drivers/net/wireless/ath9k/beacon.c

   1 /*
   2  * Copyright (c) 2008 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 "core.h"
  18
  19 /*
  20  *  This function will modify certain transmit queue properties depending on
  21  *  the operating mode of the station (AP or AdHoc).  Parameters are AIFS
  22  *  settings and channel width min/max
  23 */
  24 static int ath_beaconq_config(struct ath_softc *sc)
  25 {
  26         struct ath_hal *ah = sc->sc_ah;
  27         struct ath9k_tx_queue_info qi;
  28
  29         ath9k_hw_get_txq_props(ah, sc->beacon.beaconq, &qi);
  30         if (sc->sc_ah->ah_opmode == NL80211_IFTYPE_AP) {
  31                 /* Always burst out beacon and CAB traffic. */
  32                 qi.tqi_aifs = 1;
  33                 qi.tqi_cwmin = 0;
  34                 qi.tqi_cwmax = 0;
  35         } else {
  36                 /* Adhoc mode; important thing is to use 2x cwmin. */
  37                 qi.tqi_aifs = sc->beacon.beacon_qi.tqi_aifs;
  38                 qi.tqi_cwmin = 2*sc->beacon.beacon_qi.tqi_cwmin;
  39                 qi.tqi_cwmax = sc->beacon.beacon_qi.tqi_cwmax;
  40         }
  41
  42         if (!ath9k_hw_set_txq_props(ah, sc->beacon.beaconq, &qi)) {
  43                 DPRINTF(sc, ATH_DBG_FATAL,
  44                         "unable to update h/w beacon queue parameters\n");
  45                 return 0;
  46         } else {
  47                 ath9k_hw_resettxqueue(ah, sc->beacon.beaconq); /* push to h/w */
  48                 return 1;
  49         }
  50 }
  51
  52 static void ath_bstuck_process(struct ath_softc *sc)
  53 {
  54         DPRINTF(sc, ATH_DBG_BEACON,
  55                 "stuck beacon; resetting (bmiss count %u)\n",
  56                 sc->beacon.bmisscnt);
  57         ath_reset(sc, false);
  58 }
  59
  60 /*
  61  *  Associates the beacon frame buffer with a transmit descriptor.  Will set
  62  *  up all required antenna switch parameters, rate codes, and channel flags.
  63  *  Beacons are always sent out at the lowest rate, and are not retried.
  64 */
  65 static void ath_beacon_setup(struct ath_softc *sc,
  66                              struct ath_vap *avp, struct ath_buf *bf)
  67 {
  68         struct sk_buff *skb = (struct sk_buff *)bf->bf_mpdu;
  69         struct ath_hal *ah = sc->sc_ah;
  70         struct ath_desc *ds;
  71         struct ath9k_11n_rate_series series[4];
  72         struct ath_rate_table *rt;
  73         int flags, antenna;
  74         u8 rix, rate;
  75         int ctsrate = 0;
  76         int ctsduration = 0;
  77
  78         DPRINTF(sc, ATH_DBG_BEACON, "m %p len %u\n", skb, skb->len);
  79
  80         /* setup descriptors */
  81         ds = bf->bf_desc;
  82
  83         flags = ATH9K_TXDESC_NOACK;
  84
  85         if (sc->sc_ah->ah_opmode == NL80211_IFTYPE_ADHOC &&
  86             (ah->ah_caps.hw_caps & ATH9K_HW_CAP_VEOL)) {
  87                 ds->ds_link = bf->bf_daddr; /* self-linked */
  88                 flags |= ATH9K_TXDESC_VEOL;
  89                 /* Let hardware handle antenna switching. */
  90                 antenna = 0;
  91         } else {
  92                 ds->ds_link = 0;
  93                 /*
  94                  * Switch antenna every beacon.
  95                  * Should only switch every beacon period, not for every
  96                  * SWBA's
  97                  * XXX assumes two antenna
  98                  */
  99                 antenna = ((sc->beacon.ast_be_xmit / sc->sc_nbcnvaps) & 1 ? 2 : 1);
 100         }
 101
 102         ds->ds_data = bf->bf_buf_addr;
 103
 104         /*
 105          * Calculate rate code.
