xref: /freebsd/sys/dev/ath/if_ath_beacon.c (revision 298cf604ccf133b101c6fad42d1a078a1fac58ca)
1 /*-
2  * Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer,
10  *    without modification.
11  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12  *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
13  *    redistribution must be conditioned upon including a substantially
14  *    similar Disclaimer requirement for further binary redistribution.
15  *
16  * NO WARRANTY
17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19  * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
20  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21  * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
22  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
25  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27  * THE POSSIBILITY OF SUCH DAMAGES.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 /*
34  * Driver for the Atheros Wireless LAN controller.
35  *
36  * This software is derived from work of Atsushi Onoe; his contribution
37  * is greatly appreciated.
38  */
39 
40 #include "opt_inet.h"
41 #include "opt_ath.h"
42 /*
43  * This is needed for register operations which are performed
44  * by the driver - eg, calls to ath_hal_gettsf32().
45  *
46  * It's also required for any AH_DEBUG checks in here, eg the
47  * module dependencies.
48  */
49 #include "opt_ah.h"
50 #include "opt_wlan.h"
51 
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/sysctl.h>
55 #include <sys/mbuf.h>
56 #include <sys/malloc.h>
57 #include <sys/lock.h>
58 #include <sys/mutex.h>
59 #include <sys/kernel.h>
60 #include <sys/socket.h>
61 #include <sys/sockio.h>
62 #include <sys/errno.h>
63 #include <sys/callout.h>
64 #include <sys/bus.h>
65 #include <sys/endian.h>
66 #include <sys/kthread.h>
67 #include <sys/taskqueue.h>
68 #include <sys/priv.h>
69 #include <sys/module.h>
70 #include <sys/ktr.h>
71 #include <sys/smp.h>	/* for mp_ncpus */
72 
73 #include <machine/bus.h>
74 
75 #include <net/if.h>
76 #include <net/if_dl.h>
77 #include <net/if_media.h>
78 #include <net/if_types.h>
79 #include <net/if_arp.h>
80 #include <net/ethernet.h>
81 #include <net/if_llc.h>
82 
83 #include <net80211/ieee80211_var.h>
84 #include <net80211/ieee80211_regdomain.h>
85 #ifdef IEEE80211_SUPPORT_SUPERG
86 #include <net80211/ieee80211_superg.h>
87 #endif
88 
89 #include <net/bpf.h>
90 
91 #ifdef INET
92 #include <netinet/in.h>
93 #include <netinet/if_ether.h>
94 #endif
95 
96 #include <dev/ath/if_athvar.h>
97 
98 #include <dev/ath/if_ath_debug.h>
99 #include <dev/ath/if_ath_misc.h>
100 #include <dev/ath/if_ath_tx.h>
101 #include <dev/ath/if_ath_beacon.h>
102 
103 #ifdef ATH_TX99_DIAG
104 #include <dev/ath/ath_tx99/ath_tx99.h>
105 #endif
106 
107 /*
108  * Setup a h/w transmit queue for beacons.
109  */
110 int
111 ath_beaconq_setup(struct ath_softc *sc)
112 {
113 	struct ath_hal *ah = sc->sc_ah;
114 	HAL_TXQ_INFO qi;
115 
116 	memset(&qi, 0, sizeof(qi));
117 	qi.tqi_aifs = HAL_TXQ_USEDEFAULT;
118 	qi.tqi_cwmin = HAL_TXQ_USEDEFAULT;
119 	qi.tqi_cwmax = HAL_TXQ_USEDEFAULT;
120 	/* NB: for dynamic turbo, don't enable any other interrupts */
121 	qi.tqi_qflags = HAL_TXQ_TXDESCINT_ENABLE;
122 	if (sc->sc_isedma)
123 		qi.tqi_qflags |= HAL_TXQ_TXOKINT_ENABLE |
124 		    HAL_TXQ_TXERRINT_ENABLE;
125 
126 	return ath_hal_setuptxqueue(ah, HAL_TX_QUEUE_BEACON, &qi);
127 }
128 
129 /*
130  * Setup the transmit queue parameters for the beacon queue.
131  */
132 int
133 ath_beaconq_config(struct ath_softc *sc)
134 {
135 #define	ATH_EXPONENT_TO_VALUE(v)	((1<<(v))-1)
136 	struct ieee80211com *ic = sc->sc_ifp->if_l2com;
137 	struct ath_hal *ah = sc->sc_ah;
138 	HAL_TXQ_INFO qi;
139 
140 	ath_hal_gettxqueueprops(ah, sc->sc_bhalq, &qi);
141 	if (ic->ic_opmode == IEEE80211_M_HOSTAP ||
142 	    ic->ic_opmode == IEEE80211_M_MBSS) {
143 		/*
144 		 * Always burst out beacon and CAB traffic.
