net/mac80211/agg-tx.c

   1 /*
   2  * HT handling
   3  *
   4  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
   5  * Copyright 2002-2005, Instant802 Networks, Inc.
   6  * Copyright 2005-2006, Devicescape Software, Inc.
   7  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   8  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
   9  * Copyright 2007-2009, Intel Corporation
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  */
  15
  16 #include <linux/ieee80211.h>
  17 #include <net/mac80211.h>
  18 #include "ieee80211_i.h"
  19 #include "driver-ops.h"
  20 #include "wme.h"
  21
  22 /**
  23  * DOC: TX aggregation
  24  *
  25  * Aggregation on the TX side requires setting the hardware flag
  26  * %IEEE80211_HW_AMPDU_AGGREGATION as well as, if present, the @ampdu_queues
  27  * hardware parameter to the number of hardware AMPDU queues. If there are no
  28  * hardware queues then the driver will (currently) have to do all frame
  29  * buffering.
  30  *
  31  * When TX aggregation is started by some subsystem (usually the rate control
  32  * algorithm would be appropriate) by calling the
  33  * ieee80211_start_tx_ba_session() function, the driver will be notified via
  34  * its @ampdu_action function, with the %IEEE80211_AMPDU_TX_START action.
  35  *
  36  * In response to that, the driver is later required to call the
  37  * ieee80211_start_tx_ba_cb() (or ieee80211_start_tx_ba_cb_irqsafe())
  38  * function, which will start the aggregation session.
  39  *
  40  * Similarly, when the aggregation session is stopped by
  41  * ieee80211_stop_tx_ba_session(), the driver's @ampdu_action function will
  42  * be called with the action %IEEE80211_AMPDU_TX_STOP. In this case, the
  43  * call must not fail, and the driver must later call ieee80211_stop_tx_ba_cb()
  44  * (or ieee80211_stop_tx_ba_cb_irqsafe()).
  45  */
  46
  47 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
  48                                          const u8 *da, u16 tid,
  49                                          u8 dialog_token, u16 start_seq_num,
  50                                          u16 agg_size, u16 timeout)
  51 {
  52         struct ieee80211_local *local = sdata->local;
  53         struct sk_buff *skb;
  54         struct ieee80211_mgmt *mgmt;
  55         u16 capab;
  56
  57         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
  58
  59         if (!skb) {
  60                 printk(KERN_ERR "%s: failed to allocate buffer "
  61                                 "for addba request frame\n", sdata->dev->name);
  62                 return;
  63         }
  64         skb_reserve(skb, local->hw.extra_tx_headroom);
  65         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
  66         memset(mgmt, 0, 24);
  67         memcpy(mgmt->da, da, ETH_ALEN);
  68         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
  69         if (sdata->vif.type == NL80211_IFTYPE_AP ||
  70             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
  71                 memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
  72         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
  73                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
  74
  75         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
  76                                           IEEE80211_STYPE_ACTION);
  77
  78         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
  79
  80         mgmt->u.action.category = WLAN_CATEGORY_BACK;
  81         mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
  82
  83         mgmt->u.action.u.addba_req.dialog_token = dialog_token;
  84         capab = (u16)(1 << 1);          /* bit 1 aggregation policy */
  85         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
  86         capab |= (u16)(agg_size << 6);  /* bit 15:6 max size of aggergation */
  87
  88         mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
  89
  90         mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
  91         mgmt->u.action.u.addba_req.start_seq_num =
  92                                         cpu_to_le16(start_seq_num << 4);
  93
  94         ieee80211_tx_skb(sdata, skb, 1);
  95 }
  96
  97 void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn)
  98 {
  99         struct ieee80211_local *local = sdata->local;
 100         struct sk_buff *skb;
 101         struct ieee80211_bar *bar;
 102         u16 bar_control = 0;
 103
 104         skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
 105         if (!skb) {
 106                 printk(KERN_ERR "%s: failed to allocate buffer for "
 107                         "bar frame\n", sdata->dev->name);
 108                 return;
 109         }
 110         skb_reserve(skb, local->hw.extra_tx_headroom);
 111         bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
 112         memset(bar, 0, sizeof(*bar));
 113         bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
 114                                          IEEE80211_STYPE_BACK_REQ);
 115         memcpy(bar->ra, ra, ETH_ALEN);
 116         memcpy(bar->ta, sdata->dev->dev_addr, ETH_ALEN);
 117         bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
 118         bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
 119         bar_control |= (u16)(tid << 12);
 120         bar->control = cpu_to_le16(bar_control);
 121         bar->start_seq_num = cpu_to_le16(ssn);
 122
 123         ieee80211_tx_skb(sdata, skb, 0);
 124 }
 125
 126 static int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 127                                            enum ieee80211_back_parties initiator)
 128 {
 129         struct ieee80211_local *local = sta->local;
 130         int ret;
 131         u8 *state;
 132
 133         state = &sta->ampdu_mlme.tid_state_tx[tid];
 134
 135         *state = HT_AGG_STATE_REQ_STOP_BA_MSK |
 136                 (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
 137
 138         ret = drv_ampdu_action(local, IEEE80211_AMPDU_TX_STOP,
 139                                &sta->sta, tid, NULL);
 140
 141         /* HW shall not deny going back to legacy */
 142         if (WARN_ON(ret)) {
 143                 *state = HT_AGG_STATE_OPERATIONAL;
 144                 /*
 145                  * We may have pending packets get stuck in this case...
