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[NL80211_BAND_2GHZ];
111 	if (!sband->n_channels)
112 		sband = &common->sbands[NL80211_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 static u32 chanctx_event_delta(struct ath_softc *sc)
230 {
231 	u64 ms;
232 	struct timespec ts, *old;
233 
234 	getrawmonotonic(&ts);
235 	old = &sc->last_event_time;
236 	ms = ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
237 	ms -= old->tv_sec * 1000 + old->tv_nsec / 1000000;
238 	sc->last_event_time = ts;
239 
240 	return (u32)ms;
241 }
242 
243 void ath_chanctx_check_active(struct ath_softc *sc, struct ath_chanctx *ctx)
244 {
245 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
246 	struct ath_chanctx *ictx;
247 	struct ath_vif *avp;
248 	bool active = false;
249 	u8 n_active = 0;
250 
251 	if (!ctx)
252 		return;
253 
254 	if (ctx == &sc->offchannel.chan) {
255 		spin_lock_bh(&sc->chan_lock);
256 
257 		if (likely(sc->sched.channel_switch_time))
258 			ctx->flush_timeout =
259 				usecs_to_jiffies(sc->sched.channel_switch_time);
260 		else
261 			ctx->flush_timeout =
262 				msecs_to_jiffies(10);
263 
264 		spin_unlock_bh(&sc->chan_lock);
265 
266 		/*
267 		 * There is no need to iterate over the
268 		 * active/assigned channel contexts if
269 		 * the current context is offchannel.
270 		 */
271 		return;
272 	}
273 
274 	ictx = ctx;
275 
276 	list_for_each_entry(avp, &ctx->vifs, list) {
277 		struct ieee80211_vif *vif = avp->vif;
278 
279 		switch (vif->type) {
280 		case NL80211_IFTYPE_P2P_CLIENT:
281 		case NL80211_IFTYPE_STATION:
282 			if (avp->assoc)
283 				active = true;
284 			break;
285 		default:
286 			active = true;
287 			break;
288 		}
289 	}
290 	ctx->active = active;
291 
292 	ath_for_each_chanctx(sc, ctx) {
293 		if (!ctx->assigned || list_empty(&ctx->vifs))
294 			continue;
295 		n_active++;
296 	}
297 
298 	spin_lock_bh(&sc->chan_lock);
299 
300 	if (n_active <= 1) {
301 		ictx->flush_timeout = HZ / 5;
302 		clear_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags);
303 		spin_unlock_bh(&sc->chan_lock);
304 		return;
305 	}
306 
307 	ictx->flush_timeout = usecs_to_jiffies(sc->sched.channel_switch_time);
308 
309 	if (test_and_set_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags)) {
310 		spin_unlock_bh(&sc->chan_lock);
311 		return;
312 	}
313 
314 	spin_unlock_bh(&sc->chan_lock);
315 
316 	if (ath9k_is_chanctx_enabled()) {
317 		ath_chanctx_event(sc, NULL,
318 				  ATH_CHANCTX_EVENT_ENABLE_MULTICHANNEL);
319 	}
320 }
321 
322 static struct ath_chanctx *
323 ath_chanctx_get_next(struct ath_softc *sc, struct ath_chanctx *ctx)
324 {
325 	int idx = ctx - &sc->chanctx[0];
326 
327 	return &sc->chanctx[!idx];
328 }
329 
330 static void ath_chanctx_adjust_tbtt_delta(struct ath_softc *sc)
331 {
332 	struct ath_chanctx *prev, *cur;
333 	struct timespec ts;
334 	u32 cur_tsf, prev_tsf, beacon_int;
335 	s32 offset;
336 
337 	beacon_int = TU_TO_USEC(sc->cur_chan->beacon.beacon_interval);
338 
339 	cur = sc->cur_chan;
340 	prev = ath_chanctx_get_next(sc, cur);
341 
342 	if (!prev->switch_after_beacon)
343 		return;
344 
345 	getrawmonotonic(&ts);
346 	cur_tsf = (u32) cur->tsf_val +
347 		  ath9k_hw_get_tsf_offset(&cur->tsf_ts, &ts);
348 
349 	prev_tsf = prev->last_beacon - (u32) prev->tsf_val + cur_tsf;
350 	prev_tsf -= ath9k_hw_get_tsf_offset(&prev->tsf_ts, &ts);
351 
352 	/* Adjust the TSF time of the AP chanctx to keep its beacons
353 	 * at half beacon interval offset relative to the STA chanctx.
354 	 */
355 	offset = cur_tsf - prev_tsf;
356 
357 	/* Ignore stale data or spurious timestamps */
358 	if (offset < 0 || offset > 3 * beacon_int)
359 		return;
360 
361 	offset = beacon_int / 2 - (offset % beacon_int);
362 	prev->tsf_val += offset;
363 }
364 
365 /* Configure the TSF based hardware timer for a channel switch.
366  * Also set up backup software timer, in case the gen timer fails.
367  * This could be caused by a hardware reset.
368  */
369 static void ath_chanctx_setup_timer(struct ath_softc *sc, u32 tsf_time)
370 {
371 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
372 	struct ath_hw *ah = sc->sc_ah;
373 	unsigned long timeout;
374 
375 	ath9k_hw_gen_timer_start(ah, sc->p2p_ps_timer, tsf_time, 1000000);
376 	tsf_time -= ath9k_hw_gettsf32(ah);
377 	timeout = msecs_to_jiffies(tsf_time / 1000) + 1;
378 	mod_timer(&sc->sched.timer, jiffies + timeout);
379 
380 	ath_dbg(common, CHAN_CTX,
381 		"Setup chanctx timer with timeout: %d (%d) ms\n",
382 		tsf_time / 1000, jiffies_to_msecs(timeout));
383 }
384 
385 static void ath_chanctx_handle_bmiss(struct ath_softc *sc,
386 				     struct ath_chanctx *ctx,
387 				     struct ath_vif *avp)
388 {
389 	/*
390 	 * Clear the extend_absence flag if it had been
391 	 * set during the previous beacon transmission,
392 	 * since we need to revert to the normal NoA
393 	 * schedule.
394 	 */
395 	if (ctx->active && sc->sched.extend_absence) {
396 		avp->noa_duration = 0;
397 		sc->sched.extend_absence = false;
398 	}
399 
400 	/* If at least two consecutive beacons were missed on the STA
401 	 * chanctx, stay on the STA channel for one extra beacon period,
402 	 * to resync the timer properly.
403 	 */
404 	if (ctx->active && sc->sched.beacon_miss >= 2) {
405 		avp->noa_duration = 0;
406 		sc->sched.extend_absence = true;
407 	}
408 }
409 
410 static void ath_chanctx_offchannel_noa(struct ath_softc *sc,
411 				       struct ath_chanctx *ctx,
412 				       struct ath_vif *avp,
413 				       u32 tsf_time)
414 {
415 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
416 
417 	avp->noa_index++;
418 	avp->offchannel_start = tsf_time;
419 	avp->offchannel_duration = sc->sched.offchannel_duration;
420 
421 	ath_dbg(common, CHAN_CTX,
422 		"offchannel noa_duration: %d, noa_start: %u, noa_index: %d\n",
423 		avp->offchannel_duration,
424 		avp->offchannel_start,
425 		avp->noa_index);
426 
427 	/*
428 	 * When multiple contexts are active, the NoA
429 	 * has to be recalculated and advertised after
430 	 * an offchannel operation.
