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Merge tag 'for-linus-20170825' of git://git.infradead.org/linux-mtd
[mirror_ubuntu-artful-kernel.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 refcnt;
133 int filters;
134
135 struct cbq_class *defaults[TC_PRIO_MAX + 1];
136 };
137
138 struct cbq_sched_data {
139 struct Qdisc_class_hash clhash; /* Hash table of all classes */
140 int nclasses[TC_CBQ_MAXPRIO + 1];
141 unsigned int quanta[TC_CBQ_MAXPRIO + 1];
142
143 struct cbq_class link;
144
145 unsigned int activemask;
146 struct cbq_class *active[TC_CBQ_MAXPRIO + 1]; /* List of all classes
147 with backlog */
148
149 #ifdef CONFIG_NET_CLS_ACT
150 struct cbq_class *rx_class;
151 #endif
152 struct cbq_class *tx_class;
153 struct cbq_class *tx_borrowed;
154 int tx_len;
155 psched_time_t now; /* Cached timestamp */
156 unsigned int pmask;
157
158 struct hrtimer delay_timer;
159 struct qdisc_watchdog watchdog; /* Watchdog timer,
160 started when CBQ has
161 backlog, but cannot
162 transmit just now */
163 psched_tdiff_t wd_expires;
164 int toplevel;
165 u32 hgenerator;
166 };
167
168
169 #define L2T(cl, len) qdisc_l2t((cl)->R_tab, len)
170
171 static inline struct cbq_class *
172 cbq_class_lookup(struct cbq_sched_data *q, u32 classid)
173 {
174 struct Qdisc_class_common *clc;
175
176 clc = qdisc_class_find(&q->clhash, classid);
177 if (clc == NULL)
178 return NULL;
179 return container_of(clc, struct cbq_class, common);
180 }
181
182 #ifdef CONFIG_NET_CLS_ACT
183
184 static struct cbq_class *
185 cbq_reclassify(struct sk_buff *skb, struct cbq_class *this)
186 {
187 struct cbq_class *cl;
188
189 for (cl = this->tparent; cl; cl = cl->tparent) {
190 struct cbq_class *new = cl->defaults[TC_PRIO_BESTEFFORT];
191
192 if (new != NULL && new != this)
193 return new;
194 }
195 return NULL;
196 }
197
198 #endif
199
200 /* Classify packet. The procedure is pretty complicated, but
201 * it allows us to combine link sharing and priority scheduling
202 * transparently.
203 *
204 * Namely, you can put link sharing rules (f.e. route based) at root of CBQ,
205 * so that it resolves to split nodes. Then packets are classified
206 * by logical priority, or a more specific classifier may be attached
207 * to the split node.
208 */
209
210 static struct cbq_class *
211 cbq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
212 {
213 struct cbq_sched_data *q = qdisc_priv(sch);
214 struct cbq_class *head = &q->link;
215 struct cbq_class **defmap;
216 struct cbq_class *cl = NULL;
217 u32 prio = skb->priority;
218 struct tcf_proto *fl;
219 struct tcf_result res;
220
221 /*
222 * Step 1. If skb->priority points to one of our classes, use it.
223 */
224 if (TC_H_MAJ(prio ^ sch->handle) == 0 &&
225 (cl = cbq_class_lookup(q, prio)) != NULL)
226 return cl;
227
228 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
229 for (;;) {
230 int result = 0;
231 defmap = head->defaults;
232
233 fl = rcu_dereference_bh(head->filter_list);
234 /*
235 * Step 2+n. Apply classifier.
