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tty: serial: lpuart: avoid leaking struct tty_struct
[linux/fpc-iii.git] / net / sched / sch_cbq.c
blobf42025d53cfe1e4fcd91931bf14b7328896db1e2
1 /*
2 * net/sched/sch_cbq.c Class-Based Queueing discipline.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 *
11 */
12
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/types.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 #include <linux/skbuff.h>
20 #include <net/netlink.h>
21 #include <net/pkt_sched.h>
22 #include <net/pkt_cls.h>
23
24
25 /* Class-Based Queueing (CBQ) algorithm.
26 =======================================
27
28 Sources: [1] Sally Floyd and Van Jacobson, "Link-sharing and Resource
29 Management Models for Packet Networks",
30 IEEE/ACM Transactions on Networking, Vol.3, No.4, 1995
31
32 [2] Sally Floyd, "Notes on CBQ and Guaranteed Service", 1995
33
34 [3] Sally Floyd, "Notes on Class-Based Queueing: Setting
35 Parameters", 1996
36
37 [4] Sally Floyd and Michael Speer, "Experimental Results
38 for Class-Based Queueing", 1998, not published.
39
40 -----------------------------------------------------------------------
41
42 Algorithm skeleton was taken from NS simulator cbq.cc.
43 If someone wants to check this code against the LBL version,
44 he should take into account that ONLY the skeleton was borrowed,
45 the implementation is different. Particularly:
46
47 --- The WRR algorithm is different. Our version looks more
48 reasonable (I hope) and works when quanta are allowed to be
49 less than MTU, which is always the case when real time classes
50 have small rates. Note, that the statement of [3] is
51 incomplete, delay may actually be estimated even if class
52 per-round allotment is less than MTU. Namely, if per-round
53 allotment is W*r_i, and r_1+...+r_k = r < 1
54
55 delay_i <= ([MTU/(W*r_i)]*W*r + W*r + k*MTU)/B
56
57 In the worst case we have IntServ estimate with D = W*r+k*MTU
58 and C = MTU*r. The proof (if correct at all) is trivial.
59
60
61 --- It seems that cbq-2.0 is not very accurate. At least, I cannot
62 interpret some places, which look like wrong translations
63 from NS. Anyone is advised to find these differences
64 and explain to me, why I am wrong 8).
65
66 --- Linux has no EOI event, so that we cannot estimate true class
67 idle time. Workaround is to consider the next dequeue event
68 as sign that previous packet is finished. This is wrong because of
69 internal device queueing, but on a permanently loaded link it is true.
70 Moreover, combined with clock integrator, this scheme looks
71 very close to an ideal solution. */
72
73 struct cbq_sched_data;
74
75
76 struct cbq_class {
77 struct Qdisc_class_common common;
78 struct cbq_class *next_alive; /* next class with backlog in this priority band */
79
80 /* Parameters */
81 unsigned char priority; /* class priority */
82 unsigned char priority2; /* priority to be used after overlimit */
83 unsigned char ewma_log; /* time constant for idle time calculation */
84
85 u32 defmap;
86
87 /* Link-sharing scheduler parameters */
88 long maxidle; /* Class parameters: see below. */
89 long offtime;
90 long minidle;
91 u32 avpkt;
92 struct qdisc_rate_table *R_tab;
93
94 /* General scheduler (WRR) parameters */
95 long allot;
96 long quantum; /* Allotment per WRR round */
97 long weight; /* Relative allotment: see below */
98
99 struct Qdisc *qdisc; /* Ptr to CBQ discipline */
100 struct cbq_class *split; /* Ptr to split node */
101 struct cbq_class *share; /* Ptr to LS parent in the class tree */
102 struct cbq_class *tparent; /* Ptr to tree parent in the class tree */
103 struct cbq_class *borrow; /* NULL if class is bandwidth limited;
104 parent otherwise */
105 struct cbq_class *sibling; /* Sibling chain */
106 struct cbq_class *children; /* Pointer to children chain */
107
108 struct Qdisc *q; /* Elementary queueing discipline */
109
110
111 /* Variables */
112 unsigned char cpriority; /* Effective priority */
113 unsigned char delayed;
114 unsigned char level; /* level of the class in hierarchy:
115 0 for leaf classes, and maximal
116 level of children + 1 for nodes.
117 */
118
119 psched_time_t last; /* Last end of service */
120 psched_time_t undertime;
121 long avgidle;
122 long deficit; /* Saved deficit for WRR */
123 psched_time_t penalized;
124 struct gnet_stats_basic_packed bstats;
125 struct gnet_stats_queue qstats;
126 struct net_rate_estimator __rcu *rate_est;
127 struct tc_cbq_xstats xstats;
128
129 struct tcf_proto __rcu *filter_list;
130 struct tcf_block *block;
131
132 int filters;
133
134 struct cbq_class *defaults[TC_PRIO_MAX + 1];
135 };
136
137 struct cbq_sched_data {
138 struct Qdisc_class_hash clhash; /* Hash table of all classes */
139 int nclasses[TC_CBQ_MAXPRIO + 1];
140 unsigned int quanta[TC_CBQ_MAXPRIO + 1];
141
142 struct cbq_class link;
143
144 unsigned int activemask;
145 struct cbq_class *active[TC_CBQ_MAXPRIO + 1]; /* List of all classes
146 with backlog */
147
148 #ifdef CONFIG_NET_CLS_ACT
149 struct cbq_class *rx_class;
150 #endif
151 struct cbq_class *tx_class;
152 struct cbq_class *tx_borrowed;
153 int tx_len;
154 psched_time_t now; /* Cached timestamp */
155 unsigned int pmask;
156
157 struct hrtimer delay_timer;
158 struct qdisc_watchdog watchdog; /* Watchdog timer,
159 started when CBQ has
160 backlog, but cannot
161 transmit just now */
162 psched_tdiff_t wd_expires;
163 int toplevel;
164 u32 hgenerator;
165 };
166
167
168 #define L2T(cl, len) qdisc_l2t((cl)->R_tab, len)
169
170 static inline struct cbq_class *
171 cbq_class_lookup(struct cbq_sched_data *q, u32 classid)
172 {
173 struct Qdisc_class_common *clc;
174
175 clc = qdisc_class_find(&q->clhash, classid);
176 if (clc == NULL)
177 return NULL;
178 return container_of(clc, struct cbq_class, common);
179 }
180
181 #ifdef CONFIG_NET_CLS_ACT
182
183 static struct cbq_class *
184 cbq_reclassify(struct sk_buff *skb, struct cbq_class *this)
185 {
186 struct cbq_class *cl;
187
188 for (cl = this->tparent; cl; cl = cl->tparent) {
189 struct cbq_class *new = cl->defaults[TC_PRIO_BESTEFFORT];
190
191 if (new != NULL && new != this)
192 return new;
193 }
194 return NULL;
195 }
196
197 #endif
198
199 /* Classify packet. The procedure is pretty complicated, but
200 * it allows us to combine link sharing and priority scheduling
201 * transparently.
202 *
203 * Namely, you can put link sharing rules (f.e. route based) at root of CBQ,
204 * so that it resolves to split nodes. Then packets are classified
205 * by logical priority, or a more specific classifier may be attached
206 * to the split node.
207 */
208
209 static struct cbq_class *
210 cbq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
211 {
212 struct cbq_sched_data *q = qdisc_priv(sch);
213 struct cbq_class *head = &q->link;
214 struct cbq_class **defmap;
215 struct cbq_class *cl = NULL;
216 u32 prio = skb->priority;
217 struct tcf_proto *fl;
218 struct tcf_result res;
219
220 /*
221 * Step 1. If skb->priority points to one of our classes, use it.
