xref: /linux/net/mac80211/chan.c (revision e0a2e73e501c77037c8756137e87b12c7c3c9793)
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 		max_bw = max(max_bw, ieee80211_get_sta_bw(&sta->sta));
235 	}
236 	rcu_read_unlock();
237 
238 	return max_bw;
239 }
240 
241 static enum nl80211_chan_width
242 ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
243 				      struct ieee80211_chanctx_conf *conf)
244 {
245 	struct ieee80211_sub_if_data *sdata;
246 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
247 
248 	rcu_read_lock();
249 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
250 		struct ieee80211_vif *vif = &sdata->vif;
251 		enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT;
252 
253 		if (!ieee80211_sdata_running(sdata))
254 			continue;
255 
256 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
257 			continue;
258 
259 		switch (vif->type) {
260 		case NL80211_IFTYPE_AP:
261 		case NL80211_IFTYPE_AP_VLAN:
262 			width = ieee80211_get_max_required_bw(sdata);
263 			break;
264 		case NL80211_IFTYPE_STATION:
265 			/*
266 			 * The ap's sta->bandwidth is not set yet at this
267 			 * point, so take the width from the chandef, but
268 			 * account also for TDLS peers
269 			 */
270 			width = max(vif->bss_conf.chandef.width,
271 				    ieee80211_get_max_required_bw(sdata));
272 			break;
273 		case NL80211_IFTYPE_P2P_DEVICE:
274 		case NL80211_IFTYPE_NAN:
275 			continue;
276 		case NL80211_IFTYPE_ADHOC:
277 		case NL80211_IFTYPE_WDS:
278 		case NL80211_IFTYPE_MESH_POINT:
279 		case NL80211_IFTYPE_OCB:
280 			width = vif->bss_conf.chandef.width;
281 			break;
282 		case NL80211_IFTYPE_UNSPECIFIED:
283 		case NUM_NL80211_IFTYPES:
284 		case NL80211_IFTYPE_MONITOR:
285 		case NL80211_IFTYPE_P2P_CLIENT:
286 		case NL80211_IFTYPE_P2P_GO:
287 			WARN_ON_ONCE(1);
288 		}
289 		max_bw = max(max_bw, width);
290 	}
291 
292 	/* use the configured bandwidth in case of monitor interface */
293 	sdata = rcu_dereference(local->monitor_sdata);
294 	if (sdata && rcu_access_pointer(sdata->vif.chanctx_conf) == conf)
295 		max_bw = max(max_bw, conf->def.width);
296 
297 	rcu_read_unlock();
298 
299 	return max_bw;
300 }
301 
302 /*
303  * recalc the min required chan width of the channel context, which is
304  * the max of min required widths of all the interfaces bound to this
305  * channel context.
306  */
307 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
308 				      struct ieee80211_chanctx *ctx)
309 {
310 	enum nl80211_chan_width max_bw;
311 	struct cfg80211_chan_def min_def;
312 
313 	lockdep_assert_held(&local->chanctx_mtx);
314 
315 	/* don't optimize 5MHz, 10MHz, and radar_enabled confs */
316 	if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
317 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
318 	    ctx->conf.radar_enabled) {
319 		ctx->conf.min_def = ctx->conf.def;
320 		return;
321 	}
322 
323 	max_bw = ieee80211_get_chanctx_max_required_bw(local, &ctx->conf);
324 
325 	/* downgrade chandef up to max_bw */
326 	min_def = ctx->conf.def;
327 	while (min_def.width > max_bw)
328 		ieee80211_chandef_downgrade(&min_def);
329 
330 	if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
331 		return;
332 
333 	ctx->conf.min_def = min_def;
334 	if (!ctx->driver_present)
335 		return;
336 
337 	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_MIN_WIDTH);
338 }
339 
340 static void ieee80211_change_chanctx(struct ieee80211_local *local,
341 				     struct ieee80211_chanctx *ctx,
342 				     const struct cfg80211_chan_def *chandef)
343 {
344 	if (cfg80211_chandef_identical(&ctx->conf.def, chandef)) {
345 		ieee80211_recalc_chanctx_min_def(local, ctx);
346 		return;
347 	}
348 
349 	WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
350 
351 	ctx->conf.def = *chandef;
352 	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);
353 	ieee80211_recalc_chanctx_min_def(local, ctx);
354 
355 	if (!local->use_chanctx) {
356 		local->_oper_chandef = *chandef;
357 		ieee80211_hw_config(local, 0);
358 	}
359 }
360 
361 static struct ieee80211_chanctx *
362 ieee80211_find_chanctx(struct ieee80211_local *local,
363 		       const struct cfg80211_chan_def *chandef,
364 		       enum ieee80211_chanctx_mode mode)
365 {
366 	struct ieee80211_chanctx *ctx;
367 
368 	lockdep_assert_held(&local->chanctx_mtx);
369 
370 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
371 		return NULL;
372 
373 	list_for_each_entry(ctx, &local->chanctx_list, list) {
374 		const struct cfg80211_chan_def *compat;
375 
376 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
377 			continue;
378 
379 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
380 			continue;
381 
382 		compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
383 		if (!compat)
384 			continue;
385 
386 		compat = ieee80211_chanctx_reserved_chandef(local, ctx,
387 							    compat);
388 		if (!compat)
389 			continue;
390 
391 		ieee80211_change_chanctx(local, ctx, compat);
392 
393 		return ctx;
394 	}
395 
396 	return NULL;
397 }
398 
399 bool ieee80211_is_radar_required(struct ieee80211_local *local)
400 {
401 	struct ieee80211_sub_if_data *sdata;
402 
403 	lockdep_assert_held(&local->mtx);
404 
405 	rcu_read_lock();
406 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
407 		if (sdata->radar_required) {
408 			rcu_read_unlock();
409 			return true;
410 		}
411 	}
412 	rcu_read_unlock();
413 
414 	return false;
415 }
416 
417 static bool
418 ieee80211_chanctx_radar_required(struct ieee80211_local *local,
419 				 struct ieee80211_chanctx *ctx)
420 {
421 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
422 	struct ieee80211_sub_if_data *sdata;
