xref: /linux/net/mac80211/chan.c (revision 1a9239bb4253f9076b5b4b2a1a4e8d7defd77a95)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * mac80211 - channel management
4  * Copyright 2020 - 2025 Intel Corporation
5  */
6 
7 #include <linux/nl80211.h>
8 #include <linux/export.h>
9 #include <linux/rtnetlink.h>
10 #include <net/cfg80211.h>
11 #include "ieee80211_i.h"
12 #include "driver-ops.h"
13 #include "rate.h"
14 
ieee80211_chanctx_num_assigned(struct ieee80211_local * local,struct ieee80211_chanctx * ctx)15 static int ieee80211_chanctx_num_assigned(struct ieee80211_local *local,
16 					  struct ieee80211_chanctx *ctx)
17 {
18 	struct ieee80211_link_data *link;
19 	int num = 0;
20 
21 	lockdep_assert_wiphy(local->hw.wiphy);
22 
23 	list_for_each_entry(link, &ctx->assigned_links, assigned_chanctx_list)
24 		num++;
25 
26 	return num;
27 }
28 
ieee80211_chanctx_num_reserved(struct ieee80211_local * local,struct ieee80211_chanctx * ctx)29 static int ieee80211_chanctx_num_reserved(struct ieee80211_local *local,
30 					  struct ieee80211_chanctx *ctx)
31 {
32 	struct ieee80211_link_data *link;
33 	int num = 0;
34 
35 	lockdep_assert_wiphy(local->hw.wiphy);
36 
37 	list_for_each_entry(link, &ctx->reserved_links, reserved_chanctx_list)
38 		num++;
39 
40 	return num;
41 }
42 
ieee80211_chanctx_refcount(struct ieee80211_local * local,struct ieee80211_chanctx * ctx)43 int ieee80211_chanctx_refcount(struct ieee80211_local *local,
44 			       struct ieee80211_chanctx *ctx)
45 {
46 	return ieee80211_chanctx_num_assigned(local, ctx) +
47 	       ieee80211_chanctx_num_reserved(local, ctx);
48 }
49 
ieee80211_num_chanctx(struct ieee80211_local * local,int radio_idx)50 static int ieee80211_num_chanctx(struct ieee80211_local *local, int radio_idx)
51 {
52 	struct ieee80211_chanctx *ctx;
53 	int num = 0;
54 
55 	lockdep_assert_wiphy(local->hw.wiphy);
56 
57 	list_for_each_entry(ctx, &local->chanctx_list, list) {
58 		if (radio_idx >= 0 && ctx->conf.radio_idx != radio_idx)
59 			continue;
60 		num++;
61 	}
62 
63 	return num;
64 }
65 
ieee80211_can_create_new_chanctx(struct ieee80211_local * local,int radio_idx)66 static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local,
67 					     int radio_idx)
68 {
69 	lockdep_assert_wiphy(local->hw.wiphy);
70 
71 	return ieee80211_num_chanctx(local, radio_idx) <
72 	       ieee80211_max_num_channels(local, radio_idx);
73 }
74 
75 static struct ieee80211_chanctx *
ieee80211_link_get_chanctx(struct ieee80211_link_data * link)76 ieee80211_link_get_chanctx(struct ieee80211_link_data *link)
77 {
78 	struct ieee80211_local *local __maybe_unused = link->sdata->local;
79 	struct ieee80211_chanctx_conf *conf;
80 
81 	conf = rcu_dereference_protected(link->conf->chanctx_conf,
82 					 lockdep_is_held(&local->hw.wiphy->mtx));
83 	if (!conf)
84 		return NULL;
85 
86 	return container_of(conf, struct ieee80211_chanctx, conf);
87 }
88 
ieee80211_chanreq_identical(const struct ieee80211_chan_req * a,const struct ieee80211_chan_req * b)89 bool ieee80211_chanreq_identical(const struct ieee80211_chan_req *a,
90 				 const struct ieee80211_chan_req *b)
91 {
92 	if (!cfg80211_chandef_identical(&a->oper, &b->oper))
93 		return false;
94 	if (!a->ap.chan && !b->ap.chan)
95 		return true;
96 	return cfg80211_chandef_identical(&a->ap, &b->ap);
97 }
98 
99 static const struct ieee80211_chan_req *
ieee80211_chanreq_compatible(const struct ieee80211_chan_req * a,const struct ieee80211_chan_req * b,struct ieee80211_chan_req * tmp)100 ieee80211_chanreq_compatible(const struct ieee80211_chan_req *a,
101 			     const struct ieee80211_chan_req *b,
102 			     struct ieee80211_chan_req *tmp)
103 {
104 	const struct cfg80211_chan_def *compat;
105 
106 	if (a->ap.chan && b->ap.chan &&
107 	    !cfg80211_chandef_identical(&a->ap, &b->ap))
108 		return NULL;
109 
110 	compat = cfg80211_chandef_compatible(&a->oper, &b->oper);
111 	if (!compat)
112 		return NULL;
113 
114 	/* Note: later code assumes this always fills & returns tmp if compat */
115 	tmp->oper = *compat;
116 	tmp->ap = a->ap.chan ? a->ap : b->ap;
117 	return tmp;
118 }
119 
120 static const struct ieee80211_chan_req *
ieee80211_chanctx_compatible(struct ieee80211_chanctx * ctx,const struct ieee80211_chan_req * req,struct ieee80211_chan_req * tmp)121 ieee80211_chanctx_compatible(struct ieee80211_chanctx *ctx,
122 			     const struct ieee80211_chan_req *req,
123 			     struct ieee80211_chan_req *tmp)
124 {
125 	const struct ieee80211_chan_req *ret;
126 	struct ieee80211_chan_req tmp2;
127 
128 	*tmp = (struct ieee80211_chan_req){
129 		.oper = ctx->conf.def,
130 		.ap = ctx->conf.ap,
131 	};
132 
133 	ret = ieee80211_chanreq_compatible(tmp, req, &tmp2);
134 	if (!ret)
135 		return NULL;
136 	*tmp = *ret;
137 	return tmp;
138 }
139 
140 static const struct ieee80211_chan_req *
ieee80211_chanctx_reserved_chanreq(struct ieee80211_local * local,struct ieee80211_chanctx * ctx,const struct ieee80211_chan_req * req,struct ieee80211_chan_req * tmp)141 ieee80211_chanctx_reserved_chanreq(struct ieee80211_local *local,
142 				   struct ieee80211_chanctx *ctx,
143 				   const struct ieee80211_chan_req *req,
144 				   struct ieee80211_chan_req *tmp)
145 {
146 	struct ieee80211_link_data *link;
147 
148 	lockdep_assert_wiphy(local->hw.wiphy);
149 
150 	if (WARN_ON(!req))
151 		return NULL;
152 
153 	list_for_each_entry(link, &ctx->reserved_links, reserved_chanctx_list) {
154 		req = ieee80211_chanreq_compatible(&link->reserved, req, tmp);
155 		if (!req)
156 			break;
157 	}
158 
159 	return req;
160 }
161 
162 static const struct ieee80211_chan_req *
ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local * local,struct ieee80211_chanctx * ctx,const struct ieee80211_chan_req * compat,struct ieee80211_chan_req * tmp)163 ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local *local,
164 				       struct ieee80211_chanctx *ctx,
165 				       const struct ieee80211_chan_req *compat,
166 				       struct ieee80211_chan_req *tmp)
167 {
168 	struct ieee80211_link_data *link;
169 	const struct ieee80211_chan_req *comp_def = compat;
170 
171 	lockdep_assert_wiphy(local->hw.wiphy);
172 
173 	list_for_each_entry(link, &ctx->assigned_links, assigned_chanctx_list) {
174 		struct ieee80211_bss_conf *link_conf = link->conf;
175 
176 		if (link->reserved_chanctx)
177 			continue;
178 
179 		comp_def = ieee80211_chanreq_compatible(&link_conf->chanreq,
180 							comp_def, tmp);
181 		if (!comp_def)
182 			break;
183 	}
184 
185 	return comp_def;
186 }
187 
188 static bool
ieee80211_chanctx_can_reserve(struct ieee80211_local * local,struct ieee80211_chanctx * ctx,const struct ieee80211_chan_req * req)189 ieee80211_chanctx_can_reserve(struct ieee80211_local *local,
190 			      struct ieee80211_chanctx *ctx,
191 			      const struct ieee80211_chan_req *req)
192 {
193 	struct ieee80211_chan_req tmp;
194 
195 	lockdep_assert_wiphy(local->hw.wiphy);
196 
197 	if (!ieee80211_chanctx_reserved_chanreq(local, ctx, req, &tmp))
198 		return false;
199 
200 	if (!ieee80211_chanctx_non_reserved_chandef(local, ctx, req, &tmp))
201 		return false;
202 
203 	if (!list_empty(&ctx->reserved_links) &&
204 	    ieee80211_chanctx_reserved_chanreq(local, ctx, req, &tmp))
205 		return true;
206 
207 	return false;
208 }
209 
210 static struct ieee80211_chanctx *
ieee80211_find_reservation_chanctx(struct ieee80211_local * local,const struct ieee80211_chan_req * chanreq,enum ieee80211_chanctx_mode mode)211 ieee80211_find_reservation_chanctx(struct ieee80211_local *local,
212 				   const struct ieee80211_chan_req *chanreq,
213 				   enum ieee80211_chanctx_mode mode)
214 {
215 	struct ieee80211_chanctx *ctx;
216 
217 	lockdep_assert_wiphy(local->hw.wiphy);
218 
219 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
220 		return NULL;
221 
222 	list_for_each_entry(ctx, &local->chanctx_list, list) {
223 		if (ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED)
224 			continue;
225 
226 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
227 			continue;
228 
229 		if (!ieee80211_chanctx_can_reserve(local, ctx, chanreq))
230 			continue;
231 
232 		return ctx;
233 	}
234 
235 	return NULL;
236 }
237 
ieee80211_get_sta_bw(struct sta_info * sta,unsigned int link_id)238 static enum nl80211_chan_width ieee80211_get_sta_bw(struct sta_info *sta,
239 						    unsigned int link_id)
240 {
241 	enum ieee80211_sta_rx_bandwidth width;
242 	struct link_sta_info *link_sta;
243 
244 	link_sta = wiphy_dereference(sta->local->hw.wiphy, sta->link[link_id]);
245 
246 	/* no effect if this STA has no presence on this link */
247 	if (!link_sta)
248 		return NL80211_CHAN_WIDTH_20_NOHT;
249 
250 	/*
251 	 * We assume that TX/RX might be asymmetric (so e.g. VHT operating
252 	 * mode notification changes what a STA wants to receive, but not
253 	 * necessarily what it will transmit to us), and therefore use the
254 	 * capabilities here. Calling it RX bandwidth capability is a bit
255 	 * wrong though, since capabilities are in fact symmetric.
256 	 */
257 	width = ieee80211_sta_cap_rx_bw(link_sta);
258 
259 	switch (width) {
260 	case IEEE80211_STA_RX_BW_20:
261 		if (link_sta->pub->ht_cap.ht_supported)
262 			return NL80211_CHAN_WIDTH_20;
263 		else
264 			return NL80211_CHAN_WIDTH_20_NOHT;
265 	case IEEE80211_STA_RX_BW_40:
266 		return NL80211_CHAN_WIDTH_40;
267 	case IEEE80211_STA_RX_BW_80:
268 		return NL80211_CHAN_WIDTH_80;
269 	case IEEE80211_STA_RX_BW_160:
270 		/*
271 		 * This applied for both 160 and 80+80. since we use
272 		 * the returned value to consider degradation of
273 		 * ctx->conf.min_def, we have to make sure to take
274 		 * the bigger one (NL80211_CHAN_WIDTH_160).
