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 "wme.h"
  20
  21 /**
  22  * DOC: TX aggregation
  23  *
  24  * Aggregation on the TX side requires setting the hardware flag
  25  * %IEEE80211_HW_AMPDU_AGGREGATION as well as, if present, the @ampdu_queues
  26  * hardware parameter to the number of hardware AMPDU queues. If there are no
  27  * hardware queues then the driver will (currently) have to do all frame
  28  * buffering.
  29  *
  30  * When TX aggregation is started by some subsystem (usually the rate control
  31  * algorithm would be appropriate) by calling the
  32  * ieee80211_start_tx_ba_session() function, the driver will be notified via
  33  * its @ampdu_action function, with the %IEEE80211_AMPDU_TX_START action.
  34  *
  35  * In response to that, the driver is later required to call the
  36  * ieee80211_start_tx_ba_cb() (or ieee80211_start_tx_ba_cb_irqsafe())
  37  * function, which will start the aggregation session.
  38  *
  39  * Similarly, when the aggregation session is stopped by
  40  * ieee80211_stop_tx_ba_session(), the driver's @ampdu_action function will
  41  * be called with the action %IEEE80211_AMPDU_TX_STOP. In this case, the
  42  * call must not fail, and the driver must later call ieee80211_stop_tx_ba_cb()
  43  * (or ieee80211_stop_tx_ba_cb_irqsafe()).
  44  */
  45
  46 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
  47                                          const u8 *da, u16 tid,
  48                                          u8 dialog_token, u16 start_seq_num,
  49                                          u16 agg_size, u16 timeout)
  50 {
  51         struct ieee80211_local *local = sdata->local;
  52         struct sk_buff *skb;
  53         struct ieee80211_mgmt *mgmt;
  54         u16 capab;
  55
  56         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
  57
  58         if (!skb) {
  59                 printk(KERN_ERR "%s: failed to allocate buffer "
  60                                 "for addba request frame\n", sdata->dev->name);
  61                 return;
  62         }
  63         skb_reserve(skb, local->hw.extra_tx_headroom);
  64         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
  65         memset(mgmt, 0, 24);
  66         memcpy(mgmt->da, da, ETH_ALEN);
  67         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
  68         if (sdata->vif.type == NL80211_IFTYPE_AP ||
  69             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
  70                 memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
  71         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
  72                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
  73
  74         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
  75                                           IEEE80211_STYPE_ACTION);
  76
  77         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
  78
  79         mgmt->u.action.category = WLAN_CATEGORY_BACK;
  80         mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
  81
  82         mgmt->u.action.u.addba_req.dialog_token = dialog_token;
  83         capab = (u16)(1 << 1);          /* bit 1 aggregation policy */
  84         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
  85         capab |= (u16)(agg_size << 6);  /* bit 15:6 max size of aggergation */
  86
  87         mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
  88
  89         mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
  90         mgmt->u.action.u.addba_req.start_seq_num =
  91                                         cpu_to_le16(start_seq_num << 4);
  92
  93         ieee80211_tx_skb(sdata, skb, 1);
  94 }
  95
  96 void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn)
  97 {
  98         struct ieee80211_local *local = sdata->local;
  99         struct sk_buff *skb;
 100         struct ieee80211_bar *bar;
 101         u16 bar_control = 0;
 102
 103         skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
 104         if (!skb) {
 105                 printk(KERN_ERR "%s: failed to allocate buffer for "
 106                         "bar frame\n", sdata->dev->name);
 107                 return;
 108         }
 109         skb_reserve(skb, local->hw.extra_tx_headroom);
 110         bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
 111         memset(bar, 0, sizeof(*bar));
 112         bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
 113                                          IEEE80211_STYPE_BACK_REQ);
 114         memcpy(bar->ra, ra, ETH_ALEN);
 115         memcpy(bar->ta, sdata->dev->dev_addr, ETH_ALEN);
 116         bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
 117         bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
 118         bar_control |= (u16)(tid << 12);
 119         bar->control = cpu_to_le16(bar_control);
 120         bar->start_seq_num = cpu_to_le16(ssn);
 121
 122         ieee80211_tx_skb(sdata, skb, 0);
 123 }
 124
 125 static int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 126                                            enum ieee80211_back_parties initiator)
 127 {
 128         struct ieee80211_local *local = sta->local;
 129         int ret;
 130         u8 *state;
 131
 132         state = &sta->ampdu_mlme.tid_state_tx[tid];
 133
 134         if (local->hw.ampdu_queues) {
 135                 if (initiator) {
 136                         /*
 137                          * Stop the AC queue to avoid issues where we send
 138                          * unaggregated frames already before the delba.