222 */
223 if (TC_H_MAJ(prio ^ sch->handle) == 0 &&
224 (cl = cbq_class_lookup(q, prio)) != NULL)
225 return cl;
226
227 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
228 for (;;) {
229 int result = 0;
230 defmap = head->defaults;
231
232 fl = rcu_dereference_bh(head->filter_list);
233 /*
234 * Step 2+n. Apply classifier.
235 */
236 result = tcf_classify(skb, fl, &res, true);
237 if (!fl || result < 0)
238 goto fallback;
239
240 cl = (void *)res.class;
241 if (!cl) {
242 if (TC_H_MAJ(res.classid))
243 cl = cbq_class_lookup(q, res.classid);
244 else if ((cl = defmap[res.classid & TC_PRIO_MAX]) == NULL)
245 cl = defmap[TC_PRIO_BESTEFFORT];
246
247 if (cl == NULL)
248 goto fallback;
249 }
250 if (cl->level >= head->level)
251 goto fallback;
252 #ifdef CONFIG_NET_CLS_ACT
253 switch (result) {
254 case TC_ACT_QUEUED:
255 case TC_ACT_STOLEN:
256 case TC_ACT_TRAP:
257 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
258 /* fall through */
259 case TC_ACT_SHOT:
260 return NULL;
261 case TC_ACT_RECLASSIFY:
262 return cbq_reclassify(skb, cl);
263 }
264 #endif
265 if (cl->level == 0)
266 return cl;
267
268 /*
269 * Step 3+n. If classifier selected a link sharing class,
270 * apply agency specific classifier.
271 * Repeat this procdure until we hit a leaf node.
272 */
273 head = cl;
274 }
275
276 fallback:
277 cl = head;
278
279 /*
280 * Step 4. No success...
281 */
282 if (TC_H_MAJ(prio) == 0 &&
283 !(cl = head->defaults[prio & TC_PRIO_MAX]) &&
284 !(cl = head->defaults[TC_PRIO_BESTEFFORT]))
285 return head;
286
287 return cl;
288 }
289
290 /*
291 * A packet has just been enqueued on the empty class.
292 * cbq_activate_class adds it to the tail of active class list
293 * of its priority band.
294 */
295
296 static inline void cbq_activate_class(struct cbq_class *cl)
297 {
298 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
299 int prio = cl->cpriority;
300 struct cbq_class *cl_tail;
301
302 cl_tail = q->active[prio];
303 q->active[prio] = cl;
304
305 if (cl_tail != NULL) {
306 cl->next_alive = cl_tail->next_alive;
307 cl_tail->next_alive = cl;
308 } else {
309 cl->next_alive = cl;
310 q->activemask |= (1<<prio);
311 }
312 }
313
314 /*
315 * Unlink class from active chain.
316 * Note that this same procedure is done directly in cbq_dequeue*
317 * during round-robin procedure.
318 */
319
320 static void cbq_deactivate_class(struct cbq_class *this)
321 {
322 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
323 int prio = this->cpriority;
324 struct cbq_class *cl;
325 struct cbq_class *cl_prev = q->active[prio];
326
327 do {
328 cl = cl_prev->next_alive;
329 if (cl == this) {
330 cl_prev->next_alive = cl->next_alive;
331 cl->next_alive = NULL;
332
333 if (cl == q->active[prio]) {
334 q->active[prio] = cl_prev;
335 if (cl == q->active[prio]) {
336 q->active[prio] = NULL;
337 q->activemask &= ~(1<<prio);
338 return;
339 }
340 }
341 return;
342 }
343 } while ((cl_prev = cl) != q->active[prio]);
344 }
345
346 static void
347 cbq_mark_toplevel(struct cbq_sched_data *q, struct cbq_class *cl)
348 {
349 int toplevel = q->toplevel;
350
351 if (toplevel > cl->level) {
352 psched_time_t now = psched_get_time();
353
354 do {
355 if (cl->undertime < now) {
356 q->toplevel = cl->level;
357 return;
358 }
359 } while ((cl = cl->borrow) != NULL && toplevel > cl->level);
360 }
361 }
362
363 static int
364 cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
365 struct sk_buff **to_free)
366 {
367 struct cbq_sched_data *q = qdisc_priv(sch);
368 int uninitialized_var(ret);
369 struct cbq_class *cl = cbq_classify(skb, sch, &ret);
370
371 #ifdef CONFIG_NET_CLS_ACT
372 q->rx_class = cl;
373 #endif
374 if (cl == NULL) {
375 if (ret & __NET_XMIT_BYPASS)
376 qdisc_qstats_drop(sch);
377 __qdisc_drop(skb, to_free);
378 return ret;
379 }
380
381 ret = qdisc_enqueue(skb, cl->q, to_free);
382 if (ret == NET_XMIT_SUCCESS) {
383 sch->q.qlen++;
384 cbq_mark_toplevel(q, cl);
385 if (!cl->next_alive)
386 cbq_activate_class(cl);
387 return ret;
388 }
389
390 if (net_xmit_drop_count(ret)) {
391 qdisc_qstats_drop(sch);
392 cbq_mark_toplevel(q, cl);
393 cl->qstats.drops++;
394 }
395 return ret;
396 }
397
398 /* Overlimit action: penalize leaf class by adding offtime */
399 static void cbq_overlimit(struct cbq_class *cl)
400 {
401 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
402 psched_tdiff_t delay = cl->undertime - q->now;
403
404 if (!cl->delayed) {
405 delay += cl->offtime;
406
407 /*
408 * Class goes to sleep, so that it will have no
409 * chance to work avgidle. Let's forgive it 8)
410 *
411 * BTW cbq-2.0 has a crap in this
412 * place, apparently they forgot to shift it by cl->ewma_log.
413 */
414 if (cl->avgidle < 0)
415 delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log);
416 if (cl->avgidle < cl->minidle)
417 cl->avgidle = cl->minidle;
418 if (delay <= 0)
419 delay = 1;
420 cl->undertime = q->now + delay;
421
422 cl->xstats.overactions++;
423 cl->delayed = 1;
424 }
425 if (q->wd_expires == 0 || q->wd_expires > delay)
426 q->wd_expires = delay;
427
428 /* Dirty work! We must schedule wakeups based on
429 * real available rate, rather than leaf rate,
430 * which may be tiny (even zero).
