[NET]: Move Qdisc_class_ops and Qdisc_ops in appropriate sections.
[linux-2.6.git] / net / sched / sch_prio.c
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>
10  * Fixes:       19990609: J Hadi Salim <hadi@nortelnetworks.com>:
11  *              Init --  EINVAL when opt undefined
12  */
13
14 #include <linux/module.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
23
24 struct prio_sched_data
25 {
26         int bands;
27         int curband; /* for round-robin */
28         struct tcf_proto *filter_list;
29         u8  prio2band[TC_PRIO_MAX+1];
30         struct Qdisc *queues[TCQ_PRIO_BANDS];
31         int mq;
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;
41         int err;
42
43         *qerr = NET_XMIT_BYPASS;
44         if (TC_H_MAJ(skb->priority) != sch->handle) {
45                 err = tc_classify(skb, q->filter_list, &res);
46 #ifdef CONFIG_NET_CLS_ACT
47                 switch (err) {
48                 case TC_ACT_STOLEN:
49                 case TC_ACT_QUEUED:
50                         *qerr = NET_XMIT_SUCCESS;
51                 case TC_ACT_SHOT:
52                         return NULL;
53                 }
54 #endif
55                 if (!q->filter_list || err < 0) {
56                         if (TC_H_MAJ(band))
57                                 band = 0;
58                         band = q->prio2band[band&TC_PRIO_MAX];
59                         goto out;
60                 }
61                 band = res.classid;
62         }
63         band = TC_H_MIN(band) - 1;
64         if (band >= q->bands)
65                 band = q->prio2band[0];
66 out:
67         if (q->mq)
68                 skb_set_queue_mapping(skb, band);
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) {
81
82                 if (ret == NET_XMIT_BYPASS)
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++;
96         return ret;
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) {
109                 if (ret == NET_XMIT_BYPASS)
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++) {
135                 /* Check if the target subqueue is available before
136                  * pulling an skb.  This way we avoid excessive requeues
137                  * for slower queues.
138                  */
139                 if (!__netif_subqueue_stopped(sch->dev, (q->mq ? prio : 0))) {
140                         qdisc = q->queues[prio];
141                         skb = qdisc->dequeue(qdisc);
142                         if (skb) {
143                                 sch->q.qlen--;
144                                 return skb;
145                         }
146                 }
147         }
148         return NULL;
149
150 }
151
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                  */
168                 if (!__netif_subqueue_stopped(sch->dev,
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
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];
196                 if (qdisc->ops->drop && (len = qdisc->ops->drop(qdisc)) != 0) {
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);
221
222         tcf_destroy_chain(q->filter_list);
223         for (prio=0; prio<q->bands; prio++)
224                 qdisc_destroy(q->queues[prio]);
225 }
226
227 static int prio_tune(struct Qdisc *sch, struct rtattr *opt)
228 {
229         struct prio_sched_data *q = qdisc_priv(sch);
230         struct tc_prio_qopt *qopt;
231         struct rtattr *tb[TCA_PRIO_MAX];
232         int i;
233
234         if (rtattr_parse_nested_compat(tb, TCA_PRIO_MAX, opt, qopt,
235                                        sizeof(*qopt)))
236                 return -EINVAL;
237         q->bands = qopt->bands;
238         /* If we're multiqueue, make sure the number of incoming bands
239          * matches the number of queues on the device we're associating with.
240          * If the number of bands requested is zero, then set q->bands to
241          * dev->egress_subqueue_count.  Also, the root qdisc must be the
242          * only one that is enabled for multiqueue, since it's the only one
243          * that interacts with the underlying device.
244          */
245         q->mq = RTA_GET_FLAG(tb[TCA_PRIO_MQ - 1]);
246         if (q->mq) {
247                 if (sch->parent != TC_H_ROOT)
248                         return -EINVAL;
249                 if (netif_is_multiqueue(sch->dev)) {
250                         if (q->bands == 0)
251                                 q->bands = sch->dev->egress_subqueue_count;
252                         else if (q->bands != sch->dev->egress_subqueue_count)
253                                 return -EINVAL;
254                 } else
255                         return -EOPNOTSUPP;
256         }
257
258         if (q->bands > TCQ_PRIO_BANDS || q->bands < 2)
259                 return -EINVAL;
260
261         for (i=0; i<=TC_PRIO_MAX; i++) {
262                 if (qopt->priomap[i] >= q->bands)
263                         return -EINVAL;
264         }
265
266         sch_tree_lock(sch);
267         memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
268
269         for (i=q->bands; i<TCQ_PRIO_BANDS; i++) {
270                 struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc);
271                 if (child != &noop_qdisc) {
272                         qdisc_tree_decrease_qlen(child, child->q.qlen);
273                         qdisc_destroy(child);
274                 }
275         }
276         sch_tree_unlock(sch);
277
278         for (i=0; i<q->bands; i++) {
279                 if (q->queues[i] == &noop_qdisc) {
280                         struct Qdisc *child;
281                         child = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops,
282                                                   TC_H_MAKE(sch->handle, i + 1));
283                         if (child) {
284                                 sch_tree_lock(sch);
285                                 child = xchg(&q->queues[i], child);
286
287                                 if (child != &noop_qdisc) {
288                                         qdisc_tree_decrease_qlen(child,
289                                                                  child->q.qlen);
290                                         qdisc_destroy(child);
291                                 }
292                                 sch_tree_unlock(sch);
293                         }
