Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * net/sched/sch_prio.c Simple 3-band priority "scheduler". | |
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> | |
10297b99 | 10 | * Fixes: 19990609: J Hadi Salim <hadi@nortelnetworks.com>: |
1da177e4 LT |
11 | * Init -- EINVAL when opt undefined |
12 | */ | |
13 | ||
1da177e4 | 14 | #include <linux/module.h> |
1da177e4 LT |
15 | #include <linux/types.h> |
16 | #include <linux/kernel.h> | |
1da177e4 | 17 | #include <linux/string.h> |
1da177e4 | 18 | #include <linux/errno.h> |
1da177e4 | 19 | #include <linux/skbuff.h> |
dc5fc579 | 20 | #include <net/netlink.h> |
1da177e4 LT |
21 | #include <net/pkt_sched.h> |
22 | ||
23 | ||
24 | struct prio_sched_data | |
25 | { | |
26 | int bands; | |
d62733c8 | 27 | int curband; /* for round-robin */ |
1da177e4 LT |
28 | struct tcf_proto *filter_list; |
29 | u8 prio2band[TC_PRIO_MAX+1]; | |
30 | struct Qdisc *queues[TCQ_PRIO_BANDS]; | |
d62733c8 | 31 | int mq; |
1da177e4 LT |
32 | }; |
33 | ||
34 | ||
35 | static struct Qdisc * | |
36 | prio_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr) | |
37 | { | |
38 | struct prio_sched_data *q = qdisc_priv(sch); | |
39 | u32 band = skb->priority; | |
40 | struct tcf_result res; | |
bdba91ec | 41 | int err; |
1da177e4 | 42 | |
29f1df6c | 43 | *qerr = NET_XMIT_BYPASS; |
1da177e4 | 44 | if (TC_H_MAJ(skb->priority) != sch->handle) { |
bdba91ec | 45 | err = tc_classify(skb, q->filter_list, &res); |
1da177e4 | 46 | #ifdef CONFIG_NET_CLS_ACT |
dbaaa07a | 47 | switch (err) { |
1da177e4 LT |
48 | case TC_ACT_STOLEN: |
49 | case TC_ACT_QUEUED: | |
50 | *qerr = NET_XMIT_SUCCESS; | |
51 | case TC_ACT_SHOT: | |
52 | return NULL; | |
3ff50b79 | 53 | } |
1da177e4 | 54 | #endif |
bdba91ec | 55 | if (!q->filter_list || err < 0) { |
1da177e4 LT |
56 | if (TC_H_MAJ(band)) |
57 | band = 0; | |
d62733c8 PWJ |
58 | band = q->prio2band[band&TC_PRIO_MAX]; |
59 | goto out; | |
1da177e4 LT |
60 | } |
61 | band = res.classid; | |
62 | } | |
63 | band = TC_H_MIN(band) - 1; | |
3e5c2d3b | 64 | if (band >= q->bands) |
d62733c8 PWJ |
65 | band = q->prio2band[0]; |
66 | out: | |
67 | if (q->mq) | |
68 | skb_set_queue_mapping(skb, band); | |
1da177e4 LT |
69 | return q->queues[band]; |
70 | } | |
71 | ||
72 | static int | |
73 | prio_enqueue(struct sk_buff *skb, struct Qdisc *sch) | |
74 | { | |
75 | struct Qdisc *qdisc; | |
76 | int ret; | |
77 | ||
78 | qdisc = prio_classify(skb, sch, &ret); | |
79 | #ifdef CONFIG_NET_CLS_ACT | |
80 | if (qdisc == NULL) { | |
29f1df6c JHS |
81 | |
82 | if (ret == NET_XMIT_BYPASS) | |
1da177e4 LT |
83 | sch->qstats.drops++; |
84 | kfree_skb(skb); | |
85 | return ret; | |
86 | } | |
87 | #endif | |
88 | ||
89 | if ((ret = qdisc->enqueue(skb, qdisc)) == NET_XMIT_SUCCESS) { | |
90 | sch->bstats.bytes += skb->len; | |
91 | sch->bstats.packets++; | |
92 | sch->q.qlen++; | |
93 | return NET_XMIT_SUCCESS; | |
