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 	int old_pos = -1;
33 	int r;
34 
35 	if (test_bit(ATH_OP_INVALID, &common->op_flags))
36 		return -EIO;
37 
38 	if (ah->curchan)
39 		old_pos = ah->curchan - &ah->channels[0];
40 
41 	ath_dbg(common, CONFIG, "Set channel: %d MHz width: %d\n",
42 		chan->center_freq, chandef->width);
43 
44 	/* update survey stats for the old channel before switching */
45 	spin_lock_bh(&common->cc_lock);
46 	ath_update_survey_stats(sc);
47 	spin_unlock_bh(&common->cc_lock);
48 
49 	ath9k_cmn_get_channel(hw, ah, chandef);
50 
51 	/* If the operating channel changes, change the survey in-use flags
52 	 * along with it.
53 	 * Reset the survey data for the new channel, unless we're switching
54 	 * back to the operating channel from an off-channel operation.
55 	 */
56 	if (!sc->cur_chan->offchannel && sc->cur_survey != &sc->survey[pos]) {
57 		if (sc->cur_survey)
58 			sc->cur_survey->filled &= ~SURVEY_INFO_IN_USE;
59 
60 		sc->cur_survey = &sc->survey[pos];
61 
62 		memset(sc->cur_survey, 0, sizeof(struct survey_info));
63 		sc->cur_survey->filled |= SURVEY_INFO_IN_USE;
64 	} else if (!(sc->survey[pos].filled & SURVEY_INFO_IN_USE)) {
65 		memset(&sc->survey[pos], 0, sizeof(struct survey_info));
66 	}
67 
68 	hchan = &sc->sc_ah->channels[pos];
69 	r = ath_reset(sc, hchan);
70 	if (r)
71 		return r;
72 
73 	/* The most recent snapshot of channel->noisefloor for the old
74 	 * channel is only available after the hardware reset. Copy it to
75 	 * the survey stats now.
76 	 */
77 	if (old_pos >= 0)
78 		ath_update_survey_nf(sc, old_pos);
79 
80 	/* Enable radar pulse detection if on a DFS channel. Spectral
81 	 * scanning and radar detection can not be used concurrently.
82 	 */
83 	if (hw->conf.radar_enabled) {
84 		u32 rxfilter;
85 
86 		rxfilter = ath9k_hw_getrxfilter(ah);
87 		rxfilter |= ATH9K_RX_FILTER_PHYRADAR |
88 				ATH9K_RX_FILTER_PHYERR;
89 		ath9k_hw_setrxfilter(ah, rxfilter);
90 		ath_dbg(common, DFS, "DFS enabled at freq %d\n",
91 			chan->center_freq);
92 	} else {
93 		/* perform spectral scan if requested. */
94 		if (test_bit(ATH_OP_SCANNING, &common->op_flags) &&
95 			sc->spec_priv.spectral_mode == SPECTRAL_CHANSCAN)
96 			ath9k_cmn_spectral_scan_trigger(common, &sc->spec_priv);
97 	}
98 
99 	return 0;
100 }
101 
102 void ath_chanctx_init(struct ath_softc *sc)
103 {
104 	struct ath_chanctx *ctx;
105 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
106 	struct ieee80211_supported_band *sband;
107 	struct ieee80211_channel *chan;
108 	int i, j;
109 
110 	sband = &common->sbands[IEEE80211_BAND_2GHZ];
111 	if (!sband->n_channels)
112 		sband = &common->sbands[IEEE80211_BAND_5GHZ];
113 
114 	chan = &sband->channels[0];
115 	for (i = 0; i < ATH9K_NUM_CHANCTX; i++) {
116 		ctx = &sc->chanctx[i];
117 		cfg80211_chandef_create(&ctx->chandef, chan, NL80211_CHAN_HT20);
118 		INIT_LIST_HEAD(&ctx->vifs);
119 		ctx->txpower = ATH_TXPOWER_MAX;
120 		ctx->flush_timeout = HZ / 5; /* 200ms */
121 		for (j = 0; j < ARRAY_SIZE(ctx->acq); j++)
122 			INIT_LIST_HEAD(&ctx->acq[j]);
123 	}
124 }
125 
126 void ath_chanctx_set_channel(struct ath_softc *sc, struct ath_chanctx *ctx,
127 			     struct cfg80211_chan_def *chandef)
128 {
129 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
130 	bool cur_chan;
131 
132 	spin_lock_bh(&sc->chan_lock);
133 	if (chandef)
134 		memcpy(&ctx->chandef, chandef, sizeof(*chandef));
135 	cur_chan = sc->cur_chan == ctx;
136 	spin_unlock_bh(&sc->chan_lock);
137 
138 	if (!cur_chan) {
139 		ath_dbg(common, CHAN_CTX,
140 			"Current context differs from the new context\n");
141 		return;
142 	}
143 
144 	ath_set_channel(sc);
145 }
146 
147 #ifdef CONFIG_ATH9K_CHANNEL_CONTEXT
148 
149 /*************/
150 /* Utilities */
151 /*************/
152 
153 struct ath_chanctx* ath_is_go_chanctx_present(struct ath_softc *sc)
154 {
155 	struct ath_chanctx *ctx;
156 	struct ath_vif *avp;
157 	struct ieee80211_vif *vif;
158 
159 	spin_lock_bh(&sc->chan_lock);
160 
161 	ath_for_each_chanctx(sc, ctx) {
162 		if (!ctx->active)
163 			continue;
164 
165 		list_for_each_entry(avp, &ctx->vifs, list) {
166 			vif = avp->vif;
167 
168 			if (ieee80211_vif_type_p2p(vif) == NL80211_IFTYPE_P2P_GO) {
169 				spin_unlock_bh(&sc->chan_lock);
170 				return ctx;
171 			}
172 		}
173 	}
174 
175 	spin_unlock_bh(&sc->chan_lock);
176 	return NULL;
177 }
178 
179 /**********************************************************/
180 /* Functions to handle the channel context state machine. */
181 /**********************************************************/
182 
183 static const char *offchannel_state_string(enum ath_offchannel_state state)
184 {
185 	switch (state) {
186 		case_rtn_string(ATH_OFFCHANNEL_IDLE);
187 		case_rtn_string(ATH_OFFCHANNEL_PROBE_SEND);
188 		case_rtn_string(ATH_OFFCHANNEL_PROBE_WAIT);
189 		case_rtn_string(ATH_OFFCHANNEL_SUSPEND);
190 		case_rtn_string(ATH_OFFCHANNEL_ROC_START);
191 		case_rtn_string(ATH_OFFCHANNEL_ROC_WAIT);
192 		case_rtn_string(ATH_OFFCHANNEL_ROC_DONE);
193 	default:
194 		return "unknown";
195 	}
196 }
197 
198 static const char *chanctx_event_string(enum ath_chanctx_event ev)
199 {
200 	switch (ev) {
201 		case_rtn_string(ATH_CHANCTX_EVENT_BEACON_PREPARE);
202 		case_rtn_string(ATH_CHANCTX_EVENT_BEACON_SENT);
203 		case_rtn_string(ATH_CHANCTX_EVENT_TSF_TIMER);
204 		case_rtn_string(ATH_CHANCTX_EVENT_BEACON_RECEIVED);
205 		case_rtn_string(ATH_CHANCTX_EVENT_AUTHORIZED);
206 		case_rtn_string(ATH_CHANCTX_EVENT_SWITCH);
207 		case_rtn_string(ATH_CHANCTX_EVENT_ASSIGN);
208 		case_rtn_string(ATH_CHANCTX_EVENT_UNASSIGN);
209 		case_rtn_string(ATH_CHANCTX_EVENT_CHANGE);
210 		case_rtn_string(ATH_CHANCTX_EVENT_ENABLE_MULTICHANNEL);
211 	default:
212 		return "unknown";
213 	}
214 }
215 
216 static const char *chanctx_state_string(enum ath_chanctx_state state)
217 {
218 	switch (state) {
219 		case_rtn_string(ATH_CHANCTX_STATE_IDLE);
220 		case_rtn_string(ATH_CHANCTX_STATE_WAIT_FOR_BEACON);
221 		case_rtn_string(ATH_CHANCTX_STATE_WAIT_FOR_TIMER);
222 		case_rtn_string(ATH_CHANCTX_STATE_SWITCH);
223 		case_rtn_string(ATH_CHANCTX_STATE_FORCE_ACTIVE);
224 	default:
225 		return "unknown";
226 	}
227 }
228 
229 void ath_chanctx_check_active(struct ath_softc *sc, struct ath_chanctx *ctx)
230 {
231 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
232 	struct ath_chanctx *ictx;
233 	struct ath_vif *avp;
234 	bool active = false;
235 	u8 n_active = 0;
236 
237 	if (!ctx)
238 		return;
239 
240 	if (ctx == &sc->offchannel.chan) {
241 		spin_lock_bh(&sc->chan_lock);
242 
243 		if (likely(sc->sched.channel_switch_time))
244 			ctx->flush_timeout =
245 				usecs_to_jiffies(sc->sched.channel_switch_time);
246 		else
247 			ctx->flush_timeout =
248 				msecs_to_jiffies(10);
249 
250 		spin_unlock_bh(&sc->chan_lock);
251 
252 		/*
253 		 * There is no need to iterate over the
254 		 * active/assigned channel contexts if
255 		 * the current context is offchannel.
