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 <linux/slab.h>
  18 #include <net/mac80211.h>
  19 #include "ieee80211_i.h"
  20 #include "driver-ops.h"
  21 #include "wme.h"
  22
  23 /**
  24  * DOC: TX aggregation
  25  *
  26  * Aggregation on the TX side requires setting the hardware flag
  27  * %IEEE80211_HW_AMPDU_AGGREGATION as well as, if present, the @ampdu_queues
  28  * hardware parameter to the number of hardware AMPDU queues. If there are no
  29  * hardware queues then the driver will (currently) have to do all frame
  30  * buffering.
  31  *
  32  * When TX aggregation is started by some subsystem (usually the rate control
  33  * algorithm would be appropriate) by calling the
  34  * ieee80211_start_tx_ba_session() function, the driver will be notified via
  35  * its @ampdu_action function, with the %IEEE80211_AMPDU_TX_START action.
  36  *
  37  * In response to that, the driver is later required to call the
  38  * ieee80211_start_tx_ba_cb() (or ieee80211_start_tx_ba_cb_irqsafe())
  39  * function, which will start the aggregation session.
  40  *
  41  * Similarly, when the aggregation session is stopped by
  42  * ieee80211_stop_tx_ba_session(), the driver's @ampdu_action function will
  43  * be called with the action %IEEE80211_AMPDU_TX_STOP. In this case, the
  44  * call must not fail, and the driver must later call ieee80211_stop_tx_ba_cb()
  45  * (or ieee80211_stop_tx_ba_cb_irqsafe()).
  46  */
  47
  48 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
  49                                          const u8 *da, u16 tid,
  50                                          u8 dialog_token, u16 start_seq_num,
  51                                          u16 agg_size, u16 timeout)
  52 {
  53         struct ieee80211_local *local = sdata->local;
  54         struct sk_buff *skb;
  55         struct ieee80211_mgmt *mgmt;
  56         u16 capab;
  57
  58         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
  59
  60         if (!skb) {
  61                 printk(KERN_ERR "%s: failed to allocate buffer "
  62                                 "for addba request frame\n", sdata->name);
  63                 return;
  64         }
  65         skb_reserve(skb, local->hw.extra_tx_headroom);
  66         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
  67         memset(mgmt, 0, 24);
  68         memcpy(mgmt->da, da, ETH_ALEN);
  69         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
  70         if (sdata->vif.type == NL80211_IFTYPE_AP ||
  71             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
  72                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
  73         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
  74                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
  75
  76         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
  77                                           IEEE80211_STYPE_ACTION);
  78
  79         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
  80
  81         mgmt->u.action.category = WLAN_CATEGORY_BACK;
  82         mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
  83
  84         mgmt->u.action.u.addba_req.dialog_token = dialog_token;
  85         capab = (u16)(1 << 1);          /* bit 1 aggregation policy */
  86         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
  87         capab |= (u16)(agg_size << 6);  /* bit 15:6 max size of aggergation */
  88
  89         mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
  90
  91         mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
  92         mgmt->u.action.u.addba_req.start_seq_num =
  93                                         cpu_to_le16(start_seq_num << 4);
  94
  95         ieee80211_tx_skb(sdata, skb);
  96 }
  97
  98 void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn)
  99 {
 100         struct ieee80211_local *local = sdata->local;
 101         struct sk_buff *skb;
 102         struct ieee80211_bar *bar;
 103         u16 bar_control = 0;
 104
 105         skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
 106         if (!skb) {
 107                 printk(KERN_ERR "%s: failed to allocate buffer for "
 108                         "bar frame\n", sdata->name);
 109                 return;
 110         }
 111         skb_reserve(skb, local->hw.extra_tx_headroom);
 112         bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
 113         memset(bar, 0, sizeof(*bar));
 114         bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
 115                                          IEEE80211_STYPE_BACK_REQ);
