xref: /openbmc/linux/net/mac80211/chan.c (revision 5df29bca)
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)
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 		return;
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 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
648 					 lockdep_is_held(&local->chanctx_mtx));
649 
650 	if (conf) {
651 		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
652 
653 		drv_unassign_vif_chanctx(local, sdata, curr_ctx);
654 		conf = NULL;
655 		list_del(&sdata->assigned_chanctx_list);
656 	}
657 
658 	if (new_ctx) {
659 		ret = drv_assign_vif_chanctx(local, sdata, new_ctx);
660 		if (ret)
661 			goto out;
662 
663 		conf = &new_ctx->conf;
664 		list_add(&sdata->assigned_chanctx_list,
665 			 &new_ctx->assigned_vifs);
666 	}
667 
668 out:
669 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
670 
671 	sdata->vif.bss_conf.idle = !conf;
672 
673 	if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
674 		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
675 		ieee80211_recalc_smps_chanctx(local, curr_ctx);
676 		ieee80211_recalc_radar_chanctx(local, curr_ctx);
677 		ieee80211_recalc_chanctx_min_def(local, curr_ctx);
678 	}
679 
680 	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
681 		ieee80211_recalc_txpower(sdata, false);
682 		ieee80211_recalc_chanctx_min_def(local, new_ctx);
683 	}
684 
685 	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
686 	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
687 		ieee80211_bss_info_change_notify(sdata,
688 						 BSS_CHANGED_IDLE);
689 
690 	ieee80211_check_fast_xmit_iface(sdata);
691 
692 	return ret;
693 }
694 
695 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
696 				   struct ieee80211_chanctx *chanctx)
697 {
698 	struct ieee80211_sub_if_data *sdata;
699 	u8 rx_chains_static, rx_chains_dynamic;
700 
701 	lockdep_assert_held(&local->chanctx_mtx);
702 
703 	rx_chains_static = 1;
704 	rx_chains_dynamic = 1;
705 
706 	rcu_read_lock();
707 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
708 		u8 needed_static, needed_dynamic;
709 
710 		if (!ieee80211_sdata_running(sdata))
711 			continue;
712 
713 		if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
714 						&chanctx->conf)
715 			continue;
716 
717 		switch (sdata->vif.type) {
718 		case NL80211_IFTYPE_P2P_DEVICE:
719 			continue;
720 		case NL80211_IFTYPE_STATION:
721 			if (!sdata->u.mgd.associated)
722 				continue;
723 			break;
724 		case NL80211_IFTYPE_AP_VLAN:
725 			continue;
726 		case NL80211_IFTYPE_AP:
727 		case NL80211_IFTYPE_ADHOC:
728 		case NL80211_IFTYPE_WDS:
729 		case NL80211_IFTYPE_MESH_POINT:
730 		case NL80211_IFTYPE_OCB:
731 			break;
732 		default:
733 			WARN_ON_ONCE(1);
734 		}
735 
736 		switch (sdata->smps_mode) {
737 		default:
738 			WARN_ONCE(1, "Invalid SMPS mode %d\n",
739 				  sdata->smps_mode);
740 			/* fall through */
741 		case IEEE80211_SMPS_OFF:
742 			needed_static = sdata->needed_rx_chains;
743 			needed_dynamic = sdata->needed_rx_chains;
744 			break;
745 		case IEEE80211_SMPS_DYNAMIC:
746 			needed_static = 1;
747 			needed_dynamic = sdata->needed_rx_chains;
748 			break;
749 		case IEEE80211_SMPS_STATIC:
750 			needed_static = 1;
751 			needed_dynamic = 1;
752 			break;
753 		}
754 
755 		rx_chains_static = max(rx_chains_static, needed_static);
756 		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
757 	}
758 
759 	/* Disable SMPS for the monitor interface */
760 	sdata = rcu_dereference(local->monitor_sdata);
761 	if (sdata &&
762 	    rcu_access_pointer(sdata->vif.chanctx_conf) == &chanctx->conf)
763 		rx_chains_dynamic = rx_chains_static = local->rx_chains;
764 
765 	rcu_read_unlock();
766 
767 	if (!local->use_chanctx) {
768 		if (rx_chains_static > 1)
769 			local->smps_mode = IEEE80211_SMPS_OFF;
770 		else if (rx_chains_dynamic > 1)
771 			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
772 		else
773 			local->smps_mode = IEEE80211_SMPS_STATIC;
774 		ieee80211_hw_config(local, 0);
775 	}
776 
777 	if (rx_chains_static == chanctx->conf.rx_chains_static &&
778 	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
779 		return;
780 
781 	chanctx->conf.rx_chains_static = rx_chains_static;
782 	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
783 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
784 }
785 
786 static void
787 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
788 				      bool clear)
789 {
790 	struct ieee80211_local *local __maybe_unused = sdata->local;
791 	struct ieee80211_sub_if_data *vlan;
792 	struct ieee80211_chanctx_conf *conf;
793 
794 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
795 		return;
796 
797 	lockdep_assert_held(&local->mtx);
798 
799 	/* Check that conf exists, even when clearing this function
800 	 * must be called with the AP's channel context still there
801 	 * as it would otherwise cause VLANs to have an invalid
802 	 * channel context pointer for a while, possibly pointing
803 	 * to a channel context that has already been freed.
