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 2007-2010, 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 A-MPDU aggregation
  25  *
  26  * Aggregation on the TX side requires setting the hardware flag
  27  * %IEEE80211_HW_AMPDU_AGGREGATION. The driver will then be handed
  28  * packets with a flag indicating A-MPDU aggregation. The driver
  29  * or device is responsible for actually aggregating the frames,
  30  * as well as deciding how many and which to aggregate.
  31  *
  32  * When TX aggregation is started by some subsystem (usually the rate
  33  * control algorithm would be appropriate) by calling the
  34  * ieee80211_start_tx_ba_session() function, the driver will be
  35  * notified via its @ampdu_action function, with the
  36  * %IEEE80211_AMPDU_TX_START action.
  37  *
  38  * In response to that, the driver is later required to call the
  39  * ieee80211_start_tx_ba_cb_irqsafe() function, which will really
  40  * start the aggregation session after the peer has also responded.
  41  * If the peer responds negatively, the session will be stopped
  42  * again right away. Note that it is possible for the aggregation
  43  * session to be stopped before the driver has indicated that it
  44  * is done setting it up, in which case it must not indicate the
  45  * setup completion.
  46  *
  47  * Also note that, since we also need to wait for a response from
  48  * the peer, the driver is notified of the completion of the
  49  * handshake by the %IEEE80211_AMPDU_TX_OPERATIONAL action to the
  50  * @ampdu_action callback.
  51  *
  52  * Similarly, when the aggregation session is stopped by the peer
  53  * or something calling ieee80211_stop_tx_ba_session(), the driver's
  54  * @ampdu_action function will be called with the action
  55  * %IEEE80211_AMPDU_TX_STOP. In this case, the call must not fail,
  56  * and the driver must later call ieee80211_stop_tx_ba_cb_irqsafe().
  57  */
  58
  59 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
  60                                          const u8 *da, u16 tid,
  61                                          u8 dialog_token, u16 start_seq_num,
  62                                          u16 agg_size, u16 timeout)
  63 {
  64         struct ieee80211_local *local = sdata->local;
  65         struct sk_buff *skb;
  66         struct ieee80211_mgmt *mgmt;
  67         u16 capab;
  68
  69         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
  70
  71         if (!skb)
  72                 return;
  73
  74         skb_reserve(skb, local->hw.extra_tx_headroom);
  75         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
  76         memset(mgmt, 0, 24);
  77         memcpy(mgmt->da, da, ETH_ALEN);
  78         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
  79         if (sdata->vif.type == NL80211_IFTYPE_AP ||
  80             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
  81                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
  82         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
  83                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
  84
  85         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
  86                                           IEEE80211_STYPE_ACTION);
  87
  88         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
  89
  90         mgmt->u.action.category = WLAN_CATEGORY_BACK;
  91         mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
  92
  93         mgmt->u.action.u.addba_req.dialog_token = dialog_token;
  94         capab = (u16)(1 << 1);          /* bit 1 aggregation policy */
  95         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
  96         capab |= (u16)(agg_size << 6);  /* bit 15:6 max size of aggergation */
  97
  98         mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
  99
 100         mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
 101         mgmt->u.action.u.addba_req.start_seq_num =
 102                                         cpu_to_le16(start_seq_num << 4);
 103
 104         ieee80211_tx_skb(sdata, skb);
 105 }
 106
 107 void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn)
 108 {
 109         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 110         struct ieee80211_local *local = sdata->local;
 111         struct sk_buff *skb;
 112         struct ieee80211_bar *bar;
 113         u16 bar_control = 0;
 114
 115         skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
 116         if (!skb)
 117                 return;
 118
 119         skb_reserve(skb, local->hw.extra_tx_headroom);
 120         bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
 121         memset(bar, 0, sizeof(*bar));
 122         bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
 123                                          IEEE80211_STYPE_BACK_REQ);
 124         memcpy(bar->ra, ra, ETH_ALEN);
 125         memcpy(bar->ta, sdata->vif.addr, ETH_ALEN);
 126         bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
 127         bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