 116         memcpy(bar->ra, ra, ETH_ALEN);
 117         memcpy(bar->ta, sdata->vif.addr, ETH_ALEN);
 118         bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
 119         bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
 120         bar_control |= (u16)(tid << 12);
 121         bar->control = cpu_to_le16(bar_control);
 122         bar->start_seq_num = cpu_to_le16(ssn);
 123
 124         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 125         ieee80211_tx_skb(sdata, skb);
 126 }
 127
 128 int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 129                                     enum ieee80211_back_parties initiator)
 130 {
 131         struct ieee80211_local *local = sta->local;
 132         int ret;
 133         u8 *state;
 134
 135 #ifdef CONFIG_MAC80211_HT_DEBUG
 136         printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
 137                sta->sta.addr, tid);
 138 #endif /* CONFIG_MAC80211_HT_DEBUG */
 139
 140         state = &sta->ampdu_mlme.tid_state_tx[tid];
 141
 142         if (*state == HT_AGG_STATE_OPERATIONAL)
 143                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 144
 145         *state = HT_AGG_STATE_REQ_STOP_BA_MSK |
 146                 (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
 147
 148         ret = drv_ampdu_action(local, sta->sdata,
 149                                IEEE80211_AMPDU_TX_STOP,
 150                                &sta->sta, tid, NULL);
 151
 152         /* HW shall not deny going back to legacy */
 153         if (WARN_ON(ret)) {
 154                 /*
 155                  * We may have pending packets get stuck in this case...
 156                  * Not bothering with a workaround for now.
 157                  */
 158         }
 159
 160         return ret;
 161 }
 162
 163 /*
 164  * After sending add Block Ack request we activated a timer until
 165  * add Block Ack response will arrive from the recipient.
 166  * If this timer expires sta_addba_resp_timer_expired will be executed.
 167  */
 168 static void sta_addba_resp_timer_expired(unsigned long data)
 169 {
 170         /* not an elegant detour, but there is no choice as the timer passes
 171          * only one argument, and both sta_info and TID are needed, so init
 172          * flow in sta_info_create gives the TID as data, while the timer_to_id
 173          * array gives the sta through container_of */
 174         u16 tid = *(u8 *)data;
 175         struct sta_info *sta = container_of((void *)data,
 176                 struct sta_info, timer_to_tid[tid]);
 177         u8 *state;
 178
 179         state = &sta->ampdu_mlme.tid_state_tx[tid];
 180
 181         /* check if the TID waits for addBA response */
 182         spin_lock_bh(&sta->lock);
 183         if ((*state & (HT_ADDBA_REQUESTED_MSK | HT_ADDBA_RECEIVED_MSK |
 184                        HT_AGG_STATE_REQ_STOP_BA_MSK)) !=
 185                                                 HT_ADDBA_REQUESTED_MSK) {
 186                 spin_unlock_bh(&sta->lock);
 187 #ifdef CONFIG_MAC80211_HT_DEBUG
 188                 printk(KERN_DEBUG "timer expired on tid %d but we are not "
 189                                 "(or no longer) expecting addBA response there",
 190                         tid);
 191 #endif
 192                 return;
 193         }
 194
 195 #ifdef CONFIG_MAC80211_HT_DEBUG
 196         printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
 197 #endif
 198
 199         ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 200         spin_unlock_bh(&sta->lock);
 201 }
 202
 203 static inline int ieee80211_ac_from_tid(int tid)
 204 {
 205         return ieee802_1d_to_ac[tid & 7];
 206 }
 207
 208 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 209 {
 210         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 211         struct ieee80211_sub_if_data *sdata = sta->sdata;
 212         struct ieee80211_local *local = sdata->local;
 213         u8 *state;
 214         int ret = 0;
 215         u16 start_seq_num;
 216
 217         if (WARN_ON(!local->ops->ampdu_action))
 218                 return -EINVAL;
 219
 220         if ((tid >= STA_TID_NUM) ||
 221             !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION))
 222                 return -EINVAL;
 223
 224 #ifdef CONFIG_MAC80211_HT_DEBUG
 225         printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
 226                pubsta->addr, tid);
 227 #endif /* CONFIG_MAC80211_HT_DEBUG */
 228
 229         /*
 230          * The aggregation code is not prepared to handle
 231          * anything but STA/AP due to the BSSID handling.
