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                 *state = HT_AGG_STATE_IDLE;
 188 #ifdef CONFIG_MAC80211_HT_DEBUG
 189                 printk(KERN_DEBUG "timer expired on tid %d but we are not "
 190                                 "(or no longer) expecting addBA response there",
 191                         tid);
 192 #endif
 193                 return;
 194         }
 195
 196 #ifdef CONFIG_MAC80211_HT_DEBUG
 197         printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
 198 #endif
 199
 200         ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 201         spin_unlock_bh(&sta->lock);
 202 }
 203
 204 static inline int ieee80211_ac_from_tid(int tid)
 205 {
 206         return ieee802_1d_to_ac[tid & 7];
 207 }
 208
 209 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 210 {
 211         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 212         struct ieee80211_sub_if_data *sdata = sta->sdata;
 213         struct ieee80211_local *local = sdata->local;
 214         u8 *state;
 215         int ret = 0;
 216         u16 start_seq_num;
 217
 218         trace_api_start_tx_ba_session(pubsta, tid);
 219
 220         if (WARN_ON(!local->ops->ampdu_action))
 221                 return -EINVAL;
 222
 223         if ((tid >= STA_TID_NUM) ||
 224             !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION))
 225                 return -EINVAL;
 226
 227 #ifdef CONFIG_MAC80211_HT_DEBUG
 228         printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
 229                pubsta->addr, tid);
 230 #endif /* CONFIG_MAC80211_HT_DEBUG */
 231
 232         /*
 233          * The aggregation code is not prepared to handle
 234          * anything but STA/AP due to the BSSID handling.
 235          * IBSS could work in the code but isn't supported
 236          * by drivers or the standard.
 237          */
 238         if (sdata->vif.type != NL80211_IFTYPE_STATION &&
 239             sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
 240             sdata->vif.type != NL80211_IFTYPE_AP)
 241                 return -EINVAL;
 242
 243         if (test_sta_flags(sta, WLAN_STA_DISASSOC)) {
 244 #ifdef CONFIG_MAC80211_HT_DEBUG
 245                 printk(KERN_DEBUG "Disassociation is in progress. "
 246                        "Denying BA session request\n");
 247 #endif
 248                 return -EINVAL;
 249         }
 250
 251         if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
 252 #ifdef CONFIG_MAC80211_HT_DEBUG
 253                 printk(KERN_DEBUG "Suspend in progress. "
 254                        "Denying BA session request\n");
 255 #endif
 256                 return -EINVAL;
 257         }
 258
 259         spin_lock_bh(&sta->lock);
 260         spin_lock(&local->ampdu_lock);
 261
 262         /* we have tried too many times, receiver does not want A-MPDU */
 263         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
 264                 ret = -EBUSY;
 265                 goto err_unlock_sta;
 266         }
 267
 268         state = &sta->ampdu_mlme.tid_state_tx[tid];
 269         /* check if the TID is not in aggregation flow already */
 270         if (*state != HT_AGG_STATE_IDLE) {
 271 #ifdef CONFIG_MAC80211_HT_DEBUG
 272                 printk(KERN_DEBUG "BA request denied - session is not "
 273                                  "idle on tid %u\n", tid);
 274 #endif /* CONFIG_MAC80211_HT_DEBUG */
 275                 ret = -EAGAIN;
 276                 goto err_unlock_sta;
 277         }
 278
 279         /*
 280          * While we're asking the driver about the aggregation,
 281          * stop the AC queue so that we don't have to worry
 282          * about frames that came in while we were doing that,
 283          * which would require us to put them to the AC pending
 284          * afterwards which just makes the code more complex.
