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\n",
 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         trace_api_start_tx_ba_session(pubsta, tid);
 218
 219         if (WARN_ON(!local->ops->ampdu_action))
 220                 return -EINVAL;
 221
 222         if ((tid >= STA_TID_NUM) ||
 223             !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION))
 224                 return -EINVAL;
 225
 226 #ifdef CONFIG_MAC80211_HT_DEBUG
 227         printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
 228                pubsta->addr, tid);
 229 #endif /* CONFIG_MAC80211_HT_DEBUG */
 230
 231         /*
 232          * The aggregation code is not prepared to handle
 233          * anything but STA/AP due to the BSSID handling.
 234          * IBSS could work in the code but isn't supported
 235          * by drivers or the standard.
 236          */
 237         if (sdata->vif.type != NL80211_IFTYPE_STATION &&
 238             sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
 239             sdata->vif.type != NL80211_IFTYPE_AP)
 240                 return -EINVAL;
 241
 242         if (test_sta_flags(sta, WLAN_STA_DISASSOC)) {
 243 #ifdef CONFIG_MAC80211_HT_DEBUG
 244                 printk(KERN_DEBUG "Disassociation is in progress. "
 245                        "Denying BA session request\n");
 246 #endif
 247                 return -EINVAL;
 248         }
 249
 250         if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
 251 #ifdef CONFIG_MAC80211_HT_DEBUG
 252                 printk(KERN_DEBUG "Suspend in progress. "
 253                        "Denying BA session request\n");
 254 #endif
 255                 return -EINVAL;
 256         }
 257
 258         spin_lock_bh(&sta->lock);
 259         spin_lock(&local->ampdu_lock);
 260
 261         /* we have tried too many times, receiver does not want A-MPDU */
 262         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
 263                 ret = -EBUSY;
 264                 goto err_unlock_sta;
 265         }
 266
 267         state = &sta->ampdu_mlme.tid_state_tx[tid];
 268         /* check if the TID is not in aggregation flow already */
 269         if (*state != HT_AGG_STATE_IDLE) {
 270 #ifdef CONFIG_MAC80211_HT_DEBUG
 271                 printk(KERN_DEBUG "BA request denied - session is not "
 272                                  "idle on tid %u\n", tid);
 273 #endif /* CONFIG_MAC80211_HT_DEBUG */
 274                 ret = -EAGAIN;
 275                 goto err_unlock_sta;
 276         }
 277
 278         /*
 279          * While we're asking the driver about the aggregation,
 280          * stop the AC queue so that we don't have to worry
 281          * about frames that came in while we were doing that,
 282          * which would require us to put them to the AC pending
 283          * afterwards which just makes the code more complex.
 284          */
 285         ieee80211_stop_queue_by_reason(
 286                 &local->hw, ieee80211_ac_from_tid(tid),
 287                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 288
 289         /* prepare A-MPDU MLME for Tx aggregation */
 290         sta->ampdu_mlme.tid_tx[tid] =
 291                         kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
 292         if (!sta->ampdu_mlme.tid_tx[tid]) {
 293 #ifdef CONFIG_MAC80211_HT_DEBUG
 294                 if (net_ratelimit())
 295                         printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
 296                                         tid);
 297 #endif
 298                 ret = -ENOMEM;
 299                 goto err_wake_queue;
 300         }
 301
 302         skb_queue_head_init(&sta->ampdu_mlme.tid_tx[tid]->pending);
 303
 304         /* Tx timer */
 305         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
 306                         sta_addba_resp_timer_expired;
 307         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
 308                         (unsigned long)&sta->timer_to_tid[tid];
 309         init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 310
 311         /* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
 312          * call back right away, it must see that the flow has begun */
 313         *state |= HT_ADDBA_REQUESTED_MSK;
 314
 315         start_seq_num = sta->tid_seq[tid] >> 4;
 316
 317         ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START,
 318                                pubsta, tid, &start_seq_num);
 319
 320         if (ret) {
 321 #ifdef CONFIG_MAC80211_HT_DEBUG
 322                 printk(KERN_DEBUG "BA request denied - HW unavailable for"
