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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 PM |
6 | */ |
7 | ||
8 | #include <linux/module.h> | |
5a0e3ad6 | 9 | #include <linux/slab.h> |
13d2a1d2 PM |
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 | ||
18 | struct drr_class { | |
19 | struct Qdisc_class_common common; | |
13d2a1d2 PM |
20 | unsigned int filter_cnt; |
21 | ||
50dc9a85 | 22 | struct gnet_stats_basic_sync bstats; |
13d2a1d2 | 23 | struct gnet_stats_queue qstats; |
1c0d32fd | 24 | struct net_rate_estimator __rcu *rate_est; |
13d2a1d2 PM |
25 | struct list_head alist; |
26 | struct Qdisc *qdisc; | |
27 | ||
28 | u32 quantum; | |
29 | u32 deficit; | |
30 | }; | |
31 | ||
32 | struct drr_sched { | |
33 | struct list_head active; | |
25d8c0d5 | 34 | struct tcf_proto __rcu *filter_list; |
6529eaba | 35 | struct tcf_block *block; |
13d2a1d2 PM |
36 | struct Qdisc_class_hash clhash; |
37 | }; | |
38 | ||
39 | static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid) | |
40 | { | |
41 | struct drr_sched *q = qdisc_priv(sch); | |
42 | struct Qdisc_class_common *clc; | |
43 | ||
44 | clc = qdisc_class_find(&q->clhash, classid); | |
45 | if (clc == NULL) | |
46 | return NULL; | |
47 | return container_of(clc, struct drr_class, common); | |
48 | } | |
49 | ||
13d2a1d2 PM |
50 | static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = { |
51 | [TCA_DRR_QUANTUM] = { .type = NLA_U32 }, | |
52 | }; | |
53 | ||
54 | static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid, | |
793d81d6 AA |
55 | struct nlattr **tca, unsigned long *arg, |
56 | struct netlink_ext_ack *extack) | |
13d2a1d2 PM |
57 | { |
58 | struct drr_sched *q = qdisc_priv(sch); | |
59 | struct drr_class *cl = (struct drr_class *)*arg; | |
1844f747 | 60 | struct nlattr *opt = tca[TCA_OPTIONS]; |
13d2a1d2 PM |
61 | struct nlattr *tb[TCA_DRR_MAX + 1]; |
62 | u32 quantum; | |
63 | int err; | |
64 | ||
a7c31693 AA |
65 | if (!opt) { |
66 | NL_SET_ERR_MSG(extack, "DRR options are required for this operation"); | |
1844f747 | 67 | return -EINVAL; |
a7c31693 | 68 | } |
1844f747 | 69 | |
8cb08174 JB |
70 | err = nla_parse_nested_deprecated(tb, TCA_DRR_MAX, opt, drr_policy, |
71 | extack); | |
13d2a1d2 PM |
72 | if (err < 0) |
73 | return err; | |
74 | ||
75 | if (tb[TCA_DRR_QUANTUM]) { | |
76 | quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]); | |
a7c31693 AA |
77 | if (quantum == 0) { |
78 | NL_SET_ERR_MSG(extack, "Specified DRR quantum cannot be zero"); | |
13d2a1d2 | 79 | return -EINVAL; |
a7c31693 | 80 | } |
13d2a1d2 PM |
81 | } else |
82 | quantum = psched_mtu(qdisc_dev(sch)); | |
83 | ||
84 | if (cl != NULL) { | |
71bcb09a | 85 | if (tca[TCA_RATE]) { |
22e0f8b9 JF |
86 | err = gen_replace_estimator(&cl->bstats, NULL, |
87 | &cl->rate_est, | |
29cbcd85 | 88 | NULL, true, |
71bcb09a | 89 | tca[TCA_RATE]); |
a7c31693 AA |
90 | if (err) { |
91 | NL_SET_ERR_MSG(extack, "Failed to replace estimator"); | |
71bcb09a | 92 | return err; |
a7c31693 | 93 | } |
71bcb09a SH |
94 | } |
95 | ||
13d2a1d2 PM |
96 | sch_tree_lock(sch); |
97 | if (tb[TCA_DRR_QUANTUM]) | |
98 | cl->quantum = quantum; | |
