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 void ath9k_beacon_tasklet(unsigned long data)
295 {
296 	struct ath_softc *sc = (struct ath_softc *)data;
297 	struct ath_hw *ah = sc->sc_ah;
298 	struct ath_common *common = ath9k_hw_common(ah);
299 	struct ath_buf *bf = NULL;
300 	struct ieee80211_vif *vif;
301 	bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
302 	int slot;
303 
304 	if (test_bit(SC_OP_HW_RESET, &sc->sc_flags)) {
305 		ath_dbg(common, RESET,
306 			"reset work is pending, skip beaconing now\n");
307 		return;
308 	}
309 
310 	/*
311 	 * Check if the previous beacon has gone out.  If
312 	 * not don't try to post another, skip this period
313 	 * and wait for the next.  Missed beacons indicate
314 	 * a problem and should not occur.  If we miss too
315 	 * many consecutive beacons reset the device.
316 	 */
317 	if (ath9k_hw_numtxpending(ah, sc->beacon.beaconq) != 0) {
318 		sc->beacon.bmisscnt++;
319 
320 		if (!ath9k_hw_check_alive(ah))
321 			ieee80211_queue_work(sc->hw, &sc->hw_check_work);
322 
323 		if (sc->beacon.bmisscnt < BSTUCK_THRESH * sc->nbcnvifs) {
324 			ath_dbg(common, BSTUCK,
325 				"missed %u consecutive beacons\n",
326 				sc->beacon.bmisscnt);
327 			ath9k_hw_stop_dma_queue(ah, sc->beacon.beaconq);
328 			if (sc->beacon.bmisscnt > 3)
329 				ath9k_hw_bstuck_nfcal(ah);
330 		} else if (sc->beacon.bmisscnt >= BSTUCK_THRESH) {
331 			ath_dbg(common, BSTUCK, "beacon is officially stuck\n");
332 			sc->beacon.bmisscnt = 0;
333 			ath9k_queue_reset(sc, RESET_TYPE_BEACON_STUCK);
334 		}
335 
336 		return;
337 	}
338 
339 	slot = ath9k_beacon_choose_slot(sc);
340 	vif = sc->beacon.bslot[slot];
341 
342 	if (!vif || !vif->bss_conf.enable_beacon)
343 		return;
344 
345 	bf = ath9k_beacon_generate(sc->hw, vif);
346 
347 	if (sc->beacon.bmisscnt != 0) {
348 		ath_dbg(common, BSTUCK, "resume beacon xmit after %u misses\n",
349 			sc->beacon.bmisscnt);
350 		sc->beacon.bmisscnt = 0;
351 	}
352 
353 	/*
354 	 * Handle slot time change when a non-ERP station joins/leaves
355 	 * an 11g network.  The 802.11 layer notifies us via callback,
356 	 * we mark updateslot, then wait one beacon before effecting
357 	 * the change.  This gives associated stations at least one
358 	 * beacon interval to note the state change.
359 	 *
360 	 * NB: The slot time change state machine is clocked according
361 	 *     to whether we are bursting or staggering beacons.  We
362 	 *     recognize the request to update and record the current
363 	 *     slot then don't transition until that slot is reached
364 	 *     again.  If we miss a beacon for that slot then we'll be
365 	 *     slow to transition but we'll be sure at least one beacon
366 	 *     interval has passed.  When bursting slot is always left
367 	 *     set to ATH_BCBUF so this check is a noop.
368 	 */
369 	if (sc->beacon.updateslot == UPDATE) {
370 		sc->beacon.updateslot = COMMIT;
371 		sc->beacon.slotupdate = slot;
372 	} else if (sc->beacon.updateslot == COMMIT &&
373 		   sc->beacon.slotupdate == slot) {
374 		ah->slottime = sc->beacon.slottime;
375 		ath9k_hw_init_global_settings(ah);
376 		sc->beacon.updateslot = OK;
377 	}
378 
379 	if (bf) {
380 		ath9k_reset_beacon_status(sc);
381 
382 		ath_dbg(common, BEACON,
383 			"Transmitting beacon for slot: %d\n", slot);
384 
385 		/* NB: cabq traffic should already be queued and primed */
386 		ath9k_hw_puttxbuf(ah, sc->beacon.beaconq, bf->bf_daddr);
387 
388 		if (!edma)
389 			ath9k_hw_txstart(ah, sc->beacon.beaconq);
390 	}
391 }
392 
393 /*
394  * Both nexttbtt and intval have to be in usecs.