236 */
237 result = tcf_classify(skb, fl, &res, true);
238 if (!fl || result < 0)
239 goto fallback;
240
241 cl = (void *)res.class;
242 if (!cl) {
243 if (TC_H_MAJ(res.classid))
244 cl = cbq_class_lookup(q, res.classid);
245 else if ((cl = defmap[res.classid & TC_PRIO_MAX]) == NULL)
246 cl = defmap[TC_PRIO_BESTEFFORT];
247
248 if (cl == NULL)
249 goto fallback;
250 }
251 if (cl->level >= head->level)
252 goto fallback;
253 #ifdef CONFIG_NET_CLS_ACT
254 switch (result) {
255 case TC_ACT_QUEUED:
256 case TC_ACT_STOLEN:
257 case TC_ACT_TRAP:
258 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
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 {
1137 struct cbq_sched_data *q = qdisc_priv(sch);
1138 struct nlattr *tb[TCA_CBQ_MAX + 1];
1139 struct tc_ratespec *r;
1140 int err;
1141
1142 err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy, NULL);
1143 if (err < 0)
1144 return err;
1145
1146 if (tb[TCA_CBQ_RTAB] == NULL || tb[TCA_CBQ_RATE] == NULL)
1147 return -EINVAL;
1148
1149 r = nla_data(tb[TCA_CBQ_RATE]);
1150
1151 if ((q->link.R_tab = qdisc_get_rtab(r, tb[TCA_CBQ_RTAB])) == NULL)
1152 return -EINVAL;
1153
1154 err = qdisc_class_hash_init(&q->clhash);
1155 if (err < 0)
1156 goto put_rtab;
1157
1158 q->link.refcnt = 1;
1159 q->link.sibling = &q->link;
1160 q->link.common.classid = sch->handle;
1161 q->link.qdisc = sch;
1162 q->link.q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1163 sch->handle);
1164 if (!q->link.q)
1165 q->link.q = &noop_qdisc;
1166 else
1167 qdisc_hash_add(q->link.q, true);
1168
1169 q->link.priority = TC_CBQ_MAXPRIO - 1;
1170 q->link.priority2 = TC_CBQ_MAXPRIO - 1;
1171 q->link.cpriority = TC_CBQ_MAXPRIO - 1;
1172 q->link.allot = psched_mtu(qdisc_dev(sch));
1173 q->link.quantum = q->link.allot;
1174 q->link.weight = q->link.R_tab->rate.rate;
1175
1176 q->link.ewma_log = TC_CBQ_DEF_EWMA;
1177 q->link.avpkt = q->link.allot/2;
1178 q->link.minidle = -0x7FFFFFFF;
1179
1180 qdisc_watchdog_init(&q->watchdog, sch);
1181 hrtimer_init(&q->delay_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
1182 q->delay_timer.function = cbq_undelay;
1183 q->toplevel = TC_CBQ_MAXLEVEL;
1184 q->now = psched_get_time();
1185
1186 cbq_link_class(&q->link);
1187
1188 if (tb[TCA_CBQ_LSSOPT])
1189 cbq_set_lss(&q->link, nla_data(tb[TCA_CBQ_LSSOPT]));
1190
1191 cbq_addprio(q, &q->link);
1192 return 0;
1193
1194 put_rtab:
1195 qdisc_put_rtab(q->link.R_tab);
1196 return err;
1197 }
1198
1199 static int cbq_dump_rate(struct sk_buff *skb, struct cbq_class *cl)
1200 {
1201 unsigned char *b = skb_tail_pointer(skb);
1202
1203 if (nla_put(skb, TCA_CBQ_RATE, sizeof(cl->R_tab->rate), &cl->R_tab->rate))
1204 goto nla_put_failure;
1205 return skb->len;
1206
1207 nla_put_failure:
1208 nlmsg_trim(skb, b);
1209 return -1;
1210 }
1211
1212 static int cbq_dump_lss(struct sk_buff *skb, struct cbq_class *cl)
1213 {
1214 unsigned char *b = skb_tail_pointer(skb);
1215 struct tc_cbq_lssopt opt;
1216
1217 opt.flags = 0;
1218 if (cl->borrow == NULL)
1219 opt.flags |= TCF_CBQ_LSS_BOUNDED;
1220 if (cl->share == NULL)
1221 opt.flags |= TCF_CBQ_LSS_ISOLATED;