 128         bar_control |= (u16)(tid << IEEE80211_BAR_CTRL_TID_INFO_SHIFT);
 129         bar->control = cpu_to_le16(bar_control);
 130         bar->start_seq_num = cpu_to_le16(ssn);
 131
 132         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 133         ieee80211_tx_skb(sdata, skb);
 134 }
 135 EXPORT_SYMBOL(ieee80211_send_bar);
 136
 137 void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
 138                              struct tid_ampdu_tx *tid_tx)
 139 {
 140         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 141         lockdep_assert_held(&sta->lock);
 142         rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
 143 }
 144
 145 int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 146                                     enum ieee80211_back_parties initiator,
 147                                     bool tx)
 148 {
 149         struct ieee80211_local *local = sta->local;
 150         struct tid_ampdu_tx *tid_tx;
 151         int ret;
 152
 153         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 154
 155         spin_lock_bh(&sta->lock);
 156
 157         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 158         if (!tid_tx) {
 159                 spin_unlock_bh(&sta->lock);
 160                 return -ENOENT;
 161         }
 162
 163         if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
 164                 /* not even started yet! */
 165                 ieee80211_assign_tid_tx(sta, tid, NULL);
 166                 spin_unlock_bh(&sta->lock);
 167                 kfree_rcu(tid_tx, rcu_head);
 168                 return 0;
 169         }
 170
 171         spin_unlock_bh(&sta->lock);
 172
 173 #ifdef CONFIG_MAC80211_HT_DEBUG
 174         printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
 175                sta->sta.addr, tid);
 176 #endif /* CONFIG_MAC80211_HT_DEBUG */
 177
 178         set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
 179
 180         del_timer_sync(&tid_tx->addba_resp_timer);
 181
 182         /*
 183          * After this packets are no longer handed right through
 184          * to the driver but are put onto tid_tx->pending instead,
 185          * with locking to ensure proper access.
 186          */
 187         clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
 188
 189         tid_tx->stop_initiator = initiator;
 190         tid_tx->tx_stop = tx;
 191
 192         ret = drv_ampdu_action(local, sta->sdata,
 193                                IEEE80211_AMPDU_TX_STOP,
 194                                &sta->sta, tid, NULL, 0);
 195
 196         /* HW shall not deny going back to legacy */
 197         if (WARN_ON(ret)) {
 198                 /*
 199                  * We may have pending packets get stuck in this case...
 200                  * Not bothering with a workaround for now.
 201                  */
 202         }
 203
 204         return ret;
 205 }
 206
 207 /*
 208  * After sending add Block Ack request we activated a timer until
 209  * add Block Ack response will arrive from the recipient.
 210  * If this timer expires sta_addba_resp_timer_expired will be executed.
 211  */
 212 static void sta_addba_resp_timer_expired(unsigned long data)
 213 {
 214         /* not an elegant detour, but there is no choice as the timer passes
 215          * only one argument, and both sta_info and TID are needed, so init
 216          * flow in sta_info_create gives the TID as data, while the timer_to_id
 217          * array gives the sta through container_of */
 218         u16 tid = *(u8 *)data;
 219         struct sta_info *sta = container_of((void *)data,
 220                 struct sta_info, timer_to_tid[tid]);
 221         struct tid_ampdu_tx *tid_tx;
 222
 223         /* check if the TID waits for addBA response */
 224         rcu_read_lock();
 225         tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
 226         if (!tid_tx ||
 227             test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) {
 228                 rcu_read_unlock();
 229 #ifdef CONFIG_MAC80211_HT_DEBUG
 230                 printk(KERN_DEBUG "timer expired on tid %d but we are not "
 231                                 "(or no longer) expecting addBA response there\n",
 232                         tid);
 233 #endif
 234                 return;
 235         }
 236
 237 #ifdef CONFIG_MAC80211_HT_DEBUG
 238         printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
 239 #endif
 240
 241         ieee80211_stop_tx_ba_session(&sta->sta, tid);
 242         rcu_read_unlock();
 243 }
 244
 245 static inline int ieee80211_ac_from_tid(int tid)
 246 {
 247         return ieee802_1d_to_ac[tid & 7];
 248 }
 249
 250 /*
 251  * When multiple aggregation sessions on multiple stations
 252  * are being created/destroyed simultaneously, we need to
 253  * refcount the global queue stop caused by that in order
 254  * to not get into a situation where one of the aggregation
 255  * setup or teardown re-enables queues before the other is
 256  * ready to handle that.
