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[thirdparty/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 #include <net/pkt_cls.h>
23
24
25 /* Class-Based Queueing (CBQ) algorithm.
26 =======================================
27
28 Sources: [1] Sally Floyd and Van Jacobson, "Link-sharing and Resource
29 Management Models for Packet Networks",
30 IEEE/ACM Transactions on Networking, Vol.3, No.4, 1995
31
32 [2] Sally Floyd, "Notes on CBQ and Guaranteed Service", 1995
33
34 [3] Sally Floyd, "Notes on Class-Based Queueing: Setting
35 Parameters", 1996
36
37 [4] Sally Floyd and Michael Speer, "Experimental Results
38 for Class-Based Queueing", 1998, not published.
39
40 -----------------------------------------------------------------------
41
42 Algorithm skeleton was taken from NS simulator cbq.cc.
43 If someone wants to check this code against the LBL version,
44 he should take into account that ONLY the skeleton was borrowed,
45 the implementation is different. Particularly:
46
47 --- The WRR algorithm is different. Our version looks more
48 reasonable (I hope) and works when quanta are allowed to be
49 less than MTU, which is always the case when real time classes
50 have small rates. Note, that the statement of [3] is
51 incomplete, delay may actually be estimated even if class
52 per-round allotment is less than MTU. Namely, if per-round
53 allotment is W*r_i, and r_1+...+r_k = r < 1
54
55 delay_i <= ([MTU/(W*r_i)]*W*r + W*r + k*MTU)/B
56
57 In the worst case we have IntServ estimate with D = W*r+k*MTU
58 and C = MTU*r. The proof (if correct at all) is trivial.
59
60
61 --- It seems that cbq-2.0 is not very accurate. At least, I cannot
62 interpret some places, which look like wrong translations
63 from NS. Anyone is advised to find these differences
64 and explain to me, why I am wrong 8).
65
66 --- Linux has no EOI event, so that we cannot estimate true class
67 idle time. Workaround is to consider the next dequeue event
68 as sign that previous packet is finished. This is wrong because of
69 internal device queueing, but on a permanently loaded link it is true.
70 Moreover, combined with clock integrator, this scheme looks
71 very close to an ideal solution. */
72
73 struct cbq_sched_data;
74
75
76 struct cbq_class {
77 struct Qdisc_class_common common;
78 struct cbq_class *next_alive; /* next class with backlog in this priority band */
79
80 /* Parameters */
81 unsigned char priority; /* class priority */
82 unsigned char priority2; /* priority to be used after overlimit */
83 unsigned char ewma_log; /* time constant for idle time calculation */
84
85 u32 defmap;
86
87 /* Link-sharing scheduler parameters */
88 long maxidle; /* Class parameters: see below. */
89 long offtime;
90 long minidle;
91 u32 avpkt;
92 struct qdisc_rate_table *R_tab;
93
94 /* General scheduler (WRR) parameters */
95 long allot;
96 long quantum; /* Allotment per WRR round */
97 long weight; /* Relative allotment: see below */
98
99 struct Qdisc *qdisc; /* Ptr to CBQ discipline */
100 struct cbq_class *split; /* Ptr to split node */
101 struct cbq_class *share; /* Ptr to LS parent in the class tree */
102 struct cbq_class *tparent; /* Ptr to tree parent in the class tree */
103 struct cbq_class *borrow; /* NULL if class is bandwidth limited;
104 parent otherwise */
105 struct cbq_class *sibling; /* Sibling chain */
106 struct cbq_class *children; /* Pointer to children chain */
107
108 struct Qdisc *q; /* Elementary queueing discipline */
109
110
111 /* Variables */
112 unsigned char cpriority; /* Effective priority */
113 unsigned char delayed;
114 unsigned char level; /* level of the class in hierarchy:
115 0 for leaf classes, and maximal
116 level of children + 1 for nodes.
117 */
118
119 psched_time_t last; /* Last end of service */
120 psched_time_t undertime;
121 long avgidle;
122 long deficit; /* Saved deficit for WRR */
123 psched_time_t penalized;
124 struct gnet_stats_basic_packed bstats;
125 struct gnet_stats_queue qstats;
126 struct net_rate_estimator __rcu *rate_est;
127 struct tc_cbq_xstats xstats;
128
129 struct tcf_proto __rcu *filter_list;
130 struct tcf_block *block;
131
132 int filters;
133
134 struct cbq_class *defaults[TC_PRIO_MAX + 1];
135 };
136
137 struct cbq_sched_data {
138 struct Qdisc_class_hash clhash; /* Hash table of all classes */
139 int nclasses[TC_CBQ_MAXPRIO + 1];
140 unsigned int quanta[TC_CBQ_MAXPRIO + 1];
141
142 struct cbq_class link;
143
144 unsigned int activemask;
145 struct cbq_class *active[TC_CBQ_MAXPRIO + 1]; /* List of all classes
146 with backlog */
147
148 #ifdef CONFIG_NET_CLS_ACT
149 struct cbq_class *rx_class;
150 #endif
151 struct cbq_class *tx_class;
152 struct cbq_class *tx_borrowed;
153 int tx_len;
154 psched_time_t now; /* Cached timestamp */
155 unsigned int pmask;
156
157 struct hrtimer delay_timer;
158 struct qdisc_watchdog watchdog; /* Watchdog timer,
159 started when CBQ has
160 backlog, but cannot
161 transmit just now */
162 psched_tdiff_t wd_expires;
163 int toplevel;
164 u32 hgenerator;
165 };
166
167
168 #define L2T(cl, len) qdisc_l2t((cl)->R_tab, len)
169
170 static inline struct cbq_class *
171 cbq_class_lookup(struct cbq_sched_data *q, u32 classid)
172 {
173 struct Qdisc_class_common *clc;
174
175 clc = qdisc_class_find(&q->clhash, classid);
176 if (clc == NULL)
177 return NULL;
178 return container_of(clc, struct cbq_class, common);
179 }
180
181 #ifdef CONFIG_NET_CLS_ACT
182
183 static struct cbq_class *
184 cbq_reclassify(struct sk_buff *skb, struct cbq_class *this)
185 {
186 struct cbq_class *cl;
187
188 for (cl = this->tparent; cl; cl = cl->tparent) {
189 struct cbq_class *new = cl->defaults[TC_PRIO_BESTEFFORT];
190
191 if (new != NULL && new != this)
192 return new;
193 }
194 return NULL;
195 }
196
197 #endif
198
199 /* Classify packet. The procedure is pretty complicated, but
200 * it allows us to combine link sharing and priority scheduling
201 * transparently.
202 *
203 * Namely, you can put link sharing rules (f.e. route based) at root of CBQ,
204 * so that it resolves to split nodes. Then packets are classified
205 * by logical priority, or a more specific classifier may be attached
206 * to the split node.
207 */
208
209 static struct cbq_class *
210 cbq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
211 {
212 struct cbq_sched_data *q = qdisc_priv(sch);
213 struct cbq_class *head = &q->link;
214 struct cbq_class **defmap;
215 struct cbq_class *cl = NULL;
216 u32 prio = skb->priority;
217 struct tcf_proto *fl;
218 struct tcf_result res;
219
220 /*
221 * Step 1. If skb->priority points to one of our classes, use it.
222 */
223 if (TC_H_MAJ(prio ^ sch->handle) == 0 &&
224 (cl = cbq_class_lookup(q, prio)) != NULL)
225 return cl;
226
227 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
228 for (;;) {
229 int result = 0;
230 defmap = head->defaults;
231
232 fl = rcu_dereference_bh(head->filter_list);
233 /*
234 * Step 2+n. Apply classifier.
