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 static 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 	u32 tsfadjust;
283 
284 	if (avp->av_bslot == 0)
285 		return;
286 
287 	tsfadjust = cur_conf->beacon_interval * avp->av_bslot;
288 	tsfadjust = TU_TO_USEC(tsfadjust) / ATH_BCBUF;
289 	avp->tsf_adjust = cpu_to_le64(tsfadjust);
290 
291 	ath_dbg(common, CONFIG, "tsfadjust is: %llu for bslot: %d\n",
292 		(unsigned long long)tsfadjust, avp->av_bslot);
293 }
294 
295 bool ath9k_csa_is_finished(struct ath_softc *sc)
296 {
297 	struct ieee80211_vif *vif;
298 
299 	vif = sc->csa_vif;
300 	if (!vif || !vif->csa_active)
301 		return false;
302 
303 	if (!ieee80211_csa_is_complete(vif))
304 		return false;
305 
306 	ieee80211_csa_finish(vif);
307 
308 	sc->csa_vif = NULL;
309 	return true;
310 }
311 
312 void ath9k_beacon_tasklet(unsigned long data)
313 {
314 	struct ath_softc *sc = (struct ath_softc *)data;
315 	struct ath_hw *ah = sc->sc_ah;
316 	struct ath_common *common = ath9k_hw_common(ah);
317 	struct ath_buf *bf = NULL;
318 	struct ieee80211_vif *vif;
319 	bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
320 	int slot;
321 
322 	if (test_bit(SC_OP_HW_RESET, &sc->sc_flags)) {
323 		ath_dbg(common, RESET,
324 			"reset work is pending, skip beaconing now\n");
325 		return;
326 	}
327 
328 	/*
329 	 * Check if the previous beacon has gone out.  If
330 	 * not don't try to post another, skip this period
331 	 * and wait for the next.  Missed beacons indicate
332 	 * a problem and should not occur.  If we miss too
333 	 * many consecutive beacons reset the device.
334 	 */
335 	if (ath9k_hw_numtxpending(ah, sc->beacon.beaconq) != 0) {
336 		sc->beacon.bmisscnt++;
337 
338 		ath9k_hw_check_nav(ah);
339 
340 		/*
341 		 * If the previous beacon has not been transmitted
342 		 * and a MAC/BB hang has been identified, return
343 		 * here because a chip reset would have been
344 		 * initiated.
345 		 */
346 		if (!ath_hw_check(sc))
347 			return;
348 
349 		if (sc->beacon.bmisscnt < BSTUCK_THRESH * sc->nbcnvifs) {
350 			ath_dbg(common, BSTUCK,
351 				"missed %u consecutive beacons\n",
352 				sc->beacon.bmisscnt);
353 			ath9k_hw_stop_dma_queue(ah, sc->beacon.beaconq);
354 			if (sc->beacon.bmisscnt > 3)
355 				ath9k_hw_bstuck_nfcal(ah);
356 		} else if (sc->beacon.bmisscnt >= BSTUCK_THRESH) {
357 			ath_dbg(common, BSTUCK, "beacon is officially stuck\n");
358 			sc->beacon.bmisscnt = 0;
359 			ath9k_queue_reset(sc, RESET_TYPE_BEACON_STUCK);
360 		}
361 
362 		return;
363 	}
364 
365 	/* EDMA devices check that in the tx completion function. */
366 	if (!edma && ath9k_csa_is_finished(sc))
367 		return;
368 
369 	slot = ath9k_beacon_choose_slot(sc);
370 	vif = sc->beacon.bslot[slot];
371 
372 	if (!vif || !vif->bss_conf.enable_beacon)
373 		return;
374 
375 	bf = ath9k_beacon_generate(sc->hw, vif);
376 
377 	if (sc->beacon.bmisscnt != 0) {
378 		ath_dbg(common, BSTUCK, "resume beacon xmit after %u misses\n",
379 			sc->beacon.bmisscnt);
380 		sc->beacon.bmisscnt = 0;
381 	}
382 
383 	/*
384 	 * Handle slot time change when a non-ERP station joins/leaves
385 	 * an 11g network.  The 802.11 layer notifies us via callback,
386 	 * we mark updateslot, then wait one beacon before effecting
387 	 * the change.  This gives associated stations at least one
388 	 * beacon interval to note the state change.