145 		 */
146 		qi.tqi_aifs = ATH_BEACON_AIFS_DEFAULT;
147 		qi.tqi_cwmin = ATH_BEACON_CWMIN_DEFAULT;
148 		qi.tqi_cwmax = ATH_BEACON_CWMAX_DEFAULT;
149 	} else {
150 		struct wmeParams *wmep =
151 			&ic->ic_wme.wme_chanParams.cap_wmeParams[WME_AC_BE];
152 		/*
153 		 * Adhoc mode; important thing is to use 2x cwmin.
154 		 */
155 		qi.tqi_aifs = wmep->wmep_aifsn;
156 		qi.tqi_cwmin = 2*ATH_EXPONENT_TO_VALUE(wmep->wmep_logcwmin);
157 		qi.tqi_cwmax = ATH_EXPONENT_TO_VALUE(wmep->wmep_logcwmax);
158 	}
159 
160 	if (!ath_hal_settxqueueprops(ah, sc->sc_bhalq, &qi)) {
161 		device_printf(sc->sc_dev, "unable to update parameters for "
162 			"beacon hardware queue!\n");
163 		return 0;
164 	} else {
165 		ath_hal_resettxqueue(ah, sc->sc_bhalq); /* push to h/w */
166 		return 1;
167 	}
168 #undef ATH_EXPONENT_TO_VALUE
169 }
170 
171 /*
172  * Allocate and setup an initial beacon frame.
173  */
174 int
175 ath_beacon_alloc(struct ath_softc *sc, struct ieee80211_node *ni)
176 {
177 	struct ieee80211vap *vap = ni->ni_vap;
178 	struct ath_vap *avp = ATH_VAP(vap);
179 	struct ath_buf *bf;
180 	struct mbuf *m;
181 	int error;
182 
183 	bf = avp->av_bcbuf;
184 	DPRINTF(sc, ATH_DEBUG_NODE, "%s: bf_m=%p, bf_node=%p\n",
185 	    __func__, bf->bf_m, bf->bf_node);
186 	if (bf->bf_m != NULL) {
187 		bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
188 		m_freem(bf->bf_m);
189 		bf->bf_m = NULL;
190 	}
191 	if (bf->bf_node != NULL) {
192 		ieee80211_free_node(bf->bf_node);
193 		bf->bf_node = NULL;
194 	}
195 
196 	/*
197 	 * NB: the beacon data buffer must be 32-bit aligned;
198 	 * we assume the mbuf routines will return us something
199 	 * with this alignment (perhaps should assert).
200 	 */
201 	m = ieee80211_beacon_alloc(ni, &avp->av_boff);
202 	if (m == NULL) {
203 		device_printf(sc->sc_dev, "%s: cannot get mbuf\n", __func__);
204 		sc->sc_stats.ast_be_nombuf++;
205 		return ENOMEM;
206 	}
207 	error = bus_dmamap_load_mbuf_sg(sc->sc_dmat, bf->bf_dmamap, m,
208 				     bf->bf_segs, &bf->bf_nseg,
209 				     BUS_DMA_NOWAIT);
210 	if (error != 0) {
211 		device_printf(sc->sc_dev,
212 		    "%s: cannot map mbuf, bus_dmamap_load_mbuf_sg returns %d\n",
213 		    __func__, error);
214 		m_freem(m);
215 		return error;
216 	}
217 
218 	/*
219 	 * Calculate a TSF adjustment factor required for staggered
220 	 * beacons.  Note that we assume the format of the beacon
221 	 * frame leaves the tstamp field immediately following the
222 	 * header.
223 	 */
224 	if (sc->sc_stagbeacons && avp->av_bslot > 0) {
225 		uint64_t tsfadjust;
226 		struct ieee80211_frame *wh;
227 
228 		/*
229 		 * The beacon interval is in TU's; the TSF is in usecs.
230 		 * We figure out how many TU's to add to align the timestamp
231 		 * then convert to TSF units and handle byte swapping before
232 		 * inserting it in the frame.  The hardware will then add this
233 		 * each time a beacon frame is sent.  Note that we align vap's
234 		 * 1..N and leave vap 0 untouched.  This means vap 0 has a
235 		 * timestamp in one beacon interval while the others get a
236 		 * timstamp aligned to the next interval.
237 		 */
238 		tsfadjust = ni->ni_intval *
239 		    (ATH_BCBUF - avp->av_bslot) / ATH_BCBUF;
240 		tsfadjust = htole64(tsfadjust << 10);	/* TU -> TSF */
241 
242 		DPRINTF(sc, ATH_DEBUG_BEACON,
243 		    "%s: %s beacons bslot %d intval %u tsfadjust %llu\n",
244 		    __func__, sc->sc_stagbeacons ? "stagger" : "burst",
245 		    avp->av_bslot, ni->ni_intval,
246 		    (long long unsigned) le64toh(tsfadjust));
247 
248 		wh = mtod(m, struct ieee80211_frame *);
249 		memcpy(&wh[1], &tsfadjust, sizeof(tsfadjust));
250 	}
251 	bf->bf_m = m;
252 	bf->bf_node = ieee80211_ref_node(ni);
253 
254 	return 0;
255 }
256 
257 /*
258  * Setup the beacon frame for transmit.
