1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * net/sched/sch_ets.c Enhanced Transmission Selection scheduler
4 *
5 * Description
6 * -----------
7 *
8 * The Enhanced Transmission Selection scheduler is a classful queuing
9 * discipline that merges functionality of PRIO and DRR qdiscs in one scheduler.
10 * ETS makes it easy to configure a set of strict and bandwidth-sharing bands to
11 * implement the transmission selection described in 802.1Qaz.
12 *
13 * Although ETS is technically classful, it's not possible to add and remove
14 * classes at will. Instead one specifies number of classes, how many are
15 * PRIO-like and how many DRR-like, and quanta for the latter.
16 *
17 * Algorithm
18 * ---------
19 *
20 * The strict classes, if any, are tried for traffic first: first band 0, if it
21 * has no traffic then band 1, etc.
22 *
23 * When there is no traffic in any of the strict queues, the bandwidth-sharing
24 * ones are tried next. Each band is assigned a deficit counter, initialized to
25 * "quantum" of that band. ETS maintains a list of active bandwidth-sharing
26 * bands whose qdiscs are non-empty. A packet is dequeued from the band at the
27 * head of the list if the packet size is smaller or equal to the deficit
28 * counter. If the counter is too small, it is increased by "quantum" and the
29 * scheduler moves on to the next band in the active list.
30 */
31
32 #include <linux/module.h>
33 #include <net/gen_stats.h>
34 #include <net/netlink.h>
35 #include <net/pkt_cls.h>
36 #include <net/pkt_sched.h>
37 #include <net/sch_generic.h>
38
39 struct ets_class {
40 struct list_head alist; /* In struct ets_sched.active. */
41 struct Qdisc *qdisc;
42 u32 quantum;
43 u32 deficit;
44 struct gnet_stats_basic_sync bstats;
45 struct gnet_stats_queue qstats;
46 };
47
48 struct ets_sched {
49 struct list_head active;
50 struct tcf_proto __rcu *filter_list;
51 struct tcf_block *block;
52 unsigned int nbands;
53 unsigned int nstrict;
54 u8 prio2band[TC_PRIO_MAX + 1];
55 struct ets_class classes[TCQ_ETS_MAX_BANDS];
56 };
57
58 static const struct nla_policy ets_policy[TCA_ETS_MAX + 1] = {
59 [TCA_ETS_NBANDS] = { .type = NLA_U8 },
60 [TCA_ETS_NSTRICT] = { .type = NLA_U8 },
61 [TCA_ETS_QUANTA] = { .type = NLA_NESTED },
62 [TCA_ETS_PRIOMAP] = { .type = NLA_NESTED },
63 };
64
65 static const struct nla_policy ets_priomap_policy[TCA_ETS_MAX + 1] = {
66 [TCA_ETS_PRIOMAP_BAND] = { .type = NLA_U8 },
67 };
68
69 static const struct nla_policy ets_quanta_policy[TCA_ETS_MAX + 1] = {
70 [TCA_ETS_QUANTA_BAND] = { .type = NLA_U32 },
71 };
72
73 static const struct nla_policy ets_class_policy[TCA_ETS_MAX + 1] = {
74 [TCA_ETS_QUANTA_BAND] = { .type = NLA_U32 },
75 };
76
77 static int ets_quantum_parse(struct Qdisc *sch, const struct nlattr *attr,
78 unsigned int *quantum,
79 struct netlink_ext_ack *extack)
80 {
81 *quantum = nla_get_u32(attr);
82 if (!*quantum) {
83 NL_SET_ERR_MSG(extack, "ETS quantum cannot be zero");
84 return -EINVAL;
85 }
86 return 0;
87 }
88
89 static struct ets_class *
90 ets_class_from_arg(struct Qdisc *sch, unsigned long arg)
91 {
92 struct ets_sched *q = qdisc_priv(sch);
93
94 return &q->classes[arg - 1];
95 }
96
97 static u32 ets_class_id(struct Qdisc *sch, const struct ets_class *cl)
98 {