235 */
236 result = tcf_classify(skb, fl, &res, true);
237 if (!fl || result < 0)
238 goto fallback;
239
240 cl = (void *)res.class;
241 if (!cl) {
242 if (TC_H_MAJ(res.classid))
243 cl = cbq_class_lookup(q, res.classid);
244 else if ((cl = defmap[res.classid & TC_PRIO_MAX]) == NULL)
245 cl = defmap[TC_PRIO_BESTEFFORT];
246
247 if (cl == NULL)
248 goto fallback;
249 }
250 if (cl->level >= head->level)
251 goto fallback;
252 #ifdef CONFIG_NET_CLS_ACT
253 switch (result) {
254 case TC_ACT_QUEUED:
255 case TC_ACT_STOLEN:
256 case TC_ACT_TRAP:
257 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
258 /* fall through */
259 case TC_ACT_SHOT:
260 return NULL;
261 case TC_ACT_RECLASSIFY:
262 return cbq_reclassify(skb, cl);
263 }
264 #endif
265 if (cl->level == 0)
266 return cl;
267
268 /*
269 * Step 3+n. If classifier selected a link sharing class,
270 * apply agency specific classifier.
271 * Repeat this procdure until we hit a leaf node.
272 */
273 head = cl;
274 }
275
276 fallback:
277 cl = head;
278
279 /*
280 * Step 4. No success...
281 */
282 if (TC_H_MAJ(prio) == 0 &&
283 !(cl = head->defaults[prio & TC_PRIO_MAX]) &&
284 !(cl = head->defaults[TC_PRIO_BESTEFFORT]))
285 return head;
286
287 return cl;
288 }
289
290 /*
291 * A packet has just been enqueued on the empty class.
292 * cbq_activate_class adds it to the tail of active class list
293 * of its priority band.
294 */
295
296 static inline void cbq_activate_class(struct cbq_class *cl)
297 {
298 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
299 int prio = cl->cpriority;
300 struct cbq_class *cl_tail;
301
302 cl_tail = q->active[prio];
303 q->active[prio] = cl;
304
305 if (cl_tail != NULL) {
306 cl->next_alive = cl_tail->next_alive;
307 cl_tail->next_alive = cl;
308 } else {
309 cl->next_alive = cl;
310 q->activemask |= (1<<prio);
311 }
312 }
313
314 /*
315 * Unlink class from active chain.
316 * Note that this same procedure is done directly in cbq_dequeue*
317 * during round-robin procedure.
318 */
319
320 static void cbq_deactivate_class(struct cbq_class *this)
321 {
322 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
323 int prio = this->cpriority;
324 struct cbq_class *cl;
325 struct cbq_class *cl_prev = q->active[prio];
326
327 do {
328 cl = cl_prev->next_alive;
329 if (cl == this) {
330 cl_prev->next_alive = cl->next_alive;
331 cl->next_alive = NULL;
332
333 if (cl == q->active[prio]) {
334 q->active[prio] = cl_prev;
335 if (cl == q->active[prio]) {
336 q->active[prio] = NULL;
337 q->activemask &= ~(1<<prio);
338 return;
339 }
340 }
341 return;
342 }
343 } while ((cl_prev = cl) != q->active[prio]);
344 }
345
346 static void
347 cbq_mark_toplevel(struct cbq_sched_data *q, struct cbq_class *cl)
348 {
349 int toplevel = q->toplevel;
350
351 if (toplevel > cl->level) {
352 psched_time_t now = psched_get_time();
353
354 do {
355 if (cl->undertime < now) {
356 q->toplevel = cl->level;
357 return;
358 }
359 } while ((cl = cl->borrow) != NULL && toplevel > cl->level);
360 }
361 }
362
363 static int
364 cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
365 struct sk_buff **to_free)
366 {
367 struct cbq_sched_data *q = qdisc_priv(sch);
368 int uninitialized_var(ret);
369 struct cbq_class *cl = cbq_classify(skb, sch, &ret);
370
371 #ifdef CONFIG_NET_CLS_ACT
372 q->rx_class = cl;
373 #endif
374 if (cl == NULL) {
375 if (ret & __NET_XMIT_BYPASS)
376 qdisc_qstats_drop(sch);
377 __qdisc_drop(skb, to_free);
378 return ret;
379 }
380
381 ret = qdisc_enqueue(skb, cl->q, to_free);
382 if (ret == NET_XMIT_SUCCESS) {
383 sch->q.qlen++;
384 cbq_mark_toplevel(q, cl);
385 if (!cl->next_alive)
386 cbq_activate_class(cl);
387 return ret;
388 }
389
390 if (net_xmit_drop_count(ret)) {
391 qdisc_qstats_drop(sch);
392 cbq_mark_toplevel(q, cl);
393 cl->qstats.drops++;
394 }
395 return ret;
396 }
397
398 /* Overlimit action: penalize leaf class by adding offtime */
399 static void cbq_overlimit(struct cbq_class *cl)
400 {
401 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
402 psched_tdiff_t delay = cl->undertime - q->now;
403
404 if (!cl->delayed) {
405 delay += cl->offtime;
406
407 /*
408 * Class goes to sleep, so that it will have no
409 * chance to work avgidle. Let's forgive it 8)
410 *
411 * BTW cbq-2.0 has a crap in this
412 * place, apparently they forgot to shift it by cl->ewma_log.
413 */
414 if (cl->avgidle < 0)
415 delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log);
416 if (cl->avgidle < cl->minidle)
417 cl->avgidle = cl->minidle;
418 if (delay <= 0)
419 delay = 1;
420 cl->undertime = q->now + delay;
421
422 cl->xstats.overactions++;
423 cl->delayed = 1;
424 }
425 if (q->wd_expires == 0 || q->wd_expires > delay)
426 q->wd_expires = delay;
427
428 /* Dirty work! We must schedule wakeups based on
429 * real available rate, rather than leaf rate,
430 * which may be tiny (even zero).
431 */
432 if (q->toplevel == TC_CBQ_MAXLEVEL) {
433 struct cbq_class *b;
434 psched_tdiff_t base_delay = q->wd_expires;
435
436 for (b = cl->borrow; b; b = b->borrow) {
437 delay = b->undertime - q->now;
438 if (delay < base_delay) {
439 if (delay <= 0)
440 delay = 1;
441 base_delay = delay;
442 }
443 }
444
445 q->wd_expires = base_delay;
446 }
447 }
448
449 static psched_tdiff_t cbq_undelay_prio(struct cbq_sched_data *q, int prio,
450 psched_time_t now)
451 {
452 struct cbq_class *cl;
453 struct cbq_class *cl_prev = q->active[prio];
454 psched_time_t sched = now;
455
456 if (cl_prev == NULL)
457 return 0;
458
459 do {
460 cl = cl_prev->next_alive;
461 if (now - cl->penalized > 0) {
462 cl_prev->next_alive = cl->next_alive;
463 cl->next_alive = NULL;
464 cl->cpriority = cl->priority;
465 cl->delayed = 0;
466 cbq_activate_class(cl);
467
468 if (cl == q->active[prio]) {
469 q->active[prio] = cl_prev;
470 if (cl == q->active[prio]) {
471 q->active[prio] = NULL;
472 return 0;
473 }
474 }
475
476 cl = cl_prev->next_alive;
477 } else if (sched - cl->penalized > 0)
478 sched = cl->penalized;
479 } while ((cl_prev = cl) != q->active[prio]);
480
481 return sched - now;
482 }
483
484 static enum hrtimer_restart cbq_undelay(struct hrtimer *timer)
485 {
486 struct cbq_sched_data *q = container_of(timer, struct cbq_sched_data,
487 delay_timer);
488 struct Qdisc *sch = q->watchdog.qdisc;
489 psched_time_t now;
490 psched_tdiff_t delay = 0;
491 unsigned int pmask;
492
493 now = psched_get_time();
494
495 pmask = q->pmask;
496 q->pmask = 0;
497
498 while (pmask) {
499 int prio = ffz(~pmask);
500 psched_tdiff_t tmp;
501
502 pmask &= ~(1<<prio);
503
504 tmp = cbq_undelay_prio(q, prio, now);
505 if (tmp > 0) {
506 q->pmask |= 1<<prio;
507 if (tmp < delay || delay == 0)
508 delay = tmp;
509 }
510 }
511
512 if (delay) {
513 ktime_t time;
514
515 time = 0;
516 time = ktime_add_ns(time, PSCHED_TICKS2NS(now + delay));
517 hrtimer_start(&q->delay_timer, time, HRTIMER_MODE_ABS_PINNED);
518 }
519
520 __netif_schedule(qdisc_root(sch));
521 return HRTIMER_NORESTART;
522 }
523
524 /*
525 * It is mission critical procedure.
