?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
pkt_sched: Stop using NLA_PUT*().
[linux-2.6/btrfs-unstable.git] / net / sched / sch_cbq.c
blob6aabd77d1cfdd5cddd34b55dc69699cae9956e57
1 /*
2 * net/sched/sch_cbq.c Class-Based Queueing discipline.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 *
11 */
12
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/types.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 #include <linux/skbuff.h>
20 #include <net/netlink.h>
21 #include <net/pkt_sched.h>
22
23
24 /* Class-Based Queueing (CBQ) algorithm.
25 =======================================
26
27 Sources: [1] Sally Floyd and Van Jacobson, "Link-sharing and Resource
28 Management Models for Packet Networks",
29 IEEE/ACM Transactions on Networking, Vol.3, No.4, 1995
30
31 [2] Sally Floyd, "Notes on CBQ and Guaranteed Service", 1995
32
33 [3] Sally Floyd, "Notes on Class-Based Queueing: Setting
34 Parameters", 1996
35
36 [4] Sally Floyd and Michael Speer, "Experimental Results
37 for Class-Based Queueing", 1998, not published.
38
39 -----------------------------------------------------------------------
40
41 Algorithm skeleton was taken from NS simulator cbq.cc.
42 If someone wants to check this code against the LBL version,
43 he should take into account that ONLY the skeleton was borrowed,
44 the implementation is different. Particularly:
45
46 --- The WRR algorithm is different. Our version looks more
47 reasonable (I hope) and works when quanta are allowed to be
48 less than MTU, which is always the case when real time classes
49 have small rates. Note, that the statement of [3] is
50 incomplete, delay may actually be estimated even if class
51 per-round allotment is less than MTU. Namely, if per-round
52 allotment is W*r_i, and r_1+...+r_k = r < 1
53
54 delay_i <= ([MTU/(W*r_i)]*W*r + W*r + k*MTU)/B
55
56 In the worst case we have IntServ estimate with D = W*r+k*MTU
57 and C = MTU*r. The proof (if correct at all) is trivial.
58
59
60 --- It seems that cbq-2.0 is not very accurate. At least, I cannot
61 interpret some places, which look like wrong translations
62 from NS. Anyone is advised to find these differences
63 and explain to me, why I am wrong 8).
64
65 --- Linux has no EOI event, so that we cannot estimate true class
66 idle time. Workaround is to consider the next dequeue event
67 as sign that previous packet is finished. This is wrong because of
68 internal device queueing, but on a permanently loaded link it is true.
69 Moreover, combined with clock integrator, this scheme looks
70 very close to an ideal solution. */
71
72 struct cbq_sched_data;
73
74
75 struct cbq_class {
76 struct Qdisc_class_common common;
77 struct cbq_class *next_alive; /* next class with backlog in this priority band */
78
79 /* Parameters */
80 unsigned char priority; /* class priority */
81 unsigned char priority2; /* priority to be used after overlimit */
82 unsigned char ewma_log; /* time constant for idle time calculation */
83 unsigned char ovl_strategy;
84 #ifdef CONFIG_NET_CLS_ACT
85 unsigned char police;
86 #endif
87
88 u32 defmap;
89
90 /* Link-sharing scheduler parameters */
91 long maxidle; /* Class parameters: see below. */
92 long offtime;
93 long minidle;
94 u32 avpkt;
95 struct qdisc_rate_table *R_tab;
96
97 /* Overlimit strategy parameters */
98 void (*overlimit)(struct cbq_class *cl);
99 psched_tdiff_t penalty;
100
101 /* General scheduler (WRR) parameters */
102 long allot;
103 long quantum; /* Allotment per WRR round */
104 long weight; /* Relative allotment: see below */
105
106 struct Qdisc *qdisc; /* Ptr to CBQ discipline */
107 struct cbq_class *split; /* Ptr to split node */
108 struct cbq_class *share; /* Ptr to LS parent in the class tree */
109 struct cbq_class *tparent; /* Ptr to tree parent in the class tree */
110 struct cbq_class *borrow; /* NULL if class is bandwidth limited;
111 parent otherwise */
112 struct cbq_class *sibling; /* Sibling chain */
113 struct cbq_class *children; /* Pointer to children chain */
114
115 struct Qdisc *q; /* Elementary queueing discipline */
116
117
118 /* Variables */
119 unsigned char cpriority; /* Effective priority */
120 unsigned char delayed;
121 unsigned char level; /* level of the class in hierarchy:
122 0 for leaf classes, and maximal
123 level of children + 1 for nodes.
124 */
125
126 psched_time_t last; /* Last end of service */
127 psched_time_t undertime;
128 long avgidle;
129 long deficit; /* Saved deficit for WRR */
130 psched_time_t penalized;
131 struct gnet_stats_basic_packed bstats;
132 struct gnet_stats_queue qstats;
133 struct gnet_stats_rate_est rate_est;
134 struct tc_cbq_xstats xstats;
135
136 struct tcf_proto *filter_list;
137
138 int refcnt;
139 int filters;
140
141 struct cbq_class *defaults[TC_PRIO_MAX + 1];
142 };
143
144 struct cbq_sched_data {
145 struct Qdisc_class_hash clhash; /* Hash table of all classes */
146 int nclasses[TC_CBQ_MAXPRIO + 1];
147 unsigned int quanta[TC_CBQ_MAXPRIO + 1];
148
149 struct cbq_class link;
150
151 unsigned int activemask;
152 struct cbq_class *active[TC_CBQ_MAXPRIO + 1]; /* List of all classes
153 with backlog */
154
155 #ifdef CONFIG_NET_CLS_ACT
156 struct cbq_class *rx_class;
157 #endif
158 struct cbq_class *tx_class;
159 struct cbq_class *tx_borrowed;
160 int tx_len;
161 psched_time_t now; /* Cached timestamp */
162 psched_time_t now_rt; /* Cached real time */
163 unsigned int pmask;
164
165 struct hrtimer delay_timer;
166 struct qdisc_watchdog watchdog; /* Watchdog timer,
167 started when CBQ has
168 backlog, but cannot
169 transmit just now */
170 psched_tdiff_t wd_expires;
171 int toplevel;
172 u32 hgenerator;
173 };
174
175
176 #define L2T(cl, len) qdisc_l2t((cl)->R_tab, len)
177
178 static inline struct cbq_class *
179 cbq_class_lookup(struct cbq_sched_data *q, u32 classid)
180 {
181 struct Qdisc_class_common *clc;
182
183 clc = qdisc_class_find(&q->clhash, classid);
184 if (clc == NULL)
185 return NULL;
186 return container_of(clc, struct cbq_class, common);
187 }
188
189 #ifdef CONFIG_NET_CLS_ACT
190
191 static struct cbq_class *
192 cbq_reclassify(struct sk_buff *skb, struct cbq_class *this)
193 {
194 struct cbq_class *cl;
195
196 for (cl = this->tparent; cl; cl = cl->tparent) {
197 struct cbq_class *new = cl->defaults[TC_PRIO_BESTEFFORT];
198
199 if (new != NULL && new != this)
200 return new;
201 }
202 return NULL;
203 }
204
205 #endif
206
207 /* Classify packet. The procedure is pretty complicated, but
208 * it allows us to combine link sharing and priority scheduling
209 * transparently.
210 *
211 * Namely, you can put link sharing rules (f.e. route based) at root of CBQ,
212 * so that it resolves to split nodes. Then packets are classified
213 * by logical priority, or a more specific classifier may be attached
214 * to the split node.
215 */
216
217 static struct cbq_class *
218 cbq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
219 {
220 struct cbq_sched_data *q = qdisc_priv(sch);
221 struct cbq_class *head = &q->link;
222 struct cbq_class **defmap;
223 struct cbq_class *cl = NULL;
224 u32 prio = skb->priority;
225 struct tcf_result res;
226
227 /*
228 * Step 1. If skb->priority points to one of our classes, use it.
229 */
230 if (TC_H_MAJ(prio ^ sch->handle) == 0 &&
231 (cl = cbq_class_lookup(q, prio)) != NULL)
232 return cl;
233
234 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
235 for (;;) {
236 int result = 0;
237 defmap = head->defaults;
238
239 /*
240 * Step 2+n. Apply classifier.
241 */
242 if (!head->filter_list ||
243 (result = tc_classify_compat(skb, head->filter_list, &res)) < 0)
244 goto fallback;
245
246 cl = (void *)res.class;
247 if (!cl) {
248 if (TC_H_MAJ(res.classid))
249 cl = cbq_class_lookup(q, res.classid);
250 else if ((cl = defmap[res.classid & TC_PRIO_MAX]) == NULL)
251 cl = defmap[TC_PRIO_BESTEFFORT];
252
253 if (cl == NULL || cl->level >= head->level)
254 goto fallback;
255 }
256
257 #ifdef CONFIG_NET_CLS_ACT
258 switch (result) {
259 case TC_ACT_QUEUED:
260 case TC_ACT_STOLEN:
261 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
262 case TC_ACT_SHOT:
263 return NULL;
264 case TC_ACT_RECLASSIFY:
265 return cbq_reclassify(skb, cl);
266 }
267 #endif
268 if (cl->level == 0)
269 return cl;
270
271 /*
272 * Step 3+n. If classifier selected a link sharing class,
273 * apply agency specific classifier.
