Merge tag 'pm-6.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
[linux-block.git] / net / sched / sch_drr.c
CommitLineData
d2912cb1 1// SPDX-License-Identifier: GPL-2.0-only
13d2a1d2
PM
2/*
3 * net/sched/sch_drr.c Deficit Round Robin scheduler
4 *
5 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
13d2a1d2
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6 */
7
8#include <linux/module.h>
5a0e3ad6 9#include <linux/slab.h>
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10#include <linux/init.h>
11#include <linux/errno.h>
12#include <linux/netdevice.h>
13#include <linux/pkt_sched.h>
14#include <net/sch_generic.h>
15#include <net/pkt_sched.h>
16#include <net/pkt_cls.h>
17
18struct drr_class {
19 struct Qdisc_class_common common;
13d2a1d2 20
50dc9a85 21 struct gnet_stats_basic_sync bstats;
13d2a1d2 22 struct gnet_stats_queue qstats;
1c0d32fd 23 struct net_rate_estimator __rcu *rate_est;
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24 struct list_head alist;
25 struct Qdisc *qdisc;
26
27 u32 quantum;
28 u32 deficit;
29};
30
31struct drr_sched {
32 struct list_head active;
25d8c0d5 33 struct tcf_proto __rcu *filter_list;
6529eaba 34 struct tcf_block *block;
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35 struct Qdisc_class_hash clhash;
36};
37
f99a3fbf
VN
38static bool cl_is_active(struct drr_class *cl)
39{
40 return !list_empty(&cl->alist);
41}
42
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43static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid)
44{
45 struct drr_sched *q = qdisc_priv(sch);
46 struct Qdisc_class_common *clc;
47
48 clc = qdisc_class_find(&q->clhash, classid);
49 if (clc == NULL)
50 return NULL;
51 return container_of(clc, struct drr_class, common);
52}
53
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PM
54static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
55 [TCA_DRR_QUANTUM] = { .type = NLA_U32 },
56};
57
58static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
793d81d6
AA
59 struct nlattr **tca, unsigned long *arg,
60 struct netlink_ext_ack *extack)
13d2a1d2
PM
61{
62 struct drr_sched *q = qdisc_priv(sch);
63 struct drr_class *cl = (struct drr_class *)*arg;
1844f747 64 struct nlattr *opt = tca[TCA_OPTIONS];
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65 struct nlattr *tb[TCA_DRR_MAX + 1];
66 u32 quantum;
67 int err;
68
a7c31693
AA
69 if (!opt) {
70 NL_SET_ERR_MSG(extack, "DRR options are required for this operation");
1844f747 71 return -EINVAL;
a7c31693 72 }
1844f747 73
8cb08174
JB
74 err = nla_parse_nested_deprecated(tb, TCA_DRR_MAX, opt, drr_policy,
75 extack);
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76 if (err < 0)
77 return err;
78
79 if (tb[TCA_DRR_QUANTUM]) {
80 quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
a7c31693
AA
81 if (quantum == 0) {
82 NL_SET_ERR_MSG(extack, "Specified DRR quantum cannot be zero");
13d2a1d2 83 return -EINVAL;
a7c31693 84 }
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PM
85 } else
86 quantum = psched_mtu(qdisc_dev(sch));
87
88 if (cl != NULL) {
71bcb09a 89 if (tca[TCA_RATE]) {
22e0f8b9
JF
90 err = gen_replace_estimator(&cl->bstats, NULL,
91 &cl->rate_est,
29cbcd85 92 NULL, true,
71bcb09a 93 tca[TCA_RATE]);
a7c31693
AA
94 if (err) {
95 NL_SET_ERR_MSG(extack, "Failed to replace estimator");
71bcb09a 96 return err;
a7c31693 97 }
71bcb09a
SH
98 }
99
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100 sch_tree_lock(sch);
101 if (tb[TCA_DRR_QUANTUM])
102 cl->quantum = quantum;
103 sch_tree_unlock(sch);
104
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105 return 0;
106 }
107
108 cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
109 if (cl == NULL)
110 return -ENOBUFS;
111
50dc9a85 112 gnet_stats_basic_sync_init(&cl->bstats);
df008598 113 INIT_LIST_HEAD(&cl->alist);
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114 cl->common.classid = classid;
115 cl->quantum = quantum;
3511c913 116 cl->qdisc = qdisc_create_dflt(sch->dev_queue,
