drivers/net/wireless/ath/ath9k/recv.c

   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 #include "ar9003_mac.h"
  20
  21 #define SKB_CB_ATHBUF(__skb)    (*((struct ath_rxbuf **)__skb->cb))
  22
  23 static inline bool ath9k_check_auto_sleep(struct ath_softc *sc)
  24 {
  25         return sc->ps_enabled &&
  26                (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP);
  27 }
  28
  29 /*
  30  * Setup and link descriptors.
  31  *
  32  * 11N: we can no longer afford to self link the last descriptor.
  33  * MAC acknowledges BA status as long as it copies frames to host
  34  * buffer (or rx fifo). This can incorrectly acknowledge packets
  35  * to a sender if last desc is self-linked.
  36  */
  37 static void ath_rx_buf_link(struct ath_softc *sc, struct ath_rxbuf *bf,
  38                             bool flush)
  39 {
  40         struct ath_hw *ah = sc->sc_ah;
  41         struct ath_common *common = ath9k_hw_common(ah);
  42         struct ath_desc *ds;
  43         struct sk_buff *skb;
  44
  45         ds = bf->bf_desc;
  46         ds->ds_link = 0; /* link to null */
  47         ds->ds_data = bf->bf_buf_addr;
  48
  49         /* virtual addr of the beginning of the buffer. */
  50         skb = bf->bf_mpdu;
  51         BUG_ON(skb == NULL);
  52         ds->ds_vdata = skb->data;
  53
  54         /*
  55          * setup rx descriptors. The rx_bufsize here tells the hardware
  56          * how much data it can DMA to us and that we are prepared
  57          * to process
  58          */
  59         ath9k_hw_setuprxdesc(ah, ds,
  60                              common->rx_bufsize,
  61                              0);
  62
  63         if (sc->rx.rxlink)
  64                 *sc->rx.rxlink = bf->bf_daddr;
  65         else if (!flush)
  66                 ath9k_hw_putrxbuf(ah, bf->bf_daddr);
  67
  68         sc->rx.rxlink = &ds->ds_link;
  69 }
  70
  71 static void ath_rx_buf_relink(struct ath_softc *sc, struct ath_rxbuf *bf,
  72                               bool flush)
  73 {
  74         if (sc->rx.buf_hold)
  75                 ath_rx_buf_link(sc, sc->rx.buf_hold, flush);
  76
  77         sc->rx.buf_hold = bf;
  78 }
  79
  80 static void ath_setdefantenna(struct ath_softc *sc, u32 antenna)
  81 {
  82         /* XXX block beacon interrupts */
  83         ath9k_hw_setantenna(sc->sc_ah, antenna);
  84         sc->rx.defant = antenna;
  85         sc->rx.rxotherant = 0;
  86 }
  87
  88 static void ath_opmode_init(struct ath_softc *sc)
  89 {
  90         struct ath_hw *ah = sc->sc_ah;
  91         struct ath_common *common = ath9k_hw_common(ah);
  92
  93         u32 rfilt, mfilt[2];
  94
  95         /* configure rx filter */
  96         rfilt = ath_calcrxfilter(sc);
  97         ath9k_hw_setrxfilter(ah, rfilt);
  98
  99         /* configure bssid mask */
 100         ath_hw_setbssidmask(common);
 101
 102         /* configure operational mode */
 103         ath9k_hw_setopmode(ah);
 104
 105         /* calculate and install multicast filter */
 106         mfilt[0] = mfilt[1] = ~0;
 107         ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
 108 }
 109
 110 static bool ath_rx_edma_buf_link(struct ath_softc *sc,
 111                                  enum ath9k_rx_qtype qtype)
 112 {
 113         struct ath_hw *ah = sc->sc_ah;
 114         struct ath_rx_edma *rx_edma;
 115         struct sk_buff *skb;
 116         struct ath_rxbuf *bf;
 117
 118         rx_edma = &sc->rx.rx_edma[qtype];
 119         if (skb_queue_len(&rx_edma->rx_fifo) >= rx_edma->rx_fifo_hwsize)
 120                 return false;
 121
 122         bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
 123         list_del_init(&bf->list);
 124
 125         skb = bf->bf_mpdu;
 126
 127         memset(skb->data, 0, ah->caps.rx_status_len);
 128         dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
 129                                 ah->caps.rx_status_len, DMA_TO_DEVICE);
 130
 131         SKB_CB_ATHBUF(skb) = bf;
 132         ath9k_hw_addrxbuf_edma(ah, bf->bf_buf_addr, qtype);
 133         __skb_queue_tail(&rx_edma->rx_fifo, skb);
 134
 135         return true;
 136 }
 137
 138 static void ath_rx_addbuffer_edma(struct ath_softc *sc,
 139                                   enum ath9k_rx_qtype qtype)
 140 {
 141         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 142         struct ath_rxbuf *bf, *tbf;
 143
 144         if (list_empty(&sc->rx.rxbuf)) {
 145                 ath_dbg(common, QUEUE, "No free rx buf available\n");
 146                 return;
 147         }
 148
 149         list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list)
 150                 if (!ath_rx_edma_buf_link(sc, qtype))
 151                         break;
 152
 153 }
 154
 155 static void ath_rx_remove_buffer(struct ath_softc *sc,
 156                                  enum ath9k_rx_qtype qtype)
 157 {
 158         struct ath_rxbuf *bf;
 159         struct ath_rx_edma *rx_edma;
 160         struct sk_buff *skb;
 161
 162         rx_edma = &sc->rx.rx_edma[qtype];
 163
 164         while ((skb = __skb_dequeue(&rx_edma->rx_fifo)) != NULL) {
 165                 bf = SKB_CB_ATHBUF(skb);
 166                 BUG_ON(!bf);
 167                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 168         }
 169 }
 170
 171 static void ath_rx_edma_cleanup(struct ath_softc *sc)
 172 {
 173         struct ath_hw *ah = sc->sc_ah;
 174         struct ath_common *common = ath9k_hw_common(ah);
 175         struct ath_rxbuf *bf;
 176
 177         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