274 * Repeat this procdure until we hit a leaf node.
275 */
276 head = cl;
277 }
278
279 fallback:
280 cl = head;
281
282 /*
283 * Step 4. No success...
284 */
285 if (TC_H_MAJ(prio) == 0 &&
286 !(cl = head->defaults[prio & TC_PRIO_MAX]) &&
287 !(cl = head->defaults[TC_PRIO_BESTEFFORT]))
288 return head;
289
290 return cl;
291 }
292
293 /*
294 * A packet has just been enqueued on the empty class.
295 * cbq_activate_class adds it to the tail of active class list
296 * of its priority band.
297 */
298
299 static inline void cbq_activate_class(struct cbq_class *cl)
300 {
301 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
302 int prio = cl->cpriority;
303 struct cbq_class *cl_tail;
304
305 cl_tail = q->active[prio];
306 q->active[prio] = cl;
307
308 if (cl_tail != NULL) {
309 cl->next_alive = cl_tail->next_alive;
310 cl_tail->next_alive = cl;
311 } else {
312 cl->next_alive = cl;
313 q->activemask |= (1<<prio);
314 }
315 }
316
317 /*
318 * Unlink class from active chain.
319 * Note that this same procedure is done directly in cbq_dequeue*
320 * during round-robin procedure.
321 */
322
323 static void cbq_deactivate_class(struct cbq_class *this)
324 {
325 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
326 int prio = this->cpriority;
327 struct cbq_class *cl;
328 struct cbq_class *cl_prev = q->active[prio];
329
330 do {
331 cl = cl_prev->next_alive;
332 if (cl == this) {
333 cl_prev->next_alive = cl->next_alive;
334 cl->next_alive = NULL;
335
336 if (cl == q->active[prio]) {
337 q->active[prio] = cl_prev;
338 if (cl == q->active[prio]) {
339 q->active[prio] = NULL;
340 q->activemask &= ~(1<<prio);
341 return;
342 }
343 }
344 return;
345 }
346 } while ((cl_prev = cl) != q->active[prio]);
347 }
348
349 static void
350 cbq_mark_toplevel(struct cbq_sched_data *q, struct cbq_class *cl)
351 {
352 int toplevel = q->toplevel;
353
354 if (toplevel > cl->level && !(qdisc_is_throttled(cl->q))) {
355 psched_time_t now;
356 psched_tdiff_t incr;
357
358 now = psched_get_time();
359 incr = now - q->now_rt;
360 now = q->now + incr;
361
362 do {
363 if (cl->undertime < now) {
364 q->toplevel = cl->level;
365 return;
366 }
367 } while ((cl = cl->borrow) != NULL && toplevel > cl->level);
368 }
369 }
370
371 static int
372 cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
373 {
374 struct cbq_sched_data *q = qdisc_priv(sch);
375 int uninitialized_var(ret);
376 struct cbq_class *cl = cbq_classify(skb, sch, &ret);
377
378 #ifdef CONFIG_NET_CLS_ACT
379 q->rx_class = cl;
380 #endif
381 if (cl == NULL) {
382 if (ret & __NET_XMIT_BYPASS)
383 sch->qstats.drops++;
384 kfree_skb(skb);
385 return ret;
386 }
387
388 #ifdef CONFIG_NET_CLS_ACT
389 cl->q->__parent = sch;
390 #endif
391 ret = qdisc_enqueue(skb, cl->q);
392 if (ret == NET_XMIT_SUCCESS) {
393 sch->q.qlen++;
394 cbq_mark_toplevel(q, cl);
395 if (!cl->next_alive)
396 cbq_activate_class(cl);
397 return ret;
398 }
399
400 if (net_xmit_drop_count(ret)) {
401 sch->qstats.drops++;
402 cbq_mark_toplevel(q, cl);
403 cl->qstats.drops++;
404 }
405 return ret;
406 }
407
408 /* Overlimit actions */
409
410 /* TC_CBQ_OVL_CLASSIC: (default) penalize leaf class by adding offtime */
411
412 static void cbq_ovl_classic(struct cbq_class *cl)
413 {
414 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
415 psched_tdiff_t delay = cl->undertime - q->now;
416
417 if (!cl->delayed) {
418 delay += cl->offtime;
419
420 /*
421 * Class goes to sleep, so that it will have no
422 * chance to work avgidle. Let's forgive it 8)
423 *
424 * BTW cbq-2.0 has a crap in this
425 * place, apparently they forgot to shift it by cl->ewma_log.
426 */
427 if (cl->avgidle < 0)
428 delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log);
429 if (cl->avgidle < cl->minidle)
430 cl->avgidle = cl->minidle;
431 if (delay <= 0)
432 delay = 1;
433 cl->undertime = q->now + delay;
434
435 cl->xstats.overactions++;
436 cl->delayed = 1;
437 }
438 if (q->wd_expires == 0 || q->wd_expires > delay)
439 q->wd_expires = delay;
440
441 /* Dirty work! We must schedule wakeups based on
442 * real available rate, rather than leaf rate,
443 * which may be tiny (even zero).
444 */
445 if (q->toplevel == TC_CBQ_MAXLEVEL) {
446 struct cbq_class *b;
447 psched_tdiff_t base_delay = q->wd_expires;
448
449 for (b = cl->borrow; b; b = b->borrow) {
450 delay = b->undertime - q->now;
451 if (delay < base_delay) {
452 if (delay <= 0)
453 delay = 1;
454 base_delay = delay;
455 }
456 }
457
458 q->wd_expires = base_delay;
459 }
460 }
461
462 /* TC_CBQ_OVL_RCLASSIC: penalize by offtime classes in hierarchy, when
463 * they go overlimit
464 */
465
466 static void cbq_ovl_rclassic(struct cbq_class *cl)
467 {
468 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
469 struct cbq_class *this = cl;
470
471 do {
472 if (cl->level > q->toplevel) {
473 cl = NULL;
474 break;
475 }
476 } while ((cl = cl->borrow) != NULL);
477
478 if (cl == NULL)
479 cl = this;
480 cbq_ovl_classic(cl);
481 }
482
483 /* TC_CBQ_OVL_DELAY: delay until it will go to underlimit */
484
485 static void cbq_ovl_delay(struct cbq_class *cl)
486 {
487 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
488 psched_tdiff_t delay = cl->undertime - q->now;
489
490 if (test_bit(__QDISC_STATE_DEACTIVATED,
491 &qdisc_root_sleeping(cl->qdisc)->state))
492 return;
493
494 if (!cl->delayed) {
495 psched_time_t sched = q->now;
496 ktime_t expires;
497
498 delay += cl->offtime;
499 if (cl->avgidle < 0)
500 delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log);
501 if (cl->avgidle < cl->minidle)
502 cl->avgidle = cl->minidle;
503 cl->undertime = q->now + delay;
504
505 if (delay > 0) {
506 sched += delay + cl->penalty;
507 cl->penalized = sched;
508 cl->cpriority = TC_CBQ_MAXPRIO;
509 q->pmask |= (1<<TC_CBQ_MAXPRIO);
510
511 expires = ktime_set(0, 0);
512 expires = ktime_add_ns(expires, PSCHED_TICKS2NS(sched));
513 if (hrtimer_try_to_cancel(&q->delay_timer) &&
514 ktime_to_ns(ktime_sub(
515 hrtimer_get_expires(&q->delay_timer),
516 expires)) > 0)
517 hrtimer_set_expires(&q->delay_timer, expires);
518 hrtimer_restart(&q->delay_timer);
519 cl->delayed = 1;
520 cl->xstats.overactions++;
521 return;
522 }
523 delay = 1;
524 }
525 if (q->wd_expires == 0 || q->wd_expires > delay)
526 q->wd_expires = delay;
527 }
528
529 /* TC_CBQ_OVL_LOWPRIO: penalize class by lowering its priority band */
530
531 static void cbq_ovl_lowprio(struct cbq_class *cl)
532 {
533 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
534
535 cl->penalized = q->now + cl->penalty;
536
537 if (cl->cpriority != cl->priority2) {
538 cl->cpriority = cl->priority2;
539 q->pmask |= (1<<cl->cpriority);
540 cl->xstats.overactions++;
541 }
542 cbq_ovl_classic(cl);
543 }
544
545 /* TC_CBQ_OVL_DROP: penalize class by dropping */
546
547 static void cbq_ovl_drop(struct cbq_class *cl)
548 {
549 if (cl->q->ops->drop)
550 if (cl->q->ops->drop(cl->q))
551 cl->qdisc->q.qlen--;
552 cl->xstats.overactions++;
553 cbq_ovl_classic(cl);
554 }
555
556 static psched_tdiff_t cbq_undelay_prio(struct cbq_sched_data *q, int prio,
