xref: /openbmc/linux/drivers/net/wireless/ath/ath9k/channel.c (revision 499afaccf6f3d5d3180f4155e85becf15d09ff71)
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 static const char *offchannel_state_string(enum ath_offchannel_state state)
20 {
21 #define case_rtn_string(val) case val: return #val
22 
23 	switch (state) {
24 		case_rtn_string(ATH_OFFCHANNEL_IDLE);
25 		case_rtn_string(ATH_OFFCHANNEL_PROBE_SEND);
26 		case_rtn_string(ATH_OFFCHANNEL_PROBE_WAIT);
27 		case_rtn_string(ATH_OFFCHANNEL_SUSPEND);
28 		case_rtn_string(ATH_OFFCHANNEL_ROC_START);
29 		case_rtn_string(ATH_OFFCHANNEL_ROC_WAIT);
30 		case_rtn_string(ATH_OFFCHANNEL_ROC_DONE);
31 	default:
32 		return "unknown";
33 	}
34 }
35 
36 /* Set/change channels.  If the channel is really being changed, it's done
37  * by reseting the chip.  To accomplish this we must first cleanup any pending
38  * DMA, then restart stuff.
39  */
40 static int ath_set_channel(struct ath_softc *sc)
41 {
42 	struct ath_hw *ah = sc->sc_ah;
43 	struct ath_common *common = ath9k_hw_common(ah);
44 	struct ieee80211_hw *hw = sc->hw;
45 	struct ath9k_channel *hchan;
46 	struct cfg80211_chan_def *chandef = &sc->cur_chan->chandef;
47 	struct ieee80211_channel *chan = chandef->chan;
48 	int pos = chan->hw_value;
49 	int old_pos = -1;
50 	int r;
51 
52 	if (test_bit(ATH_OP_INVALID, &common->op_flags))
53 		return -EIO;
54 
55 	if (ah->curchan)
56 		old_pos = ah->curchan - &ah->channels[0];
57 
58 	ath_dbg(common, CONFIG, "Set channel: %d MHz width: %d\n",
59 		chan->center_freq, chandef->width);
60 
61 	/* update survey stats for the old channel before switching */
62 	spin_lock_bh(&common->cc_lock);
63 	ath_update_survey_stats(sc);
64 	spin_unlock_bh(&common->cc_lock);
65 
66 	ath9k_cmn_get_channel(hw, ah, chandef);
67 
68 	/* If the operating channel changes, change the survey in-use flags
69 	 * along with it.
70 	 * Reset the survey data for the new channel, unless we're switching
71 	 * back to the operating channel from an off-channel operation.
72 	 */
73 	if (!sc->cur_chan->offchannel && sc->cur_survey != &sc->survey[pos]) {
74 		if (sc->cur_survey)
75 			sc->cur_survey->filled &= ~SURVEY_INFO_IN_USE;
76 
77 		sc->cur_survey = &sc->survey[pos];
78 
79 		memset(sc->cur_survey, 0, sizeof(struct survey_info));
80 		sc->cur_survey->filled |= SURVEY_INFO_IN_USE;
81 	} else if (!(sc->survey[pos].filled & SURVEY_INFO_IN_USE)) {
82 		memset(&sc->survey[pos], 0, sizeof(struct survey_info));
83 	}
84 
85 	hchan = &sc->sc_ah->channels[pos];
86 	r = ath_reset_internal(sc, hchan);
87 	if (r)
88 		return r;
89 
90 	/* The most recent snapshot of channel->noisefloor for the old
91 	 * channel is only available after the hardware reset. Copy it to
92 	 * the survey stats now.
93 	 */
94 	if (old_pos >= 0)
95 		ath_update_survey_nf(sc, old_pos);
96 
97 	/* Enable radar pulse detection if on a DFS channel. Spectral
98 	 * scanning and radar detection can not be used concurrently.