 257  *
 258  * These two functions take care of this issue by keeping
 259  * a global "agg_queue_stop" refcount.
 260  */
 261 static void __acquires(agg_queue)
 262 ieee80211_stop_queue_agg(struct ieee80211_local *local, int tid)
 263 {
 264         int queue = ieee80211_ac_from_tid(tid);
 265
 266         if (atomic_inc_return(&local->agg_queue_stop[queue]) == 1)
 267                 ieee80211_stop_queue_by_reason(
 268                         &local->hw, queue,
 269                         IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 270         __acquire(agg_queue);
 271 }
 272
 273 static void __releases(agg_queue)
 274 ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid)
 275 {
 276         int queue = ieee80211_ac_from_tid(tid);
 277
 278         if (atomic_dec_return(&local->agg_queue_stop[queue]) == 0)
 279                 ieee80211_wake_queue_by_reason(
 280                         &local->hw, queue,
 281                         IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 282         __release(agg_queue);
 283 }
 284
 285 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
 286 {
 287         struct tid_ampdu_tx *tid_tx;
 288         struct ieee80211_local *local = sta->local;
 289         struct ieee80211_sub_if_data *sdata = sta->sdata;
 290         u16 start_seq_num;
 291         int ret;
 292
 293         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 294
 295         /*
 296          * While we're asking the driver about the aggregation,
 297          * stop the AC queue so that we don't have to worry
 298          * about frames that came in while we were doing that,
 299          * which would require us to put them to the AC pending
 300          * afterwards which just makes the code more complex.
 301          */
 302         ieee80211_stop_queue_agg(local, tid);
 303
 304         clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
 305
 306         /*
 307          * make sure no packets are being processed to get
 308          * valid starting sequence number
 309          */
 310         synchronize_net();
 311
 312         start_seq_num = sta->tid_seq[tid] >> 4;
 313
 314         ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START,
 315                                &sta->sta, tid, &start_seq_num, 0);
 316         if (ret) {
 317 #ifdef CONFIG_MAC80211_HT_DEBUG
 318                 printk(KERN_DEBUG "BA request denied - HW unavailable for"
 319                                         " tid %d\n", tid);
 320 #endif
 321                 spin_lock_bh(&sta->lock);
 322                 ieee80211_assign_tid_tx(sta, tid, NULL);
 323                 spin_unlock_bh(&sta->lock);
 324
 325                 ieee80211_wake_queue_agg(local, tid);
 326                 kfree_rcu(tid_tx, rcu_head);
 327                 return;
 328         }
 329
 330         /* we can take packets again now */
 331         ieee80211_wake_queue_agg(local, tid);
 332
 333         /* activate the timer for the recipient's addBA response */
 334         mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
 335 #ifdef CONFIG_MAC80211_HT_DEBUG
 336         printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
 337 #endif
 338
 339         spin_lock_bh(&sta->lock);
 340         sta->ampdu_mlme.addba_req_num[tid]++;
 341         spin_unlock_bh(&sta->lock);
 342
 343         /* send AddBA request */
 344         ieee80211_send_addba_request(sdata, sta->sta.addr, tid,
 345                                      tid_tx->dialog_token, start_seq_num,
 346                                      local->hw.max_tx_aggregation_subframes,
 347                                      tid_tx->timeout);
 348 }
 349
 350 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
 351                                   u16 timeout)
 352 {
 353         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 354         struct ieee80211_sub_if_data *sdata = sta->sdata;
 355         struct ieee80211_local *local = sdata->local;
 356         struct tid_ampdu_tx *tid_tx;
 357         int ret = 0;
 358
 359         trace_api_start_tx_ba_session(pubsta, tid);
 360
 361         if (WARN_ON(!local->ops->ampdu_action))
 362                 return -EINVAL;
 363
 364         if ((tid >= STA_TID_NUM) ||
 365             !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) ||
 366             (local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW))
 367                 return -EINVAL;
 368
 369 #ifdef CONFIG_MAC80211_HT_DEBUG
 370         printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
 371                pubsta->addr, tid);
 372 #endif /* CONFIG_MAC80211_HT_DEBUG */
 373
 374         /*
 375          * The aggregation code is not prepared to handle
 376          * anything but STA/AP due to the BSSID handling.
 377          * IBSS could work in the code but isn't supported
 378          * by drivers or the standard.