557 psched_time_t now)
558 {
559 struct cbq_class *cl;
560 struct cbq_class *cl_prev = q->active[prio];
561 psched_time_t sched = now;
562
563 if (cl_prev == NULL)
564 return 0;
565
566 do {
567 cl = cl_prev->next_alive;
568 if (now - cl->penalized > 0) {
569 cl_prev->next_alive = cl->next_alive;
570 cl->next_alive = NULL;
571 cl->cpriority = cl->priority;
572 cl->delayed = 0;
573 cbq_activate_class(cl);
574
575 if (cl == q->active[prio]) {
576 q->active[prio] = cl_prev;
577 if (cl == q->active[prio]) {
578 q->active[prio] = NULL;
579 return 0;
580 }
581 }
582
583 cl = cl_prev->next_alive;
584 } else if (sched - cl->penalized > 0)
585 sched = cl->penalized;
586 } while ((cl_prev = cl) != q->active[prio]);
587
588 return sched - now;
589 }
590
591 static enum hrtimer_restart cbq_undelay(struct hrtimer *timer)
592 {
593 struct cbq_sched_data *q = container_of(timer, struct cbq_sched_data,
594 delay_timer);
595 struct Qdisc *sch = q->watchdog.qdisc;
596 psched_time_t now;
597 psched_tdiff_t delay = 0;
598 unsigned int pmask;
599
600 now = psched_get_time();
601
602 pmask = q->pmask;
603 q->pmask = 0;
604
605 while (pmask) {
606 int prio = ffz(~pmask);
607 psched_tdiff_t tmp;
608
609 pmask &= ~(1<<prio);
610
611 tmp = cbq_undelay_prio(q, prio, now);
612 if (tmp > 0) {
613 q->pmask |= 1<<prio;
614 if (tmp < delay || delay == 0)
615 delay = tmp;
616 }
617 }
618
619 if (delay) {
620 ktime_t time;
621
622 time = ktime_set(0, 0);
623 time = ktime_add_ns(time, PSCHED_TICKS2NS(now + delay));
624 hrtimer_start(&q->delay_timer, time, HRTIMER_MODE_ABS);
625 }
626
627 qdisc_unthrottled(sch);
628 __netif_schedule(qdisc_root(sch));
629 return HRTIMER_NORESTART;
630 }
631
632 #ifdef CONFIG_NET_CLS_ACT
633 static int cbq_reshape_fail(struct sk_buff *skb, struct Qdisc *child)
634 {
635 struct Qdisc *sch = child->__parent;
636 struct cbq_sched_data *q = qdisc_priv(sch);
637 struct cbq_class *cl = q->rx_class;
638
639 q->rx_class = NULL;
640
641 if (cl && (cl = cbq_reclassify(skb, cl)) != NULL) {
642 int ret;
643
644 cbq_mark_toplevel(q, cl);
645
646 q->rx_class = cl;
647 cl->q->__parent = sch;
648
649 ret = qdisc_enqueue(skb, cl->q);
650 if (ret == NET_XMIT_SUCCESS) {
651 sch->q.qlen++;
652 if (!cl->next_alive)
653 cbq_activate_class(cl);
654 return 0;
655 }
656 if (net_xmit_drop_count(ret))
657 sch->qstats.drops++;
658 return 0;
659 }
660
661 sch->qstats.drops++;
662 return -1;
663 }
664 #endif
665
666 /*
667 * It is mission critical procedure.
668 *
669 * We "regenerate" toplevel cutoff, if transmitting class
670 * has backlog and it is not regulated. It is not part of
671 * original CBQ description, but looks more reasonable.
672 * Probably, it is wrong. This question needs further investigation.
673 */
674
675 static inline void
676 cbq_update_toplevel(struct cbq_sched_data *q, struct cbq_class *cl,
677 struct cbq_class *borrowed)
678 {
679 if (cl && q->toplevel >= borrowed->level) {
680 if (cl->q->q.qlen > 1) {
681 do {
682 if (borrowed->undertime == PSCHED_PASTPERFECT) {
683 q->toplevel = borrowed->level;
684 return;
685 }
686 } while ((borrowed = borrowed->borrow) != NULL);
687 }
688 #if 0
689 /* It is not necessary now. Uncommenting it
690 will save CPU cycles, but decrease fairness.
691 */
692 q->toplevel = TC_CBQ_MAXLEVEL;
693 #endif
694 }
695 }
696
697 static void
698 cbq_update(struct cbq_sched_data *q)
699 {
700 struct cbq_class *this = q->tx_class;
701 struct cbq_class *cl = this;
702 int len = q->tx_len;
703
704 q->tx_class = NULL;
705
706 for ( ; cl; cl = cl->share) {
707 long avgidle = cl->avgidle;
708 long idle;
709
710 cl->bstats.packets++;
711 cl->bstats.bytes += len;
712
713 /*
714 * (now - last) is total time between packet right edges.
715 * (last_pktlen/rate) is "virtual" busy time, so that
716 *
717 * idle = (now - last) - last_pktlen/rate
718 */
719
720 idle = q->now - cl->last;
721 if ((unsigned long)idle > 128*1024*1024) {
722 avgidle = cl->maxidle;
723 } else {
724 idle -= L2T(cl, len);
725
726 /* true_avgidle := (1-W)*true_avgidle + W*idle,
727 * where W=2^{-ewma_log}. But cl->avgidle is scaled:
728 * cl->avgidle == true_avgidle/W,
729 * hence:
730 */
731 avgidle += idle - (avgidle>>cl->ewma_log);
732 }
733
734 if (avgidle <= 0) {
735 /* Overlimit or at-limit */
736
737 if (avgidle < cl->minidle)
738 avgidle = cl->minidle;
739
740 cl->avgidle = avgidle;
741
742 /* Calculate expected time, when this class
743 * will be allowed to send.
744 * It will occur, when:
745 * (1-W)*true_avgidle + W*delay = 0, i.e.
746 * idle = (1/W - 1)*(-true_avgidle)
747 * or
748 * idle = (1 - W)*(-cl->avgidle);
749 */
750 idle = (-avgidle) - ((-avgidle) >> cl->ewma_log);
751
752 /*
753 * That is not all.
754 * To maintain the rate allocated to the class,
755 * we add to undertime virtual clock,
756 * necessary to complete transmitted packet.
757 * (len/phys_bandwidth has been already passed
758 * to the moment of cbq_update)
759 */
760
761 idle -= L2T(&q->link, len);
762 idle += L2T(cl, len);
763
764 cl->undertime = q->now + idle;
765 } else {
766 /* Underlimit */
767
768 cl->undertime = PSCHED_PASTPERFECT;
769 if (avgidle > cl->maxidle)
770 cl->avgidle = cl->maxidle;
771 else
772 cl->avgidle = avgidle;
773 }
774 cl->last = q->now;
775 }
776
777 cbq_update_toplevel(q, this, q->tx_borrowed);
778 }
779
780 static inline struct cbq_class *
781 cbq_under_limit(struct cbq_class *cl)
782 {
783 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
784 struct cbq_class *this_cl = cl;
785
786 if (cl->tparent == NULL)
787 return cl;
788
789 if (cl->undertime == PSCHED_PASTPERFECT || q->now >= cl->undertime) {
790 cl->delayed = 0;
791 return cl;
792 }
793
794 do {
795 /* It is very suspicious place. Now overlimit
796 * action is generated for not bounded classes
797 * only if link is completely congested.
798 * Though it is in agree with ancestor-only paradigm,
799 * it looks very stupid. Particularly,
800 * it means that this chunk of code will either
801 * never be called or result in strong amplification
802 * of burstiness. Dangerous, silly, and, however,
803 * no another solution exists.
804 */
805 cl = cl->borrow;
806 if (!cl) {
807 this_cl->qstats.overlimits++;
808 this_cl->overlimit(this_cl);
809 return NULL;
810 }
811 if (cl->level > q->toplevel)
812 return NULL;
813 } while (cl->undertime != PSCHED_PASTPERFECT && q->now < cl->undertime);
814
815 cl->delayed = 0;
816 return cl;
817 }
818
819 static inline struct sk_buff *
820 cbq_dequeue_prio(struct Qdisc *sch, int prio)
821 {
822 struct cbq_sched_data *q = qdisc_priv(sch);
823 struct cbq_class *cl_tail, *cl_prev, *cl;
824 struct sk_buff *skb;
825 int deficit;
826
827 cl_tail = cl_prev = q->active[prio];
828 cl = cl_prev->next_alive;
829
830 do {
831 deficit = 0;
832
833 /* Start round */
834 do {
835 struct cbq_class *borrow = cl;
836
837 if (cl->q->q.qlen &&
838 (borrow = cbq_under_limit(cl)) == NULL)
839 goto skip_class;
840
841 if (cl->deficit <= 0) {
842 /* Class exhausted its allotment per
843 * this round. Switch to the next one.