804 	 */
805 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
806 					 lockdep_is_held(&local->chanctx_mtx));
807 	WARN_ON(!conf);
808 
809 	if (clear)
810 		conf = NULL;
811 
812 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
813 		rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
814 }
815 
816 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
817 					 bool clear)
818 {
819 	struct ieee80211_local *local = sdata->local;
820 
821 	mutex_lock(&local->chanctx_mtx);
822 
823 	__ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
824 
825 	mutex_unlock(&local->chanctx_mtx);
826 }
827 
828 int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
829 {
830 	struct ieee80211_chanctx *ctx = sdata->reserved_chanctx;
831 
832 	lockdep_assert_held(&sdata->local->chanctx_mtx);
833 
834 	if (WARN_ON(!ctx))
835 		return -EINVAL;
836 
837 	list_del(&sdata->reserved_chanctx_list);
838 	sdata->reserved_chanctx = NULL;
839 
840 	if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
841 		if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
842 			if (WARN_ON(!ctx->replace_ctx))
843 				return -EINVAL;
844 
845 			WARN_ON(ctx->replace_ctx->replace_state !=
846 			        IEEE80211_CHANCTX_WILL_BE_REPLACED);
847 			WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
848 
849 			ctx->replace_ctx->replace_ctx = NULL;
850 			ctx->replace_ctx->replace_state =
851 					IEEE80211_CHANCTX_REPLACE_NONE;
852 
853 			list_del_rcu(&ctx->list);
854 			kfree_rcu(ctx, rcu_head);
855 		} else {
856 			ieee80211_free_chanctx(sdata->local, ctx);
857 		}
858 	}
859 
860 	return 0;
861 }
862 
863 int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
864 				  const struct cfg80211_chan_def *chandef,
865 				  enum ieee80211_chanctx_mode mode,
866 				  bool radar_required)
867 {
868 	struct ieee80211_local *local = sdata->local;
869 	struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
870 
871 	lockdep_assert_held(&local->chanctx_mtx);
872 
873 	curr_ctx = ieee80211_vif_get_chanctx(sdata);
874 	if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
875 		return -ENOTSUPP;
876 
877 	new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
878 	if (!new_ctx) {
879 		if (ieee80211_can_create_new_chanctx(local)) {
880 			new_ctx = ieee80211_new_chanctx(local, chandef, mode);
881 			if (IS_ERR(new_ctx))
882 				return PTR_ERR(new_ctx);
883 		} else {
884 			if (!curr_ctx ||
885 			    (curr_ctx->replace_state ==
886 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
887 			    !list_empty(&curr_ctx->reserved_vifs)) {
888 				/*
889 				 * Another vif already requested this context
890 				 * for a reservation. Find another one hoping
891 				 * all vifs assigned to it will also switch
892 				 * soon enough.
893 				 *
894 				 * TODO: This needs a little more work as some
895 				 * cases (more than 2 chanctx capable devices)
896 				 * may fail which could otherwise succeed
897 				 * provided some channel context juggling was
898 				 * performed.
899 				 *
900 				 * Consider ctx1..3, vif1..6, each ctx has 2
901 				 * vifs. vif1 and vif2 from ctx1 request new
902 				 * different chandefs starting 2 in-place
903 				 * reserations with ctx4 and ctx5 replacing
904 				 * ctx1 and ctx2 respectively. Next vif5 and
905 				 * vif6 from ctx3 reserve ctx4. If vif3 and
906 				 * vif4 remain on ctx2 as they are then this
907 				 * fails unless `replace_ctx` from ctx5 is
908 				 * replaced with ctx3.
909 				 */
910 				list_for_each_entry(ctx, &local->chanctx_list,
911 						    list) {
912 					if (ctx->replace_state !=
913 					    IEEE80211_CHANCTX_REPLACE_NONE)
914 						continue;
915 
916 					if (!list_empty(&ctx->reserved_vifs))
917 						continue;
918 
919 					curr_ctx = ctx;
920 					break;
921 				}
922 			}
923 
924 			/*
925 			 * If that's true then all available contexts already
926 			 * have reservations and cannot be used.