 323                                         " tid %d\n", tid);
 324 #endif /* CONFIG_MAC80211_HT_DEBUG */
 325                 *state = HT_AGG_STATE_IDLE;
 326                 goto err_free;
 327         }
 328
 329         /* Driver vetoed or OKed, but we can take packets again now */
 330         ieee80211_wake_queue_by_reason(
 331                 &local->hw, ieee80211_ac_from_tid(tid),
 332                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 333
 334         spin_unlock(&local->ampdu_lock);
 335         spin_unlock_bh(&sta->lock);
 336
 337         /* send an addBA request */
 338         sta->ampdu_mlme.dialog_token_allocator++;
 339         sta->ampdu_mlme.tid_tx[tid]->dialog_token =
 340                         sta->ampdu_mlme.dialog_token_allocator;
 341         sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;
 342
 343         ieee80211_send_addba_request(sdata, pubsta->addr, tid,
 344                          sta->ampdu_mlme.tid_tx[tid]->dialog_token,
 345                          sta->ampdu_mlme.tid_tx[tid]->ssn,
 346                          0x40, 5000);
 347         sta->ampdu_mlme.addba_req_num[tid]++;
 348         /* activate the timer for the recipient's addBA response */
 349         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
 350                                 jiffies + ADDBA_RESP_INTERVAL;
 351         add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 352 #ifdef CONFIG_MAC80211_HT_DEBUG
 353         printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
 354 #endif
 355         return 0;
 356
 357  err_free:
 358         kfree(sta->ampdu_mlme.tid_tx[tid]);
 359         sta->ampdu_mlme.tid_tx[tid] = NULL;
 360  err_wake_queue:
 361         ieee80211_wake_queue_by_reason(
 362                 &local->hw, ieee80211_ac_from_tid(tid),
 363                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 364  err_unlock_sta:
 365         spin_unlock(&local->ampdu_lock);
 366         spin_unlock_bh(&sta->lock);
 367         return ret;
 368 }
 369 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
 370
 371 /*
 372  * splice packets from the STA's pending to the local pending,
 373  * requires a call to ieee80211_agg_splice_finish and holding
 374  * local->ampdu_lock across both calls.
 375  */
 376 static void ieee80211_agg_splice_packets(struct ieee80211_local *local,
 377                                          struct sta_info *sta, u16 tid)
 378 {
 379         unsigned long flags;
 380         u16 queue = ieee80211_ac_from_tid(tid);
 381
 382         ieee80211_stop_queue_by_reason(
 383                 &local->hw, queue,
 384                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 385
 386         if (!(sta->ampdu_mlme.tid_state_tx[tid] & HT_ADDBA_REQUESTED_MSK))
 387                 return;
 388
 389         if (WARN(!sta->ampdu_mlme.tid_tx[tid],
 390                  "TID %d gone but expected when splicing aggregates from"
 391                  "the pending queue\n", tid))
 392                 return;
 393
 394         if (!skb_queue_empty(&sta->ampdu_mlme.tid_tx[tid]->pending)) {
 395                 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
 396                 /* copy over remaining packets */
 397                 skb_queue_splice_tail_init(
 398                         &sta->ampdu_mlme.tid_tx[tid]->pending,
 399                         &local->pending[queue]);
 400                 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 401         }
 402 }
 403
 404 static void ieee80211_agg_splice_finish(struct ieee80211_local *local,
 405                                         struct sta_info *sta, u16 tid)
 406 {
 407         u16 queue = ieee80211_ac_from_tid(tid);
 408
 409         ieee80211_wake_queue_by_reason(
 410                 &local->hw, queue,
 411                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 412 }
 413
 414 /* caller must hold sta->lock */
 415 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
 416                                          struct sta_info *sta, u16 tid)
 417 {
 418 #ifdef CONFIG_MAC80211_HT_DEBUG
 419         printk(KERN_DEBUG "Aggregation is on for tid %d\n", tid);
 420 #endif
 421
 422         spin_lock(&local->ampdu_lock);
 423         ieee80211_agg_splice_packets(local, sta, tid);
 424         /*
 425          * NB: we rely on sta->lock being taken in the TX
 426          * processing here when adding to the pending queue,
 427          * otherwise we could only change the state of the
 428          * session to OPERATIONAL _here_.