94 | } | |
95 | sch->qstats.drops++; | |
10297b99 | 96 | return ret; |
1da177e4 LT |
97 | } |
98 | ||
99 | ||
100 | static int | |
101 | prio_requeue(struct sk_buff *skb, struct Qdisc* sch) | |
102 | { | |
103 | struct Qdisc *qdisc; | |
104 | int ret; | |
105 | ||
106 | qdisc = prio_classify(skb, sch, &ret); | |
107 | #ifdef CONFIG_NET_CLS_ACT | |
108 | if (qdisc == NULL) { | |
29f1df6c | 109 | if (ret == NET_XMIT_BYPASS) |
1da177e4 LT |
110 | sch->qstats.drops++; |
111 | kfree_skb(skb); | |
112 | return ret; | |
113 | } | |
114 | #endif | |
115 | ||
116 | if ((ret = qdisc->ops->requeue(skb, qdisc)) == NET_XMIT_SUCCESS) { | |
117 | sch->q.qlen++; | |
118 | sch->qstats.requeues++; | |
119 | return 0; | |
120 | } | |
121 | sch->qstats.drops++; | |
122 | return NET_XMIT_DROP; | |
123 | } | |
124 | ||
125 | ||
126 | static struct sk_buff * | |
127 | prio_dequeue(struct Qdisc* sch) | |
128 | { | |
129 | struct sk_buff *skb; | |
130 | struct prio_sched_data *q = qdisc_priv(sch); | |
131 | int prio; | |
132 | struct Qdisc *qdisc; | |
133 | ||
134 | for (prio = 0; prio < q->bands; prio++) { | |
d62733c8 PWJ |
135 | /* Check if the target subqueue is available before |
136 | * pulling an skb. This way we avoid excessive requeues | |
137 | * for slower queues. | |
138 | */ | |
00346226 | 139 | if (!__netif_subqueue_stopped(sch->dev, (q->mq ? prio : 0))) { |
d62733c8 PWJ |
140 | qdisc = q->queues[prio]; |
141 | skb = qdisc->dequeue(qdisc); | |
142 | if (skb) { | |
143 | sch->q.qlen--; | |
144 | return skb; | |
145 | } | |
1da177e4 LT |
146 | } |
147 | } | |
148 | return NULL; | |
149 | ||
150 | } | |
151 | ||
d62733c8 PWJ |
152 | static struct sk_buff *rr_dequeue(struct Qdisc* sch) |
153 | { | |
154 | struct sk_buff *skb; | |
155 | struct prio_sched_data *q = qdisc_priv(sch); | |
156 | struct Qdisc *qdisc; | |
157 | int bandcount; | |
158 | ||
159 | /* Only take one pass through the queues. If nothing is available, | |
160 | * return nothing. | |
161 | */ | |
162 | for (bandcount = 0; bandcount < q->bands; bandcount++) { | |
163 | /* Check if the target subqueue is available before | |
164 | * pulling an skb. This way we avoid excessive requeues | |
165 | * for slower queues. If the queue is stopped, try the | |
166 | * next queue. | |
167 | */ | |
00346226 | 168 | if (!__netif_subqueue_stopped(sch->dev, |
d62733c8 PWJ |
169 | (q->mq ? q->curband : 0))) { |
170 | qdisc = q->queues[q->curband]; | |
171 | skb = qdisc->dequeue(qdisc); | |
172 | if (skb) { | |
173 | sch->q.qlen--; | |
174 | q->curband++; | |
175 | if (q->curband >= q->bands) | |
176 | q->curband = 0; | |
177 | return skb; | |
178 | } | |
179 | } | |
180 | q->curband++; | |
181 | if (q->curband >= q->bands) | |
182 | q->curband = 0; | |
183 | } | |
184 | return NULL; | |
185 | } | |
186 | ||
1da177e4 LT |
187 | static unsigned int prio_drop(struct Qdisc* sch) |
188 | { | |
