xref: /openbmc/linux/net/mac80211/chan.c (revision 52cdded0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * mac80211 - channel management
4  */
5 
6 #include <linux/nl80211.h>
7 #include <linux/export.h>
8 #include <linux/rtnetlink.h>
9 #include <net/cfg80211.h>
10 #include "ieee80211_i.h"
11 #include "driver-ops.h"
12 
13 static int ieee80211_chanctx_num_assigned(struct ieee80211_local *local,
14 					  struct ieee80211_chanctx *ctx)
15 {
16 	struct ieee80211_sub_if_data *sdata;
17 	int num = 0;
18 
19 	lockdep_assert_held(&local->chanctx_mtx);
20 
21 	list_for_each_entry(sdata, &ctx->assigned_vifs, assigned_chanctx_list)
22 		num++;
23 
24 	return num;
25 }
26 
27 static int ieee80211_chanctx_num_reserved(struct ieee80211_local *local,
28 					  struct ieee80211_chanctx *ctx)
29 {
30 	struct ieee80211_sub_if_data *sdata;
31 	int num = 0;
32 
33 	lockdep_assert_held(&local->chanctx_mtx);
34 
35 	list_for_each_entry(sdata, &ctx->reserved_vifs, reserved_chanctx_list)
36 		num++;
37 
38 	return num;
39 }
40 
41 int ieee80211_chanctx_refcount(struct ieee80211_local *local,
42 			       struct ieee80211_chanctx *ctx)
43 {
44 	return ieee80211_chanctx_num_assigned(local, ctx) +
45 	       ieee80211_chanctx_num_reserved(local, ctx);
46 }
47 
48 static int ieee80211_num_chanctx(struct ieee80211_local *local)
49 {
50 	struct ieee80211_chanctx *ctx;
51 	int num = 0;
52 
53 	lockdep_assert_held(&local->chanctx_mtx);
54 
55 	list_for_each_entry(ctx, &local->chanctx_list, list)
56 		num++;
57 
58 	return num;
59 }
60 
61 static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local)
62 {
63 	lockdep_assert_held(&local->chanctx_mtx);
64 	return ieee80211_num_chanctx(local) < ieee80211_max_num_channels(local);
65 }
66 
67 static struct ieee80211_chanctx *
68 ieee80211_vif_get_chanctx(struct ieee80211_sub_if_data *sdata)
69 {
70 	struct ieee80211_local *local __maybe_unused = sdata->local;
71 	struct ieee80211_chanctx_conf *conf;
72 
73 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
74 					 lockdep_is_held(&local->chanctx_mtx));
75 	if (!conf)
76 		return NULL;
77 
78 	return container_of(conf, struct ieee80211_chanctx, conf);
79 }
80 
81 static const struct cfg80211_chan_def *
82 ieee80211_chanctx_reserved_chandef(struct ieee80211_local *local,
83 				   struct ieee80211_chanctx *ctx,
84 				   const struct cfg80211_chan_def *compat)
85 {
86 	struct ieee80211_sub_if_data *sdata;
87 
88 	lockdep_assert_held(&local->chanctx_mtx);
89 
90 	list_for_each_entry(sdata, &ctx->reserved_vifs,
91 			    reserved_chanctx_list) {
92 		if (!compat)
93 			compat = &sdata->reserved_chandef;
94 
95 		compat = cfg80211_chandef_compatible(&sdata->reserved_chandef,
96 						     compat);
97 		if (!compat)
98 			break;
99 	}
100 
101 	return compat;
102 }
103 
104 static const struct cfg80211_chan_def *
105 ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local *local,
106 				       struct ieee80211_chanctx *ctx,
107 				       const struct cfg80211_chan_def *compat)
108 {
109 	struct ieee80211_sub_if_data *sdata;
110 
111 	lockdep_assert_held(&local->chanctx_mtx);
112 
113 	list_for_each_entry(sdata, &ctx->assigned_vifs,
114 			    assigned_chanctx_list) {
115 		if (sdata->reserved_chanctx != NULL)
116 			continue;
117 
118 		if (!compat)
119 			compat = &sdata->vif.bss_conf.chandef;
120 
121 		compat = cfg80211_chandef_compatible(
122 				&sdata->vif.bss_conf.chandef, compat);
123 		if (!compat)
124 			break;
125 	}
126 
127 	return compat;
128 }
129 
130 static const struct cfg80211_chan_def *
131 ieee80211_chanctx_combined_chandef(struct ieee80211_local *local,
132 				   struct ieee80211_chanctx *ctx,
133 				   const struct cfg80211_chan_def *compat)
134 {
135 	lockdep_assert_held(&local->chanctx_mtx);
136 
137 	compat = ieee80211_chanctx_reserved_chandef(local, ctx, compat);
138 	if (!compat)
139 		return NULL;
140 
141 	compat = ieee80211_chanctx_non_reserved_chandef(local, ctx, compat);
142 	if (!compat)
143 		return NULL;
144 
145 	return compat;
146 }
147 
148 static bool
149 ieee80211_chanctx_can_reserve_chandef(struct ieee80211_local *local,
150 				      struct ieee80211_chanctx *ctx,
151 				      const struct cfg80211_chan_def *def)
152 {
153 	lockdep_assert_held(&local->chanctx_mtx);
154 
155 	if (ieee80211_chanctx_combined_chandef(local, ctx, def))
156 		return true;
157 
158 	if (!list_empty(&ctx->reserved_vifs) &&
159 	    ieee80211_chanctx_reserved_chandef(local, ctx, def))
160 		return true;
161 
162 	return false;
163 }
164 
165 static struct ieee80211_chanctx *
166 ieee80211_find_reservation_chanctx(struct ieee80211_local *local,
167 				   const struct cfg80211_chan_def *chandef,
168 				   enum ieee80211_chanctx_mode mode)
169 {
170 	struct ieee80211_chanctx *ctx;
171 
172 	lockdep_assert_held(&local->chanctx_mtx);
173 
174 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
175 		return NULL;
176 
177 	list_for_each_entry(ctx, &local->chanctx_list, list) {
178 		if (ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED)
179 			continue;
180 
181 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
182 			continue;
183 
184 		if (!ieee80211_chanctx_can_reserve_chandef(local, ctx,
185 							   chandef))
186 			continue;
187 
188 		return ctx;
189 	}
190 
191 	return NULL;
192 }
193 
194 enum nl80211_chan_width ieee80211_get_sta_bw(struct ieee80211_sta *sta)
195 {
196 	switch (sta->bandwidth) {
197 	case IEEE80211_STA_RX_BW_20:
198 		if (sta->ht_cap.ht_supported)
199 			return NL80211_CHAN_WIDTH_20;
200 		else
201 			return NL80211_CHAN_WIDTH_20_NOHT;
202 	case IEEE80211_STA_RX_BW_40:
203 		return NL80211_CHAN_WIDTH_40;
204 	case IEEE80211_STA_RX_BW_80:
205 		return NL80211_CHAN_WIDTH_80;
206 	case IEEE80211_STA_RX_BW_160:
207 		/*
208 		 * This applied for both 160 and 80+80. since we use
209 		 * the returned value to consider degradation of
210 		 * ctx->conf.min_def, we have to make sure to take
211 		 * the bigger one (NL80211_CHAN_WIDTH_160).
212 		 * Otherwise we might try degrading even when not
213 		 * needed, as the max required sta_bw returned (80+80)
214 		 * might be smaller than the configured bw (160).