259  */
260 static void
261 ath_beacon_setup(struct ath_softc *sc, struct ath_buf *bf)
262 {
263 #define	USE_SHPREAMBLE(_ic) \
264 	(((_ic)->ic_flags & (IEEE80211_F_SHPREAMBLE | IEEE80211_F_USEBARKER))\
265 		== IEEE80211_F_SHPREAMBLE)
266 	struct ieee80211_node *ni = bf->bf_node;
267 	struct ieee80211com *ic = ni->ni_ic;
268 	struct mbuf *m = bf->bf_m;
269 	struct ath_hal *ah = sc->sc_ah;
270 	struct ath_desc *ds;
271 	int flags, antenna;
272 	const HAL_RATE_TABLE *rt;
273 	u_int8_t rix, rate;
274 	HAL_DMA_ADDR bufAddrList[4];
275 	uint32_t segLenList[4];
276 	HAL_11N_RATE_SERIES rc[4];
277 
278 	DPRINTF(sc, ATH_DEBUG_BEACON_PROC, "%s: m %p len %u\n",
279 		__func__, m, m->m_len);
280 
281 	/* setup descriptors */
282 	ds = bf->bf_desc;
283 	bf->bf_last = bf;
284 	bf->bf_lastds = ds;
285 
286 	flags = HAL_TXDESC_NOACK;
287 	if (ic->ic_opmode == IEEE80211_M_IBSS && sc->sc_hasveol) {
288 		/* self-linked descriptor */
289 		ath_hal_settxdesclink(sc->sc_ah, ds, bf->bf_daddr);
290 		flags |= HAL_TXDESC_VEOL;
291 		/*
292 		 * Let hardware handle antenna switching.
293 		 */
294 		antenna = sc->sc_txantenna;
295 	} else {
296 		ath_hal_settxdesclink(sc->sc_ah, ds, 0);
297 		/*
298 		 * Switch antenna every 4 beacons.
299 		 * XXX assumes two antenna
300 		 */
301 		if (sc->sc_txantenna != 0)
302 			antenna = sc->sc_txantenna;
303 		else if (sc->sc_stagbeacons && sc->sc_nbcnvaps != 0)
304 			antenna = ((sc->sc_stats.ast_be_xmit / sc->sc_nbcnvaps) & 4 ? 2 : 1);
305 		else
306 			antenna = (sc->sc_stats.ast_be_xmit & 4 ? 2 : 1);
307 	}
308 
309 	KASSERT(bf->bf_nseg == 1,
310 		("multi-segment beacon frame; nseg %u", bf->bf_nseg));
311 
312 	/*
313 	 * Calculate rate code.
314 	 * XXX everything at min xmit rate
315 	 */
316 	rix = 0;
317 	rt = sc->sc_currates;
318 	rate = rt->info[rix].rateCode;
319 	if (USE_SHPREAMBLE(ic))
320 		rate |= rt->info[rix].shortPreamble;
321 	ath_hal_setuptxdesc(ah, ds
322 		, m->m_len + IEEE80211_CRC_LEN	/* frame length */
323 		, sizeof(struct ieee80211_frame)/* header length */
324 		, HAL_PKT_TYPE_BEACON		/* Atheros packet type */
325 		, ni->ni_txpower		/* txpower XXX */
326 		, rate, 1			/* series 0 rate/tries */
327 		, HAL_TXKEYIX_INVALID		/* no encryption */
328 		, antenna			/* antenna mode */
329 		, flags				/* no ack, veol for beacons */
330 		, 0				/* rts/cts rate */
331 		, 0				/* rts/cts duration */
332 	);
333 
334 	/*
335 	 * The EDMA HAL currently assumes that _all_ rate control
336 	 * settings are done in ath_hal_set11nratescenario(), rather
337 	 * than in ath_hal_setuptxdesc().
