1 /*
2  * Copyright (c) 2014 Qualcomm Atheros, Inc.
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "ath9k.h"
18 
19 /* Set/change channels.  If the channel is really being changed, it's done
20  * by reseting the chip.  To accomplish this we must first cleanup any pending
21  * DMA, then restart stuff.
22  */
23 static int ath_set_channel(struct ath_softc *sc)
24 {
25 	struct ath_hw *ah = sc->sc_ah;
26 	struct ath_common *common = ath9k_hw_common(ah);
27 	struct ieee80211_hw *hw = sc->hw;
28 	struct ath9k_channel *hchan;
29 	struct cfg80211_chan_def *chandef = &sc->cur_chan->chandef;
30 	struct ieee80211_channel *chan = chandef->chan;
31 	int pos = chan->hw_value;
32 	unsigned long flags;
33 	int old_pos = -1;
34 	int r;
35 
36 	if (test_bit(ATH_OP_INVALID, &common->op_flags))
37 		return -EIO;
38 
39 	if (ah->curchan)
40 		old_pos = ah->curchan - &ah->channels[0];
41 
42 	ath_dbg(common, CONFIG, "Set channel: %d MHz width: %d\n",
43 		chan->center_freq, chandef->width);
44 
45 	/* update survey stats for the old channel before switching */
46 	spin_lock_irqsave(&common->cc_lock, flags);
47 	ath_update_survey_stats(sc);
48 	spin_unlock_irqrestore(&common->cc_lock, flags);
49 
50 	ath9k_cmn_get_channel(hw, ah, chandef);
51 
52 	/* If the operating channel changes, change the survey in-use flags
53 	 * along with it.
54 	 * Reset the survey data for the new channel, unless we're switching
55 	 * back to the operating channel from an off-channel operation.
56 	 */
57 	if (!sc->cur_chan->offchannel && sc->cur_survey != &sc->survey[pos]) {
58 		if (sc->cur_survey)
59 			sc->cur_survey->filled &= ~SURVEY_INFO_IN_USE;
60 
61 		sc->cur_survey = &sc->survey[pos];
62 
63 		memset(sc->cur_survey, 0, sizeof(struct survey_info));
64 		sc->cur_survey->filled |= SURVEY_INFO_IN_USE;
65 	} else if (!(sc->survey[pos].filled & SURVEY_INFO_IN_USE)) {
66 		memset(&sc->survey[pos], 0, sizeof(struct survey_info));
67 	}
68 
69 	hchan = &sc->sc_ah->channels[pos];
70 	r = ath_reset(sc, hchan);
71 	if (r)
72 		return r;
73 
74 	/* The most recent snapshot of channel->noisefloor for the old
75 	 * channel is only available after the hardware reset. Copy it to
76 	 * the survey stats now.
77 	 */
78 	if (old_pos >= 0)
79 		ath_update_survey_nf(sc, old_pos);
80 
81 	/* Enable radar pulse detection if on a DFS channel. Spectral
82 	 * scanning and radar detection can not be used concurrently.
83 	 */
84 	if (hw->conf.radar_enabled) {
85 		u32 rxfilter;
86 
87 		rxfilter = ath9k_hw_getrxfilter(ah);
88 		rxfilter |= ATH9K_RX_FILTER_PHYRADAR |
89 				ATH9K_RX_FILTER_PHYERR;
90 		ath9k_hw_setrxfilter(ah, rxfilter);
91 		ath_dbg(common, DFS, "DFS enabled at freq %d\n",
92 			chan->center_freq);
93 	} else {
94 		/* perform spectral scan if requested. */
95 		if (test_bit(ATH_OP_SCANNING, &common->op_flags) &&
96 			sc->spec_priv.spectral_mode == SPECTRAL_CHANSCAN)
97 			ath9k_cmn_spectral_scan_trigger(common, &sc->spec_priv);
98 	}
99 
100 	return 0;
101 }
102 
103 void ath_chanctx_init(struct ath_softc *sc)
104 {
105 	struct ath_chanctx *ctx;
106 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
107 	struct ieee80211_supported_band *sband;
108 	struct ieee80211_channel *chan;
109 	int i, j;
110 
111 	sband = &common->sbands[NL80211_BAND_2GHZ];
112 	if (!sband->n_channels)
113 		sband = &common->sbands[NL80211_BAND_5GHZ];
114 
115 	chan = &sband->channels[0];
116 	for (i = 0; i < ATH9K_NUM_CHANCTX; i++) {
117 		ctx = &sc->chanctx[i];
118 		cfg80211_chandef_create(&ctx->chandef, chan, NL80211_CHAN_HT20);
119 		INIT_LIST_HEAD(&ctx->vifs);
120 		ctx->txpower = ATH_TXPOWER_MAX;
121 		ctx->flush_timeout = HZ / 5; /* 200ms */
122 		for (j = 0; j < ARRAY_SIZE(ctx->acq); j++) {
123 			INIT_LIST_HEAD(&ctx->acq[j].acq_new);
124 			INIT_LIST_HEAD(&ctx->acq[j].acq_old);
125 			spin_lock_init(&ctx->acq[j].lock);
126 		}
127 	}
128 }
129 
130 void ath_chanctx_set_channel(struct ath_softc *sc, struct ath_chanctx *ctx,
131 			     struct cfg80211_chan_def *chandef)
132 {
133 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
134 	bool cur_chan;
135 
136 	spin_lock_bh(&sc->chan_lock);
137 	if (chandef)
138 		memcpy(&ctx->chandef, chandef, sizeof(*chandef));
139 	cur_chan = sc->cur_chan == ctx;
140 	spin_unlock_bh(&sc->chan_lock);
141 
142 	if (!cur_chan) {
143 		ath_dbg(common, CHAN_CTX,
144 			"Current context differs from the new context\n");
145 		return;
146 	}
147 
148 	ath_set_channel(sc);
149 }
150 
151 #ifdef CONFIG_ATH9K_CHANNEL_CONTEXT
152 
153 /*************/
154 /* Utilities */
155 /*************/
156 
157 struct ath_chanctx* ath_is_go_chanctx_present(struct ath_softc *sc)
158 {
159 	struct ath_chanctx *ctx;
160 	struct ath_vif *avp;
161 	struct ieee80211_vif *vif;
162 
163 	spin_lock_bh(&sc->chan_lock);
164 
165 	ath_for_each_chanctx(sc, ctx) {
166 		if (!ctx->active)
167 			continue;
168 
169 		list_for_each_entry(avp, &ctx->vifs, list) {
170 			vif = avp->vif;
171 
172 			if (ieee80211_vif_type_p2p(vif) == NL80211_IFTYPE_P2P_GO) {
173 				spin_unlock_bh(&sc->chan_lock);
174 				return ctx;
175 			}
176 		}
177 	}
178 
179 	spin_unlock_bh(&sc->chan_lock);
180 	return NULL;
181 }
182 
183 /**********************************************************/
184 /* Functions to handle the channel context state machine. */
185 /**********************************************************/
186 
187 static const char *offchannel_state_string(enum ath_offchannel_state state)
188 {
189 	switch (state) {
190 		case_rtn_string(ATH_OFFCHANNEL_IDLE);
191 		case_rtn_string(ATH_OFFCHANNEL_PROBE_SEND);
192 		case_rtn_string(ATH_OFFCHANNEL_PROBE_WAIT);
193 		case_rtn_string(ATH_OFFCHANNEL_SUSPEND);
194 		case_rtn_string(ATH_OFFCHANNEL_ROC_START);
195 		case_rtn_string(ATH_OFFCHANNEL_ROC_WAIT);
196 		case_rtn_string(ATH_OFFCHANNEL_ROC_DONE);
197 	default:
198 		return "unknown";
199 	}
200 }
201 
202 static const char *chanctx_event_string(enum ath_chanctx_event ev)
203 {
204 	switch (ev) {
205 		case_rtn_string(ATH_CHANCTX_EVENT_BEACON_PREPARE);
206 		case_rtn_string(ATH_CHANCTX_EVENT_BEACON_SENT);
207 		case_rtn_string(ATH_CHANCTX_EVENT_TSF_TIMER);
208 		case_rtn_string(ATH_CHANCTX_EVENT_BEACON_RECEIVED);
209 		case_rtn_string(ATH_CHANCTX_EVENT_AUTHORIZED);
210 		case_rtn_string(ATH_CHANCTX_EVENT_SWITCH);
211 		case_rtn_string(ATH_CHANCTX_EVENT_ASSIGN);
212 		case_rtn_string(ATH_CHANCTX_EVENT_UNASSIGN);
213 		case_rtn_string(ATH_CHANCTX_EVENT_CHANGE);