a38a9882
AA
117 &pfifo_qdisc_ops, classid,
118 NULL);
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119 if (cl->qdisc == NULL)
120 cl->qdisc = &noop_qdisc;
49b49971
JK
121 else
122 qdisc_hash_add(cl->qdisc, true);
13d2a1d2 123
71bcb09a 124 if (tca[TCA_RATE]) {
22e0f8b9 125 err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est,
29cbcd85 126 NULL, true, tca[TCA_RATE]);
71bcb09a 127 if (err) {
a7c31693 128 NL_SET_ERR_MSG(extack, "Failed to replace estimator");
86bd446b 129 qdisc_put(cl->qdisc);
71bcb09a
SH
130 kfree(cl);
131 return err;
132 }
133 }
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134
135 sch_tree_lock(sch);
136 qdisc_class_hash_insert(&q->clhash, &cl->common);
137 sch_tree_unlock(sch);
138
139 qdisc_class_hash_grow(sch, &q->clhash);
140
141 *arg = (unsigned long)cl;
142 return 0;
143}
144
145static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl)
146{
1c0d32fd 147 gen_kill_estimator(&cl->rate_est);
86bd446b 148 qdisc_put(cl->qdisc);
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149 kfree(cl);
150}
151
4dd78a73
MM
152static int drr_delete_class(struct Qdisc *sch, unsigned long arg,
153 struct netlink_ext_ack *extack)
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154{
155 struct drr_sched *q = qdisc_priv(sch);
156 struct drr_class *cl = (struct drr_class *)arg;
157
daf8d918
PT
158 if (qdisc_class_in_use(&cl->common)) {
159 NL_SET_ERR_MSG(extack, "DRR class is in use");
13d2a1d2 160 return -EBUSY;
daf8d918 161 }
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162
163 sch_tree_lock(sch);
164
e5f0e8f8 165 qdisc_purge_queue(cl->qdisc);
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166 qdisc_class_hash_remove(&q->clhash, &cl->common);
167
13d2a1d2 168 sch_tree_unlock(sch);
13d2a1d2 169
143976ce
WC
170 drr_destroy_class(sch, cl);
171 return 0;
13d2a1d2
PM
172}
173
143976ce 174static unsigned long drr_search_class(struct Qdisc *sch, u32 classid)
13d2a1d2 175{
143976ce 176 return (unsigned long)drr_find_class(sch, classid);
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177}
178
cbaacc4e
AA
179static struct tcf_block *drr_tcf_block(struct Qdisc *sch, unsigned long cl,
180 struct netlink_ext_ack *extack)
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PM
181{
182 struct drr_sched *q = qdisc_priv(sch);
183
a7c31693
AA
184 if (cl) {
185 NL_SET_ERR_MSG(extack, "DRR classid must be zero");
13d2a1d2 186 return NULL;
a7c31693 187 }
13d2a1d2 188
6529eaba 189 return q->block;
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190}
191
192static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
193 u32 classid)
194{
195 struct drr_class *cl = drr_find_class(sch, classid);
196
8798481b
PT
197 if (cl)
198 qdisc_class_get(&cl->common);
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PM
199
200 return (unsigned long)cl;
201}
202
203static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
204{
205 struct drr_class *cl = (struct drr_class *)arg;
206
8798481b 207 qdisc_class_put(&cl->common);
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208}
209
210static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
653d6fd6
AA
211 struct Qdisc *new, struct Qdisc **old,
212 struct netlink_ext_ack *extack)
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PM
213{
214 struct drr_class *cl = (struct drr_class *)arg;
215
216 if (new == NULL) {
a38a9882
AA
217 new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
218 cl->common.classid, NULL);
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PM
219 if (new == NULL)
220 new = &noop_qdisc;
221 }
222
86a7996c 223 *old = qdisc_replace(sch, new, &cl->qdisc);
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PM
224 return 0;
225}
226
227static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg)
228{
229 struct drr_class *cl = (struct drr_class *)arg;
230
231 return cl->qdisc;
232}
233
234static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
235{
236 struct drr_class *cl = (struct drr_class *)arg;
