net/sched/sch_cbq.c

   1 /*
   2  * net/sched/sch_cbq.c  Class-Based Queueing discipline.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  *
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15 #include <linux/types.h>
  16 #include <linux/kernel.h>
  17 #include <linux/string.h>
  18 #include <linux/errno.h>
  19 #include <linux/skbuff.h>
  20 #include <net/netlink.h>
  21 #include <net/pkt_sched.h>
  22
  23
  24 /*      Class-Based Queueing (CBQ) algorithm.
  25         =======================================
  26
  27         Sources: [1] Sally Floyd and Van Jacobson, "Link-sharing and Resource
  28                  Management Models for Packet Networks",
  29                  IEEE/ACM Transactions on Networking, Vol.3, No.4, 1995
  30
  31                  [2] Sally Floyd, "Notes on CBQ and Guaranteed Service", 1995
  32
  33                  [3] Sally Floyd, "Notes on Class-Based Queueing: Setting
  34                  Parameters", 1996
  35
  36                  [4] Sally Floyd and Michael Speer, "Experimental Results
  37                  for Class-Based Queueing", 1998, not published.
  38
  39         -----------------------------------------------------------------------
  40
  41         Algorithm skeleton was taken from NS simulator cbq.cc.
  42         If someone wants to check this code against the LBL version,
  43         he should take into account that ONLY the skeleton was borrowed,
  44         the implementation is different. Particularly:
  45
  46         --- The WRR algorithm is different. Our version looks more
  47         reasonable (I hope) and works when quanta are allowed to be
  48         less than MTU, which is always the case when real time classes
  49         have small rates. Note, that the statement of [3] is
  50         incomplete, delay may actually be estimated even if class
  51         per-round allotment is less than MTU. Namely, if per-round
  52         allotment is W*r_i, and r_1+...+r_k = r < 1
  53
  54         delay_i <= ([MTU/(W*r_i)]*W*r + W*r + k*MTU)/B
  55
  56         In the worst case we have IntServ estimate with D = W*r+k*MTU
  57         and C = MTU*r. The proof (if correct at all) is trivial.
  58
  59
  60         --- It seems that cbq-2.0 is not very accurate. At least, I cannot
  61         interpret some places, which look like wrong translations
  62         from NS. Anyone is advised to find these differences
  63         and explain to me, why I am wrong 8).
  64
  65         --- Linux has no EOI event, so that we cannot estimate true class
  66         idle time. Workaround is to consider the next dequeue event
  67         as sign that previous packet is finished. This is wrong because of
  68         internal device queueing, but on a permanently loaded link it is true.
  69         Moreover, combined with clock integrator, this scheme looks
  70         very close to an ideal solution.  */
  71
  72 struct cbq_sched_data;
  73
  74
  75 struct cbq_class {
  76         struct Qdisc_class_common common;
  77         struct cbq_class        *next_alive;    /* next class with backlog in this priority band */
  78
  79 /* Parameters */
  80         unsigned char           priority;       /* class priority */
  81         unsigned char           priority2;      /* priority to be used after overlimit */
  82         unsigned char           ewma_log;       /* time constant for idle time calculation */
  83         unsigned char           ovl_strategy;
  84 #ifdef CONFIG_NET_CLS_ACT
  85         unsigned char           police;
  86 #endif
  87
  88         u32                     defmap;
  89
  90         /* Link-sharing scheduler parameters */
  91         long                    maxidle;        /* Class parameters: see below. */
  92         long                    offtime;
  93         long                    minidle;
  94         u32                     avpkt;
  95         struct qdisc_rate_table *R_tab;
  96
  97         /* Overlimit strategy parameters */
  98         void                    (*overlimit)(struct cbq_class *cl);
  99         psched_tdiff_t          penalty;
 100
 101         /* General scheduler (WRR) parameters */
 102         long                    allot;
 103         long                    quantum;        /* Allotment per WRR round */
 104         long                    weight;         /* Relative allotment: see below */
 105
 106         struct Qdisc            *qdisc;         /* Ptr to CBQ discipline */
 107         struct cbq_class        *split;         /* Ptr to split node */
 108         struct cbq_class        *share;         /* Ptr to LS parent in the class tree */
 109         struct cbq_class        *tparent;       /* Ptr to tree parent in the class tree */
 110         struct cbq_class        *borrow;        /* NULL if class is bandwidth limited;
 111                                                    parent otherwise */
 112         struct cbq_class        *sibling;       /* Sibling chain */
 113         struct cbq_class        *children;      /* Pointer to children chain */
 114
 115         struct Qdisc            *q;             /* Elementary queueing discipline */
 116
 117
 118 /* Variables */
 119         unsigned char           cpriority;      /* Effective priority */
 120         unsigned char           delayed;
 121         unsigned char           level;          /* level of the class in hierarchy:
 122                                                    0 for leaf classes, and maximal
 123                                                    level of children + 1 for nodes.
 124                                                  */
 125
 126         psched_time_t           last;           /* Last end of service */
 127         psched_time_t           undertime;
 128         long                    avgidle;
 129         long                    deficit;        /* Saved deficit for WRR */
 130         psched_time_t           penalized;
 131         struct gnet_stats_basic_packed bstats;
 132         struct gnet_stats_queue qstats;
 133         struct gnet_stats_rate_est rate_est;
 134         struct tc_cbq_xstats    xstats;
 135
 136         struct tcf_proto        *filter_list;
 137
 138         int                     refcnt;
 139         int                     filters;
 140
 141         struct cbq_class        *defaults[TC_PRIO_MAX + 1];
 142 };
 143
 144 struct cbq_sched_data {
 145         struct Qdisc_class_hash clhash;                 /* Hash table of all classes */
 146         int                     nclasses[TC_CBQ_MAXPRIO + 1];
 147         unsigned int            quanta[TC_CBQ_MAXPRIO + 1];
 148
 149         struct cbq_class        link;
 150
 151         unsigned int            activemask;
 152         struct cbq_class        *active[TC_CBQ_MAXPRIO + 1];    /* List of all classes
 153                                                                    with backlog */
 154
 155 #ifdef CONFIG_NET_CLS_ACT
 156         struct cbq_class        *rx_class;
 157 #endif
 158         struct cbq_class        *tx_class;
 159         struct cbq_class        *tx_borrowed;
 160         int                     tx_len;
 161         psched_time_t           now;            /* Cached timestamp */
 162         psched_time_t           now_rt;         /* Cached real time */
 163         unsigned int            pmask;
 164
 165         struct hrtimer          delay_timer;
 166         struct qdisc_watchdog   watchdog;       /* Watchdog timer,
 167                                                    started when CBQ has
 168                                                    backlog, but cannot
 169                                                    transmit just now */
 170         psched_tdiff_t          wd_expires;
 171         int                     toplevel;
 172         u32                     hgenerator;
 173 };
 174
 175
 176 #define L2T(cl, len)    qdisc_l2t((cl)->R_tab, len)
 177
 178 static inline struct cbq_class *
 179 cbq_class_lookup(struct cbq_sched_data *q, u32 classid)
 180 {
 181         struct Qdisc_class_common *clc;
 182
 183         clc = qdisc_class_find(&q->clhash, classid);
 184         if (clc == NULL)
 185                 return NULL;
 186         return container_of(clc, struct cbq_class, common);
 187 }
 188
 189 #ifdef CONFIG_NET_CLS_ACT
 190
 191 static struct cbq_class *
 192 cbq_reclassify(struct sk_buff *skb, struct cbq_class *this)
 193 {
 194         struct cbq_class *cl;
 195
 196         for (cl = this->tparent; cl; cl = cl->tparent) {
 197                 struct cbq_class *new = cl->defaults[TC_PRIO_BESTEFFORT];
 198
 199                 if (new != NULL && new != this)
 200                         return new;
 201         }
 202         return NULL;
 203 }
 204
 205 #endif
 206
 207 /* Classify packet. The procedure is pretty complicated, but
 208  * it allows us to combine link sharing and priority scheduling
 209  * transparently.
 210  *
 211  * Namely, you can put link sharing rules (f.e. route based) at root of CBQ,
 212  * so that it resolves to split nodes. Then packets are classified
 213  * by logical priority, or a more specific classifier may be attached
 214  * to the split node.
 215  */
 216
 217 static struct cbq_class *
 218 cbq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
 219 {
 220         struct cbq_sched_data *q = qdisc_priv(sch);
 221         struct cbq_class *head = &q->link;
 222         struct cbq_class **defmap;
 223         struct cbq_class *cl = NULL;
 224         u32 prio = skb->priority;
 225         struct tcf_result res;
 226
 227         /*
 228          *  Step 1. If skb->priority points to one of our classes, use it.
 229          */
 230         if (TC_H_MAJ(prio ^ sch->handle) == 0 &&
 231             (cl = cbq_class_lookup(q, prio)) != NULL)
 232                 return cl;
 233
 234         *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
 235         for (;;) {
 236                 int result = 0;
 237                 defmap = head->defaults;
 238
 239                 /*
 240                  * Step 2+n. Apply classifier.