 429          */
 430         ieee80211_agg_splice_finish(local, sta, tid);
 431         spin_unlock(&local->ampdu_lock);
 432
 433         drv_ampdu_action(local, sta->sdata,
 434                          IEEE80211_AMPDU_TX_OPERATIONAL,
 435                          &sta->sta, tid, NULL);
 436 }
 437
 438 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
 439 {
 440         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 441         struct ieee80211_local *local = sdata->local;
 442         struct sta_info *sta;
 443         u8 *state;
 444
 445         trace_api_start_tx_ba_cb(sdata, ra, tid);
 446
 447         if (tid >= STA_TID_NUM) {
 448 #ifdef CONFIG_MAC80211_HT_DEBUG
 449                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 450                                 tid, STA_TID_NUM);
 451 #endif
 452                 return;
 453         }
 454
 455         rcu_read_lock();
 456         sta = sta_info_get(sdata, ra);
 457         if (!sta) {
 458                 rcu_read_unlock();
 459 #ifdef CONFIG_MAC80211_HT_DEBUG
 460                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 461 #endif
 462                 return;
 463         }
 464
 465         state = &sta->ampdu_mlme.tid_state_tx[tid];
 466         spin_lock_bh(&sta->lock);
 467
 468         if (WARN_ON(!(*state & HT_ADDBA_REQUESTED_MSK))) {
 469 #ifdef CONFIG_MAC80211_HT_DEBUG
 470                 printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
 471                                 *state);
 472 #endif
 473                 spin_unlock_bh(&sta->lock);
 474                 rcu_read_unlock();
 475                 return;
 476         }
 477
 478         if (WARN_ON(*state & HT_ADDBA_DRV_READY_MSK))
 479                 goto out;
 480
 481         *state |= HT_ADDBA_DRV_READY_MSK;
 482
 483         if (*state == HT_AGG_STATE_OPERATIONAL)
 484                 ieee80211_agg_tx_operational(local, sta, tid);
 485
 486  out:
 487         spin_unlock_bh(&sta->lock);
 488         rcu_read_unlock();
 489 }
 490 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);
 491
 492 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 493                                       const u8 *ra, u16 tid)
 494 {
 495         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 496         struct ieee80211_local *local = sdata->local;
 497         struct ieee80211_ra_tid *ra_tid;
 498         struct sk_buff *skb = dev_alloc_skb(0);
 499
 500         if (unlikely(!skb)) {
 501 #ifdef CONFIG_MAC80211_HT_DEBUG
 502                 if (net_ratelimit())
 503                         printk(KERN_WARNING "%s: Not enough memory, "
 504                                "dropping start BA session", sdata->name);
 505 #endif
 506                 return;
 507         }
 508         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 509         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 510         ra_tid->tid = tid;
 511         ra_tid->vif = vif;
 512
 513         skb->pkt_type = IEEE80211_ADDBA_MSG;
 514         skb_queue_tail(&local->skb_queue, skb);
 515         tasklet_schedule(&local->tasklet);
 516 }
 517 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
 518
 519 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 520                                    enum ieee80211_back_parties initiator)
 521 {
 522         u8 *state;
 523         int ret;
 524
 525         /* check if the TID is in aggregation */
 526         state = &sta->ampdu_mlme.tid_state_tx[tid];
 527         spin_lock_bh(&sta->lock);
 528
 529         if (*state != HT_AGG_STATE_OPERATIONAL) {
 530                 ret = -ENOENT;
 531                 goto unlock;
 532         }
 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_sta *pubsta, u16 tid,
 542                                  enum ieee80211_back_parties initiator)
 543 {
 544         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 545         struct ieee80211_sub_if_data *sdata = sta->sdata;
 546         struct ieee80211_local *local = sdata->local;
 547
 548         trace_api_stop_tx_ba_session(pubsta, tid, initiator);
 549
 550         if (!local->ops->ampdu_action)
 551                 return -EINVAL;
 552
 553         if (tid >= STA_TID_NUM)
 554                 return -EINVAL;
 555
 556         return __ieee80211_stop_tx_ba_session(sta, tid, initiator);
 557 }
 558 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
 559
 560 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
 561 {
 562         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 563         struct ieee80211_local *local = sdata->local;
 564         struct sta_info *sta;
 565         u8 *state;
 566
 567         trace_api_stop_tx_ba_cb(sdata, ra, tid);
 568
 569         if (tid >= STA_TID_NUM) {
 570 #ifdef CONFIG_MAC80211_HT_DEBUG
 571                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 572                                 tid, STA_TID_NUM);
