1 /*
2  * Copyright (c) 2008-2011 Atheros Communications 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 <linux/dma-mapping.h>
18 #include "ath9k.h"
19 
20 #define FUDGE 2
21 
22 static void ath9k_reset_beacon_status(struct ath_softc *sc)
23 {
24 	sc->beacon.tx_processed = false;
25 	sc->beacon.tx_last = false;
26 }
27 
28 /*
29  *  This function will modify certain transmit queue properties depending on
30  *  the operating mode of the station (AP or AdHoc).  Parameters are AIFS
31  *  settings and channel width min/max
32 */
33 static void ath9k_beaconq_config(struct ath_softc *sc)
34 {
35 	struct ath_hw *ah = sc->sc_ah;
36 	struct ath_common *common = ath9k_hw_common(ah);
37 	struct ath9k_tx_queue_info qi, qi_be;
38 	struct ath_txq *txq;
39 
40 	ath9k_hw_get_txq_props(ah, sc->beacon.beaconq, &qi);
41 
42 	if (sc->sc_ah->opmode == NL80211_IFTYPE_AP ||
43 	    sc->sc_ah->opmode == NL80211_IFTYPE_MESH_POINT) {
44 		/* Always burst out beacon and CAB traffic. */
45 		qi.tqi_aifs = 1;
46 		qi.tqi_cwmin = 0;
47 		qi.tqi_cwmax = 0;
48 	} else {
49 		/* Adhoc mode; important thing is to use 2x cwmin. */
50 		txq = sc->tx.txq_map[IEEE80211_AC_BE];
51 		ath9k_hw_get_txq_props(ah, txq->axq_qnum, &qi_be);
52 		qi.tqi_aifs = qi_be.tqi_aifs;
53 		if (ah->slottime == ATH9K_SLOT_TIME_20)
54 			qi.tqi_cwmin = 2*qi_be.tqi_cwmin;
55 		else
56 			qi.tqi_cwmin = 4*qi_be.tqi_cwmin;
57 		qi.tqi_cwmax = qi_be.tqi_cwmax;
58 	}
59 
60 	if (!ath9k_hw_set_txq_props(ah, sc->beacon.beaconq, &qi)) {
61 		ath_err(common, "Unable to update h/w beacon queue parameters\n");
62 	} else {
63 		ath9k_hw_resettxqueue(ah, sc->beacon.beaconq);
64 	}
65 }
66 
67 /*
68  *  Associates the beacon frame buffer with a transmit descriptor.  Will set
69  *  up rate codes, and channel flags. Beacons are always sent out at the
70  *  lowest rate, and are not retried.
71 */
72 static void ath9k_beacon_setup(struct ath_softc *sc, struct ieee80211_vif *vif,
73 			     struct ath_buf *bf, int rateidx)
74 {
75 	struct sk_buff *skb = bf->bf_mpdu;
76 	struct ath_hw *ah = sc->sc_ah;
77 	struct ath_common *common = ath9k_hw_common(ah);
78 	struct ath_tx_info info;
79 	struct ieee80211_supported_band *sband;
80 	u8 chainmask = ah->txchainmask;
81 	u8 rate = 0;
82 
83 	sband = &sc->sbands[common->hw->conf.chandef.chan->band];
84 	rate = sband->bitrates[rateidx].hw_value;
85 	if (vif->bss_conf.use_short_preamble)
86 		rate |= sband->bitrates[rateidx].hw_value_short;
87 
88 	memset(&info, 0, sizeof(info));
89 	info.pkt_len = skb->len + FCS_LEN;
90 	info.type = ATH9K_PKT_TYPE_BEACON;
91 	info.txpower = MAX_RATE_POWER;
92 	info.keyix = ATH9K_TXKEYIX_INVALID;
93 	info.keytype = ATH9K_KEY_TYPE_CLEAR;