99 	 */
100 	if (hw->conf.radar_enabled) {
101 		u32 rxfilter;
102 
103 		/* set HW specific DFS configuration */
104 		ath9k_hw_set_radar_params(ah);
105 		rxfilter = ath9k_hw_getrxfilter(ah);
106 		rxfilter |= ATH9K_RX_FILTER_PHYRADAR |
107 				ATH9K_RX_FILTER_PHYERR;
108 		ath9k_hw_setrxfilter(ah, rxfilter);
109 		ath_dbg(common, DFS, "DFS enabled at freq %d\n",
110 			chan->center_freq);
111 	} else {
112 		/* perform spectral scan if requested. */
113 		if (test_bit(ATH_OP_SCANNING, &common->op_flags) &&
114 			sc->spectral_mode == SPECTRAL_CHANSCAN)
115 			ath9k_spectral_scan_trigger(hw);
116 	}
117 
118 	return 0;
119 }
120 
121 static bool
122 ath_chanctx_send_vif_ps_frame(struct ath_softc *sc, struct ath_vif *avp,
123 			      bool powersave)
124 {
125 	struct ieee80211_vif *vif = avp->vif;
126 	struct ieee80211_sta *sta = NULL;
127 	struct ieee80211_hdr_3addr *nullfunc;
128 	struct ath_tx_control txctl;
129 	struct sk_buff *skb;
130 	int band = sc->cur_chan->chandef.chan->band;
131 
132 	switch (vif->type) {
133 	case NL80211_IFTYPE_STATION:
134 		if (!vif->bss_conf.assoc)
135 			return false;
136 
137 		skb = ieee80211_nullfunc_get(sc->hw, vif);
138 		if (!skb)
139 			return false;
140 
141 		nullfunc = (struct ieee80211_hdr_3addr *) skb->data;
142 		if (powersave)
143 			nullfunc->frame_control |=
144 				cpu_to_le16(IEEE80211_FCTL_PM);
145 
146 		skb_set_queue_mapping(skb, IEEE80211_AC_VO);
147 		if (!ieee80211_tx_prepare_skb(sc->hw, vif, skb, band, &sta)) {
148 			dev_kfree_skb_any(skb);
149 			return false;
150 		}
151 		break;
152 	default:
153 		return false;
154 	}
155 
156 	memset(&txctl, 0, sizeof(txctl));
157 	txctl.txq = sc->tx.txq_map[IEEE80211_AC_VO];
158 	txctl.sta = sta;
159 	txctl.force_channel = true;
160 	if (ath_tx_start(sc->hw, skb, &txctl)) {
161 		ieee80211_free_txskb(sc->hw, skb);
162 		return false;
163 	}
164 
165 	return true;
166 }
167 
168 void ath_chanctx_check_active(struct ath_softc *sc, struct ath_chanctx *ctx)
169 {
170 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
171 	struct ath_vif *avp;
172 	bool active = false;
173 	u8 n_active = 0;
174 
175 	if (!ctx)
176 		return;
177 
178 	list_for_each_entry(avp, &ctx->vifs, list) {
179 		struct ieee80211_vif *vif = avp->vif;
180 
181 		switch (vif->type) {
182 		case NL80211_IFTYPE_P2P_CLIENT:
183 		case NL80211_IFTYPE_STATION:
184 			if (vif->bss_conf.assoc)
185 				active = true;
186 			break;
187 		default:
188 			active = true;
189 			break;
190 		}
191 	}
192 	ctx->active = active;
193 
194 	ath_for_each_chanctx(sc, ctx) {
195 		if (!ctx->assigned || list_empty(&ctx->vifs))
196 			continue;
197 		n_active++;
198 	}
199 
200 	if (n_active <= 1) {
201 		clear_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags);
202 		return;
203 	}
204 	if (test_and_set_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags))
205 		return;
206 	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_ENABLE_MULTICHANNEL);
207 }
208 
209 static bool
210 ath_chanctx_send_ps_frame(struct ath_softc *sc, bool powersave)
211 {
212 	struct ath_vif *avp;
213 	bool sent = false;
214 
215 	rcu_read_lock();
216 	list_for_each_entry(avp, &sc->cur_chan->vifs, list) {
217 		if (ath_chanctx_send_vif_ps_frame(sc, avp, powersave))
218 			sent = true;
219 	}
220 	rcu_read_unlock();
221 
222 	return sent;
223 }
224 
225 static bool ath_chanctx_defer_switch(struct ath_softc *sc)
226 {
227 	if (sc->cur_chan == &sc->offchannel.chan)
228 		return false;
229 
230 	switch (sc->sched.state) {
231 	case ATH_CHANCTX_STATE_SWITCH:
232 		return false;
233 	case ATH_CHANCTX_STATE_IDLE:
234 		if (!sc->cur_chan->switch_after_beacon)
235 			return false;
236 
237 		sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
238 		break;
239 	default:
240 		break;
241 	}
242 
243 	return true;
244 }
245 
246 static void ath_chanctx_set_next(struct ath_softc *sc, bool force)
247 {
248 	struct timespec ts;
249 	bool measure_time = false;
250 	bool send_ps = false;
251 
252 	spin_lock_bh(&sc->chan_lock);
253 	if (!sc->next_chan) {
254 		spin_unlock_bh(&sc->chan_lock);
255 		return;
256 	}
257 
258 	if (!force && ath_chanctx_defer_switch(sc)) {
259 		spin_unlock_bh(&sc->chan_lock);
260 		return;
261 	}
262 
263 	if (sc->cur_chan != sc->next_chan) {
264 		sc->cur_chan->stopped = true;
265 		spin_unlock_bh(&sc->chan_lock);
266 
267 		if (sc->next_chan == &sc->offchannel.chan) {
268 			getrawmonotonic(&ts);
269 			measure_time = true;
270 		}
271 		__ath9k_flush(sc->hw, ~0, true);
272 
273 		if (ath_chanctx_send_ps_frame(sc, true))
274 			__ath9k_flush(sc->hw, BIT(IEEE80211_AC_VO), false);
275 
276 		send_ps = true;
277 		spin_lock_bh(&sc->chan_lock);
278 
279 		if (sc->cur_chan != &sc->offchannel.chan) {
280 			getrawmonotonic(&sc->cur_chan->tsf_ts);
281 			sc->cur_chan->tsf_val = ath9k_hw_gettsf64(sc->sc_ah);
282 		}
283 	}
284 	sc->cur_chan = sc->next_chan;