 241                  */
 242                 if (!head->filter_list ||
 243                     (result = tc_classify_compat(skb, head->filter_list, &res)) < 0)
 244                         goto fallback;
 245
 246                 cl = (void *)res.class;
 247                 if (!cl) {
 248                         if (TC_H_MAJ(res.classid))
 249                                 cl = cbq_class_lookup(q, res.classid);
 250                         else if ((cl = defmap[res.classid & TC_PRIO_MAX]) == NULL)
 251                                 cl = defmap[TC_PRIO_BESTEFFORT];
 252
 253                         if (cl == NULL)
 254                                 goto fallback;
 255                 }
 256                 if (cl->level >= head->level)
 257                         goto fallback;
 258 #ifdef CONFIG_NET_CLS_ACT
 259                 switch (result) {
 260                 case TC_ACT_QUEUED:
 261                 case TC_ACT_STOLEN:
 262                         *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
 263                 case TC_ACT_SHOT:
 264                         return NULL;
 265                 case TC_ACT_RECLASSIFY:
 266                         return cbq_reclassify(skb, cl);
 267                 }
 268 #endif
 269                 if (cl->level == 0)
 270                         return cl;
 271
 272                 /*
 273                  * Step 3+n. If classifier selected a link sharing class,
 274                  *         apply agency specific classifier.
 275                  *         Repeat this procdure until we hit a leaf node.
 276                  */
 277                 head = cl;
 278         }
 279
 280 fallback:
 281         cl = head;
 282
 283         /*
 284          * Step 4. No success...
 285          */
 286         if (TC_H_MAJ(prio) == 0 &&
 287             !(cl = head->defaults[prio & TC_PRIO_MAX]) &&
 288             !(cl = head->defaults[TC_PRIO_BESTEFFORT]))
 289                 return head;
 290
 291         return cl;
 292 }
 293
 294 /*
 295  * A packet has just been enqueued on the empty class.
 296  * cbq_activate_class adds it to the tail of active class list
 297  * of its priority band.
 298  */
 299
 300 static inline void cbq_activate_class(struct cbq_class *cl)
 301 {
 302         struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
 303         int prio = cl->cpriority;
 304         struct cbq_class *cl_tail;
 305
 306         cl_tail = q->active[prio];
 307         q->active[prio] = cl;
 308
 309         if (cl_tail != NULL) {
 310                 cl->next_alive = cl_tail->next_alive;
 311                 cl_tail->next_alive = cl;
 312         } else {
 313                 cl->next_alive = cl;
 314                 q->activemask |= (1<<prio);
 315         }
 316 }
 317
 318 /*
 319  * Unlink class from active chain.
 320  * Note that this same procedure is done directly in cbq_dequeue*
 321  * during round-robin procedure.
 322  */
 323
 324 static void cbq_deactivate_class(struct cbq_class *this)
 325 {
 326         struct cbq_sched_data *q = qdisc_priv(this->qdisc);
 327         int prio = this->cpriority;
 328         struct cbq_class *cl;
 329         struct cbq_class *cl_prev = q->active[prio];
 330
 331         do {
 332                 cl = cl_prev->next_alive;
 333                 if (cl == this) {
 334                         cl_prev->next_alive = cl->next_alive;
 335                         cl->next_alive = NULL;
 336
 337                         if (cl == q->active[prio]) {
 338                                 q->active[prio] = cl_prev;
 339                                 if (cl == q->active[prio]) {
 340                                         q->active[prio] = NULL;
 341                                         q->activemask &= ~(1<<prio);
 342                                         return;
 343                                 }
 344                         }
 345                         return;
 346                 }
 347         } while ((cl_prev = cl) != q->active[prio]);
 348 }
 349
 350 static void
 351 cbq_mark_toplevel(struct cbq_sched_data *q, struct cbq_class *cl)
 352 {
 353         int toplevel = q->toplevel;
 354
 355         if (toplevel > cl->level && !(qdisc_is_throttled(cl->q))) {
 356                 psched_time_t now;
 357                 psched_tdiff_t incr;
 358
 359                 now = psched_get_time();
 360                 incr = now - q->now_rt;
 361                 now = q->now + incr;
 362
 363                 do {
 364                         if (cl->undertime < now) {
 365                                 q->toplevel = cl->level;
 366                                 return;
 367                         }
 368                 } while ((cl = cl->borrow) != NULL && toplevel > cl->level);
 369         }
 370 }
 371
 372 static int
 373 cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 374 {
 375         struct cbq_sched_data *q = qdisc_priv(sch);
 376         int uninitialized_var(ret);
 377         struct cbq_class *cl = cbq_classify(skb, sch, &ret);
 378
 379 #ifdef CONFIG_NET_CLS_ACT
 380         q->rx_class = cl;
 381 #endif
 382         if (cl == NULL) {
 383                 if (ret & __NET_XMIT_BYPASS)
 384                         sch->qstats.drops++;
 385                 kfree_skb(skb);
 386                 return ret;
 387         }
 388
 389 #ifdef CONFIG_NET_CLS_ACT
 390         cl->q->__parent = sch;
 391 #endif
 392         ret = qdisc_enqueue(skb, cl->q);
 393         if (ret == NET_XMIT_SUCCESS) {
 394                 sch->q.qlen++;
 395                 cbq_mark_toplevel(q, cl);
 396                 if (!cl->next_alive)
 397                         cbq_activate_class(cl);
 398                 return ret;
 399         }
 400
 401         if (net_xmit_drop_count(ret)) {
 402                 sch->qstats.drops++;
 403                 cbq_mark_toplevel(q, cl);
 404                 cl->qstats.drops++;
 405         }
 406         return ret;
 407 }
 408
 409 /* Overlimit actions */
 410
 411 /* TC_CBQ_OVL_CLASSIC: (default) penalize leaf class by adding offtime */
 412
 413 static void cbq_ovl_classic(struct cbq_class *cl)
 414 {
 415         struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
 416         psched_tdiff_t delay = cl->undertime - q->now;
 417
 418         if (!cl->delayed) {
 419                 delay += cl->offtime;
 420
 421                 /*
 422                  * Class goes to sleep, so that it will have no
 423                  * chance to work avgidle. Let's forgive it 8)
 424                  *
 425                  * BTW cbq-2.0 has a crap in this
 426                  * place, apparently they forgot to shift it by cl->ewma_log.
 427                  */
 428                 if (cl->avgidle < 0)
 429                         delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log);
 430                 if (cl->avgidle < cl->minidle)
 431                         cl->avgidle = cl->minidle;
 432                 if (delay <= 0)
 433                         delay = 1;
 434                 cl->undertime = q->now + delay;
 435
 436                 cl->xstats.overactions++;
 437                 cl->delayed = 1;
 438         }
 439         if (q->wd_expires == 0 || q->wd_expires > delay)
 440                 q->wd_expires = delay;
 441
 442         /* Dirty work! We must schedule wakeups based on
 443          * real available rate, rather than leaf rate,
 444          * which may be tiny (even zero).
 445          */
 446         if (q->toplevel == TC_CBQ_MAXLEVEL) {
 447                 struct cbq_class *b;
 448                 psched_tdiff_t base_delay = q->wd_expires;
 449
 450                 for (b = cl->borrow; b; b = b->borrow) {
 451                         delay = b->undertime - q->now;
 452                         if (delay < base_delay) {
 453                                 if (delay <= 0)
 454                                         delay = 1;
 455                                 base_delay = delay;
 456                         }
 457                 }
 458
 459                 q->wd_expires = base_delay;
 460         }
 461 }
 462
 463 /* TC_CBQ_OVL_RCLASSIC: penalize by offtime classes in hierarchy, when
 464  * they go overlimit
 465  */
 466
 467 static void cbq_ovl_rclassic(struct cbq_class *cl)
 468 {
 469         struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
 470         struct cbq_class *this = cl;
 471
 472         do {
 473                 if (cl->level > q->toplevel) {
 474                         cl = NULL;
 475                         break;
 476                 }
 477         } while ((cl = cl->borrow) != NULL);
 478
 479         if (cl == NULL)
 480                 cl = this;
 481         cbq_ovl_classic(cl);
 482 }
 483
 484 /* TC_CBQ_OVL_DELAY: delay until it will go to underlimit */
 485
 486 static void cbq_ovl_delay(struct cbq_class *cl)
 487 {
 488         struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
 489         psched_tdiff_t delay = cl->undertime - q->now;
 490
 491         if (test_bit(__QDISC_STATE_DEACTIVATED,
 492                      &qdisc_root_sleeping(cl->qdisc)->state))
 493                 return;
 494
 495         if (!cl->delayed) {
 496                 psched_time_t sched = q->now;
 497                 ktime_t expires;
 498
 499                 delay += cl->offtime;
 500                 if (cl->avgidle < 0)
 501                         delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log);
 502                 if (cl->avgidle < cl->minidle)
 503                         cl->avgidle = cl->minidle;
 504                 cl->undertime = q->now + delay;
 505
 506                 if (delay > 0) {
 507                         sched += delay + cl->penalty;
 508                         cl->penalized = sched;
 509                         cl->cpriority = TC_CBQ_MAXPRIO;
 510                         q->pmask |= (1<<TC_CBQ_MAXPRIO);
 511
 512                         expires = ktime_set(0, 0);
 513                         expires = ktime_add_ns(expires, PSCHED_TICKS2NS(sched));
 514                         if (hrtimer_try_to_cancel(&q->delay_timer) &&
 515                             ktime_to_ns(ktime_sub(
 516                                         hrtimer_get_expires(&q->delay_timer),
 517                                         expires)) > 0)
 518                                 hrtimer_set_expires(&q->delay_timer, expires);