94 	info.flags = ATH9K_TXDESC_NOACK | ATH9K_TXDESC_CLRDMASK;
95 
96 	info.buf_addr[0] = bf->bf_buf_addr;
97 	info.buf_len[0] = roundup(skb->len, 4);
98 
99 	info.is_first = true;
100 	info.is_last = true;
101 
102 	info.qcu = sc->beacon.beaconq;
103 
104 	info.rates[0].Tries = 1;
105 	info.rates[0].Rate = rate;
106 	info.rates[0].ChSel = ath_txchainmask_reduction(sc, chainmask, rate);
107 
108 	ath9k_hw_set_txdesc(ah, bf->bf_desc, &info);
109 }
110 
111 static struct ath_buf *ath9k_beacon_generate(struct ieee80211_hw *hw,
112 					     struct ieee80211_vif *vif)
113 {
114 	struct ath_softc *sc = hw->priv;
115 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
116 	struct ath_buf *bf;
117 	struct ath_vif *avp = (void *)vif->drv_priv;
118 	struct sk_buff *skb;
119 	struct ath_txq *cabq = sc->beacon.cabq;
120 	struct ieee80211_tx_info *info;
121 	struct ieee80211_mgmt *mgmt_hdr;
122 	int cabq_depth;
123 
124 	if (avp->av_bcbuf == NULL)
125 		return NULL;
126 
127 	bf = avp->av_bcbuf;
128 	skb = bf->bf_mpdu;
129 	if (skb) {
130 		dma_unmap_single(sc->dev, bf->bf_buf_addr,
131 				 skb->len, DMA_TO_DEVICE);
132 		dev_kfree_skb_any(skb);
133 		bf->bf_buf_addr = 0;
134 		bf->bf_mpdu = NULL;
135 	}
136 
137 	skb = ieee80211_beacon_get(hw, vif);
138 	if (skb == NULL)
139 		return NULL;
140 
141 	bf->bf_mpdu = skb;
142 
143 	mgmt_hdr = (struct ieee80211_mgmt *)skb->data;
144 	mgmt_hdr->u.beacon.timestamp = avp->tsf_adjust;
145 
146 	info = IEEE80211_SKB_CB(skb);
147 	if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {
148 		/*
149 		 * TODO: make sure the seq# gets assigned properly (vs. other
150 		 * TX frames)
151 		 */
152 		struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
153 		sc->tx.seq_no += 0x10;
154 		hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
155 		hdr->seq_ctrl |= cpu_to_le16(sc->tx.seq_no);
156 	}
157 
158 	bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
159 					 skb->len, DMA_TO_DEVICE);
160 	if (unlikely(dma_mapping_error(sc->dev, bf->bf_buf_addr))) {
161 		dev_kfree_skb_any(skb);
162 		bf->bf_mpdu = NULL;
163 		bf->bf_buf_addr = 0;
164 		ath_err(common, "dma_mapping_error on beaconing\n");
165 		return NULL;
166 	}
167 
168 	skb = ieee80211_get_buffered_bc(hw, vif);
169 
170 	/*
171 	 * if the CABQ traffic from previous DTIM is pending and the current
172 	 *  beacon is also a DTIM.
173 	 *  1) if there is only one vif let the cab traffic continue.
174 	 *  2) if there are more than one vif and we are using staggered
175 	 *     beacons, then drain the cabq by dropping all the frames in
176 	 *     the cabq so that the current vifs cab traffic can be scheduled.