 106          * XXX everything at min xmit rate
 107          */
 108         rix = 0;
 109         rt = sc->cur_rate_table;
 110         rate = rt->info[rix].ratecode;
 111         if (sc->sc_flags & SC_OP_PREAMBLE_SHORT)
 112                 rate |= rt->info[rix].short_preamble;
 113
 114         ath9k_hw_set11n_txdesc(ah, ds,
 115                                skb->len + FCS_LEN,     /* frame length */
 116                                ATH9K_PKT_TYPE_BEACON,  /* Atheros packet type */
 117                                MAX_RATE_POWER,         /* FIXME */
 118                                ATH9K_TXKEYIX_INVALID,  /* no encryption */
 119                                ATH9K_KEY_TYPE_CLEAR,   /* no encryption */
 120                                flags                   /* no ack,
 121                                                           veol for beacons */
 122                 );
 123
 124         /* NB: beacon's BufLen must be a multiple of 4 bytes */
 125         ath9k_hw_filltxdesc(ah, ds,
 126                             roundup(skb->len, 4), /* buffer length */
 127                             true,                 /* first segment */
 128                             true,                 /* last segment */
 129                             ds                    /* first descriptor */
 130                 );
 131
 132         memset(series, 0, sizeof(struct ath9k_11n_rate_series) * 4);
 133         series[0].Tries = 1;
 134         series[0].Rate = rate;
 135         series[0].ChSel = sc->sc_tx_chainmask;
 136         series[0].RateFlags = (ctsrate) ? ATH9K_RATESERIES_RTS_CTS : 0;
 137         ath9k_hw_set11n_ratescenario(ah, ds, ds, 0,
 138                 ctsrate, ctsduration, series, 4, 0);
 139 }
 140
 141 /* Generate beacon frame and queue cab data for a vap */
 142 static struct ath_buf *ath_beacon_generate(struct ath_softc *sc, int if_id)
 143 {
 144         struct ath_buf *bf;
 145         struct ath_vap *avp;
 146         struct sk_buff *skb;
 147         struct ath_txq *cabq;
 148         struct ieee80211_vif *vif;
 149         struct ieee80211_tx_info *info;
 150         int cabq_depth;
 151
 152         vif = sc->sc_vaps[if_id];
 153         ASSERT(vif);
 154
 155         avp = (void *)vif->drv_priv;
 156         cabq = sc->beacon.cabq;
 157
 158         if (avp->av_bcbuf == NULL) {
 159                 DPRINTF(sc, ATH_DBG_BEACON, "avp=%p av_bcbuf=%p\n",
 160                         avp, avp->av_bcbuf);
 161                 return NULL;
 162         }
 163
 164         bf = avp->av_bcbuf;
 165         skb = (struct sk_buff *)bf->bf_mpdu;
 166         if (skb) {
 167                 pci_unmap_single(sc->pdev, bf->bf_dmacontext,
 168                                  skb->len,
 169                                  PCI_DMA_TODEVICE);
 170                 dev_kfree_skb_any(skb);
 171         }
 172
 173         skb = ieee80211_beacon_get(sc->hw, vif);
 174         bf->bf_mpdu = skb;
 175         if (skb == NULL)
 176                 return NULL;
 177
 178         info = IEEE80211_SKB_CB(skb);
 179         if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {
 180                 /*
 181                  * TODO: make sure the seq# gets assigned properly (vs. other
 182                  * TX frames)
 183                  */
 184                 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 185                 sc->tx.seq_no += 0x10;
 186                 hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
 187                 hdr->seq_ctrl |= cpu_to_le16(sc->tx.seq_no);
 188         }
 189
 190         bf->bf_buf_addr = bf->bf_dmacontext =
 191                 pci_map_single(sc->pdev, skb->data,
 192                                skb->len,
 193                                PCI_DMA_TODEVICE);
 194         if (unlikely(pci_dma_mapping_error(sc->pdev, bf->bf_buf_addr))) {
 195                 dev_kfree_skb_any(skb);
 196                 bf->bf_mpdu = NULL;
 197                 DPRINTF(sc, ATH_DBG_CONFIG,
 198                         "pci_dma_mapping_error() on beaconing\n");
 199                 return NULL;
 200         }
 201
 202         skb = ieee80211_get_buffered_bc(sc->hw, vif);
 203
 204         /*
 205          * if the CABQ traffic from previous DTIM is pending and the current
 206          *  beacon is also a DTIM.
 207          *  1) if there is only one vap let the cab traffic continue.
 208          *  2) if there are more than one vap and we are using staggered
 209          *     beacons, then drain the cabq by dropping all the frames in
 210          *     the cabq so that the current vaps cab traffic can be scheduled.
 211          */
 212         spin_lock_bh(&cabq->axq_lock);
 213         cabq_depth = cabq->axq_depth;
 214         spin_unlock_bh(&cabq->axq_lock);
 215
 216         if (skb && cabq_depth) {
 217                 /*
 218                  * Unlock the cabq lock as ath_tx_draintxq acquires
 219                  * the lock again which is a common function and that
 220                  * acquires txq lock inside.
 221                  */
 222                 if (sc->sc_nvaps > 1) {
 223                         ath_tx_draintxq(sc, cabq, false);
 224                         DPRINTF(sc, ATH_DBG_BEACON,
 225                                 "flush previous cabq traffic\n");
 226                 }
 227         }
 228
 229         /* Construct tx descriptor. */
 230         ath_beacon_setup(sc, avp, bf);
 231
 232         /*
 233          * Enable the CAB queue before the beacon queue to
 234          * insure cab frames are triggered by this beacon.