 146                  * Not bothering with a workaround for now.
 147                  */
 148         }
 149
 150         return ret;
 151 }
 152
 153 /*
 154  * After sending add Block Ack request we activated a timer until
 155  * add Block Ack response will arrive from the recipient.
 156  * If this timer expires sta_addba_resp_timer_expired will be executed.
 157  */
 158 static void sta_addba_resp_timer_expired(unsigned long data)
 159 {
 160         /* not an elegant detour, but there is no choice as the timer passes
 161          * only one argument, and both sta_info and TID are needed, so init
 162          * flow in sta_info_create gives the TID as data, while the timer_to_id
 163          * array gives the sta through container_of */
 164         u16 tid = *(u8 *)data;
 165         struct sta_info *sta = container_of((void *)data,
 166                 struct sta_info, timer_to_tid[tid]);
 167         u8 *state;
 168
 169         state = &sta->ampdu_mlme.tid_state_tx[tid];
 170
 171         /* check if the TID waits for addBA response */
 172         spin_lock_bh(&sta->lock);
 173         if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
 174                 spin_unlock_bh(&sta->lock);
 175                 *state = HT_AGG_STATE_IDLE;
 176 #ifdef CONFIG_MAC80211_HT_DEBUG
 177                 printk(KERN_DEBUG "timer expired on tid %d but we are not "
 178                                 "expecting addBA response there", tid);
 179 #endif
 180                 return;
 181         }
 182
 183 #ifdef CONFIG_MAC80211_HT_DEBUG
 184         printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
 185 #endif
 186
 187         ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 188         spin_unlock_bh(&sta->lock);
 189 }
 190
 191 static inline int ieee80211_ac_from_tid(int tid)
 192 {
 193         return ieee802_1d_to_ac[tid & 7];
 194 }
 195
 196 int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 197 {
 198         struct ieee80211_local *local = hw_to_local(hw);
 199         struct sta_info *sta;
 200         struct ieee80211_sub_if_data *sdata;
 201         u8 *state;
 202         int ret = 0;
 203         u16 start_seq_num;
 204
 205         if (WARN_ON(!local->ops->ampdu_action))
 206                 return -EINVAL;
 207
 208         if ((tid >= STA_TID_NUM) || !(hw->flags & IEEE80211_HW_AMPDU_AGGREGATION))
 209                 return -EINVAL;
 210
 211 #ifdef CONFIG_MAC80211_HT_DEBUG
 212         printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
 213                ra, tid);
 214 #endif /* CONFIG_MAC80211_HT_DEBUG */
 215
 216         rcu_read_lock();
 217
 218         sta = sta_info_get(local, ra);
 219         if (!sta) {
 220 #ifdef CONFIG_MAC80211_HT_DEBUG
 221                 printk(KERN_DEBUG "Could not find the station\n");
 222 #endif
 223                 ret = -ENOENT;
 224                 goto unlock;
 225         }
 226
 227         /*
 228          * The aggregation code is not prepared to handle
 229          * anything but STA/AP due to the BSSID handling.
