net/mac80211/wme.c

   1 /*
   2  * Copyright 2004, Instant802 Networks, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/netdevice.h>
  10 #include <linux/skbuff.h>
  11 #include <linux/module.h>
  12 #include <linux/if_arp.h>
  13 #include <linux/types.h>
  14 #include <net/ip.h>
  15 #include <net/pkt_sched.h>
  16
  17 #include <net/mac80211.h>
  18 #include "ieee80211_i.h"
  19 #include "wme.h"
  20
  21 /* maximum number of hardware queues we support. */
  22 #define QD_MAX_QUEUES (IEEE80211_MAX_AMPDU_QUEUES + IEEE80211_MAX_QUEUES)
  23 /* current number of hardware queues we support. */
  24 #define QD_NUM(hw) ((hw)->queues + (hw)->ampdu_queues)
  25
  26 /*
  27  * Default mapping in classifier to work with default
  28  * queue setup.
  29  */
  30 const int ieee802_1d_to_ac[8] = { 2, 3, 3, 2, 1, 1, 0, 0 };
  31
  32 struct ieee80211_sched_data
  33 {
  34         unsigned long qdisc_pool[BITS_TO_LONGS(QD_MAX_QUEUES)];
  35         struct tcf_proto *filter_list;
  36         struct Qdisc *queues[QD_MAX_QUEUES];
  37         struct sk_buff_head requeued[QD_MAX_QUEUES];
  38 };
  39
  40 static const char llc_ip_hdr[8] = {0xAA, 0xAA, 0x3, 0, 0, 0, 0x08, 0};
  41
  42 /* given a data frame determine the 802.1p/1d tag to use */
  43 static inline unsigned classify_1d(struct sk_buff *skb, struct Qdisc *qd)
  44 {
  45         struct iphdr *ip;
  46         int dscp;
  47         int offset;
  48
  49         struct ieee80211_sched_data *q = qdisc_priv(qd);
  50         struct tcf_result res = { -1, 0 };
  51
  52         /* if there is a user set filter list, call out to that */
  53         if (q->filter_list) {
  54                 tc_classify(skb, q->filter_list, &res);
  55                 if (res.class != -1)
  56                         return res.class;
  57         }
  58
  59         /* skb->priority values from 256->263 are magic values to
  60          * directly indicate a specific 802.1d priority.
  61          * This is used to allow 802.1d priority to be passed directly in
  62          * from VLAN tags, etc. */
  63         if (skb->priority >= 256 && skb->priority <= 263)
  64                 return skb->priority - 256;
  65
  66         /* check there is a valid IP header present */
  67         offset = ieee80211_get_hdrlen_from_skb(skb);
  68         if (skb->len < offset + sizeof(llc_ip_hdr) + sizeof(*ip) ||
  69             memcmp(skb->data + offset, llc_ip_hdr, sizeof(llc_ip_hdr)))
  70                 return 0;
  71
  72         ip = (struct iphdr *) (skb->data + offset + sizeof(llc_ip_hdr));
  73
  74         dscp = ip->tos & 0xfc;
  75         if (dscp & 0x1c)
  76                 return 0;
  77         return dscp >> 5;
  78 }
  79
  80
  81 static inline int wme_downgrade_ac(struct sk_buff *skb)
  82 {
  83         switch (skb->priority) {
  84         case 6:
  85         case 7:
  86                 skb->priority = 5; /* VO -> VI */
  87                 return 0;
  88         case 4:
  89         case 5:
  90                 skb->priority = 3; /* VI -> BE */
  91                 return 0;
  92         case 0:
  93         case 3:
  94                 skb->priority = 2; /* BE -> BK */
  95                 return 0;
  96         default:
  97                 return -1;
  98         }
  99 }
 100
 101
 102 /* positive return value indicates which queue to use
 103  * negative return value indicates to drop the frame */
 104 static int classify80211(struct sk_buff *skb, struct Qdisc *qd)
 105 {
 106         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 107         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 108
 109         if (!ieee80211_is_data(hdr->frame_control)) {
 110                 /* management frames go on AC_VO queue, but are sent
 111                 * without QoS control fields */
 112                 return 0;
 113         }
 114
 115         if (0 /* injected */) {
 116                 /* use AC from radiotap */
 117         }
 118
 119         if (!ieee80211_is_data_qos(hdr->frame_control)) {
 120                 skb->priority = 0; /* required for correct WPA/11i MIC */