275 		 * Otherwise we might try degrading even when not
276 		 * needed, as the max required sta_bw returned (80+80)
277 		 * might be smaller than the configured bw (160).
278 		 */
279 		return NL80211_CHAN_WIDTH_160;
280 	case IEEE80211_STA_RX_BW_320:
281 		return NL80211_CHAN_WIDTH_320;
282 	default:
283 		WARN_ON(1);
284 		return NL80211_CHAN_WIDTH_20;
285 	}
286 }
287 
288 static enum nl80211_chan_width
ieee80211_get_max_required_bw(struct ieee80211_link_data * link)289 ieee80211_get_max_required_bw(struct ieee80211_link_data *link)
290 {
291 	struct ieee80211_sub_if_data *sdata = link->sdata;
292 	unsigned int link_id = link->link_id;
293 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
294 	struct sta_info *sta;
295 
296 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
297 
298 	list_for_each_entry(sta, &sdata->local->sta_list, list) {
299 		if (sdata != sta->sdata &&
300 		    !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
301 			continue;
302 
303 		max_bw = max(max_bw, ieee80211_get_sta_bw(sta, link_id));
304 	}
305 
306 	return max_bw;
307 }
308 
309 static enum nl80211_chan_width
ieee80211_get_chanctx_max_required_bw(struct ieee80211_local * local,struct ieee80211_chanctx * ctx,struct ieee80211_link_data * rsvd_for,bool check_reserved)310 ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
311 				      struct ieee80211_chanctx *ctx,
312 				      struct ieee80211_link_data *rsvd_for,
313 				      bool check_reserved)
314 {
315 	struct ieee80211_sub_if_data *sdata;
316 	struct ieee80211_link_data *link;
317 	enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
318 
319 	if (WARN_ON(check_reserved && rsvd_for))
320 		return ctx->conf.def.width;
321 
322 	for_each_sdata_link(local, link) {
323 		enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT;
324 
325 		if (check_reserved) {
326 			if (link->reserved_chanctx != ctx)
327 				continue;
328 		} else if (link != rsvd_for &&
329 			   rcu_access_pointer(link->conf->chanctx_conf) != &ctx->conf)
330 			continue;
331 
332 		switch (link->sdata->vif.type) {
333 		case NL80211_IFTYPE_STATION:
334 			if (!link->sdata->vif.cfg.assoc) {
335 				/*
336 				 * The AP's sta->bandwidth may not yet be set
337 				 * at this point (pre-association), so simply
338 				 * take the width from the chandef. We cannot
339 				 * have TDLS peers yet (only after association).
340 				 */
341 				width = link->conf->chanreq.oper.width;
342 				break;
343 			}
344 			/*
345 			 * otherwise just use min_def like in AP, depending on what
346 			 * we currently think the AP STA (and possibly TDLS peers)
347 			 * require(s)
348 			 */
349 			fallthrough;
350 		case NL80211_IFTYPE_AP:
351 		case NL80211_IFTYPE_AP_VLAN:
352 			width = ieee80211_get_max_required_bw(link);
353 			break;
354 		case NL80211_IFTYPE_P2P_DEVICE:
355 		case NL80211_IFTYPE_NAN:
356 			continue;
357 		case NL80211_IFTYPE_MONITOR:
358 			WARN_ON_ONCE(!ieee80211_hw_check(&local->hw,
359 							 NO_VIRTUAL_MONITOR));
360 			fallthrough;
361 		case NL80211_IFTYPE_ADHOC:
362 		case NL80211_IFTYPE_MESH_POINT:
363 		case NL80211_IFTYPE_OCB:
364 			width = link->conf->chanreq.oper.width;
365 			break;
366 		case NL80211_IFTYPE_WDS:
367 		case NL80211_IFTYPE_UNSPECIFIED:
368 		case NUM_NL80211_IFTYPES:
369 		case NL80211_IFTYPE_P2P_CLIENT:
370 		case NL80211_IFTYPE_P2P_GO:
371 			WARN_ON_ONCE(1);
372 		}
373 
374 		max_bw = max(max_bw, width);
375 	}
376 
377 	/* use the configured bandwidth in case of monitor interface */
378 	sdata = wiphy_dereference(local->hw.wiphy, local->monitor_sdata);
379 	if (sdata &&
380 	    rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) == &ctx->conf)
381 		max_bw = max(max_bw, ctx->conf.def.width);
382 
383 	return max_bw;
384 }
385 
386 /*
387  * recalc the min required chan width of the channel context, which is
388  * the max of min required widths of all the interfaces bound to this
389  * channel context.
390  */
391 static u32
_ieee80211_recalc_chanctx_min_def(struct ieee80211_local * local,struct ieee80211_chanctx * ctx,struct ieee80211_link_data * rsvd_for,bool check_reserved)392 _ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
393 				  struct ieee80211_chanctx *ctx,
394 				  struct ieee80211_link_data *rsvd_for,
395 				  bool check_reserved)
396 {
397 	enum nl80211_chan_width max_bw;
398 	struct cfg80211_chan_def min_def;
399 
400 	lockdep_assert_wiphy(local->hw.wiphy);
401 
402 	/* don't optimize non-20MHz based and radar_enabled confs */
403 	if (ctx->conf.def.width == NL80211_CHAN_WIDTH_5 ||
404 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_10 ||
405 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_1 ||
406 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_2 ||
407 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_4 ||
408 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_8 ||
409 	    ctx->conf.def.width == NL80211_CHAN_WIDTH_16 ||
410 	    ctx->conf.radar_enabled) {
411 		ctx->conf.min_def = ctx->conf.def;
412 		return 0;
413 	}
414 
415 	max_bw = ieee80211_get_chanctx_max_required_bw(local, ctx, rsvd_for,
416 						       check_reserved);
417 
418 	/* downgrade chandef up to max_bw */
419 	min_def = ctx->conf.def;
420 	while (min_def.width > max_bw)
421 		ieee80211_chandef_downgrade(&min_def, NULL);
422 
423 	if (cfg80211_chandef_identical(&ctx->conf.min_def, &min_def))
424 		return 0;
425 
426 	ctx->conf.min_def = min_def;
427 	if (!ctx->driver_present)
428 		return 0;
429 
430 	return IEEE80211_CHANCTX_CHANGE_MIN_DEF;
431 }
432 
ieee80211_chan_bw_change(struct ieee80211_local * local,struct ieee80211_chanctx * ctx,bool reserved,bool narrowed)433 static void ieee80211_chan_bw_change(struct ieee80211_local *local,
434 				     struct ieee80211_chanctx *ctx,
435 				     bool reserved, bool narrowed)
436 {
437 	struct sta_info *sta;
438 	struct ieee80211_supported_band *sband =
439 		local->hw.wiphy->bands[ctx->conf.def.chan->band];
440 
441 	rcu_read_lock();
442 	list_for_each_entry_rcu(sta, &local->sta_list,
443 				list) {
444 		struct ieee80211_sub_if_data *sdata = sta->sdata;
445 		enum ieee80211_sta_rx_bandwidth new_sta_bw;
446 		unsigned int link_id;
447 
448 		if (!ieee80211_sdata_running(sta->sdata))
449 			continue;
450 
451 		for (link_id = 0; link_id < ARRAY_SIZE(sta->sdata->link); link_id++) {
452 			struct ieee80211_link_data *link =
453 				rcu_dereference(sdata->link[link_id]);
454 			struct ieee80211_bss_conf *link_conf;
455 			struct cfg80211_chan_def *new_chandef;
456 			struct link_sta_info *link_sta;
457 
458 			if (!link)
459 				continue;
460 
461 			link_conf = link->conf;
462 
463 			if (rcu_access_pointer(link_conf->chanctx_conf) != &ctx->conf)
464 				continue;
465 
466 			link_sta = rcu_dereference(sta->link[link_id]);
467 			if (!link_sta)
468 				continue;
469 
470 			if (reserved)
471 				new_chandef = &link->reserved.oper;
472 			else
473 				new_chandef = &link_conf->chanreq.oper;
474 
475 			new_sta_bw = _ieee80211_sta_cur_vht_bw(link_sta,
476 							       new_chandef);
477 
478 			/* nothing change */
479 			if (new_sta_bw == link_sta->pub->bandwidth)
480 				continue;
481 
482 			/* vif changed to narrow BW and narrow BW for station wasn't
483 			 * requested or vice versa */
484 			if ((new_sta_bw < link_sta->pub->bandwidth) == !narrowed)
485 				continue;
486 
487 			link_sta->pub->bandwidth = new_sta_bw;
488 			rate_control_rate_update(local, sband, link_sta,
489 						 IEEE80211_RC_BW_CHANGED);
490 		}
491 	}
492 	rcu_read_unlock();
493 }
494 
495 /*
496  * recalc the min required chan width of the channel context, which is
497  * the max of min required widths of all the interfaces bound to this
498  * channel context.
499  */
ieee80211_recalc_chanctx_min_def(struct ieee80211_local * local,struct ieee80211_chanctx * ctx,struct ieee80211_link_data * rsvd_for,bool check_reserved)500 void ieee80211_recalc_chanctx_min_def(struct ieee80211_local *local,
501 				      struct ieee80211_chanctx *ctx,
502 				      struct ieee80211_link_data *rsvd_for,
503 				      bool check_reserved)
504 {
505 	u32 changed = _ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for,
506 							check_reserved);
507 
508 	if (!changed)
509 		return;
510 
511 	/* check is BW narrowed */
512 	ieee80211_chan_bw_change(local, ctx, false, true);
513 
514 	drv_change_chanctx(local, ctx, changed);
515 
516 	/* check is BW wider */
517 	ieee80211_chan_bw_change(local, ctx, false, false);
518 }
519 
_ieee80211_change_chanctx(struct ieee80211_local * local,struct ieee80211_chanctx * ctx,struct ieee80211_chanctx * old_ctx,const struct ieee80211_chan_req * chanreq,struct ieee80211_link_data * rsvd_for)520 static void _ieee80211_change_chanctx(struct ieee80211_local *local,
521 				      struct ieee80211_chanctx *ctx,
522 				      struct ieee80211_chanctx *old_ctx,
523 				      const struct ieee80211_chan_req *chanreq,
524 				      struct ieee80211_link_data *rsvd_for)
525 {
526 	const struct cfg80211_chan_def *chandef = &chanreq->oper;
527 	struct ieee80211_chan_req ctx_req = {
528 		.oper = ctx->conf.def,
529 		.ap = ctx->conf.ap,
530 	};
531 	u32 changed = 0;
532 
533 	/* expected to handle only 20/40/80/160/320 channel widths */
534 	switch (chandef->width) {
535 	case NL80211_CHAN_WIDTH_20_NOHT:
536 	case NL80211_CHAN_WIDTH_20:
537 	case NL80211_CHAN_WIDTH_40:
538 	case NL80211_CHAN_WIDTH_80:
539 	case NL80211_CHAN_WIDTH_80P80:
540 	case NL80211_CHAN_WIDTH_160:
541 	case NL80211_CHAN_WIDTH_320:
542 		break;
543 	default:
544 		WARN_ON(1);
545 	}
546 
547 	/* Check maybe BW narrowed - we do this _before_ calling recalc_chanctx_min_def
548 	 * due to maybe not returning from it, e.g in case new context was added
549 	 * first time with all parameters up to date.
