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 static void kfree_tid_tx(struct rcu_head *rcu_head)
 129 {
 130         struct tid_ampdu_tx *tid_tx =
 131             container_of(rcu_head, struct tid_ampdu_tx, rcu_head);
 132
 133         kfree(tid_tx);
 134 }
 135
 136 static int ___ieee80211_stop_tx_ba_session(
 137                 struct sta_info *sta, u16 tid,
 138                 enum ieee80211_back_parties initiator)
 139 {
 140         struct ieee80211_local *local = sta->local;
 141         struct tid_ampdu_tx *tid_tx = sta->ampdu_mlme.tid_tx[tid];
 142         int ret;
 143
 144         lockdep_assert_held(&sta->lock);
 145
 146         if (WARN_ON(!tid_tx))
 147                 return -ENOENT;
 148
 149 #ifdef CONFIG_MAC80211_HT_DEBUG
 150         printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
 151                sta->sta.addr, tid);
 152 #endif /* CONFIG_MAC80211_HT_DEBUG */
 153
 154         set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
 155
 156         /*
 157          * After this packets are no longer handed right through
 158          * to the driver but are put onto tid_tx->pending instead,
 159          * with locking to ensure proper access.
 160          */
 161         clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
 162
 163         tid_tx->stop_initiator = initiator;
 164
 165         ret = drv_ampdu_action(local, sta->sdata,
 166                                IEEE80211_AMPDU_TX_STOP,
 167                                &sta->sta, tid, NULL);
 168
 169         /* HW shall not deny going back to legacy */
 170         if (WARN_ON(ret)) {
 171                 /*
 172                  * We may have pending packets get stuck in this case...
 173                  * Not bothering with a workaround for now.
 174                  */
 175         }
 176
 177         return ret;
 178 }
 179
 180 /*
 181  * After sending add Block Ack request we activated a timer until
 182  * add Block Ack response will arrive from the recipient.
 183  * If this timer expires sta_addba_resp_timer_expired will be executed.
 184  */
 185 static void sta_addba_resp_timer_expired(unsigned long data)
 186 {
 187         /* not an elegant detour, but there is no choice as the timer passes
 188          * only one argument, and both sta_info and TID are needed, so init
 189          * flow in sta_info_create gives the TID as data, while the timer_to_id
 190          * array gives the sta through container_of */
 191         u16 tid = *(u8 *)data;
 192         struct sta_info *sta = container_of((void *)data,
 193                 struct sta_info, timer_to_tid[tid]);
 194         struct tid_ampdu_tx *tid_tx;
 195
 196         /* check if the TID waits for addBA response */
 197         spin_lock_bh(&sta->lock);
 198         tid_tx = sta->ampdu_mlme.tid_tx[tid];
 199         if (!tid_tx ||
 200             test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) {
 201                 spin_unlock_bh(&sta->lock);
 202 #ifdef CONFIG_MAC80211_HT_DEBUG
 203                 printk(KERN_DEBUG "timer expired on tid %d but we are not "
 204                                 "(or no longer) expecting addBA response there\n",
 205                         tid);
 206 #endif
 207                 return;
 208         }
 209
 210 #ifdef CONFIG_MAC80211_HT_DEBUG
 211         printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
 212 #endif
 213
 214         ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 215         spin_unlock_bh(&sta->lock);
 216 }
 217
 218 static inline int ieee80211_ac_from_tid(int tid)
 219 {
 220         return ieee802_1d_to_ac[tid & 7];
 221 }
 222
 223 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 224 {
 225         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 226         struct ieee80211_sub_if_data *sdata = sta->sdata;
 227         struct ieee80211_local *local = sdata->local;
 228         struct tid_ampdu_tx *tid_tx;
 229         int ret = 0;
 230         u16 start_seq_num;
 231
 232         trace_api_start_tx_ba_session(pubsta, tid);
 233
 234         if (WARN_ON(!local->ops->ampdu_action))
 235                 return -EINVAL;
 236
 237         if ((tid >= STA_TID_NUM) ||
 238             !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION))
 239                 return -EINVAL;
 240
 241 #ifdef CONFIG_MAC80211_HT_DEBUG
 242         printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
 243                pubsta->addr, tid);
 244 #endif /* CONFIG_MAC80211_HT_DEBUG */
 245
 246         /*
 247          * The aggregation code is not prepared to handle
 248          * anything but STA/AP due to the BSSID handling.
 249          * IBSS could work in the code but isn't supported
 250          * by drivers or the standard.