927 			 */
928 			if (!curr_ctx ||
929 			    (curr_ctx->replace_state ==
930 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
931 			    !list_empty(&curr_ctx->reserved_vifs))
932 				return -EBUSY;
933 
934 			new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
935 			if (!new_ctx)
936 				return -ENOMEM;
937 
938 			new_ctx->replace_ctx = curr_ctx;
939 			new_ctx->replace_state =
940 					IEEE80211_CHANCTX_REPLACES_OTHER;
941 
942 			curr_ctx->replace_ctx = new_ctx;
943 			curr_ctx->replace_state =
944 					IEEE80211_CHANCTX_WILL_BE_REPLACED;
945 
946 			list_add_rcu(&new_ctx->list, &local->chanctx_list);
947 		}
948 	}
949 
950 	list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);
951 	sdata->reserved_chanctx = new_ctx;
952 	sdata->reserved_chandef = *chandef;
953 	sdata->reserved_radar_required = radar_required;
954 	sdata->reserved_ready = false;
955 
956 	return 0;
957 }
958 
959 static void
960 ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
961 {
962 	switch (sdata->vif.type) {
963 	case NL80211_IFTYPE_ADHOC:
964 	case NL80211_IFTYPE_AP:
965 	case NL80211_IFTYPE_MESH_POINT:
966 	case NL80211_IFTYPE_OCB:
967 		ieee80211_queue_work(&sdata->local->hw,
968 				     &sdata->csa_finalize_work);
969 		break;
970 	case NL80211_IFTYPE_STATION:
971 		ieee80211_queue_work(&sdata->local->hw,
972 				     &sdata->u.mgd.chswitch_work);
973 		break;
974 	case NL80211_IFTYPE_UNSPECIFIED:
975 	case NL80211_IFTYPE_AP_VLAN:
976 	case NL80211_IFTYPE_WDS:
977 	case NL80211_IFTYPE_MONITOR:
978 	case NL80211_IFTYPE_P2P_CLIENT:
979 	case NL80211_IFTYPE_P2P_GO:
980 	case NL80211_IFTYPE_P2P_DEVICE:
981 	case NUM_NL80211_IFTYPES:
982 		WARN_ON(1);
983 		break;
984 	}
985 }
986 
987 static void
988 ieee80211_vif_update_chandef(struct ieee80211_sub_if_data *sdata,
989 			     const struct cfg80211_chan_def *chandef)
990 {
991 	struct ieee80211_sub_if_data *vlan;
992 
993 	sdata->vif.bss_conf.chandef = *chandef;
994 
995 	if (sdata->vif.type != NL80211_IFTYPE_AP)
996 		return;
997 
998 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
999 		vlan->vif.bss_conf.chandef = *chandef;
1000 }
1001 
1002 static int
1003 ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
1004 {
1005 	struct ieee80211_local *local = sdata->local;
1006 	struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1007 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1008 	const struct cfg80211_chan_def *chandef;
1009 	u32 changed = 0;
1010 	int err;
1011 
1012 	lockdep_assert_held(&local->mtx);
1013 	lockdep_assert_held(&local->chanctx_mtx);
1014 
1015 	new_ctx = sdata->reserved_chanctx;
1016 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1017 
1018 	if (WARN_ON(!sdata->reserved_ready))
1019 		return -EBUSY;
1020 
1021 	if (WARN_ON(!new_ctx))
1022 		return -EINVAL;
1023 
1024 	if (WARN_ON(!old_ctx))
1025 		return -EINVAL;
1026 
1027 	if (WARN_ON(new_ctx->replace_state ==
1028 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1029 		return -EINVAL;
1030 
1031 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1032 				&sdata->reserved_chandef);
1033 	if (WARN_ON(!chandef))
1034 		return -EINVAL;
1035 
1036 	ieee80211_change_chanctx(local, new_ctx, chandef);
1037 
1038 	vif_chsw[0].vif = &sdata->vif;
1039 	vif_chsw[0].old_ctx = &old_ctx->conf;
1040 	vif_chsw[0].new_ctx = &new_ctx->conf;
1041 
1042 	list_del(&sdata->reserved_chanctx_list);
1043 	sdata->reserved_chanctx = NULL;
1044 
1045 	err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1046 				     CHANCTX_SWMODE_REASSIGN_VIF);
1047 	if (err) {
1048 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1049 			ieee80211_free_chanctx(local, new_ctx);
1050 
1051 		goto out;
1052 	}
1053 
1054 	list_move(&sdata->assigned_chanctx_list, &new_ctx->assigned_vifs);
1055 	rcu_assign_pointer(sdata->vif.chanctx_conf, &new_ctx->conf);
1056 
1057 	if (sdata->vif.type == NL80211_IFTYPE_AP)
1058 		__ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
1059 
1060 	ieee80211_check_fast_xmit_iface(sdata);
1061 
1062 	if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1063 		ieee80211_free_chanctx(local, old_ctx);
1064 
1065 	if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