 121                 return ieee802_1d_to_ac[skb->priority];
 122         }
 123
 124         /* use the data classifier to determine what 802.1d tag the
 125          * data frame has */
 126         skb->priority = classify_1d(skb, qd);
 127
 128         /* in case we are a client verify acm is not set for this ac */
 129         while (unlikely(local->wmm_acm & BIT(skb->priority))) {
 130                 if (wme_downgrade_ac(skb)) {
 131                         /* No AC with lower priority has acm=0, drop packet. */
 132                         return -1;
 133                 }
 134         }
 135
 136         /* look up which queue to use for frames with this 1d tag */
 137         return ieee802_1d_to_ac[skb->priority];
 138 }
 139
 140
 141 static int wme_qdiscop_enqueue(struct sk_buff *skb, struct Qdisc* qd)
 142 {
 143         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 144         struct ieee80211_hw *hw = &local->hw;
 145         struct ieee80211_sched_data *q = qdisc_priv(qd);
 146         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 147         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 148         struct Qdisc *qdisc;
 149         struct sta_info *sta;
 150         int err, queue;
 151         u8 tid;
 152
 153         if (info->flags & IEEE80211_TX_CTL_REQUEUE) {
 154                 queue = skb_get_queue_mapping(skb);
 155                 rcu_read_lock();
 156                 sta = sta_info_get(local, hdr->addr1);
 157                 tid = skb->priority & QOS_CONTROL_TAG1D_MASK;
 158                 if (sta) {
 159                         int ampdu_queue = sta->tid_to_tx_q[tid];
 160                         if ((ampdu_queue < QD_NUM(hw)) &&
 161                             test_bit(ampdu_queue, q->qdisc_pool)) {
 162                                 queue = ampdu_queue;
 163                                 info->flags |= IEEE80211_TX_CTL_AMPDU;
 164                         } else {
 165                                 info->flags &= ~IEEE80211_TX_CTL_AMPDU;
 166                         }
 167                 }
 168                 rcu_read_unlock();
 169                 skb_queue_tail(&q->requeued[queue], skb);
 170                 qd->q.qlen++;
 171                 return 0;
 172         }
 173
 174         queue = classify80211(skb, qd);
 175
 176         if (unlikely(queue >= local->hw.queues))
 177                 queue = local->hw.queues - 1;
 178
 179         /* now we know the 1d priority, fill in the QoS header if there is one
 180          */
 181         if (ieee80211_is_data_qos(hdr->frame_control)) {
 182                 u8 *p = ieee80211_get_qos_ctl(hdr);
 183                 u8 ack_policy = 0;
 184                 tid = skb->priority & QOS_CONTROL_TAG1D_MASK;
 185                 if (local->wifi_wme_noack_test)
 186                         ack_policy |= QOS_CONTROL_ACK_POLICY_NOACK <<
 187                                         QOS_CONTROL_ACK_POLICY_SHIFT;
 188                 /* qos header is 2 bytes, second reserved */
 189                 *p++ = ack_policy | tid;
 190                 *p = 0;
 191
 192                 rcu_read_lock();
 193
 194                 sta = sta_info_get(local, hdr->addr1);
 195                 if (sta) {
 196                         int ampdu_queue = sta->tid_to_tx_q[tid];
 197                         if ((ampdu_queue < QD_NUM(hw)) &&
 198                             test_bit(ampdu_queue, q->qdisc_pool)) {
 199                                 queue = ampdu_queue;
 200                                 info->flags |= IEEE80211_TX_CTL_AMPDU;
 201                         } else {
 202                                 info->flags &= ~IEEE80211_TX_CTL_AMPDU;
 203                         }
 204                 }
 205
 206                 rcu_read_unlock();
 207         }
 208
 209         if (unlikely(queue < 0)) {
 210                         kfree_skb(skb);
 211                         err = NET_XMIT_DROP;
 212         } else {
 213                 skb_set_queue_mapping(skb, queue);
 214                 qdisc = q->queues[queue];
