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[deliverable/linux.git] / 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/types.h>
15 #include <linux/kernel.h>
16 #include <linux/string.h>
17 #include <linux/errno.h>
18 #include <linux/skbuff.h>
19 #include <net/netlink.h>
20 #include <net/pkt_sched.h>
21
22
23 /* Class-Based Queueing (CBQ) algorithm.
24 =======================================
25
26 Sources: [1] Sally Floyd and Van Jacobson, "Link-sharing and Resource
27 Management Models for Packet Networks",
28 IEEE/ACM Transactions on Networking, Vol.3, No.4, 1995
29
30 [2] Sally Floyd, "Notes on CBQ and Guaranteed Service", 1995
31
32 [3] Sally Floyd, "Notes on Class-Based Queueing: Setting
33 Parameters", 1996
34
35 [4] Sally Floyd and Michael Speer, "Experimental Results
36 for Class-Based Queueing", 1998, not published.
37
38 -----------------------------------------------------------------------
39
40 Algorithm skeleton was taken from NS simulator cbq.cc.
41 If someone wants to check this code against the LBL version,
42 he should take into account that ONLY the skeleton was borrowed,
43 the implementation is different. Particularly:
44
45 --- The WRR algorithm is different. Our version looks more
46 reasonable (I hope) and works when quanta are allowed to be
47 less than MTU, which is always the case when real time classes
48 have small rates. Note, that the statement of [3] is
49 incomplete, delay may actually be estimated even if class
50 per-round allotment is less than MTU. Namely, if per-round
51 allotment is W*r_i, and r_1+...+r_k = r < 1
52
53 delay_i <= ([MTU/(W*r_i)]*W*r + W*r + k*MTU)/B
54
55 In the worst case we have IntServ estimate with D = W*r+k*MTU
56 and C = MTU*r. The proof (if correct at all) is trivial.
57
58
59 --- It seems that cbq-2.0 is not very accurate. At least, I cannot
60 interpret some places, which look like wrong translations
61 from NS. Anyone is advised to find these differences
62 and explain to me, why I am wrong 8).
63
64 --- Linux has no EOI event, so that we cannot estimate true class
65 idle time. Workaround is to consider the next dequeue event
66 as sign that previous packet is finished. This is wrong because of
67 internal device queueing, but on a permanently loaded link it is true.
68 Moreover, combined with clock integrator, this scheme looks
69 very close to an ideal solution. */
70
71 struct cbq_sched_data;
72
73
74 struct cbq_class
75 {
76 struct cbq_class *next; /* hash table link */
77 struct cbq_class *next_alive; /* next class with backlog in this priority band */
78
79 /* Parameters */
80 u32 classid;
81 unsigned char priority; /* class priority */
82 unsigned char priority2; /* priority to be used after overlimit */
83 unsigned char ewma_log; /* time constant for idle time calculation */
84 unsigned char ovl_strategy;
85 #ifdef CONFIG_NET_CLS_ACT
86 unsigned char police;
87 #endif
88
89 u32 defmap;
90
91 /* Link-sharing scheduler parameters */
92 long maxidle; /* Class parameters: see below. */
93 long offtime;
94 long minidle;
95 u32 avpkt;
96 struct qdisc_rate_table *R_tab;
97
98 /* Overlimit strategy parameters */
99 void (*overlimit)(struct cbq_class *cl);
100 psched_tdiff_t penalty;
101
102 /* General scheduler (WRR) parameters */
103 long allot;
104 long quantum; /* Allotment per WRR round */
105 long weight; /* Relative allotment: see below */
106
107 struct Qdisc *qdisc; /* Ptr to CBQ discipline */
108 struct cbq_class *split; /* Ptr to split node */
109 struct cbq_class *share; /* Ptr to LS parent in the class tree */
110 struct cbq_class *tparent; /* Ptr to tree parent in the class tree */
111 struct cbq_class *borrow; /* NULL if class is bandwidth limited;
112 parent otherwise */
113 struct cbq_class *sibling; /* Sibling chain */
114 struct cbq_class *children; /* Pointer to children chain */
115
116 struct Qdisc *q; /* Elementary queueing discipline */
117
118
119 /* Variables */
120 unsigned char cpriority; /* Effective priority */
121 unsigned char delayed;
122 unsigned char level; /* level of the class in hierarchy:
123 0 for leaf classes, and maximal
124 level of children + 1 for nodes.
125 */
126
127 psched_time_t last; /* Last end of service */
128 psched_time_t undertime;
129 long avgidle;
130 long deficit; /* Saved deficit for WRR */
131 psched_time_t penalized;
132 struct gnet_stats_basic bstats;
133 struct gnet_stats_queue qstats;
134 struct gnet_stats_rate_est rate_est;
135 struct tc_cbq_xstats xstats;
136
137 struct tcf_proto *filter_list;
138
139 int refcnt;
140 int filters;
141
142 struct cbq_class *defaults[TC_PRIO_MAX+1];
143 };
144
145 struct cbq_sched_data
146 {
147 struct cbq_class *classes[16]; /* Hash table of all classes */
148 int nclasses[TC_CBQ_MAXPRIO+1];
149 unsigned quanta[TC_CBQ_MAXPRIO+1];
150
151 struct cbq_class link;
152
153 unsigned activemask;
154 struct cbq_class *active[TC_CBQ_MAXPRIO+1]; /* List of all classes
155 with backlog */
156
157 #ifdef CONFIG_NET_CLS_ACT
158 struct cbq_class *rx_class;
159 #endif
160 struct cbq_class *tx_class;
161 struct cbq_class *tx_borrowed;
162 int tx_len;
163 psched_time_t now; /* Cached timestamp */
164 psched_time_t now_rt; /* Cached real time */
165 unsigned pmask;
166
167 struct hrtimer delay_timer;
168 struct qdisc_watchdog watchdog; /* Watchdog timer,
169 started when CBQ has
170 backlog, but cannot
171 transmit just now */
172 psched_tdiff_t wd_expires;
173 int toplevel;
174 u32 hgenerator;
175 };
176
177
178 #define L2T(cl,len) qdisc_l2t((cl)->R_tab,len)
179
180
181 static __inline__ unsigned cbq_hash(u32 h)
182 {
183 h ^= h>>8;
184 h ^= h>>4;
185 return h&0xF;
186 }
187
188 static __inline__ struct cbq_class *
189 cbq_class_lookup(struct cbq_sched_data *q, u32 classid)
190 {
191 struct cbq_class *cl;
192
193 for (cl = q->classes[cbq_hash(classid)]; cl; cl = cl->next)
194 if (cl->classid == classid)
195 return cl;
196 return NULL;
197 }
198
199 #ifdef CONFIG_NET_CLS_ACT
200
201 static struct cbq_class *
202 cbq_reclassify(struct sk_buff *skb, struct cbq_class *this)
203 {
204 struct cbq_class *cl, *new;
205
206 for (cl = this->tparent; cl; cl = cl->tparent)
207 if ((new = cl->defaults[TC_PRIO_BESTEFFORT]) != NULL && new != this)
208 return new;
209
210 return NULL;
211 }
212
213 #endif
214
215 /* Classify packet. The procedure is pretty complicated, but
216 it allows us to combine link sharing and priority scheduling
217 transparently.
218
219 Namely, you can put link sharing rules (f.e. route based) at root of CBQ,
220 so that it resolves to split nodes. Then packets are classified
221 by logical priority, or a more specific classifier may be attached
222 to the split node.
223 */
224
225 static struct cbq_class *
226 cbq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
227 {
228 struct cbq_sched_data *q = qdisc_priv(sch);
229 struct cbq_class *head = &q->link;
230 struct cbq_class **defmap;
231 struct cbq_class *cl = NULL;
232 u32 prio = skb->priority;
233 struct tcf_result res;
234
235 /*
236 * Step 1. If skb->priority points to one of our classes, use it.
237 */
238 if (TC_H_MAJ(prio^sch->handle) == 0 &&
239 (cl = cbq_class_lookup(q, prio)) != NULL)
240 return cl;
241
242 *qerr = NET_XMIT_BYPASS;
243 for (;;) {
244 int result = 0;
245 defmap = head->defaults;
246
247 /*
248 * Step 2+n. Apply classifier.
249 */
250 if (!head->filter_list ||
251 (result = tc_classify_compat(skb, head->filter_list, &res)) < 0)
252 goto fallback;
253
254 if ((cl = (void*)res.class) == NULL) {
255 if (TC_H_MAJ(res.classid))
256 cl = cbq_class_lookup(q, res.classid);
257 else if ((cl = defmap[res.classid&TC_PRIO_MAX]) == NULL)
258 cl = defmap[TC_PRIO_BESTEFFORT];
259
260 if (cl == NULL || cl->level >= head->level)
261 goto fallback;
262 }
263
264 #ifdef CONFIG_NET_CLS_ACT
265 switch (result) {
266 case TC_ACT_QUEUED:
267 case TC_ACT_STOLEN:
268 *qerr = NET_XMIT_SUCCESS;
269 case TC_ACT_SHOT:
270 return NULL;
271 case TC_ACT_RECLASSIFY:
272 return cbq_reclassify(skb, cl);
273 }
274 #endif
275 if (cl->level == 0)
276 return cl;
277
278 /*
279 * Step 3+n. If classifier selected a link sharing class,
280 * apply agency specific classifier.