214 		case_rtn_string(ATH_CHANCTX_EVENT_ENABLE_MULTICHANNEL);
215 	default:
216 		return "unknown";
217 	}
218 }
219 
220 static const char *chanctx_state_string(enum ath_chanctx_state state)
221 {
222 	switch (state) {
223 		case_rtn_string(ATH_CHANCTX_STATE_IDLE);
224 		case_rtn_string(ATH_CHANCTX_STATE_WAIT_FOR_BEACON);
225 		case_rtn_string(ATH_CHANCTX_STATE_WAIT_FOR_TIMER);
226 		case_rtn_string(ATH_CHANCTX_STATE_SWITCH);
227 		case_rtn_string(ATH_CHANCTX_STATE_FORCE_ACTIVE);
228 	default:
229 		return "unknown";
230 	}
231 }
232 
233 static u32 chanctx_event_delta(struct ath_softc *sc)
234 {
235 	u64 ms;
236 	struct timespec ts, *old;
237 
238 	getrawmonotonic(&ts);
239 	old = &sc->last_event_time;
240 	ms = ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
241 	ms -= old->tv_sec * 1000 + old->tv_nsec / 1000000;
242 	sc->last_event_time = ts;
243 
244 	return (u32)ms;
245 }
246 
247 void ath_chanctx_check_active(struct ath_softc *sc, struct ath_chanctx *ctx)
248 {
249 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
250 	struct ath_chanctx *ictx;
251 	struct ath_vif *avp;
252 	bool active = false;
253 	u8 n_active = 0;
254 
255 	if (!ctx)
256 		return;
257 
258 	if (ctx == &sc->offchannel.chan) {
259 		spin_lock_bh(&sc->chan_lock);
260 
261 		if (likely(sc->sched.channel_switch_time))
262 			ctx->flush_timeout =
263 				usecs_to_jiffies(sc->sched.channel_switch_time);
264 		else
265 			ctx->flush_timeout =
266 				msecs_to_jiffies(10);
267 
268 		spin_unlock_bh(&sc->chan_lock);
269 
270 		/*
271 		 * There is no need to iterate over the
272 		 * active/assigned channel contexts if
273 		 * the current context is offchannel.
274 		 */
275 		return;
276 	}
277 
278 	ictx = ctx;
279 
280 	list_for_each_entry(avp, &ctx->vifs, list) {
281 		struct ieee80211_vif *vif = avp->vif;
282 
283 		switch (vif->type) {
284 		case NL80211_IFTYPE_P2P_CLIENT:
285 		case NL80211_IFTYPE_STATION:
286 			if (avp->assoc)
287 				active = true;
288 			break;
289 		default:
290 			active = true;
291 			break;
292 		}
293 	}
294 	ctx->active = active;
295 
296 	ath_for_each_chanctx(sc, ctx) {
297 		if (!ctx->assigned || list_empty(&ctx->vifs))
298 			continue;
299 		n_active++;
300 	}
301 
302 	spin_lock_bh(&sc->chan_lock);
303 
304 	if (n_active <= 1) {
305 		ictx->flush_timeout = HZ / 5;
306 		clear_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags);
307 		spin_unlock_bh(&sc->chan_lock);
308 		return;
309 	}
310 
311 	ictx->flush_timeout = usecs_to_jiffies(sc->sched.channel_switch_time);
312 
313 	if (test_and_set_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags)) {
314 		spin_unlock_bh(&sc->chan_lock);
315 		return;
316 	}
317 
318 	spin_unlock_bh(&sc->chan_lock);
319 
320 	if (ath9k_is_chanctx_enabled()) {
321 		ath_chanctx_event(sc, NULL,
322 				  ATH_CHANCTX_EVENT_ENABLE_MULTICHANNEL);
323 	}
324 }
325 
326 static struct ath_chanctx *
327 ath_chanctx_get_next(struct ath_softc *sc, struct ath_chanctx *ctx)
328 {
329 	int idx = ctx - &sc->chanctx[0];
330 
331 	return &sc->chanctx[!idx];
332 }
333 
334 static void ath_chanctx_adjust_tbtt_delta(struct ath_softc *sc)
335 {
336 	struct ath_chanctx *prev, *cur;
337 	struct timespec ts;
338 	u32 cur_tsf, prev_tsf, beacon_int;
339 	s32 offset;
340 
341 	beacon_int = TU_TO_USEC(sc->cur_chan->beacon.beacon_interval);
342 
343 	cur = sc->cur_chan;
344 	prev = ath_chanctx_get_next(sc, cur);
345 
346 	if (!prev->switch_after_beacon)
347 		return;
348 
349 	getrawmonotonic(&ts);
350 	cur_tsf = (u32) cur->tsf_val +
351 		  ath9k_hw_get_tsf_offset(&cur->tsf_ts, &ts);
352 
353 	prev_tsf = prev->last_beacon - (u32) prev->tsf_val + cur_tsf;
354 	prev_tsf -= ath9k_hw_get_tsf_offset(&prev->tsf_ts, &ts);
355 
356 	/* Adjust the TSF time of the AP chanctx to keep its beacons
357 	 * at half beacon interval offset relative to the STA chanctx.
358 	 */
359 	offset = cur_tsf - prev_tsf;
360 
361 	/* Ignore stale data or spurious timestamps */
362 	if (offset < 0 || offset > 3 * beacon_int)
363 		return;
364 
365 	offset = beacon_int / 2 - (offset % beacon_int);
366 	prev->tsf_val += offset;
367 }
368 
369 /* Configure the TSF based hardware timer for a channel switch.
370  * Also set up backup software timer, in case the gen timer fails.
371  * This could be caused by a hardware reset.
372  */
373 static void ath_chanctx_setup_timer(struct ath_softc *sc, u32 tsf_time)
374 {
375 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
376 	struct ath_hw *ah = sc->sc_ah;
377 	unsigned long timeout;
378 
379 	ath9k_hw_gen_timer_start(ah, sc->p2p_ps_timer, tsf_time, 1000000);
380 	tsf_time -= ath9k_hw_gettsf32(ah);
381 	timeout = msecs_to_jiffies(tsf_time / 1000) + 1;
382 	mod_timer(&sc->sched.timer, jiffies + timeout);
383 
384 	ath_dbg(common, CHAN_CTX,
385 		"Setup chanctx timer with timeout: %d (%d) ms\n",
386 		tsf_time / 1000, jiffies_to_msecs(timeout));
387 }
388 
389 static void ath_chanctx_handle_bmiss(struct ath_softc *sc,
390 				     struct ath_chanctx *ctx,
391 				     struct ath_vif *avp)
392 {
393 	/*
394 	 * Clear the extend_absence flag if it had been
395 	 * set during the previous beacon transmission,
396 	 * since we need to revert to the normal NoA
397 	 * schedule.
398 	 */
399 	if (ctx->active && sc->sched.extend_absence) {
400 		avp->noa_duration = 0;
401 		sc->sched.extend_absence = false;
402 	}
403 
404 	/* If at least two consecutive beacons were missed on the STA
405 	 * chanctx, stay on the STA channel for one extra beacon period,
406 	 * to resync the timer properly.
407 	 */
408 	if (ctx->active && sc->sched.beacon_miss >= 2) {
409 		avp->noa_duration = 0;
410 		sc->sched.extend_absence = true;
411 	}
412 }
413 
414 static void ath_chanctx_offchannel_noa(struct ath_softc *sc,
415 				       struct ath_chanctx *ctx,
416 				       struct ath_vif *avp,
417 				       u32 tsf_time)
418 {
419 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
420 
421 	avp->noa_index++;
422 	avp->offchannel_start = tsf_time;
423 	avp->offchannel_duration = sc->sched.offchannel_duration;
424 
425 	ath_dbg(common, CHAN_CTX,
426 		"offchannel noa_duration: %d, noa_start: %u, noa_index: %d\n",
427 		avp->offchannel_duration,
428 		avp->offchannel_start,
429 		avp->noa_index);
430 
431 	/*
432 	 * When multiple contexts are active, the NoA
433 	 * has to be recalculated and advertised after
434 	 * an offchannel operation.