395  */
396 static void ath9k_beacon_init(struct ath_softc *sc, u32 nexttbtt,
397 			      u32 intval, bool reset_tsf)
398 {
399 	struct ath_hw *ah = sc->sc_ah;
400 
401 	ath9k_hw_disable_interrupts(ah);
402 	if (reset_tsf)
403 		ath9k_hw_reset_tsf(ah);
404 	ath9k_beaconq_config(sc);
405 	ath9k_hw_beaconinit(ah, nexttbtt, intval);
406 	sc->beacon.bmisscnt = 0;
407 	ath9k_hw_set_interrupts(ah);
408 	ath9k_hw_enable_interrupts(ah);
409 }
410 
411 /*
412  * For multi-bss ap support beacons are either staggered evenly over N slots or
413  * burst together.  For the former arrange for the SWBA to be delivered for each
414  * slot. Slots that are not occupied will generate nothing.
415  */
416 static void ath9k_beacon_config_ap(struct ath_softc *sc,
417 				   struct ath_beacon_config *conf)
418 {
419 	struct ath_hw *ah = sc->sc_ah;
420 	struct ath_common *common = ath9k_hw_common(ah);
421 	u32 nexttbtt, intval;
422 
423 	/* NB: the beacon interval is kept internally in TU's */
424 	intval = TU_TO_USEC(conf->beacon_interval);
425 	intval /= ATH_BCBUF;
426 	nexttbtt = intval;
427 
428 	if (conf->enable_beacon)
429 		ah->imask |= ATH9K_INT_SWBA;
430 	else
431 		ah->imask &= ~ATH9K_INT_SWBA;
432 
433 	ath_dbg(common, BEACON,
434 		"AP (%s) nexttbtt: %u intval: %u conf_intval: %u\n",
435 		(conf->enable_beacon) ? "Enable" : "Disable",
436 		nexttbtt, intval, conf->beacon_interval);
437 
438 	ath9k_beacon_init(sc, nexttbtt, intval, true);
439 }
440 
441 /*
442  * This sets up the beacon timers according to the timestamp of the last
443  * received beacon and the current TSF, configures PCF and DTIM
444  * handling, programs the sleep registers so the hardware will wakeup in
445  * time to receive beacons, and configures the beacon miss handling so
446  * we'll receive a BMISS interrupt when we stop seeing beacons from the AP
447  * we've associated with.
448  */
449 static void ath9k_beacon_config_sta(struct ath_softc *sc,
450 				    struct ath_beacon_config *conf)
451 {
452 	struct ath_hw *ah = sc->sc_ah;
453 	struct ath_common *common = ath9k_hw_common(ah);
454 	struct ath9k_beacon_state bs;
455 	int dtimperiod, dtimcount, sleepduration;
456 	int cfpperiod, cfpcount;
457 	u32 nexttbtt = 0, intval, tsftu;
458 	u64 tsf;
459 	int num_beacons, offset, dtim_dec_count, cfp_dec_count;
460 
461 	/* No need to configure beacon if we are not associated */
462 	if (!test_bit(SC_OP_PRIM_STA_VIF, &sc->sc_flags)) {
463 		ath_dbg(common, BEACON,
464 			"STA is not yet associated..skipping beacon config\n");
465 		return;
466 	}
467 
468 	memset(&bs, 0, sizeof(bs));
469 	intval = conf->beacon_interval;
470 
471 	/*
472 	 * Setup dtim and cfp parameters according to
473 	 * last beacon we received (which may be none).
474 	 */
475 	dtimperiod = conf->dtim_period;
476 	dtimcount = conf->dtim_count;
477 	if (dtimcount >= dtimperiod)	/* NB: sanity check */
478 		dtimcount = 0;
479 	cfpperiod = 1;			/* NB: no PCF support yet */
480 	cfpcount = 0;
481 
482 	sleepduration = conf->listen_interval * intval;
483 
484 	/*
485 	 * Pull nexttbtt forward to reflect the current
486 	 * TSF and calculate dtim+cfp state for the result.