281 * Repeat this procdure until we hit a leaf node.
282 */
283 head = cl;
284 }
285
286 fallback:
287 cl = head;
288
289 /*
290 * Step 4. No success...
291 */
292 if (TC_H_MAJ(prio) == 0 &&
293 !(cl = head->defaults[prio&TC_PRIO_MAX]) &&
294 !(cl = head->defaults[TC_PRIO_BESTEFFORT]))
295 return head;
296
297 return cl;
298 }
299
300 /*
301 A packet has just been enqueued on the empty class.
302 cbq_activate_class adds it to the tail of active class list
303 of its priority band.
304 */
305
306 static __inline__ void cbq_activate_class(struct cbq_class *cl)
307 {
308 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
309 int prio = cl->cpriority;
310 struct cbq_class *cl_tail;
311
312 cl_tail = q->active[prio];
313 q->active[prio] = cl;
314
315 if (cl_tail != NULL) {
316 cl->next_alive = cl_tail->next_alive;
317 cl_tail->next_alive = cl;
318 } else {
319 cl->next_alive = cl;
320 q->activemask |= (1<<prio);
321 }
322 }
323
324 /*
325 Unlink class from active chain.
326 Note that this same procedure is done directly in cbq_dequeue*
327 during round-robin procedure.
328 */
329
330 static void cbq_deactivate_class(struct cbq_class *this)
331 {
332 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
333 int prio = this->cpriority;
334 struct cbq_class *cl;
335 struct cbq_class *cl_prev = q->active[prio];
336
337 do {
338 cl = cl_prev->next_alive;
339 if (cl == this) {
340 cl_prev->next_alive = cl->next_alive;
341 cl->next_alive = NULL;
342
343 if (cl == q->active[prio]) {
344 q->active[prio] = cl_prev;
345 if (cl == q->active[prio]) {
346 q->active[prio] = NULL;
347 q->activemask &= ~(1<<prio);
348 return;
349 }
350 }
351 return;
352 }
353 } while ((cl_prev = cl) != q->active[prio]);
354 }
355
356 static void
357 cbq_mark_toplevel(struct cbq_sched_data *q, struct cbq_class *cl)
358 {
359 int toplevel = q->toplevel;
360
361 if (toplevel > cl->level && !(cl->q->flags&TCQ_F_THROTTLED)) {
362 psched_time_t now;
363 psched_tdiff_t incr;
364
365 now = psched_get_time();
366 incr = now - q->now_rt;
367 now = q->now + incr;
368
369 do {
370 if (cl->undertime < now) {
371 q->toplevel = cl->level;
372 return;
373 }
374 } while ((cl=cl->borrow) != NULL && toplevel > cl->level);
375 }
376 }
377
378 static int
379 cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
380 {
381 struct cbq_sched_data *q = qdisc_priv(sch);
382 int len = skb->len;
383 int uninitialized_var(ret);
384 struct cbq_class *cl = cbq_classify(skb, sch, &ret);
385
386 #ifdef CONFIG_NET_CLS_ACT
387 q->rx_class = cl;
388 #endif
389 if (cl == NULL) {
390 if (ret == NET_XMIT_BYPASS)
391 sch->qstats.drops++;
392 kfree_skb(skb);
393 return ret;
394 }
395
396 #ifdef CONFIG_NET_CLS_ACT
397 cl->q->__parent = sch;
398 #endif
399 if ((ret = cl->q->enqueue(skb, cl->q)) == NET_XMIT_SUCCESS) {
400 sch->q.qlen++;
401 sch->bstats.packets++;
402 sch->bstats.bytes+=len;
403 cbq_mark_toplevel(q, cl);
404 if (!cl->next_alive)
405 cbq_activate_class(cl);
406 return ret;
407 }
408
409 sch->qstats.drops++;
410 cbq_mark_toplevel(q, cl);
411 cl->qstats.drops++;
412 return ret;
413 }
414
415 static int
416 cbq_requeue(struct sk_buff *skb, struct Qdisc *sch)
417 {
418 struct cbq_sched_data *q = qdisc_priv(sch);
419 struct cbq_class *cl;
420 int ret;
421
422 if ((cl = q->tx_class) == NULL) {
423 kfree_skb(skb);
424 sch->qstats.drops++;
425 return NET_XMIT_CN;
426 }
427 q->tx_class = NULL;
428
429 cbq_mark_toplevel(q, cl);
430
431 #ifdef CONFIG_NET_CLS_ACT
432 q->rx_class = cl;
433 cl->q->__parent = sch;
434 #endif
435 if ((ret = cl->q->ops->requeue(skb, cl->q)) == 0) {
436 sch->q.qlen++;
437 sch->qstats.requeues++;
438 if (!cl->next_alive)
439 cbq_activate_class(cl);
440 return 0;
441 }
442 sch->qstats.drops++;
443 cl->qstats.drops++;
444 return ret;
445 }
446
447 /* Overlimit actions */
448
449 /* TC_CBQ_OVL_CLASSIC: (default) penalize leaf class by adding offtime */
450
451 static void cbq_ovl_classic(struct cbq_class *cl)
452 {
453 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
454 psched_tdiff_t delay = cl->undertime - q->now;
455
456 if (!cl->delayed) {
457 delay += cl->offtime;
458
459 /*
460 Class goes to sleep, so that it will have no
461 chance to work avgidle. Let's forgive it 8)
462
463 BTW cbq-2.0 has a crap in this
464 place, apparently they forgot to shift it by cl->ewma_log.
465 */
466 if (cl->avgidle < 0)
467 delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log);
468 if (cl->avgidle < cl->minidle)
469 cl->avgidle = cl->minidle;
470 if (delay <= 0)
471 delay = 1;
472 cl->undertime = q->now + delay;
473
474 cl->xstats.overactions++;
475 cl->delayed = 1;
476 }
477 if (q->wd_expires == 0 || q->wd_expires > delay)
478 q->wd_expires = delay;
479
480 /* Dirty work! We must schedule wakeups based on
481 real available rate, rather than leaf rate,
482 which may be tiny (even zero).