 519                         hrtimer_restart(&q->delay_timer);
 520                         cl->delayed = 1;
 521                         cl->xstats.overactions++;
 522                         return;
 523                 }
 524                 delay = 1;
 525         }
 526         if (q->wd_expires == 0 || q->wd_expires > delay)
 527                 q->wd_expires = delay;
 528 }
 529
 530 /* TC_CBQ_OVL_LOWPRIO: penalize class by lowering its priority band */
 531
 532 static void cbq_ovl_lowprio(struct cbq_class *cl)
 533 {
 534         struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
 535
 536         cl->penalized = q->now + cl->penalty;
 537
 538         if (cl->cpriority != cl->priority2) {
 539                 cl->cpriority = cl->priority2;
 540                 q->pmask |= (1<<cl->cpriority);
 541                 cl->xstats.overactions++;
 542         }
 543         cbq_ovl_classic(cl);
 544 }
 545
 546 /* TC_CBQ_OVL_DROP: penalize class by dropping */
 547
 548 static void cbq_ovl_drop(struct cbq_class *cl)
 549 {
 550         if (cl->q->ops->drop)
 551                 if (cl->q->ops->drop(cl->q))
 552                         cl->qdisc->q.qlen--;
 553         cl->xstats.overactions++;
 554         cbq_ovl_classic(cl);
 555 }
 556
 557 static psched_tdiff_t cbq_undelay_prio(struct cbq_sched_data *q, int prio,
 558                                        psched_time_t now)
 559 {
 560         struct cbq_class *cl;
 561         struct cbq_class *cl_prev = q->active[prio];
 562         psched_time_t sched = now;
 563
 564         if (cl_prev == NULL)
 565                 return 0;
 566
 567         do {
 568                 cl = cl_prev->next_alive;
 569                 if (now - cl->penalized > 0) {
 570                         cl_prev->next_alive = cl->next_alive;
 571                         cl->next_alive = NULL;
 572                         cl->cpriority = cl->priority;
 573                         cl->delayed = 0;
 574                         cbq_activate_class(cl);
 575
 576                         if (cl == q->active[prio]) {
 577                                 q->active[prio] = cl_prev;
 578                                 if (cl == q->active[prio]) {
 579                                         q->active[prio] = NULL;
 580                                         return 0;
 581                                 }
 582                         }
 583
 584                         cl = cl_prev->next_alive;
 585                 } else if (sched - cl->penalized > 0)
 586                         sched = cl->penalized;
 587         } while ((cl_prev = cl) != q->active[prio]);
 588
 589         return sched - now;
 590 }
 591
 592 static enum hrtimer_restart cbq_undelay(struct hrtimer *timer)
 593 {
 594         struct cbq_sched_data *q = container_of(timer, struct cbq_sched_data,
 595                                                 delay_timer);
 596         struct Qdisc *sch = q->watchdog.qdisc;
 597         psched_time_t now;
 598         psched_tdiff_t delay = 0;
 599         unsigned int pmask;
 600
 601         now = psched_get_time();
 602
 603         pmask = q->pmask;
 604         q->pmask = 0;
 605
 606         while (pmask) {
 607                 int prio = ffz(~pmask);
 608                 psched_tdiff_t tmp;
 609
 610                 pmask &= ~(1<<prio);
 611
 612                 tmp = cbq_undelay_prio(q, prio, now);
 613                 if (tmp > 0) {
 614                         q->pmask |= 1<<prio;
 615                         if (tmp < delay || delay == 0)
 616                                 delay = tmp;
 617                 }
 618         }
 619
 620         if (delay) {
 621                 ktime_t time;
 622
 623                 time = ktime_set(0, 0);
 624                 time = ktime_add_ns(time, PSCHED_TICKS2NS(now + delay));
 625                 hrtimer_start(&q->delay_timer, time, HRTIMER_MODE_ABS);
 626         }
 627
 628         qdisc_unthrottled(sch);
 629         __netif_schedule(qdisc_root(sch));
 630         return HRTIMER_NORESTART;
 631 }
 632
 633 #ifdef CONFIG_NET_CLS_ACT
 634 static int cbq_reshape_fail(struct sk_buff *skb, struct Qdisc *child)
 635 {
 636         struct Qdisc *sch = child->__parent;
 637         struct cbq_sched_data *q = qdisc_priv(sch);
 638         struct cbq_class *cl = q->rx_class;
 639
 640         q->rx_class = NULL;
 641
 642         if (cl && (cl = cbq_reclassify(skb, cl)) != NULL) {
 643                 int ret;
 644
 645                 cbq_mark_toplevel(q, cl);
 646
 647                 q->rx_class = cl;
 648                 cl->q->__parent = sch;
 649
 650                 ret = qdisc_enqueue(skb, cl->q);
 651                 if (ret == NET_XMIT_SUCCESS) {
 652                         sch->q.qlen++;
 653                         if (!cl->next_alive)
 654                                 cbq_activate_class(cl);
 655                         return 0;
 656                 }
 657                 if (net_xmit_drop_count(ret))
 658                         sch->qstats.drops++;
 659                 return 0;
 660         }
 661
 662         sch->qstats.drops++;
 663         return -1;
 664 }
 665 #endif
 666
 667 /*
 668  * It is mission critical procedure.
 669  *
 670  * We "regenerate" toplevel cutoff, if transmitting class
 671  * has backlog and it is not regulated. It is not part of
 672  * original CBQ description, but looks more reasonable.
 673  * Probably, it is wrong. This question needs further investigation.
 674  */
 675
 676 static inline void
 677 cbq_update_toplevel(struct cbq_sched_data *q, struct cbq_class *cl,
 678                     struct cbq_class *borrowed)
 679 {
 680         if (cl && q->toplevel >= borrowed->level) {
 681                 if (cl->q->q.qlen > 1) {
 682                         do {
 683                                 if (borrowed->undertime == PSCHED_PASTPERFECT) {
 684                                         q->toplevel = borrowed->level;
 685                                         return;
 686                                 }
 687                         } while ((borrowed = borrowed->borrow) != NULL);
 688                 }
 689 #if 0
 690         /* It is not necessary now. Uncommenting it
 691            will save CPU cycles, but decrease fairness.
 692          */
 693                 q->toplevel = TC_CBQ_MAXLEVEL;
 694 #endif
 695         }
 696 }
 697
 698 static void
 699 cbq_update(struct cbq_sched_data *q)
 700 {
 701         struct cbq_class *this = q->tx_class;
 702         struct cbq_class *cl = this;
 703         int len = q->tx_len;
 704
 705         q->tx_class = NULL;
 706
 707         for ( ; cl; cl = cl->share) {
 708                 long avgidle = cl->avgidle;
 709                 long idle;
 710
 711                 cl->bstats.packets++;
 712                 cl->bstats.bytes += len;
 713
 714                 /*
 715                  * (now - last) is total time between packet right edges.
 716                  * (last_pktlen/rate) is "virtual" busy time, so that
 717                  *
 718                  *      idle = (now - last) - last_pktlen/rate
 719                  */
 720
 721                 idle = q->now - cl->last;
 722                 if ((unsigned long)idle > 128*1024*1024) {
 723                         avgidle = cl->maxidle;
 724                 } else {
 725                         idle -= L2T(cl, len);
 726
 727                 /* true_avgidle := (1-W)*true_avgidle + W*idle,
 728                  * where W=2^{-ewma_log}. But cl->avgidle is scaled:
 729                  * cl->avgidle == true_avgidle/W,
 730                  * hence:
 731                  */
 732                         avgidle += idle - (avgidle>>cl->ewma_log);
 733                 }
 734
 735                 if (avgidle <= 0) {
 736                         /* Overlimit or at-limit */
 737
 738                         if (avgidle < cl->minidle)
 739                                 avgidle = cl->minidle;
 740
 741                         cl->avgidle = avgidle;
 742
 743                         /* Calculate expected time, when this class
 744                          * will be allowed to send.
 745                          * It will occur, when:
 746                          * (1-W)*true_avgidle + W*delay = 0, i.e.
 747                          * idle = (1/W - 1)*(-true_avgidle)
 748                          * or
 749                          * idle = (1 - W)*(-cl->avgidle);
 750                          */
 751                         idle = (-avgidle) - ((-avgidle) >> cl->ewma_log);
 752
 753                         /*
 754                          * That is not all.
 755                          * To maintain the rate allocated to the class,
 756                          * we add to undertime virtual clock,
 757                          * necessary to complete transmitted packet.
 758                          * (len/phys_bandwidth has been already passed
 759                          * to the moment of cbq_update)
 760                          */
 761
 762                         idle -= L2T(&q->link, len);
 763                         idle += L2T(cl, len);
 764
 765                         cl->undertime = q->now + idle;
 766                 } else {
 767                         /* Underlimit */
 768
 769                         cl->undertime = PSCHED_PASTPERFECT;
 770                         if (avgidle > cl->maxidle)
 771                                 cl->avgidle = cl->maxidle;
 772                         else
 773                                 cl->avgidle = avgidle;
 774                 }
 775                 cl->last = q->now;
 776         }
 777
 778         cbq_update_toplevel(q, this, q->tx_borrowed);
 779 }
 780
 781 static inline struct cbq_class *
 782 cbq_under_limit(struct cbq_class *cl)
 783 {
 784         struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
 785         struct cbq_class *this_cl = cl;
 786
 787         if (cl->tparent == NULL)
 788                 return cl;
 789
 790         if (cl->undertime == PSCHED_PASTPERFECT || q->now >= cl->undertime) {
 791                 cl->delayed = 0;
 792                 return cl;
 793         }
 794
 795         do {
 796                 /* It is very suspicious place. Now overlimit
 797                  * action is generated for not bounded classes
 798                  * only if link is completely congested.