435 	 */
436 	if (ctx->active && avp->noa_duration)
437 		avp->noa_duration = 0;
438 }
439 
440 static void ath_chanctx_set_periodic_noa(struct ath_softc *sc,
441 					 struct ath_vif *avp,
442 					 struct ath_beacon_config *cur_conf,
443 					 u32 tsf_time,
444 					 u32 beacon_int)
445 {
446 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
447 
448 	avp->noa_index++;
449 	avp->noa_start = tsf_time;
450 
451 	if (sc->sched.extend_absence)
452 		avp->noa_duration = (3 * beacon_int / 2) +
453 			sc->sched.channel_switch_time;
454 	else
455 		avp->noa_duration =
456 			TU_TO_USEC(cur_conf->beacon_interval) / 2 +
457 			sc->sched.channel_switch_time;
458 
459 	if (test_bit(ATH_OP_SCANNING, &common->op_flags) ||
460 	    sc->sched.extend_absence)
461 		avp->periodic_noa = false;
462 	else
463 		avp->periodic_noa = true;
464 
465 	ath_dbg(common, CHAN_CTX,
466 		"noa_duration: %d, noa_start: %u, noa_index: %d, periodic: %d\n",
467 		avp->noa_duration,
468 		avp->noa_start,
469 		avp->noa_index,
470 		avp->periodic_noa);
471 }
472 
473 static void ath_chanctx_set_oneshot_noa(struct ath_softc *sc,
474 					struct ath_vif *avp,
475 					u32 tsf_time,
476 					u32 duration)
477 {
478 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
479 
480 	avp->noa_index++;
481 	avp->noa_start = tsf_time;
482 	avp->periodic_noa = false;
483 	avp->oneshot_noa = true;
484 	avp->noa_duration = duration + sc->sched.channel_switch_time;
485 
486 	ath_dbg(common, CHAN_CTX,
487 		"oneshot noa_duration: %d, noa_start: %u, noa_index: %d, periodic: %d\n",
488 		avp->noa_duration,
489 		avp->noa_start,
490 		avp->noa_index,
491 		avp->periodic_noa);
492 }
493 
494 void ath_chanctx_event(struct ath_softc *sc, struct ieee80211_vif *vif,
495 		       enum ath_chanctx_event ev)
496 {
497 	struct ath_hw *ah = sc->sc_ah;
498 	struct ath_common *common = ath9k_hw_common(ah);
499 	struct ath_beacon_config *cur_conf;
500 	struct ath_vif *avp = NULL;
501 	struct ath_chanctx *ctx;
502 	u32 tsf_time;
503 	u32 beacon_int;
504 
505 	if (vif)
506 		avp = (struct ath_vif *) vif->drv_priv;
507 
508 	spin_lock_bh(&sc->chan_lock);
509 
510 	ath_dbg(common, CHAN_CTX, "cur_chan: %d MHz, event: %s, state: %s, delta: %u ms\n",
511 		sc->cur_chan->chandef.center_freq1,
512 		chanctx_event_string(ev),
513 		chanctx_state_string(sc->sched.state),
514 		chanctx_event_delta(sc));
515 
516 	switch (ev) {
517 	case ATH_CHANCTX_EVENT_BEACON_PREPARE:
518 		if (avp->offchannel_duration)
519 			avp->offchannel_duration = 0;
520 
521 		if (avp->oneshot_noa) {
522 			avp->noa_duration = 0;
523 			avp->oneshot_noa = false;
524 
525 			ath_dbg(common, CHAN_CTX,
526 				"Clearing oneshot NoA\n");
527 		}
528 
529 		if (avp->chanctx != sc->cur_chan) {
530 			ath_dbg(common, CHAN_CTX,
531 				"Contexts differ, not preparing beacon\n");
532 			break;
533 		}
534 
535 		if (sc->sched.offchannel_pending && !sc->sched.wait_switch) {
536 			sc->sched.offchannel_pending = false;
537 			sc->next_chan = &sc->offchannel.chan;
538 			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
539 			ath_dbg(common, CHAN_CTX,
540 				"Setting offchannel_pending to false\n");
541 		}
542 
543 		ctx = ath_chanctx_get_next(sc, sc->cur_chan);
544 		if (ctx->active && sc->sched.state == ATH_CHANCTX_STATE_IDLE) {
545 			sc->next_chan = ctx;
546 			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
547 			ath_dbg(common, CHAN_CTX,
548 				"Set next context, move chanctx state to WAIT_FOR_BEACON\n");
549 		}
550 
551 		/* if the timer missed its window, use the next interval */
552 		if (sc->sched.state == ATH_CHANCTX_STATE_WAIT_FOR_TIMER) {
553 			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
554 			ath_dbg(common, CHAN_CTX,
555 				"Move chanctx state from WAIT_FOR_TIMER to WAIT_FOR_BEACON\n");
556 		}
557 
558 		if (sc->sched.mgd_prepare_tx)
559 			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
560 
561 		/*
562 		 * When a context becomes inactive, for example,
563 		 * disassociation of a station context, the NoA
564 		 * attribute needs to be removed from subsequent
565 		 * beacons.
566 		 */
567 		if (!ctx->active && avp->noa_duration &&
568 		    sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON) {
569 			avp->noa_duration = 0;
570 			avp->periodic_noa = false;
571 
572 			ath_dbg(common, CHAN_CTX,
573 				"Clearing NoA schedule\n");
574 		}
575 
576 		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON)
577 			break;
578 
579 		ath_dbg(common, CHAN_CTX, "Preparing beacon for vif: %pM\n", vif->addr);
580 
581 		sc->sched.beacon_pending = true;
582 		sc->sched.next_tbtt = REG_READ(ah, AR_NEXT_TBTT_TIMER);
583 
584 		cur_conf = &sc->cur_chan->beacon;
585 		beacon_int = TU_TO_USEC(cur_conf->beacon_interval);
586 
587 		/* defer channel switch by a quarter beacon interval */
588 		tsf_time = sc->sched.next_tbtt + beacon_int / 4;
589 		sc->sched.switch_start_time = tsf_time;
590 		sc->cur_chan->last_beacon = sc->sched.next_tbtt;
591 
592 		/*
593 		 * If an offchannel switch is scheduled to happen after
594 		 * a beacon transmission, update the NoA with one-shot
595 		 * values and increment the index.
596 		 */
597 		if (sc->next_chan == &sc->offchannel.chan) {
598 			ath_chanctx_offchannel_noa(sc, ctx, avp, tsf_time);
599 			break;
600 		}
601 
602 		ath_chanctx_handle_bmiss(sc, ctx, avp);
603 
604 		/*
605 		 * If a mgd_prepare_tx() has been called by mac80211,
606 		 * a one-shot NoA needs to be sent. This can happen
607 		 * with one or more active channel contexts - in both
608 		 * cases, a new NoA schedule has to be advertised.
609 		 */
610 		if (sc->sched.mgd_prepare_tx) {
611 			ath_chanctx_set_oneshot_noa(sc, avp, tsf_time,
612 						    jiffies_to_usecs(HZ / 5));
613 			break;
614 		}
615 
616 		/* Prevent wrap-around issues */
617 		if (avp->noa_duration && tsf_time - avp->noa_start > BIT(30))
618 			avp->noa_duration = 0;
619 
620 		/*
621 		 * If multiple contexts are active, start periodic
622 		 * NoA and increment the index for the first
623 		 * announcement.