1222 opt.ewma_log = cl->ewma_log;
1223 opt.level = cl->level;
1224 opt.avpkt = cl->avpkt;
1225 opt.maxidle = cl->maxidle;
1226 opt.minidle = (u32)(-cl->minidle);
1227 opt.offtime = cl->offtime;
1228 opt.change = ~0;
1229 if (nla_put(skb, TCA_CBQ_LSSOPT, sizeof(opt), &opt))
1230 goto nla_put_failure;
1231 return skb->len;
1232
1233 nla_put_failure:
1234 nlmsg_trim(skb, b);
1235 return -1;
1236 }
1237
1238 static int cbq_dump_wrr(struct sk_buff *skb, struct cbq_class *cl)
1239 {
1240 unsigned char *b = skb_tail_pointer(skb);
1241 struct tc_cbq_wrropt opt;
1242
1243 memset(&opt, 0, sizeof(opt));
1244 opt.flags = 0;
1245 opt.allot = cl->allot;
1246 opt.priority = cl->priority + 1;
1247 opt.cpriority = cl->cpriority + 1;
1248 opt.weight = cl->weight;
1249 if (nla_put(skb, TCA_CBQ_WRROPT, sizeof(opt), &opt))
1250 goto nla_put_failure;
1251 return skb->len;
1252
1253 nla_put_failure:
1254 nlmsg_trim(skb, b);
1255 return -1;
1256 }
1257
1258 static int cbq_dump_fopt(struct sk_buff *skb, struct cbq_class *cl)
1259 {
1260 unsigned char *b = skb_tail_pointer(skb);
1261 struct tc_cbq_fopt opt;
1262
1263 if (cl->split || cl->defmap) {
1264 opt.split = cl->split ? cl->split->common.classid : 0;
1265 opt.defmap = cl->defmap;
1266 opt.defchange = ~0;
1267 if (nla_put(skb, TCA_CBQ_FOPT, sizeof(opt), &opt))
1268 goto nla_put_failure;
1269 }
1270 return skb->len;
1271
1272 nla_put_failure:
1273 nlmsg_trim(skb, b);
1274 return -1;
1275 }
1276
1277 static int cbq_dump_attr(struct sk_buff *skb, struct cbq_class *cl)
1278 {
1279 if (cbq_dump_lss(skb, cl) < 0 ||
1280 cbq_dump_rate(skb, cl) < 0 ||
1281 cbq_dump_wrr(skb, cl) < 0 ||
1282 cbq_dump_fopt(skb, cl) < 0)
1283 return -1;
1284 return 0;
1285 }
1286
1287 static int cbq_dump(struct Qdisc *sch, struct sk_buff *skb)
1288 {
1289 struct cbq_sched_data *q = qdisc_priv(sch);
1290 struct nlattr *nest;
1291
1292 nest = nla_nest_start(skb, TCA_OPTIONS);
1293 if (nest == NULL)
1294 goto nla_put_failure;
1295 if (cbq_dump_attr(skb, &q->link) < 0)
1296 goto nla_put_failure;
1297 return nla_nest_end(skb, nest);
1298
1299 nla_put_failure:
1300 nla_nest_cancel(skb, nest);
1301 return -1;
1302 }
1303
1304 static int
1305 cbq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
1306 {
1307 struct cbq_sched_data *q = qdisc_priv(sch);
1308
1309 q->link.xstats.avgidle = q->link.avgidle;
1310 return gnet_stats_copy_app(d, &q->link.xstats, sizeof(q->link.xstats));
1311 }
1312
1313 static int
1314 cbq_dump_class(struct Qdisc *sch, unsigned long arg,
1315 struct sk_buff *skb, struct tcmsg *tcm)
1316 {
1317 struct cbq_class *cl = (struct cbq_class *)arg;
1318 struct nlattr *nest;
1319
1320 if (cl->tparent)
1321 tcm->tcm_parent = cl->tparent->common.classid;
1322 else
1323 tcm->tcm_parent = TC_H_ROOT;
1324 tcm->tcm_handle = cl->common.classid;
1325 tcm->tcm_info = cl->q->handle;
1326
1327 nest = nla_nest_start(skb, TCA_OPTIONS);
1328 if (nest == NULL)
1329 goto nla_put_failure;
1330 if (cbq_dump_attr(skb, cl) < 0)
1331 goto nla_put_failure;
1332 return nla_nest_end(skb, nest);
1333
1334 nla_put_failure:
1335 nla_nest_cancel(skb, nest);