285 	sc->cur_chan->stopped = false;
286 	sc->next_chan = NULL;
287 	sc->sched.offchannel_duration = 0;
288 	if (sc->sched.state != ATH_CHANCTX_STATE_FORCE_ACTIVE)
289 		sc->sched.state = ATH_CHANCTX_STATE_IDLE;
290 
291 	spin_unlock_bh(&sc->chan_lock);
292 
293 	if (sc->sc_ah->chip_fullsleep ||
294 	    memcmp(&sc->cur_chandef, &sc->cur_chan->chandef,
295 		   sizeof(sc->cur_chandef))) {
296 		ath_set_channel(sc);
297 		if (measure_time)
298 			sc->sched.channel_switch_time =
299 				ath9k_hw_get_tsf_offset(&ts, NULL);
300 	}
301 	if (send_ps)
302 		ath_chanctx_send_ps_frame(sc, false);
303 
304 	ath_offchannel_channel_change(sc);
305 	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_SWITCH);
306 }
307 
308 void ath_chanctx_work(struct work_struct *work)
309 {
310 	struct ath_softc *sc = container_of(work, struct ath_softc,
311 					    chanctx_work);
312 	mutex_lock(&sc->mutex);
313 	ath_chanctx_set_next(sc, false);
314 	mutex_unlock(&sc->mutex);
315 }
316 
317 void ath_chanctx_init(struct ath_softc *sc)
318 {
319 	struct ath_chanctx *ctx;
320 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
321 	struct ieee80211_supported_band *sband;
322 	struct ieee80211_channel *chan;
323 	int i, j;
324 
325 	sband = &common->sbands[IEEE80211_BAND_2GHZ];
326 	if (!sband->n_channels)
327 		sband = &common->sbands[IEEE80211_BAND_5GHZ];
328 
329 	chan = &sband->channels[0];
330 	for (i = 0; i < ATH9K_NUM_CHANCTX; i++) {
331 		ctx = &sc->chanctx[i];
332 		cfg80211_chandef_create(&ctx->chandef, chan, NL80211_CHAN_HT20);
333 		INIT_LIST_HEAD(&ctx->vifs);
334 		ctx->txpower = ATH_TXPOWER_MAX;
335 		for (j = 0; j < ARRAY_SIZE(ctx->acq); j++)
336 			INIT_LIST_HEAD(&ctx->acq[j]);
337 	}
338 	ctx = &sc->offchannel.chan;
339 	cfg80211_chandef_create(&ctx->chandef, chan, NL80211_CHAN_HT20);
340 	INIT_LIST_HEAD(&ctx->vifs);
341 	ctx->txpower = ATH_TXPOWER_MAX;
342 	for (j = 0; j < ARRAY_SIZE(ctx->acq); j++)
343 		INIT_LIST_HEAD(&ctx->acq[j]);
344 	sc->offchannel.chan.offchannel = true;
345 
346 }
347 
348 void ath9k_chanctx_force_active(struct ieee80211_hw *hw,
349 				struct ieee80211_vif *vif)
350 {
351 	struct ath_softc *sc = hw->priv;
352 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
353 	struct ath_vif *avp = (struct ath_vif *) vif->drv_priv;
354 	bool changed = false;
355 
356 	if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags))
357 		return;
358 
359 	if (!avp->chanctx)
360 		return;
361 
362 	mutex_lock(&sc->mutex);
363 
364 	spin_lock_bh(&sc->chan_lock);
365 	if (sc->next_chan || (sc->cur_chan != avp->chanctx)) {
366 		sc->next_chan = avp->chanctx;
367 		changed = true;
368 	}
369 	sc->sched.state = ATH_CHANCTX_STATE_FORCE_ACTIVE;
370 	spin_unlock_bh(&sc->chan_lock);
371 
372 	if (changed)
373 		ath_chanctx_set_next(sc, true);
374 
375 	mutex_unlock(&sc->mutex);
376 }
377 
378 void ath_chanctx_switch(struct ath_softc *sc, struct ath_chanctx *ctx,
379 			struct cfg80211_chan_def *chandef)
380 {
381 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
382 
383 	spin_lock_bh(&sc->chan_lock);
384 
385 	if (test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) &&
386 	    (sc->cur_chan != ctx) && (ctx == &sc->offchannel.chan)) {
387 		sc->sched.offchannel_pending = true;
388 		spin_unlock_bh(&sc->chan_lock);
389 		return;
390 	}
391 
392 	sc->next_chan = ctx;
393 	if (chandef) {
394 		ctx->chandef = *chandef;
395 		ath_dbg(common, CHAN_CTX,
396 			"Assigned next_chan to %d MHz\n", chandef->center_freq1);
397 	}
398 
399 	if (sc->next_chan == &sc->offchannel.chan) {
400 		sc->sched.offchannel_duration =
401 			TU_TO_USEC(sc->offchannel.duration) +
402 			sc->sched.channel_switch_time;
403 
404 		if (chandef) {
405 			ath_dbg(common, CHAN_CTX,
406 				"Offchannel duration for chan %d MHz : %u\n",
407 				chandef->center_freq1,
408 				sc->sched.offchannel_duration);
409 		}
410 	}
411 	spin_unlock_bh(&sc->chan_lock);
412 	ieee80211_queue_work(sc->hw, &sc->chanctx_work);
413 }
414 
415 void ath_chanctx_set_channel(struct ath_softc *sc, struct ath_chanctx *ctx,
416 			     struct cfg80211_chan_def *chandef)
417 {
418 	bool cur_chan;
419 
420 	spin_lock_bh(&sc->chan_lock);
421 	if (chandef)
422 		memcpy(&ctx->chandef, chandef, sizeof(*chandef));
423 	cur_chan = sc->cur_chan == ctx;
424 	spin_unlock_bh(&sc->chan_lock);
425 
426 	if (!cur_chan)
427 		return;
428 
429 	ath_set_channel(sc);
430 }
431 
432 struct ath_chanctx *ath_chanctx_get_oper_chan(struct ath_softc *sc, bool active)
433 {
434 	struct ath_chanctx *ctx;
435 
436 	ath_for_each_chanctx(sc, ctx) {
437 		if (!ctx->assigned || list_empty(&ctx->vifs))
438 			continue;
439 		if (active && !ctx->active)
440 			continue;
441 
442 		if (ctx->switch_after_beacon)
443 			return ctx;
444 	}
445 
446 	return &sc->chanctx[0];
447 }
448 
449 void ath_chanctx_offchan_switch(struct ath_softc *sc,
450 				struct ieee80211_channel *chan)
451 {
