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Linux 4.1.16
[linux/fpc-iii.git] / net / sched / sch_cbq.c
blobbeeb75f80fdb970139b030fbb9ac268983b617e9
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_est64 rate_est;
134 struct tc_cbq_xstats xstats;
135
136 struct tcf_proto __rcu *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 unsigned int pmask;
163
164 struct hrtimer delay_timer;
165 struct qdisc_watchdog watchdog; /* Watchdog timer,
166 started when CBQ has
167 backlog, but cannot
168 transmit just now */
169 psched_tdiff_t wd_expires;
170 int toplevel;
171 u32 hgenerator;
172 };
173
174
175 #define L2T(cl, len) qdisc_l2t((cl)->R_tab, len)
176
177 static inline struct cbq_class *
178 cbq_class_lookup(struct cbq_sched_data *q, u32 classid)
179 {
180 struct Qdisc_class_common *clc;
181
182 clc = qdisc_class_find(&q->clhash, classid);
183 if (clc == NULL)
184 return NULL;
185 return container_of(clc, struct cbq_class, common);
186 }
187
188 #ifdef CONFIG_NET_CLS_ACT
189
190 static struct cbq_class *
191 cbq_reclassify(struct sk_buff *skb, struct cbq_class *this)
192 {
193 struct cbq_class *cl;
194
195 for (cl = this->tparent; cl; cl = cl->tparent) {
196 struct cbq_class *new = cl->defaults[TC_PRIO_BESTEFFORT];
197
198 if (new != NULL && new != this)
199 return new;
200 }
201 return NULL;
202 }
203
204 #endif
205
206 /* Classify packet. The procedure is pretty complicated, but
207 * it allows us to combine link sharing and priority scheduling
208 * transparently.
209 *
210 * Namely, you can put link sharing rules (f.e. route based) at root of CBQ,
211 * so that it resolves to split nodes. Then packets are classified
212 * by logical priority, or a more specific classifier may be attached
213 * to the split node.
214 */
215
216 static struct cbq_class *
217 cbq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
218 {
219 struct cbq_sched_data *q = qdisc_priv(sch);
220 struct cbq_class *head = &q->link;
221 struct cbq_class **defmap;
222 struct cbq_class *cl = NULL;
223 u32 prio = skb->priority;
224 struct tcf_proto *fl;
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 fl = rcu_dereference_bh(head->filter_list);
240 /*
241 * Step 2+n. Apply classifier.
242 */
243 result = tc_classify_compat(skb, fl, &res);
244 if (!fl || result < 0)
245 goto fallback;
246
247 cl = (void *)res.class;
248 if (!cl) {
249 if (TC_H_MAJ(res.classid))
250 cl = cbq_class_lookup(q, res.classid);
251 else if ((cl = defmap[res.classid & TC_PRIO_MAX]) == NULL)
252 cl = defmap[TC_PRIO_BESTEFFORT];
253
254 if (cl == NULL)
255 goto fallback;
256 }
257 if (cl->level >= head->level)
258 goto fallback;
259 #ifdef CONFIG_NET_CLS_ACT
260 switch (result) {
261 case TC_ACT_QUEUED:
262 case TC_ACT_STOLEN:
263 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
264 case TC_ACT_SHOT:
265 return NULL;
266 case TC_ACT_RECLASSIFY:
267 return cbq_reclassify(skb, cl);
268 }
269 #endif
270 if (cl->level == 0)
271 return cl;
272
273 /*
274 * Step 3+n. If classifier selected a link sharing class,
275 * apply agency specific classifier.
276 * Repeat this procdure until we hit a leaf node.
277 */
278 head = cl;
279 }
280
281 fallback:
282 cl = head;
283
284 /*
285 * Step 4. No success...
286 */
287 if (TC_H_MAJ(prio) == 0 &&
288 !(cl = head->defaults[prio & TC_PRIO_MAX]) &&
289 !(cl = head->defaults[TC_PRIO_BESTEFFORT]))
290 return head;
291
292 return cl;
293 }
294
295 /*
296 * A packet has just been enqueued on the empty class.
297 * cbq_activate_class adds it to the tail of active class list
298 * of its priority band.
299 */
300
301 static inline void cbq_activate_class(struct cbq_class *cl)
302 {
303 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
304 int prio = cl->cpriority;
305 struct cbq_class *cl_tail;
306
307 cl_tail = q->active[prio];
308 q->active[prio] = cl;
309
310 if (cl_tail != NULL) {
311 cl->next_alive = cl_tail->next_alive;
312 cl_tail->next_alive = cl;
313 } else {
314 cl->next_alive = cl;
315 q->activemask |= (1<<prio);
316 }
317 }
318
319 /*
320 * Unlink class from active chain.
321 * Note that this same procedure is done directly in cbq_dequeue*
322 * during round-robin procedure.
323 */
324
325 static void cbq_deactivate_class(struct cbq_class *this)
326 {
327 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
328 int prio = this->cpriority;
329 struct cbq_class *cl;
330 struct cbq_class *cl_prev = q->active[prio];
331
332 do {
333 cl = cl_prev->next_alive;
334 if (cl == this) {
335 cl_prev->next_alive = cl->next_alive;
336 cl->next_alive = NULL;
337
338 if (cl == q->active[prio]) {
339 q->active[prio] = cl_prev;
340 if (cl == q->active[prio]) {
341 q->active[prio] = NULL;
342 q->activemask &= ~(1<<prio);
343 return;
344 }
345 }
346 return;
347 }
348 } while ((cl_prev = cl) != q->active[prio]);
349 }
350
351 static void
352 cbq_mark_toplevel(struct cbq_sched_data *q, struct cbq_class *cl)
353 {
354 int toplevel = q->toplevel;
355
356 if (toplevel > cl->level && !(qdisc_is_throttled(cl->q))) {
357 psched_time_t now = psched_get_time();
358
359 do {
360 if (cl->undertime < now) {
361 q->toplevel = cl->level;
362 return;
363 }
364 } while ((cl = cl->borrow) != NULL && toplevel > cl->level);
365 }
366 }
367
368 static int
369 cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
370 {
371 struct cbq_sched_data *q = qdisc_priv(sch);
372 int uninitialized_var(ret);
373 struct cbq_class *cl = cbq_classify(skb, sch, &ret);
374
375 #ifdef CONFIG_NET_CLS_ACT
376 q->rx_class = cl;
377 #endif
378 if (cl == NULL) {
379 if (ret & __NET_XMIT_BYPASS)
380 qdisc_qstats_drop(sch);
381 kfree_skb(skb);
382 return ret;
383 }
384
385 #ifdef CONFIG_NET_CLS_ACT
386 cl->q->__parent = sch;
387 #endif
388 ret = qdisc_enqueue(skb, cl->q);
389 if (ret == NET_XMIT_SUCCESS) {
390 sch->q.qlen++;
391 cbq_mark_toplevel(q, cl);
392 if (!cl->next_alive)
393 cbq_activate_class(cl);
394 return ret;
395 }
396
397 if (net_xmit_drop_count(ret)) {
398 qdisc_qstats_drop(sch);
399 cbq_mark_toplevel(q, cl);
400 cl->qstats.drops++;
401 }
402 return ret;
403 }
404
405 /* Overlimit actions */
406
407 /* TC_CBQ_OVL_CLASSIC: (default) penalize leaf class by adding offtime */
408
409 static void cbq_ovl_classic(struct cbq_class *cl)
410 {
411 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
412 psched_tdiff_t delay = cl->undertime - q->now;
413
414 if (!cl->delayed) {
415 delay += cl->offtime;
416
417 /*
418 * Class goes to sleep, so that it will have no
419 * chance to work avgidle. Let's forgive it 8)
420 *
421 * BTW cbq-2.0 has a crap in this
422 * place, apparently they forgot to shift it by cl->ewma_log.
