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                 printk(KERN_ERR "%s: failed to allocate buffer "
  73                                 "for addba request frame\n", sdata->name);
  74                 return;
  75         }
  76         skb_reserve(skb, local->hw.extra_tx_headroom);
  77         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
  78         memset(mgmt, 0, 24);
  79         memcpy(mgmt->da, da, ETH_ALEN);
  80         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
  81         if (sdata->vif.type == NL80211_IFTYPE_AP ||
  82             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
  83                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
  84         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
  85                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
  86
  87         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
  88                                           IEEE80211_STYPE_ACTION);
  89
  90         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
  91
  92         mgmt->u.action.category = WLAN_CATEGORY_BACK;
  93         mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
  94
  95         mgmt->u.action.u.addba_req.dialog_token = dialog_token;
  96         capab = (u16)(1 << 1);          /* bit 1 aggregation policy */
  97         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
  98         capab |= (u16)(agg_size << 6);  /* bit 15:6 max size of aggergation */
  99
 100         mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
 101
 102         mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
 103         mgmt->u.action.u.addba_req.start_seq_num =
 104                                         cpu_to_le16(start_seq_num << 4);
 105
 106         ieee80211_tx_skb(sdata, skb);
 107 }
 108
 109 void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn)
 110 {
 111         struct ieee80211_local *local = sdata->local;
 112         struct sk_buff *skb;
 113         struct ieee80211_bar *bar;
 114         u16 bar_control = 0;
 115
 116         skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
 117         if (!skb) {
 118                 printk(KERN_ERR "%s: failed to allocate buffer for "
 119                         "bar frame\n", sdata->name);
 120                 return;
 121         }
 122         skb_reserve(skb, local->hw.extra_tx_headroom);
 123         bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
 124         memset(bar, 0, sizeof(*bar));
 125         bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
 126                                          IEEE80211_STYPE_BACK_REQ);
 127         memcpy(bar->ra, ra, ETH_ALEN);
 128         memcpy(bar->ta, sdata->vif.addr, ETH_ALEN);
 129         bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
 130         bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
 131         bar_control |= (u16)(tid << 12);
 132         bar->control = cpu_to_le16(bar_control);
 133         bar->start_seq_num = cpu_to_le16(ssn);
 134
 135         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
 136         ieee80211_tx_skb(sdata, skb);
 137 }
 138
 139 static void kfree_tid_tx(struct rcu_head *rcu_head)
 140 {
 141         struct tid_ampdu_tx *tid_tx =
 142             container_of(rcu_head, struct tid_ampdu_tx, rcu_head);
 143
 144         kfree(tid_tx);
 145 }
 146
 147 int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
 148                                     enum ieee80211_back_parties initiator,
 149                                     bool tx)
 150 {
 151         struct ieee80211_local *local = sta->local;
 152         struct tid_ampdu_tx *tid_tx = sta->ampdu_mlme.tid_tx[tid];
 153         int ret;
 154
 155         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 156
 157         if (!tid_tx)
 158                 return -ENOENT;
 159
 160         spin_lock_bh(&sta->lock);
 161
 162         if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
 163                 /* not even started yet! */
 164                 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
 165                 spin_unlock_bh(&sta->lock);
 166                 call_rcu(&tid_tx->rcu_head, kfree_tid_tx);
 167                 return 0;
 168         }
 169
 170         spin_unlock_bh(&sta->lock);
 171
 172 #ifdef CONFIG_MAC80211_HT_DEBUG
 173         printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
 174                sta->sta.addr, tid);
 175 #endif /* CONFIG_MAC80211_HT_DEBUG */
 176
 177         set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state);
 178
 179         del_timer_sync(&tid_tx->addba_resp_timer);
 180
 181         /*
 182          * After this packets are no longer handed right through
 183          * to the driver but are put onto tid_tx->pending instead,
 184          * with locking to ensure proper access.