431 	 */
432 	if (ctx->active && avp->noa_duration)
433 		avp->noa_duration = 0;
434 }
435 
436 static void ath_chanctx_set_periodic_noa(struct ath_softc *sc,
437 					 struct ath_vif *avp,
438 					 struct ath_beacon_config *cur_conf,
439 					 u32 tsf_time,
440 					 u32 beacon_int)
441 {
442 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
443 
444 	avp->noa_index++;
445 	avp->noa_start = tsf_time;
446 
447 	if (sc->sched.extend_absence)
448 		avp->noa_duration = (3 * beacon_int / 2) +
449 			sc->sched.channel_switch_time;
450 	else
451 		avp->noa_duration =
452 			TU_TO_USEC(cur_conf->beacon_interval) / 2 +
453 			sc->sched.channel_switch_time;
454 
455 	if (test_bit(ATH_OP_SCANNING, &common->op_flags) ||
456 	    sc->sched.extend_absence)
457 		avp->periodic_noa = false;
458 	else
459 		avp->periodic_noa = true;
460 
461 	ath_dbg(common, CHAN_CTX,
462 		"noa_duration: %d, noa_start: %u, noa_index: %d, periodic: %d\n",
463 		avp->noa_duration,
464 		avp->noa_start,
465 		avp->noa_index,
466 		avp->periodic_noa);
467 }
468 
469 static void ath_chanctx_set_oneshot_noa(struct ath_softc *sc,
470 					struct ath_vif *avp,
471 					u32 tsf_time,
472 					u32 duration)
473 {
474 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
475 
476 	avp->noa_index++;
477 	avp->noa_start = tsf_time;
478 	avp->periodic_noa = false;
479 	avp->oneshot_noa = true;
480 	avp->noa_duration = duration + sc->sched.channel_switch_time;
481 
482 	ath_dbg(common, CHAN_CTX,
483 		"oneshot noa_duration: %d, noa_start: %u, noa_index: %d, periodic: %d\n",
484 		avp->noa_duration,
485 		avp->noa_start,
486 		avp->noa_index,
487 		avp->periodic_noa);
488 }
489 
490 void ath_chanctx_event(struct ath_softc *sc, struct ieee80211_vif *vif,
491 		       enum ath_chanctx_event ev)
492 {
493 	struct ath_hw *ah = sc->sc_ah;
494 	struct ath_common *common = ath9k_hw_common(ah);
495 	struct ath_beacon_config *cur_conf;
496 	struct ath_vif *avp = NULL;
497 	struct ath_chanctx *ctx;
498 	u32 tsf_time;
499 	u32 beacon_int;
500 
501 	if (vif)
502 		avp = (struct ath_vif *) vif->drv_priv;
503 
504 	spin_lock_bh(&sc->chan_lock);
505 
506 	ath_dbg(common, CHAN_CTX, "cur_chan: %d MHz, event: %s, state: %s, delta: %u ms\n",
507 		sc->cur_chan->chandef.center_freq1,
508 		chanctx_event_string(ev),
509 		chanctx_state_string(sc->sched.state),
510 		chanctx_event_delta(sc));
511 
512 	switch (ev) {
513 	case ATH_CHANCTX_EVENT_BEACON_PREPARE:
514 		if (avp->offchannel_duration)
515 			avp->offchannel_duration = 0;
516 
517 		if (avp->oneshot_noa) {
518 			avp->noa_duration = 0;
519 			avp->oneshot_noa = false;
520 
521 			ath_dbg(common, CHAN_CTX,
522 				"Clearing oneshot NoA\n");
523 		}
524 
525 		if (avp->chanctx != sc->cur_chan) {
526 			ath_dbg(common, CHAN_CTX,
527 				"Contexts differ, not preparing beacon\n");
528 			break;
529 		}
530 
531 		if (sc->sched.offchannel_pending && !sc->sched.wait_switch) {
532 			sc->sched.offchannel_pending = false;
533 			sc->next_chan = &sc->offchannel.chan;
534 			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
535 			ath_dbg(common, CHAN_CTX,
536 				"Setting offchannel_pending to false\n");
537 		}
538 
539 		ctx = ath_chanctx_get_next(sc, sc->cur_chan);
540 		if (ctx->active && sc->sched.state == ATH_CHANCTX_STATE_IDLE) {
541 			sc->next_chan = ctx;
542 			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
543 			ath_dbg(common, CHAN_CTX,
544 				"Set next context, move chanctx state to WAIT_FOR_BEACON\n");
545 		}
546 
547 		/* if the timer missed its window, use the next interval */
548 		if (sc->sched.state == ATH_CHANCTX_STATE_WAIT_FOR_TIMER) {
549 			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
550 			ath_dbg(common, CHAN_CTX,
551 				"Move chanctx state from WAIT_FOR_TIMER to WAIT_FOR_BEACON\n");
552 		}
553 
554 		if (sc->sched.mgd_prepare_tx)
555 			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
556 
557 		/*
558 		 * When a context becomes inactive, for example,
559 		 * disassociation of a station context, the NoA
560 		 * attribute needs to be removed from subsequent
561 		 * beacons.
562 		 */
563 		if (!ctx->active && avp->noa_duration &&
564 		    sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON) {
565 			avp->noa_duration = 0;
566 			avp->periodic_noa = false;
567 
568 			ath_dbg(common, CHAN_CTX,
569 				"Clearing NoA schedule\n");
570 		}
571 
572 		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON)
573 			break;
574 
575 		ath_dbg(common, CHAN_CTX, "Preparing beacon for vif: %pM\n", vif->addr);
576 
577 		sc->sched.beacon_pending = true;
578 		sc->sched.next_tbtt = REG_READ(ah, AR_NEXT_TBTT_TIMER);
579 
580 		cur_conf = &sc->cur_chan->beacon;
581 		beacon_int = TU_TO_USEC(cur_conf->beacon_interval);
582 
583 		/* defer channel switch by a quarter beacon interval */
584 		tsf_time = sc->sched.next_tbtt + beacon_int / 4;
585 		sc->sched.switch_start_time = tsf_time;
586 		sc->cur_chan->last_beacon = sc->sched.next_tbtt;
587 
588 		/*
589 		 * If an offchannel switch is scheduled to happen after
590 		 * a beacon transmission, update the NoA with one-shot
591 		 * values and increment the index.
592 		 */
593 		if (sc->next_chan == &sc->offchannel.chan) {
594 			ath_chanctx_offchannel_noa(sc, ctx, avp, tsf_time);
595 			break;
596 		}
597 
598 		ath_chanctx_handle_bmiss(sc, ctx, avp);
599 
600 		/*
601 		 * If a mgd_prepare_tx() has been called by mac80211,
602 		 * a one-shot NoA needs to be sent. This can happen
603 		 * with one or more active channel contexts - in both
604 		 * cases, a new NoA schedule has to be advertised.