423 */
424 if (cl->avgidle < 0)
425 delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log);
426 if (cl->avgidle < cl->minidle)
427 cl->avgidle = cl->minidle;
428 if (delay <= 0)
429 delay = 1;
430 cl->undertime = q->now + delay;
431
432 cl->xstats.overactions++;
433 cl->delayed = 1;
434 }
435 if (q->wd_expires == 0 || q->wd_expires > delay)
436 q->wd_expires = delay;
437
438 /* Dirty work! We must schedule wakeups based on
439 * real available rate, rather than leaf rate,
440 * which may be tiny (even zero).
441 */
442 if (q->toplevel == TC_CBQ_MAXLEVEL) {
443 struct cbq_class *b;
444 psched_tdiff_t base_delay = q->wd_expires;
445
446 for (b = cl->borrow; b; b = b->borrow) {
447 delay = b->undertime - q->now;
448 if (delay < base_delay) {
449 if (delay <= 0)
450 delay = 1;
451 base_delay = delay;
452 }
453 }
454
455 q->wd_expires = base_delay;
456 }
457 }
458
459 /* TC_CBQ_OVL_RCLASSIC: penalize by offtime classes in hierarchy, when
460 * they go overlimit
461 */
462
463 static void cbq_ovl_rclassic(struct cbq_class *cl)
464 {
465 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
466 struct cbq_class *this = cl;
467
468 do {
469 if (cl->level > q->toplevel) {
470 cl = NULL;
471 break;
472 }
473 } while ((cl = cl->borrow) != NULL);
474
475 if (cl == NULL)
476 cl = this;
477 cbq_ovl_classic(cl);
478 }
479
480 /* TC_CBQ_OVL_DELAY: delay until it will go to underlimit */
481
482 static void cbq_ovl_delay(struct cbq_class *cl)
483 {
484 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
485 psched_tdiff_t delay = cl->undertime - q->now;
486
487 if (test_bit(__QDISC_STATE_DEACTIVATED,
488 &qdisc_root_sleeping(cl->qdisc)->state))
489 return;
490
491 if (!cl->delayed) {
492 psched_time_t sched = q->now;
493 ktime_t expires;
494
495 delay += cl->offtime;
496 if (cl->avgidle < 0)
497 delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log);
498 if (cl->avgidle < cl->minidle)
499 cl->avgidle = cl->minidle;
500 cl->undertime = q->now + delay;
501
502 if (delay > 0) {
503 sched += delay + cl->penalty;
504 cl->penalized = sched;
505 cl->cpriority = TC_CBQ_MAXPRIO;
506 q->pmask |= (1<<TC_CBQ_MAXPRIO);
507
508 expires = ns_to_ktime(PSCHED_TICKS2NS(sched));
509 if (hrtimer_try_to_cancel(&q->delay_timer) &&
510 ktime_to_ns(ktime_sub(
511 hrtimer_get_expires(&q->delay_timer),
512 expires)) > 0)
513 hrtimer_set_expires(&q->delay_timer, expires);
514 hrtimer_restart(&q->delay_timer);
515 cl->delayed = 1;
516 cl->xstats.overactions++;
517 return;
518 }
519 delay = 1;
520 }
521 if (q->wd_expires == 0 || q->wd_expires > delay)
522 q->wd_expires = delay;
523 }
524
525 /* TC_CBQ_OVL_LOWPRIO: penalize class by lowering its priority band */
526
527 static void cbq_ovl_lowprio(struct cbq_class *cl)
528 {
529 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
530
531 cl->penalized = q->now + cl->penalty;
532
533 if (cl->cpriority != cl->priority2) {
534 cl->cpriority = cl->priority2;
535 q->pmask |= (1<<cl->cpriority);
536 cl->xstats.overactions++;
537 }
538 cbq_ovl_classic(cl);
539 }
540
541 /* TC_CBQ_OVL_DROP: penalize class by dropping */
542
543 static void cbq_ovl_drop(struct cbq_class *cl)
544 {
545 if (cl->q->ops->drop)
546 if (cl->q->ops->drop(cl->q))
547 cl->qdisc->q.qlen--;
548 cl->xstats.overactions++;
549 cbq_ovl_classic(cl);
550 }
551
552 static psched_tdiff_t cbq_undelay_prio(struct cbq_sched_data *q, int prio,
553 psched_time_t now)
554 {
555 struct cbq_class *cl;
556 struct cbq_class *cl_prev = q->active[prio];
557 psched_time_t sched = now;
558
559 if (cl_prev == NULL)
560 return 0;
561
562 do {
563 cl = cl_prev->next_alive;
564 if (now - cl->penalized > 0) {
565 cl_prev->next_alive = cl->next_alive;
566 cl->next_alive = NULL;
567 cl->cpriority = cl->priority;
568 cl->delayed = 0;
569 cbq_activate_class(cl);
570
571 if (cl == q->active[prio]) {
572 q->active[prio] = cl_prev;
573 if (cl == q->active[prio]) {
574 q->active[prio] = NULL;
575 return 0;
576 }
577 }
578
579 cl = cl_prev->next_alive;
580 } else if (sched - cl->penalized > 0)
581 sched = cl->penalized;
582 } while ((cl_prev = cl) != q->active[prio]);
583
584 return sched - now;
585 }
586
587 static enum hrtimer_restart cbq_undelay(struct hrtimer *timer)
588 {
589 struct cbq_sched_data *q = container_of(timer, struct cbq_sched_data,
590 delay_timer);
591 struct Qdisc *sch = q->watchdog.qdisc;
592 psched_time_t now;
593 psched_tdiff_t delay = 0;
594 unsigned int pmask;
595
596 now = psched_get_time();
597
598 pmask = q->pmask;
599 q->pmask = 0;
600
601 while (pmask) {
602 int prio = ffz(~pmask);
603 psched_tdiff_t tmp;
604
605 pmask &= ~(1<<prio);
606
607 tmp = cbq_undelay_prio(q, prio, now);
608 if (tmp > 0) {
609 q->pmask |= 1<<prio;
610 if (tmp < delay || delay == 0)
611 delay = tmp;
612 }
613 }
614
615 if (delay) {
616 ktime_t time;
617
618 time = ktime_set(0, 0);
619 time = ktime_add_ns(time, PSCHED_TICKS2NS(now + delay));
620 hrtimer_start(&q->delay_timer, time, HRTIMER_MODE_ABS_PINNED);
621 }
622
623 qdisc_unthrottled(sch);
624 __netif_schedule(qdisc_root(sch));
625 return HRTIMER_NORESTART;
626 }
627
628 #ifdef CONFIG_NET_CLS_ACT
629 static int cbq_reshape_fail(struct sk_buff *skb, struct Qdisc *child)
630 {
631 struct Qdisc *sch = child->__parent;
632 struct cbq_sched_data *q = qdisc_priv(sch);
633 struct cbq_class *cl = q->rx_class;
634
635 q->rx_class = NULL;
636
637 if (cl && (cl = cbq_reclassify(skb, cl)) != NULL) {
638 int ret;
639
640 cbq_mark_toplevel(q, cl);
641
642 q->rx_class = cl;
643 cl->q->__parent = sch;
644
645 ret = qdisc_enqueue(skb, cl->q);
646 if (ret == NET_XMIT_SUCCESS) {
647 sch->q.qlen++;
648 if (!cl->next_alive)
649 cbq_activate_class(cl);
650 return 0;
651 }
652 if (net_xmit_drop_count(ret))
653 qdisc_qstats_drop(sch);
654 return 0;
655 }
656
657 qdisc_qstats_drop(sch);
658 return -1;
659 }
660 #endif
661
662 /*
663 * It is mission critical procedure.