 235          */
 236         while (skb) {
 237                 ath_tx_cabq(sc, skb);
 238                 skb = ieee80211_get_buffered_bc(sc->hw, vif);
 239         }
 240
 241         return bf;
 242 }
 243
 244 /*
 245  * Startup beacon transmission for adhoc mode when they are sent entirely
 246  * by the hardware using the self-linked descriptor + veol trick.
 247 */
 248 static void ath_beacon_start_adhoc(struct ath_softc *sc, int if_id)
 249 {
 250         struct ieee80211_vif *vif;
 251         struct ath_hal *ah = sc->sc_ah;
 252         struct ath_buf *bf;
 253         struct ath_vap *avp;
 254         struct sk_buff *skb;
 255
 256         vif = sc->sc_vaps[if_id];
 257         ASSERT(vif);
 258
 259         avp = (void *)vif->drv_priv;
 260
 261         if (avp->av_bcbuf == NULL) {
 262                 DPRINTF(sc, ATH_DBG_BEACON, "avp=%p av_bcbuf=%p\n",
 263                         avp, avp != NULL ? avp->av_bcbuf : NULL);
 264                 return;
 265         }
 266         bf = avp->av_bcbuf;
 267         skb = (struct sk_buff *) bf->bf_mpdu;
 268
 269         /* Construct tx descriptor. */
 270         ath_beacon_setup(sc, avp, bf);
 271
 272         /* NB: caller is known to have already stopped tx dma */
 273         ath9k_hw_puttxbuf(ah, sc->beacon.beaconq, bf->bf_daddr);
 274         ath9k_hw_txstart(ah, sc->beacon.beaconq);
 275         DPRINTF(sc, ATH_DBG_BEACON, "TXDP%u = %llx (%p)\n",
 276                 sc->beacon.beaconq, ito64(bf->bf_daddr), bf->bf_desc);
 277 }
 278
 279 int ath_beaconq_setup(struct ath_hal *ah)
 280 {
 281         struct ath9k_tx_queue_info qi;
 282
 283         memset(&qi, 0, sizeof(qi));
 284         qi.tqi_aifs = 1;
 285         qi.tqi_cwmin = 0;
 286         qi.tqi_cwmax = 0;
 287         /* NB: don't enable any interrupts */
 288         return ath9k_hw_setuptxqueue(ah, ATH9K_TX_QUEUE_BEACON, &qi);
 289 }
 290
 291 int ath_beacon_alloc(struct ath_softc *sc, int if_id)
 292 {
 293         struct ieee80211_vif *vif;
 294         struct ath_vap *avp;
 295         struct ieee80211_hdr *hdr;
 296         struct ath_buf *bf;
 297         struct sk_buff *skb;
 298         __le64 tstamp;
 299
 300         vif = sc->sc_vaps[if_id];
 301         ASSERT(vif);
 302
 303         avp = (void *)vif->drv_priv;
 304
 305         /* Allocate a beacon descriptor if we haven't done so. */
 306         if (!avp->av_bcbuf) {
 307                 /* Allocate beacon state for hostap/ibss.  We know
 308                  * a buffer is available. */
 309                 avp->av_bcbuf = list_first_entry(&sc->beacon.bbuf,
 310                                                  struct ath_buf, list);
 311                 list_del(&avp->av_bcbuf->list);
 312
 313                 if (sc->sc_ah->ah_opmode == NL80211_IFTYPE_AP ||
 314                     !(sc->sc_ah->ah_caps.hw_caps & ATH9K_HW_CAP_VEOL)) {
 315                         int slot;
 316                         /*
 317                          * Assign the vap to a beacon xmit slot. As
 318                          * above, this cannot fail to find one.
 319                          */
 320                         avp->av_bslot = 0;
 321                         for (slot = 0; slot < ATH_BCBUF; slot++)
 322                                 if (sc->beacon.bslot[slot] == ATH_IF_ID_ANY) {
 323                                         /*
 324                                          * XXX hack, space out slots to better
 325                                          * deal with misses
 326                                          */
 327                                         if (slot+1 < ATH_BCBUF &&
 328                                             sc->beacon.bslot[slot+1] ==
 329                                                 ATH_IF_ID_ANY) {
 330                                                 avp->av_bslot = slot+1;
 331                                                 break;
 332                                         }
 333                                         avp->av_bslot = slot;
 334                                         /* NB: keep looking for a double slot */
 335                                 }
 336                         BUG_ON(sc->beacon.bslot[avp->av_bslot] != ATH_IF_ID_ANY);
 337                         sc->beacon.bslot[avp->av_bslot] = if_id;
 338                         sc->sc_nbcnvaps++;
 339                 }
 340         }
 341
 342         /* release the previous beacon frame , if it already exists. */
 343         bf = avp->av_bcbuf;
 344         if (bf->bf_mpdu != NULL) {
 345                 skb = (struct sk_buff *)bf->bf_mpdu;
 346                 pci_unmap_single(sc->pdev, bf->bf_dmacontext,
 347                                  skb->len,
 348                                  PCI_DMA_TODEVICE);
 349                 dev_kfree_skb_any(skb);
 350                 bf->bf_mpdu = NULL;
 351         }
 352
 353         /*
 354          * NB: the beacon data buffer must be 32-bit aligned.