 215                 err = qdisc->enqueue(skb, qdisc);
 216                 if (err == NET_XMIT_SUCCESS) {
 217                         qd->q.qlen++;
 218                         qd->bstats.bytes += skb->len;
 219                         qd->bstats.packets++;
 220                         return NET_XMIT_SUCCESS;
 221                 }
 222         }
 223         qd->qstats.drops++;
 224         return err;
 225 }
 226
 227
 228 /* TODO: clean up the cases where master_hard_start_xmit
 229  * returns non 0 - it shouldn't ever do that. Once done we
 230  * can remove this function */
 231 static int wme_qdiscop_requeue(struct sk_buff *skb, struct Qdisc* qd)
 232 {
 233         struct ieee80211_sched_data *q = qdisc_priv(qd);
 234         struct Qdisc *qdisc;
 235         int err;
 236
 237         /* we recorded which queue to use earlier! */
 238         qdisc = q->queues[skb_get_queue_mapping(skb)];
 239
 240         if ((err = qdisc->ops->requeue(skb, qdisc)) == 0) {
 241                 qd->q.qlen++;
 242                 return 0;
 243         }
 244         qd->qstats.drops++;
 245         return err;
 246 }
 247
 248
 249 static struct sk_buff *wme_qdiscop_dequeue(struct Qdisc* qd)
 250 {
 251         struct ieee80211_sched_data *q = qdisc_priv(qd);
 252         struct net_device *dev = qd->dev;
 253         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 254         struct ieee80211_hw *hw = &local->hw;
 255         struct sk_buff *skb;
 256         struct Qdisc *qdisc;
 257         int queue;
 258
 259         /* check all the h/w queues in numeric/priority order */
 260         for (queue = 0; queue < QD_NUM(hw); queue++) {
 261                 /* see if there is room in this hardware queue */
 262                 if (__netif_subqueue_stopped(local->mdev, queue) ||
 263                     !test_bit(queue, q->qdisc_pool))
 264                         continue;
 265
 266                 /* there is space - try and get a frame */
 267                 skb = skb_dequeue(&q->requeued[queue]);
 268                 if (skb) {
 269                         qd->q.qlen--;
 270                         return skb;
 271                 }
 272
 273                 qdisc = q->queues[queue];
 274                 skb = qdisc->dequeue(qdisc);
 275                 if (skb) {
 276                         qd->q.qlen--;
 277                         return skb;
 278                 }
 279         }
 280         /* returning a NULL here when all the h/w queues are full means we
 281          * never need to call netif_stop_queue in the driver */
 282         return NULL;
 283 }
 284
 285
 286 static void wme_qdiscop_reset(struct Qdisc* qd)
 287 {
 288         struct ieee80211_sched_data *q = qdisc_priv(qd);
 289         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 290         struct ieee80211_hw *hw = &local->hw;
 291         int queue;
 292
 293         /* QUESTION: should we have some hardware flush functionality here? */
 294
 295         for (queue = 0; queue < QD_NUM(hw); queue++) {
 296                 skb_queue_purge(&q->requeued[queue]);
 297                 qdisc_reset(q->queues[queue]);
 298         }
 299         qd->q.qlen = 0;
 300 }
 301
 302
 303 static void wme_qdiscop_destroy(struct Qdisc* qd)
 304 {
 305         struct ieee80211_sched_data *q = qdisc_priv(qd);
 306         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 307         struct ieee80211_hw *hw = &local->hw;
 308         int queue;
 309
 310         tcf_destroy_chain(&q->filter_list);
 311
 312         for (queue = 0; queue < QD_NUM(hw); queue++) {
 313                 skb_queue_purge(&q->requeued[queue]);
 314                 qdisc_destroy(q->queues[queue]);
 315                 q->queues[queue] = &noop_qdisc;
 316         }
 317 }
 318
 319
 320 /* called whenever parameters are updated on existing qdisc */
 321 static int wme_qdiscop_tune(struct Qdisc *qd, struct nlattr *opt)
 322 {
 323         return 0;
 324 }
 325
 326
 327 /* called during initial creation of qdisc on device */
 328 static int wme_qdiscop_init(struct Qdisc *qd, struct nlattr *opt)
 329 {