452 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
453 	struct cfg80211_chan_def chandef;
454 
455 	cfg80211_chandef_create(&chandef, chan, NL80211_CHAN_NO_HT);
456 	ath_dbg(common, CHAN_CTX,
457 		"Channel definition created: %d MHz\n", chandef.center_freq1);
458 
459 	ath_chanctx_switch(sc, &sc->offchannel.chan, &chandef);
460 }
461 
462 static struct ath_chanctx *
463 ath_chanctx_get_next(struct ath_softc *sc, struct ath_chanctx *ctx)
464 {
465 	int idx = ctx - &sc->chanctx[0];
466 
467 	return &sc->chanctx[!idx];
468 }
469 
470 static void ath_chanctx_adjust_tbtt_delta(struct ath_softc *sc)
471 {
472 	struct ath_chanctx *prev, *cur;
473 	struct timespec ts;
474 	u32 cur_tsf, prev_tsf, beacon_int;
475 	s32 offset;
476 
477 	beacon_int = TU_TO_USEC(sc->cur_chan->beacon.beacon_interval);
478 
479 	cur = sc->cur_chan;
480 	prev = ath_chanctx_get_next(sc, cur);
481 
482 	getrawmonotonic(&ts);
483 	cur_tsf = (u32) cur->tsf_val +
484 		  ath9k_hw_get_tsf_offset(&cur->tsf_ts, &ts);
485 
486 	prev_tsf = prev->last_beacon - (u32) prev->tsf_val + cur_tsf;
487 	prev_tsf -= ath9k_hw_get_tsf_offset(&prev->tsf_ts, &ts);
488 
489 	/* Adjust the TSF time of the AP chanctx to keep its beacons
490 	 * at half beacon interval offset relative to the STA chanctx.
491 	 */
492 	offset = cur_tsf - prev_tsf;
493 
494 	/* Ignore stale data or spurious timestamps */
495 	if (offset < 0 || offset > 3 * beacon_int)
496 		return;
497 
498 	offset = beacon_int / 2 - (offset % beacon_int);
499 	prev->tsf_val += offset;
500 }
501 
502 void ath_chanctx_timer(unsigned long data)
503 {
504 	struct ath_softc *sc = (struct ath_softc *) data;
505 
506 	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_TSF_TIMER);
507 }
508 
509 /* Configure the TSF based hardware timer for a channel switch.
510  * Also set up backup software timer, in case the gen timer fails.
511  * This could be caused by a hardware reset.
512  */
513 static void ath_chanctx_setup_timer(struct ath_softc *sc, u32 tsf_time)
514 {
515 	struct ath_hw *ah = sc->sc_ah;
516 
517 #ifdef CONFIG_ATH9K_CHANNEL_CONTEXT
518 	ath9k_hw_gen_timer_start(ah, sc->p2p_ps_timer, tsf_time, 1000000);
519 #endif
520 	tsf_time -= ath9k_hw_gettsf32(ah);
521 	tsf_time = msecs_to_jiffies(tsf_time / 1000) + 1;
522 	mod_timer(&sc->sched.timer, tsf_time);
523 }
524 
525 void ath_chanctx_event(struct ath_softc *sc, struct ieee80211_vif *vif,
526 		       enum ath_chanctx_event ev)
527 {
528 	struct ath_hw *ah = sc->sc_ah;
529 	struct ath_common *common = ath9k_hw_common(ah);
530 	struct ath_beacon_config *cur_conf;
531 	struct ath_vif *avp = NULL;
532 	struct ath_chanctx *ctx;
533 	u32 tsf_time;
534 	u32 beacon_int;
535 	bool noa_changed = false;
536 
537 	if (vif)
538 		avp = (struct ath_vif *) vif->drv_priv;
539 
540 	spin_lock_bh(&sc->chan_lock);
541 
542 	switch (ev) {
543 	case ATH_CHANCTX_EVENT_BEACON_PREPARE:
544 		if (avp->offchannel_duration)
545 			avp->offchannel_duration = 0;
546 
547 		if (avp->chanctx != sc->cur_chan)
548 			break;
549 
550 		if (sc->sched.offchannel_pending) {
551 			sc->sched.offchannel_pending = false;
552 			sc->next_chan = &sc->offchannel.chan;
553 			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
554 		}
555 
556 		ctx = ath_chanctx_get_next(sc, sc->cur_chan);
557 		if (ctx->active && sc->sched.state == ATH_CHANCTX_STATE_IDLE) {
558 			sc->next_chan = ctx;
559 			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
560 		}
561 
562 		/* if the timer missed its window, use the next interval */
563 		if (sc->sched.state == ATH_CHANCTX_STATE_WAIT_FOR_TIMER)
564 			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
565 
566 		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON)
567 			break;
568 
569 		sc->sched.beacon_pending = true;
570 		sc->sched.next_tbtt = REG_READ(ah, AR_NEXT_TBTT_TIMER);
571 
572 		cur_conf = &sc->cur_chan->beacon;
573 		beacon_int = TU_TO_USEC(cur_conf->beacon_interval);
574 
575 		/* defer channel switch by a quarter beacon interval */
576 		tsf_time = sc->sched.next_tbtt + beacon_int / 4;
577 		sc->sched.switch_start_time = tsf_time;
578 		sc->cur_chan->last_beacon = sc->sched.next_tbtt;
579 
580 		/* Prevent wrap-around issues */
581 		if (avp->periodic_noa_duration &&
582 		    tsf_time - avp->periodic_noa_start > BIT(30))
583 			avp->periodic_noa_duration = 0;
584 
585 		if (ctx->active && !avp->periodic_noa_duration) {
586 			avp->periodic_noa_start = tsf_time;
587 			avp->periodic_noa_duration =
588 				TU_TO_USEC(cur_conf->beacon_interval) / 2 -
589 				sc->sched.channel_switch_time;
590 			noa_changed = true;
591 		} else if (!ctx->active && avp->periodic_noa_duration) {
592 			avp->periodic_noa_duration = 0;
593 			noa_changed = true;
594 		}
595 
596 		/* If at least two consecutive beacons were missed on the STA
597 		 * chanctx, stay on the STA channel for one extra beacon period,
598 		 * to resync the timer properly.