431 */
432 if (q->toplevel == TC_CBQ_MAXLEVEL) {
433 struct cbq_class *b;
434 psched_tdiff_t base_delay = q->wd_expires;
435
436 for (b = cl->borrow; b; b = b->borrow) {
437 delay = b->undertime - q->now;
438 if (delay < base_delay) {
439 if (delay <= 0)
440 delay = 1;
441 base_delay = delay;
442 }
443 }
444
445 q->wd_expires = base_delay;
446 }
447 }
448
449 static psched_tdiff_t cbq_undelay_prio(struct cbq_sched_data *q, int prio,
450 psched_time_t now)
451 {
452 struct cbq_class *cl;
453 struct cbq_class *cl_prev = q->active[prio];
454 psched_time_t sched = now;
455
456 if (cl_prev == NULL)
457 return 0;
458
459 do {
460 cl = cl_prev->next_alive;
461 if (now - cl->penalized > 0) {
462 cl_prev->next_alive = cl->next_alive;
463 cl->next_alive = NULL;
464 cl->cpriority = cl->priority;
465 cl->delayed = 0;
466 cbq_activate_class(cl);
467
468 if (cl == q->active[prio]) {
469 q->active[prio] = cl_prev;
470 if (cl == q->active[prio]) {
471 q->active[prio] = NULL;
472 return 0;
473 }
474 }
475
476 cl = cl_prev->next_alive;
477 } else if (sched - cl->penalized > 0)
478 sched = cl->penalized;
479 } while ((cl_prev = cl) != q->active[prio]);
480
481 return sched - now;
482 }
483
484 static enum hrtimer_restart cbq_undelay(struct hrtimer *timer)
485 {
486 struct cbq_sched_data *q = container_of(timer, struct cbq_sched_data,
487 delay_timer);
488 struct Qdisc *sch = q->watchdog.qdisc;
489 psched_time_t now;
490 psched_tdiff_t delay = 0;
491 unsigned int pmask;
492
493 now = psched_get_time();
494
495 pmask = q->pmask;
496 q->pmask = 0;
497
498 while (pmask) {
499 int prio = ffz(~pmask);
500 psched_tdiff_t tmp;
501
502 pmask &= ~(1<<prio);
503
504 tmp = cbq_undelay_prio(q, prio, now);
505 if (tmp > 0) {
506 q->pmask |= 1<<prio;
507 if (tmp < delay || delay == 0)
508 delay = tmp;
509 }
510 }
511
512 if (delay) {
513 ktime_t time;
514
515 time = 0;
516 time = ktime_add_ns(time, PSCHED_TICKS2NS(now + delay));
517 hrtimer_start(&q->delay_timer, time, HRTIMER_MODE_ABS_PINNED);
518 }
519
520 __netif_schedule(qdisc_root(sch));
521 return HRTIMER_NORESTART;
522 }
523
524 /*
525 * It is mission critical procedure.
526 *
527 * We "regenerate" toplevel cutoff, if transmitting class
528 * has backlog and it is not regulated. It is not part of
529 * original CBQ description, but looks more reasonable.
530 * Probably, it is wrong. This question needs further investigation.
531 */
532
533 static inline void
534 cbq_update_toplevel(struct cbq_sched_data *q, struct cbq_class *cl,
535 struct cbq_class *borrowed)
536 {
537 if (cl && q->toplevel >= borrowed->level) {
538 if (cl->q->q.qlen > 1) {
539 do {
540 if (borrowed->undertime == PSCHED_PASTPERFECT) {
541 q->toplevel = borrowed->level;
542 return;
543 }
544 } while ((borrowed = borrowed->borrow) != NULL);
545 }
546 #if 0
547 /* It is not necessary now. Uncommenting it
548 will save CPU cycles, but decrease fairness.
549 */
550 q->toplevel = TC_CBQ_MAXLEVEL;
551 #endif
552 }
553 }
554
555 static void
556 cbq_update(struct cbq_sched_data *q)
557 {
558 struct cbq_class *this = q->tx_class;
559 struct cbq_class *cl = this;
560 int len = q->tx_len;
561 psched_time_t now;
562
563 q->tx_class = NULL;
564 /* Time integrator. We calculate EOS time
565 * by adding expected packet transmission time.
566 */
567 now = q->now + L2T(&q->link, len);
568
569 for ( ; cl; cl = cl->share) {
570 long avgidle = cl->avgidle;
571 long idle;
572
573 cl->bstats.packets++;
574 cl->bstats.bytes += len;
575
576 /*
577 * (now - last) is total time between packet right edges.
578 * (last_pktlen/rate) is "virtual" busy time, so that
579 *
580 * idle = (now - last) - last_pktlen/rate
581 */
582
583 idle = now - cl->last;
584 if ((unsigned long)idle > 128*1024*1024) {
585 avgidle = cl->maxidle;
586 } else {
587 idle -= L2T(cl, len);
588
589 /* true_avgidle := (1-W)*true_avgidle + W*idle,
590 * where W=2^{-ewma_log}. But cl->avgidle is scaled:
591 * cl->avgidle == true_avgidle/W,
592 * hence:
593 */
594 avgidle += idle - (avgidle>>cl->ewma_log);
595 }
596
597 if (avgidle <= 0) {
598 /* Overlimit or at-limit */
599
600 if (avgidle < cl->minidle)
601 avgidle = cl->minidle;
602
603 cl->avgidle = avgidle;
604
605 /* Calculate expected time, when this class
606 * will be allowed to send.
607 * It will occur, when:
608 * (1-W)*true_avgidle + W*delay = 0, i.e.
609 * idle = (1/W - 1)*(-true_avgidle)
610 * or
611 * idle = (1 - W)*(-cl->avgidle);
612 */
613 idle = (-avgidle) - ((-avgidle) >> cl->ewma_log);
614
615 /*
616 * That is not all.
617 * To maintain the rate allocated to the class,
618 * we add to undertime virtual clock,
619 * necessary to complete transmitted packet.
620 * (len/phys_bandwidth has been already passed
621 * to the moment of cbq_update)
622 */
623
624 idle -= L2T(&q->link, len);
625 idle += L2T(cl, len);
626
627 cl->undertime = now + idle;
628 } else {
629 /* Underlimit */
630
631 cl->undertime = PSCHED_PASTPERFECT;
632 if (avgidle > cl->maxidle)
633 cl->avgidle = cl->maxidle;
634 else
635 cl->avgidle = avgidle;
636 }
637 if ((s64)(now - cl->last) > 0)
638 cl->last = now;
639 }
640
641 cbq_update_toplevel(q, this, q->tx_borrowed);
642 }
643
644 static inline struct cbq_class *
645 cbq_under_limit(struct cbq_class *cl)
646 {
647 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
648 struct cbq_class *this_cl = cl;
649
650 if (cl->tparent == NULL)
651 return cl;
652
653 if (cl->undertime == PSCHED_PASTPERFECT || q->now >= cl->undertime) {
654 cl->delayed = 0;
655 return cl;
656 }
657
658 do {
659 /* It is very suspicious place. Now overlimit
660 * action is generated for not bounded classes
661 * only if link is completely congested.
662 * Though it is in agree with ancestor-only paradigm,
663 * it looks very stupid. Particularly,
664 * it means that this chunk of code will either
665 * never be called or result in strong amplification
666 * of burstiness. Dangerous, silly, and, however,
667 * no another solution exists.
668 */
669 cl = cl->borrow;
670 if (!cl) {
671 this_cl->qstats.overlimits++;
672 cbq_overlimit(this_cl);
673 return NULL;
674 }
675 if (cl->level > q->toplevel)
676 return NULL;
677 } while (cl->undertime != PSCHED_PASTPERFECT && q->now < cl->undertime);
678
679 cl->delayed = 0;
680 return cl;
681 }
682
683 static inline struct sk_buff *
684 cbq_dequeue_prio(struct Qdisc *sch, int prio)
685 {
686 struct cbq_sched_data *q = qdisc_priv(sch);
687 struct cbq_class *cl_tail, *cl_prev, *cl;
688 struct sk_buff *skb;
689 int deficit;
690
691 cl_tail = cl_prev = q->active[prio];
692 cl = cl_prev->next_alive;
693
694 do {
695 deficit = 0;
696
697 /* Start round */
698 do {
699 struct cbq_class *borrow = cl;
700
701 if (cl->q->q.qlen &&
702 (borrow = cbq_under_limit(cl)) == NULL)
703 goto skip_class;
704
705 if (cl->deficit <= 0) {
706 /* Class exhausted its allotment per
707 * this round. Switch to the next one.