605 		 */
606 		if (sc->sched.mgd_prepare_tx) {
607 			ath_chanctx_set_oneshot_noa(sc, avp, tsf_time,
608 						    jiffies_to_usecs(HZ / 5));
609 			break;
610 		}
611 
612 		/* Prevent wrap-around issues */
613 		if (avp->noa_duration && tsf_time - avp->noa_start > BIT(30))
614 			avp->noa_duration = 0;
615 
616 		/*
617 		 * If multiple contexts are active, start periodic
618 		 * NoA and increment the index for the first
619 		 * announcement.
620 		 */
621 		if (ctx->active &&
622 		    (!avp->noa_duration || sc->sched.force_noa_update))
623 			ath_chanctx_set_periodic_noa(sc, avp, cur_conf,
624 						     tsf_time, beacon_int);
625 
626 		if (ctx->active && sc->sched.force_noa_update)
627 			sc->sched.force_noa_update = false;
628 
629 		break;
630 	case ATH_CHANCTX_EVENT_BEACON_SENT:
631 		if (!sc->sched.beacon_pending) {
632 			ath_dbg(common, CHAN_CTX,
633 				"No pending beacon\n");
634 			break;
635 		}
636 
637 		sc->sched.beacon_pending = false;
638 
639 		if (sc->sched.mgd_prepare_tx) {
640 			sc->sched.mgd_prepare_tx = false;
641 			complete(&sc->go_beacon);
642 			ath_dbg(common, CHAN_CTX,
643 				"Beacon sent, complete go_beacon\n");
644 			break;
645 		}
646 
647 		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON)
648 			break;
649 
650 		ath_dbg(common, CHAN_CTX,
651 			"Move chanctx state to WAIT_FOR_TIMER\n");
652 
653 		sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_TIMER;
654 		ath_chanctx_setup_timer(sc, sc->sched.switch_start_time);
655 		break;
656 	case ATH_CHANCTX_EVENT_TSF_TIMER:
657 		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_TIMER)
658 			break;
659 
660 		if (!sc->cur_chan->switch_after_beacon &&
661 		    sc->sched.beacon_pending)
662 			sc->sched.beacon_miss++;
663 
664 		ath_dbg(common, CHAN_CTX,
665 			"Move chanctx state to SWITCH\n");
666 
667 		sc->sched.state = ATH_CHANCTX_STATE_SWITCH;
668 		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
669 		break;
670 	case ATH_CHANCTX_EVENT_BEACON_RECEIVED:
671 		if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) ||
672 		    sc->cur_chan == &sc->offchannel.chan)
673 			break;
674 
675 		sc->sched.beacon_pending = false;
676 		sc->sched.beacon_miss = 0;
677 
678 		if (sc->sched.state == ATH_CHANCTX_STATE_FORCE_ACTIVE ||
679 		    !sc->sched.beacon_adjust ||
680 		    !sc->cur_chan->tsf_val)
681 			break;
682 
683 		ath_chanctx_adjust_tbtt_delta(sc);
684 
685 		/* TSF time might have been updated by the incoming beacon,
686 		 * need update the channel switch timer to reflect the change.
687 		 */
688 		tsf_time = sc->sched.switch_start_time;
689 		tsf_time -= (u32) sc->cur_chan->tsf_val +
690 			ath9k_hw_get_tsf_offset(&sc->cur_chan->tsf_ts, NULL);
691 		tsf_time += ath9k_hw_gettsf32(ah);
692 
693 		sc->sched.beacon_adjust = false;
694 		ath_chanctx_setup_timer(sc, tsf_time);
695 		break;
696 	case ATH_CHANCTX_EVENT_AUTHORIZED:
697 		if (sc->sched.state != ATH_CHANCTX_STATE_FORCE_ACTIVE ||
698 		    avp->chanctx != sc->cur_chan)
699 			break;
700 
701 		ath_dbg(common, CHAN_CTX,
702 			"Move chanctx state from FORCE_ACTIVE to IDLE\n");
703 
704 		sc->sched.state = ATH_CHANCTX_STATE_IDLE;
705 		/* fall through */
706 	case ATH_CHANCTX_EVENT_SWITCH:
707 		if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) ||
708 		    sc->sched.state == ATH_CHANCTX_STATE_FORCE_ACTIVE ||
709 		    sc->cur_chan->switch_after_beacon ||
710 		    sc->cur_chan == &sc->offchannel.chan)
711 			break;
712 
713 		/* If this is a station chanctx, stay active for a half
714 		 * beacon period (minus channel switch time)
715 		 */
716 		sc->next_chan = ath_chanctx_get_next(sc, sc->cur_chan);
717 		cur_conf = &sc->cur_chan->beacon;
718 
719 		ath_dbg(common, CHAN_CTX,
720 			"Move chanctx state to WAIT_FOR_TIMER (event SWITCH)\n");
721 
722 		sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_TIMER;
723 		sc->sched.wait_switch = false;
724 
725 		tsf_time = TU_TO_USEC(cur_conf->beacon_interval) / 2;
726 
727 		if (sc->sched.extend_absence) {
728 			sc->sched.beacon_miss = 0;
729 			tsf_time *= 3;
730 		}
731 
732 		tsf_time -= sc->sched.channel_switch_time;
733 		tsf_time += ath9k_hw_gettsf32(sc->sc_ah);
734 		sc->sched.switch_start_time = tsf_time;
735 
736 		ath_chanctx_setup_timer(sc, tsf_time);
737 		sc->sched.beacon_pending = true;
738 		sc->sched.beacon_adjust = true;
739 		break;
740 	case ATH_CHANCTX_EVENT_ENABLE_MULTICHANNEL:
741 		if (sc->cur_chan == &sc->offchannel.chan ||
742 		    sc->cur_chan->switch_after_beacon)
743 			break;
744 
745 		sc->next_chan = ath_chanctx_get_next(sc, sc->cur_chan);
746 		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
747 		break;
748 	case ATH_CHANCTX_EVENT_UNASSIGN:
749 		if (sc->cur_chan->assigned) {
750 			if (sc->next_chan && !sc->next_chan->assigned &&
751 			    sc->next_chan != &sc->offchannel.chan)
752 				sc->sched.state = ATH_CHANCTX_STATE_IDLE;
753 			break;
754 		}
755 
756 		ctx = ath_chanctx_get_next(sc, sc->cur_chan);
757 		sc->sched.state = ATH_CHANCTX_STATE_IDLE;
758 		if (!ctx->assigned)
759 			break;
760 
761 		sc->next_chan = ctx;
762 		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
763 		break;
764 	case ATH_CHANCTX_EVENT_ASSIGN:
765 		break;
766 	case ATH_CHANCTX_EVENT_CHANGE:
767 		break;
768 	}
769 
770 	spin_unlock_bh(&sc->chan_lock);
771 }
772 