844 */
845 deficit = 1;
846 cl->deficit += cl->quantum;
847 goto next_class;
848 }
849
850 skb = cl->q->dequeue(cl->q);
851
852 /* Class did not give us any skb :-(
853 * It could occur even if cl->q->q.qlen != 0
854 * f.e. if cl->q == "tbf"
855 */
856 if (skb == NULL)
857 goto skip_class;
858
859 cl->deficit -= qdisc_pkt_len(skb);
860 q->tx_class = cl;
861 q->tx_borrowed = borrow;
862 if (borrow != cl) {
863 #ifndef CBQ_XSTATS_BORROWS_BYTES
864 borrow->xstats.borrows++;
865 cl->xstats.borrows++;
866 #else
867 borrow->xstats.borrows += qdisc_pkt_len(skb);
868 cl->xstats.borrows += qdisc_pkt_len(skb);
869 #endif
870 }
871 q->tx_len = qdisc_pkt_len(skb);
872
873 if (cl->deficit <= 0) {
874 q->active[prio] = cl;
875 cl = cl->next_alive;
876 cl->deficit += cl->quantum;
877 }
878 return skb;
879
880 skip_class:
881 if (cl->q->q.qlen == 0 || prio != cl->cpriority) {
882 /* Class is empty or penalized.
883 * Unlink it from active chain.
884 */
885 cl_prev->next_alive = cl->next_alive;
886 cl->next_alive = NULL;
887
888 /* Did cl_tail point to it? */
889 if (cl == cl_tail) {
890 /* Repair it! */
891 cl_tail = cl_prev;
892
893 /* Was it the last class in this band? */
894 if (cl == cl_tail) {
895 /* Kill the band! */
896 q->active[prio] = NULL;
897 q->activemask &= ~(1<<prio);
898 if (cl->q->q.qlen)
899 cbq_activate_class(cl);
900 return NULL;
901 }
902
903 q->active[prio] = cl_tail;
904 }
905 if (cl->q->q.qlen)
906 cbq_activate_class(cl);
907
908 cl = cl_prev;
909 }
910
911 next_class:
912 cl_prev = cl;
913 cl = cl->next_alive;
914 } while (cl_prev != cl_tail);
915 } while (deficit);
916
917 q->active[prio] = cl_prev;
918
919 return NULL;
920 }
921
922 static inline struct sk_buff *
923 cbq_dequeue_1(struct Qdisc *sch)
924 {
925 struct cbq_sched_data *q = qdisc_priv(sch);
926 struct sk_buff *skb;
927 unsigned int activemask;
928
929 activemask = q->activemask & 0xFF;
930 while (activemask) {
931 int prio = ffz(~activemask);
932 activemask &= ~(1<<prio);
933 skb = cbq_dequeue_prio(sch, prio);
934 if (skb)
935 return skb;
936 }
937 return NULL;
938 }
939
940 static struct sk_buff *
941 cbq_dequeue(struct Qdisc *sch)
942 {
943 struct sk_buff *skb;
944 struct cbq_sched_data *q = qdisc_priv(sch);
945 psched_time_t now;
946 psched_tdiff_t incr;
947
948 now = psched_get_time();
949 incr = now - q->now_rt;
950
951 if (q->tx_class) {
952 psched_tdiff_t incr2;
953 /* Time integrator. We calculate EOS time
954 * by adding expected packet transmission time.
955 * If real time is greater, we warp artificial clock,
956 * so that:
957 *
958 * cbq_time = max(real_time, work);
959 */
960 incr2 = L2T(&q->link, q->tx_len);
961 q->now += incr2;
962 cbq_update(q);
963 if ((incr -= incr2) < 0)
964 incr = 0;
965 }
966 q->now += incr;
967 q->now_rt = now;
968
969 for (;;) {
970 q->wd_expires = 0;
971
972 skb = cbq_dequeue_1(sch);
973 if (skb) {
974 qdisc_bstats_update(sch, skb);
975 sch->q.qlen--;
976 qdisc_unthrottled(sch);
977 return skb;
978 }
979
980 /* All the classes are overlimit.
981 *
982 * It is possible, if:
983 *
984 * 1. Scheduler is empty.
985 * 2. Toplevel cutoff inhibited borrowing.
986 * 3. Root class is overlimit.
987 *
988 * Reset 2d and 3d conditions and retry.
989 *
990 * Note, that NS and cbq-2.0 are buggy, peeking
991 * an arbitrary class is appropriate for ancestor-only
992 * sharing, but not for toplevel algorithm.
993 *
994 * Our version is better, but slower, because it requires
995 * two passes, but it is unavoidable with top-level sharing.
996 */
997
998 if (q->toplevel == TC_CBQ_MAXLEVEL &&
999 q->link.undertime == PSCHED_PASTPERFECT)
1000 break;
1001
1002 q->toplevel = TC_CBQ_MAXLEVEL;
1003 q->link.undertime = PSCHED_PASTPERFECT;
1004 }
1005
1006 /* No packets in scheduler or nobody wants to give them to us :-(
1007 * Sigh... start watchdog timer in the last case.
1008 */
1009
1010 if (sch->q.qlen) {
1011 sch->qstats.overlimits++;
1012 if (q->wd_expires)
1013 qdisc_watchdog_schedule(&q->watchdog,
1014 now + q->wd_expires);
1015 }
1016 return NULL;
1017 }
1018
1019 /* CBQ class maintanance routines */
1020
1021 static void cbq_adjust_levels(struct cbq_class *this)
1022 {
1023 if (this == NULL)
1024 return;
1025
1026 do {
1027 int level = 0;
1028 struct cbq_class *cl;
1029
1030 cl = this->children;
1031 if (cl) {
1032 do {
1033 if (cl->level > level)
1034 level = cl->level;
1035 } while ((cl = cl->sibling) != this->children);
1036 }
1037 this->level = level + 1;
1038 } while ((this = this->tparent) != NULL);
1039 }
1040
1041 static void cbq_normalize_quanta(struct cbq_sched_data *q, int prio)
1042 {
1043 struct cbq_class *cl;
1044 struct hlist_node *n;
1045 unsigned int h;
1046
1047 if (q->quanta[prio] == 0)
1048 return;
1049
1050 for (h = 0; h < q->clhash.hashsize; h++) {
1051 hlist_for_each_entry(cl, n, &q->clhash.hash[h], common.hnode) {
1052 /* BUGGGG... Beware! This expression suffer of
1053 * arithmetic overflows!