708 */
709 deficit = 1;
710 cl->deficit += cl->quantum;
711 goto next_class;
712 }
713
714 skb = cl->q->dequeue(cl->q);
715
716 /* Class did not give us any skb :-(
717 * It could occur even if cl->q->q.qlen != 0
718 * f.e. if cl->q == "tbf"
719 */
720 if (skb == NULL)
721 goto skip_class;
722
723 cl->deficit -= qdisc_pkt_len(skb);
724 q->tx_class = cl;
725 q->tx_borrowed = borrow;
726 if (borrow != cl) {
727 #ifndef CBQ_XSTATS_BORROWS_BYTES
728 borrow->xstats.borrows++;
729 cl->xstats.borrows++;
730 #else
731 borrow->xstats.borrows += qdisc_pkt_len(skb);
732 cl->xstats.borrows += qdisc_pkt_len(skb);
733 #endif
734 }
735 q->tx_len = qdisc_pkt_len(skb);
736
737 if (cl->deficit <= 0) {
738 q->active[prio] = cl;
739 cl = cl->next_alive;
740 cl->deficit += cl->quantum;
741 }
742 return skb;
743
744 skip_class:
745 if (cl->q->q.qlen == 0 || prio != cl->cpriority) {
746 /* Class is empty or penalized.
747 * Unlink it from active chain.
748 */
749 cl_prev->next_alive = cl->next_alive;
750 cl->next_alive = NULL;
751
752 /* Did cl_tail point to it? */
753 if (cl == cl_tail) {
754 /* Repair it! */
755 cl_tail = cl_prev;
756
757 /* Was it the last class in this band? */
758 if (cl == cl_tail) {
759 /* Kill the band! */
760 q->active[prio] = NULL;
761 q->activemask &= ~(1<<prio);
762 if (cl->q->q.qlen)
763 cbq_activate_class(cl);
764 return NULL;
765 }
766
767 q->active[prio] = cl_tail;
768 }
769 if (cl->q->q.qlen)
770 cbq_activate_class(cl);
771
772 cl = cl_prev;
773 }
774
775 next_class:
776 cl_prev = cl;
777 cl = cl->next_alive;
778 } while (cl_prev != cl_tail);
779 } while (deficit);
780
781 q->active[prio] = cl_prev;
782
783 return NULL;
784 }
785
786 static inline struct sk_buff *
787 cbq_dequeue_1(struct Qdisc *sch)
788 {
789 struct cbq_sched_data *q = qdisc_priv(sch);
790 struct sk_buff *skb;
791 unsigned int activemask;
792
793 activemask = q->activemask & 0xFF;
794 while (activemask) {
795 int prio = ffz(~activemask);
796 activemask &= ~(1<<prio);
797 skb = cbq_dequeue_prio(sch, prio);
798 if (skb)
799 return skb;
800 }
801 return NULL;
802 }
803
804 static struct sk_buff *
805 cbq_dequeue(struct Qdisc *sch)
806 {
807 struct sk_buff *skb;
808 struct cbq_sched_data *q = qdisc_priv(sch);
809 psched_time_t now;
810
811 now = psched_get_time();
812
813 if (q->tx_class)
814 cbq_update(q);
815
816 q->now = now;
817
818 for (;;) {
819 q->wd_expires = 0;
820
821 skb = cbq_dequeue_1(sch);
822 if (skb) {
823 qdisc_bstats_update(sch, skb);
824 sch->q.qlen--;
825 return skb;
826 }
827
828 /* All the classes are overlimit.
829 *
830 * It is possible, if:
831 *
832 * 1. Scheduler is empty.
833 * 2. Toplevel cutoff inhibited borrowing.
834 * 3. Root class is overlimit.
835 *
836 * Reset 2d and 3d conditions and retry.
837 *
838 * Note, that NS and cbq-2.0 are buggy, peeking
839 * an arbitrary class is appropriate for ancestor-only
840 * sharing, but not for toplevel algorithm.
841 *
842 * Our version is better, but slower, because it requires
843 * two passes, but it is unavoidable with top-level sharing.
844 */
845
846 if (q->toplevel == TC_CBQ_MAXLEVEL &&
847 q->link.undertime == PSCHED_PASTPERFECT)
848 break;
849
850 q->toplevel = TC_CBQ_MAXLEVEL;
851 q->link.undertime = PSCHED_PASTPERFECT;
852 }
853
854 /* No packets in scheduler or nobody wants to give them to us :-(
855 * Sigh... start watchdog timer in the last case.
856 */
857
858 if (sch->q.qlen) {
859 qdisc_qstats_overlimit(sch);
860 if (q->wd_expires)
861 qdisc_watchdog_schedule(&q->watchdog,
862 now + q->wd_expires);
863 }
864 return NULL;
865 }
866
867 /* CBQ class maintanance routines */
868
869 static void cbq_adjust_levels(struct cbq_class *this)
870 {
871 if (this == NULL)
872 return;
873
874 do {
875 int level = 0;
876 struct cbq_class *cl;
877
878 cl = this->children;
879 if (cl) {
880 do {
881 if (cl->level > level)
882 level = cl->level;
883 } while ((cl = cl->sibling) != this->children);
884 }
885 this->level = level + 1;
886 } while ((this = this->tparent) != NULL);
887 }
888
889 static void cbq_normalize_quanta(struct cbq_sched_data *q, int prio)
890 {
891 struct cbq_class *cl;
892 unsigned int h;
893
894 if (q->quanta[prio] == 0)
895 return;
896
897 for (h = 0; h < q->clhash.hashsize; h++) {
898 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
899 /* BUGGGG... Beware! This expression suffer of
900 * arithmetic overflows!