423 	bool required = false;
424 
425 	lockdep_assert_held(&local->chanctx_mtx);
426 	lockdep_assert_held(&local->mtx);
427 
428 	rcu_read_lock();
429 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
430 		if (!ieee80211_sdata_running(sdata))
431 			continue;
432 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
433 			continue;
434 		if (!sdata->radar_required)
435 			continue;
436 
437 		required = true;
438 		break;
439 	}
440 	rcu_read_unlock();
441 
442 	return required;
443 }
444 
445 static struct ieee80211_chanctx *
446 ieee80211_alloc_chanctx(struct ieee80211_local *local,
447 			const struct cfg80211_chan_def *chandef,
448 			enum ieee80211_chanctx_mode mode)
449 {
450 	struct ieee80211_chanctx *ctx;
451 
452 	lockdep_assert_held(&local->chanctx_mtx);
453 
454 	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
455 	if (!ctx)
456 		return NULL;
457 
458 	INIT_LIST_HEAD(&ctx->assigned_vifs);
459 	INIT_LIST_HEAD(&ctx->reserved_vifs);
460 	ctx->conf.def = *chandef;
461 	ctx->conf.rx_chains_static = 1;
462 	ctx->conf.rx_chains_dynamic = 1;
463 	ctx->mode = mode;
464 	ctx->conf.radar_enabled = false;
465 	ieee80211_recalc_chanctx_min_def(local, ctx);
466 
467 	return ctx;
468 }
469 
470 static int ieee80211_add_chanctx(struct ieee80211_local *local,
471 				 struct ieee80211_chanctx *ctx)
472 {
473 	u32 changed;
474 	int err;
475 
476 	lockdep_assert_held(&local->mtx);
477 	lockdep_assert_held(&local->chanctx_mtx);
478 
479 	if (!local->use_chanctx)
480 		local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
481 
482 	/* turn idle off *before* setting channel -- some drivers need that */
483 	changed = ieee80211_idle_off(local);
484 	if (changed)
485 		ieee80211_hw_config(local, changed);
486 
487 	if (!local->use_chanctx) {
488 		local->_oper_chandef = ctx->conf.def;
489 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
490 	} else {
491 		err = drv_add_chanctx(local, ctx);
492 		if (err) {
493 			ieee80211_recalc_idle(local);
494 			return err;
495 		}
496 	}
497 
498 	return 0;
499 }
500 
501 static struct ieee80211_chanctx *
502 ieee80211_new_chanctx(struct ieee80211_local *local,
503 		      const struct cfg80211_chan_def *chandef,
504 		      enum ieee80211_chanctx_mode mode)
505 {
506 	struct ieee80211_chanctx *ctx;
507 	int err;
508 
509 	lockdep_assert_held(&local->mtx);
510 	lockdep_assert_held(&local->chanctx_mtx);
511 
512 	ctx = ieee80211_alloc_chanctx(local, chandef, mode);
513 	if (!ctx)
514 		return ERR_PTR(-ENOMEM);
515 
516 	err = ieee80211_add_chanctx(local, ctx);
517 	if (err) {
518 		kfree(ctx);
519 		return ERR_PTR(err);
520 	}
521 
522 	list_add_rcu(&ctx->list, &local->chanctx_list);
523 	return ctx;
524 }
525 
526 static void ieee80211_del_chanctx(struct ieee80211_local *local,
527 				  struct ieee80211_chanctx *ctx)
528 {
529 	lockdep_assert_held(&local->chanctx_mtx);
530 
531 	if (!local->use_chanctx) {
532 		struct cfg80211_chan_def *chandef = &local->_oper_chandef;
533 		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
534 		chandef->center_freq1 = chandef->chan->center_freq;
535 		chandef->center_freq2 = 0;
536 
537 		/* NOTE: Disabling radar is only valid here for
538 		 * single channel context. To be sure, check it ...
539 		 */
540 		WARN_ON(local->hw.conf.radar_enabled &&
541 			!list_empty(&local->chanctx_list));
542 
543 		local->hw.conf.radar_enabled = false;
544 
545 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
546 	} else {
547 		drv_remove_chanctx(local, ctx);
548 	}
549 
550 	ieee80211_recalc_idle(local);
551 }
552 
553 static void ieee80211_free_chanctx(struct ieee80211_local *local,
554 				   struct ieee80211_chanctx *ctx)
555 {
556 	lockdep_assert_held(&local->chanctx_mtx);
557 
558 	WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
559 
560 	list_del_rcu(&ctx->list);
561 	ieee80211_del_chanctx(local, ctx);
562 	kfree_rcu(ctx, rcu_head);
563 }
564 
565 void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
566 				       struct ieee80211_chanctx *ctx)
567 {
568 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
569 	struct ieee80211_sub_if_data *sdata;
570 	const struct cfg80211_chan_def *compat = NULL;
571 	struct sta_info *sta;
572 
573 	lockdep_assert_held(&local->chanctx_mtx);
574 
575 	rcu_read_lock();
576 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
577 
578 		if (!ieee80211_sdata_running(sdata))
579 			continue;
580 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
581 			continue;
582 		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
583 			continue;
584 
585 		if (!compat)
586 			compat = &sdata->vif.bss_conf.chandef;
587 
588 		compat = cfg80211_chandef_compatible(
589 				&sdata->vif.bss_conf.chandef, compat);
590 		if (WARN_ON_ONCE(!compat))
591 			break;
592 	}
593 
594 	/* TDLS peers can sometimes affect the chandef width */
595 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
596 		if (!sta->uploaded ||
597 		    !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
598 		    !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
599 		    !sta->tdls_chandef.chan)
600 			continue;
601 
602 		compat = cfg80211_chandef_compatible(&sta->tdls_chandef,
603 						     compat);
604 		if (WARN_ON_ONCE(!compat))
605 			break;
606 	}
607 	rcu_read_unlock();
608 
609 	if (!compat)
610 		return;
611 
612 	ieee80211_change_chanctx(local, ctx, compat);
613 }
614 
615 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
616 					   struct ieee80211_chanctx *chanctx)
617 {
618 	bool radar_enabled;
619 
620 	lockdep_assert_held(&local->chanctx_mtx);
621 	/* for ieee80211_is_radar_required */
622 	lockdep_assert_held(&local->mtx);