 178         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
 179
 180         list_for_each_entry(bf, &sc->rx.rxbuf, list) {
 181                 if (bf->bf_mpdu) {
 182                         dma_unmap_single(sc->dev, bf->bf_buf_addr,
 183                                         common->rx_bufsize,
 184                                         DMA_BIDIRECTIONAL);
 185                         dev_kfree_skb_any(bf->bf_mpdu);
 186                         bf->bf_buf_addr = 0;
 187                         bf->bf_mpdu = NULL;
 188                 }
 189         }
 190 }
 191
 192 static void ath_rx_edma_init_queue(struct ath_rx_edma *rx_edma, int size)
 193 {
 194         __skb_queue_head_init(&rx_edma->rx_fifo);
 195         rx_edma->rx_fifo_hwsize = size;
 196 }
 197
 198 static int ath_rx_edma_init(struct ath_softc *sc, int nbufs)
 199 {
 200         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 201         struct ath_hw *ah = sc->sc_ah;
 202         struct sk_buff *skb;
 203         struct ath_rxbuf *bf;
 204         int error = 0, i;
 205         u32 size;
 206
 207         ath9k_hw_set_rx_bufsize(ah, common->rx_bufsize -
 208                                     ah->caps.rx_status_len);
 209
 210         ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_LP],
 211                                ah->caps.rx_lp_qdepth);
 212         ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_HP],
 213                                ah->caps.rx_hp_qdepth);
 214
 215         size = sizeof(struct ath_rxbuf) * nbufs;
 216         bf = devm_kzalloc(sc->dev, size, GFP_KERNEL);
 217         if (!bf)
 218                 return -ENOMEM;
 219
 220         INIT_LIST_HEAD(&sc->rx.rxbuf);
 221
 222         for (i = 0; i < nbufs; i++, bf++) {
 223                 skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_KERNEL);
 224                 if (!skb) {
 225                         error = -ENOMEM;
 226                         goto rx_init_fail;
 227                 }
 228
 229                 memset(skb->data, 0, common->rx_bufsize);
 230                 bf->bf_mpdu = skb;
 231
 232                 bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
 233                                                  common->rx_bufsize,
 234                                                  DMA_BIDIRECTIONAL);
 235                 if (unlikely(dma_mapping_error(sc->dev,
 236                                                 bf->bf_buf_addr))) {
 237                                 dev_kfree_skb_any(skb);
 238                                 bf->bf_mpdu = NULL;
 239                                 bf->bf_buf_addr = 0;
 240                                 ath_err(common,
 241                                         "dma_mapping_error() on RX init\n");
 242                                 error = -ENOMEM;
 243                                 goto rx_init_fail;
 244                 }
 245
 246                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 247         }
 248
 249         return 0;
 250
 251 rx_init_fail:
 252         ath_rx_edma_cleanup(sc);
 253         return error;
 254 }
 255
 256 static void ath_edma_start_recv(struct ath_softc *sc)
 257 {
 258         ath9k_hw_rxena(sc->sc_ah);
 259         ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_HP);
 260         ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_LP);
 261         ath_opmode_init(sc);
 262         ath9k_hw_startpcureceive(sc->sc_ah, sc->cur_chan->offchannel);
 263 }
 264
 265 static void ath_edma_stop_recv(struct ath_softc *sc)
 266 {
 267         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
 268         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
 269 }
 270
 271 int ath_rx_init(struct ath_softc *sc, int nbufs)
 272 {
 273         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 274         struct sk_buff *skb;
 275         struct ath_rxbuf *bf;
 276         int error = 0;
 277
 278         spin_lock_init(&sc->sc_pcu_lock);
 279
 280         common->rx_bufsize = IEEE80211_MAX_MPDU_LEN / 2 +
 281                              sc->sc_ah->caps.rx_status_len;
 282
 283         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
 284                 return ath_rx_edma_init(sc, nbufs);
 285
 286         ath_dbg(common, CONFIG, "cachelsz %u rxbufsize %u\n",
 287                 common->cachelsz, common->rx_bufsize);
 288
 289         /* Initialize rx descriptors */
 290
 291         error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
 292                                   "rx", nbufs, 1, 0);
 293         if (error != 0) {
 294                 ath_err(common,
 295                         "failed to allocate rx descriptors: %d\n",
 296                         error);
 297                 goto err;
 298         }
 299
 300         list_for_each_entry(bf, &sc->rx.rxbuf, list) {
 301                 skb = ath_rxbuf_alloc(common, common->rx_bufsize,
 302                                       GFP_KERNEL);
 303                 if (skb == NULL) {
 304                         error = -ENOMEM;
 305                         goto err;
 306                 }
 307
 308                 bf->bf_mpdu = skb;
 309                 bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
 310                                                  common->rx_bufsize,
 311                                                  DMA_FROM_DEVICE);
 312                 if (unlikely(dma_mapping_error(sc->dev,
 313                                                bf->bf_buf_addr))) {
 314                         dev_kfree_skb_any(skb);