624 		 */
625 		if (ctx->active &&
626 		    (!avp->noa_duration || sc->sched.force_noa_update))
627 			ath_chanctx_set_periodic_noa(sc, avp, cur_conf,
628 						     tsf_time, beacon_int);
629 
630 		if (ctx->active && sc->sched.force_noa_update)
631 			sc->sched.force_noa_update = false;
632 
633 		break;
634 	case ATH_CHANCTX_EVENT_BEACON_SENT:
635 		if (!sc->sched.beacon_pending) {
636 			ath_dbg(common, CHAN_CTX,
637 				"No pending beacon\n");
638 			break;
639 		}
640 
641 		sc->sched.beacon_pending = false;
642 
643 		if (sc->sched.mgd_prepare_tx) {
644 			sc->sched.mgd_prepare_tx = false;
645 			complete(&sc->go_beacon);
646 			ath_dbg(common, CHAN_CTX,
647 				"Beacon sent, complete go_beacon\n");
648 			break;
649 		}
650 
651 		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON)
652 			break;
653 
654 		ath_dbg(common, CHAN_CTX,
655 			"Move chanctx state to WAIT_FOR_TIMER\n");
656 
657 		sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_TIMER;
658 		ath_chanctx_setup_timer(sc, sc->sched.switch_start_time);
659 		break;
660 	case ATH_CHANCTX_EVENT_TSF_TIMER:
661 		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_TIMER)
662 			break;
663 
664 		if (!sc->cur_chan->switch_after_beacon &&
665 		    sc->sched.beacon_pending)
666 			sc->sched.beacon_miss++;
667 
668 		ath_dbg(common, CHAN_CTX,
669 			"Move chanctx state to SWITCH\n");
670 
671 		sc->sched.state = ATH_CHANCTX_STATE_SWITCH;
672 		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
673 		break;
674 	case ATH_CHANCTX_EVENT_BEACON_RECEIVED:
675 		if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) ||
676 		    sc->cur_chan == &sc->offchannel.chan)
677 			break;
678 
679 		sc->sched.beacon_pending = false;
680 		sc->sched.beacon_miss = 0;
681 
682 		if (sc->sched.state == ATH_CHANCTX_STATE_FORCE_ACTIVE ||
683 		    !sc->sched.beacon_adjust ||
684 		    !sc->cur_chan->tsf_val)
685 			break;
686 
687 		ath_chanctx_adjust_tbtt_delta(sc);
688 
689 		/* TSF time might have been updated by the incoming beacon,
690 		 * need update the channel switch timer to reflect the change.
691 		 */
692 		tsf_time = sc->sched.switch_start_time;
693 		tsf_time -= (u32) sc->cur_chan->tsf_val +
694 			ath9k_hw_get_tsf_offset(&sc->cur_chan->tsf_ts, NULL);
695 		tsf_time += ath9k_hw_gettsf32(ah);
696 
697 		sc->sched.beacon_adjust = false;
698 		ath_chanctx_setup_timer(sc, tsf_time);
699 		break;
700 	case ATH_CHANCTX_EVENT_AUTHORIZED:
701 		if (sc->sched.state != ATH_CHANCTX_STATE_FORCE_ACTIVE ||
702 		    avp->chanctx != sc->cur_chan)
703 			break;
704 
705 		ath_dbg(common, CHAN_CTX,
706 			"Move chanctx state from FORCE_ACTIVE to IDLE\n");
707 
708 		sc->sched.state = ATH_CHANCTX_STATE_IDLE;
709 		/* fall through */
710 	case ATH_CHANCTX_EVENT_SWITCH:
711 		if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) ||
712 		    sc->sched.state == ATH_CHANCTX_STATE_FORCE_ACTIVE ||
713 		    sc->cur_chan->switch_after_beacon ||
714 		    sc->cur_chan == &sc->offchannel.chan)
715 			break;
716 
717 		/* If this is a station chanctx, stay active for a half
718 		 * beacon period (minus channel switch time)
719 		 */
720 		sc->next_chan = ath_chanctx_get_next(sc, sc->cur_chan);
721 		cur_conf = &sc->cur_chan->beacon;
722 
723 		ath_dbg(common, CHAN_CTX,
724 			"Move chanctx state to WAIT_FOR_TIMER (event SWITCH)\n");
725 
726 		sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_TIMER;
727 		sc->sched.wait_switch = false;
728 
729 		tsf_time = TU_TO_USEC(cur_conf->beacon_interval) / 2;
730 
731 		if (sc->sched.extend_absence) {
732 			sc->sched.beacon_miss = 0;
733 			tsf_time *= 3;
734 		}
735 
736 		tsf_time -= sc->sched.channel_switch_time;
737 		tsf_time += ath9k_hw_gettsf32(sc->sc_ah);
738 		sc->sched.switch_start_time = tsf_time;
739 
740 		ath_chanctx_setup_timer(sc, tsf_time);
741 		sc->sched.beacon_pending = true;
742 		sc->sched.beacon_adjust = true;
743 		break;
744 	case ATH_CHANCTX_EVENT_ENABLE_MULTICHANNEL:
745 		if (sc->cur_chan == &sc->offchannel.chan ||
746 		    sc->cur_chan->switch_after_beacon)
747 			break;
748 
749 		sc->next_chan = ath_chanctx_get_next(sc, sc->cur_chan);
750 		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
751 		break;
752 	case ATH_CHANCTX_EVENT_UNASSIGN:
753 		if (sc->cur_chan->assigned) {
754 			if (sc->next_chan && !sc->next_chan->assigned &&
755 			    sc->next_chan != &sc->offchannel.chan)
756 				sc->sched.state = ATH_CHANCTX_STATE_IDLE;
757 			break;
758 		}
759 
760 		ctx = ath_chanctx_get_next(sc, sc->cur_chan);
761 		sc->sched.state = ATH_CHANCTX_STATE_IDLE;
762 		if (!ctx->assigned)
763 			break;
764 
765 		sc->next_chan = ctx;
766 		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
767 		break;
768 	case ATH_CHANCTX_EVENT_ASSIGN:
769 		break;
770 	case ATH_CHANCTX_EVENT_CHANGE:
771 		break;
772 	}
773 
774 	spin_unlock_bh(&sc->chan_lock);
775 }
776 
777 void ath_chanctx_beacon_sent_ev(struct ath_softc *sc,
778 				enum ath_chanctx_event ev)
779 {
780 	if (sc->sched.beacon_pending)
781 		ath_chanctx_event(sc, NULL, ev);
782 }
783 
784 void ath_chanctx_beacon_recv_ev(struct ath_softc *sc,
785 				enum ath_chanctx_event ev)
786 {
787 	ath_chanctx_event(sc, NULL, ev);
788 }
789 
790 static int ath_scan_channel_duration(struct ath_softc *sc,
791 				     struct ieee80211_channel *chan)
792 {
793 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
794 
795 	if (!req->n_ssids || (chan->flags & IEEE80211_CHAN_NO_IR))
796 		return (HZ / 9); /* ~110 ms */
797 
798 	return (HZ / 16); /* ~60 ms */
799 }
800 
801 static void ath_chanctx_switch(struct ath_softc *sc, struct ath_chanctx *ctx,
802 			       struct cfg80211_chan_def *chandef)
803 {
804 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
805 
806 	spin_lock_bh(&sc->chan_lock);
807 
808 	if (test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) &&
809 	    (sc->cur_chan != ctx) && (ctx == &sc->offchannel.chan)) {
810 		if (chandef)
811 			ctx->chandef = *chandef;
812 
813 		sc->sched.offchannel_pending = true;
814 		sc->sched.wait_switch = true;
815 		sc->sched.offchannel_duration =
816 			jiffies_to_usecs(sc->offchannel.duration) +
817 			sc->sched.channel_switch_time;
818 
819 		spin_unlock_bh(&sc->chan_lock);
820 		ath_dbg(common, CHAN_CTX,
821 			"Set offchannel_pending to true\n");
822 		return;
823 	}
824 
825 	sc->next_chan = ctx;
826 	if (chandef) {
827 		ctx->chandef = *chandef;
828 		ath_dbg(common, CHAN_CTX,
829 			"Assigned next_chan to %d MHz\n", chandef->center_freq1);
830 	}
831 
832 	if (sc->next_chan == &sc->offchannel.chan) {
833 		sc->sched.offchannel_duration =
834 			jiffies_to_usecs(sc->offchannel.duration) +
835 			sc->sched.channel_switch_time;
836 
837 		if (chandef) {
838 			ath_dbg(common, CHAN_CTX,
839 				"Offchannel duration for chan %d MHz : %u\n",
840 				chandef->center_freq1,
841 				sc->sched.offchannel_duration);
842 		}
843 	}
844 	spin_unlock_bh(&sc->chan_lock);
845 	ieee80211_queue_work(sc->hw, &sc->chanctx_work);