215 		 */
216 		return NL80211_CHAN_WIDTH_160;
217 	default:
218 		WARN_ON(1);
219 		return NL80211_CHAN_WIDTH_20;
220 	}
221 }
222 
223 static enum nl80211_chan_width
224 ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata)
225 {
226 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
227 	struct sta_info *sta;
228 
229 	rcu_read_lock();
230 	list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
231 		if (sdata != sta->sdata &&
232 		    !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
233 			continue;
234 
235 		max_bw = max(max_bw, ieee80211_get_sta_bw(&sta->sta));
236 	}
237 	rcu_read_unlock();
238 
239 	return max_bw;
240 }
241 
242 static enum nl80211_chan_width
243 ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
244 				      struct ieee80211_chanctx_conf *conf)
245 {
246 	struct ieee80211_sub_if_data *sdata;
247 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
248 
249 	rcu_read_lock();
250 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
251 		struct ieee80211_vif *vif = &sdata->vif;
252 		enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT;
253 
254 		if (!ieee80211_sdata_running(sdata))
255 			continue;
256 
257 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
258 			continue;
259 
260 		switch (vif->type) {
261 		case NL80211_IFTYPE_AP:
262 		case NL80211_IFTYPE_AP_VLAN:
263 			width = ieee80211_get_max_required_bw(sdata);
264 			break;
265 		case NL80211_IFTYPE_STATION:
266 			/*
267 			 * The ap's sta->bandwidth is not set yet at this
268 			 * point, so take the width from the chandef, but
269 			 * account also for TDLS peers
270 			 */
271 			width = max(vif->bss_conf.chandef.width,
272 				    ieee80211_get_max_required_bw(sdata));
273 			break;
274 		case NL80211_IFTYPE_P2P_DEVICE:
275 		case NL80211_IFTYPE_NAN:
276 			continue;
277 		case NL80211_IFTYPE_ADHOC:
278 		case NL80211_IFTYPE_WDS:
279 		case NL80211_IFTYPE_MESH_POINT:
280 		case NL80211_IFTYPE_OCB:
281 			width = vif->bss_conf.chandef.width;
282 			break;
283 		case NL80211_IFTYPE_UNSPECIFIED:
284 		case NUM_NL80211_IFTYPES:
285 		case NL80211_IFTYPE_MONITOR:
286 		case NL80211_IFTYPE_P2P_CLIENT:
287 		case NL80211_IFTYPE_P2P_GO:
288 			WARN_ON_ONCE(1);
289 		}
290 		max_bw = max(max_bw, width);
291 	}
292 
293 	/* use the configured bandwidth in case of monitor interface */
294 	sdata = rcu_dereference(local->monitor_sdata);
295 	if (sdata && rcu_access_pointer(sdata->vif.chanctx_conf) == conf)
296 		max_bw = max(max_bw, conf->def.width);
297 
298 	rcu_read_unlock();
299 
300 	return max_bw;
301 }
302 
303 /*
304  * recalc the min required chan width of the channel context, which is
305  * the max of min required widths of all the interfaces bound to this
306  * channel context.
307  */
308 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
309 				      struct ieee80211_chanctx *ctx)
310 {
311 	enum nl80211_chan_width max_bw;
312 	struct cfg80211_chan_def min_def;
313 
314 	lockdep_assert_held(&local->chanctx_mtx);
315 
316 	/* don't optimize non-20MHz based and radar_enabled confs */
317 	if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
318 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
319 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_1 ||
320 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_2 ||
321 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_4 ||
322 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_8 ||
323 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_16 ||
324 	    ctx->conf.radar_enabled) {
325 		ctx->conf.min_def = ctx->conf.def;
326 		return;
327 	}
328 
329 	max_bw = ieee80211_get_chanctx_max_required_bw(local, &ctx->conf);
330 
331 	/* downgrade chandef up to max_bw */
332 	min_def = ctx->conf.def;
333 	while (min_def.width > max_bw)
334 		ieee80211_chandef_downgrade(&min_def);
335 
336 	if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
337 		return;
338 
339 	ctx->conf.min_def = min_def;
340 	if (!ctx->driver_present)
341 		return;
342 
343 	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_MIN_WIDTH);
344 }
345 
346 static void ieee80211_change_chanctx(struct ieee80211_local *local,
347 				     struct ieee80211_chanctx *ctx,
348 				     const struct cfg80211_chan_def *chandef)
349 {
350 	if (cfg80211_chandef_identical(&ctx->conf.def, chandef)) {
351 		ieee80211_recalc_chanctx_min_def(local, ctx);
352 		return;
353 	}
354 
355 	WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));
356 
357 	ctx->conf.def = *chandef;
358 	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);
359 	ieee80211_recalc_chanctx_min_def(local, ctx);
360 
361 	if (!local->use_chanctx) {
362 		local->_oper_chandef = *chandef;
363 		ieee80211_hw_config(local, 0);
364 	}
365 }
366 
367 static struct ieee80211_chanctx *
368 ieee80211_find_chanctx(struct ieee80211_local *local,
369 		       const struct cfg80211_chan_def *chandef,
370 		       enum ieee80211_chanctx_mode mode)
371 {
372 	struct ieee80211_chanctx *ctx;
373 
374 	lockdep_assert_held(&local->chanctx_mtx);
375 
376 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
377 		return NULL;
378 
379 	list_for_each_entry(ctx, &local->chanctx_list, list) {
380 		const struct cfg80211_chan_def *compat;
381 
382 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
383 			continue;
384 
385 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
386 			continue;
387 
388 		compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
389 		if (!compat)
390 			continue;
391 
392 		compat = ieee80211_chanctx_reserved_chandef(local, ctx,
393 							    compat);
394 		if (!compat)
395 			continue;
396 
397 		ieee80211_change_chanctx(local, ctx, compat);
398 
399 		return ctx;
400 	}
401 
402 	return NULL;
403 }
404 
405 bool ieee80211_is_radar_required(struct ieee80211_local *local)
406 {
407 	struct ieee80211_sub_if_data *sdata;
408 
409 	lockdep_assert_held(&local->mtx);
410 
411 	rcu_read_lock();
412 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
413 		if (sdata->radar_required) {
414 			rcu_read_unlock();
415 			return true;
416 		}
417 	}
418 	rcu_read_unlock();
419 
420 	return false;
421 }
422 
423 static bool
424 ieee80211_chanctx_radar_required(struct ieee80211_local *local,
425 				 struct ieee80211_chanctx *ctx)
426 {
427 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
428 	struct ieee80211_sub_if_data *sdata;
429 	bool required = false;
430 
431 	lockdep_assert_held(&local->chanctx_mtx);
432 	lockdep_assert_held(&local->mtx);
433 
434 	rcu_read_lock();
435 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
436 		if (!ieee80211_sdata_running(sdata))
437 			continue;
438 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
439 			continue;
440 		if (!sdata->radar_required)
441 			continue;
442 
443 		required = true;
444 		break;
445 	}
446 	rcu_read_unlock();
447 
448 	return required;
449 }
450 
451 static struct ieee80211_chanctx *
452 ieee80211_alloc_chanctx(struct ieee80211_local *local,
453 			const struct cfg80211_chan_def *chandef,
454 			enum ieee80211_chanctx_mode mode)
455 {