623 
624 	radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
625 
626 	if (radar_enabled == chanctx->conf.radar_enabled)
627 		return;
628 
629 	chanctx->conf.radar_enabled = radar_enabled;
630 
631 	if (!local->use_chanctx) {
632 		local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
633 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
634 	}
635 
636 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
637 }
638 
639 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
640 					struct ieee80211_chanctx *new_ctx)
641 {
642 	struct ieee80211_local *local = sdata->local;
643 	struct ieee80211_chanctx_conf *conf;
644 	struct ieee80211_chanctx *curr_ctx = NULL;
645 	int ret = 0;
646 
647 	if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN))
648 		return -ENOTSUPP;
649 
650 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
651 					 lockdep_is_held(&local->chanctx_mtx));
652 
653 	if (conf) {
654 		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
655 
656 		drv_unassign_vif_chanctx(local, sdata, curr_ctx);
657 		conf = NULL;
658 		list_del(&sdata->assigned_chanctx_list);
659 	}
660 
661 	if (new_ctx) {
662 		ret = drv_assign_vif_chanctx(local, sdata, new_ctx);
663 		if (ret)
664 			goto out;
665 
666 		conf = &new_ctx->conf;
667 		list_add(&sdata->assigned_chanctx_list,
668 			 &new_ctx->assigned_vifs);
669 	}
670 
671 out:
672 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
673 
674 	sdata->vif.bss_conf.idle = !conf;
675 
676 	if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
677 		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
678 		ieee80211_recalc_smps_chanctx(local, curr_ctx);
679 		ieee80211_recalc_radar_chanctx(local, curr_ctx);
680 		ieee80211_recalc_chanctx_min_def(local, curr_ctx);
681 	}
682 
683 	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
684 		ieee80211_recalc_txpower(sdata, false);
685 		ieee80211_recalc_chanctx_min_def(local, new_ctx);
686 	}
687 
688 	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
689 	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
690 		ieee80211_bss_info_change_notify(sdata,
691 						 BSS_CHANGED_IDLE);
692 
693 	ieee80211_check_fast_xmit_iface(sdata);
694 
695 	return ret;
696 }
697 
698 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
699 				   struct ieee80211_chanctx *chanctx)
700 {
701 	struct ieee80211_sub_if_data *sdata;
702 	u8 rx_chains_static, rx_chains_dynamic;
703 
704 	lockdep_assert_held(&local->chanctx_mtx);
705 
706 	rx_chains_static = 1;
707 	rx_chains_dynamic = 1;
708 
709 	rcu_read_lock();
710 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
711 		u8 needed_static, needed_dynamic;
712 
713 		if (!ieee80211_sdata_running(sdata))
714 			continue;
715 
716 		if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
717 						&chanctx->conf)
718 			continue;
719 
720 		switch (sdata->vif.type) {
721 		case NL80211_IFTYPE_P2P_DEVICE:
722 		case NL80211_IFTYPE_NAN:
723 			continue;
724 		case NL80211_IFTYPE_STATION:
725 			if (!sdata->u.mgd.associated)
726 				continue;
727 			break;
728 		case NL80211_IFTYPE_AP_VLAN:
729 			continue;
730 		case NL80211_IFTYPE_AP:
731 		case NL80211_IFTYPE_ADHOC:
732 		case NL80211_IFTYPE_WDS:
733 		case NL80211_IFTYPE_MESH_POINT:
734 		case NL80211_IFTYPE_OCB:
735 			break;
736 		default:
737 			WARN_ON_ONCE(1);
738 		}
739 
740 		switch (sdata->smps_mode) {
741 		default:
742 			WARN_ONCE(1, "Invalid SMPS mode %d\n",
743 				  sdata->smps_mode);
744 			/* fall through */
745 		case IEEE80211_SMPS_OFF:
746 			needed_static = sdata->needed_rx_chains;
747 			needed_dynamic = sdata->needed_rx_chains;
748 			break;
749 		case IEEE80211_SMPS_DYNAMIC:
750 			needed_static = 1;
751 			needed_dynamic = sdata->needed_rx_chains;
752 			break;
753 		case IEEE80211_SMPS_STATIC:
754 			needed_static = 1;
755 			needed_dynamic = 1;
756 			break;
757 		}
758 
759 		rx_chains_static = max(rx_chains_static, needed_static);
760 		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
761 	}
762 
763 	/* Disable SMPS for the monitor interface */
764 	sdata = rcu_dereference(local->monitor_sdata);
765 	if (sdata &&
766 	    rcu_access_pointer(sdata->vif.chanctx_conf) == &chanctx->conf)
767 		rx_chains_dynamic = rx_chains_static = local->rx_chains;
768 
769 	rcu_read_unlock();
770 
771 	if (!local->use_chanctx) {
772 		if (rx_chains_static > 1)
773 			local->smps_mode = IEEE80211_SMPS_OFF;
774 		else if (rx_chains_dynamic > 1)
775 			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
776 		else
777 			local->smps_mode = IEEE80211_SMPS_STATIC;
778 		ieee80211_hw_config(local, 0);
779 	}
780 
781 	if (rx_chains_static == chanctx->conf.rx_chains_static &&
782 	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
783 		return;
784 
785 	chanctx->conf.rx_chains_static = rx_chains_static;
786 	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
787 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
788 }
789 
790 static void
791 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
792 				      bool clear)
793 {
794 	struct ieee80211_local *local __maybe_unused = sdata->local;
795 	struct ieee80211_sub_if_data *vlan;
796 	struct ieee80211_chanctx_conf *conf;
797 
798 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
799 		return;
800 
801 	lockdep_assert_held(&local->mtx);
802 
803 	/* Check that conf exists, even when clearing this function
804 	 * must be called with the AP's channel context still there
805 	 * as it would otherwise cause VLANs to have an invalid
806 	 * channel context pointer for a while, possibly pointing
807 	 * to a channel context that has already been freed.