256 		 */
257 		return;
258 	}
259 
260 	ictx = ctx;
261 
262 	list_for_each_entry(avp, &ctx->vifs, list) {
263 		struct ieee80211_vif *vif = avp->vif;
264 
265 		switch (vif->type) {
266 		case NL80211_IFTYPE_P2P_CLIENT:
267 		case NL80211_IFTYPE_STATION:
268 			if (avp->assoc)
269 				active = true;
270 			break;
271 		default:
272 			active = true;
273 			break;
274 		}
275 	}
276 	ctx->active = active;
277 
278 	ath_for_each_chanctx(sc, ctx) {
279 		if (!ctx->assigned || list_empty(&ctx->vifs))
280 			continue;
281 		n_active++;
282 	}
283 
284 	spin_lock_bh(&sc->chan_lock);
285 
286 	if (n_active <= 1) {
287 		ictx->flush_timeout = HZ / 5;
288 		clear_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags);
289 		spin_unlock_bh(&sc->chan_lock);
290 		return;
291 	}
292 
293 	ictx->flush_timeout = usecs_to_jiffies(sc->sched.channel_switch_time);
294 
295 	if (test_and_set_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags)) {
296 		spin_unlock_bh(&sc->chan_lock);
297 		return;
298 	}
299 
300 	spin_unlock_bh(&sc->chan_lock);
301 
302 	if (ath9k_is_chanctx_enabled()) {
303 		ath_chanctx_event(sc, NULL,
304 				  ATH_CHANCTX_EVENT_ENABLE_MULTICHANNEL);
305 	}
306 }
307 
308 static struct ath_chanctx *
309 ath_chanctx_get_next(struct ath_softc *sc, struct ath_chanctx *ctx)
310 {
311 	int idx = ctx - &sc->chanctx[0];
312 
313 	return &sc->chanctx[!idx];
314 }
315 
316 static void ath_chanctx_adjust_tbtt_delta(struct ath_softc *sc)
317 {
318 	struct ath_chanctx *prev, *cur;
319 	struct timespec ts;
320 	u32 cur_tsf, prev_tsf, beacon_int;
321 	s32 offset;
322 
323 	beacon_int = TU_TO_USEC(sc->cur_chan->beacon.beacon_interval);
324 
325 	cur = sc->cur_chan;
326 	prev = ath_chanctx_get_next(sc, cur);
327 
328 	if (!prev->switch_after_beacon)
329 		return;
330 
331 	getrawmonotonic(&ts);
332 	cur_tsf = (u32) cur->tsf_val +
333 		  ath9k_hw_get_tsf_offset(&cur->tsf_ts, &ts);
334 
335 	prev_tsf = prev->last_beacon - (u32) prev->tsf_val + cur_tsf;
336 	prev_tsf -= ath9k_hw_get_tsf_offset(&prev->tsf_ts, &ts);
337 
338 	/* Adjust the TSF time of the AP chanctx to keep its beacons
339 	 * at half beacon interval offset relative to the STA chanctx.
340 	 */
341 	offset = cur_tsf - prev_tsf;
342 
343 	/* Ignore stale data or spurious timestamps */
344 	if (offset < 0 || offset > 3 * beacon_int)
345 		return;
346 
347 	offset = beacon_int / 2 - (offset % beacon_int);
348 	prev->tsf_val += offset;
349 }
350 
351 /* Configure the TSF based hardware timer for a channel switch.
352  * Also set up backup software timer, in case the gen timer fails.
353  * This could be caused by a hardware reset.
354  */
355 static void ath_chanctx_setup_timer(struct ath_softc *sc, u32 tsf_time)
356 {
357 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
358 	struct ath_hw *ah = sc->sc_ah;
359 
360 	ath9k_hw_gen_timer_start(ah, sc->p2p_ps_timer, tsf_time, 1000000);
361 	tsf_time -= ath9k_hw_gettsf32(ah);
362 	tsf_time = msecs_to_jiffies(tsf_time / 1000) + 1;
363 	mod_timer(&sc->sched.timer, jiffies + tsf_time);
364 
365 	ath_dbg(common, CHAN_CTX,
366 		"Setup chanctx timer with timeout: %d ms\n", jiffies_to_msecs(tsf_time));
367 }
368 
369 static void ath_chanctx_handle_bmiss(struct ath_softc *sc,
370 				     struct ath_chanctx *ctx,
371 				     struct ath_vif *avp)
372 {
373 	/*
374 	 * Clear the extend_absence flag if it had been
375 	 * set during the previous beacon transmission,
376 	 * since we need to revert to the normal NoA
377 	 * schedule.
378 	 */
379 	if (ctx->active && sc->sched.extend_absence) {
380 		avp->noa_duration = 0;
381 		sc->sched.extend_absence = false;
382 	}
383 
384 	/* If at least two consecutive beacons were missed on the STA
385 	 * chanctx, stay on the STA channel for one extra beacon period,
386 	 * to resync the timer properly.
387 	 */
388 	if (ctx->active && sc->sched.beacon_miss >= 2) {
389 		avp->noa_duration = 0;
390 		sc->sched.extend_absence = true;
391 	}
392 }
393 
394 static void ath_chanctx_offchannel_noa(struct ath_softc *sc,
395 				       struct ath_chanctx *ctx,
396 				       struct ath_vif *avp,
397 				       u32 tsf_time)
398 {
399 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
400 
401 	avp->noa_index++;
402 	avp->offchannel_start = tsf_time;
403 	avp->offchannel_duration = sc->sched.offchannel_duration;
404 
405 	ath_dbg(common, CHAN_CTX,
406 		"offchannel noa_duration: %d, noa_start: %d, noa_index: %d\n",
407 		avp->offchannel_duration,
408 		avp->offchannel_start,
409 		avp->noa_index);
410 
411 	/*
412 	 * When multiple contexts are active, the NoA
413 	 * has to be recalculated and advertised after
414 	 * an offchannel operation.
