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         if (*state == HT_AGG_STATE_OPERATIONAL)
 136                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 137
 138         *state = HT_AGG_STATE_REQ_STOP_BA_MSK |
 139                 (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
 140
 141         ret = drv_ampdu_action(local, IEEE80211_AMPDU_TX_STOP,
 142                                &sta->sta, tid, NULL);
 143
 144         /* HW shall not deny going back to legacy */
 145         if (WARN_ON(ret)) {
 146                 *state = HT_AGG_STATE_OPERATIONAL;
 147                 /*
 148                  * We may have pending packets get stuck in this case...
 149                  * Not bothering with a workaround for now.
 150                  */
 151         }
 152
 153         return ret;
 154 }
 155
 156 /*
 157  * After sending add Block Ack request we activated a timer until
 158  * add Block Ack response will arrive from the recipient.
 159  * If this timer expires sta_addba_resp_timer_expired will be executed.
 160  */
 161 static void sta_addba_resp_timer_expired(unsigned long data)
 162 {
 163         /* not an elegant detour, but there is no choice as the timer passes
 164          * only one argument, and both sta_info and TID are needed, so init
 165          * flow in sta_info_create gives the TID as data, while the timer_to_id
 166          * array gives the sta through container_of */
 167         u16 tid = *(u8 *)data;
 168         struct sta_info *sta = container_of((void *)data,
 169                 struct sta_info, timer_to_tid[tid]);
 170         u8 *state;
 171
 172         state = &sta->ampdu_mlme.tid_state_tx[tid];
 173
 174         /* check if the TID waits for addBA response */
 175         spin_lock_bh(&sta->lock);
 176         if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
 177                 spin_unlock_bh(&sta->lock);
 178                 *state = HT_AGG_STATE_IDLE;
 179 #ifdef CONFIG_MAC80211_HT_DEBUG
 180                 printk(KERN_DEBUG "timer expired on tid %d but we are not "
 181                                 "expecting addBA response there", tid);
 182 #endif
 183                 return;
 184         }
 185
 186 #ifdef CONFIG_MAC80211_HT_DEBUG
 187         printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
 188 #endif
 189
 190         ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 191         spin_unlock_bh(&sta->lock);
 192 }
 193
 194 static inline int ieee80211_ac_from_tid(int tid)
 195 {
 196         return ieee802_1d_to_ac[tid & 7];
 197 }
 198
 199 int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 200 {
 201         struct ieee80211_local *local = hw_to_local(hw);
 202         struct sta_info *sta;
 203         struct ieee80211_sub_if_data *sdata;
 204         u8 *state;
 205         int ret = 0;
 206         u16 start_seq_num;
 207
 208         if (WARN_ON(!local->ops->ampdu_action))
 209                 return -EINVAL;
 210
 211         if ((tid >= STA_TID_NUM) || !(hw->flags & IEEE80211_HW_AMPDU_AGGREGATION))
 212                 return -EINVAL;
 213
 214 #ifdef CONFIG_MAC80211_HT_DEBUG
 215         printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
 216                ra, tid);
 217 #endif /* CONFIG_MAC80211_HT_DEBUG */
 218
 219         rcu_read_lock();
 220
 221         sta = sta_info_get(local, ra);
 222         if (!sta) {
 223 #ifdef CONFIG_MAC80211_HT_DEBUG
 224                 printk(KERN_DEBUG "Could not find the station\n");
 225 #endif
 226                 ret = -ENOENT;
 227                 goto unlock;
 228         }
 229
 230         /*
 231          * The aggregation code is not prepared to handle
 232          * anything but STA/AP due to the BSSID handling.
 233          * IBSS could work in the code but isn't supported
 234          * by drivers or the standard.