189 | struct prio_sched_data *q = qdisc_priv(sch); | |
190 | int prio; | |
191 | unsigned int len; | |
192 | struct Qdisc *qdisc; | |
193 | ||
194 | for (prio = q->bands-1; prio >= 0; prio--) { | |
195 | qdisc = q->queues[prio]; | |
6d037a26 | 196 | if (qdisc->ops->drop && (len = qdisc->ops->drop(qdisc)) != 0) { |
1da177e4 LT |
197 | sch->q.qlen--; |
198 | return len; | |
199 | } | |
200 | } | |
201 | return 0; | |
202 | } | |
203 | ||
204 | ||
205 | static void | |
206 | prio_reset(struct Qdisc* sch) | |
207 | { | |
208 | int prio; | |
209 | struct prio_sched_data *q = qdisc_priv(sch); | |
210 | ||
211 | for (prio=0; prio<q->bands; prio++) | |
212 | qdisc_reset(q->queues[prio]); | |
213 | sch->q.qlen = 0; | |
214 | } | |
215 | ||
216 | static void | |
217 | prio_destroy(struct Qdisc* sch) | |
218 | { | |
219 | int prio; | |
220 | struct prio_sched_data *q = qdisc_priv(sch); | |
1da177e4 | 221 | |
a48b5a61 | 222 | tcf_destroy_chain(q->filter_list); |
1da177e4 LT |
223 | for (prio=0; prio<q->bands; prio++) |
224 | qdisc_destroy(q->queues[prio]); | |
225 | } | |
226 | ||
1e90474c | 227 | static int prio_tune(struct Qdisc *sch, struct nlattr *opt) |
1da177e4 LT |
228 | { |
229 | struct prio_sched_data *q = qdisc_priv(sch); | |
d62733c8 | 230 | struct tc_prio_qopt *qopt; |
1e90474c | 231 | struct nlattr *tb[TCA_PRIO_MAX + 1]; |
cee63723 | 232 | int err; |
1da177e4 LT |
233 | int i; |
234 | ||
cee63723 PM |
235 | err = nla_parse_nested_compat(tb, TCA_PRIO_MAX, opt, NULL, qopt, |
236 | sizeof(*qopt)); | |
237 | if (err < 0) | |
238 | return err; | |
239 | ||
d62733c8 PWJ |
240 | q->bands = qopt->bands; |
241 | /* If we're multiqueue, make sure the number of incoming bands | |
242 | * matches the number of queues on the device we're associating with. | |
243 | * If the number of bands requested is zero, then set q->bands to | |
0773192b PWJ |
244 | * dev->egress_subqueue_count. Also, the root qdisc must be the |
245 | * only one that is enabled for multiqueue, since it's the only one | |
246 | * that interacts with the underlying device. | |
d62733c8 | 247 | */ |
1e90474c | 248 | q->mq = nla_get_flag(tb[TCA_PRIO_MQ]); |
d62733c8 | 249 | if (q->mq) { |
0773192b | 250 | if (sch->parent != TC_H_ROOT) |
d62733c8 PWJ |
251 | return -EINVAL; |
252 | if (netif_is_multiqueue(sch->dev)) { | |
253 | if (q->bands == 0) | |
254 | q->bands = sch->dev->egress_subqueue_count; | |
255 | else if (q->bands != sch->dev->egress_subqueue_count) | |
256 | return -EINVAL; | |
257 | } else | |
258 | return -EOPNOTSUPP; | |
259 | } | |
260 | ||
261 | if (q->bands > TCQ_PRIO_BANDS || q->bands < 2) | |
1da177e4 LT |
262 | return -EINVAL; |
263 | ||
264 | for (i=0; i<=TC_PRIO_MAX; i++) { | |
d62733c8 | 265 | if (qopt->priomap[i] >= q->bands) |
1da177e4 LT |
266 | return -EINVAL; |
267 | } | |
268 | ||
269 | sch_tree_lock(sch); | |
1da177e4 LT |
270 | memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1); |