599 		 */
600 		if (ctx->active && sc->sched.beacon_miss >= 2)
601 			sc->sched.offchannel_duration = 3 * beacon_int / 2;
602 
603 		if (sc->sched.offchannel_duration) {
604 			noa_changed = true;
605 			avp->offchannel_start = tsf_time;
606 			avp->offchannel_duration =
607 				sc->sched.offchannel_duration;
608 		}
609 
610 		if (noa_changed)
611 			avp->noa_index++;
612 		break;
613 	case ATH_CHANCTX_EVENT_BEACON_SENT:
614 		if (!sc->sched.beacon_pending)
615 			break;
616 
617 		sc->sched.beacon_pending = false;
618 		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON)
619 			break;
620 
621 		sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_TIMER;
622 		ath_chanctx_setup_timer(sc, sc->sched.switch_start_time);
623 		break;
624 	case ATH_CHANCTX_EVENT_TSF_TIMER:
625 		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_TIMER)
626 			break;
627 
628 		if (!sc->cur_chan->switch_after_beacon &&
629 		    sc->sched.beacon_pending)
630 			sc->sched.beacon_miss++;
631 
632 		sc->sched.state = ATH_CHANCTX_STATE_SWITCH;
633 		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
634 		break;
635 	case ATH_CHANCTX_EVENT_BEACON_RECEIVED:
636 		if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) ||
637 		    sc->cur_chan == &sc->offchannel.chan)
638 			break;
639 
640 		ath_chanctx_adjust_tbtt_delta(sc);
641 		sc->sched.beacon_pending = false;
642 		sc->sched.beacon_miss = 0;
643 
644 		/* TSF time might have been updated by the incoming beacon,
645 		 * need update the channel switch timer to reflect the change.
646 		 */
647 		tsf_time = sc->sched.switch_start_time;
648 		tsf_time -= (u32) sc->cur_chan->tsf_val +
649 			ath9k_hw_get_tsf_offset(&sc->cur_chan->tsf_ts, NULL);
650 		tsf_time += ath9k_hw_gettsf32(ah);
651 
652 
653 		ath_chanctx_setup_timer(sc, tsf_time);
654 		break;
655 	case ATH_CHANCTX_EVENT_ASSOC:
656 		if (sc->sched.state != ATH_CHANCTX_STATE_FORCE_ACTIVE ||
657 		    avp->chanctx != sc->cur_chan)
658 			break;
659 
660 		sc->sched.state = ATH_CHANCTX_STATE_IDLE;
661 		/* fall through */
662 	case ATH_CHANCTX_EVENT_SWITCH:
663 		if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) ||
664 		    sc->sched.state == ATH_CHANCTX_STATE_FORCE_ACTIVE ||
665 		    sc->cur_chan->switch_after_beacon ||
666 		    sc->cur_chan == &sc->offchannel.chan)
667 			break;
668 
669 		/* If this is a station chanctx, stay active for a half
670 		 * beacon period (minus channel switch time)
671 		 */
672 		sc->next_chan = ath_chanctx_get_next(sc, sc->cur_chan);
673 		cur_conf = &sc->cur_chan->beacon;
674 
675 		sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_TIMER;
676 
677 		tsf_time = TU_TO_USEC(cur_conf->beacon_interval) / 2;
678 		if (sc->sched.beacon_miss >= 2) {
679 			sc->sched.beacon_miss = 0;
680 			tsf_time *= 3;
681 		}
682 
683 		tsf_time -= sc->sched.channel_switch_time;
684 		tsf_time += ath9k_hw_gettsf32(sc->sc_ah);
685 		sc->sched.switch_start_time = tsf_time;
686 
687 		ath_chanctx_setup_timer(sc, tsf_time);
688 		sc->sched.beacon_pending = true;
689 		break;
690 	case ATH_CHANCTX_EVENT_ENABLE_MULTICHANNEL:
691 		if (sc->cur_chan == &sc->offchannel.chan ||
692 		    sc->cur_chan->switch_after_beacon)
693 			break;
694 
695 		sc->next_chan = ath_chanctx_get_next(sc, sc->cur_chan);
696 		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
697 		break;
698 	case ATH_CHANCTX_EVENT_UNASSIGN:
699 		if (sc->cur_chan->assigned) {
700 			if (sc->next_chan && !sc->next_chan->assigned &&
701 			    sc->next_chan != &sc->offchannel.chan)
702 				sc->sched.state = ATH_CHANCTX_STATE_IDLE;
703 			break;
704 		}
705 
706 		ctx = ath_chanctx_get_next(sc, sc->cur_chan);
707 		sc->sched.state = ATH_CHANCTX_STATE_IDLE;