456 	struct ieee80211_chanctx *ctx;
457 
458 	lockdep_assert_held(&local->chanctx_mtx);
459 
460 	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
461 	if (!ctx)
462 		return NULL;
463 
464 	INIT_LIST_HEAD(&ctx->assigned_vifs);
465 	INIT_LIST_HEAD(&ctx->reserved_vifs);
466 	ctx->conf.def = *chandef;
467 	ctx->conf.rx_chains_static = 1;
468 	ctx->conf.rx_chains_dynamic = 1;
469 	ctx->mode = mode;
470 	ctx->conf.radar_enabled = false;
471 	ieee80211_recalc_chanctx_min_def(local, ctx);
472 
473 	return ctx;
474 }
475 
476 static int ieee80211_add_chanctx(struct ieee80211_local *local,
477 				 struct ieee80211_chanctx *ctx)
478 {
479 	u32 changed;
480 	int err;
481 
482 	lockdep_assert_held(&local->mtx);
483 	lockdep_assert_held(&local->chanctx_mtx);
484 
485 	if (!local->use_chanctx)
486 		local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
487 
488 	/* turn idle off *before* setting channel -- some drivers need that */
489 	changed = ieee80211_idle_off(local);
490 	if (changed)
491 		ieee80211_hw_config(local, changed);
492 
493 	if (!local->use_chanctx) {
494 		local->_oper_chandef = ctx->conf.def;
495 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
496 	} else {
497 		err = drv_add_chanctx(local, ctx);
498 		if (err) {
499 			ieee80211_recalc_idle(local);
500 			return err;
501 		}
502 	}
503 
504 	return 0;
505 }
506 
507 static struct ieee80211_chanctx *
508 ieee80211_new_chanctx(struct ieee80211_local *local,
509 		      const struct cfg80211_chan_def *chandef,
510 		      enum ieee80211_chanctx_mode mode)
511 {
512 	struct ieee80211_chanctx *ctx;
513 	int err;
514 
515 	lockdep_assert_held(&local->mtx);
516 	lockdep_assert_held(&local->chanctx_mtx);
517 
518 	ctx = ieee80211_alloc_chanctx(local, chandef, mode);
519 	if (!ctx)
520 		return ERR_PTR(-ENOMEM);
521 
522 	err = ieee80211_add_chanctx(local, ctx);
523 	if (err) {
524 		kfree(ctx);
525 		return ERR_PTR(err);
526 	}
527 
528 	list_add_rcu(&ctx->list, &local->chanctx_list);
529 	return ctx;
530 }
531 
532 static void ieee80211_del_chanctx(struct ieee80211_local *local,
533 				  struct ieee80211_chanctx *ctx)
534 {
535 	lockdep_assert_held(&local->chanctx_mtx);
536 
537 	if (!local->use_chanctx) {
538 		struct cfg80211_chan_def *chandef = &local->_oper_chandef;
539 		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
540 		chandef->center_freq1 = chandef->chan->center_freq;
541 		chandef->freq1_offset = chandef->chan->freq_offset;
542 		chandef->center_freq2 = 0;
543 
544 		/* NOTE: Disabling radar is only valid here for
545 		 * single channel context. To be sure, check it ...
546 		 */
547 		WARN_ON(local->hw.conf.radar_enabled &&
548 			!list_empty(&local->chanctx_list));
549 
550 		local->hw.conf.radar_enabled = false;
551 
552 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
553 	} else {
554 		drv_remove_chanctx(local, ctx);
555 	}
556 
557 	ieee80211_recalc_idle(local);
558 }
559 
560 static void ieee80211_free_chanctx(struct ieee80211_local *local,
561 				   struct ieee80211_chanctx *ctx)
562 {
563 	lockdep_assert_held(&local->chanctx_mtx);
564 
565 	WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
566 
567 	list_del_rcu(&ctx->list);
568 	ieee80211_del_chanctx(local, ctx);
569 	kfree_rcu(ctx, rcu_head);
570 }
571 
572 void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
573 				       struct ieee80211_chanctx *ctx)
574 {
575 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
576 	struct ieee80211_sub_if_data *sdata;
577 	const struct cfg80211_chan_def *compat = NULL;
578 	struct sta_info *sta;
579 
580 	lockdep_assert_held(&local->chanctx_mtx);
581 
582 	rcu_read_lock();
583 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
584 
585 		if (!ieee80211_sdata_running(sdata))
586 			continue;
587 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
588 			continue;
589 		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
590 			continue;
591 
592 		if (!compat)
593 			compat = &sdata->vif.bss_conf.chandef;
594 
595 		compat = cfg80211_chandef_compatible(
596 				&sdata->vif.bss_conf.chandef, compat);
597 		if (WARN_ON_ONCE(!compat))
598 			break;
599 	}
600 
601 	/* TDLS peers can sometimes affect the chandef width */
602 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
603 		if (!sta->uploaded ||
604 		    !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
605 		    !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
606 		    !sta->tdls_chandef.chan)
607 			continue;
608 
609 		compat = cfg80211_chandef_compatible(&sta->tdls_chandef,
610 						     compat);
611 		if (WARN_ON_ONCE(!compat))
612 			break;
613 	}
614 	rcu_read_unlock();
615 
616 	if (!compat)
617 		return;
618 
619 	ieee80211_change_chanctx(local, ctx, compat);
620 }
621 
622 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
623 					   struct ieee80211_chanctx *chanctx)
624 {
625 	bool radar_enabled;
626 
627 	lockdep_assert_held(&local->chanctx_mtx);
628 	/* for ieee80211_is_radar_required */
629 	lockdep_assert_held(&local->mtx);
630 
631 	radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
632 
633 	if (radar_enabled == chanctx->conf.radar_enabled)
634 		return;
635 
636 	chanctx->conf.radar_enabled = radar_enabled;
637 
638 	if (!local->use_chanctx) {
639 		local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
640 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
641 	}
642 
643 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
644 }
645 
646 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
647 					struct ieee80211_chanctx *new_ctx)
648 {
649 	struct ieee80211_local *local = sdata->local;
650 	struct ieee80211_chanctx_conf *conf;
651 	struct ieee80211_chanctx *curr_ctx = NULL;
652 	int ret = 0;
653 
654 	if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN))
655 		return -ENOTSUPP;
656 
657 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
658 					 lockdep_is_held(&local->chanctx_mtx));
659 
660 	if (conf) {
661 		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
662 
663 		drv_unassign_vif_chanctx(local, sdata, curr_ctx);
664 		conf = NULL;
665 		list_del(&sdata->assigned_chanctx_list);
666 	}
667 
668 	if (new_ctx) {
669 		ret = drv_assign_vif_chanctx(local, sdata, new_ctx);
670 		if (ret)
671 			goto out;
672 
673 		conf = &new_ctx->conf;
674 		list_add(&sdata->assigned_chanctx_list,
675 			 &new_ctx->assigned_vifs);
676 	}
677 
678 out:
679 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
680 
681 	sdata->vif.bss_conf.idle = !conf;
682 
683 	if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
684 		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
685 		ieee80211_recalc_smps_chanctx(local, curr_ctx);
686 		ieee80211_recalc_radar_chanctx(local, curr_ctx);
687 		ieee80211_recalc_chanctx_min_def(local, curr_ctx);
688 	}
689 
690 	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
691 		ieee80211_recalc_txpower(sdata, false);
692 		ieee80211_recalc_chanctx_min_def(local, new_ctx);
693 	}
694 
695 	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
696 	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