177 	 */
178 	spin_lock_bh(&cabq->axq_lock);
179 	cabq_depth = cabq->axq_depth;
180 	spin_unlock_bh(&cabq->axq_lock);
181 
182 	if (skb && cabq_depth) {
183 		if (sc->nvifs > 1) {
184 			ath_dbg(common, BEACON,
185 				"Flushing previous cabq traffic\n");
186 			ath_draintxq(sc, cabq);
187 		}
188 	}
189 
190 	ath9k_beacon_setup(sc, vif, bf, info->control.rates[0].idx);
191 
192 	if (skb)
193 		ath_tx_cabq(hw, vif, skb);
194 
195 	return bf;
196 }
197 
198 void ath9k_beacon_assign_slot(struct ath_softc *sc, struct ieee80211_vif *vif)
199 {
200 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
201 	struct ath_vif *avp = (void *)vif->drv_priv;
202 	int slot;
203 
204 	avp->av_bcbuf = list_first_entry(&sc->beacon.bbuf, struct ath_buf, list);
205 	list_del(&avp->av_bcbuf->list);
206 
207 	for (slot = 0; slot < ATH_BCBUF; slot++) {
208 		if (sc->beacon.bslot[slot] == NULL) {
209 			avp->av_bslot = slot;
210 			break;
211 		}
212 	}
213 
214 	sc->beacon.bslot[avp->av_bslot] = vif;
215 	sc->nbcnvifs++;
216 
217 	ath_dbg(common, CONFIG, "Added interface at beacon slot: %d\n",
218 		avp->av_bslot);
219 }
220 
221 void ath9k_beacon_remove_slot(struct ath_softc *sc, struct ieee80211_vif *vif)
222 {
223 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
224 	struct ath_vif *avp = (void *)vif->drv_priv;
225 	struct ath_buf *bf = avp->av_bcbuf;
226 
227 	ath_dbg(common, CONFIG, "Removing interface at beacon slot: %d\n",
228 		avp->av_bslot);
229 
230 	tasklet_disable(&sc->bcon_tasklet);
231 
232 	if (bf && bf->bf_mpdu) {
233 		struct sk_buff *skb = bf->bf_mpdu;
234 		dma_unmap_single(sc->dev, bf->bf_buf_addr,
235 				 skb->len, DMA_TO_DEVICE);
236 		dev_kfree_skb_any(skb);
237 		bf->bf_mpdu = NULL;
238 		bf->bf_buf_addr = 0;
239 	}
240 
241 	avp->av_bcbuf = NULL;
242 	sc->beacon.bslot[avp->av_bslot] = NULL;
243 	sc->nbcnvifs--;
244 	list_add_tail(&bf->list, &sc->beacon.bbuf);
245 
246 	tasklet_enable(&sc->bcon_tasklet);
247 }
248 
249 static int ath9k_beacon_choose_slot(struct ath_softc *sc)
250 {
251 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
252 	struct ath_beacon_config *cur_conf = &sc->cur_beacon_conf;
253 	u16 intval;
254 	u32 tsftu;
255 	u64 tsf;
256 	int slot;
257 
258 	if (sc->sc_ah->opmode != NL80211_IFTYPE_AP &&
259 	    sc->sc_ah->opmode != NL80211_IFTYPE_MESH_POINT) {
260 		ath_dbg(common, BEACON, "slot 0, tsf: %llu\n",
261 			ath9k_hw_gettsf64(sc->sc_ah));
262 		return 0;
263 	}
264 
265 	intval = cur_conf->beacon_interval ? : ATH_DEFAULT_BINTVAL;
266 	tsf = ath9k_hw_gettsf64(sc->sc_ah);
267 	tsf += TU_TO_USEC(sc->sc_ah->config.sw_beacon_response_time);
268 	tsftu = TSF_TO_TU((tsf * ATH_BCBUF) >>32, tsf * ATH_BCBUF);
269 	slot = (tsftu % (intval * ATH_BCBUF)) / intval;
270 
271 	ath_dbg(common, BEACON, "slot: %d tsf: %llu tsftu: %u\n",
272 		slot, tsf, tsftu / ATH_BCBUF);
273 
274 	return slot;
275 }
276 
277 void ath9k_set_tsfadjust(struct ath_softc *sc, struct ieee80211_vif *vif)
278 {
279 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
280 	struct ath_beacon_config *cur_conf = &sc->cur_beacon_conf;
281 	struct ath_vif *avp = (void *)vif->drv_priv;
282 	u64 tsfadjust;
283 
284 	if (avp->av_bslot == 0)
285 		return;
286 
287 	tsfadjust = cur_conf->beacon_interval * avp->av_bslot / ATH_BCBUF;
288 	avp->tsf_adjust = cpu_to_le64(TU_TO_USEC(tsfadjust));
289 
290 	ath_dbg(common, CONFIG, "tsfadjust is: %llu for bslot: %d\n",
291 		(unsigned long long)tsfadjust, avp->av_bslot);
292 }
293 
294 bool ath9k_csa_is_finished(struct ath_softc *sc)
295 {
296 	struct ieee80211_vif *vif;
297 
298 	vif = sc->csa_vif;
299 	if (!vif || !vif->csa_active)
300 		return false;
301 
302 	if (!ieee80211_csa_is_complete(vif))
303 		return false;
304 
305 	ieee80211_csa_finish(vif);
306 
307 	sc->csa_vif = NULL;
308 	return true;
309 }
310 
311 void ath9k_beacon_tasklet(unsigned long data)
312 {
313 	struct ath_softc *sc = (struct ath_softc *)data;
314 	struct ath_hw *ah = sc->sc_ah;
315 	struct ath_common *common = ath9k_hw_common(ah);
316 	struct ath_buf *bf = NULL;
317 	struct ieee80211_vif *vif;
318 	bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
319 	int slot;
320 
321 	if (test_bit(SC_OP_HW_RESET, &sc->sc_flags)) {
322 		ath_dbg(common, RESET,
323 			"reset work is pending, skip beaconing now\n");
324 		return;
325 	}
326 
327 	/*
328 	 * Check if the previous beacon has gone out.  If
329 	 * not don't try to post another, skip this period
330 	 * and wait for the next.  Missed beacons indicate
331 	 * a problem and should not occur.  If we miss too
332 	 * many consecutive beacons reset the device.