389 	 *
390 	 * NB: The slot time change state machine is clocked according
391 	 *     to whether we are bursting or staggering beacons.  We
392 	 *     recognize the request to update and record the current
393 	 *     slot then don't transition until that slot is reached
394 	 *     again.  If we miss a beacon for that slot then we'll be
395 	 *     slow to transition but we'll be sure at least one beacon
396 	 *     interval has passed.  When bursting slot is always left
397 	 *     set to ATH_BCBUF so this check is a noop.
398 	 */
399 	if (sc->beacon.updateslot == UPDATE) {
400 		sc->beacon.updateslot = COMMIT;
401 		sc->beacon.slotupdate = slot;
402 	} else if (sc->beacon.updateslot == COMMIT &&
403 		   sc->beacon.slotupdate == slot) {
404 		ah->slottime = sc->beacon.slottime;
405 		ath9k_hw_init_global_settings(ah);
406 		sc->beacon.updateslot = OK;
407 	}
408 
409 	if (bf) {
410 		ath9k_reset_beacon_status(sc);
411 
412 		ath_dbg(common, BEACON,
413 			"Transmitting beacon for slot: %d\n", slot);
414 
415 		/* NB: cabq traffic should already be queued and primed */
416 		ath9k_hw_puttxbuf(ah, sc->beacon.beaconq, bf->bf_daddr);
417 
418 		if (!edma)
419 			ath9k_hw_txstart(ah, sc->beacon.beaconq);
420 	}
421 }
422 
423 /*
424  * Both nexttbtt and intval have to be in usecs.
425  */
426 static void ath9k_beacon_init(struct ath_softc *sc, u32 nexttbtt,
427 			      u32 intval, bool reset_tsf)
428 {
429 	struct ath_hw *ah = sc->sc_ah;
430 
431 	ath9k_hw_disable_interrupts(ah);
432 	if (reset_tsf)
433 		ath9k_hw_reset_tsf(ah);
434 	ath9k_beaconq_config(sc);
435 	ath9k_hw_beaconinit(ah, nexttbtt, intval);
436 	sc->beacon.bmisscnt = 0;
437 	ath9k_hw_set_interrupts(ah);
438 	ath9k_hw_enable_interrupts(ah);
439 }
440 
441 /* Calculate the modulo of a 64 bit TSF snapshot with a TU divisor */
442 static u32 ath9k_mod_tsf64_tu(u64 tsf, u32 div_tu)
443 {
444 	u32 tsf_mod, tsf_hi, tsf_lo, mod_hi, mod_lo;
445 
446 	tsf_mod = tsf & (BIT(10) - 1);
447 	tsf_hi = tsf >> 32;
448 	tsf_lo = ((u32) tsf) >> 10;
449 
450 	mod_hi = tsf_hi % div_tu;
451 	mod_lo = ((mod_hi << 22) + tsf_lo) % div_tu;
452 
453 	return (mod_lo << 10) | tsf_mod;
454 }
455 
456 static u32 ath9k_get_next_tbtt(struct ath_softc *sc, u64 tsf,
457 			       unsigned int interval)
458 {
459 	struct ath_hw *ah = sc->sc_ah;
460 	unsigned int offset;
461 
462 	tsf += TU_TO_USEC(FUDGE + ah->config.sw_beacon_response_time);
463 	offset = ath9k_mod_tsf64_tu(tsf, interval);
464 
465 	return (u32) tsf + TU_TO_USEC(interval) - offset;
466 }
467 
468 /*
469  * For multi-bss ap support beacons are either staggered evenly over N slots or
470  * burst together.  For the former arrange for the SWBA to be delivered for each
471  * slot. Slots that are not occupied will generate nothing.