 185          */
 186         clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
 187
 188         tid_tx->stop_initiator = initiator;
 189         tid_tx->tx_stop = tx;
 190
 191         ret = drv_ampdu_action(local, sta->sdata,
 192                                IEEE80211_AMPDU_TX_STOP,
 193                                &sta->sta, tid, NULL);
 194
 195         /* HW shall not deny going back to legacy */
 196         if (WARN_ON(ret)) {
 197                 /*
 198                  * We may have pending packets get stuck in this case...
 199                  * Not bothering with a workaround for now.
 200                  */
 201         }
 202
 203         return ret;
 204 }
 205
 206 /*
 207  * After sending add Block Ack request we activated a timer until
 208  * add Block Ack response will arrive from the recipient.
 209  * If this timer expires sta_addba_resp_timer_expired will be executed.
 210  */
 211 static void sta_addba_resp_timer_expired(unsigned long data)
 212 {
 213         /* not an elegant detour, but there is no choice as the timer passes
 214          * only one argument, and both sta_info and TID are needed, so init
 215          * flow in sta_info_create gives the TID as data, while the timer_to_id
 216          * array gives the sta through container_of */
 217         u16 tid = *(u8 *)data;
 218         struct sta_info *sta = container_of((void *)data,
 219                 struct sta_info, timer_to_tid[tid]);
 220         struct tid_ampdu_tx *tid_tx;
 221
 222         /* check if the TID waits for addBA response */
 223         rcu_read_lock();
 224         tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
 225         if (!tid_tx ||
 226             test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) {
 227                 rcu_read_unlock();
 228 #ifdef CONFIG_MAC80211_HT_DEBUG
 229                 printk(KERN_DEBUG "timer expired on tid %d but we are not "
 230                                 "(or no longer) expecting addBA response there\n",
 231                         tid);
 232 #endif
 233                 return;
 234         }
 235
 236 #ifdef CONFIG_MAC80211_HT_DEBUG
 237         printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
 238 #endif
 239
 240         ieee80211_stop_tx_ba_session(&sta->sta, tid);
 241         rcu_read_unlock();
 242 }
 243
 244 static inline int ieee80211_ac_from_tid(int tid)
 245 {
 246         return ieee802_1d_to_ac[tid & 7];
 247 }
 248
 249 /*
 250  * When multiple aggregation sessions on multiple stations
 251  * are being created/destroyed simultaneously, we need to
 252  * refcount the global queue stop caused by that in order
 253  * to not get into a situation where one of the aggregation
 254  * setup or teardown re-enables queues before the other is
 255  * ready to handle that.
 256  *
 257  * These two functions take care of this issue by keeping
 258  * a global "agg_queue_stop" refcount.
 259  */
 260 static void __acquires(agg_queue)
 261 ieee80211_stop_queue_agg(struct ieee80211_local *local, int tid)
 262 {
 263         int queue = ieee80211_ac_from_tid(tid);
 264
 265         if (atomic_inc_return(&local->agg_queue_stop[queue]) == 1)
 266                 ieee80211_stop_queue_by_reason(
 267                         &local->hw, queue,
 268                         IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 269         __acquire(agg_queue);
 270 }
 271
 272 static void __releases(agg_queue)
 273 ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid)
 274 {
 275         int queue = ieee80211_ac_from_tid(tid);
 276
 277         if (atomic_dec_return(&local->agg_queue_stop[queue]) == 0)
 278                 ieee80211_wake_queue_by_reason(
 279                         &local->hw, queue,
 280                         IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 281         __release(agg_queue);
 282 }
 283
 284 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
 285 {
 286         struct tid_ampdu_tx *tid_tx = sta->ampdu_mlme.tid_tx[tid];
 287         struct ieee80211_local *local = sta->local;
 288         struct ieee80211_sub_if_data *sdata = sta->sdata;
 289         u16 start_seq_num;
 290         int ret;
 291
 292         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 293
 294         /*
 295          * While we're asking the driver about the aggregation,
 296          * stop the AC queue so that we don't have to worry
 297          * about frames that came in while we were doing that,
 298          * which would require us to put them to the AC pending
 299          * afterwards which just makes the code more complex.