333 	 */
334 	if (ath9k_hw_numtxpending(ah, sc->beacon.beaconq) != 0) {
335 		sc->beacon.bmisscnt++;
336 
337 		ath9k_hw_check_nav(ah);
338 
339 		if (!ath9k_hw_check_alive(ah))
340 			ieee80211_queue_work(sc->hw, &sc->hw_check_work);
341 
342 		if (sc->beacon.bmisscnt < BSTUCK_THRESH * sc->nbcnvifs) {
343 			ath_dbg(common, BSTUCK,
344 				"missed %u consecutive beacons\n",
345 				sc->beacon.bmisscnt);
346 			ath9k_hw_stop_dma_queue(ah, sc->beacon.beaconq);
347 			if (sc->beacon.bmisscnt > 3)
348 				ath9k_hw_bstuck_nfcal(ah);
349 		} else if (sc->beacon.bmisscnt >= BSTUCK_THRESH) {
350 			ath_dbg(common, BSTUCK, "beacon is officially stuck\n");
351 			sc->beacon.bmisscnt = 0;
352 			ath9k_queue_reset(sc, RESET_TYPE_BEACON_STUCK);
353 		}
354 
355 		return;
356 	}
357 
358 	/* EDMA devices check that in the tx completion function. */
359 	if (!edma && ath9k_csa_is_finished(sc))
360 		return;
361 
362 	slot = ath9k_beacon_choose_slot(sc);
363 	vif = sc->beacon.bslot[slot];
364 
365 	if (!vif || !vif->bss_conf.enable_beacon)
366 		return;
367 
368 	bf = ath9k_beacon_generate(sc->hw, vif);
369 
370 	if (sc->beacon.bmisscnt != 0) {
371 		ath_dbg(common, BSTUCK, "resume beacon xmit after %u misses\n",
372 			sc->beacon.bmisscnt);
373 		sc->beacon.bmisscnt = 0;
374 	}
375 
376 	/*
377 	 * Handle slot time change when a non-ERP station joins/leaves
378 	 * an 11g network.  The 802.11 layer notifies us via callback,
379 	 * we mark updateslot, then wait one beacon before effecting
380 	 * the change.  This gives associated stations at least one
381 	 * beacon interval to note the state change.
382 	 *
383 	 * NB: The slot time change state machine is clocked according
384 	 *     to whether we are bursting or staggering beacons.  We
385 	 *     recognize the request to update and record the current
386 	 *     slot then don't transition until that slot is reached
387 	 *     again.  If we miss a beacon for that slot then we'll be
388 	 *     slow to transition but we'll be sure at least one beacon
389 	 *     interval has passed.  When bursting slot is always left
390 	 *     set to ATH_BCBUF so this check is a noop.