 379          */
 380         if (sdata->vif.type != NL80211_IFTYPE_STATION &&
 381             sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
 382             sdata->vif.type != NL80211_IFTYPE_AP)
 383                 return -EINVAL;
 384
 385         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
 386 #ifdef CONFIG_MAC80211_HT_DEBUG
 387                 printk(KERN_DEBUG "BA sessions blocked. "
 388                        "Denying BA session request\n");
 389 #endif
 390                 return -EINVAL;
 391         }
 392
 393         spin_lock_bh(&sta->lock);
 394
 395         /* we have tried too many times, receiver does not want A-MPDU */
 396         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
 397                 ret = -EBUSY;
 398                 goto err_unlock_sta;
 399         }
 400
 401         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 402         /* check if the TID is not in aggregation flow already */
 403         if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) {
 404 #ifdef CONFIG_MAC80211_HT_DEBUG
 405                 printk(KERN_DEBUG "BA request denied - session is not "
 406                                  "idle on tid %u\n", tid);
 407 #endif /* CONFIG_MAC80211_HT_DEBUG */
 408                 ret = -EAGAIN;
 409                 goto err_unlock_sta;
 410         }
 411
 412         /* prepare A-MPDU MLME for Tx aggregation */
 413         tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
 414         if (!tid_tx) {
 415                 ret = -ENOMEM;
 416                 goto err_unlock_sta;
 417         }
 418
 419         skb_queue_head_init(&tid_tx->pending);
 420         __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
 421
 422         tid_tx->timeout = timeout;
 423
 424         /* Tx timer */
 425         tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired;
 426         tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 427         init_timer(&tid_tx->addba_resp_timer);
 428
 429         /* assign a dialog token */
 430         sta->ampdu_mlme.dialog_token_allocator++;
 431         tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
 432
 433         /*
 434          * Finally, assign it to the start array; the work item will
 435          * collect it and move it to the normal array.
 436          */
 437         sta->ampdu_mlme.tid_start_tx[tid] = tid_tx;
 438
 439         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 440
 441         /* this flow continues off the work */
 442  err_unlock_sta:
 443         spin_unlock_bh(&sta->lock);
 444         return ret;
 445 }
 446 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
 447
 448 /*
 449  * splice packets from the STA's pending to the local pending,
 450  * requires a call to ieee80211_agg_splice_finish later
 451  */
 452 static void __acquires(agg_queue)
 453 ieee80211_agg_splice_packets(struct ieee80211_local *local,
 454                              struct tid_ampdu_tx *tid_tx, u16 tid)
 455 {
 456         int queue = ieee80211_ac_from_tid(tid);
 457         unsigned long flags;
 458
 459         ieee80211_stop_queue_agg(local, tid);
 460
 461         if (WARN(!tid_tx, "TID %d gone but expected when splicing aggregates"
 462                           " from the pending queue\n", tid))
 463                 return;
 464
 465         if (!skb_queue_empty(&tid_tx->pending)) {
 466                 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
 467                 /* copy over remaining packets */
 468                 skb_queue_splice_tail_init(&tid_tx->pending,
 469                                            &local->pending[queue]);
 470                 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 471         }
 472 }
 473
 474 static void __releases(agg_queue)
 475 ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid)
 476 {
 477         ieee80211_wake_queue_agg(local, tid);
 478 }
 479
 480 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
 481                                          struct sta_info *sta, u16 tid)
 482 {
 483         struct tid_ampdu_tx *tid_tx;
 484
 485         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 486
 487         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 488
 489 #ifdef CONFIG_MAC80211_HT_DEBUG
 490         printk(KERN_DEBUG "Aggregation is on for tid %d\n", tid);
 491 #endif
 492
 493         drv_ampdu_action(local, sta->sdata,
 494                          IEEE80211_AMPDU_TX_OPERATIONAL,
 495                          &sta->sta, tid, NULL, tid_tx->buf_size);
 496
 497         /*
 498          * synchronize with TX path, while splicing the TX path
 499          * should block so it won't put more packets onto pending.
 500          */
 501         spin_lock_bh(&sta->lock);
 502
 503         ieee80211_agg_splice_packets(local, tid_tx, tid);
 504         /*
 505          * Now mark as operational. This will be visible
 506          * in the TX path, and lets it go lock-free in
 507          * the common case.