 799                  * Though it is in agree with ancestor-only paradigm,
 800                  * it looks very stupid. Particularly,
 801                  * it means that this chunk of code will either
 802                  * never be called or result in strong amplification
 803                  * of burstiness. Dangerous, silly, and, however,
 804                  * no another solution exists.
 805                  */
 806                 cl = cl->borrow;
 807                 if (!cl) {
 808                         this_cl->qstats.overlimits++;
 809                         this_cl->overlimit(this_cl);
 810                         return NULL;
 811                 }
 812                 if (cl->level > q->toplevel)
 813                         return NULL;
 814         } while (cl->undertime != PSCHED_PASTPERFECT && q->now < cl->undertime);
 815
 816         cl->delayed = 0;
 817         return cl;
 818 }
 819
 820 static inline struct sk_buff *
 821 cbq_dequeue_prio(struct Qdisc *sch, int prio)
 822 {
 823         struct cbq_sched_data *q = qdisc_priv(sch);
 824         struct cbq_class *cl_tail, *cl_prev, *cl;
 825         struct sk_buff *skb;
 826         int deficit;
 827
 828         cl_tail = cl_prev = q->active[prio];
 829         cl = cl_prev->next_alive;
 830
 831         do {
 832                 deficit = 0;
 833
 834                 /* Start round */
 835                 do {
 836                         struct cbq_class *borrow = cl;
 837
 838                         if (cl->q->q.qlen &&
 839                             (borrow = cbq_under_limit(cl)) == NULL)
 840                                 goto skip_class;
 841
 842                         if (cl->deficit <= 0) {
 843                                 /* Class exhausted its allotment per
 844                                  * this round. Switch to the next one.
 845                                  */
 846                                 deficit = 1;
 847                                 cl->deficit += cl->quantum;
 848                                 goto next_class;
 849                         }
 850
 851                         skb = cl->q->dequeue(cl->q);
 852
 853                         /* Class did not give us any skb :-(
 854                          * It could occur even if cl->q->q.qlen != 0
 855                          * f.e. if cl->q == "tbf"
 856                          */
 857                         if (skb == NULL)
 858                                 goto skip_class;
 859
 860                         cl->deficit -= qdisc_pkt_len(skb);
 861                         q->tx_class = cl;
 862                         q->tx_borrowed = borrow;
 863                         if (borrow != cl) {
 864 #ifndef CBQ_XSTATS_BORROWS_BYTES
 865                                 borrow->xstats.borrows++;
 866                                 cl->xstats.borrows++;
 867 #else
 868                                 borrow->xstats.borrows += qdisc_pkt_len(skb);
 869                                 cl->xstats.borrows += qdisc_pkt_len(skb);
 870 #endif
 871                         }
 872                         q->tx_len = qdisc_pkt_len(skb);
 873
 874                         if (cl->deficit <= 0) {
 875                                 q->active[prio] = cl;
 876                                 cl = cl->next_alive;
 877                                 cl->deficit += cl->quantum;
 878                         }
 879                         return skb;
 880
 881 skip_class:
 882                         if (cl->q->q.qlen == 0 || prio != cl->cpriority) {
 883                                 /* Class is empty or penalized.
 884                                  * Unlink it from active chain.
 885                                  */
 886                                 cl_prev->next_alive = cl->next_alive;
 887                                 cl->next_alive = NULL;
 888
 889                                 /* Did cl_tail point to it? */
 890                                 if (cl == cl_tail) {
 891                                         /* Repair it! */
 892                                         cl_tail = cl_prev;
 893
 894                                         /* Was it the last class in this band? */
 895                                         if (cl == cl_tail) {
 896                                                 /* Kill the band! */
 897                                                 q->active[prio] = NULL;
 898                                                 q->activemask &= ~(1<<prio);
 899                                                 if (cl->q->q.qlen)
 900                                                         cbq_activate_class(cl);
 901                                                 return NULL;
 902                                         }
 903
 904                                         q->active[prio] = cl_tail;
 905                                 }
 906                                 if (cl->q->q.qlen)
 907                                         cbq_activate_class(cl);
 908
 909                                 cl = cl_prev;
 910                         }
 911
 912 next_class:
 913                         cl_prev = cl;
 914                         cl = cl->next_alive;
 915                 } while (cl_prev != cl_tail);
 916         } while (deficit);
 917
 918         q->active[prio] = cl_prev;
 919
 920         return NULL;
 921 }
 922
 923 static inline struct sk_buff *
 924 cbq_dequeue_1(struct Qdisc *sch)
 925 {
 926         struct cbq_sched_data *q = qdisc_priv(sch);
 927         struct sk_buff *skb;
 928         unsigned int activemask;
 929
 930         activemask = q->activemask & 0xFF;
 931         while (activemask) {
 932                 int prio = ffz(~activemask);
 933                 activemask &= ~(1<<prio);
 934                 skb = cbq_dequeue_prio(sch, prio);
 935                 if (skb)
 936                         return skb;
 937         }
 938         return NULL;
 939 }
 940
 941 static struct sk_buff *
 942 cbq_dequeue(struct Qdisc *sch)
 943 {
 944         struct sk_buff *skb;
 945         struct cbq_sched_data *q = qdisc_priv(sch);
 946         psched_time_t now;
 947         psched_tdiff_t incr;
 948
 949         now = psched_get_time();
 950         incr = now - q->now_rt;
 951
 952         if (q->tx_class) {
 953                 psched_tdiff_t incr2;
 954                 /* Time integrator. We calculate EOS time
 955                  * by adding expected packet transmission time.
 956                  * If real time is greater, we warp artificial clock,
 957                  * so that:
 958                  *
 959                  * cbq_time = max(real_time, work);
 960                  */
 961                 incr2 = L2T(&q->link, q->tx_len);
 962                 q->now += incr2;
 963                 cbq_update(q);
 964                 if ((incr -= incr2) < 0)
 965                         incr = 0;
 966                 q->now += incr;
 967         } else {
 968                 if (now > q->now)
 969                         q->now = now;
 970         }
 971         q->now_rt = now;
 972
 973         for (;;) {
 974                 q->wd_expires = 0;
 975
 976                 skb = cbq_dequeue_1(sch);
 977                 if (skb) {
 978                         qdisc_bstats_update(sch, skb);
 979                         sch->q.qlen--;
 980                         qdisc_unthrottled(sch);
 981                         return skb;
 982                 }
 983
 984                 /* All the classes are overlimit.
 985                  *
 986                  * It is possible, if:
 987                  *
 988                  * 1. Scheduler is empty.
 989                  * 2. Toplevel cutoff inhibited borrowing.
 990                  * 3. Root class is overlimit.
 991                  *
 992                  * Reset 2d and 3d conditions and retry.
 993                  *
 994                  * Note, that NS and cbq-2.0 are buggy, peeking
 995                  * an arbitrary class is appropriate for ancestor-only
 996                  * sharing, but not for toplevel algorithm.
 997                  *
 998                  * Our version is better, but slower, because it requires
 999                  * two passes, but it is unavoidable with top-level sharing.
1000                  */
1001
1002                 if (q->toplevel == TC_CBQ_MAXLEVEL &&
1003                     q->link.undertime == PSCHED_PASTPERFECT)
1004                         break;
1005
1006                 q->toplevel = TC_CBQ_MAXLEVEL;
1007                 q->link.undertime = PSCHED_PASTPERFECT;
1008         }
1009
1010         /* No packets in scheduler or nobody wants to give them to us :-(
1011          * Sigh... start watchdog timer in the last case.
1012          */
1013
1014         if (sch->q.qlen) {
1015                 sch->qstats.overlimits++;
1016                 if (q->wd_expires)
1017                         qdisc_watchdog_schedule(&q->watchdog,
1018                                                 now + q->wd_expires);
1019         }
1020         return NULL;
1021 }
1022
1023 /* CBQ class maintanance routines */
1024
1025 static void cbq_adjust_levels(struct cbq_class *this)
1026 {
1027         if (this == NULL)
1028                 return;
1029
1030         do {
1031                 int level = 0;
1032                 struct cbq_class *cl;
1033
1034                 cl = this->children;
1035                 if (cl) {
1036                         do {
1037                                 if (cl->level > level)
1038                                         level = cl->level;
1039                         } while ((cl = cl->sibling) != this->children);
1040                 }
1041                 this->level = level + 1;
1042         } while ((this = this->tparent) != NULL);
1043 }
1044
1045 static void cbq_normalize_quanta(struct cbq_sched_data *q, int prio)
1046 {
1047         struct cbq_class *cl;
1048         struct hlist_node *n;
1049         unsigned int h;
1050
1051         if (q->quanta[prio] == 0)
1052                 return;
1053
1054         for (h = 0; h < q->clhash.hashsize; h++) {
1055                 hlist_for_each_entry(cl, n, &q->clhash.hash[h], common.hnode) {
1056                         /* BUGGGG... Beware! This expression suffer of
1057                          * arithmetic overflows!