 235          */
 236         if (sta->sdata->vif.type != NL80211_IFTYPE_STATION &&
 237             sta->sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
 238             sta->sdata->vif.type != NL80211_IFTYPE_AP) {
 239                 ret = -EINVAL;
 240                 goto unlock;
 241         }
 242
 243         if (test_sta_flags(sta, WLAN_STA_SUSPEND)) {
 244 #ifdef CONFIG_MAC80211_HT_DEBUG
 245                 printk(KERN_DEBUG "Suspend in progress. "
 246                        "Denying BA session request\n");
 247 #endif
 248                 ret = -EINVAL;
 249                 goto unlock;
 250         }
 251
 252         spin_lock_bh(&sta->lock);
 253         spin_lock(&local->ampdu_lock);
 254
 255         sdata = sta->sdata;
 256
 257         /* we have tried too many times, receiver does not want A-MPDU */
 258         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
 259                 ret = -EBUSY;
 260                 goto err_unlock_sta;
 261         }
 262
 263         state = &sta->ampdu_mlme.tid_state_tx[tid];
 264         /* check if the TID is not in aggregation flow already */
 265         if (*state != HT_AGG_STATE_IDLE) {
 266 #ifdef CONFIG_MAC80211_HT_DEBUG
 267                 printk(KERN_DEBUG "BA request denied - session is not "
 268                                  "idle on tid %u\n", tid);
 269 #endif /* CONFIG_MAC80211_HT_DEBUG */
 270                 ret = -EAGAIN;
 271                 goto err_unlock_sta;
 272         }
 273
 274         /*
 275          * While we're asking the driver about the aggregation,
 276          * stop the AC queue so that we don't have to worry
 277          * about frames that came in while we were doing that,
 278          * which would require us to put them to the AC pending
 279          * afterwards which just makes the code more complex.
 280          */
 281         ieee80211_stop_queue_by_reason(
 282                 &local->hw, ieee80211_ac_from_tid(tid),
 283                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 284
 285         /* prepare A-MPDU MLME for Tx aggregation */
 286         sta->ampdu_mlme.tid_tx[tid] =
 287                         kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
 288         if (!sta->ampdu_mlme.tid_tx[tid]) {
 289 #ifdef CONFIG_MAC80211_HT_DEBUG
 290                 if (net_ratelimit())
 291                         printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
 292                                         tid);
 293 #endif
 294                 ret = -ENOMEM;
 295                 goto err_wake_queue;
 296         }
 297
 298         skb_queue_head_init(&sta->ampdu_mlme.tid_tx[tid]->pending);
 299
 300         /* Tx timer */
 301         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
 302                         sta_addba_resp_timer_expired;
 303         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
 304                         (unsigned long)&sta->timer_to_tid[tid];
 305         init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 306
 307         /* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
 308          * call back right away, it must see that the flow has begun */
 309         *state |= HT_ADDBA_REQUESTED_MSK;
 310
 311         start_seq_num = sta->tid_seq[tid];
 312
 313         ret = drv_ampdu_action(local, IEEE80211_AMPDU_TX_START,
 314                                &sta->sta, tid, &start_seq_num);
 315
 316         if (ret) {
 317 #ifdef CONFIG_MAC80211_HT_DEBUG
 318                 printk(KERN_DEBUG "BA request denied - HW unavailable for"
 319                                         " tid %d\n", tid);
 320 #endif /* CONFIG_MAC80211_HT_DEBUG */
 321                 *state = HT_AGG_STATE_IDLE;
 322                 goto err_free;
 323         }
 324
 325         /* Driver vetoed or OKed, but we can take packets again now */
 326         ieee80211_wake_queue_by_reason(
 327                 &local->hw, ieee80211_ac_from_tid(tid),
 328                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 329
 330         spin_unlock(&local->ampdu_lock);
 331         spin_unlock_bh(&sta->lock);
 332
 333         /* send an addBA request */
 334         sta->ampdu_mlme.dialog_token_allocator++;
 335         sta->ampdu_mlme.tid_tx[tid]->dialog_token =
 336                         sta->ampdu_mlme.dialog_token_allocator;
 337         sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;
 338
 339         ieee80211_send_addba_request(sta->sdata, ra, tid,
 340                          sta->ampdu_mlme.tid_tx[tid]->dialog_token,
 341                          sta->ampdu_mlme.tid_tx[tid]->ssn,
 342                          0x40, 5000);
 343         sta->ampdu_mlme.addba_req_num[tid]++;
 344         /* activate the timer for the recipient's addBA response */
 345         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
 346                                 jiffies + ADDBA_RESP_INTERVAL;
 347         add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 348 #ifdef CONFIG_MAC80211_HT_DEBUG
 349         printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
 350 #endif
 351         goto unlock;
 352
 353  err_free:
 354         kfree(sta->ampdu_mlme.tid_tx[tid]);
 355         sta->ampdu_mlme.tid_tx[tid] = NULL;
 356  err_wake_queue:
 357         ieee80211_wake_queue_by_reason(
 358                 &local->hw, ieee80211_ac_from_tid(tid),
 359                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 360  err_unlock_sta:
 361         spin_unlock(&local->ampdu_lock);
 362         spin_unlock_bh(&sta->lock);
 363  unlock:
 364         rcu_read_unlock();
 365         return ret;
 366 }
 367 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
 368
 369 /*
 370  * splice packets from the STA's pending to the local pending,
 371  * requires a call to ieee80211_agg_splice_finish and holding
 372  * local->ampdu_lock across both calls.
