assigned_chanctx_list) {
1309 			n_assigned++;
1310 			if (sdata->reserved_chanctx) {
1311 				n_reserved++;
1312 				if (sdata->reserved_ready)
1313 					n_ready++;
1314 			}
1315 		}
1316 
1317 		if (n_assigned != n_reserved) {
1318 			if (n_ready == n_reserved) {
1319 				wiphy_info(local->hw.wiphy,
1320 					   "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1321 				err = -EBUSY;
1322 				goto err;
1323 			}
1324 
1325 			return -EAGAIN;
1326 		}
1327 
1328 		ctx->conf.radar_enabled = false;
1329 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1330 				    reserved_chanctx_list) {
1331 			if (ieee80211_vif_has_in_place_reservation(sdata) &&
1332 			    !sdata->reserved_ready)
1333 				return -EAGAIN;
1334 
1335 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1336 			if (old_ctx) {
1337 				if (old_ctx->replace_state ==
1338 				    IEEE80211_CHANCTX_WILL_BE_REPLACED)
1339 					n_vifs_switch++;
1340 				else
1341 					n_vifs_assign++;
1342 			} else {
1343 				n_vifs_ctxless++;
1344 			}
1345 
1346 			if (sdata->reserved_radar_required)
1347 				ctx->conf.radar_enabled = true;
1348 		}
1349 	}
1350 
1351 	if (WARN_ON(n_ctx == 0) ||
1352 	    WARN_ON(n_vifs_switch == 0 &&
1353 		    n_vifs_assign == 0 &&
1354 		    n_vifs_ctxless == 0) ||
1355 	    WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1356 	    WARN_ON(!new_ctx && !local->use_chanctx)) {
1357 		err = -EINVAL;
1358 		goto err;
1359 	}
1360 
1361 	/*
1362 	 * All necessary vifs are ready. Perform the switch now depending on
1363 	 * reservations and driver capabilities.
1364 	 */
1365 
1366 	if (local->use_chanctx) {
1367 		if (n_vifs_switch > 0) {
1368 			err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1369 			if (err)
1370 				goto err;
1371 		}
1372 
1373 		if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1374 			err = ieee80211_chsw_switch_ctxs(local);
1375 			if (err)
1376 				goto err;
1377 		}
1378 	} else {
1379 		err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1380 		if (err)
1381 			goto err;
1382 	}
1383 
1384 	/*
1385 	 * Update all structures, values and pointers to point to new channel
1386 	 * context(s).
1387 	 */
1388 
1389 	i = 0;
1390 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1391 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1392 			continue;
1393 
1394 		if (WARN_ON(!ctx->replace_ctx)) {
1395 			err = -EINVAL;
1396 			goto err;
1397 		}
1398 
1399 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1400 				    reserved_chanctx_list) {
1401 			u32 changed = 0;
1402 
1403 			if (!ieee80211_vif_has_in_place_reservation(sdata))
1404 				continue;
1405 
1406 			rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
1407 
1408 			if (sdata->vif.type == NL80211_IFTYPE_AP)
1409 				__ieee80211_vif_copy_chanctx_to_vlans(sdata,
1410 								      false);
1411 
1412 			ieee80211_check_fast_xmit_iface(sdata);
1413 
1414 			sdata->radar_required = sdata->reserved_radar_required;
1415 
1416 			if (sdata->vif.bss_conf.chandef.width !=
1417 			    sdata->reserved_chandef.width)
1418 				changed = BSS_CHANGED_BANDWIDTH;
1419 
1420 			ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1421 			if (changed)
1422 				ieee80211_bss_info_change_notify(sdata,
1423 								 changed);
1424 
1425 			ieee80211_recalc_txpower(sdata, false);
1426 		}
1427 
1428 		ieee80211_recalc_chanctx_chantype(local, ctx);
1429 		ieee80211_recalc_smps_chanctx(local, ctx);
1430 		ieee80211_recalc_radar_chanctx(local, ctx);
1431 		ieee80211_recalc_chanctx_min_def(local, ctx);
1432 
1433 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1434 					 reserved_chanctx_list) {
1435 			if (ieee80211_vif_get_chanctx(sdata) != ctx)
1436 				continue;
1437 
1438 			list_del(&sdata->reserved_chanctx_list);
1439 			list_move(&sdata->assigned_chanctx_list,
1440 				  &ctx->assigned_vifs);
1441 			sdata->reserved_chanctx = NULL;
1442 
1443 			ieee80211_vif_chanctx_reservation_complete(sdata);
1444 		}
1445 
1446 		/*
1447 		 * This context might have been a dependency for an already
1448 		 * ready re-assign reservation interface that was deferred. Do
1449 		 * not propagate error to the caller though. The in-place
1450 		 * reservation for originally requested interface has already
1451 		 * succeeded at this point.