808 	 */
809 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
810 					 lockdep_is_held(&local->chanctx_mtx));
811 	WARN_ON(!conf);
812 
813 	if (clear)
814 		conf = NULL;
815 
816 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
817 		rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
818 }
819 
820 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
821 					 bool clear)
822 {
823 	struct ieee80211_local *local = sdata->local;
824 
825 	mutex_lock(&local->chanctx_mtx);
826 
827 	__ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
828 
829 	mutex_unlock(&local->chanctx_mtx);
830 }
831 
832 int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
833 {
834 	struct ieee80211_chanctx *ctx = sdata->reserved_chanctx;
835 
836 	lockdep_assert_held(&sdata->local->chanctx_mtx);
837 
838 	if (WARN_ON(!ctx))
839 		return -EINVAL;
840 
841 	list_del(&sdata->reserved_chanctx_list);
842 	sdata->reserved_chanctx = NULL;
843 
844 	if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
845 		if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
846 			if (WARN_ON(!ctx->replace_ctx))
847 				return -EINVAL;
848 
849 			WARN_ON(ctx->replace_ctx->replace_state !=
850 			        IEEE80211_CHANCTX_WILL_BE_REPLACED);
851 			WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
852 
853 			ctx->replace_ctx->replace_ctx = NULL;
854 			ctx->replace_ctx->replace_state =
855 					IEEE80211_CHANCTX_REPLACE_NONE;
856 
857 			list_del_rcu(&ctx->list);
858 			kfree_rcu(ctx, rcu_head);
859 		} else {
860 			ieee80211_free_chanctx(sdata->local, ctx);
861 		}
862 	}
863 
864 	return 0;
865 }
866 
867 int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
868 				  const struct cfg80211_chan_def *chandef,
869 				  enum ieee80211_chanctx_mode mode,
870 				  bool radar_required)
871 {
872 	struct ieee80211_local *local = sdata->local;
873 	struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
874 
875 	lockdep_assert_held(&local->chanctx_mtx);
876 
877 	curr_ctx = ieee80211_vif_get_chanctx(sdata);
878 	if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
879 		return -ENOTSUPP;
880 
881 	new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
882 	if (!new_ctx) {
883 		if (ieee80211_can_create_new_chanctx(local)) {
884 			new_ctx = ieee80211_new_chanctx(local, chandef, mode);
885 			if (IS_ERR(new_ctx))
886 				return PTR_ERR(new_ctx);
887 		} else {
888 			if (!curr_ctx ||
889 			    (curr_ctx->replace_state ==
890 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
891 			    !list_empty(&curr_ctx->reserved_vifs)) {
892 				/*
893 				 * Another vif already requested this context
894 				 * for a reservation. Find another one hoping
895 				 * all vifs assigned to it will also switch
896 				 * soon enough.
897 				 *
898 				 * TODO: This needs a little more work as some
899 				 * cases (more than 2 chanctx capable devices)
900 				 * may fail which could otherwise succeed
901 				 * provided some channel context juggling was
902 				 * performed.
903 				 *
904 				 * Consider ctx1..3, vif1..6, each ctx has 2
905 				 * vifs. vif1 and vif2 from ctx1 request new
906 				 * different chandefs starting 2 in-place
907 				 * reserations with ctx4 and ctx5 replacing
908 				 * ctx1 and ctx2 respectively. Next vif5 and
909 				 * vif6 from ctx3 reserve ctx4. If vif3 and
910 				 * vif4 remain on ctx2 as they are then this
911 				 * fails unless `replace_ctx` from ctx5 is
912 				 * replaced with ctx3.
913 				 */
914 				list_for_each_entry(ctx, &local->chanctx_list,
915 						    list) {
916 					if (ctx->replace_state !=
917 					    IEEE80211_CHANCTX_REPLACE_NONE)
918 						continue;
919 
920 					if (!list_empty(&ctx->reserved_vifs))
921 						continue;
922 
923 					curr_ctx = ctx;
924 					break;
925 				}
926 			}
927 
928 			/*
929 			 * If that's true then all available contexts already
930 			 * have reservations and cannot be used.
931 			 */
932 			if (!curr_ctx ||
933 			    (curr_ctx->replace_state ==
934 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
935 			    !list_empty(&curr_ctx->reserved_vifs))
936 				return -EBUSY;
937 
938 			new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
939 			if (!new_ctx)
940 				return -ENOMEM;
941 
942 			new_ctx->replace_ctx = curr_ctx;
943 			new_ctx->replace_state =
944 					IEEE80211_CHANCTX_REPLACES_OTHER;
945 
946 			curr_ctx->replace_ctx = new_ctx;
947 			curr_ctx->replace_state =
948 					IEEE80211_CHANCTX_WILL_BE_REPLACED;
949 
950 			list_add_rcu(&new_ctx->list, &local->chanctx_list);
951 		}
952 	}
953 
954 	list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);
955 	sdata->reserved_chanctx = new_ctx;
956 	sdata->reserved_chandef = *chandef;
957 	sdata->reserved_radar_required = radar_required;
958 	sdata->reserved_ready = false;
959 
960 	return 0;
961 }
962 
963 static void
964 ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
965 {
966 	switch (sdata->vif.type) {
967 	case NL80211_IFTYPE_ADHOC:
968 	case NL80211_IFTYPE_AP:
969 	case NL80211_IFTYPE_MESH_POINT:
970 	case NL80211_IFTYPE_OCB:
971 		ieee80211_queue_work(&sdata->local->hw,
972 				     &sdata->csa_finalize_work);
973 		break;
974 	case NL80211_IFTYPE_STATION:
975 		ieee80211_queue_work(&sdata->local->hw,
976 				     &sdata->u.mgd.chswitch_work);
977 		break;
978 	case NL80211_IFTYPE_UNSPECIFIED:
979 	case NL80211_IFTYPE_AP_VLAN:
980 	case NL80211_IFTYPE_WDS:
981 	case NL80211_IFTYPE_MONITOR:
982 	case NL80211_IFTYPE_P2P_CLIENT:
983 	case NL80211_IFTYPE_P2P_GO:
984 	case NL80211_IFTYPE_P2P_DEVICE:
985 	case NL80211_IFTYPE_NAN:
986 	case NUM_NL80211_IFTYPES:
987 		WARN_ON(1);
988 		break;
989 	}
990 }
991 
992 static void
993 ieee80211_vif_update_chandef(struct ieee80211_sub_if_data *sdata,
994 			     const struct cfg80211_chan_def *chandef)
995 {
996 	struct ieee80211_sub_if_data *vlan;
997 
998 	sdata->vif.bss_conf.chandef = *chandef;
999 
1000 	if (sdata->vif.type != NL80211_IFTYPE_AP)
1001 		return;
1002 
1003 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
1004 		vlan->vif.bss_conf.chandef = *chandef;
1005 }
1006 
1007 static int
1008 ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
1009 {
1010 	struct ieee80211_local *local = sdata->local;
1011 	struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1012 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1013 	const struct cfg80211_chan_def *chandef;
1014 	u32 changed = 0;
1015 	int err;
1016 
1017 	lockdep_assert_held(&local->mtx);
1018 	lockdep_assert_held(&local->chanctx_mtx);
1019 
1020 	new_ctx = sdata->reserved_chanctx;
1021 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1022 
1023 	if (WARN_ON(!sdata->reserved_ready))
1024 		return -EBUSY;
1025 
1026 	if (WARN_ON(!new_ctx))
1027 		return -EINVAL;
1028 
1029 	if (WARN_ON(!old_ctx))
1030 		return -EINVAL;
1031 
1032 	if (WARN_ON(new_ctx->replace_state ==
1033 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1034 		return -EINVAL;
1035 
1036 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1037 				&sdata->reserved_chandef);
1038 	if (WARN_ON(!chandef))
1039 		return -EINVAL;