901 */
902 if (cl->priority == prio) {
903 cl->quantum = (cl->weight*cl->allot*q->nclasses[prio])/
904 q->quanta[prio];
905 }
906 if (cl->quantum <= 0 ||
907 cl->quantum > 32*qdisc_dev(cl->qdisc)->mtu) {
908 pr_warn("CBQ: class %08x has bad quantum==%ld, repaired.\n",
909 cl->common.classid, cl->quantum);
910 cl->quantum = qdisc_dev(cl->qdisc)->mtu/2 + 1;
911 }
912 }
913 }
914 }
915
916 static void cbq_sync_defmap(struct cbq_class *cl)
917 {
918 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
919 struct cbq_class *split = cl->split;
920 unsigned int h;
921 int i;
922
923 if (split == NULL)
924 return;
925
926 for (i = 0; i <= TC_PRIO_MAX; i++) {
927 if (split->defaults[i] == cl && !(cl->defmap & (1<<i)))
928 split->defaults[i] = NULL;
929 }
930
931 for (i = 0; i <= TC_PRIO_MAX; i++) {
932 int level = split->level;
933
934 if (split->defaults[i])
935 continue;
936
937 for (h = 0; h < q->clhash.hashsize; h++) {
938 struct cbq_class *c;
939
940 hlist_for_each_entry(c, &q->clhash.hash[h],
941 common.hnode) {
942 if (c->split == split && c->level < level &&
943 c->defmap & (1<<i)) {
944 split->defaults[i] = c;
945 level = c->level;
946 }
947 }
948 }
949 }
950 }
951
952 static void cbq_change_defmap(struct cbq_class *cl, u32 splitid, u32 def, u32 mask)
953 {
954 struct cbq_class *split = NULL;
955
956 if (splitid == 0) {
957 split = cl->split;
958 if (!split)
959 return;
960 splitid = split->common.classid;
961 }
962
963 if (split == NULL || split->common.classid != splitid) {
964 for (split = cl->tparent; split; split = split->tparent)
965 if (split->common.classid == splitid)
966 break;
967 }
968
969 if (split == NULL)
970 return;
971
972 if (cl->split != split) {
973 cl->defmap = 0;
974 cbq_sync_defmap(cl);
975 cl->split = split;
976 cl->defmap = def & mask;
977 } else
978 cl->defmap = (cl->defmap & ~mask) | (def & mask);
979
980 cbq_sync_defmap(cl);
981 }
982
983 static void cbq_unlink_class(struct cbq_class *this)
984 {
985 struct cbq_class *cl, **clp;
986 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
987
988 qdisc_class_hash_remove(&q->clhash, &this->common);
989
990 if (this->tparent) {
991 clp = &this->sibling;
992 cl = *clp;
993 do {
994 if (cl == this) {
995 *clp = cl->sibling;
996 break;
997 }
998 clp = &cl->sibling;
999 } while ((cl = *clp) != this->sibling);
1000
1001 if (this->tparent->children == this) {
1002 this->tparent->children = this->sibling;
1003 if (this->sibling == this)
1004 this->tparent->children = NULL;
1005 }
1006 } else {
1007 WARN_ON(this->sibling != this);
1008 }
1009 }
1010
1011 static void cbq_link_class(struct cbq_class *this)
1012 {
1013 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
1014 struct cbq_class *parent = this->tparent;
1015
1016 this->sibling = this;
1017 qdisc_class_hash_insert(&q->clhash, &this->common);
1018
1019 if (parent == NULL)
1020 return;
1021
1022 if (parent->children == NULL) {
1023 parent->children = this;
1024 } else {
1025 this->sibling = parent->children->sibling;
1026 parent->children->sibling = this;
1027 }
1028 }
1029
1030 static void
1031 cbq_reset(struct Qdisc *sch)
1032 {
1033 struct cbq_sched_data *q = qdisc_priv(sch);
1034 struct cbq_class *cl;
1035 int prio;
1036 unsigned int h;
1037
1038 q->activemask = 0;
1039 q->pmask = 0;
1040 q->tx_class = NULL;
1041 q->tx_borrowed = NULL;
1042 qdisc_watchdog_cancel(&q->watchdog);
1043 hrtimer_cancel(&q->delay_timer);
1044 q->toplevel = TC_CBQ_MAXLEVEL;
1045 q->now = psched_get_time();
1046
1047 for (prio = 0; prio <= TC_CBQ_MAXPRIO; prio++)
1048 q->active[prio] = NULL;
1049
1050 for (h = 0; h < q->clhash.hashsize; h++) {
1051 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
1052 qdisc_reset(cl->q);
1053
1054 cl->next_alive = NULL;
1055 cl->undertime = PSCHED_PASTPERFECT;
1056 cl->avgidle = cl->maxidle;
1057 cl->deficit = cl->quantum;
1058 cl->cpriority = cl->priority;
1059 }
1060 }
1061 sch->q.qlen = 0;
1062 }
1063
1064
1065 static int cbq_set_lss(struct cbq_class *cl, struct tc_cbq_lssopt *lss)
1066 {
1067 if (lss->change & TCF_CBQ_LSS_FLAGS) {
1068 cl->share = (lss->flags & TCF_CBQ_LSS_ISOLATED) ? NULL : cl->tparent;
1069 cl->borrow = (lss->flags & TCF_CBQ_LSS_BOUNDED) ? NULL : cl->tparent;
1070 }
1071 if (lss->change & TCF_CBQ_LSS_EWMA)
1072 cl->ewma_log = lss->ewma_log;
1073 if (lss->change & TCF_CBQ_LSS_AVPKT)
1074 cl->avpkt = lss->avpkt;
1075 if (lss->change & TCF_CBQ_LSS_MINIDLE)
1076 cl->minidle = -(long)lss->minidle;
1077 if (lss->change & TCF_CBQ_LSS_MAXIDLE) {
1078 cl->maxidle = lss->maxidle;
1079 cl->avgidle = lss->maxidle;
1080 }
1081 if (lss->change & TCF_CBQ_LSS_OFFTIME)
1082 cl->offtime = lss->offtime;
1083 return 0;
1084 }
1085
1086 static void cbq_rmprio(struct cbq_sched_data *q, struct cbq_class *cl)
1087 {
1088 q->nclasses[cl->priority]--;
1089 q->quanta[cl->priority] -= cl->weight;
1090 cbq_normalize_quanta(q, cl->priority);
1091 }
1092
1093 static void cbq_addprio(struct cbq_sched_data *q, struct cbq_class *cl)
1094 {
1095 q->nclasses[cl->priority]++;
1096 q->quanta[cl->priority] += cl->weight;
1097 cbq_normalize_quanta(q, cl->priority);
1098 }
1099
1100 static int cbq_set_wrr(struct cbq_class *cl, struct tc_cbq_wrropt *wrr)
1101 {
1102 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
1103
1104 if (wrr->allot)
1105 cl->allot = wrr->allot;
1106 if (wrr->weight)
1107 cl->weight = wrr->weight;
1108 if (wrr->priority) {
1109 cl->priority = wrr->priority - 1;
1110 cl->cpriority = cl->priority;
1111 if (cl->priority >= cl->priority2)
1112 cl->priority2 = TC_CBQ_MAXPRIO - 1;
1113 }
1114
1115 cbq_addprio(q, cl);
1116 return 0;
1117 }
1118
1119 static int cbq_set_fopt(struct cbq_class *cl, struct tc_cbq_fopt *fopt)
1120 {
1121 cbq_change_defmap(cl, fopt->split, fopt->defmap, fopt->defchange);
1122 return 0;
1123 }
1124
1125 static const struct nla_policy cbq_policy[TCA_CBQ_MAX + 1] = {
1126 [TCA_CBQ_LSSOPT] = { .len = sizeof(struct tc_cbq_lssopt) },