415 	 */
416 	if (ctx->active && avp->noa_duration)
417 		avp->noa_duration = 0;
418 }
419 
420 static void ath_chanctx_set_periodic_noa(struct ath_softc *sc,
421 					 struct ath_vif *avp,
422 					 struct ath_beacon_config *cur_conf,
423 					 u32 tsf_time,
424 					 u32 beacon_int)
425 {
426 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
427 
428 	avp->noa_index++;
429 	avp->noa_start = tsf_time;
430 
431 	if (sc->sched.extend_absence)
432 		avp->noa_duration = (3 * beacon_int / 2) +
433 			sc->sched.channel_switch_time;
434 	else
435 		avp->noa_duration =
436 			TU_TO_USEC(cur_conf->beacon_interval) / 2 +
437 			sc->sched.channel_switch_time;
438 
439 	if (test_bit(ATH_OP_SCANNING, &common->op_flags) ||
440 	    sc->sched.extend_absence)
441 		avp->periodic_noa = false;
442 	else
443 		avp->periodic_noa = true;
444 
445 	ath_dbg(common, CHAN_CTX,
446 		"noa_duration: %d, noa_start: %d, noa_index: %d, periodic: %d\n",
447 		avp->noa_duration,
448 		avp->noa_start,
449 		avp->noa_index,
450 		avp->periodic_noa);
451 }
452 
453 static void ath_chanctx_set_oneshot_noa(struct ath_softc *sc,
454 					struct ath_vif *avp,
455 					u32 tsf_time,
456 					u32 duration)
457 {
458 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
459 
460 	avp->noa_index++;
461 	avp->noa_start = tsf_time;
462 	avp->periodic_noa = false;
463 	avp->oneshot_noa = true;
464 	avp->noa_duration = duration + sc->sched.channel_switch_time;
465 
466 	ath_dbg(common, CHAN_CTX,
467 		"oneshot noa_duration: %d, noa_start: %d, noa_index: %d, periodic: %d\n",
468 		avp->noa_duration,
469 		avp->noa_start,
470 		avp->noa_index,
471 		avp->periodic_noa);
472 }
473 
474 void ath_chanctx_event(struct ath_softc *sc, struct ieee80211_vif *vif,
475 		       enum ath_chanctx_event ev)
476 {
477 	struct ath_hw *ah = sc->sc_ah;
478 	struct ath_common *common = ath9k_hw_common(ah);
479 	struct ath_beacon_config *cur_conf;
480 	struct ath_vif *avp = NULL;
481 	struct ath_chanctx *ctx;
482 	u32 tsf_time;
483 	u32 beacon_int;
484 
485 	if (vif)
486 		avp = (struct ath_vif *) vif->drv_priv;
487 
488 	spin_lock_bh(&sc->chan_lock);
489 
490 	ath_dbg(common, CHAN_CTX, "cur_chan: %d MHz, event: %s, state: %s\n",
491 		sc->cur_chan->chandef.center_freq1,
492 		chanctx_event_string(ev),
493 		chanctx_state_string(sc->sched.state));
494 
495 	switch (ev) {
496 	case ATH_CHANCTX_EVENT_BEACON_PREPARE:
497 		if (avp->offchannel_duration)
498 			avp->offchannel_duration = 0;
499 
500 		if (avp->oneshot_noa) {
501 			avp->noa_duration = 0;
502 			avp->oneshot_noa = false;
503 
504 			ath_dbg(common, CHAN_CTX,
505 				"Clearing oneshot NoA\n");
506 		}
507 
508 		if (avp->chanctx != sc->cur_chan) {
509 			ath_dbg(common, CHAN_CTX,
510 				"Contexts differ, not preparing beacon\n");
511 			break;
512 		}
513 
514 		if (sc->sched.offchannel_pending && !sc->sched.wait_switch) {
515 			sc->sched.offchannel_pending = false;
516 			sc->next_chan = &sc->offchannel.chan;
517 			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
518 			ath_dbg(common, CHAN_CTX,
519 				"Setting offchannel_pending to false\n");
520 		}
521 
522 		ctx = ath_chanctx_get_next(sc, sc->cur_chan);
523 		if (ctx->active && sc->sched.state == ATH_CHANCTX_STATE_IDLE) {
524 			sc->next_chan = ctx;
525 			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
526 			ath_dbg(common, CHAN_CTX,
527 				"Set next context, move chanctx state to WAIT_FOR_BEACON\n");
528 		}
529 
530 		/* if the timer missed its window, use the next interval */
531 		if (sc->sched.state == ATH_CHANCTX_STATE_WAIT_FOR_TIMER) {
532 			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
533 			ath_dbg(common, CHAN_CTX,
534 				"Move chanctx state from WAIT_FOR_TIMER to WAIT_FOR_BEACON\n");
535 		}
536 
537 		if (sc->sched.mgd_prepare_tx)
538 			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
539 
540 		/*
541 		 * When a context becomes inactive, for example,
542 		 * disassociation of a station context, the NoA
543 		 * attribute needs to be removed from subsequent
544 		 * beacons.
545 		 */
546 		if (!ctx->active && avp->noa_duration &&
547 		    sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON) {
548 			avp->noa_duration = 0;
549 			avp->periodic_noa = false;
550 
551 			ath_dbg(common, CHAN_CTX,
552 				"Clearing NoA schedule\n");
553 		}
554 
555 		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON)
556 			break;
557 
558 		ath_dbg(common, CHAN_CTX, "Preparing beacon for vif: %pM\n", vif->addr);
559 
560 		sc->sched.beacon_pending = true;
561 		sc->sched.next_tbtt = REG_READ(ah, AR_NEXT_TBTT_TIMER);
562 
563 		cur_conf = &sc->cur_chan->beacon;
564 		beacon_int = TU_TO_USEC(cur_conf->beacon_interval);
565 
566 		/* defer channel switch by a quarter beacon interval */
567 		tsf_time = sc->sched.next_tbtt + beacon_int / 4;
568 		sc->sched.switch_start_time = tsf_time;
569 		sc->cur_chan->last_beacon = sc->sched.next_tbtt;
570 
571 		/*
572 		 * If an offchannel switch is scheduled to happen after
573 		 * a beacon transmission, update the NoA with one-shot
574 		 * values and increment the index.
575 		 */
576 		if (sc->next_chan == &sc->offchannel.chan) {
577 			ath_chanctx_offchannel_noa(sc, ctx, avp, tsf_time);
578 			break;
579 		}
580 
581 		ath_chanctx_handle_bmiss(sc, ctx, avp);
582 
583 		/*
584 		 * If a mgd_prepare_tx() has been called by mac80211,
585 		 * a one-shot NoA needs to be sent. This can happen
586 		 * with one or more active channel contexts - in both
587 		 * cases, a new NoA schedule has to be advertised.
588 		 */
589 		if (sc->sched.mgd_prepare_tx) {
590 			ath_chanctx_set_oneshot_noa(sc, avp, tsf_time,
591 						    jiffies_to_usecs(HZ / 5));
592 			break;
593 		}
594 
595 		/* Prevent wrap-around issues */
596 		if (avp->noa_duration && tsf_time - avp->noa_start > BIT(30))
597 			avp->noa_duration = 0;
598 
599 		/*
600 		 * If multiple contexts are active, start periodic
601 		 * NoA and increment the index for the first
602 		 * announcement.
603 		 */
604 		if (ctx->active &&
605 		    (!avp->noa_duration || sc->sched.force_noa_update))
606 			ath_chanctx_set_periodic_noa(sc, avp, cur_conf,
607 						     tsf_time, beacon_int);
608 
609 		if (ctx->active && sc->sched.force_noa_update)
610 			sc->sched.force_noa_update = false;
611 
612 		break;
613 	case ATH_CHANCTX_EVENT_BEACON_SENT:
614 		if (!sc->sched.beacon_pending) {
615 			ath_dbg(common, CHAN_CTX,
616 				"No pending beacon\n");
617 			break;
618 		}
619 
620 		sc->sched.beacon_pending = false;
621 
622 		if (sc->sched.mgd_prepare_tx) {
623 			sc->sched.mgd_prepare_tx = false;
624 			complete(&sc->go_beacon);
625 			ath_dbg(common, CHAN_CTX,
626 				"Beacon sent, complete go_beacon\n");
627 			break;
628 		}
629 
630 		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON)
631 			break;
632 
633 		ath_dbg(common, CHAN_CTX,
634 			"Move chanctx state to WAIT_FOR_TIMER\n");
635 
636 		sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_TIMER;
637 		ath_chanctx_setup_timer(sc, sc->sched.switch_start_time);
638 		break;
639 	case ATH_CHANCTX_EVENT_TSF_TIMER:
640 		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_TIMER)
641 			break;
642 
643 		if (!sc->cur_chan->switch_after_beacon &&
644 		    sc->sched.beacon_pending)
645 			sc->sched.beacon_miss++;
646 
647 		ath_dbg(common, CHAN_CTX,
648 			"Move chanctx state to SWITCH\n");
649 
650 		sc->sched.state = ATH_CHANCTX_STATE_SWITCH;
651 		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
652 		break;
653 	case ATH_CHANCTX_EVENT_BEACON_RECEIVED:
654 		if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) ||
655 		    sc->cur_chan == &sc->offchannel.chan)
656 			break;
657 
658 		sc->sched.beacon_pending = false;
659 		sc->sched.beacon_miss = 0;
660 
661 		if (sc->sched.state == ATH_CHANCTX_STATE_FORCE_ACTIVE ||
662 		    !sc->sched.beacon_adjust ||
663 		    !sc->cur_chan->tsf_val)
664 			break;
665 
666 		ath_chanctx_adjust_tbtt_delta(sc);
667 
668 		/* TSF time might have been updated by the incoming beacon,
669 		 * need update the channel switch timer to reflect the change.