 315                         bf->bf_mpdu = NULL;
 316                         bf->bf_buf_addr = 0;
 317                         ath_err(common,
 318                                 "dma_mapping_error() on RX init\n");
 319                         error = -ENOMEM;
 320                         goto err;
 321                 }
 322         }
 323         sc->rx.rxlink = NULL;
 324 err:
 325         if (error)
 326                 ath_rx_cleanup(sc);
 327
 328         return error;
 329 }
 330
 331 void ath_rx_cleanup(struct ath_softc *sc)
 332 {
 333         struct ath_hw *ah = sc->sc_ah;
 334         struct ath_common *common = ath9k_hw_common(ah);
 335         struct sk_buff *skb;
 336         struct ath_rxbuf *bf;
 337
 338         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
 339                 ath_rx_edma_cleanup(sc);
 340                 return;
 341         }
 342
 343         list_for_each_entry(bf, &sc->rx.rxbuf, list) {
 344                 skb = bf->bf_mpdu;
 345                 if (skb) {
 346                         dma_unmap_single(sc->dev, bf->bf_buf_addr,
 347                                          common->rx_bufsize,
 348                                          DMA_FROM_DEVICE);
 349                         dev_kfree_skb(skb);
 350                         bf->bf_buf_addr = 0;
 351                         bf->bf_mpdu = NULL;
 352                 }
 353         }
 354 }
 355
 356 /*
 357  * Calculate the receive filter according to the
 358  * operating mode and state:
 359  *
 360  * o always accept unicast, broadcast, and multicast traffic
 361  * o maintain current state of phy error reception (the hal
 362  *   may enable phy error frames for noise immunity work)
 363  * o probe request frames are accepted only when operating in
 364  *   hostap, adhoc, or monitor modes
 365  * o enable promiscuous mode according to the interface state
 366  * o accept beacons:
 367  *   - when operating in adhoc mode so the 802.11 layer creates
 368  *     node table entries for peers,
 369  *   - when operating in station mode for collecting rssi data when
 370  *     the station is otherwise quiet, or
 371  *   - when operating as a repeater so we see repeater-sta beacons
 372  *   - when scanning
 373  */
 374
 375 u32 ath_calcrxfilter(struct ath_softc *sc)
 376 {
 377         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 378         u32 rfilt;
 379
 380         if (config_enabled(CONFIG_ATH9K_TX99))
 381                 return 0;
 382
 383         rfilt = ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
 384                 | ATH9K_RX_FILTER_MCAST;
 385
 386         /* if operating on a DFS channel, enable radar pulse detection */
 387         if (sc->hw->conf.radar_enabled)
 388                 rfilt |= ATH9K_RX_FILTER_PHYRADAR | ATH9K_RX_FILTER_PHYERR;
 389
 390         spin_lock_bh(&sc->chan_lock);
 391
 392         if (sc->cur_chan->rxfilter & FIF_PROBE_REQ)
 393                 rfilt |= ATH9K_RX_FILTER_PROBEREQ;
 394
 395         if (sc->sc_ah->is_monitoring)
 396                 rfilt |= ATH9K_RX_FILTER_PROM;
 397
 398         if ((sc->cur_chan->rxfilter & FIF_CONTROL) ||
 399             sc->sc_ah->dynack.enabled)
 400                 rfilt |= ATH9K_RX_FILTER_CONTROL;
 401
 402         if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
 403             (sc->cur_chan->nvifs <= 1) &&
 404             !(sc->cur_chan->rxfilter & FIF_BCN_PRBRESP_PROMISC))
 405                 rfilt |= ATH9K_RX_FILTER_MYBEACON;
 406         else if (sc->sc_ah->opmode != NL80211_IFTYPE_OCB)
 407                 rfilt |= ATH9K_RX_FILTER_BEACON;
 408
 409         if ((sc->sc_ah->opmode == NL80211_IFTYPE_AP) ||
 410             (sc->cur_chan->rxfilter & FIF_PSPOLL))
 411                 rfilt |= ATH9K_RX_FILTER_PSPOLL;
 412
 413         if (sc->cur_chandef.width != NL80211_CHAN_WIDTH_20_NOHT)
 414                 rfilt |= ATH9K_RX_FILTER_COMP_BAR;
 415
 416         if (sc->cur_chan->nvifs > 1 || (sc->cur_chan->rxfilter & FIF_OTHER_BSS)) {
 417                 /* This is needed for older chips */
 418                 if (sc->sc_ah->hw_version.macVersion <= AR_SREV_VERSION_9160)
 419                         rfilt |= ATH9K_RX_FILTER_PROM;
 420                 rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
 421         }
 422
 423         if (AR_SREV_9550(sc->sc_ah) || AR_SREV_9531(sc->sc_ah) ||
 424             AR_SREV_9561(sc->sc_ah))
 425                 rfilt |= ATH9K_RX_FILTER_4ADDRESS;
 426
 427         if (ath9k_is_chanctx_enabled() &&
 428             test_bit(ATH_OP_SCANNING, &common->op_flags))
 429                 rfilt |= ATH9K_RX_FILTER_BEACON;
 430
 431         spin_unlock_bh(&sc->chan_lock);
 432
 433         return rfilt;
 434
 435 }
 436
 437 void ath_startrecv(struct ath_softc *sc)
 438 {
 439         struct ath_hw *ah = sc->sc_ah;
 440         struct ath_rxbuf *bf, *tbf;
 441
 442         if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
 443                 ath_edma_start_recv(sc);
 444                 return;
 445         }
 446
 447         if (list_empty(&sc->rx.rxbuf))
 448                 goto start_recv;
 449
 450         sc->rx.buf_hold = NULL;
 451         sc->rx.rxlink = NULL;
 452         list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
 453                 ath_rx_buf_link(sc, bf, false);
 454         }
 455
 456         /* We could have deleted elements so the list may be empty now */
 457         if (list_empty(&sc->rx.rxbuf))
 458                 goto start_recv;
 459
 460         bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
 461         ath9k_hw_putrxbuf(ah, bf->bf_daddr);