697 		ieee80211_bss_info_change_notify(sdata,
698 						 BSS_CHANGED_IDLE);
699 
700 	ieee80211_check_fast_xmit_iface(sdata);
701 
702 	return ret;
703 }
704 
705 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
706 				   struct ieee80211_chanctx *chanctx)
707 {
708 	struct ieee80211_sub_if_data *sdata;
709 	u8 rx_chains_static, rx_chains_dynamic;
710 
711 	lockdep_assert_held(&local->chanctx_mtx);
712 
713 	rx_chains_static = 1;
714 	rx_chains_dynamic = 1;
715 
716 	rcu_read_lock();
717 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
718 		u8 needed_static, needed_dynamic;
719 
720 		if (!ieee80211_sdata_running(sdata))
721 			continue;
722 
723 		if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
724 						&chanctx->conf)
725 			continue;
726 
727 		switch (sdata->vif.type) {
728 		case NL80211_IFTYPE_P2P_DEVICE:
729 		case NL80211_IFTYPE_NAN:
730 			continue;
731 		case NL80211_IFTYPE_STATION:
732 			if (!sdata->u.mgd.associated)
733 				continue;
734 			break;
735 		case NL80211_IFTYPE_AP_VLAN:
736 			continue;
737 		case NL80211_IFTYPE_AP:
738 		case NL80211_IFTYPE_ADHOC:
739 		case NL80211_IFTYPE_WDS:
740 		case NL80211_IFTYPE_MESH_POINT:
741 		case NL80211_IFTYPE_OCB:
742 			break;
743 		default:
744 			WARN_ON_ONCE(1);
745 		}
746 
747 		switch (sdata->smps_mode) {
748 		default:
749 			WARN_ONCE(1, "Invalid SMPS mode %d\n",
750 				  sdata->smps_mode);
751 			fallthrough;
752 		case IEEE80211_SMPS_OFF:
753 			needed_static = sdata->needed_rx_chains;
754 			needed_dynamic = sdata->needed_rx_chains;
755 			break;
756 		case IEEE80211_SMPS_DYNAMIC:
757 			needed_static = 1;
758 			needed_dynamic = sdata->needed_rx_chains;
759 			break;
760 		case IEEE80211_SMPS_STATIC:
761 			needed_static = 1;
762 			needed_dynamic = 1;
763 			break;
764 		}
765 
766 		rx_chains_static = max(rx_chains_static, needed_static);
767 		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
768 	}
769 
770 	/* Disable SMPS for the monitor interface */
771 	sdata = rcu_dereference(local->monitor_sdata);
772 	if (sdata &&
773 	    rcu_access_pointer(sdata->vif.chanctx_conf) == &chanctx->conf)
774 		rx_chains_dynamic = rx_chains_static = local->rx_chains;
775 
776 	rcu_read_unlock();
777 
778 	if (!local->use_chanctx) {
779 		if (rx_chains_static > 1)
780 			local->smps_mode = IEEE80211_SMPS_OFF;
781 		else if (rx_chains_dynamic > 1)
782 			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
783 		else
784 			local->smps_mode = IEEE80211_SMPS_STATIC;
785 		ieee80211_hw_config(local, 0);
786 	}
787 
788 	if (rx_chains_static == chanctx->conf.rx_chains_static &&
789 	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
790 		return;
791 
792 	chanctx->conf.rx_chains_static = rx_chains_static;
793 	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
794 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
795 }
796 
797 static void
798 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
799 				      bool clear)
800 {
801 	struct ieee80211_local *local __maybe_unused = sdata->local;
802 	struct ieee80211_sub_if_data *vlan;
803 	struct ieee80211_chanctx_conf *conf;
804 
805 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
806 		return;
807 
808 	lockdep_assert_held(&local->mtx);
809 
810 	/* Check that conf exists, even when clearing this function
811 	 * must be called with the AP's channel context still there
812 	 * as it would otherwise cause VLANs to have an invalid
813 	 * channel context pointer for a while, possibly pointing
814 	 * to a channel context that has already been freed.
815 	 */
816 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
817 					 lockdep_is_held(&local->chanctx_mtx));
818 	WARN_ON(!conf);
819 
820 	if (clear)
821 		conf = NULL;
822 
823 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
824 		rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
825 }
826 
827 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
828 					 bool clear)
829 {
830 	struct ieee80211_local *local = sdata->local;
831 
832 	mutex_lock(&local->chanctx_mtx);
833 
834 	__ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
835 
836 	mutex_unlock(&local->chanctx_mtx);
837 }
838 
839 int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
840 {
841 	struct ieee80211_chanctx *ctx = sdata->reserved_chanctx;
842 
843 	lockdep_assert_held(&sdata->local->chanctx_mtx);
844 
845 	if (WARN_ON(!ctx))
846 		return -EINVAL;
847 
848 	list_del(&sdata->reserved_chanctx_list);
849 	sdata->reserved_chanctx = NULL;
850 
851 	if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
852 		if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
853 			if (WARN_ON(!ctx->replace_ctx))
854 				return -EINVAL;
855 
856 			WARN_ON(ctx->replace_ctx->replace_state !=
857 			        IEEE80211_CHANCTX_WILL_BE_REPLACED);
858 			WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
859 
860 			ctx->replace_ctx->replace_ctx = NULL;
861 			ctx->replace_ctx->replace_state =
862 					IEEE80211_CHANCTX_REPLACE_NONE;
863 
864 			list_del_rcu(&ctx->list);
865 			kfree_rcu(ctx, rcu_head);
866 		} else {
867 			ieee80211_free_chanctx(sdata->local, ctx);
868 		}
869 	}
870 
871 	return 0;
872 }
873 
874 int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
875 				  const struct cfg80211_chan_def *chandef,
876 				  enum ieee80211_chanctx_mode mode,
877 				  bool radar_required)
878 {
879 	struct ieee80211_local *local = sdata->local;
880 	struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx;
881 
882 	lockdep_assert_held(&local->chanctx_mtx);
883 
884 	curr_ctx = ieee80211_vif_get_chanctx(sdata);
885 	if (curr_ctx && local->use_chanctx && !local->ops->switch_vif_chanctx)
886 		return -ENOTSUPP;
887 
888 	new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
889 	if (!new_ctx) {
890 		if (ieee80211_can_create_new_chanctx(local)) {
891 			new_ctx = ieee80211_new_chanctx(local, chandef, mode);
892 			if (IS_ERR(new_ctx))
893 				return PTR_ERR(new_ctx);
894 		} else {
895 			if (!curr_ctx ||
896 			    (curr_ctx->replace_state ==
897 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
898 			    !list_empty(&curr_ctx->reserved_vifs)) {
899 				/*
900 				 * Another vif already requested this context
901 				 * for a reservation. Find another one hoping
902 				 * all vifs assigned to it will also switch
903 				 * soon enough.
904 				 *
905 				 * TODO: This needs a little more work as some
906 				 * cases (more than 2 chanctx capable devices)
907 				 * may fail which could otherwise succeed
908 				 * provided some channel context juggling was
909 				 * performed.
910 				 *
911 				 * Consider ctx1..3, vif1..6, each ctx has 2
912 				 * vifs. vif1 and vif2 from ctx1 request new
913 				 * different chandefs starting 2 in-place
914 				 * reserations with ctx4 and ctx5 replacing
915 				 * ctx1 and ctx2 respectively. Next vif5 and
916 				 * vif6 from ctx3 reserve ctx4. If vif3 and
917 				 * vif4 remain on ctx2 as they are then this
918 				 * fails unless `replace_ctx` from ctx5 is
919 				 * replaced with ctx3.