99 | sch_tree_unlock(sch); | |
100 | ||
13d2a1d2 PM |
101 | return 0; |
102 | } | |
103 | ||
104 | cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL); | |
105 | if (cl == NULL) | |
106 | return -ENOBUFS; | |
107 | ||
50dc9a85 | 108 | gnet_stats_basic_sync_init(&cl->bstats); |
13d2a1d2 PM |
109 | cl->common.classid = classid; |
110 | cl->quantum = quantum; | |
3511c913 | 111 | cl->qdisc = qdisc_create_dflt(sch->dev_queue, |
a38a9882 AA |
112 | &pfifo_qdisc_ops, classid, |
113 | NULL); | |
13d2a1d2 PM |
114 | if (cl->qdisc == NULL) |
115 | cl->qdisc = &noop_qdisc; | |
49b49971 JK |
116 | else |
117 | qdisc_hash_add(cl->qdisc, true); | |
13d2a1d2 | 118 | |
71bcb09a | 119 | if (tca[TCA_RATE]) { |
22e0f8b9 | 120 | err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est, |
29cbcd85 | 121 | NULL, true, tca[TCA_RATE]); |
71bcb09a | 122 | if (err) { |
a7c31693 | 123 | NL_SET_ERR_MSG(extack, "Failed to replace estimator"); |
86bd446b | 124 | qdisc_put(cl->qdisc); |
71bcb09a SH |
125 | kfree(cl); |
126 | return err; | |
127 | } | |
128 | } | |
13d2a1d2 PM |
129 | |
130 | sch_tree_lock(sch); | |
131 | qdisc_class_hash_insert(&q->clhash, &cl->common); | |
132 | sch_tree_unlock(sch); | |
133 | ||
134 | qdisc_class_hash_grow(sch, &q->clhash); | |
135 | ||
136 | *arg = (unsigned long)cl; | |
137 | return 0; | |
138 | } | |
139 | ||
140 | static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl) | |
141 | { | |
1c0d32fd | 142 | gen_kill_estimator(&cl->rate_est); |
86bd446b | 143 | qdisc_put(cl->qdisc); |
13d2a1d2 PM |
144 | kfree(cl); |
145 | } | |
146 | ||
4dd78a73 MM |
147 | static int drr_delete_class(struct Qdisc *sch, unsigned long arg, |
148 | struct netlink_ext_ack *extack) | |
13d2a1d2 PM |
149 | { |
150 | struct drr_sched *q = qdisc_priv(sch); | |
151 | struct drr_class *cl = (struct drr_class *)arg; | |
152 | ||
153 | if (cl->filter_cnt > 0) | |
154 | return -EBUSY; | |
155 | ||
156 | sch_tree_lock(sch); | |
157 | ||
e5f0e8f8 | 158 | qdisc_purge_queue(cl->qdisc); |
13d2a1d2 PM |
159 | qdisc_class_hash_remove(&q->clhash, &cl->common); |
160 | ||
13d2a1d2 | 161 | sch_tree_unlock(sch); |
13d2a1d2 | 162 | |
143976ce WC |
163 | drr_destroy_class(sch, cl); |
164 | return 0; | |
13d2a1d2 PM |
165 | } |
166 | ||
143976ce | 167 | static unsigned long drr_search_class(struct Qdisc *sch, u32 classid) |
13d2a1d2 | 168 | { |
143976ce | 169 | return (unsigned long)drr_find_class(sch, classid); |
13d2a1d2 PM |
170 | } |
171 | ||
cbaacc4e AA |
172 | static struct tcf_block *drr_tcf_block(struct Qdisc *sch, unsigned long cl, |
173 | struct netlink_ext_ack *extack) | |
13d2a1d2 PM |
174 | { |
175 | struct drr_sched *q = qdisc_priv(sch); | |
176 | ||
a7c31693 AA |
177 | if (cl) { |
178 | NL_SET_ERR_MSG(extack, "DRR classid must be zero"); | |
13d2a1d2 | 179 | return NULL; |
a7c31693 | 180 | } |
13d2a1d2 | 181 | |
6529eaba | 182 | return q->block; |
13d2a1d2 PM |
183 | } |
184 | ||
185 | static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent, | |
186 | u32 classid) | |
187 | { | |
188 | struct drr_class *cl = drr_find_class(sch, classid); | |
189 | ||
190 | if (cl != NULL) | |
191 | cl->filter_cnt++; | |