472  */
473 static void ath9k_beacon_config_ap(struct ath_softc *sc,
474 				   struct ath_beacon_config *conf)
475 {
476 	struct ath_hw *ah = sc->sc_ah;
477 	struct ath_common *common = ath9k_hw_common(ah);
478 	u32 nexttbtt, intval;
479 
480 	/* NB: the beacon interval is kept internally in TU's */
481 	intval = TU_TO_USEC(conf->beacon_interval);
482 	intval /= ATH_BCBUF;
483 	nexttbtt = ath9k_get_next_tbtt(sc, ath9k_hw_gettsf64(ah),
484 				       conf->beacon_interval);
485 
486 	if (conf->enable_beacon)
487 		ah->imask |= ATH9K_INT_SWBA;
488 	else
489 		ah->imask &= ~ATH9K_INT_SWBA;
490 
491 	ath_dbg(common, BEACON,
492 		"AP (%s) nexttbtt: %u intval: %u conf_intval: %u\n",
493 		(conf->enable_beacon) ? "Enable" : "Disable",
494 		nexttbtt, intval, conf->beacon_interval);
495 
496 	ath9k_beacon_init(sc, nexttbtt, intval, false);
497 }
498 
499 /*
500  * This sets up the beacon timers according to the timestamp of the last
501  * received beacon and the current TSF, configures PCF and DTIM
502  * handling, programs the sleep registers so the hardware will wakeup in
503  * time to receive beacons, and configures the beacon miss handling so
504  * we'll receive a BMISS interrupt when we stop seeing beacons from the AP
505  * we've associated with.
506  */
507 static void ath9k_beacon_config_sta(struct ath_softc *sc,
508 				    struct ath_beacon_config *conf)
509 {
510 	struct ath_hw *ah = sc->sc_ah;
511 	struct ath_common *common = ath9k_hw_common(ah);
512 	struct ath9k_beacon_state bs;
513 	int dtim_intval, sleepduration;
514 	u32 nexttbtt = 0, intval;
515 	u64 tsf;
516 
517 	/* No need to configure beacon if we are not associated */
518 	if (!test_bit(SC_OP_PRIM_STA_VIF, &sc->sc_flags)) {
519 		ath_dbg(common, BEACON,
520 			"STA is not yet associated..skipping beacon config\n");
521 		return;
522 	}
523 
524 	memset(&bs, 0, sizeof(bs));
525 	intval = conf->beacon_interval;
526 
527 	/*
528 	 * Setup dtim parameters according to
529 	 * last beacon we received (which may be none).
530 	 */
531 	dtim_intval = intval * conf->dtim_period;
532 	sleepduration = conf->listen_interval * intval;
533 
534 	/*
535 	 * Pull nexttbtt forward to reflect the current
536 	 * TSF and calculate dtim state for the result.
537 	 */
538 	tsf = ath9k_hw_gettsf64(ah);
539 	nexttbtt = ath9k_get_next_tbtt(sc, tsf, intval);
540 
541 	bs.bs_intval = TU_TO_USEC(intval);
542 	bs.bs_dtimperiod = conf->dtim_period * bs.bs_intval;
543 	bs.bs_nexttbtt = nexttbtt;
544 	bs.bs_nextdtim = nexttbtt;
545 	if (conf->dtim_period > 1)
546 		bs.bs_nextdtim = ath9k_get_next_tbtt(sc, tsf, dtim_intval);
547 
548 	/*
549 	 * Calculate the number of consecutive beacons to miss* before taking
550 	 * a BMISS interrupt. The configuration is specified in TU so we only
551 	 * need calculate based	on the beacon interval.  Note that we clamp the
552 	 * result to at most 15 beacons.
553 	 */
554 	if (sleepduration > intval) {
555 		bs.bs_bmissthreshold = conf->listen_interval *
556 			ATH_DEFAULT_BMISS_LIMIT / 2;
557 	} else {
558 		bs.bs_bmissthreshold = DIV_ROUND_UP(conf->bmiss_timeout, intval);
559 		if (bs.bs_bmissthreshold > 15)
560 			bs.bs_bmissthreshold = 15;
561 		else if (bs.bs_bmissthreshold <= 0)
562 			bs.bs_bmissthreshold = 1;
563 	}
564 
565 	/*
566 	 * Calculate sleep duration. The configuration is given in ms.
567 	 * We ensure a multiple of the beacon period is used. Also, if the sleep
568 	 * duration is greater than the DTIM period then it makes senses
569 	 * to make it a multiple of that.