483 */
484 if (q->toplevel == TC_CBQ_MAXLEVEL) {
485 struct cbq_class *b;
486 psched_tdiff_t base_delay = q->wd_expires;
487
488 for (b = cl->borrow; b; b = b->borrow) {
489 delay = b->undertime - q->now;
490 if (delay < base_delay) {
491 if (delay <= 0)
492 delay = 1;
493 base_delay = delay;
494 }
495 }
496
497 q->wd_expires = base_delay;
498 }
499 }
500
501 /* TC_CBQ_OVL_RCLASSIC: penalize by offtime classes in hierarchy, when
502 they go overlimit
503 */
504
505 static void cbq_ovl_rclassic(struct cbq_class *cl)
506 {
507 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
508 struct cbq_class *this = cl;
509
510 do {
511 if (cl->level > q->toplevel) {
512 cl = NULL;
513 break;
514 }
515 } while ((cl = cl->borrow) != NULL);
516
517 if (cl == NULL)
518 cl = this;
519 cbq_ovl_classic(cl);
520 }
521
522 /* TC_CBQ_OVL_DELAY: delay until it will go to underlimit */
523
524 static void cbq_ovl_delay(struct cbq_class *cl)
525 {
526 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
527 psched_tdiff_t delay = cl->undertime - q->now;
528
529 if (!cl->delayed) {
530 psched_time_t sched = q->now;
531 ktime_t expires;
532
533 delay += cl->offtime;
534 if (cl->avgidle < 0)
535 delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log);
536 if (cl->avgidle < cl->minidle)
537 cl->avgidle = cl->minidle;
538 cl->undertime = q->now + delay;
539
540 if (delay > 0) {
541 sched += delay + cl->penalty;
542 cl->penalized = sched;
543 cl->cpriority = TC_CBQ_MAXPRIO;
544 q->pmask |= (1<<TC_CBQ_MAXPRIO);
545
546 expires = ktime_set(0, 0);
547 expires = ktime_add_ns(expires, PSCHED_US2NS(sched));
548 if (hrtimer_try_to_cancel(&q->delay_timer) &&
549 ktime_to_ns(ktime_sub(q->delay_timer.expires,
550 expires)) > 0)
551 q->delay_timer.expires = expires;
552 hrtimer_restart(&q->delay_timer);
553 cl->delayed = 1;
554 cl->xstats.overactions++;
555 return;
556 }
557 delay = 1;
558 }
559 if (q->wd_expires == 0 || q->wd_expires > delay)
560 q->wd_expires = delay;
561 }
562
563 /* TC_CBQ_OVL_LOWPRIO: penalize class by lowering its priority band */
564
565 static void cbq_ovl_lowprio(struct cbq_class *cl)
566 {
567 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
568
569 cl->penalized = q->now + cl->penalty;
570
571 if (cl->cpriority != cl->priority2) {
572 cl->cpriority = cl->priority2;
573 q->pmask |= (1<<cl->cpriority);
574 cl->xstats.overactions++;
575 }
576 cbq_ovl_classic(cl);
577 }
578
579 /* TC_CBQ_OVL_DROP: penalize class by dropping */
580
581 static void cbq_ovl_drop(struct cbq_class *cl)
582 {
583 if (cl->q->ops->drop)
584 if (cl->q->ops->drop(cl->q))
585 cl->qdisc->q.qlen--;
586 cl->xstats.overactions++;
587 cbq_ovl_classic(cl);
588 }
589
590 static psched_tdiff_t cbq_undelay_prio(struct cbq_sched_data *q, int prio,
591 psched_time_t now)
592 {
593 struct cbq_class *cl;
594 struct cbq_class *cl_prev = q->active[prio];
595 psched_time_t sched = now;
596
597 if (cl_prev == NULL)
598 return 0;
599
600 do {
601 cl = cl_prev->next_alive;
602 if (now - cl->penalized > 0) {
603 cl_prev->next_alive = cl->next_alive;
604 cl->next_alive = NULL;
605 cl->cpriority = cl->priority;
606 cl->delayed = 0;
607 cbq_activate_class(cl);
608
609 if (cl == q->active[prio]) {
610 q->active[prio] = cl_prev;
611 if (cl == q->active[prio]) {
612 q->active[prio] = NULL;
613 return 0;
614 }
615 }
616
617 cl = cl_prev->next_alive;
618 } else if (sched - cl->penalized > 0)
619 sched = cl->penalized;
620 } while ((cl_prev = cl) != q->active[prio]);
621
622 return sched - now;
623 }
624
625 static enum hrtimer_restart cbq_undelay(struct hrtimer *timer)
626 {
627 struct cbq_sched_data *q = container_of(timer, struct cbq_sched_data,
628 delay_timer);
629 struct Qdisc *sch = q->watchdog.qdisc;
630 psched_time_t now;
631 psched_tdiff_t delay = 0;
632 unsigned pmask;
633
634 now = psched_get_time();
635
636 pmask = q->pmask;
637 q->pmask = 0;
638
639 while (pmask) {
640 int prio = ffz(~pmask);
641 psched_tdiff_t tmp;
642
643 pmask &= ~(1<<prio);
644
645 tmp = cbq_undelay_prio(q, prio, now);
646 if (tmp > 0) {
647 q->pmask |= 1<<prio;
648 if (tmp < delay || delay == 0)
649 delay = tmp;
650 }
651 }
652
653 if (delay) {
654 ktime_t time;
655
656 time = ktime_set(0, 0);
657 time = ktime_add_ns(time, PSCHED_US2NS(now + delay));
658 hrtimer_start(&q->delay_timer, time, HRTIMER_MODE_ABS);
659 }
660
661 sch->flags &= ~TCQ_F_THROTTLED;
662 netif_schedule(sch->dev);
663 return HRTIMER_NORESTART;
664 }
665
666 #ifdef CONFIG_NET_CLS_ACT
667 static int cbq_reshape_fail(struct sk_buff *skb, struct Qdisc *child)
668 {
669 int len = skb->len;
670 struct Qdisc *sch = child->__parent;
671 struct cbq_sched_data *q = qdisc_priv(sch);
672 struct cbq_class *cl = q->rx_class;
673
674 q->rx_class = NULL;
675
676 if (cl && (cl = cbq_reclassify(skb, cl)) != NULL) {
677
678 cbq_mark_toplevel(q, cl);
679
680 q->rx_class = cl;
681 cl->q->__parent = sch;
682
683 if (cl->q->enqueue(skb, cl->q) == 0) {
684 sch->q.qlen++;
685 sch->bstats.packets++;
686 sch->bstats.bytes+=len;
687 if (!cl->next_alive)
688 cbq_activate_class(cl);
689 return 0;
690 }
691 sch->qstats.drops++;
692 return 0;
693 }
694
695 sch->qstats.drops++;
696 return -1;
697 }
698 #endif
699
700 /*
701 It is mission critical procedure.
702
703 We "regenerate" toplevel cutoff, if transmitting class
704 has backlog and it is not regulated. It is not part of
705 original CBQ description, but looks more reasonable.
706 Probably, it is wrong. This question needs further investigation.
707 */
708
709 static __inline__ void
710 cbq_update_toplevel(struct cbq_sched_data *q, struct cbq_class *cl,
711 struct cbq_class *borrowed)
712 {
713 if (cl && q->toplevel >= borrowed->level) {
714 if (cl->q->q.qlen > 1) {
715 do {
716 if (borrowed->undertime == PSCHED_PASTPERFECT) {
717 q->toplevel = borrowed->level;
718 return;
719 }
720 } while ((borrowed=borrowed->borrow) != NULL);
721 }
722 #if 0
723 /* It is not necessary now. Uncommenting it
724 will save CPU cycles, but decrease fairness.
725 */
726 q->toplevel = TC_CBQ_MAXLEVEL;
727 #endif
728 }
729 }
730
731 static void
732 cbq_update(struct cbq_sched_data *q)
733 {
734 struct cbq_class *this = q->tx_class;
735 struct cbq_class *cl = this;
736 int len = q->tx_len;
737
738 q->tx_class = NULL;
739
740 for ( ; cl; cl = cl->share) {
741 long avgidle = cl->avgidle;
742 long idle;
743
744 cl->bstats.packets++;
745 cl->bstats.bytes += len;
746
747 /*
748 (now - last) is total time between packet right edges.
749 (last_pktlen/rate) is "virtual" busy time, so that
750
751 idle = (now - last) - last_pktlen/rate
752 */
753
754 idle = q->now - cl->last;
755 if ((unsigned long)idle > 128*1024*1024) {
756 avgidle = cl->maxidle;
757 } else {
758 idle -= L2T(cl, len);
759
760 /* true_avgidle := (1-W)*true_avgidle + W*idle,
761 where W=2^{-ewma_log}. But cl->avgidle is scaled:
762 cl->avgidle == true_avgidle/W,
763 hence:
764 */
765 avgidle += idle - (avgidle>>cl->ewma_log);
766 }
767
768 if (avgidle <= 0) {
769 /* Overlimit or at-limit */
770
771 if (avgidle < cl->minidle)
772 avgidle = cl->minidle;
773
774 cl->avgidle = avgidle;
775
776 /* Calculate expected time, when this class
777 will be allowed to send.
778 It will occur, when:
779 (1-W)*true_avgidle + W*delay = 0, i.e.
780 idle = (1/W - 1)*(-true_avgidle)
781 or
782 idle = (1 - W)*(-cl->avgidle);
783 */
784 idle = (-avgidle) - ((-avgidle) >> cl->ewma_log);
785
786 /*
787 That is not all.
788 To maintain the rate allocated to the class,
789 we add to undertime virtual clock,
790 necessary to complete transmitted packet.
791 (len/phys_bandwidth has been already passed
792 to the moment of cbq_update)
793 */
794
795 idle -= L2T(&q->link, len);
796 idle += L2T(cl, len);
797
798 cl->undertime = q->now + idle;
799 } else {
800 /* Underlimit */
801
802 cl->undertime = PSCHED_PASTPERFECT;
803 if (avgidle > cl->maxidle)
804 cl->avgidle = cl->maxidle;
805 else
806 cl->avgidle = avgidle;
807 }
808 cl->last = q->now;
809 }
810
811 cbq_update_toplevel(q, this, q->tx_borrowed);
812 }
813
814 static __inline__ struct cbq_class *
815 cbq_under_limit(struct cbq_class *cl)
816 {
817 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
818 struct cbq_class *this_cl = cl;
819
820 if (cl->tparent == NULL)
821 return cl;
822
823 if (cl->undertime == PSCHED_PASTPERFECT || q->now >= cl->undertime) {
824 cl->delayed = 0;
825 return cl;
826 }
827
828 do {
829 /* It is very suspicious place. Now overlimit
830 action is generated for not bounded classes
831 only if link is completely congested.
832 Though it is in agree with ancestor-only paradigm,
833 it looks very stupid. Particularly,
834 it means that this chunk of code will either
835 never be called or result in strong amplification
836 of burstiness. Dangerous, silly, and, however,
837 no another solution exists.