920 				 */
921 				list_for_each_entry(ctx, &local->chanctx_list,
922 						    list) {
923 					if (ctx->replace_state !=
924 					    IEEE80211_CHANCTX_REPLACE_NONE)
925 						continue;
926 
927 					if (!list_empty(&ctx->reserved_vifs))
928 						continue;
929 
930 					curr_ctx = ctx;
931 					break;
932 				}
933 			}
934 
935 			/*
936 			 * If that's true then all available contexts already
937 			 * have reservations and cannot be used.
938 			 */
939 			if (!curr_ctx ||
940 			    (curr_ctx->replace_state ==
941 			     IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
942 			    !list_empty(&curr_ctx->reserved_vifs))
943 				return -EBUSY;
944 
945 			new_ctx = ieee80211_alloc_chanctx(local, chandef, mode);
946 			if (!new_ctx)
947 				return -ENOMEM;
948 
949 			new_ctx->replace_ctx = curr_ctx;
950 			new_ctx->replace_state =
951 					IEEE80211_CHANCTX_REPLACES_OTHER;
952 
953 			curr_ctx->replace_ctx = new_ctx;
954 			curr_ctx->replace_state =
955 					IEEE80211_CHANCTX_WILL_BE_REPLACED;
956 
957 			list_add_rcu(&new_ctx->list, &local->chanctx_list);
958 		}
959 	}
960 
961 	list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);
962 	sdata->reserved_chanctx = new_ctx;
963 	sdata->reserved_chandef = *chandef;
964 	sdata->reserved_radar_required = radar_required;
965 	sdata->reserved_ready = false;
966 
967 	return 0;
968 }
969 
970 static void
971 ieee80211_vif_chanctx_reservation_complete(struct ieee80211_sub_if_data *sdata)
972 {
973 	switch (sdata->vif.type) {
974 	case NL80211_IFTYPE_ADHOC:
975 	case NL80211_IFTYPE_AP:
976 	case NL80211_IFTYPE_MESH_POINT:
977 	case NL80211_IFTYPE_OCB:
978 		ieee80211_queue_work(&sdata->local->hw,
979 				     &sdata->csa_finalize_work);
980 		break;
981 	case NL80211_IFTYPE_STATION:
982 		ieee80211_queue_work(&sdata->local->hw,
983 				     &sdata->u.mgd.chswitch_work);
984 		break;
985 	case NL80211_IFTYPE_UNSPECIFIED:
986 	case NL80211_IFTYPE_AP_VLAN:
987 	case NL80211_IFTYPE_WDS:
988 	case NL80211_IFTYPE_MONITOR:
989 	case NL80211_IFTYPE_P2P_CLIENT:
990 	case NL80211_IFTYPE_P2P_GO:
991 	case NL80211_IFTYPE_P2P_DEVICE:
992 	case NL80211_IFTYPE_NAN:
993 	case NUM_NL80211_IFTYPES:
994 		WARN_ON(1);
995 		break;
996 	}
997 }
998 
999 static void
1000 ieee80211_vif_update_chandef(struct ieee80211_sub_if_data *sdata,
1001 			     const struct cfg80211_chan_def *chandef)
1002 {
1003 	struct ieee80211_sub_if_data *vlan;
1004 
1005 	sdata->vif.bss_conf.chandef = *chandef;
1006 
1007 	if (sdata->vif.type != NL80211_IFTYPE_AP)
1008 		return;
1009 
1010 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
1011 		vlan->vif.bss_conf.chandef = *chandef;
1012 }
1013 
1014 static int
1015 ieee80211_vif_use_reserved_reassign(struct ieee80211_sub_if_data *sdata)
1016 {
1017 	struct ieee80211_local *local = sdata->local;
1018 	struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1019 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1020 	const struct cfg80211_chan_def *chandef;
1021 	u32 changed = 0;
1022 	int err;
1023 
1024 	lockdep_assert_held(&local->mtx);
1025 	lockdep_assert_held(&local->chanctx_mtx);
1026 
1027 	new_ctx = sdata->reserved_chanctx;
1028 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1029 
1030 	if (WARN_ON(!sdata->reserved_ready))
1031 		return -EBUSY;
1032 
1033 	if (WARN_ON(!new_ctx))
1034 		return -EINVAL;
1035 
1036 	if (WARN_ON(!old_ctx))
1037 		return -EINVAL;
1038 
1039 	if (WARN_ON(new_ctx->replace_state ==
1040 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1041 		return -EINVAL;
1042 
1043 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1044 				&sdata->reserved_chandef);
1045 	if (WARN_ON(!chandef))
1046 		return -EINVAL;
1047 
1048 	ieee80211_change_chanctx(local, new_ctx, chandef);
1049 
1050 	vif_chsw[0].vif = &sdata->vif;
1051 	vif_chsw[0].old_ctx = &old_ctx->conf;
1052 	vif_chsw[0].new_ctx = &new_ctx->conf;
1053 
1054 	list_del(&sdata->reserved_chanctx_list);
1055 	sdata->reserved_chanctx = NULL;
1056 
1057 	err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1058 				     CHANCTX_SWMODE_REASSIGN_VIF);
1059 	if (err) {
1060 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1061 			ieee80211_free_chanctx(local, new_ctx);
1062 
1063 		goto out;
1064 	}
1065 
1066 	list_move(&sdata->assigned_chanctx_list, &new_ctx->assigned_vifs);
1067 	rcu_assign_pointer(sdata->vif.chanctx_conf, &new_ctx->conf);
1068 
1069 	if (sdata->vif.type == NL80211_IFTYPE_AP)
1070 		__ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
1071 
1072 	ieee80211_check_fast_xmit_iface(sdata);
1073 
1074 	if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1075 		ieee80211_free_chanctx(local, old_ctx);
1076 
1077 	if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
1078 		changed = BSS_CHANGED_BANDWIDTH;
1079 
1080 	ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1081 
1082 	ieee80211_recalc_smps_chanctx(local, new_ctx);
1083 	ieee80211_recalc_radar_chanctx(local, new_ctx);
1084 	ieee80211_recalc_chanctx_min_def(local, new_ctx);
1085 
1086 	if (changed)
1087 		ieee80211_bss_info_change_notify(sdata, changed);
1088 
1089 out:
1090 	ieee80211_vif_chanctx_reservation_complete(sdata);
1091 	return err;
1092 }
1093 
1094 static int
1095 ieee80211_vif_use_reserved_assign(struct ieee80211_sub_if_data *sdata)
1096 {
1097 	struct ieee80211_local *local = sdata->local;
1098 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1099 	const struct cfg80211_chan_def *chandef;
1100 	int err;
1101 
1102 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1103 	new_ctx = sdata->reserved_chanctx;
1104 
1105 	if (WARN_ON(!sdata->reserved_ready))
1106 		return -EINVAL;
1107 
1108 	if (WARN_ON(old_ctx))
1109 		return -EINVAL;
1110 
1111 	if (WARN_ON(!new_ctx))
1112 		return -EINVAL;
1113 
1114 	if (WARN_ON(new_ctx->replace_state ==
1115 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1116 		return -EINVAL;
1117 
1118 	chandef = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1119 				&sdata->reserved_chandef);
1120 	if (WARN_ON(!chandef))
1121 		return -EINVAL;
1122 
1123 	ieee80211_change_chanctx(local, new_ctx, chandef);
1124 
1125 	list_del(&sdata->reserved_chanctx_list);
1126 	sdata->reserved_chanctx = NULL;
1127 
1128 	err = ieee80211_assign_vif_chanctx(sdata, new_ctx);
1129 	if (err) {
1130 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1131 			ieee80211_free_chanctx(local, new_ctx);
1132 
1133 		goto out;
1134 	}
1135 
1136 out:
1137 	ieee80211_vif_chanctx_reservation_complete(sdata);
1138 	return err;
1139 }
1140 
1141 static bool