 330         struct ieee80211_sched_data *q = qdisc_priv(qd);
 331         struct net_device *dev = qd->dev;
 332         struct ieee80211_local *local;
 333         struct ieee80211_hw *hw;
 334         int err = 0, i;
 335
 336         /* check that device is a mac80211 device */
 337         if (!dev->ieee80211_ptr ||
 338             dev->ieee80211_ptr->wiphy->privid != mac80211_wiphy_privid)
 339                 return -EINVAL;
 340
 341         local = wdev_priv(dev->ieee80211_ptr);
 342         hw = &local->hw;
 343
 344         /* only allow on master dev */
 345         if (dev != local->mdev)
 346                 return -EINVAL;
 347
 348         /* ensure that we are root qdisc */
 349         if (qd->parent != TC_H_ROOT)
 350                 return -EINVAL;
 351
 352         if (qd->flags & TCQ_F_INGRESS)
 353                 return -EINVAL;
 354
 355         /* if options were passed in, set them */
 356         if (opt)
 357                 err = wme_qdiscop_tune(qd, opt);
 358
 359         /* create child queues */
 360         for (i = 0; i < QD_NUM(hw); i++) {
 361                 skb_queue_head_init(&q->requeued[i]);
 362                 q->queues[i] = qdisc_create_dflt(qd->dev, &pfifo_qdisc_ops,
 363                                                  qd->handle);
 364                 if (!q->queues[i]) {
 365                         q->queues[i] = &noop_qdisc;
 366                         printk(KERN_ERR "%s child qdisc %i creation failed\n",
 367                                dev->name, i);
 368                 }
 369         }
 370
 371         /* non-aggregation queues: reserve/mark as used */
 372         for (i = 0; i < local->hw.queues; i++)
 373                 set_bit(i, q->qdisc_pool);
 374
 375         return err;
 376 }
 377
 378 static int wme_qdiscop_dump(struct Qdisc *qd, struct sk_buff *skb)
 379 {
 380         return -1;
 381 }
 382
 383
 384 static int wme_classop_graft(struct Qdisc *qd, unsigned long arg,
 385                              struct Qdisc *new, struct Qdisc **old)
 386 {
 387         struct ieee80211_sched_data *q = qdisc_priv(qd);
 388         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 389         struct ieee80211_hw *hw = &local->hw;
 390         unsigned long queue = arg - 1;
 391
 392         if (queue >= QD_NUM(hw))
 393                 return -EINVAL;
 394
 395         if (!new)
 396                 new = &noop_qdisc;
 397
 398         sch_tree_lock(qd);
 399         *old = q->queues[queue];
 400         q->queues[queue] = new;
 401         qdisc_reset(*old);
 402         sch_tree_unlock(qd);
 403
 404         return 0;
 405 }
 406
 407
 408 static struct Qdisc *
 409 wme_classop_leaf(struct Qdisc *qd, unsigned long arg)
 410 {
 411         struct ieee80211_sched_data *q = qdisc_priv(qd);
 412         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 413         struct ieee80211_hw *hw = &local->hw;
 414         unsigned long queue = arg - 1;
 415
 416         if (queue >= QD_NUM(hw))
 417                 return NULL;
 418
 419         return q->queues[queue];
 420 }
 421
 422
 423 static unsigned long wme_classop_get(struct Qdisc *qd, u32 classid)
 424 {
 425         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 426         struct ieee80211_hw *hw = &local->hw;
 427         unsigned long queue = TC_H_MIN(classid);
 428
 429         if (queue - 1 >= QD_NUM(hw))
 430                 return 0;
 431
 432         return queue;
 433 }
 434
 435
 436 static unsigned long wme_classop_bind(struct Qdisc *qd, unsigned long parent,
 437                                       u32 classid)
 438 {
 439         return wme_classop_get(qd, classid);
 440 }
 441
 442
 443 static void wme_classop_put(struct Qdisc *q, unsigned long cl)
 444 {
 445 }
 446
 447
 448 static int wme_classop_change(struct Qdisc *qd, u32 handle, u32 parent,
 449                               struct nlattr **tca, unsigned long *arg)
 450 {
 451         unsigned long cl = *arg;
 452         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 453         struct ieee80211_hw *hw = &local->hw;
 454
 455         if (cl - 1 > QD_NUM(hw))