 462         ath9k_hw_rxena(ah);
 463
 464 start_recv:
 465         ath_opmode_init(sc);
 466         ath9k_hw_startpcureceive(ah, sc->cur_chan->offchannel);
 467 }
 468
 469 static void ath_flushrecv(struct ath_softc *sc)
 470 {
 471         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
 472                 ath_rx_tasklet(sc, 1, true);
 473         ath_rx_tasklet(sc, 1, false);
 474 }
 475
 476 bool ath_stoprecv(struct ath_softc *sc)
 477 {
 478         struct ath_hw *ah = sc->sc_ah;
 479         bool stopped, reset = false;
 480
 481         ath9k_hw_abortpcurecv(ah);
 482         ath9k_hw_setrxfilter(ah, 0);
 483         stopped = ath9k_hw_stopdmarecv(ah, &reset);
 484
 485         ath_flushrecv(sc);
 486
 487         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
 488                 ath_edma_stop_recv(sc);
 489         else
 490                 sc->rx.rxlink = NULL;
 491
 492         if (!(ah->ah_flags & AH_UNPLUGGED) &&
 493             unlikely(!stopped)) {
 494                 ath_dbg(ath9k_hw_common(sc->sc_ah), RESET,
 495                         "Failed to stop Rx DMA\n");
 496                 RESET_STAT_INC(sc, RESET_RX_DMA_ERROR);
 497         }
 498         return stopped && !reset;
 499 }
 500
 501 static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
 502 {
 503         /* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
 504         struct ieee80211_mgmt *mgmt;
 505         u8 *pos, *end, id, elen;
 506         struct ieee80211_tim_ie *tim;
 507
 508         mgmt = (struct ieee80211_mgmt *)skb->data;
 509         pos = mgmt->u.beacon.variable;
 510         end = skb->data + skb->len;
 511
 512         while (pos + 2 < end) {
 513                 id = *pos++;
 514                 elen = *pos++;
 515                 if (pos + elen > end)
 516                         break;
 517
 518                 if (id == WLAN_EID_TIM) {
 519                         if (elen < sizeof(*tim))
 520                                 break;
 521                         tim = (struct ieee80211_tim_ie *) pos;
 522                         if (tim->dtim_count != 0)
 523                                 break;
 524                         return tim->bitmap_ctrl & 0x01;
 525                 }
 526
 527                 pos += elen;
 528         }
 529
 530         return false;
 531 }
 532
 533 static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
 534 {
 535         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 536         bool skip_beacon = false;
 537
 538         if (skb->len < 24 + 8 + 2 + 2)
 539                 return;
 540
 541         sc->ps_flags &= ~PS_WAIT_FOR_BEACON;
 542
 543         if (sc->ps_flags & PS_BEACON_SYNC) {
 544                 sc->ps_flags &= ~PS_BEACON_SYNC;
 545                 ath_dbg(common, PS,
 546                         "Reconfigure beacon timers based on synchronized timestamp\n");
 547
 548 #ifdef CONFIG_ATH9K_CHANNEL_CONTEXT
 549                 if (ath9k_is_chanctx_enabled()) {
 550                         if (sc->cur_chan == &sc->offchannel.chan)
 551                                 skip_beacon = true;
 552                 }
 553 #endif
 554
 555                 if (!skip_beacon &&
 556                     !(WARN_ON_ONCE(sc->cur_chan->beacon.beacon_interval == 0)))
 557                         ath9k_set_beacon(sc);
 558
 559                 ath9k_p2p_beacon_sync(sc);
 560         }
 561
 562         if (ath_beacon_dtim_pending_cab(skb)) {
 563                 /*
 564                  * Remain awake waiting for buffered broadcast/multicast
 565                  * frames. If the last broadcast/multicast frame is not
 566                  * received properly, the next beacon frame will work as
 567                  * a backup trigger for returning into NETWORK SLEEP state,
 568                  * so we are waiting for it as well.
 569                  */
 570                 ath_dbg(common, PS,
 571                         "Received DTIM beacon indicating buffered broadcast/multicast frame(s)\n");
 572                 sc->ps_flags |= PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON;
 573                 return;
 574         }
 575
 576         if (sc->ps_flags & PS_WAIT_FOR_CAB) {
 577                 /*
 578                  * This can happen if a broadcast frame is dropped or the AP
 579                  * fails to send a frame indicating that all CAB frames have
 580                  * been delivered.
 581                  */
 582                 sc->ps_flags &= ~PS_WAIT_FOR_CAB;
 583                 ath_dbg(common, PS, "PS wait for CAB frames timed out\n");
 584         }
 585 }
 586
 587 static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb, bool mybeacon)
 588 {
 589         struct ieee80211_hdr *hdr;
 590         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 591
 592         hdr = (struct ieee80211_hdr *)skb->data;
 593
 594         /* Process Beacon and CAB receive in PS state */
 595         if (((sc->ps_flags & PS_WAIT_FOR_BEACON) || ath9k_check_auto_sleep(sc))
 596             && mybeacon) {
 597                 ath_rx_ps_beacon(sc, skb);
 598         } else if ((sc->ps_flags & PS_WAIT_FOR_CAB) &&
 599                    (ieee80211_is_data(hdr->frame_control) ||
 600                     ieee80211_is_action(hdr->frame_control)) &&
 601                    is_multicast_ether_addr(hdr->addr1) &&
 602                    !ieee80211_has_moredata(hdr->frame_control)) {
 603                 /*
 604                  * No more broadcast/multicast frames to be received at this
 605                  * point.