 300          */
 301         ieee80211_stop_queue_agg(local, tid);
 302
 303         clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
 304
 305         /*
 306          * make sure no packets are being processed to get
 307          * valid starting sequence number
 308          */
 309         synchronize_net();
 310
 311         start_seq_num = sta->tid_seq[tid] >> 4;
 312
 313         ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START,
 314                                &sta->sta, tid, &start_seq_num);
 315         if (ret) {
 316 #ifdef CONFIG_MAC80211_HT_DEBUG
 317                 printk(KERN_DEBUG "BA request denied - HW unavailable for"
 318                                         " tid %d\n", tid);
 319 #endif
 320                 spin_lock_bh(&sta->lock);
 321                 rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
 322                 spin_unlock_bh(&sta->lock);
 323
 324                 ieee80211_wake_queue_agg(local, tid);
 325                 call_rcu(&tid_tx->rcu_head, kfree_tid_tx);
 326                 return;
 327         }
 328
 329         /* we can take packets again now */
 330         ieee80211_wake_queue_agg(local, tid);
 331
 332         /* activate the timer for the recipient's addBA response */
 333         mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL);
 334 #ifdef CONFIG_MAC80211_HT_DEBUG
 335         printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
 336 #endif
 337
 338         spin_lock_bh(&sta->lock);
 339         sta->ampdu_mlme.addba_req_num[tid]++;
 340         spin_unlock_bh(&sta->lock);
 341
 342         /* send AddBA request */
 343         ieee80211_send_addba_request(sdata, sta->sta.addr, tid,
 344                                      tid_tx->dialog_token, start_seq_num,
 345                                      0x40, tid_tx->timeout);
 346 }
 347
 348 int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
 349                                   u16 timeout)
 350 {
 351         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 352         struct ieee80211_sub_if_data *sdata = sta->sdata;
 353         struct ieee80211_local *local = sdata->local;
 354         struct tid_ampdu_tx *tid_tx;
 355         int ret = 0;
 356
 357         trace_api_start_tx_ba_session(pubsta, tid);
 358
 359         if (WARN_ON(!local->ops->ampdu_action))
 360                 return -EINVAL;
 361
 362         if ((tid >= STA_TID_NUM) ||
 363             !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION))
 364                 return -EINVAL;
 365
 366 #ifdef CONFIG_MAC80211_HT_DEBUG
 367         printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
 368                pubsta->addr, tid);
 369 #endif /* CONFIG_MAC80211_HT_DEBUG */
 370
 371         /*
 372          * The aggregation code is not prepared to handle
 373          * anything but STA/AP due to the BSSID handling.
 374          * IBSS could work in the code but isn't supported
 375          * by drivers or the standard.
 376          */
 377         if (sdata->vif.type != NL80211_IFTYPE_STATION &&
 378             sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
 379             sdata->vif.type != NL80211_IFTYPE_AP)
 380                 return -EINVAL;
 381
 382         if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
 383 #ifdef CONFIG_MAC80211_HT_DEBUG
 384                 printk(KERN_DEBUG "BA sessions blocked. "
 385                        "Denying BA session request\n");
 386 #endif
 387                 return -EINVAL;
 388         }
 389
 390         spin_lock_bh(&sta->lock);
 391
 392         /* we have tried too many times, receiver does not want A-MPDU */
 393         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
 394                 ret = -EBUSY;
 395                 goto err_unlock_sta;
 396         }
 397
 398         tid_tx = sta->ampdu_mlme.tid_tx[tid];
 399         /* check if the TID is not in aggregation flow already */
 400         if (tid_tx) {