570 	 *
571 	 * XXX fixed at 100ms
572 	 */
573 
574 	bs.bs_sleepduration = TU_TO_USEC(roundup(IEEE80211_MS_TO_TU(100),
575 						 sleepduration));
576 	if (bs.bs_sleepduration > bs.bs_dtimperiod)
577 		bs.bs_sleepduration = bs.bs_dtimperiod;
578 
579 	/* TSF out of range threshold fixed at 1 second */
580 	bs.bs_tsfoor_threshold = ATH9K_TSFOOR_THRESHOLD;
581 
582 	ath_dbg(common, BEACON, "bmiss: %u sleep: %u\n",
583 		bs.bs_bmissthreshold, bs.bs_sleepduration);
584 
585 	/* Set the computed STA beacon timers */
586 
587 	ath9k_hw_disable_interrupts(ah);
588 	ath9k_hw_set_sta_beacon_timers(ah, &bs);
589 	ah->imask |= ATH9K_INT_BMISS;
590 
591 	ath9k_hw_set_interrupts(ah);
592 	ath9k_hw_enable_interrupts(ah);
593 }
594 
595 static void ath9k_beacon_config_adhoc(struct ath_softc *sc,
596 				      struct ath_beacon_config *conf)
597 {
598 	struct ath_hw *ah = sc->sc_ah;
599 	struct ath_common *common = ath9k_hw_common(ah);
600 	u32 intval, nexttbtt;
601 
602 	ath9k_reset_beacon_status(sc);
603 
604 	intval = TU_TO_USEC(conf->beacon_interval);
605 
606 	if (conf->ibss_creator)
607 		nexttbtt = intval;
608 	else
609 		nexttbtt = ath9k_get_next_tbtt(sc, ath9k_hw_gettsf64(ah),
610 					       conf->beacon_interval);
611 
612 	if (conf->enable_beacon)
613 		ah->imask |= ATH9K_INT_SWBA;
614 	else
615 		ah->imask &= ~ATH9K_INT_SWBA;
616 
617 	ath_dbg(common, BEACON,
618 		"IBSS (%s) nexttbtt: %u intval: %u conf_intval: %u\n",
619 		(conf->enable_beacon) ? "Enable" : "Disable",
620 		nexttbtt, intval, conf->beacon_interval);
621 
622 	ath9k_beacon_init(sc, nexttbtt, intval, conf->ibss_creator);
623 
624 	/*
625 	 * Set the global 'beacon has been configured' flag for the
626 	 * joiner case in IBSS mode.
627 	 */
628 	if (!conf->ibss_creator && conf->enable_beacon)
629 		set_bit(SC_OP_BEACONS, &sc->sc_flags);
630 }
631 
632 static bool ath9k_allow_beacon_config(struct ath_softc *sc,
633 				      struct ieee80211_vif *vif)
634 {
635 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
636 	struct ath_vif *avp = (void *)vif->drv_priv;
637 
638 	if (sc->sc_ah->opmode == NL80211_IFTYPE_AP) {
639 		if ((vif->type != NL80211_IFTYPE_AP) ||
640 		    (sc->nbcnvifs > 1)) {
641 			ath_dbg(common, CONFIG,
642 				"An AP interface is already present !\n");
643 			return false;
644 		}
645 	}
646 
647 	if (sc->sc_ah->opmode == NL80211_IFTYPE_STATION) {
648 		if ((vif->type == NL80211_IFTYPE_STATION) &&
649 		    test_bit(SC_OP_BEACONS, &sc->sc_flags) &&
650 		    !avp->primary_sta_vif) {
651 			ath_dbg(common, CONFIG,
652 				"Beacon already configured for a station interface\n");
653 			return false;
654 		}
655 	}
656 
657 	return true;
658 }
659 
660 static void ath9k_cache_beacon_config(struct ath_softc *sc,
661 				      struct ieee80211_bss_conf *bss_conf)
662 {
663 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
664 	struct ath_beacon_config *cur_conf = &sc->cur_beacon_conf;
665 
666 	ath_dbg(common, BEACON,
667 		"Caching beacon data for BSS: %pM\n", bss_conf->bssid);
668 
669 	cur_conf->beacon_interval = bss_conf->beacon_int;
670 	cur_conf->dtim_period = bss_conf->dtim_period;
671 	cur_conf->listen_interval = 1;
672 	cur_conf->dtim_count = 1;
673 	cur_conf->ibss_creator = bss_conf->ibss_creator;
674 	cur_conf->bmiss_timeout =
675 		ATH_DEFAULT_BMISS_LIMIT * cur_conf->beacon_interval;
676 
677 	/*
678 	 * It looks like mac80211 may end up using beacon interval of zero in
679 	 * some cases (at least for mesh point). Avoid getting into an
680 	 * infinite loop by using a bit safer value instead. To be safe,
681 	 * do sanity check on beacon interval for all operating modes.