846 }
847 
848 static void ath_chanctx_offchan_switch(struct ath_softc *sc,
849 				       struct ieee80211_channel *chan)
850 {
851 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
852 	struct cfg80211_chan_def chandef;
853 
854 	cfg80211_chandef_create(&chandef, chan, NL80211_CHAN_NO_HT);
855 	ath_dbg(common, CHAN_CTX,
856 		"Channel definition created: %d MHz\n", chandef.center_freq1);
857 
858 	ath_chanctx_switch(sc, &sc->offchannel.chan, &chandef);
859 }
860 
861 static struct ath_chanctx *ath_chanctx_get_oper_chan(struct ath_softc *sc,
862 						     bool active)
863 {
864 	struct ath_chanctx *ctx;
865 
866 	ath_for_each_chanctx(sc, ctx) {
867 		if (!ctx->assigned || list_empty(&ctx->vifs))
868 			continue;
869 		if (active && !ctx->active)
870 			continue;
871 
872 		if (ctx->switch_after_beacon)
873 			return ctx;
874 	}
875 
876 	return &sc->chanctx[0];
877 }
878 
879 static void
880 ath_scan_next_channel(struct ath_softc *sc)
881 {
882 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
883 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
884 	struct ieee80211_channel *chan;
885 
886 	if (sc->offchannel.scan_idx >= req->n_channels) {
887 		ath_dbg(common, CHAN_CTX,
888 			"Moving offchannel state to ATH_OFFCHANNEL_IDLE, "
889 			"scan_idx: %d, n_channels: %d\n",
890 			sc->offchannel.scan_idx,
891 			req->n_channels);
892 
893 		sc->offchannel.state = ATH_OFFCHANNEL_IDLE;
894 		ath_chanctx_switch(sc, ath_chanctx_get_oper_chan(sc, false),
895 				   NULL);
896 		return;
897 	}
898 
899 	ath_dbg(common, CHAN_CTX,
900 		"Moving offchannel state to ATH_OFFCHANNEL_PROBE_SEND, scan_idx: %d\n",
901 		sc->offchannel.scan_idx);
902 
903 	chan = req->channels[sc->offchannel.scan_idx++];
904 	sc->offchannel.duration = ath_scan_channel_duration(sc, chan);
905 	sc->offchannel.state = ATH_OFFCHANNEL_PROBE_SEND;
906 
907 	ath_chanctx_offchan_switch(sc, chan);
908 }
909 
910 void ath_offchannel_next(struct ath_softc *sc)
911 {
912 	struct ieee80211_vif *vif;
913 
914 	if (sc->offchannel.scan_req) {
915 		vif = sc->offchannel.scan_vif;
916 		sc->offchannel.chan.txpower = vif->bss_conf.txpower;
917 		ath_scan_next_channel(sc);
918 	} else if (sc->offchannel.roc_vif) {
919 		vif = sc->offchannel.roc_vif;
920 		sc->offchannel.chan.txpower = vif->bss_conf.txpower;
921 		sc->offchannel.duration =
922 			msecs_to_jiffies(sc->offchannel.roc_duration);
923 		sc->offchannel.state = ATH_OFFCHANNEL_ROC_START;
924 		ath_chanctx_offchan_switch(sc, sc->offchannel.roc_chan);
925 	} else {
926 		spin_lock_bh(&sc->chan_lock);
927 		sc->sched.offchannel_pending = false;
928 		sc->sched.wait_switch = false;
929 		spin_unlock_bh(&sc->chan_lock);
930 
931 		ath_chanctx_switch(sc, ath_chanctx_get_oper_chan(sc, false),
932 				   NULL);
933 		sc->offchannel.state = ATH_OFFCHANNEL_IDLE;
934 		if (sc->ps_idle)
935 			ath_cancel_work(sc);
936 	}
937 }
938 
939 void ath_roc_complete(struct ath_softc *sc, enum ath_roc_complete_reason reason)
940 {
941 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
942 
943 	sc->offchannel.roc_vif = NULL;
944 	sc->offchannel.roc_chan = NULL;
945 
946 	switch (reason) {
947 	case ATH_ROC_COMPLETE_ABORT:
948 		ath_dbg(common, CHAN_CTX, "RoC aborted\n");
949 		ieee80211_remain_on_channel_expired(sc->hw);
950 		break;
951 	case ATH_ROC_COMPLETE_EXPIRE:
952 		ath_dbg(common, CHAN_CTX, "RoC expired\n");
953 		ieee80211_remain_on_channel_expired(sc->hw);
954 		break;
955 	case ATH_ROC_COMPLETE_CANCEL:
956 		ath_dbg(common, CHAN_CTX, "RoC canceled\n");
957 		break;
958 	}
959 
960 	ath_offchannel_next(sc);
961 	ath9k_ps_restore(sc);
962 }
963 
964 void ath_scan_complete(struct ath_softc *sc, bool abort)
965 {
966 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
967 	struct cfg80211_scan_info info = {
968 		.aborted = abort,
969 	};
970 
971 	if (abort)
972 		ath_dbg(common, CHAN_CTX, "HW scan aborted\n");
973 	else
974 		ath_dbg(common, CHAN_CTX, "HW scan complete\n");
975 
976 	sc->offchannel.scan_req = NULL;
977 	sc->offchannel.scan_vif = NULL;
978 	sc->offchannel.state = ATH_OFFCHANNEL_IDLE;
979 	ieee80211_scan_completed(sc->hw, &info);
980 	clear_bit(ATH_OP_SCANNING, &common->op_flags);
981 	spin_lock_bh(&sc->chan_lock);
982 	if (test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags))
983 		sc->sched.force_noa_update = true;
984 	spin_unlock_bh(&sc->chan_lock);
985 	ath_offchannel_next(sc);
986 	ath9k_ps_restore(sc);
987 }
988 
989 static void ath_scan_send_probe(struct ath_softc *sc,
990 				struct cfg80211_ssid *ssid)
991 {
992 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
993 	struct ieee80211_vif *vif = sc->offchannel.scan_vif;
994 	struct ath_tx_control txctl = {};
995 	struct sk_buff *skb;
996 	struct ieee80211_tx_info *info;
997 	int band = sc->offchannel.chan.chandef.chan->band;
998 
999 	skb = ieee80211_probereq_get(sc->hw, vif->addr,
1000 			ssid->ssid, ssid->ssid_len, req->ie_len);
1001 	if (!skb)
1002 		return;
1003 
1004 	info = IEEE80211_SKB_CB(skb);
1005 	if (req->no_cck)
1006 		info->flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
1007 
1008 	if (req->ie_len)
1009 		skb_put_data(skb, req->ie, req->ie_len);
1010 
1011 	skb_set_queue_mapping(skb, IEEE80211_AC_VO);
1012 
1013 	if (!ieee80211_tx_prepare_skb(sc->hw, vif, skb, band, NULL))
1014 		goto error;
1015 
1016 	txctl.txq = sc->tx.txq_map[IEEE80211_AC_VO];
1017 	if (ath_tx_start(sc->hw, skb, &txctl))
1018 		goto error;
1019 
1020 	return;
1021 
1022 error:
1023 	ieee80211_free_txskb(sc->hw, skb);
1024 }
1025 
1026 static void ath_scan_channel_start(struct ath_softc *sc)
1027 {
1028 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1029 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
1030 	int i;
1031 
1032 	if (!(sc->cur_chan->chandef.chan->flags & IEEE80211_CHAN_NO_IR) &&
1033 	    req->n_ssids) {
1034 		for (i = 0; i < req->n_ssids; i++)
1035 			ath_scan_send_probe(sc, &req->ssids[i]);
1036 
1037 	}
1038 
1039 	ath_dbg(common, CHAN_CTX,
1040 		"Moving offchannel state to ATH_OFFCHANNEL_PROBE_WAIT\n");
1041 
1042 	sc->offchannel.state = ATH_OFFCHANNEL_PROBE_WAIT;
1043 	mod_timer(&sc->offchannel.timer, jiffies + sc->offchannel.duration);
1044 }
1045 
1046 static void ath_chanctx_timer(struct timer_list *t)
1047 {
1048 	struct ath_softc *sc = from_timer(sc, t, sched.timer);
1049 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1050 
1051 	ath_dbg(common, CHAN_CTX,
1052 		"Channel context timer invoked\n");
1053 
1054 	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_TSF_TIMER);
1055 }
1056 
1057 static void ath_offchannel_timer(struct timer_list *t)
1058 {
1059 	struct ath_softc *sc = from_timer(sc, t, offchannel.timer);
1060 	struct ath_chanctx *ctx;
1061 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1062 
1063 	ath_dbg(common, CHAN_CTX, "%s: offchannel state: %s\n",
1064 		__func__, offchannel_state_string(sc->offchannel.state));
1065 
1066 	switch (sc->offchannel.state) {