338 	 */
339 	if (sc->sc_isedma) {
340 		memset(&rc, 0, sizeof(rc));
341 
342 		rc[0].ChSel = sc->sc_txchainmask;
343 		rc[0].Tries = 1;
344 		rc[0].Rate = rt->info[rix].rateCode;
345 		rc[0].RateIndex = rix;
346 		rc[0].tx_power_cap = 0x3f;
347 		rc[0].PktDuration =
348 		    ath_hal_computetxtime(ah, rt, roundup(m->m_len, 4),
349 		        rix, 0);
350 		ath_hal_set11nratescenario(ah, ds, 0, 0, rc, 4, flags);
351 	}
352 
353 	/* NB: beacon's BufLen must be a multiple of 4 bytes */
354 	segLenList[0] = roundup(m->m_len, 4);
355 	segLenList[1] = segLenList[2] = segLenList[3] = 0;
356 	bufAddrList[0] = bf->bf_segs[0].ds_addr;
357 	bufAddrList[1] = bufAddrList[2] = bufAddrList[3] = 0;
358 	ath_hal_filltxdesc(ah, ds
359 		, bufAddrList
360 		, segLenList
361 		, 0				/* XXX desc id */
362 		, sc->sc_bhalq			/* hardware TXQ */
363 		, AH_TRUE			/* first segment */
364 		, AH_TRUE			/* last segment */
365 		, ds				/* first descriptor */
366 	);
367 #if 0
368 	ath_desc_swap(ds);
369 #endif
370 #undef USE_SHPREAMBLE
371 }
372 
373 void
374 ath_beacon_update(struct ieee80211vap *vap, int item)
375 {
376 	struct ieee80211_beacon_offsets *bo = &ATH_VAP(vap)->av_boff;
377 
378 	setbit(bo->bo_flags, item);
379 }
380 
381 /*
382  * Transmit a beacon frame at SWBA.  Dynamic updates to the
383  * frame contents are done as needed and the slot time is
384  * also adjusted based on current state.
385  */
386 void
387 ath_beacon_proc(void *arg, int pending)
388 {
389 	struct ath_softc *sc = arg;
390 	struct ath_hal *ah = sc->sc_ah;
391 	struct ieee80211vap *vap;
392 	struct ath_buf *bf;
393 	int slot, otherant;
394 	uint32_t bfaddr;
395 
396 	DPRINTF(sc, ATH_DEBUG_BEACON_PROC, "%s: pending %u\n",
397 		__func__, pending);
398 	/*
399 	 * Check if the previous beacon has gone out.  If
400 	 * not don't try to post another, skip this period
401 	 * and wait for the next.  Missed beacons indicate
402 	 * a problem and should not occur.  If we miss too
403 	 * many consecutive beacons reset the device.
404 	 */
405 	if (ath_hal_numtxpending(ah, sc->sc_bhalq) != 0) {
406 		sc->sc_bmisscount++;
407 		sc->sc_stats.ast_be_missed++;
408 		DPRINTF(sc, ATH_DEBUG_BEACON,
409 			"%s: missed %u consecutive beacons\n",
410 			__func__, sc->sc_bmisscount);
411 		if (sc->sc_bmisscount >= ath_bstuck_threshold)
412 			taskqueue_enqueue(sc->sc_tq, &sc->sc_bstucktask);
413 		return;
414 	}
415 	if (sc->sc_bmisscount != 0) {
416 		DPRINTF(sc, ATH_DEBUG_BEACON,
417 			"%s: resume beacon xmit after %u misses\n",
418 			__func__, sc->sc_bmisscount);
419 		sc->sc_bmisscount = 0;
420 	}
421 
422 	if (sc->sc_stagbeacons) {			/* staggered beacons */
423 		struct ieee80211com *ic = sc->sc_ifp->if_l2com;
424 		uint32_t tsftu;
425 
426 		tsftu = ath_hal_gettsf32(ah) >> 10;
427 		/* XXX lintval */
428 		slot = ((tsftu % ic->ic_lintval) * ATH_BCBUF) / ic->ic_lintval;
429 		vap = sc->sc_bslot[(slot+1) % ATH_BCBUF];
430 		bfaddr = 0;
431 		if (vap != NULL && vap->iv_state >= IEEE80211_S_RUN) {
432 			bf = ath_beacon_generate(sc, vap);
433 			if (bf != NULL)
434 				bfaddr = bf->bf_daddr;
435 		}
436 	} else {					/* burst'd beacons */
437 		uint32_t *bflink = &bfaddr;
438 
439 		for (slot = 0; slot < ATH_BCBUF; slot++) {
440 			vap = sc->sc_bslot[slot];
441 			if (vap != NULL && vap->iv_state >= IEEE80211_S_RUN) {
442 				bf = ath_beacon_generate(sc, vap);
443 				if (bf != NULL) {
444 					/* XXX should do this using the ds */
445 					*bflink = bf->bf_daddr;
446 					ath_hal_gettxdesclinkptr(sc->sc_ah,
447 					    bf->bf_desc, &bflink);
448 				}
449 			}
450 		}
451 		*bflink = 0;				/* terminate list */
452 	}
453 
454 	/*
455 	 * Handle slot time change when a non-ERP station joins/leaves
456 	 * an 11g network.  The 802.11 layer notifies us via callback,
457 	 * we mark updateslot, then wait one beacon before effecting
458 	 * the change.  This gives associated stations at least one
459 	 * beacon interval to note the state change.
460 	 */
461 	/* XXX locking */
462 	if (sc->sc_updateslot == UPDATE) {
463 		sc->sc_updateslot = COMMIT;	/* commit next beacon */
464 		sc->sc_slotupdate = slot;
465 	} else if (sc->sc_updateslot == COMMIT && sc->sc_slotupdate == slot)
466 		ath_setslottime(sc);		/* commit change to h/w */
467 
468 	/*
469 	 * Check recent per-antenna transmit statistics and flip
470 	 * the default antenna if noticeably more frames went out
471 	 * on the non-default antenna.