 573 #endif
 574                 return;
 575         }
 576
 577 #ifdef CONFIG_MAC80211_HT_DEBUG
 578         printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
 579                ra, tid);
 580 #endif /* CONFIG_MAC80211_HT_DEBUG */
 581
 582         rcu_read_lock();
 583         sta = sta_info_get(sdata, ra);
 584         if (!sta) {
 585 #ifdef CONFIG_MAC80211_HT_DEBUG
 586                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 587 #endif
 588                 rcu_read_unlock();
 589                 return;
 590         }
 591         state = &sta->ampdu_mlme.tid_state_tx[tid];
 592
 593         /* NOTE: no need to use sta->lock in this state check, as
 594          * ieee80211_stop_tx_ba_session will let only one stop call to
 595          * pass through per sta/tid
 596          */
 597         if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
 598 #ifdef CONFIG_MAC80211_HT_DEBUG
 599                 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
 600 #endif
 601                 rcu_read_unlock();
 602                 return;
 603         }
 604
 605         if (*state & HT_AGG_STATE_INITIATOR_MSK)
 606                 ieee80211_send_delba(sta->sdata, ra, tid,
 607                         WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
 608
 609         spin_lock_bh(&sta->lock);
 610         spin_lock(&local->ampdu_lock);
 611
 612         ieee80211_agg_splice_packets(local, sta, tid);
 613
 614         *state = HT_AGG_STATE_IDLE;
 615         /* from now on packets are no longer put onto sta->pending */
 616         kfree(sta->ampdu_mlme.tid_tx[tid]);
 617         sta->ampdu_mlme.tid_tx[tid] = NULL;
 618
 619         ieee80211_agg_splice_finish(local, sta, tid);
 620
 621         spin_unlock(&local->ampdu_lock);
 622         spin_unlock_bh(&sta->lock);
 623
 624         rcu_read_unlock();
 625 }
 626 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);
 627
 628 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 629                                      const u8 *ra, u16 tid)
 630 {
 631         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 632         struct ieee80211_local *local = sdata->local;
 633         struct ieee80211_ra_tid *ra_tid;
 634         struct sk_buff *skb = dev_alloc_skb(0);
 635
 636         if (unlikely(!skb)) {
 637 #ifdef CONFIG_MAC80211_HT_DEBUG
 638                 if (net_ratelimit())
 639                         printk(KERN_WARNING "%s: Not enough memory, "
 640                                "dropping stop BA session", sdata->name);
 641 #endif
 642                 return;
 643         }
 644         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 645         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 646         ra_tid->tid = tid;
 647         ra_tid->vif = vif;
 648
 649         skb->pkt_type = IEEE80211_DELBA_MSG;
 650         skb_queue_tail(&local->skb_queue, skb);
 651         tasklet_schedule(&local->tasklet);
 652 }
 653 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
 654
 655
 656 void ieee80211_process_addba_resp(struct ieee80211_local *local,
 657                                   struct sta_info *sta,
 658                                   struct ieee80211_mgmt *mgmt,
 659                                   size_t len)
 660 {
 661         u16 capab, tid;
 662         u8 *state;
 663
 664         capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
 665         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 666
 667         state = &sta->ampdu_mlme.tid_state_tx[tid];
 668
 669         spin_lock_bh(&sta->lock);
 670
 671         if (!(*state & HT_ADDBA_REQUESTED_MSK))
 672                 goto out;
 673
 674         if (mgmt->u.action.u.addba_resp.dialog_token !=
 675                 sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
 676 #ifdef CONFIG_MAC80211_HT_DEBUG
 677                 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
 678 #endif /* CONFIG_MAC80211_HT_DEBUG */
 679                 goto out;
 680         }
 681
 682         del_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 683
 684 #ifdef CONFIG_MAC80211_HT_DEBUG
 685         printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid);
 686 #endif /* CONFIG_MAC80211_HT_DEBUG */
 687
 688         if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
 689                         == WLAN_STATUS_SUCCESS) {
 690                 u8 curstate = *state;
 691
 692                 *state |= HT_ADDBA_RECEIVED_MSK;
 693
 694                 if (*state != curstate && *state == HT_AGG_STATE_OPERATIONAL)
 695                         ieee80211_agg_tx_operational(local, sta, tid);
 696
 697                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 698         } else {
 699                 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 700         }
 701
 702  out:
 703         spin_unlock_bh(&sta->lock);
 704 }