 355          * FIXME: Fill avp->av_btxctl.txpower and
 356          * avp->av_btxctl.shortPreamble
 357          */
 358         skb = ieee80211_beacon_get(sc->hw, vif);
 359         if (skb == NULL) {
 360                 DPRINTF(sc, ATH_DBG_BEACON, "cannot get skb\n");
 361                 return -ENOMEM;
 362         }
 363
 364         tstamp = ((struct ieee80211_mgmt *)skb->data)->u.beacon.timestamp;
 365         sc->beacon.bc_tstamp = le64_to_cpu(tstamp);
 366
 367         /*
 368          * Calculate a TSF adjustment factor required for
 369          * staggered beacons.  Note that we assume the format
 370          * of the beacon frame leaves the tstamp field immediately
 371          * following the header.
 372          */
 373         if (avp->av_bslot > 0) {
 374                 u64 tsfadjust;
 375                 __le64 val;
 376                 int intval;
 377
 378                 intval = sc->hw->conf.beacon_int ?
 379                         sc->hw->conf.beacon_int : ATH_DEFAULT_BINTVAL;
 380
 381                 /*
 382                  * The beacon interval is in TU's; the TSF in usecs.
 383                  * We figure out how many TU's to add to align the
 384                  * timestamp then convert to TSF units and handle
 385                  * byte swapping before writing it in the frame.
 386                  * The hardware will then add this each time a beacon
 387                  * frame is sent.  Note that we align vap's 1..N
 388                  * and leave vap 0 untouched.  This means vap 0
 389                  * has a timestamp in one beacon interval while the
 390                  * others get a timestamp aligned to the next interval.
 391                  */
 392                 tsfadjust = (intval * (ATH_BCBUF - avp->av_bslot)) / ATH_BCBUF;
 393                 val = cpu_to_le64(tsfadjust << 10);     /* TU->TSF */
 394
 395                 DPRINTF(sc, ATH_DBG_BEACON,
 396                         "stagger beacons, bslot %d intval %u tsfadjust %llu\n",
 397                         avp->av_bslot, intval, (unsigned long long)tsfadjust);
 398
 399                 hdr = (struct ieee80211_hdr *)skb->data;
 400                 memcpy(&hdr[1], &val, sizeof(val));
 401         }
 402
 403         bf->bf_mpdu = skb;
 404         bf->bf_buf_addr = bf->bf_dmacontext =
 405                 pci_map_single(sc->pdev, skb->data,
 406                                skb->len,
 407                                PCI_DMA_TODEVICE);
 408         if (unlikely(pci_dma_mapping_error(sc->pdev, bf->bf_buf_addr))) {
 409                 dev_kfree_skb_any(skb);
 410                 bf->bf_mpdu = NULL;
 411                 DPRINTF(sc, ATH_DBG_CONFIG,
 412                         "pci_dma_mapping_error() on beacon alloc\n");
 413                 return -ENOMEM;
 414         }
 415
 416         return 0;
 417 }
 418
 419 void ath_beacon_return(struct ath_softc *sc, struct ath_vap *avp)
 420 {
 421         if (avp->av_bcbuf != NULL) {
 422                 struct ath_buf *bf;
 423
 424                 if (avp->av_bslot != -1) {
 425                         sc->beacon.bslot[avp->av_bslot] = ATH_IF_ID_ANY;
 426                         sc->sc_nbcnvaps--;
 427                 }
 428
 429                 bf = avp->av_bcbuf;
 430                 if (bf->bf_mpdu != NULL) {
 431                         struct sk_buff *skb = (struct sk_buff *)bf->bf_mpdu;
 432                         pci_unmap_single(sc->pdev, bf->bf_dmacontext,
 433                                          skb->len,
 434                                          PCI_DMA_TODEVICE);
 435                         dev_kfree_skb_any(skb);
 436                         bf->bf_mpdu = NULL;
 437                 }
 438                 list_add_tail(&bf->list, &sc->beacon.bbuf);
 439
 440                 avp->av_bcbuf = NULL;
 441         }
 442 }
 443
 444 void ath9k_beacon_tasklet(unsigned long data)
 445 {
 446         struct ath_softc *sc = (struct ath_softc *)data;
 447         struct ath_hal *ah = sc->sc_ah;
 448         struct ath_buf *bf = NULL;
 449         int slot, if_id;
 450         u32 bfaddr;
 451         u32 rx_clear = 0, rx_frame = 0, tx_frame = 0;
 452         u32 show_cycles = 0;
 453         u32 bc = 0; /* beacon count */
 454         u64 tsf;
 455         u32 tsftu;
 456         u16 intval;
 457
 458         if (sc->sc_flags & SC_OP_NO_RESET) {
 459                 show_cycles = ath9k_hw_GetMibCycleCountsPct(ah,
 460                                             &rx_clear, &rx_frame, &tx_frame);
 461         }
 462
 463         /*
 464          * Check if the previous beacon has gone out.  If
 465          * not don't try to post another, skip this period
 466          * and wait for the next.  Missed beacons indicate
 467          * a problem and should not occur.  If we miss too
 468          * many consecutive beacons reset the device.