1058                          */
1059                         if (cl->priority == prio) {
1060                                 cl->quantum = (cl->weight*cl->allot*q->nclasses[prio])/
1061                                         q->quanta[prio];
1062                         }
1063                         if (cl->quantum <= 0 || cl->quantum>32*qdisc_dev(cl->qdisc)->mtu) {
1064                                 pr_warning("CBQ: class %08x has bad quantum==%ld, repaired.\n",
1065                                            cl->common.classid, cl->quantum);
1066                                 cl->quantum = qdisc_dev(cl->qdisc)->mtu/2 + 1;
1067                         }
1068                 }
1069         }
1070 }
1071
1072 static void cbq_sync_defmap(struct cbq_class *cl)
1073 {
1074         struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
1075         struct cbq_class *split = cl->split;
1076         unsigned int h;
1077         int i;
1078
1079         if (split == NULL)
1080                 return;
1081
1082         for (i = 0; i <= TC_PRIO_MAX; i++) {
1083                 if (split->defaults[i] == cl && !(cl->defmap & (1<<i)))
1084                         split->defaults[i] = NULL;
1085         }
1086
1087         for (i = 0; i <= TC_PRIO_MAX; i++) {
1088                 int level = split->level;
1089
1090                 if (split->defaults[i])
1091                         continue;
1092
1093                 for (h = 0; h < q->clhash.hashsize; h++) {
1094                         struct hlist_node *n;
1095                         struct cbq_class *c;
1096
1097                         hlist_for_each_entry(c, n, &q->clhash.hash[h],
1098                                              common.hnode) {
1099                                 if (c->split == split && c->level < level &&
1100                                     c->defmap & (1<<i)) {
1101                                         split->defaults[i] = c;
1102                                         level = c->level;
1103                                 }
1104                         }
1105                 }
1106         }
1107 }
1108
1109 static void cbq_change_defmap(struct cbq_class *cl, u32 splitid, u32 def, u32 mask)
1110 {
1111         struct cbq_class *split = NULL;
1112
1113         if (splitid == 0) {
1114                 split = cl->split;
1115                 if (!split)
1116                         return;
1117                 splitid = split->common.classid;
1118         }
1119
1120         if (split == NULL || split->common.classid != splitid) {
1121                 for (split = cl->tparent; split; split = split->tparent)
1122                         if (split->common.classid == splitid)
1123                                 break;
1124         }
1125
1126         if (split == NULL)
1127                 return;
1128
1129         if (cl->split != split) {
1130                 cl->defmap = 0;
1131                 cbq_sync_defmap(cl);
1132                 cl->split = split;
1133                 cl->defmap = def & mask;
1134         } else
1135                 cl->defmap = (cl->defmap & ~mask) | (def & mask);
1136
1137         cbq_sync_defmap(cl);
1138 }
1139
1140 static void cbq_unlink_class(struct cbq_class *this)
1141 {
1142         struct cbq_class *cl, **clp;
1143         struct cbq_sched_data *q = qdisc_priv(this->qdisc);
1144
1145         qdisc_class_hash_remove(&q->clhash, &this->common);
1146
1147         if (this->tparent) {
1148                 clp = &this->sibling;
1149                 cl = *clp;
1150                 do {
1151                         if (cl == this) {
1152                                 *clp = cl->sibling;
1153                                 break;
1154                         }
1155                         clp = &cl->sibling;
1156                 } while ((cl = *clp) != this->sibling);
1157
1158                 if (this->tparent->children == this) {
1159                         this->tparent->children = this->sibling;
1160                         if (this->sibling == this)
1161                                 this->tparent->children = NULL;
1162                 }
1163         } else {
1164                 WARN_ON(this->sibling != this);
1165         }
1166 }
1167
1168 static void cbq_link_class(struct cbq_class *this)
1169 {
1170         struct cbq_sched_data *q = qdisc_priv(this->qdisc);
1171         struct cbq_class *parent = this->tparent;
1172
1173         this->sibling = this;
1174         qdisc_class_hash_insert(&q->clhash, &this->common);
1175
1176         if (parent == NULL)
1177                 return;
1178
1179         if (parent->children == NULL) {
1180                 parent->children = this;
1181         } else {
1182                 this->sibling = parent->children->sibling;
1183                 parent->children->sibling = this;
1184         }
1185 }
1186
1187 static unsigned int cbq_drop(struct Qdisc *sch)
1188 {
1189         struct cbq_sched_data *q = qdisc_priv(sch);
1190         struct cbq_class *cl, *cl_head;
1191         int prio;
1192         unsigned int len;
1193
1194         for (prio = TC_CBQ_MAXPRIO; prio >= 0; prio--) {
1195                 cl_head = q->active[prio];
1196                 if (!cl_head)
1197                         continue;
1198
1199                 cl = cl_head;
1200                 do {
1201                         if (cl->q->ops->drop && (len = cl->q->ops->drop(cl->q))) {
1202                                 sch->q.qlen--;
1203                                 if (!cl->q->q.qlen)
1204                                         cbq_deactivate_class(cl);
1205                                 return len;
1206                         }
1207                 } while ((cl = cl->next_alive) != cl_head);
1208         }
1209         return 0;
1210 }
1211
1212 static void
1213 cbq_reset(struct Qdisc *sch)
1214 {
1215         struct cbq_sched_data *q = qdisc_priv(sch);
1216         struct cbq_class *cl;
1217         struct hlist_node *n;
1218         int prio;
1219         unsigned int h;
1220
1221         q->activemask = 0;
1222         q->pmask = 0;
1223         q->tx_class = NULL;
1224         q->tx_borrowed = NULL;
1225         qdisc_watchdog_cancel(&q->watchdog);
1226         hrtimer_cancel(&q->delay_timer);
1227         q->toplevel = TC_CBQ_MAXLEVEL;
1228         q->now = psched_get_time();
1229         q->now_rt = q->now;
1230
1231         for (prio = 0; prio <= TC_CBQ_MAXPRIO; prio++)
1232                 q->active[prio] = NULL;
1233
1234         for (h = 0; h < q->clhash.hashsize; h++) {
1235                 hlist_for_each_entry(cl, n, &q->clhash.hash[h], common.hnode) {
1236                         qdisc_reset(cl->q);
1237
1238                         cl->next_alive = NULL;
1239                         cl->undertime = PSCHED_PASTPERFECT;
1240                         cl->avgidle = cl->maxidle;
1241                         cl->deficit = cl->quantum;
1242                         cl->cpriority = cl->priority;
1243                 }
1244         }
1245         sch->q.qlen = 0;
1246 }
1247
1248
1249 static int cbq_set_lss(struct cbq_class *cl, struct tc_cbq_lssopt *lss)
1250 {
1251         if (lss->change & TCF_CBQ_LSS_FLAGS) {
1252                 cl->share = (lss->flags & TCF_CBQ_LSS_ISOLATED) ? NULL : cl->tparent;
1253                 cl->borrow = (lss->flags & TCF_CBQ_LSS_BOUNDED) ? NULL : cl->tparent;
1254         }
1255         if (lss->change & TCF_CBQ_LSS_EWMA)
1256                 cl->ewma_log = lss->ewma_log;
1257         if (lss->change & TCF_CBQ_LSS_AVPKT)
1258                 cl->avpkt = lss->avpkt;
1259         if (lss->change & TCF_CBQ_LSS_MINIDLE)
1260                 cl->minidle = -(long)lss->minidle;
1261         if (lss->change & TCF_CBQ_LSS_MAXIDLE) {
1262                 cl->maxidle = lss->maxidle;
1263                 cl->avgidle = lss->maxidle;
1264         }
1265         if (lss->change & TCF_CBQ_LSS_OFFTIME)
1266                 cl->offtime = lss->offtime;
1267         return 0;
1268 }
1269
1270 static void cbq_rmprio(struct cbq_sched_data *q, struct cbq_class *cl)
1271 {
1272         q->nclasses[cl->priority]--;
1273         q->quanta[cl->priority] -= cl->weight;
1274         cbq_normalize_quanta(q, cl->priority);
1275 }
1276
1277 static void cbq_addprio(struct cbq_sched_data *q, struct cbq_class *cl)
1278 {
1279         q->nclasses[cl->priority]++;
1280         q->quanta[cl->priority] += cl->weight;
1281         cbq_normalize_quanta(q, cl->priority);
1282 }
1283
1284 static int cbq_set_wrr(struct cbq_class *cl, struct tc_cbq_wrropt *wrr)
1285 {
1286         struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
1287
1288         if (wrr->allot)
1289                 cl->allot = wrr->allot;
1290         if (wrr->weight)
1291                 cl->weight = wrr->weight;
1292         if (wrr->priority) {
1293                 cl->priority = wrr->priority - 1;
1294                 cl->cpriority = cl->priority;
1295                 if (cl->priority >= cl->priority2)
1296                         cl->priority2 = TC_CBQ_MAXPRIO - 1;
1297         }
1298
1299         cbq_addprio(q, cl);
1300         return 0;
1301 }
1302
1303 static int cbq_set_overlimit(struct cbq_class *cl, struct tc_cbq_ovl *ovl)
1304 {