1142 ieee80211_vif_has_in_place_reservation(struct ieee80211_sub_if_data *sdata)
1143 {
1144 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1145 
1146 	lockdep_assert_held(&sdata->local->chanctx_mtx);
1147 
1148 	new_ctx = sdata->reserved_chanctx;
1149 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1150 
1151 	if (!old_ctx)
1152 		return false;
1153 
1154 	if (WARN_ON(!new_ctx))
1155 		return false;
1156 
1157 	if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1158 		return false;
1159 
1160 	if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1161 		return false;
1162 
1163 	return true;
1164 }
1165 
1166 static int ieee80211_chsw_switch_hwconf(struct ieee80211_local *local,
1167 					struct ieee80211_chanctx *new_ctx)
1168 {
1169 	const struct cfg80211_chan_def *chandef;
1170 
1171 	lockdep_assert_held(&local->mtx);
1172 	lockdep_assert_held(&local->chanctx_mtx);
1173 
1174 	chandef = ieee80211_chanctx_reserved_chandef(local, new_ctx, NULL);
1175 	if (WARN_ON(!chandef))
1176 		return -EINVAL;
1177 
1178 	local->hw.conf.radar_enabled = new_ctx->conf.radar_enabled;
1179 	local->_oper_chandef = *chandef;
1180 	ieee80211_hw_config(local, 0);
1181 
1182 	return 0;
1183 }
1184 
1185 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1186 				      int n_vifs)
1187 {
1188 	struct ieee80211_vif_chanctx_switch *vif_chsw;
1189 	struct ieee80211_sub_if_data *sdata;
1190 	struct ieee80211_chanctx *ctx, *old_ctx;
1191 	int i, err;
1192 
1193 	lockdep_assert_held(&local->mtx);
1194 	lockdep_assert_held(&local->chanctx_mtx);
1195 
1196 	vif_chsw = kcalloc(n_vifs, sizeof(vif_chsw[0]), GFP_KERNEL);
1197 	if (!vif_chsw)
1198 		return -ENOMEM;
1199 
1200 	i = 0;
1201 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1202 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1203 			continue;
1204 
1205 		if (WARN_ON(!ctx->replace_ctx)) {
1206 			err = -EINVAL;
1207 			goto out;
1208 		}
1209 
1210 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1211 				    reserved_chanctx_list) {
1212 			if (!ieee80211_vif_has_in_place_reservation(
1213 					sdata))
1214 				continue;
1215 
1216 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1217 			vif_chsw[i].vif = &sdata->vif;
1218 			vif_chsw[i].old_ctx = &old_ctx->conf;
1219 			vif_chsw[i].new_ctx = &ctx->conf;
1220 
1221 			i++;
1222 		}
1223 	}
1224 
1225 	err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1226 				     CHANCTX_SWMODE_SWAP_CONTEXTS);
1227 
1228 out:
1229 	kfree(vif_chsw);
1230 	return err;
1231 }
1232 
1233 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1234 {
1235 	struct ieee80211_chanctx *ctx;
1236 	int err;
1237 
1238 	lockdep_assert_held(&local->mtx);
1239 	lockdep_assert_held(&local->chanctx_mtx);
1240 
1241 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1242 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1243 			continue;
1244 
1245 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1246 			continue;
1247 
1248 		ieee80211_del_chanctx(local, ctx->replace_ctx);
1249 		err = ieee80211_add_chanctx(local, ctx);
1250 		if (err)
1251 			goto err;
1252 	}
1253 
1254 	return 0;
1255 
1256 err:
1257 	WARN_ON(ieee80211_add_chanctx(local, ctx));
1258 	list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1259 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1260 			continue;
1261 
1262 		if (!list_empty(&ctx->replace_ctx->assigned_vifs))
1263 			continue;
1264 
1265 		ieee80211_del_chanctx(local, ctx);
1266 		WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1267 	}
1268 
1269 	return err;
1270 }
1271 
1272 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1273 {
1274 	struct ieee80211_sub_if_data *sdata, *sdata_tmp;
1275 	struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1276 	struct ieee80211_chanctx *new_ctx = NULL;
1277 	int err, n_assigned, n_reserved, n_ready;
1278 	int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1279 
1280 	lockdep_assert_held(&local->mtx);
1281 	lockdep_assert_held(&local->chanctx_mtx);
1282 
1283 	/*
1284 	 * If there are 2 independent pairs of channel contexts performing
1285 	 * cross-switch of their vifs this code will still wait until both are
1286 	 * ready even though it could be possible to switch one before the
1287 	 * other is ready.
1288 	 *
1289 	 * For practical reasons and code simplicity just do a single huge
1290 	 * switch.
1291 	 */
1292 
1293 	/*
1294 	 * Verify if the reservation is still feasible.
1295 	 *  - if it's not then disconnect
1296 	 *  - if it is but not all vifs necessary are ready then defer
1297 	 */
1298 
1299 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1300 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1301 			continue;
1302 
1303 		if (WARN_ON(!ctx->replace_ctx)) {
1304 			err = -EINVAL;
1305 			goto err;
1306 		}
1307 
1308 		if (!local->use_chanctx)
1309 			new_ctx = ctx;
1310 
1311 		n_ctx++;
1312 
1313 		n_assigned = 0;
1314 		n_reserved = 0;
1315 		n_ready = 0;
1316 
1317 		list_for_each_entry(sdata, &ctx->replace_ctx->assigned_vifs,
1318 				    assigned_chanctx_list) {
1319 			n_assigned++;
1320 			if (sdata->reserved_chanctx) {
1321 				n_reserved++;
1322 				if (sdata->reserved_ready)
1323 					n_ready++;
1324 			}
1325 		}
1326 
1327 		if (n_assigned != n_reserved) {
1328 			if (n_ready == n_reserved) {
1329 				wiphy_info(local->hw.wiphy,
1330 					   "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1331 				err = -EBUSY;
1332 				goto err;
1333 			}
1334 
1335 			return -EAGAIN;
1336 		}
1337 
1338 		ctx->conf.radar_enabled = false;
1339 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1340 				    reserved_chanctx_list) {
1341 			if (ieee80211_vif_has_in_place_reservation(sdata) &&
1342 			    !sdata->reserved_ready)
1343 				return -EAGAIN;
1344 
1345 			old_ctx = ieee80211_vif_get_chanctx(sdata);
1346 			if (old_ctx) {
1347 				if (old_ctx->replace_state ==
1348 				    IEEE80211_CHANCTX_WILL_BE_REPLACED)
1349 					n_vifs_switch++;
1350 				else
1351 					n_vifs_assign++;
1352 			} else {
1353 				n_vifs_ctxless++;
1354 			}
1355 
1356 			if (sdata->reserved_radar_required)
1357 				ctx->conf.radar_enabled = true;
1358 		}
1359 	}
1360 
1361 	if (WARN_ON(n_ctx == 0) ||
1362 	    WARN_ON(n_vifs_switch == 0 &&
1363 		    n_vifs_assign == 0 &&
1364 		    n_vifs_ctxless == 0) ||
1365 	    WARN_ON(n_ctx > 1 && !local->use_chanctx) ||
1366 	    WARN_ON(!new_ctx && !local->use_chanctx)) {
1367 		err = -EINVAL;
1368 		goto err;
1369 	}
1370 
1371 	/*
1372 	 * All necessary vifs are ready. Perform the switch now depending on
1373 	 * reservations and driver capabilities.