773 void ath_chanctx_beacon_sent_ev(struct ath_softc *sc,
774 				enum ath_chanctx_event ev)
775 {
776 	if (sc->sched.beacon_pending)
777 		ath_chanctx_event(sc, NULL, ev);
778 }
779 
780 void ath_chanctx_beacon_recv_ev(struct ath_softc *sc,
781 				enum ath_chanctx_event ev)
782 {
783 	ath_chanctx_event(sc, NULL, ev);
784 }
785 
786 static int ath_scan_channel_duration(struct ath_softc *sc,
787 				     struct ieee80211_channel *chan)
788 {
789 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
790 
791 	if (!req->n_ssids || (chan->flags & IEEE80211_CHAN_NO_IR))
792 		return (HZ / 9); /* ~110 ms */
793 
794 	return (HZ / 16); /* ~60 ms */
795 }
796 
797 static void ath_chanctx_switch(struct ath_softc *sc, struct ath_chanctx *ctx,
798 			       struct cfg80211_chan_def *chandef)
799 {
800 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
801 
802 	spin_lock_bh(&sc->chan_lock);
803 
804 	if (test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) &&
805 	    (sc->cur_chan != ctx) && (ctx == &sc->offchannel.chan)) {
806 		if (chandef)
807 			ctx->chandef = *chandef;
808 
809 		sc->sched.offchannel_pending = true;
810 		sc->sched.wait_switch = true;
811 		sc->sched.offchannel_duration =
812 			jiffies_to_usecs(sc->offchannel.duration) +
813 			sc->sched.channel_switch_time;
814 
815 		spin_unlock_bh(&sc->chan_lock);
816 		ath_dbg(common, CHAN_CTX,
817 			"Set offchannel_pending to true\n");
818 		return;
819 	}
820 
821 	sc->next_chan = ctx;
822 	if (chandef) {
823 		ctx->chandef = *chandef;
824 		ath_dbg(common, CHAN_CTX,
825 			"Assigned next_chan to %d MHz\n", chandef->center_freq1);
826 	}
827 
828 	if (sc->next_chan == &sc->offchannel.chan) {
829 		sc->sched.offchannel_duration =
830 			jiffies_to_usecs(sc->offchannel.duration) +
831 			sc->sched.channel_switch_time;
832 
833 		if (chandef) {
834 			ath_dbg(common, CHAN_CTX,
835 				"Offchannel duration for chan %d MHz : %u\n",
836 				chandef->center_freq1,
837 				sc->sched.offchannel_duration);
838 		}
839 	}
840 	spin_unlock_bh(&sc->chan_lock);
841 	ieee80211_queue_work(sc->hw, &sc->chanctx_work);
842 }
843 
844 static void ath_chanctx_offchan_switch(struct ath_softc *sc,
845 				       struct ieee80211_channel *chan)
846 {
847 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
848 	struct cfg80211_chan_def chandef;
849 
850 	cfg80211_chandef_create(&chandef, chan, NL80211_CHAN_NO_HT);
851 	ath_dbg(common, CHAN_CTX,
852 		"Channel definition created: %d MHz\n", chandef.center_freq1);
853 
854 	ath_chanctx_switch(sc, &sc->offchannel.chan, &chandef);
855 }
856 
857 static struct ath_chanctx *ath_chanctx_get_oper_chan(struct ath_softc *sc,
858 						     bool active)
859 {
860 	struct ath_chanctx *ctx;
861 
862 	ath_for_each_chanctx(sc, ctx) {
863 		if (!ctx->assigned || list_empty(&ctx->vifs))
864 			continue;
865 		if (active && !ctx->active)
866 			continue;
867 
868 		if (ctx->switch_after_beacon)
869 			return ctx;
870 	}
871 
872 	return &sc->chanctx[0];
873 }
874 
875 static void
876 ath_scan_next_channel(struct ath_softc *sc)
877 {
878 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
879 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
880 	struct ieee80211_channel *chan;
881 
882 	if (sc->offchannel.scan_idx >= req->n_channels) {
883 		ath_dbg(common, CHAN_CTX,
884 			"Moving offchannel state to ATH_OFFCHANNEL_IDLE, "
885 			"scan_idx: %d, n_channels: %d\n",
886 			sc->offchannel.scan_idx,
887 			req->n_channels);
888 
889 		sc->offchannel.state = ATH_OFFCHANNEL_IDLE;
890 		ath_chanctx_switch(sc, ath_chanctx_get_oper_chan(sc, false),
891 				   NULL);
892 		return;
893 	}
894 
895 	ath_dbg(common, CHAN_CTX,
896 		"Moving offchannel state to ATH_OFFCHANNEL_PROBE_SEND, scan_idx: %d\n",
897 		sc->offchannel.scan_idx);
898 
899 	chan = req->channels[sc->offchannel.scan_idx++];
900 	sc->offchannel.duration = ath_scan_channel_duration(sc, chan);
901 	sc->offchannel.state = ATH_OFFCHANNEL_PROBE_SEND;
902 
903 	ath_chanctx_offchan_switch(sc, chan);
904 }
905 
906 void ath_offchannel_next(struct ath_softc *sc)
907 {
908 	struct ieee80211_vif *vif;
909 
910 	if (sc->offchannel.scan_req) {
911 		vif = sc->offchannel.scan_vif;
912 		sc->offchannel.chan.txpower = vif->bss_conf.txpower;
913 		ath_scan_next_channel(sc);
914 	} else if (sc->offchannel.roc_vif) {
915 		vif = sc->offchannel.roc_vif;
916 		sc->offchannel.chan.txpower = vif->bss_conf.txpower;
917 		sc->offchannel.duration =
918 			msecs_to_jiffies(sc->offchannel.roc_duration);
919 		sc->offchannel.state = ATH_OFFCHANNEL_ROC_START;
920 		ath_chanctx_offchan_switch(sc, sc->offchannel.roc_chan);
921 	} else {
922 		spin_lock_bh(&sc->chan_lock);
923 		sc->sched.offchannel_pending = false;
924 		sc->sched.wait_switch = false;
925 		spin_unlock_bh(&sc->chan_lock);
926 
927 		ath_chanctx_switch(sc, ath_chanctx_get_oper_chan(sc, false),
928 				   NULL);
929 		sc->offchannel.state = ATH_OFFCHANNEL_IDLE;
930 		if (sc->ps_idle)
931 			ath_cancel_work(sc);
932 	}
933 }
934 
935 void ath_roc_complete(struct ath_softc *sc, enum ath_roc_complete_reason reason)
936 {
937 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
938 
939 	sc->offchannel.roc_vif = NULL;
940 	sc->offchannel.roc_chan = NULL;
941 
942 	switch (reason) {
943 	case ATH_ROC_COMPLETE_ABORT:
944 		ath_dbg(common, CHAN_CTX, "RoC aborted\n");
945 		ieee80211_remain_on_channel_expired(sc->hw);