838 */
839 if ((cl = cl->borrow) == NULL) {
840 this_cl->qstats.overlimits++;
841 this_cl->overlimit(this_cl);
842 return NULL;
843 }
844 if (cl->level > q->toplevel)
845 return NULL;
846 } while (cl->undertime != PSCHED_PASTPERFECT && q->now < cl->undertime);
847
848 cl->delayed = 0;
849 return cl;
850 }
851
852 static __inline__ struct sk_buff *
853 cbq_dequeue_prio(struct Qdisc *sch, int prio)
854 {
855 struct cbq_sched_data *q = qdisc_priv(sch);
856 struct cbq_class *cl_tail, *cl_prev, *cl;
857 struct sk_buff *skb;
858 int deficit;
859
860 cl_tail = cl_prev = q->active[prio];
861 cl = cl_prev->next_alive;
862
863 do {
864 deficit = 0;
865
866 /* Start round */
867 do {
868 struct cbq_class *borrow = cl;
869
870 if (cl->q->q.qlen &&
871 (borrow = cbq_under_limit(cl)) == NULL)
872 goto skip_class;
873
874 if (cl->deficit <= 0) {
875 /* Class exhausted its allotment per
876 this round. Switch to the next one.
877 */
878 deficit = 1;
879 cl->deficit += cl->quantum;
880 goto next_class;
881 }
882
883 skb = cl->q->dequeue(cl->q);
884
885 /* Class did not give us any skb :-(
886 It could occur even if cl->q->q.qlen != 0
887 f.e. if cl->q == "tbf"
888 */
889 if (skb == NULL)
890 goto skip_class;
891
892 cl->deficit -= skb->len;
893 q->tx_class = cl;
894 q->tx_borrowed = borrow;
895 if (borrow != cl) {
896 #ifndef CBQ_XSTATS_BORROWS_BYTES
897 borrow->xstats.borrows++;
898 cl->xstats.borrows++;
899 #else
900 borrow->xstats.borrows += skb->len;
901 cl->xstats.borrows += skb->len;
902 #endif
903 }
904 q->tx_len = skb->len;
905
906 if (cl->deficit <= 0) {
907 q->active[prio] = cl;
908 cl = cl->next_alive;
909 cl->deficit += cl->quantum;
910 }
911 return skb;
912
913 skip_class:
914 if (cl->q->q.qlen == 0 || prio != cl->cpriority) {
915 /* Class is empty or penalized.
916 Unlink it from active chain.
917 */
918 cl_prev->next_alive = cl->next_alive;
919 cl->next_alive = NULL;
920
921 /* Did cl_tail point to it? */
922 if (cl == cl_tail) {
923 /* Repair it! */
924 cl_tail = cl_prev;
925
926 /* Was it the last class in this band? */
927 if (cl == cl_tail) {
928 /* Kill the band! */
929 q->active[prio] = NULL;
930 q->activemask &= ~(1<<prio);
931 if (cl->q->q.qlen)
932 cbq_activate_class(cl);
933 return NULL;
934 }
935
936 q->active[prio] = cl_tail;
937 }
938 if (cl->q->q.qlen)
939 cbq_activate_class(cl);
940
941 cl = cl_prev;
942 }
943
944 next_class:
945 cl_prev = cl;
946 cl = cl->next_alive;
947 } while (cl_prev != cl_tail);
948 } while (deficit);
949
950 q->active[prio] = cl_prev;
951
952 return NULL;
953 }
954
955 static __inline__ struct sk_buff *
956 cbq_dequeue_1(struct Qdisc *sch)
957 {
958 struct cbq_sched_data *q = qdisc_priv(sch);
959 struct sk_buff *skb;
960 unsigned activemask;
961
962 activemask = q->activemask&0xFF;
963 while (activemask) {
964 int prio = ffz(~activemask);
965 activemask &= ~(1<<prio);
966 skb = cbq_dequeue_prio(sch, prio);
967 if (skb)
968 return skb;
969 }
970 return NULL;
971 }
972
973 static struct sk_buff *
974 cbq_dequeue(struct Qdisc *sch)
975 {
976 struct sk_buff *skb;
977 struct cbq_sched_data *q = qdisc_priv(sch);
978 psched_time_t now;
979 psched_tdiff_t incr;
980
981 now = psched_get_time();
982 incr = now - q->now_rt;
983
984 if (q->tx_class) {
985 psched_tdiff_t incr2;
986 /* Time integrator. We calculate EOS time
987 by adding expected packet transmission time.
988 If real time is greater, we warp artificial clock,
989 so that:
990
991 cbq_time = max(real_time, work);
992 */
993 incr2 = L2T(&q->link, q->tx_len);
994 q->now += incr2;
995 cbq_update(q);
996 if ((incr -= incr2) < 0)
997 incr = 0;
998 }
999 q->now += incr;
1000 q->now_rt = now;
1001
1002 for (;;) {
1003 q->wd_expires = 0;
1004
1005 skb = cbq_dequeue_1(sch);
1006 if (skb) {
1007 sch->q.qlen--;
1008 sch->flags &= ~TCQ_F_THROTTLED;
1009 return skb;
1010 }
1011
1012 /* All the classes are overlimit.
1013
1014 It is possible, if:
1015
1016 1. Scheduler is empty.
1017 2. Toplevel cutoff inhibited borrowing.
1018 3. Root class is overlimit.
1019
1020 Reset 2d and 3d conditions and retry.
1021
1022 Note, that NS and cbq-2.0 are buggy, peeking
1023 an arbitrary class is appropriate for ancestor-only
1024 sharing, but not for toplevel algorithm.
1025
1026 Our version is better, but slower, because it requires
1027 two passes, but it is unavoidable with top-level sharing.
1028 */
1029
1030 if (q->toplevel == TC_CBQ_MAXLEVEL &&
1031 q->link.undertime == PSCHED_PASTPERFECT)
1032 break;
1033
1034 q->toplevel = TC_CBQ_MAXLEVEL;
1035 q->link.undertime = PSCHED_PASTPERFECT;
1036 }
1037
1038 /* No packets in scheduler or nobody wants to give them to us :-(
1039 Sigh... start watchdog timer in the last case. */
1040
1041 if (sch->q.qlen) {
1042 sch->qstats.overlimits++;
1043 if (q->wd_expires)
1044 qdisc_watchdog_schedule(&q->watchdog,
1045 now + q->wd_expires);
1046 }
1047 return NULL;
1048 }
1049
1050 /* CBQ class maintanance routines */
1051
1052 static void cbq_adjust_levels(struct cbq_class *this)
1053 {
1054 if (this == NULL)
1055 return;
1056
1057 do {
1058 int level = 0;
1059 struct cbq_class *cl;
1060
1061 if ((cl = this->children) != NULL) {
1062 do {
1063 if (cl->level > level)
1064 level = cl->level;
1065 } while ((cl = cl->sibling) != this->children);
1066 }
1067 this->level = level+1;
1068 } while ((this = this->tparent) != NULL);
1069 }
1070
1071 static void cbq_normalize_quanta(struct cbq_sched_data *q, int prio)
1072 {
1073 struct cbq_class *cl;
1074 unsigned h;
1075
1076 if (q->quanta[prio] == 0)
1077 return;
1078
1079 for (h=0; h<16; h++) {
1080 for (cl = q->classes[h]; cl; cl = cl->next) {
1081 /* BUGGGG... Beware! This expression suffer of
1082 arithmetic overflows!