664 *
665 * We "regenerate" toplevel cutoff, if transmitting class
666 * has backlog and it is not regulated. It is not part of
667 * original CBQ description, but looks more reasonable.
668 * Probably, it is wrong. This question needs further investigation.
669 */
670
671 static inline void
672 cbq_update_toplevel(struct cbq_sched_data *q, struct cbq_class *cl,
673 struct cbq_class *borrowed)
674 {
675 if (cl && q->toplevel >= borrowed->level) {
676 if (cl->q->q.qlen > 1) {
677 do {
678 if (borrowed->undertime == PSCHED_PASTPERFECT) {
679 q->toplevel = borrowed->level;
680 return;
681 }
682 } while ((borrowed = borrowed->borrow) != NULL);
683 }
684 #if 0
685 /* It is not necessary now. Uncommenting it
686 will save CPU cycles, but decrease fairness.
687 */
688 q->toplevel = TC_CBQ_MAXLEVEL;
689 #endif
690 }
691 }
692
693 static void
694 cbq_update(struct cbq_sched_data *q)
695 {
696 struct cbq_class *this = q->tx_class;
697 struct cbq_class *cl = this;
698 int len = q->tx_len;
699 psched_time_t now;
700
701 q->tx_class = NULL;
702 /* Time integrator. We calculate EOS time
703 * by adding expected packet transmission time.
704 */
705 now = q->now + L2T(&q->link, len);
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 = 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 = 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 if ((s64)(now - cl->last) > 0)
776 cl->last = now;
777 }
778
779 cbq_update_toplevel(q, this, q->tx_borrowed);
780 }
781
782 static inline struct cbq_class *
783 cbq_under_limit(struct cbq_class *cl)
784 {
785 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
786 struct cbq_class *this_cl = cl;
787
788 if (cl->tparent == NULL)
789 return cl;
790
791 if (cl->undertime == PSCHED_PASTPERFECT || q->now >= cl->undertime) {
792 cl->delayed = 0;
793 return cl;
794 }
795
796 do {
797 /* It is very suspicious place. Now overlimit
798 * action is generated for not bounded classes
799 * only if link is completely congested.
800 * Though it is in agree with ancestor-only paradigm,
801 * it looks very stupid. Particularly,
802 * it means that this chunk of code will either
803 * never be called or result in strong amplification
804 * of burstiness. Dangerous, silly, and, however,
805 * no another solution exists.
806 */
807 cl = cl->borrow;
808 if (!cl) {
809 this_cl->qstats.overlimits++;
810 this_cl->overlimit(this_cl);
811 return NULL;
812 }
813 if (cl->level > q->toplevel)
814 return NULL;
815 } while (cl->undertime != PSCHED_PASTPERFECT && q->now < cl->undertime);
816
817 cl->delayed = 0;
818 return cl;
819 }
820
821 static inline struct sk_buff *
822 cbq_dequeue_prio(struct Qdisc *sch, int prio)
823 {
824 struct cbq_sched_data *q = qdisc_priv(sch);
825 struct cbq_class *cl_tail, *cl_prev, *cl;
826 struct sk_buff *skb;
827 int deficit;
828
829 cl_tail = cl_prev = q->active[prio];
830 cl = cl_prev->next_alive;
831
832 do {
833 deficit = 0;
834
835 /* Start round */
836 do {
837 struct cbq_class *borrow = cl;
838
839 if (cl->q->q.qlen &&
840 (borrow = cbq_under_limit(cl)) == NULL)
841 goto skip_class;
842
843 if (cl->deficit <= 0) {
844 /* Class exhausted its allotment per
845 * this round. Switch to the next one.
846 */
847 deficit = 1;
848 cl->deficit += cl->quantum;
849 goto next_class;
850 }
851
852 skb = cl->q->dequeue(cl->q);
853
854 /* Class did not give us any skb :-(
855 * It could occur even if cl->q->q.qlen != 0
856 * f.e. if cl->q == "tbf"
857 */
858 if (skb == NULL)
859 goto skip_class;
860
861 cl->deficit -= qdisc_pkt_len(skb);
862 q->tx_class = cl;
863 q->tx_borrowed = borrow;
864 if (borrow != cl) {
865 #ifndef CBQ_XSTATS_BORROWS_BYTES
866 borrow->xstats.borrows++;
867 cl->xstats.borrows++;
868 #else
869 borrow->xstats.borrows += qdisc_pkt_len(skb);
870 cl->xstats.borrows += qdisc_pkt_len(skb);
871 #endif
872 }
873 q->tx_len = qdisc_pkt_len(skb);
874
875 if (cl->deficit <= 0) {
876 q->active[prio] = cl;
877 cl = cl->next_alive;
878 cl->deficit += cl->quantum;
879 }
880 return skb;
881
882 skip_class:
883 if (cl->q->q.qlen == 0 || prio != cl->cpriority) {
884 /* Class is empty or penalized.
885 * Unlink it from active chain.
886 */
887 cl_prev->next_alive = cl->next_alive;
888 cl->next_alive = NULL;
889
890 /* Did cl_tail point to it? */
891 if (cl == cl_tail) {
892 /* Repair it! */
893 cl_tail = cl_prev;
894
895 /* Was it the last class in this band? */
896 if (cl == cl_tail) {
897 /* Kill the band! */
898 q->active[prio] = NULL;
899 q->activemask &= ~(1<<prio);
900 if (cl->q->q.qlen)
901 cbq_activate_class(cl);
902 return NULL;
903 }
904
905 q->active[prio] = cl_tail;
906 }
907 if (cl->q->q.qlen)
908 cbq_activate_class(cl);
909
910 cl = cl_prev;
911 }
912
913 next_class:
914 cl_prev = cl;
915 cl = cl->next_alive;
916 } while (cl_prev != cl_tail);
917 } while (deficit);
918
919 q->active[prio] = cl_prev;
920
921 return NULL;
922 }
923
924 static inline struct sk_buff *
925 cbq_dequeue_1(struct Qdisc *sch)
926 {
927 struct cbq_sched_data *q = qdisc_priv(sch);
928 struct sk_buff *skb;
929 unsigned int activemask;
930
931 activemask = q->activemask & 0xFF;
932 while (activemask) {
933 int prio = ffz(~activemask);
934 activemask &= ~(1<<prio);
935 skb = cbq_dequeue_prio(sch, prio);
936 if (skb)
937 return skb;
938 }
939 return NULL;
940 }
941
942 static struct sk_buff *
943 cbq_dequeue(struct Qdisc *sch)
944 {
945 struct sk_buff *skb;
946 struct cbq_sched_data *q = qdisc_priv(sch);
947 psched_time_t now;
948
949 now = psched_get_time();
950
951 if (q->tx_class)
952 cbq_update(q);
953
954 q->now = now;
955
956 for (;;) {
957 q->wd_expires = 0;
958
959 skb = cbq_dequeue_1(sch);
960 if (skb) {
961 qdisc_bstats_update(sch, skb);
962 sch->q.qlen--;
963 qdisc_unthrottled(sch);
964 return skb;
965 }
966
967 /* All the classes are overlimit.
968 *
969 * It is possible, if:
970 *
971 * 1. Scheduler is empty.
972 * 2. Toplevel cutoff inhibited borrowing.
973 * 3. Root class is overlimit.
974 *
975 * Reset 2d and 3d conditions and retry.
976 *
977 * Note, that NS and cbq-2.0 are buggy, peeking
978 * an arbitrary class is appropriate for ancestor-only
979 * sharing, but not for toplevel algorithm.
980 *
981 * Our version is better, but slower, because it requires
982 * two passes, but it is unavoidable with top-level sharing.