526 *
527 * We "regenerate" toplevel cutoff, if transmitting class
528 * has backlog and it is not regulated. It is not part of
529 * original CBQ description, but looks more reasonable.
530 * Probably, it is wrong. This question needs further investigation.
531 */
532
533 static inline void
534 cbq_update_toplevel(struct cbq_sched_data *q, struct cbq_class *cl,
535 struct cbq_class *borrowed)
536 {
537 if (cl && q->toplevel >= borrowed->level) {
538 if (cl->q->q.qlen > 1) {
539 do {
540 if (borrowed->undertime == PSCHED_PASTPERFECT) {
541 q->toplevel = borrowed->level;
542 return;
543 }
544 } while ((borrowed = borrowed->borrow) != NULL);
545 }
546 #if 0
547 /* It is not necessary now. Uncommenting it
548 will save CPU cycles, but decrease fairness.
549 */
550 q->toplevel = TC_CBQ_MAXLEVEL;
551 #endif
552 }
553 }
554
555 static void
556 cbq_update(struct cbq_sched_data *q)
557 {
558 struct cbq_class *this = q->tx_class;
559 struct cbq_class *cl = this;
560 int len = q->tx_len;
561 psched_time_t now;
562
563 q->tx_class = NULL;
564 /* Time integrator. We calculate EOS time
565 * by adding expected packet transmission time.
566 */
567 now = q->now + L2T(&q->link, len);
568
569 for ( ; cl; cl = cl->share) {
570 long avgidle = cl->avgidle;
571 long idle;
572
573 cl->bstats.packets++;
574 cl->bstats.bytes += len;
575
576 /*
577 * (now - last) is total time between packet right edges.
578 * (last_pktlen/rate) is "virtual" busy time, so that
579 *
580 * idle = (now - last) - last_pktlen/rate
581 */
582
583 idle = now - cl->last;
584 if ((unsigned long)idle > 128*1024*1024) {
585 avgidle = cl->maxidle;
586 } else {
587 idle -= L2T(cl, len);
588
589 /* true_avgidle := (1-W)*true_avgidle + W*idle,
590 * where W=2^{-ewma_log}. But cl->avgidle is scaled:
591 * cl->avgidle == true_avgidle/W,
592 * hence:
593 */
594 avgidle += idle - (avgidle>>cl->ewma_log);
595 }
596
597 if (avgidle <= 0) {
598 /* Overlimit or at-limit */
599
600 if (avgidle < cl->minidle)
601 avgidle = cl->minidle;
602
603 cl->avgidle = avgidle;
604
605 /* Calculate expected time, when this class
606 * will be allowed to send.
607 * It will occur, when:
608 * (1-W)*true_avgidle + W*delay = 0, i.e.
609 * idle = (1/W - 1)*(-true_avgidle)
610 * or
611 * idle = (1 - W)*(-cl->avgidle);
612 */
613 idle = (-avgidle) - ((-avgidle) >> cl->ewma_log);
614
615 /*
616 * That is not all.
617 * To maintain the rate allocated to the class,
618 * we add to undertime virtual clock,
619 * necessary to complete transmitted packet.
620 * (len/phys_bandwidth has been already passed
621 * to the moment of cbq_update)
622 */
623
624 idle -= L2T(&q->link, len);
625 idle += L2T(cl, len);
626
627 cl->undertime = now + idle;
628 } else {
629 /* Underlimit */
630
631 cl->undertime = PSCHED_PASTPERFECT;
632 if (avgidle > cl->maxidle)
633 cl->avgidle = cl->maxidle;
634 else
635 cl->avgidle = avgidle;
636 }
637 if ((s64)(now - cl->last) > 0)
638 cl->last = now;
639 }
640
641 cbq_update_toplevel(q, this, q->tx_borrowed);
642 }
643
644 static inline struct cbq_class *
645 cbq_under_limit(struct cbq_class *cl)
646 {
647 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
648 struct cbq_class *this_cl = cl;
649
650 if (cl->tparent == NULL)
651 return cl;
652
653 if (cl->undertime == PSCHED_PASTPERFECT || q->now >= cl->undertime) {
654 cl->delayed = 0;
655 return cl;
656 }
657
658 do {
659 /* It is very suspicious place. Now overlimit
660 * action is generated for not bounded classes
661 * only if link is completely congested.
662 * Though it is in agree with ancestor-only paradigm,
663 * it looks very stupid. Particularly,
664 * it means that this chunk of code will either
665 * never be called or result in strong amplification
666 * of burstiness. Dangerous, silly, and, however,
667 * no another solution exists.
668 */
669 cl = cl->borrow;
670 if (!cl) {
671 this_cl->qstats.overlimits++;
672 cbq_overlimit(this_cl);
673 return NULL;
674 }
675 if (cl->level > q->toplevel)
676 return NULL;
677 } while (cl->undertime != PSCHED_PASTPERFECT && q->now < cl->undertime);
678
679 cl->delayed = 0;
680 return cl;
681 }
682
683 static inline struct sk_buff *
684 cbq_dequeue_prio(struct Qdisc *sch, int prio)
685 {
686 struct cbq_sched_data *q = qdisc_priv(sch);
687 struct cbq_class *cl_tail, *cl_prev, *cl;
688 struct sk_buff *skb;
689 int deficit;
690
691 cl_tail = cl_prev = q->active[prio];
692 cl = cl_prev->next_alive;
693
694 do {
695 deficit = 0;
696
697 /* Start round */
698 do {
699 struct cbq_class *borrow = cl;
700
701 if (cl->q->q.qlen &&
702 (borrow = cbq_under_limit(cl)) == NULL)
703 goto skip_class;
704
705 if (cl->deficit <= 0) {
706 /* Class exhausted its allotment per
707 * this round. Switch to the next one.