391 	 */
392 	if (sc->beacon.updateslot == UPDATE) {
393 		sc->beacon.updateslot = COMMIT;
394 		sc->beacon.slotupdate = slot;
395 	} else if (sc->beacon.updateslot == COMMIT &&
396 		   sc->beacon.slotupdate == slot) {
397 		ah->slottime = sc->beacon.slottime;
398 		ath9k_hw_init_global_settings(ah);
399 		sc->beacon.updateslot = OK;
400 	}
401 
402 	if (bf) {
403 		ath9k_reset_beacon_status(sc);
404 
405 		ath_dbg(common, BEACON,
406 			"Transmitting beacon for slot: %d\n", slot);
407 
408 		/* NB: cabq traffic should already be queued and primed */
409 		ath9k_hw_puttxbuf(ah, sc->beacon.beaconq, bf->bf_daddr);
410 
411 		if (!edma)
412 			ath9k_hw_txstart(ah, sc->beacon.beaconq);
413 	}
414 }
415 
416 /*
417  * Both nexttbtt and intval have to be in usecs.
418  */
419 static void ath9k_beacon_init(struct ath_softc *sc, u32 nexttbtt,
420 			      u32 intval, bool reset_tsf)
421 {
422 	struct ath_hw *ah = sc->sc_ah;
423 
424 	ath9k_hw_disable_interrupts(ah);
425 	if (reset_tsf)
426 		ath9k_hw_reset_tsf(ah);
427 	ath9k_beaconq_config(sc);
428 	ath9k_hw_beaconinit(ah, nexttbtt, intval);
429 	sc->beacon.bmisscnt = 0;
430 	ath9k_hw_set_interrupts(ah);
431 	ath9k_hw_enable_interrupts(ah);
432 }
433 
434 /*
435  * For multi-bss ap support beacons are either staggered evenly over N slots or
436  * burst together.  For the former arrange for the SWBA to be delivered for each
437  * slot. Slots that are not occupied will generate nothing.
438  */
439 static void ath9k_beacon_config_ap(struct ath_softc *sc,
440 				   struct ath_beacon_config *conf)
441 {
442 	struct ath_hw *ah = sc->sc_ah;
443 	struct ath_common *common = ath9k_hw_common(ah);
444 	u32 nexttbtt, intval;
445 
446 	/* NB: the beacon interval is kept internally in TU's */
447 	intval = TU_TO_USEC(conf->beacon_interval);
448 	intval /= ATH_BCBUF;
449 	nexttbtt = intval;
450 
451 	if (conf->enable_beacon)
452 		ah->imask |= ATH9K_INT_SWBA;
453 	else
454 		ah->imask &= ~ATH9K_INT_SWBA;
455 
456 	ath_dbg(common, BEACON,
457 		"AP (%s) nexttbtt: %u intval: %u conf_intval: %u\n",
458 		(conf->enable_beacon) ? "Enable" : "Disable",
459 		nexttbtt, intval, conf->beacon_interval);
460 
461 	ath9k_beacon_init(sc, nexttbtt, intval, true);
462 }
463 
464 /*
465  * This sets up the beacon timers according to the timestamp of the last
466  * received beacon and the current TSF, configures PCF and DTIM
467  * handling, programs the sleep registers so the hardware will wakeup in
468  * time to receive beacons, and configures the beacon miss handling so
469  * we'll receive a BMISS interrupt when we stop seeing beacons from the AP
470  * we've associated with.
471  */
472 static void ath9k_beacon_config_sta(struct ath_softc *sc,
473 				    struct ath_beacon_config *conf)
474 {
475 	struct ath_hw *ah = sc->sc_ah;
476 	struct ath_common *common = ath9k_hw_common(ah);
477 	struct ath9k_beacon_state bs;
478 	int dtimperiod, dtimcount, sleepduration;
479 	int cfpperiod, cfpcount;
480 	u32 nexttbtt = 0, intval, tsftu;
481 	u64 tsf;
482 	int num_beacons, offset, dtim_dec_count, cfp_dec_count;
483 
484 	/* No need to configure beacon if we are not associated */
485 	if (!test_bit(SC_OP_PRIM_STA_VIF, &sc->sc_flags)) {
486 		ath_dbg(common, BEACON,
487 			"STA is not yet associated..skipping beacon config\n");
488 		return;
489 	}
490 
491 	memset(&bs, 0, sizeof(bs));
492 	intval = conf->beacon_interval;
493 
494 	/*
495 	 * Setup dtim and cfp parameters according to
496 	 * last beacon we received (which may be none).