 373  */
 374 static void ieee80211_agg_splice_packets(struct ieee80211_local *local,
 375                                          struct sta_info *sta, u16 tid)
 376 {
 377         unsigned long flags;
 378         u16 queue = ieee80211_ac_from_tid(tid);
 379
 380         ieee80211_stop_queue_by_reason(
 381                 &local->hw, queue,
 382                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 383
 384         if (!(sta->ampdu_mlme.tid_state_tx[tid] & HT_ADDBA_REQUESTED_MSK))
 385                 return;
 386
 387         if (WARN(!sta->ampdu_mlme.tid_tx[tid],
 388                  "TID %d gone but expected when splicing aggregates from"
 389                  "the pending queue\n", tid))
 390                 return;
 391
 392         if (!skb_queue_empty(&sta->ampdu_mlme.tid_tx[tid]->pending)) {
 393                 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
 394                 /* mark queue as pending, it is stopped already */
 395                 __set_bit(IEEE80211_QUEUE_STOP_REASON_PENDING,
 396                           &local->queue_stop_reasons[queue]);
 397                 /* copy over remaining packets */
 398                 skb_queue_splice_tail_init(
 399                         &sta->ampdu_mlme.tid_tx[tid]->pending,
 400                         &local->pending[queue]);
 401                 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 402         }
 403 }
 404
 405 static void ieee80211_agg_splice_finish(struct ieee80211_local *local,
 406                                         struct sta_info *sta, u16 tid)
 407 {
 408         u16 queue = ieee80211_ac_from_tid(tid);
 409
 410         ieee80211_wake_queue_by_reason(
 411                 &local->hw, queue,
 412                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 413 }
 414
 415 /* caller must hold sta->lock */
 416 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
 417                                          struct sta_info *sta, u16 tid)
 418 {
 419 #ifdef CONFIG_MAC80211_HT_DEBUG
 420         printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
 421 #endif
 422
 423         spin_lock(&local->ampdu_lock);
 424         ieee80211_agg_splice_packets(local, sta, tid);
 425         /*
 426          * NB: we rely on sta->lock being taken in the TX
 427          * processing here when adding to the pending queue,
 428          * otherwise we could only change the state of the
 429          * session to OPERATIONAL _here_.