 230          * IBSS could work in the code but isn't supported
 231          * by drivers or the standard.
 232          */
 233         if (sta->sdata->vif.type != NL80211_IFTYPE_STATION &&
 234             sta->sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
 235             sta->sdata->vif.type != NL80211_IFTYPE_AP) {
 236                 ret = -EINVAL;
 237                 goto unlock;
 238         }
 239
 240         if (test_sta_flags(sta, WLAN_STA_SUSPEND)) {
 241 #ifdef CONFIG_MAC80211_HT_DEBUG
 242                 printk(KERN_DEBUG "Suspend in progress. "
 243                        "Denying BA session request\n");
 244 #endif
 245                 ret = -EINVAL;
 246                 goto unlock;
 247         }
 248
 249         spin_lock_bh(&sta->lock);
 250         spin_lock(&local->ampdu_lock);
 251
 252         sdata = sta->sdata;
 253
 254         /* we have tried too many times, receiver does not want A-MPDU */
 255         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
 256                 ret = -EBUSY;
 257                 goto err_unlock_sta;
 258         }
 259
 260         state = &sta->ampdu_mlme.tid_state_tx[tid];
 261         /* check if the TID is not in aggregation flow already */
 262         if (*state != HT_AGG_STATE_IDLE) {
 263 #ifdef CONFIG_MAC80211_HT_DEBUG
 264                 printk(KERN_DEBUG "BA request denied - session is not "
 265                                  "idle on tid %u\n", tid);
 266 #endif /* CONFIG_MAC80211_HT_DEBUG */
 267                 ret = -EAGAIN;
 268                 goto err_unlock_sta;
 269         }
 270
 271         /*
 272          * While we're asking the driver about the aggregation,
 273          * stop the AC queue so that we don't have to worry
 274          * about frames that came in while we were doing that,
 275          * which would require us to put them to the AC pending
 276          * afterwards which just makes the code more complex.
 277          */
 278         ieee80211_stop_queue_by_reason(
 279                 &local->hw, ieee80211_ac_from_tid(tid),
 280                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 281
 282         /* prepare A-MPDU MLME for Tx aggregation */
 283         sta->ampdu_mlme.tid_tx[tid] =
 284                         kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
 285         if (!sta->ampdu_mlme.tid_tx[tid]) {
 286 #ifdef CONFIG_MAC80211_HT_DEBUG
 287                 if (net_ratelimit())
 288                         printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
 289                                         tid);
 290 #endif
 291                 ret = -ENOMEM;
 292                 goto err_wake_queue;
 293         }
 294
 295         skb_queue_head_init(&sta->ampdu_mlme.tid_tx[tid]->pending);
 296
 297         /* Tx timer */
 298         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
 299                         sta_addba_resp_timer_expired;
 300         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
 301                         (unsigned long)&sta->timer_to_tid[tid];
 302         init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 303
 304         /* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
 305          * call back right away, it must see that the flow has begun */
 306         *state |= HT_ADDBA_REQUESTED_MSK;
 307
 308         start_seq_num = sta->tid_seq[tid];
 309
 310         ret = drv_ampdu_action(local, IEEE80211_AMPDU_TX_START,
 311                                &sta->sta, tid, &start_seq_num);
 312
 313         if (ret) {
 314 #ifdef CONFIG_MAC80211_HT_DEBUG
 315                 printk(KERN_DEBUG "BA request denied - HW unavailable for"
 316                                         " tid %d\n", tid);
 317 #endif /* CONFIG_MAC80211_HT_DEBUG */
 318                 *state = HT_AGG_STATE_IDLE;
 319                 goto err_free;
 320         }
 321
 322         /* Driver vetoed or OKed, but we can take packets again now */
 323         ieee80211_wake_queue_by_reason(
 324                 &local->hw, ieee80211_ac_from_tid(tid),