708 */
709 deficit = 1;
710 cl->deficit += cl->quantum;
711 goto next_class;
712 }
713
714 skb = cl->q->dequeue(cl->q);
715
716 /* Class did not give us any skb :-(
717 * It could occur even if cl->q->q.qlen != 0
718 * f.e. if cl->q == "tbf"
719 */
720 if (skb == NULL)
721 goto skip_class;
722
723 cl->deficit -= qdisc_pkt_len(skb);
724 q->tx_class = cl;
725 q->tx_borrowed = borrow;
726 if (borrow != cl) {
727 #ifndef CBQ_XSTATS_BORROWS_BYTES
728 borrow->xstats.borrows++;
729 cl->xstats.borrows++;
730 #else
731 borrow->xstats.borrows += qdisc_pkt_len(skb);
732 cl->xstats.borrows += qdisc_pkt_len(skb);
733 #endif
734 }
735 q->tx_len = qdisc_pkt_len(skb);
736
737 if (cl->deficit <= 0) {
738 q->active[prio] = cl;
739 cl = cl->next_alive;
740 cl->deficit += cl->quantum;
741 }
742 return skb;
743
744 skip_class:
745 if (cl->q->q.qlen == 0 || prio != cl->cpriority) {
746 /* Class is empty or penalized.
747 * Unlink it from active chain.
748 */
749 cl_prev->next_alive = cl->next_alive;
750 cl->next_alive = NULL;
751
752 /* Did cl_tail point to it? */
753 if (cl == cl_tail) {
754 /* Repair it! */
755 cl_tail = cl_prev;
756
757 /* Was it the last class in this band? */
758 if (cl == cl_tail) {
759 /* Kill the band! */
760 q->active[prio] = NULL;
761 q->activemask &= ~(1<<prio);
762 if (cl->q->q.qlen)
763 cbq_activate_class(cl);
764 return NULL;
765 }
766
767 q->active[prio] = cl_tail;
768 }
769 if (cl->q->q.qlen)
770 cbq_activate_class(cl);
771
772 cl = cl_prev;
773 }
774
775 next_class:
776 cl_prev = cl;
777 cl = cl->next_alive;
778 } while (cl_prev != cl_tail);
779 } while (deficit);
780
781 q->active[prio] = cl_prev;
782
783 return NULL;
784 }
785
786 static inline struct sk_buff *
787 cbq_dequeue_1(struct Qdisc *sch)
788 {
789 struct cbq_sched_data *q = qdisc_priv(sch);
790 struct sk_buff *skb;
791 unsigned int activemask;
792
793 activemask = q->activemask & 0xFF;
794 while (activemask) {
795 int prio = ffz(~activemask);
796 activemask &= ~(1<<prio);
797 skb = cbq_dequeue_prio(sch, prio);
798 if (skb)
799 return skb;
800 }
801 return NULL;
802 }
803
804 static struct sk_buff *
805 cbq_dequeue(struct Qdisc *sch)
806 {
807 struct sk_buff *skb;
808 struct cbq_sched_data *q = qdisc_priv(sch);
809 psched_time_t now;
810
811 now = psched_get_time();
812
813 if (q->tx_class)
814 cbq_update(q);
815
816 q->now = now;
817
818 for (;;) {
819 q->wd_expires = 0;
820
821 skb = cbq_dequeue_1(sch);
822 if (skb) {
823 qdisc_bstats_update(sch, skb);
824 sch->q.qlen--;
825 return skb;
826 }
827
828 /* All the classes are overlimit.
829 *
830 * It is possible, if:
831 *
832 * 1. Scheduler is empty.
833 * 2. Toplevel cutoff inhibited borrowing.
834 * 3. Root class is overlimit.
835 *
836 * Reset 2d and 3d conditions and retry.
837 *
838 * Note, that NS and cbq-2.0 are buggy, peeking
839 * an arbitrary class is appropriate for ancestor-only
840 * sharing, but not for toplevel algorithm.
841 *
842 * Our version is better, but slower, because it requires
843 * two passes, but it is unavoidable with top-level sharing.
844 */
845
846 if (q->toplevel == TC_CBQ_MAXLEVEL &&
847 q->link.undertime == PSCHED_PASTPERFECT)
848 break;
849
850 q->toplevel = TC_CBQ_MAXLEVEL;
851 q->link.undertime = PSCHED_PASTPERFECT;
852 }
853
854 /* No packets in scheduler or nobody wants to give them to us :-(
855 * Sigh... start watchdog timer in the last case.
856 */
857
858 if (sch->q.qlen) {
859 qdisc_qstats_overlimit(sch);
860 if (q->wd_expires)
861 qdisc_watchdog_schedule(&q->watchdog,
862 now + q->wd_expires);
863 }
864 return NULL;
865 }
866
867 /* CBQ class maintanance routines */
868
869 static void cbq_adjust_levels(struct cbq_class *this)
870 {
871 if (this == NULL)
872 return;
873
874 do {
875 int level = 0;
876 struct cbq_class *cl;
877
878 cl = this->children;
879 if (cl) {
880 do {
881 if (cl->level > level)
882 level = cl->level;
883 } while ((cl = cl->sibling) != this->children);
884 }
885 this->level = level + 1;
886 } while ((this = this->tparent) != NULL);
887 }
888
889 static void cbq_normalize_quanta(struct cbq_sched_data *q, int prio)
890 {
891 struct cbq_class *cl;
892 unsigned int h;
893
894 if (q->quanta[prio] == 0)
895 return;
896
897 for (h = 0; h < q->clhash.hashsize; h++) {
898 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
899 /* BUGGGG... Beware! This expression suffer of
900 * arithmetic overflows!
901 */
902 if (cl->priority == prio) {
903 cl->quantum = (cl->weight*cl->allot*q->nclasses[prio])/
904 q->quanta[prio];
905 }
906 if (cl->quantum <= 0 ||
907 cl->quantum > 32*qdisc_dev(cl->qdisc)->mtu) {
908 pr_warn("CBQ: class %08x has bad quantum==%ld, repaired.\n",
909 cl->common.classid, cl->quantum);
910 cl->quantum = qdisc_dev(cl->qdisc)->mtu/2 + 1;
911 }
912 }
913 }
914 }
915
916 static void cbq_sync_defmap(struct cbq_class *cl)
917 {
918 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
919 struct cbq_class *split = cl->split;
920 unsigned int h;
921 int i;
922
923 if (split == NULL)
924 return;
925
926 for (i = 0; i <= TC_PRIO_MAX; i++) {
927 if (split->defaults[i] == cl && !(cl->defmap & (1<<i)))
928 split->defaults[i] = NULL;
929 }
930
931 for (i = 0; i <= TC_PRIO_MAX; i++) {
932 int level = split->level;
933
934 if (split->defaults[i])
935 continue;
936
937 for (h = 0; h < q->clhash.hashsize; h++) {
938 struct cbq_class *c;
939
940 hlist_for_each_entry(c, &q->clhash.hash[h],
941 common.hnode) {
942 if (c->split == split && c->level < level &&
943 c->defmap & (1<<i)) {
944 split->defaults[i] = c;
945 level = c->level;
946 }
947 }
948 }
949 }
950 }
951
952 static void cbq_change_defmap(struct cbq_class *cl, u32 splitid, u32 def, u32 mask)
953 {
954 struct cbq_class *split = NULL;
955
956 if (splitid == 0) {
957 split = cl->split;
958 if (!split)