1040 
1041 	ieee80211_change_chanctx(local, new_ctx, chandef);
1042 
1043 	vif_chsw[0].vif = &sdata->vif;
1044 	vif_chsw[0].old_ctx = &old_ctx->conf;
1045 	vif_chsw[0].new_ctx = &new_ctx->conf;
1046 
1047 	list_del(&sdata->reserved_chanctx_list);
1048 	sdata->reserved_chanctx = NULL;
1049 
1050 	err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1051 				     CHANCTX_SWMODE_REASSIGN_VIF);
1052 	if (err) {
1053 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1054 			ieee80211_free_chanctx(local, new_ctx);
1055 
1056 		goto out;
1057 	}
1058 
1059 	list_move(&sdata->assigned_chanctx_list, &new_ctx->assigned_vifs);
1060 	rcu_assign_pointer(sdata->vif.chanctx_conf, &new_ctx->conf);
1061 
1062 	if (sdata->vif.type == NL80211_IFTYPE_AP)
1063 		__ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
1064 
1065 	ieee80211_check_fast_xmit_iface(sdata);
1066 
1067 	if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1068 		ieee80211_free_chanctx(local, old_ctx);
1069 
1070 	if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
1071 		changed = BSS_CHANGED_BANDWIDTH;
1072 
1073 	ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1074 
1075 	ieee80211_recalc_smps_chanctx(local, new_ctx);
1076 	ieee80211_recalc_radar_chanctx(local, new_ctx);
1077 	ieee80211_recalc_chanctx_min_def(local, new_ctx);
1078 
1079 	if (changed)
1080 		ieee80211_bss_info_change_notify(sdata, changed);
1081 
1082 out:
1083 	ieee80211_vif_chanctx_reservation_complete(sdata);
1084 	return err;
1085 }
1086 
1087 static int
1088 ieee80211_vif_use_reserved_assign(struct ieee80211_sub_if_data *sdata)
1089 {
1090 	struct ieee80211_local *local = sdata->local;
1091 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1092 	const struct cfg80211_chan_def *chandef;
1093 	int err;
1094 
1095 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1096 	new_ctx = sdata->reserved_chanctx;
1097 
1098 	if (WARN_ON(!sdata->reserved_ready))
1099 		return -EINVAL;
1100 
1101 	if (WARN_ON(old_ctx))
1102 		return -EINVAL;
1103 
1104 	if (WARN_ON(!new_ctx))
1105 		return -EINVAL;
1106 
1107 	if (WARN_ON(new_ctx->replace_state ==
1108 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1109 		return -EINVAL;
1110 
1111 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1112 				&sdata->reserved_chandef);
1113 	if (WARN_ON(!chandef))
1114 		return -EINVAL;
1115 
1116 	ieee80211_change_chanctx(local, new_ctx, chandef);
1117 
1118 	list_del(&sdata->reserved_chanctx_list);
1119 	sdata->reserved_chanctx = NULL;
1120 
1121 	err = ieee80211_assign_vif_chanctx(sdata, new_ctx);
1122 	if (err) {
1123 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1124 			ieee80211_free_chanctx(local, new_ctx);
1125 
1126 		goto out;
1127 	}
1128 
1129 out:
1130 	ieee80211_vif_chanctx_reservation_complete(sdata);
1131 	return err;
1132 }
1133 
1134 static bool
1135 ieee80211_vif_has_in_place_reservation(struct ieee80211_sub_if_data *sdata)
1136 {
1137 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1138 
1139 	lockdep_assert_held(&sdata->local->chanctx_mtx);
1140 
1141 	new_ctx = sdata->reserved_chanctx;
1142 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1143 
1144 	if (!old_ctx)
1145 		return false;
1146 
1147 	if (WARN_ON(!new_ctx))
1148 		return false;
1149 
1150 	if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1151 		return false;
1152 
1153 	if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1154 		return false;
1155 
1156 	return true;
1157 }
1158 
1159 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1160 					struct ieee80211_chanctx *new_ctx)
1161 {
1162 	const struct cfg80211_chan_def *chandef;
1163 
1164 	lockdep_assert_held(&local->mtx);
1165 	lockdep_assert_held(&local->chanctx_mtx);
1166 
1167 	chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1168 	if (WARN_ON(!chandef))
1169 		return -EINVAL;
1170 
1171 	local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1172 	local->_oper_chandef = *chandef;
1173 	ieee80211_hw_config(local, 0);
1174 
1175 	return 0;
1176 }
1177 
1178 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1179 				      int n_vifs)
1180 {
1181 	struct ieee80211_vif_chanctx_switch *vif_chsw;
1182 	struct ieee80211_sub_if_data *sdata;
1183 	struct ieee80211_chanctx *ctx, *old_ctx;
1184 	int i, err;
1185 
1186 	lockdep_assert_held(&local->mtx);
1187 	lockdep_assert_held(&local->chanctx_mtx);
1188 
1189 	vif_chsw = kcalloc(n_vifs, sizeof(vif_chsw[0]), GFP_KERNEL);
1190 	if (!vif_chsw)
1191 		return -ENOMEM;
1192 
1193 	i = 0;
1194 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1195 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1196 			continue;
1197 
1198 		if (WARN_ON(!ctx->replace_ctx)) {
1199 			err = -EINVAL;
1200 			goto out;
1201 		}
1202 
1203 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1204 				    reserved_chanctx_list) {
1205 			if (!ieee80211_vif_has_in_place_reservation(
1206 					sdata))
1207 				continue;
1208 
1209 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1210 			vif_chsw[i].vif = &sdata->vif;
1211 			vif_chsw[i].old_ctx = &old_ctx->conf;
1212 			vif_chsw[i].new_ctx = &ctx->conf;
1213 
1214 			i++;
1215 		}
1216 	}
1217 
1218 	err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1219 				     CHANCTX_SWMODE_SWAP_CONTEXTS);
1220 
1221 out:
1222 	kfree(vif_chsw);
1223 	return err;
1224 }
1225 
1226 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1227 {
1228 	struct ieee80211_chanctx *ctx;
1229 	int err;
1230 
1231 	lockdep_assert_held(&local->mtx);
1232 	lockdep_assert_held(&local->chanctx_mtx);
1233 
1234 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1235 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1236 			continue;
1237 
1238 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1239 			continue;
1240 
1241 		ieee80211_del_chanctx(local, ctx->replace_ctx);
1242 		err = ieee80211_add_chanctx(local, ctx);
1243 		if (err)
1244 			goto err;
1245 	}
1246 
1247 	return 0;
1248 
1249 err:
1250 	WARN_ON(ieee80211_add_chanctx(local, ctx));
1251 	list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1252 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1253 			continue;
1254 
1255 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1256 			continue;
1257 
1258 		ieee80211_del_chanctx(local, ctx);
1259 		WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1260 	}
1261 
1262 	return err;
1263 }
1264 
1265 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1266 {
1267 	struct ieee80211_sub_if_data *sdata, *sdata_tmp;
1268 	struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1269 	struct ieee80211_chanctx *new_ctx = NULL;
1270 	int err, n_assigned, n_reserved, n_ready;
1271 	int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1272 
1273 	lockdep_assert_held(&local->mtx);
1274 	lockdep_assert_held(&local->chanctx_mtx);
1275 
1276 	/*
1277 	 * If there are 2 independent pairs of channel contexts performing
1278 	 * cross-switch of their vifs this code will still wait until both are
1279 	 * ready even though it could be possible to switch one before the
1280 	 * other is ready.