 606                  */
 607                 sc->ps_flags &= ~(PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON);
 608                 ath_dbg(common, PS,
 609                         "All PS CAB frames received, back to sleep\n");
 610         } else if ((sc->ps_flags & PS_WAIT_FOR_PSPOLL_DATA) &&
 611                    !is_multicast_ether_addr(hdr->addr1) &&
 612                    !ieee80211_has_morefrags(hdr->frame_control)) {
 613                 sc->ps_flags &= ~PS_WAIT_FOR_PSPOLL_DATA;
 614                 ath_dbg(common, PS,
 615                         "Going back to sleep after having received PS-Poll data (0x%lx)\n",
 616                         sc->ps_flags & (PS_WAIT_FOR_BEACON |
 617                                         PS_WAIT_FOR_CAB |
 618                                         PS_WAIT_FOR_PSPOLL_DATA |
 619                                         PS_WAIT_FOR_TX_ACK));
 620         }
 621 }
 622
 623 static bool ath_edma_get_buffers(struct ath_softc *sc,
 624                                  enum ath9k_rx_qtype qtype,
 625                                  struct ath_rx_status *rs,
 626                                  struct ath_rxbuf **dest)
 627 {
 628         struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
 629         struct ath_hw *ah = sc->sc_ah;
 630         struct ath_common *common = ath9k_hw_common(ah);
 631         struct sk_buff *skb;
 632         struct ath_rxbuf *bf;
 633         int ret;
 634
 635         skb = skb_peek(&rx_edma->rx_fifo);
 636         if (!skb)
 637                 return false;
 638
 639         bf = SKB_CB_ATHBUF(skb);
 640         BUG_ON(!bf);
 641
 642         dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
 643                                 common->rx_bufsize, DMA_FROM_DEVICE);
 644
 645         ret = ath9k_hw_process_rxdesc_edma(ah, rs, skb->data);
 646         if (ret == -EINPROGRESS) {
 647                 /*let device gain the buffer again*/
 648                 dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
 649                                 common->rx_bufsize, DMA_FROM_DEVICE);
 650                 return false;
 651         }
 652
 653         __skb_unlink(skb, &rx_edma->rx_fifo);
 654         if (ret == -EINVAL) {
 655                 /* corrupt descriptor, skip this one and the following one */
 656                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 657                 ath_rx_edma_buf_link(sc, qtype);
 658
 659                 skb = skb_peek(&rx_edma->rx_fifo);
 660                 if (skb) {
 661                         bf = SKB_CB_ATHBUF(skb);
 662                         BUG_ON(!bf);
 663
 664                         __skb_unlink(skb, &rx_edma->rx_fifo);
 665                         list_add_tail(&bf->list, &sc->rx.rxbuf);
 666                         ath_rx_edma_buf_link(sc, qtype);
 667                 }
 668
 669                 bf = NULL;
 670         }
 671
 672         *dest = bf;
 673         return true;
 674 }
 675
 676 static struct ath_rxbuf *ath_edma_get_next_rx_buf(struct ath_softc *sc,
 677                                                 struct ath_rx_status *rs,
 678                                                 enum ath9k_rx_qtype qtype)
 679 {
 680         struct ath_rxbuf *bf = NULL;
 681
 682         while (ath_edma_get_buffers(sc, qtype, rs, &bf)) {
 683                 if (!bf)
 684                         continue;
 685
 686                 return bf;
 687         }
 688         return NULL;
 689 }
 690
 691 static struct ath_rxbuf *ath_get_next_rx_buf(struct ath_softc *sc,
 692                                            struct ath_rx_status *rs)
 693 {
 694         struct ath_hw *ah = sc->sc_ah;
 695         struct ath_common *common = ath9k_hw_common(ah);
 696         struct ath_desc *ds;
 697         struct ath_rxbuf *bf;
 698         int ret;
 699
 700         if (list_empty(&sc->rx.rxbuf)) {
 701                 sc->rx.rxlink = NULL;
 702                 return NULL;
 703         }
 704
 705         bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
 706         if (bf == sc->rx.buf_hold)
 707                 return NULL;
 708
 709         ds = bf->bf_desc;
 710
 711         /*
 712          * Must provide the virtual address of the current
 713          * descriptor, the physical address, and the virtual
 714          * address of the next descriptor in the h/w chain.
 715          * This allows the HAL to look ahead to see if the
 716          * hardware is done with a descriptor by checking the
 717          * done bit in the following descriptor and the address
 718          * of the current descriptor the DMA engine is working
 719          * on.  All this is necessary because of our use of
 720          * a self-linked list to avoid rx overruns.
 721          */
 722         ret = ath9k_hw_rxprocdesc(ah, ds, rs);
 723         if (ret == -EINPROGRESS) {
 724                 struct ath_rx_status trs;
 725                 struct ath_rxbuf *tbf;
 726                 struct ath_desc *tds;
 727
 728                 memset(&trs, 0, sizeof(trs));
 729                 if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
 730                         sc->rx.rxlink = NULL;
 731                         return NULL;
 732                 }
 733
 734                 tbf = list_entry(bf->list.next, struct ath_rxbuf, list);
 735
 736                 /*
 737                  * On some hardware the descriptor status words could
 738                  * get corrupted, including the done bit. Because of
 739                  * this, check if the next descriptor's done bit is
 740                  * set or not.
 741                  *
 742                  * If the next descriptor's done bit is set, the current
 743                  * descriptor has been corrupted. Force s/w to discard
 744                  * this descriptor and continue...
 745                  */
 746
 747                 tds = tbf->bf_desc;
 748                 ret = ath9k_hw_rxprocdesc(ah, tds, &trs);
 749                 if (ret == -EINPROGRESS)
 750                         return NULL;
 751
 752                 /*
 753                  * Re-check previous descriptor, in case it has been filled
 754                  * in the mean time.