99 struct ets_sched *q = qdisc_priv(sch);
100 int band = cl - q->classes;
101
102 return TC_H_MAKE(sch->handle, band + 1);
103 }
104
105 static void ets_offload_change(struct Qdisc *sch)
106 {
107 struct net_device *dev = qdisc_dev(sch);
108 struct ets_sched *q = qdisc_priv(sch);
109 struct tc_ets_qopt_offload qopt;
110 unsigned int w_psum_prev = 0;
111 unsigned int q_psum = 0;
112 unsigned int q_sum = 0;
113 unsigned int quantum;
114 unsigned int w_psum;
115 unsigned int weight;
116 unsigned int i;
117
118 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
119 return;
120
121 qopt.command = TC_ETS_REPLACE;
122 qopt.handle = sch->handle;
123 qopt.parent = sch->parent;
124 qopt.replace_params.bands = q->nbands;
125 qopt.replace_params.qstats = &sch->qstats;
126 memcpy(&qopt.replace_params.priomap,
127 q->prio2band, sizeof(q->prio2band));
128
129 for (i = 0; i < q->nbands; i++)
130 q_sum += q->classes[i].quantum;
131
132 for (i = 0; i < q->nbands; i++) {
133 quantum = q->classes[i].quantum;
134 q_psum += quantum;
135 w_psum = quantum ? q_psum * 100 / q_sum : 0;
136 weight = w_psum - w_psum_prev;
137 w_psum_prev = w_psum;
138
139 qopt.replace_params.quanta[i] = quantum;
140 qopt.replace_params.weights[i] = weight;
141 }
142
143 dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_ETS, &qopt);
144 }
145
146 static void ets_offload_destroy(struct Qdisc *sch)
147 {
148 struct net_device *dev = qdisc_dev(sch);
149 struct tc_ets_qopt_offload qopt;
150
151 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
152 return;
153
154 qopt.command = TC_ETS_DESTROY;
155 qopt.handle = sch->handle;
156 qopt.parent = sch->parent;
157 dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_ETS, &qopt);
158 }
159
160 static void ets_offload_graft(struct Qdisc *sch, struct Qdisc *new,
161 struct Qdisc *old, unsigned long arg,
162 struct netlink_ext_ack *extack)
163 {
164 struct net_device *dev = qdisc_dev(sch);
165 struct tc_ets_qopt_offload qopt;
166
167 qopt.command = TC_ETS_GRAFT;
168 qopt.handle = sch->handle;
169 qopt.parent = sch->parent;
170 qopt.graft_params.band = arg - 1;
171 qopt.graft_params.child_handle = new->handle;
172
173 qdisc_offload_graft_helper(dev, sch, new, old, TC_SETUP_QDISC_ETS,
174 &qopt, extack);
175 }
176
177 static int ets_offload_dump(struct Qdisc *sch)
178 {
179 struct tc_ets_qopt_offload qopt;
180
181 qopt.command = TC_ETS_STATS;
182 qopt.handle = sch->handle;
183 qopt.parent = sch->parent;
184 qopt.stats.bstats = &sch->bstats;
185 qopt.stats.qstats = &sch->qstats;
186
187 return qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_ETS, &qopt);
188 }
189
190 static bool ets_class_is_strict(struct ets_sched *q, const struct ets_class *cl)
191 {
192 unsigned int band = cl - q->classes;
193
194 return band < q->nstrict;
195 }
196
197 static int ets_class_change(struct Qdisc *sch, u32 classid, u32 parentid,
198 struct nlattr **tca, unsigned long *arg,
199 struct netlink_ext_ack *extack)
200 {
201 struct ets_class *cl = ets_class_from_arg(sch, *arg);
202 struct ets_sched *q = qdisc_priv(sch);
203 struct nlattr *opt = tca[TCA_OPTIONS];
204 struct nlattr *tb[TCA_ETS_MAX + 1];
205 unsigned int quantum;
206 int err;
207
208 /* Classes can be added and removed only through Qdisc_ops.change
209 * interface.