1066 		changed = BSS_CHANGED_BANDWIDTH;
1067 
1068 	ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1069 
1070 	ieee80211_recalc_smps_chanctx(local, new_ctx);
1071 	ieee80211_recalc_radar_chanctx(local, new_ctx);
1072 	ieee80211_recalc_chanctx_min_def(local, new_ctx);
1073 
1074 	if (changed)
1075 		ieee80211_bss_info_change_notify(sdata, changed);
1076 
1077 out:
1078 	ieee80211_vif_chanctx_reservation_complete(sdata);
1079 	return err;
1080 }
1081 
1082 static int
1083 ieee80211_vif_use_reserved_assign(struct ieee80211_sub_if_data *sdata)
1084 {
1085 	struct ieee80211_local *local = sdata->local;
1086 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1087 	const struct cfg80211_chan_def *chandef;
1088 	int err;
1089 
1090 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1091 	new_ctx = sdata->reserved_chanctx;
1092 
1093 	if (WARN_ON(!sdata->reserved_ready))
1094 		return -EINVAL;
1095 
1096 	if (WARN_ON(old_ctx))
1097 		return -EINVAL;
1098 
1099 	if (WARN_ON(!new_ctx))
1100 		return -EINVAL;
1101 
1102 	if (WARN_ON(new_ctx->replace_state ==
1103 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1104 		return -EINVAL;
1105 
1106 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1107 				&sdata->reserved_chandef);
1108 	if (WARN_ON(!chandef))
1109 		return -EINVAL;
1110 
1111 	ieee80211_change_chanctx(local, new_ctx, chandef);
1112 
1113 	list_del(&sdata->reserved_chanctx_list);
1114 	sdata->reserved_chanctx = NULL;
1115 
1116 	err = ieee80211_assign_vif_chanctx(sdata, new_ctx);
1117 	if (err) {
1118 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1119 			ieee80211_free_chanctx(local, new_ctx);
1120 
1121 		goto out;
1122 	}
1123 
1124 out:
1125 	ieee80211_vif_chanctx_reservation_complete(sdata);
1126 	return err;
1127 }
1128 
1129 static bool
1130 ieee80211_vif_has_in_place_reservation(struct ieee80211_sub_if_data *sdata)
1131 {
1132 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1133 
1134 	lockdep_assert_held(&sdata->local->chanctx_mtx);
1135 
1136 	new_ctx = sdata->reserved_chanctx;
1137 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1138 
1139 	if (!old_ctx)
1140 		return false;
1141 
1142 	if (WARN_ON(!new_ctx))
1143 		return false;
1144 
1145 	if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1146 		return false;
1147 
1148 	if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1149 		return false;
1150 
1151 	return true;
1152 }
1153 
1154 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1155 					struct ieee80211_chanctx *new_ctx)
1156 {
1157 	const struct cfg80211_chan_def *chandef;
1158 
1159 	lockdep_assert_held(&local->mtx);
1160 	lockdep_assert_held(&local->chanctx_mtx);
1161 
1162 	chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1163 	if (WARN_ON(!chandef))
1164 		return -EINVAL;
1165 
1166 	local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1167 	local->_oper_chandef = *chandef;
1168 	ieee80211_hw_config(local, 0);
1169 
1170 	return 0;
1171 }
1172 
1173 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1174 				      int n_vifs)
1175 {
1176 	struct ieee80211_vif_chanctx_switch *vif_chsw;
1177 	struct ieee80211_sub_if_data *sdata;
1178 	struct ieee80211_chanctx *ctx, *old_ctx;
1179 	int i, err;
1180 
1181 	lockdep_assert_held(&local->mtx);
1182 	lockdep_assert_held(&local->chanctx_mtx);
1183 
1184 	vif_chsw = kzalloc(sizeof(vif_chsw[0]) * n_vifs, GFP_KERNEL);
1185 	if (!vif_chsw)
1186 		return -ENOMEM;
1187 
1188 	i = 0;
1189 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1190 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1191 			continue;
1192 
1193 		if (WARN_ON(!ctx->replace_ctx)) {
1194 			err = -EINVAL;
1195 			goto out;
1196 		}
1197 
1198 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1199 				    reserved_chanctx_list) {
1200 			if (!ieee80211_vif_has_in_place_reservation(
1201 					sdata))
1202 				continue;
1203 
1204 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1205 			vif_chsw[i].vif = &sdata->vif;
1206 			vif_chsw[i].old_ctx = &old_ctx->conf;
1207 			vif_chsw[i].new_ctx = &ctx->conf;
1208 
1209 			i++;
1210 		}
1211 	}
1212 
1213 	err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1214 				     CHANCTX_SWMODE_SWAP_CONTEXTS);