1067 	case ATH_OFFCHANNEL_PROBE_WAIT:
1068 		if (!sc->offchannel.scan_req)
1069 			return;
1070 
1071 		/* get first active channel context */
1072 		ctx = ath_chanctx_get_oper_chan(sc, true);
1073 		if (ctx->active) {
1074 			ath_dbg(common, CHAN_CTX,
1075 				"Switch to oper/active context, "
1076 				"move offchannel state to ATH_OFFCHANNEL_SUSPEND\n");
1077 
1078 			sc->offchannel.state = ATH_OFFCHANNEL_SUSPEND;
1079 			ath_chanctx_switch(sc, ctx, NULL);
1080 			mod_timer(&sc->offchannel.timer, jiffies + HZ / 10);
1081 			break;
1082 		}
1083 		/* fall through */
1084 	case ATH_OFFCHANNEL_SUSPEND:
1085 		if (!sc->offchannel.scan_req)
1086 			return;
1087 
1088 		ath_scan_next_channel(sc);
1089 		break;
1090 	case ATH_OFFCHANNEL_ROC_START:
1091 	case ATH_OFFCHANNEL_ROC_WAIT:
1092 		sc->offchannel.state = ATH_OFFCHANNEL_ROC_DONE;
1093 		ath_roc_complete(sc, ATH_ROC_COMPLETE_EXPIRE);
1094 		break;
1095 	default:
1096 		break;
1097 	}
1098 }
1099 
1100 static bool
1101 ath_chanctx_send_vif_ps_frame(struct ath_softc *sc, struct ath_vif *avp,
1102 			      bool powersave)
1103 {
1104 	struct ieee80211_vif *vif = avp->vif;
1105 	struct ieee80211_sta *sta = NULL;
1106 	struct ieee80211_hdr_3addr *nullfunc;
1107 	struct ath_tx_control txctl;
1108 	struct sk_buff *skb;
1109 	int band = sc->cur_chan->chandef.chan->band;
1110 
1111 	switch (vif->type) {
1112 	case NL80211_IFTYPE_STATION:
1113 		if (!avp->assoc)
1114 			return false;
1115 
1116 		skb = ieee80211_nullfunc_get(sc->hw, vif);
1117 		if (!skb)
1118 			return false;
1119 
1120 		nullfunc = (struct ieee80211_hdr_3addr *) skb->data;
1121 		if (powersave)
1122 			nullfunc->frame_control |=
1123 				cpu_to_le16(IEEE80211_FCTL_PM);
1124 
1125 		skb->priority = 7;
1126 		skb_set_queue_mapping(skb, IEEE80211_AC_VO);
1127 		if (!ieee80211_tx_prepare_skb(sc->hw, vif, skb, band, &sta)) {
1128 			dev_kfree_skb_any(skb);
1129 			return false;
1130 		}
1131 		break;
1132 	default:
1133 		return false;
1134 	}
1135 
1136 	memset(&txctl, 0, sizeof(txctl));
1137 	txctl.txq = sc->tx.txq_map[IEEE80211_AC_VO];
1138 	txctl.sta = sta;
1139 	if (ath_tx_start(sc->hw, skb, &txctl)) {
1140 		ieee80211_free_txskb(sc->hw, skb);
1141 		return false;
1142 	}
1143 
1144 	return true;
1145 }
1146 
1147 static bool
1148 ath_chanctx_send_ps_frame(struct ath_softc *sc, bool powersave)
1149 {
1150 	struct ath_vif *avp;
1151 	bool sent = false;
1152 
1153 	rcu_read_lock();
1154 	list_for_each_entry(avp, &sc->cur_chan->vifs, list) {
1155 		if (ath_chanctx_send_vif_ps_frame(sc, avp, powersave))
1156 			sent = true;
1157 	}
1158 	rcu_read_unlock();
1159 
1160 	return sent;
1161 }
1162 
1163 static bool ath_chanctx_defer_switch(struct ath_softc *sc)
1164 {
1165 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1166 
1167 	if (sc->cur_chan == &sc->offchannel.chan)
1168 		return false;
1169 
1170 	switch (sc->sched.state) {
1171 	case ATH_CHANCTX_STATE_SWITCH:
1172 		return false;
1173 	case ATH_CHANCTX_STATE_IDLE:
1174 		if (!sc->cur_chan->switch_after_beacon)
1175 			return false;
1176 
1177 		ath_dbg(common, CHAN_CTX,
1178 			"Defer switch, set chanctx state to WAIT_FOR_BEACON\n");
1179 
1180 		sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
1181 		break;
1182 	default:
1183 		break;
1184 	}
1185 
1186 	return true;
1187 }
1188 
1189 static void ath_offchannel_channel_change(struct ath_softc *sc)
1190 {
1191 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1192 
1193 	ath_dbg(common, CHAN_CTX, "%s: offchannel state: %s\n",
1194 		__func__, offchannel_state_string(sc->offchannel.state));
1195 
1196 	switch (sc->offchannel.state) {
1197 	case ATH_OFFCHANNEL_PROBE_SEND:
1198 		if (!sc->offchannel.scan_req)
1199 			return;
1200 
1201 		if (sc->cur_chan->chandef.chan !=
1202 		    sc->offchannel.chan.chandef.chan)
1203 			return;
1204 
1205 		ath_scan_channel_start(sc);
1206 		break;
1207 	case ATH_OFFCHANNEL_IDLE:
1208 		if (!sc->offchannel.scan_req)
1209 			return;
1210 
1211 		ath_scan_complete(sc, false);
1212 		break;
1213 	case ATH_OFFCHANNEL_ROC_START:
1214 		if (sc->cur_chan != &sc->offchannel.chan)
1215 			break;
1216 
1217 		sc->offchannel.state = ATH_OFFCHANNEL_ROC_WAIT;
1218 		mod_timer(&sc->offchannel.timer,
1219 			  jiffies + sc->offchannel.duration);
1220 		ieee80211_ready_on_channel(sc->hw);
1221 		break;
1222 	case ATH_OFFCHANNEL_ROC_DONE:
1223 		break;
1224 	default:
1225 		break;
1226 	}
1227 }
1228 
1229 void ath_chanctx_set_next(struct ath_softc *sc, bool force)
1230 {
1231 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1232 	struct ath_chanctx *old_ctx;
1233 	struct timespec ts;
1234 	bool measure_time = false;
1235 	bool send_ps = false;
1236 	bool queues_stopped = false;
1237 
1238 	spin_lock_bh(&sc->chan_lock);
1239 	if (!sc->next_chan) {
1240 		spin_unlock_bh(&sc->chan_lock);
1241 		return;
1242 	}
1243 
1244 	if (!force && ath_chanctx_defer_switch(sc)) {
1245 		spin_unlock_bh(&sc->chan_lock);
1246 		return;
1247 	}
1248 
1249 	ath_dbg(common, CHAN_CTX,
1250 		"%s: current: %d MHz, next: %d MHz\n",
1251 		__func__,
1252 		sc->cur_chan->chandef.center_freq1,
1253 		sc->next_chan->chandef.center_freq1);
1254 
1255 	if (sc->cur_chan != sc->next_chan) {
1256 		ath_dbg(common, CHAN_CTX,
1257 			"Stopping current chanctx: %d\n",
1258 			sc->cur_chan->chandef.center_freq1);
1259 		sc->cur_chan->stopped = true;
1260 		spin_unlock_bh(&sc->chan_lock);
1261 
1262 		if (sc->next_chan == &sc->offchannel.chan) {
1263 			getrawmonotonic(&ts);
1264 			measure_time = true;
1265 		}
1266 
1267 		ath9k_chanctx_stop_queues(sc, sc->cur_chan);
1268 		queues_stopped = true;
1269 
1270 		__ath9k_flush(sc->hw, ~0, true, false, false);
1271 
1272 		if (ath_chanctx_send_ps_frame(sc, true))
1273 			__ath9k_flush(sc->hw, BIT(IEEE80211_AC_VO),
1274 				      false, false, false);
1275 
1276 		send_ps = true;
1277 		spin_lock_bh(&sc->chan_lock);
1278 
1279 		if (sc->cur_chan != &sc->offchannel.chan) {
1280 			getrawmonotonic(&sc->cur_chan->tsf_ts);
1281 			sc->cur_chan->tsf_val = ath9k_hw_gettsf64(sc->sc_ah);
1282 		}
1283 	}
1284 	old_ctx = sc->cur_chan;
1285 	sc->cur_chan = sc->next_chan;
1286 	sc->cur_chan->stopped = false;
1287 	sc->next_chan = NULL;
1288 
1289 	if (!sc->sched.offchannel_pending)
1290 		sc->sched.offchannel_duration = 0;
1291 
1292 	if (sc->sched.state != ATH_CHANCTX_STATE_FORCE_ACTIVE)
1293 		sc->sched.state = ATH_CHANCTX_STATE_IDLE;
1294 
1295 	spin_unlock_bh(&sc->chan_lock);
1296 
1297 	if (sc->sc_ah->chip_fullsleep ||
1298 	    memcmp(&sc->cur_chandef, &sc->cur_chan->chandef,
1299 		   sizeof(sc->cur_chandef))) {
1300 		ath_dbg(common, CHAN_CTX,
1301 			"%s: Set channel %d MHz\n",
1302 			__func__, sc->cur_chan->chandef.center_freq1);
1303 		ath_set_channel(sc);
1304 		if (measure_time)
1305 			sc->sched.channel_switch_time =
1306 				ath9k_hw_get_tsf_offset(&ts, NULL);
1307 		/*
1308 		 * A reset will ensure that all queues are woken up,
1309 		 * so there is no need to awaken them again.