983 */
984
985 if (q->toplevel == TC_CBQ_MAXLEVEL &&
986 q->link.undertime == PSCHED_PASTPERFECT)
987 break;
988
989 q->toplevel = TC_CBQ_MAXLEVEL;
990 q->link.undertime = PSCHED_PASTPERFECT;
991 }
992
993 /* No packets in scheduler or nobody wants to give them to us :-(
994 * Sigh... start watchdog timer in the last case.
995 */
996
997 if (sch->q.qlen) {
998 qdisc_qstats_overlimit(sch);
999 if (q->wd_expires)
1000 qdisc_watchdog_schedule(&q->watchdog,
1001 now + q->wd_expires);
1002 }
1003 return NULL;
1004 }
1005
1006 /* CBQ class maintanance routines */
1007
1008 static void cbq_adjust_levels(struct cbq_class *this)
1009 {
1010 if (this == NULL)
1011 return;
1012
1013 do {
1014 int level = 0;
1015 struct cbq_class *cl;
1016
1017 cl = this->children;
1018 if (cl) {
1019 do {
1020 if (cl->level > level)
1021 level = cl->level;
1022 } while ((cl = cl->sibling) != this->children);
1023 }
1024 this->level = level + 1;
1025 } while ((this = this->tparent) != NULL);
1026 }
1027
1028 static void cbq_normalize_quanta(struct cbq_sched_data *q, int prio)
1029 {
1030 struct cbq_class *cl;
1031 unsigned int h;
1032
1033 if (q->quanta[prio] == 0)
1034 return;
1035
1036 for (h = 0; h < q->clhash.hashsize; h++) {
1037 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
1038 /* BUGGGG... Beware! This expression suffer of
1039 * arithmetic overflows!
1040 */
1041 if (cl->priority == prio) {
1042 cl->quantum = (cl->weight*cl->allot*q->nclasses[prio])/
1043 q->quanta[prio];
1044 }
1045 if (cl->quantum <= 0 ||
1046 cl->quantum > 32*qdisc_dev(cl->qdisc)->mtu) {
1047 pr_warn("CBQ: class %08x has bad quantum==%ld, repaired.\n",
1048 cl->common.classid, cl->quantum);
1049 cl->quantum = qdisc_dev(cl->qdisc)->mtu/2 + 1;
1050 }
1051 }
1052 }
1053 }
1054
1055 static void cbq_sync_defmap(struct cbq_class *cl)
1056 {
1057 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
1058 struct cbq_class *split = cl->split;
1059 unsigned int h;
1060 int i;
1061
1062 if (split == NULL)
1063 return;
1064
1065 for (i = 0; i <= TC_PRIO_MAX; i++) {
1066 if (split->defaults[i] == cl && !(cl->defmap & (1<<i)))
1067 split->defaults[i] = NULL;
1068 }
1069
1070 for (i = 0; i <= TC_PRIO_MAX; i++) {
1071 int level = split->level;
1072
1073 if (split->defaults[i])
1074 continue;
1075
1076 for (h = 0; h < q->clhash.hashsize; h++) {
1077 struct cbq_class *c;
1078
1079 hlist_for_each_entry(c, &q->clhash.hash[h],
1080 common.hnode) {
1081 if (c->split == split && c->level < level &&
1082 c->defmap & (1<<i)) {
1083 split->defaults[i] = c;
1084 level = c->level;
1085 }
1086 }
1087 }
1088 }
1089 }
1090
1091 static void cbq_change_defmap(struct cbq_class *cl, u32 splitid, u32 def, u32 mask)
1092 {
1093 struct cbq_class *split = NULL;
1094
1095 if (splitid == 0) {
1096 split = cl->split;
1097 if (!split)
1098 return;
1099 splitid = split->common.classid;
1100 }
1101
1102 if (split == NULL || split->common.classid != splitid) {
1103 for (split = cl->tparent; split; split = split->tparent)
1104 if (split->common.classid == splitid)
1105 break;
1106 }
1107
1108 if (split == NULL)
1109 return;
1110
1111 if (cl->split != split) {
1112 cl->defmap = 0;
1113 cbq_sync_defmap(cl);
1114 cl->split = split;
1115 cl->defmap = def & mask;
1116 } else
1117 cl->defmap = (cl->defmap & ~mask) | (def & mask);
1118
1119 cbq_sync_defmap(cl);
1120 }
1121
1122 static void cbq_unlink_class(struct cbq_class *this)
1123 {
1124 struct cbq_class *cl, **clp;
1125 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
1126
1127 qdisc_class_hash_remove(&q->clhash, &this->common);
1128
1129 if (this->tparent) {
1130 clp = &this->sibling;
1131 cl = *clp;
1132 do {
1133 if (cl == this) {
1134 *clp = cl->sibling;
1135 break;
1136 }
1137 clp = &cl->sibling;
1138 } while ((cl = *clp) != this->sibling);
1139
1140 if (this->tparent->children == this) {
1141 this->tparent->children = this->sibling;
1142 if (this->sibling == this)
1143 this->tparent->children = NULL;
1144 }
1145 } else {
1146 WARN_ON(this->sibling != this);
1147 }
1148 }
1149
1150 static void cbq_link_class(struct cbq_class *this)
1151 {
1152 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
1153 struct cbq_class *parent = this->tparent;
1154
1155 this->sibling = this;
1156 qdisc_class_hash_insert(&q->clhash, &this->common);
1157
1158 if (parent == NULL)
1159 return;
1160
1161 if (parent->children == NULL) {
1162 parent->children = this;
1163 } else {
1164 this->sibling = parent->children->sibling;
1165 parent->children->sibling = this;
1166 }
1167 }
1168
1169 static unsigned int cbq_drop(struct Qdisc *sch)
1170 {
1171 struct cbq_sched_data *q = qdisc_priv(sch);
1172 struct cbq_class *cl, *cl_head;
1173 int prio;
1174 unsigned int len;
1175
1176 for (prio = TC_CBQ_MAXPRIO; prio >= 0; prio--) {
1177 cl_head = q->active[prio];
1178 if (!cl_head)
1179 continue;
1180
1181 cl = cl_head;
1182 do {
1183 if (cl->q->ops->drop && (len = cl->q->ops->drop(cl->q))) {
1184 sch->q.qlen--;
1185 if (!cl->q->q.qlen)
1186 cbq_deactivate_class(cl);
1187 return len;
1188 }
1189 } while ((cl = cl->next_alive) != cl_head);
1190 }
1191 return 0;
1192 }
1193
1194 static void
1195 cbq_reset(struct Qdisc *sch)
1196 {
1197 struct cbq_sched_data *q = qdisc_priv(sch);
1198 struct cbq_class *cl;
1199 int prio;
1200 unsigned int h;
1201
1202 q->activemask = 0;
1203 q->pmask = 0;
1204 q->tx_class = NULL;
1205 q->tx_borrowed = NULL;
1206 qdisc_watchdog_cancel(&q->watchdog);
1207 hrtimer_cancel(&q->delay_timer);
1208 q->toplevel = TC_CBQ_MAXLEVEL;
1209 q->now = psched_get_time();
1210
1211 for (prio = 0; prio <= TC_CBQ_MAXPRIO; prio++)
1212 q->active[prio] = NULL;
1213
1214 for (h = 0; h < q->clhash.hashsize; h++) {
1215 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