 139                          */
 140                         ieee80211_stop_queue_by_reason(&local->hw,
 141                                 local->hw.queues + sta->tid_to_tx_q[tid],
 142                                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 143                 }
 144
 145                 /*
 146                  * Pretend the driver woke the queue, just in case
 147                  * it disabled it before the session was stopped.
 148                  */
 149                 ieee80211_wake_queue(
 150                         &local->hw, local->hw.queues + sta->tid_to_tx_q[tid]);
 151         }
 152         *state = HT_AGG_STATE_REQ_STOP_BA_MSK |
 153                 (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
 154
 155         ret = local->ops->ampdu_action(&local->hw, IEEE80211_AMPDU_TX_STOP,
 156                                        &sta->sta, tid, NULL);
 157
 158         /* HW shall not deny going back to legacy */
 159         if (WARN_ON(ret)) {
 160                 *state = HT_AGG_STATE_OPERATIONAL;
 161         }
 162
 163         return ret;
 164 }
 165
 166 /*
 167  * After sending add Block Ack request we activated a timer until
 168  * add Block Ack response will arrive from the recipient.
 169  * If this timer expires sta_addba_resp_timer_expired will be executed.
 170  */
 171 static void sta_addba_resp_timer_expired(unsigned long data)
 172 {
 173         /* not an elegant detour, but there is no choice as the timer passes
 174          * only one argument, and both sta_info and TID are needed, so init
 175          * flow in sta_info_create gives the TID as data, while the timer_to_id
 176          * array gives the sta through container_of */
 177         u16 tid = *(u8 *)data;
 178         struct sta_info *sta = container_of((void *)data,
 179                 struct sta_info, timer_to_tid[tid]);
 180         u8 *state;
 181
 182         state = &sta->ampdu_mlme.tid_state_tx[tid];
 183
 184         /* check if the TID waits for addBA response */
 185         spin_lock_bh(&sta->lock);
 186         if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
 187                 spin_unlock_bh(&sta->lock);
 188                 *state = HT_AGG_STATE_IDLE;
 189 #ifdef CONFIG_MAC80211_HT_DEBUG
 190                 printk(KERN_DEBUG "timer expired on tid %d but we are not "
 191                                 "expecting addBA response there", 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_hw *hw, u8 *ra, u16 tid)
 210 {
 211         struct ieee80211_local *local = hw_to_local(hw);
 212         struct sta_info *sta;
 213         struct ieee80211_sub_if_data *sdata;
 214         u8 *state;
 215         int i, qn = -1, ret = 0;
 216         u16 start_seq_num;
 217
 218         if (WARN_ON(!local->ops->ampdu_action))
 219                 return -EINVAL;
 220
 221         if ((tid >= STA_TID_NUM) || !(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                ra, tid);
 227 #endif /* CONFIG_MAC80211_HT_DEBUG */
 228
 229         if (hw->ampdu_queues && ieee80211_ac_from_tid(tid) == 0) {
 230 #ifdef CONFIG_MAC80211_HT_DEBUG
 231                 printk(KERN_DEBUG "rejecting on voice AC\n");
 232 #endif
 233                 return -EINVAL;
 234         }
 235
 236         rcu_read_lock();
 237
 238         sta = sta_info_get(local, ra);
 239         if (!sta) {
 240 #ifdef CONFIG_MAC80211_HT_DEBUG
 241                 printk(KERN_DEBUG "Could not find the station\n");
 242 #endif
 243                 ret = -ENOENT;
 244                 goto unlock;
 245         }
 246
 247         /*
 248          * The aggregation code is not prepared to handle
 249          * anything but STA/AP due to the BSSID handling.