 755                  */
 756                 ret = ath9k_hw_rxprocdesc(ah, ds, rs);
 757                 if (ret == -EINPROGRESS) {
 758                         /*
 759                          * mark descriptor as zero-length and set the 'more'
 760                          * flag to ensure that both buffers get discarded
 761                          */
 762                         rs->rs_datalen = 0;
 763                         rs->rs_more = true;
 764                 }
 765         }
 766
 767         list_del(&bf->list);
 768         if (!bf->bf_mpdu)
 769                 return bf;
 770
 771         /*
 772          * Synchronize the DMA transfer with CPU before
 773          * 1. accessing the frame
 774          * 2. requeueing the same buffer to h/w
 775          */
 776         dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
 777                         common->rx_bufsize,
 778                         DMA_FROM_DEVICE);
 779
 780         return bf;
 781 }
 782
 783 static void ath9k_process_tsf(struct ath_rx_status *rs,
 784                               struct ieee80211_rx_status *rxs,
 785                               u64 tsf)
 786 {
 787         u32 tsf_lower = tsf & 0xffffffff;
 788
 789         rxs->mactime = (tsf & ~0xffffffffULL) | rs->rs_tstamp;
 790         if (rs->rs_tstamp > tsf_lower &&
 791             unlikely(rs->rs_tstamp - tsf_lower > 0x10000000))
 792                 rxs->mactime -= 0x100000000ULL;
 793
 794         if (rs->rs_tstamp < tsf_lower &&
 795             unlikely(tsf_lower - rs->rs_tstamp > 0x10000000))
 796                 rxs->mactime += 0x100000000ULL;
 797 }
 798
 799 /*
 800  * For Decrypt or Demic errors, we only mark packet status here and always push
 801  * up the frame up to let mac80211 handle the actual error case, be it no
 802  * decryption key or real decryption error. This let us keep statistics there.
 803  */
 804 static int ath9k_rx_skb_preprocess(struct ath_softc *sc,
 805                                    struct sk_buff *skb,
 806                                    struct ath_rx_status *rx_stats,
 807                                    struct ieee80211_rx_status *rx_status,
 808                                    bool *decrypt_error, u64 tsf)
 809 {
 810         struct ieee80211_hw *hw = sc->hw;
 811         struct ath_hw *ah = sc->sc_ah;
 812         struct ath_common *common = ath9k_hw_common(ah);
 813         struct ieee80211_hdr *hdr;
 814         bool discard_current = sc->rx.discard_next;
 815
 816         /*
 817          * Discard corrupt descriptors which are marked in
 818          * ath_get_next_rx_buf().
 819          */
 820         if (discard_current)
 821                 goto corrupt;
 822
 823         sc->rx.discard_next = false;
 824
 825         /*
 826          * Discard zero-length packets.
 827          */
 828         if (!rx_stats->rs_datalen) {
 829                 RX_STAT_INC(rx_len_err);
 830                 goto corrupt;
 831         }
 832
 833         /*
 834          * rs_status follows rs_datalen so if rs_datalen is too large
 835          * we can take a hint that hardware corrupted it, so ignore
 836          * those frames.
 837          */
 838         if (rx_stats->rs_datalen > (common->rx_bufsize - ah->caps.rx_status_len)) {
 839                 RX_STAT_INC(rx_len_err);
 840                 goto corrupt;
 841         }
 842
 843         /* Only use status info from the last fragment */
 844         if (rx_stats->rs_more)
 845                 return 0;
 846
 847         /*
 848          * Return immediately if the RX descriptor has been marked
 849          * as corrupt based on the various error bits.
 850          *
 851          * This is different from the other corrupt descriptor
 852          * condition handled above.
 853          */
 854         if (rx_stats->rs_status & ATH9K_RXERR_CORRUPT_DESC)
 855                 goto corrupt;
 856
 857         hdr = (struct ieee80211_hdr *) (skb->data + ah->caps.rx_status_len);
 858
 859         ath9k_process_tsf(rx_stats, rx_status, tsf);
 860         ath_debug_stat_rx(sc, rx_stats);
 861
 862         /*
 863          * Process PHY errors and return so that the packet
 864          * can be dropped.
 865          */
 866         if (rx_stats->rs_status & ATH9K_RXERR_PHY) {
 867                 ath9k_dfs_process_phyerr(sc, hdr, rx_stats, rx_status->mactime);
 868                 if (ath_cmn_process_fft(&sc->spec_priv, hdr, rx_stats, rx_status->mactime))
 869                         RX_STAT_INC(rx_spectral);
 870
 871                 return -EINVAL;
 872         }
 873
 874         /*
 875          * everything but the rate is checked here, the rate check is done
 876          * separately to avoid doing two lookups for a rate for each frame.
 877          */
 878         spin_lock_bh(&sc->chan_lock);
 879         if (!ath9k_cmn_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error,
 880                                  sc->cur_chan->rxfilter)) {
 881                 spin_unlock_bh(&sc->chan_lock);
 882                 return -EINVAL;
 883         }
 884         spin_unlock_bh(&sc->chan_lock);
 885
 886         if (ath_is_mybeacon(common, hdr)) {
 887                 RX_STAT_INC(rx_beacons);
 888                 rx_stats->is_mybeacon = true;
 889         }
 890
 891         /*
 892          * This shouldn't happen, but have a safety check anyway.