959 return;
960 splitid = split->common.classid;
961 }
962
963 if (split == NULL || split->common.classid != splitid) {
964 for (split = cl->tparent; split; split = split->tparent)
965 if (split->common.classid == splitid)
966 break;
967 }
968
969 if (split == NULL)
970 return;
971
972 if (cl->split != split) {
973 cl->defmap = 0;
974 cbq_sync_defmap(cl);
975 cl->split = split;
976 cl->defmap = def & mask;
977 } else
978 cl->defmap = (cl->defmap & ~mask) | (def & mask);
979
980 cbq_sync_defmap(cl);
981 }
982
983 static void cbq_unlink_class(struct cbq_class *this)
984 {
985 struct cbq_class *cl, **clp;
986 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
987
988 qdisc_class_hash_remove(&q->clhash, &this->common);
989
990 if (this->tparent) {
991 clp = &this->sibling;
992 cl = *clp;
993 do {
994 if (cl == this) {
995 *clp = cl->sibling;
996 break;
997 }
998 clp = &cl->sibling;
999 } while ((cl = *clp) != this->sibling);
1000
1001 if (this->tparent->children == this) {
1002 this->tparent->children = this->sibling;
1003 if (this->sibling == this)
1004 this->tparent->children = NULL;
1005 }
1006 } else {
1007 WARN_ON(this->sibling != this);
1008 }
1009 }
1010
1011 static void cbq_link_class(struct cbq_class *this)
1012 {
1013 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
1014 struct cbq_class *parent = this->tparent;
1015
1016 this->sibling = this;
1017 qdisc_class_hash_insert(&q->clhash, &this->common);
1018
1019 if (parent == NULL)
1020 return;
1021
1022 if (parent->children == NULL) {
1023 parent->children = this;
1024 } else {
1025 this->sibling = parent->children->sibling;
1026 parent->children->sibling = this;
1027 }
1028 }
1029
1030 static void
1031 cbq_reset(struct Qdisc *sch)
1032 {
1033 struct cbq_sched_data *q = qdisc_priv(sch);
1034 struct cbq_class *cl;
1035 int prio;
1036 unsigned int h;
1037
1038 q->activemask = 0;
1039 q->pmask = 0;
1040 q->tx_class = NULL;
1041 q->tx_borrowed = NULL;
1042 qdisc_watchdog_cancel(&q->watchdog);
1043 hrtimer_cancel(&q->delay_timer);
1044 q->toplevel = TC_CBQ_MAXLEVEL;
1045 q->now = psched_get_time();
1046
1047 for (prio = 0; prio <= TC_CBQ_MAXPRIO; prio++)
1048 q->active[prio] = NULL;
1049
1050 for (h = 0; h < q->clhash.hashsize; h++) {
1051 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
1052 qdisc_reset(cl->q);
1053
1054 cl->next_alive = NULL;
1055 cl->undertime = PSCHED_PASTPERFECT;
1056 cl->avgidle = cl->maxidle;
1057 cl->deficit = cl->quantum;
1058 cl->cpriority = cl->priority;
1059 }
1060 }
1061 sch->q.qlen = 0;
1062 }
1063
1064
1065 static int cbq_set_lss(struct cbq_class *cl, struct tc_cbq_lssopt *lss)
1066 {
1067 if (lss->change & TCF_CBQ_LSS_FLAGS) {
1068 cl->share = (lss->flags & TCF_CBQ_LSS_ISOLATED) ? NULL : cl->tparent;
1069 cl->borrow = (lss->flags & TCF_CBQ_LSS_BOUNDED) ? NULL : cl->tparent;
1070 }
1071 if (lss->change & TCF_CBQ_LSS_EWMA)
1072 cl->ewma_log = lss->ewma_log;
1073 if (lss->change & TCF_CBQ_LSS_AVPKT)
1074 cl->avpkt = lss->avpkt;
1075 if (lss->change & TCF_CBQ_LSS_MINIDLE)
1076 cl->minidle = -(long)lss->minidle;
1077 if (lss->change & TCF_CBQ_LSS_MAXIDLE) {
1078 cl->maxidle = lss->maxidle;
1079 cl->avgidle = lss->maxidle;
1080 }
1081 if (lss->change & TCF_CBQ_LSS_OFFTIME)
1082 cl->offtime = lss->offtime;
1083 return 0;
1084 }
1085
1086 static void cbq_rmprio(struct cbq_sched_data *q, struct cbq_class *cl)
1087 {
1088 q->nclasses[cl->priority]--;
1089 q->quanta[cl->priority] -= cl->weight;
1090 cbq_normalize_quanta(q, cl->priority);
1091 }
1092
1093 static void cbq_addprio(struct cbq_sched_data *q, struct cbq_class *cl)
1094 {
1095 q->nclasses[cl->priority]++;
1096 q->quanta[cl->priority] += cl->weight;
1097 cbq_normalize_quanta(q, cl->priority);
1098 }
1099
1100 static int cbq_set_wrr(struct cbq_class *cl, struct tc_cbq_wrropt *wrr)
1101 {
1102 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
1103
1104 if (wrr->allot)
1105 cl->allot = wrr->allot;
1106 if (wrr->weight)
1107 cl->weight = wrr->weight;
1108 if (wrr->priority) {
1109 cl->priority = wrr->priority - 1;
1110 cl->cpriority = cl->priority;
1111 if (cl->priority >= cl->priority2)
1112 cl->priority2 = TC_CBQ_MAXPRIO - 1;
1113 }
1114
1115 cbq_addprio(q, cl);
1116 return 0;
1117 }
1118
1119 static int cbq_set_fopt(struct cbq_class *cl, struct tc_cbq_fopt *fopt)
1120 {
1121 cbq_change_defmap(cl, fopt->split, fopt->defmap, fopt->defchange);
1122 return 0;
1123 }
1124
1125 static const struct nla_policy cbq_policy[TCA_CBQ_MAX + 1] = {
1126 [TCA_CBQ_LSSOPT] = { .len = sizeof(struct tc_cbq_lssopt) },
1127 [TCA_CBQ_WRROPT] = { .len = sizeof(struct tc_cbq_wrropt) },
1128 [TCA_CBQ_FOPT] = { .len = sizeof(struct tc_cbq_fopt) },
1129 [TCA_CBQ_OVL_STRATEGY] = { .len = sizeof(struct tc_cbq_ovl) },
1130 [TCA_CBQ_RATE] = { .len = sizeof(struct tc_ratespec) },
1131 [TCA_CBQ_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
1132 [TCA_CBQ_POLICE] = { .len = sizeof(struct tc_cbq_police) },
1133 };
1134
1135 static int cbq_init(struct Qdisc *sch, struct nlattr *opt,
1136 struct netlink_ext_ack *extack)
1137 {
1138 struct cbq_sched_data *q = qdisc_priv(sch);
1139 struct nlattr *tb[TCA_CBQ_MAX + 1];
1140 struct tc_ratespec *r;
1141 int err;
1142
1143 qdisc_watchdog_init(&q->watchdog, sch);
1144 hrtimer_init(&q->delay_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
1145 q->delay_timer.function = cbq_undelay;
1146
1147 if (!opt) {
1148 NL_SET_ERR_MSG(extack, "CBQ options are required for this operation");
1149 return -EINVAL;
1150 }
1151
1152 err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy, extack);
1153 if (err < 0)
1154 return err;
1155
1156 if (!tb[TCA_CBQ_RTAB] || !tb[TCA_CBQ_RATE]) {
1157 NL_SET_ERR_MSG(extack, "Rate specification missing or incomplete");
1158 return -EINVAL;
1159 }
1160