 469          *
 470          * FIXME: Clean up this mess !!
 471          */
 472         if (ath9k_hw_numtxpending(ah, sc->beacon.beaconq) != 0) {
 473                 sc->beacon.bmisscnt++;
 474                 /* XXX: doth needs the chanchange IE countdown decremented.
 475                  *      We should consider adding a mac80211 call to indicate
 476                  *      a beacon miss so appropriate action could be taken
 477                  *      (in that layer).
 478                  */
 479                 if (sc->beacon.bmisscnt < BSTUCK_THRESH) {
 480                         if (sc->sc_flags & SC_OP_NO_RESET) {
 481                                 DPRINTF(sc, ATH_DBG_BEACON,
 482                                         "missed %u consecutive beacons\n",
 483                                         sc->beacon.bmisscnt);
 484                                 if (show_cycles) {
 485                                         /*
 486                                          * Display cycle counter stats from HW
 487                                          * to aide in debug of stickiness.
 488                                          */
 489                                         DPRINTF(sc, ATH_DBG_BEACON,
 490                                                 "busy times: rx_clear=%d, "
 491                                                 "rx_frame=%d, tx_frame=%d\n",
 492                                                 rx_clear, rx_frame,
 493                                                 tx_frame);
 494                                 } else {
 495                                         DPRINTF(sc, ATH_DBG_BEACON,
 496                                                 "unable to obtain "
 497                                                 "busy times\n");
 498                                 }
 499                         } else {
 500                                 DPRINTF(sc, ATH_DBG_BEACON,
 501                                         "missed %u consecutive beacons\n",
 502                                         sc->beacon.bmisscnt);
 503                         }
 504                 } else if (sc->beacon.bmisscnt >= BSTUCK_THRESH) {
 505                         if (sc->sc_flags & SC_OP_NO_RESET) {
 506                                 if (sc->beacon.bmisscnt == BSTUCK_THRESH) {
 507                                         DPRINTF(sc, ATH_DBG_BEACON,
 508                                                 "beacon is officially "
 509                                                 "stuck\n");
 510                                 }
 511                         } else {
 512                                 DPRINTF(sc, ATH_DBG_BEACON,
 513                                         "beacon is officially stuck\n");
 514                                 ath_bstuck_process(sc);
 515                         }
 516                 }
 517                 return;
 518         }
 519
 520         if (sc->beacon.bmisscnt != 0) {
 521                 if (sc->sc_flags & SC_OP_NO_RESET) {
 522                         DPRINTF(sc, ATH_DBG_BEACON,
 523                                 "resume beacon xmit after %u misses\n",
 524                                 sc->beacon.bmisscnt);
 525                 } else {
 526                         DPRINTF(sc, ATH_DBG_BEACON,
 527                                 "resume beacon xmit after %u misses\n",
 528                                 sc->beacon.bmisscnt);
 529                 }
 530                 sc->beacon.bmisscnt = 0;
 531         }
 532
 533         /*
 534          * Generate beacon frames. we are sending frames
 535          * staggered so calculate the slot for this frame based
 536          * on the tsf to safeguard against missing an swba.
 537          */
 538
 539         intval = sc->hw->conf.beacon_int ?