708 		if (!ctx->assigned)
709 			break;
710 
711 		sc->next_chan = ctx;
712 		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
713 		break;
714 	}
715 
716 	spin_unlock_bh(&sc->chan_lock);
717 }
718 
719 static int ath_scan_channel_duration(struct ath_softc *sc,
720 				     struct ieee80211_channel *chan)
721 {
722 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
723 
724 	if (!req->n_ssids || (chan->flags & IEEE80211_CHAN_NO_IR))
725 		return (HZ / 9); /* ~110 ms */
726 
727 	return (HZ / 16); /* ~60 ms */
728 }
729 
730 static void
731 ath_scan_next_channel(struct ath_softc *sc)
732 {
733 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
734 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
735 	struct ieee80211_channel *chan;
736 
737 	if (sc->offchannel.scan_idx >= req->n_channels) {
738 		ath_dbg(common, CHAN_CTX,
739 			"Moving to ATH_OFFCHANNEL_IDLE state, scan_idx: %d, n_channels: %d\n",
740 			sc->offchannel.scan_idx,
741 			req->n_channels);
742 
743 		sc->offchannel.state = ATH_OFFCHANNEL_IDLE;
744 		ath_chanctx_switch(sc, ath_chanctx_get_oper_chan(sc, false),
745 				   NULL);
746 		return;
747 	}
748 
749 	ath_dbg(common, CHAN_CTX,
750 		"Moving to ATH_OFFCHANNEL_PROBE_SEND state, scan_idx: %d\n",
751 		sc->offchannel.scan_idx);
752 
753 	chan = req->channels[sc->offchannel.scan_idx++];
754 	sc->offchannel.duration = ath_scan_channel_duration(sc, chan);
755 	sc->offchannel.state = ATH_OFFCHANNEL_PROBE_SEND;
756 
757 	ath_chanctx_offchan_switch(sc, chan);
758 }
759 
760 void ath_offchannel_next(struct ath_softc *sc)
761 {
762 	struct ieee80211_vif *vif;
763 
764 	if (sc->offchannel.scan_req) {
765 		vif = sc->offchannel.scan_vif;
766 		sc->offchannel.chan.txpower = vif->bss_conf.txpower;
767 		ath_scan_next_channel(sc);
768 	} else if (sc->offchannel.roc_vif) {
769 		vif = sc->offchannel.roc_vif;
770 		sc->offchannel.chan.txpower = vif->bss_conf.txpower;
771 		sc->offchannel.duration = sc->offchannel.roc_duration;
772 		sc->offchannel.state = ATH_OFFCHANNEL_ROC_START;
773 		ath_chanctx_offchan_switch(sc, sc->offchannel.roc_chan);
774 	} else {
775 		ath_chanctx_switch(sc, ath_chanctx_get_oper_chan(sc, false),
776 				   NULL);
777 		sc->offchannel.state = ATH_OFFCHANNEL_IDLE;
778 		if (sc->ps_idle)
779 			ath_cancel_work(sc);
780 	}
781 }
782 
783 void ath_roc_complete(struct ath_softc *sc, bool abort)
784 {
785 	sc->offchannel.roc_vif = NULL;
786 	sc->offchannel.roc_chan = NULL;
787 	if (!abort)
788 		ieee80211_remain_on_channel_expired(sc->hw);
789 	ath_offchannel_next(sc);
790 	ath9k_ps_restore(sc);
791 }
792 
793 void ath_scan_complete(struct ath_softc *sc, bool abort)
794 {
795 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
796 
797 	if (abort)
798 		ath_dbg(common, CHAN_CTX, "HW scan aborted\n");
799 	else
800 		ath_dbg(common, CHAN_CTX, "HW scan complete\n");
801 
802 	sc->offchannel.scan_req = NULL;
803 	sc->offchannel.scan_vif = NULL;
804 	sc->offchannel.state = ATH_OFFCHANNEL_IDLE;
805 	ieee80211_scan_completed(sc->hw, abort);
806 	clear_bit(ATH_OP_SCANNING, &common->op_flags);
807 	ath_offchannel_next(sc);
808 	ath9k_ps_restore(sc);
809 }
810 
811 static void ath_scan_send_probe(struct ath_softc *sc,
812 				struct cfg80211_ssid *ssid)
813 {
814 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
815 	struct ieee80211_vif *vif = sc->offchannel.scan_vif;
816 	struct ath_tx_control txctl = {};
817 	struct sk_buff *skb;
818 	struct ieee80211_tx_info *info;
819 	int band = sc->offchannel.chan.chandef.chan->band;
820 
821 	skb = ieee80211_probereq_get(sc->hw, vif,
822 			ssid->ssid, ssid->ssid_len, req->ie_len);
823 	if (!skb)
824 		return;
825 
826 	info = IEEE80211_SKB_CB(skb);
827 	if (req->no_cck)