237
df008598 238 list_del_init(&cl->alist);
13d2a1d2
PM
239}
240
241static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
242 struct sk_buff *skb, struct tcmsg *tcm)
243{
244 struct drr_class *cl = (struct drr_class *)arg;
245 struct nlattr *nest;
246
247 tcm->tcm_parent = TC_H_ROOT;
248 tcm->tcm_handle = cl->common.classid;
249 tcm->tcm_info = cl->qdisc->handle;
250
ae0be8de 251 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
13d2a1d2
PM
252 if (nest == NULL)
253 goto nla_put_failure;
1b34ec43
DM
254 if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
255 goto nla_put_failure;
13d2a1d2
PM
256 return nla_nest_end(skb, nest);
257
258nla_put_failure:
259 nla_nest_cancel(skb, nest);
260 return -EMSGSIZE;
261}
262
263static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
264 struct gnet_dump *d)
265{
266 struct drr_class *cl = (struct drr_class *)arg;
5dd431b6
PA
267 __u32 qlen = qdisc_qlen_sum(cl->qdisc);
268 struct Qdisc *cl_q = cl->qdisc;
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269 struct tc_drr_stats xstats;
270
271 memset(&xstats, 0, sizeof(xstats));
64015853 272 if (qlen)
13d2a1d2
PM
273 xstats.deficit = cl->deficit;
274
29cbcd85 275 if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 ||
1c0d32fd 276 gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
5dd431b6 277 gnet_stats_copy_queue(d, cl_q->cpu_qstats, &cl_q->qstats, qlen) < 0)
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278 return -1;
279
280 return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
281}
282
283static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
284{
285 struct drr_sched *q = qdisc_priv(sch);
286 struct drr_class *cl;
13d2a1d2
PM
287 unsigned int i;
288
289 if (arg->stop)
290 return;
291
292 for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d 293 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
e046fa89 294 if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
13d2a1d2 295 return;
13d2a1d2
PM
296 }
297 }
298}
299
300static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
301 int *qerr)
302{
303 struct drr_sched *q = qdisc_priv(sch);
304 struct drr_class *cl;
305 struct tcf_result res;
25d8c0d5 306 struct tcf_proto *fl;
13d2a1d2
PM
307 int result;
308
309 if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
310 cl = drr_find_class(sch, skb->priority);
311 if (cl != NULL)
312 return cl;
313 }
314
315 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
25d8c0d5 316 fl = rcu_dereference_bh(q->filter_list);
3aa26055 317 result = tcf_classify(skb, NULL, fl, &res, false);
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318 if (result >= 0) {
319#ifdef CONFIG_NET_CLS_ACT
320 switch (result) {
321 case TC_ACT_QUEUED:
322 case TC_ACT_STOLEN:
e25ea21f 323 case TC_ACT_TRAP:
13d2a1d2 324 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
964201de 325 fallthrough;
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PM
326 case TC_ACT_SHOT:
327 return NULL;
328 }
329#endif
330 cl = (struct drr_class *)res.class;
331 if (cl == NULL)
332 cl = drr_find_class(sch, res.classid);
333 return cl;
334 }
335 return NULL;
336}
337
ac5c66f2 338static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch,
520ac30f 339 struct sk_buff **to_free)
13d2a1d2 340{
f6bab199 341 unsigned int len = qdisc_pkt_len(skb);
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PM
342 struct drr_sched *q = qdisc_priv(sch);
343 struct drr_class *cl;
f54ba779 344 int err = 0;
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345
346 cl = drr_classify(skb, sch, &err);
347 if (cl == NULL) {
348 if (err & __NET_XMIT_BYPASS)
25331d6c 349 qdisc_qstats_drop(sch);
520ac30f 350 __qdisc_drop(skb, to_free);
13d2a1d2
PM
351 return err;
352 }
353
ac5c66f2 354 err = qdisc_enqueue(skb, cl->qdisc, to_free);
13d2a1d2
PM
355 if (unlikely(err != NET_XMIT_SUCCESS)) {
356 if (net_xmit_drop_count(err)) {
357 cl->qstats.drops++;
25331d6c 358 qdisc_qstats_drop(sch);
13d2a1d2
PM
359 }