1374 	 */
1375 
1376 	if (local->use_chanctx) {
1377 		if (n_vifs_switch > 0) {
1378 			err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1379 			if (err)
1380 				goto err;
1381 		}
1382 
1383 		if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1384 			err = ieee80211_chsw_switch_ctxs(local);
1385 			if (err)
1386 				goto err;
1387 		}
1388 	} else {
1389 		err = ieee80211_chsw_switch_hwconf(local, new_ctx);
1390 		if (err)
1391 			goto err;
1392 	}
1393 
1394 	/*
1395 	 * Update all structures, values and pointers to point to new channel
1396 	 * context(s).
1397 	 */
1398 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1399 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1400 			continue;
1401 
1402 		if (WARN_ON(!ctx->replace_ctx)) {
1403 			err = -EINVAL;
1404 			goto err;
1405 		}
1406 
1407 		list_for_each_entry(sdata, &ctx->reserved_vifs,
1408 				    reserved_chanctx_list) {
1409 			u32 changed = 0;
1410 
1411 			if (!ieee80211_vif_has_in_place_reservation(sdata))
1412 				continue;
1413 
1414 			rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
1415 
1416 			if (sdata->vif.type == NL80211_IFTYPE_AP)
1417 				__ieee80211_vif_copy_chanctx_to_vlans(sdata,
1418 								      false);
1419 
1420 			ieee80211_check_fast_xmit_iface(sdata);
1421 
1422 			sdata->radar_required = sdata->reserved_radar_required;
1423 
1424 			if (sdata->vif.bss_conf.chandef.width !=
1425 			    sdata->reserved_chandef.width)
1426 				changed = BSS_CHANGED_BANDWIDTH;
1427 
1428 			ieee80211_vif_update_chandef(sdata, &sdata->reserved_chandef);
1429 			if (changed)
1430 				ieee80211_bss_info_change_notify(sdata,
1431 								 changed);
1432 
1433 			ieee80211_recalc_txpower(sdata, false);
1434 		}
1435 
1436 		ieee80211_recalc_chanctx_chantype(local, ctx);
1437 		ieee80211_recalc_smps_chanctx(local, ctx);
1438 		ieee80211_recalc_radar_chanctx(local, ctx);
1439 		ieee80211_recalc_chanctx_min_def(local, ctx);
1440 
1441 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1442 					 reserved_chanctx_list) {
1443 			if (ieee80211_vif_get_chanctx(sdata) != ctx)
1444 				continue;
1445 
1446 			list_del(&sdata->reserved_chanctx_list);
1447 			list_move(&sdata->assigned_chanctx_list,
1448 				  &ctx->assigned_vifs);
1449 			sdata->reserved_chanctx = NULL;
1450 
1451 			ieee80211_vif_chanctx_reservation_complete(sdata);
1452 		}
1453 
1454 		/*
1455 		 * This context might have been a dependency for an already
1456 		 * ready re-assign reservation interface that was deferred. Do
1457 		 * not propagate error to the caller though. The in-place
1458 		 * reservation for originally requested interface has already
1459 		 * succeeded at this point.
1460 		 */
1461 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1462 					 reserved_chanctx_list) {
1463 			if (WARN_ON(ieee80211_vif_has_in_place_reservation(
1464 					sdata)))
1465 				continue;
1466 
1467 			if (WARN_ON(sdata->reserved_chanctx != ctx))
1468 				continue;
1469 
1470 			if (!sdata->reserved_ready)
1471 				continue;
1472 
1473 			if (ieee80211_vif_get_chanctx(sdata))
1474 				err = ieee80211_vif_use_reserved_reassign(
1475 						sdata);
1476 			else
1477 				err = ieee80211_vif_use_reserved_assign(sdata);
1478 
1479 			if (err) {
1480 				sdata_info(sdata,
1481 					   "failed to finalize (re-)assign reservation (err=%d)\n",
1482 					   err);
1483 				ieee80211_vif_unreserve_chanctx(sdata);
1484 				cfg80211_stop_iface(local->hw.wiphy,
1485 						    &sdata->wdev,
1486 						    GFP_KERNEL);
1487 			}
1488 		}
1489 	}
1490 
1491 	/*
1492 	 * Finally free old contexts
1493 	 */
1494 
1495 	list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1496 		if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1497 			continue;
1498 
1499 		ctx->replace_ctx->replace_ctx = NULL;
1500 		ctx->replace_ctx->replace_state =
1501 				IEEE80211_CHANCTX_REPLACE_NONE;
1502 
1503 		list_del_rcu(&ctx->list);
1504 		kfree_rcu(ctx, rcu_head);
1505 	}
1506 
1507 	return 0;
1508 
1509 err:
1510 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1511 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1512 			continue;
1513 
1514 		list_for_each_entry_safe(sdata, sdata_tmp, &ctx->reserved_vifs,
1515 					 reserved_chanctx_list) {
1516 			ieee80211_vif_unreserve_chanctx(sdata);
1517 			ieee80211_vif_chanctx_reservation_complete(sdata);
1518 		}
1519 	}
1520 
1521 	return err;
1522 }
1523 
1524 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1525 {
1526 	struct ieee80211_local *local = sdata->local;
1527 	struct ieee80211_chanctx_conf *conf;
1528 	struct ieee80211_chanctx *ctx;
1529 	bool use_reserved_switch = false;
1530 
1531 	lockdep_assert_held(&local->chanctx_mtx);
1532 
1533 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1534 					 lockdep_is_held(&local->chanctx_mtx));
1535 	if (!conf)
1536 		return;
1537 
1538 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1539 
1540 	if (sdata->reserved_chanctx) {
1541 		if (sdata->reserved_chanctx->replace_state ==
1542 		    IEEE80211_CHANCTX_REPLACES_OTHER &&
1543 		    ieee80211_chanctx_num_reserved(local,
1544 						   sdata->reserved_chanctx) > 1)
1545 			use_reserved_switch = true;
1546 
1547 		ieee80211_vif_unreserve_chanctx(sdata);
1548 	}
1549 
1550 	ieee80211_assign_vif_chanctx(sdata, NULL);
1551 	if (ieee80211_chanctx_refcount(local, ctx) == 0)
1552 		ieee80211_free_chanctx(local, ctx);
1553 
1554 	sdata->radar_required = false;
1555 
1556 	/* Unreserving may ready an in-place reservation. */
1557 	if (use_reserved_switch)
1558 		ieee80211_vif_use_reserved_switch(local);
1559 }
1560 
1561 int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
1562 			      const struct cfg80211_chan_def *chandef,
1563 			      enum ieee80211_chanctx_mode mode)
1564 {
1565 	struct ieee80211_local *local = sdata->local;
1566 	struct ieee80211_chanctx *ctx;
1567 	u8 radar_detect_width = 0;
1568 	int ret;
1569 
1570 	lockdep_assert_held(&local->mtx);
1571 
1572 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1573 
1574 	mutex_lock(&local->chanctx_mtx);
1575 
1576 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1577 					    chandef,
1578 					    sdata->wdev.iftype);
1579 	if (ret < 0)
1580 		goto out;
1581 	if (ret > 0)
1582 		radar_detect_width = BIT(chandef->width);
1583 
1584 	sdata->radar_required = ret;
1585 
1586 	ret = ieee80211_check_combinations(sdata, chandef, mode,
1587 					   radar_detect_width);
1588 	if (ret < 0)
1589 		goto out;
1590 
1591 	__ieee80211_vif_release_channel(sdata);