946 		break;
947 	case ATH_ROC_COMPLETE_EXPIRE:
948 		ath_dbg(common, CHAN_CTX, "RoC expired\n");
949 		ieee80211_remain_on_channel_expired(sc->hw);
950 		break;
951 	case ATH_ROC_COMPLETE_CANCEL:
952 		ath_dbg(common, CHAN_CTX, "RoC canceled\n");
953 		break;
954 	}
955 
956 	ath_offchannel_next(sc);
957 	ath9k_ps_restore(sc);
958 }
959 
960 void ath_scan_complete(struct ath_softc *sc, bool abort)
961 {
962 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
963 	struct cfg80211_scan_info info = {
964 		.aborted = abort,
965 	};
966 
967 	if (abort)
968 		ath_dbg(common, CHAN_CTX, "HW scan aborted\n");
969 	else
970 		ath_dbg(common, CHAN_CTX, "HW scan complete\n");
971 
972 	sc->offchannel.scan_req = NULL;
973 	sc->offchannel.scan_vif = NULL;
974 	sc->offchannel.state = ATH_OFFCHANNEL_IDLE;
975 	ieee80211_scan_completed(sc->hw, &info);
976 	clear_bit(ATH_OP_SCANNING, &common->op_flags);
977 	spin_lock_bh(&sc->chan_lock);
978 	if (test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags))
979 		sc->sched.force_noa_update = true;
980 	spin_unlock_bh(&sc->chan_lock);
981 	ath_offchannel_next(sc);
982 	ath9k_ps_restore(sc);
983 }
984 
985 static void ath_scan_send_probe(struct ath_softc *sc,
986 				struct cfg80211_ssid *ssid)
987 {
988 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
989 	struct ieee80211_vif *vif = sc->offchannel.scan_vif;
990 	struct ath_tx_control txctl = {};
991 	struct sk_buff *skb;
992 	struct ieee80211_tx_info *info;
993 	int band = sc->offchannel.chan.chandef.chan->band;
994 
995 	skb = ieee80211_probereq_get(sc->hw, vif->addr,
996 			ssid->ssid, ssid->ssid_len, req->ie_len);
997 	if (!skb)
998 		return;
999 
1000 	info = IEEE80211_SKB_CB(skb);
1001 	if (req->no_cck)
1002 		info->flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
1003 
1004 	if (req->ie_len)
1005 		memcpy(skb_put(skb, req->ie_len), req->ie, req->ie_len);
1006 
1007 	skb_set_queue_mapping(skb, IEEE80211_AC_VO);
1008 
1009 	if (!ieee80211_tx_prepare_skb(sc->hw, vif, skb, band, NULL))
1010 		goto error;
1011 
1012 	txctl.txq = sc->tx.txq_map[IEEE80211_AC_VO];
1013 	txctl.force_channel = true;
1014 	if (ath_tx_start(sc->hw, skb, &txctl))
1015 		goto error;
1016 
1017 	return;
1018 
1019 error:
1020 	ieee80211_free_txskb(sc->hw, skb);
1021 }
1022 
1023 static void ath_scan_channel_start(struct ath_softc *sc)
1024 {
1025 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1026 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
1027 	int i;
1028 
1029 	if (!(sc->cur_chan->chandef.chan->flags & IEEE80211_CHAN_NO_IR) &&
1030 	    req->n_ssids) {
1031 		for (i = 0; i < req->n_ssids; i++)
1032 			ath_scan_send_probe(sc, &req->ssids[i]);
1033 
1034 	}
1035 
1036 	ath_dbg(common, CHAN_CTX,
1037 		"Moving offchannel state to ATH_OFFCHANNEL_PROBE_WAIT\n");
1038 
1039 	sc->offchannel.state = ATH_OFFCHANNEL_PROBE_WAIT;
1040 	mod_timer(&sc->offchannel.timer, jiffies + sc->offchannel.duration);
1041 }
1042 
1043 static void ath_chanctx_timer(unsigned long data)
1044 {
1045 	struct ath_softc *sc = (struct ath_softc *) data;
1046 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1047 
1048 	ath_dbg(common, CHAN_CTX,
1049 		"Channel context timer invoked\n");
1050 
1051 	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_TSF_TIMER);
1052 }
1053 
1054 static void ath_offchannel_timer(unsigned long data)
1055 {
1056 	struct ath_softc *sc = (struct ath_softc *)data;
1057 	struct ath_chanctx *ctx;
1058 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1059 
1060 	ath_dbg(common, CHAN_CTX, "%s: offchannel state: %s\n",
1061 		__func__, offchannel_state_string(sc->offchannel.state));
1062 
1063 	switch (sc->offchannel.state) {
1064 	case ATH_OFFCHANNEL_PROBE_WAIT:
1065 		if (!sc->offchannel.scan_req)
1066 			return;
1067 
1068 		/* get first active channel context */
1069 		ctx = ath_chanctx_get_oper_chan(sc, true);
1070 		if (ctx->active) {
1071 			ath_dbg(common, CHAN_CTX,
1072 				"Switch to oper/active context, "
1073 				"move offchannel state to ATH_OFFCHANNEL_SUSPEND\n");
1074 
1075 			sc->offchannel.state = ATH_OFFCHANNEL_SUSPEND;
1076 			ath_chanctx_switch(sc, ctx, NULL);
1077 			mod_timer(&sc->offchannel.timer, jiffies + HZ / 10);
1078 			break;
1079 		}
1080 		/* fall through */
1081 	case ATH_OFFCHANNEL_SUSPEND:
1082 		if (!sc->offchannel.scan_req)
1083 			return;
1084 
1085 		ath_scan_next_channel(sc);
1086 		break;
1087 	case ATH_OFFCHANNEL_ROC_START:
1088 	case ATH_OFFCHANNEL_ROC_WAIT:
1089 		sc->offchannel.state = ATH_OFFCHANNEL_ROC_DONE;
1090 		ath_roc_complete(sc, ATH_ROC_COMPLETE_EXPIRE);
1091 		break;
1092 	default:
1093 		break;
1094 	}
1095 }
1096 
1097 static bool
1098 ath_chanctx_send_vif_ps_frame(struct ath_softc *sc, struct ath_vif *avp,
1099 			      bool powersave)
1100 {
1101 	struct ieee80211_vif *vif = avp->vif;
1102 	struct ieee80211_sta *sta = NULL;
1103 	struct ieee80211_hdr_3addr *nullfunc;
1104 	struct ath_tx_control txctl;
1105 	struct sk_buff *skb;
1106 	int band = sc->cur_chan->chandef.chan->band;
1107 
1108 	switch (vif->type) {
1109 	case NL80211_IFTYPE_STATION:
1110 		if (!avp->assoc)
1111 			return false;
1112 
1113 		skb = ieee80211_nullfunc_get(sc->hw, vif);
1114 		if (!skb)
1115 			return false;
1116 
1117 		nullfunc = (struct ieee80211_hdr_3addr *) skb->data;
1118 		if (powersave)
1119 			nullfunc->frame_control |=