1216 qdisc_reset(cl->q);
1217
1218 cl->next_alive = NULL;
1219 cl->undertime = PSCHED_PASTPERFECT;
1220 cl->avgidle = cl->maxidle;
1221 cl->deficit = cl->quantum;
1222 cl->cpriority = cl->priority;
1223 }
1224 }
1225 sch->q.qlen = 0;
1226 }
1227
1228
1229 static int cbq_set_lss(struct cbq_class *cl, struct tc_cbq_lssopt *lss)
1230 {
1231 if (lss->change & TCF_CBQ_LSS_FLAGS) {
1232 cl->share = (lss->flags & TCF_CBQ_LSS_ISOLATED) ? NULL : cl->tparent;
1233 cl->borrow = (lss->flags & TCF_CBQ_LSS_BOUNDED) ? NULL : cl->tparent;
1234 }
1235 if (lss->change & TCF_CBQ_LSS_EWMA)
1236 cl->ewma_log = lss->ewma_log;
1237 if (lss->change & TCF_CBQ_LSS_AVPKT)
1238 cl->avpkt = lss->avpkt;
1239 if (lss->change & TCF_CBQ_LSS_MINIDLE)
1240 cl->minidle = -(long)lss->minidle;
1241 if (lss->change & TCF_CBQ_LSS_MAXIDLE) {
1242 cl->maxidle = lss->maxidle;
1243 cl->avgidle = lss->maxidle;
1244 }
1245 if (lss->change & TCF_CBQ_LSS_OFFTIME)
1246 cl->offtime = lss->offtime;
1247 return 0;
1248 }
1249
1250 static void cbq_rmprio(struct cbq_sched_data *q, struct cbq_class *cl)
1251 {
1252 q->nclasses[cl->priority]--;
1253 q->quanta[cl->priority] -= cl->weight;
1254 cbq_normalize_quanta(q, cl->priority);
1255 }
1256
1257 static void cbq_addprio(struct cbq_sched_data *q, struct cbq_class *cl)
1258 {
1259 q->nclasses[cl->priority]++;
1260 q->quanta[cl->priority] += cl->weight;
1261 cbq_normalize_quanta(q, cl->priority);
1262 }
1263
1264 static int cbq_set_wrr(struct cbq_class *cl, struct tc_cbq_wrropt *wrr)
1265 {
1266 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
1267
1268 if (wrr->allot)
1269 cl->allot = wrr->allot;
1270 if (wrr->weight)
1271 cl->weight = wrr->weight;
1272 if (wrr->priority) {
1273 cl->priority = wrr->priority - 1;
1274 cl->cpriority = cl->priority;
1275 if (cl->priority >= cl->priority2)
1276 cl->priority2 = TC_CBQ_MAXPRIO - 1;
1277 }
1278
1279 cbq_addprio(q, cl);
1280 return 0;
1281 }
1282
1283 static int cbq_set_overlimit(struct cbq_class *cl, struct tc_cbq_ovl *ovl)
1284 {
1285 switch (ovl->strategy) {
1286 case TC_CBQ_OVL_CLASSIC:
1287 cl->overlimit = cbq_ovl_classic;
1288 break;
1289 case TC_CBQ_OVL_DELAY:
1290 cl->overlimit = cbq_ovl_delay;
1291 break;
1292 case TC_CBQ_OVL_LOWPRIO:
1293 if (ovl->priority2 - 1 >= TC_CBQ_MAXPRIO ||
1294 ovl->priority2 - 1 <= cl->priority)
1295 return -EINVAL;
1296 cl->priority2 = ovl->priority2 - 1;
1297 cl->overlimit = cbq_ovl_lowprio;
1298 break;
1299 case TC_CBQ_OVL_DROP:
1300 cl->overlimit = cbq_ovl_drop;
1301 break;
1302 case TC_CBQ_OVL_RCLASSIC:
1303 cl->overlimit = cbq_ovl_rclassic;
1304 break;
1305 default:
1306 return -EINVAL;
1307 }
1308 cl->penalty = ovl->penalty;
1309 return 0;
1310 }
1311
1312 #ifdef CONFIG_NET_CLS_ACT
1313 static int cbq_set_police(struct cbq_class *cl, struct tc_cbq_police *p)
1314 {
1315 cl->police = p->police;
1316
1317 if (cl->q->handle) {
1318 if (p->police == TC_POLICE_RECLASSIFY)
1319 cl->q->reshape_fail = cbq_reshape_fail;
1320 else
1321 cl->q->reshape_fail = NULL;
1322 }
1323 return 0;
1324 }
1325 #endif
1326
1327 static int cbq_set_fopt(struct cbq_class *cl, struct tc_cbq_fopt *fopt)
1328 {
1329 cbq_change_defmap(cl, fopt->split, fopt->defmap, fopt->defchange);
1330 return 0;
1331 }
1332
1333 static const struct nla_policy cbq_policy[TCA_CBQ_MAX + 1] = {
1334 [TCA_CBQ_LSSOPT] = { .len = sizeof(struct tc_cbq_lssopt) },
1335 [TCA_CBQ_WRROPT] = { .len = sizeof(struct tc_cbq_wrropt) },
1336 [TCA_CBQ_FOPT] = { .len = sizeof(struct tc_cbq_fopt) },
1337 [TCA_CBQ_OVL_STRATEGY] = { .len = sizeof(struct tc_cbq_ovl) },
1338 [TCA_CBQ_RATE] = { .len = sizeof(struct tc_ratespec) },
1339 [TCA_CBQ_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
1340 [TCA_CBQ_POLICE] = { .len = sizeof(struct tc_cbq_police) },
1341 };
1342
1343 static int cbq_init(struct Qdisc *sch, struct nlattr *opt)
1344 {
1345 struct cbq_sched_data *q = qdisc_priv(sch);
1346 struct nlattr *tb[TCA_CBQ_MAX + 1];
1347 struct tc_ratespec *r;
1348 int err;
1349
1350 err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy);
1351 if (err < 0)
1352 return err;
1353
1354 if (tb[TCA_CBQ_RTAB] == NULL || tb[TCA_CBQ_RATE] == NULL)
1355 return -EINVAL;
1356
1357 r = nla_data(tb[TCA_CBQ_RATE]);
1358
1359 if ((q->link.R_tab = qdisc_get_rtab(r, tb[TCA_CBQ_RTAB])) == NULL)
1360 return -EINVAL;
1361
1362 err = qdisc_class_hash_init(&q->clhash);
1363 if (err < 0)
1364 goto put_rtab;
1365
1366 q->link.refcnt = 1;
1367 q->link.sibling = &q->link;
1368 q->link.common.classid = sch->handle;
1369 q->link.qdisc = sch;
1370 q->link.q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1371 sch->handle);
1372 if (!q->link.q)
1373 q->link.q = &noop_qdisc;
1374
1375 q->link.priority = TC_CBQ_MAXPRIO - 1;
1376 q->link.priority2 = TC_CBQ_MAXPRIO - 1;
1377 q->link.cpriority = TC_CBQ_MAXPRIO - 1;
1378 q->link.ovl_strategy = TC_CBQ_OVL_CLASSIC;
1379 q->link.overlimit = cbq_ovl_classic;
1380 q->link.allot = psched_mtu(qdisc_dev(sch));
1381 q->link.quantum = q->link.allot;
1382 q->link.weight = q->link.R_tab->rate.rate;
1383
1384 q->link.ewma_log = TC_CBQ_DEF_EWMA;
1385 q->link.avpkt = q->link.allot/2;
1386 q->link.minidle = -0x7FFFFFFF;
1387
1388 qdisc_watchdog_init(&q->watchdog, sch);
1389 hrtimer_init(&q->delay_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
1390 q->delay_timer.function = cbq_undelay;
1391 q->toplevel = TC_CBQ_MAXLEVEL;
1392 q->now = psched_get_time();
1393
1394 cbq_link_class(&q->link);
1395
1396 if (tb[TCA_CBQ_LSSOPT])
1397 cbq_set_lss(&q->link, nla_data(tb[TCA_CBQ_LSSOPT]));
1398
1399 cbq_addprio(q, &q->link);
1400 return 0;
1401
1402 put_rtab:
1403 qdisc_put_rtab(q->link.R_tab);
1404 return err;
1405 }
1406
1407 static int cbq_dump_rate(struct sk_buff *skb, struct cbq_class *cl)
1408 {