271 | ||
272 | for (i=q->bands; i<TCQ_PRIO_BANDS; i++) { | |
273 | struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc); | |
5e50da01 PM |
274 | if (child != &noop_qdisc) { |
275 | qdisc_tree_decrease_qlen(child, child->q.qlen); | |
1da177e4 | 276 | qdisc_destroy(child); |
5e50da01 | 277 | } |
1da177e4 LT |
278 | } |
279 | sch_tree_unlock(sch); | |
280 | ||
dd914b40 AA |
281 | for (i=0; i<q->bands; i++) { |
282 | if (q->queues[i] == &noop_qdisc) { | |
1da177e4 | 283 | struct Qdisc *child; |
9f9afec4 PM |
284 | child = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, |
285 | TC_H_MAKE(sch->handle, i + 1)); | |
1da177e4 LT |
286 | if (child) { |
287 | sch_tree_lock(sch); | |
dd914b40 | 288 | child = xchg(&q->queues[i], child); |
1da177e4 | 289 | |
5e50da01 PM |
290 | if (child != &noop_qdisc) { |
291 | qdisc_tree_decrease_qlen(child, | |
292 | child->q.qlen); | |
1da177e4 | 293 | qdisc_destroy(child); |
5e50da01 | 294 | } |
1da177e4 LT |
295 | sch_tree_unlock(sch); |
296 | } | |
297 | } | |
298 | } | |
299 | return 0; | |
300 | } | |
301 | ||
1e90474c | 302 | static int prio_init(struct Qdisc *sch, struct nlattr *opt) |
1da177e4 LT |
303 | { |
304 | struct prio_sched_data *q = qdisc_priv(sch); | |
305 | int i; | |
306 | ||
307 | for (i=0; i<TCQ_PRIO_BANDS; i++) | |
308 | q->queues[i] = &noop_qdisc; | |
309 | ||
310 | if (opt == NULL) { | |
311 | return -EINVAL; | |
312 | } else { | |
313 | int err; | |
314 | ||
315 | if ((err= prio_tune(sch, opt)) != 0) | |
316 | return err; | |
317 | } | |
318 | return 0; | |
319 | } | |
320 | ||
321 | static int prio_dump(struct Qdisc *sch, struct sk_buff *skb) | |
322 | { | |
323 | struct prio_sched_data *q = qdisc_priv(sch); | |
27a884dc | 324 | unsigned char *b = skb_tail_pointer(skb); |
1e90474c | 325 | struct nlattr *nest; |
1da177e4 LT |
326 | struct tc_prio_qopt opt; |
327 | ||
328 | opt.bands = q->bands; | |
329 | memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX+1); | |
d62733c8 | 330 | |
1e90474c PM |
331 | nest = nla_nest_compat_start(skb, TCA_OPTIONS, sizeof(opt), &opt); |
332 | if (nest == NULL) | |
333 | goto nla_put_failure; | |
334 | if (q->mq) { | |
335 | if (nla_put_flag(skb, TCA_PRIO_MQ) < 0) | |
336 | goto nla_put_failure; | |
337 | } | |
338 | nla_nest_compat_end(skb, nest); | |
d62733c8 | 339 | |
1da177e4 LT |
340 | return skb->len; |
341 | ||
1e90474c | 342 | nla_put_failure: |
dc5fc579 | 343 | nlmsg_trim(skb, b); |
1da177e4 LT |
344 | return -1; |
345 | } | |
346 | ||
347 | static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, | |
348 | struct Qdisc **old) | |
349 | { | |
350 | struct prio_sched_data *q = qdisc_priv(sch); | |
351 | unsigned long band = arg - 1; | |
352 | ||
353 | if (band >= q->bands) | |
354 | return -EINVAL; | |
355 | ||
356 | if (new == NULL) | |
357 | new = &noop_qdisc; | |
358 | ||
359 | sch_tree_lock(sch); | |
360 | *old = q->queues[band]; | |