1054 */
1055 if (cl->priority == prio) {
1056 cl->quantum = (cl->weight*cl->allot*q->nclasses[prio])/
1057 q->quanta[prio];
1058 }
1059 if (cl->quantum <= 0 || cl->quantum>32*qdisc_dev(cl->qdisc)->mtu) {
1060 pr_warning("CBQ: class %08x has bad quantum==%ld, repaired.\n",
1061 cl->common.classid, cl->quantum);
1062 cl->quantum = qdisc_dev(cl->qdisc)->mtu/2 + 1;
1063 }
1064 }
1065 }
1066 }
1067
1068 static void cbq_sync_defmap(struct cbq_class *cl)
1069 {
1070 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
1071 struct cbq_class *split = cl->split;
1072 unsigned int h;
1073 int i;
1074
1075 if (split == NULL)
1076 return;
1077
1078 for (i = 0; i <= TC_PRIO_MAX; i++) {
1079 if (split->defaults[i] == cl && !(cl->defmap & (1<<i)))
1080 split->defaults[i] = NULL;
1081 }
1082
1083 for (i = 0; i <= TC_PRIO_MAX; i++) {
1084 int level = split->level;
1085
1086 if (split->defaults[i])
1087 continue;
1088
1089 for (h = 0; h < q->clhash.hashsize; h++) {
1090 struct hlist_node *n;
1091 struct cbq_class *c;
1092
1093 hlist_for_each_entry(c, n, &q->clhash.hash[h],
1094 common.hnode) {
1095 if (c->split == split && c->level < level &&
1096 c->defmap & (1<<i)) {
1097 split->defaults[i] = c;
1098 level = c->level;
1099 }
1100 }
1101 }
1102 }
1103 }
1104
1105 static void cbq_change_defmap(struct cbq_class *cl, u32 splitid, u32 def, u32 mask)
1106 {
1107 struct cbq_class *split = NULL;
1108
1109 if (splitid == 0) {
1110 split = cl->split;
1111 if (!split)
1112 return;
1113 splitid = split->common.classid;
1114 }
1115
1116 if (split == NULL || split->common.classid != splitid) {
1117 for (split = cl->tparent; split; split = split->tparent)
1118 if (split->common.classid == splitid)
1119 break;
1120 }
1121
1122 if (split == NULL)
1123 return;
1124
1125 if (cl->split != split) {
1126 cl->defmap = 0;
1127 cbq_sync_defmap(cl);
1128 cl->split = split;
1129 cl->defmap = def & mask;
1130 } else
1131 cl->defmap = (cl->defmap & ~mask) | (def & mask);
1132
1133 cbq_sync_defmap(cl);
1134 }
1135
1136 static void cbq_unlink_class(struct cbq_class *this)
1137 {
1138 struct cbq_class *cl, **clp;
1139 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
1140
1141 qdisc_class_hash_remove(&q->clhash, &this->common);
1142
1143 if (this->tparent) {
1144 clp = &this->sibling;
1145 cl = *clp;
1146 do {
1147 if (cl == this) {
1148 *clp = cl->sibling;
1149 break;
1150 }
1151 clp = &cl->sibling;
1152 } while ((cl = *clp) != this->sibling);
1153
1154 if (this->tparent->children == this) {
1155 this->tparent->children = this->sibling;
1156 if (this->sibling == this)
1157 this->tparent->children = NULL;
1158 }
1159 } else {
1160 WARN_ON(this->sibling != this);
1161 }
1162 }
1163
1164 static void cbq_link_class(struct cbq_class *this)
1165 {
1166 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
1167 struct cbq_class *parent = this->tparent;
1168
1169 this->sibling = this;
1170 qdisc_class_hash_insert(&q->clhash, &this->common);
1171
1172 if (parent == NULL)
1173 return;
1174
1175 if (parent->children == NULL) {
1176 parent->children = this;
1177 } else {
1178 this->sibling = parent->children->sibling;
1179 parent->children->sibling = this;
1180 }
1181 }
1182
1183 static unsigned int cbq_drop(struct Qdisc *sch)
1184 {
1185 struct cbq_sched_data *q = qdisc_priv(sch);
1186 struct cbq_class *cl, *cl_head;
1187 int prio;
1188 unsigned int len;
1189
1190 for (prio = TC_CBQ_MAXPRIO; prio >= 0; prio--) {
1191 cl_head = q->active[prio];
1192 if (!cl_head)
1193 continue;
1194
1195 cl = cl_head;
1196 do {
1197 if (cl->q->ops->drop && (len = cl->q->ops->drop(cl->q))) {
1198 sch->q.qlen--;
1199 if (!cl->q->q.qlen)
1200 cbq_deactivate_class(cl);
1201 return len;
1202 }
1203 } while ((cl = cl->next_alive) != cl_head);
1204 }
1205 return 0;
1206 }
1207
1208 static void
1209 cbq_reset(struct Qdisc *sch)
1210 {
1211 struct cbq_sched_data *q = qdisc_priv(sch);
1212 struct cbq_class *cl;
1213 struct hlist_node *n;
1214 int prio;
1215 unsigned int h;
1216
1217 q->activemask = 0;
1218 q->pmask = 0;
1219 q->tx_class = NULL;
1220 q->tx_borrowed = NULL;
1221 qdisc_watchdog_cancel(&q->watchdog);
1222 hrtimer_cancel(&q->delay_timer);
1223 q->toplevel = TC_CBQ_MAXLEVEL;
1224 q->now = psched_get_time();
1225 q->now_rt = q->now;
1226
1227 for (prio = 0; prio <= TC_CBQ_MAXPRIO; prio++)
1228 q->active[prio] = NULL;
1229
1230 for (h = 0; h < q->clhash.hashsize; h++) {
1231 hlist_for_each_entry(cl, n, &q->clhash.hash[h], common.hnode) {
1232 qdisc_reset(cl->q);
1233
1234 cl->next_alive = NULL;
1235 cl->undertime = PSCHED_PASTPERFECT;
1236 cl->avgidle = cl->maxidle;
1237 cl->deficit = cl->quantum;
1238 cl->cpriority = cl->priority;
1239 }
1240 }
1241 sch->q.qlen = 0;
1242 }
1243
1244
1245 static int cbq_set_lss(struct cbq_class *cl, struct tc_cbq_lssopt *lss)
1246 {
1247 if (lss->change & TCF_CBQ_LSS_FLAGS) {
1248 cl->share = (lss->flags & TCF_CBQ_LSS_ISOLATED) ? NULL : cl->tparent;
1249 cl->borrow = (lss->flags & TCF_CBQ_LSS_BOUNDED) ? NULL : cl->tparent;
1250 }
1251 if (lss->change & TCF_CBQ_LSS_EWMA)
1252 cl->ewma_log = lss->ewma_log;
1253 if (lss->change & TCF_CBQ_LSS_AVPKT)
1254 cl->avpkt = lss->avpkt;
1255 if (lss->change & TCF_CBQ_LSS_MINIDLE)
1256 cl->minidle = -(long)lss->minidle;
1257 if (lss->change & TCF_CBQ_LSS_MAXIDLE) {
1258 cl->maxidle = lss->maxidle;
1259 cl->avgidle = lss->maxidle;
1260 }
1261 if (lss->change & TCF_CBQ_LSS_OFFTIME)
1262 cl->offtime = lss->offtime;
1263 return 0;
1264 }
1265
1266 static void cbq_rmprio(struct cbq_sched_data *q, struct cbq_class *cl)
1267 {
1268 q->nclasses[cl->priority]--;
1269 q->quanta[cl->priority] -= cl->weight;
1270 cbq_normalize_quanta(q, cl->priority);
1271 }
1272
1273 static void cbq_addprio(struct cbq_sched_data *q, struct cbq_class *cl)
1274 {
1275 q->nclasses[cl->priority]++;
1276 q->quanta[cl->priority] += cl->weight;
1277 cbq_normalize_quanta(q, cl->priority);
1278 }
1279
1280 static int cbq_set_wrr(struct cbq_class *cl, struct tc_cbq_wrropt *wrr)
1281 {
1282 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
1283
1284 if (wrr->allot)
1285 cl->allot = wrr->allot;
1286 if (wrr->weight)
1287 cl->weight = wrr->weight;
1288 if (wrr->priority) {
1289 cl->priority = wrr->priority - 1;
1290 cl->cpriority = cl->priority;
1291 if (cl->priority >= cl->priority2)
1292 cl->priority2 = TC_CBQ_MAXPRIO - 1;
1293 }
1294
1295 cbq_addprio(q, cl);
1296 return 0;
1297 }
1298
1299 static int cbq_set_overlimit(struct cbq_class *cl, struct tc_cbq_ovl *ovl)
1300 {
1301 switch (ovl->strategy) {
1302 case TC_CBQ_OVL_CLASSIC:
1303 cl->overlimit = cbq_ovl_classic;
1304 break;
1305 case TC_CBQ_OVL_DELAY:
1306 cl->overlimit = cbq_ovl_delay;
1307 break;
1308 case TC_CBQ_OVL_LOWPRIO:
1309 if (ovl->priority2 - 1 >= TC_CBQ_MAXPRIO ||
1310 ovl->priority2 - 1 <= cl->priority)
1311 return -EINVAL;
1312 cl->priority2 = ovl->priority2 - 1;
1313 cl->overlimit = cbq_ovl_lowprio;