210 */
211 if (!cl) {
212 NL_SET_ERR_MSG(extack, "Fine-grained class addition and removal is not supported");
213 return -EOPNOTSUPP;
214 }
215
216 if (!opt) {
217 NL_SET_ERR_MSG(extack, "ETS options are required for this operation");
218 return -EINVAL;
219 }
220
221 err = nla_parse_nested(tb, TCA_ETS_MAX, opt, ets_class_policy, extack);
222 if (err < 0)
223 return err;
224
225 if (!tb[TCA_ETS_QUANTA_BAND])
226 /* Nothing to configure. */
227 return 0;
228
229 if (ets_class_is_strict(q, cl)) {
230 NL_SET_ERR_MSG(extack, "Strict bands do not have a configurable quantum");
231 return -EINVAL;
232 }
233
234 err = ets_quantum_parse(sch, tb[TCA_ETS_QUANTA_BAND], &quantum,
235 extack);
236 if (err)
237 return err;
238
239 sch_tree_lock(sch);
240 cl->quantum = quantum;
241 sch_tree_unlock(sch);
242
243 ets_offload_change(sch);
244 return 0;
245 }
246
247 static int ets_class_graft(struct Qdisc *sch, unsigned long arg,
248 struct Qdisc *new, struct Qdisc **old,
249 struct netlink_ext_ack *extack)
250 {
251 struct ets_class *cl = ets_class_from_arg(sch, arg);
252
253 if (!new) {
254 new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
255 ets_class_id(sch, cl), NULL);
256 if (!new)
257 new = &noop_qdisc;
258 else
259 qdisc_hash_add(new, true);
260 }
261
262 *old = qdisc_replace(sch, new, &cl->qdisc);
263 ets_offload_graft(sch, new, *old, arg, extack);
264 return 0;
265 }
266
267 static struct Qdisc *ets_class_leaf(struct Qdisc *sch, unsigned long arg)
268 {
269 struct ets_class *cl = ets_class_from_arg(sch, arg);
270
271 return cl->qdisc;
272 }
273
274 static unsigned long ets_class_find(struct Qdisc *sch, u32 classid)
275 {
276 unsigned long band = TC_H_MIN(classid);
277 struct ets_sched *q = qdisc_priv(sch);
278
279 if (band - 1 >= q->nbands)
280 return 0;
281 return band;
282 }
283
284 static void ets_class_qlen_notify(struct Qdisc *sch, unsigned long arg)
285 {
286 struct ets_class *cl = ets_class_from_arg(sch, arg);
287 struct ets_sched *q = qdisc_priv(sch);
288
289 /* We get notified about zero-length child Qdiscs as well if they are
290 * offloaded. Those aren't on the active list though, so don't attempt
291 * to remove them.
292 */
293 if (!ets_class_is_strict(q, cl) && sch->q.qlen)
294 list_del(&cl->alist);
295 }
296
297 static int ets_class_dump(struct Qdisc *sch, unsigned long arg,
298 struct sk_buff *skb, struct tcmsg *tcm)
299 {
300 struct ets_class *cl = ets_class_from_arg(sch, arg);
301 struct ets_sched *q = qdisc_priv(sch);
302 struct nlattr *nest;
303
304 tcm->tcm_parent = TC_H_ROOT;
305 tcm->tcm_handle = ets_class_id(sch, cl);
306 tcm->tcm_info = cl->qdisc->handle;
307
308 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
309 if (!nest)
310 goto nla_put_failure;
311 if (!ets_class_is_strict(q, cl)) {
312 if (nla_put_u32(skb, TCA_ETS_QUANTA_BAND, cl->quantum))
313 goto nla_put_failure;
314 }
315 return nla_nest_end(skb, nest);
316
317 nla_put_failure:
318 nla_nest_cancel(skb, nest);
319 return -EMSGSIZE;
320 }
321
322 static int ets_class_dump_stats(struct Qdisc *sch, unsigned long arg,
323 struct gnet_dump *d)
324 {
325 struct ets_class *cl = ets_class_from_arg(sch, arg);
326 struct Qdisc *cl_q = cl->qdisc;
327
328 if (gnet_stats_copy_basic(d, NULL, &cl_q->bstats, true) < 0 ||
329 qdisc_qstats_copy(d, cl_q) < 0)
330 return -1;
331
332 return 0;
333 }
334
335 static void ets_qdisc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
336 {
337 struct ets_sched *q = qdisc_priv(sch);
338 int i;
339
340 if (arg->stop)
341 return;
342
343 for (i = 0; i < q->nbands; i++) {
344 if (!tc_qdisc_stats_dump(sch, i + 1, arg))
345 break;
346 }
347 }