1215 
1216 out:
1217 	kfree(vif_chsw);
1218 	return err;
1219 }
1220 
1221 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1222 {
1223 	struct ieee80211_chanctx *ctx;
1224 	int err;
1225 
1226 	lockdep_assert_held(&local->mtx);
1227 	lockdep_assert_held(&local->chanctx_mtx);
1228 
1229 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1230 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1231 			continue;
1232 
1233 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1234 			continue;
1235 
1236 		ieee80211_del_chanctx(local, ctx->replace_ctx);
1237 		err = ieee80211_add_chanctx(local, ctx);
1238 		if (err)
1239 			goto err;
1240 	}
1241 
1242 	return 0;
1243 
1244 err:
1245 	WARN_ON(ieee80211_add_chanctx(local, ctx));
1246 	list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1247 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1248 			continue;
1249 
1250 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1251 			continue;
1252 
1253 		ieee80211_del_chanctx(local, ctx);
1254 		WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1255 	}
1256 
1257 	return err;
1258 }
1259 
1260 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1261 {
1262 	struct ieee80211_sub_if_data *sdata, *sdata_tmp;
1263 	struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1264 	struct ieee80211_chanctx *new_ctx = NULL;
1265 	int i, err, n_assigned, n_reserved, n_ready;
1266 	int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1267 
1268 	lockdep_assert_held(&local->mtx);
1269 	lockdep_assert_held(&local->chanctx_mtx);
1270 
1271 	/*
1272 	 * If there are 2 independent pairs of channel contexts performing
1273 	 * cross-switch of their vifs this code will still wait until both are
1274 	 * ready even though it could be possible to switch one before the
1275 	 * other is ready.
1276 	 *
1277 	 * For practical reasons and code simplicity just do a single huge
1278 	 * switch.
1279 	 */
1280 
1281 	/*
1282 	 * Verify if the reservation is still feasible.
1283 	 *  - if it's not then disconnect
1284 	 *  - if it is but not all vifs necessary are ready then defer
1285 	 */
1286 
1287 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1288 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1289 			continue;
1290 
1291 		if (WARN_ON(!ctx->replace_ctx)) {
1292 			err = -EINVAL;
1293 			goto err;
1294 		}
1295 
1296 		if (!local->use_chanctx)
1297 			new_ctx = ctx;
1298 
1299 		n_ctx++;
1300 
1301 		n_assigned = 0;
1302 		n_reserved = 0;
1303 		n_ready = 0;
1304 
1305 		list_for_each_entry(sdata, &ctx->replace_ctx->assigned_vifs,
1306 				    assigned_chanctx_list) {
1307 			n_assigned++;
1308 			if (sdata->reserved_chanctx) {
1309 				n_reserved++;
1310 				if (sdata->reserved_ready)
1311 					n_ready++;
1312 			}
1313 		}
1314 
1315 		if (n_assigned != n_reserved) {
1316 			if (n_ready == n_reserved) {
1317 				wiphy_info(local->hw.wiphy,
1318 					   "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1319 				err = -EBUSY;
1320 				goto err;
1321 			}
1322 
1323 			return -EAGAIN;
1324 		}
1325 
1326 		ctx->conf.radar_enabled = false;
1327 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1328 				    reserved_chanctx_list) {
1329 			if (ieee80211_vif_has_in_place_reservation(sdata) &&
1330 			    !sdata->reserved_ready)
1331 				return -EAGAIN;
1332 
1333 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1334 			if (old_ctx) {
1335 				if (old_ctx->replace_state ==
1336 				    IEEE80211_CHANCTX_WILL_BE_REPLACED)
1337 					n_vifs_switch++;
1338 				else
1339 					n_vifs_assign++;
1340 			} else {
1341 				n_vifs_ctxless++;
1342 			}
1343 
1344 			if (sdata->reserved_radar_required)
1345 				ctx->conf.radar_enabled = true;
1346 		}
1347 	}
1348 
1349 	if (WARN_ON(n_ctx == 0) ||
1350 	    WARN_ON(n_vifs_switch == 0 &&
1351 		    n_vifs_assign == 0 &&
1352 		    n_vifs_ctxless == 0) ||
1353 	    WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1354 	    WARN_ON(!new_ctx && !local->use_chanctx)) {
1355 		err = -EINVAL;
1356 		goto err;
1357 	}
1358 
1359 	/*
1360 	 * All necessary vifs are ready. Perform the switch now depending on
1361 	 * reservations and driver capabilities.