192 | ||
193 | return (unsigned long)cl; | |
194 | } | |
195 | ||
196 | static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg) | |
197 | { | |
198 | struct drr_class *cl = (struct drr_class *)arg; | |
199 | ||
200 | cl->filter_cnt--; | |
201 | } | |
202 | ||
203 | static int drr_graft_class(struct Qdisc *sch, unsigned long arg, | |
653d6fd6 AA |
204 | struct Qdisc *new, struct Qdisc **old, |
205 | struct netlink_ext_ack *extack) | |
13d2a1d2 PM |
206 | { |
207 | struct drr_class *cl = (struct drr_class *)arg; | |
208 | ||
209 | if (new == NULL) { | |
a38a9882 AA |
210 | new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, |
211 | cl->common.classid, NULL); | |
13d2a1d2 PM |
212 | if (new == NULL) |
213 | new = &noop_qdisc; | |
214 | } | |
215 | ||
86a7996c | 216 | *old = qdisc_replace(sch, new, &cl->qdisc); |
13d2a1d2 PM |
217 | return 0; |
218 | } | |
219 | ||
220 | static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg) | |
221 | { | |
222 | struct drr_class *cl = (struct drr_class *)arg; | |
223 | ||
224 | return cl->qdisc; | |
225 | } | |
226 | ||
227 | static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg) | |
228 | { | |
229 | struct drr_class *cl = (struct drr_class *)arg; | |
230 | ||
95946658 | 231 | list_del(&cl->alist); |
13d2a1d2 PM |
232 | } |
233 | ||
234 | static int drr_dump_class(struct Qdisc *sch, unsigned long arg, | |
235 | struct sk_buff *skb, struct tcmsg *tcm) | |
236 | { | |
237 | struct drr_class *cl = (struct drr_class *)arg; | |
238 | struct nlattr *nest; | |
239 | ||
240 | tcm->tcm_parent = TC_H_ROOT; | |
241 | tcm->tcm_handle = cl->common.classid; | |
242 | tcm->tcm_info = cl->qdisc->handle; | |
243 | ||
ae0be8de | 244 | nest = nla_nest_start_noflag(skb, TCA_OPTIONS); |
13d2a1d2 PM |
245 | if (nest == NULL) |
246 | goto nla_put_failure; | |
1b34ec43 DM |
247 | if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum)) |
248 | goto nla_put_failure; | |
13d2a1d2 PM |
249 | return nla_nest_end(skb, nest); |
250 | ||
251 | nla_put_failure: | |
252 | nla_nest_cancel(skb, nest); | |
253 | return -EMSGSIZE; | |
254 | } | |
255 | ||
256 | static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg, | |
257 | struct gnet_dump *d) | |
258 | { | |
259 | struct drr_class *cl = (struct drr_class *)arg; | |
5dd431b6 PA |
260 | __u32 qlen = qdisc_qlen_sum(cl->qdisc); |
261 | struct Qdisc *cl_q = cl->qdisc; | |
13d2a1d2 PM |
262 | struct tc_drr_stats xstats; |
263 | ||
264 | memset(&xstats, 0, sizeof(xstats)); | |
64015853 | 265 | if (qlen) |
13d2a1d2 PM |
266 | xstats.deficit = cl->deficit; |
267 | ||
29cbcd85 | 268 | if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 || |
1c0d32fd | 269 | gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 || |
5dd431b6 | 270 | gnet_stats_copy_queue(d, cl_q->cpu_qstats, &cl_q->qstats, qlen) < 0) |
13d2a1d2 PM |
271 | return -1; |
272 | ||
273 | return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); | |
274 | } | |
275 | ||
276 | static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg) | |
277 | { | |
278 | struct drr_sched *q = qdisc_priv(sch); | |
279 | struct drr_class *cl; | |