 250          * IBSS could work in the code but isn't supported
 251          * by drivers or the standard.
 252          */
 253         if (sta->sdata->vif.type != NL80211_IFTYPE_STATION &&
 254             sta->sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
 255             sta->sdata->vif.type != NL80211_IFTYPE_AP) {
 256                 ret = -EINVAL;
 257                 goto unlock;
 258         }
 259
 260         spin_lock_bh(&sta->lock);
 261
 262         sdata = sta->sdata;
 263
 264         /* we have tried too many times, receiver does not want A-MPDU */
 265         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
 266                 ret = -EBUSY;
 267                 goto err_unlock_sta;
 268         }
 269
 270         state = &sta->ampdu_mlme.tid_state_tx[tid];
 271         /* check if the TID is not in aggregation flow already */
 272         if (*state != HT_AGG_STATE_IDLE) {
 273 #ifdef CONFIG_MAC80211_HT_DEBUG
 274                 printk(KERN_DEBUG "BA request denied - session is not "
 275                                  "idle on tid %u\n", tid);
 276 #endif /* CONFIG_MAC80211_HT_DEBUG */
 277                 ret = -EAGAIN;
 278                 goto err_unlock_sta;
 279         }
 280
 281         if (hw->ampdu_queues) {
 282                 spin_lock(&local->queue_stop_reason_lock);
 283                 /* reserve a new queue for this session */
 284                 for (i = 0; i < local->hw.ampdu_queues; i++) {
 285                         if (local->ampdu_ac_queue[i] < 0) {
 286                                 qn = i;
 287                                 local->ampdu_ac_queue[qn] =
 288                                         ieee80211_ac_from_tid(tid);
 289                                 break;
 290                         }
 291                 }
 292                 spin_unlock(&local->queue_stop_reason_lock);
 293
 294                 if (qn < 0) {
 295 #ifdef CONFIG_MAC80211_HT_DEBUG
 296                         printk(KERN_DEBUG "BA request denied - "
 297                                "queue unavailable for tid %d\n", tid);
 298 #endif /* CONFIG_MAC80211_HT_DEBUG */
 299                         ret = -ENOSPC;
 300                         goto err_unlock_sta;
 301                 }
 302
 303                 /*
 304                  * If we successfully allocate the session, we can't have
 305                  * anything going on on the queue this TID maps into, so
 306                  * stop it for now. This is a "virtual" stop using the same
 307                  * mechanism that drivers will use.
 308                  *
 309                  * XXX: queue up frames for this session in the sta_info
 310                  *      struct instead to avoid hitting all other STAs.
 311                  */
 312                 ieee80211_stop_queue_by_reason(
 313                         &local->hw, hw->queues + qn,
 314                         IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 315         }
 316
 317         /* prepare A-MPDU MLME for Tx aggregation */
 318         sta->ampdu_mlme.tid_tx[tid] =
 319                         kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
 320         if (!sta->ampdu_mlme.tid_tx[tid]) {
 321 #ifdef CONFIG_MAC80211_HT_DEBUG
 322                 if (net_ratelimit())
 323                         printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
 324                                         tid);
 325 #endif
 326                 ret = -ENOMEM;
 327                 goto err_return_queue;
 328         }
 329
 330         /* Tx timer */
 331         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
 332                         sta_addba_resp_timer_expired;
 333         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
 334                         (unsigned long)&sta->timer_to_tid[tid];
 335         init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 336
 337         /* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
 338          * call back right away, it must see that the flow has begun */
 339         *state |= HT_ADDBA_REQUESTED_MSK;
 340
 341         start_seq_num = sta->tid_seq[tid];
 342