1314 break;
1315 case TC_CBQ_OVL_DROP:
1316 cl->overlimit = cbq_ovl_drop;
1317 break;
1318 case TC_CBQ_OVL_RCLASSIC:
1319 cl->overlimit = cbq_ovl_rclassic;
1320 break;
1321 default:
1322 return -EINVAL;
1323 }
1324 cl->penalty = ovl->penalty;
1325 return 0;
1326 }
1327
1328 #ifdef CONFIG_NET_CLS_ACT
1329 static int cbq_set_police(struct cbq_class *cl, struct tc_cbq_police *p)
1330 {
1331 cl->police = p->police;
1332
1333 if (cl->q->handle) {
1334 if (p->police == TC_POLICE_RECLASSIFY)
1335 cl->q->reshape_fail = cbq_reshape_fail;
1336 else
1337 cl->q->reshape_fail = NULL;
1338 }
1339 return 0;
1340 }
1341 #endif
1342
1343 static int cbq_set_fopt(struct cbq_class *cl, struct tc_cbq_fopt *fopt)
1344 {
1345 cbq_change_defmap(cl, fopt->split, fopt->defmap, fopt->defchange);
1346 return 0;
1347 }
1348
1349 static const struct nla_policy cbq_policy[TCA_CBQ_MAX + 1] = {
1350 [TCA_CBQ_LSSOPT] = { .len = sizeof(struct tc_cbq_lssopt) },
1351 [TCA_CBQ_WRROPT] = { .len = sizeof(struct tc_cbq_wrropt) },
1352 [TCA_CBQ_FOPT] = { .len = sizeof(struct tc_cbq_fopt) },
1353 [TCA_CBQ_OVL_STRATEGY] = { .len = sizeof(struct tc_cbq_ovl) },
1354 [TCA_CBQ_RATE] = { .len = sizeof(struct tc_ratespec) },
1355 [TCA_CBQ_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
1356 [TCA_CBQ_POLICE] = { .len = sizeof(struct tc_cbq_police) },
1357 };
1358
1359 static int cbq_init(struct Qdisc *sch, struct nlattr *opt)
1360 {
1361 struct cbq_sched_data *q = qdisc_priv(sch);
1362 struct nlattr *tb[TCA_CBQ_MAX + 1];
1363 struct tc_ratespec *r;
1364 int err;
1365
1366 err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy);
1367 if (err < 0)
1368 return err;
1369
1370 if (tb[TCA_CBQ_RTAB] == NULL || tb[TCA_CBQ_RATE] == NULL)
1371 return -EINVAL;
1372
1373 r = nla_data(tb[TCA_CBQ_RATE]);
1374
1375 if ((q->link.R_tab = qdisc_get_rtab(r, tb[TCA_CBQ_RTAB])) == NULL)
1376 return -EINVAL;
1377
1378 err = qdisc_class_hash_init(&q->clhash);
1379 if (err < 0)
1380 goto put_rtab;
1381
1382 q->link.refcnt = 1;
1383 q->link.sibling = &q->link;
1384 q->link.common.classid = sch->handle;
1385 q->link.qdisc = sch;
1386 q->link.q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1387 sch->handle);
1388 if (!q->link.q)
1389 q->link.q = &noop_qdisc;
1390
1391 q->link.priority = TC_CBQ_MAXPRIO - 1;
1392 q->link.priority2 = TC_CBQ_MAXPRIO - 1;
1393 q->link.cpriority = TC_CBQ_MAXPRIO - 1;
1394 q->link.ovl_strategy = TC_CBQ_OVL_CLASSIC;
1395 q->link.overlimit = cbq_ovl_classic;
1396 q->link.allot = psched_mtu(qdisc_dev(sch));
1397 q->link.quantum = q->link.allot;
1398 q->link.weight = q->link.R_tab->rate.rate;
1399
1400 q->link.ewma_log = TC_CBQ_DEF_EWMA;
1401 q->link.avpkt = q->link.allot/2;
1402 q->link.minidle = -0x7FFFFFFF;
1403
1404 qdisc_watchdog_init(&q->watchdog, sch);
1405 hrtimer_init(&q->delay_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
1406 q->delay_timer.function = cbq_undelay;
1407 q->toplevel = TC_CBQ_MAXLEVEL;
1408 q->now = psched_get_time();
1409 q->now_rt = q->now;
1410
1411 cbq_link_class(&q->link);
1412
1413 if (tb[TCA_CBQ_LSSOPT])
1414 cbq_set_lss(&q->link, nla_data(tb[TCA_CBQ_LSSOPT]));
1415
1416 cbq_addprio(q, &q->link);
1417 return 0;
1418
1419 put_rtab:
1420 qdisc_put_rtab(q->link.R_tab);
1421 return err;
1422 }
1423
1424 static int cbq_dump_rate(struct sk_buff *skb, struct cbq_class *cl)
1425 {
1426 unsigned char *b = skb_tail_pointer(skb);
1427
1428 if (nla_put(skb, TCA_CBQ_RATE, sizeof(cl->R_tab->rate), &cl->R_tab->rate))
1429 goto nla_put_failure;
1430 return skb->len;
1431
1432 nla_put_failure:
1433 nlmsg_trim(skb, b);
1434 return -1;
1435 }
1436
1437 static int cbq_dump_lss(struct sk_buff *skb, struct cbq_class *cl)
1438 {
1439 unsigned char *b = skb_tail_pointer(skb);
1440 struct tc_cbq_lssopt opt;
1441
1442 opt.flags = 0;
1443 if (cl->borrow == NULL)
1444 opt.flags |= TCF_CBQ_LSS_BOUNDED;
1445 if (cl->share == NULL)
1446 opt.flags |= TCF_CBQ_LSS_ISOLATED;
1447 opt.ewma_log = cl->ewma_log;
1448 opt.level = cl->level;
1449 opt.avpkt = cl->avpkt;
1450 opt.maxidle = cl->maxidle;
1451 opt.minidle = (u32)(-cl->minidle);
1452 opt.offtime = cl->offtime;
1453 opt.change = ~0;
1454 if (nla_put(skb, TCA_CBQ_LSSOPT, sizeof(opt), &opt))
1455 goto nla_put_failure;
1456 return skb->len;
1457
1458 nla_put_failure:
1459 nlmsg_trim(skb, b);
1460 return -1;
1461 }
1462
1463 static int cbq_dump_wrr(struct sk_buff *skb, struct cbq_class *cl)
1464 {
1465 unsigned char *b = skb_tail_pointer(skb);
1466 struct tc_cbq_wrropt opt;
1467
1468 opt.flags = 0;
1469 opt.allot = cl->allot;
1470 opt.priority = cl->priority + 1;
1471 opt.cpriority = cl->cpriority + 1;
1472 opt.weight = cl->weight;
1473 if (nla_put(skb, TCA_CBQ_WRROPT, sizeof(opt), &opt))
1474 goto nla_put_failure;
1475 return skb->len;
1476
1477 nla_put_failure:
1478 nlmsg_trim(skb, b);
1479 return -1;
1480 }
1481
1482 static int cbq_dump_ovl(struct sk_buff *skb, struct cbq_class *cl)
1483 {
1484 unsigned char *b = skb_tail_pointer(skb);
1485 struct tc_cbq_ovl opt;
1486
1487 opt.strategy = cl->ovl_strategy;
1488 opt.priority2 = cl->priority2 + 1;
1489 opt.pad = 0;
1490 opt.penalty = cl->penalty;
1491 if (nla_put(skb, TCA_CBQ_OVL_STRATEGY, sizeof(opt), &opt))
1492 goto nla_put_failure;
1493 return skb->len;
1494
1495 nla_put_failure:
1496 nlmsg_trim(skb, b);
1497 return -1;
1498 }
1499
1500 static int cbq_dump_fopt(struct sk_buff *skb, struct cbq_class *cl)
1501 {
1502 unsigned char *b = skb_tail_pointer(skb);
1503 struct tc_cbq_fopt opt;
1504
1505 if (cl->split || cl->defmap) {
1506 opt.split = cl->split ? cl->split->common.classid : 0;
1507 opt.defmap = cl->defmap;
1508 opt.defchange = ~0;
1509 if (nla_put(skb, TCA_CBQ_FOPT, sizeof(opt), &opt))
1510 goto nla_put_failure;
1511 }
1512 return skb->len;
1513
1514 nla_put_failure:
1515 nlmsg_trim(skb, b);
1516 return -1;
1517 }
1518
1519 #ifdef CONFIG_NET_CLS_ACT
1520 static int cbq_dump_police(struct sk_buff *skb, struct cbq_class *cl)
1521 {
1522 unsigned char *b = skb_tail_pointer(skb);
1523 struct tc_cbq_police opt;
1524
1525 if (cl->police) {
1526 opt.police = cl->police;
1527 opt.__res1 = 0;
1528 opt.__res2 = 0;
1529 if (nla_put(skb, TCA_CBQ_POLICE, sizeof(opt), &opt))
1530 goto nla_put_failure;
1531 }
1532 return skb->len;
1533
1534 nla_put_failure:
1535 nlmsg_trim(skb, b);
1536 return -1;
1537 }
1538 #endif
1539
1540 static int cbq_dump_attr(struct sk_buff *skb, struct cbq_class *cl)
1541 {
1542 if (cbq_dump_lss(skb, cl) < 0 ||
1543 cbq_dump_rate(skb, cl) < 0 ||
1544 cbq_dump_wrr(skb, cl) < 0 ||
1545 cbq_dump_ovl(skb, cl) < 0 ||
1546 #ifdef CONFIG_NET_CLS_ACT
1547 cbq_dump_police(skb, cl) < 0 ||
1548 #endif
1549 cbq_dump_fopt(skb, cl) < 0)
1550 return -1;
1551 return 0;
1552 }
1553
1554 static int cbq_dump(struct Qdisc *sch, struct sk_buff *skb)
1555 {
1556 struct cbq_sched_data *q = qdisc_priv(sch);
1557 struct nlattr *nest;
1558
1559 nest = nla_nest_start(skb, TCA_OPTIONS);