348
349 static struct tcf_block *
350 ets_qdisc_tcf_block(struct Qdisc *sch, unsigned long cl,
351 struct netlink_ext_ack *extack)
352 {
353 struct ets_sched *q = qdisc_priv(sch);
354
355 if (cl) {
356 NL_SET_ERR_MSG(extack, "ETS classid must be zero");
357 return NULL;
358 }
359
360 return q->block;
361 }
362
363 static unsigned long ets_qdisc_bind_tcf(struct Qdisc *sch, unsigned long parent,
364 u32 classid)
365 {
366 return ets_class_find(sch, classid);
367 }
368
369 static void ets_qdisc_unbind_tcf(struct Qdisc *sch, unsigned long arg)
370 {
371 }
372
373 static struct ets_class *ets_classify(struct sk_buff *skb, struct Qdisc *sch,
374 int *qerr)
375 {
376 struct ets_sched *q = qdisc_priv(sch);
377 u32 band = skb->priority;
378 struct tcf_result res;
379 struct tcf_proto *fl;
380 int err;
381
382 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
383 if (TC_H_MAJ(skb->priority) != sch->handle) {
384 fl = rcu_dereference_bh(q->filter_list);
385 err = tcf_classify(skb, NULL, fl, &res, false);
386 #ifdef CONFIG_NET_CLS_ACT
387 switch (err) {
388 case TC_ACT_STOLEN:
389 case TC_ACT_QUEUED:
390 case TC_ACT_TRAP:
391 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
392 fallthrough;
393 case TC_ACT_SHOT:
394 return NULL;
395 }
396 #endif
397 if (!fl || err < 0) {
398 if (TC_H_MAJ(band))
399 band = 0;
400 return &q->classes[q->prio2band[band & TC_PRIO_MAX]];
401 }
402 band = res.classid;
403 }
404 band = TC_H_MIN(band) - 1;
405 if (band >= q->nbands)
406 return &q->classes[q->prio2band[0]];
407 return &q->classes[band];
408 }
409
410 static int ets_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
411 struct sk_buff **to_free)
412 {
413 unsigned int len = qdisc_pkt_len(skb);
414 struct ets_sched *q = qdisc_priv(sch);
415 struct ets_class *cl;
416 int err = 0;
417 bool first;
418
419 cl = ets_classify(skb, sch, &err);
420 if (!cl) {
421 if (err & __NET_XMIT_BYPASS)
422 qdisc_qstats_drop(sch);
423 __qdisc_drop(skb, to_free);
424 return err;
425 }
426
427 first = !cl->qdisc->q.qlen;
428 err = qdisc_enqueue(skb, cl->qdisc, to_free);
429 if (unlikely(err != NET_XMIT_SUCCESS)) {
430 if (net_xmit_drop_count(err)) {
431 cl->qstats.drops++;
432 qdisc_qstats_drop(sch);
433 }
434 return err;
435 }
436
437 if (first && !ets_class_is_strict(q, cl)) {
438 list_add_tail(&cl->alist, &q->active);
439 cl->deficit = cl->quantum;
440 }
441
442 sch->qstats.backlog += len;
443 sch->q.qlen++;
444 return err;
445 }
446
447 static struct sk_buff *
448 ets_qdisc_dequeue_skb(struct Qdisc *sch, struct sk_buff *skb)
449 {
450 qdisc_bstats_update(sch, skb);
451 qdisc_qstats_backlog_dec(sch, skb);
452 sch->q.qlen--;
453 return skb;
454 }
455
456 static struct sk_buff *ets_qdisc_dequeue(struct Qdisc *sch)
457 {
458 struct ets_sched *q = qdisc_priv(sch);
459 struct ets_class *cl;
460 struct sk_buff *skb;
461 unsigned int band;
462 unsigned int len;
463
464 while (1) {
465 for (band = 0; band < q->nstrict; band++) {
466 cl = &q->classes[band];
467 skb = qdisc_dequeue_peeked(cl->qdisc);
468 if (skb)
469 return ets_qdisc_dequeue_skb(sch, skb);
470 }
471
472 if (list_empty(&q->active))
473 goto out;
474
475 cl = list_first_entry(&q->active, struct ets_class, alist);
476 skb = cl->qdisc->ops->peek(cl->qdisc);
477 if (!skb) {
478 qdisc_warn_nonwc(__func__, cl->qdisc);
479 goto out;
480 }
481
482 len = qdisc_pkt_len(skb);
483 if (len <= cl->deficit) {
484 cl->deficit -= len;
485 skb = qdisc_dequeue_peeked(cl->qdisc);
486 if (unlikely(!skb))
487 goto out;
488 if (cl->qdisc->q.qlen == 0)
489 list_del(&cl->alist);
490 return ets_qdisc_dequeue_skb(sch, skb);
491 }
492
493 cl->deficit += cl->quantum;