682 	 */
683 	if (cur_conf->beacon_interval == 0)
684 		cur_conf->beacon_interval = 100;
685 
686 	/*
687 	 * We don't parse dtim period from mac80211 during the driver
688 	 * initialization as it breaks association with hidden-ssid
689 	 * AP and it causes latency in roaming
690 	 */
691 	if (cur_conf->dtim_period == 0)
692 		cur_conf->dtim_period = 1;
693 
694 }
695 
696 void ath9k_beacon_config(struct ath_softc *sc, struct ieee80211_vif *vif,
697 			 u32 changed)
698 {
699 	struct ieee80211_bss_conf *bss_conf = &vif->bss_conf;
700 	struct ath_beacon_config *cur_conf = &sc->cur_beacon_conf;
701 	unsigned long flags;
702 	bool skip_beacon = false;
703 
704 	if (vif->type == NL80211_IFTYPE_AP)
705 		ath9k_set_tsfadjust(sc, vif);
706 
707 	if (!ath9k_allow_beacon_config(sc, vif))
708 		return;
709 
710 	if (sc->sc_ah->opmode == NL80211_IFTYPE_STATION) {
711 		ath9k_cache_beacon_config(sc, bss_conf);
712 		ath9k_set_beacon(sc);
713 		set_bit(SC_OP_BEACONS, &sc->sc_flags);
714 		return;
715 	}
716 
717 	/*
718 	 * Take care of multiple interfaces when
719 	 * enabling/disabling SWBA.
720 	 */
721 	if (changed & BSS_CHANGED_BEACON_ENABLED) {
722 		if (!bss_conf->enable_beacon &&
723 		    (sc->nbcnvifs <= 1)) {
724 			cur_conf->enable_beacon = false;
725 		} else if (bss_conf->enable_beacon) {
726 			cur_conf->enable_beacon = true;
727 			ath9k_cache_beacon_config(sc, bss_conf);
728 		}
729 	}
730 
731 	/*
732 	 * Configure the HW beacon registers only when we have a valid
733 	 * beacon interval.
734 	 */
735 	if (cur_conf->beacon_interval) {
736 		/*
737 		 * If we are joining an existing IBSS network, start beaconing
738 		 * only after a TSF-sync has taken place. Ensure that this
739 		 * happens by setting the appropriate flags.
740 		 */
741 		if ((changed & BSS_CHANGED_IBSS) && !bss_conf->ibss_creator &&
742 		    bss_conf->enable_beacon) {
743 			spin_lock_irqsave(&sc->sc_pm_lock, flags);
744 			sc->ps_flags |= PS_BEACON_SYNC | PS_WAIT_FOR_BEACON;
745 			spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
746 			skip_beacon = true;
747 		} else {
748 			ath9k_set_beacon(sc);
749 		}
750 
751 		/*
752 		 * Do not set the SC_OP_BEACONS flag for IBSS joiner mode
753 		 * here, it is done in ath9k_beacon_config_adhoc().
754 		 */
755 		if (cur_conf->enable_beacon && !skip_beacon)
756 			set_bit(SC_OP_BEACONS, &sc->sc_flags);
757 		else
758 			clear_bit(SC_OP_BEACONS, &sc->sc_flags);
759 	}
760 }
761 
762 void ath9k_set_beacon(struct ath_softc *sc)
763 {
764 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
765 	struct ath_beacon_config *cur_conf = &sc->cur_beacon_conf;
766 
767 	switch (sc->sc_ah->opmode) {
768 	case NL80211_IFTYPE_AP:
769 	case NL80211_IFTYPE_MESH_POINT:
770 		ath9k_beacon_config_ap(sc, cur_conf);
771 		break;
772 	case NL80211_IFTYPE_ADHOC:
773 		ath9k_beacon_config_adhoc(sc, cur_conf);
774 		break;
775 	case NL80211_IFTYPE_STATION:
776 		ath9k_beacon_config_sta(sc, cur_conf);
777 		break;
778 	default:
779 		ath_dbg(common, CONFIG, "Unsupported beaconing mode\n");
780 		return;
781 	}
782 }
783