1362 	 */
1363 
1364 	if (local->use_chanctx) {
1365 		if (n_vifs_switch > 0) {
1366 			err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1367 			if (err)
1368 				goto err;
1369 		}
1370 
1371 		if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1372 			err = ieee80211_chsw_switch_ctxs(local);
1373 			if (err)
1374 				goto err;
1375 		}
1376 	} else {
1377 		err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1378 		if (err)
1379 			goto err;
1380 	}
1381 
1382 	/*
1383 	 * Update all structures, values and pointers to point to new channel
1384 	 * context(s).
1385 	 */
1386 
1387 	i = 0;
1388 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1389 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1390 			continue;
1391 
1392 		if (WARN_ON(!ctx->replace_ctx)) {
1393 			err = -EINVAL;
1394 			goto err;
1395 		}
1396 
1397 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1398 				    reserved_chanctx_list) {
1399 			u32 changed = 0;
1400 
1401 			if (!ieee80211_vif_has_in_place_reservation(sdata))
1402 				continue;
1403 
1404 			rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
1405 
1406 			if (sdata->vif.type == NL80211_IFTYPE_AP)
1407 				__ieee80211_vif_copy_chanctx_to_vlans(sdata,
1408 								      false);
1409 
1410 			ieee80211_check_fast_xmit_iface(sdata);
1411 
1412 			sdata->radar_required = sdata->reserved_radar_required;
1413 
1414 			if (sdata->vif.bss_conf.chandef.width !=
1415 			    sdata->reserved_chandef.width)
1416 				changed = BSS_CHANGED_BANDWIDTH;
1417 
1418 			ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1419 			if (changed)
1420 				ieee80211_bss_info_change_notify(sdata,
1421 								 changed);
1422 
1423 			ieee80211_recalc_txpower(sdata, false);
1424 		}
1425 
1426 		ieee80211_recalc_chanctx_chantype(local, ctx);
1427 		ieee80211_recalc_smps_chanctx(local, ctx);
1428 		ieee80211_recalc_radar_chanctx(local, ctx);
1429 		ieee80211_recalc_chanctx_min_def(local, ctx);
1430 
1431 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1432 					 reserved_chanctx_list) {
1433 			if (ieee80211_vif_get_chanctx(sdata) != ctx)
1434 				continue;
1435 
1436 			list_del(&sdata->reserved_chanctx_list);
1437 			list_move(&sdata->assigned_chanctx_list,
1438 				  &ctx->assigned_vifs);
1439 			sdata->reserved_chanctx = NULL;
1440 
1441 			ieee80211_vif_chanctx_reservation_complete(sdata);
1442 		}
1443 
1444 		/*
1445 		 * This context might have been a dependency for an already
1446 		 * ready re-assign reservation interface that was deferred. Do
1447 		 * not propagate error to the caller though. The in-place
1448 		 * reservation for originally requested interface has already
1449 		 * succeeded at this point.
1450 		 */
1451 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1452 					 reserved_chanctx_list) {
1453 			if (WARN_ON(ieee80211_vif_has_in_place_reservation(
1454 					sdata)))
1455 				continue;
1456 
1457 			if (WARN_ON(sdata->reserved_chanctx != ctx))
1458 				continue;
1459 
1460 			if (!sdata->reserved_ready)
1461 				continue;
1462 
1463 			if (ieee80211_vif_get_chanctx(sdata))
1464 				err = ieee80211_vif_use_reserved_reassign(
1465 						sdata);
1466 			else
1467 				err = ieee80211_vif_use_reserved_assign(sdata);
1468 
1469 			if (err) {
1470 				sdata_info(sdata,
1471 					   "failed to finalize (re-)assign reservation (err=%d)\n",
1472 					   err);
1473 				ieee80211_vif_unreserve_chanctx(sdata);
1474 				cfg80211_stop_iface(local->hw.wiphy,
1475 						    &sdata->wdev,
1476 						    GFP_KERNEL);
1477 			}
1478 		}
1479 	}
1480 
1481 	/*
1482 	 * Finally free old contexts
1483 	 */
1484 
1485 	list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1486 		if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1487 			continue;
1488 
1489 		ctx->replace_ctx->replace_ctx = NULL;
1490 		ctx->replace_ctx->replace_state =
1491 				IEEE80211_CHANCTX_REPLACE_NONE;
1492 
1493 		list_del_rcu(&ctx->list);
1494 		kfree_rcu(ctx, rcu_head);
1495 	}
1496 
1497 	return 0;
1498 
1499 err:
1500 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1501 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1502 			continue;
1503 
1504 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1505 					 reserved_chanctx_list) {
1506 			ieee80211_vif_unreserve_chanctx(sdata);
1507 			ieee80211_vif_chanctx_reservation_complete(sdata);
1508 		}