 251          */
 252         if (sdata->vif.type != NL80211_IFTYPE_STATION &&
 253             sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
 254             sdata->vif.type != NL80211_IFTYPE_AP)
 255                 return -EINVAL;
 256
 257         if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
 258 #ifdef CONFIG_MAC80211_HT_DEBUG
 259                 printk(KERN_DEBUG "BA sessions blocked. "
 260                        "Denying BA session request\n");
 261 #endif
 262                 return -EINVAL;
 263         }
 264
 265         spin_lock_bh(&sta->lock);
 266         spin_lock(&local->ampdu_lock);
 267
 268         /* we have tried too many times, receiver does not want A-MPDU */
 269         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
 270                 ret = -EBUSY;
 271                 goto err_unlock_sta;
 272         }
 273
 274         tid_tx = sta->ampdu_mlme.tid_tx[tid];
 275         /* check if the TID is not in aggregation flow already */
 276         if (tid_tx) {
 277 #ifdef CONFIG_MAC80211_HT_DEBUG
 278                 printk(KERN_DEBUG "BA request denied - session is not "
 279                                  "idle on tid %u\n", tid);
 280 #endif /* CONFIG_MAC80211_HT_DEBUG */
 281                 ret = -EAGAIN;
 282                 goto err_unlock_sta;
 283         }
 284
 285         /*
 286          * While we're asking the driver about the aggregation,
 287          * stop the AC queue so that we don't have to worry
 288          * about frames that came in while we were doing that,
 289          * which would require us to put them to the AC pending
 290          * afterwards which just makes the code more complex.
 291          */
 292         ieee80211_stop_queue_by_reason(
 293                 &local->hw, ieee80211_ac_from_tid(tid),
 294                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 295
 296         /* prepare A-MPDU MLME for Tx aggregation */
 297         tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
 298         if (!tid_tx) {
 299 #ifdef CONFIG_MAC80211_HT_DEBUG
 300                 if (net_ratelimit())
 301                         printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
 302                                         tid);
 303 #endif
 304                 ret = -ENOMEM;
 305                 goto err_wake_queue;
 306         }
 307
 308         skb_queue_head_init(&tid_tx->pending);
 309
 310         /* Tx timer */
 311         tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired;
 312         tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 313         init_timer(&tid_tx->addba_resp_timer);
 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         if (ret) {
 320 #ifdef CONFIG_MAC80211_HT_DEBUG
 321                 printk(KERN_DEBUG "BA request denied - HW unavailable for"
 322                                         " tid %d\n", tid);
 323 #endif /* CONFIG_MAC80211_HT_DEBUG */
 324                 goto err_free;
 325         }
 326
 327         rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
 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
 336         /* activate the timer for the recipient's addBA response */
 337         tid_tx->addba_resp_timer.expires = jiffies + ADDBA_RESP_INTERVAL;
 338         add_timer(&tid_tx->addba_resp_timer);
 339 #ifdef CONFIG_MAC80211_HT_DEBUG
 340         printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
 341 #endif
 342
 343         /* prepare tid data */
 344         sta->ampdu_mlme.dialog_token_allocator++;
 345         tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
 346         tid_tx->ssn = start_seq_num;
 347
 348         sta->ampdu_mlme.addba_req_num[tid]++;
 349
 350         spin_unlock_bh(&sta->lock);
 351
 352         /* send AddBA request */
 353         ieee80211_send_addba_request(sdata, pubsta->addr, tid,
 354                          tid_tx->dialog_token, tid_tx->ssn,
 355                          0x40, 5000);
 356         return 0;
 357
 358  err_free:
 359         kfree(tid_tx);
 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 tid_ampdu_tx *tid_tx,
 378                                          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 (WARN(!tid_tx, "TID %d gone but expected when splicing aggregates"
 388                           " from the pending queue\n", tid))
 389                 return;
 390
 391         if (!skb_queue_empty(&tid_tx->pending)) {
 392                 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
 393                 /* copy over remaining packets */
 394                 skb_queue_splice_tail_init(&tid_tx->pending,
 395                                            &local->pending[queue]);
 396                 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 397         }
 398 }
 399
 400 static void ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid)
 401 {
 402         ieee80211_wake_queue_by_reason(
 403                 &local->hw, ieee80211_ac_from_tid(tid),
 404                 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 405 }
 406
 407 /* caller must hold sta->lock */
 408 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
 409                                          struct sta_info *sta, u16 tid)
 410 {
 411         lockdep_assert_held(&sta->lock);
 412
 413 #ifdef CONFIG_MAC80211_HT_DEBUG
 414         printk(KERN_DEBUG "Aggregation is on for tid %d\n", tid);
 415 #endif
 416
 417         spin_lock(&local->ampdu_lock);
 418         ieee80211_agg_splice_packets(local, sta->ampdu_mlme.tid_tx[tid], tid);
 419         /*
 420          * Now mark as operational. This will be visible
 421          * in the TX path, and lets it go lock-free in
 422          * the common case.