 893          */
 894         if (WARN_ON(!ah->curchan))
 895                 return -EINVAL;
 896
 897         if (ath9k_cmn_process_rate(common, hw, rx_stats, rx_status)) {
 898                 /*
 899                  * No valid hardware bitrate found -- we should not get here
 900                  * because hardware has already validated this frame as OK.
 901                  */
 902                 ath_dbg(common, ANY, "unsupported hw bitrate detected 0x%02x using 1 Mbit\n",
 903                         rx_stats->rs_rate);
 904                 RX_STAT_INC(rx_rate_err);
 905                 return -EINVAL;
 906         }
 907
 908         if (ath9k_is_chanctx_enabled()) {
 909                 if (rx_stats->is_mybeacon)
 910                         ath_chanctx_beacon_recv_ev(sc,
 911                                            ATH_CHANCTX_EVENT_BEACON_RECEIVED);
 912         }
 913
 914         ath9k_cmn_process_rssi(common, hw, rx_stats, rx_status);
 915
 916         rx_status->band = ah->curchan->chan->band;
 917         rx_status->freq = ah->curchan->chan->center_freq;
 918         rx_status->antenna = rx_stats->rs_antenna;
 919         rx_status->flag |= RX_FLAG_MACTIME_END;
 920
 921 #ifdef CONFIG_ATH9K_BTCOEX_SUPPORT
 922         if (ieee80211_is_data_present(hdr->frame_control) &&
 923             !ieee80211_is_qos_nullfunc(hdr->frame_control))
 924                 sc->rx.num_pkts++;
 925 #endif
 926
 927         return 0;
 928
 929 corrupt:
 930         sc->rx.discard_next = rx_stats->rs_more;
 931         return -EINVAL;
 932 }
 933
 934 /*
 935  * Run the LNA combining algorithm only in these cases:
 936  *
 937  * Standalone WLAN cards with both LNA/Antenna diversity
 938  * enabled in the EEPROM.
 939  *
 940  * WLAN+BT cards which are in the supported card list
 941  * in ath_pci_id_table and the user has loaded the
 942  * driver with "bt_ant_diversity" set to true.
 943  */
 944 static void ath9k_antenna_check(struct ath_softc *sc,
 945                                 struct ath_rx_status *rs)
 946 {
 947         struct ath_hw *ah = sc->sc_ah;
 948         struct ath9k_hw_capabilities *pCap = &ah->caps;
 949         struct ath_common *common = ath9k_hw_common(ah);
 950
 951         if (!(ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB))
 952                 return;
 953
 954         /*
 955          * Change the default rx antenna if rx diversity
 956          * chooses the other antenna 3 times in a row.
 957          */
 958         if (sc->rx.defant != rs->rs_antenna) {
 959                 if (++sc->rx.rxotherant >= 3)
 960                         ath_setdefantenna(sc, rs->rs_antenna);
 961         } else {
 962                 sc->rx.rxotherant = 0;
 963         }
 964
 965         if (pCap->hw_caps & ATH9K_HW_CAP_BT_ANT_DIV) {
 966                 if (common->bt_ant_diversity)
 967                         ath_ant_comb_scan(sc, rs);
 968         } else {
 969                 ath_ant_comb_scan(sc, rs);
 970         }
 971 }
 972
 973 static void ath9k_apply_ampdu_details(struct ath_softc *sc,
 974         struct ath_rx_status *rs, struct ieee80211_rx_status *rxs)
 975 {
 976         if (rs->rs_isaggr) {
 977                 rxs->flag |= RX_FLAG_AMPDU_DETAILS | RX_FLAG_AMPDU_LAST_KNOWN;
 978
 979                 rxs->ampdu_reference = sc->rx.ampdu_ref;
 980
 981                 if (!rs->rs_moreaggr) {
 982                         rxs->flag |= RX_FLAG_AMPDU_IS_LAST;
 983                         sc->rx.ampdu_ref++;
 984                 }
 985
 986                 if (rs->rs_flags & ATH9K_RX_DELIM_CRC_PRE)
 987                         rxs->flag |= RX_FLAG_AMPDU_DELIM_CRC_ERROR;
 988         }
 989 }
 990
 991 int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
 992 {
 993         struct ath_rxbuf *bf;
 994         struct sk_buff *skb = NULL, *requeue_skb, *hdr_skb;
 995         struct ieee80211_rx_status *rxs;
 996         struct ath_hw *ah = sc->sc_ah;
 997         struct ath_common *common = ath9k_hw_common(ah);
 998         struct ieee80211_hw *hw = sc->hw;
 999         int retval;
1000         struct ath_rx_status rs;
1001         enum ath9k_rx_qtype qtype;
1002         bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
1003         int dma_type;
1004         u64 tsf = 0;
1005         unsigned long flags;
1006         dma_addr_t new_buf_addr;
1007         unsigned int budget = 512;
1008         struct ieee80211_hdr *hdr;
1009
1010         if (edma)
1011                 dma_type = DMA_BIDIRECTIONAL;
1012         else
1013                 dma_type = DMA_FROM_DEVICE;
1014
1015         qtype = hp ? ATH9K_RX_QUEUE_HP : ATH9K_RX_QUEUE_LP;
1016
1017         tsf = ath9k_hw_gettsf64(ah);
1018
1019         do {
1020                 bool decrypt_error = false;
1021
1022                 memset(&rs, 0, sizeof(rs));
1023                 if (edma)
1024                         bf = ath_edma_get_next_rx_buf(sc, &rs, qtype);
1025                 else
1026                         bf = ath_get_next_rx_buf(sc, &rs);
1027
1028                 if (!bf)
1029                         break;
1030
1031                 skb = bf->bf_mpdu;
1032                 if (!skb)
1033                         continue;
1034
1035                 /*
1036                  * Take frame header from the first fragment and RX status from
1037                  * the last one.