1083 */
1084 if (cl->priority == prio) {
1085 cl->quantum = (cl->weight*cl->allot*q->nclasses[prio])/
1086 q->quanta[prio];
1087 }
1088 if (cl->quantum <= 0 || cl->quantum>32*cl->qdisc->dev->mtu) {
1089 printk(KERN_WARNING "CBQ: class %08x has bad quantum==%ld, repaired.\n", cl->classid, cl->quantum);
1090 cl->quantum = cl->qdisc->dev->mtu/2 + 1;
1091 }
1092 }
1093 }
1094 }
1095
1096 static void cbq_sync_defmap(struct cbq_class *cl)
1097 {
1098 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
1099 struct cbq_class *split = cl->split;
1100 unsigned h;
1101 int i;
1102
1103 if (split == NULL)
1104 return;
1105
1106 for (i=0; i<=TC_PRIO_MAX; i++) {
1107 if (split->defaults[i] == cl && !(cl->defmap&(1<<i)))
1108 split->defaults[i] = NULL;
1109 }
1110
1111 for (i=0; i<=TC_PRIO_MAX; i++) {
1112 int level = split->level;
1113
1114 if (split->defaults[i])
1115 continue;
1116
1117 for (h=0; h<16; h++) {
1118 struct cbq_class *c;
1119
1120 for (c = q->classes[h]; c; c = c->next) {
1121 if (c->split == split && c->level < level &&
1122 c->defmap&(1<<i)) {
1123 split->defaults[i] = c;
1124 level = c->level;
1125 }
1126 }
1127 }
1128 }
1129 }
1130
1131 static void cbq_change_defmap(struct cbq_class *cl, u32 splitid, u32 def, u32 mask)
1132 {
1133 struct cbq_class *split = NULL;
1134
1135 if (splitid == 0) {
1136 if ((split = cl->split) == NULL)
1137 return;
1138 splitid = split->classid;
1139 }
1140
1141 if (split == NULL || split->classid != splitid) {
1142 for (split = cl->tparent; split; split = split->tparent)
1143 if (split->classid == splitid)
1144 break;
1145 }
1146
1147 if (split == NULL)
1148 return;
1149
1150 if (cl->split != split) {
1151 cl->defmap = 0;
1152 cbq_sync_defmap(cl);
1153 cl->split = split;
1154 cl->defmap = def&mask;
1155 } else
1156 cl->defmap = (cl->defmap&~mask)|(def&mask);
1157
1158 cbq_sync_defmap(cl);
1159 }
1160
1161 static void cbq_unlink_class(struct cbq_class *this)
1162 {
1163 struct cbq_class *cl, **clp;
1164 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
1165
1166 for (clp = &q->classes[cbq_hash(this->classid)]; (cl = *clp) != NULL; clp = &cl->next) {
1167 if (cl == this) {
1168 *clp = cl->next;
1169 cl->next = NULL;
1170 break;
1171 }
1172 }
1173
1174 if (this->tparent) {
1175 clp=&this->sibling;
1176 cl = *clp;
1177 do {
1178 if (cl == this) {
1179 *clp = cl->sibling;
1180 break;
1181 }
1182 clp = &cl->sibling;
1183 } while ((cl = *clp) != this->sibling);
1184
1185 if (this->tparent->children == this) {
1186 this->tparent->children = this->sibling;
1187 if (this->sibling == this)
1188 this->tparent->children = NULL;
1189 }
1190 } else {
1191 BUG_TRAP(this->sibling == this);
1192 }
1193 }
1194
1195 static void cbq_link_class(struct cbq_class *this)
1196 {
1197 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
1198 unsigned h = cbq_hash(this->classid);
1199 struct cbq_class *parent = this->tparent;
1200
1201 this->sibling = this;
1202 this->next = q->classes[h];
1203 q->classes[h] = this;
1204
1205 if (parent == NULL)
1206 return;
1207
1208 if (parent->children == NULL) {
1209 parent->children = this;
1210 } else {
1211 this->sibling = parent->children->sibling;
1212 parent->children->sibling = this;
1213 }
1214 }
1215
1216 static unsigned int cbq_drop(struct Qdisc* sch)
1217 {
1218 struct cbq_sched_data *q = qdisc_priv(sch);
1219 struct cbq_class *cl, *cl_head;
1220 int prio;
1221 unsigned int len;
1222
1223 for (prio = TC_CBQ_MAXPRIO; prio >= 0; prio--) {
1224 if ((cl_head = q->active[prio]) == NULL)
1225 continue;
1226
1227 cl = cl_head;
1228 do {
1229 if (cl->q->ops->drop && (len = cl->q->ops->drop(cl->q))) {
1230 sch->q.qlen--;
1231 if (!cl->q->q.qlen)
1232 cbq_deactivate_class(cl);
1233 return len;
1234 }
1235 } while ((cl = cl->next_alive) != cl_head);
1236 }
1237 return 0;
1238 }
1239
1240 static void
1241 cbq_reset(struct Qdisc* sch)
1242 {
1243 struct cbq_sched_data *q = qdisc_priv(sch);
1244 struct cbq_class *cl;
1245 int prio;
1246 unsigned h;
1247
1248 q->activemask = 0;
1249 q->pmask = 0;
1250 q->tx_class = NULL;
1251 q->tx_borrowed = NULL;
1252 qdisc_watchdog_cancel(&q->watchdog);
1253 hrtimer_cancel(&q->delay_timer);
1254 q->toplevel = TC_CBQ_MAXLEVEL;
1255 q->now = psched_get_time();
1256 q->now_rt = q->now;
1257
1258 for (prio = 0; prio <= TC_CBQ_MAXPRIO; prio++)
1259 q->active[prio] = NULL;
1260
1261 for (h = 0; h < 16; h++) {
1262 for (cl = q->classes[h]; cl; cl = cl->next) {
1263 qdisc_reset(cl->q);
1264
1265 cl->next_alive = NULL;
1266 cl->undertime = PSCHED_PASTPERFECT;
1267 cl->avgidle = cl->maxidle;
1268 cl->deficit = cl->quantum;
1269 cl->cpriority = cl->priority;
1270 }
1271 }
1272 sch->q.qlen = 0;
1273 }
1274
1275
1276 static int cbq_set_lss(struct cbq_class *cl, struct tc_cbq_lssopt *lss)
1277 {
1278 if (lss->change&TCF_CBQ_LSS_FLAGS) {
1279 cl->share = (lss->flags&TCF_CBQ_LSS_ISOLATED) ? NULL : cl->tparent;
1280 cl->borrow = (lss->flags&TCF_CBQ_LSS_BOUNDED) ? NULL : cl->tparent;
1281 }
1282 if (lss->change&TCF_CBQ_LSS_EWMA)
1283 cl->ewma_log = lss->ewma_log;
1284 if (lss->change&TCF_CBQ_LSS_AVPKT)
1285 cl->avpkt = lss->avpkt;
1286 if (lss->change&TCF_CBQ_LSS_MINIDLE)
1287 cl->minidle = -(long)lss->minidle;
1288 if (lss->change&TCF_CBQ_LSS_MAXIDLE) {
1289 cl->maxidle = lss->maxidle;
1290 cl->avgidle = lss->maxidle;
1291 }
1292 if (lss->change&TCF_CBQ_LSS_OFFTIME)
1293 cl->offtime = lss->offtime;
1294 return 0;
1295 }
1296
1297 static void cbq_rmprio(struct cbq_sched_data *q, struct cbq_class *cl)
1298 {
1299 q->nclasses[cl->priority]--;
1300 q->quanta[cl->priority] -= cl->weight;
1301 cbq_normalize_quanta(q, cl->priority);
1302 }
1303
1304 static void cbq_addprio(struct cbq_sched_data *q, struct cbq_class *cl)
1305 {
1306 q->nclasses[cl->priority]++;
1307 q->quanta[cl->priority] += cl->weight;
1308 cbq_normalize_quanta(q, cl->priority);
1309 }
1310
1311 static int cbq_set_wrr(struct cbq_class *cl, struct tc_cbq_wrropt *wrr)
1312 {
1313 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
1314
1315 if (wrr->allot)
1316 cl->allot = wrr->allot;
1317 if (wrr->weight)
1318 cl->weight = wrr->weight;
1319 if (wrr->priority) {
1320 cl->priority = wrr->priority-1;
1321 cl->cpriority = cl->priority;
1322 if (cl->priority >= cl->priority2)
1323 cl->priority2 = TC_CBQ_MAXPRIO-1;
1324 }
1325
1326 cbq_addprio(q, cl);
1327 return 0;
1328 }
1329
1330 static int cbq_set_overlimit(struct cbq_class *cl, struct tc_cbq_ovl *ovl)
1331 {
1332 switch (ovl->strategy) {
1333 case TC_CBQ_OVL_CLASSIC:
1334 cl->overlimit = cbq_ovl_classic;
1335 break;
1336 case TC_CBQ_OVL_DELAY:
1337 cl->overlimit = cbq_ovl_delay;
1338 break;
1339 case TC_CBQ_OVL_LOWPRIO:
1340 if (ovl->priority2-1 >= TC_CBQ_MAXPRIO ||
1341 ovl->priority2-1 <= cl->priority)
1342 return -EINVAL;
1343 cl->priority2 = ovl->priority2-1;