1310 		 */
1311 		goto out;
1312 	}
1313 
1314 	if (queues_stopped)
1315 		ath9k_chanctx_wake_queues(sc, old_ctx);
1316 out:
1317 	if (send_ps)
1318 		ath_chanctx_send_ps_frame(sc, false);
1319 
1320 	ath_offchannel_channel_change(sc);
1321 	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_SWITCH);
1322 }
1323 
1324 static void ath_chanctx_work(struct work_struct *work)
1325 {
1326 	struct ath_softc *sc = container_of(work, struct ath_softc,
1327 					    chanctx_work);
1328 	mutex_lock(&sc->mutex);
1329 	ath_chanctx_set_next(sc, false);
1330 	mutex_unlock(&sc->mutex);
1331 }
1332 
1333 void ath9k_offchannel_init(struct ath_softc *sc)
1334 {
1335 	struct ath_chanctx *ctx;
1336 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1337 	struct ieee80211_supported_band *sband;
1338 	struct ieee80211_channel *chan;
1339 	int i;
1340 
1341 	sband = &common->sbands[NL80211_BAND_2GHZ];
1342 	if (!sband->n_channels)
1343 		sband = &common->sbands[NL80211_BAND_5GHZ];
1344 
1345 	chan = &sband->channels[0];
1346 
1347 	ctx = &sc->offchannel.chan;
1348 	INIT_LIST_HEAD(&ctx->vifs);
1349 	ctx->txpower = ATH_TXPOWER_MAX;
1350 	cfg80211_chandef_create(&ctx->chandef, chan, NL80211_CHAN_HT20);
1351 
1352 	for (i = 0; i < ARRAY_SIZE(ctx->acq); i++) {
1353 		INIT_LIST_HEAD(&ctx->acq[i].acq_new);
1354 		INIT_LIST_HEAD(&ctx->acq[i].acq_old);
1355 		spin_lock_init(&ctx->acq[i].lock);
1356 	}
1357 
1358 	sc->offchannel.chan.offchannel = true;
1359 }
1360 
1361 void ath9k_init_channel_context(struct ath_softc *sc)
1362 {
1363 	INIT_WORK(&sc->chanctx_work, ath_chanctx_work);
1364 
1365 	timer_setup(&sc->offchannel.timer, ath_offchannel_timer, 0);
1366 	timer_setup(&sc->sched.timer, ath_chanctx_timer, 0);
1367 
1368 	init_completion(&sc->go_beacon);
1369 }
1370 
1371 void ath9k_deinit_channel_context(struct ath_softc *sc)
1372 {
1373 	cancel_work_sync(&sc->chanctx_work);
1374 }
1375 
1376 bool ath9k_is_chanctx_enabled(void)
1377 {
1378 	return (ath9k_use_chanctx == 1);
1379 }
1380 
1381 /********************/
1382 /* Queue management */
1383 /********************/
1384 
1385 void ath9k_chanctx_stop_queues(struct ath_softc *sc, struct ath_chanctx *ctx)
1386 {
1387 	struct ath_hw *ah = sc->sc_ah;
1388 	int i;
1389 
1390 	if (ctx == &sc->offchannel.chan) {
1391 		ieee80211_stop_queue(sc->hw,
1392 				     sc->hw->offchannel_tx_hw_queue);
1393 	} else {
1394 		for (i = 0; i < IEEE80211_NUM_ACS; i++)
1395 			ieee80211_stop_queue(sc->hw,
1396 					     ctx->hw_queue_base + i);
1397 	}
1398 
1399 	if (ah->opmode == NL80211_IFTYPE_AP)
1400 		ieee80211_stop_queue(sc->hw, sc->hw->queues - 2);
1401 }
1402 
1403 
1404 void ath9k_chanctx_wake_queues(struct ath_softc *sc, struct ath_chanctx *ctx)
1405 {
1406 	struct ath_hw *ah = sc->sc_ah;
1407 	int i;
1408 
1409 	if (ctx == &sc->offchannel.chan) {
1410 		ieee80211_wake_queue(sc->hw,
1411 				     sc->hw->offchannel_tx_hw_queue);
1412 	} else {
1413 		for (i = 0; i < IEEE80211_NUM_ACS; i++)
1414 			ieee80211_wake_queue(sc->hw,
1415 					     ctx->hw_queue_base + i);
1416 	}
1417 
1418 	if (ah->opmode == NL80211_IFTYPE_AP)
1419 		ieee80211_wake_queue(sc->hw, sc->hw->queues - 2);
1420 }
1421 
1422 /*****************/
1423 /* P2P Powersave */
1424 /*****************/
1425 
1426 static void ath9k_update_p2p_ps_timer(struct ath_softc *sc, struct ath_vif *avp)
1427 {
1428 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1429 	struct ath_hw *ah = sc->sc_ah;
1430 	u32 tsf, target_tsf;
1431 
1432 	if (!avp || !avp->noa.has_next_tsf)
1433 		return;
1434 
1435 	ath9k_hw_gen_timer_stop(ah, sc->p2p_ps_timer);
1436 
1437 	tsf = ath9k_hw_gettsf32(sc->sc_ah);
1438 
1439 	target_tsf = avp->noa.next_tsf;
1440 	if (!avp->noa.absent)
1441 		target_tsf -= ATH_P2P_PS_STOP_TIME;
1442 	else
1443 		target_tsf += ATH_P2P_PS_STOP_TIME;
1444 
1445 	if (target_tsf - tsf < ATH_P2P_PS_STOP_TIME)
1446 		target_tsf = tsf + ATH_P2P_PS_STOP_TIME;
1447 
1448 	ath_dbg(common, CHAN_CTX, "%s absent %d tsf 0x%08X next_tsf 0x%08X (%dms)\n",
1449 		__func__, avp->noa.absent, tsf, target_tsf,
1450 		(target_tsf - tsf) / 1000);
1451 
1452 	ath9k_hw_gen_timer_start(ah, sc->p2p_ps_timer, target_tsf, 1000000);
1453 }
1454 
1455 static void ath9k_update_p2p_ps(struct ath_softc *sc, struct ieee80211_vif *vif)
1456 {
1457 	struct ath_vif *avp = (void *)vif->drv_priv;
1458 	u32 tsf;
1459 
1460 	if (!sc->p2p_ps_timer)
1461 		return;
1462 
1463 	if (vif->type != NL80211_IFTYPE_STATION)
1464 		return;
1465 
1466 	sc->p2p_ps_vif = avp;
1467 
1468 	if (sc->ps_flags & PS_BEACON_SYNC)
1469 		return;
1470 
1471 	tsf = ath9k_hw_gettsf32(sc->sc_ah);
1472 	ieee80211_parse_p2p_noa(&vif->bss_conf.p2p_noa_attr, &avp->noa, tsf);
1473 	ath9k_update_p2p_ps_timer(sc, avp);
1474 }
1475 
1476 static u8 ath9k_get_ctwin(struct ath_softc *sc, struct ath_vif *avp)
1477 {
1478 	struct ath_beacon_config *cur_conf = &sc->cur_chan->beacon;
1479 	u8 switch_time, ctwin;
1480 
1481 	/*
1482 	 * Channel switch in multi-channel mode is deferred
1483 	 * by a quarter beacon interval when handling
1484 	 * ATH_CHANCTX_EVENT_BEACON_PREPARE, so the P2P-GO
1485 	 * interface is guaranteed to be discoverable
1486 	 * for that duration after a TBTT.