494 list_move_tail(&cl->alist, &q->active);
495 }
496 out:
497 return NULL;
498 }
499
500 static int ets_qdisc_priomap_parse(struct nlattr *priomap_attr,
501 unsigned int nbands, u8 *priomap,
502 struct netlink_ext_ack *extack)
503 {
504 const struct nlattr *attr;
505 int prio = 0;
506 u8 band;
507 int rem;
508 int err;
509
510 err = __nla_validate_nested(priomap_attr, TCA_ETS_MAX,
511 ets_priomap_policy, NL_VALIDATE_STRICT,
512 extack);
513 if (err)
514 return err;
515
516 nla_for_each_nested(attr, priomap_attr, rem) {
517 switch (nla_type(attr)) {
518 case TCA_ETS_PRIOMAP_BAND:
519 if (prio > TC_PRIO_MAX) {
520 NL_SET_ERR_MSG_MOD(extack, "Too many priorities in ETS priomap");
521 return -EINVAL;
522 }
523 band = nla_get_u8(attr);
524 if (band >= nbands) {
525 NL_SET_ERR_MSG_MOD(extack, "Invalid band number in ETS priomap");
526 return -EINVAL;
527 }
528 priomap[prio++] = band;
529 break;
530 default:
531 WARN_ON_ONCE(1); /* Validate should have caught this. */
532 return -EINVAL;
533 }
534 }
535
536 return 0;
537 }
538
539 static int ets_qdisc_quanta_parse(struct Qdisc *sch, struct nlattr *quanta_attr,
540 unsigned int nbands, unsigned int nstrict,
541 unsigned int *quanta,
542 struct netlink_ext_ack *extack)
543 {
544 const struct nlattr *attr;
545 int band = nstrict;
546 int rem;
547 int err;
548
549 err = __nla_validate_nested(quanta_attr, TCA_ETS_MAX,
550 ets_quanta_policy, NL_VALIDATE_STRICT,
551 extack);
552 if (err < 0)
553 return err;
554
555 nla_for_each_nested(attr, quanta_attr, rem) {
556 switch (nla_type(attr)) {
557 case TCA_ETS_QUANTA_BAND:
558 if (band >= nbands) {
559 NL_SET_ERR_MSG_MOD(extack, "ETS quanta has more values than bands");
560 return -EINVAL;
561 }
562 err = ets_quantum_parse(sch, attr, &quanta[band++],
563 extack);
564 if (err)
565 return err;
566 break;
567 default:
568 WARN_ON_ONCE(1); /* Validate should have caught this. */
569 return -EINVAL;
570 }
571 }
572
573 return 0;
574 }
575
576 static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt,
577 struct netlink_ext_ack *extack)
578 {
579 unsigned int quanta[TCQ_ETS_MAX_BANDS] = {0};
580 struct Qdisc *queues[TCQ_ETS_MAX_BANDS];
581 struct ets_sched *q = qdisc_priv(sch);
582 struct nlattr *tb[TCA_ETS_MAX + 1];
583 unsigned int oldbands = q->nbands;
584 u8 priomap[TC_PRIO_MAX + 1];
585 unsigned int nstrict = 0;
586 unsigned int nbands;
587 unsigned int i;
588 int err;
589
590 err = nla_parse_nested(tb, TCA_ETS_MAX, opt, ets_policy, extack);
591 if (err < 0)
592 return err;
593
594 if (!tb[TCA_ETS_NBANDS]) {
595 NL_SET_ERR_MSG_MOD(extack, "Number of bands is a required argument");
596 return -EINVAL;
597 }
598 nbands = nla_get_u8(tb[TCA_ETS_NBANDS]);
599 if (nbands < 1 || nbands > TCQ_ETS_MAX_BANDS) {
600 NL_SET_ERR_MSG_MOD(extack, "Invalid number of bands");
601 return -EINVAL;
602 }
603 /* Unless overridden, traffic goes to the last band. */
604 memset(priomap, nbands - 1, sizeof(priomap));
605
606 if (tb[TCA_ETS_NSTRICT]) {
607 nstrict = nla_get_u8(tb[TCA_ETS_NSTRICT]);
608 if (nstrict > nbands) {
609 NL_SET_ERR_MSG_MOD(extack, "Invalid number of strict bands");
610 return -EINVAL;
611 }
612 }
613
614 if (tb[TCA_ETS_PRIOMAP]) {
615 err = ets_qdisc_priomap_parse(tb[TCA_ETS_PRIOMAP],
616 nbands, priomap, extack);
617 if (err)
618 return err;
619 }
620
621 if (tb[TCA_ETS_QUANTA]) {
622 err = ets_qdisc_quanta_parse(sch, tb[TCA_ETS_QUANTA],
623 nbands, nstrict, quanta, extack);
624 if (err)
625 return err;
626 }
627 /* If there are more bands than strict + quanta provided, the remaining
628 * ones are ETS with quantum of MTU. Initialize the missing values here.