550 	 */
551 	ieee80211_chan_bw_change(local, old_ctx, false, true);
552 
553 	if (ieee80211_chanreq_identical(&ctx_req, chanreq)) {
554 		ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for, false);
555 		return;
556 	}
557 
558 	WARN_ON(ieee80211_chanctx_refcount(local, ctx) > 1 &&
559 		!cfg80211_chandef_compatible(&ctx->conf.def, &chanreq->oper));
560 
561 	ieee80211_remove_wbrf(local, &ctx->conf.def);
562 
563 	if (!cfg80211_chandef_identical(&ctx->conf.def, &chanreq->oper)) {
564 		if (ctx->conf.def.width != chanreq->oper.width)
565 			changed |= IEEE80211_CHANCTX_CHANGE_WIDTH;
566 		if (ctx->conf.def.punctured != chanreq->oper.punctured)
567 			changed |= IEEE80211_CHANCTX_CHANGE_PUNCTURING;
568 	}
569 	if (!cfg80211_chandef_identical(&ctx->conf.ap, &chanreq->ap))
570 		changed |= IEEE80211_CHANCTX_CHANGE_AP;
571 	ctx->conf.def = *chandef;
572 	ctx->conf.ap = chanreq->ap;
573 
574 	/* check if min chanctx also changed */
575 	changed |= _ieee80211_recalc_chanctx_min_def(local, ctx, rsvd_for, false);
576 
577 	ieee80211_add_wbrf(local, &ctx->conf.def);
578 
579 	drv_change_chanctx(local, ctx, changed);
580 
581 	/* check if BW is wider */
582 	ieee80211_chan_bw_change(local, old_ctx, false, false);
583 }
584 
ieee80211_change_chanctx(struct ieee80211_local * local,struct ieee80211_chanctx * ctx,struct ieee80211_chanctx * old_ctx,const struct ieee80211_chan_req * chanreq)585 static void ieee80211_change_chanctx(struct ieee80211_local *local,
586 				     struct ieee80211_chanctx *ctx,
587 				     struct ieee80211_chanctx *old_ctx,
588 				     const struct ieee80211_chan_req *chanreq)
589 {
590 	_ieee80211_change_chanctx(local, ctx, old_ctx, chanreq, NULL);
591 }
592 
593 /* Note: if successful, the returned chanctx is reserved for the link */
594 static struct ieee80211_chanctx *
ieee80211_find_chanctx(struct ieee80211_local * local,struct ieee80211_link_data * link,const struct ieee80211_chan_req * chanreq,enum ieee80211_chanctx_mode mode)595 ieee80211_find_chanctx(struct ieee80211_local *local,
596 		       struct ieee80211_link_data *link,
597 		       const struct ieee80211_chan_req *chanreq,
598 		       enum ieee80211_chanctx_mode mode)
599 {
600 	struct ieee80211_chan_req tmp;
601 	struct ieee80211_chanctx *ctx;
602 
603 	lockdep_assert_wiphy(local->hw.wiphy);
604 
605 	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
606 		return NULL;
607 
608 	if (WARN_ON(link->reserved_chanctx))
609 		return NULL;
610 
611 	list_for_each_entry(ctx, &local->chanctx_list, list) {
612 		const struct ieee80211_chan_req *compat;
613 
614 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACE_NONE)
615 			continue;
616 
617 		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
618 			continue;
619 
620 		compat = ieee80211_chanctx_compatible(ctx, chanreq, &tmp);
621 		if (!compat)
622 			continue;
623 
624 		compat = ieee80211_chanctx_reserved_chanreq(local, ctx,
625 							    compat, &tmp);
626 		if (!compat)
627 			continue;
628 
629 		/*
630 		 * Reserve the chanctx temporarily, as the driver might change
631 		 * active links during callbacks we make into it below and/or
632 		 * later during assignment, which could (otherwise) cause the
633 		 * context to actually be removed.
634 		 */
635 		link->reserved_chanctx = ctx;
636 		list_add(&link->reserved_chanctx_list,
637 			 &ctx->reserved_links);
638 
639 		ieee80211_change_chanctx(local, ctx, ctx, compat);
640 
641 		return ctx;
642 	}
643 
644 	return NULL;
645 }
646 
ieee80211_is_radar_required(struct ieee80211_local * local)647 bool ieee80211_is_radar_required(struct ieee80211_local *local)
648 {
649 	struct ieee80211_link_data *link;
650 
651 	lockdep_assert_wiphy(local->hw.wiphy);
652 
653 	for_each_sdata_link(local, link) {
654 		if (link->radar_required)
655 			return true;
656 	}
657 
658 	return false;
659 }
660 
661 static bool
ieee80211_chanctx_radar_required(struct ieee80211_local * local,struct ieee80211_chanctx * ctx)662 ieee80211_chanctx_radar_required(struct ieee80211_local *local,
663 				 struct ieee80211_chanctx *ctx)
664 {
665 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
666 	struct ieee80211_link_data *link;
667 
668 	lockdep_assert_wiphy(local->hw.wiphy);
669 
670 	for_each_sdata_link(local, link) {
671 		if (rcu_access_pointer(link->conf->chanctx_conf) != conf)
672 			continue;
673 		if (!link->radar_required)
674 			continue;
675 		return true;
676 	}
677 
678 	return false;
679 }
680 
681 static struct ieee80211_chanctx *
ieee80211_alloc_chanctx(struct ieee80211_local * local,const struct ieee80211_chan_req * chanreq,enum ieee80211_chanctx_mode mode,int radio_idx)682 ieee80211_alloc_chanctx(struct ieee80211_local *local,
683 			const struct ieee80211_chan_req *chanreq,
684 			enum ieee80211_chanctx_mode mode,
685 			int radio_idx)
686 {
687 	struct ieee80211_chanctx *ctx;
688 
689 	lockdep_assert_wiphy(local->hw.wiphy);
690 
691 	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
692 	if (!ctx)
693 		return NULL;
694 
695 	INIT_LIST_HEAD(&ctx->assigned_links);
696 	INIT_LIST_HEAD(&ctx->reserved_links);
697 	ctx->conf.def = chanreq->oper;
698 	ctx->conf.ap = chanreq->ap;
699 	ctx->conf.rx_chains_static = 1;
700 	ctx->conf.rx_chains_dynamic = 1;
701 	ctx->mode = mode;
702 	ctx->conf.radar_enabled = false;
703 	ctx->conf.radio_idx = radio_idx;
704 	ctx->radar_detected = false;
705 	_ieee80211_recalc_chanctx_min_def(local, ctx, NULL, false);
706 
707 	return ctx;
708 }
709 
ieee80211_add_chanctx(struct ieee80211_local * local,struct ieee80211_chanctx * ctx)710 static int ieee80211_add_chanctx(struct ieee80211_local *local,
711 				 struct ieee80211_chanctx *ctx)
712 {
713 	u32 changed;
714 	int err;
715 
716 	lockdep_assert_wiphy(local->hw.wiphy);
717 
718 	ieee80211_add_wbrf(local, &ctx->conf.def);
719 
720 	/* turn idle off *before* setting channel -- some drivers need that */
721 	changed = ieee80211_idle_off(local);
722 	if (changed)
723 		ieee80211_hw_config(local, changed);
724 
725 	err = drv_add_chanctx(local, ctx);
726 	if (err) {
727 		ieee80211_recalc_idle(local);
728 		return err;
729 	}
730 
731 	return 0;
732 }
733 
734 static struct ieee80211_chanctx *
ieee80211_new_chanctx(struct ieee80211_local * local,const struct ieee80211_chan_req * chanreq,enum ieee80211_chanctx_mode mode,bool assign_on_failure,int radio_idx)735 ieee80211_new_chanctx(struct ieee80211_local *local,
736 		      const struct ieee80211_chan_req *chanreq,
737 		      enum ieee80211_chanctx_mode mode,
738 		      bool assign_on_failure,
739 		      int radio_idx)
740 {
741 	struct ieee80211_chanctx *ctx;
742 	int err;
743 
744 	lockdep_assert_wiphy(local->hw.wiphy);
745 
746 	ctx = ieee80211_alloc_chanctx(local, chanreq, mode, radio_idx);
747 	if (!ctx)
748 		return ERR_PTR(-ENOMEM);
749 
750 	err = ieee80211_add_chanctx(local, ctx);
751 	if (!assign_on_failure && err) {
752 		kfree(ctx);
753 		return ERR_PTR(err);
754 	}
755 	/* We ignored a driver error, see _ieee80211_set_active_links */
756 	WARN_ON_ONCE(err && !local->in_reconfig);
757 
758 	list_add_rcu(&ctx->list, &local->chanctx_list);
759 	return ctx;
760 }
761 
ieee80211_del_chanctx(struct ieee80211_local * local,struct ieee80211_chanctx * ctx,bool skip_idle_recalc)762 static void ieee80211_del_chanctx(struct ieee80211_local *local,
763 				  struct ieee80211_chanctx *ctx,
764 				  bool skip_idle_recalc)
765 {
766 	lockdep_assert_wiphy(local->hw.wiphy);
767 
768 	drv_remove_chanctx(local, ctx);
769 
770 	if (!skip_idle_recalc)
771 		ieee80211_recalc_idle(local);
772 
773 	ieee80211_remove_wbrf(local, &ctx->conf.def);
774 }
775 
ieee80211_free_chanctx(struct ieee80211_local * local,struct ieee80211_chanctx * ctx,bool skip_idle_recalc)776 static void ieee80211_free_chanctx(struct ieee80211_local *local,
777 				   struct ieee80211_chanctx *ctx,
778 				   bool skip_idle_recalc)
779 {
780 	lockdep_assert_wiphy(local->hw.wiphy);
781 
782 	WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
783 
784 	list_del_rcu(&ctx->list);
785 	ieee80211_del_chanctx(local, ctx, skip_idle_recalc);
786 	kfree_rcu(ctx, rcu_head);
787 }
788 
ieee80211_recalc_chanctx_chantype(struct ieee80211_local * local,struct ieee80211_chanctx * ctx)789 void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
790 				       struct ieee80211_chanctx *ctx)
791 {
792 	struct ieee80211_chanctx_conf *conf = &ctx->conf;
793 	const struct ieee80211_chan_req *compat = NULL;
794 	struct ieee80211_link_data *link;
795 	struct ieee80211_chan_req tmp;
796 	struct sta_info *sta;
797 
798 	lockdep_assert_wiphy(local->hw.wiphy);
799 
800 	for_each_sdata_link(local, link) {
801 		struct ieee80211_bss_conf *link_conf;
802 
803 		if (link->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
804 			continue;
805 
806 		link_conf = link->conf;
807 
808 		if (rcu_access_pointer(link_conf->chanctx_conf) != conf)
809 			continue;
810 
811 		if (!compat)
812 			compat = &link_conf->chanreq;
813 
814 		compat = ieee80211_chanreq_compatible(&link_conf->chanreq,
815 						      compat, &tmp);
816 		if (WARN_ON_ONCE(!compat))
817 			return;
818 	}
819 
820 	if (WARN_ON_ONCE(!compat))
821 		return;
822 
823 	/* TDLS peers can sometimes affect the chandef width */
824 	list_for_each_entry(sta, &local->sta_list, list) {
825 		struct ieee80211_sub_if_data *sdata = sta->sdata;
826 		struct ieee80211_chan_req tdls_chanreq = {};
827 		int tdls_link_id;
828 
829 		if (!sta->uploaded ||
830 		    !test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
831 		    !test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
832 		    !sta->tdls_chandef.chan)
833 			continue;
834 
835 		tdls_link_id = ieee80211_tdls_sta_link_id(sta);
836 		link = sdata_dereference(sdata->link[tdls_link_id], sdata);
837 		if (!link)
838 			continue;
839 
840 		if (rcu_access_pointer(link->conf->chanctx_conf) != conf)
841 			continue;
842 
843 		tdls_chanreq.oper = sta->tdls_chandef;
844 
845 		/* note this always fills and returns &tmp if compat */
846 		compat = ieee80211_chanreq_compatible(&tdls_chanreq,