1127 [TCA_CBQ_WRROPT] = { .len = sizeof(struct tc_cbq_wrropt) },
1128 [TCA_CBQ_FOPT] = { .len = sizeof(struct tc_cbq_fopt) },
1129 [TCA_CBQ_OVL_STRATEGY] = { .len = sizeof(struct tc_cbq_ovl) },
1130 [TCA_CBQ_RATE] = { .len = sizeof(struct tc_ratespec) },
1131 [TCA_CBQ_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
1132 [TCA_CBQ_POLICE] = { .len = sizeof(struct tc_cbq_police) },
1133 };
1134
1135 static int cbq_init(struct Qdisc *sch, struct nlattr *opt,
1136 struct netlink_ext_ack *extack)
1137 {
1138 struct cbq_sched_data *q = qdisc_priv(sch);
1139 struct nlattr *tb[TCA_CBQ_MAX + 1];
1140 struct tc_ratespec *r;
1141 int err;
1142
1143 qdisc_watchdog_init(&q->watchdog, sch);
1144 hrtimer_init(&q->delay_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
1145 q->delay_timer.function = cbq_undelay;
1146
1147 if (!opt) {
1148 NL_SET_ERR_MSG(extack, "CBQ options are required for this operation");
1149 return -EINVAL;
1150 }
1151
1152 err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy, extack);
1153 if (err < 0)
1154 return err;
1155
1156 if (!tb[TCA_CBQ_RTAB] || !tb[TCA_CBQ_RATE]) {
1157 NL_SET_ERR_MSG(extack, "Rate specification missing or incomplete");
1158 return -EINVAL;
1159 }
1160
1161 r = nla_data(tb[TCA_CBQ_RATE]);
1162
1163 q->link.R_tab = qdisc_get_rtab(r, tb[TCA_CBQ_RTAB], extack);
1164 if (!q->link.R_tab)
1165 return -EINVAL;
1166
1167 err = tcf_block_get(&q->link.block, &q->link.filter_list, sch, extack);
1168 if (err)
1169 goto put_rtab;
1170
1171 err = qdisc_class_hash_init(&q->clhash);
1172 if (err < 0)
1173 goto put_block;
1174
1175 q->link.sibling = &q->link;
1176 q->link.common.classid = sch->handle;
1177 q->link.qdisc = sch;
1178 q->link.q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1179 sch->handle, NULL);
1180 if (!q->link.q)
1181 q->link.q = &noop_qdisc;
1182 else
1183 qdisc_hash_add(q->link.q, true);
1184
1185 q->link.priority = TC_CBQ_MAXPRIO - 1;
1186 q->link.priority2 = TC_CBQ_MAXPRIO - 1;
1187 q->link.cpriority = TC_CBQ_MAXPRIO - 1;
1188 q->link.allot = psched_mtu(qdisc_dev(sch));
1189 q->link.quantum = q->link.allot;
1190 q->link.weight = q->link.R_tab->rate.rate;
1191
1192 q->link.ewma_log = TC_CBQ_DEF_EWMA;
1193 q->link.avpkt = q->link.allot/2;
1194 q->link.minidle = -0x7FFFFFFF;
1195
1196 q->toplevel = TC_CBQ_MAXLEVEL;
1197 q->now = psched_get_time();
1198
1199 cbq_link_class(&q->link);
1200
1201 if (tb[TCA_CBQ_LSSOPT])
1202 cbq_set_lss(&q->link, nla_data(tb[TCA_CBQ_LSSOPT]));
1203
1204 cbq_addprio(q, &q->link);
1205 return 0;
1206
1207 put_block:
1208 tcf_block_put(q->link.block);
1209
1210 put_rtab:
1211 qdisc_put_rtab(q->link.R_tab);
1212 return err;
1213 }
1214
1215 static int cbq_dump_rate(struct sk_buff *skb, struct cbq_class *cl)
1216 {
1217 unsigned char *b = skb_tail_pointer(skb);
1218
1219 if (nla_put(skb, TCA_CBQ_RATE, sizeof(cl->R_tab->rate), &cl->R_tab->rate))
1220 goto nla_put_failure;
1221 return skb->len;
1222
1223 nla_put_failure:
1224 nlmsg_trim(skb, b);
1225 return -1;
1226 }
1227
1228 static int cbq_dump_lss(struct sk_buff *skb, struct cbq_class *cl)
1229 {
1230 unsigned char *b = skb_tail_pointer(skb);
1231 struct tc_cbq_lssopt opt;
1232
1233 opt.flags = 0;
1234 if (cl->borrow == NULL)
1235 opt.flags |= TCF_CBQ_LSS_BOUNDED;
1236 if (cl->share == NULL)
1237 opt.flags |= TCF_CBQ_LSS_ISOLATED;
1238 opt.ewma_log = cl->ewma_log;
1239 opt.level = cl->level;
1240 opt.avpkt = cl->avpkt;
1241 opt.maxidle = cl->maxidle;
1242 opt.minidle = (u32)(-cl->minidle);
1243 opt.offtime = cl->offtime;
1244 opt.change = ~0;
1245 if (nla_put(skb, TCA_CBQ_LSSOPT, sizeof(opt), &opt))
1246 goto nla_put_failure;
1247 return skb->len;
1248
1249 nla_put_failure:
1250 nlmsg_trim(skb, b);
1251 return -1;
1252 }
1253
1254 static int cbq_dump_wrr(struct sk_buff *skb, struct cbq_class *cl)
1255 {
1256 unsigned char *b = skb_tail_pointer(skb);
1257 struct tc_cbq_wrropt opt;
1258
1259 memset(&opt, 0, sizeof(opt));
1260 opt.flags = 0;
1261 opt.allot = cl->allot;
1262 opt.priority = cl->priority + 1;
1263 opt.cpriority = cl->cpriority + 1;
1264 opt.weight = cl->weight;
1265 if (nla_put(skb, TCA_CBQ_WRROPT, sizeof(opt), &opt))
1266 goto nla_put_failure;
1267 return skb->len;
1268
1269 nla_put_failure:
1270 nlmsg_trim(skb, b);
1271 return -1;
1272 }
1273
1274 static int cbq_dump_fopt(struct sk_buff *skb, struct cbq_class *cl)
1275 {
1276 unsigned char *b = skb_tail_pointer(skb);
1277 struct tc_cbq_fopt opt;
1278
1279 if (cl->split || cl->defmap) {
1280 opt.split = cl->split ? cl->split->common.classid : 0;
1281 opt.defmap = cl->defmap;
1282 opt.defchange = ~0;
1283 if (nla_put(skb, TCA_CBQ_FOPT, sizeof(opt), &opt))
1284 goto nla_put_failure;
1285 }
1286 return skb->len;
1287
1288 nla_put_failure:
1289 nlmsg_trim(skb, b);
1290 return -1;
1291 }
1292
1293 static int cbq_dump_attr(struct sk_buff *skb, struct cbq_class *cl)
1294 {
1295 if (cbq_dump_lss(skb, cl) < 0 ||
1296 cbq_dump_rate(skb, cl) < 0 ||
1297 cbq_dump_wrr(skb, cl) < 0 ||
1298 cbq_dump_fopt(skb, cl) < 0)
1299 return -1;
1300 return 0;
1301 }
1302
1303 static int cbq_dump(struct Qdisc *sch, struct sk_buff *skb)
1304 {
1305 struct cbq_sched_data *q = qdisc_priv(sch);
1306 struct nlattr *nest;
1307
1308 nest = nla_nest_start(skb, TCA_OPTIONS);
1309 if (nest == NULL)
1310 goto nla_put_failure;
1311 if (cbq_dump_attr(skb, &q->link) < 0)
1312 goto nla_put_failure;
1313 return nla_nest_end(skb, nest);
1314
1315 nla_put_failure:
1316 nla_nest_cancel(skb, nest);
1317 return -1;
1318 }
1319
1320 static int
1321 cbq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
1322 {
1323 struct cbq_sched_data *q = qdisc_priv(sch);
1324
1325 q->link.xstats.avgidle = q->link.avgidle;
1326 return gnet_stats_copy_app(d, &q->link.xstats, sizeof(q->link.xstats));
1327 }
1328
1329 static int
1330 cbq_dump_class(struct Qdisc *sch, unsigned long arg,
1331 struct sk_buff *skb, struct tcmsg *tcm)
1332 {
1333 struct cbq_class *cl = (struct cbq_class *)arg;