 325                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 326
 327         spin_unlock(&local->ampdu_lock);
 328         spin_unlock_bh(&sta->lock);
 329
 330         /* send an addBA request */
 331         sta->ampdu_mlme.dialog_token_allocator++;
 332         sta->ampdu_mlme.tid_tx[tid]->dialog_token =
 333                         sta->ampdu_mlme.dialog_token_allocator;
 334         sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;
 335
 336         ieee80211_send_addba_request(sta->sdata, ra, tid,
 337                          sta->ampdu_mlme.tid_tx[tid]->dialog_token,
 338                          sta->ampdu_mlme.tid_tx[tid]->ssn,
 339                          0x40, 5000);
 340         /* activate the timer for the recipient's addBA response */
 341         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
 342                                 jiffies + ADDBA_RESP_INTERVAL;
 343         add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 344 #ifdef CONFIG_MAC80211_HT_DEBUG
 345         printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
 346 #endif
 347         goto unlock;
 348
 349  err_free:
 350         kfree(sta->ampdu_mlme.tid_tx[tid]);
 351         sta->ampdu_mlme.tid_tx[tid] = NULL;
 352  err_wake_queue:
 353         ieee80211_wake_queue_by_reason(
 354                 &local->hw, ieee80211_ac_from_tid(tid),
 355                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 356  err_unlock_sta:
 357         spin_unlock(&local->ampdu_lock);
 358         spin_unlock_bh(&sta->lock);
 359  unlock:
 360         rcu_read_unlock();
 361         return ret;
 362 }
 363 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
 364
 365 /*
 366  * splice packets from the STA's pending to the local pending,
 367  * requires a call to ieee80211_agg_splice_finish and holding
 368  * local->ampdu_lock across both calls.
 369  */
 370 static void ieee80211_agg_splice_packets(struct ieee80211_local *local,
 371                                          struct sta_info *sta, u16 tid)
 372 {
 373         unsigned long flags;
 374         u16 queue = ieee80211_ac_from_tid(tid);
 375
 376         ieee80211_stop_queue_by_reason(
 377                 &local->hw, queue,
 378                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 379
 380         if (!skb_queue_empty(&sta->ampdu_mlme.tid_tx[tid]->pending)) {
 381                 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
 382                 /* mark queue as pending, it is stopped already */
 383                 __set_bit(IEEE80211_QUEUE_STOP_REASON_PENDING,
 384                           &local->queue_stop_reasons[queue]);
 385                 /* copy over remaining packets */
 386                 skb_queue_splice_tail_init(
 387                         &sta->ampdu_mlme.tid_tx[tid]->pending,
 388                         &local->pending[queue]);
 389                 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 390         }
 391 }
 392
 393 static void ieee80211_agg_splice_finish(struct ieee80211_local *local,
 394                                         struct sta_info *sta, u16 tid)
 395 {
 396         u16 queue = ieee80211_ac_from_tid(tid);
 397
 398         ieee80211_wake_queue_by_reason(
 399                 &local->hw, queue,
 400                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 401 }
 402
 403 /* caller must hold sta->lock */
 404 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
 405                                          struct sta_info *sta, u16 tid)
 406 {
 407 #ifdef CONFIG_MAC80211_HT_DEBUG
 408         printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
 409 #endif
 410
 411         spin_lock(&local->ampdu_lock);
 412         ieee80211_agg_splice_packets(local, sta, tid);
 413         /*
 414          * NB: we rely on sta->lock being taken in the TX
 415          * processing here when adding to the pending queue,
 416          * otherwise we could only change the state of the
 417          * session to OPERATIONAL _here_.