 285          */
 286         ieee80211_stop_queue_by_reason(
 287                 &local->hw, ieee80211_ac_from_tid(tid),
 288                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 289
 290         /* prepare A-MPDU MLME for Tx aggregation */
 291         sta->ampdu_mlme.tid_tx[tid] =
 292                         kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
 293         if (!sta->ampdu_mlme.tid_tx[tid]) {
 294 #ifdef CONFIG_MAC80211_HT_DEBUG
 295                 if (net_ratelimit())
 296                         printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
 297                                         tid);
 298 #endif
 299                 ret = -ENOMEM;
 300                 goto err_wake_queue;
 301         }
 302
 303         skb_queue_head_init(&sta->ampdu_mlme.tid_tx[tid]->pending);
 304
 305         /* Tx timer */
 306         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
 307                         sta_addba_resp_timer_expired;
 308         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
 309                         (unsigned long)&sta->timer_to_tid[tid];
 310         init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 311
 312         /* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
 313          * call back right away, it must see that the flow has begun */
 314         *state |= HT_ADDBA_REQUESTED_MSK;
 315
 316         start_seq_num = sta->tid_seq[tid] >> 4;
 317
 318         ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START,
 319                                pubsta, tid, &start_seq_num);
 320
 321         if (ret) {
 322 #ifdef CONFIG_MAC80211_HT_DEBUG
 323                 printk(KERN_DEBUG "BA request denied - HW unavailable for"
 324                                         " tid %d\n", tid);
 325 #endif /* CONFIG_MAC80211_HT_DEBUG */
 326                 *state = HT_AGG_STATE_IDLE;
 327                 goto err_free;
 328         }
 329
 330         /* Driver vetoed or OKed, but we can take packets again now */
 331         ieee80211_wake_queue_by_reason(
 332                 &local->hw, ieee80211_ac_from_tid(tid),
 333                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 334
 335         spin_unlock(&local->ampdu_lock);
 336         spin_unlock_bh(&sta->lock);
 337
 338         /* send an addBA request */
 339         sta->ampdu_mlme.dialog_token_allocator++;
 340         sta->ampdu_mlme.tid_tx[tid]->dialog_token =
 341                         sta->ampdu_mlme.dialog_token_allocator;
 342         sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;
 343
 344         ieee80211_send_addba_request(sdata, pubsta->addr, tid,
 345                          sta->ampdu_mlme.tid_tx[tid]->dialog_token,
 346                          sta->ampdu_mlme.tid_tx[tid]->ssn,
 347                          0x40, 5000);
 348         sta->ampdu_mlme.addba_req_num[tid]++;
 349         /* activate the timer for the recipient's addBA response */
 350         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
 351                                 jiffies + ADDBA_RESP_INTERVAL;
 352         add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 353 #ifdef CONFIG_MAC80211_HT_DEBUG
 354         printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
 355 #endif
 356         return 0;
 357
 358  err_free:
 359         kfree(sta->ampdu_mlme.tid_tx[tid]);
 360         sta->ampdu_mlme.tid_tx[tid] = NULL;
 361  err_wake_queue:
 362         ieee80211_wake_queue_by_reason(
 363                 &local->hw, ieee80211_ac_from_tid(tid),
 364                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 365  err_unlock_sta:
 366         spin_unlock(&local->ampdu_lock);
 367         spin_unlock_bh(&sta->lock);
 368         return ret;
 369 }
 370 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
 371
 372 /*
 373  * splice packets from the STA's pending to the local pending,
 374  * requires a call to ieee80211_agg_splice_finish and holding
 375  * local->ampdu_lock across both calls.
 376  */
 377 static void ieee80211_agg_splice_packets(struct ieee80211_local *local,
 378                                          struct sta_info *sta, u16 tid)
 379 {
 380         unsigned long flags;
 381         u16 queue = ieee80211_ac_from_tid(tid);
 382
 383         ieee80211_stop_queue_by_reason(
 384                 &local->hw, queue,
 385                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 386
 387         if (!(sta->ampdu_mlme.tid_state_tx[tid] & HT_ADDBA_REQUESTED_MSK))
 388                 return;
 389
 390         if (WARN(!sta->ampdu_mlme.tid_tx[tid],
 391                  "TID %d gone but expected when splicing aggregates from"
 392                  "the pending queue\n", tid))
 393                 return;
 394
 395         if (!skb_queue_empty(&sta->ampdu_mlme.tid_tx[tid]->pending)) {
 396                 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