1409 unsigned char *b = skb_tail_pointer(skb);
1410
1411 if (nla_put(skb, TCA_CBQ_RATE, sizeof(cl->R_tab->rate), &cl->R_tab->rate))
1412 goto nla_put_failure;
1413 return skb->len;
1414
1415 nla_put_failure:
1416 nlmsg_trim(skb, b);
1417 return -1;
1418 }
1419
1420 static int cbq_dump_lss(struct sk_buff *skb, struct cbq_class *cl)
1421 {
1422 unsigned char *b = skb_tail_pointer(skb);
1423 struct tc_cbq_lssopt opt;
1424
1425 opt.flags = 0;
1426 if (cl->borrow == NULL)
1427 opt.flags |= TCF_CBQ_LSS_BOUNDED;
1428 if (cl->share == NULL)
1429 opt.flags |= TCF_CBQ_LSS_ISOLATED;
1430 opt.ewma_log = cl->ewma_log;
1431 opt.level = cl->level;
1432 opt.avpkt = cl->avpkt;
1433 opt.maxidle = cl->maxidle;
1434 opt.minidle = (u32)(-cl->minidle);
1435 opt.offtime = cl->offtime;
1436 opt.change = ~0;
1437 if (nla_put(skb, TCA_CBQ_LSSOPT, sizeof(opt), &opt))
1438 goto nla_put_failure;
1439 return skb->len;
1440
1441 nla_put_failure:
1442 nlmsg_trim(skb, b);
1443 return -1;
1444 }
1445
1446 static int cbq_dump_wrr(struct sk_buff *skb, struct cbq_class *cl)
1447 {
1448 unsigned char *b = skb_tail_pointer(skb);
1449 struct tc_cbq_wrropt opt;
1450
1451 memset(&opt, 0, sizeof(opt));
1452 opt.flags = 0;
1453 opt.allot = cl->allot;
1454 opt.priority = cl->priority + 1;
1455 opt.cpriority = cl->cpriority + 1;
1456 opt.weight = cl->weight;
1457 if (nla_put(skb, TCA_CBQ_WRROPT, sizeof(opt), &opt))
1458 goto nla_put_failure;
1459 return skb->len;
1460
1461 nla_put_failure:
1462 nlmsg_trim(skb, b);
1463 return -1;
1464 }
1465
1466 static int cbq_dump_ovl(struct sk_buff *skb, struct cbq_class *cl)
1467 {
1468 unsigned char *b = skb_tail_pointer(skb);
1469 struct tc_cbq_ovl opt;
1470
1471 opt.strategy = cl->ovl_strategy;
1472 opt.priority2 = cl->priority2 + 1;
1473 opt.pad = 0;
1474 opt.penalty = cl->penalty;
1475 if (nla_put(skb, TCA_CBQ_OVL_STRATEGY, sizeof(opt), &opt))
1476 goto nla_put_failure;
1477 return skb->len;
1478
1479 nla_put_failure:
1480 nlmsg_trim(skb, b);
1481 return -1;
1482 }
1483
1484 static int cbq_dump_fopt(struct sk_buff *skb, struct cbq_class *cl)
1485 {
1486 unsigned char *b = skb_tail_pointer(skb);
1487 struct tc_cbq_fopt opt;
1488
1489 if (cl->split || cl->defmap) {
1490 opt.split = cl->split ? cl->split->common.classid : 0;
1491 opt.defmap = cl->defmap;
1492 opt.defchange = ~0;
1493 if (nla_put(skb, TCA_CBQ_FOPT, sizeof(opt), &opt))
1494 goto nla_put_failure;
1495 }
1496 return skb->len;
1497
1498 nla_put_failure:
1499 nlmsg_trim(skb, b);
1500 return -1;
1501 }
1502
1503 #ifdef CONFIG_NET_CLS_ACT
1504 static int cbq_dump_police(struct sk_buff *skb, struct cbq_class *cl)
1505 {
1506 unsigned char *b = skb_tail_pointer(skb);
1507 struct tc_cbq_police opt;
1508
1509 if (cl->police) {
1510 opt.police = cl->police;
1511 opt.__res1 = 0;
1512 opt.__res2 = 0;
1513 if (nla_put(skb, TCA_CBQ_POLICE, sizeof(opt), &opt))
1514 goto nla_put_failure;
1515 }
1516 return skb->len;
1517
1518 nla_put_failure:
1519 nlmsg_trim(skb, b);
1520 return -1;
1521 }
1522 #endif
1523
1524 static int cbq_dump_attr(struct sk_buff *skb, struct cbq_class *cl)
1525 {
1526 if (cbq_dump_lss(skb, cl) < 0 ||
1527 cbq_dump_rate(skb, cl) < 0 ||
1528 cbq_dump_wrr(skb, cl) < 0 ||
1529 cbq_dump_ovl(skb, cl) < 0 ||
1530 #ifdef CONFIG_NET_CLS_ACT
1531 cbq_dump_police(skb, cl) < 0 ||
1532 #endif
1533 cbq_dump_fopt(skb, cl) < 0)
1534 return -1;
1535 return 0;
1536 }
1537
1538 static int cbq_dump(struct Qdisc *sch, struct sk_buff *skb)
1539 {
1540 struct cbq_sched_data *q = qdisc_priv(sch);
1541 struct nlattr *nest;
1542
1543 nest = nla_nest_start(skb, TCA_OPTIONS);
1544 if (nest == NULL)
1545 goto nla_put_failure;
1546 if (cbq_dump_attr(skb, &q->link) < 0)
1547 goto nla_put_failure;
1548 return nla_nest_end(skb, nest);
1549
1550 nla_put_failure:
1551 nla_nest_cancel(skb, nest);
1552 return -1;
1553 }
1554
1555 static int
1556 cbq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
1557 {
1558 struct cbq_sched_data *q = qdisc_priv(sch);
1559
1560 q->link.xstats.avgidle = q->link.avgidle;
1561 return gnet_stats_copy_app(d, &q->link.xstats, sizeof(q->link.xstats));
1562 }
1563
1564 static int
1565 cbq_dump_class(struct Qdisc *sch, unsigned long arg,
1566 struct sk_buff *skb, struct tcmsg *tcm)
1567 {
1568 struct cbq_class *cl = (struct cbq_class *)arg;
1569 struct nlattr *nest;
1570
1571 if (cl->tparent)
1572 tcm->tcm_parent = cl->tparent->common.classid;
1573 else
1574 tcm->tcm_parent = TC_H_ROOT;
1575 tcm->tcm_handle = cl->common.classid;
1576 tcm->tcm_info = cl->q->handle;
1577
1578 nest = nla_nest_start(skb, TCA_OPTIONS);
1579 if (nest == NULL)
1580 goto nla_put_failure;
1581 if (cbq_dump_attr(skb, cl) < 0)
1582 goto nla_put_failure;
1583 return nla_nest_end(skb, nest);
1584
1585 nla_put_failure:
1586 nla_nest_cancel(skb, nest);
1587 return -1;
1588 }
1589
1590 static int
1591 cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1592 struct gnet_dump *d)
1593 {
1594 struct cbq_sched_data *q = qdisc_priv(sch);
1595 struct cbq_class *cl = (struct cbq_class *)arg;
1596
1597 cl->xstats.avgidle = cl->avgidle;
1598 cl->xstats.undertime = 0;
1599
1600 if (cl->undertime != PSCHED_PASTPERFECT)
1601 cl->xstats.undertime = cl->undertime - q->now;
1602
1603 if (gnet_stats_copy_basic(d, NULL, &cl->bstats) < 0 ||
1604 gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
1605 gnet_stats_copy_queue(d, NULL, &cl->qstats, cl->q->q.qlen) < 0)
1606 return -1;
1607
1608 return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));
1609 }
1610
1611 static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1612 struct Qdisc **old)
1613 {
1614 struct cbq_class *cl = (struct cbq_class *)arg;
1615
1616 if (new == NULL) {
1617 new = qdisc_create_dflt(sch->dev_queue,
1618 &pfifo_qdisc_ops, cl->common.classid);