1305         switch (ovl->strategy) {
1306         case TC_CBQ_OVL_CLASSIC:
1307                 cl->overlimit = cbq_ovl_classic;
1308                 break;
1309         case TC_CBQ_OVL_DELAY:
1310                 cl->overlimit = cbq_ovl_delay;
1311                 break;
1312         case TC_CBQ_OVL_LOWPRIO:
1313                 if (ovl->priority2 - 1 >= TC_CBQ_MAXPRIO ||
1314                     ovl->priority2 - 1 <= cl->priority)
1315                         return -EINVAL;
1316                 cl->priority2 = ovl->priority2 - 1;
1317                 cl->overlimit = cbq_ovl_lowprio;
1318                 break;
1319         case TC_CBQ_OVL_DROP:
1320                 cl->overlimit = cbq_ovl_drop;
1321                 break;
1322         case TC_CBQ_OVL_RCLASSIC:
1323                 cl->overlimit = cbq_ovl_rclassic;
1324                 break;
1325         default:
1326                 return -EINVAL;
1327         }
1328         cl->penalty = ovl->penalty;
1329         return 0;
1330 }
1331
1332 #ifdef CONFIG_NET_CLS_ACT
1333 static int cbq_set_police(struct cbq_class *cl, struct tc_cbq_police *p)
1334 {
1335         cl->police = p->police;
1336
1337         if (cl->q->handle) {
1338                 if (p->police == TC_POLICE_RECLASSIFY)
1339                         cl->q->reshape_fail = cbq_reshape_fail;
1340                 else
1341                         cl->q->reshape_fail = NULL;
1342         }
1343         return 0;
1344 }
1345 #endif
1346
1347 static int cbq_set_fopt(struct cbq_class *cl, struct tc_cbq_fopt *fopt)
1348 {
1349         cbq_change_defmap(cl, fopt->split, fopt->defmap, fopt->defchange);
1350         return 0;
1351 }
1352
1353 static const struct nla_policy cbq_policy[TCA_CBQ_MAX + 1] = {
1354         [TCA_CBQ_LSSOPT]        = { .len = sizeof(struct tc_cbq_lssopt) },
1355         [TCA_CBQ_WRROPT]        = { .len = sizeof(struct tc_cbq_wrropt) },
1356         [TCA_CBQ_FOPT]          = { .len = sizeof(struct tc_cbq_fopt) },
1357         [TCA_CBQ_OVL_STRATEGY]  = { .len = sizeof(struct tc_cbq_ovl) },
1358         [TCA_CBQ_RATE]          = { .len = sizeof(struct tc_ratespec) },
1359         [TCA_CBQ_RTAB]          = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
1360         [TCA_CBQ_POLICE]        = { .len = sizeof(struct tc_cbq_police) },
1361 };
1362
1363 static int cbq_init(struct Qdisc *sch, struct nlattr *opt)
1364 {
1365         struct cbq_sched_data *q = qdisc_priv(sch);
1366         struct nlattr *tb[TCA_CBQ_MAX + 1];
1367         struct tc_ratespec *r;
1368         int err;
1369
1370         err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy);
1371         if (err < 0)
1372                 return err;
1373
1374         if (tb[TCA_CBQ_RTAB] == NULL || tb[TCA_CBQ_RATE] == NULL)
1375                 return -EINVAL;
1376
1377         r = nla_data(tb[TCA_CBQ_RATE]);
1378
1379         if ((q->link.R_tab = qdisc_get_rtab(r, tb[TCA_CBQ_RTAB])) == NULL)
1380                 return -EINVAL;
1381
1382         err = qdisc_class_hash_init(&q->clhash);
1383         if (err < 0)
1384                 goto put_rtab;
1385
1386         q->link.refcnt = 1;
1387         q->link.sibling = &q->link;
1388         q->link.common.classid = sch->handle;
1389         q->link.qdisc = sch;
1390         q->link.q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1391                                       sch->handle);
1392         if (!q->link.q)
1393                 q->link.q = &noop_qdisc;
1394
1395         q->link.priority = TC_CBQ_MAXPRIO - 1;
1396         q->link.priority2 = TC_CBQ_MAXPRIO - 1;
1397         q->link.cpriority = TC_CBQ_MAXPRIO - 1;
1398         q->link.ovl_strategy = TC_CBQ_OVL_CLASSIC;
1399         q->link.overlimit = cbq_ovl_classic;
1400         q->link.allot = psched_mtu(qdisc_dev(sch));
1401         q->link.quantum = q->link.allot;
1402         q->link.weight = q->link.R_tab->rate.rate;
1403
1404         q->link.ewma_log = TC_CBQ_DEF_EWMA;
1405         q->link.avpkt = q->link.allot/2;
1406         q->link.minidle = -0x7FFFFFFF;
1407
1408         qdisc_watchdog_init(&q->watchdog, sch);
1409         hrtimer_init(&q->delay_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
1410         q->delay_timer.function = cbq_undelay;
1411         q->toplevel = TC_CBQ_MAXLEVEL;
1412         q->now = psched_get_time();
1413         q->now_rt = q->now;
1414
1415         cbq_link_class(&q->link);
1416
1417         if (tb[TCA_CBQ_LSSOPT])
1418                 cbq_set_lss(&q->link, nla_data(tb[TCA_CBQ_LSSOPT]));
1419
1420         cbq_addprio(q, &q->link);
1421         return 0;
1422
1423 put_rtab:
1424         qdisc_put_rtab(q->link.R_tab);
1425         return err;
1426 }
1427
1428 static int cbq_dump_rate(struct sk_buff *skb, struct cbq_class *cl)
1429 {
1430         unsigned char *b = skb_tail_pointer(skb);
1431
1432         NLA_PUT(skb, TCA_CBQ_RATE, sizeof(cl->R_tab->rate), &cl->R_tab->rate);
1433         return skb->len;
1434
1435 nla_put_failure:
1436         nlmsg_trim(skb, b);
1437         return -1;
1438 }
1439
1440 static int cbq_dump_lss(struct sk_buff *skb, struct cbq_class *cl)
1441 {
1442         unsigned char *b = skb_tail_pointer(skb);
1443         struct tc_cbq_lssopt opt;
1444
1445         opt.flags = 0;
1446         if (cl->borrow == NULL)
1447                 opt.flags |= TCF_CBQ_LSS_BOUNDED;
1448         if (cl->share == NULL)
1449                 opt.flags |= TCF_CBQ_LSS_ISOLATED;
1450         opt.ewma_log = cl->ewma_log;
1451         opt.level = cl->level;
1452         opt.avpkt = cl->avpkt;
1453         opt.maxidle = cl->maxidle;
1454         opt.minidle = (u32)(-cl->minidle);
1455         opt.offtime = cl->offtime;
1456         opt.change = ~0;
1457         NLA_PUT(skb, TCA_CBQ_LSSOPT, sizeof(opt), &opt);
1458         return skb->len;
1459
1460 nla_put_failure:
1461         nlmsg_trim(skb, b);
1462         return -1;
1463 }
1464
1465 static int cbq_dump_wrr(struct sk_buff *skb, struct cbq_class *cl)
1466 {
1467         unsigned char *b = skb_tail_pointer(skb);
1468         struct tc_cbq_wrropt opt;
1469
1470         memset(&opt, 0, sizeof(opt));
1471         opt.flags = 0;
1472         opt.allot = cl->allot;
1473         opt.priority = cl->priority + 1;
1474         opt.cpriority = cl->cpriority + 1;
1475         opt.weight = cl->weight;
1476         NLA_PUT(skb, TCA_CBQ_WRROPT, sizeof(opt), &opt);
1477         return skb->len;
1478
1479 nla_put_failure:
1480         nlmsg_trim(skb, b);
1481         return -1;
1482 }
1483
1484 static int cbq_dump_ovl(struct sk_buff *skb, struct cbq_class *cl)
1485 {
1486         unsigned char *b = skb_tail_pointer(skb);
1487         struct tc_cbq_ovl opt;
1488
1489         opt.strategy = cl->ovl_strategy;
1490         opt.priority2 = cl->priority2 + 1;
1491         opt.pad = 0;
1492         opt.penalty = cl->penalty;
1493         NLA_PUT(skb, TCA_CBQ_OVL_STRATEGY, sizeof(opt), &opt);
1494         return skb->len;
1495
1496 nla_put_failure:
1497         nlmsg_trim(skb, b);
1498         return -1;
1499 }
1500
1501 static int cbq_dump_fopt(struct sk_buff *skb, struct cbq_class *cl)
1502 {
1503         unsigned char *b = skb_tail_pointer(skb);
1504         struct tc_cbq_fopt opt;
1505
1506         if (cl->split || cl->defmap) {
1507                 opt.split = cl->split ? cl->split->common.classid : 0;
1508                 opt.defmap = cl->defmap;
1509                 opt.defchange = ~0;
1510                 NLA_PUT(skb, TCA_CBQ_FOPT, sizeof(opt), &opt);
1511         }
1512         return skb->len;
1513
1514 nla_put_failure:
1515         nlmsg_trim(skb, b);
1516         return -1;
1517 }
1518
1519 #ifdef CONFIG_NET_CLS_ACT
1520 static int cbq_dump_police(struct sk_buff *skb, struct cbq_class *cl)
1521 {
1522         unsigned char *b = skb_tail_pointer(skb);
1523         struct tc_cbq_police opt;
1524
1525         if (cl->police) {
1526                 opt.police = cl->police;
1527                 opt.__res1 = 0;
1528                 opt.__res2 = 0;
1529                 NLA_PUT(skb, TCA_CBQ_POLICE, sizeof(opt), &opt);
1530         }
1531         return skb->len;
1532
1533 nla_put_failure:
1534         nlmsg_trim(skb, b);
1535         return -1;
1536 }
1537 #endif
1538
1539 static int cbq_dump_attr(struct sk_buff *skb, struct cbq_class *cl)
1540 {
1541         if (cbq_dump_lss(skb, cl) < 0 ||
1542             cbq_dump_rate(skb, cl) < 0 ||
1543             cbq_dump_wrr(skb, cl) < 0 ||
1544             cbq_dump_ovl(skb, cl) < 0 ||
1545 #ifdef CONFIG_NET_CLS_ACT
1546             cbq_dump_police(skb, cl) < 0 ||
1547 #endif
1548             cbq_dump_fopt(skb, cl) < 0)
1549                 return -1;
1550         return 0;
1551 }
1552
1553 static int cbq_dump(struct Qdisc *sch, struct sk_buff *skb)
1554 {
1555         struct cbq_sched_data *q = qdisc_priv(sch);
1556         struct nlattr *nest;
1557
1558         nest = nla_nest_start(skb, TCA_OPTIONS);
1559         if (nest == NULL)
1560                 goto nla_put_failure;
1561         if (cbq_dump_attr(skb, &q->link) < 0)
1562                 goto nla_put_failure;
1563         nla_nest_end(skb, nest);
1564         return skb->len;
1565
1566 nla_put_failure:
1567         nla_nest_cancel(skb, nest);
1568         return -1;
1569 }
1570
1571 static int