 343         ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_START,
 344                                        &sta->sta, tid, &start_seq_num);
 345
 346         if (ret) {
 347 #ifdef CONFIG_MAC80211_HT_DEBUG
 348                 printk(KERN_DEBUG "BA request denied - HW unavailable for"
 349                                         " tid %d\n", tid);
 350 #endif /* CONFIG_MAC80211_HT_DEBUG */
 351                 *state = HT_AGG_STATE_IDLE;
 352                 goto err_free;
 353         }
 354         sta->tid_to_tx_q[tid] = qn;
 355
 356         spin_unlock_bh(&sta->lock);
 357
 358         /* send an addBA request */
 359         sta->ampdu_mlme.dialog_token_allocator++;
 360         sta->ampdu_mlme.tid_tx[tid]->dialog_token =
 361                         sta->ampdu_mlme.dialog_token_allocator;
 362         sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;
 363
 364         ieee80211_send_addba_request(sta->sdata, ra, tid,
 365                          sta->ampdu_mlme.tid_tx[tid]->dialog_token,
 366                          sta->ampdu_mlme.tid_tx[tid]->ssn,
 367                          0x40, 5000);
 368         /* activate the timer for the recipient's addBA response */
 369         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
 370                                 jiffies + ADDBA_RESP_INTERVAL;
 371         add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 372 #ifdef CONFIG_MAC80211_HT_DEBUG
 373         printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
 374 #endif
 375         goto unlock;
 376
 377  err_free:
 378         kfree(sta->ampdu_mlme.tid_tx[tid]);
 379         sta->ampdu_mlme.tid_tx[tid] = NULL;
 380  err_return_queue:
 381         if (qn >= 0) {
 382                 /* We failed, so start queue again right away. */
 383                 ieee80211_wake_queue_by_reason(hw, hw->queues + qn,
 384                         IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 385                 /* give queue back to pool */
 386                 spin_lock(&local->queue_stop_reason_lock);
 387                 local->ampdu_ac_queue[qn] = -1;
 388                 spin_unlock(&local->queue_stop_reason_lock);
 389         }
 390  err_unlock_sta:
 391         spin_unlock_bh(&sta->lock);
 392  unlock:
 393         rcu_read_unlock();
 394         return ret;
 395 }
 396 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
 397
 398 void ieee80211_start_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 399 {
 400         struct ieee80211_local *local = hw_to_local(hw);
 401         struct sta_info *sta;
 402         u8 *state;
 403
 404         if (tid >= STA_TID_NUM) {
 405 #ifdef CONFIG_MAC80211_HT_DEBUG
 406                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 407                                 tid, STA_TID_NUM);
 408 #endif
 409                 return;
 410         }
 411
 412         rcu_read_lock();
 413         sta = sta_info_get(local, ra);
 414         if (!sta) {
 415                 rcu_read_unlock();
 416 #ifdef CONFIG_MAC80211_HT_DEBUG
 417                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 418 #endif
 419                 return;
 420         }
 421
 422         state = &sta->ampdu_mlme.tid_state_tx[tid];
 423         spin_lock_bh(&sta->lock);
 424
 425         if (WARN_ON(!(*state & HT_ADDBA_REQUESTED_MSK))) {
 426 #ifdef CONFIG_MAC80211_HT_DEBUG
 427                 printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
 428                                 *state);
 429 #endif
 430                 spin_unlock_bh(&sta->lock);
 431                 rcu_read_unlock();
 432                 return;
 433         }
 434
 435         if (WARN_ON(*state & HT_ADDBA_DRV_READY_MSK))
 436                 goto out;
 437
 438         *state |= HT_ADDBA_DRV_READY_MSK;
 439
 440         if (*state == HT_AGG_STATE_OPERATIONAL) {
 441 #ifdef CONFIG_MAC80211_HT_DEBUG
 442                 printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
 443 #endif
 444                 if (hw->ampdu_queues) {
 445                         /*
 446                          * Wake up this queue, we stopped it earlier,
 447                          * this will in turn wake the entire AC.