 401 #ifdef CONFIG_MAC80211_HT_DEBUG
 402                 printk(KERN_DEBUG "BA request denied - session is not "
 403                                  "idle on tid %u\n", tid);
 404 #endif /* CONFIG_MAC80211_HT_DEBUG */
 405                 ret = -EAGAIN;
 406                 goto err_unlock_sta;
 407         }
 408
 409         /* prepare A-MPDU MLME for Tx aggregation */
 410         tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
 411         if (!tid_tx) {
 412 #ifdef CONFIG_MAC80211_HT_DEBUG
 413                 if (net_ratelimit())
 414                         printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
 415                                         tid);
 416 #endif
 417                 ret = -ENOMEM;
 418                 goto err_unlock_sta;
 419         }
 420
 421         skb_queue_head_init(&tid_tx->pending);
 422         __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state);
 423
 424         tid_tx->timeout = timeout;
 425
 426         /* Tx timer */
 427         tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired;
 428         tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid];
 429         init_timer(&tid_tx->addba_resp_timer);
 430
 431         /* assign a dialog token */
 432         sta->ampdu_mlme.dialog_token_allocator++;
 433         tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
 434
 435         /* finally, assign it to the array */
 436         rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
 437
 438         ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 439
 440         /* this flow continues off the work */
 441  err_unlock_sta:
 442         spin_unlock_bh(&sta->lock);
 443         return ret;
 444 }
 445 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
 446
 447 /*
 448  * splice packets from the STA's pending to the local pending,
 449  * requires a call to ieee80211_agg_splice_finish later
 450  */
 451 static void __acquires(agg_queue)
 452 ieee80211_agg_splice_packets(struct ieee80211_local *local,
 453                              struct tid_ampdu_tx *tid_tx, u16 tid)
 454 {
 455         int queue = ieee80211_ac_from_tid(tid);
 456         unsigned long flags;
 457
 458         ieee80211_stop_queue_agg(local, tid);
 459
 460         if (WARN(!tid_tx, "TID %d gone but expected when splicing aggregates"
 461                           " from the pending queue\n", tid))
 462                 return;
 463
 464         if (!skb_queue_empty(&tid_tx->pending)) {
 465                 spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
 466                 /* copy over remaining packets */
 467                 skb_queue_splice_tail_init(&tid_tx->pending,
 468                                            &local->pending[queue]);
 469                 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 470         }
 471 }
 472
 473 static void __releases(agg_queue)
 474 ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid)
 475 {
 476         ieee80211_wake_queue_agg(local, tid);
 477 }
 478
 479 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
 480                                          struct sta_info *sta, u16 tid)
 481 {
 482         lockdep_assert_held(&sta->ampdu_mlme.mtx);
 483
 484 #ifdef CONFIG_MAC80211_HT_DEBUG
 485         printk(KERN_DEBUG "Aggregation is on for tid %d\n", tid);
 486 #endif
 487
 488         drv_ampdu_action(local, sta->sdata,
 489                          IEEE80211_AMPDU_TX_OPERATIONAL,
 490                          &sta->sta, tid, NULL);
 491
 492         /*
 493          * synchronize with TX path, while splicing the TX path
 494          * should block so it won't put more packets onto pending.
 495          */
 496         spin_lock_bh(&sta->lock);
 497
 498         ieee80211_agg_splice_packets(local, sta->ampdu_mlme.tid_tx[tid], tid);
 499         /*
 500          * Now mark as operational. This will be visible
 501          * in the TX path, and lets it go lock-free in
 502          * the common case.
