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);
  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_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 124         ieee80211_tx_skb(sdata, skb);
 125 }
 126
 127 int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 128                                     enum ieee80211_back_parties initiator)
 129 {
 130         struct ieee80211_local *local = sta->local;
 131         int ret;
 132         u8 *state;
 133
 134 #ifdef CONFIG_MAC80211_HT_DEBUG
 135         printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
 136                sta->sta.addr, tid);
 137 #endif /* CONFIG_MAC80211_HT_DEBUG */
 138
 139         state = &sta->ampdu_mlme.tid_state_tx[tid];
 140
 141         if (*state == HT_AGG_STATE_OPERATIONAL)
 142                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 143
 144         *state = HT_AGG_STATE_REQ_STOP_BA_MSK |
 145                 (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
 146
 147         ret = drv_ampdu_action(local, &sta->sdata->vif,
 148                                IEEE80211_AMPDU_TX_STOP,
 149                                &sta->sta, tid, NULL);
 150
 151         /* HW shall not deny going back to legacy */
 152         if (WARN_ON(ret)) {
 153                 /*
 154                  * We may have pending packets get stuck in this case...
 155                  * Not bothering with a workaround for now.
 156                  */
 157         }
 158
 159         return ret;
 160 }
 161
 162 /*
 163  * After sending add Block Ack request we activated a timer until
 164  * add Block Ack response will arrive from the recipient.
 165  * If this timer expires sta_addba_resp_timer_expired will be executed.
 166  */
 167 static void sta_addba_resp_timer_expired(unsigned long data)
 168 {
 169         /* not an elegant detour, but there is no choice as the timer passes
 170          * only one argument, and both sta_info and TID are needed, so init
 171          * flow in sta_info_create gives the TID as data, while the timer_to_id
 172          * array gives the sta through container_of */
 173         u16 tid = *(u8 *)data;
 174         struct sta_info *sta = container_of((void *)data,
 175                 struct sta_info, timer_to_tid[tid]);
 176         u8 *state;
 177
 178         state = &sta->ampdu_mlme.tid_state_tx[tid];
 179
 180         /* check if the TID waits for addBA response */
 181         spin_lock_bh(&sta->lock);
 182         if ((*state & (HT_ADDBA_REQUESTED_MSK | HT_ADDBA_RECEIVED_MSK |
 183                        HT_AGG_STATE_REQ_STOP_BA_MSK)) !=
 184                                                 HT_ADDBA_REQUESTED_MSK) {
 185                 spin_unlock_bh(&sta->lock);
 186                 *state = HT_AGG_STATE_IDLE;
 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_SUSPEND)) {
 241 #ifdef CONFIG_MAC80211_HT_DEBUG
 242                 printk(KERN_DEBUG "Suspend in progress. "
 243                        "Denying BA session request\n");
 244 #endif
 245                 return -EINVAL;
 246         }
 247
 248         spin_lock_bh(&sta->lock);
 249         spin_lock(&local->ampdu_lock);
 250
 251         /* we have tried too many times, receiver does not want A-MPDU */
 252         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
 253                 ret = -EBUSY;
 254                 goto err_unlock_sta;
 255         }
 256
 257         state = &sta->ampdu_mlme.tid_state_tx[tid];
 258         /* check if the TID is not in aggregation flow already */
 259         if (*state != HT_AGG_STATE_IDLE) {
 260 #ifdef CONFIG_MAC80211_HT_DEBUG
 261                 printk(KERN_DEBUG "BA request denied - session is not "
 262                                  "idle on tid %u\n", tid);
 263 #endif /* CONFIG_MAC80211_HT_DEBUG */
 264                 ret = -EAGAIN;
 265                 goto err_unlock_sta;
 266         }
 267
 268         /*
 269          * While we're asking the driver about the aggregation,
 270          * stop the AC queue so that we don't have to worry
 271          * about frames that came in while we were doing that,
 272          * which would require us to put them to the AC pending
 273          * afterwards which just makes the code more complex.