1336 return -1;
1337 }
1338
1339 static int
1340 cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1341 struct gnet_dump *d)
1342 {
1343 struct cbq_sched_data *q = qdisc_priv(sch);
1344 struct cbq_class *cl = (struct cbq_class *)arg;
1345
1346 cl->xstats.avgidle = cl->avgidle;
1347 cl->xstats.undertime = 0;
1348
1349 if (cl->undertime != PSCHED_PASTPERFECT)
1350 cl->xstats.undertime = cl->undertime - q->now;
1351
1352 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
1353 d, NULL, &cl->bstats) < 0 ||
1354 gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
1355 gnet_stats_copy_queue(d, NULL, &cl->qstats, cl->q->q.qlen) < 0)
1356 return -1;
1357
1358 return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));
1359 }
1360
1361 static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1362 struct Qdisc **old)
1363 {
1364 struct cbq_class *cl = (struct cbq_class *)arg;
1365
1366 if (new == NULL) {
1367 new = qdisc_create_dflt(sch->dev_queue,
1368 &pfifo_qdisc_ops, cl->common.classid);
1369 if (new == NULL)
1370 return -ENOBUFS;
1371 }
1372
1373 *old = qdisc_replace(sch, new, &cl->q);
1374 return 0;
1375 }
1376
1377 static struct Qdisc *cbq_leaf(struct Qdisc *sch, unsigned long arg)
1378 {
1379 struct cbq_class *cl = (struct cbq_class *)arg;
1380
1381 return cl->q;
1382 }
1383
1384 static void cbq_qlen_notify(struct Qdisc *sch, unsigned long arg)
1385 {
1386 struct cbq_class *cl = (struct cbq_class *)arg;
1387
1388 if (cl->q->q.qlen == 0)
1389 cbq_deactivate_class(cl);
1390 }
1391
1392 static unsigned long cbq_get(struct Qdisc *sch, u32 classid)
1393 {
1394 struct cbq_sched_data *q = qdisc_priv(sch);
1395 struct cbq_class *cl = cbq_class_lookup(q, classid);
1396
1397 if (cl) {
1398 cl->refcnt++;
1399 return (unsigned long)cl;
1400 }
1401 return 0;
1402 }
1403
1404 static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl)
1405 {
1406 struct cbq_sched_data *q = qdisc_priv(sch);
1407
1408 WARN_ON(cl->filters);
1409
1410 tcf_block_put(cl->block);
1411 qdisc_destroy(cl->q);
1412 qdisc_put_rtab(cl->R_tab);
1413 gen_kill_estimator(&cl->rate_est);
1414 if (cl != &q->link)
1415 kfree(cl);
1416 }
1417
1418 static void cbq_destroy(struct Qdisc *sch)
1419 {
1420 struct cbq_sched_data *q = qdisc_priv(sch);
1421 struct hlist_node *next;
1422 struct cbq_class *cl;
1423 unsigned int h;
1424
1425 #ifdef CONFIG_NET_CLS_ACT
1426 q->rx_class = NULL;
1427 #endif
1428 /*
1429 * Filters must be destroyed first because we don't destroy the
1430 * classes from root to leafs which means that filters can still
1431 * be bound to classes which have been destroyed already. --TGR '04
1432 */
1433 for (h = 0; h < q->clhash.hashsize; h++) {
1434 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
1435 tcf_block_put(cl->block);
1436 cl->block = NULL;
1437 }
1438 }
1439 for (h = 0; h < q->clhash.hashsize; h++) {
1440 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[h],
1441 common.hnode)
1442 cbq_destroy_class(sch, cl);
1443 }
1444 qdisc_class_hash_destroy(&q->clhash);
1445 }
1446
1447 static void cbq_put(struct Qdisc *sch, unsigned long arg)
1448 {