1619 if (new == NULL)
1620 return -ENOBUFS;
1621 } else {
1622 #ifdef CONFIG_NET_CLS_ACT
1623 if (cl->police == TC_POLICE_RECLASSIFY)
1624 new->reshape_fail = cbq_reshape_fail;
1625 #endif
1626 }
1627 sch_tree_lock(sch);
1628 *old = cl->q;
1629 cl->q = new;
1630 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
1631 qdisc_reset(*old);
1632 sch_tree_unlock(sch);
1633
1634 return 0;
1635 }
1636
1637 static struct Qdisc *cbq_leaf(struct Qdisc *sch, unsigned long arg)
1638 {
1639 struct cbq_class *cl = (struct cbq_class *)arg;
1640
1641 return cl->q;
1642 }
1643
1644 static void cbq_qlen_notify(struct Qdisc *sch, unsigned long arg)
1645 {
1646 struct cbq_class *cl = (struct cbq_class *)arg;
1647
1648 if (cl->q->q.qlen == 0)
1649 cbq_deactivate_class(cl);
1650 }
1651
1652 static unsigned long cbq_get(struct Qdisc *sch, u32 classid)
1653 {
1654 struct cbq_sched_data *q = qdisc_priv(sch);
1655 struct cbq_class *cl = cbq_class_lookup(q, classid);
1656
1657 if (cl) {
1658 cl->refcnt++;
1659 return (unsigned long)cl;
1660 }
1661 return 0;
1662 }
1663
1664 static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl)
1665 {
1666 struct cbq_sched_data *q = qdisc_priv(sch);
1667
1668 WARN_ON(cl->filters);
1669
1670 tcf_destroy_chain(&cl->filter_list);
1671 qdisc_destroy(cl->q);
1672 qdisc_put_rtab(cl->R_tab);
1673 gen_kill_estimator(&cl->bstats, &cl->rate_est);
1674 if (cl != &q->link)
1675 kfree(cl);
1676 }
1677
1678 static void cbq_destroy(struct Qdisc *sch)
1679 {
1680 struct cbq_sched_data *q = qdisc_priv(sch);
1681 struct hlist_node *next;
1682 struct cbq_class *cl;
1683 unsigned int h;
1684
1685 #ifdef CONFIG_NET_CLS_ACT
1686 q->rx_class = NULL;
1687 #endif
1688 /*
1689 * Filters must be destroyed first because we don't destroy the
1690 * classes from root to leafs which means that filters can still
1691 * be bound to classes which have been destroyed already. --TGR '04
1692 */
1693 for (h = 0; h < q->clhash.hashsize; h++) {
1694 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode)
1695 tcf_destroy_chain(&cl->filter_list);
1696 }
1697 for (h = 0; h < q->clhash.hashsize; h++) {
1698 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[h],
1699 common.hnode)
1700 cbq_destroy_class(sch, cl);
1701 }
1702 qdisc_class_hash_destroy(&q->clhash);
1703 }
1704
1705 static void cbq_put(struct Qdisc *sch, unsigned long arg)
1706 {
1707 struct cbq_class *cl = (struct cbq_class *)arg;
1708
1709 if (--cl->refcnt == 0) {
1710 #ifdef CONFIG_NET_CLS_ACT
1711 spinlock_t *root_lock = qdisc_root_sleeping_lock(sch);
1712 struct cbq_sched_data *q = qdisc_priv(sch);
1713
1714 spin_lock_bh(root_lock);
1715 if (q->rx_class == cl)
1716 q->rx_class = NULL;
1717 spin_unlock_bh(root_lock);
1718 #endif
1719
1720 cbq_destroy_class(sch, cl);
1721 }
1722 }
1723
1724 static int
1725 cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **tca,
1726 unsigned long *arg)
1727 {
1728 int err;
1729 struct cbq_sched_data *q = qdisc_priv(sch);
1730 struct cbq_class *cl = (struct cbq_class *)*arg;
1731 struct nlattr *opt = tca[TCA_OPTIONS];
1732 struct nlattr *tb[TCA_CBQ_MAX + 1];
1733 struct cbq_class *parent;
1734 struct qdisc_rate_table *rtab = NULL;
1735
1736 if (opt == NULL)
1737 return -EINVAL;
1738
1739 err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy);
1740 if (err < 0)
1741 return err;
1742
1743 if (cl) {
1744 /* Check parent */
1745 if (parentid) {
1746 if (cl->tparent &&
1747 cl->tparent->common.classid != parentid)
1748 return -EINVAL;
1749 if (!cl->tparent && parentid != TC_H_ROOT)
1750 return -EINVAL;
1751 }
1752
1753 if (tb[TCA_CBQ_RATE]) {
1754 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]),
1755 tb[TCA_CBQ_RTAB]);
1756 if (rtab == NULL)
1757 return -EINVAL;
1758 }
1759
1760 if (tca[TCA_RATE]) {
1761 err = gen_replace_estimator(&cl->bstats, NULL,
1762 &cl->rate_est,
1763 qdisc_root_sleeping_lock(sch),
1764 tca[TCA_RATE]);
1765 if (err) {
1766 qdisc_put_rtab(rtab);
1767 return err;
1768 }
1769 }
1770
1771 /* Change class parameters */
1772 sch_tree_lock(sch);
1773
1774 if (cl->next_alive != NULL)
1775 cbq_deactivate_class(cl);
1776
1777 if (rtab) {
1778 qdisc_put_rtab(cl->R_tab);
1779 cl->R_tab = rtab;
1780 }
1781
1782 if (tb[TCA_CBQ_LSSOPT])
1783 cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
1784
1785 if (tb[TCA_CBQ_WRROPT]) {
1786 cbq_rmprio(q, cl);
1787 cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
1788 }
1789
1790 if (tb[TCA_CBQ_OVL_STRATEGY])
1791 cbq_set_overlimit(cl, nla_data(tb[TCA_CBQ_OVL_STRATEGY]));
1792
1793 #ifdef CONFIG_NET_CLS_ACT
1794 if (tb[TCA_CBQ_POLICE])
1795 cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE]));
1796 #endif
1797
1798 if (tb[TCA_CBQ_FOPT])
1799 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
1800
1801 if (cl->q->q.qlen)
1802 cbq_activate_class(cl);
1803
1804 sch_tree_unlock(sch);
1805
1806 return 0;
1807 }
1808
1809 if (parentid == TC_H_ROOT)
1810 return -EINVAL;
1811
1812 if (tb[TCA_CBQ_WRROPT] == NULL || tb[TCA_CBQ_RATE] == NULL ||
1813 tb[TCA_CBQ_LSSOPT] == NULL)
1814 return -EINVAL;
1815
1816 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]), tb[TCA_CBQ_RTAB]);
1817 if (rtab == NULL)
1818 return -EINVAL;
1819
1820 if (classid) {
1821 err = -EINVAL;
1822 if (TC_H_MAJ(classid ^ sch->handle) ||
1823 cbq_class_lookup(q, classid))
1824 goto failure;
1825 } else {
1826 int i;
1827 classid = TC_H_MAKE(sch->handle, 0x8000);
1828
1829 for (i = 0; i < 0x8000; i++) {
1830 if (++q->hgenerator >= 0x8000)
1831 q->hgenerator = 1;
1832 if (cbq_class_lookup(q, classid|q->hgenerator) == NULL)
1833 break;
1834 }
1835 err = -ENOSR;
1836 if (i >= 0x8000)
1837 goto failure;
1838 classid = classid|q->hgenerator;
1839 }
1840
1841 parent = &q->link;
1842 if (parentid) {