497 	 */
498 	dtimperiod = conf->dtim_period;
499 	dtimcount = conf->dtim_count;
500 	if (dtimcount >= dtimperiod)	/* NB: sanity check */
501 		dtimcount = 0;
502 	cfpperiod = 1;			/* NB: no PCF support yet */
503 	cfpcount = 0;
504 
505 	sleepduration = conf->listen_interval * intval;
506 
507 	/*
508 	 * Pull nexttbtt forward to reflect the current
509 	 * TSF and calculate dtim+cfp state for the result.
510 	 */
511 	tsf = ath9k_hw_gettsf64(ah);
512 	tsftu = TSF_TO_TU(tsf>>32, tsf) + FUDGE;
513 
514 	num_beacons = tsftu / intval + 1;
515 	offset = tsftu % intval;
516 	nexttbtt = tsftu - offset;
517 	if (offset)
518 		nexttbtt += intval;
519 
520 	/* DTIM Beacon every dtimperiod Beacon */
521 	dtim_dec_count = num_beacons % dtimperiod;
522 	/* CFP every cfpperiod DTIM Beacon */
523 	cfp_dec_count = (num_beacons / dtimperiod) % cfpperiod;
524 	if (dtim_dec_count)
525 		cfp_dec_count++;
526 
527 	dtimcount -= dtim_dec_count;
528 	if (dtimcount < 0)
529 		dtimcount += dtimperiod;
530 
531 	cfpcount -= cfp_dec_count;
532 	if (cfpcount < 0)
533 		cfpcount += cfpperiod;
534 
535 	bs.bs_intval = intval;
536 	bs.bs_nexttbtt = nexttbtt;
537 	bs.bs_dtimperiod = dtimperiod*intval;
538 	bs.bs_nextdtim = bs.bs_nexttbtt + dtimcount*intval;
539 	bs.bs_cfpperiod = cfpperiod*bs.bs_dtimperiod;
540 	bs.bs_cfpnext = bs.bs_nextdtim + cfpcount*bs.bs_dtimperiod;
541 	bs.bs_cfpmaxduration = 0;
542 
543 	/*
544 	 * Calculate the number of consecutive beacons to miss* before taking
545 	 * a BMISS interrupt. The configuration is specified in TU so we only
546 	 * need calculate based	on the beacon interval.  Note that we clamp the
547 	 * result to at most 15 beacons.
548 	 */
549 	if (sleepduration > intval) {
550 		bs.bs_bmissthreshold = conf->listen_interval *
551 			ATH_DEFAULT_BMISS_LIMIT / 2;
552 	} else {
553 		bs.bs_bmissthreshold = DIV_ROUND_UP(conf->bmiss_timeout, intval);
554 		if (bs.bs_bmissthreshold > 15)
555 			bs.bs_bmissthreshold = 15;
556 		else if (bs.bs_bmissthreshold <= 0)
557 			bs.bs_bmissthreshold = 1;
558 	}
559 
560 	/*
561 	 * Calculate sleep duration. The configuration is given in ms.
562 	 * We ensure a multiple of the beacon period is used. Also, if the sleep
563 	 * duration is greater than the DTIM period then it makes senses
564 	 * to make it a multiple of that.
565 	 *
566 	 * XXX fixed at 100ms
567 	 */
568 
569 	bs.bs_sleepduration = roundup(IEEE80211_MS_TO_TU(100), sleepduration);
570 	if (bs.bs_sleepduration > bs.bs_dtimperiod)
571 		bs.bs_sleepduration = bs.bs_dtimperiod;
572 
573 	/* TSF out of range threshold fixed at 1 second */
574 	bs.bs_tsfoor_threshold = ATH9K_TSFOOR_THRESHOLD;
575 
576 	ath_dbg(common, BEACON, "tsf: %llu tsftu: %u\n", tsf, tsftu);
577 	ath_dbg(common, BEACON,
578 		"bmiss: %u sleep: %u cfp-period: %u maxdur: %u next: %u\n",
579 		bs.bs_bmissthreshold, bs.bs_sleepduration,
580 		bs.bs_cfpperiod, bs.bs_cfpmaxduration, bs.bs_cfpnext);
581 
582 	/* Set the computed STA beacon timers */
583 
584 	ath9k_hw_disable_interrupts(ah);
585 	ath9k_hw_set_sta_beacon_timers(ah, &bs);
586 	ah->imask |= ATH9K_INT_BMISS;
587 
588 	ath9k_hw_set_interrupts(ah);
589 	ath9k_hw_enable_interrupts(ah);
590 }
591 
592 static void ath9k_beacon_config_adhoc(struct ath_softc *sc,
593 				      struct ath_beacon_config *conf)
594 {
595 	struct ath_hw *ah = sc->sc_ah;
596 	struct ath_common *common = ath9k_hw_common(ah);
597 	u32 intval, nexttbtt;
598 
599 	ath9k_reset_beacon_status(sc);
600 
601 	intval = TU_TO_USEC(conf->beacon_interval);
602 
603 	if (conf->ibss_creator) {
604 		nexttbtt = intval;
605 	} else {
606 		u32 tbtt, offset, tsftu;
607 		u64 tsf;
608 
609 		/*
610 		 * Pull nexttbtt forward to reflect the current
611 		 * sync'd TSF.