 274          */
 275         ieee80211_stop_queue_by_reason(
 276                 &local->hw, ieee80211_ac_from_tid(tid),
 277                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 278
 279         /* prepare A-MPDU MLME for Tx aggregation */
 280         sta->ampdu_mlme.tid_tx[tid] =
 281                         kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
 282         if (!sta->ampdu_mlme.tid_tx[tid]) {
 283 #ifdef CONFIG_MAC80211_HT_DEBUG
 284                 if (net_ratelimit())
 285                         printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
 286                                         tid);
 287 #endif
 288                 ret = -ENOMEM;
 289                 goto err_wake_queue;
 290         }
 291
 292         skb_queue_head_init(&sta->ampdu_mlme.tid_tx[tid]->pending);
 293
 294         /* Tx timer */
 295         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
 296                         sta_addba_resp_timer_expired;
 297         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
 298                         (unsigned long)&sta->timer_to_tid[tid];
 299         init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 300
 301         /* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
 302          * call back right away, it must see that the flow has begun */
 303         *state |= HT_ADDBA_REQUESTED_MSK;
 304
 305         start_seq_num = sta->tid_seq[tid];
 306
 307         ret = drv_ampdu_action(local, &sdata->vif,
 308                                IEEE80211_AMPDU_TX_START,
 309                                pubsta, tid, &start_seq_num);
 310
 311         if (ret) {
 312 #ifdef CONFIG_MAC80211_HT_DEBUG
 313                 printk(KERN_DEBUG "BA request denied - HW unavailable for"
 314                                         " tid %d\n", tid);
 315 #endif /* CONFIG_MAC80211_HT_DEBUG */
 316                 *state = HT_AGG_STATE_IDLE;
 317                 goto err_free;
 318         }
 319
 320         /* Driver vetoed or OKed, but we can take packets again now */
 321         ieee80211_wake_queue_by_reason(
 322                 &local->hw, ieee80211_ac_from_tid(tid),
 323                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 324
 325         spin_unlock(&local->ampdu_lock);
 326         spin_unlock_bh(&sta->lock);
 327
 328         /* send an addBA request */
 329         sta->ampdu_mlme.dialog_token_allocator++;
 330         sta->ampdu_mlme.tid_tx[tid]->dialog_token =
 331                         sta->ampdu_mlme.dialog_token_allocator;
 332         sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;
 333
 334         ieee80211_send_addba_request(sdata, pubsta->addr, tid,
 335                          sta->ampdu_mlme.tid_tx[tid]->dialog_token,
 336                          sta->ampdu_mlme.tid_tx[tid]->ssn,
 337                          0x40, 5000);
 338         sta->ampdu_mlme.addba_req_num[tid]++;
 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         return 0;
 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         return ret;
 359 }
 360 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
 361
 362 /*
 363  * splice packets from the STA's pending to the local pending,
 364  * requires a call to ieee80211_agg_splice_finish and holding
 365  * local->ampdu_lock across both calls.
 366  */
 367 static void ieee80211_agg_splice_packets(struct ieee80211_local *local,
 368                                          struct sta_info *sta, u16 tid)
 369 {
 370         unsigned long flags;
 371         u16 queue = ieee80211_ac_from_tid(tid);
 372
 373         ieee80211_stop_queue_by_reason(
 374                 &local->hw, queue,
 375                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 376
 377         if (!(sta->ampdu_mlme.tid_state_tx[tid] & HT_ADDBA_REQUESTED_MSK))
 378                 return;
 379
 380         if (WARN(!sta->ampdu_mlme.tid_tx[tid],
 381                  "TID %d gone but expected when splicing aggregates from"
 382                  "the pending queue\n", tid))
 383                 return;
 384
 385         if (!skb_queue_empty(&sta->ampdu_mlme.tid_tx[tid]->pending)) {
 386                 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
 387                 /* copy over remaining packets */
 388                 skb_queue_splice_tail_init(
 389                         &sta->ampdu_mlme.tid_tx[tid]->pending,
 390                         &local->pending[queue]);
 391                 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 392         }
 393 }
 394
 395 static void ieee80211_agg_splice_finish(struct ieee80211_local *local,
 396                                         struct sta_info *sta, u16 tid)
 397 {
 398         u16 queue = ieee80211_ac_from_tid(tid);
 399
 400         ieee80211_wake_queue_by_reason(
 401                 &local->hw, queue,
 402                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 403 }
 404
 405 /* caller must hold sta->lock */
 406 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
 407                                          struct sta_info *sta, u16 tid)
 408 {
 409 #ifdef CONFIG_MAC80211_HT_DEBUG
 410         printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
 411 #endif
 412
 413         spin_lock(&local->ampdu_lock);
 414         ieee80211_agg_splice_packets(local, sta, tid);
 415         /*
 416          * NB: we rely on sta->lock being taken in the TX
 417          * processing here when adding to the pending queue,
 418          * otherwise we could only change the state of the
 419          * session to OPERATIONAL _here_.