487 	 */
488 	tsf = ath9k_hw_gettsf64(ah);
489 	tsftu = TSF_TO_TU(tsf>>32, tsf) + FUDGE;
490 
491 	num_beacons = tsftu / intval + 1;
492 	offset = tsftu % intval;
493 	nexttbtt = tsftu - offset;
494 	if (offset)
495 		nexttbtt += intval;
496 
497 	/* DTIM Beacon every dtimperiod Beacon */
498 	dtim_dec_count = num_beacons % dtimperiod;
499 	/* CFP every cfpperiod DTIM Beacon */
500 	cfp_dec_count = (num_beacons / dtimperiod) % cfpperiod;
501 	if (dtim_dec_count)
502 		cfp_dec_count++;
503 
504 	dtimcount -= dtim_dec_count;
505 	if (dtimcount < 0)
506 		dtimcount += dtimperiod;
507 
508 	cfpcount -= cfp_dec_count;
509 	if (cfpcount < 0)
510 		cfpcount += cfpperiod;
511 
512 	bs.bs_intval = intval;
513 	bs.bs_nexttbtt = nexttbtt;
514 	bs.bs_dtimperiod = dtimperiod*intval;
515 	bs.bs_nextdtim = bs.bs_nexttbtt + dtimcount*intval;
516 	bs.bs_cfpperiod = cfpperiod*bs.bs_dtimperiod;
517 	bs.bs_cfpnext = bs.bs_nextdtim + cfpcount*bs.bs_dtimperiod;
518 	bs.bs_cfpmaxduration = 0;
519 
520 	/*
521 	 * Calculate the number of consecutive beacons to miss* before taking
522 	 * a BMISS interrupt. The configuration is specified in TU so we only
523 	 * need calculate based	on the beacon interval.  Note that we clamp the
524 	 * result to at most 15 beacons.
525 	 */
526 	if (sleepduration > intval) {
527 		bs.bs_bmissthreshold = conf->listen_interval *
528 			ATH_DEFAULT_BMISS_LIMIT / 2;
529 	} else {
530 		bs.bs_bmissthreshold = DIV_ROUND_UP(conf->bmiss_timeout, intval);
531 		if (bs.bs_bmissthreshold > 15)
532 			bs.bs_bmissthreshold = 15;
533 		else if (bs.bs_bmissthreshold <= 0)
534 			bs.bs_bmissthreshold = 1;
535 	}
536 
537 	/*
538 	 * Calculate sleep duration. The configuration is given in ms.
539 	 * We ensure a multiple of the beacon period is used. Also, if the sleep
540 	 * duration is greater than the DTIM period then it makes senses
541 	 * to make it a multiple of that.
542 	 *
543 	 * XXX fixed at 100ms
544 	 */
545 
546 	bs.bs_sleepduration = roundup(IEEE80211_MS_TO_TU(100), sleepduration);
547 	if (bs.bs_sleepduration > bs.bs_dtimperiod)
548 		bs.bs_sleepduration = bs.bs_dtimperiod;
549 
550 	/* TSF out of range threshold fixed at 1 second */
551 	bs.bs_tsfoor_threshold = ATH9K_TSFOOR_THRESHOLD;
552 
553 	ath_dbg(common, BEACON, "tsf: %llu tsftu: %u\n", tsf, tsftu);
554 	ath_dbg(common, BEACON,
555 		"bmiss: %u sleep: %u cfp-period: %u maxdur: %u next: %u\n",
556 		bs.bs_bmissthreshold, bs.bs_sleepduration,
557 		bs.bs_cfpperiod, bs.bs_cfpmaxduration, bs.bs_cfpnext);
558 
559 	/* Set the computed STA beacon timers */
560 
561 	ath9k_hw_disable_interrupts(ah);
562 	ath9k_hw_set_sta_beacon_timers(ah, &bs);
563 	ah->imask |= ATH9K_INT_BMISS;
564 
565 	ath9k_hw_set_interrupts(ah);
566 	ath9k_hw_enable_interrupts(ah);
567 }
568 
569 static void ath9k_beacon_config_adhoc(struct ath_softc *sc,
570 				      struct ath_beacon_config *conf)
571 {
572 	struct ath_hw *ah = sc->sc_ah;
573 	struct ath_common *common = ath9k_hw_common(ah);
574 	u32 intval, nexttbtt;
575 
576 	ath9k_reset_beacon_status(sc);
577 
578 	intval = TU_TO_USEC(conf->beacon_interval);
579 
580 	if (conf->ibss_creator) {
581 		nexttbtt = intval;
582 	} else {
583 		u32 tbtt, offset, tsftu;
584 		u64 tsf;
585 
586 		/*
587 		 * Pull nexttbtt forward to reflect the current
588 		 * sync'd TSF.