1592 
1593 	ctx = ieee80211_find_chanctx(local, chandef, mode);
1594 	if (!ctx)
1595 		ctx = ieee80211_new_chanctx(local, chandef, mode);
1596 	if (IS_ERR(ctx)) {
1597 		ret = PTR_ERR(ctx);
1598 		goto out;
1599 	}
1600 
1601 	ieee80211_vif_update_chandef(sdata, chandef);
1602 
1603 	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
1604 	if (ret) {
1605 		/* if assign fails refcount stays the same */
1606 		if (ieee80211_chanctx_refcount(local, ctx) == 0)
1607 			ieee80211_free_chanctx(local, ctx);
1608 		goto out;
1609 	}
1610 
1611 	ieee80211_recalc_smps_chanctx(local, ctx);
1612 	ieee80211_recalc_radar_chanctx(local, ctx);
1613  out:
1614 	if (ret)
1615 		sdata->radar_required = false;
1616 
1617 	mutex_unlock(&local->chanctx_mtx);
1618 	return ret;
1619 }
1620 
1621 int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata)
1622 {
1623 	struct ieee80211_local *local = sdata->local;
1624 	struct ieee80211_chanctx *new_ctx;
1625 	struct ieee80211_chanctx *old_ctx;
1626 	int err;
1627 
1628 	lockdep_assert_held(&local->mtx);
1629 	lockdep_assert_held(&local->chanctx_mtx);
1630 
1631 	new_ctx = sdata->reserved_chanctx;
1632 	old_ctx = ieee80211_vif_get_chanctx(sdata);
1633 
1634 	if (WARN_ON(!new_ctx))
1635 		return -EINVAL;
1636 
1637 	if (WARN_ON(new_ctx->replace_state ==
1638 		    IEEE80211_CHANCTX_WILL_BE_REPLACED))
1639 		return -EINVAL;
1640 
1641 	if (WARN_ON(sdata->reserved_ready))
1642 		return -EINVAL;
1643 
1644 	sdata->reserved_ready = true;
1645 
1646 	if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1647 		if (old_ctx)
1648 			err = ieee80211_vif_use_reserved_reassign(sdata);
1649 		else
1650 			err = ieee80211_vif_use_reserved_assign(sdata);
1651 
1652 		if (err)
1653 			return err;
1654 	}
1655 
1656 	/*
1657 	 * In-place reservation may need to be finalized now either if:
1658 	 *  a) sdata is taking part in the swapping itself and is the last one
1659 	 *  b) sdata has switched with a re-assign reservation to an existing
1660 	 *     context readying in-place switching of old_ctx
1661 	 *
1662 	 * In case of (b) do not propagate the error up because the requested
1663 	 * sdata already switched successfully. Just spill an extra warning.
1664 	 * The ieee80211_vif_use_reserved_switch() already stops all necessary
1665 	 * interfaces upon failure.
1666 	 */
1667 	if ((old_ctx &&
1668 	     old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1669 	    new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1670 		err = ieee80211_vif_use_reserved_switch(local);
1671 		if (err && err != -EAGAIN) {
1672 			if (new_ctx->replace_state ==
1673 			    IEEE80211_CHANCTX_REPLACES_OTHER)
1674 				return err;
1675 
1676 			wiphy_info(local->hw.wiphy,
1677 				   "depending in-place reservation failed (err=%d)\n",
1678 				   err);
1679 		}
1680 	}
1681 
1682 	return 0;
1683 }
1684 
1685 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
1686 				   const struct cfg80211_chan_def *chandef,
1687 				   u32 *changed)
1688 {
1689 	struct ieee80211_local *local = sdata->local;
1690 	struct ieee80211_chanctx_conf *conf;
1691 	struct ieee80211_chanctx *ctx;
1692 	const struct cfg80211_chan_def *compat;
1693 	int ret;
1694 
1695 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
1696 				     IEEE80211_CHAN_DISABLED))
1697 		return -EINVAL;
1698 
1699 	mutex_lock(&local->chanctx_mtx);
1700 	if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
1701 		ret = 0;
1702 		goto out;
1703 	}
1704 
1705 	if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
1706 	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
1707 		ret = -EINVAL;
1708 		goto out;
1709 	}
1710 
1711 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
1712 					 lockdep_is_held(&local->chanctx_mtx));
1713 	if (!conf) {
1714 		ret = -EINVAL;
1715 		goto out;
1716 	}
1717 
1718 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1719 
1720 	compat = cfg80211_chandef_compatible(&conf->def, chandef);
1721 	if (!compat) {
1722 		ret = -EINVAL;
1723 		goto out;
1724 	}
1725 
1726 	switch (ctx->replace_state) {
1727 	case IEEE80211_CHANCTX_REPLACE_NONE:
1728 		if (!ieee80211_chanctx_reserved_chandef(local, ctx, compat)) {
1729 			ret = -EBUSY;
1730 			goto out;
1731 		}
1732 		break;
1733 	case IEEE80211_CHANCTX_WILL_BE_REPLACED:
1734 		/* TODO: Perhaps the bandwidth change could be treated as a
1735 		 * reservation itself? */
1736 		ret = -EBUSY;
1737 		goto out;
1738 	case IEEE80211_CHANCTX_REPLACES_OTHER:
1739 		/* channel context that is going to replace another channel
1740 		 * context doesn't really exist and shouldn't be assigned
1741 		 * anywhere yet */
1742 		WARN_ON(1);
1743 		break;
1744 	}
1745 
1746 	ieee80211_vif_update_chandef(sdata, chandef);
1747 
1748 	ieee80211_recalc_chanctx_chantype(local, ctx);
1749 
1750 	*changed |= BSS_CHANGED_BANDWIDTH;
1751 	ret = 0;
1752  out:
1753 	mutex_unlock(&local->chanctx_mtx);
1754 	return ret;
1755 }
1756 
1757 void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
1758 {
1759 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
1760 
1761 	lockdep_assert_held(&sdata->local->mtx);
1762 
1763 	mutex_lock(&sdata->local->chanctx_mtx);
1764 	__ieee80211_vif_release_channel(sdata);
1765 	mutex_unlock(&sdata->local->chanctx_mtx);
1766 }
1767 
1768 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
1769 {
1770 	struct ieee80211_local *local = sdata->local;
1771 	struct ieee80211_sub_if_data *ap;
1772 	struct ieee80211_chanctx_conf *conf;
1773 
1774 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
1775 		return;
1776 
1777 	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
1778 
1779 	mutex_lock(&local->chanctx_mtx);
1780 
1781 	conf = rcu_dereference_protected(ap->vif.chanctx_conf,
1782 					 lockdep_is_held(&local->chanctx_mtx));
1783 	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
1784 	mutex_unlock(&local->chanctx_mtx);
1785 }
1786 
1787 void ieee80211_iter_chan_contexts_atomic(
1788 	struct ieee80211_hw *hw,
1789 	void (*iter)(struct ieee80211_hw *hw,
1790 		     struct ieee80211_chanctx_conf *chanctx_conf,
1791 		     void *data),
1792 	void *iter_data)
1793 {
1794 	struct ieee80211_local *local = hw_to_local(hw);
1795 	struct ieee80211_chanctx *ctx;
1796 
1797 	rcu_read_lock();
1798 	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
1799 		if (ctx->driver_present)
1800 			iter(hw, &ctx->conf, iter_data);
1801 	rcu_read_unlock();
1802 }
1803 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);
1804