 420          */
 421         ieee80211_agg_splice_finish(local, sta, tid);
 422         spin_unlock(&local->ampdu_lock);
 423
 424         drv_ampdu_action(local, &sta->sdata->vif,
 425                          IEEE80211_AMPDU_TX_OPERATIONAL,
 426                          &sta->sta, tid, NULL);
 427 }
 428
 429 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
 430 {
 431         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 432         struct ieee80211_local *local = sdata->local;
 433         struct sta_info *sta;
 434         u8 *state;
 435
 436         if (tid >= STA_TID_NUM) {
 437 #ifdef CONFIG_MAC80211_HT_DEBUG
 438                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 439                                 tid, STA_TID_NUM);
 440 #endif
 441                 return;
 442         }
 443
 444         rcu_read_lock();
 445         sta = sta_info_get(local, ra);
 446         if (!sta) {
 447                 rcu_read_unlock();
 448 #ifdef CONFIG_MAC80211_HT_DEBUG
 449                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 450 #endif
 451                 return;
 452         }
 453
 454         state = &sta->ampdu_mlme.tid_state_tx[tid];
 455         spin_lock_bh(&sta->lock);
 456
 457         if (WARN_ON(!(*state & HT_ADDBA_REQUESTED_MSK))) {
 458 #ifdef CONFIG_MAC80211_HT_DEBUG
 459                 printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
 460                                 *state);
 461 #endif
 462                 spin_unlock_bh(&sta->lock);
 463                 rcu_read_unlock();
 464                 return;
 465         }
 466
 467         if (WARN_ON(*state & HT_ADDBA_DRV_READY_MSK))
 468                 goto out;
 469
 470         *state |= HT_ADDBA_DRV_READY_MSK;
 471
 472         if (*state == HT_AGG_STATE_OPERATIONAL)
 473                 ieee80211_agg_tx_operational(local, sta, tid);
 474
 475  out:
 476         spin_unlock_bh(&sta->lock);
 477         rcu_read_unlock();
 478 }
 479 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);
 480
 481 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 482                                       const u8 *ra, u16 tid)
 483 {
 484         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 485         struct ieee80211_local *local = sdata->local;
 486         struct ieee80211_ra_tid *ra_tid;
 487         struct sk_buff *skb = dev_alloc_skb(0);
 488
 489         if (unlikely(!skb)) {
 490 #ifdef CONFIG_MAC80211_HT_DEBUG
 491                 if (net_ratelimit())
 492                         printk(KERN_WARNING "%s: Not enough memory, "
 493                                "dropping start BA session", skb->dev->name);
 494 #endif
 495                 return;
 496         }
 497         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 498         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 499         ra_tid->tid = tid;
 500         ra_tid->vif = vif;
 501
 502         skb->pkt_type = IEEE80211_ADDBA_MSG;
 503         skb_queue_tail(&local->skb_queue, skb);
 504         tasklet_schedule(&local->tasklet);
 505 }
 506 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
 507
 508 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 509                                    enum ieee80211_back_parties initiator)
 510 {
 511         u8 *state;
 512         int ret;
 513
 514         /* check if the TID is in aggregation */
 515         state = &sta->ampdu_mlme.tid_state_tx[tid];
 516         spin_lock_bh(&sta->lock);
 517
 518         if (*state != HT_AGG_STATE_OPERATIONAL) {
 519                 ret = -ENOENT;
 520                 goto unlock;
 521         }
 522
 523         ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator);
 524
 525  unlock:
 526         spin_unlock_bh(&sta->lock);
 527         return ret;
 528 }
 529
 530 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
 531                                  enum ieee80211_back_parties initiator)
 532 {
 533         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 534         struct ieee80211_sub_if_data *sdata = sta->sdata;
 535         struct ieee80211_local *local = sdata->local;
 536
 537         if (!local->ops->ampdu_action)
 538                 return -EINVAL;
 539
 540         if (tid >= STA_TID_NUM)
 541                 return -EINVAL;
 542
 543         return __ieee80211_stop_tx_ba_session(sta, tid, initiator);
 544 }
 545 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
 546
 547 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
 548 {
 549         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 550         struct ieee80211_local *local = sdata->local;
 551         struct sta_info *sta;
 552         u8 *state;
 553
 554         if (tid >= STA_TID_NUM) {
 555 #ifdef CONFIG_MAC80211_HT_DEBUG
 556                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 557                                 tid, STA_TID_NUM);