589 		 */
590 		tsf = ath9k_hw_gettsf64(ah);
591 		tsftu = TSF_TO_TU(tsf >> 32, tsf) + FUDGE;
592 		offset = tsftu % conf->beacon_interval;
593 		tbtt = tsftu - offset;
594 		if (offset)
595 			tbtt += conf->beacon_interval;
596 
597 		nexttbtt = TU_TO_USEC(tbtt);
598 	}
599 
600 	if (conf->enable_beacon)
601 		ah->imask |= ATH9K_INT_SWBA;
602 	else
603 		ah->imask &= ~ATH9K_INT_SWBA;
604 
605 	ath_dbg(common, BEACON,
606 		"IBSS (%s) nexttbtt: %u intval: %u conf_intval: %u\n",
607 		(conf->enable_beacon) ? "Enable" : "Disable",
608 		nexttbtt, intval, conf->beacon_interval);
609 
610 	ath9k_beacon_init(sc, nexttbtt, intval, conf->ibss_creator);
611 
612 	/*
613 	 * Set the global 'beacon has been configured' flag for the
614 	 * joiner case in IBSS mode.
615 	 */
616 	if (!conf->ibss_creator && conf->enable_beacon)
617 		set_bit(SC_OP_BEACONS, &sc->sc_flags);
618 }
619 
620 bool ath9k_allow_beacon_config(struct ath_softc *sc, struct ieee80211_vif *vif)
621 {
622 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
623 	struct ath_vif *avp = (void *)vif->drv_priv;
624 
625 	if (sc->sc_ah->opmode == NL80211_IFTYPE_AP) {
626 		if ((vif->type != NL80211_IFTYPE_AP) ||
627 		    (sc->nbcnvifs > 1)) {
628 			ath_dbg(common, CONFIG,
629 				"An AP interface is already present !\n");
630 			return false;
631 		}
632 	}
633 
634 	if (sc->sc_ah->opmode == NL80211_IFTYPE_STATION) {
635 		if ((vif->type == NL80211_IFTYPE_STATION) &&
636 		    test_bit(SC_OP_BEACONS, &sc->sc_flags) &&
637 		    !avp->primary_sta_vif) {
638 			ath_dbg(common, CONFIG,
639 				"Beacon already configured for a station interface\n");
640 			return false;
641 		}
642 	}
643 
644 	return true;
645 }
646 
647 static void ath9k_cache_beacon_config(struct ath_softc *sc,
648 				      struct ieee80211_bss_conf *bss_conf)
649 {
650 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
651 	struct ath_beacon_config *cur_conf = &sc->cur_beacon_conf;
652 
653 	ath_dbg(common, BEACON,
654 		"Caching beacon data for BSS: %pM\n", bss_conf->bssid);
655 
656 	cur_conf->beacon_interval = bss_conf->beacon_int;
657 	cur_conf->dtim_period = bss_conf->dtim_period;
658 	cur_conf->listen_interval = 1;
659 	cur_conf->dtim_count = 1;
660 	cur_conf->ibss_creator = bss_conf->ibss_creator;
661 	cur_conf->bmiss_timeout =
662 		ATH_DEFAULT_BMISS_LIMIT * cur_conf->beacon_interval;
663 
664 	/*
665 	 * It looks like mac80211 may end up using beacon interval of zero in
666 	 * some cases (at least for mesh point). Avoid getting into an
667 	 * infinite loop by using a bit safer value instead. To be safe,
668 	 * do sanity check on beacon interval for all operating modes.