1560 if (nest == NULL)
1561 goto nla_put_failure;
1562 if (cbq_dump_attr(skb, &q->link) < 0)
1563 goto nla_put_failure;
1564 nla_nest_end(skb, nest);
1565 return skb->len;
1566
1567 nla_put_failure:
1568 nla_nest_cancel(skb, nest);
1569 return -1;
1570 }
1571
1572 static int
1573 cbq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
1574 {
1575 struct cbq_sched_data *q = qdisc_priv(sch);
1576
1577 q->link.xstats.avgidle = q->link.avgidle;
1578 return gnet_stats_copy_app(d, &q->link.xstats, sizeof(q->link.xstats));
1579 }
1580
1581 static int
1582 cbq_dump_class(struct Qdisc *sch, unsigned long arg,
1583 struct sk_buff *skb, struct tcmsg *tcm)
1584 {
1585 struct cbq_class *cl = (struct cbq_class *)arg;
1586 struct nlattr *nest;
1587
1588 if (cl->tparent)
1589 tcm->tcm_parent = cl->tparent->common.classid;
1590 else
1591 tcm->tcm_parent = TC_H_ROOT;
1592 tcm->tcm_handle = cl->common.classid;
1593 tcm->tcm_info = cl->q->handle;
1594
1595 nest = nla_nest_start(skb, TCA_OPTIONS);
1596 if (nest == NULL)
1597 goto nla_put_failure;
1598 if (cbq_dump_attr(skb, cl) < 0)
1599 goto nla_put_failure;
1600 nla_nest_end(skb, nest);
1601 return skb->len;
1602
1603 nla_put_failure:
1604 nla_nest_cancel(skb, nest);
1605 return -1;
1606 }
1607
1608 static int
1609 cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1610 struct gnet_dump *d)
1611 {
1612 struct cbq_sched_data *q = qdisc_priv(sch);
1613 struct cbq_class *cl = (struct cbq_class *)arg;
1614
1615 cl->qstats.qlen = cl->q->q.qlen;
1616 cl->xstats.avgidle = cl->avgidle;
1617 cl->xstats.undertime = 0;
1618
1619 if (cl->undertime != PSCHED_PASTPERFECT)
1620 cl->xstats.undertime = cl->undertime - q->now;
1621
1622 if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
1623 gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
1624 gnet_stats_copy_queue(d, &cl->qstats) < 0)
1625 return -1;
1626
1627 return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));
1628 }
1629
1630 static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1631 struct Qdisc **old)
1632 {
1633 struct cbq_class *cl = (struct cbq_class *)arg;
1634
1635 if (new == NULL) {
1636 new = qdisc_create_dflt(sch->dev_queue,
1637 &pfifo_qdisc_ops, cl->common.classid);
1638 if (new == NULL)
1639 return -ENOBUFS;
1640 } else {
1641 #ifdef CONFIG_NET_CLS_ACT
1642 if (cl->police == TC_POLICE_RECLASSIFY)
1643 new->reshape_fail = cbq_reshape_fail;
1644 #endif
1645 }
1646 sch_tree_lock(sch);
1647 *old = cl->q;
1648 cl->q = new;
1649 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
1650 qdisc_reset(*old);
1651 sch_tree_unlock(sch);
1652
1653 return 0;
1654 }
1655
1656 static struct Qdisc *cbq_leaf(struct Qdisc *sch, unsigned long arg)
1657 {
1658 struct cbq_class *cl = (struct cbq_class *)arg;
1659
1660 return cl->q;
1661 }
1662
1663 static void cbq_qlen_notify(struct Qdisc *sch, unsigned long arg)
1664 {
1665 struct cbq_class *cl = (struct cbq_class *)arg;
1666
1667 if (cl->q->q.qlen == 0)
1668 cbq_deactivate_class(cl);
1669 }
1670
1671 static unsigned long cbq_get(struct Qdisc *sch, u32 classid)
1672 {
1673 struct cbq_sched_data *q = qdisc_priv(sch);
1674 struct cbq_class *cl = cbq_class_lookup(q, classid);
1675
1676 if (cl) {
1677 cl->refcnt++;
1678 return (unsigned long)cl;
1679 }
1680 return 0;
1681 }
1682
1683 static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl)
1684 {
1685 struct cbq_sched_data *q = qdisc_priv(sch);
1686
1687 WARN_ON(cl->filters);
1688
1689 tcf_destroy_chain(&cl->filter_list);
1690 qdisc_destroy(cl->q);
1691 qdisc_put_rtab(cl->R_tab);
1692 gen_kill_estimator(&cl->bstats, &cl->rate_est);
1693 if (cl != &q->link)
1694 kfree(cl);
1695 }
1696
1697 static void cbq_destroy(struct Qdisc *sch)
1698 {
1699 struct cbq_sched_data *q = qdisc_priv(sch);
1700 struct hlist_node *n, *next;
1701 struct cbq_class *cl;
1702 unsigned int h;
1703
1704 #ifdef CONFIG_NET_CLS_ACT
1705 q->rx_class = NULL;
1706 #endif
1707 /*
1708 * Filters must be destroyed first because we don't destroy the
1709 * classes from root to leafs which means that filters can still
1710 * be bound to classes which have been destroyed already. --TGR '04
1711 */
1712 for (h = 0; h < q->clhash.hashsize; h++) {
1713 hlist_for_each_entry(cl, n, &q->clhash.hash[h], common.hnode)
1714 tcf_destroy_chain(&cl->filter_list);
1715 }
1716 for (h = 0; h < q->clhash.hashsize; h++) {
1717 hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[h],
1718 common.hnode)
1719 cbq_destroy_class(sch, cl);
1720 }
1721 qdisc_class_hash_destroy(&q->clhash);
1722 }
1723
1724 static void cbq_put(struct Qdisc *sch, unsigned long arg)
1725 {
1726 struct cbq_class *cl = (struct cbq_class *)arg;
1727
1728 if (--cl->refcnt == 0) {
1729 #ifdef CONFIG_NET_CLS_ACT
1730 spinlock_t *root_lock = qdisc_root_sleeping_lock(sch);
1731 struct cbq_sched_data *q = qdisc_priv(sch);
1732
1733 spin_lock_bh(root_lock);
1734 if (q->rx_class == cl)
1735 q->rx_class = NULL;
1736 spin_unlock_bh(root_lock);
1737 #endif
1738
1739 cbq_destroy_class(sch, cl);
1740 }
1741 }
1742
1743 static int
1744 cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **tca,
1745 unsigned long *arg)
1746 {
1747 int err;
1748 struct cbq_sched_data *q = qdisc_priv(sch);
1749 struct cbq_class *cl = (struct cbq_class *)*arg;
1750 struct nlattr *opt = tca[TCA_OPTIONS];
1751 struct nlattr *tb[TCA_CBQ_MAX + 1];
1752 struct cbq_class *parent;
1753 struct qdisc_rate_table *rtab = NULL;
1754
1755 if (opt == NULL)
1756 return -EINVAL;
1757
1758 err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy);
1759 if (err < 0)
1760 return err;
1761
1762 if (cl) {
1763 /* Check parent */
1764 if (parentid) {
1765 if (cl->tparent &&
1766 cl->tparent->common.classid != parentid)
1767 return -EINVAL;
1768 if (!cl->tparent && parentid != TC_H_ROOT)
1769 return -EINVAL;
1770 }
1771
1772 if (tb[TCA_CBQ_RATE]) {
1773 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]),
1774 tb[TCA_CBQ_RTAB]);
1775 if (rtab == NULL)
1776 return -EINVAL;
1777 }
1778
1779 if (tca[TCA_RATE]) {
1780 err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
1781 qdisc_root_sleeping_lock(sch),
1782 tca[TCA_RATE]);
1783 if (err) {
1784 if (rtab)
1785 qdisc_put_rtab(rtab);
1786 return err;
1787 }
1788 }
1789
1790 /* Change class parameters */
1791 sch_tree_lock(sch);
1792
1793 if (cl->next_alive != NULL)
1794 cbq_deactivate_class(cl);
1795
1796 if (rtab) {
1797 qdisc_put_rtab(cl->R_tab);
1798 cl->R_tab = rtab;
1799 }
1800
1801 if (tb[TCA_CBQ_LSSOPT])
1802 cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
1803
1804 if (tb[TCA_CBQ_WRROPT]) {
1805 cbq_rmprio(q, cl);
1806 cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
1807 }
1808
1809 if (tb[TCA_CBQ_OVL_STRATEGY])
1810 cbq_set_overlimit(cl, nla_data(tb[TCA_CBQ_OVL_STRATEGY]));
1811
1812 #ifdef CONFIG_NET_CLS_ACT
1813 if (tb[TCA_CBQ_POLICE])
1814 cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE]));