1161 r = nla_data(tb[TCA_CBQ_RATE]);
1162
1163 q->link.R_tab = qdisc_get_rtab(r, tb[TCA_CBQ_RTAB], extack);
1164 if (!q->link.R_tab)
1165 return -EINVAL;
1166
1167 err = tcf_block_get(&q->link.block, &q->link.filter_list, sch, extack);
1168 if (err)
1169 goto put_rtab;
1170
1171 err = qdisc_class_hash_init(&q->clhash);
1172 if (err < 0)
1173 goto put_block;
1174
1175 q->link.sibling = &q->link;
1176 q->link.common.classid = sch->handle;
1177 q->link.qdisc = sch;
1178 q->link.q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1179 sch->handle, NULL);
1180 if (!q->link.q)
1181 q->link.q = &noop_qdisc;
1182 else
1183 qdisc_hash_add(q->link.q, true);
1184
1185 q->link.priority = TC_CBQ_MAXPRIO - 1;
1186 q->link.priority2 = TC_CBQ_MAXPRIO - 1;
1187 q->link.cpriority = TC_CBQ_MAXPRIO - 1;
1188 q->link.allot = psched_mtu(qdisc_dev(sch));
1189 q->link.quantum = q->link.allot;
1190 q->link.weight = q->link.R_tab->rate.rate;
1191
1192 q->link.ewma_log = TC_CBQ_DEF_EWMA;
1193 q->link.avpkt = q->link.allot/2;
1194 q->link.minidle = -0x7FFFFFFF;
1195
1196 q->toplevel = TC_CBQ_MAXLEVEL;
1197 q->now = psched_get_time();
1198
1199 cbq_link_class(&q->link);
1200
1201 if (tb[TCA_CBQ_LSSOPT])
1202 cbq_set_lss(&q->link, nla_data(tb[TCA_CBQ_LSSOPT]));
1203
1204 cbq_addprio(q, &q->link);
1205 return 0;
1206
1207 put_block:
1208 tcf_block_put(q->link.block);
1209
1210 put_rtab:
1211 qdisc_put_rtab(q->link.R_tab);
1212 return err;
1213 }
1214
1215 static int cbq_dump_rate(struct sk_buff *skb, struct cbq_class *cl)
1216 {
1217 unsigned char *b = skb_tail_pointer(skb);
1218
1219 if (nla_put(skb, TCA_CBQ_RATE, sizeof(cl->R_tab->rate), &cl->R_tab->rate))
1220 goto nla_put_failure;
1221 return skb->len;
1222
1223 nla_put_failure:
1224 nlmsg_trim(skb, b);
1225 return -1;
1226 }
1227
1228 static int cbq_dump_lss(struct sk_buff *skb, struct cbq_class *cl)
1229 {
1230 unsigned char *b = skb_tail_pointer(skb);
1231 struct tc_cbq_lssopt opt;
1232
1233 opt.flags = 0;
1234 if (cl->borrow == NULL)
1235 opt.flags |= TCF_CBQ_LSS_BOUNDED;
1236 if (cl->share == NULL)
1237 opt.flags |= TCF_CBQ_LSS_ISOLATED;
1238 opt.ewma_log = cl->ewma_log;
1239 opt.level = cl->level;
1240 opt.avpkt = cl->avpkt;
1241 opt.maxidle = cl->maxidle;
1242 opt.minidle = (u32)(-cl->minidle);
1243 opt.offtime = cl->offtime;
1244 opt.change = ~0;
1245 if (nla_put(skb, TCA_CBQ_LSSOPT, sizeof(opt), &opt))
1246 goto nla_put_failure;
1247 return skb->len;
1248
1249 nla_put_failure:
1250 nlmsg_trim(skb, b);
1251 return -1;
1252 }
1253
1254 static int cbq_dump_wrr(struct sk_buff *skb, struct cbq_class *cl)
1255 {
1256 unsigned char *b = skb_tail_pointer(skb);
1257 struct tc_cbq_wrropt opt;
1258
1259 memset(&opt, 0, sizeof(opt));
1260 opt.flags = 0;
1261 opt.allot = cl->allot;
1262 opt.priority = cl->priority + 1;
1263 opt.cpriority = cl->cpriority + 1;
1264 opt.weight = cl->weight;
1265 if (nla_put(skb, TCA_CBQ_WRROPT, sizeof(opt), &opt))
1266 goto nla_put_failure;
1267 return skb->len;
1268
1269 nla_put_failure:
1270 nlmsg_trim(skb, b);
1271 return -1;
1272 }
1273
1274 static int cbq_dump_fopt(struct sk_buff *skb, struct cbq_class *cl)
1275 {
1276 unsigned char *b = skb_tail_pointer(skb);
1277 struct tc_cbq_fopt opt;
1278
1279 if (cl->split || cl->defmap) {
1280 opt.split = cl->split ? cl->split->common.classid : 0;
1281 opt.defmap = cl->defmap;
1282 opt.defchange = ~0;
1283 if (nla_put(skb, TCA_CBQ_FOPT, sizeof(opt), &opt))
1284 goto nla_put_failure;
1285 }
1286 return skb->len;
1287
1288 nla_put_failure:
1289 nlmsg_trim(skb, b);
1290 return -1;
1291 }
1292
1293 static int cbq_dump_attr(struct sk_buff *skb, struct cbq_class *cl)
1294 {
1295 if (cbq_dump_lss(skb, cl) < 0 ||
1296 cbq_dump_rate(skb, cl) < 0 ||
1297 cbq_dump_wrr(skb, cl) < 0 ||
1298 cbq_dump_fopt(skb, cl) < 0)
1299 return -1;
1300 return 0;
1301 }
1302
1303 static int cbq_dump(struct Qdisc *sch, struct sk_buff *skb)
1304 {
1305 struct cbq_sched_data *q = qdisc_priv(sch);
1306 struct nlattr *nest;
1307
1308 nest = nla_nest_start(skb, TCA_OPTIONS);
1309 if (nest == NULL)
1310 goto nla_put_failure;
1311 if (cbq_dump_attr(skb, &q->link) < 0)
1312 goto nla_put_failure;
1313 return nla_nest_end(skb, nest);
1314
1315 nla_put_failure:
1316 nla_nest_cancel(skb, nest);
1317 return -1;
1318 }
1319
1320 static int
1321 cbq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
1322 {
1323 struct cbq_sched_data *q = qdisc_priv(sch);
1324
1325 q->link.xstats.avgidle = q->link.avgidle;
1326 return gnet_stats_copy_app(d, &q->link.xstats, sizeof(q->link.xstats));
1327 }
1328
1329 static int
1330 cbq_dump_class(struct Qdisc *sch, unsigned long arg,
1331 struct sk_buff *skb, struct tcmsg *tcm)
1332 {
1333 struct cbq_class *cl = (struct cbq_class *)arg;
1334 struct nlattr *nest;
1335
1336 if (cl->tparent)
1337 tcm->tcm_parent = cl->tparent->common.classid;
1338 else
1339 tcm->tcm_parent = TC_H_ROOT;
1340 tcm->tcm_handle = cl->common.classid;
1341 tcm->tcm_info = cl->q->handle;
1342
1343 nest = nla_nest_start(skb, TCA_OPTIONS);
1344 if (nest == NULL)
1345 goto nla_put_failure;
1346 if (cbq_dump_attr(skb, cl) < 0)
1347 goto nla_put_failure;
1348 return nla_nest_end(skb, nest);
1349
1350 nla_put_failure:
1351 nla_nest_cancel(skb, nest);
1352 return -1;
1353 }
1354
1355 static int
1356 cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1357 struct gnet_dump *d)
1358 {
1359 struct cbq_sched_data *q = qdisc_priv(sch);
1360 struct cbq_class *cl = (struct cbq_class *)arg;
1361 __u32 qlen;
1362
1363 cl->xstats.avgidle = cl->avgidle;
1364 cl->xstats.undertime = 0;
1365 qdisc_qstats_qlen_backlog(cl->q, &qlen, &cl->qstats.backlog);
1366
1367 if (cl->undertime != PSCHED_PASTPERFECT)
1368 cl->xstats.undertime = cl->undertime - q->now;
1369
1370 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