670 		 */
671 		tsf_time = sc->sched.switch_start_time;
672 		tsf_time -= (u32) sc->cur_chan->tsf_val +
673 			ath9k_hw_get_tsf_offset(&sc->cur_chan->tsf_ts, NULL);
674 		tsf_time += ath9k_hw_gettsf32(ah);
675 
676 		sc->sched.beacon_adjust = false;
677 		ath_chanctx_setup_timer(sc, tsf_time);
678 		break;
679 	case ATH_CHANCTX_EVENT_AUTHORIZED:
680 		if (sc->sched.state != ATH_CHANCTX_STATE_FORCE_ACTIVE ||
681 		    avp->chanctx != sc->cur_chan)
682 			break;
683 
684 		ath_dbg(common, CHAN_CTX,
685 			"Move chanctx state from FORCE_ACTIVE to IDLE\n");
686 
687 		sc->sched.state = ATH_CHANCTX_STATE_IDLE;
688 		/* fall through */
689 	case ATH_CHANCTX_EVENT_SWITCH:
690 		if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) ||
691 		    sc->sched.state == ATH_CHANCTX_STATE_FORCE_ACTIVE ||
692 		    sc->cur_chan->switch_after_beacon ||
693 		    sc->cur_chan == &sc->offchannel.chan)
694 			break;
695 
696 		/* If this is a station chanctx, stay active for a half
697 		 * beacon period (minus channel switch time)
698 		 */
699 		sc->next_chan = ath_chanctx_get_next(sc, sc->cur_chan);
700 		cur_conf = &sc->cur_chan->beacon;
701 
702 		ath_dbg(common, CHAN_CTX,
703 			"Move chanctx state to WAIT_FOR_TIMER (event SWITCH)\n");
704 
705 		sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_TIMER;
706 		sc->sched.wait_switch = false;
707 
708 		tsf_time = TU_TO_USEC(cur_conf->beacon_interval) / 2;
709 
710 		if (sc->sched.extend_absence) {
711 			sc->sched.beacon_miss = 0;
712 			tsf_time *= 3;
713 		}
714 
715 		tsf_time -= sc->sched.channel_switch_time;
716 		tsf_time += ath9k_hw_gettsf32(sc->sc_ah);
717 		sc->sched.switch_start_time = tsf_time;
718 
719 		ath_chanctx_setup_timer(sc, tsf_time);
720 		sc->sched.beacon_pending = true;
721 		sc->sched.beacon_adjust = true;
722 		break;
723 	case ATH_CHANCTX_EVENT_ENABLE_MULTICHANNEL:
724 		if (sc->cur_chan == &sc->offchannel.chan ||
725 		    sc->cur_chan->switch_after_beacon)
726 			break;
727 
728 		sc->next_chan = ath_chanctx_get_next(sc, sc->cur_chan);
729 		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
730 		break;
731 	case ATH_CHANCTX_EVENT_UNASSIGN:
732 		if (sc->cur_chan->assigned) {
733 			if (sc->next_chan && !sc->next_chan->assigned &&
734 			    sc->next_chan != &sc->offchannel.chan)
735 				sc->sched.state = ATH_CHANCTX_STATE_IDLE;
736 			break;
737 		}
738 
739 		ctx = ath_chanctx_get_next(sc, sc->cur_chan);
740 		sc->sched.state = ATH_CHANCTX_STATE_IDLE;
741 		if (!ctx->assigned)
742 			break;
743 
744 		sc->next_chan = ctx;
745 		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
746 		break;
747 	case ATH_CHANCTX_EVENT_ASSIGN:
748 		break;
749 	case ATH_CHANCTX_EVENT_CHANGE:
750 		break;
751 	}
752 
753 	spin_unlock_bh(&sc->chan_lock);
754 }
755 
756 void ath_chanctx_beacon_sent_ev(struct ath_softc *sc,
757 				enum ath_chanctx_event ev)
758 {
759 	if (sc->sched.beacon_pending)
760 		ath_chanctx_event(sc, NULL, ev);
761 }
762 
763 void ath_chanctx_beacon_recv_ev(struct ath_softc *sc,
764 				enum ath_chanctx_event ev)
765 {
766 	ath_chanctx_event(sc, NULL, ev);
767 }
768 
769 static int ath_scan_channel_duration(struct ath_softc *sc,
770 				     struct ieee80211_channel *chan)
771 {
772 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
773 
774 	if (!req->n_ssids || (chan->flags & IEEE80211_CHAN_NO_IR))
775 		return (HZ / 9); /* ~110 ms */
776 
777 	return (HZ / 16); /* ~60 ms */
778 }
779 
780 static void ath_chanctx_switch(struct ath_softc *sc, struct ath_chanctx *ctx,
781 			       struct cfg80211_chan_def *chandef)
782 {
783 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
784 
785 	spin_lock_bh(&sc->chan_lock);
786 
787 	if (test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) &&
788 	    (sc->cur_chan != ctx) && (ctx == &sc->offchannel.chan)) {
789 		if (chandef)
790 			ctx->chandef = *chandef;
791 
792 		sc->sched.offchannel_pending = true;
793 		sc->sched.wait_switch = true;
794 		sc->sched.offchannel_duration =
795 			jiffies_to_usecs(sc->offchannel.duration) +
796 			sc->sched.channel_switch_time;
797 
798 		spin_unlock_bh(&sc->chan_lock);
799 		ath_dbg(common, CHAN_CTX,
800 			"Set offchannel_pending to true\n");
801 		return;
802 	}
803 
804 	sc->next_chan = ctx;
805 	if (chandef) {
806 		ctx->chandef = *chandef;
807 		ath_dbg(common, CHAN_CTX,
808 			"Assigned next_chan to %d MHz\n", chandef->center_freq1);
809 	}
810 
811 	if (sc->next_chan == &sc->offchannel.chan) {
812 		sc->sched.offchannel_duration =
813 			jiffies_to_usecs(sc->offchannel.duration) +
814 			sc->sched.channel_switch_time;
815 
816 		if (chandef) {
817 			ath_dbg(common, CHAN_CTX,
818 				"Offchannel duration for chan %d MHz : %u\n",
819 				chandef->center_freq1,
820 				sc->sched.offchannel_duration);
821 		}
822 	}
823 	spin_unlock_bh(&sc->chan_lock);
824 	ieee80211_queue_work(sc->hw, &sc->chanctx_work);
825 }
826 
827 static void ath_chanctx_offchan_switch(struct ath_softc *sc,
828 				       struct ieee80211_channel *chan)
829 {
830 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
831 	struct cfg80211_chan_def chandef;
832 
833 	cfg80211_chandef_create(&chandef, chan, NL80211_CHAN_NO_HT);
834 	ath_dbg(common, CHAN_CTX,
835 		"Channel definition created: %d MHz\n", chandef.center_freq1);
836 
837 	ath_chanctx_switch(sc, &sc->offchannel.chan, &chandef);
838 }
839 
840 static struct ath_chanctx *ath_chanctx_get_oper_chan(struct ath_softc *sc,
841 						     bool active)
842 {
843 	struct ath_chanctx *ctx;
844 
845 	ath_for_each_chanctx(sc, ctx) {
846 		if (!ctx->assigned || list_empty(&ctx->vifs))
847 			continue;
848 		if (active && !ctx->active)
849 			continue;
850 
851 		if (ctx->switch_after_beacon)
852 			return ctx;
853 	}
854 
855 	return &sc->chanctx[0];
856 }
857 
858 static void
859 ath_scan_next_channel(struct ath_softc *sc)
860 {
861 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
862 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
863 	struct ieee80211_channel *chan;
864 
865 	if (sc->offchannel.scan_idx >= req->n_channels) {
866 		ath_dbg(common, CHAN_CTX,
867 			"Moving offchannel state to ATH_OFFCHANNEL_IDLE, "
868 			"scan_idx: %d, n_channels: %d\n",
869 			sc->offchannel.scan_idx,
870 			req->n_channels);
871 