1815 #endif
1816
1817 if (tb[TCA_CBQ_FOPT])
1818 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
1819
1820 if (cl->q->q.qlen)
1821 cbq_activate_class(cl);
1822
1823 sch_tree_unlock(sch);
1824
1825 return 0;
1826 }
1827
1828 if (parentid == TC_H_ROOT)
1829 return -EINVAL;
1830
1831 if (tb[TCA_CBQ_WRROPT] == NULL || tb[TCA_CBQ_RATE] == NULL ||
1832 tb[TCA_CBQ_LSSOPT] == NULL)
1833 return -EINVAL;
1834
1835 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]), tb[TCA_CBQ_RTAB]);
1836 if (rtab == NULL)
1837 return -EINVAL;
1838
1839 if (classid) {
1840 err = -EINVAL;
1841 if (TC_H_MAJ(classid ^ sch->handle) ||
1842 cbq_class_lookup(q, classid))
1843 goto failure;
1844 } else {
1845 int i;
1846 classid = TC_H_MAKE(sch->handle, 0x8000);
1847
1848 for (i = 0; i < 0x8000; i++) {
1849 if (++q->hgenerator >= 0x8000)
1850 q->hgenerator = 1;
1851 if (cbq_class_lookup(q, classid|q->hgenerator) == NULL)
1852 break;
1853 }
1854 err = -ENOSR;
1855 if (i >= 0x8000)
1856 goto failure;
1857 classid = classid|q->hgenerator;
1858 }
1859
1860 parent = &q->link;
1861 if (parentid) {
1862 parent = cbq_class_lookup(q, parentid);
1863 err = -EINVAL;
1864 if (parent == NULL)
1865 goto failure;
1866 }
1867
1868 err = -ENOBUFS;
1869 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
1870 if (cl == NULL)
1871 goto failure;
1872
1873 if (tca[TCA_RATE]) {
1874 err = gen_new_estimator(&cl->bstats, &cl->rate_est,
1875 qdisc_root_sleeping_lock(sch),
1876 tca[TCA_RATE]);
1877 if (err) {
1878 kfree(cl);
1879 goto failure;
1880 }
1881 }
1882
1883 cl->R_tab = rtab;
1884 rtab = NULL;
1885 cl->refcnt = 1;
1886 cl->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid);
1887 if (!cl->q)
1888 cl->q = &noop_qdisc;
1889 cl->common.classid = classid;
1890 cl->tparent = parent;
1891 cl->qdisc = sch;
1892 cl->allot = parent->allot;
1893 cl->quantum = cl->allot;
1894 cl->weight = cl->R_tab->rate.rate;
1895
1896 sch_tree_lock(sch);
1897 cbq_link_class(cl);
1898 cl->borrow = cl->tparent;
1899 if (cl->tparent != &q->link)
1900 cl->share = cl->tparent;
1901 cbq_adjust_levels(parent);
1902 cl->minidle = -0x7FFFFFFF;
1903 cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
1904 cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
1905 if (cl->ewma_log == 0)
1906 cl->ewma_log = q->link.ewma_log;
1907 if (cl->maxidle == 0)
1908 cl->maxidle = q->link.maxidle;
1909 if (cl->avpkt == 0)
1910 cl->avpkt = q->link.avpkt;
1911 cl->overlimit = cbq_ovl_classic;
1912 if (tb[TCA_CBQ_OVL_STRATEGY])
1913 cbq_set_overlimit(cl, nla_data(tb[TCA_CBQ_OVL_STRATEGY]));
1914 #ifdef CONFIG_NET_CLS_ACT
1915 if (tb[TCA_CBQ_POLICE])
1916 cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE]));
1917 #endif
1918 if (tb[TCA_CBQ_FOPT])
1919 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
1920 sch_tree_unlock(sch);
1921
1922 qdisc_class_hash_grow(sch, &q->clhash);
1923
1924 *arg = (unsigned long)cl;
1925 return 0;
1926
1927 failure:
1928 qdisc_put_rtab(rtab);
1929 return err;
1930 }
1931
1932 static int cbq_delete(struct Qdisc *sch, unsigned long arg)
1933 {
1934 struct cbq_sched_data *q = qdisc_priv(sch);
1935 struct cbq_class *cl = (struct cbq_class *)arg;
1936 unsigned int qlen;
1937
1938 if (cl->filters || cl->children || cl == &q->link)
1939 return -EBUSY;
1940
1941 sch_tree_lock(sch);
1942
1943 qlen = cl->q->q.qlen;
1944 qdisc_reset(cl->q);
1945 qdisc_tree_decrease_qlen(cl->q, qlen);
1946
1947 if (cl->next_alive)
1948 cbq_deactivate_class(cl);
1949
1950 if (q->tx_borrowed == cl)
1951 q->tx_borrowed = q->tx_class;
1952 if (q->tx_class == cl) {
1953 q->tx_class = NULL;
1954 q->tx_borrowed = NULL;
1955 }
1956 #ifdef CONFIG_NET_CLS_ACT
1957 if (q->rx_class == cl)
1958 q->rx_class = NULL;
1959 #endif
1960
1961 cbq_unlink_class(cl);
1962 cbq_adjust_levels(cl->tparent);
1963 cl->defmap = 0;
1964 cbq_sync_defmap(cl);
1965
1966 cbq_rmprio(q, cl);
1967 sch_tree_unlock(sch);
1968
1969 BUG_ON(--cl->refcnt == 0);
1970 /*
1971 * This shouldn't happen: we "hold" one cops->get() when called
1972 * from tc_ctl_tclass; the destroy method is done from cops->put().
1973 */
1974
1975 return 0;
1976 }
1977
1978 static struct tcf_proto **cbq_find_tcf(struct Qdisc *sch, unsigned long arg)
1979 {
1980 struct cbq_sched_data *q = qdisc_priv(sch);
1981 struct cbq_class *cl = (struct cbq_class *)arg;
1982
1983 if (cl == NULL)
1984 cl = &q->link;
1985
1986 return &cl->filter_list;
1987 }
1988
1989 static unsigned long cbq_bind_filter(struct Qdisc *sch, unsigned long parent,
1990 u32 classid)
1991 {
1992 struct cbq_sched_data *q = qdisc_priv(sch);
1993 struct cbq_class *p = (struct cbq_class *)parent;
1994 struct cbq_class *cl = cbq_class_lookup(q, classid);
1995
1996 if (cl) {
1997 if (p && p->level <= cl->level)
1998 return 0;
1999 cl->filters++;
2000 return (unsigned long)cl;
2001 }
2002 return 0;
2003 }
2004
2005 static void cbq_unbind_filter(struct Qdisc *sch, unsigned long arg)
2006 {
2007 struct cbq_class *cl = (struct cbq_class *)arg;
2008
2009 cl->filters--;
2010 }
2011
2012 static void cbq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
2013 {
2014 struct cbq_sched_data *q = qdisc_priv(sch);
2015 struct cbq_class *cl;
2016 struct hlist_node *n;
2017 unsigned int h;
2018
2019 if (arg->stop)
2020 return;
2021
2022 for (h = 0; h < q->clhash.hashsize; h++) {
2023 hlist_for_each_entry(cl, n, &q->clhash.hash[h], common.hnode) {
2024 if (arg->count < arg->skip) {
2025 arg->count++;
2026 continue;
2027 }
2028 if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
2029 arg->stop = 1;
2030 return;
2031 }
2032 arg->count++;
2033 }
2034 }
2035 }
2036
2037 static const struct Qdisc_class_ops cbq_class_ops = {
2038 .graft = cbq_graft,
2039 .leaf = cbq_leaf,
2040 .qlen_notify = cbq_qlen_notify,
2041 .get = cbq_get,
2042 .put = cbq_put,
2043 .change = cbq_change_class,
2044 .delete = cbq_delete,
2045 .walk = cbq_walk,
2046 .tcf_chain = cbq_find_tcf,
2047 .bind_tcf = cbq_bind_filter,
2048 .unbind_tcf = cbq_unbind_filter,
2049 .dump = cbq_dump_class,
2050 .dump_stats = cbq_dump_class_stats,
2051 };
2052
2053 static struct Qdisc_ops cbq_qdisc_ops __read_mostly = {
2054 .next = NULL,
2055 .cl_ops = &cbq_class_ops,
2056 .id = "cbq",
2057 .priv_size = sizeof(struct cbq_sched_data),
2058 .enqueue = cbq_enqueue,
2059 .dequeue = cbq_dequeue,
2060 .peek = qdisc_peek_dequeued,
2061 .drop = cbq_drop,
2062 .init = cbq_init,
2063 .reset = cbq_reset,
2064 .destroy = cbq_destroy,
2065 .change = NULL,
2066 .dump = cbq_dump,
2067 .dump_stats = cbq_dump_stats,
2068 .owner = THIS_MODULE,
2069 };
2070
2071 static int __init cbq_module_init(void)
2072 {
2073 return register_qdisc(&cbq_qdisc_ops);
2074 }
2075 static void __exit cbq_module_exit(void)
2076 {
2077 unregister_qdisc(&cbq_qdisc_ops);
2078 }
2079 module_init(cbq_module_init)
2080 module_exit(cbq_module_exit)
2081 MODULE_LICENSE("GPL");
(deprecated) Btrfs devel tree