 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, sta->sdata,
 435                          IEEE80211_AMPDU_TX_OPERATIONAL,
 436                          &sta->sta, tid, NULL);
 437 }
 438
 439 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
 440 {
 441         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 442         struct ieee80211_local *local = sdata->local;
 443         struct sta_info *sta;
 444         u8 *state;
 445
 446         trace_api_start_tx_ba_cb(sdata, ra, tid);
 447
 448         if (tid >= STA_TID_NUM) {
 449 #ifdef CONFIG_MAC80211_HT_DEBUG
 450                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 451                                 tid, STA_TID_NUM);
 452 #endif
 453                 return;
 454         }
 455
 456         rcu_read_lock();
 457         sta = sta_info_get(sdata, ra);
 458         if (!sta) {
 459                 rcu_read_unlock();
 460 #ifdef CONFIG_MAC80211_HT_DEBUG
 461                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 462 #endif
 463                 return;
 464         }
 465
 466         state = &sta->ampdu_mlme.tid_state_tx[tid];
 467         spin_lock_bh(&sta->lock);
 468
 469         if (WARN_ON(!(*state & HT_ADDBA_REQUESTED_MSK))) {
 470 #ifdef CONFIG_MAC80211_HT_DEBUG
 471                 printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
 472                                 *state);
 473 #endif
 474                 spin_unlock_bh(&sta->lock);
 475                 rcu_read_unlock();
 476                 return;
 477         }
 478
 479         if (WARN_ON(*state & HT_ADDBA_DRV_READY_MSK))
 480                 goto out;
 481
 482         *state |= HT_ADDBA_DRV_READY_MSK;
 483
 484         if (*state == HT_AGG_STATE_OPERATIONAL)
 485                 ieee80211_agg_tx_operational(local, sta, tid);
 486
 487  out:
 488         spin_unlock_bh(&sta->lock);
 489         rcu_read_unlock();
 490 }
 491 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);
 492
 493 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 494                                       const u8 *ra, u16 tid)
 495 {
 496         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 497         struct ieee80211_local *local = sdata->local;
 498         struct ieee80211_ra_tid *ra_tid;
 499         struct sk_buff *skb = dev_alloc_skb(0);
 500
 501         if (unlikely(!skb)) {
 502 #ifdef CONFIG_MAC80211_HT_DEBUG
 503                 if (net_ratelimit())
 504                         printk(KERN_WARNING "%s: Not enough memory, "
 505                                "dropping start BA session", sdata->name);
 506 #endif
 507                 return;
 508         }
 509         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 510         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 511         ra_tid->tid = tid;
 512         ra_tid->vif = vif;
 513
 514         skb->pkt_type = IEEE80211_ADDBA_MSG;
 515         skb_queue_tail(&local->skb_queue, skb);
 516         tasklet_schedule(&local->tasklet);
 517 }
 518 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
 519
 520 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 521                                    enum ieee80211_back_parties initiator)
 522 {
 523         u8 *state;
 524         int ret;
 525
 526         /* check if the TID is in aggregation */
 527         state = &sta->ampdu_mlme.tid_state_tx[tid];
 528         spin_lock_bh(&sta->lock);
 529
 530         if (*state != HT_AGG_STATE_OPERATIONAL) {
 531                 ret = -ENOENT;
 532                 goto unlock;
 533         }
 534
 535         ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator);
 536
 537  unlock:
 538         spin_unlock_bh(&sta->lock);
 539         return ret;
 540 }
 541
 542 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
 543                                  enum ieee80211_back_parties initiator)
 544 {
 545         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 546         struct ieee80211_sub_if_data *sdata = sta->sdata;
 547         struct ieee80211_local *local = sdata->local;
 548
 549         trace_api_stop_tx_ba_session(pubsta, tid, initiator);
 550
 551         if (!local->ops->ampdu_action)
 552                 return -EINVAL;
 553
 554         if (tid >= STA_TID_NUM)
 555                 return -EINVAL;
 556
 557         return __ieee80211_stop_tx_ba_session(sta, tid, initiator);
 558 }
 559 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
 560
 561 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
 562 {
 563         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 564         struct ieee80211_local *local = sdata->local;
 565         struct sta_info *sta;
 566         u8 *state;
 567
 568         trace_api_stop_tx_ba_cb(sdata, ra, tid);
 569
 570         if (tid >= STA_TID_NUM) {
 571 #ifdef CONFIG_MAC80211_HT_DEBUG
 572                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 573                                 tid, STA_TID_NUM);