1449 struct cbq_class *cl = (struct cbq_class *)arg;
1450
1451 if (--cl->refcnt == 0) {
1452 #ifdef CONFIG_NET_CLS_ACT
1453 spinlock_t *root_lock = qdisc_root_sleeping_lock(sch);
1454 struct cbq_sched_data *q = qdisc_priv(sch);
1455
1456 spin_lock_bh(root_lock);
1457 if (q->rx_class == cl)
1458 q->rx_class = NULL;
1459 spin_unlock_bh(root_lock);
1460 #endif
1461
1462 cbq_destroy_class(sch, cl);
1463 }
1464 }
1465
1466 static int
1467 cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **tca,
1468 unsigned long *arg)
1469 {
1470 int err;
1471 struct cbq_sched_data *q = qdisc_priv(sch);
1472 struct cbq_class *cl = (struct cbq_class *)*arg;
1473 struct nlattr *opt = tca[TCA_OPTIONS];
1474 struct nlattr *tb[TCA_CBQ_MAX + 1];
1475 struct cbq_class *parent;
1476 struct qdisc_rate_table *rtab = NULL;
1477
1478 if (opt == NULL)
1479 return -EINVAL;
1480
1481 err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy, NULL);
1482 if (err < 0)
1483 return err;
1484
1485 if (tb[TCA_CBQ_OVL_STRATEGY] || tb[TCA_CBQ_POLICE])
1486 return -EOPNOTSUPP;
1487
1488 if (cl) {
1489 /* Check parent */
1490 if (parentid) {
1491 if (cl->tparent &&
1492 cl->tparent->common.classid != parentid)
1493 return -EINVAL;
1494 if (!cl->tparent && parentid != TC_H_ROOT)
1495 return -EINVAL;
1496 }
1497
1498 if (tb[TCA_CBQ_RATE]) {
1499 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]),
1500 tb[TCA_CBQ_RTAB]);
1501 if (rtab == NULL)
1502 return -EINVAL;
1503 }
1504
1505 if (tca[TCA_RATE]) {
1506 err = gen_replace_estimator(&cl->bstats, NULL,
1507 &cl->rate_est,
1508 NULL,
1509 qdisc_root_sleeping_running(sch),
1510 tca[TCA_RATE]);
1511 if (err) {
1512 qdisc_put_rtab(rtab);
1513 return err;
1514 }
1515 }
1516
1517 /* Change class parameters */
1518 sch_tree_lock(sch);
1519
1520 if (cl->next_alive != NULL)
1521 cbq_deactivate_class(cl);
1522
1523 if (rtab) {
1524 qdisc_put_rtab(cl->R_tab);
1525 cl->R_tab = rtab;
1526 }
1527
1528 if (tb[TCA_CBQ_LSSOPT])
1529 cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
1530
1531 if (tb[TCA_CBQ_WRROPT]) {
1532 cbq_rmprio(q, cl);
1533 cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
1534 }
1535
1536 if (tb[TCA_CBQ_FOPT])
1537 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
1538
1539 if (cl->q->q.qlen)
1540 cbq_activate_class(cl);
1541
1542 sch_tree_unlock(sch);
1543
1544 return 0;
1545 }
1546
1547 if (parentid == TC_H_ROOT)
1548 return -EINVAL;
1549
1550 if (tb[TCA_CBQ_WRROPT] == NULL || tb[TCA_CBQ_RATE] == NULL ||
1551 tb[TCA_CBQ_LSSOPT] == NULL)
1552 return -EINVAL;
1553
1554 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]), tb[TCA_CBQ_RTAB]);
1555 if (rtab == NULL)
1556 return -EINVAL;
1557
1558 if (classid) {
1559 err = -EINVAL;
1560 if (TC_H_MAJ(classid ^ sch->handle) ||
1561 cbq_class_lookup(q, classid))
1562 goto failure;
1563 } else {
1564 int i;
1565 classid = TC_H_MAKE(sch->handle, 0x8000);
1566
1567 for (i = 0; i < 0x8000; i++) {
1568 if (++q->hgenerator >= 0x8000)
1569 q->hgenerator = 1;
1570 if (cbq_class_lookup(q, classid|q->hgenerator) == NULL)
1571 break;
1572 }
1573 err = -ENOSR;
1574 if (i >= 0x8000)
