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