1509 	}
1510 
1511 	return err;
1512 }
1513 
1514 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1515 {
1516 	struct ieee80211_local *local = sdata->local;
1517 	struct ieee80211_chanctx_conf *conf;
1518 	struct ieee80211_chanctx *ctx;
1519 	bool use_reserved_switch = false;
1520 
1521 	lockdep_assert_held(&local->chanctx_mtx);
1522 
1523 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1524 					 lockdep_is_held(&local->chanctx_mtx));
1525 	if (!conf)
1526 		return;
1527 
1528 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1529 
1530 	if (sdata->reserved_chanctx) {
1531 		if (sdata->reserved_chanctx->replace_state ==
1532 		    IEEE80211_CHANCTX_REPLACES_OTHER &&
1533 		    ieee80211_chanctx_num_reserved(local,
1534 						   sdata->reserved_chanctx) > 1)
1535 			use_reserved_switch = true;
1536 
1537 		ieee80211_vif_unreserve_chanctx(sdata);
1538 	}
1539 
1540 	ieee80211_assign_vif_chanctx(sdata, NULL);
1541 	if (ieee80211_chanctx_refcount(local, ctx) == 0)
1542 		ieee80211_free_chanctx(local, ctx);
1543 
1544 	sdata->radar_required = false;
1545 
1546 	/* Unreserving may ready an in-place reservation. */
1547 	if (use_reserved_switch)
1548 		ieee80211_vif_use_reserved_switch(local);
1549 }
1550 
1551 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
1552 			      const struct cfg80211_chan_def *chandef,
1553 			      enum ieee80211_chanctx_mode mode)
1554 {
1555 	struct ieee80211_local *local = sdata->local;
1556 	struct ieee80211_chanctx *ctx;
1557 	u8 radar_detect_width = 0;
1558 	int ret;
1559 
1560 	lockdep_assert_held(&local->mtx);
1561 
1562 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1563 
1564 	mutex_lock(&local->chanctx_mtx);
1565 
1566 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1567 					    chandef,
1568 					    sdata->wdev.iftype);
1569 	if (ret < 0)
1570 		goto out;
1571 	if (ret > 0)
1572 		radar_detect_width = BIT(chandef->width);
1573 
1574 	sdata->radar_required = ret;
1575 
1576 	ret = ieee80211_check_combinations(sdata, chandef, mode,
1577 					   radar_detect_width);
1578 	if (ret < 0)
1579 		goto out;
1580 
1581 	__ieee80211_vif_release_channel(sdata);
1582 
1583 	ctx = ieee80211_find_chanctx(local, chandef, mode);
1584 	if (!ctx)
1585 		ctx = ieee80211_new_chanctx(local, chandef, mode);
1586 	if (IS_ERR(ctx)) {
1587 		ret = PTR_ERR(ctx);
1588 		goto out;
1589 	}
1590 
1591 	ieee80211_vif_update_chandef(sdata, chandef);
1592 
1593 	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
1594 	if (ret) {
1595 		/* if assign fails refcount stays the same */
1596 		if (ieee80211_chanctx_refcount(local, ctx) == 0)
1597 			ieee80211_free_chanctx(local, ctx);
1598 		goto out;
1599 	}
1600 
1601 	ieee80211_recalc_smps_chanctx(local, ctx);
1602 	ieee80211_recalc_radar_chanctx(local, ctx);
1603  out:
1604 	if (ret)
1605 		sdata->radar_required = false;
1606 
1607 	mutex_unlock(&local->chanctx_mtx);
1608 	return ret;
1609 }
1610 
1611 int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata)
1612 {
1613 	struct ieee80211_local *local = sdata->local;
1614 	struct ieee80211_chanctx *new_ctx;
1615 	struct ieee80211_chanctx *old_ctx;
1616 	int err;
1617 
1618 	lockdep_assert_held(&local->mtx);
1619 	lockdep_assert_held(&local->chanctx_mtx);
1620 
1621 	new_ctx = sdata->reserved_chanctx;
1622 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1623 
1624 	if (WARN_ON(!new_ctx))
1625 		return -EINVAL;
1626 
1627 	if (WARN_ON(new_ctx->replace_state ==
1628 		    IEEE80211_CHANCTX_WILL_BE_REPLACED))
1629 		return -EINVAL;
1630 
1631 	if (WARN_ON(sdata->reserved_ready))
1632 		return -EINVAL;
1633 
1634 	sdata->reserved_ready = true;
1635 
1636 	if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1637 		if (old_ctx)
1638 			err = ieee80211_vif_use_reserved_reassign(sdata);
1639 		else
1640 			err = ieee80211_vif_use_reserved_assign(sdata);
1641 
1642 		if (err)
1643 			return err;
1644 	}
1645 
1646 	/*
1647 	 * In-place reservation may need to be finalized now either if:
1648 	 *  a) sdata is taking part in the swapping itself and is the last one
1649 	 *  b) sdata has switched with a re-assign reservation to an existing
1650 	 *     context readying in-place switching of old_ctx
1651 	 *
1652 	 * In case of (b) do not propagate the error up because the requested
1653 	 * sdata already switched successfully. Just spill an extra warning.