1371 d, NULL, &cl->bstats) < 0 ||
1372 gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
1373 gnet_stats_copy_queue(d, NULL, &cl->qstats, qlen) < 0)
1374 return -1;
1375
1376 return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));
1377 }
1378
1379 static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1380 struct Qdisc **old, struct netlink_ext_ack *extack)
1381 {
1382 struct cbq_class *cl = (struct cbq_class *)arg;
1383
1384 if (new == NULL) {
1385 new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1386 cl->common.classid, extack);
1387 if (new == NULL)
1388 return -ENOBUFS;
1389 }
1390
1391 *old = qdisc_replace(sch, new, &cl->q);
1392 return 0;
1393 }
1394
1395 static struct Qdisc *cbq_leaf(struct Qdisc *sch, unsigned long arg)
1396 {
1397 struct cbq_class *cl = (struct cbq_class *)arg;
1398
1399 return cl->q;
1400 }
1401
1402 static void cbq_qlen_notify(struct Qdisc *sch, unsigned long arg)
1403 {
1404 struct cbq_class *cl = (struct cbq_class *)arg;
1405
1406 cbq_deactivate_class(cl);
1407 }
1408
1409 static unsigned long cbq_find(struct Qdisc *sch, u32 classid)
1410 {
1411 struct cbq_sched_data *q = qdisc_priv(sch);
1412
1413 return (unsigned long)cbq_class_lookup(q, classid);
1414 }
1415
1416 static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl)
1417 {
1418 struct cbq_sched_data *q = qdisc_priv(sch);
1419
1420 WARN_ON(cl->filters);
1421
1422 tcf_block_put(cl->block);
1423 qdisc_put(cl->q);
1424 qdisc_put_rtab(cl->R_tab);
1425 gen_kill_estimator(&cl->rate_est);
1426 if (cl != &q->link)
1427 kfree(cl);
1428 }
1429
1430 static void cbq_destroy(struct Qdisc *sch)
1431 {
1432 struct cbq_sched_data *q = qdisc_priv(sch);
1433 struct hlist_node *next;
1434 struct cbq_class *cl;
1435 unsigned int h;
1436
1437 #ifdef CONFIG_NET_CLS_ACT
1438 q->rx_class = NULL;
1439 #endif
1440 /*
1441 * Filters must be destroyed first because we don't destroy the
1442 * classes from root to leafs which means that filters can still
1443 * be bound to classes which have been destroyed already. --TGR '04
1444 */
1445 for (h = 0; h < q->clhash.hashsize; h++) {
1446 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
1447 tcf_block_put(cl->block);
1448 cl->block = NULL;
1449 }
1450 }
1451 for (h = 0; h < q->clhash.hashsize; h++) {
1452 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[h],
1453 common.hnode)
1454 cbq_destroy_class(sch, cl);
1455 }
1456 qdisc_class_hash_destroy(&q->clhash);
1457 }
1458
1459 static int
1460 cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **tca,
1461 unsigned long *arg, struct netlink_ext_ack *extack)
1462 {
1463 int err;
1464 struct cbq_sched_data *q = qdisc_priv(sch);
1465 struct cbq_class *cl = (struct cbq_class *)*arg;
1466 struct nlattr *opt = tca[TCA_OPTIONS];
1467 struct nlattr *tb[TCA_CBQ_MAX + 1];
1468 struct cbq_class *parent;
1469 struct qdisc_rate_table *rtab = NULL;
1470
1471 if (!opt) {
1472 NL_SET_ERR_MSG(extack, "Mandatory qdisc options missing");
1473 return -EINVAL;
1474 }
1475
1476 err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy, extack);
1477 if (err < 0)
1478 return err;
1479
1480 if (tb[TCA_CBQ_OVL_STRATEGY] || tb[TCA_CBQ_POLICE]) {
1481 NL_SET_ERR_MSG(extack, "Neither overlimit strategy nor policing attributes can be used for changing class params");
1482 return -EOPNOTSUPP;
1483 }
1484
1485 if (cl) {
1486 /* Check parent */
1487 if (parentid) {
1488 if (cl->tparent &&
1489 cl->tparent->common.classid != parentid) {
1490 NL_SET_ERR_MSG(extack, "Invalid parent id");
1491 return -EINVAL;
1492 }
1493 if (!cl->tparent && parentid != TC_H_ROOT) {
1494 NL_SET_ERR_MSG(extack, "Parent must be root");
1495 return -EINVAL;
1496 }
1497 }
1498
1499 if (tb[TCA_CBQ_RATE]) {
1500 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]),
1501 tb[TCA_CBQ_RTAB], extack);
1502 if (rtab == NULL)
1503 return -EINVAL;
1504 }
1505
1506 if (tca[TCA_RATE]) {
1507 err = gen_replace_estimator(&cl->bstats, NULL,
1508 &cl->rate_est,
1509 NULL,
1510 qdisc_root_sleeping_running(sch),
1511 tca[TCA_RATE]);
1512 if (err) {
1513 NL_SET_ERR_MSG(extack, "Failed to replace specified rate estimator");
1514 qdisc_put_rtab(rtab);
1515 return err;
1516 }
1517 }
1518
1519 /* Change class parameters */
1520 sch_tree_lock(sch);
1521
1522 if (cl->next_alive != NULL)
1523 cbq_deactivate_class(cl);
1524
1525 if (rtab) {
1526 qdisc_put_rtab(cl->R_tab);
1527 cl->R_tab = rtab;
1528 }
1529
1530 if (tb[TCA_CBQ_LSSOPT])
1531 cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
1532
1533 if (tb[TCA_CBQ_WRROPT]) {
1534 cbq_rmprio(q, cl);
1535 cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
1536 }
1537
1538 if (tb[TCA_CBQ_FOPT])
1539 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
1540
1541 if (cl->q->q.qlen)
1542 cbq_activate_class(cl);
1543
1544 sch_tree_unlock(sch);
1545
1546 return 0;
1547 }
1548
1549 if (parentid == TC_H_ROOT)
1550 return -EINVAL;
1551
1552 if (!tb[TCA_CBQ_WRROPT] || !tb[TCA_CBQ_RATE] || !tb[TCA_CBQ_LSSOPT]) {
1553 NL_SET_ERR_MSG(extack, "One of the following attributes MUST be specified: WRR, rate or link sharing");
1554 return -EINVAL;
1555 }
1556
1557 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]), tb[TCA_CBQ_RTAB],
1558 extack);
1559 if (rtab == NULL)
1560 return -EINVAL;
1561
1562 if (classid) {
1563 err = -EINVAL;
1564 if (TC_H_MAJ(classid ^ sch->handle) ||
1565 cbq_class_lookup(q, classid)) {
1566 NL_SET_ERR_MSG(extack, "Specified class not found");
1567 goto failure;
1568 }
1569 } else {
1570 int i;
1571 classid = TC_H_MAKE(sch->handle, 0x8000);
1572
1573 for (i = 0; i < 0x8000; i++) {
1574 if (++q->hgenerator >= 0x8000)
1575 q->hgenerator = 1;
1576 if (cbq_class_lookup(q, classid|q->hgenerator) == NULL)
1577 break;
1578 }
1579 err = -ENOSR;