 423          */
 424         set_bit(HT_AGG_STATE_OPERATIONAL, &sta->ampdu_mlme.tid_tx[tid]->state);
 425         ieee80211_agg_splice_finish(local, tid);
 426         spin_unlock(&local->ampdu_lock);
 427
 428         drv_ampdu_action(local, sta->sdata,
 429                          IEEE80211_AMPDU_TX_OPERATIONAL,
 430                          &sta->sta, tid, NULL);
 431 }
 432
 433 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
 434 {
 435         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 436         struct ieee80211_local *local = sdata->local;
 437         struct sta_info *sta;
 438         struct tid_ampdu_tx *tid_tx;
 439
 440         trace_api_start_tx_ba_cb(sdata, ra, tid);
 441
 442         if (tid >= STA_TID_NUM) {
 443 #ifdef CONFIG_MAC80211_HT_DEBUG
 444                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 445                                 tid, STA_TID_NUM);
 446 #endif
 447                 return;
 448         }
 449
 450         rcu_read_lock();
 451         sta = sta_info_get(sdata, ra);
 452         if (!sta) {
 453                 rcu_read_unlock();
 454 #ifdef CONFIG_MAC80211_HT_DEBUG
 455                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 456 #endif
 457                 return;
 458         }
 459
 460         spin_lock_bh(&sta->lock);
 461         tid_tx = sta->ampdu_mlme.tid_tx[tid];
 462
 463         if (WARN_ON(!tid_tx)) {
 464 #ifdef CONFIG_MAC80211_HT_DEBUG
 465                 printk(KERN_DEBUG "addBA was not requested!\n");
 466 #endif
 467                 spin_unlock_bh(&sta->lock);
 468                 rcu_read_unlock();
 469                 return;
 470         }
 471
 472         if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
 473                 goto out;
 474
 475         if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state))
 476                 ieee80211_agg_tx_operational(local, sta, tid);
 477
 478  out:
 479         spin_unlock_bh(&sta->lock);
 480         rcu_read_unlock();
 481 }
 482 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);
 483
 484 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 485                                       const u8 *ra, u16 tid)
 486 {
 487         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 488         struct ieee80211_local *local = sdata->local;
 489         struct ieee80211_ra_tid *ra_tid;
 490         struct sk_buff *skb = dev_alloc_skb(0);
 491
 492         if (unlikely(!skb)) {
 493 #ifdef CONFIG_MAC80211_HT_DEBUG
 494                 if (net_ratelimit())
 495                         printk(KERN_WARNING "%s: Not enough memory, "
 496                                "dropping start BA session", sdata->name);
 497 #endif
 498                 return;
 499         }
 500         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 501         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 502         ra_tid->tid = tid;
 503
 504         skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_START;
 505         skb_queue_tail(&sdata->skb_queue, skb);
 506         ieee80211_queue_work(&local->hw, &sdata->work);
 507 }
 508 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
 509
 510 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 511                                    enum ieee80211_back_parties initiator)
 512 {
 513         struct tid_ampdu_tx *tid_tx;
 514         int ret;
 515
 516         spin_lock_bh(&sta->lock);
 517         tid_tx = sta->ampdu_mlme.tid_tx[tid];
 518
 519         /* check if the TID is in aggregation */
 520         if (!tid_tx || !test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
 521                 ret = -ENOENT;
 522                 goto unlock;
 523         }
 524
 525         ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator);
 526
 527  unlock:
 528         spin_unlock_bh(&sta->lock);
 529         return ret;
 530 }
 531
 532 int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid)
 533 {
 534         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 535         struct ieee80211_sub_if_data *sdata = sta->sdata;
 536         struct ieee80211_local *local = sdata->local;
 537
 538         trace_api_stop_tx_ba_session(pubsta, tid);
 539
 540         if (!local->ops->ampdu_action)
 541                 return -EINVAL;
 542
 543         if (tid >= STA_TID_NUM)
 544                 return -EINVAL;
 545
 546         return __ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 547 }
 548 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
 549
 550 void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
 551 {
 552         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 553         struct ieee80211_local *local = sdata->local;
 554         struct sta_info *sta;
 555         struct tid_ampdu_tx *tid_tx;
 556
 557         trace_api_stop_tx_ba_cb(sdata, ra, tid);
 558
 559         if (tid >= STA_TID_NUM) {
 560 #ifdef CONFIG_MAC80211_HT_DEBUG
 561                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 562                                 tid, STA_TID_NUM);
 563 #endif
 564                 return;
 565         }
 566
 567 #ifdef CONFIG_MAC80211_HT_DEBUG