13d2a1d2 PM |
280 | unsigned int i; |
281 | ||
282 | if (arg->stop) | |
283 | return; | |
284 | ||
285 | for (i = 0; i < q->clhash.hashsize; i++) { | |
b67bfe0d | 286 | hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) { |
13d2a1d2 PM |
287 | if (arg->count < arg->skip) { |
288 | arg->count++; | |
289 | continue; | |
290 | } | |
291 | if (arg->fn(sch, (unsigned long)cl, arg) < 0) { | |
292 | arg->stop = 1; | |
293 | return; | |
294 | } | |
295 | arg->count++; | |
296 | } | |
297 | } | |
298 | } | |
299 | ||
300 | static 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); |
13d2a1d2 PM |
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; |
13d2a1d2 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 | 338 | static 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); |
13d2a1d2 PM |
342 | struct drr_sched *q = qdisc_priv(sch); |
343 | struct drr_class *cl; | |
f54ba779 | 344 | int err = 0; |
37d9cf1a | 345 | bool first; |
13d2a1d2 PM |
346 | |
347 | cl = drr_classify(skb, sch, &err); | |
348 | if (cl == NULL) { | |
349 | if (err & __NET_XMIT_BYPASS) | |
25331d6c | 350 | qdisc_qstats_drop(sch); |
520ac30f | 351 | __qdisc_drop(skb, to_free); |
13d2a1d2 PM |
352 | return err; |
353 | } | |
354 | ||
37d9cf1a | 355 | first = !cl->qdisc->q.qlen; |
ac5c66f2 | 356 | err = qdisc_enqueue(skb, cl->qdisc, to_free); |
13d2a1d2 PM |
357 | if (unlikely(err != NET_XMIT_SUCCESS)) { |
358 | if (net_xmit_drop_count(err)) { | |
359 | cl->qstats.drops++; | |
25331d6c | 360 | qdisc_qstats_drop(sch); |
13d2a1d2 PM |
361 | } |
362 | return err; | |
363 | } | |
364 | ||
37d9cf1a | 365 | if (first) { |
13d2a1d2 PM |
366 | list_add_tail(&cl->alist, &q->active); |
367 | cl->deficit = cl->quantum; | |
368 | } | |
369 | ||
f6bab199 | 370 | sch->qstats.backlog += len; |
13d2a1d2 PM |
371 | sch->q.qlen++; |
372 | return err; | |
373 | } | |
374 | ||
375 | static struct sk_buff *drr_dequeue(struct Qdisc *sch) | |
376 | { | |
377 | struct drr_sched *q = qdisc_priv(sch); | |
378 | struct drr_class *cl; | |
379 | struct sk_buff *skb; | |
380 | unsigned int len; | |
381 | ||
3f0947c3 PM |
382 | if (list_empty(&q->active)) |
383 | goto out; | |
384 | while (1) { | |
13d2a1d2 PM |
385 | cl = list_first_entry(&q->active, struct drr_class, alist); |
386 | skb = cl->qdisc->ops->peek(cl->qdisc); | |
6e765a00 FW |
387 | if (skb == NULL) { |
388 | qdisc_warn_nonwc(__func__, cl->qdisc); | |
3f0947c3 | 389 | goto out; |
6e765a00 | 390 | } |
13d2a1d2 PM |
391 | |
392 | len = qdisc_pkt_len(skb); | |
393 | if (len <= cl->deficit) { | |
394 | cl->deficit -= len; | |
395 | skb = qdisc_dequeue_peeked(cl->qdisc); | |
df3eb6cd BH |
396 | if (unlikely(skb == NULL)) |
397 | goto out; | |
13d2a1d2 PM |
398 | if (cl->qdisc->q.qlen == 0) |
399 | list_del(&cl->alist); | |
2dd875ff ED |
400 | |
401 | bstats_update(&cl->bstats, skb); | |
9190b3b3 | 402 | qdisc_bstats_update(sch, skb); |
6a73b571 | 403 | qdisc_qstats_backlog_dec(sch, skb); |
13d2a1d2 PM |
404 | sch->q.qlen--; |
405 | return skb; | |
406 | } | |
407 | ||
408 | cl->deficit += cl->quantum; | |
13d2a1d2 PM |
409 | list_move_tail(&cl->alist, &q->active); |
410 | } | |