847 						      compat, &tmp);
848 		if (WARN_ON_ONCE(!compat))
849 			return;
850 	}
851 
852 	ieee80211_change_chanctx(local, ctx, ctx, compat);
853 }
854 
ieee80211_recalc_radar_chanctx(struct ieee80211_local * local,struct ieee80211_chanctx * chanctx)855 static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
856 					   struct ieee80211_chanctx *chanctx)
857 {
858 	bool radar_enabled;
859 
860 	lockdep_assert_wiphy(local->hw.wiphy);
861 
862 	radar_enabled = ieee80211_chanctx_radar_required(local, chanctx);
863 
864 	if (radar_enabled == chanctx->conf.radar_enabled)
865 		return;
866 
867 	chanctx->conf.radar_enabled = radar_enabled;
868 
869 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
870 }
871 
ieee80211_assign_link_chanctx(struct ieee80211_link_data * link,struct ieee80211_chanctx * new_ctx,bool assign_on_failure)872 static int ieee80211_assign_link_chanctx(struct ieee80211_link_data *link,
873 					 struct ieee80211_chanctx *new_ctx,
874 					 bool assign_on_failure)
875 {
876 	struct ieee80211_sub_if_data *sdata = link->sdata;
877 	struct ieee80211_local *local = sdata->local;
878 	struct ieee80211_chanctx_conf *conf;
879 	struct ieee80211_chanctx *curr_ctx = NULL;
880 	bool new_idle;
881 	int ret;
882 
883 	if (WARN_ON(sdata->vif.type == NL80211_IFTYPE_NAN))
884 		return -EOPNOTSUPP;
885 
886 	conf = rcu_dereference_protected(link->conf->chanctx_conf,
887 					 lockdep_is_held(&local->hw.wiphy->mtx));
888 
889 	if (conf) {
890 		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
891 
892 		drv_unassign_vif_chanctx(local, sdata, link->conf, curr_ctx);
893 		conf = NULL;
894 		list_del(&link->assigned_chanctx_list);
895 	}
896 
897 	if (new_ctx) {
898 		/* recalc considering the link we'll use it for now */
899 		ieee80211_recalc_chanctx_min_def(local, new_ctx, link, false);
900 
901 		ret = drv_assign_vif_chanctx(local, sdata, link->conf, new_ctx);
902 		if (assign_on_failure || !ret) {
903 			/* Need to continue, see _ieee80211_set_active_links */
904 			WARN_ON_ONCE(ret && !local->in_reconfig);
905 			ret = 0;
906 
907 			/* succeeded, so commit it to the data structures */
908 			conf = &new_ctx->conf;
909 			list_add(&link->assigned_chanctx_list,
910 				 &new_ctx->assigned_links);
911 		}
912 	} else {
913 		ret = 0;
914 	}
915 
916 	rcu_assign_pointer(link->conf->chanctx_conf, conf);
917 
918 	if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
919 		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
920 		ieee80211_recalc_smps_chanctx(local, curr_ctx);
921 		ieee80211_recalc_radar_chanctx(local, curr_ctx);
922 		ieee80211_recalc_chanctx_min_def(local, curr_ctx, NULL, false);
923 	}
924 
925 	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
926 		ieee80211_recalc_txpower(link, false);
927 		ieee80211_recalc_chanctx_min_def(local, new_ctx, NULL, false);
928 	}
929 
930 	if (conf) {
931 		new_idle = false;
932 	} else {
933 		struct ieee80211_link_data *tmp;
934 
935 		new_idle = true;
936 		for_each_sdata_link(local, tmp) {
937 			if (rcu_access_pointer(tmp->conf->chanctx_conf)) {
938 				new_idle = false;
939 				break;
940 			}
941 		}
942 	}
943 
944 	if (new_idle != sdata->vif.cfg.idle) {
945 		sdata->vif.cfg.idle = new_idle;
946 
947 		if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
948 		    sdata->vif.type != NL80211_IFTYPE_MONITOR)
949 			ieee80211_vif_cfg_change_notify(sdata, BSS_CHANGED_IDLE);
950 	}
951 
952 	ieee80211_check_fast_xmit_iface(sdata);
953 
954 	return ret;
955 }
956 
ieee80211_recalc_smps_chanctx(struct ieee80211_local * local,struct ieee80211_chanctx * chanctx)957 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
958 				   struct ieee80211_chanctx *chanctx)
959 {
960 	struct ieee80211_sub_if_data *sdata;
961 	u8 rx_chains_static, rx_chains_dynamic;
962 	struct ieee80211_link_data *link;
963 
964 	lockdep_assert_wiphy(local->hw.wiphy);
965 
966 	rx_chains_static = 1;
967 	rx_chains_dynamic = 1;
968 
969 	for_each_sdata_link(local, link) {
970 		u8 needed_static, needed_dynamic;
971 
972 		switch (link->sdata->vif.type) {
973 		case NL80211_IFTYPE_STATION:
974 			if (!link->sdata->u.mgd.associated)
975 				continue;
976 			break;
977 		case NL80211_IFTYPE_MONITOR:
978 			if (!ieee80211_hw_check(&local->hw, NO_VIRTUAL_MONITOR))
979 				continue;
980 			break;
981 		case NL80211_IFTYPE_AP:
982 		case NL80211_IFTYPE_ADHOC:
983 		case NL80211_IFTYPE_MESH_POINT:
984 		case NL80211_IFTYPE_OCB:
985 			break;
986 		default:
987 			continue;
988 		}
989 
990 		if (rcu_access_pointer(link->conf->chanctx_conf) != &chanctx->conf)
991 			continue;
992 
993 		if (link->sdata->vif.type == NL80211_IFTYPE_MONITOR) {
994 			rx_chains_dynamic = rx_chains_static = local->rx_chains;
995 			break;
996 		}
997 
998 		switch (link->smps_mode) {
999 		default:
1000 			WARN_ONCE(1, "Invalid SMPS mode %d\n",
1001 				  link->smps_mode);
1002 			fallthrough;
1003 		case IEEE80211_SMPS_OFF:
1004 			needed_static = link->needed_rx_chains;
1005 			needed_dynamic = link->needed_rx_chains;
1006 			break;
1007 		case IEEE80211_SMPS_DYNAMIC:
1008 			needed_static = 1;
1009 			needed_dynamic = link->needed_rx_chains;
1010 			break;
1011 		case IEEE80211_SMPS_STATIC:
1012 			needed_static = 1;
1013 			needed_dynamic = 1;
1014 			break;
1015 		}
1016 
1017 		rx_chains_static = max(rx_chains_static, needed_static);
1018 		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
1019 	}
1020 
1021 	/* Disable SMPS for the monitor interface */
1022 	sdata = wiphy_dereference(local->hw.wiphy, local->monitor_sdata);
1023 	if (sdata &&
1024 	    rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) == &chanctx->conf)
1025 		rx_chains_dynamic = rx_chains_static = local->rx_chains;
1026 
1027 	if (rx_chains_static == chanctx->conf.rx_chains_static &&
1028 	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
1029 		return;
1030 
1031 	chanctx->conf.rx_chains_static = rx_chains_static;
1032 	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
1033 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
1034 }
1035 
1036 static void
__ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data * link,bool clear)1037 __ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link,
1038 				       bool clear)
1039 {
1040 	struct ieee80211_sub_if_data *sdata = link->sdata;
1041 	unsigned int link_id = link->link_id;
1042 	struct ieee80211_bss_conf *link_conf = link->conf;
1043 	struct ieee80211_local *local __maybe_unused = sdata->local;
1044 	struct ieee80211_sub_if_data *vlan;
1045 	struct ieee80211_chanctx_conf *conf;
1046 
1047 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
1048 		return;
1049 
1050 	lockdep_assert_wiphy(local->hw.wiphy);
1051 
1052 	/* Check that conf exists, even when clearing this function
1053 	 * must be called with the AP's channel context still there
1054 	 * as it would otherwise cause VLANs to have an invalid
1055 	 * channel context pointer for a while, possibly pointing
1056 	 * to a channel context that has already been freed.
1057 	 */
1058 	conf = rcu_dereference_protected(link_conf->chanctx_conf,
1059 					 lockdep_is_held(&local->hw.wiphy->mtx));
1060 	WARN_ON(!conf);
1061 
1062 	if (clear)
1063 		conf = NULL;
1064 
1065 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
1066 		struct ieee80211_bss_conf *vlan_conf;
1067 
1068 		vlan_conf = wiphy_dereference(local->hw.wiphy,
1069 					      vlan->vif.link_conf[link_id]);
1070 		if (WARN_ON(!vlan_conf))
1071 			continue;
1072 
1073 		rcu_assign_pointer(vlan_conf->chanctx_conf, conf);
1074 	}
1075 }
1076 
ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data * link,bool clear)1077 void ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link,
1078 					  bool clear)
1079 {
1080 	struct ieee80211_local *local = link->sdata->local;
1081 
1082 	lockdep_assert_wiphy(local->hw.wiphy);
1083 
1084 	__ieee80211_link_copy_chanctx_to_vlans(link, clear);
1085 }
1086 
ieee80211_link_unreserve_chanctx(struct ieee80211_link_data * link)1087 int ieee80211_link_unreserve_chanctx(struct ieee80211_link_data *link)
1088 {
1089 	struct ieee80211_sub_if_data *sdata = link->sdata;
1090 	struct ieee80211_chanctx *ctx = link->reserved_chanctx;
1091 
1092 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
1093 
1094 	if (WARN_ON(!ctx))
1095 		return -EINVAL;
1096 
1097 	list_del(&link->reserved_chanctx_list);
1098 	link->reserved_chanctx = NULL;
1099 
1100 	if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0) {
1101 		if (ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
1102 			if (WARN_ON(!ctx->replace_ctx))
1103 				return -EINVAL;
1104 
1105 			WARN_ON(ctx->replace_ctx->replace_state !=
1106 			        IEEE80211_CHANCTX_WILL_BE_REPLACED);
1107 			WARN_ON(ctx->replace_ctx->replace_ctx != ctx);
1108 
1109 			ctx->replace_ctx->replace_ctx = NULL;
1110 			ctx->replace_ctx->replace_state =
1111 					IEEE80211_CHANCTX_REPLACE_NONE;
1112 
1113 			list_del_rcu(&ctx->list);
1114 			kfree_rcu(ctx, rcu_head);
1115 		} else {
1116 			ieee80211_free_chanctx(sdata->local, ctx, false);
1117 		}
1118 	}
1119 
1120 	return 0;
1121 }
1122 
1123 static struct ieee80211_chanctx *
ieee80211_replace_chanctx(struct ieee80211_local * local,const struct ieee80211_chan_req * chanreq,enum ieee80211_chanctx_mode mode,struct ieee80211_chanctx * curr_ctx)1124 ieee80211_replace_chanctx(struct ieee80211_local *local,
1125 			  const struct ieee80211_chan_req *chanreq,
1126 			  enum ieee80211_chanctx_mode mode,
1127 			  struct ieee80211_chanctx *curr_ctx)
1128 {
1129 	struct ieee80211_chanctx *new_ctx, *ctx;
1130 	struct wiphy *wiphy = local->hw.wiphy;
1131 	const struct wiphy_radio *radio;
1132 
1133 	if (!curr_ctx || (curr_ctx->replace_state ==
1134 			  IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1135 	    !list_empty(&curr_ctx->reserved_links)) {
1136 		/*
1137 		 * Another link already requested this context for a
1138 		 * reservation. Find another one hoping all links assigned
1139 		 * to it will also switch soon enough.