1120 				cpu_to_le16(IEEE80211_FCTL_PM);
1121 
1122 		skb->priority = 7;
1123 		skb_set_queue_mapping(skb, IEEE80211_AC_VO);
1124 		if (!ieee80211_tx_prepare_skb(sc->hw, vif, skb, band, &sta)) {
1125 			dev_kfree_skb_any(skb);
1126 			return false;
1127 		}
1128 		break;
1129 	default:
1130 		return false;
1131 	}
1132 
1133 	memset(&txctl, 0, sizeof(txctl));
1134 	txctl.txq = sc->tx.txq_map[IEEE80211_AC_VO];
1135 	txctl.sta = sta;
1136 	txctl.force_channel = true;
1137 	if (ath_tx_start(sc->hw, skb, &txctl)) {
1138 		ieee80211_free_txskb(sc->hw, skb);
1139 		return false;
1140 	}
1141 
1142 	return true;
1143 }
1144 
1145 static bool
1146 ath_chanctx_send_ps_frame(struct ath_softc *sc, bool powersave)
1147 {
1148 	struct ath_vif *avp;
1149 	bool sent = false;
1150 
1151 	rcu_read_lock();
1152 	list_for_each_entry(avp, &sc->cur_chan->vifs, list) {
1153 		if (ath_chanctx_send_vif_ps_frame(sc, avp, powersave))
1154 			sent = true;
1155 	}
1156 	rcu_read_unlock();
1157 
1158 	return sent;
1159 }
1160 
1161 static bool ath_chanctx_defer_switch(struct ath_softc *sc)
1162 {
1163 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1164 
1165 	if (sc->cur_chan == &sc->offchannel.chan)
1166 		return false;
1167 
1168 	switch (sc->sched.state) {
1169 	case ATH_CHANCTX_STATE_SWITCH:
1170 		return false;
1171 	case ATH_CHANCTX_STATE_IDLE:
1172 		if (!sc->cur_chan->switch_after_beacon)
1173 			return false;
1174 
1175 		ath_dbg(common, CHAN_CTX,
1176 			"Defer switch, set chanctx state to WAIT_FOR_BEACON\n");
1177 
1178 		sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
1179 		break;
1180 	default:
1181 		break;
1182 	}
1183 
1184 	return true;
1185 }
1186 
1187 static void ath_offchannel_channel_change(struct ath_softc *sc)
1188 {
1189 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1190 
1191 	ath_dbg(common, CHAN_CTX, "%s: offchannel state: %s\n",
1192 		__func__, offchannel_state_string(sc->offchannel.state));
1193 
1194 	switch (sc->offchannel.state) {
1195 	case ATH_OFFCHANNEL_PROBE_SEND:
1196 		if (!sc->offchannel.scan_req)
1197 			return;
1198 
1199 		if (sc->cur_chan->chandef.chan !=
1200 		    sc->offchannel.chan.chandef.chan)
1201 			return;
1202 
1203 		ath_scan_channel_start(sc);
1204 		break;
1205 	case ATH_OFFCHANNEL_IDLE:
1206 		if (!sc->offchannel.scan_req)
1207 			return;
1208 
1209 		ath_scan_complete(sc, false);
1210 		break;
1211 	case ATH_OFFCHANNEL_ROC_START:
1212 		if (sc->cur_chan != &sc->offchannel.chan)
1213 			break;
1214 
1215 		sc->offchannel.state = ATH_OFFCHANNEL_ROC_WAIT;
1216 		mod_timer(&sc->offchannel.timer,
1217 			  jiffies + sc->offchannel.duration);
1218 		ieee80211_ready_on_channel(sc->hw);
1219 		break;
1220 	case ATH_OFFCHANNEL_ROC_DONE:
1221 		break;
1222 	default:
1223 		break;
1224 	}
1225 }
1226 
1227 void ath_chanctx_set_next(struct ath_softc *sc, bool force)
1228 {
1229 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1230 	struct ath_chanctx *old_ctx;
1231 	struct timespec ts;
1232 	bool measure_time = false;
1233 	bool send_ps = false;
1234 	bool queues_stopped = false;
1235 
1236 	spin_lock_bh(&sc->chan_lock);
1237 	if (!sc->next_chan) {
1238 		spin_unlock_bh(&sc->chan_lock);
1239 		return;
1240 	}
1241 
1242 	if (!force && ath_chanctx_defer_switch(sc)) {
1243 		spin_unlock_bh(&sc->chan_lock);
1244 		return;
1245 	}
1246 
1247 	ath_dbg(common, CHAN_CTX,
1248 		"%s: current: %d MHz, next: %d MHz\n",
1249 		__func__,
1250 		sc->cur_chan->chandef.center_freq1,
1251 		sc->next_chan->chandef.center_freq1);
1252 
1253 	if (sc->cur_chan != sc->next_chan) {
1254 		ath_dbg(common, CHAN_CTX,
1255 			"Stopping current chanctx: %d\n",
1256 			sc->cur_chan->chandef.center_freq1);
1257 		sc->cur_chan->stopped = true;
1258 		spin_unlock_bh(&sc->chan_lock);
1259 
1260 		if (sc->next_chan == &sc->offchannel.chan) {
1261 			getrawmonotonic(&ts);
1262 			measure_time = true;
1263 		}
1264 
1265 		ath9k_chanctx_stop_queues(sc, sc->cur_chan);
1266 		queues_stopped = true;
1267 
1268 		__ath9k_flush(sc->hw, ~0, true, false, false);
1269 
1270 		if (ath_chanctx_send_ps_frame(sc, true))
1271 			__ath9k_flush(sc->hw, BIT(IEEE80211_AC_VO),
1272 				      false, false, false);
1273 
1274 		send_ps = true;
1275 		spin_lock_bh(&sc->chan_lock);
1276 
1277 		if (sc->cur_chan != &sc->offchannel.chan) {
1278 			getrawmonotonic(&sc->cur_chan->tsf_ts);
1279 			sc->cur_chan->tsf_val = ath9k_hw_gettsf64(sc->sc_ah);
1280 		}
1281 	}
1282 	old_ctx = sc->cur_chan;
1283 	sc->cur_chan = sc->next_chan;
1284 	sc->cur_chan->stopped = false;
1285 	sc->next_chan = NULL;
1286 
1287 	if (!sc->sched.offchannel_pending)
1288 		sc->sched.offchannel_duration = 0;
1289 
1290 	if (sc->sched.state != ATH_CHANCTX_STATE_FORCE_ACTIVE)
1291 		sc->sched.state = ATH_CHANCTX_STATE_IDLE;
1292 
1293 	spin_unlock_bh(&sc->chan_lock);
1294 
1295 	if (sc->sc_ah->chip_fullsleep ||
1296 	    memcmp(&sc->cur_chandef, &sc->cur_chan->chandef,
1297 		   sizeof(sc->cur_chandef))) {
1298 		ath_dbg(common, CHAN_CTX,
1299 			"%s: Set channel %d MHz\n",
1300 			__func__, sc->cur_chan->chandef.center_freq1);
1301 		ath_set_channel(sc);
1302 		if (measure_time)
1303 			sc->sched.channel_switch_time =
1304 				ath9k_hw_get_tsf_offset(&ts, NULL);
1305 		/*
1306 		 * A reset will ensure that all queues are woken up,
1307 		 * so there is no need to awaken them again.