 448                          */
 449                         ieee80211_wake_queue_by_reason(hw,
 450                                 hw->queues + sta->tid_to_tx_q[tid],
 451                                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 452                 }
 453         }
 454
 455  out:
 456         spin_unlock_bh(&sta->lock);
 457         rcu_read_unlock();
 458 }
 459 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);
 460
 461 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
 462                                       const u8 *ra, u16 tid)
 463 {
 464         struct ieee80211_local *local = hw_to_local(hw);
 465         struct ieee80211_ra_tid *ra_tid;
 466         struct sk_buff *skb = dev_alloc_skb(0);
 467
 468         if (unlikely(!skb)) {
 469 #ifdef CONFIG_MAC80211_HT_DEBUG
 470                 if (net_ratelimit())
 471                         printk(KERN_WARNING "%s: Not enough memory, "
 472                                "dropping start BA session", skb->dev->name);
 473 #endif
 474                 return;
 475         }
 476         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 477         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 478         ra_tid->tid = tid;
 479
 480         skb->pkt_type = IEEE80211_ADDBA_MSG;
 481         skb_queue_tail(&local->skb_queue, skb);
 482         tasklet_schedule(&local->tasklet);
 483 }
 484 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
 485
 486 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 487                                    enum ieee80211_back_parties initiator)
 488 {
 489         u8 *state;
 490         int ret;
 491
 492         /* check if the TID is in aggregation */
 493         state = &sta->ampdu_mlme.tid_state_tx[tid];
 494         spin_lock_bh(&sta->lock);
 495
 496         if (*state != HT_AGG_STATE_OPERATIONAL) {
 497                 ret = -ENOENT;
 498                 goto unlock;
 499         }
 500
 501 #ifdef CONFIG_MAC80211_HT_DEBUG
 502         printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
 503                sta->sta.addr, tid);
 504 #endif /* CONFIG_MAC80211_HT_DEBUG */
 505
 506         ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator);
 507
 508  unlock:
 509         spin_unlock_bh(&sta->lock);
 510         return ret;
 511 }
 512
 513 int ieee80211_stop_tx_ba_session(struct ieee80211_hw *hw,
 514                                  u8 *ra, u16 tid,
 515                                  enum ieee80211_back_parties initiator)
 516 {
 517         struct ieee80211_local *local = hw_to_local(hw);
 518         struct sta_info *sta;
 519         int ret = 0;
 520
 521         if (WARN_ON(!local->ops->ampdu_action))
 522                 return -EINVAL;
 523
 524         if (tid >= STA_TID_NUM)
 525                 return -EINVAL;
 526
 527         rcu_read_lock();
 528         sta = sta_info_get(local, ra);
 529         if (!sta) {
 530                 rcu_read_unlock();
 531                 return -ENOENT;
 532         }
 533
 534         ret = __ieee80211_stop_tx_ba_session(sta, tid, initiator);
 535         rcu_read_unlock();
 536         return ret;
 537 }
 538 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
 539
 540 void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
 541 {
 542         struct ieee80211_local *local = hw_to_local(hw);
 543         struct sta_info *sta;
 544         u8 *state;
 545
 546         if (tid >= STA_TID_NUM) {
 547 #ifdef CONFIG_MAC80211_HT_DEBUG
 548                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 549                                 tid, STA_TID_NUM);
 550 #endif
 551                 return;
 552         }
 553
 554 #ifdef CONFIG_MAC80211_HT_DEBUG
 555         printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
 556                ra, tid);
 557 #endif /* CONFIG_MAC80211_HT_DEBUG */
 558
 559         rcu_read_lock();
 560         sta = sta_info_get(local, ra);
 561         if (!sta) {
 562 #ifdef CONFIG_MAC80211_HT_DEBUG
 563                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 564 #endif
 565                 rcu_read_unlock();
 566                 return;
 567         }
 568         state = &sta->ampdu_mlme.tid_state_tx[tid];
 569
 570         /* NOTE: no need to use sta->lock in this state check, as
 571          * ieee80211_stop_tx_ba_session will let only one stop call to
 572          * pass through per sta/tid
 573          */
 574         if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
 575 #ifdef CONFIG_MAC80211_HT_DEBUG
 576                 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
 577 #endif
 578                 rcu_read_unlock();
 579                 return;
 580         }
 581
 582         if (*state & HT_AGG_STATE_INITIATOR_MSK)
 583                 ieee80211_send_delba(sta->sdata, ra, tid,
 584                         WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
 585
 586         spin_lock_bh(&sta->lock);
 587
 588         if (*state & HT_AGG_STATE_INITIATOR_MSK &&
 589             hw->ampdu_queues) {
 590                 /*
 591                  * Wake up this queue, we stopped it earlier,
 592                  * this will in turn wake the entire AC.