 503          */
 504         set_bit(HT_AGG_STATE_OPERATIONAL, &sta->ampdu_mlme.tid_tx[tid]->state);
 505         ieee80211_agg_splice_finish(local, tid);
 506
 507         spin_unlock_bh(&sta->lock);
 508 }
 509
 510 void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid)
 511 {
 512         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 513         struct ieee80211_local *local = sdata->local;
 514         struct sta_info *sta;
 515         struct tid_ampdu_tx *tid_tx;
 516
 517         trace_api_start_tx_ba_cb(sdata, ra, tid);
 518
 519         if (tid >= STA_TID_NUM) {
 520 #ifdef CONFIG_MAC80211_HT_DEBUG
 521                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
 522                                 tid, STA_TID_NUM);
 523 #endif
 524                 return;
 525         }
 526
 527         mutex_lock(&local->sta_mtx);
 528         sta = sta_info_get(sdata, ra);
 529         if (!sta) {
 530                 mutex_unlock(&local->sta_mtx);
 531 #ifdef CONFIG_MAC80211_HT_DEBUG
 532                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
 533 #endif
 534                 return;
 535         }
 536
 537         mutex_lock(&sta->ampdu_mlme.mtx);
 538         tid_tx = sta->ampdu_mlme.tid_tx[tid];
 539
 540         if (WARN_ON(!tid_tx)) {
 541 #ifdef CONFIG_MAC80211_HT_DEBUG
 542                 printk(KERN_DEBUG "addBA was not requested!\n");
 543 #endif
 544                 goto unlock;
 545         }
 546
 547         if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
 548                 goto unlock;
 549
 550         if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state))
 551                 ieee80211_agg_tx_operational(local, sta, tid);
 552
 553  unlock:
 554         mutex_unlock(&sta->ampdu_mlme.mtx);
 555         mutex_unlock(&local->sta_mtx);
 556 }
 557
 558 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif,
 559                                       const u8 *ra, u16 tid)
 560 {
 561         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 562         struct ieee80211_local *local = sdata->local;
 563         struct ieee80211_ra_tid *ra_tid;
 564         struct sk_buff *skb = dev_alloc_skb(0);
 565
 566         if (unlikely(!skb)) {
 567 #ifdef CONFIG_MAC80211_HT_DEBUG
 568                 if (net_ratelimit())
 569                         printk(KERN_WARNING "%s: Not enough memory, "
 570                                "dropping start BA session", sdata->name);
 571 #endif
 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 = sta->ampdu_mlme.tid_tx[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 = sta->ampdu_mlme.tid_tx[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         rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
 699
 700         ieee80211_agg_splice_finish(local, tid);
 701
 702         call_rcu(&tid_tx->rcu_head, kfree_tid_tx);
 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 #ifdef CONFIG_MAC80211_HT_DEBUG
 721                 if (net_ratelimit())
 722                         printk(KERN_WARNING "%s: Not enough memory, "
 723                                "dropping stop BA session", sdata->name);
 724 #endif
 725                 return;
 726         }
 727         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
 728         memcpy(&ra_tid->ra, ra, ETH_ALEN);
 729         ra_tid->tid = tid;
 730
 731         skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_STOP;
 732         skb_queue_tail(&sdata->skb_queue, skb);
 733         ieee80211_queue_work(&local->hw, &sdata->work);
 734 }
 735 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
 736
 737
 738 void ieee80211_process_addba_resp(struct ieee80211_local *local,
 739                                   struct sta_info *sta,
 740                                   struct ieee80211_mgmt *mgmt,
 741                                   size_t len)
 742 {
 743         struct tid_ampdu_tx *tid_tx;
 744         u16 capab, tid;
 745
 746         capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
 747         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 748
 749         mutex_lock(&sta->ampdu_mlme.mtx);
 750
 751         tid_tx = sta->ampdu_mlme.tid_tx[tid];
 752         if (!tid_tx)
 753                 goto out;
 754
 755         if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) {
 756 #ifdef CONFIG_MAC80211_HT_DEBUG
 757                 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
 758 #endif
 759                 goto out;
 760         }
 761
 762         del_timer(&tid_tx->addba_resp_timer);
 763
 764 #ifdef CONFIG_MAC80211_HT_DEBUG
 765         printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid);
 766 #endif
 767
 768         if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
 769                         == WLAN_STATUS_SUCCESS) {
 770                 if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
 771                                      &tid_tx->state)) {
 772                         /* ignore duplicate response */
 773                         goto out;
 774                 }
 775
 776                 if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))
 777                         ieee80211_agg_tx_operational(local, sta, tid);
 778
 779                 sta->ampdu_mlme.addba_req_num[tid] = 0;
 780         } else {
 781                 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR,
 782                                                 true);
 783         }
 784
 785  out:
 786         mutex_unlock(&sta->ampdu_mlme.mtx);
 787 }