361 | q->queues[band] = new; | |
5e50da01 | 362 | qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); |
1da177e4 LT |
363 | qdisc_reset(*old); |
364 | sch_tree_unlock(sch); | |
365 | ||
366 | return 0; | |
367 | } | |
368 | ||
369 | static struct Qdisc * | |
370 | prio_leaf(struct Qdisc *sch, unsigned long arg) | |
371 | { | |
372 | struct prio_sched_data *q = qdisc_priv(sch); | |
373 | unsigned long band = arg - 1; | |
374 | ||
375 | if (band >= q->bands) | |
376 | return NULL; | |
377 | ||
378 | return q->queues[band]; | |
379 | } | |
380 | ||
381 | static unsigned long prio_get(struct Qdisc *sch, u32 classid) | |
382 | { | |
383 | struct prio_sched_data *q = qdisc_priv(sch); | |
384 | unsigned long band = TC_H_MIN(classid); | |
385 | ||
386 | if (band - 1 >= q->bands) | |
387 | return 0; | |
388 | return band; | |
389 | } | |
390 | ||
391 | static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid) | |
392 | { | |
393 | return prio_get(sch, classid); | |
394 | } | |
395 | ||
396 | ||
397 | static void prio_put(struct Qdisc *q, unsigned long cl) | |
398 | { | |
399 | return; | |
400 | } | |
401 | ||
1e90474c | 402 | static int prio_change(struct Qdisc *sch, u32 handle, u32 parent, struct nlattr **tca, unsigned long *arg) |
1da177e4 LT |
403 | { |
404 | unsigned long cl = *arg; | |
405 | struct prio_sched_data *q = qdisc_priv(sch); | |
406 | ||
407 | if (cl - 1 > q->bands) | |
408 | return -ENOENT; | |
409 | return 0; | |
410 | } | |
411 | ||
412 | static int prio_delete(struct Qdisc *sch, unsigned long cl) | |
413 | { | |
414 | struct prio_sched_data *q = qdisc_priv(sch); | |
415 | if (cl - 1 > q->bands) | |
416 | return -ENOENT; | |
417 | return 0; | |
418 | } | |
419 | ||
420 | ||
421 | static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb, | |
422 | struct tcmsg *tcm) | |
423 | { | |
424 | struct prio_sched_data *q = qdisc_priv(sch); | |
425 | ||
426 | if (cl - 1 > q->bands) | |
427 | return -ENOENT; | |
428 | tcm->tcm_handle |= TC_H_MIN(cl); | |
429 | if (q->queues[cl-1]) | |
430 | tcm->tcm_info = q->queues[cl-1]->handle; | |
431 | return 0; | |
432 | } | |
433 | ||
2cf6c36c JP |
434 | static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl, |
435 | struct gnet_dump *d) | |
436 | { | |
437 | struct prio_sched_data *q = qdisc_priv(sch); | |
438 | struct Qdisc *cl_q; | |
439 | ||
440 | cl_q = q->queues[cl - 1]; | |
441 | if (gnet_stats_copy_basic(d, &cl_q->bstats) < 0 || | |
442 | gnet_stats_copy_queue(d, &cl_q->qstats) < 0) | |
443 | return -1; | |
444 | ||
445 | return 0; | |
446 | } | |
447 | ||
1da177e4 LT |
448 | static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg) |
449 | { | |
450 | struct prio_sched_data *q = qdisc_priv(sch); | |
451 | int prio; | |
452 | ||
453 | if (arg->stop) | |
454 | return; | |
455 | ||
456 | for (prio = 0; prio < q->bands; prio++) { | |
457 | if (arg->count < arg->skip) { | |