1281 	 *
1282 	 * For practical reasons and code simplicity just do a single huge
1283 	 * switch.
1284 	 */
1285 
1286 	/*
1287 	 * Verify if the reservation is still feasible.
1288 	 *  - if it's not then disconnect
1289 	 *  - if it is but not all vifs necessary are ready then defer
1290 	 */
1291 
1292 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1293 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1294 			continue;
1295 
1296 		if (WARN_ON(!ctx->replace_ctx)) {
1297 			err = -EINVAL;
1298 			goto err;
1299 		}
1300 
1301 		if (!local->use_chanctx)
1302 			new_ctx = ctx;
1303 
1304 		n_ctx++;
1305 
1306 		n_assigned = 0;
1307 		n_reserved = 0;
1308 		n_ready = 0;
1309 
1310 		list_for_each_entry(sdata, &ctx->replace_ctx->assigned_vifs,
1311 				    assigned_chanctx_list) {
1312 			n_assigned++;
1313 			if (sdata->reserved_chanctx) {
1314 				n_reserved++;
1315 				if (sdata->reserved_ready)
1316 					n_ready++;
1317 			}
1318 		}
1319 
1320 		if (n_assigned != n_reserved) {
1321 			if (n_ready == n_reserved) {
1322 				wiphy_info(local->hw.wiphy,
1323 					   "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1324 				err = -EBUSY;
1325 				goto err;
1326 			}
1327 
1328 			return -EAGAIN;
1329 		}
1330 
1331 		ctx->conf.radar_enabled = false;
1332 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1333 				    reserved_chanctx_list) {
1334 			if (ieee80211_vif_has_in_place_reservation(sdata) &&
1335 			    !sdata->reserved_ready)
1336 				return -EAGAIN;
1337 
1338 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1339 			if (old_ctx) {
1340 				if (old_ctx->replace_state ==
1341 				    IEEE80211_CHANCTX_WILL_BE_REPLACED)
1342 					n_vifs_switch++;
1343 				else
1344 					n_vifs_assign++;
1345 			} else {
1346 				n_vifs_ctxless++;
1347 			}
1348 
1349 			if (sdata->reserved_radar_required)
1350 				ctx->conf.radar_enabled = true;
1351 		}
1352 	}
1353 
1354 	if (WARN_ON(n_ctx == 0) ||
1355 	    WARN_ON(n_vifs_switch == 0 &&
1356 		    n_vifs_assign == 0 &&
1357 		    n_vifs_ctxless == 0) ||
1358 	    WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1359 	    WARN_ON(!new_ctx && !local->use_chanctx)) {
1360 		err = -EINVAL;
1361 		goto err;
1362 	}
1363 
1364 	/*
1365 	 * All necessary vifs are ready. Perform the switch now depending on
1366 	 * reservations and driver capabilities.
1367 	 */
1368 
1369 	if (local->use_chanctx) {
1370 		if (n_vifs_switch > 0) {
1371 			err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1372 			if (err)
1373 				goto err;
1374 		}
1375 
1376 		if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1377 			err = ieee80211_chsw_switch_ctxs(local);
1378 			if (err)
1379 				goto err;
1380 		}
1381 	} else {
1382 		err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1383 		if (err)
1384 			goto err;
1385 	}
1386 
1387 	/*
1388 	 * Update all structures, values and pointers to point to new channel
1389 	 * context(s).