669 	 */
670 	if (cur_conf->beacon_interval == 0)
671 		cur_conf->beacon_interval = 100;
672 
673 	/*
674 	 * We don't parse dtim period from mac80211 during the driver
675 	 * initialization as it breaks association with hidden-ssid
676 	 * AP and it causes latency in roaming
677 	 */
678 	if (cur_conf->dtim_period == 0)
679 		cur_conf->dtim_period = 1;
680 
681 }
682 
683 void ath9k_beacon_config(struct ath_softc *sc, struct ieee80211_vif *vif,
684 			 u32 changed)
685 {
686 	struct ieee80211_bss_conf *bss_conf = &vif->bss_conf;
687 	struct ath_beacon_config *cur_conf = &sc->cur_beacon_conf;
688 	unsigned long flags;
689 	bool skip_beacon = false;
690 
691 	if (sc->sc_ah->opmode == NL80211_IFTYPE_STATION) {
692 		ath9k_cache_beacon_config(sc, bss_conf);
693 		ath9k_set_beacon(sc);
694 		set_bit(SC_OP_BEACONS, &sc->sc_flags);
695 		return;
696 
697 	}
698 
699 	/*
700 	 * Take care of multiple interfaces when
701 	 * enabling/disabling SWBA.
702 	 */
703 	if (changed & BSS_CHANGED_BEACON_ENABLED) {
704 		if (!bss_conf->enable_beacon &&
705 		    (sc->nbcnvifs <= 1)) {
706 			cur_conf->enable_beacon = false;
707 		} else if (bss_conf->enable_beacon) {
708 			cur_conf->enable_beacon = true;
709 			ath9k_cache_beacon_config(sc, bss_conf);
710 		}
711 	}
712 
713 	/*
714 	 * Configure the HW beacon registers only when we have a valid
715 	 * beacon interval.
716 	 */
717 	if (cur_conf->beacon_interval) {
718 		/*
719 		 * If we are joining an existing IBSS network, start beaconing
720 		 * only after a TSF-sync has taken place. Ensure that this
721 		 * happens by setting the appropriate flags.
722 		 */
723 		if ((changed & BSS_CHANGED_IBSS) && !bss_conf->ibss_creator &&
724 		    bss_conf->enable_beacon) {
725 			spin_lock_irqsave(&sc->sc_pm_lock, flags);
726 			sc->ps_flags |= PS_BEACON_SYNC | PS_WAIT_FOR_BEACON;
727 			spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
728 			skip_beacon = true;
729 		} else {
730 			ath9k_set_beacon(sc);
731 		}
732 
733 		/*
734 		 * Do not set the SC_OP_BEACONS flag for IBSS joiner mode
735 		 * here, it is done in ath9k_beacon_config_adhoc().
736 		 */
737 		if (cur_conf->enable_beacon && !skip_beacon)
738 			set_bit(SC_OP_BEACONS, &sc->sc_flags);
739 		else
740 			clear_bit(SC_OP_BEACONS, &sc->sc_flags);
741 	}
742 }
743 
744 void ath9k_set_beacon(struct ath_softc *sc)
745 {
746 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
747 	struct ath_beacon_config *cur_conf = &sc->cur_beacon_conf;
748 
749 	switch (sc->sc_ah->opmode) {
750 	case NL80211_IFTYPE_AP:
751 	case NL80211_IFTYPE_MESH_POINT:
752 		ath9k_beacon_config_ap(sc, cur_conf);
753 		break;
754 	case NL80211_IFTYPE_ADHOC:
755 		ath9k_beacon_config_adhoc(sc, cur_conf);
756 		break;
757 	case NL80211_IFTYPE_STATION:
758 		ath9k_beacon_config_sta(sc, cur_conf);
759 		break;
760 	default:
761 		ath_dbg(common, CONFIG, "Unsupported beaconing mode\n");
762 		return;
763 	}
764 }
765