612 		 */
613 		tsf = ath9k_hw_gettsf64(ah);
614 		tsftu = TSF_TO_TU(tsf >> 32, tsf) + FUDGE;
615 		offset = tsftu % conf->beacon_interval;
616 		tbtt = tsftu - offset;
617 		if (offset)
618 			tbtt += conf->beacon_interval;
619 
620 		nexttbtt = TU_TO_USEC(tbtt);
621 	}
622 
623 	if (conf->enable_beacon)
624 		ah->imask |= ATH9K_INT_SWBA;
625 	else
626 		ah->imask &= ~ATH9K_INT_SWBA;
627 
628 	ath_dbg(common, BEACON,
629 		"IBSS (%s) nexttbtt: %u intval: %u conf_intval: %u\n",
630 		(conf->enable_beacon) ? "Enable" : "Disable",
631 		nexttbtt, intval, conf->beacon_interval);
632 
633 	ath9k_beacon_init(sc, nexttbtt, intval, conf->ibss_creator);
634 
635 	/*
636 	 * Set the global 'beacon has been configured' flag for the
637 	 * joiner case in IBSS mode.
638 	 */
639 	if (!conf->ibss_creator && conf->enable_beacon)
640 		set_bit(SC_OP_BEACONS, &sc->sc_flags);
641 }
642 
643 bool ath9k_allow_beacon_config(struct ath_softc *sc, struct ieee80211_vif *vif)
644 {
645 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
646 	struct ath_vif *avp = (void *)vif->drv_priv;
647 
648 	if (sc->sc_ah->opmode == NL80211_IFTYPE_AP) {
649 		if ((vif->type != NL80211_IFTYPE_AP) ||
650 		    (sc->nbcnvifs > 1)) {
651 			ath_dbg(common, CONFIG,
652 				"An AP interface is already present !\n");
653 			return false;
654 		}
655 	}
656 
657 	if (sc->sc_ah->opmode == NL80211_IFTYPE_STATION) {
658 		if ((vif->type == NL80211_IFTYPE_STATION) &&
659 		    test_bit(SC_OP_BEACONS, &sc->sc_flags) &&
660 		    !avp->primary_sta_vif) {
661 			ath_dbg(common, CONFIG,
662 				"Beacon already configured for a station interface\n");
663 			return false;
664 		}
665 	}
666 
667 	return true;
668 }
669 
670 static void ath9k_cache_beacon_config(struct ath_softc *sc,
671 				      struct ieee80211_bss_conf *bss_conf)
672 {
673 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
674 	struct ath_beacon_config *cur_conf = &sc->cur_beacon_conf;
675 
676 	ath_dbg(common, BEACON,
677 		"Caching beacon data for BSS: %pM\n", bss_conf->bssid);
678 
679 	cur_conf->beacon_interval = bss_conf->beacon_int;
680 	cur_conf->dtim_period = bss_conf->dtim_period;
681 	cur_conf->listen_interval = 1;
682 	cur_conf->dtim_count = 1;
683 	cur_conf->ibss_creator = bss_conf->ibss_creator;
684 	cur_conf->bmiss_timeout =
685 		ATH_DEFAULT_BMISS_LIMIT * cur_conf->beacon_interval;
686 
687 	/*
688 	 * It looks like mac80211 may end up using beacon interval of zero in
689 	 * some cases (at least for mesh point). Avoid getting into an
690 	 * infinite loop by using a bit safer value instead. To be safe,
691 	 * do sanity check on beacon interval for all operating modes.