 574 #endif
 575                 return;
 576         }
 577
 578 #ifdef CONFIG_MAC80211_HT_DEBUG
 579         printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
 580                ra, tid);
 581 #endif /* CONFIG_MAC80211_HT_DEBUG */
 582
 583         rcu_read_lock();
 584         sta = sta_info_get(sdata, ra);
 585         if (!sta) {
 586 #ifdef CONFIG_MAC80211_HT_DEBUG
 587                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 588 #endif
 589                 rcu_read_unlock();
 590                 return;
 591         }
 592         state = &sta->ampdu_mlme.tid_state_tx[tid];
 593
 594         /* NOTE: no need to use sta->lock in this state check, as
 595          * ieee80211_stop_tx_ba_session will let only one stop call to
 596          * pass through per sta/tid
 597          */
 598         if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
 599 #ifdef CONFIG_MAC80211_HT_DEBUG
 600                 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
 601 #endif
 602                 rcu_read_unlock();
 603                 return;
 604         }
 605
 606         if (*state & HT_AGG_STATE_INITIATOR_MSK)
 607                 ieee80211_send_delba(sta->sdata, ra, tid,
 608                         WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
 609
 610         spin_lock_bh(&sta->lock);
 611         spin_lock(&local->ampdu_lock);
 612
 613         ieee80211_agg_splice_packets(local, sta, tid);
 614
 615         *state = HT_AGG_STATE_IDLE;
 616         /* from now on packets are no longer put onto sta->pending */
 617         kfree(sta->ampdu_mlme.tid_tx[tid]);
 618         sta->ampdu_mlme.tid_tx[tid] = NULL;
 619
 620         ieee80211_agg_splice_finish(local, sta, tid);
 621
 622         spin_unlock(&local->ampdu_lock);
 623         spin_unlock_bh(&sta->lock);
 624
 625         rcu_read_unlock();
 626 }
 627 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);
 628
 629 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 630                                      const u8 *ra, u16 tid)
 631 {
 632         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 633         struct ieee80211_local *local = sdata->local;
 634         struct ieee80211_ra_tid *ra_tid;
 635         struct sk_buff *skb = dev_alloc_skb(0);
 636
 637         if (unlikely(!skb)) {
 638 #ifdef CONFIG_MAC80211_HT_DEBUG
 639                 if (net_ratelimit())
 640                         printk(KERN_WARNING "%s: Not enough memory, "
 641                                "dropping stop BA session", sdata->name);
 642 #endif
 643                 return;
 644         }
 645         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 646         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 647         ra_tid->tid = tid;
 648         ra_tid->vif = vif;
 649
 650         skb->pkt_type = IEEE80211_DELBA_MSG;
 651         skb_queue_tail(&local->skb_queue, skb);
 652         tasklet_schedule(&local->tasklet);
 653 }
 654 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
 655
 656
 657 void ieee80211_process_addba_resp(struct ieee80211_local *local,
 658                                   struct sta_info *sta,
 659                                   struct ieee80211_mgmt *mgmt,
 660                                   size_t len)
 661 {
 662         u16 capab, tid;
 663         u8 *state;
 664
 665         capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
 666         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 667
 668         state = &sta->ampdu_mlme.tid_state_tx[tid];
 669
 670         spin_lock_bh(&sta->lock);
 671
 672         if (!(*state & HT_ADDBA_REQUESTED_MSK))
 673                 goto out;
 674
 675         if (mgmt->u.action.u.addba_resp.dialog_token !=
 676                 sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
 677 #ifdef CONFIG_MAC80211_HT_DEBUG
 678                 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
 679 #endif /* CONFIG_MAC80211_HT_DEBUG */
 680                 goto out;
 681         }
 682
 683         del_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 684
 685 #ifdef CONFIG_MAC80211_HT_DEBUG
 686         printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid);
 687 #endif /* CONFIG_MAC80211_HT_DEBUG */
 688
 689         if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
 690                         == WLAN_STATUS_SUCCESS) {
 691                 u8 curstate = *state;
 692
 693                 *state |= HT_ADDBA_RECEIVED_MSK;
 694
 695                 if (*state != curstate && *state == HT_AGG_STATE_OPERATIONAL)
 696                         ieee80211_agg_tx_operational(local, sta, tid);
 697
 698                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 699         } else {
 700                 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 701         }
 702
 703  out:
 704         spin_unlock_bh(&sta->lock);
 705 }