1308 		 */
1309 		goto out;
1310 	}
1311 
1312 	if (queues_stopped)
1313 		ath9k_chanctx_wake_queues(sc, old_ctx);
1314 out:
1315 	if (send_ps)
1316 		ath_chanctx_send_ps_frame(sc, false);
1317 
1318 	ath_offchannel_channel_change(sc);
1319 	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_SWITCH);
1320 }
1321 
1322 static void ath_chanctx_work(struct work_struct *work)
1323 {
1324 	struct ath_softc *sc = container_of(work, struct ath_softc,
1325 					    chanctx_work);
1326 	mutex_lock(&sc->mutex);
1327 	ath_chanctx_set_next(sc, false);
1328 	mutex_unlock(&sc->mutex);
1329 }
1330 
1331 void ath9k_offchannel_init(struct ath_softc *sc)
1332 {
1333 	struct ath_chanctx *ctx;
1334 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1335 	struct ieee80211_supported_band *sband;
1336 	struct ieee80211_channel *chan;
1337 	int i;
1338 
1339 	sband = &common->sbands[NL80211_BAND_2GHZ];
1340 	if (!sband->n_channels)
1341 		sband = &common->sbands[NL80211_BAND_5GHZ];
1342 
1343 	chan = &sband->channels[0];
1344 
1345 	ctx = &sc->offchannel.chan;
1346 	INIT_LIST_HEAD(&ctx->vifs);
1347 	ctx->txpower = ATH_TXPOWER_MAX;
1348 	cfg80211_chandef_create(&ctx->chandef, chan, NL80211_CHAN_HT20);
1349 
1350 	for (i = 0; i < ARRAY_SIZE(ctx->acq); i++)
1351 		INIT_LIST_HEAD(&ctx->acq[i]);
1352 
1353 	sc->offchannel.chan.offchannel = true;
1354 }
1355 
1356 void ath9k_init_channel_context(struct ath_softc *sc)
1357 {
1358 	INIT_WORK(&sc->chanctx_work, ath_chanctx_work);
1359 
1360 	setup_timer(&sc->offchannel.timer, ath_offchannel_timer,
1361 		    (unsigned long)sc);
1362 	setup_timer(&sc->sched.timer, ath_chanctx_timer,
1363 		    (unsigned long)sc);
1364 
1365 	init_completion(&sc->go_beacon);
1366 }
1367 
1368 void ath9k_deinit_channel_context(struct ath_softc *sc)
1369 {
1370 	cancel_work_sync(&sc->chanctx_work);
1371 }
1372 
1373 bool ath9k_is_chanctx_enabled(void)
1374 {
1375 	return (ath9k_use_chanctx == 1);
1376 }
1377 
1378 /********************/
1379 /* Queue management */
1380 /********************/
1381 
1382 void ath9k_chanctx_stop_queues(struct ath_softc *sc, struct ath_chanctx *ctx)
1383 {
1384 	struct ath_hw *ah = sc->sc_ah;
1385 	int i;
1386 
1387 	if (ctx == &sc->offchannel.chan) {
1388 		ieee80211_stop_queue(sc->hw,
1389 				     sc->hw->offchannel_tx_hw_queue);
1390 	} else {
1391 		for (i = 0; i < IEEE80211_NUM_ACS; i++)
1392 			ieee80211_stop_queue(sc->hw,
1393 					     ctx->hw_queue_base + i);
1394 	}
1395 
1396 	if (ah->opmode == NL80211_IFTYPE_AP)
1397 		ieee80211_stop_queue(sc->hw, sc->hw->queues - 2);
1398 }
1399 
1400 
1401 void ath9k_chanctx_wake_queues(struct ath_softc *sc, struct ath_chanctx *ctx)
1402 {
1403 	struct ath_hw *ah = sc->sc_ah;
1404 	int i;
1405 
1406 	if (ctx == &sc->offchannel.chan) {
1407 		ieee80211_wake_queue(sc->hw,
1408 				     sc->hw->offchannel_tx_hw_queue);
1409 	} else {
1410 		for (i = 0; i < IEEE80211_NUM_ACS; i++)
1411 			ieee80211_wake_queue(sc->hw,
1412 					     ctx->hw_queue_base + i);
1413 	}
1414 
1415 	if (ah->opmode == NL80211_IFTYPE_AP)
1416 		ieee80211_wake_queue(sc->hw, sc->hw->queues - 2);
1417 }
1418 
1419 /*****************/
1420 /* P2P Powersave */
1421 /*****************/
1422 
1423 static void ath9k_update_p2p_ps_timer(struct ath_softc *sc, struct ath_vif *avp)
1424 {
1425 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
1426 	struct ath_hw *ah = sc->sc_ah;
1427 	u32 tsf, target_tsf;
1428 
1429 	if (!avp || !avp->noa.has_next_tsf)
1430 		return;
1431 
1432 	ath9k_hw_gen_timer_stop(ah, sc->p2p_ps_timer);
1433 
1434 	tsf = ath9k_hw_gettsf32(sc->sc_ah);
1435 
1436 	target_tsf = avp->noa.next_tsf;
1437 	if (!avp->noa.absent)
1438 		target_tsf -= ATH_P2P_PS_STOP_TIME;
1439 	else
1440 		target_tsf += ATH_P2P_PS_STOP_TIME;
1441 
1442 	if (target_tsf - tsf < ATH_P2P_PS_STOP_TIME)
1443 		target_tsf = tsf + ATH_P2P_PS_STOP_TIME;
1444 
1445 	ath_dbg(common, CHAN_CTX, "%s absent %d tsf 0x%08X next_tsf 0x%08X (%dms)\n",
1446 		__func__, avp->noa.absent, tsf, target_tsf,
1447 		(target_tsf - tsf) / 1000);
1448 
1449 	ath9k_hw_gen_timer_start(ah, sc->p2p_ps_timer, target_tsf, 1000000);
1450 }
1451 
1452 static void ath9k_update_p2p_ps(struct ath_softc *sc, struct ieee80211_vif *vif)
1453 {
1454 	struct ath_vif *avp = (void *)vif->drv_priv;
1455 	u32 tsf;
1456 
1457 	if (!sc->p2p_ps_timer)
1458 		return;
1459 
1460 	if (vif->type != NL80211_IFTYPE_STATION)
1461 		return;
1462 
1463 	sc->p2p_ps_vif = avp;
1464 
1465 	if (sc->ps_flags & PS_BEACON_SYNC)
1466 		return;
1467 
1468 	tsf = ath9k_hw_gettsf32(sc->sc_ah);
1469 	ieee80211_parse_p2p_noa(&vif->bss_conf.p2p_noa_attr, &avp->noa, tsf);
1470 	ath9k_update_p2p_ps_timer(sc, avp);
1471 }
1472 
1473 static u8 ath9k_get_ctwin(struct ath_softc *sc, struct ath_vif *avp)
1474 {
1475 	struct ath_beacon_config *cur_conf = &sc->cur_chan->beacon;
1476 	u8 switch_time, ctwin;
1477 
1478 	/*
1479 	 * Channel switch in multi-channel mode is deferred
1480 	 * by a quarter beacon interval when handling
1481 	 * ATH_CHANCTX_EVENT_BEACON_PREPARE, so the P2P-GO
1482 	 * interface is guaranteed to be discoverable
1483 	 * for that duration after a TBTT.