828 		info->flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
829 
830 	if (req->ie_len)
831 		memcpy(skb_put(skb, req->ie_len), req->ie, req->ie_len);
832 
833 	skb_set_queue_mapping(skb, IEEE80211_AC_VO);
834 
835 	if (!ieee80211_tx_prepare_skb(sc->hw, vif, skb, band, NULL))
836 		goto error;
837 
838 	txctl.txq = sc->tx.txq_map[IEEE80211_AC_VO];
839 	txctl.force_channel = true;
840 	if (ath_tx_start(sc->hw, skb, &txctl))
841 		goto error;
842 
843 	return;
844 
845 error:
846 	ieee80211_free_txskb(sc->hw, skb);
847 }
848 
849 static void ath_scan_channel_start(struct ath_softc *sc)
850 {
851 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
852 	struct cfg80211_scan_request *req = sc->offchannel.scan_req;
853 	int i;
854 
855 	if (!(sc->cur_chan->chandef.chan->flags & IEEE80211_CHAN_NO_IR) &&
856 	    req->n_ssids) {
857 		for (i = 0; i < req->n_ssids; i++)
858 			ath_scan_send_probe(sc, &req->ssids[i]);
859 
860 	}
861 
862 	ath_dbg(common, CHAN_CTX,
863 		"Moving to ATH_OFFCHANNEL_PROBE_WAIT state\n");
864 
865 	sc->offchannel.state = ATH_OFFCHANNEL_PROBE_WAIT;
866 	mod_timer(&sc->offchannel.timer, jiffies + sc->offchannel.duration);
867 }
868 
869 void ath_offchannel_channel_change(struct ath_softc *sc)
870 {
871 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
872 
873 	ath_dbg(common, CHAN_CTX, "%s: state: %s\n",
874 		__func__, offchannel_state_string(sc->offchannel.state));
875 
876 	switch (sc->offchannel.state) {
877 	case ATH_OFFCHANNEL_PROBE_SEND:
878 		if (!sc->offchannel.scan_req)
879 			return;
880 
881 		if (sc->cur_chan->chandef.chan !=
882 		    sc->offchannel.chan.chandef.chan)
883 			return;
884 
885 		ath_scan_channel_start(sc);
886 		break;
887 	case ATH_OFFCHANNEL_IDLE:
888 		if (!sc->offchannel.scan_req)
889 			return;
890 
891 		ath_scan_complete(sc, false);
892 		break;
893 	case ATH_OFFCHANNEL_ROC_START:
894 		if (sc->cur_chan != &sc->offchannel.chan)
895 			break;
896 
897 		sc->offchannel.state = ATH_OFFCHANNEL_ROC_WAIT;
898 		mod_timer(&sc->offchannel.timer, jiffies +
899 			  msecs_to_jiffies(sc->offchannel.duration));
900 		ieee80211_ready_on_channel(sc->hw);
901 		break;
902 	case ATH_OFFCHANNEL_ROC_DONE:
903 		ath_roc_complete(sc, false);
904 		break;
905 	default:
906 		break;
907 	}
908 }
909 
910 void ath_offchannel_timer(unsigned long data)
911 {
912 	struct ath_softc *sc = (struct ath_softc *)data;
913 	struct ath_chanctx *ctx;
914 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
915 
916 	ath_dbg(common, CHAN_CTX, "%s: state: %s\n",
917 		__func__, offchannel_state_string(sc->offchannel.state));
918 
919 	switch (sc->offchannel.state) {
920 	case ATH_OFFCHANNEL_PROBE_WAIT:
921 		if (!sc->offchannel.scan_req)
922 			return;
923 
924 		/* get first active channel context */
925 		ctx = ath_chanctx_get_oper_chan(sc, true);
926 		if (ctx->active) {
927 			sc->offchannel.state = ATH_OFFCHANNEL_SUSPEND;
928 			ath_chanctx_switch(sc, ctx, NULL);
929 			mod_timer(&sc->offchannel.timer, jiffies + HZ / 10);
930 			break;
931 		}
932 		/* fall through */
933 	case ATH_OFFCHANNEL_SUSPEND:
934 		if (!sc->offchannel.scan_req)
935 			return;
936 
937 		ath_scan_next_channel(sc);
938 		break;
939 	case ATH_OFFCHANNEL_ROC_START:
940 	case ATH_OFFCHANNEL_ROC_WAIT:
941 		ctx = ath_chanctx_get_oper_chan(sc, false);
942 		sc->offchannel.state = ATH_OFFCHANNEL_ROC_DONE;
943 		ath_chanctx_switch(sc, ctx, NULL);
944 		break;
945 	default:
946 		break;
947 	}
948 }
949 
950 #ifdef CONFIG_ATH9K_CHANNEL_CONTEXT
951 
952 bool ath9k_is_chanctx_enabled(void)
953 {
954 	return (ath9k_use_chanctx == 1);
955 }
956 
957 /*****************/
958 /* P2P Powersave */
959 /*****************/
960 