1580 if (i >= 0x8000) {
1581 NL_SET_ERR_MSG(extack, "Unable to generate classid");
1582 goto failure;
1583 }
1584 classid = classid|q->hgenerator;
1585 }
1586
1587 parent = &q->link;
1588 if (parentid) {
1589 parent = cbq_class_lookup(q, parentid);
1590 err = -EINVAL;
1591 if (!parent) {
1592 NL_SET_ERR_MSG(extack, "Failed to find parentid");
1593 goto failure;
1594 }
1595 }
1596
1597 err = -ENOBUFS;
1598 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
1599 if (cl == NULL)
1600 goto failure;
1601
1602 err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack);
1603 if (err) {
1604 kfree(cl);
1605 return err;
1606 }
1607
1608 if (tca[TCA_RATE]) {
1609 err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
1610 NULL,
1611 qdisc_root_sleeping_running(sch),
1612 tca[TCA_RATE]);
1613 if (err) {
1614 NL_SET_ERR_MSG(extack, "Couldn't create new estimator");
1615 tcf_block_put(cl->block);
1616 kfree(cl);
1617 goto failure;
1618 }
1619 }
1620
1621 cl->R_tab = rtab;
1622 rtab = NULL;
1623 cl->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid,
1624 NULL);
1625 if (!cl->q)
1626 cl->q = &noop_qdisc;
1627 else
1628 qdisc_hash_add(cl->q, true);
1629
1630 cl->common.classid = classid;
1631 cl->tparent = parent;
1632 cl->qdisc = sch;
1633 cl->allot = parent->allot;
1634 cl->quantum = cl->allot;
1635 cl->weight = cl->R_tab->rate.rate;
1636
1637 sch_tree_lock(sch);
1638 cbq_link_class(cl);
1639 cl->borrow = cl->tparent;
1640 if (cl->tparent != &q->link)
1641 cl->share = cl->tparent;
1642 cbq_adjust_levels(parent);
1643 cl->minidle = -0x7FFFFFFF;
1644 cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
1645 cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
1646 if (cl->ewma_log == 0)
1647 cl->ewma_log = q->link.ewma_log;
1648 if (cl->maxidle == 0)
1649 cl->maxidle = q->link.maxidle;
1650 if (cl->avpkt == 0)
1651 cl->avpkt = q->link.avpkt;
1652 if (tb[TCA_CBQ_FOPT])
1653 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
1654 sch_tree_unlock(sch);
1655
1656 qdisc_class_hash_grow(sch, &q->clhash);
1657
1658 *arg = (unsigned long)cl;
1659 return 0;
1660
1661 failure:
1662 qdisc_put_rtab(rtab);
1663 return err;
1664 }
1665
1666 static int cbq_delete(struct Qdisc *sch, unsigned long arg)
1667 {
1668 struct cbq_sched_data *q = qdisc_priv(sch);
1669 struct cbq_class *cl = (struct cbq_class *)arg;
1670
1671 if (cl->filters || cl->children || cl == &q->link)
1672 return -EBUSY;
1673
1674 sch_tree_lock(sch);
1675
1676 qdisc_purge_queue(cl->q);
1677
1678 if (cl->next_alive)
1679 cbq_deactivate_class(cl);
1680
1681 if (q->tx_borrowed == cl)
1682 q->tx_borrowed = q->tx_class;
1683 if (q->tx_class == cl) {
1684 q->tx_class = NULL;
1685 q->tx_borrowed = NULL;
1686 }
1687 #ifdef CONFIG_NET_CLS_ACT
1688 if (q->rx_class == cl)
1689 q->rx_class = NULL;
1690 #endif
1691
1692 cbq_unlink_class(cl);
1693 cbq_adjust_levels(cl->tparent);
1694 cl->defmap = 0;
1695 cbq_sync_defmap(cl);
1696
1697 cbq_rmprio(q, cl);
1698 sch_tree_unlock(sch);
1699
1700 cbq_destroy_class(sch, cl);
1701 return 0;
1702 }
1703
1704 static struct tcf_block *cbq_tcf_block(struct Qdisc *sch, unsigned long arg,
1705 struct netlink_ext_ack *extack)
1706 {
1707 struct cbq_sched_data *q = qdisc_priv(sch);
1708 struct cbq_class *cl = (struct cbq_class *)arg;
1709
1710 if (cl == NULL)
1711 cl = &q->link;
1712
1713 return cl->block;
1714 }
1715
1716 static unsigned long cbq_bind_filter(struct Qdisc *sch, unsigned long parent,
1717 u32 classid)
1718 {
1719 struct cbq_sched_data *q = qdisc_priv(sch);
1720 struct cbq_class *p = (struct cbq_class *)parent;
1721 struct cbq_class *cl = cbq_class_lookup(q, classid);
1722
1723 if (cl) {
1724 if (p && p->level <= cl->level)
1725 return 0;
1726 cl->filters++;
1727 return (unsigned long)cl;
1728 }
1729 return 0;
1730 }
1731
1732 static void cbq_unbind_filter(struct Qdisc *sch, unsigned long arg)
1733 {
1734 struct cbq_class *cl = (struct cbq_class *)arg;
1735
1736 cl->filters--;
1737 }
1738
1739 static void cbq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1740 {
1741 struct cbq_sched_data *q = qdisc_priv(sch);
1742 struct cbq_class *cl;
1743 unsigned int h;
1744
1745 if (arg->stop)
1746 return;
1747
1748 for (h = 0; h < q->clhash.hashsize; h++) {
1749 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
1750 if (arg->count < arg->skip) {
1751 arg->count++;
1752 continue;
1753 }
1754 if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
1755 arg->stop = 1;
1756 return;
1757 }
1758 arg->count++;
1759 }
1760 }
1761 }
1762
1763 static const struct Qdisc_class_ops cbq_class_ops = {
1764 .graft = cbq_graft,
1765 .leaf = cbq_leaf,
1766 .qlen_notify = cbq_qlen_notify,
1767 .find = cbq_find,
1768 .change = cbq_change_class,
1769 .delete = cbq_delete,
1770 .walk = cbq_walk,
1771 .tcf_block = cbq_tcf_block,
1772 .bind_tcf = cbq_bind_filter,
1773 .unbind_tcf = cbq_unbind_filter,
1774 .dump = cbq_dump_class,
1775 .dump_stats = cbq_dump_class_stats,
1776 };
1777
1778 static struct Qdisc_ops cbq_qdisc_ops __read_mostly = {
1779 .next = NULL,
1780 .cl_ops = &cbq_class_ops,
1781 .id = "cbq",
1782 .priv_size = sizeof(struct cbq_sched_data),
1783 .enqueue = cbq_enqueue,
1784 .dequeue = cbq_dequeue,
1785 .peek = qdisc_peek_dequeued,
1786 .init = cbq_init,
1787 .reset = cbq_reset,
1788 .destroy = cbq_destroy,
1789 .change = NULL,
1790 .dump = cbq_dump,
1791 .dump_stats = cbq_dump_stats,
1792 .owner = THIS_MODULE,
1793 };
1794
1795 static int __init cbq_module_init(void)
1796 {
1797 return register_qdisc(&cbq_qdisc_ops);
1798 }
1799 static void __exit cbq_module_exit(void)
1800 {
1801 unregister_qdisc(&cbq_qdisc_ops);
1802 }
1803 module_init(cbq_module_init)
1804 module_exit(cbq_module_exit)
1805 MODULE_LICENSE("GPL");
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