1344 cl->overlimit = cbq_ovl_lowprio;
1345 break;
1346 case TC_CBQ_OVL_DROP:
1347 cl->overlimit = cbq_ovl_drop;
1348 break;
1349 case TC_CBQ_OVL_RCLASSIC:
1350 cl->overlimit = cbq_ovl_rclassic;
1351 break;
1352 default:
1353 return -EINVAL;
1354 }
1355 cl->penalty = ovl->penalty;
1356 return 0;
1357 }
1358
1359 #ifdef CONFIG_NET_CLS_ACT
1360 static int cbq_set_police(struct cbq_class *cl, struct tc_cbq_police *p)
1361 {
1362 cl->police = p->police;
1363
1364 if (cl->q->handle) {
1365 if (p->police == TC_POLICE_RECLASSIFY)
1366 cl->q->reshape_fail = cbq_reshape_fail;
1367 else
1368 cl->q->reshape_fail = NULL;
1369 }
1370 return 0;
1371 }
1372 #endif
1373
1374 static int cbq_set_fopt(struct cbq_class *cl, struct tc_cbq_fopt *fopt)
1375 {
1376 cbq_change_defmap(cl, fopt->split, fopt->defmap, fopt->defchange);
1377 return 0;
1378 }
1379
1380 static int cbq_init(struct Qdisc *sch, struct nlattr *opt)
1381 {
1382 struct cbq_sched_data *q = qdisc_priv(sch);
1383 struct nlattr *tb[TCA_CBQ_MAX + 1];
1384 struct tc_ratespec *r;
1385 int err;
1386
1387 err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, NULL);
1388 if (err < 0)
1389 return err;
1390
1391 if (tb[TCA_CBQ_RTAB] == NULL || tb[TCA_CBQ_RATE] == NULL ||
1392 nla_len(tb[TCA_CBQ_RATE]) < sizeof(struct tc_ratespec))
1393 return -EINVAL;
1394
1395 if (tb[TCA_CBQ_LSSOPT] &&
1396 nla_len(tb[TCA_CBQ_LSSOPT]) < sizeof(struct tc_cbq_lssopt))
1397 return -EINVAL;
1398
1399 r = nla_data(tb[TCA_CBQ_RATE]);
1400
1401 if ((q->link.R_tab = qdisc_get_rtab(r, tb[TCA_CBQ_RTAB])) == NULL)
1402 return -EINVAL;
1403
1404 q->link.refcnt = 1;
1405 q->link.sibling = &q->link;
1406 q->link.classid = sch->handle;
1407 q->link.qdisc = sch;
1408 if (!(q->link.q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops,
1409 sch->handle)))
1410 q->link.q = &noop_qdisc;
1411
1412 q->link.priority = TC_CBQ_MAXPRIO-1;
1413 q->link.priority2 = TC_CBQ_MAXPRIO-1;
1414 q->link.cpriority = TC_CBQ_MAXPRIO-1;
1415 q->link.ovl_strategy = TC_CBQ_OVL_CLASSIC;
1416 q->link.overlimit = cbq_ovl_classic;
1417 q->link.allot = psched_mtu(sch->dev);
1418 q->link.quantum = q->link.allot;
1419 q->link.weight = q->link.R_tab->rate.rate;
1420
1421 q->link.ewma_log = TC_CBQ_DEF_EWMA;
1422 q->link.avpkt = q->link.allot/2;
1423 q->link.minidle = -0x7FFFFFFF;
1424
1425 qdisc_watchdog_init(&q->watchdog, sch);
1426 hrtimer_init(&q->delay_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
1427 q->delay_timer.function = cbq_undelay;
1428 q->toplevel = TC_CBQ_MAXLEVEL;
1429 q->now = psched_get_time();
1430 q->now_rt = q->now;
1431
1432 cbq_link_class(&q->link);
1433
1434 if (tb[TCA_CBQ_LSSOPT])
1435 cbq_set_lss(&q->link, nla_data(tb[TCA_CBQ_LSSOPT]));
1436
1437 cbq_addprio(q, &q->link);
1438 return 0;
1439 }
1440
1441 static __inline__ int cbq_dump_rate(struct sk_buff *skb, struct cbq_class *cl)
1442 {
1443 unsigned char *b = skb_tail_pointer(skb);
1444
1445 NLA_PUT(skb, TCA_CBQ_RATE, sizeof(cl->R_tab->rate), &cl->R_tab->rate);
1446 return skb->len;
1447
1448 nla_put_failure:
1449 nlmsg_trim(skb, b);
1450 return -1;
1451 }
1452
1453 static __inline__ int cbq_dump_lss(struct sk_buff *skb, struct cbq_class *cl)
1454 {
1455 unsigned char *b = skb_tail_pointer(skb);
1456 struct tc_cbq_lssopt opt;
1457
1458 opt.flags = 0;
1459 if (cl->borrow == NULL)
1460 opt.flags |= TCF_CBQ_LSS_BOUNDED;
1461 if (cl->share == NULL)
1462 opt.flags |= TCF_CBQ_LSS_ISOLATED;
1463 opt.ewma_log = cl->ewma_log;
1464 opt.level = cl->level;
1465 opt.avpkt = cl->avpkt;
1466 opt.maxidle = cl->maxidle;
1467 opt.minidle = (u32)(-cl->minidle);
1468 opt.offtime = cl->offtime;
1469 opt.change = ~0;
1470 NLA_PUT(skb, TCA_CBQ_LSSOPT, sizeof(opt), &opt);
1471 return skb->len;
1472
1473 nla_put_failure:
1474 nlmsg_trim(skb, b);
1475 return -1;
1476 }
1477
1478 static __inline__ int cbq_dump_wrr(struct sk_buff *skb, struct cbq_class *cl)
1479 {
1480 unsigned char *b = skb_tail_pointer(skb);
1481 struct tc_cbq_wrropt opt;
1482
1483 opt.flags = 0;
1484 opt.allot = cl->allot;
1485 opt.priority = cl->priority+1;
1486 opt.cpriority = cl->cpriority+1;
1487 opt.weight = cl->weight;
1488 NLA_PUT(skb, TCA_CBQ_WRROPT, sizeof(opt), &opt);
1489 return skb->len;
1490
1491 nla_put_failure:
1492 nlmsg_trim(skb, b);
1493 return -1;
1494 }
1495
1496 static __inline__ int cbq_dump_ovl(struct sk_buff *skb, struct cbq_class *cl)
1497 {
1498 unsigned char *b = skb_tail_pointer(skb);
1499 struct tc_cbq_ovl opt;
1500
1501 opt.strategy = cl->ovl_strategy;
1502 opt.priority2 = cl->priority2+1;
1503 opt.pad = 0;
1504 opt.penalty = cl->penalty;
1505 NLA_PUT(skb, TCA_CBQ_OVL_STRATEGY, sizeof(opt), &opt);
1506 return skb->len;
1507
1508 nla_put_failure:
1509 nlmsg_trim(skb, b);
1510 return -1;
1511 }
1512
1513 static __inline__ int cbq_dump_fopt(struct sk_buff *skb, struct cbq_class *cl)
1514 {
1515 unsigned char *b = skb_tail_pointer(skb);
1516 struct tc_cbq_fopt opt;
1517
1518 if (cl->split || cl->defmap) {
1519 opt.split = cl->split ? cl->split->classid : 0;
1520 opt.defmap = cl->defmap;
1521 opt.defchange = ~0;
1522 NLA_PUT(skb, TCA_CBQ_FOPT, sizeof(opt), &opt);
1523 }
1524 return skb->len;
1525
1526 nla_put_failure:
1527 nlmsg_trim(skb, b);
1528 return -1;
1529 }
1530
1531 #ifdef CONFIG_NET_CLS_ACT
1532 static __inline__ int cbq_dump_police(struct sk_buff *skb, struct cbq_class *cl)
1533 {
1534 unsigned char *b = skb_tail_pointer(skb);
1535 struct tc_cbq_police opt;
1536
1537 if (cl->police) {
1538 opt.police = cl->police;
1539 opt.__res1 = 0;
1540 opt.__res2 = 0;
1541 NLA_PUT(skb, TCA_CBQ_POLICE, sizeof(opt), &opt);
1542 }
1543 return skb->len;
1544
1545 nla_put_failure:
1546 nlmsg_trim(skb, b);
1547 return -1;
1548 }
1549 #endif
1550
1551 static int cbq_dump_attr(struct sk_buff *skb, struct cbq_class *cl)
1552 {
1553 if (cbq_dump_lss(skb, cl) < 0 ||
1554 cbq_dump_rate(skb, cl) < 0 ||
1555 cbq_dump_wrr(skb, cl) < 0 ||
1556 cbq_dump_ovl(skb, cl) < 0 ||
1557 #ifdef CONFIG_NET_CLS_ACT
1558 cbq_dump_police(skb, cl) < 0 ||
1559 #endif
1560 cbq_dump_fopt(skb, cl) < 0)
1561 return -1;
1562 return 0;
1563 }
1564
1565 static int cbq_dump(struct Qdisc *sch, struct sk_buff *skb)
1566 {
1567 struct cbq_sched_data *q = qdisc_priv(sch);
1568 struct nlattr *nest;
1569
1570 nest = nla_nest_start(skb, TCA_OPTIONS);
1571 if (nest == NULL)
1572 goto nla_put_failure;
1573 if (cbq_dump_attr(skb, &q->link) < 0)
1574 goto nla_put_failure;
1575 nla_nest_end(skb, nest);
1576 return skb->len;
1577
1578 nla_put_failure:
1579 nla_nest_cancel(skb, nest);
1580 return -1;
1581 }
1582
1583 static int
1584 cbq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
1585 {
1586 struct cbq_sched_data *q = qdisc_priv(sch);
1587
1588 q->link.xstats.avgidle = q->link.avgidle;
1589 return gnet_stats_copy_app(d, &q->link.xstats, sizeof(q->link.xstats));