1390 	 */
1391 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1392 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1393 			continue;
1394 
1395 		if (WARN_ON(!ctx->replace_ctx)) {
1396 			err = -EINVAL;
1397 			goto err;
1398 		}
1399 
1400 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1401 				    reserved_chanctx_list) {
1402 			u32 changed = 0;
1403 
1404 			if (!ieee80211_vif_has_in_place_reservation(sdata))
1405 				continue;
1406 
1407 			rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
1408 
1409 			if (sdata->vif.type == NL80211_IFTYPE_AP)
1410 				__ieee80211_vif_copy_chanctx_to_vlans(sdata,
1411 								      false);
1412 
1413 			ieee80211_check_fast_xmit_iface(sdata);
1414 
1415 			sdata->radar_required = sdata->reserved_radar_required;
1416 
1417 			if (sdata->vif.bss_conf.chandef.width !=
1418 			    sdata->reserved_chandef.width)
1419 				changed = BSS_CHANGED_BANDWIDTH;
1420 
1421 			ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1422 			if (changed)
1423 				ieee80211_bss_info_change_notify(sdata,
1424 								 changed);
1425 
1426 			ieee80211_recalc_txpower(sdata, false);
1427 		}
1428 
1429 		ieee80211_recalc_chanctx_chantype(local, ctx);
1430 		ieee80211_recalc_smps_chanctx(local, ctx);
1431 		ieee80211_recalc_radar_chanctx(local, ctx);
1432 		ieee80211_recalc_chanctx_min_def(local, ctx);
1433 
1434 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1435 					 reserved_chanctx_list) {
1436 			if (ieee80211_vif_get_chanctx(sdata) != ctx)
1437 				continue;
1438 
1439 			list_del(&sdata->reserved_chanctx_list);
1440 			list_move(&sdata->assigned_chanctx_list,
1441 				  &ctx->assigned_vifs);
1442 			sdata->reserved_chanctx = NULL;
1443 
1444 			ieee80211_vif_chanctx_reservation_complete(sdata);
1445 		}
1446 
1447 		/*
1448 		 * This context might have been a dependency for an already
1449 		 * ready re-assign reservation interface that was deferred. Do
1450 		 * not propagate error to the caller though. The in-place
1451 		 * reservation for originally requested interface has already
1452 		 * succeeded at this point.
1453 		 */
1454 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1455 					 reserved_chanctx_list) {
1456 			if (WARN_ON(ieee80211_vif_has_in_place_reservation(
1457 					sdata)))
1458 				continue;
1459 
1460 			if (WARN_ON(sdata->reserved_chanctx != ctx))
1461 				continue;
1462 
1463 			if (!sdata->reserved_ready)
1464 				continue;
1465 
1466 			if (ieee80211_vif_get_chanctx(sdata))
1467 				err = ieee80211_vif_use_reserved_reassign(
1468 						sdata);
1469 			else
1470 				err = ieee80211_vif_use_reserved_assign(sdata);
1471 
1472 			if (err) {
1473 				sdata_info(sdata,
1474 					   "failed to finalize (re-)assign reservation (err=%d)\n",
1475 					   err);
1476 				ieee80211_vif_unreserve_chanctx(sdata);
1477 				cfg80211_stop_iface(local->hw.wiphy,
1478 						    &sdata->wdev,
1479 						    GFP_KERNEL);
1480 			}
1481 		}
1482 	}
1483 
1484 	/*
1485 	 * Finally free old contexts
1486 	 */
1487 
1488 	list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1489 		if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1490 			continue;
1491 
1492 		ctx->replace_ctx->replace_ctx = NULL;
1493 		ctx->replace_ctx->replace_state =
1494 				IEEE80211_CHANCTX_REPLACE_NONE;
1495 
1496 		list_del_rcu(&ctx->list);
1497 		kfree_rcu(ctx, rcu_head);
1498 	}
1499 
1500 	return 0;
1501 
1502 err:
1503 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1504 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1505 			continue;
1506 
1507 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1508 					 reserved_chanctx_list) {
1509 			ieee80211_vif_unreserve_chanctx(sdata);
1510 			ieee80211_vif_chanctx_reservation_complete(sdata);
1511 		}
1512 	}
1513 
1514 	return err;
1515 }
1516 
1517 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1518 {
1519 	struct ieee80211_local *local = sdata->local;
1520 	struct ieee80211_chanctx_conf *conf;
1521 	struct ieee80211_chanctx *ctx;
1522 	bool use_reserved_switch = false;
1523 
1524 	lockdep_assert_held(&local->chanctx_mtx);
1525 
1526 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1527 					 lockdep_is_held(&local->chanctx_mtx));
1528 	if (!conf)
1529 		return;
1530 
1531 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1532 
1533 	if (sdata->reserved_chanctx) {
1534 		if (sdata->reserved_chanctx->replace_state ==
1535 		    IEEE80211_CHANCTX_REPLACES_OTHER &&
1536 		    ieee80211_chanctx_num_reserved(local,
1537 						   sdata->reserved_chanctx) > 1)
1538 			use_reserved_switch = true;
1539 
1540 		ieee80211_vif_unreserve_chanctx(sdata);
1541 	}
1542 
1543 	ieee80211_assign_vif_chanctx(sdata, NULL);
1544 	if (ieee80211_chanctx_refcount(local, ctx) == 0)
1545 		ieee80211_free_chanctx(local, ctx);
1546 
1547 	sdata->radar_required = false;
1548 
1549 	/* Unreserving may ready an in-place reservation. */
1550 	if (use_reserved_switch)
1551 		ieee80211_vif_use_reserved_switch(local);
1552 }
1553 
1554 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
1555 			      const struct cfg80211_chan_def *chandef,
1556 			      enum ieee80211_chanctx_mode mode)
1557 {
1558 	struct ieee80211_local *local = sdata->local;
1559 	struct ieee80211_chanctx *ctx;
1560 	u8 radar_detect_width = 0;
1561 	int ret;
1562 
1563 	lockdep_assert_held(&local->mtx);
1564 
1565 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1566 
1567 	mutex_lock(&local->chanctx_mtx);
1568 
1569 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1570 					    chandef,
1571 					    sdata->wdev.iftype);
1572 	if (ret < 0)
1573 		goto out;
1574 	if (ret > 0)
1575 		radar_detect_width = BIT(chandef->width);
1576 
1577 	sdata->radar_required = ret;
1578 
1579 	ret = ieee80211_check_combinations(sdata, chandef, mode,
1580 					   radar_detect_width);
1581 	if (ret < 0)
1582 		goto out;
1583 
1584 	__ieee80211_vif_release_channel(sdata);
1585 
1586 	ctx = ieee80211_find_chanctx(local, chandef, mode);
1587 	if (!ctx)
1588 		ctx = ieee80211_new_chanctx(local, chandef, mode);
1589 	if (IS_ERR(ctx)) {
1590 		ret = PTR_ERR(ctx);
1591 		goto out;
1592 	}
1593 
1594 	ieee80211_vif_update_chandef(sdata, chandef);
1595 
1596 	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
1597 	if (ret) {
1598 		/* if assign fails refcount stays the same */
1599 		if (ieee80211_chanctx_refcount(local, ctx) == 0)
1600 			ieee80211_free_chanctx(local, ctx);
1601 		goto out;
1602 	}
1603 
1604 	ieee80211_recalc_smps_chanctx(local, ctx);
1605 	ieee80211_recalc_radar_chanctx(local, ctx);
1606  out:
1607 	if (ret)
1608 		sdata->radar_required = false;
1609 
1610 	mutex_unlock(&local->chanctx_mtx);
1611 	return ret;
1612 }
1613 
1614 int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata)
1615 {
1616 	struct ieee80211_local *local = sdata->local;
1617 	struct ieee80211_chanctx *new_ctx;
1618 	struct ieee80211_chanctx *old_ctx;
1619 	int err;
1620 
1621 	lockdep_assert_held(&local->mtx);
1622 	lockdep_assert_held(&local->chanctx_mtx);
1623 
1624 	new_ctx = sdata->reserved_chanctx;
1625 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1626 
1627 	if (WARN_ON(!new_ctx))
1628 		return -EINVAL;
1629 
1630 	if (WARN_ON(new_ctx->replace_state ==
1631 		    IEEE80211_CHANCTX_WILL_BE_REPLACED))
1632 		return -EINVAL;
1633 
1634 	if (WARN_ON(sdata->reserved_ready))
1635 		return -EINVAL;
1636 
1637 	sdata->reserved_ready = true;
1638 
1639 	if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1640 		if (old_ctx)
1641 			err = ieee80211_vif_use_reserved_reassign(sdata);
1642 		else
1643 			err = ieee80211_vif_use_reserved_assign(sdata);
1644 
1645 		if (err)
1646 			return err;
1647 	}
1648 
1649 	/*
1650 	 * In-place reservation may need to be finalized now either if:
1651 	 *  a) sdata is taking part in the swapping itself and is the last one
1652 	 *  b) sdata has switched with a re-assign reservation to an existing
1653 	 *     context readying in-place switching of old_ctx
1654 	 *
1655 	 * In case of (b) do not propagate the error up because the requested
1656 	 * sdata already switched successfully. Just spill an extra warning.