872 		sc->offchannel.state = ATH_OFFCHANNEL_IDLE;
873 		ath_chanctx_switch(sc, ath_chanctx_get_oper_chan(sc, false),
874 				   NULL);
875 		return;
876 	}
877 
878 	ath_dbg(common, CHAN_CTX,
879 		"Moving offchannel state to ATH_OFFCHANNEL_PROBE_SEND, scan_idx: %d\n",
880 		sc->offchannel.scan_idx);
881 
882 	chan = req->channels[sc->offchannel.scan_idx++];
883 	sc->offchannel.duration = ath_scan_channel_duration(sc, chan);
884 	sc->offchannel.state = ATH_OFFCHANNEL_PROBE_SEND;
885 
886 	ath_chanctx_offchan_switch(sc, chan);
887 }
888 
889 void ath_offchannel_next(struct ath_softc *sc)
890 {
891 	struct ieee80211_vif *vif;
892 
893 	if (sc->offchannel.scan_req) {
894 		vif = sc->offchannel.scan_vif;
895 		sc->offchannel.chan.txpower = vif->bss_conf.txpower;
896 		ath_scan_next_channel(sc);
897 	} else if (sc->offchannel.roc_vif) {
898 		vif = sc->offchannel.roc_vif;
899 		sc->offchannel.chan.txpower = vif->bss_conf.txpower;
900 		sc->offchannel.duration =
901 			msecs_to_jiffies(sc->offchannel.roc_duration);
902 		sc->offchannel.state = ATH_OFFCHANNEL_ROC_START;
903 		ath_chanctx_offchan_switch(sc, sc->offchannel.roc_chan);
904 	} else {
905 		spin_lock_bh(&sc->chan_lock);
906 		sc->sched.offchannel_pending = false;
907 		sc->sched.wait_switch = false;
908 		spin_unlock_bh(&sc->chan_lock);
909 
910 		ath_chanctx_switch(sc, ath_chanctx_get_oper_chan(sc, false),
911 				   NULL);
912 		sc->offchannel.state = ATH_OFFCHANNEL_IDLE;
913 		if (sc->ps_idle)
914 			ath_cancel_work(sc);
915 	}
916 }
917 
918 void ath_roc_complete(struct ath_softc *sc, enum ath_roc_complete_reason reason)
919 {
920 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
921 
922 	sc->offchannel.roc_vif = NULL;
923 	sc->offchannel.roc_chan = NULL;
924 
925 	switch (reason) {
926 	case ATH_ROC_COMPLETE_ABORT:
927 		ath_dbg(common, CHAN_CTX, "RoC aborted\n");
928 		ieee80211_remain_on_channel_expired(sc->hw);
929 		break;
930 	case ATH_ROC_COMPLETE_EXPIRE:
931 		ath_dbg(common, CHAN_CTX, "RoC expired\n");
932 		ieee80211_remain_on_channel_expired(sc->hw);
933 		break;
934 	case ATH_ROC_COMPLETE_CANCEL:
935 		ath_dbg(common, CHAN_CTX, "RoC canceled\n");
936 		break;
937 	}
938 
939 	ath_offchannel_next(sc);
940 	ath9k_ps_restore(sc);
941 }
942 
943 void ath_scan_complete(struct ath_softc *sc, bool abort)
944 {
945 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
946 
947 	if (abort)
948 		ath_dbg(common, CHAN_CTX, "HW scan aborted\n");
949 	else
950 		ath_dbg(common, CHAN_CTX, "HW scan complete\n");
951 
952 	sc->offchannel.scan_req = NULL;
953 	sc->offchannel.scan_vif = NULL;
954 	sc->offchannel.state = ATH_OFFCHANNEL_IDLE;
955 	ieee80211_scan_completed(sc->hw, abort);
956 	clear_bit(ATH_OP_SCANNING, &common->op_flags);
957 	spin_lock_bh(&sc->chan_lock);
958 	if (test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags))
959 		sc->sched.force_noa_update = true;
960 	spin_unlock_bh(&sc->chan_lock);
961 	ath_offchannel_next(sc);
962 	ath9k_ps_restore(sc);
963 }
964 
965 static void ath_scan_send_probe(struct ath_softc *sc,
966 				struct cfg80211_ssid *ssid)
967 {
968 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
969 	struct ieee80211_vif *vif = sc->offchannel.scan_vif;
970 	struct ath_tx_control txctl = {};
971 	struct sk_buff *skb;
972 	struct ieee80211_tx_info *info;
973 	int band = sc->offchannel.chan.chandef.chan->band;
974 
975 	skb = ieee80211_probereq_get(sc->hw, vif->addr,
976 			ssid->ssid, ssid->ssid_len, req->ie_len);
977 	if (!skb)
978 		return;
979 
980 	info = IEEE80211_SKB_CB(skb);
981 	if (req->no_cck)
982 		info->flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
983 
984 	if (req->ie_len)
985 		memcpy(skb_put(skb, req->ie_len), req->ie, req->ie_len);
986 
987 	skb_set_queue_mapping(skb, IEEE80211_AC_VO);
988 
989 	if (!ieee80211_tx_prepare_skb(sc->hw, vif, skb, band, NULL))
990 		goto error;
991 
992 	txctl.txq = sc->tx.txq_map[IEEE80211_AC_VO];
993 	txctl.force_channel = true;
994 	if (ath_tx_start(sc->hw, skb, &txctl))
995 		goto error;
996 
997 	return;
998 
999 error:
1000 	ieee80211_free_txskb(sc->hw, skb);
1001 }
1002 
1003 static void ath_scan_channel_start(struct ath_softc *sc)
1004 {
1005 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1006 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
1007 	int i;
1008 
1009 	if (!(sc->cur_chan->chandef.chan->flags & IEEE80211_CHAN_NO_IR) &&
1010 	    req->n_ssids) {
1011 		for (i = 0; i < req->n_ssids; i++)
1012 			ath_scan_send_probe(sc, &req->ssids[i]);
1013 
1014 	}
1015 
1016 	ath_dbg(common, CHAN_CTX,
1017 		"Moving offchannel state to ATH_OFFCHANNEL_PROBE_WAIT\n");
1018 
1019 	sc->offchannel.state = ATH_OFFCHANNEL_PROBE_WAIT;
1020 	mod_timer(&sc->offchannel.timer, jiffies + sc->offchannel.duration);
1021 }
1022 
1023 static void ath_chanctx_timer(unsigned long data)
1024 {
1025 	struct ath_softc *sc = (struct ath_softc *) data;
1026 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1027 
1028 	ath_dbg(common, CHAN_CTX,
1029 		"Channel context timer invoked\n");
1030 
1031 	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_TSF_TIMER);
1032 }
1033 
1034 static void ath_offchannel_timer(unsigned long data)
1035 {
1036 	struct ath_softc *sc = (struct ath_softc *)data;
1037 	struct ath_chanctx *ctx;
1038 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1039 
1040 	ath_dbg(common, CHAN_CTX, "%s: offchannel state: %s\n",
1041 		__func__, offchannel_state_string(sc->offchannel.state));
1042 
1043 	switch (sc->offchannel.state) {
1044 	case ATH_OFFCHANNEL_PROBE_WAIT:
1045 		if (!sc->offchannel.scan_req)
1046 			return;
1047 
1048 		/* get first active channel context */
1049 		ctx = ath_chanctx_get_oper_chan(sc, true);
1050 		if (ctx->active) {
1051 			ath_dbg(common, CHAN_CTX,
1052 				"Switch to oper/active context, "
1053 				"move offchannel state to ATH_OFFCHANNEL_SUSPEND\n");
1054 
1055 			sc->offchannel.state = ATH_OFFCHANNEL_SUSPEND;
1056 			ath_chanctx_switch(sc, ctx, NULL);
1057 			mod_timer(&sc->offchannel.timer, jiffies + HZ / 10);
1058 			break;
1059 		}
1060 		/* fall through */
1061 	case ATH_OFFCHANNEL_SUSPEND:
1062 		if (!sc->offchannel.scan_req)
1063 			return;
1064 
1065 		ath_scan_next_channel(sc);
1066 		break;
1067 	case ATH_OFFCHANNEL_ROC_START:
1068 	case ATH_OFFCHANNEL_ROC_WAIT:
1069 		sc->offchannel.state = ATH_OFFCHANNEL_ROC_DONE;
1070 		ath_roc_complete(sc, ATH_ROC_COMPLETE_EXPIRE);
1071 		break;
1072 	default:
1073 		break;
1074 	}
1075 }
1076 
1077 static bool
1078 ath_chanctx_send_vif_ps_frame(struct ath_softc *sc, struct ath_vif *avp,
1079 			      bool powersave)
1080 {
1081 	struct ieee80211_vif *vif = avp->vif;
1082 	struct ieee80211_sta *sta = NULL;
1083 	struct ieee80211_hdr_3addr *nullfunc;
1084 	struct ath_tx_control txctl;
1085 	struct sk_buff *skb;
1086 	int band = sc->cur_chan->chandef.chan->band;
1087 
1088 	switch (vif->type) {
1089 	case NL80211_IFTYPE_STATION:
1090 		if (!avp->assoc)
1091 			return false;
1092 
1093 		skb = ieee80211_nullfunc_get(sc->hw, vif);
1094 		if (!skb)
1095 			return false;
1096 
1097 		nullfunc = (struct ieee80211_hdr_3addr *) skb->data;
1098 		if (powersave)
1099 			nullfunc->frame_control |=
1100 				cpu_to_le16(IEEE80211_FCTL_PM);
1101 
1102 		skb_set_queue_mapping(skb, IEEE80211_AC_VO);
1103 		if (!ieee80211_tx_prepare_skb(sc->hw, vif, skb, band, &sta)) {
1104 			dev_kfree_skb_any(skb);
1105 			return false;
1106 		}
1107 		break;
1108 	default:
1109 		return false;
1110 	}
1111 
1112 	memset(&txctl, 0, sizeof(txctl));
1113 	txctl.txq = sc->tx.txq_map[IEEE80211_AC_VO];
1114 	txctl.sta = sta;
1115 	txctl.force_channel = true;
1116 	if (ath_tx_start(sc->hw, skb, &txctl)) {
1117 		ieee80211_free_txskb(sc->hw, skb);
1118 		return false;
1119 	}
1120 
1121 	return true;
1122 }
1123 
1124 static bool
1125 ath_chanctx_send_ps_frame(struct ath_softc *sc, bool powersave)
1126 {
1127 	struct ath_vif *avp;
1128 	bool sent = false;
1129 
1130 	rcu_read_lock();
1131 	list_for_each_entry(avp, &sc->cur_chan->vifs, list) {
1132 		if (ath_chanctx_send_vif_ps_frame(sc, avp, powersave))
1133 			sent = true;
1134 	}
1135 	rcu_read_unlock();
1136 
1137 	return sent;
1138 }
1139 
1140 static bool ath_chanctx_defer_switch(struct ath_softc *sc)
1141 {
1142 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1143 
1144 	if (sc->cur_chan == &sc->offchannel.chan)
1145 		return false;
1146 
1147 	switch (sc->sched.state) {
1148 	case ATH_CHANCTX_STATE_SWITCH:
1149 		return false;
1150 	case ATH_CHANCTX_STATE_IDLE:
1151 		if (!sc->cur_chan->switch_after_beacon)
1152 			return false;
1153 
1154 		ath_dbg(common, CHAN_CTX,
1155 			"Defer switch, set chanctx state to WAIT_FOR_BEACON\n");
1156 
1157 		sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
1158 		break;
1159 	default:
1160 		break;
1161 	}
1162 
1163 	return true;
1164 }
1165 
1166 static void ath_offchannel_channel_change(struct ath_softc *sc)
1167 {
1168 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1169 
1170 	ath_dbg(common, CHAN_CTX, "%s: offchannel state: %s\n",
1171 		__func__, offchannel_state_string(sc->offchannel.state));
1172 
1173 	switch (sc->offchannel.state) {
1174 	case ATH_OFFCHANNEL_PROBE_SEND:
1175 		if (!sc->offchannel.scan_req)
1176 			return;
1177 
1178 		if (sc->cur_chan->chandef.chan !=
1179 		    sc->offchannel.chan.chandef.chan)
1180 			return;
1181 
1182 		ath_scan_channel_start(sc);
1183 		break;
1184 	case ATH_OFFCHANNEL_IDLE:
1185 		if (!sc->offchannel.scan_req)
1186 			return;
1187 
1188 		ath_scan_complete(sc, false);
1189 		break;
1190 	case ATH_OFFCHANNEL_ROC_START:
1191 		if (sc->cur_chan != &sc->offchannel.chan)
1192 			break;
1193 
1194 		sc->offchannel.state = ATH_OFFCHANNEL_ROC_WAIT;
1195 		mod_timer(&sc->offchannel.timer,
1196 			  jiffies + sc->offchannel.duration);
1197 		ieee80211_ready_on_channel(sc->hw);
1198 		break;
1199 	case ATH_OFFCHANNEL_ROC_DONE:
1200 		break;
1201 	default:
1202 		break;
1203 	}
1204 }
1205 
1206 void ath_chanctx_set_next(struct ath_softc *sc, bool force)
1207 {
1208 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1209 	struct ath_chanctx *old_ctx;
1210 	struct timespec ts;
1211 	bool measure_time = false;
1212 	bool send_ps = false;
1213 	bool queues_stopped = false;
1214 
1215 	spin_lock_bh(&sc->chan_lock);
1216 	if (!sc->next_chan) {
1217 		spin_unlock_bh(&sc->chan_lock);
1218 		return;
1219 	}
1220 
1221 	if (!force && ath_chanctx_defer_switch(sc)) {
1222 		spin_unlock_bh(&sc->chan_lock);
1223 		return;
1224 	}
1225 
1226 	ath_dbg(common, CHAN_CTX,
1227 		"%s: current: %d MHz, next: %d MHz\n",
1228 		__func__,
1229 		sc->cur_chan->chandef.center_freq1,
1230 		sc->next_chan->chandef.center_freq1);
1231 
1232 	if (sc->cur_chan != sc->next_chan) {
1233 		ath_dbg(common, CHAN_CTX,
1234 			"Stopping current chanctx: %d\n",
1235 			sc->cur_chan->chandef.center_freq1);
1236 		sc->cur_chan->stopped = true;
1237 		spin_unlock_bh(&sc->chan_lock);
1238 
1239 		if (sc->next_chan == &sc->offchannel.chan) {
1240 			getrawmonotonic(&ts);
1241 			measure_time = true;
1242 		}
1243 
1244 		ath9k_chanctx_stop_queues(sc, sc->cur_chan);
1245 		queues_stopped = true;
1246 
1247 		__ath9k_flush(sc->hw, ~0, true, false, false);
1248 
1249 		if (ath_chanctx_send_ps_frame(sc, true))
1250 			__ath9k_flush(sc->hw, BIT(IEEE80211_AC_VO),
1251 				      false, false, false);
1252 
1253 		send_ps = true;
1254 		spin_lock_bh(&sc->chan_lock);
1255 
1256 		if (sc->cur_chan != &sc->offchannel.chan) {
1257 			getrawmonotonic(&sc->cur_chan->tsf_ts);
1258 			sc->cur_chan->tsf_val = ath9k_hw_gettsf64(sc->sc_ah);
1259 		}
1260 	}
1261 	old_ctx = sc->cur_chan;
1262 	sc->cur_chan = sc->next_chan;
1263 	sc->cur_chan->stopped = false;
1264 	sc->next_chan = NULL;
1265 
1266 	if (!sc->sched.offchannel_pending)
1267 		sc->sched.offchannel_duration = 0;
1268 
1269 	if (sc->sched.state != ATH_CHANCTX_STATE_FORCE_ACTIVE)
1270 		sc->sched.state = ATH_CHANCTX_STATE_IDLE;
1271 
1272 	spin_unlock_bh(&sc->chan_lock);
1273 
1274 	if (sc->sc_ah->chip_fullsleep ||
1275 	    memcmp(&sc->cur_chandef, &sc->cur_chan->chandef,
1276 		   sizeof(sc->cur_chandef))) {
1277 		ath_dbg(common, CHAN_CTX,
1278 			"%s: Set channel %d MHz\n",
1279 			__func__, sc->cur_chan->chandef.center_freq1);
1280 		ath_set_channel(sc);
1281 		if (measure_time)
1282 			sc->sched.channel_switch_time =
1283 				ath9k_hw_get_tsf_offset(&ts, NULL);
1284 		/*
1285 		 * A reset will ensure that all queues are woken up,
1286 		 * so there is no need to awaken them again.
