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