1657 	 * The ieee80211_vif_use_reserved_switch() already stops all necessary
1658 	 * interfaces upon failure.
1659 	 */
1660 	if ((old_ctx &&
1661 	     old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1662 	    new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1663 		err = ieee80211_vif_use_reserved_switch(local);
1664 		if (err && err != -EAGAIN) {
1665 			if (new_ctx->replace_state ==
1666 			    IEEE80211_CHANCTX_REPLACES_OTHER)
1667 				return err;
1668 
1669 			wiphy_info(local->hw.wiphy,
1670 				   "depending in-place reservation failed (err=%d)\n",
1671 				   err);
1672 		}
1673 	}
1674 
1675 	return 0;
1676 }
1677 
1678 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
1679 				   const struct cfg80211_chan_def *chandef,
1680 				   u32 *changed)
1681 {
1682 	struct ieee80211_local *local = sdata->local;
1683 	struct ieee80211_chanctx_conf *conf;
1684 	struct ieee80211_chanctx *ctx;
1685 	const struct cfg80211_chan_def *compat;
1686 	int ret;
1687 
1688 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1689 				     IEEE80211_CHAN_DISABLED))
1690 		return -EINVAL;
1691 
1692 	mutex_lock(&local->chanctx_mtx);
1693 	if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
1694 		ret = 0;
1695 		goto out;
1696 	}
1697 
1698 	if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1699 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1700 		ret = -EINVAL;
1701 		goto out;
1702 	}
1703 
1704 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1705 					 lockdep_is_held(&local->chanctx_mtx));
1706 	if (!conf) {
1707 		ret = -EINVAL;
1708 		goto out;
1709 	}
1710 
1711 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1712 
1713 	compat = cfg80211_chandef_compatible(&conf->def, chandef);
1714 	if (!compat) {
1715 		ret = -EINVAL;
1716 		goto out;
1717 	}
1718 
1719 	switch (ctx->replace_state) {
1720 	case IEEE80211_CHANCTX_REPLACE_NONE:
1721 		if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1722 			ret = -EBUSY;
1723 			goto out;
1724 		}
1725 		break;
1726 	case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1727 		/* TODO: Perhaps the bandwidth change could be treated as a
1728 		 * reservation itself? */
1729 		ret = -EBUSY;
1730 		goto out;
1731 	case IEEE80211_CHANCTX_REPLACES_OTHER:
1732 		/* channel context that is going to replace another channel
1733 		 * context doesn't really exist and shouldn't be assigned
1734 		 * anywhere yet */
1735 		WARN_ON(1);
1736 		break;
1737 	}
1738 
1739 	ieee80211_vif_update_chandef(sdata, chandef);
1740 
1741 	ieee80211_recalc_chanctx_chantype(local, ctx);
1742 
1743 	*changed |= BSS_CHANGED_BANDWIDTH;
1744 	ret = 0;
1745  out:
1746 	mutex_unlock(&local->chanctx_mtx);
1747 	return ret;
1748 }
1749 
1750 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1751 {
1752 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1753 
1754 	lockdep_assert_held(&sdata->local->mtx);
1755 
1756 	mutex_lock(&sdata->local->chanctx_mtx);
1757 	__ieee80211_vif_release_channel(sdata);
1758 	mutex_unlock(&sdata->local->chanctx_mtx);
1759 }
1760 
1761 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
1762 {
1763 	struct ieee80211_local *local = sdata->local;
1764 	struct ieee80211_sub_if_data *ap;
1765 	struct ieee80211_chanctx_conf *conf;
1766 
1767 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
1768 		return;
1769 
1770 	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
1771 
1772 	mutex_lock(&local->chanctx_mtx);
1773 
1774 	conf = rcu_dereference_protected(ap->vif.chanctx_conf,
1775 					 lockdep_is_held(&local->chanctx_mtx));
1776 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
1777 	mutex_unlock(&local->chanctx_mtx);
1778 }
1779 
1780 void ieee80211_iter_chan_contexts_atomic(
1781 	struct ieee80211_hw *hw,
1782 	void (*iter)(struct ieee80211_hw *hw,
1783 		     struct ieee80211_chanctx_conf *chanctx_conf,
1784 		     void *data),
1785 	void *iter_data)
1786 {
1787 	struct ieee80211_local *local = hw_to_local(hw);
1788 	struct ieee80211_chanctx *ctx;
1789 
1790 	rcu_read_lock();
1791 	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
1792 		if (ctx->driver_present)
1793 			iter(hw, &ctx->conf, iter_data);
1794 	rcu_read_unlock();
1795 }
1796 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);
1797