1590 }
1591
1592 static int
1593 cbq_dump_class(struct Qdisc *sch, unsigned long arg,
1594 struct sk_buff *skb, struct tcmsg *tcm)
1595 {
1596 struct cbq_class *cl = (struct cbq_class*)arg;
1597 struct nlattr *nest;
1598
1599 if (cl->tparent)
1600 tcm->tcm_parent = cl->tparent->classid;
1601 else
1602 tcm->tcm_parent = TC_H_ROOT;
1603 tcm->tcm_handle = cl->classid;
1604 tcm->tcm_info = cl->q->handle;
1605
1606 nest = nla_nest_start(skb, TCA_OPTIONS);
1607 if (nest == NULL)
1608 goto nla_put_failure;
1609 if (cbq_dump_attr(skb, cl) < 0)
1610 goto nla_put_failure;
1611 nla_nest_end(skb, nest);
1612 return skb->len;
1613
1614 nla_put_failure:
1615 nla_nest_cancel(skb, nest);
1616 return -1;
1617 }
1618
1619 static int
1620 cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1621 struct gnet_dump *d)
1622 {
1623 struct cbq_sched_data *q = qdisc_priv(sch);
1624 struct cbq_class *cl = (struct cbq_class*)arg;
1625
1626 cl->qstats.qlen = cl->q->q.qlen;
1627 cl->xstats.avgidle = cl->avgidle;
1628 cl->xstats.undertime = 0;
1629
1630 if (cl->undertime != PSCHED_PASTPERFECT)
1631 cl->xstats.undertime = cl->undertime - q->now;
1632
1633 if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
1634 gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
1635 gnet_stats_copy_queue(d, &cl->qstats) < 0)
1636 return -1;
1637
1638 return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));
1639 }
1640
1641 static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1642 struct Qdisc **old)
1643 {
1644 struct cbq_class *cl = (struct cbq_class*)arg;
1645
1646 if (cl) {
1647 if (new == NULL) {
1648 if ((new = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops,
1649 cl->classid)) == NULL)
1650 return -ENOBUFS;
1651 } else {
1652 #ifdef CONFIG_NET_CLS_ACT
1653 if (cl->police == TC_POLICE_RECLASSIFY)
1654 new->reshape_fail = cbq_reshape_fail;
1655 #endif
1656 }
1657 sch_tree_lock(sch);
1658 *old = xchg(&cl->q, new);
1659 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
1660 qdisc_reset(*old);
1661 sch_tree_unlock(sch);
1662
1663 return 0;
1664 }
1665 return -ENOENT;
1666 }
1667
1668 static struct Qdisc *
1669 cbq_leaf(struct Qdisc *sch, unsigned long arg)
1670 {
1671 struct cbq_class *cl = (struct cbq_class*)arg;
1672
1673 return cl ? cl->q : NULL;
1674 }
1675
1676 static void cbq_qlen_notify(struct Qdisc *sch, unsigned long arg)
1677 {
1678 struct cbq_class *cl = (struct cbq_class *)arg;
1679
1680 if (cl->q->q.qlen == 0)
1681 cbq_deactivate_class(cl);
1682 }
1683
1684 static unsigned long cbq_get(struct Qdisc *sch, u32 classid)
1685 {
1686 struct cbq_sched_data *q = qdisc_priv(sch);
1687 struct cbq_class *cl = cbq_class_lookup(q, classid);
1688
1689 if (cl) {
1690 cl->refcnt++;
1691 return (unsigned long)cl;
1692 }
1693 return 0;
1694 }
1695
1696 static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl)
1697 {
1698 struct cbq_sched_data *q = qdisc_priv(sch);
1699
1700 BUG_TRAP(!cl->filters);
1701
1702 tcf_destroy_chain(cl->filter_list);
1703 qdisc_destroy(cl->q);
1704 qdisc_put_rtab(cl->R_tab);
1705 gen_kill_estimator(&cl->bstats, &cl->rate_est);
1706 if (cl != &q->link)
1707 kfree(cl);
1708 }
1709
1710 static void
1711 cbq_destroy(struct Qdisc* sch)
1712 {
1713 struct cbq_sched_data *q = qdisc_priv(sch);
1714 struct cbq_class *cl;
1715 unsigned h;
1716
1717 #ifdef CONFIG_NET_CLS_ACT
1718 q->rx_class = NULL;
1719 #endif
1720 /*
1721 * Filters must be destroyed first because we don't destroy the
1722 * classes from root to leafs which means that filters can still
1723 * be bound to classes which have been destroyed already. --TGR '04
1724 */
1725 for (h = 0; h < 16; h++) {
1726 for (cl = q->classes[h]; cl; cl = cl->next) {
1727 tcf_destroy_chain(cl->filter_list);
1728 cl->filter_list = NULL;
1729 }
1730 }
1731 for (h = 0; h < 16; h++) {
1732 struct cbq_class *next;
1733
1734 for (cl = q->classes[h]; cl; cl = next) {
1735 next = cl->next;
1736 cbq_destroy_class(sch, cl);
1737 }
1738 }
1739 }
1740
1741 static void cbq_put(struct Qdisc *sch, unsigned long arg)
1742 {
1743 struct cbq_class *cl = (struct cbq_class*)arg;
1744
1745 if (--cl->refcnt == 0) {
1746 #ifdef CONFIG_NET_CLS_ACT
1747 struct cbq_sched_data *q = qdisc_priv(sch);
1748
1749 spin_lock_bh(&sch->dev->queue_lock);
1750 if (q->rx_class == cl)
1751 q->rx_class = NULL;
1752 spin_unlock_bh(&sch->dev->queue_lock);
1753 #endif
1754
1755 cbq_destroy_class(sch, cl);
1756 }
1757 }
1758
1759 static int
1760 cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **tca,
1761 unsigned long *arg)
1762 {
1763 int err;
1764 struct cbq_sched_data *q = qdisc_priv(sch);
1765 struct cbq_class *cl = (struct cbq_class*)*arg;
1766 struct nlattr *opt = tca[TCA_OPTIONS];
1767 struct nlattr *tb[TCA_CBQ_MAX + 1];
1768 struct cbq_class *parent;
1769 struct qdisc_rate_table *rtab = NULL;
1770
1771 if (opt == NULL)
1772 return -EINVAL;
1773
1774 err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, NULL);
1775 if (err < 0)
1776 return err;
1777
1778 if (tb[TCA_CBQ_OVL_STRATEGY] &&
1779 nla_len(tb[TCA_CBQ_OVL_STRATEGY]) < sizeof(struct tc_cbq_ovl))
1780 return -EINVAL;
1781
1782 if (tb[TCA_CBQ_FOPT] &&
1783 nla_len(tb[TCA_CBQ_FOPT]) < sizeof(struct tc_cbq_fopt))
1784 return -EINVAL;
1785
1786 if (tb[TCA_CBQ_RATE] &&
1787 nla_len(tb[TCA_CBQ_RATE]) < sizeof(struct tc_ratespec))
1788 return -EINVAL;
1789
1790 if (tb[TCA_CBQ_LSSOPT] &&
1791 nla_len(tb[TCA_CBQ_LSSOPT]) < sizeof(struct tc_cbq_lssopt))
1792 return -EINVAL;
1793
1794 if (tb[TCA_CBQ_WRROPT] &&
1795 nla_len(tb[TCA_CBQ_WRROPT]) < sizeof(struct tc_cbq_wrropt))
1796 return -EINVAL;
1797
1798 #ifdef CONFIG_NET_CLS_ACT
1799 if (tb[TCA_CBQ_POLICE] &&
1800 nla_len(tb[TCA_CBQ_POLICE]) < sizeof(struct tc_cbq_police))
1801 return -EINVAL;
1802 #endif
1803
1804 if (cl) {
1805 /* Check parent */
1806 if (parentid) {
1807 if (cl->tparent && cl->tparent->classid != parentid)
1808 return -EINVAL;
1809 if (!cl->tparent && parentid != TC_H_ROOT)
1810 return -EINVAL;
1811 }
1812
1813 if (tb[TCA_CBQ_RATE]) {
1814 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]), tb[TCA_CBQ_RTAB]);
1815 if (rtab == NULL)
1816 return -EINVAL;
1817 }
1818
1819 /* Change class parameters */
1820 sch_tree_lock(sch);
1821
1822 if (cl->next_alive != NULL)
1823 cbq_deactivate_class(cl);
1824
1825 if (rtab) {
1826 rtab = xchg(&cl->R_tab, rtab);
1827 qdisc_put_rtab(rtab);
1828 }
1829
1830 if (tb[TCA_CBQ_LSSOPT])
1831 cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
1832
1833 if (tb[TCA_CBQ_WRROPT]) {
1834 cbq_rmprio(q, cl);
1835 cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
1836 }
1837
1838 if (tb[TCA_CBQ_OVL_STRATEGY])
1839 cbq_set_overlimit(cl, nla_data(tb[TCA_CBQ_OVL_STRATEGY]));
1840
1841 #ifdef CONFIG_NET_CLS_ACT