 418          */
 419         ieee80211_agg_splice_finish(local, sta, tid);
 420         spin_unlock(&local->ampdu_lock);
 421
 422         drv_ampdu_action(local, IEEE80211_AMPDU_TX_OPERATIONAL,
 423                          &sta->sta, tid, NULL);
 424 }
 425
 426 void ieee80211_start_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 427 {
 428         struct ieee80211_local *local = hw_to_local(hw);
 429         struct sta_info *sta;
 430         u8 *state;
 431
 432         if (tid >= STA_TID_NUM) {
 433 #ifdef CONFIG_MAC80211_HT_DEBUG
 434                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 435                                 tid, STA_TID_NUM);
 436 #endif
 437                 return;
 438         }
 439
 440         rcu_read_lock();
 441         sta = sta_info_get(local, ra);
 442         if (!sta) {
 443                 rcu_read_unlock();
 444 #ifdef CONFIG_MAC80211_HT_DEBUG
 445                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 446 #endif
 447                 return;
 448         }
 449
 450         state = &sta->ampdu_mlme.tid_state_tx[tid];
 451         spin_lock_bh(&sta->lock);
 452
 453         if (WARN_ON(!(*state & HT_ADDBA_REQUESTED_MSK))) {
 454 #ifdef CONFIG_MAC80211_HT_DEBUG
 455                 printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
 456                                 *state);
 457 #endif
 458                 spin_unlock_bh(&sta->lock);
 459                 rcu_read_unlock();
 460                 return;
 461         }
 462
 463         if (WARN_ON(*state & HT_ADDBA_DRV_READY_MSK))
 464                 goto out;
 465
 466         *state |= HT_ADDBA_DRV_READY_MSK;
 467
 468         if (*state == HT_AGG_STATE_OPERATIONAL)
 469                 ieee80211_agg_tx_operational(local, sta, tid);
 470
 471  out:
 472         spin_unlock_bh(&sta->lock);
 473         rcu_read_unlock();
 474 }
 475 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);
 476
 477 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
 478                                       const u8 *ra, u16 tid)
 479 {
 480         struct ieee80211_local *local = hw_to_local(hw);
 481         struct ieee80211_ra_tid *ra_tid;
 482         struct sk_buff *skb = dev_alloc_skb(0);
 483
 484         if (unlikely(!skb)) {
 485 #ifdef CONFIG_MAC80211_HT_DEBUG
 486                 if (net_ratelimit())
 487                         printk(KERN_WARNING "%s: Not enough memory, "
 488                                "dropping start BA session", skb->dev->name);
 489 #endif
 490                 return;
 491         }
 492         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 493         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 494         ra_tid->tid = tid;
 495
 496         skb->pkt_type = IEEE80211_ADDBA_MSG;
 497         skb_queue_tail(&local->skb_queue, skb);
 498         tasklet_schedule(&local->tasklet);
 499 }
 500 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
 501
 502 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 503                                    enum ieee80211_back_parties initiator)
 504 {
 505         u8 *state;
 506         int ret;
 507
 508         /* check if the TID is in aggregation */
 509         state = &sta->ampdu_mlme.tid_state_tx[tid];
 510         spin_lock_bh(&sta->lock);
 511
 512         if (*state != HT_AGG_STATE_OPERATIONAL) {
 513                 ret = -ENOENT;
 514                 goto unlock;
 515         }
 516
 517 #ifdef CONFIG_MAC80211_HT_DEBUG
 518         printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
 519                sta->sta.addr, tid);
 520 #endif /* CONFIG_MAC80211_HT_DEBUG */
 521
 522         ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator);
 523
 524  unlock:
 525         spin_unlock_bh(&sta->lock);
 526         return ret;
 527 }
 528
 529 int ieee80211_stop_tx_ba_session(struct ieee80211_hw *hw,
 530                                  u8 *ra, u16 tid,
 531                                  enum ieee80211_back_parties initiator)
 532 {
 533         struct ieee80211_local *local = hw_to_local(hw);
 534         struct sta_info *sta;
 535         int ret = 0;
 536
 537         if (WARN_ON(!local->ops->ampdu_action))
 538                 return -EINVAL;
 539
 540         if (tid >= STA_TID_NUM)
 541                 return -EINVAL;
 542
 543         rcu_read_lock();
 544         sta = sta_info_get(local, ra);
 545         if (!sta) {
 546                 rcu_read_unlock();
 547                 return -ENOENT;
 548         }
 549
 550         ret = __ieee80211_stop_tx_ba_session(sta, tid, initiator);
 551         rcu_read_unlock();
 552         return ret;
 553 }
 554 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
 555
 556 void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
 557 {
 558         struct ieee80211_local *local = hw_to_local(hw);
 559         struct sta_info *sta;
 560         u8 *state;
 561
 562         if (tid >= STA_TID_NUM) {
 563 #ifdef CONFIG_MAC80211_HT_DEBUG
 564                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 565                                 tid, STA_TID_NUM);