1140 		 *
1141 		 * TODO: This needs a little more work as some cases
1142 		 * (more than 2 chanctx capable devices) may fail which could
1143 		 * otherwise succeed provided some channel context juggling was
1144 		 * performed.
1145 		 *
1146 		 * Consider ctx1..3, link1..6, each ctx has 2 links. link1 and
1147 		 * link2 from ctx1 request new different chandefs starting 2
1148 		 * in-place reservations with ctx4 and ctx5 replacing ctx1 and
1149 		 * ctx2 respectively. Next link5 and link6 from ctx3 reserve
1150 		 * ctx4. If link3 and link4 remain on ctx2 as they are then this
1151 		 * fails unless `replace_ctx` from ctx5 is replaced with ctx3.
1152 		 */
1153 		list_for_each_entry(ctx, &local->chanctx_list, list) {
1154 			if (ctx->replace_state !=
1155 			    IEEE80211_CHANCTX_REPLACE_NONE)
1156 				continue;
1157 
1158 			if (!list_empty(&ctx->reserved_links))
1159 				continue;
1160 
1161 			if (ctx->conf.radio_idx >= 0) {
1162 				radio = &wiphy->radio[ctx->conf.radio_idx];
1163 				if (!cfg80211_radio_chandef_valid(radio, &chanreq->oper))
1164 					continue;
1165 			}
1166 
1167 			curr_ctx = ctx;
1168 			break;
1169 		}
1170 	}
1171 
1172 	/*
1173 	 * If that's true then all available contexts already have reservations
1174 	 * and cannot be used.
1175 	 */
1176 	if (!curr_ctx || (curr_ctx->replace_state ==
1177 			  IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
1178 	    !list_empty(&curr_ctx->reserved_links))
1179 		return ERR_PTR(-EBUSY);
1180 
1181 	new_ctx = ieee80211_alloc_chanctx(local, chanreq, mode, -1);
1182 	if (!new_ctx)
1183 		return ERR_PTR(-ENOMEM);
1184 
1185 	new_ctx->replace_ctx = curr_ctx;
1186 	new_ctx->replace_state = IEEE80211_CHANCTX_REPLACES_OTHER;
1187 
1188 	curr_ctx->replace_ctx = new_ctx;
1189 	curr_ctx->replace_state = IEEE80211_CHANCTX_WILL_BE_REPLACED;
1190 
1191 	list_add_rcu(&new_ctx->list, &local->chanctx_list);
1192 
1193 	return new_ctx;
1194 }
1195 
1196 static bool
ieee80211_find_available_radio(struct ieee80211_local * local,const struct ieee80211_chan_req * chanreq,u32 radio_mask,int * radio_idx)1197 ieee80211_find_available_radio(struct ieee80211_local *local,
1198 			       const struct ieee80211_chan_req *chanreq,
1199 			       u32 radio_mask, int *radio_idx)
1200 {
1201 	struct wiphy *wiphy = local->hw.wiphy;
1202 	const struct wiphy_radio *radio;
1203 	int i;
1204 
1205 	*radio_idx = -1;
1206 	if (!wiphy->n_radio)
1207 		return true;
1208 
1209 	for (i = 0; i < wiphy->n_radio; i++) {
1210 		if (!(radio_mask & BIT(i)))
1211 			continue;
1212 
1213 		radio = &wiphy->radio[i];
1214 		if (!cfg80211_radio_chandef_valid(radio, &chanreq->oper))
1215 			continue;
1216 
1217 		if (!ieee80211_can_create_new_chanctx(local, i))
1218 			continue;
1219 
1220 		*radio_idx = i;
1221 		return true;
1222 	}
1223 
1224 	return false;
1225 }
1226 
ieee80211_link_reserve_chanctx(struct ieee80211_link_data * link,const struct ieee80211_chan_req * chanreq,enum ieee80211_chanctx_mode mode,bool radar_required)1227 int ieee80211_link_reserve_chanctx(struct ieee80211_link_data *link,
1228 				   const struct ieee80211_chan_req *chanreq,
1229 				   enum ieee80211_chanctx_mode mode,
1230 				   bool radar_required)
1231 {
1232 	struct ieee80211_sub_if_data *sdata = link->sdata;
1233 	struct ieee80211_local *local = sdata->local;
1234 	struct ieee80211_chanctx *new_ctx, *curr_ctx;
1235 	int radio_idx;
1236 
1237 	lockdep_assert_wiphy(local->hw.wiphy);
1238 
1239 	curr_ctx = ieee80211_link_get_chanctx(link);
1240 	if (curr_ctx && !local->ops->switch_vif_chanctx)
1241 		return -EOPNOTSUPP;
1242 
1243 	new_ctx = ieee80211_find_reservation_chanctx(local, chanreq, mode);
1244 	if (!new_ctx) {
1245 		if (ieee80211_can_create_new_chanctx(local, -1) &&
1246 		    ieee80211_find_available_radio(local, chanreq,
1247 						   sdata->wdev.radio_mask,
1248 						   &radio_idx))
1249 			new_ctx = ieee80211_new_chanctx(local, chanreq, mode,
1250 							false, radio_idx);
1251 		else
1252 			new_ctx = ieee80211_replace_chanctx(local, chanreq,
1253 							    mode, curr_ctx);
1254 		if (IS_ERR(new_ctx))
1255 			return PTR_ERR(new_ctx);
1256 	}
1257 
1258 	list_add(&link->reserved_chanctx_list, &new_ctx->reserved_links);
1259 	link->reserved_chanctx = new_ctx;
1260 	link->reserved = *chanreq;
1261 	link->reserved_radar_required = radar_required;
1262 	link->reserved_ready = false;
1263 
1264 	return 0;
1265 }
1266 
1267 static void
ieee80211_link_chanctx_reservation_complete(struct ieee80211_link_data * link)1268 ieee80211_link_chanctx_reservation_complete(struct ieee80211_link_data *link)
1269 {
1270 	struct ieee80211_sub_if_data *sdata = link->sdata;
1271 
1272 	switch (sdata->vif.type) {
1273 	case NL80211_IFTYPE_ADHOC:
1274 	case NL80211_IFTYPE_AP:
1275 	case NL80211_IFTYPE_MESH_POINT:
1276 	case NL80211_IFTYPE_OCB:
1277 		wiphy_work_queue(sdata->local->hw.wiphy,
1278 				 &link->csa.finalize_work);
1279 		break;
1280 	case NL80211_IFTYPE_STATION:
1281 		wiphy_delayed_work_queue(sdata->local->hw.wiphy,
1282 					 &link->u.mgd.csa.switch_work, 0);
1283 		break;
1284 	case NL80211_IFTYPE_UNSPECIFIED:
1285 	case NL80211_IFTYPE_AP_VLAN:
1286 	case NL80211_IFTYPE_WDS:
1287 	case NL80211_IFTYPE_MONITOR:
1288 	case NL80211_IFTYPE_P2P_CLIENT:
1289 	case NL80211_IFTYPE_P2P_GO:
1290 	case NL80211_IFTYPE_P2P_DEVICE:
1291 	case NL80211_IFTYPE_NAN:
1292 	case NUM_NL80211_IFTYPES:
1293 		WARN_ON(1);
1294 		break;
1295 	}
1296 }
1297 
1298 static void
ieee80211_link_update_chanreq(struct ieee80211_link_data * link,const struct ieee80211_chan_req * chanreq)1299 ieee80211_link_update_chanreq(struct ieee80211_link_data *link,
1300 			      const struct ieee80211_chan_req *chanreq)
1301 {
1302 	struct ieee80211_sub_if_data *sdata = link->sdata;
1303 	unsigned int link_id = link->link_id;
1304 	struct ieee80211_sub_if_data *vlan;
1305 
1306 	link->conf->chanreq = *chanreq;
1307 
1308 	if (sdata->vif.type != NL80211_IFTYPE_AP)
1309 		return;
1310 
1311 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
1312 		struct ieee80211_bss_conf *vlan_conf;
1313 
1314 		vlan_conf = wiphy_dereference(sdata->local->hw.wiphy,
1315 					      vlan->vif.link_conf[link_id]);
1316 		if (WARN_ON(!vlan_conf))
1317 			continue;
1318 
1319 		vlan_conf->chanreq = *chanreq;
1320 	}
1321 }
1322 
1323 static int
ieee80211_link_use_reserved_reassign(struct ieee80211_link_data * link)1324 ieee80211_link_use_reserved_reassign(struct ieee80211_link_data *link)
1325 {
1326 	struct ieee80211_sub_if_data *sdata = link->sdata;
1327 	struct ieee80211_bss_conf *link_conf = link->conf;
1328 	struct ieee80211_local *local = sdata->local;
1329 	struct ieee80211_vif_chanctx_switch vif_chsw[1] = {};
1330 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1331 	const struct ieee80211_chan_req *chanreq;
1332 	struct ieee80211_chan_req tmp;
1333 	u64 changed = 0;
1334 	int err;
1335 
1336 	lockdep_assert_wiphy(local->hw.wiphy);
1337 
1338 	new_ctx = link->reserved_chanctx;
1339 	old_ctx = ieee80211_link_get_chanctx(link);
1340 
1341 	if (WARN_ON(!link->reserved_ready))
1342 		return -EBUSY;
1343 
1344 	if (WARN_ON(!new_ctx))
1345 		return -EINVAL;
1346 
1347 	if (WARN_ON(!old_ctx))
1348 		return -EINVAL;
1349 
1350 	if (WARN_ON(new_ctx->replace_state ==
1351 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1352 		return -EINVAL;
1353 
1354 	chanreq = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1355 							 &link->reserved,
1356 							 &tmp);
1357 	if (WARN_ON(!chanreq))
1358 		return -EINVAL;
1359 
1360 	if (link_conf->chanreq.oper.width != link->reserved.oper.width)
1361 		changed = BSS_CHANGED_BANDWIDTH;
1362 
1363 	ieee80211_link_update_chanreq(link, &link->reserved);
1364 
1365 	_ieee80211_change_chanctx(local, new_ctx, old_ctx, chanreq, link);
1366 
1367 	vif_chsw[0].vif = &sdata->vif;
1368 	vif_chsw[0].old_ctx = &old_ctx->conf;
1369 	vif_chsw[0].new_ctx = &new_ctx->conf;
1370 	vif_chsw[0].link_conf = link->conf;
1371 
1372 	list_del(&link->reserved_chanctx_list);
1373 	link->reserved_chanctx = NULL;
1374 
1375 	err = drv_switch_vif_chanctx(local, vif_chsw, 1,
1376 				     CHANCTX_SWMODE_REASSIGN_VIF);
1377 	if (err) {
1378 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1379 			ieee80211_free_chanctx(local, new_ctx, false);
1380 
1381 		goto out;
1382 	}
1383 
1384 	list_move(&link->assigned_chanctx_list, &new_ctx->assigned_links);
1385 	rcu_assign_pointer(link_conf->chanctx_conf, &new_ctx->conf);
1386 
1387 	if (sdata->vif.type == NL80211_IFTYPE_AP)
1388 		__ieee80211_link_copy_chanctx_to_vlans(link, false);
1389 
1390 	ieee80211_check_fast_xmit_iface(sdata);
1391 
1392 	if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
1393 		ieee80211_free_chanctx(local, old_ctx, false);
1394 