 593                  */
 594                 ieee80211_wake_queue_by_reason(hw,
 595                         hw->queues + sta->tid_to_tx_q[tid],
 596                         IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 597         }
 598
 599         *state = HT_AGG_STATE_IDLE;
 600         sta->ampdu_mlme.addba_req_num[tid] = 0;
 601         kfree(sta->ampdu_mlme.tid_tx[tid]);
 602         sta->ampdu_mlme.tid_tx[tid] = NULL;
 603         spin_unlock_bh(&sta->lock);
 604
 605         rcu_read_unlock();
 606 }
 607 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);
 608
 609 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
 610                                      const u8 *ra, u16 tid)
 611 {
 612         struct ieee80211_local *local = hw_to_local(hw);
 613         struct ieee80211_ra_tid *ra_tid;
 614         struct sk_buff *skb = dev_alloc_skb(0);
 615
 616         if (unlikely(!skb)) {
 617 #ifdef CONFIG_MAC80211_HT_DEBUG
 618                 if (net_ratelimit())
 619                         printk(KERN_WARNING "%s: Not enough memory, "
 620                                "dropping stop BA session", skb->dev->name);
 621 #endif
 622                 return;
 623         }
 624         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 625         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 626         ra_tid->tid = tid;
 627
 628         skb->pkt_type = IEEE80211_DELBA_MSG;
 629         skb_queue_tail(&local->skb_queue, skb);
 630         tasklet_schedule(&local->tasklet);
 631 }
 632 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
 633
 634
 635 void ieee80211_process_addba_resp(struct ieee80211_local *local,
 636                                   struct sta_info *sta,
 637                                   struct ieee80211_mgmt *mgmt,
 638                                   size_t len)
 639 {
 640         struct ieee80211_hw *hw = &local->hw;
 641         u16 capab;
 642         u16 tid, start_seq_num;
 643         u8 *state;
 644
 645         capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
 646         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 647
 648         state = &sta->ampdu_mlme.tid_state_tx[tid];
 649
 650         spin_lock_bh(&sta->lock);
 651
 652         if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
 653                 spin_unlock_bh(&sta->lock);
 654                 return;
 655         }
 656
 657         if (mgmt->u.action.u.addba_resp.dialog_token !=
 658                 sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
 659                 spin_unlock_bh(&sta->lock);
 660 #ifdef CONFIG_MAC80211_HT_DEBUG
 661                 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
 662 #endif /* CONFIG_MAC80211_HT_DEBUG */
 663                 return;
 664         }
 665
 666         del_timer_sync(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 667 #ifdef CONFIG_MAC80211_HT_DEBUG
 668         printk(KERN_DEBUG "switched off addBA timer for tid %d \n", tid);
 669 #endif /* CONFIG_MAC80211_HT_DEBUG */
 670         if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
 671                         == WLAN_STATUS_SUCCESS) {
 672                 u8 curstate = *state;
 673
 674                 *state |= HT_ADDBA_RECEIVED_MSK;
 675
 676                 if (hw->ampdu_queues && *state != curstate &&
 677                     *state == HT_AGG_STATE_OPERATIONAL) {
 678                         /*
 679                          * Wake up this queue, we stopped it earlier,
 680                          * this will in turn wake the entire AC.
 681                          */
 682                         ieee80211_wake_queue_by_reason(hw,
 683                                 hw->queues + sta->tid_to_tx_q[tid],
 684                                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 685                 }
 686                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 687
 688                 if (local->ops->ampdu_action) {
 689                         (void)local->ops->ampdu_action(hw,
 690                                                IEEE80211_AMPDU_TX_RESUME,
 691                                                &sta->sta, tid, &start_seq_num);
 692                 }
 693 #ifdef CONFIG_MAC80211_HT_DEBUG
 694                 printk(KERN_DEBUG "Resuming TX aggregation for tid %d\n", tid);
 695 #endif /* CONFIG_MAC80211_HT_DEBUG */
 696         } else {
 697                 sta->ampdu_mlme.addba_req_num[tid]++;
 698                 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 699         }
 700         spin_unlock_bh(&sta->lock);
 701 }