 566 #endif
 567                 return;
 568         }
 569
 570 #ifdef CONFIG_MAC80211_HT_DEBUG
 571         printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
 572                ra, tid);
 573 #endif /* CONFIG_MAC80211_HT_DEBUG */
 574
 575         rcu_read_lock();
 576         sta = sta_info_get(local, ra);
 577         if (!sta) {
 578 #ifdef CONFIG_MAC80211_HT_DEBUG
 579                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 580 #endif
 581                 rcu_read_unlock();
 582                 return;
 583         }
 584         state = &sta->ampdu_mlme.tid_state_tx[tid];
 585
 586         /* NOTE: no need to use sta->lock in this state check, as
 587          * ieee80211_stop_tx_ba_session will let only one stop call to
 588          * pass through per sta/tid
 589          */
 590         if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
 591 #ifdef CONFIG_MAC80211_HT_DEBUG
 592                 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
 593 #endif
 594                 rcu_read_unlock();
 595                 return;
 596         }
 597
 598         if (*state & HT_AGG_STATE_INITIATOR_MSK)
 599                 ieee80211_send_delba(sta->sdata, ra, tid,
 600                         WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
 601
 602         spin_lock_bh(&sta->lock);
 603         spin_lock(&local->ampdu_lock);
 604
 605         ieee80211_agg_splice_packets(local, sta, tid);
 606
 607         *state = HT_AGG_STATE_IDLE;
 608         /* from now on packets are no longer put onto sta->pending */
 609         sta->ampdu_mlme.addba_req_num[tid] = 0;
 610         kfree(sta->ampdu_mlme.tid_tx[tid]);
 611         sta->ampdu_mlme.tid_tx[tid] = NULL;
 612
 613         ieee80211_agg_splice_finish(local, sta, tid);
 614
 615         spin_unlock(&local->ampdu_lock);
 616         spin_unlock_bh(&sta->lock);
 617
 618         rcu_read_unlock();
 619 }
 620 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);
 621
 622 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
 623                                      const u8 *ra, u16 tid)
 624 {
 625         struct ieee80211_local *local = hw_to_local(hw);
 626         struct ieee80211_ra_tid *ra_tid;
 627         struct sk_buff *skb = dev_alloc_skb(0);
 628
 629         if (unlikely(!skb)) {
 630 #ifdef CONFIG_MAC80211_HT_DEBUG
 631                 if (net_ratelimit())
 632                         printk(KERN_WARNING "%s: Not enough memory, "
 633                                "dropping stop BA session", skb->dev->name);
 634 #endif
 635                 return;
 636         }
 637         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 638         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 639         ra_tid->tid = tid;
 640
 641         skb->pkt_type = IEEE80211_DELBA_MSG;
 642         skb_queue_tail(&local->skb_queue, skb);
 643         tasklet_schedule(&local->tasklet);
 644 }
 645 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
 646
 647
 648 void ieee80211_process_addba_resp(struct ieee80211_local *local,
 649                                   struct sta_info *sta,
 650                                   struct ieee80211_mgmt *mgmt,
 651                                   size_t len)
 652 {
 653         u16 capab, tid;
 654         u8 *state;
 655
 656         capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
 657         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 658
 659         state = &sta->ampdu_mlme.tid_state_tx[tid];
 660
 661         spin_lock_bh(&sta->lock);
 662
 663         if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
 664                 spin_unlock_bh(&sta->lock);
 665                 return;
 666         }
 667
 668         if (mgmt->u.action.u.addba_resp.dialog_token !=
 669                 sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
 670                 spin_unlock_bh(&sta->lock);
 671 #ifdef CONFIG_MAC80211_HT_DEBUG
 672                 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
 673 #endif /* CONFIG_MAC80211_HT_DEBUG */
 674                 return;
 675         }
 676
 677         del_timer_sync(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 678 #ifdef CONFIG_MAC80211_HT_DEBUG
 679         printk(KERN_DEBUG "switched off addBA timer for tid %d \n", tid);
 680 #endif /* CONFIG_MAC80211_HT_DEBUG */
 681         if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
 682                         == WLAN_STATUS_SUCCESS) {
 683                 u8 curstate = *state;
 684
 685                 *state |= HT_ADDBA_RECEIVED_MSK;
 686
 687                 if (*state != curstate && *state == HT_AGG_STATE_OPERATIONAL)
 688                         ieee80211_agg_tx_operational(local, sta, tid);
 689
 690                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 691         } else {
 692                 sta->ampdu_mlme.addba_req_num[tid]++;
 693                 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 694         }
 695         spin_unlock_bh(&sta->lock);
 696 }