1452 		 */
1453 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1454 					 reserved_chanctx_list) {
1455 			if (WARN_ON(ieee80211_vif_has_in_place_reservation(
1456 					sdata)))
1457 				continue;
1458 
1459 			if (WARN_ON(sdata->reserved_chanctx != ctx))
1460 				continue;
1461 
1462 			if (!sdata->reserved_ready)
1463 				continue;
1464 
1465 			if (ieee80211_vif_get_chanctx(sdata))
1466 				err = ieee80211_vif_use_reserved_reassign(
1467 						sdata);
1468 			else
1469 				err = ieee80211_vif_use_reserved_assign(sdata);
1470 
1471 			if (err) {
1472 				sdata_info(sdata,
1473 					   "failed to finalize (re-)assign reservation (err=%d)\n",
1474 					   err);
1475 				ieee80211_vif_unreserve_chanctx(sdata);
1476 				cfg80211_stop_iface(local->hw.wiphy,
1477 						    &sdata->wdev,
1478 						    GFP_KERNEL);
1479 			}
1480 		}
1481 	}
1482 
1483 	/*
1484 	 * Finally free old contexts
1485 	 */
1486 
1487 	list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1488 		if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1489 			continue;
1490 
1491 		ctx->replace_ctx->replace_ctx = NULL;
1492 		ctx->replace_ctx->replace_state =
1493 				IEEE80211_CHANCTX_REPLACE_NONE;
1494 
1495 		list_del_rcu(&ctx->list);
1496 		kfree_rcu(ctx, rcu_head);
1497 	}
1498 
1499 	return 0;
1500 
1501 err:
1502 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1503 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1504 			continue;
1505 
1506 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1507 					 reserved_chanctx_list) {
1508 			ieee80211_vif_unreserve_chanctx(sdata);
1509 			ieee80211_vif_chanctx_reservation_complete(sdata);
1510 		}
1511 	}
1512 
1513 	return err;
1514 }
1515 
1516 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1517 {
1518 	struct ieee80211_local *local = sdata->local;
1519 	struct ieee80211_chanctx_conf *conf;
1520 	struct ieee80211_chanctx *ctx;
1521 	bool use_reserved_switch = false;
1522 
1523 	lockdep_assert_held(&local->chanctx_mtx);
1524 
1525 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1526 					 lockdep_is_held(&local->chanctx_mtx));
1527 	if (!conf)
1528 		return;
1529 
1530 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1531 
1532 	if (sdata->reserved_chanctx) {
1533 		if (sdata->reserved_chanctx->replace_state ==
1534 		    IEEE80211_CHANCTX_REPLACES_OTHER &&
1535 		    ieee80211_chanctx_num_reserved(local,
1536 						   sdata->reserved_chanctx) > 1)
1537 			use_reserved_switch = true;
1538 
1539 		ieee80211_vif_unreserve_chanctx(sdata);
1540 	}
1541 
1542 	ieee80211_assign_vif_chanctx(sdata, NULL);
1543 	if (ieee80211_chanctx_refcount(local, ctx) == 0)
1544 		ieee80211_free_chanctx(local, ctx);
1545 
1546 	sdata->radar_required = false;
1547 
1548 	/* Unreserving may ready an in-place reservation. */
1549 	if (use_reserved_switch)
1550 		ieee80211_vif_use_reserved_switch(local);
1551 }
1552 
1553 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
1554 			      const struct cfg80211_chan_def *chandef,
1555 			      enum ieee80211_chanctx_mode mode)
1556 {