1287 		 */
1288 		goto out;
1289 	}
1290 
1291 	if (queues_stopped)
1292 		ath9k_chanctx_wake_queues(sc, old_ctx);
1293 out:
1294 	if (send_ps)
1295 		ath_chanctx_send_ps_frame(sc, false);
1296 
1297 	ath_offchannel_channel_change(sc);
1298 	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_SWITCH);
1299 }
1300 
1301 static void ath_chanctx_work(struct work_struct *work)
1302 {
1303 	struct ath_softc *sc = container_of(work, struct ath_softc,
1304 					    chanctx_work);
1305 	mutex_lock(&sc->mutex);
1306 	ath_chanctx_set_next(sc, false);
1307 	mutex_unlock(&sc->mutex);
1308 }
1309 
1310 void ath9k_offchannel_init(struct ath_softc *sc)
1311 {
1312 	struct ath_chanctx *ctx;
1313 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1314 	struct ieee80211_supported_band *sband;
1315 	struct ieee80211_channel *chan;
1316 	int i;
1317 
1318 	sband = &common->sbands[IEEE80211_BAND_2GHZ];
1319 	if (!sband->n_channels)
1320 		sband = &common->sbands[IEEE80211_BAND_5GHZ];
1321 
1322 	chan = &sband->channels[0];
1323 
1324 	ctx = &sc->offchannel.chan;
1325 	INIT_LIST_HEAD(&ctx->vifs);
1326 	ctx->txpower = ATH_TXPOWER_MAX;
1327 	cfg80211_chandef_create(&ctx->chandef, chan, NL80211_CHAN_HT20);
1328 
1329 	for (i = 0; i < ARRAY_SIZE(ctx->acq); i++)
1330 		INIT_LIST_HEAD(&ctx->acq[i]);
1331 
1332 	sc->offchannel.chan.offchannel = true;
1333 }
1334 
1335 void ath9k_init_channel_context(struct ath_softc *sc)
1336 {
1337 	INIT_WORK(&sc->chanctx_work, ath_chanctx_work);
1338 
1339 	setup_timer(&sc->offchannel.timer, ath_offchannel_timer,
1340 		    (unsigned long)sc);
1341 	setup_timer(&sc->sched.timer, ath_chanctx_timer,
1342 		    (unsigned long)sc);
1343 
1344 	init_completion(&sc->go_beacon);
1345 }
1346 
1347 void ath9k_deinit_channel_context(struct ath_softc *sc)
1348 {
1349 	cancel_work_sync(&sc->chanctx_work);
1350 }
1351 
1352 bool ath9k_is_chanctx_enabled(void)
1353 {
1354 	return (ath9k_use_chanctx == 1);
1355 }
1356 
1357 /********************/
1358 /* Queue management */
1359 /********************/
1360 
1361 void ath9k_chanctx_stop_queues(struct ath_softc *sc, struct ath_chanctx *ctx)
1362 {
1363 	struct ath_hw *ah = sc->sc_ah;
1364 	int i;
1365 
1366 	if (ctx == &sc->offchannel.chan) {
1367 		ieee80211_stop_queue(sc->hw,
1368 				     sc->hw->offchannel_tx_hw_queue);
1369 	} else {
1370 		for (i = 0; i < IEEE80211_NUM_ACS; i++)
1371 			ieee80211_stop_queue(sc->hw,
1372 					     ctx->hw_queue_base + i);
1373 	}
1374 
1375 	if (ah->opmode == NL80211_IFTYPE_AP)
1376 		ieee80211_stop_queue(sc->hw, sc->hw->queues - 2);
1377 }
1378 
1379 
1380 void ath9k_chanctx_wake_queues(struct ath_softc *sc, struct ath_chanctx *ctx)
1381 {
1382 	struct ath_hw *ah = sc->sc_ah;
1383 	int i;
1384 
1385 	if (ctx == &sc->offchannel.chan) {
1386 		ieee80211_wake_queue(sc->hw,
1387 				     sc->hw->offchannel_tx_hw_queue);
1388 	} else {
1389 		for (i = 0; i < IEEE80211_NUM_ACS; i++)
1390 			ieee80211_wake_queue(sc->hw,
1391 					     ctx->hw_queue_base + i);
1392 	}
1393 
1394 	if (ah->opmode == NL80211_IFTYPE_AP)
1395 		ieee80211_wake_queue(sc->hw, sc->hw->queues - 2);
1396 }
1397 
1398 /*****************/
1399 /* P2P Powersave */
1400 /*****************/
1401 
1402 static void ath9k_update_p2p_ps_timer(struct ath_softc *sc, struct ath_vif *avp)
1403 {
1404 	struct ath_hw *ah = sc->sc_ah;
1405 	s32 tsf, target_tsf;
1406 
1407 	if (!avp || !avp->noa.has_next_tsf)
1408 		return;
1409 
1410 	ath9k_hw_gen_timer_stop(ah, sc->p2p_ps_timer);
1411 
1412 	tsf = ath9k_hw_gettsf32(sc->sc_ah);
1413 
1414 	target_tsf = avp->noa.next_tsf;
1415 	if (!avp->noa.absent)
1416 		target_tsf -= ATH_P2P_PS_STOP_TIME;
1417 
1418 	if (target_tsf - tsf < ATH_P2P_PS_STOP_TIME)
1419 		target_tsf = tsf + ATH_P2P_PS_STOP_TIME;
1420 
1421 	ath9k_hw_gen_timer_start(ah, sc->p2p_ps_timer, (u32) target_tsf, 1000000);
1422 }
1423 
1424 static void ath9k_update_p2p_ps(struct ath_softc *sc, struct ieee80211_vif *vif)
1425 {
1426 	struct ath_vif *avp = (void *)vif->drv_priv;
1427 	u32 tsf;
1428 
1429 	if (!sc->p2p_ps_timer)
1430 		return;
1431 
1432 	if (vif->type != NL80211_IFTYPE_STATION || !vif->p2p)
1433 		return;
1434 
1435 	sc->p2p_ps_vif = avp;
1436 	tsf = ath9k_hw_gettsf32(sc->sc_ah);
1437 	ieee80211_parse_p2p_noa(&vif->bss_conf.p2p_noa_attr, &avp->noa, tsf);
1438 	ath9k_update_p2p_ps_timer(sc, avp);
1439 }
1440 
1441 static u8 ath9k_get_ctwin(struct ath_softc *sc, struct ath_vif *avp)
1442 {
1443 	struct ath_beacon_config *cur_conf = &sc->cur_chan->beacon;
1444 	u8 switch_time, ctwin;
1445 
1446 	/*
1447 	 * Channel switch in multi-channel mode is deferred
1448 	 * by a quarter beacon interval when handling
1449 	 * ATH_CHANCTX_EVENT_BEACON_PREPARE, so the P2P-GO
1450 	 * interface is guaranteed to be discoverable
1451 	 * for that duration after a TBTT.