1395 	ieee80211_recalc_chanctx_min_def(local, new_ctx, NULL, false);
1396 	ieee80211_recalc_smps_chanctx(local, new_ctx);
1397 	ieee80211_recalc_radar_chanctx(local, new_ctx);
1398 
1399 	if (changed)
1400 		ieee80211_link_info_change_notify(sdata, link, changed);
1401 
1402 out:
1403 	ieee80211_link_chanctx_reservation_complete(link);
1404 	return err;
1405 }
1406 
1407 static int
ieee80211_link_use_reserved_assign(struct ieee80211_link_data * link)1408 ieee80211_link_use_reserved_assign(struct ieee80211_link_data *link)
1409 {
1410 	struct ieee80211_sub_if_data *sdata = link->sdata;
1411 	struct ieee80211_local *local = sdata->local;
1412 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1413 	const struct ieee80211_chan_req *chanreq;
1414 	struct ieee80211_chan_req tmp;
1415 	int err;
1416 
1417 	old_ctx = ieee80211_link_get_chanctx(link);
1418 	new_ctx = link->reserved_chanctx;
1419 
1420 	if (WARN_ON(!link->reserved_ready))
1421 		return -EINVAL;
1422 
1423 	if (WARN_ON(old_ctx))
1424 		return -EINVAL;
1425 
1426 	if (WARN_ON(!new_ctx))
1427 		return -EINVAL;
1428 
1429 	if (WARN_ON(new_ctx->replace_state ==
1430 		    IEEE80211_CHANCTX_REPLACES_OTHER))
1431 		return -EINVAL;
1432 
1433 	chanreq = ieee80211_chanctx_non_reserved_chandef(local, new_ctx,
1434 							 &link->reserved,
1435 							 &tmp);
1436 	if (WARN_ON(!chanreq))
1437 		return -EINVAL;
1438 
1439 	ieee80211_change_chanctx(local, new_ctx, new_ctx, chanreq);
1440 
1441 	list_del(&link->reserved_chanctx_list);
1442 	link->reserved_chanctx = NULL;
1443 
1444 	err = ieee80211_assign_link_chanctx(link, new_ctx, false);
1445 	if (err) {
1446 		if (ieee80211_chanctx_refcount(local, new_ctx) == 0)
1447 			ieee80211_free_chanctx(local, new_ctx, false);
1448 
1449 		goto out;
1450 	}
1451 
1452 out:
1453 	ieee80211_link_chanctx_reservation_complete(link);
1454 	return err;
1455 }
1456 
1457 static bool
ieee80211_link_has_in_place_reservation(struct ieee80211_link_data * link)1458 ieee80211_link_has_in_place_reservation(struct ieee80211_link_data *link)
1459 {
1460 	struct ieee80211_sub_if_data *sdata = link->sdata;
1461 	struct ieee80211_chanctx *old_ctx, *new_ctx;
1462 
1463 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
1464 
1465 	new_ctx = link->reserved_chanctx;
1466 	old_ctx = ieee80211_link_get_chanctx(link);
1467 
1468 	if (!old_ctx)
1469 		return false;
1470 
1471 	if (WARN_ON(!new_ctx))
1472 		return false;
1473 
1474 	if (old_ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1475 		return false;
1476 
1477 	if (new_ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1478 		return false;
1479 
1480 	return true;
1481 }
1482 
ieee80211_chsw_switch_vifs(struct ieee80211_local * local,int n_vifs)1483 static int ieee80211_chsw_switch_vifs(struct ieee80211_local *local,
1484 				      int n_vifs)
1485 {
1486 	struct ieee80211_vif_chanctx_switch *vif_chsw;
1487 	struct ieee80211_link_data *link;
1488 	struct ieee80211_chanctx *ctx, *old_ctx;
1489 	int i, err;
1490 
1491 	lockdep_assert_wiphy(local->hw.wiphy);
1492 
1493 	vif_chsw = kcalloc(n_vifs, sizeof(vif_chsw[0]), GFP_KERNEL);
1494 	if (!vif_chsw)
1495 		return -ENOMEM;
1496 
1497 	i = 0;
1498 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1499 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1500 			continue;
1501 
1502 		if (WARN_ON(!ctx->replace_ctx)) {
1503 			err = -EINVAL;
1504 			goto out;
1505 		}
1506 
1507 		list_for_each_entry(link, &ctx->reserved_links,
1508 				    reserved_chanctx_list) {
1509 			if (!ieee80211_link_has_in_place_reservation(link))
1510 				continue;
1511 
1512 			old_ctx = ieee80211_link_get_chanctx(link);
1513 			vif_chsw[i].vif = &link->sdata->vif;
1514 			vif_chsw[i].old_ctx = &old_ctx->conf;
1515 			vif_chsw[i].new_ctx = &ctx->conf;
1516 			vif_chsw[i].link_conf = link->conf;
1517 
1518 			i++;
1519 		}
1520 	}
1521 
1522 	err = drv_switch_vif_chanctx(local, vif_chsw, n_vifs,
1523 				     CHANCTX_SWMODE_SWAP_CONTEXTS);
1524 
1525 out:
1526 	kfree(vif_chsw);
1527 	return err;
1528 }
1529 
ieee80211_chsw_switch_ctxs(struct ieee80211_local * local)1530 static int ieee80211_chsw_switch_ctxs(struct ieee80211_local *local)
1531 {
1532 	struct ieee80211_chanctx *ctx;
1533 	int err;
1534 
1535 	lockdep_assert_wiphy(local->hw.wiphy);
1536 
1537 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1538 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1539 			continue;
1540 
1541 		if (!list_empty(&ctx->replace_ctx->assigned_links))
1542 			continue;
1543 
1544 		ieee80211_del_chanctx(local, ctx->replace_ctx, false);
1545 		err = ieee80211_add_chanctx(local, ctx);
1546 		if (err)
1547 			goto err;
1548 	}
1549 
1550 	return 0;
1551 
1552 err:
1553 	WARN_ON(ieee80211_add_chanctx(local, ctx));
1554 	list_for_each_entry_continue_reverse(ctx, &local->chanctx_list, list) {
1555 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1556 			continue;
1557 
1558 		if (!list_empty(&ctx->replace_ctx->assigned_links))
1559 			continue;
1560 
1561 		ieee80211_del_chanctx(local, ctx, false);
1562 		WARN_ON(ieee80211_add_chanctx(local, ctx->replace_ctx));
1563 	}
1564 
1565 	return err;
1566 }
1567 
ieee80211_vif_use_reserved_switch(struct ieee80211_local * local)1568 static int ieee80211_vif_use_reserved_switch(struct ieee80211_local *local)
1569 {
1570 	struct ieee80211_chanctx *ctx, *ctx_tmp, *old_ctx;
1571 	int err, n_assigned, n_reserved, n_ready;
1572 	int n_ctx = 0, n_vifs_switch = 0, n_vifs_assign = 0, n_vifs_ctxless = 0;
1573 
1574 	lockdep_assert_wiphy(local->hw.wiphy);
1575 
1576 	/*
1577 	 * If there are 2 independent pairs of channel contexts performing
1578 	 * cross-switch of their vifs this code will still wait until both are
1579 	 * ready even though it could be possible to switch one before the
1580 	 * other is ready.
1581 	 *
1582 	 * For practical reasons and code simplicity just do a single huge
1583 	 * switch.
1584 	 */
1585 
1586 	/*
1587 	 * Verify if the reservation is still feasible.
1588 	 *  - if it's not then disconnect
1589 	 *  - if it is but not all vifs necessary are ready then defer
1590 	 */
1591 
1592 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1593 		struct ieee80211_link_data *link;
1594 
1595 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1596 			continue;
1597 
1598 		if (WARN_ON(!ctx->replace_ctx)) {
1599 			err = -EINVAL;
1600 			goto err;
1601 		}
1602 
1603 		n_ctx++;
1604 
1605 		n_assigned = 0;
1606 		n_reserved = 0;
1607 		n_ready = 0;
1608 
1609 		list_for_each_entry(link, &ctx->replace_ctx->assigned_links,
1610 				    assigned_chanctx_list) {
1611 			n_assigned++;
1612 			if (link->reserved_chanctx) {
1613 				n_reserved++;
1614 				if (link->reserved_ready)
1615 					n_ready++;
1616 			}
1617 		}
1618 
1619 		if (n_assigned != n_reserved) {
1620 			if (n_ready == n_reserved) {
1621 				wiphy_info(local->hw.wiphy,
1622 					   "channel context reservation cannot be finalized because some interfaces aren't switching\n");
1623 				err = -EBUSY;
1624 				goto err;
1625 			}
1626 
1627 			return -EAGAIN;
1628 		}
1629 
1630 		ctx->conf.radar_enabled = false;
1631 		list_for_each_entry(link, &ctx->reserved_links,
1632 				    reserved_chanctx_list) {
1633 			if (ieee80211_link_has_in_place_reservation(link) &&
1634 			    !link->reserved_ready)
1635 				return -EAGAIN;
1636 
1637 			old_ctx = ieee80211_link_get_chanctx(link);
1638 			if (old_ctx) {
1639 				if (old_ctx->replace_state ==
1640 				    IEEE80211_CHANCTX_WILL_BE_REPLACED)
1641 					n_vifs_switch++;
1642 				else
1643 					n_vifs_assign++;
1644 			} else {
1645 				n_vifs_ctxless++;
1646 			}
1647 
1648 			if (link->reserved_radar_required)
1649 				ctx->conf.radar_enabled = true;
1650 		}
1651 	}
1652 
1653 	if (WARN_ON(n_ctx == 0) ||
1654 	    WARN_ON(n_vifs_switch == 0 &&
1655 		    n_vifs_assign == 0 &&
1656 		    n_vifs_ctxless == 0)) {
1657 		err = -EINVAL;
1658 		goto err;
1659 	}
1660 
1661 	/* update station rate control and min width before switch */
1662 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1663 		struct ieee80211_link_data *link;
1664 
1665 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1666 			continue;
1667 
1668 		if (WARN_ON(!ctx->replace_ctx)) {
1669 			err = -EINVAL;
1670 			goto err;
1671 		}
1672 
1673 		list_for_each_entry(link, &ctx->reserved_links,
1674 				    reserved_chanctx_list) {
1675 			if (!ieee80211_link_has_in_place_reservation(link))
1676 				continue;
1677 
1678 			ieee80211_chan_bw_change(local,
1679 						 ieee80211_link_get_chanctx(link),
1680 						 true, true);
1681 		}
1682 
1683 		ieee80211_recalc_chanctx_min_def(local, ctx, NULL, true);
1684 	}
1685 
1686 	/*
1687 	 * All necessary vifs are ready. Perform the switch now depending on
1688 	 * reservations and driver capabilities.