1038                  */
1039                 if (sc->rx.frag)
1040                         hdr_skb = sc->rx.frag;
1041                 else
1042                         hdr_skb = skb;
1043
1044                 rxs = IEEE80211_SKB_RXCB(hdr_skb);
1045                 memset(rxs, 0, sizeof(struct ieee80211_rx_status));
1046
1047                 retval = ath9k_rx_skb_preprocess(sc, hdr_skb, &rs, rxs,
1048                                                  &decrypt_error, tsf);
1049                 if (retval)
1050                         goto requeue_drop_frag;
1051
1052                 /* Ensure we always have an skb to requeue once we are done
1053                  * processing the current buffer's skb */
1054                 requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC);
1055
1056                 /* If there is no memory we ignore the current RX'd frame,
1057                  * tell hardware it can give us a new frame using the old
1058                  * skb and put it at the tail of the sc->rx.rxbuf list for
1059                  * processing. */
1060                 if (!requeue_skb) {
1061                         RX_STAT_INC(rx_oom_err);
1062                         goto requeue_drop_frag;
1063                 }
1064
1065                 /* We will now give hardware our shiny new allocated skb */
1066                 new_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
1067                                               common->rx_bufsize, dma_type);
1068                 if (unlikely(dma_mapping_error(sc->dev, new_buf_addr))) {
1069                         dev_kfree_skb_any(requeue_skb);
1070                         goto requeue_drop_frag;
1071                 }
1072
1073                 /* Unmap the frame */
1074                 dma_unmap_single(sc->dev, bf->bf_buf_addr,
1075                                  common->rx_bufsize, dma_type);
1076
1077                 bf->bf_mpdu = requeue_skb;
1078                 bf->bf_buf_addr = new_buf_addr;
1079
1080                 skb_put(skb, rs.rs_datalen + ah->caps.rx_status_len);
1081                 if (ah->caps.rx_status_len)
1082                         skb_pull(skb, ah->caps.rx_status_len);
1083
1084                 if (!rs.rs_more)
1085                         ath9k_cmn_rx_skb_postprocess(common, hdr_skb, &rs,
1086                                                      rxs, decrypt_error);
1087
1088                 if (rs.rs_more) {
1089                         RX_STAT_INC(rx_frags);
1090                         /*
1091                          * rs_more indicates chained descriptors which can be
1092                          * used to link buffers together for a sort of
1093                          * scatter-gather operation.
1094                          */
1095                         if (sc->rx.frag) {
1096                                 /* too many fragments - cannot handle frame */
1097                                 dev_kfree_skb_any(sc->rx.frag);
1098                                 dev_kfree_skb_any(skb);
1099                                 RX_STAT_INC(rx_too_many_frags_err);
1100                                 skb = NULL;
1101                         }
1102                         sc->rx.frag = skb;
1103                         goto requeue;
1104                 }
1105
1106                 if (sc->rx.frag) {
1107                         int space = skb->len - skb_tailroom(hdr_skb);
1108
1109                         if (pskb_expand_head(hdr_skb, 0, space, GFP_ATOMIC) < 0) {
1110                                 dev_kfree_skb(skb);
1111                                 RX_STAT_INC(rx_oom_err);
1112                                 goto requeue_drop_frag;
1113                         }
1114
1115                         sc->rx.frag = NULL;
1116
1117                         skb_copy_from_linear_data(skb, skb_put(hdr_skb, skb->len),
1118                                                   skb->len);
1119                         dev_kfree_skb_any(skb);
1120                         skb = hdr_skb;
1121                 }
1122
1123                 if (rxs->flag & RX_FLAG_MMIC_STRIPPED)
1124                         skb_trim(skb, skb->len - 8);
1125
1126                 spin_lock_irqsave(&sc->sc_pm_lock, flags);
1127                 if ((sc->ps_flags & (PS_WAIT_FOR_BEACON |
1128                                      PS_WAIT_FOR_CAB |
1129                                      PS_WAIT_FOR_PSPOLL_DATA)) ||
1130                     ath9k_check_auto_sleep(sc))
1131                         ath_rx_ps(sc, skb, rs.is_mybeacon);
1132                 spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
1133
1134                 ath9k_antenna_check(sc, &rs);
1135                 ath9k_apply_ampdu_details(sc, &rs, rxs);
1136                 ath_debug_rate_stats(sc, &rs, skb);
1137
1138                 hdr = (struct ieee80211_hdr *)skb->data;
1139                 if (ieee80211_is_ack(hdr->frame_control))
1140                         ath_dynack_sample_ack_ts(sc->sc_ah, skb, rs.rs_tstamp);
1141
1142                 ieee80211_rx(hw, skb);
1143
1144 requeue_drop_frag:
1145                 if (sc->rx.frag) {
1146                         dev_kfree_skb_any(sc->rx.frag);
1147                         sc->rx.frag = NULL;
1148                 }
1149 requeue:
1150                 list_add_tail(&bf->list, &sc->rx.rxbuf);
1151
1152                 if (!edma) {
1153                         ath_rx_buf_relink(sc, bf, flush);
1154                         if (!flush)
1155                                 ath9k_hw_rxena(ah);
1156                 } else if (!flush) {
1157                         ath_rx_edma_buf_link(sc, qtype);
1158                 }
1159
1160                 if (!budget--)
1161                         break;
1162         } while (1);
1163
1164         if (!(ah->imask & ATH9K_INT_RXEOL)) {
1165                 ah->imask |= (ATH9K_INT_RXEOL | ATH9K_INT_RXORN);
1166                 ath9k_hw_set_interrupts(ah);
1167         }
1168
1169         return 0;
1170 }