1575 goto failure;
1576 classid = classid|q->hgenerator;
1577 }
1578
1579 parent = &q->link;
1580 if (parentid) {
1581 parent = cbq_class_lookup(q, parentid);
1582 err = -EINVAL;
1583 if (parent == NULL)
1584 goto failure;
1585 }
1586
1587 err = -ENOBUFS;
1588 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
1589 if (cl == NULL)
1590 goto failure;
1591
1592 err = tcf_block_get(&cl->block, &cl->filter_list);
1593 if (err) {
1594 kfree(cl);
1595 return err;
1596 }
1597
1598 if (tca[TCA_RATE]) {
1599 err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
1600 NULL,
1601 qdisc_root_sleeping_running(sch),
1602 tca[TCA_RATE]);
1603 if (err) {
1604 tcf_block_put(cl->block);
1605 kfree(cl);
1606 goto failure;
1607 }
1608 }
1609
1610 cl->R_tab = rtab;
1611 rtab = NULL;
1612 cl->refcnt = 1;
1613 cl->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid);
1614 if (!cl->q)
1615 cl->q = &noop_qdisc;
1616 else
1617 qdisc_hash_add(cl->q, true);
1618
1619 cl->common.classid = classid;
1620 cl->tparent = parent;
1621 cl->qdisc = sch;
1622 cl->allot = parent->allot;
1623 cl->quantum = cl->allot;
1624 cl->weight = cl->R_tab->rate.rate;
1625
1626 sch_tree_lock(sch);
1627 cbq_link_class(cl);
1628 cl->borrow = cl->tparent;
1629 if (cl->tparent != &q->link)
1630 cl->share = cl->tparent;
1631 cbq_adjust_levels(parent);
1632 cl->minidle = -0x7FFFFFFF;
1633 cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
1634 cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
1635 if (cl->ewma_log == 0)
1636 cl->ewma_log = q->link.ewma_log;
1637 if (cl->maxidle == 0)
1638 cl->maxidle = q->link.maxidle;
1639 if (cl->avpkt == 0)
1640 cl->avpkt = q->link.avpkt;
1641 if (tb[TCA_CBQ_FOPT])
1642 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
1643 sch_tree_unlock(sch);
1644
1645 qdisc_class_hash_grow(sch, &q->clhash);
1646
1647 *arg = (unsigned long)cl;
1648 return 0;
1649
1650 failure:
1651 qdisc_put_rtab(rtab);
1652 return err;
1653 }
1654
1655 static int cbq_delete(struct Qdisc *sch, unsigned long arg)
1656 {
1657 struct cbq_sched_data *q = qdisc_priv(sch);
1658 struct cbq_class *cl = (struct cbq_class *)arg;
1659 unsigned int qlen, backlog;
1660
1661 if (cl->filters || cl->children || cl == &q->link)
1662 return -EBUSY;
1663
1664 sch_tree_lock(sch);
1665
1666 qlen = cl->q->q.qlen;
1667 backlog = cl->q->qstats.backlog;
1668 qdisc_reset(cl->q);
1669 qdisc_tree_reduce_backlog(cl->q, qlen, backlog);
1670
1671 if (cl->next_alive)
1672 cbq_deactivate_class(cl);
1673
1674 if (q->tx_borrowed == cl)
1675 q->tx_borrowed = q->tx_class;
1676 if (q->tx_class == cl) {
1677 q->tx_class = NULL;
1678 q->tx_borrowed = NULL;
1679 }
1680 #ifdef CONFIG_NET_CLS_ACT
1681 if (q->rx_class == cl)
1682 q->rx_class = NULL;
1683 #endif
1684
1685 cbq_unlink_class(cl);
1686 cbq_adjust_levels(cl->tparent);
1687 cl->defmap = 0;
1688 cbq_sync_defmap(cl);
1689
1690 cbq_rmprio(q, cl);
1691 sch_tree_unlock(sch);
1692
1693 BUG_ON(--cl->refcnt == 0);
1694 /*
1695 * This shouldn't happen: we "hold" one cops->get() when called
1696 * from tc_ctl_tclass; the destroy method is done from cops->put().