 540                 sc->hw->conf.beacon_int : ATH_DEFAULT_BINTVAL;
 541
 542         tsf = ath9k_hw_gettsf64(ah);
 543         tsftu = TSF_TO_TU(tsf>>32, tsf);
 544         slot = ((tsftu % intval) * ATH_BCBUF) / intval;
 545         if_id = sc->beacon.bslot[(slot + 1) % ATH_BCBUF];
 546
 547         DPRINTF(sc, ATH_DBG_BEACON,
 548                 "slot %d [tsf %llu tsftu %u intval %u] if_id %d\n",
 549                 slot, (unsigned long long)tsf, tsftu,
 550                 intval, if_id);
 551
 552         bfaddr = 0;
 553         if (if_id != ATH_IF_ID_ANY) {
 554                 bf = ath_beacon_generate(sc, if_id);
 555                 if (bf != NULL) {
 556                         bfaddr = bf->bf_daddr;
 557                         bc = 1;
 558                 }
 559         }
 560         /*
 561          * Handle slot time change when a non-ERP station joins/leaves
 562          * an 11g network.  The 802.11 layer notifies us via callback,
 563          * we mark updateslot, then wait one beacon before effecting
 564          * the change.  This gives associated stations at least one
 565          * beacon interval to note the state change.
 566          *
 567          * NB: The slot time change state machine is clocked according
 568          *     to whether we are bursting or staggering beacons.  We
 569          *     recognize the request to update and record the current
 570          *     slot then don't transition until that slot is reached
 571          *     again.  If we miss a beacon for that slot then we'll be
 572          *     slow to transition but we'll be sure at least one beacon
 573          *     interval has passed.  When bursting slot is always left
 574          *     set to ATH_BCBUF so this check is a noop.
 575          */
 576         /* XXX locking */
 577         if (sc->beacon.updateslot == UPDATE) {
 578                 sc->beacon.updateslot = COMMIT; /* commit next beacon */
 579                 sc->beacon.slotupdate = slot;
 580         } else if (sc->beacon.updateslot == COMMIT && sc->beacon.slotupdate == slot) {
 581                 ath9k_hw_setslottime(sc->sc_ah, sc->beacon.slottime);
 582                 sc->beacon.updateslot = OK;
 583         }
 584         if (bfaddr != 0) {
 585                 /*
 586                  * Stop any current dma and put the new frame(s) on the queue.
 587                  * This should never fail since we check above that no frames
 588                  * are still pending on the queue.
 589                  */
 590                 if (!ath9k_hw_stoptxdma(ah, sc->beacon.beaconq)) {
 591                         DPRINTF(sc, ATH_DBG_FATAL,
 592                                 "beacon queue %u did not stop?\n", sc->beacon.beaconq);
 593                         /* NB: the HAL still stops DMA, so proceed */
 594                 }
 595
 596                 /* NB: cabq traffic should already be queued and primed */
 597                 ath9k_hw_puttxbuf(ah, sc->beacon.beaconq, bfaddr);
 598                 ath9k_hw_txstart(ah, sc->beacon.beaconq);
 599
 600                 sc->beacon.ast_be_xmit += bc;     /* XXX per-vap? */
 601         }
 602 }
 603
 604 /*
 605  * Configure the beacon and sleep timers.
 606  *
 607  * When operating as an AP this resets the TSF and sets
 608  * up the hardware to notify us when we need to issue beacons.
 609  *
 610  * When operating in station mode this sets up the beacon
 611  * timers according to the timestamp of the last received
 612  * beacon and the current TSF, configures PCF and DTIM
 613  * handling, programs the sleep registers so the hardware
 614  * will wakeup in time to receive beacons, and configures
 615  * the beacon miss handling so we'll receive a BMISS
 616  * interrupt when we stop seeing beacons from the AP
 617  * we've associated with.
 618  */
 619 void ath_beacon_config(struct ath_softc *sc, int if_id)
 620 {
 621         struct ieee80211_vif *vif;
 622         struct ath_hal *ah = sc->sc_ah;
 623         struct ath_beacon_config conf;
 624         struct ath_vap *avp;
 625         enum nl80211_iftype opmode;
 626         u32 nexttbtt, intval;
 627
 628         if (if_id != ATH_IF_ID_ANY) {
 629                 vif = sc->sc_vaps[if_id];
 630                 ASSERT(vif);
 631                 avp = (void *)vif->drv_priv;
 632                 opmode = avp->av_opmode;
 633         } else {
 634                 opmode = sc->sc_ah->ah_opmode;
 635         }
 636
 637         memset(&conf, 0, sizeof(struct ath_beacon_config));
 638
 639         conf.beacon_interval = sc->hw->conf.beacon_int ?
 640                 sc->hw->conf.beacon_int : ATH_DEFAULT_BINTVAL;
 641         conf.listen_interval = 1;
 642         conf.dtim_period = conf.beacon_interval;
 643         conf.dtim_count = 1;
 644         conf.bmiss_timeout = ATH_DEFAULT_BMISS_LIMIT * conf.beacon_interval;
 645
 646         /* extract tstamp from last beacon and convert to TU */
 647         nexttbtt = TSF_TO_TU(sc->beacon.bc_tstamp >> 32, sc->beacon.bc_tstamp);
 648
 649         /* XXX conditionalize multi-bss support? */
 650         if (sc->sc_ah->ah_opmode == NL80211_IFTYPE_AP) {
 651                 /*
 652                  * For multi-bss ap support beacons are either staggered
 653                  * evenly over N slots or burst together.  For the former
 654                  * arrange for the SWBA to be delivered for each slot.