1484 	 */
1485 	switch_time = cur_conf->beacon_interval / 4;
1486 
1487 	ctwin = avp->vif->bss_conf.p2p_noa_attr.oppps_ctwindow;
1488 	if (ctwin && (ctwin < switch_time))
1489 		return ctwin;
1490 
1491 	if (switch_time < P2P_DEFAULT_CTWIN)
1492 		return 0;
1493 
1494 	return P2P_DEFAULT_CTWIN;
1495 }
1496 
1497 void ath9k_beacon_add_noa(struct ath_softc *sc, struct ath_vif *avp,
1498 			  struct sk_buff *skb)
1499 {
1500 	static const u8 noa_ie_hdr[] = {
1501 		WLAN_EID_VENDOR_SPECIFIC,	/* type */
1502 		0,				/* length */
1503 		0x50, 0x6f, 0x9a,		/* WFA OUI */
1504 		0x09,				/* P2P subtype */
1505 		0x0c,				/* Notice of Absence */
1506 		0x00,				/* LSB of little-endian len */
1507 		0x00,				/* MSB of little-endian len */
1508 	};
1509 
1510 	struct ieee80211_p2p_noa_attr *noa;
1511 	int noa_len, noa_desc, i = 0;
1512 	u8 *hdr;
1513 
1514 	if (!avp->offchannel_duration && !avp->noa_duration)
1515 		return;
1516 
1517 	noa_desc = !!avp->offchannel_duration + !!avp->noa_duration;
1518 	noa_len = 2 + sizeof(struct ieee80211_p2p_noa_desc) * noa_desc;
1519 
1520 	hdr = skb_put(skb, sizeof(noa_ie_hdr));
1521 	memcpy(hdr, noa_ie_hdr, sizeof(noa_ie_hdr));
1522 	hdr[1] = sizeof(noa_ie_hdr) + noa_len - 2;
1523 	hdr[7] = noa_len;
1524 
1525 	noa = (void *) skb_put(skb, noa_len);
1526 	memset(noa, 0, noa_len);
1527 
1528 	noa->index = avp->noa_index;
1529 	noa->oppps_ctwindow = ath9k_get_ctwin(sc, avp);
1530 	if (noa->oppps_ctwindow)
1531 		noa->oppps_ctwindow |= BIT(7);
1532 
1533 	if (avp->noa_duration) {
1534 		if (avp->periodic_noa) {
1535 			u32 interval = TU_TO_USEC(sc->cur_chan->beacon.beacon_interval);
1536 			noa->desc[i].count = 255;
1537 			noa->desc[i].interval = cpu_to_le32(interval);
1538 		} else {
1539 			noa->desc[i].count = 1;
1540 		}
1541 
1542 		noa->desc[i].start_time = cpu_to_le32(avp->noa_start);
1543 		noa->desc[i].duration = cpu_to_le32(avp->noa_duration);
1544 		i++;
1545 	}
1546 
1547 	if (avp->offchannel_duration) {
1548 		noa->desc[i].count = 1;
1549 		noa->desc[i].start_time = cpu_to_le32(avp->offchannel_start);
1550 		noa->desc[i].duration = cpu_to_le32(avp->offchannel_duration);
1551 	}
1552 }
1553 
1554 void ath9k_p2p_ps_timer(void *priv)
1555 {
1556 	struct ath_softc *sc = priv;
1557 	struct ath_vif *avp = sc->p2p_ps_vif;
1558 	struct ieee80211_vif *vif;
1559 	struct ieee80211_sta *sta;
1560 	struct ath_node *an;
1561 	u32 tsf;
1562 
1563 	del_timer_sync(&sc->sched.timer);
1564 	ath9k_hw_gen_timer_stop(sc->sc_ah, sc->p2p_ps_timer);
1565 	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_TSF_TIMER);
1566 
1567 	if (!avp || avp->chanctx != sc->cur_chan)
1568 		return;
1569 
1570 	tsf = ath9k_hw_gettsf32(sc->sc_ah);
1571 	if (!avp->noa.absent)
1572 		tsf += ATH_P2P_PS_STOP_TIME;
1573 	else
1574 		tsf -= ATH_P2P_PS_STOP_TIME;
1575 
1576 	if (!avp->noa.has_next_tsf ||
1577 	    avp->noa.next_tsf - tsf > BIT(31))
1578 		ieee80211_update_p2p_noa(&avp->noa, tsf);
1579 
1580 	ath9k_update_p2p_ps_timer(sc, avp);
1581 
1582 	rcu_read_lock();
1583 
1584 	vif = avp->vif;
1585 	sta = ieee80211_find_sta(vif, avp->bssid);
1586 	if (!sta)
1587 		goto out;
1588 
1589 	an = (void *) sta->drv_priv;
1590 	if (an->sleeping == !!avp->noa.absent)
1591 		goto out;
1592 
1593 	an->sleeping = avp->noa.absent;
1594 	if (an->sleeping)
1595 		ath_tx_aggr_sleep(sta, sc, an);
1596 	else
1597 		ath_tx_aggr_wakeup(sc, an);
1598 
1599 out:
1600 	rcu_read_unlock();
1601 }
1602 
1603 void ath9k_p2p_bss_info_changed(struct ath_softc *sc,
1604 				struct ieee80211_vif *vif)
1605 {
1606 	unsigned long flags;
1607 
1608 	spin_lock_bh(&sc->sc_pcu_lock);
1609 	spin_lock_irqsave(&sc->sc_pm_lock, flags);
1610 	ath9k_update_p2p_ps(sc, vif);
1611 	spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
1612 	spin_unlock_bh(&sc->sc_pcu_lock);
1613 }
1614 
1615 void ath9k_p2p_beacon_sync(struct ath_softc *sc)
1616 {
1617 	if (sc->p2p_ps_vif)
1618 		ath9k_update_p2p_ps(sc, sc->p2p_ps_vif->vif);
1619 }
1620 
1621 void ath9k_p2p_remove_vif(struct ath_softc *sc,
1622 			  struct ieee80211_vif *vif)
1623 {
1624 	struct ath_vif *avp = (void *)vif->drv_priv;
1625 
1626 	spin_lock_bh(&sc->sc_pcu_lock);
1627 	if (avp == sc->p2p_ps_vif) {
1628 		sc->p2p_ps_vif = NULL;
1629 		ath9k_update_p2p_ps_timer(sc, NULL);
1630 	}
1631 	spin_unlock_bh(&sc->sc_pcu_lock);
1632 }
1633 
1634 int ath9k_init_p2p(struct ath_softc *sc)
1635 {
1636 	sc->p2p_ps_timer = ath_gen_timer_alloc(sc->sc_ah, ath9k_p2p_ps_timer,
1637 					       NULL, sc, AR_FIRST_NDP_TIMER);
1638 	if (!sc->p2p_ps_timer)
1639 		return -ENOMEM;
1640 
1641 	return 0;
1642 }
1643 
1644 void ath9k_deinit_p2p(struct ath_softc *sc)
1645 {
1646 	if (sc->p2p_ps_timer)
1647 		ath_gen_timer_free(sc->sc_ah, sc->p2p_ps_timer);
1648 }
1649 
1650 #endif /* CONFIG_ATH9K_CHANNEL_CONTEXT */
1651