1572 cbq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
1573 {
1574         struct cbq_sched_data *q = qdisc_priv(sch);
1575
1576         q->link.xstats.avgidle = q->link.avgidle;
1577         return gnet_stats_copy_app(d, &q->link.xstats, sizeof(q->link.xstats));
1578 }
1579
1580 static int
1581 cbq_dump_class(struct Qdisc *sch, unsigned long arg,
1582                struct sk_buff *skb, struct tcmsg *tcm)
1583 {
1584         struct cbq_class *cl = (struct cbq_class *)arg;
1585         struct nlattr *nest;
1586
1587         if (cl->tparent)
1588                 tcm->tcm_parent = cl->tparent->common.classid;
1589         else
1590                 tcm->tcm_parent = TC_H_ROOT;
1591         tcm->tcm_handle = cl->common.classid;
1592         tcm->tcm_info = cl->q->handle;
1593
1594         nest = nla_nest_start(skb, TCA_OPTIONS);
1595         if (nest == NULL)
1596                 goto nla_put_failure;
1597         if (cbq_dump_attr(skb, cl) < 0)
1598                 goto nla_put_failure;
1599         nla_nest_end(skb, nest);
1600         return skb->len;
1601
1602 nla_put_failure:
1603         nla_nest_cancel(skb, nest);
1604         return -1;
1605 }
1606
1607 static int
1608 cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1609         struct gnet_dump *d)
1610 {
1611         struct cbq_sched_data *q = qdisc_priv(sch);
1612         struct cbq_class *cl = (struct cbq_class *)arg;
1613
1614         cl->qstats.qlen = cl->q->q.qlen;
1615         cl->xstats.avgidle = cl->avgidle;
1616         cl->xstats.undertime = 0;
1617
1618         if (cl->undertime != PSCHED_PASTPERFECT)
1619                 cl->xstats.undertime = cl->undertime - q->now;
1620
1621         if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
1622             gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
1623             gnet_stats_copy_queue(d, &cl->qstats) < 0)
1624                 return -1;
1625
1626         return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));
1627 }
1628
1629 static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1630                      struct Qdisc **old)
1631 {
1632         struct cbq_class *cl = (struct cbq_class *)arg;
1633
1634         if (new == NULL) {
1635                 new = qdisc_create_dflt(sch->dev_queue,
1636                                         &pfifo_qdisc_ops, cl->common.classid);
1637                 if (new == NULL)
1638                         return -ENOBUFS;
1639         } else {
1640 #ifdef CONFIG_NET_CLS_ACT
1641                 if (cl->police == TC_POLICE_RECLASSIFY)
1642                         new->reshape_fail = cbq_reshape_fail;
1643 #endif
1644         }
1645         sch_tree_lock(sch);
1646         *old = cl->q;
1647         cl->q = new;
1648         qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
1649         qdisc_reset(*old);
1650         sch_tree_unlock(sch);
1651
1652         return 0;
1653 }
1654
1655 static struct Qdisc *cbq_leaf(struct Qdisc *sch, unsigned long arg)
1656 {
1657         struct cbq_class *cl = (struct cbq_class *)arg;
1658
1659         return cl->q;
1660 }
1661
1662 static void cbq_qlen_notify(struct Qdisc *sch, unsigned long arg)
1663 {
1664         struct cbq_class *cl = (struct cbq_class *)arg;
1665
1666         if (cl->q->q.qlen == 0)
1667                 cbq_deactivate_class(cl);
1668 }
1669
1670 static unsigned long cbq_get(struct Qdisc *sch, u32 classid)
1671 {
1672         struct cbq_sched_data *q = qdisc_priv(sch);
1673         struct cbq_class *cl = cbq_class_lookup(q, classid);
1674
1675         if (cl) {
1676                 cl->refcnt++;
1677                 return (unsigned long)cl;
1678         }
1679         return 0;
1680 }
1681
1682 static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl)
1683 {
1684         struct cbq_sched_data *q = qdisc_priv(sch);
1685
1686         WARN_ON(cl->filters);
1687
1688         tcf_destroy_chain(&cl->filter_list);
1689         qdisc_destroy(cl->q);
1690         qdisc_put_rtab(cl->R_tab);
1691         gen_kill_estimator(&cl->bstats, &cl->rate_est);
1692         if (cl != &q->link)
1693                 kfree(cl);
1694 }
1695
1696 static void cbq_destroy(struct Qdisc *sch)
1697 {
1698         struct cbq_sched_data *q = qdisc_priv(sch);
1699         struct hlist_node *n, *next;
1700         struct cbq_class *cl;
1701         unsigned int h;
1702
1703 #ifdef CONFIG_NET_CLS_ACT
1704         q->rx_class = NULL;
1705 #endif
1706         /*
1707          * Filters must be destroyed first because we don't destroy the
1708          * classes from root to leafs which means that filters can still
1709          * be bound to classes which have been destroyed already. --TGR '04
1710          */
1711         for (h = 0; h < q->clhash.hashsize; h++) {
1712                 hlist_for_each_entry(cl, n, &q->clhash.hash[h], common.hnode)
1713                         tcf_destroy_chain(&cl->filter_list);
1714         }
1715         for (h = 0; h < q->clhash.hashsize; h++) {
1716                 hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[h],
1717                                           common.hnode)
1718                         cbq_destroy_class(sch, cl);
1719         }
1720         qdisc_class_hash_destroy(&q->clhash);
1721 }
1722
1723 static void cbq_put(struct Qdisc *sch, unsigned long arg)
1724 {
1725         struct cbq_class *cl = (struct cbq_class *)arg;
1726
1727         if (--cl->refcnt == 0) {
1728 #ifdef CONFIG_NET_CLS_ACT
1729                 spinlock_t *root_lock = qdisc_root_sleeping_lock(sch);
1730                 struct cbq_sched_data *q = qdisc_priv(sch);
1731
1732                 spin_lock_bh(root_lock);
1733                 if (q->rx_class == cl)
1734                         q->rx_class = NULL;
1735                 spin_unlock_bh(root_lock);
1736 #endif
1737
1738                 cbq_destroy_class(sch, cl);
1739         }
1740 }
1741
1742 static int
1743 cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **tca,
1744                  unsigned long *arg)
1745 {
1746         int err;
1747         struct cbq_sched_data *q = qdisc_priv(sch);
1748         struct cbq_class *cl = (struct cbq_class *)*arg;
1749         struct nlattr *opt = tca[TCA_OPTIONS];
1750         struct nlattr *tb[TCA_CBQ_MAX + 1];
1751         struct cbq_class *parent;
1752         struct qdisc_rate_table *rtab = NULL;
1753
1754         if (opt == NULL)
1755                 return -EINVAL;
1756
1757         err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy);
1758         if (err < 0)
1759                 return err;
1760
1761         if (cl) {
1762                 /* Check parent */
1763                 if (parentid) {
1764                         if (cl->tparent &&
1765                             cl->tparent->common.classid != parentid)
1766                                 return -EINVAL;
1767                         if (!cl->tparent && parentid != TC_H_ROOT)
1768                                 return -EINVAL;
1769                 }
1770
1771                 if (tb[TCA_CBQ_RATE]) {
1772                         rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]),
1773                                               tb[TCA_CBQ_RTAB]);
1774                         if (rtab == NULL)
1775                                 return -EINVAL;
1776                 }
1777
1778                 if (tca[TCA_RATE]) {
1779                         err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
1780                                                     qdisc_root_sleeping_lock(sch),
1781                                                     tca[TCA_RATE]);
1782                         if (err) {
1783                                 if (rtab)
1784                                         qdisc_put_rtab(rtab);
1785                                 return err;
1786                         }
1787                 }
1788
1789                 /* Change class parameters */
1790                 sch_tree_lock(sch);
1791
1792                 if (cl->next_alive != NULL)
1793                         cbq_deactivate_class(cl);
1794
1795                 if (rtab) {
1796                         qdisc_put_rtab(cl->R_tab);
1797                         cl->R_tab = rtab;
1798                 }
1799
1800                 if (tb[TCA_CBQ_LSSOPT])
1801                         cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
1802
1803                 if (tb[TCA_CBQ_WRROPT]) {
1804                         cbq_rmprio(q, cl);
1805                         cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
1806                 }
1807
1808                 if (tb[TCA_CBQ_OVL_STRATEGY])
1809                         cbq_set_overlimit(cl, nla_data(tb[TCA_CBQ_OVL_STRATEGY]));
1810
1811 #ifdef CONFIG_NET_CLS_ACT
1812                 if (tb[TCA_CBQ_POLICE])
1813                         cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE]));
1814 #endif
1815
1816                 if (tb[TCA_CBQ_FOPT])
1817                         cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
1818
1819                 if (cl->q->q.qlen)
1820                         cbq_activate_class(cl);
1821
1822                 sch_tree_unlock(sch);
1823
1824                 return 0;
1825         }
1826