472 	 * XXX assumes 2 anntenae
473 	 */
474 	if (!sc->sc_diversity && (!sc->sc_stagbeacons || slot == 0)) {
475 		otherant = sc->sc_defant & 1 ? 2 : 1;
476 		if (sc->sc_ant_tx[otherant] > sc->sc_ant_tx[sc->sc_defant] + 2)
477 			ath_setdefantenna(sc, otherant);
478 		sc->sc_ant_tx[1] = sc->sc_ant_tx[2] = 0;
479 	}
480 
481 	if (bfaddr != 0) {
482 		/*
483 		 * Stop any current dma and put the new frame on the queue.
484 		 * This should never fail since we check above that no frames
485 		 * are still pending on the queue.
486 		 */
487 		if (! sc->sc_isedma) {
488 			if (!ath_hal_stoptxdma(ah, sc->sc_bhalq)) {
489 				DPRINTF(sc, ATH_DEBUG_ANY,
490 					"%s: beacon queue %u did not stop?\n",
491 					__func__, sc->sc_bhalq);
492 			}
493 		}
494 		/* NB: cabq traffic should already be queued and primed */
495 
496 		ath_hal_puttxbuf(ah, sc->sc_bhalq, bfaddr);
497 		ath_hal_txstart(ah, sc->sc_bhalq);
498 
499 		sc->sc_stats.ast_be_xmit++;
500 	}
501 }
502 
503 struct ath_buf *
504 ath_beacon_generate(struct ath_softc *sc, struct ieee80211vap *vap)
505 {
506 	struct ath_vap *avp = ATH_VAP(vap);
507 	struct ath_txq *cabq = sc->sc_cabq;
508 	struct ath_buf *bf;
509 	struct mbuf *m;
510 	int nmcastq, error;
511 
512 	KASSERT(vap->iv_state >= IEEE80211_S_RUN,
513 	    ("not running, state %d", vap->iv_state));
514 	KASSERT(avp->av_bcbuf != NULL, ("no beacon buffer"));
515 
516 	/*
517 	 * Update dynamic beacon contents.  If this returns
518 	 * non-zero then we need to remap the memory because
519 	 * the beacon frame changed size (probably because
520 	 * of the TIM bitmap).
521 	 */
522 	bf = avp->av_bcbuf;
523 	m = bf->bf_m;
524 	/* XXX lock mcastq? */
525 	nmcastq = avp->av_mcastq.axq_depth;
526 
527 	if (ieee80211_beacon_update(bf->bf_node, &avp->av_boff, m, nmcastq)) {
528 		/* XXX too conservative? */
529 		bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
530 		error = bus_dmamap_load_mbuf_sg(sc->sc_dmat, bf->bf_dmamap, m,
531 					     bf->bf_segs, &bf->bf_nseg,
532 					     BUS_DMA_NOWAIT);
533 		if (error != 0) {
534 			if_printf(vap->iv_ifp,
535 			    "%s: bus_dmamap_load_mbuf_sg failed, error %u\n",
536 			    __func__, error);
537 			return NULL;
538 		}
539 	}
540 	if ((avp->av_boff.bo_tim[4] & 1) && cabq->axq_depth) {
541 		DPRINTF(sc, ATH_DEBUG_BEACON,
542 		    "%s: cabq did not drain, mcastq %u cabq %u\n",
543 		    __func__, nmcastq, cabq->axq_depth);
544 		sc->sc_stats.ast_cabq_busy++;
545 		if (sc->sc_nvaps > 1 && sc->sc_stagbeacons) {
546 			/*
547 			 * CABQ traffic from a previous vap is still pending.
548 			 * We must drain the q before this beacon frame goes
549 			 * out as otherwise this vap's stations will get cab
550 			 * frames from a different vap.
551 			 * XXX could be slow causing us to miss DBA
552 			 */
553 			ath_tx_draintxq(sc, cabq);
554 		}
555 	}
556 	ath_beacon_setup(sc, bf);
557 	bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap, BUS_DMASYNC_PREWRITE);
558 
559 	/*
560 	 * Enable the CAB queue before the beacon queue to
561 	 * insure cab frames are triggered by this beacon.
562 	 */
563 	if (avp->av_boff.bo_tim[4] & 1) {
564 		struct ath_hal *ah = sc->sc_ah;
565 
566 		/* NB: only at DTIM */
567 		ATH_TX_LOCK(sc);
568 		if (nmcastq) {
569 			struct ath_buf *bfm;
570 
571 			/*
572 			 * Move frames from the s/w mcast q to the h/w cab q.