629 */
630 for (i = nstrict; i < nbands; i++) {
631 if (!quanta[i])
632 quanta[i] = psched_mtu(qdisc_dev(sch));
633 }
634
635 /* Before commit, make sure we can allocate all new qdiscs */
636 for (i = oldbands; i < nbands; i++) {
637 queues[i] = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
638 ets_class_id(sch, &q->classes[i]),
639 extack);
640 if (!queues[i]) {
641 while (i > oldbands)
642 qdisc_put(queues[--i]);
643 return -ENOMEM;
644 }
645 }
646
647 sch_tree_lock(sch);
648
649 WRITE_ONCE(q->nbands, nbands);
650 for (i = nstrict; i < q->nstrict; i++) {
651 if (q->classes[i].qdisc->q.qlen) {
652 list_add_tail(&q->classes[i].alist, &q->active);
653 q->classes[i].deficit = quanta[i];
654 }
655 }
656 for (i = q->nbands; i < oldbands; i++) {
657 if (i >= q->nstrict && q->classes[i].qdisc->q.qlen)
658 list_del(&q->classes[i].alist);
659 qdisc_tree_flush_backlog(q->classes[i].qdisc);
660 }
661 WRITE_ONCE(q->nstrict, nstrict);
662 memcpy(q->prio2band, priomap, sizeof(priomap));
663
664 for (i = 0; i < q->nbands; i++)
665 WRITE_ONCE(q->classes[i].quantum, quanta[i]);
666
667 for (i = oldbands; i < q->nbands; i++) {
668 q->classes[i].qdisc = queues[i];
669 if (q->classes[i].qdisc != &noop_qdisc)
670 qdisc_hash_add(q->classes[i].qdisc, true);
671 }
672
673 sch_tree_unlock(sch);
674
675 ets_offload_change(sch);
676 for (i = q->nbands; i < oldbands; i++) {
677 qdisc_put(q->classes[i].qdisc);
678 q->classes[i].qdisc = NULL;
679 WRITE_ONCE(q->classes[i].quantum, 0);
680 q->classes[i].deficit = 0;
681 gnet_stats_basic_sync_init(&q->classes[i].bstats);
682 memset(&q->classes[i].qstats, 0, sizeof(q->classes[i].qstats));
683 }
684 return 0;
685 }
686
687 static int ets_qdisc_init(struct Qdisc *sch, struct nlattr *opt,
688 struct netlink_ext_ack *extack)
689 {
690 struct ets_sched *q = qdisc_priv(sch);
691 int err, i;
692
693 if (!opt)
694 return -EINVAL;
695
696 err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
697 if (err)
698 return err;
699
700 INIT_LIST_HEAD(&q->active);
701 for (i = 0; i < TCQ_ETS_MAX_BANDS; i++)
702 INIT_LIST_HEAD(&q->classes[i].alist);
703
704 return ets_qdisc_change(sch, opt, extack);
705 }
706
707 static void ets_qdisc_reset(struct Qdisc *sch)
708 {
709 struct ets_sched *q = qdisc_priv(sch);
710 int band;
711
712 for (band = q->nstrict; band < q->nbands; band++) {
713 if (q->classes[band].qdisc->q.qlen)
714 list_del(&q->classes[band].alist);
715 }
716 for (band = 0; band < q->nbands; band++)
717 qdisc_reset(q->classes[band].qdisc);
718 }
719
720 static void ets_qdisc_destroy(struct Qdisc *sch)
721 {
722 struct ets_sched *q = qdisc_priv(sch);
723 int band;
724
725 ets_offload_destroy(sch);
726 tcf_block_put(q->block);
727 for (band = 0; band < q->nbands; band++)