1827         if (parentid == TC_H_ROOT)
1828                 return -EINVAL;
1829
1830         if (tb[TCA_CBQ_WRROPT] == NULL || tb[TCA_CBQ_RATE] == NULL ||
1831             tb[TCA_CBQ_LSSOPT] == NULL)
1832                 return -EINVAL;
1833
1834         rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]), tb[TCA_CBQ_RTAB]);
1835         if (rtab == NULL)
1836                 return -EINVAL;
1837
1838         if (classid) {
1839                 err = -EINVAL;
1840                 if (TC_H_MAJ(classid ^ sch->handle) ||
1841                     cbq_class_lookup(q, classid))
1842                         goto failure;
1843         } else {
1844                 int i;
1845                 classid = TC_H_MAKE(sch->handle, 0x8000);
1846
1847                 for (i = 0; i < 0x8000; i++) {
1848                         if (++q->hgenerator >= 0x8000)
1849                                 q->hgenerator = 1;
1850                         if (cbq_class_lookup(q, classid|q->hgenerator) == NULL)
1851                                 break;
1852                 }
1853                 err = -ENOSR;
1854                 if (i >= 0x8000)
1855                         goto failure;
1856                 classid = classid|q->hgenerator;
1857         }
1858
1859         parent = &q->link;
1860         if (parentid) {
1861                 parent = cbq_class_lookup(q, parentid);
1862                 err = -EINVAL;
1863                 if (parent == NULL)
1864                         goto failure;
1865         }
1866
1867         err = -ENOBUFS;
1868         cl = kzalloc(sizeof(*cl), GFP_KERNEL);
1869         if (cl == NULL)
1870                 goto failure;
1871
1872         if (tca[TCA_RATE]) {
1873                 err = gen_new_estimator(&cl->bstats, &cl->rate_est,
1874                                         qdisc_root_sleeping_lock(sch),
1875                                         tca[TCA_RATE]);
1876                 if (err) {
1877                         kfree(cl);
1878                         goto failure;
1879                 }
1880         }
1881
1882         cl->R_tab = rtab;
1883         rtab = NULL;
1884         cl->refcnt = 1;
1885         cl->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid);
1886         if (!cl->q)
1887                 cl->q = &noop_qdisc;
1888         cl->common.classid = classid;
1889         cl->tparent = parent;
1890         cl->qdisc = sch;
1891         cl->allot = parent->allot;
1892         cl->quantum = cl->allot;
1893         cl->weight = cl->R_tab->rate.rate;
1894
1895         sch_tree_lock(sch);
1896         cbq_link_class(cl);
1897         cl->borrow = cl->tparent;
1898         if (cl->tparent != &q->link)
1899                 cl->share = cl->tparent;
1900         cbq_adjust_levels(parent);
1901         cl->minidle = -0x7FFFFFFF;
1902         cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
1903         cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
1904         if (cl->ewma_log == 0)
1905                 cl->ewma_log = q->link.ewma_log;
1906         if (cl->maxidle == 0)
1907                 cl->maxidle = q->link.maxidle;
1908         if (cl->avpkt == 0)
1909                 cl->avpkt = q->link.avpkt;
1910         cl->overlimit = cbq_ovl_classic;
1911         if (tb[TCA_CBQ_OVL_STRATEGY])
1912                 cbq_set_overlimit(cl, nla_data(tb[TCA_CBQ_OVL_STRATEGY]));
1913 #ifdef CONFIG_NET_CLS_ACT
1914         if (tb[TCA_CBQ_POLICE])
1915                 cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE]));
1916 #endif
1917         if (tb[TCA_CBQ_FOPT])
1918                 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
1919         sch_tree_unlock(sch);
1920
1921         qdisc_class_hash_grow(sch, &q->clhash);
1922
1923         *arg = (unsigned long)cl;
1924         return 0;
1925
1926 failure:
1927         qdisc_put_rtab(rtab);
1928         return err;
1929 }
1930
1931 static int cbq_delete(struct Qdisc *sch, unsigned long arg)
1932 {
1933         struct cbq_sched_data *q = qdisc_priv(sch);
1934         struct cbq_class *cl = (struct cbq_class *)arg;
1935         unsigned int qlen;
1936
1937         if (cl->filters || cl->children || cl == &q->link)
1938                 return -EBUSY;
1939
1940         sch_tree_lock(sch);
1941
1942         qlen = cl->q->q.qlen;
1943         qdisc_reset(cl->q);
1944         qdisc_tree_decrease_qlen(cl->q, qlen);
1945
1946         if (cl->next_alive)
1947                 cbq_deactivate_class(cl);
1948
1949         if (q->tx_borrowed == cl)
1950                 q->tx_borrowed = q->tx_class;
1951         if (q->tx_class == cl) {
1952                 q->tx_class = NULL;
1953                 q->tx_borrowed = NULL;
1954         }
1955 #ifdef CONFIG_NET_CLS_ACT
1956         if (q->rx_class == cl)
1957                 q->rx_class = NULL;
1958 #endif
1959
1960         cbq_unlink_class(cl);
1961         cbq_adjust_levels(cl->tparent);
1962         cl->defmap = 0;
1963         cbq_sync_defmap(cl);
1964
1965         cbq_rmprio(q, cl);
1966         sch_tree_unlock(sch);
1967
1968         BUG_ON(--cl->refcnt == 0);
1969         /*
1970          * This shouldn't happen: we "hold" one cops->get() when called
1971          * from tc_ctl_tclass; the destroy method is done from cops->put().
1972          */
1973
1974         return 0;
1975 }
1976
1977 static struct tcf_proto **cbq_find_tcf(struct Qdisc *sch, unsigned long arg)
1978 {
1979         struct cbq_sched_data *q = qdisc_priv(sch);
1980         struct cbq_class *cl = (struct cbq_class *)arg;
1981
1982         if (cl == NULL)
1983                 cl = &q->link;
1984
1985         return &cl->filter_list;
1986 }
1987
1988 static unsigned long cbq_bind_filter(struct Qdisc *sch, unsigned long parent,
1989                                      u32 classid)
1990 {
1991         struct cbq_sched_data *q = qdisc_priv(sch);
1992         struct cbq_class *p = (struct cbq_class *)parent;
1993         struct cbq_class *cl = cbq_class_lookup(q, classid);
1994
1995         if (cl) {
1996                 if (p && p->level <= cl->level)
1997                         return 0;
1998                 cl->filters++;
1999                 return (unsigned long)cl;
2000         }
2001         return 0;
2002 }
2003
2004 static void cbq_unbind_filter(struct Qdisc *sch, unsigned long arg)
2005 {
2006         struct cbq_class *cl = (struct cbq_class *)arg;
2007
2008         cl->filters--;
2009 }
2010
2011 static void cbq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
2012 {
2013         struct cbq_sched_data *q = qdisc_priv(sch);
2014         struct cbq_class *cl;
2015         struct hlist_node *n;
2016         unsigned int h;
2017
2018         if (arg->stop)
2019                 return;
2020
2021         for (h = 0; h < q->clhash.hashsize; h++) {
2022                 hlist_for_each_entry(cl, n, &q->clhash.hash[h], common.hnode) {
2023                         if (arg->count < arg->skip) {
2024                                 arg->count++;
2025                                 continue;
2026                         }
2027                         if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
2028                                 arg->stop = 1;
2029                                 return;
2030                         }
2031                         arg->count++;
2032                 }
2033         }
2034 }
2035
2036 static const struct Qdisc_class_ops cbq_class_ops = {
2037         .graft          =       cbq_graft,
2038         .leaf           =       cbq_leaf,
2039         .qlen_notify    =       cbq_qlen_notify,
2040         .get            =       cbq_get,
2041         .put            =       cbq_put,
2042         .change         =       cbq_change_class,
2043         .delete         =       cbq_delete,
2044         .walk           =       cbq_walk,
2045         .tcf_chain      =       cbq_find_tcf,
2046         .bind_tcf       =       cbq_bind_filter,
2047         .unbind_tcf     =       cbq_unbind_filter,
2048         .dump           =       cbq_dump_class,
2049         .dump_stats     =       cbq_dump_class_stats,
2050 };
2051
2052 static struct Qdisc_ops cbq_qdisc_ops __read_mostly = {
2053         .next           =       NULL,
2054         .cl_ops         =       &cbq_class_ops,
2055         .id             =       "cbq",
2056         .priv_size      =       sizeof(struct cbq_sched_data),
2057         .enqueue        =       cbq_enqueue,
2058         .dequeue        =       cbq_dequeue,
2059         .peek           =       qdisc_peek_dequeued,
2060         .drop           =       cbq_drop,
2061         .init           =       cbq_init,
2062         .reset          =       cbq_reset,
2063         .destroy        =       cbq_destroy,
2064         .change         =       NULL,
2065         .dump           =       cbq_dump,
2066         .dump_stats     =       cbq_dump_stats,
2067         .owner          =       THIS_MODULE,
2068 };
2069
2070 static int __init cbq_module_init(void)
2071 {
2072         return register_qdisc(&cbq_qdisc_ops);
2073 }
2074 static void __exit cbq_module_exit(void)
2075 {
2076         unregister_qdisc(&cbq_qdisc_ops);
2077 }
2078 module_init(cbq_module_init)
2079 module_exit(cbq_module_exit)
2080 MODULE_LICENSE("GPL");