1689 	 */
1690 
1691 	if (n_vifs_switch > 0) {
1692 		err = ieee80211_chsw_switch_vifs(local, n_vifs_switch);
1693 		if (err)
1694 			goto err;
1695 	}
1696 
1697 	if (n_vifs_assign > 0 || n_vifs_ctxless > 0) {
1698 		err = ieee80211_chsw_switch_ctxs(local);
1699 		if (err)
1700 			goto err;
1701 	}
1702 
1703 	/*
1704 	 * Update all structures, values and pointers to point to new channel
1705 	 * context(s).
1706 	 */
1707 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1708 		struct ieee80211_link_data *link, *link_tmp;
1709 
1710 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1711 			continue;
1712 
1713 		if (WARN_ON(!ctx->replace_ctx)) {
1714 			err = -EINVAL;
1715 			goto err;
1716 		}
1717 
1718 		list_for_each_entry(link, &ctx->reserved_links,
1719 				    reserved_chanctx_list) {
1720 			struct ieee80211_sub_if_data *sdata = link->sdata;
1721 			struct ieee80211_bss_conf *link_conf = link->conf;
1722 			u64 changed = 0;
1723 
1724 			if (!ieee80211_link_has_in_place_reservation(link))
1725 				continue;
1726 
1727 			rcu_assign_pointer(link_conf->chanctx_conf,
1728 					   &ctx->conf);
1729 
1730 			if (sdata->vif.type == NL80211_IFTYPE_AP)
1731 				__ieee80211_link_copy_chanctx_to_vlans(link,
1732 								       false);
1733 
1734 			ieee80211_check_fast_xmit_iface(sdata);
1735 
1736 			link->radar_required = link->reserved_radar_required;
1737 
1738 			if (link_conf->chanreq.oper.width != link->reserved.oper.width)
1739 				changed = BSS_CHANGED_BANDWIDTH;
1740 
1741 			ieee80211_link_update_chanreq(link, &link->reserved);
1742 			if (changed)
1743 				ieee80211_link_info_change_notify(sdata,
1744 								  link,
1745 								  changed);
1746 
1747 			ieee80211_recalc_txpower(link, false);
1748 		}
1749 
1750 		ieee80211_recalc_chanctx_chantype(local, ctx);
1751 		ieee80211_recalc_smps_chanctx(local, ctx);
1752 		ieee80211_recalc_radar_chanctx(local, ctx);
1753 		ieee80211_recalc_chanctx_min_def(local, ctx, NULL, false);
1754 
1755 		list_for_each_entry_safe(link, link_tmp, &ctx->reserved_links,
1756 					 reserved_chanctx_list) {
1757 			if (ieee80211_link_get_chanctx(link) != ctx)
1758 				continue;
1759 
1760 			list_del(&link->reserved_chanctx_list);
1761 			list_move(&link->assigned_chanctx_list,
1762 				  &ctx->assigned_links);
1763 			link->reserved_chanctx = NULL;
1764 
1765 			ieee80211_link_chanctx_reservation_complete(link);
1766 			ieee80211_chan_bw_change(local, ctx, false, false);
1767 		}
1768 
1769 		/*
1770 		 * This context might have been a dependency for an already
1771 		 * ready re-assign reservation interface that was deferred. Do
1772 		 * not propagate error to the caller though. The in-place
1773 		 * reservation for originally requested interface has already
1774 		 * succeeded at this point.
1775 		 */
1776 		list_for_each_entry_safe(link, link_tmp, &ctx->reserved_links,
1777 					 reserved_chanctx_list) {
1778 			if (WARN_ON(ieee80211_link_has_in_place_reservation(link)))
1779 				continue;
1780 
1781 			if (WARN_ON(link->reserved_chanctx != ctx))
1782 				continue;
1783 
1784 			if (!link->reserved_ready)
1785 				continue;
1786 
1787 			if (ieee80211_link_get_chanctx(link))
1788 				err = ieee80211_link_use_reserved_reassign(link);
1789 			else
1790 				err = ieee80211_link_use_reserved_assign(link);
1791 
1792 			if (err) {
1793 				link_info(link,
1794 					  "failed to finalize (re-)assign reservation (err=%d)\n",
1795 					  err);
1796 				ieee80211_link_unreserve_chanctx(link);
1797 				cfg80211_stop_iface(local->hw.wiphy,
1798 						    &link->sdata->wdev,
1799 						    GFP_KERNEL);
1800 			}
1801 		}
1802 	}
1803 
1804 	/*
1805 	 * Finally free old contexts
1806 	 */
1807 
1808 	list_for_each_entry_safe(ctx, ctx_tmp, &local->chanctx_list, list) {
1809 		if (ctx->replace_state != IEEE80211_CHANCTX_WILL_BE_REPLACED)
1810 			continue;
1811 
1812 		ctx->replace_ctx->replace_ctx = NULL;
1813 		ctx->replace_ctx->replace_state =
1814 				IEEE80211_CHANCTX_REPLACE_NONE;
1815 
1816 		list_del_rcu(&ctx->list);
1817 		kfree_rcu(ctx, rcu_head);
1818 	}
1819 
1820 	return 0;
1821 
1822 err:
1823 	list_for_each_entry(ctx, &local->chanctx_list, list) {
1824 		struct ieee80211_link_data *link, *link_tmp;
1825 
1826 		if (ctx->replace_state != IEEE80211_CHANCTX_REPLACES_OTHER)
1827 			continue;
1828 
1829 		list_for_each_entry_safe(link, link_tmp, &ctx->reserved_links,
1830 					 reserved_chanctx_list) {
1831 			ieee80211_link_unreserve_chanctx(link);
1832 			ieee80211_link_chanctx_reservation_complete(link);
1833 		}
1834 	}
1835 
1836 	return err;
1837 }
1838 
__ieee80211_link_release_channel(struct ieee80211_link_data * link,bool skip_idle_recalc)1839 void __ieee80211_link_release_channel(struct ieee80211_link_data *link,
1840 				      bool skip_idle_recalc)
1841 {
1842 	struct ieee80211_sub_if_data *sdata = link->sdata;
1843 	struct ieee80211_bss_conf *link_conf = link->conf;
1844 	struct ieee80211_local *local = sdata->local;
1845 	struct ieee80211_chanctx_conf *conf;
1846 	struct ieee80211_chanctx *ctx;
1847 	bool use_reserved_switch = false;
1848 
1849 	lockdep_assert_wiphy(local->hw.wiphy);
1850 
1851 	conf = rcu_dereference_protected(link_conf->chanctx_conf,
1852 					 lockdep_is_held(&local->hw.wiphy->mtx));
1853 	if (!conf)
1854 		return;
1855 
1856 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
1857 
1858 	if (link->reserved_chanctx) {
1859 		if (link->reserved_chanctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER &&
1860 		    ieee80211_chanctx_num_reserved(local, link->reserved_chanctx) > 1)
1861 			use_reserved_switch = true;
1862 
1863 		ieee80211_link_unreserve_chanctx(link);
1864 	}
1865 
1866 	ieee80211_assign_link_chanctx(link, NULL, false);
1867 	if (ieee80211_chanctx_refcount(local, ctx) == 0)
1868 		ieee80211_free_chanctx(local, ctx, skip_idle_recalc);
1869 
1870 	link->radar_required = false;
1871 
1872 	/* Unreserving may ready an in-place reservation. */
1873 	if (use_reserved_switch)
1874 		ieee80211_vif_use_reserved_switch(local);
1875 }
1876 
_ieee80211_link_use_channel(struct ieee80211_link_data * link,const struct ieee80211_chan_req * chanreq,enum ieee80211_chanctx_mode mode,bool assign_on_failure)1877 int _ieee80211_link_use_channel(struct ieee80211_link_data *link,
1878 				const struct ieee80211_chan_req *chanreq,
1879 				enum ieee80211_chanctx_mode mode,
1880 				bool assign_on_failure)
1881 {
1882 	struct ieee80211_sub_if_data *sdata = link->sdata;
1883 	struct ieee80211_local *local = sdata->local;
1884 	struct ieee80211_chanctx *ctx;
1885 	u8 radar_detect_width = 0;
1886 	bool reserved = false;
1887 	int radio_idx;
1888 	int ret;
1889 
1890 	lockdep_assert_wiphy(local->hw.wiphy);
1891 
1892 	if (!ieee80211_vif_link_active(&sdata->vif, link->link_id)) {
1893 		ieee80211_link_update_chanreq(link, chanreq);
1894 		return 0;
1895 	}
1896 
1897 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1898 					    &chanreq->oper,
1899 					    sdata->wdev.iftype);
1900 	if (ret < 0)
1901 		goto out;
1902 	if (ret > 0)
1903 		radar_detect_width = BIT(chanreq->oper.width);
1904 
1905 	link->radar_required = ret;
1906 
1907 	ret = ieee80211_check_combinations(sdata, &chanreq->oper, mode,
1908 					   radar_detect_width, -1);
1909 	if (ret < 0)
1910 		goto out;
1911 
1912 	__ieee80211_link_release_channel(link, false);
1913 
1914 	ctx = ieee80211_find_chanctx(local, link, chanreq, mode);
1915 	/* Note: context is now reserved */
1916 	if (ctx)
1917 		reserved = true;
1918 	else if (!ieee80211_find_available_radio(local, chanreq,
1919 						 sdata->wdev.radio_mask,
1920 						 &radio_idx))
1921 		ctx = ERR_PTR(-EBUSY);
1922 	else
1923 		ctx = ieee80211_new_chanctx(local, chanreq, mode,
1924 					    assign_on_failure, radio_idx);
1925 	if (IS_ERR(ctx)) {
1926 		ret = PTR_ERR(ctx);
1927 		goto out;
1928 	}
1929 
1930 	ieee80211_link_update_chanreq(link, chanreq);
1931 
1932 	ret = ieee80211_assign_link_chanctx(link, ctx, assign_on_failure);
1933 
1934 	if (reserved) {
1935 		/* remove reservation */
1936 		WARN_ON(link->reserved_chanctx != ctx);
1937 		link->reserved_chanctx = NULL;
1938 		list_del(&link->reserved_chanctx_list);
1939 	}
1940 
1941 	if (ret) {
1942 		/* if assign fails refcount stays the same */
1943 		if (ieee80211_chanctx_refcount(local, ctx) == 0)
1944 			ieee80211_free_chanctx(local, ctx, false);
1945 		goto out;
1946 	}
1947 
1948 	ieee80211_recalc_smps_chanctx(local, ctx);
1949 	ieee80211_recalc_radar_chanctx(local, ctx);
1950  out:
1951 	if (ret)
1952 		link->radar_required = false;
1953 
1954 	return ret;
1955 }
1956 
ieee80211_link_use_reserved_context(struct ieee80211_link_data * link)1957 int ieee80211_link_use_reserved_context(struct ieee80211_link_data *link)
1958 {
1959 	struct ieee80211_sub_if_data *sdata = link->sdata;
1960 	struct ieee80211_local *local = sdata->local;
1961 	struct ieee80211_chanctx *new_ctx;
1962 	struct ieee80211_chanctx *old_ctx;
1963 	int err;
1964 
1965 	lockdep_assert_wiphy(local->hw.wiphy);
1966 
1967 	new_ctx = link->reserved_chanctx;
1968 	old_ctx = ieee80211_link_get_chanctx(link);
1969 
1970 	if (WARN_ON(!new_ctx))
1971 		return -EINVAL;
1972 
1973 	if (WARN_ON(new_ctx->replace_state ==
1974 		    IEEE80211_CHANCTX_WILL_BE_REPLACED))
1975 		return -EINVAL;
1976 
1977 	if (WARN_ON(link->reserved_ready))
1978 		return -EINVAL;
1979 
1980 	link->reserved_ready = true;
1981 
1982 	if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
1983 		if (old_ctx)
1984 			return ieee80211_link_use_reserved_reassign(link);
1985 
1986 		return ieee80211_link_use_reserved_assign(link);
1987 	}
1988 
1989 	/*
1990 	 * In-place reservation may need to be finalized now either if:
1991 	 *  a) sdata is taking part in the swapping itself and is the last one
1992 	 *  b) sdata has switched with a re-assign reservation to an existing
1993 	 *     context readying in-place switching of old_ctx
1994 	 *
1995 	 * In case of (b) do not propagate the error up because the requested
1996 	 * sdata already switched successfully. Just spill an extra warning.