1557 	struct ieee80211_local *local = sdata->local;
1558 	struct ieee80211_chanctx *ctx;
1559 	u8 radar_detect_width = 0;
1560 	int ret;
1561 
1562 	lockdep_assert_held(&local->mtx);
1563 
1564 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1565 
1566 	mutex_lock(&local->chanctx_mtx);
1567 
1568 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1569 					    chandef,
1570 					    sdata->wdev.iftype);
1571 	if (ret < 0)
1572 		goto out;
1573 	if (ret > 0)
1574 		radar_detect_width = BIT(chandef->width);
1575 
1576 	sdata->radar_required = ret;
1577 
1578 	ret = ieee80211_check_combinations(sdata, chandef, mode,
1579 					   radar_detect_width);
1580 	if (ret < 0)
1581 		goto out;
1582 
1583 	__ieee80211_vif_release_channel(sdata);
1584 
1585 	ctx = ieee80211_find_chanctx(local, chandef, mode);
1586 	if (!ctx)
1587 		ctx = ieee80211_new_chanctx(local, chandef, mode);
1588 	if (IS_ERR(ctx)) {
1589 		ret = PTR_ERR(ctx);
1590 		goto out;
1591 	}
1592 
1593 	ieee80211_vif_update_chandef(sdata, chandef);
1594 
1595 	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
1596 	if (ret) {
1597 		/* if assign fails refcount stays the same */
1598 		if (ieee80211_chanctx_refcount(local, ctx) == 0)
1599 			ieee80211_free_chanctx(local, ctx);
1600 		goto out;
1601 	}
1602 
1603 	ieee80211_recalc_smps_chanctx(local, ctx);
1604 	ieee80211_recalc_radar_chanctx(local, ctx);
1605  out:
1606 	if (ret)
1607 		sdata->radar_required = false;
1608 
1609 	mutex_unlock(&local->chanctx_mtx);
1610 	return ret;
1611 }
1612 
1613 int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata)
1614 {
1615 	struct ieee80211_local *local = sdata->local;
1616 	struct ieee80211_chanctx *new_ctx;
1617 	struct ieee80211_chanctx *old_ctx;
1618 	int err;
1619 
1620 	lockdep_assert_held(&local->mtx);
1621 	lockdep_assert_held(&local->chanctx_mtx);
1622 
1623 	new_ctx = sdata->reserved_chanctx;
1624 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1625 
1626 	if (WARN_ON(!new_ctx))
1627 		return -EINVAL;
1628 
1629 	if (WARN_ON(new_ctx->replace_state ==
1630 		    IEEE80211_CHANCTX_WILL_BE_REPLACED))
1631 		return -EINVAL;
1632 
1633 	if (WARN_ON(sdata->reserved_ready))
1634 		return -EINVAL;
1635 
1636 	sdata->reserved_ready = true;
1637 
1638 	if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1639 		if (old_ctx)
1640 			err = ieee80211_vif_use_reserved_reassign(sdata);
1641 		else
1642 			err = ieee80211_vif_use_reserved_assign(sdata);
1643 
1644 		if (err)
1645 			return err;
1646 	}
1647 
1648 	/*
1649 	 * In-place reservation may need to be finalized now either if:
1650 	 *  a) sdata is taking part in the swapping itself and is the last one
1651 	 *  b) sdata has switched with a re-assign reservation to an existing
1652 	 *     context readying in-place switching of old_ctx
1653 	 *
1654 	 * In case of (b) do not propagate the error up because the requested
1655 	 * sdata already switched successfully. Just spill an extra warning.
1656 	 * The ieee80211_vif_use_reserved_switch() already stops all necessary
1657 	 * interfaces upon failure.