 456                 return -ENOENT;
 457
 458         /* TODO: put code to program hardware queue parameters here,
 459          * to allow programming from tc command line */
 460
 461         return 0;
 462 }
 463
 464
 465 /* we don't support deleting hardware queues
 466  * when we add WMM-SA support - TSPECs may be deleted here */
 467 static int wme_classop_delete(struct Qdisc *qd, unsigned long cl)
 468 {
 469         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 470         struct ieee80211_hw *hw = &local->hw;
 471
 472         if (cl - 1 > QD_NUM(hw))
 473                 return -ENOENT;
 474         return 0;
 475 }
 476
 477
 478 static int wme_classop_dump_class(struct Qdisc *qd, unsigned long cl,
 479                                   struct sk_buff *skb, struct tcmsg *tcm)
 480 {
 481         struct ieee80211_sched_data *q = qdisc_priv(qd);
 482         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 483         struct ieee80211_hw *hw = &local->hw;
 484
 485         if (cl - 1 > QD_NUM(hw))
 486                 return -ENOENT;
 487         tcm->tcm_handle = TC_H_MIN(cl);
 488         tcm->tcm_parent = qd->handle;
 489         tcm->tcm_info = q->queues[cl-1]->handle; /* do we need this? */
 490         return 0;
 491 }
 492
 493
 494 static void wme_classop_walk(struct Qdisc *qd, struct qdisc_walker *arg)
 495 {
 496         struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
 497         struct ieee80211_hw *hw = &local->hw;
 498         int queue;
 499
 500         if (arg->stop)
 501                 return;
 502
 503         for (queue = 0; queue < QD_NUM(hw); queue++) {
 504                 if (arg->count < arg->skip) {
 505                         arg->count++;
 506                         continue;
 507                 }
 508                 /* we should return classids for our internal queues here
 509                  * as well as the external ones */
 510                 if (arg->fn(qd, queue+1, arg) < 0) {
 511                         arg->stop = 1;
 512                         break;
 513                 }
 514                 arg->count++;
 515         }
 516 }
 517
 518
 519 static struct tcf_proto ** wme_classop_find_tcf(struct Qdisc *qd,
 520                                                 unsigned long cl)
 521 {
 522         struct ieee80211_sched_data *q = qdisc_priv(qd);
 523
 524         if (cl)
 525                 return NULL;
 526
 527         return &q->filter_list;
 528 }
 529
 530
 531 /* this qdisc is classful (i.e. has classes, some of which may have leaf qdiscs attached)
 532  * - these are the operations on the classes */
 533 static const struct Qdisc_class_ops class_ops =
 534 {
 535         .graft = wme_classop_graft,
 536         .leaf = wme_classop_leaf,
 537
 538         .get = wme_classop_get,
 539         .put = wme_classop_put,
 540         .change = wme_classop_change,
 541         .delete = wme_classop_delete,
 542         .walk = wme_classop_walk,
 543
 544         .tcf_chain = wme_classop_find_tcf,
 545         .bind_tcf = wme_classop_bind,
 546         .unbind_tcf = wme_classop_put,
 547
 548         .dump = wme_classop_dump_class,
 549 };
 550
 551
 552 /* queueing discipline operations */
 553 static struct Qdisc_ops wme_qdisc_ops __read_mostly =
 554 {
 555         .next = NULL,
 556         .cl_ops = &class_ops,
 557         .id = "ieee80211",
 558         .priv_size = sizeof(struct ieee80211_sched_data),
 559
 560         .enqueue = wme_qdiscop_enqueue,
 561         .dequeue = wme_qdiscop_dequeue,
 562         .requeue = wme_qdiscop_requeue,
 563         .drop = NULL, /* drop not needed since we are always the root qdisc */
 564
 565         .init = wme_qdiscop_init,
 566         .reset = wme_qdiscop_reset,
 567         .destroy = wme_qdiscop_destroy,
 568         .change = wme_qdiscop_tune,
 569
 570         .dump = wme_qdiscop_dump,
 571 };
 572
 573
 574 void ieee80211_install_qdisc(struct net_device *dev)
 575 {
 576         struct Qdisc *qdisc;
 577
 578         qdisc = qdisc_create_dflt(dev, &wme_qdisc_ops, TC_H_ROOT);
 579         if (!qdisc) {