 558 #endif
 559                 return;
 560         }
 561
 562 #ifdef CONFIG_MAC80211_HT_DEBUG
 563         printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
 564                ra, tid);
 565 #endif /* CONFIG_MAC80211_HT_DEBUG */
 566
 567         rcu_read_lock();
 568         sta = sta_info_get(local, ra);
 569         if (!sta) {
 570 #ifdef CONFIG_MAC80211_HT_DEBUG
 571                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 572 #endif
 573                 rcu_read_unlock();
 574                 return;
 575         }
 576         state = &sta->ampdu_mlme.tid_state_tx[tid];
 577
 578         /* NOTE: no need to use sta->lock in this state check, as
 579          * ieee80211_stop_tx_ba_session will let only one stop call to
 580          * pass through per sta/tid
 581          */
 582         if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
 583 #ifdef CONFIG_MAC80211_HT_DEBUG
 584                 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
 585 #endif
 586                 rcu_read_unlock();
 587                 return;
 588         }
 589
 590         if (*state & HT_AGG_STATE_INITIATOR_MSK)
 591                 ieee80211_send_delba(sta->sdata, ra, tid,
 592                         WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
 593
 594         spin_lock_bh(&sta->lock);
 595         spin_lock(&local->ampdu_lock);
 596
 597         ieee80211_agg_splice_packets(local, sta, tid);
 598
 599         *state = HT_AGG_STATE_IDLE;
 600         /* from now on packets are no longer put onto sta->pending */
 601         kfree(sta->ampdu_mlme.tid_tx[tid]);
 602         sta->ampdu_mlme.tid_tx[tid] = NULL;
 603
 604         ieee80211_agg_splice_finish(local, sta, tid);
 605
 606         spin_unlock(&local->ampdu_lock);
 607         spin_unlock_bh(&sta->lock);
 608
 609         rcu_read_unlock();
 610 }
 611 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);
 612
 613 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 614                                      const u8 *ra, u16 tid)
 615 {
 616         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 617         struct ieee80211_local *local = sdata->local;
 618         struct ieee80211_ra_tid *ra_tid;
 619         struct sk_buff *skb = dev_alloc_skb(0);
 620
 621         if (unlikely(!skb)) {
 622 #ifdef CONFIG_MAC80211_HT_DEBUG
 623                 if (net_ratelimit())
 624                         printk(KERN_WARNING "%s: Not enough memory, "
 625                                "dropping stop BA session", skb->dev->name);
 626 #endif
 627                 return;
 628         }
 629         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 630         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 631         ra_tid->tid = tid;
 632         ra_tid->vif = vif;
 633
 634         skb->pkt_type = IEEE80211_DELBA_MSG;
 635         skb_queue_tail(&local->skb_queue, skb);
 636         tasklet_schedule(&local->tasklet);
 637 }
 638 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
 639
 640
 641 void ieee80211_process_addba_resp(struct ieee80211_local *local,
 642                                   struct sta_info *sta,
 643                                   struct ieee80211_mgmt *mgmt,
 644                                   size_t len)
 645 {
 646         u16 capab, tid;
 647         u8 *state;
 648
 649         capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
 650         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 651
 652         state = &sta->ampdu_mlme.tid_state_tx[tid];
 653
 654         spin_lock_bh(&sta->lock);
 655
 656         if (!(*state & HT_ADDBA_REQUESTED_MSK))
 657                 goto out;
 658
 659         if (mgmt->u.action.u.addba_resp.dialog_token !=
 660                 sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
 661 #ifdef CONFIG_MAC80211_HT_DEBUG
 662                 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
 663 #endif /* CONFIG_MAC80211_HT_DEBUG */
 664                 goto out;
 665         }
 666
 667         del_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 668
 669 #ifdef CONFIG_MAC80211_HT_DEBUG
 670         printk(KERN_DEBUG "switched off addBA timer for tid %d \n", tid);
 671 #endif /* CONFIG_MAC80211_HT_DEBUG */
 672
 673         if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
 674                         == WLAN_STATUS_SUCCESS) {
 675                 u8 curstate = *state;
 676
 677                 *state |= HT_ADDBA_RECEIVED_MSK;
 678
 679                 if (*state != curstate && *state == HT_AGG_STATE_OPERATIONAL)
 680                         ieee80211_agg_tx_operational(local, sta, tid);
 681
 682                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 683         } else {
 684                 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 685         }
 686
 687  out:
 688         spin_unlock_bh(&sta->lock);
 689 }