1452 	 */
1453 	switch_time = cur_conf->beacon_interval / 4;
1454 
1455 	ctwin = avp->vif->bss_conf.p2p_noa_attr.oppps_ctwindow;
1456 	if (ctwin && (ctwin < switch_time))
1457 		return ctwin;
1458 
1459 	if (switch_time < P2P_DEFAULT_CTWIN)
1460 		return 0;
1461 
1462 	return P2P_DEFAULT_CTWIN;
1463 }
1464 
1465 void ath9k_beacon_add_noa(struct ath_softc *sc, struct ath_vif *avp,
1466 			  struct sk_buff *skb)
1467 {
1468 	static const u8 noa_ie_hdr[] = {
1469 		WLAN_EID_VENDOR_SPECIFIC,	/* type */
1470 		0,				/* length */
1471 		0x50, 0x6f, 0x9a,		/* WFA OUI */
1472 		0x09,				/* P2P subtype */
1473 		0x0c,				/* Notice of Absence */
1474 		0x00,				/* LSB of little-endian len */
1475 		0x00,				/* MSB of little-endian len */
1476 	};
1477 
1478 	struct ieee80211_p2p_noa_attr *noa;
1479 	int noa_len, noa_desc, i = 0;
1480 	u8 *hdr;
1481 
1482 	if (!avp->offchannel_duration && !avp->noa_duration)
1483 		return;
1484 
1485 	noa_desc = !!avp->offchannel_duration + !!avp->noa_duration;
1486 	noa_len = 2 + sizeof(struct ieee80211_p2p_noa_desc) * noa_desc;
1487 
1488 	hdr = skb_put(skb, sizeof(noa_ie_hdr));
1489 	memcpy(hdr, noa_ie_hdr, sizeof(noa_ie_hdr));
1490 	hdr[1] = sizeof(noa_ie_hdr) + noa_len - 2;
1491 	hdr[7] = noa_len;
1492 
1493 	noa = (void *) skb_put(skb, noa_len);
1494 	memset(noa, 0, noa_len);
1495 
1496 	noa->index = avp->noa_index;
1497 	noa->oppps_ctwindow = ath9k_get_ctwin(sc, avp);
1498 
1499 	if (avp->noa_duration) {
1500 		if (avp->periodic_noa) {
1501 			u32 interval = TU_TO_USEC(sc->cur_chan->beacon.beacon_interval);
1502 			noa->desc[i].count = 255;
1503 			noa->desc[i].interval = cpu_to_le32(interval);
1504 		} else {
1505 			noa->desc[i].count = 1;
1506 		}
1507 
1508 		noa->desc[i].start_time = cpu_to_le32(avp->noa_start);
1509 		noa->desc[i].duration = cpu_to_le32(avp->noa_duration);
1510 		i++;
1511 	}
1512 
1513 	if (avp->offchannel_duration) {
1514 		noa->desc[i].count = 1;
1515 		noa->desc[i].start_time = cpu_to_le32(avp->offchannel_start);
1516 		noa->desc[i].duration = cpu_to_le32(avp->offchannel_duration);
1517 	}
1518 }
1519 
1520 void ath9k_p2p_ps_timer(void *priv)
1521 {
1522 	struct ath_softc *sc = priv;
1523 	struct ath_vif *avp = sc->p2p_ps_vif;
1524 	struct ieee80211_vif *vif;
1525 	struct ieee80211_sta *sta;
1526 	struct ath_node *an;
1527 	u32 tsf;
1528 
1529 	del_timer_sync(&sc->sched.timer);
1530 	ath9k_hw_gen_timer_stop(sc->sc_ah, sc->p2p_ps_timer);
1531 	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_TSF_TIMER);
1532 
1533 	if (!avp || avp->chanctx != sc->cur_chan)
1534 		return;
1535 
1536 	tsf = ath9k_hw_gettsf32(sc->sc_ah);
1537 	if (!avp->noa.absent)
1538 		tsf += ATH_P2P_PS_STOP_TIME;
1539 
1540 	if (!avp->noa.has_next_tsf ||
1541 	    avp->noa.next_tsf - tsf > BIT(31))
1542 		ieee80211_update_p2p_noa(&avp->noa, tsf);
1543 
1544 	ath9k_update_p2p_ps_timer(sc, avp);
1545 
1546 	rcu_read_lock();
1547 
1548 	vif = avp->vif;
1549 	sta = ieee80211_find_sta(vif, avp->bssid);
1550 	if (!sta)
1551 		goto out;
1552 
1553 	an = (void *) sta->drv_priv;
1554 	if (an->sleeping == !!avp->noa.absent)
1555 		goto out;
1556 
1557 	an->sleeping = avp->noa.absent;
1558 	if (an->sleeping)
1559 		ath_tx_aggr_sleep(sta, sc, an);
1560 	else
1561 		ath_tx_aggr_wakeup(sc, an);
1562 
1563 out:
1564 	rcu_read_unlock();
1565 }
1566 
1567 void ath9k_p2p_bss_info_changed(struct ath_softc *sc,
1568 				struct ieee80211_vif *vif)
1569 {
1570 	unsigned long flags;
1571 
1572 	spin_lock_bh(&sc->sc_pcu_lock);
1573 	spin_lock_irqsave(&sc->sc_pm_lock, flags);
1574 	if (!(sc->ps_flags & PS_BEACON_SYNC))
1575 		ath9k_update_p2p_ps(sc, vif);
1576 	spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
1577 	spin_unlock_bh(&sc->sc_pcu_lock);
1578 }
1579 
1580 void ath9k_p2p_beacon_sync(struct ath_softc *sc)
1581 {
1582 	if (sc->p2p_ps_vif)
1583 		ath9k_update_p2p_ps(sc, sc->p2p_ps_vif->vif);
1584 }
1585 
1586 void ath9k_p2p_remove_vif(struct ath_softc *sc,
1587 			  struct ieee80211_vif *vif)
1588 {
1589 	struct ath_vif *avp = (void *)vif->drv_priv;
1590 
1591 	spin_lock_bh(&sc->sc_pcu_lock);
1592 	if (avp == sc->p2p_ps_vif) {
1593 		sc->p2p_ps_vif = NULL;
1594 		ath9k_update_p2p_ps_timer(sc, NULL);
1595 	}
1596 	spin_unlock_bh(&sc->sc_pcu_lock);
1597 }
1598 
1599 int ath9k_init_p2p(struct ath_softc *sc)
1600 {
1601 	sc->p2p_ps_timer = ath_gen_timer_alloc(sc->sc_ah, ath9k_p2p_ps_timer,
1602 					       NULL, sc, AR_FIRST_NDP_TIMER);
1603 	if (!sc->p2p_ps_timer)
1604 		return -ENOMEM;
1605 
1606 	return 0;
1607 }
1608 
1609 void ath9k_deinit_p2p(struct ath_softc *sc)
1610 {
1611 	if (sc->p2p_ps_timer)
1612 		ath_gen_timer_free(sc->sc_ah, sc->p2p_ps_timer);
1613 }
1614 
1615 #endif /* CONFIG_ATH9K_CHANNEL_CONTEXT */
1616