1487 	 */
1488 	switch_time = cur_conf->beacon_interval / 4;
1489 
1490 	ctwin = avp->vif->bss_conf.p2p_noa_attr.oppps_ctwindow;
1491 	if (ctwin && (ctwin < switch_time))
1492 		return ctwin;
1493 
1494 	if (switch_time < P2P_DEFAULT_CTWIN)
1495 		return 0;
1496 
1497 	return P2P_DEFAULT_CTWIN;
1498 }
1499 
1500 void ath9k_beacon_add_noa(struct ath_softc *sc, struct ath_vif *avp,
1501 			  struct sk_buff *skb)
1502 {
1503 	static const u8 noa_ie_hdr[] = {
1504 		WLAN_EID_VENDOR_SPECIFIC,	/* type */
1505 		0,				/* length */
1506 		0x50, 0x6f, 0x9a,		/* WFA OUI */
1507 		0x09,				/* P2P subtype */
1508 		0x0c,				/* Notice of Absence */
1509 		0x00,				/* LSB of little-endian len */
1510 		0x00,				/* MSB of little-endian len */
1511 	};
1512 
1513 	struct ieee80211_p2p_noa_attr *noa;
1514 	int noa_len, noa_desc, i = 0;
1515 	u8 *hdr;
1516 
1517 	if (!avp->offchannel_duration && !avp->noa_duration)
1518 		return;
1519 
1520 	noa_desc = !!avp->offchannel_duration + !!avp->noa_duration;
1521 	noa_len = 2 + sizeof(struct ieee80211_p2p_noa_desc) * noa_desc;
1522 
1523 	hdr = skb_put_data(skb, noa_ie_hdr, sizeof(noa_ie_hdr));
1524 	hdr[1] = sizeof(noa_ie_hdr) + noa_len - 2;
1525 	hdr[7] = noa_len;
1526 
1527 	noa = skb_put_zero(skb, noa_len);
1528 
1529 	noa->index = avp->noa_index;
1530 	noa->oppps_ctwindow = ath9k_get_ctwin(sc, avp);
1531 	if (noa->oppps_ctwindow)
1532 		noa->oppps_ctwindow |= BIT(7);
1533 
1534 	if (avp->noa_duration) {
1535 		if (avp->periodic_noa) {
1536 			u32 interval = TU_TO_USEC(sc->cur_chan->beacon.beacon_interval);
1537 			noa->desc[i].count = 255;
1538 			noa->desc[i].interval = cpu_to_le32(interval);
1539 		} else {
1540 			noa->desc[i].count = 1;
1541 		}
1542 
1543 		noa->desc[i].start_time = cpu_to_le32(avp->noa_start);
1544 		noa->desc[i].duration = cpu_to_le32(avp->noa_duration);
1545 		i++;
1546 	}
1547 
1548 	if (avp->offchannel_duration) {
1549 		noa->desc[i].count = 1;
1550 		noa->desc[i].start_time = cpu_to_le32(avp->offchannel_start);
1551 		noa->desc[i].duration = cpu_to_le32(avp->offchannel_duration);
1552 	}
1553 }
1554 
1555 void ath9k_p2p_ps_timer(void *priv)
1556 {
1557 	struct ath_softc *sc = priv;
1558 	struct ath_vif *avp = sc->p2p_ps_vif;
1559 	struct ieee80211_vif *vif;
1560 	struct ieee80211_sta *sta;
1561 	struct ath_node *an;
1562 	u32 tsf;
1563 
1564 	del_timer_sync(&sc->sched.timer);
1565 	ath9k_hw_gen_timer_stop(sc->sc_ah, sc->p2p_ps_timer);
1566 	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_TSF_TIMER);
1567 
1568 	if (!avp || avp->chanctx != sc->cur_chan)
1569 		return;
1570 
1571 	tsf = ath9k_hw_gettsf32(sc->sc_ah);
1572 	if (!avp->noa.absent)
1573 		tsf += ATH_P2P_PS_STOP_TIME;
1574 	else
1575 		tsf -= ATH_P2P_PS_STOP_TIME;
1576 
1577 	if (!avp->noa.has_next_tsf ||
1578 	    avp->noa.next_tsf - tsf > BIT(31))
1579 		ieee80211_update_p2p_noa(&avp->noa, tsf);
1580 
1581 	ath9k_update_p2p_ps_timer(sc, avp);
1582 
1583 	rcu_read_lock();
1584 
1585 	vif = avp->vif;
1586 	sta = ieee80211_find_sta(vif, avp->bssid);
1587 	if (!sta)
1588 		goto out;
1589 
1590 	an = (void *) sta->drv_priv;
1591 	if (an->sleeping == !!avp->noa.absent)
1592 		goto out;
1593 
1594 	an->sleeping = avp->noa.absent;
1595 	if (an->sleeping)
1596 		ath_tx_aggr_sleep(sta, sc, an);
1597 	else
1598 		ath_tx_aggr_wakeup(sc, an);
1599 
1600 out:
1601 	rcu_read_unlock();
1602 }
1603 
1604 void ath9k_p2p_bss_info_changed(struct ath_softc *sc,
1605 				struct ieee80211_vif *vif)
1606 {
1607 	unsigned long flags;
1608 
1609 	spin_lock_bh(&sc->sc_pcu_lock);
1610 	spin_lock_irqsave(&sc->sc_pm_lock, flags);
1611 	ath9k_update_p2p_ps(sc, vif);
1612 	spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
1613 	spin_unlock_bh(&sc->sc_pcu_lock);
1614 }
1615 
1616 void ath9k_p2p_beacon_sync(struct ath_softc *sc)
1617 {
1618 	if (sc->p2p_ps_vif)
1619 		ath9k_update_p2p_ps(sc, sc->p2p_ps_vif->vif);
1620 }
1621 
1622 void ath9k_p2p_remove_vif(struct ath_softc *sc,
1623 			  struct ieee80211_vif *vif)
1624 {
1625 	struct ath_vif *avp = (void *)vif->drv_priv;
1626 
1627 	spin_lock_bh(&sc->sc_pcu_lock);
1628 	if (avp == sc->p2p_ps_vif) {
1629 		sc->p2p_ps_vif = NULL;
1630 		ath9k_update_p2p_ps_timer(sc, NULL);
1631 	}
1632 	spin_unlock_bh(&sc->sc_pcu_lock);
1633 }
1634 
1635 int ath9k_init_p2p(struct ath_softc *sc)
1636 {
1637 	sc->p2p_ps_timer = ath_gen_timer_alloc(sc->sc_ah, ath9k_p2p_ps_timer,
1638 					       NULL, sc, AR_FIRST_NDP_TIMER);
1639 	if (!sc->p2p_ps_timer)
1640 		return -ENOMEM;
1641 
1642 	return 0;
1643 }
1644 
1645 void ath9k_deinit_p2p(struct ath_softc *sc)
1646 {
1647 	if (sc->p2p_ps_timer)
1648 		ath_gen_timer_free(sc->sc_ah, sc->p2p_ps_timer);
1649 }
1650 
1651 #endif /* CONFIG_ATH9K_CHANNEL_CONTEXT */
1652