961 static void ath9k_update_p2p_ps_timer(struct ath_softc *sc, struct ath_vif *avp)
962 {
963 	struct ath_hw *ah = sc->sc_ah;
964 	s32 tsf, target_tsf;
965 
966 	if (!avp || !avp->noa.has_next_tsf)
967 		return;
968 
969 	ath9k_hw_gen_timer_stop(ah, sc->p2p_ps_timer);
970 
971 	tsf = ath9k_hw_gettsf32(sc->sc_ah);
972 
973 	target_tsf = avp->noa.next_tsf;
974 	if (!avp->noa.absent)
975 		target_tsf -= ATH_P2P_PS_STOP_TIME;
976 
977 	if (target_tsf - tsf < ATH_P2P_PS_STOP_TIME)
978 		target_tsf = tsf + ATH_P2P_PS_STOP_TIME;
979 
980 	ath9k_hw_gen_timer_start(ah, sc->p2p_ps_timer, (u32) target_tsf, 1000000);
981 }
982 
983 static void ath9k_update_p2p_ps(struct ath_softc *sc, struct ieee80211_vif *vif)
984 {
985 	struct ath_vif *avp = (void *)vif->drv_priv;
986 	u32 tsf;
987 
988 	if (!sc->p2p_ps_timer)
989 		return;
990 
991 	if (vif->type != NL80211_IFTYPE_STATION || !vif->p2p)
992 		return;
993 
994 	sc->p2p_ps_vif = avp;
995 	tsf = ath9k_hw_gettsf32(sc->sc_ah);
996 	ieee80211_parse_p2p_noa(&vif->bss_conf.p2p_noa_attr, &avp->noa, tsf);
997 	ath9k_update_p2p_ps_timer(sc, avp);
998 }
999 
1000 void ath9k_p2p_ps_timer(void *priv)
1001 {
1002 	struct ath_softc *sc = priv;
1003 	struct ath_vif *avp = sc->p2p_ps_vif;
1004 	struct ieee80211_vif *vif;
1005 	struct ieee80211_sta *sta;
1006 	struct ath_node *an;
1007 	u32 tsf;
1008 
1009 	del_timer_sync(&sc->sched.timer);
1010 	ath9k_hw_gen_timer_stop(sc->sc_ah, sc->p2p_ps_timer);
1011 	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_TSF_TIMER);
1012 
1013 	if (!avp || avp->chanctx != sc->cur_chan)
1014 		return;
1015 
1016 	tsf = ath9k_hw_gettsf32(sc->sc_ah);
1017 	if (!avp->noa.absent)
1018 		tsf += ATH_P2P_PS_STOP_TIME;
1019 
1020 	if (!avp->noa.has_next_tsf ||
1021 	    avp->noa.next_tsf - tsf > BIT(31))
1022 		ieee80211_update_p2p_noa(&avp->noa, tsf);
1023 
1024 	ath9k_update_p2p_ps_timer(sc, avp);
1025 
1026 	rcu_read_lock();
1027 
1028 	vif = avp->vif;
1029 	sta = ieee80211_find_sta(vif, vif->bss_conf.bssid);
1030 	if (!sta)
1031 		goto out;
1032 
1033 	an = (void *) sta->drv_priv;
1034 	if (an->sleeping == !!avp->noa.absent)
1035 		goto out;
1036 
1037 	an->sleeping = avp->noa.absent;
1038 	if (an->sleeping)
1039 		ath_tx_aggr_sleep(sta, sc, an);
1040 	else
1041 		ath_tx_aggr_wakeup(sc, an);
1042 
1043 out:
1044 	rcu_read_unlock();
1045 }
1046 
1047 void ath9k_p2p_bss_info_changed(struct ath_softc *sc,
1048 				struct ieee80211_vif *vif)
1049 {
1050 	unsigned long flags;
1051 
1052 	spin_lock_bh(&sc->sc_pcu_lock);
1053 	spin_lock_irqsave(&sc->sc_pm_lock, flags);
1054 	if (!(sc->ps_flags & PS_BEACON_SYNC))
1055 		ath9k_update_p2p_ps(sc, vif);
1056 	spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
1057 	spin_unlock_bh(&sc->sc_pcu_lock);
1058 }
1059 
1060 void ath9k_p2p_beacon_sync(struct ath_softc *sc)
1061 {
1062 	if (sc->p2p_ps_vif)
1063 		ath9k_update_p2p_ps(sc, sc->p2p_ps_vif->vif);
1064 }
1065 
1066 void ath9k_p2p_remove_vif(struct ath_softc *sc,
1067 			  struct ieee80211_vif *vif)
1068 {
1069 	struct ath_vif *avp = (void *)vif->drv_priv;
1070 
1071 	spin_lock_bh(&sc->sc_pcu_lock);
1072 	if (avp == sc->p2p_ps_vif) {
1073 		sc->p2p_ps_vif = NULL;
1074 		ath9k_update_p2p_ps_timer(sc, NULL);
1075 	}
1076 	spin_unlock_bh(&sc->sc_pcu_lock);
1077 }
1078 
1079 int ath9k_init_p2p(struct ath_softc *sc)
1080 {
1081 	sc->p2p_ps_timer = ath_gen_timer_alloc(sc->sc_ah, ath9k_p2p_ps_timer,
1082 					       NULL, sc, AR_FIRST_NDP_TIMER);
1083 	if (!sc->p2p_ps_timer)
1084 		return -ENOMEM;
1085 
1086 	return 0;
1087 }
1088 
1089 void ath9k_deinit_p2p(struct ath_softc *sc)
1090 {
1091 	if (sc->p2p_ps_timer)
1092 		ath_gen_timer_free(sc->sc_ah, sc->p2p_ps_timer);
1093 }
1094 
1095 #endif /* CONFIG_ATH9K_CHANNEL_CONTEXT */
1096