3f0947c3 | 411 | out: |
13d2a1d2 PM |
412 | return NULL; |
413 | } | |
414 | ||
e63d7dfd AA |
415 | static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt, |
416 | struct netlink_ext_ack *extack) | |
13d2a1d2 PM |
417 | { |
418 | struct drr_sched *q = qdisc_priv(sch); | |
419 | int err; | |
420 | ||
8d1a77f9 | 421 | err = tcf_block_get(&q->block, &q->filter_list, sch, extack); |
6529eaba JP |
422 | if (err) |
423 | return err; | |
13d2a1d2 PM |
424 | err = qdisc_class_hash_init(&q->clhash); |
425 | if (err < 0) | |
426 | return err; | |
427 | INIT_LIST_HEAD(&q->active); | |
428 | return 0; | |
429 | } | |
430 | ||
431 | static void drr_reset_qdisc(struct Qdisc *sch) | |
432 | { | |
433 | struct drr_sched *q = qdisc_priv(sch); | |
434 | struct drr_class *cl; | |
13d2a1d2 PM |
435 | unsigned int i; |
436 | ||
437 | for (i = 0; i < q->clhash.hashsize; i++) { | |
b67bfe0d | 438 | hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) { |
13d2a1d2 PM |
439 | if (cl->qdisc->q.qlen) |
440 | list_del(&cl->alist); | |
441 | qdisc_reset(cl->qdisc); | |
442 | } | |
443 | } | |
6a73b571 | 444 | sch->qstats.backlog = 0; |
13d2a1d2 PM |
445 | sch->q.qlen = 0; |
446 | } | |
447 | ||
448 | static void drr_destroy_qdisc(struct Qdisc *sch) | |
449 | { | |
450 | struct drr_sched *q = qdisc_priv(sch); | |
451 | struct drr_class *cl; | |
b67bfe0d | 452 | struct hlist_node *next; |
13d2a1d2 PM |
453 | unsigned int i; |
454 | ||
6529eaba | 455 | tcf_block_put(q->block); |
13d2a1d2 PM |
456 | |
457 | for (i = 0; i < q->clhash.hashsize; i++) { | |
b67bfe0d | 458 | hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i], |
13d2a1d2 PM |
459 | common.hnode) |
460 | drr_destroy_class(sch, cl); | |
461 | } | |
462 | qdisc_class_hash_destroy(&q->clhash); | |
463 | } | |
464 | ||
465 | static const struct Qdisc_class_ops drr_class_ops = { | |
466 | .change = drr_change_class, | |
467 | .delete = drr_delete_class, | |
143976ce | 468 | .find = drr_search_class, |
6529eaba | 469 | .tcf_block = drr_tcf_block, |
13d2a1d2 PM |
470 | .bind_tcf = drr_bind_tcf, |
471 | .unbind_tcf = drr_unbind_tcf, | |
472 | .graft = drr_graft_class, | |
473 | .leaf = drr_class_leaf, | |
474 | .qlen_notify = drr_qlen_notify, | |
475 | .dump = drr_dump_class, | |
476 | .dump_stats = drr_dump_class_stats, | |
477 | .walk = drr_walk, | |
478 | }; | |
479 | ||
480 | static struct Qdisc_ops drr_qdisc_ops __read_mostly = { | |
481 | .cl_ops = &drr_class_ops, | |
482 | .id = "drr", | |
483 | .priv_size = sizeof(struct drr_sched), | |
484 | .enqueue = drr_enqueue, | |
485 | .dequeue = drr_dequeue, | |
486 | .peek = qdisc_peek_dequeued, | |
13d2a1d2 PM |
487 | .init = drr_init_qdisc, |
488 | .reset = drr_reset_qdisc, | |
489 | .destroy = drr_destroy_qdisc, | |
490 | .owner = THIS_MODULE, | |
491 | }; | |
492 | ||
493 | static int __init drr_init(void) | |
494 | { | |
495 | return register_qdisc(&drr_qdisc_ops); | |
496 | } | |
497 | ||
498 | static void __exit drr_exit(void) | |
499 | { | |
500 | unregister_qdisc(&drr_qdisc_ops); | |
501 | } | |
502 | ||
503 | module_init(drr_init); | |
504 | module_exit(drr_exit); | |
505 | MODULE_LICENSE("GPL"); |