 232          * IBSS could work in the code but isn't supported
 233          * by drivers or the standard.
 234          */
 235         if (sdata->vif.type != NL80211_IFTYPE_STATION &&
 236             sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
 237             sdata->vif.type != NL80211_IFTYPE_AP)
 238                 return -EINVAL;
 239
 240         if (test_sta_flags(sta, WLAN_STA_DISASSOC)) {
 241 #ifdef CONFIG_MAC80211_HT_DEBUG
 242                 printk(KERN_DEBUG "Disassociation is in progress. "
 243                        "Denying BA session request\n");
 244 #endif
 245                 return -EINVAL;
 246         }
 247
 248         if (test_sta_flags(sta, WLAN_STA_SUSPEND)) {
 249 #ifdef CONFIG_MAC80211_HT_DEBUG
 250                 printk(KERN_DEBUG "Suspend in progress. "
 251                        "Denying BA session request\n");
 252 #endif
 253                 return -EINVAL;
 254         }
 255
 256         spin_lock_bh(&sta->lock);
 257         spin_lock(&local->ampdu_lock);
 258
 259         /* we have tried too many times, receiver does not want A-MPDU */
 260         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
 261                 ret = -EBUSY;
 262                 goto err_unlock_sta;
 263         }
 264
 265         state = &sta->ampdu_mlme.tid_state_tx[tid];
 266         /* check if the TID is not in aggregation flow already */
 267         if (*state != HT_AGG_STATE_IDLE) {
 268 #ifdef CONFIG_MAC80211_HT_DEBUG
 269                 printk(KERN_DEBUG "BA request denied - session is not "
 270                                  "idle on tid %u\n", tid);
 271 #endif /* CONFIG_MAC80211_HT_DEBUG */
 272                 ret = -EAGAIN;
 273                 goto err_unlock_sta;
 274         }
 275
 276         /*
 277          * While we're asking the driver about the aggregation,
 278          * stop the AC queue so that we don't have to worry
 279          * about frames that came in while we were doing that,
 280          * which would require us to put them to the AC pending
 281          * afterwards which just makes the code more complex.
 282          */
 283         ieee80211_stop_queue_by_reason(
 284                 &local->hw, ieee80211_ac_from_tid(tid),
 285                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 286
 287         /* prepare A-MPDU MLME for Tx aggregation */
 288         sta->ampdu_mlme.tid_tx[tid] =
 289                         kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
 290         if (!sta->ampdu_mlme.tid_tx[tid]) {
 291 #ifdef CONFIG_MAC80211_HT_DEBUG
 292                 if (net_ratelimit())
 293                         printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
 294                                         tid);
 295 #endif
 296                 ret = -ENOMEM;
 297                 goto err_wake_queue;
 298         }
 299
 300         skb_queue_head_init(&sta->ampdu_mlme.tid_tx[tid]->pending);
 301
 302         /* Tx timer */
 303         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
 304                         sta_addba_resp_timer_expired;
 305         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
 306                         (unsigned long)&sta->timer_to_tid[tid];
 307         init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 308
 309         /* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
 310          * call back right away, it must see that the flow has begun */
 311         *state |= HT_ADDBA_REQUESTED_MSK;
 312
 313         start_seq_num = sta->tid_seq[tid] >> 4;
 314
 315         ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START,