1843 parent = cbq_class_lookup(q, parentid);
1844 err = -EINVAL;
1845 if (parent == NULL)
1846 goto failure;
1847 }
1848
1849 err = -ENOBUFS;
1850 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
1851 if (cl == NULL)
1852 goto failure;
1853
1854 if (tca[TCA_RATE]) {
1855 err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
1856 qdisc_root_sleeping_lock(sch),
1857 tca[TCA_RATE]);
1858 if (err) {
1859 kfree(cl);
1860 goto failure;
1861 }
1862 }
1863
1864 cl->R_tab = rtab;
1865 rtab = NULL;
1866 cl->refcnt = 1;
1867 cl->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid);
1868 if (!cl->q)
1869 cl->q = &noop_qdisc;
1870 cl->common.classid = classid;
1871 cl->tparent = parent;
1872 cl->qdisc = sch;
1873 cl->allot = parent->allot;
1874 cl->quantum = cl->allot;
1875 cl->weight = cl->R_tab->rate.rate;
1876
1877 sch_tree_lock(sch);
1878 cbq_link_class(cl);
1879 cl->borrow = cl->tparent;
1880 if (cl->tparent != &q->link)
1881 cl->share = cl->tparent;
1882 cbq_adjust_levels(parent);
1883 cl->minidle = -0x7FFFFFFF;
1884 cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
1885 cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
1886 if (cl->ewma_log == 0)
1887 cl->ewma_log = q->link.ewma_log;
1888 if (cl->maxidle == 0)
1889 cl->maxidle = q->link.maxidle;
1890 if (cl->avpkt == 0)
1891 cl->avpkt = q->link.avpkt;
1892 cl->overlimit = cbq_ovl_classic;
1893 if (tb[TCA_CBQ_OVL_STRATEGY])
1894 cbq_set_overlimit(cl, nla_data(tb[TCA_CBQ_OVL_STRATEGY]));
1895 #ifdef CONFIG_NET_CLS_ACT
1896 if (tb[TCA_CBQ_POLICE])
1897 cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE]));
1898 #endif
1899 if (tb[TCA_CBQ_FOPT])
1900 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
1901 sch_tree_unlock(sch);
1902
1903 qdisc_class_hash_grow(sch, &q->clhash);
1904
1905 *arg = (unsigned long)cl;
1906 return 0;
1907
1908 failure:
1909 qdisc_put_rtab(rtab);
1910 return err;
1911 }
1912
1913 static int cbq_delete(struct Qdisc *sch, unsigned long arg)
1914 {
1915 struct cbq_sched_data *q = qdisc_priv(sch);
1916 struct cbq_class *cl = (struct cbq_class *)arg;
1917 unsigned int qlen;
1918
1919 if (cl->filters || cl->children || cl == &q->link)
1920 return -EBUSY;
1921
1922 sch_tree_lock(sch);
1923
1924 qlen = cl->q->q.qlen;
1925 qdisc_reset(cl->q);
1926 qdisc_tree_decrease_qlen(cl->q, qlen);
1927
1928 if (cl->next_alive)
1929 cbq_deactivate_class(cl);
1930
1931 if (q->tx_borrowed == cl)
1932 q->tx_borrowed = q->tx_class;
1933 if (q->tx_class == cl) {
1934 q->tx_class = NULL;
1935 q->tx_borrowed = NULL;
1936 }
1937 #ifdef CONFIG_NET_CLS_ACT
1938 if (q->rx_class == cl)
1939 q->rx_class = NULL;
1940 #endif
1941
1942 cbq_unlink_class(cl);
1943 cbq_adjust_levels(cl->tparent);
1944 cl->defmap = 0;
1945 cbq_sync_defmap(cl);
1946
1947 cbq_rmprio(q, cl);
1948 sch_tree_unlock(sch);
1949
1950 BUG_ON(--cl->refcnt == 0);
1951 /*
1952 * This shouldn't happen: we "hold" one cops->get() when called
1953 * from tc_ctl_tclass; the destroy method is done from cops->put().
1954 */
1955
1956 return 0;
1957 }
1958
1959 static struct tcf_proto __rcu **cbq_find_tcf(struct Qdisc *sch,
1960 unsigned long arg)
1961 {
1962 struct cbq_sched_data *q = qdisc_priv(sch);
1963 struct cbq_class *cl = (struct cbq_class *)arg;
1964
1965 if (cl == NULL)
1966 cl = &q->link;
1967
1968 return &cl->filter_list;
1969 }
1970
1971 static unsigned long cbq_bind_filter(struct Qdisc *sch, unsigned long parent,
1972 u32 classid)
1973 {
1974 struct cbq_sched_data *q = qdisc_priv(sch);
1975 struct cbq_class *p = (struct cbq_class *)parent;
1976 struct cbq_class *cl = cbq_class_lookup(q, classid);
1977
1978 if (cl) {
1979 if (p && p->level <= cl->level)
1980 return 0;
1981 cl->filters++;
1982 return (unsigned long)cl;
1983 }
1984 return 0;
1985 }
1986
1987 static void cbq_unbind_filter(struct Qdisc *sch, unsigned long arg)
1988 {
1989 struct cbq_class *cl = (struct cbq_class *)arg;
1990
1991 cl->filters--;
1992 }
1993
1994 static void cbq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1995 {
1996 struct cbq_sched_data *q = qdisc_priv(sch);
1997 struct cbq_class *cl;
1998 unsigned int h;
1999
2000 if (arg->stop)
2001 return;
2002
2003 for (h = 0; h < q->clhash.hashsize; h++) {
2004 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
2005 if (arg->count < arg->skip) {
2006 arg->count++;
2007 continue;
2008 }
2009 if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
2010 arg->stop = 1;
2011 return;
2012 }
2013 arg->count++;
2014 }
2015 }
2016 }
2017
2018 static const struct Qdisc_class_ops cbq_class_ops = {
2019 .graft = cbq_graft,
2020 .leaf = cbq_leaf,
2021 .qlen_notify = cbq_qlen_notify,
2022 .get = cbq_get,
2023 .put = cbq_put,
2024 .change = cbq_change_class,
2025 .delete = cbq_delete,
2026 .walk = cbq_walk,
2027 .tcf_chain = cbq_find_tcf,
2028 .bind_tcf = cbq_bind_filter,
2029 .unbind_tcf = cbq_unbind_filter,
2030 .dump = cbq_dump_class,
2031 .dump_stats = cbq_dump_class_stats,
2032 };
2033
2034 static struct Qdisc_ops cbq_qdisc_ops __read_mostly = {
2035 .next = NULL,
2036 .cl_ops = &cbq_class_ops,
2037 .id = "cbq",
2038 .priv_size = sizeof(struct cbq_sched_data),
2039 .enqueue = cbq_enqueue,
2040 .dequeue = cbq_dequeue,
2041 .peek = qdisc_peek_dequeued,
2042 .drop = cbq_drop,
2043 .init = cbq_init,
2044 .reset = cbq_reset,
2045 .destroy = cbq_destroy,
2046 .change = NULL,
2047 .dump = cbq_dump,
2048 .dump_stats = cbq_dump_stats,
2049 .owner = THIS_MODULE,
2050 };
2051
2052 static int __init cbq_module_init(void)
2053 {
2054 return register_qdisc(&cbq_qdisc_ops);
2055 }
2056 static void __exit cbq_module_exit(void)
2057 {
2058 unregister_qdisc(&cbq_qdisc_ops);
2059 }
2060 module_init(cbq_module_init)
2061 module_exit(cbq_module_exit)
2062 MODULE_LICENSE("GPL");
Linux with added FPC-III support