692 	 */
693 	if (cur_conf->beacon_interval == 0)
694 		cur_conf->beacon_interval = 100;
695 
696 	/*
697 	 * We don't parse dtim period from mac80211 during the driver
698 	 * initialization as it breaks association with hidden-ssid
699 	 * AP and it causes latency in roaming
700 	 */
701 	if (cur_conf->dtim_period == 0)
702 		cur_conf->dtim_period = 1;
703 
704 }
705 
706 void ath9k_beacon_config(struct ath_softc *sc, struct ieee80211_vif *vif,
707 			 u32 changed)
708 {
709 	struct ieee80211_bss_conf *bss_conf = &vif->bss_conf;
710 	struct ath_beacon_config *cur_conf = &sc->cur_beacon_conf;
711 	unsigned long flags;
712 	bool skip_beacon = false;
713 
714 	if (sc->sc_ah->opmode == NL80211_IFTYPE_STATION) {
715 		ath9k_cache_beacon_config(sc, bss_conf);
716 		ath9k_set_beacon(sc);
717 		set_bit(SC_OP_BEACONS, &sc->sc_flags);
718 		return;
719 
720 	}
721 
722 	/*
723 	 * Take care of multiple interfaces when
724 	 * enabling/disabling SWBA.
725 	 */
726 	if (changed & BSS_CHANGED_BEACON_ENABLED) {
727 		if (!bss_conf->enable_beacon &&
728 		    (sc->nbcnvifs <= 1)) {
729 			cur_conf->enable_beacon = false;
730 		} else if (bss_conf->enable_beacon) {
731 			cur_conf->enable_beacon = true;
732 			ath9k_cache_beacon_config(sc, bss_conf);
733 		}
734 	}
735 
736 	/*
737 	 * Configure the HW beacon registers only when we have a valid
738 	 * beacon interval.
739 	 */
740 	if (cur_conf->beacon_interval) {
741 		/*
742 		 * If we are joining an existing IBSS network, start beaconing
743 		 * only after a TSF-sync has taken place. Ensure that this
744 		 * happens by setting the appropriate flags.
745 		 */
746 		if ((changed & BSS_CHANGED_IBSS) && !bss_conf->ibss_creator &&
747 		    bss_conf->enable_beacon) {
748 			spin_lock_irqsave(&sc->sc_pm_lock, flags);
749 			sc->ps_flags |= PS_BEACON_SYNC | PS_WAIT_FOR_BEACON;
750 			spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
751 			skip_beacon = true;
752 		} else {
753 			ath9k_set_beacon(sc);
754 		}
755 
756 		/*
757 		 * Do not set the SC_OP_BEACONS flag for IBSS joiner mode
758 		 * here, it is done in ath9k_beacon_config_adhoc().
759 		 */
760 		if (cur_conf->enable_beacon && !skip_beacon)
761 			set_bit(SC_OP_BEACONS, &sc->sc_flags);
762 		else
763 			clear_bit(SC_OP_BEACONS, &sc->sc_flags);
764 	}
765 }
766 
767 void ath9k_set_beacon(struct ath_softc *sc)
768 {
769 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
770 	struct ath_beacon_config *cur_conf = &sc->cur_beacon_conf;
771 
772 	switch (sc->sc_ah->opmode) {
773 	case NL80211_IFTYPE_AP:
774 	case NL80211_IFTYPE_MESH_POINT:
775 		ath9k_beacon_config_ap(sc, cur_conf);
776 		break;
777 	case NL80211_IFTYPE_ADHOC:
778 		ath9k_beacon_config_adhoc(sc, cur_conf);
779 		break;
780 	case NL80211_IFTYPE_STATION:
781 		ath9k_beacon_config_sta(sc, cur_conf);
782 		break;
783 	default:
784 		ath_dbg(common, CONFIG, "Unsupported beaconing mode\n");
785 		return;
786 	}
787 }
788