1334 struct nlattr *nest;
1335
1336 if (cl->tparent)
1337 tcm->tcm_parent = cl->tparent->common.classid;
1338 else
1339 tcm->tcm_parent = TC_H_ROOT;
1340 tcm->tcm_handle = cl->common.classid;
1341 tcm->tcm_info = cl->q->handle;
1342
1343 nest = nla_nest_start(skb, TCA_OPTIONS);
1344 if (nest == NULL)
1345 goto nla_put_failure;
1346 if (cbq_dump_attr(skb, cl) < 0)
1347 goto nla_put_failure;
1348 return nla_nest_end(skb, nest);
1349
1350 nla_put_failure:
1351 nla_nest_cancel(skb, nest);
1352 return -1;
1353 }
1354
1355 static int
1356 cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1357 struct gnet_dump *d)
1358 {
1359 struct cbq_sched_data *q = qdisc_priv(sch);
1360 struct cbq_class *cl = (struct cbq_class *)arg;
1361
1362 cl->xstats.avgidle = cl->avgidle;
1363 cl->xstats.undertime = 0;
1364
1365 if (cl->undertime != PSCHED_PASTPERFECT)
1366 cl->xstats.undertime = cl->undertime - q->now;
1367
1368 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
1369 d, NULL, &cl->bstats) < 0 ||
1370 gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
1371 gnet_stats_copy_queue(d, NULL, &cl->qstats, cl->q->q.qlen) < 0)
1372 return -1;
1373
1374 return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));
1375 }
1376
1377 static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1378 struct Qdisc **old, struct netlink_ext_ack *extack)
1379 {
1380 struct cbq_class *cl = (struct cbq_class *)arg;
1381
1382 if (new == NULL) {
1383 new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1384 cl->common.classid, extack);
1385 if (new == NULL)
1386 return -ENOBUFS;
1387 }
1388
1389 *old = qdisc_replace(sch, new, &cl->q);
1390 return 0;
1391 }
1392
1393 static struct Qdisc *cbq_leaf(struct Qdisc *sch, unsigned long arg)
1394 {
1395 struct cbq_class *cl = (struct cbq_class *)arg;
1396
1397 return cl->q;
1398 }
1399
1400 static void cbq_qlen_notify(struct Qdisc *sch, unsigned long arg)
1401 {
1402 struct cbq_class *cl = (struct cbq_class *)arg;
1403
1404 cbq_deactivate_class(cl);
1405 }
1406
1407 static unsigned long cbq_find(struct Qdisc *sch, u32 classid)
1408 {
1409 struct cbq_sched_data *q = qdisc_priv(sch);
1410
1411 return (unsigned long)cbq_class_lookup(q, classid);
1412 }
1413
1414 static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl)
1415 {
1416 struct cbq_sched_data *q = qdisc_priv(sch);
1417
1418 WARN_ON(cl->filters);
1419
1420 tcf_block_put(cl->block);
1421 qdisc_destroy(cl->q);
1422 qdisc_put_rtab(cl->R_tab);
1423 gen_kill_estimator(&cl->rate_est);
1424 if (cl != &q->link)
1425 kfree(cl);
1426 }
1427
1428 static void cbq_destroy(struct Qdisc *sch)
1429 {
1430 struct cbq_sched_data *q = qdisc_priv(sch);
1431 struct hlist_node *next;
1432 struct cbq_class *cl;
1433 unsigned int h;
1434
1435 #ifdef CONFIG_NET_CLS_ACT
1436 q->rx_class = NULL;
1437 #endif
1438 /*
1439 * Filters must be destroyed first because we don't destroy the
1440 * classes from root to leafs which means that filters can still
1441 * be bound to classes which have been destroyed already. --TGR '04
1442 */
1443 for (h = 0; h < q->clhash.hashsize; h++) {
1444 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
1445 tcf_block_put(cl->block);
1446 cl->block = NULL;
1447 }
1448 }
1449 for (h = 0; h < q->clhash.hashsize; h++) {
1450 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[h],
1451 common.hnode)
1452 cbq_destroy_class(sch, cl);
1453 }
1454 qdisc_class_hash_destroy(&q->clhash);
1455 }
1456
1457 static int
1458 cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **tca,
1459 unsigned long *arg, struct netlink_ext_ack *extack)
1460 {
1461 int err;
1462 struct cbq_sched_data *q = qdisc_priv(sch);
1463 struct cbq_class *cl = (struct cbq_class *)*arg;
1464 struct nlattr *opt = tca[TCA_OPTIONS];
1465 struct nlattr *tb[TCA_CBQ_MAX + 1];
1466 struct cbq_class *parent;
1467 struct qdisc_rate_table *rtab = NULL;
1468
1469 if (!opt) {
1470 NL_SET_ERR_MSG(extack, "Mandatory qdisc options missing");
1471 return -EINVAL;
1472 }
1473
1474 err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy, extack);
1475 if (err < 0)
1476 return err;
1477
1478 if (tb[TCA_CBQ_OVL_STRATEGY] || tb[TCA_CBQ_POLICE]) {
1479 NL_SET_ERR_MSG(extack, "Neither overlimit strategy nor policing attributes can be used for changing class params");
1480 return -EOPNOTSUPP;
1481 }
1482
1483 if (cl) {
1484 /* Check parent */
1485 if (parentid) {
1486 if (cl->tparent &&
1487 cl->tparent->common.classid != parentid) {
1488 NL_SET_ERR_MSG(extack, "Invalid parent id");
1489 return -EINVAL;
1490 }
1491 if (!cl->tparent && parentid != TC_H_ROOT) {
1492 NL_SET_ERR_MSG(extack, "Parent must be root");
1493 return -EINVAL;
1494 }
1495 }
1496
1497 if (tb[TCA_CBQ_RATE]) {
1498 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]),
1499 tb[TCA_CBQ_RTAB], extack);
1500 if (rtab == NULL)
1501 return -EINVAL;
1502 }
1503
1504 if (tca[TCA_RATE]) {
1505 err = gen_replace_estimator(&cl->bstats, NULL,
1506 &cl->rate_est,
1507 NULL,
1508 qdisc_root_sleeping_running(sch),
1509 tca[TCA_RATE]);
1510 if (err) {
1511 NL_SET_ERR_MSG(extack, "Failed to replace specified rate estimator");
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] || !tb[TCA_CBQ_RATE] || !tb[TCA_CBQ_LSSOPT]) {
1551 NL_SET_ERR_MSG(extack, "One of the following attributes MUST be specified: WRR, rate or link sharing");
1552 return -EINVAL;
1553 }
1554
1555 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]), tb[TCA_CBQ_RTAB],
1556 extack);
1557 if (rtab == NULL)
1558 return -EINVAL;
1559
1560 if (classid) {
1561 err = -EINVAL;
1562 if (TC_H_MAJ(classid ^ sch->handle) ||
1563 cbq_class_lookup(q, classid)) {
1564 NL_SET_ERR_MSG(extack, "Specified class not found");
1565 goto failure;
1566 }
1567 } else {
1568 int i;
1569 classid = TC_H_MAKE(sch->handle, 0x8000);
1570
1571 for (i = 0; i < 0x8000; i++) {
1572 if (++q->hgenerator >= 0x8000)
1573 q->hgenerator = 1;
1574 if (cbq_class_lookup(q, classid|q->hgenerator) == NULL)