1697 */
1698
1699 return 0;
1700 }
1701
1702 static struct tcf_block *cbq_tcf_block(struct Qdisc *sch, unsigned long arg)
1703 {
1704 struct cbq_sched_data *q = qdisc_priv(sch);
1705 struct cbq_class *cl = (struct cbq_class *)arg;
1706
1707 if (cl == NULL)
1708 cl = &q->link;
1709
1710 return cl->block;
1711 }
1712
1713 static unsigned long cbq_bind_filter(struct Qdisc *sch, unsigned long parent,
1714 u32 classid)
1715 {
1716 struct cbq_sched_data *q = qdisc_priv(sch);
1717 struct cbq_class *p = (struct cbq_class *)parent;
1718 struct cbq_class *cl = cbq_class_lookup(q, classid);
1719
1720 if (cl) {
1721 if (p && p->level <= cl->level)
1722 return 0;
1723 cl->filters++;
1724 return (unsigned long)cl;
1725 }
1726 return 0;
1727 }
1728
1729 static void cbq_unbind_filter(struct Qdisc *sch, unsigned long arg)
1730 {
1731 struct cbq_class *cl = (struct cbq_class *)arg;
1732
1733 cl->filters--;
1734 }
1735
1736 static void cbq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1737 {
1738 struct cbq_sched_data *q = qdisc_priv(sch);
1739 struct cbq_class *cl;
1740 unsigned int h;
1741
1742 if (arg->stop)
1743 return;
1744
1745 for (h = 0; h < q->clhash.hashsize; h++) {
1746 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
1747 if (arg->count < arg->skip) {
1748 arg->count++;
1749 continue;
1750 }
1751 if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
1752 arg->stop = 1;
1753 return;
1754 }
1755 arg->count++;
1756 }
1757 }
1758 }
1759
1760 static const struct Qdisc_class_ops cbq_class_ops = {
1761 .graft = cbq_graft,
1762 .leaf = cbq_leaf,
1763 .qlen_notify = cbq_qlen_notify,
1764 .get = cbq_get,
1765 .put = cbq_put,
1766 .change = cbq_change_class,
1767 .delete = cbq_delete,
1768 .walk = cbq_walk,
1769 .tcf_block = cbq_tcf_block,
1770 .bind_tcf = cbq_bind_filter,
1771 .unbind_tcf = cbq_unbind_filter,
1772 .dump = cbq_dump_class,
1773 .dump_stats = cbq_dump_class_stats,
1774 };
1775
1776 static struct Qdisc_ops cbq_qdisc_ops __read_mostly = {
1777 .next = NULL,
1778 .cl_ops = &cbq_class_ops,
1779 .id = "cbq",
1780 .priv_size = sizeof(struct cbq_sched_data),
1781 .enqueue = cbq_enqueue,
1782 .dequeue = cbq_dequeue,
1783 .peek = qdisc_peek_dequeued,
1784 .init = cbq_init,
1785 .reset = cbq_reset,
1786 .destroy = cbq_destroy,
1787 .change = NULL,
1788 .dump = cbq_dump,
1789 .dump_stats = cbq_dump_stats,
1790 .owner = THIS_MODULE,
1791 };
1792
1793 static int __init cbq_module_init(void)
1794 {
1795 return register_qdisc(&cbq_qdisc_ops);
1796 }
1797 static void __exit cbq_module_exit(void)
1798 {
1799 unregister_qdisc(&cbq_qdisc_ops);
1800 }
1801 module_init(cbq_module_init)
1802 module_exit(cbq_module_exit)
1803 MODULE_LICENSE("GPL");
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