 508          */
 509         set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
 510         ieee80211_agg_splice_finish(local, tid);
 511
 512         spin_unlock_bh(&sta->lock);
 513 }
 514
 515 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
 516 {
 517         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 518         struct ieee80211_local *local = sdata->local;
 519         struct sta_info *sta;
 520         struct tid_ampdu_tx *tid_tx;
 521
 522         trace_api_start_tx_ba_cb(sdata, ra, tid);
 523
 524         if (tid >= STA_TID_NUM) {
 525 #ifdef CONFIG_MAC80211_HT_DEBUG
 526                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 527                                 tid, STA_TID_NUM);
 528 #endif
 529                 return;
 530         }
 531
 532         mutex_lock(&local->sta_mtx);
 533         sta = sta_info_get(sdata, ra);
 534         if (!sta) {
 535                 mutex_unlock(&local->sta_mtx);
 536 #ifdef CONFIG_MAC80211_HT_DEBUG
 537                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 538 #endif
 539                 return;
 540         }
 541
 542         mutex_lock(&sta->ampdu_mlme.mtx);
 543         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 544
 545         if (WARN_ON(!tid_tx)) {
 546 #ifdef CONFIG_MAC80211_HT_DEBUG
 547                 printk(KERN_DEBUG "addBA was not requested!\n");
 548 #endif
 549                 goto unlock;
 550         }
 551
 552         if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
 553                 goto unlock;
 554
 555         if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state))
 556                 ieee80211_agg_tx_operational(local, sta, tid);
 557
 558  unlock:
 559         mutex_unlock(&sta->ampdu_mlme.mtx);
 560         mutex_unlock(&local->sta_mtx);
 561 }
 562
 563 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 564                                       const u8 *ra, u16 tid)
 565 {
 566         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 567         struct ieee80211_local *local = sdata->local;
 568         struct ieee80211_ra_tid *ra_tid;
 569         struct sk_buff *skb = dev_alloc_skb(0);
 570
 571         if (unlikely(!skb))
 572                 return;
 573
 574         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 575         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 576         ra_tid->tid = tid;
 577
 578         skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_START;
 579         skb_queue_tail(&sdata->skb_queue, skb);
 580         ieee80211_queue_work(&local->hw, &sdata->work);
 581 }
 582 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
 583
 584 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 585                                    enum ieee80211_back_parties initiator,
 586                                    bool tx)
 587 {
 588         int ret;
 589
 590         mutex_lock(&sta->ampdu_mlme.mtx);
 591
 592         ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator, tx);
 593
 594         mutex_unlock(&sta->ampdu_mlme.mtx);
 595
 596         return ret;
 597 }
 598
 599 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 600 {
 601         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 602         struct ieee80211_sub_if_data *sdata = sta->sdata;
 603         struct ieee80211_local *local = sdata->local;
 604         struct tid_ampdu_tx *tid_tx;
 605         int ret = 0;
 606
 607         trace_api_stop_tx_ba_session(pubsta, tid);
 608
 609         if (!local->ops->ampdu_action)
 610                 return -EINVAL;
 611
 612         if (tid >= STA_TID_NUM)
 613                 return -EINVAL;
 614
 615         spin_lock_bh(&sta->lock);
 616         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 617
 618         if (!tid_tx) {
 619                 ret = -ENOENT;
 620                 goto unlock;
 621         }
 622
 623         if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
 624                 /* already in progress stopping it */
 625                 ret = 0;
 626                 goto unlock;
 627         }
 628
 629         set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state);
 630         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 631
 632  unlock:
 633         spin_unlock_bh(&sta->lock);
 634         return ret;
 635 }
 636 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
 637
 638 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
 639 {
 640         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 641         struct ieee80211_local *local = sdata->local;
 642         struct sta_info *sta;
 643         struct tid_ampdu_tx *tid_tx;
 644
 645         trace_api_stop_tx_ba_cb(sdata, ra, tid);
 646
 647         if (tid >= STA_TID_NUM) {
 648 #ifdef CONFIG_MAC80211_HT_DEBUG
 649                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 650                                 tid, STA_TID_NUM);
 651 #endif
 652                 return;
 653         }
 654
 655 #ifdef CONFIG_MAC80211_HT_DEBUG
 656         printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
 657                ra, tid);
 658 #endif /* CONFIG_MAC80211_HT_DEBUG */
 659
 660         mutex_lock(&local->sta_mtx);
 661
 662         sta = sta_info_get(sdata, ra);
 663         if (!sta) {
 664 #ifdef CONFIG_MAC80211_HT_DEBUG
 665                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 666 #endif
 667                 goto unlock;
 668         }
 669
 670         mutex_lock(&sta->ampdu_mlme.mtx);
 671         spin_lock_bh(&sta->lock);
 672         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 673
 674         if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
 675 #ifdef CONFIG_MAC80211_HT_DEBUG
 676                 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
 677 #endif
 678                 goto unlock_sta;
 679         }
 680
 681         if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop)
 682                 ieee80211_send_delba(sta->sdata, ra, tid,
 683                         WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
 684
 685         /*
 686          * When we get here, the TX path will not be lockless any more wrt.