573 			 * XXX MORE_DATA bit
574 			 */
575 			bfm = TAILQ_FIRST(&avp->av_mcastq.axq_q);
576 			if (cabq->axq_link != NULL) {
577 				*cabq->axq_link = bfm->bf_daddr;
578 			} else
579 				ath_hal_puttxbuf(ah, cabq->axq_qnum,
580 					bfm->bf_daddr);
581 			ath_txqmove(cabq, &avp->av_mcastq);
582 
583 			sc->sc_stats.ast_cabq_xmit += nmcastq;
584 		}
585 		/* NB: gated by beacon so safe to start here */
586 		if (! TAILQ_EMPTY(&(cabq->axq_q)))
587 			ath_hal_txstart(ah, cabq->axq_qnum);
588 		ATH_TX_UNLOCK(sc);
589 	}
590 	return bf;
591 }
592 
593 void
594 ath_beacon_start_adhoc(struct ath_softc *sc, struct ieee80211vap *vap)
595 {
596 	struct ath_vap *avp = ATH_VAP(vap);
597 	struct ath_hal *ah = sc->sc_ah;
598 	struct ath_buf *bf;
599 	struct mbuf *m;
600 	int error;
601 
602 	KASSERT(avp->av_bcbuf != NULL, ("no beacon buffer"));
603 
604 	/*
605 	 * Update dynamic beacon contents.  If this returns
606 	 * non-zero then we need to remap the memory because
607 	 * the beacon frame changed size (probably because
608 	 * of the TIM bitmap).
609 	 */
610 	bf = avp->av_bcbuf;
611 	m = bf->bf_m;
612 	if (ieee80211_beacon_update(bf->bf_node, &avp->av_boff, m, 0)) {
613 		/* XXX too conservative? */
614 		bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
615 		error = bus_dmamap_load_mbuf_sg(sc->sc_dmat, bf->bf_dmamap, m,
616 					     bf->bf_segs, &bf->bf_nseg,
617 					     BUS_DMA_NOWAIT);
618 		if (error != 0) {
619 			if_printf(vap->iv_ifp,
620 			    "%s: bus_dmamap_load_mbuf_sg failed, error %u\n",
621 			    __func__, error);
622 			return;
623 		}
624 	}
625 	ath_beacon_setup(sc, bf);
626 	bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap, BUS_DMASYNC_PREWRITE);
627 
628 	/* NB: caller is known to have already stopped tx dma */
629 	ath_hal_puttxbuf(ah, sc->sc_bhalq, bf->bf_daddr);
630 	ath_hal_txstart(ah, sc->sc_bhalq);
631 }
632 
633 /*
634  * Reclaim beacon resources and return buffer to the pool.
635  */
636 void
637 ath_beacon_return(struct ath_softc *sc, struct ath_buf *bf)
638 {
639 
640 	DPRINTF(sc, ATH_DEBUG_NODE, "%s: free bf=%p, bf_m=%p, bf_node=%p\n",
641 	    __func__, bf, bf->bf_m, bf->bf_node);
642 	if (bf->bf_m != NULL) {
643 		bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
644 		m_freem(bf->bf_m);
645 		bf->bf_m = NULL;
646 	}
647 	if (bf->bf_node != NULL) {
648 		ieee80211_free_node(bf->bf_node);
649 		bf->bf_node = NULL;
650 	}
651 	TAILQ_INSERT_TAIL(&sc->sc_bbuf, bf, bf_list);
652 }
653 
654 /*
655  * Reclaim beacon resources.
656  */
657 void
658 ath_beacon_free(struct ath_softc *sc)
659 {
660 	struct ath_buf *bf;
661 
662 	TAILQ_FOREACH(bf, &sc->sc_bbuf, bf_list) {
663 		DPRINTF(sc, ATH_DEBUG_NODE,
664 		    "%s: free bf=%p, bf_m=%p, bf_node=%p\n",
665 		        __func__, bf, bf->bf_m, bf->bf_node);
666 		if (bf->bf_m != NULL) {
667 			bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
668 			m_freem(bf->bf_m);
669 			bf->bf_m = NULL;
670 		}
671 		if (bf->bf_node != NULL) {
672 			ieee80211_free_node(bf->bf_node);
673 			bf->bf_node = NULL;
674 		}
675 	}
676 }
677 
678 /*
679  * Configure the beacon and sleep timers.
680  *
681  * When operating as an AP this resets the TSF and sets
682  * up the hardware to notify us when we need to issue beacons.
683  *
684  * When operating in station mode this sets up the beacon
685  * timers according to the timestamp of the last received
686  * beacon and the current TSF, configures PCF and DTIM
687  * handling, programs the sleep registers so the hardware
688  * will wakeup in time to receive beacons, and configures
689  * the beacon miss handling so we'll receive a BMISS
690  * interrupt when we stop seeing beacons from the AP
691  * we've associated with.