 655                  * Slots that are not occupied will generate nothing.
 656                  */
 657                 /* NB: the beacon interval is kept internally in TU's */
 658                 intval = conf.beacon_interval & ATH9K_BEACON_PERIOD;
 659                 intval /= ATH_BCBUF;    /* for staggered beacons */
 660         } else {
 661                 intval = conf.beacon_interval & ATH9K_BEACON_PERIOD;
 662         }
 663
 664         if (nexttbtt == 0)      /* e.g. for ap mode */
 665                 nexttbtt = intval;
 666         else if (intval)        /* NB: can be 0 for monitor mode */
 667                 nexttbtt = roundup(nexttbtt, intval);
 668
 669         DPRINTF(sc, ATH_DBG_BEACON, "nexttbtt %u intval %u (%u)\n",
 670                 nexttbtt, intval, conf.beacon_interval);
 671
 672         /* Check for NL80211_IFTYPE_AP and sc_nostabeacons for WDS client */
 673         if (sc->sc_ah->ah_opmode == NL80211_IFTYPE_STATION) {
 674                 struct ath9k_beacon_state bs;
 675                 u64 tsf;
 676                 u32 tsftu;
 677                 int dtimperiod, dtimcount, sleepduration;
 678                 int cfpperiod, cfpcount;
 679
 680                 /*
 681                  * Setup dtim and cfp parameters according to
 682                  * last beacon we received (which may be none).
 683                  */
 684                 dtimperiod = conf.dtim_period;
 685                 if (dtimperiod <= 0)            /* NB: 0 if not known */
 686                         dtimperiod = 1;
 687                 dtimcount = conf.dtim_count;
 688                 if (dtimcount >= dtimperiod)    /* NB: sanity check */
 689                         dtimcount = 0;
 690                 cfpperiod = 1;                  /* NB: no PCF support yet */
 691                 cfpcount = 0;
 692
 693                 sleepduration = conf.listen_interval * intval;
 694                 if (sleepduration <= 0)
 695                         sleepduration = intval;
 696
 697 #define FUDGE 2
 698                 /*
 699                  * Pull nexttbtt forward to reflect the current
 700                  * TSF and calculate dtim+cfp state for the result.
 701                  */
 702                 tsf = ath9k_hw_gettsf64(ah);
 703                 tsftu = TSF_TO_TU(tsf>>32, tsf) + FUDGE;
 704                 do {
 705                         nexttbtt += intval;
 706                         if (--dtimcount < 0) {
 707                                 dtimcount = dtimperiod - 1;
 708                                 if (--cfpcount < 0)
 709                                         cfpcount = cfpperiod - 1;
 710                         }
 711                 } while (nexttbtt < tsftu);
 712 #undef FUDGE
 713                 memset(&bs, 0, sizeof(bs));
 714                 bs.bs_intval = intval;
 715                 bs.bs_nexttbtt = nexttbtt;
 716                 bs.bs_dtimperiod = dtimperiod*intval;
 717                 bs.bs_nextdtim = bs.bs_nexttbtt + dtimcount*intval;
 718                 bs.bs_cfpperiod = cfpperiod*bs.bs_dtimperiod;
 719                 bs.bs_cfpnext = bs.bs_nextdtim + cfpcount*bs.bs_dtimperiod;
 720                 bs.bs_cfpmaxduration = 0;
 721
 722                 /*
 723                  * Calculate the number of consecutive beacons to miss
 724                  * before taking a BMISS interrupt.  The configuration
 725                  * is specified in TU so we only need calculate based
 726                  * on the beacon interval.  Note that we clamp the
 727                  * result to at most 15 beacons.
 728                  */
 729                 if (sleepduration > intval) {
 730                         bs.bs_bmissthreshold = conf.listen_interval *
 731                                 ATH_DEFAULT_BMISS_LIMIT / 2;
 732                 } else {
 733                         bs.bs_bmissthreshold =
 734                                 DIV_ROUND_UP(conf.bmiss_timeout, intval);
 735                         if (bs.bs_bmissthreshold > 15)
 736                                 bs.bs_bmissthreshold = 15;
 737                         else if (bs.bs_bmissthreshold <= 0)
 738                                 bs.bs_bmissthreshold = 1;
 739                 }
 740
 741                 /*
 742                  * Calculate sleep duration.  The configuration is
 743                  * given in ms.  We insure a multiple of the beacon
 744                  * period is used.  Also, if the sleep duration is
 745                  * greater than the DTIM period then it makes senses
 746                  * to make it a multiple of that.