 430          */
 431         ieee80211_agg_splice_finish(local, sta, tid);
 432         spin_unlock(&local->ampdu_lock);
 433
 434         drv_ampdu_action(local, IEEE80211_AMPDU_TX_OPERATIONAL,
 435                          &sta->sta, tid, NULL);
 436 }
 437
 438 void ieee80211_start_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 439 {
 440         struct ieee80211_local *local = hw_to_local(hw);
 441         struct sta_info *sta;
 442         u8 *state;
 443
 444         if (tid >= STA_TID_NUM) {
 445 #ifdef CONFIG_MAC80211_HT_DEBUG
 446                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 447                                 tid, STA_TID_NUM);
 448 #endif
 449                 return;
 450         }
 451
 452         rcu_read_lock();
 453         sta = sta_info_get(local, ra);
 454         if (!sta) {
 455                 rcu_read_unlock();
 456 #ifdef CONFIG_MAC80211_HT_DEBUG
 457                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 458 #endif
 459                 return;
 460         }
 461
 462         state = &sta->ampdu_mlme.tid_state_tx[tid];
 463         spin_lock_bh(&sta->lock);
 464
 465         if (WARN_ON(!(*state & HT_ADDBA_REQUESTED_MSK))) {
 466 #ifdef CONFIG_MAC80211_HT_DEBUG
 467                 printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
 468                                 *state);
 469 #endif
 470                 spin_unlock_bh(&sta->lock);
 471                 rcu_read_unlock();
 472                 return;
 473         }
 474
 475         if (WARN_ON(*state & HT_ADDBA_DRV_READY_MSK))
 476                 goto out;
 477
 478         *state |= HT_ADDBA_DRV_READY_MSK;
 479
 480         if (*state == HT_AGG_STATE_OPERATIONAL)
 481                 ieee80211_agg_tx_operational(local, sta, tid);
 482
 483  out:
 484         spin_unlock_bh(&sta->lock);
 485         rcu_read_unlock();
 486 }
 487 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);
 488
 489 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
 490                                       const u8 *ra, u16 tid)
 491 {
 492         struct ieee80211_local *local = hw_to_local(hw);
 493         struct ieee80211_ra_tid *ra_tid;
 494         struct sk_buff *skb = dev_alloc_skb(0);
 495
 496         if (unlikely(!skb)) {
 497 #ifdef CONFIG_MAC80211_HT_DEBUG
 498                 if (net_ratelimit())
 499                         printk(KERN_WARNING "%s: Not enough memory, "
 500                                "dropping start BA session", skb->dev->name);
 501 #endif
 502                 return;
 503         }
 504         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 505         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 506         ra_tid->tid = tid;
 507
 508         skb->pkt_type = IEEE80211_ADDBA_MSG;
 509         skb_queue_tail(&local->skb_queue, skb);
 510         tasklet_schedule(&local->tasklet);
 511 }
 512 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
 513
 514 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 515                                    enum ieee80211_back_parties initiator)
 516 {
 517         u8 *state;
 518         int ret;
 519
 520         /* check if the TID is in aggregation */
 521         state = &sta->ampdu_mlme.tid_state_tx[tid];
 522         spin_lock_bh(&sta->lock);
 523
 524         if (*state != HT_AGG_STATE_OPERATIONAL) {
 525                 ret = -ENOENT;
 526                 goto unlock;
 527         }
 528
 529 #ifdef CONFIG_MAC80211_HT_DEBUG
 530         printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
 531                sta->sta.addr, tid);
 532 #endif /* CONFIG_MAC80211_HT_DEBUG */
 533
 534         ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator);
 535
 536  unlock:
 537         spin_unlock_bh(&sta->lock);
 538         return ret;
 539 }
 540
 541 int ieee80211_stop_tx_ba_session(struct ieee80211_hw *hw,
 542                                  u8 *ra, u16 tid,
 543                                  enum ieee80211_back_parties initiator)
 544 {
 545         struct ieee80211_local *local = hw_to_local(hw);
 546         struct sta_info *sta;
 547         int ret = 0;
 548
 549         if (WARN_ON(!local->ops->ampdu_action))
 550                 return -EINVAL;
 551
 552         if (tid >= STA_TID_NUM)
 553                 return -EINVAL;
 554
 555         rcu_read_lock();
 556         sta = sta_info_get(local, ra);
 557         if (!sta) {
 558                 rcu_read_unlock();
 559                 return -ENOENT;
 560         }
 561
 562         ret = __ieee80211_stop_tx_ba_session(sta, tid, initiator);
 563         rcu_read_unlock();
 564         return ret;
 565 }
 566 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
 567
 568 void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
 569 {
 570         struct ieee80211_local *local = hw_to_local(hw);
 571         struct sta_info *sta;
 572         u8 *state;
 573
 574         if (tid >= STA_TID_NUM) {
 575 #ifdef CONFIG_MAC80211_HT_DEBUG