 687          * aggregation, since the OPERATIONAL bit has long been cleared.
 688          * Thus it will block on getting the lock, if it occurs. So if we
 689          * stop the queue now, we will not get any more packets, and any
 690          * that might be being processed will wait for us here, thereby
 691          * guaranteeing that no packets go to the tid_tx pending queue any
 692          * more.
 693          */
 694
 695         ieee80211_agg_splice_packets(local, tid_tx, tid);
 696
 697         /* future packets must not find the tid_tx struct any more */
 698         ieee80211_assign_tid_tx(sta, tid, NULL);
 699
 700         ieee80211_agg_splice_finish(local, tid);
 701
 702         kfree_rcu(tid_tx, rcu_head);
 703
 704  unlock_sta:
 705         spin_unlock_bh(&sta->lock);
 706         mutex_unlock(&sta->ampdu_mlme.mtx);
 707  unlock:
 708         mutex_unlock(&local->sta_mtx);
 709 }
 710
 711 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 712                                      const u8 *ra, u16 tid)
 713 {
 714         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 715         struct ieee80211_local *local = sdata->local;
 716         struct ieee80211_ra_tid *ra_tid;
 717         struct sk_buff *skb = dev_alloc_skb(0);
 718
 719         if (unlikely(!skb))
 720                 return;
 721
 722         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 723         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 724         ra_tid->tid = tid;
 725
 726         skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_STOP;
 727         skb_queue_tail(&sdata->skb_queue, skb);
 728         ieee80211_queue_work(&local->hw, &sdata->work);
 729 }
 730 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
 731
 732
 733 void ieee80211_process_addba_resp(struct ieee80211_local *local,
 734                                   struct sta_info *sta,
 735                                   struct ieee80211_mgmt *mgmt,
 736                                   size_t len)
 737 {
 738         struct tid_ampdu_tx *tid_tx;
 739         u16 capab, tid;
 740         u8 buf_size;
 741
 742         capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
 743         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 744         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 745
 746         mutex_lock(&sta->ampdu_mlme.mtx);
 747
 748         tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 749         if (!tid_tx)
 750                 goto out;
 751
 752         if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) {
 753 #ifdef CONFIG_MAC80211_HT_DEBUG
 754                 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
 755 #endif
 756                 goto out;
 757         }
 758
 759         del_timer(&tid_tx->addba_resp_timer);
 760
 761 #ifdef CONFIG_MAC80211_HT_DEBUG
 762         printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid);
 763 #endif
 764         /*
 765          * IEEE 802.11-2007 7.3.1.14:
 766          * In an ADDBA Response frame, when the Status Code field
 767          * is set to 0, the Buffer Size subfield is set to a value
 768          * of at least 1.
 769          */
 770         if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
 771                         == WLAN_STATUS_SUCCESS && buf_size) {
 772                 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
 773                                      &tid_tx->state)) {
 774                         /* ignore duplicate response */
 775                         goto out;
 776                 }
 777
 778                 tid_tx->buf_size = buf_size;
 779
 780                 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))
 781                         ieee80211_agg_tx_operational(local, sta, tid);
 782
 783                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 784         } else {
 785                 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR,
 786                                                 true);
 787         }
 788
 789  out:
 790         mutex_unlock(&sta->ampdu_mlme.mtx);
 791 }