 747                  *
 748                  * XXX fixed at 100ms
 749                  */
 750
 751                 bs.bs_sleepduration = roundup(IEEE80211_MS_TO_TU(100),
 752                                               sleepduration);
 753                 if (bs.bs_sleepduration > bs.bs_dtimperiod)
 754                         bs.bs_sleepduration = bs.bs_dtimperiod;
 755
 756                 DPRINTF(sc, ATH_DBG_BEACON,
 757                         "tsf %llu "
 758                         "tsf:tu %u "
 759                         "intval %u "
 760                         "nexttbtt %u "
 761                         "dtim %u "
 762                         "nextdtim %u "
 763                         "bmiss %u "
 764                         "sleep %u "
 765                         "cfp:period %u "
 766                         "maxdur %u "
 767                         "next %u "
 768                         "timoffset %u\n",
 769                         (unsigned long long)tsf, tsftu,
 770                         bs.bs_intval,
 771                         bs.bs_nexttbtt,
 772                         bs.bs_dtimperiod,
 773                         bs.bs_nextdtim,
 774                         bs.bs_bmissthreshold,
 775                         bs.bs_sleepduration,
 776                         bs.bs_cfpperiod,
 777                         bs.bs_cfpmaxduration,
 778                         bs.bs_cfpnext,
 779                         bs.bs_timoffset
 780                         );
 781
 782                 ath9k_hw_set_interrupts(ah, 0);
 783                 ath9k_hw_set_sta_beacon_timers(ah, &bs);
 784                 sc->sc_imask |= ATH9K_INT_BMISS;
 785                 ath9k_hw_set_interrupts(ah, sc->sc_imask);
 786         } else {
 787                 u64 tsf;
 788                 u32 tsftu;
 789                 ath9k_hw_set_interrupts(ah, 0);
 790                 if (nexttbtt == intval)
 791                         intval |= ATH9K_BEACON_RESET_TSF;
 792                 if (sc->sc_ah->ah_opmode == NL80211_IFTYPE_ADHOC) {
 793                         /*
 794                          * Pull nexttbtt forward to reflect the current
 795                          * TSF
 796                          */
 797 #define FUDGE 2
 798                         if (!(intval & ATH9K_BEACON_RESET_TSF)) {
 799                                 tsf = ath9k_hw_gettsf64(ah);
 800                                 tsftu = TSF_TO_TU((u32)(tsf>>32),
 801                                         (u32)tsf) + FUDGE;
 802                                 do {
 803                                         nexttbtt += intval;
 804                                 } while (nexttbtt < tsftu);
 805                         }
 806 #undef FUDGE
 807                         DPRINTF(sc, ATH_DBG_BEACON,
 808                                 "IBSS nexttbtt %u intval %u (%u)\n",
 809                                 nexttbtt,
 810                                 intval & ~ATH9K_BEACON_RESET_TSF,
 811                                 conf.beacon_interval);
 812
 813                         /*
 814                          * In IBSS mode enable the beacon timers but only
 815                          * enable SWBA interrupts if we need to manually
 816                          * prepare beacon frames.  Otherwise we use a
 817                          * self-linked tx descriptor and let the hardware
 818                          * deal with things.
 819                          */
 820                         intval |= ATH9K_BEACON_ENA;
 821                         if (!(ah->ah_caps.hw_caps & ATH9K_HW_CAP_VEOL))
 822                                 sc->sc_imask |= ATH9K_INT_SWBA;
 823                         ath_beaconq_config(sc);
 824                 } else if (sc->sc_ah->ah_opmode == NL80211_IFTYPE_AP) {
 825                         /*
 826                          * In AP mode we enable the beacon timers and
 827                          * SWBA interrupts to prepare beacon frames.
 828                          */
 829                         intval |= ATH9K_BEACON_ENA;
 830                         sc->sc_imask |= ATH9K_INT_SWBA;   /* beacon prepare */
 831                         ath_beaconq_config(sc);
 832                 }
 833                 ath9k_hw_beaconinit(ah, nexttbtt, intval);
 834                 sc->beacon.bmisscnt = 0;
 835                 ath9k_hw_set_interrupts(ah, sc->sc_imask);
 836                 /*
 837                  * When using a self-linked beacon descriptor in
 838                  * ibss mode load it once here.
 839                  */
 840                 if (sc->sc_ah->ah_opmode == NL80211_IFTYPE_ADHOC &&
 841                     (ah->ah_caps.hw_caps & ATH9K_HW_CAP_VEOL))
 842                         ath_beacon_start_adhoc(sc, 0);
 843         }
 844 }
 845
 846 void ath_beacon_sync(struct ath_softc *sc, int if_id)
 847 {
 848         /*
 849          * Resync beacon timers using the tsf of the
 850          * beacon frame we just received.
 851          */
 852         ath_beacon_config(sc, if_id);
 853         sc->sc_flags |= SC_OP_BEACONS;
 854 }