 568         printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
 569                ra, tid);
 570 #endif /* CONFIG_MAC80211_HT_DEBUG */
 571
 572         rcu_read_lock();
 573         sta = sta_info_get(sdata, ra);
 574         if (!sta) {
 575 #ifdef CONFIG_MAC80211_HT_DEBUG
 576                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 577 #endif
 578                 rcu_read_unlock();
 579                 return;
 580         }
 581
 582         spin_lock_bh(&sta->lock);
 583         tid_tx = sta->ampdu_mlme.tid_tx[tid];
 584
 585         if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
 586 #ifdef CONFIG_MAC80211_HT_DEBUG
 587                 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
 588 #endif
 589                 spin_unlock_bh(&sta->lock);
 590                 rcu_read_unlock();
 591                 return;
 592         }
 593
 594         if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR)
 595                 ieee80211_send_delba(sta->sdata, ra, tid,
 596                         WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
 597
 598         /*
 599          * When we get here, the TX path will not be lockless any more wrt.
 600          * aggregation, since the OPERATIONAL bit has long been cleared.
 601          * Thus it will block on getting the lock, if it occurs. So if we
 602          * stop the queue now, we will not get any more packets, and any
 603          * that might be being processed will wait for us here, thereby
 604          * guaranteeing that no packets go to the tid_tx pending queue any
 605          * more.
 606          */
 607
 608         spin_lock(&local->ampdu_lock);
 609         ieee80211_agg_splice_packets(local, tid_tx, tid);
 610
 611         /* future packets must not find the tid_tx struct any more */
 612         rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
 613
 614         ieee80211_agg_splice_finish(local, tid);
 615
 616         call_rcu(&tid_tx->rcu_head, kfree_tid_tx);
 617         spin_unlock(&local->ampdu_lock);
 618
 619         spin_unlock_bh(&sta->lock);
 620         rcu_read_unlock();
 621 }
 622 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);
 623
 624 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 625                                      const u8 *ra, u16 tid)
 626 {
 627         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 628         struct ieee80211_local *local = sdata->local;
 629         struct ieee80211_ra_tid *ra_tid;
 630         struct sk_buff *skb = dev_alloc_skb(0);
 631
 632         if (unlikely(!skb)) {
 633 #ifdef CONFIG_MAC80211_HT_DEBUG
 634                 if (net_ratelimit())
 635                         printk(KERN_WARNING "%s: Not enough memory, "
 636                                "dropping stop BA session", sdata->name);
 637 #endif
 638                 return;
 639         }
 640         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 641         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 642         ra_tid->tid = tid;
 643
 644         skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_STOP;
 645         skb_queue_tail(&sdata->skb_queue, skb);
 646         ieee80211_queue_work(&local->hw, &sdata->work);
 647 }
 648 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
 649
 650
 651 void ieee80211_process_addba_resp(struct ieee80211_local *local,
 652                                   struct sta_info *sta,
 653                                   struct ieee80211_mgmt *mgmt,
 654                                   size_t len)
 655 {
 656         struct tid_ampdu_tx *tid_tx;
 657         u16 capab, tid;
 658
 659         capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
 660         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 661
 662         spin_lock_bh(&sta->lock);
 663
 664         tid_tx = sta->ampdu_mlme.tid_tx[tid];
 665
 666         if (!tid_tx)
 667                 goto out;
 668
 669         if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) {
 670 #ifdef CONFIG_MAC80211_HT_DEBUG
 671                 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
 672 #endif
 673                 goto out;
 674         }
 675
 676         del_timer(&tid_tx->addba_resp_timer);
 677
 678 #ifdef CONFIG_MAC80211_HT_DEBUG
 679         printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid);
 680 #endif
 681
 682         if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
 683                         == WLAN_STATUS_SUCCESS) {
 684                 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
 685                                      &tid_tx->state)) {
 686                         /* ignore duplicate response */
 687                         goto out;
 688                 }
 689
 690                 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))
 691                         ieee80211_agg_tx_operational(local, sta, tid);
 692
 693                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 694         } else {
 695                 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
 696         }
 697
 698  out:
 699         spin_unlock_bh(&sta->lock);
 700 }