 576                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 577                                 tid, STA_TID_NUM);
 578 #endif
 579                 return;
 580         }
 581
 582 #ifdef CONFIG_MAC80211_HT_DEBUG
 583         printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
 584                ra, tid);
 585 #endif /* CONFIG_MAC80211_HT_DEBUG */
 586
 587         rcu_read_lock();
 588         sta = sta_info_get(local, ra);
 589         if (!sta) {
 590 #ifdef CONFIG_MAC80211_HT_DEBUG
 591                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 592 #endif
 593                 rcu_read_unlock();
 594                 return;
 595         }
 596         state = &sta->ampdu_mlme.tid_state_tx[tid];
 597
 598         /* NOTE: no need to use sta->lock in this state check, as
 599          * ieee80211_stop_tx_ba_session will let only one stop call to
 600          * pass through per sta/tid
 601          */
 602         if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
 603 #ifdef CONFIG_MAC80211_HT_DEBUG
 604                 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
 605 #endif
 606                 rcu_read_unlock();
 607                 return;
 608         }
 609
 610         if (*state & HT_AGG_STATE_INITIATOR_MSK)
 611                 ieee80211_send_delba(sta->sdata, ra, tid,
 612                         WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
 613
 614         spin_lock_bh(&sta->lock);
 615         spin_lock(&local->ampdu_lock);
 616
 617         ieee80211_agg_splice_packets(local, sta, tid);
 618
 619         *state = HT_AGG_STATE_IDLE;
 620         /* from now on packets are no longer put onto sta->pending */
 621         kfree(sta->ampdu_mlme.tid_tx[tid]);
 622         sta->ampdu_mlme.tid_tx[tid] = NULL;
 623
 624         ieee80211_agg_splice_finish(local, sta, tid);
 625
 626         spin_unlock(&local->ampdu_lock);
 627         spin_unlock_bh(&sta->lock);
 628
 629         rcu_read_unlock();
 630 }
 631 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);
 632
 633 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
 634                                      const u8 *ra, u16 tid)
 635 {
 636         struct ieee80211_local *local = hw_to_local(hw);
 637         struct ieee80211_ra_tid *ra_tid;
 638         struct sk_buff *skb = dev_alloc_skb(0);
 639
 640         if (unlikely(!skb)) {
 641 #ifdef CONFIG_MAC80211_HT_DEBUG
 642                 if (net_ratelimit())
 643                         printk(KERN_WARNING "%s: Not enough memory, "
 644                                "dropping stop BA session", skb->dev->name);
 645 #endif
 646                 return;
 647         }
 648         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 649         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 650         ra_tid->tid = tid;
 651
 652         skb->pkt_type = IEEE80211_DELBA_MSG;
 653         skb_queue_tail(&local->skb_queue, skb);
 654         tasklet_schedule(&local->tasklet);
 655 }
 656 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
 657
 658
 659 void ieee80211_process_addba_resp(struct ieee80211_local *local,
 660                                   struct sta_info *sta,
 661                                   struct ieee80211_mgmt *mgmt,
 662                                   size_t len)
 663 {
 664         u16 capab, tid;
 665         u8 *state;
 666
 667         capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
 668         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 669
 670         state = &sta->ampdu_mlme.tid_state_tx[tid];
 671
 672         spin_lock_bh(&sta->lock);
 673
 674         if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
 675                 spin_unlock_bh(&sta->lock);
 676                 return;
 677         }
 678
 679         if (mgmt->u.action.u.addba_resp.dialog_token !=
 680                 sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
 681                 spin_unlock_bh(&sta->lock);
 682 #ifdef CONFIG_MAC80211_HT_DEBUG
 683                 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
 684 #endif /* CONFIG_MAC80211_HT_DEBUG */
 685                 return;
 686         }
 687
 688         del_timer_sync(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 689 #ifdef CONFIG_MAC80211_HT_DEBUG
 690         printk(KERN_DEBUG "switched off addBA timer for tid %d \n", tid);
 691 #endif /* CONFIG_MAC80211_HT_DEBUG */
 692         if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
 693                         == WLAN_STATUS_SUCCESS) {
 694                 u8 curstate = *state;
 695
 696                 *state |= HT_ADDBA_RECEIVED_MSK;
 697
 698                 if (*state != curstate && *state == HT_AGG_STATE_OPERATIONAL)
 699                         ieee80211_agg_tx_operational(local, sta, tid);
 700
 701                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 702         } else {
 703                 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 704         }
 705         spin_unlock_bh(&sta->lock);
 706 }