728 qdisc_put(q->classes[band].qdisc);
729 }
730
731 static int ets_qdisc_dump(struct Qdisc *sch, struct sk_buff *skb)
732 {
733 struct ets_sched *q = qdisc_priv(sch);
734 struct nlattr *opts;
735 struct nlattr *nest;
736 u8 nbands, nstrict;
737 int band;
738 int prio;
739 int err;
740
741 err = ets_offload_dump(sch);
742 if (err)
743 return err;
744
745 opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
746 if (!opts)
747 goto nla_err;
748
749 nbands = READ_ONCE(q->nbands);
750 if (nla_put_u8(skb, TCA_ETS_NBANDS, nbands))
751 goto nla_err;
752
753 nstrict = READ_ONCE(q->nstrict);
754 if (nstrict && nla_put_u8(skb, TCA_ETS_NSTRICT, nstrict))
755 goto nla_err;
756
757 if (nbands > nstrict) {
758 nest = nla_nest_start(skb, TCA_ETS_QUANTA);
759 if (!nest)
760 goto nla_err;
761
762 for (band = nstrict; band < nbands; band++) {
763 if (nla_put_u32(skb, TCA_ETS_QUANTA_BAND,
764 READ_ONCE(q->classes[band].quantum)))
765 goto nla_err;
766 }
767
768 nla_nest_end(skb, nest);
769 }
770
771 nest = nla_nest_start(skb, TCA_ETS_PRIOMAP);
772 if (!nest)
773 goto nla_err;
774
775 for (prio = 0; prio <= TC_PRIO_MAX; prio++) {
776 if (nla_put_u8(skb, TCA_ETS_PRIOMAP_BAND,
777 READ_ONCE(q->prio2band[prio])))
778 goto nla_err;
779 }
780
781 nla_nest_end(skb, nest);
782
783 return nla_nest_end(skb, opts);
784
785 nla_err:
786 nla_nest_cancel(skb, opts);
787 return -EMSGSIZE;
788 }
789
790 static const struct Qdisc_class_ops ets_class_ops = {
791 .change = ets_class_change,
792 .graft = ets_class_graft,
793 .leaf = ets_class_leaf,
794 .find = ets_class_find,
795 .qlen_notify = ets_class_qlen_notify,
796 .dump = ets_class_dump,
797 .dump_stats = ets_class_dump_stats,
798 .walk = ets_qdisc_walk,
799 .tcf_block = ets_qdisc_tcf_block,
800 .bind_tcf = ets_qdisc_bind_tcf,
801 .unbind_tcf = ets_qdisc_unbind_tcf,
802 };
803
804 static struct Qdisc_ops ets_qdisc_ops __read_mostly = {
805 .cl_ops = &ets_class_ops,
806 .id = "ets",
807 .priv_size = sizeof(struct ets_sched),
808 .enqueue = ets_qdisc_enqueue,
809 .dequeue = ets_qdisc_dequeue,
810 .peek = qdisc_peek_dequeued,
811 .change = ets_qdisc_change,
812 .init = ets_qdisc_init,
813 .reset = ets_qdisc_reset,
814 .destroy = ets_qdisc_destroy,
815 .dump = ets_qdisc_dump,
816 .owner = THIS_MODULE,
817 };
818 MODULE_ALIAS_NET_SCH("ets");
819
820 static int __init ets_init(void)
821 {
822 return register_qdisc(&ets_qdisc_ops);
823 }
824
825 static void __exit ets_exit(void)
826 {
827 unregister_qdisc(&ets_qdisc_ops);
828 }
829
830 module_init(ets_init);
831 module_exit(ets_exit);
832 MODULE_LICENSE("GPL");
833 MODULE_DESCRIPTION("Enhanced Transmission Selection(ETS) scheduler");
834
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