692  */
693 void
694 ath_beacon_config(struct ath_softc *sc, struct ieee80211vap *vap)
695 {
696 #define	TSF_TO_TU(_h,_l) \
697 	((((u_int32_t)(_h)) << 22) | (((u_int32_t)(_l)) >> 10))
698 #define	FUDGE	2
699 	struct ath_hal *ah = sc->sc_ah;
700 	struct ieee80211com *ic = sc->sc_ifp->if_l2com;
701 	struct ieee80211_node *ni;
702 	u_int32_t nexttbtt, intval, tsftu;
703 	u_int32_t nexttbtt_u8, intval_u8;
704 	u_int64_t tsf;
705 
706 	if (vap == NULL)
707 		vap = TAILQ_FIRST(&ic->ic_vaps);	/* XXX */
708 	ni = ieee80211_ref_node(vap->iv_bss);
709 
710 	/* extract tstamp from last beacon and convert to TU */
711 	nexttbtt = TSF_TO_TU(LE_READ_4(ni->ni_tstamp.data + 4),
712 			     LE_READ_4(ni->ni_tstamp.data));
713 	if (ic->ic_opmode == IEEE80211_M_HOSTAP ||
714 	    ic->ic_opmode == IEEE80211_M_MBSS) {
715 		/*
716 		 * For multi-bss ap/mesh support beacons are either staggered
717 		 * evenly over N slots or burst together.  For the former
718 		 * arrange for the SWBA to be delivered for each slot.
719 		 * Slots that are not occupied will generate nothing.
720 		 */
721 		/* NB: the beacon interval is kept internally in TU's */
722 		intval = ni->ni_intval & HAL_BEACON_PERIOD;
723 		if (sc->sc_stagbeacons)
724 			intval /= ATH_BCBUF;
725 	} else {
726 		/* NB: the beacon interval is kept internally in TU's */
727 		intval = ni->ni_intval & HAL_BEACON_PERIOD;
728 	}
729 	if (nexttbtt == 0)		/* e.g. for ap mode */
730 		nexttbtt = intval;
731 	else if (intval)		/* NB: can be 0 for monitor mode */
732 		nexttbtt = roundup(nexttbtt, intval);
733 	DPRINTF(sc, ATH_DEBUG_BEACON, "%s: nexttbtt %u intval %u (%u)\n",
734 		__func__, nexttbtt, intval, ni->ni_intval);
735 	if (ic->ic_opmode == IEEE80211_M_STA && !sc->sc_swbmiss) {
736 		HAL_BEACON_STATE bs;
737 		int dtimperiod, dtimcount;
738 		int cfpperiod, cfpcount;
739 
740 		/*
741 		 * Setup dtim and cfp parameters according to
742 		 * last beacon we received (which may be none).
743 		 */
744 		dtimperiod = ni->ni_dtim_period;
745 		if (dtimperiod <= 0)		/* NB: 0 if not known */
746 			dtimperiod = 1;
747 		dtimcount = ni->ni_dtim_count;
748 		if (dtimcount >= dtimperiod)	/* NB: sanity check */
749 			dtimcount = 0;		/* XXX? */
750 		cfpperiod = 1;			/* NB: no PCF support yet */
751 		cfpcount = 0;
752 		/*
753 		 * Pull nexttbtt forward to reflect the current
754 		 * TSF and calculate dtim+cfp state for the result.
755 		 */
756 		tsf = ath_hal_gettsf64(ah);
757 		tsftu = TSF_TO_TU(tsf>>32, tsf) + FUDGE;
758 		do {
759 			nexttbtt += intval;
760 			if (--dtimcount < 0) {
761 				dtimcount = dtimperiod - 1;
762 				if (--cfpcount < 0)
763 					cfpcount = cfpperiod - 1;
764 			}
765 		} while (nexttbtt < tsftu);
766 		memset(&bs, 0, sizeof(bs));
767 		bs.bs_intval = intval;
768 		bs.bs_nexttbtt = nexttbtt;
769 		bs.bs_dtimperiod = dtimperiod*intval;
770 		bs.bs_nextdtim = bs.bs_nexttbtt + dtimcount*intval;
771 		bs.bs_cfpperiod = cfpperiod*bs.bs_dtimperiod;
772 		bs.bs_cfpnext = bs.bs_nextdtim + cfpcount*bs.bs_dtimperiod;
773 		bs.bs_cfpmaxduration = 0;
774 #if 0
775 		/*
776 		 * The 802.11 layer records the offset to the DTIM
777 		 * bitmap while receiving beacons; use it here to
778 		 * enable h/w detection of our AID being marked in
779 		 * the bitmap vector (to indicate frames for us are
780 		 * pending at the AP).
781 		 * XXX do DTIM handling in s/w to WAR old h/w bugs
782 		 * XXX enable based on h/w rev for newer chips
783 		 */
784 		bs.bs_timoffset = ni->ni_timoff;
785 #endif
786 		/*
787 		 * Calculate the number of consecutive beacons to miss
788 		 * before taking a BMISS interrupt.
789 		 * Note that we clamp the result to at most 10 beacons.
