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
12static 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
26static 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
40int 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
47static 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
60static 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
66static struct ieee80211_chanctx *
67ieee80211_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
80static const struct cfg80211_chan_def *
81ieee80211_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
103static const struct cfg80211_chan_def *
104ieee80211_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
129static const struct cfg80211_chan_def *
130ieee80211_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
147static bool
148ieee80211_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
164static struct ieee80211_chanctx *
165ieee80211_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
193enum 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
222static enum nl80211_chan_width
223ieee80211_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
244static enum nl80211_chan_width
245ieee80211_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 */
309void 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
342static 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
361static struct ieee80211_chanctx *
362ieee80211_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
399bool 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
417static bool
418ieee80211_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
445static struct ieee80211_chanctx *
446ieee80211_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
470static 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
501static struct ieee80211_chanctx *
502ieee80211_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
526static 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
553static 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
565void 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
615static 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
639static 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
668out:
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
695void 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
786static 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
816void 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
828int 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
863int 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
959static void
960ieee80211_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
987static void
988ieee80211_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
1002static int
1003ieee80211_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
1077out:
1078	ieee80211_vif_chanctx_reservation_complete(sdata);
1079	return err;
1080}
1081
1082static int
1083ieee80211_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
1124out:
1125	ieee80211_vif_chanctx_reservation_complete(sdata);
1126	return err;
1127}
1128
1129static bool
1130ieee80211_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
1154static 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
1173static 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
1216out:
1217	kfree(vif_chsw);
1218	return err;
1219}
1220
1221static 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
1244err:
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
1260static 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
1499err:
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
1514static 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
1551int 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
1611int 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
1675int 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
1747void 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
1758void 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
1777void 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}
1793EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);
1794