360 return err;
361 }
362
f99a3fbf 363 if (!cl_is_active(cl)) {
13d2a1d2
PM
364 list_add_tail(&cl->alist, &q->active);
365 cl->deficit = cl->quantum;
366 }
367
f6bab199 368 sch->qstats.backlog += len;
13d2a1d2
PM
369 sch->q.qlen++;
370 return err;
371}
372
373static struct sk_buff *drr_dequeue(struct Qdisc *sch)
374{
375 struct drr_sched *q = qdisc_priv(sch);
376 struct drr_class *cl;
377 struct sk_buff *skb;
378 unsigned int len;
379
3f0947c3
PM
380 if (list_empty(&q->active))
381 goto out;
382 while (1) {
13d2a1d2
PM
383 cl = list_first_entry(&q->active, struct drr_class, alist);
384 skb = cl->qdisc->ops->peek(cl->qdisc);
6e765a00
FW
385 if (skb == NULL) {
386 qdisc_warn_nonwc(__func__, cl->qdisc);
3f0947c3 387 goto out;
6e765a00 388 }
13d2a1d2
PM
389
390 len = qdisc_pkt_len(skb);
391 if (len <= cl->deficit) {
392 cl->deficit -= len;
393 skb = qdisc_dequeue_peeked(cl->qdisc);
df3eb6cd
BH
394 if (unlikely(skb == NULL))
395 goto out;
13d2a1d2 396 if (cl->qdisc->q.qlen == 0)
df008598 397 list_del_init(&cl->alist);
2dd875ff
ED
398
399 bstats_update(&cl->bstats, skb);
9190b3b3 400 qdisc_bstats_update(sch, skb);
6a73b571 401 qdisc_qstats_backlog_dec(sch, skb);
13d2a1d2
PM
402 sch->q.qlen--;
403 return skb;
404 }
405
406 cl->deficit += cl->quantum;
13d2a1d2
PM
407 list_move_tail(&cl->alist, &q->active);
408 }
3f0947c3 409out:
13d2a1d2
PM
410 return NULL;
411}
412
e63d7dfd
AA
413static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt,
414 struct netlink_ext_ack *extack)
13d2a1d2
PM
415{
416 struct drr_sched *q = qdisc_priv(sch);
417 int err;
418
8d1a77f9 419 err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
6529eaba
JP
420 if (err)
421 return err;
13d2a1d2
PM
422 err = qdisc_class_hash_init(&q->clhash);
423 if (err < 0)
424 return err;
425 INIT_LIST_HEAD(&q->active);
426 return 0;
427}
428
429static void drr_reset_qdisc(struct Qdisc *sch)
430{
431 struct drr_sched *q = qdisc_priv(sch);
432 struct drr_class *cl;
13d2a1d2
PM
433 unsigned int i;
434
435 for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d 436 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
13d2a1d2 437 if (cl->qdisc->q.qlen)
df008598 438 list_del_init(&cl->alist);
13d2a1d2
PM
439 qdisc_reset(cl->qdisc);
440 }
441 }
13d2a1d2
PM
442}
443
444static void drr_destroy_qdisc(struct Qdisc *sch)
445{
446 struct drr_sched *q = qdisc_priv(sch);
447 struct drr_class *cl;
b67bfe0d 448 struct hlist_node *next;
13d2a1d2
PM
449 unsigned int i;
450
6529eaba 451 tcf_block_put(q->block);
13d2a1d2
PM
452
453 for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d 454 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
13d2a1d2
PM
455 common.hnode)
456 drr_destroy_class(sch, cl);
457 }
458 qdisc_class_hash_destroy(&q->clhash);
459}
460
461static const struct Qdisc_class_ops drr_class_ops = {
462 .change = drr_change_class,
463 .delete = drr_delete_class,
143976ce 464 .find = drr_search_class,
6529eaba 465 .tcf_block = drr_tcf_block,
13d2a1d2
PM
466 .bind_tcf = drr_bind_tcf,
467 .unbind_tcf = drr_unbind_tcf,
468 .graft = drr_graft_class,
469 .leaf = drr_class_leaf,
470 .qlen_notify = drr_qlen_notify,
471 .dump = drr_dump_class,
472 .dump_stats = drr_dump_class_stats,
473 .walk = drr_walk,
474};
475
476static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
477 .cl_ops = &drr_class_ops,
478 .id = "drr",
479 .priv_size = sizeof(struct drr_sched),
480 .enqueue = drr_enqueue,
481 .dequeue = drr_dequeue,
482 .peek = qdisc_peek_dequeued,
13d2a1d2
PM
483 .init = drr_init_qdisc,
484 .reset = drr_reset_qdisc,
485 .destroy = drr_destroy_qdisc,
486 .owner = THIS_MODULE,
487};
241a94ab 488MODULE_ALIAS_NET_SCH("drr");
13d2a1d2
PM
489
490static int __init drr_init(void)
491{
492 return register_qdisc(&drr_qdisc_ops);
493}
494
495static void __exit drr_exit(void)
496{
497 unregister_qdisc(&drr_qdisc_ops);
498}
499
500module_init(drr_init);
501module_exit(drr_exit);
502MODULE_LICENSE("GPL");
f96118c5 503MODULE_DESCRIPTION("Deficit Round Robin scheduler");