 316                                pubsta, tid, &start_seq_num);
 317
 318         if (ret) {
 319 #ifdef CONFIG_MAC80211_HT_DEBUG
 320                 printk(KERN_DEBUG "BA request denied - HW unavailable for"
 321                                         " tid %d\n", tid);
 322 #endif /* CONFIG_MAC80211_HT_DEBUG */
 323                 *state = HT_AGG_STATE_IDLE;
 324                 goto err_free;
 325         }
 326
 327         /* Driver vetoed or OKed, but we can take packets again now */
 328         ieee80211_wake_queue_by_reason(
 329                 &local->hw, ieee80211_ac_from_tid(tid),
 330                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 331
 332         spin_unlock(&local->ampdu_lock);
 333         spin_unlock_bh(&sta->lock);
 334
 335         /* send an addBA request */
 336         sta->ampdu_mlme.dialog_token_allocator++;
 337         sta->ampdu_mlme.tid_tx[tid]->dialog_token =
 338                         sta->ampdu_mlme.dialog_token_allocator;
 339         sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;
 340
 341         ieee80211_send_addba_request(sdata, pubsta->addr, tid,
 342                          sta->ampdu_mlme.tid_tx[tid]->dialog_token,
 343                          sta->ampdu_mlme.tid_tx[tid]->ssn,
 344                          0x40, 5000);
 345         sta->ampdu_mlme.addba_req_num[tid]++;
 346         /* activate the timer for the recipient's addBA response */
 347         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
 348                                 jiffies + ADDBA_RESP_INTERVAL;
 349         add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 350 #ifdef CONFIG_MAC80211_HT_DEBUG
 351         printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
 352 #endif
 353         return 0;
 354
 355  err_free:
 356         kfree(sta->ampdu_mlme.tid_tx[tid]);
 357         sta->ampdu_mlme.tid_tx[tid] = NULL;
 358  err_wake_queue:
 359         ieee80211_wake_queue_by_reason(
 360                 &local->hw, ieee80211_ac_from_tid(tid),
 361                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 362  err_unlock_sta:
 363         spin_unlock(&local->ampdu_lock);
 364         spin_unlock_bh(&sta->lock);
 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                 /* copy over remaining packets */
 395                 skb_queue_splice_tail_init(
 396                         &sta->ampdu_mlme.tid_tx[tid]->pending,
 397                         &local->pending[queue]);
 398                 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 399         }
 400 }
 401
 402 static void ieee80211_agg_splice_finish(struct ieee80211_local *local,
 403                                         struct sta_info *sta, u16 tid)
 404 {
 405         u16 queue = ieee80211_ac_from_tid(tid);
 406
 407         ieee80211_wake_queue_by_reason(
 408                 &local->hw, queue,
 409                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 410 }
 411
 412 /* caller must hold sta->lock */
 413 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
 414                                          struct sta_info *sta, u16 tid)
 415 {
 416 #ifdef CONFIG_MAC80211_HT_DEBUG
 417         printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
 418 #endif
 419
 420         spin_lock(&local->ampdu_lock);
 421         ieee80211_agg_splice_packets(local, sta, tid);
 422         /*
 423          * NB: we rely on sta->lock being taken in the TX
 424          * processing here when adding to the pending queue,
 425          * otherwise we could only change the state of the
 426          * session to OPERATIONAL _here_.