1997 	 * The ieee80211_vif_use_reserved_switch() already stops all necessary
1998 	 * interfaces upon failure.
1999 	 */
2000 	if ((old_ctx &&
2001 	     old_ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED) ||
2002 	    new_ctx->replace_state == IEEE80211_CHANCTX_REPLACES_OTHER) {
2003 		err = ieee80211_vif_use_reserved_switch(local);
2004 		if (err && err != -EAGAIN) {
2005 			if (new_ctx->replace_state ==
2006 			    IEEE80211_CHANCTX_REPLACES_OTHER)
2007 				return err;
2008 
2009 			wiphy_info(local->hw.wiphy,
2010 				   "depending in-place reservation failed (err=%d)\n",
2011 				   err);
2012 		}
2013 	}
2014 
2015 	return 0;
2016 }
2017 
2018 /*
2019  * This is similar to ieee80211_chanctx_compatible(), but rechecks
2020  * against all the links actually using it (except the one that's
2021  * passed, since that one is changing).
2022  * This is done in order to allow changes to the AP's bandwidth for
2023  * wider bandwidth OFDMA purposes, which wouldn't be treated as
2024  * compatible by ieee80211_chanctx_recheck() but is OK if the link
2025  * requesting the update is the only one using it.
2026  */
2027 static const struct ieee80211_chan_req *
ieee80211_chanctx_recheck(struct ieee80211_local * local,struct ieee80211_link_data * skip_link,struct ieee80211_chanctx * ctx,const struct ieee80211_chan_req * req,struct ieee80211_chan_req * tmp)2028 ieee80211_chanctx_recheck(struct ieee80211_local *local,
2029 			  struct ieee80211_link_data *skip_link,
2030 			  struct ieee80211_chanctx *ctx,
2031 			  const struct ieee80211_chan_req *req,
2032 			  struct ieee80211_chan_req *tmp)
2033 {
2034 	const struct ieee80211_chan_req *ret = req;
2035 	struct ieee80211_link_data *link;
2036 
2037 	lockdep_assert_wiphy(local->hw.wiphy);
2038 
2039 	for_each_sdata_link(local, link) {
2040 		if (link == skip_link)
2041 			continue;
2042 
2043 		if (rcu_access_pointer(link->conf->chanctx_conf) == &ctx->conf) {
2044 			ret = ieee80211_chanreq_compatible(ret,
2045 							   &link->conf->chanreq,
2046 							   tmp);
2047 			if (!ret)
2048 				return NULL;
2049 		}
2050 
2051 		if (link->reserved_chanctx == ctx) {
2052 			ret = ieee80211_chanreq_compatible(ret,
2053 							   &link->reserved,
2054 							   tmp);
2055 			if (!ret)
2056 				return NULL;
2057 		}
2058 	}
2059 
2060 	*tmp = *ret;
2061 	return tmp;
2062 }
2063 
ieee80211_link_change_chanreq(struct ieee80211_link_data * link,const struct ieee80211_chan_req * chanreq,u64 * changed)2064 int ieee80211_link_change_chanreq(struct ieee80211_link_data *link,
2065 				  const struct ieee80211_chan_req *chanreq,
2066 				  u64 *changed)
2067 {
2068 	struct ieee80211_sub_if_data *sdata = link->sdata;
2069 	struct ieee80211_bss_conf *link_conf = link->conf;
2070 	struct ieee80211_local *local = sdata->local;
2071 	struct ieee80211_chanctx_conf *conf;
2072 	struct ieee80211_chanctx *ctx;
2073 	const struct ieee80211_chan_req *compat;
2074 	struct ieee80211_chan_req tmp;
2075 
2076 	lockdep_assert_wiphy(local->hw.wiphy);
2077 
2078 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy,
2079 				     &chanreq->oper,
2080 				     IEEE80211_CHAN_DISABLED))
2081 		return -EINVAL;
2082 
2083 	/* for non-HT 20 MHz the rest doesn't matter */
2084 	if (chanreq->oper.width == NL80211_CHAN_WIDTH_20_NOHT &&
2085 	    cfg80211_chandef_identical(&chanreq->oper, &link_conf->chanreq.oper))
2086 		return 0;
2087 
2088 	/* but you cannot switch to/from it */
2089 	if (chanreq->oper.width == NL80211_CHAN_WIDTH_20_NOHT ||
2090 	    link_conf->chanreq.oper.width == NL80211_CHAN_WIDTH_20_NOHT)
2091 		return -EINVAL;
2092 
2093 	conf = rcu_dereference_protected(link_conf->chanctx_conf,
2094 					 lockdep_is_held(&local->hw.wiphy->mtx));
2095 	if (!conf)
2096 		return -EINVAL;
2097 
2098 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
2099 
2100 	compat = ieee80211_chanctx_recheck(local, link, ctx, chanreq, &tmp);
2101 	if (!compat)
2102 		return -EINVAL;
2103 
2104 	switch (ctx->replace_state) {
2105 	case IEEE80211_CHANCTX_REPLACE_NONE:
2106 		if (!ieee80211_chanctx_reserved_chanreq(local, ctx, compat,
2107 							&tmp))
2108 			return -EBUSY;
2109 		break;
2110 	case IEEE80211_CHANCTX_WILL_BE_REPLACED:
2111 		/* TODO: Perhaps the bandwidth change could be treated as a
2112 		 * reservation itself? */
2113 		return -EBUSY;
2114 	case IEEE80211_CHANCTX_REPLACES_OTHER:
2115 		/* channel context that is going to replace another channel
2116 		 * context doesn't really exist and shouldn't be assigned
2117 		 * anywhere yet */
2118 		WARN_ON(1);
2119 		break;
2120 	}
2121 
2122 	ieee80211_link_update_chanreq(link, chanreq);
2123 
2124 	ieee80211_recalc_chanctx_chantype(local, ctx);
2125 
2126 	*changed |= BSS_CHANGED_BANDWIDTH;
2127 	return 0;
2128 }
2129 
ieee80211_link_release_channel(struct ieee80211_link_data * link)2130 void ieee80211_link_release_channel(struct ieee80211_link_data *link)
2131 {
2132 	struct ieee80211_sub_if_data *sdata = link->sdata;
2133 
2134 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
2135 
2136 	if (rcu_access_pointer(link->conf->chanctx_conf))
2137 		__ieee80211_link_release_channel(link, false);
2138 }
2139 
ieee80211_link_vlan_copy_chanctx(struct ieee80211_link_data * link)2140 void ieee80211_link_vlan_copy_chanctx(struct ieee80211_link_data *link)
2141 {
2142 	struct ieee80211_sub_if_data *sdata = link->sdata;
2143 	unsigned int link_id = link->link_id;
2144 	struct ieee80211_bss_conf *link_conf = link->conf;
2145 	struct ieee80211_bss_conf *ap_conf;
2146 	struct ieee80211_local *local = sdata->local;
2147 	struct ieee80211_sub_if_data *ap;
2148 	struct ieee80211_chanctx_conf *conf;
2149 
2150 	lockdep_assert_wiphy(local->hw.wiphy);
2151 
2152 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
2153 		return;
2154 
2155 	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
2156 
2157 	ap_conf = wiphy_dereference(local->hw.wiphy,
2158 				    ap->vif.link_conf[link_id]);
2159 	conf = wiphy_dereference(local->hw.wiphy,
2160 				 ap_conf->chanctx_conf);
2161 	rcu_assign_pointer(link_conf->chanctx_conf, conf);
2162 }
2163 
ieee80211_iter_chan_contexts_atomic(struct ieee80211_hw * hw,void (* iter)(struct ieee80211_hw * hw,struct ieee80211_chanctx_conf * chanctx_conf,void * data),void * iter_data)2164 void ieee80211_iter_chan_contexts_atomic(
2165 	struct ieee80211_hw *hw,
2166 	void (*iter)(struct ieee80211_hw *hw,
2167 		     struct ieee80211_chanctx_conf *chanctx_conf,
2168 		     void *data),
2169 	void *iter_data)
2170 {
2171 	struct ieee80211_local *local = hw_to_local(hw);
2172 	struct ieee80211_chanctx *ctx;
2173 
2174 	rcu_read_lock();
2175 	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
2176 		if (ctx->driver_present)
2177 			iter(hw, &ctx->conf, iter_data);
2178 	rcu_read_unlock();
2179 }
2180 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);
2181 
ieee80211_iter_chan_contexts_mtx(struct ieee80211_hw * hw,void (* iter)(struct ieee80211_hw * hw,struct ieee80211_chanctx_conf * chanctx_conf,void * data),void * iter_data)2182 void ieee80211_iter_chan_contexts_mtx(
2183 	struct ieee80211_hw *hw,
2184 	void (*iter)(struct ieee80211_hw *hw,
2185 		     struct ieee80211_chanctx_conf *chanctx_conf,
2186 		     void *data),
2187 	void *iter_data)
2188 {
2189 	struct ieee80211_local *local = hw_to_local(hw);
2190 	struct ieee80211_chanctx *ctx;
2191 
2192 	lockdep_assert_wiphy(hw->wiphy);
2193 
2194 	list_for_each_entry(ctx, &local->chanctx_list, list)
2195 		if (ctx->driver_present)
2196 			iter(hw, &ctx->conf, iter_data);
2197 }
2198 EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_mtx);
2199