1654 	 * The ieee80211_vif_use_reserved_switch() already stops all necessary
1655 	 * interfaces upon failure.
1656 	 */
1657 	if ((old_ctx &&
1658 	     old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1659 	    new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1660 		err = ieee80211_vif_use_reserved_switch(local);
1661 		if (err && err != -EAGAIN) {
1662 			if (new_ctx->replace_state ==
1663 			    IEEE80211_CHANCTX_REPLACES_OTHER)
1664 				return err;
1665 
1666 			wiphy_info(local->hw.wiphy,
1667 				   "depending in-place reservation failed (err=%d)\n",
1668 				   err);
1669 		}
1670 	}
1671 
1672 	return 0;
1673 }
1674 
1675 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
1676 				   const struct cfg80211_chan_def *chandef,
1677 				   u32 *changed)
1678 {
1679 	struct ieee80211_local *local = sdata->local;
1680 	struct ieee80211_chanctx_conf *conf;
1681 	struct ieee80211_chanctx *ctx;
1682 	const struct cfg80211_chan_def *compat;
1683 	int ret;
1684 
1685 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1686 				     IEEE80211_CHAN_DISABLED))
1687 		return -EINVAL;
1688 
1689 	mutex_lock(&local->chanctx_mtx);
1690 	if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
1691 		ret = 0;
1692 		goto out;
1693 	}
1694 
1695 	if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1696 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1697 		ret = -EINVAL;
1698 		goto out;
1699 	}
1700 
1701 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1702 					 lockdep_is_held(&local->chanctx_mtx));
1703 	if (!conf) {
1704 		ret = -EINVAL;
1705 		goto out;
1706 	}
1707 
1708 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1709 
1710 	compat = cfg80211_chandef_compatible(&conf->def, chandef);
1711 	if (!compat) {
1712 		ret = -EINVAL;
1713 		goto out;
1714 	}
1715 
1716 	switch (ctx->replace_state) {
1717 	case IEEE80211_CHANCTX_REPLACE_NONE:
1718 		if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1719 			ret = -EBUSY;
1720 			goto out;
1721 		}
1722 		break;
1723 	case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1724 		/* TODO: Perhaps the bandwidth change could be treated as a
1725 		 * reservation itself? */
1726 		ret = -EBUSY;
1727 		goto out;
1728 	case IEEE80211_CHANCTX_REPLACES_OTHER:
1729 		/* channel context that is going to replace another channel
1730 		 * context doesn't really exist and shouldn't be assigned
1731 		 * anywhere yet */
1732 		WARN_ON(1);
1733 		break;
1734 	}
1735 
1736 	ieee80211_vif_update_chandef(sdata, chandef);
1737 
1738 	ieee80211_recalc_chanctx_chantype(local, ctx);
1739 
1740 	*changed |= BSS_CHANGED_BANDWIDTH;
1741 	ret = 0;
1742  out:
1743 	mutex_unlock(&local->chanctx_mtx);
1744 	return ret;
1745 }
1746 
1747 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1748 {
1749 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1750 
1751 	lockdep_assert_held(&sdata->local->mtx);
1752 
1753 	mutex_lock(&sdata->local->chanctx_mtx);
1754 	__ieee80211_vif_release_channel(sdata);
1755 	mutex_unlock(&sdata->local->chanctx_mtx);
1756 }
1757 
1758 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
1759 {
1760 	struct ieee80211_local *local = sdata->local;
1761 	struct ieee80211_sub_if_data *ap;
1762 	struct ieee80211_chanctx_conf *conf;
1763 
1764 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
1765 		return;
1766 
1767 	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
1768 
1769 	mutex_lock(&local->chanctx_mtx);
1770 
1771 	conf = rcu_dereference_protected(ap->vif.chanctx_conf,
1772 					 lockdep_is_held(&local->chanctx_mtx));
1773 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
1774 	mutex_unlock(&local->chanctx_mtx);
1775 }
1776 
1777 void ieee80211_iter_chan_contexts_atomic(
1778 	struct ieee80211_hw *hw,
1779 	void (*iter)(struct ieee80211_hw *hw,
1780 		     struct ieee80211_chanctx_conf *chanctx_conf,
1781 		     void *data),
1782 	void *iter_data)
1783 {
1784 	struct ieee80211_local *local = hw_to_local(hw);
1785 	struct ieee80211_chanctx *ctx;
1786 
1787 	rcu_read_lock();
1788 	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
1789 		if (ctx->driver_present)
1790 			iter(hw, &ctx->conf, iter_data);
1791 	rcu_read_unlock();
1792 }
1793 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);
1794