 427          */
 428         ieee80211_agg_splice_finish(local, sta, tid);
 429         spin_unlock(&local->ampdu_lock);
 430
 431         drv_ampdu_action(local, sta->sdata,
 432                          IEEE80211_AMPDU_TX_OPERATIONAL,
 433                          &sta->sta, tid, NULL);
 434 }
 435
 436 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
 437 {
 438         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 439         struct ieee80211_local *local = sdata->local;
 440         struct sta_info *sta;
 441         u8 *state;
 442
 443         if (tid >= STA_TID_NUM) {
 444 #ifdef CONFIG_MAC80211_HT_DEBUG
 445                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 446                                 tid, STA_TID_NUM);
 447 #endif
 448                 return;
 449         }
 450
 451         rcu_read_lock();
 452         sta = sta_info_get(sdata, ra);
 453         if (!sta) {
 454                 rcu_read_unlock();
 455 #ifdef CONFIG_MAC80211_HT_DEBUG
 456                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 457 #endif
 458                 return;
 459         }
 460
 461         state = &sta->ampdu_mlme.tid_state_tx[tid];
 462         spin_lock_bh(&sta->lock);
 463
 464         if (WARN_ON(!(*state & HT_ADDBA_REQUESTED_MSK))) {
 465 #ifdef CONFIG_MAC80211_HT_DEBUG
 466                 printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
 467                                 *state);
 468 #endif
 469                 spin_unlock_bh(&sta->lock);
 470                 rcu_read_unlock();
 471                 return;
 472         }
 473
 474         if (WARN_ON(*state & HT_ADDBA_DRV_READY_MSK))
 475                 goto out;
 476
 477         *state |= HT_ADDBA_DRV_READY_MSK;
 478
 479         if (*state == HT_AGG_STATE_OPERATIONAL)
 480                 ieee80211_agg_tx_operational(local, sta, tid);
 481
 482  out:
 483         spin_unlock_bh(&sta->lock);
 484         rcu_read_unlock();
 485 }
 486 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);
 487
 488 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 489                                       const u8 *ra, u16 tid)
 490 {
 491         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 492         struct ieee80211_local *local = sdata->local;
 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", sdata->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         ra_tid->vif = vif;
 508
 509         skb->pkt_type = IEEE80211_ADDBA_MSG;
 510         skb_queue_tail(&local->skb_queue, skb);
 511         tasklet_schedule(&local->tasklet);
 512 }
 513 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
 514
 515 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 516                                    enum ieee80211_back_parties initiator)
 517 {
 518         u8 *state;
 519         int ret;
 520
 521         /* check if the TID is in aggregation */
 522         state = &sta->ampdu_mlme.tid_state_tx[tid];
 523         spin_lock_bh(&sta->lock);
 524
 525         if (*state != HT_AGG_STATE_OPERATIONAL) {
 526                 ret = -ENOENT;
 527                 goto unlock;
 528         }
 529
 530         ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator);
 531
 532  unlock:
 533         spin_unlock_bh(&sta->lock);
 534         return ret;
 535 }
 536
 537 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
 538                                  enum ieee80211_back_parties initiator)
 539 {
 540         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 541         struct ieee80211_sub_if_data *sdata = sta->sdata;
 542         struct ieee80211_local *local = sdata->local;
 543
 544         if (!local->ops->ampdu_action)
 545                 return -EINVAL;
 546
 547         if (tid >= STA_TID_NUM)
 548                 return -EINVAL;
 549
 550         return __ieee80211_stop_tx_ba_session(sta, tid, initiator);
 551 }
 552 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
 553
 554 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
 555 {
 556         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 557         struct ieee80211_local *local = sdata->local;
 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(sdata, 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         kfree(sta->ampdu_mlme.tid_tx[tid]);
 609         sta->ampdu_mlme.tid_tx[tid] = NULL;
 610
 611         ieee80211_agg_splice_finish(local, sta, tid);
 612
 613         spin_unlock(&local->ampdu_lock);
 614         spin_unlock_bh(&sta->lock);
 615
 616         rcu_read_unlock();
 617 }
 618 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);
 619
 620 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 621                                      const u8 *ra, u16 tid)
 622 {
 623         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 624         struct ieee80211_local *local = sdata->local;
 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", sdata->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         ra_tid->vif = vif;
 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                 goto out;
 665
 666         if (mgmt->u.action.u.addba_resp.dialog_token !=
 667                 sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
 668 #ifdef CONFIG_MAC80211_HT_DEBUG
 669                 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
 670 #endif /* CONFIG_MAC80211_HT_DEBUG */
 671                 goto out;
 672         }
 673
 674         del_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 675
 676 #ifdef CONFIG_MAC80211_HT_DEBUG
 677         printk(KERN_DEBUG "switched off addBA timer for tid %d \n", tid);
 678 #endif /* CONFIG_MAC80211_HT_DEBUG */
 679
 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                 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 692         }
 693
 694  out:
 695         spin_unlock_bh(&sta->lock);
 696 }