1575 break;
1576 }
1577 err = -ENOSR;
1578 if (i >= 0x8000) {
1579 NL_SET_ERR_MSG(extack, "Unable to generate classid");
1580 goto failure;
1581 }
1582 classid = classid|q->hgenerator;
1583 }
1584
1585 parent = &q->link;
1586 if (parentid) {
1587 parent = cbq_class_lookup(q, parentid);
1588 err = -EINVAL;
1589 if (!parent) {
1590 NL_SET_ERR_MSG(extack, "Failed to find parentid");
1591 goto failure;
1592 }
1593 }
1594
1595 err = -ENOBUFS;
1596 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
1597 if (cl == NULL)
1598 goto failure;
1599
1600 err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack);
1601 if (err) {
1602 kfree(cl);
1603 return err;
1604 }
1605
1606 if (tca[TCA_RATE]) {
1607 err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
1608 NULL,
1609 qdisc_root_sleeping_running(sch),
1610 tca[TCA_RATE]);
1611 if (err) {
1612 NL_SET_ERR_MSG(extack, "Couldn't create new estimator");
1613 tcf_block_put(cl->block);
1614 kfree(cl);
1615 goto failure;
1616 }
1617 }
1618
1619 cl->R_tab = rtab;
1620 rtab = NULL;
1621 cl->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid,
1622 NULL);
1623 if (!cl->q)
1624 cl->q = &noop_qdisc;
1625 else
1626 qdisc_hash_add(cl->q, true);
1627
1628 cl->common.classid = classid;
1629 cl->tparent = parent;
1630 cl->qdisc = sch;
1631 cl->allot = parent->allot;
1632 cl->quantum = cl->allot;
1633 cl->weight = cl->R_tab->rate.rate;
1634
1635 sch_tree_lock(sch);
1636 cbq_link_class(cl);
1637 cl->borrow = cl->tparent;
1638 if (cl->tparent != &q->link)
1639 cl->share = cl->tparent;
1640 cbq_adjust_levels(parent);
1641 cl->minidle = -0x7FFFFFFF;
1642 cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
1643 cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
1644 if (cl->ewma_log == 0)
1645 cl->ewma_log = q->link.ewma_log;
1646 if (cl->maxidle == 0)
1647 cl->maxidle = q->link.maxidle;
1648 if (cl->avpkt == 0)
1649 cl->avpkt = q->link.avpkt;
1650 if (tb[TCA_CBQ_FOPT])
1651 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
1652 sch_tree_unlock(sch);
1653
1654 qdisc_class_hash_grow(sch, &q->clhash);
1655
1656 *arg = (unsigned long)cl;
1657 return 0;
1658
1659 failure:
1660 qdisc_put_rtab(rtab);
1661 return err;
1662 }
1663
1664 static int cbq_delete(struct Qdisc *sch, unsigned long arg)
1665 {
1666 struct cbq_sched_data *q = qdisc_priv(sch);
1667 struct cbq_class *cl = (struct cbq_class *)arg;
1668 unsigned int qlen, backlog;
1669
1670 if (cl->filters || cl->children || cl == &q->link)
1671 return -EBUSY;
1672
1673 sch_tree_lock(sch);
1674
1675 qlen = cl->q->q.qlen;
1676 backlog = cl->q->qstats.backlog;
1677 qdisc_reset(cl->q);
1678 qdisc_tree_reduce_backlog(cl->q, qlen, backlog);
1679
1680 if (cl->next_alive)
1681 cbq_deactivate_class(cl);
1682
1683 if (q->tx_borrowed == cl)
1684 q->tx_borrowed = q->tx_class;
1685 if (q->tx_class == cl) {
1686 q->tx_class = NULL;
1687 q->tx_borrowed = NULL;
1688 }
1689 #ifdef CONFIG_NET_CLS_ACT
1690 if (q->rx_class == cl)
1691 q->rx_class = NULL;
1692 #endif
1693
1694 cbq_unlink_class(cl);
1695 cbq_adjust_levels(cl->tparent);
1696 cl->defmap = 0;
1697 cbq_sync_defmap(cl);
1698
1699 cbq_rmprio(q, cl);
1700 sch_tree_unlock(sch);
1701
1702 cbq_destroy_class(sch, cl);
1703 return 0;
1704 }
1705
1706 static struct tcf_block *cbq_tcf_block(struct Qdisc *sch, unsigned long arg,
1707 struct netlink_ext_ack *extack)
1708 {
1709 struct cbq_sched_data *q = qdisc_priv(sch);
1710 struct cbq_class *cl = (struct cbq_class *)arg;
1711
1712 if (cl == NULL)
1713 cl = &q->link;
1714
1715 return cl->block;
1716 }
1717
1718 static unsigned long cbq_bind_filter(struct Qdisc *sch, unsigned long parent,
1719 u32 classid)
1720 {
1721 struct cbq_sched_data *q = qdisc_priv(sch);
1722 struct cbq_class *p = (struct cbq_class *)parent;
1723 struct cbq_class *cl = cbq_class_lookup(q, classid);
1724
1725 if (cl) {
1726 if (p && p->level <= cl->level)
1727 return 0;
1728 cl->filters++;
1729 return (unsigned long)cl;
1730 }
1731 return 0;
1732 }
1733
1734 static void cbq_unbind_filter(struct Qdisc *sch, unsigned long arg)
1735 {
1736 struct cbq_class *cl = (struct cbq_class *)arg;
1737
1738 cl->filters--;
1739 }
1740
1741 static void cbq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1742 {
1743 struct cbq_sched_data *q = qdisc_priv(sch);
1744 struct cbq_class *cl;
1745 unsigned int h;
1746
1747 if (arg->stop)
1748 return;
1749
1750 for (h = 0; h < q->clhash.hashsize; h++) {
1751 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
1752 if (arg->count < arg->skip) {
1753 arg->count++;
1754 continue;
1755 }
1756 if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
1757 arg->stop = 1;
1758 return;
1759 }
1760 arg->count++;
1761 }
1762 }
1763 }
1764
1765 static const struct Qdisc_class_ops cbq_class_ops = {
1766 .graft = cbq_graft,
1767 .leaf = cbq_leaf,
1768 .qlen_notify = cbq_qlen_notify,
1769 .find = cbq_find,
1770 .change = cbq_change_class,
1771 .delete = cbq_delete,
1772 .walk = cbq_walk,
1773 .tcf_block = cbq_tcf_block,
1774 .bind_tcf = cbq_bind_filter,
1775 .unbind_tcf = cbq_unbind_filter,
1776 .dump = cbq_dump_class,
1777 .dump_stats = cbq_dump_class_stats,
1778 };
1779
1780 static struct Qdisc_ops cbq_qdisc_ops __read_mostly = {
1781 .next = NULL,
1782 .cl_ops = &cbq_class_ops,
1783 .id = "cbq",
1784 .priv_size = sizeof(struct cbq_sched_data),
1785 .enqueue = cbq_enqueue,
1786 .dequeue = cbq_dequeue,
1787 .peek = qdisc_peek_dequeued,
1788 .init = cbq_init,
1789 .reset = cbq_reset,
1790 .destroy = cbq_destroy,
1791 .change = NULL,
1792 .dump = cbq_dump,
1793 .dump_stats = cbq_dump_stats,
1794 .owner = THIS_MODULE,
1795 };
1796
1797 static int __init cbq_module_init(void)
1798 {
1799 return register_qdisc(&cbq_qdisc_ops);
1800 }
1801 static void __exit cbq_module_exit(void)
1802 {
1803 unregister_qdisc(&cbq_qdisc_ops);
1804 }
1805 module_init(cbq_module_init)
1806 module_exit(cbq_module_exit)
1807 MODULE_LICENSE("GPL");
Linux with added FPC-III support