790 		 */
791 		bs.bs_bmissthreshold = vap->iv_bmissthreshold;
792 		if (bs.bs_bmissthreshold > 10)
793 			bs.bs_bmissthreshold = 10;
794 		else if (bs.bs_bmissthreshold <= 0)
795 			bs.bs_bmissthreshold = 1;
796 
797 		/*
798 		 * Calculate sleep duration.  The configuration is
799 		 * given in ms.  We insure a multiple of the beacon
800 		 * period is used.  Also, if the sleep duration is
801 		 * greater than the DTIM period then it makes senses
802 		 * to make it a multiple of that.
803 		 *
804 		 * XXX fixed at 100ms
805 		 */
806 		bs.bs_sleepduration =
807 			roundup(IEEE80211_MS_TO_TU(100), bs.bs_intval);
808 		if (bs.bs_sleepduration > bs.bs_dtimperiod)
809 			bs.bs_sleepduration = roundup(bs.bs_sleepduration, bs.bs_dtimperiod);
810 
811 		DPRINTF(sc, ATH_DEBUG_BEACON,
812 			"%s: tsf %ju tsf:tu %u intval %u nexttbtt %u dtim %u nextdtim %u bmiss %u sleep %u cfp:period %u maxdur %u next %u timoffset %u\n"
813 			, __func__
814 			, tsf, tsftu
815 			, bs.bs_intval
816 			, bs.bs_nexttbtt
817 			, bs.bs_dtimperiod
818 			, bs.bs_nextdtim
819 			, bs.bs_bmissthreshold
820 			, bs.bs_sleepduration
821 			, bs.bs_cfpperiod
822 			, bs.bs_cfpmaxduration
823 			, bs.bs_cfpnext
824 			, bs.bs_timoffset
825 		);
826 		ath_hal_intrset(ah, 0);
827 		ath_hal_beacontimers(ah, &bs);
828 		sc->sc_imask |= HAL_INT_BMISS;
829 		ath_hal_intrset(ah, sc->sc_imask);
830 	} else {
831 		ath_hal_intrset(ah, 0);
832 		if (nexttbtt == intval)
833 			intval |= HAL_BEACON_RESET_TSF;
834 		if (ic->ic_opmode == IEEE80211_M_IBSS) {
835 			/*
836 			 * In IBSS mode enable the beacon timers but only
837 			 * enable SWBA interrupts if we need to manually
838 			 * prepare beacon frames.  Otherwise we use a
839 			 * self-linked tx descriptor and let the hardware
840 			 * deal with things.
841 			 */
842 			intval |= HAL_BEACON_ENA;
843 			if (!sc->sc_hasveol)
844 				sc->sc_imask |= HAL_INT_SWBA;
845 			if ((intval & HAL_BEACON_RESET_TSF) == 0) {
846 				/*
847 				 * Pull nexttbtt forward to reflect
848 				 * the current TSF.
849 				 */
850 				tsf = ath_hal_gettsf64(ah);
851 				tsftu = TSF_TO_TU(tsf>>32, tsf) + FUDGE;
852 				do {
853 					nexttbtt += intval;
854 				} while (nexttbtt < tsftu);
855 			}
856 			ath_beaconq_config(sc);
857 		} else if (ic->ic_opmode == IEEE80211_M_HOSTAP ||
858 		    ic->ic_opmode == IEEE80211_M_MBSS) {
859 			/*
860 			 * In AP/mesh mode we enable the beacon timers
861 			 * and SWBA interrupts to prepare beacon frames.
862 			 */
863 			intval |= HAL_BEACON_ENA;
864 			sc->sc_imask |= HAL_INT_SWBA;	/* beacon prepare */
865 			ath_beaconq_config(sc);
866 		}
867 
868 		/*
869 		 * Now dirty things because for now, the EDMA HAL has
870 		 * nexttbtt and intval is TU/8.
871 		 */
872 		if (sc->sc_isedma) {
873 			nexttbtt_u8 = (nexttbtt << 3);
874 			intval_u8 = (intval << 3);
875 			if (intval & HAL_BEACON_ENA)
876 				intval_u8 |= HAL_BEACON_ENA;
877 			if (intval & HAL_BEACON_RESET_TSF)
878 				intval_u8 |= HAL_BEACON_RESET_TSF;
879 			ath_hal_beaconinit(ah, nexttbtt_u8, intval_u8);
880 		} else
881 			ath_hal_beaconinit(ah, nexttbtt, intval);
882 		sc->sc_bmisscount = 0;
883 		ath_hal_intrset(ah, sc->sc_imask);
884 		/*
885 		 * When using a self-linked beacon descriptor in
886 		 * ibss mode load it once here.
887 		 */
888 		if (ic->ic_opmode == IEEE80211_M_IBSS && sc->sc_hasveol)
889 			ath_beacon_start_adhoc(sc, vap);
890 	}
891 	sc->sc_syncbeacon = 0;
892 	ieee80211_free_node(ni);
893 #undef FUDGE
894 #undef TSF_TO_TU
895 }
896