 580                 printk(KERN_ERR "%s: qdisc installation failed\n", dev->name);
 581                 return;
 582         }
 583
 584         /* same handle as would be allocated by qdisc_alloc_handle() */
 585         qdisc->handle = 0x80010000;
 586
 587         qdisc_lock_tree(dev);
 588         list_add_tail(&qdisc->list, &dev->qdisc_list);
 589         dev->qdisc_sleeping = qdisc;
 590         qdisc_unlock_tree(dev);
 591 }
 592
 593
 594 int ieee80211_qdisc_installed(struct net_device *dev)
 595 {
 596         return dev->qdisc_sleeping->ops == &wme_qdisc_ops;
 597 }
 598
 599
 600 int ieee80211_wme_register(void)
 601 {
 602         return register_qdisc(&wme_qdisc_ops);
 603 }
 604
 605
 606 void ieee80211_wme_unregister(void)
 607 {
 608         unregister_qdisc(&wme_qdisc_ops);
 609 }
 610
 611 int ieee80211_ht_agg_queue_add(struct ieee80211_local *local,
 612                         struct sta_info *sta, u16 tid)
 613 {
 614         int i;
 615         struct ieee80211_sched_data *q =
 616                         qdisc_priv(local->mdev->qdisc_sleeping);
 617         DECLARE_MAC_BUF(mac);
 618
 619         /* prepare the filter and save it for the SW queue
 620          * matching the received HW queue */
 621
 622         if (!local->hw.ampdu_queues)
 623                 return -EPERM;
 624
 625         /* try to get a Qdisc from the pool */
 626         for (i = local->hw.queues; i < QD_NUM(&local->hw); i++)
 627                 if (!test_and_set_bit(i, q->qdisc_pool)) {
 628                         ieee80211_stop_queue(local_to_hw(local), i);
 629                         sta->tid_to_tx_q[tid] = i;
 630
 631                         /* IF there are already pending packets
 632                          * on this tid first we need to drain them
 633                          * on the previous queue
 634                          * since HT is strict in order */
 635 #ifdef CONFIG_MAC80211_HT_DEBUG
 636                         if (net_ratelimit())
 637                                 printk(KERN_DEBUG "allocated aggregation queue"
 638                                         " %d tid %d addr %s pool=0x%lX\n",
 639                                         i, tid, print_mac(mac, sta->addr),
 640                                         q->qdisc_pool[0]);
 641 #endif /* CONFIG_MAC80211_HT_DEBUG */
 642                         return 0;
 643                 }
 644
 645         return -EAGAIN;
 646 }
 647
 648 /**
 649  * the caller needs to hold local->mdev->queue_lock
 650  */
 651 void ieee80211_ht_agg_queue_remove(struct ieee80211_local *local,
 652                                    struct sta_info *sta, u16 tid,
 653                                    u8 requeue)
 654 {
 655         struct ieee80211_hw *hw = &local->hw;
 656         struct ieee80211_sched_data *q =
 657                 qdisc_priv(local->mdev->qdisc_sleeping);
 658         int agg_queue = sta->tid_to_tx_q[tid];
 659
 660         /* return the qdisc to the pool */
 661         clear_bit(agg_queue, q->qdisc_pool);
 662         sta->tid_to_tx_q[tid] = QD_NUM(hw);
 663
 664         if (requeue)
 665                 ieee80211_requeue(local, agg_queue);
 666         else
 667                 q->queues[agg_queue]->ops->reset(q->queues[agg_queue]);
 668 }
 669
 670 void ieee80211_requeue(struct ieee80211_local *local, int queue)
 671 {
 672         struct Qdisc *root_qd = local->mdev->qdisc_sleeping;
 673         struct ieee80211_sched_data *q = qdisc_priv(root_qd);
 674         struct Qdisc *qdisc = q->queues[queue];
 675         struct sk_buff *skb = NULL;
 676         u32 len;
 677
 678         if (!qdisc || !qdisc->dequeue)
 679                 return;
 680
 681         for (len = qdisc->q.qlen; len > 0; len--) {
 682                 skb = qdisc->dequeue(qdisc);
 683                 root_qd->q.qlen--;
 684                 /* packet will be classified again and */
 685                 /* skb->packet_data->queue will be overridden if needed */
 686                 if (skb)
 687                         wme_qdiscop_enqueue(skb, root_qd);
 688         }
 689 }