458 | arg->count++; | |
459 | continue; | |
460 | } | |
461 | if (arg->fn(sch, prio+1, arg) < 0) { | |
462 | arg->stop = 1; | |
463 | break; | |
464 | } | |
465 | arg->count++; | |
466 | } | |
467 | } | |
468 | ||
469 | static struct tcf_proto ** prio_find_tcf(struct Qdisc *sch, unsigned long cl) | |
470 | { | |
471 | struct prio_sched_data *q = qdisc_priv(sch); | |
472 | ||
473 | if (cl) | |
474 | return NULL; | |
475 | return &q->filter_list; | |
476 | } | |
477 | ||
20fea08b | 478 | static const struct Qdisc_class_ops prio_class_ops = { |
1da177e4 LT |
479 | .graft = prio_graft, |
480 | .leaf = prio_leaf, | |
481 | .get = prio_get, | |
482 | .put = prio_put, | |
483 | .change = prio_change, | |
484 | .delete = prio_delete, | |
485 | .walk = prio_walk, | |
486 | .tcf_chain = prio_find_tcf, | |
487 | .bind_tcf = prio_bind, | |
488 | .unbind_tcf = prio_put, | |
489 | .dump = prio_dump_class, | |
2cf6c36c | 490 | .dump_stats = prio_dump_class_stats, |
1da177e4 LT |
491 | }; |
492 | ||
20fea08b | 493 | static struct Qdisc_ops prio_qdisc_ops __read_mostly = { |
1da177e4 LT |
494 | .next = NULL, |
495 | .cl_ops = &prio_class_ops, | |
496 | .id = "prio", | |
497 | .priv_size = sizeof(struct prio_sched_data), | |
498 | .enqueue = prio_enqueue, | |
499 | .dequeue = prio_dequeue, | |
500 | .requeue = prio_requeue, | |
501 | .drop = prio_drop, | |
502 | .init = prio_init, | |
503 | .reset = prio_reset, | |
504 | .destroy = prio_destroy, | |
505 | .change = prio_tune, | |
506 | .dump = prio_dump, | |
507 | .owner = THIS_MODULE, | |
508 | }; | |
509 | ||
20fea08b | 510 | static struct Qdisc_ops rr_qdisc_ops __read_mostly = { |
d62733c8 PWJ |
511 | .next = NULL, |
512 | .cl_ops = &prio_class_ops, | |
513 | .id = "rr", | |
514 | .priv_size = sizeof(struct prio_sched_data), | |
515 | .enqueue = prio_enqueue, | |
516 | .dequeue = rr_dequeue, | |
517 | .requeue = prio_requeue, | |
518 | .drop = prio_drop, | |
519 | .init = prio_init, | |
520 | .reset = prio_reset, | |
521 | .destroy = prio_destroy, | |
522 | .change = prio_tune, | |
523 | .dump = prio_dump, | |
524 | .owner = THIS_MODULE, | |
525 | }; | |
526 | ||
1da177e4 LT |
527 | static int __init prio_module_init(void) |
528 | { | |
d62733c8 PWJ |
529 | int err; |
530 | ||
531 | err = register_qdisc(&prio_qdisc_ops); | |
532 | if (err < 0) | |
533 | return err; | |
534 | err = register_qdisc(&rr_qdisc_ops); | |
535 | if (err < 0) | |
536 | unregister_qdisc(&prio_qdisc_ops); | |
537 | return err; | |
1da177e4 LT |
538 | } |
539 | ||
10297b99 | 540 | static void __exit prio_module_exit(void) |
1da177e4 LT |
541 | { |
542 | unregister_qdisc(&prio_qdisc_ops); | |
d62733c8 | 543 | unregister_qdisc(&rr_qdisc_ops); |
1da177e4 LT |
544 | } |
545 | ||
546 | module_init(prio_module_init) | |
547 | module_exit(prio_module_exit) | |
548 | ||
549 | MODULE_LICENSE("GPL"); | |
d62733c8 | 550 | MODULE_ALIAS("sch_rr"); |