1842 if (tb[TCA_CBQ_POLICE])
1843 cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE]));
1844 #endif
1845
1846 if (tb[TCA_CBQ_FOPT])
1847 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
1848
1849 if (cl->q->q.qlen)
1850 cbq_activate_class(cl);
1851
1852 sch_tree_unlock(sch);
1853
1854 if (tca[TCA_RATE])
1855 gen_replace_estimator(&cl->bstats, &cl->rate_est,
1856 &sch->dev->queue_lock,
1857 tca[TCA_RATE]);
1858 return 0;
1859 }
1860
1861 if (parentid == TC_H_ROOT)
1862 return -EINVAL;
1863
1864 if (tb[TCA_CBQ_WRROPT] == NULL || tb[TCA_CBQ_RATE] == NULL ||
1865 tb[TCA_CBQ_LSSOPT] == NULL)
1866 return -EINVAL;
1867
1868 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]), tb[TCA_CBQ_RTAB]);
1869 if (rtab == NULL)
1870 return -EINVAL;
1871
1872 if (classid) {
1873 err = -EINVAL;
1874 if (TC_H_MAJ(classid^sch->handle) || cbq_class_lookup(q, classid))
1875 goto failure;
1876 } else {
1877 int i;
1878 classid = TC_H_MAKE(sch->handle,0x8000);
1879
1880 for (i=0; i<0x8000; i++) {
1881 if (++q->hgenerator >= 0x8000)
1882 q->hgenerator = 1;
1883 if (cbq_class_lookup(q, classid|q->hgenerator) == NULL)
1884 break;
1885 }
1886 err = -ENOSR;
1887 if (i >= 0x8000)
1888 goto failure;
1889 classid = classid|q->hgenerator;
1890 }
1891
1892 parent = &q->link;
1893 if (parentid) {
1894 parent = cbq_class_lookup(q, parentid);
1895 err = -EINVAL;
1896 if (parent == NULL)
1897 goto failure;
1898 }
1899
1900 err = -ENOBUFS;
1901 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
1902 if (cl == NULL)
1903 goto failure;
1904 cl->R_tab = rtab;
1905 rtab = NULL;
1906 cl->refcnt = 1;
1907 if (!(cl->q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, classid)))
1908 cl->q = &noop_qdisc;
1909 cl->classid = classid;
1910 cl->tparent = parent;
1911 cl->qdisc = sch;
1912 cl->allot = parent->allot;
1913 cl->quantum = cl->allot;
1914 cl->weight = cl->R_tab->rate.rate;
1915
1916 sch_tree_lock(sch);
1917 cbq_link_class(cl);
1918 cl->borrow = cl->tparent;
1919 if (cl->tparent != &q->link)
1920 cl->share = cl->tparent;
1921 cbq_adjust_levels(parent);
1922 cl->minidle = -0x7FFFFFFF;
1923 cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
1924 cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
1925 if (cl->ewma_log==0)
1926 cl->ewma_log = q->link.ewma_log;
1927 if (cl->maxidle==0)
1928 cl->maxidle = q->link.maxidle;
1929 if (cl->avpkt==0)
1930 cl->avpkt = q->link.avpkt;
1931 cl->overlimit = cbq_ovl_classic;
1932 if (tb[TCA_CBQ_OVL_STRATEGY])
1933 cbq_set_overlimit(cl, nla_data(tb[TCA_CBQ_OVL_STRATEGY]));
1934 #ifdef CONFIG_NET_CLS_ACT
1935 if (tb[TCA_CBQ_POLICE])
1936 cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE]));
1937 #endif
1938 if (tb[TCA_CBQ_FOPT])
1939 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
1940 sch_tree_unlock(sch);
1941
1942 if (tca[TCA_RATE])
1943 gen_new_estimator(&cl->bstats, &cl->rate_est,
1944 &sch->dev->queue_lock, tca[TCA_RATE]);
1945
1946 *arg = (unsigned long)cl;
1947 return 0;
1948
1949 failure:
1950 qdisc_put_rtab(rtab);
1951 return err;
1952 }
1953
1954 static int cbq_delete(struct Qdisc *sch, unsigned long arg)
1955 {
1956 struct cbq_sched_data *q = qdisc_priv(sch);
1957 struct cbq_class *cl = (struct cbq_class*)arg;
1958 unsigned int qlen;
1959
1960 if (cl->filters || cl->children || cl == &q->link)
1961 return -EBUSY;
1962
1963 sch_tree_lock(sch);
1964
1965 qlen = cl->q->q.qlen;
1966 qdisc_reset(cl->q);
1967 qdisc_tree_decrease_qlen(cl->q, qlen);
1968
1969 if (cl->next_alive)
1970 cbq_deactivate_class(cl);
1971
1972 if (q->tx_borrowed == cl)
1973 q->tx_borrowed = q->tx_class;
1974 if (q->tx_class == cl) {
1975 q->tx_class = NULL;
1976 q->tx_borrowed = NULL;
1977 }
1978 #ifdef CONFIG_NET_CLS_ACT
1979 if (q->rx_class == cl)
1980 q->rx_class = NULL;
1981 #endif
1982
1983 cbq_unlink_class(cl);
1984 cbq_adjust_levels(cl->tparent);
1985 cl->defmap = 0;
1986 cbq_sync_defmap(cl);
1987
1988 cbq_rmprio(q, cl);
1989 sch_tree_unlock(sch);
1990
1991 if (--cl->refcnt == 0)
1992 cbq_destroy_class(sch, cl);
1993
1994 return 0;
1995 }
1996
1997 static struct tcf_proto **cbq_find_tcf(struct Qdisc *sch, unsigned long arg)
1998 {
1999 struct cbq_sched_data *q = qdisc_priv(sch);
2000 struct cbq_class *cl = (struct cbq_class *)arg;
2001
2002 if (cl == NULL)
2003 cl = &q->link;
2004
2005 return &cl->filter_list;
2006 }
2007
2008 static unsigned long cbq_bind_filter(struct Qdisc *sch, unsigned long parent,
2009 u32 classid)
2010 {
2011 struct cbq_sched_data *q = qdisc_priv(sch);
2012 struct cbq_class *p = (struct cbq_class*)parent;
2013 struct cbq_class *cl = cbq_class_lookup(q, classid);
2014
2015 if (cl) {
2016 if (p && p->level <= cl->level)
2017 return 0;
2018 cl->filters++;
2019 return (unsigned long)cl;
2020 }
2021 return 0;
2022 }
2023
2024 static void cbq_unbind_filter(struct Qdisc *sch, unsigned long arg)
2025 {
2026 struct cbq_class *cl = (struct cbq_class*)arg;
2027
2028 cl->filters--;
2029 }
2030
2031 static void cbq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
2032 {
2033 struct cbq_sched_data *q = qdisc_priv(sch);
2034 unsigned h;
2035
2036 if (arg->stop)
2037 return;
2038
2039 for (h = 0; h < 16; h++) {
2040 struct cbq_class *cl;
2041
2042 for (cl = q->classes[h]; cl; cl = cl->next) {
2043 if (arg->count < arg->skip) {
2044 arg->count++;
2045 continue;
2046 }
2047 if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
2048 arg->stop = 1;
2049 return;
2050 }
2051 arg->count++;
2052 }
2053 }
2054 }
2055
2056 static const struct Qdisc_class_ops cbq_class_ops = {
2057 .graft = cbq_graft,
2058 .leaf = cbq_leaf,
2059 .qlen_notify = cbq_qlen_notify,
2060 .get = cbq_get,
2061 .put = cbq_put,
2062 .change = cbq_change_class,
2063 .delete = cbq_delete,
2064 .walk = cbq_walk,
2065 .tcf_chain = cbq_find_tcf,
2066 .bind_tcf = cbq_bind_filter,
2067 .unbind_tcf = cbq_unbind_filter,
2068 .dump = cbq_dump_class,
2069 .dump_stats = cbq_dump_class_stats,
2070 };
2071
2072 static struct Qdisc_ops cbq_qdisc_ops __read_mostly = {
2073 .next = NULL,
2074 .cl_ops = &cbq_class_ops,
2075 .id = "cbq",
2076 .priv_size = sizeof(struct cbq_sched_data),
2077 .enqueue = cbq_enqueue,
2078 .dequeue = cbq_dequeue,
2079 .requeue = cbq_requeue,
2080 .drop = cbq_drop,
2081 .init = cbq_init,
2082 .reset = cbq_reset,
2083 .destroy = cbq_destroy,
2084 .change = NULL,
2085 .dump = cbq_dump,
2086 .dump_stats = cbq_dump_stats,
2087 .owner = THIS_MODULE,
2088 };
2089
2090 static int __init cbq_module_init(void)
2091 {
2092 return register_qdisc(&cbq_qdisc_ops);
2093 }
2094 static void __exit cbq_module_exit(void)
2095 {
2096 unregister_qdisc(&cbq_qdisc_ops);
2097 }
2098 module_init(cbq_module_init)
2099 module_exit(cbq_module_exit)
2100 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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