1658 	 */
1659 	if ((old_ctx &&
1660 	     old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1661 	    new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1662 		err = ieee80211_vif_use_reserved_switch(local);
1663 		if (err && err != -EAGAIN) {
1664 			if (new_ctx->replace_state ==
1665 			    IEEE80211_CHANCTX_REPLACES_OTHER)
1666 				return err;
1667 
1668 			wiphy_info(local->hw.wiphy,
1669 				   "depending in-place reservation failed (err=%d)\n",
1670 				   err);
1671 		}
1672 	}
1673 
1674 	return 0;
1675 }
1676 
1677 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
1678 				   const struct cfg80211_chan_def *chandef,
1679 				   u32 *changed)
1680 {
1681 	struct ieee80211_local *local = sdata->local;
1682 	struct ieee80211_chanctx_conf *conf;
1683 	struct ieee80211_chanctx *ctx;
1684 	const struct cfg80211_chan_def *compat;
1685 	int ret;
1686 
1687 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1688 				     IEEE80211_CHAN_DISABLED))
1689 		return -EINVAL;
1690 
1691 	mutex_lock(&local->chanctx_mtx);
1692 	if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
1693 		ret = 0;
1694 		goto out;
1695 	}
1696 
1697 	if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1698 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1699 		ret = -EINVAL;
1700 		goto out;
1701 	}
1702 
1703 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1704 					 lockdep_is_held(&local->chanctx_mtx));
1705 	if (!conf) {
1706 		ret = -EINVAL;
1707 		goto out;
1708 	}
1709 
1710 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1711 
1712 	compat = cfg80211_chandef_compatible(&conf->def, chandef);
1713 	if (!compat) {
1714 		ret = -EINVAL;
1715 		goto out;
1716 	}
1717 
1718 	switch (ctx->replace_state) {
1719 	case IEEE80211_CHANCTX_REPLACE_NONE:
1720 		if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1721 			ret = -EBUSY;
1722 			goto out;
1723 		}
1724 		break;
1725 	case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1726 		/* TODO: Perhaps the bandwidth change could be treated as a
1727 		 * reservation itself? */
1728 		ret = -EBUSY;
1729 		goto out;
1730 	case IEEE80211_CHANCTX_REPLACES_OTHER:
1731 		/* channel context that is going to replace another channel
1732 		 * context doesn't really exist and shouldn't be assigned
1733 		 * anywhere yet */
1734 		WARN_ON(1);
1735 		break;
1736 	}
1737 
1738 	ieee80211_vif_update_chandef(sdata, chandef);
1739 
1740 	ieee80211_recalc_chanctx_chantype(local, ctx);
1741 
1742 	*changed |= BSS_CHANGED_BANDWIDTH;
1743 	ret = 0;
1744  out:
1745 	mutex_unlock(&local->chanctx_mtx);
1746 	return ret;
1747 }
1748 
1749 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1750 {
1751 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1752 
1753 	lockdep_assert_held(&sdata->local->mtx);
1754 
1755 	mutex_lock(&sdata->local->chanctx_mtx);
1756 	__ieee80211_vif_release_channel(sdata);
1757 	mutex_unlock(&sdata->local->chanctx_mtx);
1758 }
1759 
1760 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
1761 {
1762 	struct ieee80211_local *local = sdata->local;
1763 	struct ieee80211_sub_if_data *ap;
1764 	struct ieee80211_chanctx_conf *conf;
1765 
1766 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
1767 		return;
1768 
1769 	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
1770 
1771 	mutex_lock(&local->chanctx_mtx);
1772 
1773 	conf = rcu_dereference_protected(ap->vif.chanctx_conf,
1774 					 lockdep_is_held(&local->chanctx_mtx));
1775 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
1776 	mutex_unlock(&local->chanctx_mtx);
1777 }
1778 
1779 void ieee80211_iter_chan_contexts_atomic(
1780 	struct ieee80211_hw *hw,
1781 	void (*iter)(struct ieee80211_hw *hw,
1782 		     struct ieee80211_chanctx_conf *chanctx_conf,
1783 		     void *data),
1784 	void *iter_data)
1785 {
1786 	struct ieee80211_local *local = hw_to_local(hw);
1787 	struct ieee80211_chanctx *ctx;
1788 
1789 	rcu_read_lock();
1790 	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
1791 		if (ctx->driver_present)
1792 			iter(hw, &ctx->conf, iter_data);
1793 	rcu_read_unlock();
1794 }
1795 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);
1796