294                 }
295         }
296         return 0;
297 }
298
299 static int prio_init(struct Qdisc *sch, struct rtattr *opt)
300 {
301         struct prio_sched_data *q = qdisc_priv(sch);
302         int i;
303
304         for (i=0; i<TCQ_PRIO_BANDS; i++)
305                 q->queues[i] = &noop_qdisc;
306
307         if (opt == NULL) {
308                 return -EINVAL;
309         } else {
310                 int err;
311
312                 if ((err= prio_tune(sch, opt)) != 0)
313                         return err;
314         }
315         return 0;
316 }
317
318 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
319 {
320         struct prio_sched_data *q = qdisc_priv(sch);
321         unsigned char *b = skb_tail_pointer(skb);
322         struct rtattr *nest;
323         struct tc_prio_qopt opt;
324
325         opt.bands = q->bands;
326         memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX+1);
327
328         nest = RTA_NEST_COMPAT(skb, TCA_OPTIONS, sizeof(opt), &opt);
329         if (q->mq)
330                 RTA_PUT_FLAG(skb, TCA_PRIO_MQ);
331         RTA_NEST_COMPAT_END(skb, nest);
332
333         return skb->len;
334
335 rtattr_failure:
336         nlmsg_trim(skb, b);
337         return -1;
338 }
339
340 static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
341                       struct Qdisc **old)
342 {
343         struct prio_sched_data *q = qdisc_priv(sch);
344         unsigned long band = arg - 1;
345
346         if (band >= q->bands)
347                 return -EINVAL;
348
349         if (new == NULL)
350                 new = &noop_qdisc;
351
352         sch_tree_lock(sch);
353         *old = q->queues[band];
354         q->queues[band] = new;
355         qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
356         qdisc_reset(*old);
357         sch_tree_unlock(sch);
358
359         return 0;
360 }
361
362 static struct Qdisc *
363 prio_leaf(struct Qdisc *sch, unsigned long arg)
364 {
365         struct prio_sched_data *q = qdisc_priv(sch);
366         unsigned long band = arg - 1;
367
368         if (band >= q->bands)
369                 return NULL;
370
371         return q->queues[band];
372 }
373
374 static unsigned long prio_get(struct Qdisc *sch, u32 classid)
375 {
376         struct prio_sched_data *q = qdisc_priv(sch);
377         unsigned long band = TC_H_MIN(classid);
378
379         if (band - 1 >= q->bands)
380                 return 0;
381         return band;
382 }
383
384 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
385 {
386         return prio_get(sch, classid);
387 }
388
389
390 static void prio_put(struct Qdisc *q, unsigned long cl)
391 {
392         return;
393 }
394
395 static int prio_change(struct Qdisc *sch, u32 handle, u32 parent, struct rtattr **tca, unsigned long *arg)
396 {
397         unsigned long cl = *arg;
398         struct prio_sched_data *q = qdisc_priv(sch);
399
400         if (cl - 1 > q->bands)
401                 return -ENOENT;
402         return 0;
403 }
404
405 static int prio_delete(struct Qdisc *sch, unsigned long cl)
406 {
407         struct prio_sched_data *q = qdisc_priv(sch);
408         if (cl - 1 > q->bands)
409                 return -ENOENT;
410         return 0;
411 }
412
413
414 static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
415                            struct tcmsg *tcm)
416 {
417         struct prio_sched_data *q = qdisc_priv(sch);
418
419         if (cl - 1 > q->bands)
420                 return -ENOENT;
421         tcm->tcm_handle |= TC_H_MIN(cl);
422         if (q->queues[cl-1])
423                 tcm->tcm_info = q->queues[cl-1]->handle;
424         return 0;
425 }
426
427 static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
428                                  struct gnet_dump *d)
429 {
430         struct prio_sched_data *q = qdisc_priv(sch);
431         struct Qdisc *cl_q;
432
433         cl_q = q->queues[cl - 1];
434         if (gnet_stats_copy_basic(d, &cl_q->bstats) < 0 ||
435             gnet_stats_copy_queue(d, &cl_q->qstats) < 0)
436                 return -1;
437
438         return 0;
439 }
440
441 static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
442 {
443         struct prio_sched_data *q = qdisc_priv(sch);
444         int prio;
445
446         if (arg->stop)
447                 return;
448
449         for (prio = 0; prio < q->bands; prio++) {
450                 if (arg->count < arg->skip) {
451                         arg->count++;
452                         continue;
453                 }
454                 if (arg->fn(sch, prio+1, arg) < 0) {
455                         arg->stop = 1;
456                         break;
457                 }
458                 arg->count++;
459         }
460 }
461
462 static struct tcf_proto ** prio_find_tcf(struct Qdisc *sch, unsigned long cl)
463 {
464         struct prio_sched_data *q = qdisc_priv(sch);
465
466         if (cl)
467                 return NULL;
468         return &q->filter_list;
469 }
470
471 static const struct Qdisc_class_ops prio_class_ops = {
472         .graft          =       prio_graft,
473         .leaf           =       prio_leaf,
474         .get            =       prio_get,
475         .put            =       prio_put,
476         .change         =       prio_change,
477         .delete         =       prio_delete,
478         .walk           =       prio_walk,
479         .tcf_chain      =       prio_find_tcf,
480         .bind_tcf       =       prio_bind,
481         .unbind_tcf     =       prio_put,
482         .dump           =       prio_dump_class,
483         .dump_stats     =       prio_dump_class_stats,
484 };
485
486 static struct Qdisc_ops prio_qdisc_ops __read_mostly = {
487         .next           =       NULL,
488         .cl_ops         =       &prio_class_ops,
489         .id             =       "prio",
490         .priv_size      =       sizeof(struct prio_sched_data),
491         .enqueue        =       prio_enqueue,
492         .dequeue        =       prio_dequeue,
493         .requeue        =       prio_requeue,
494         .drop           =       prio_drop,
495         .init           =       prio_init,
496         .reset          =       prio_reset,
497         .destroy        =       prio_destroy,
498         .change         =       prio_tune,
499         .dump           =       prio_dump,
500         .owner          =       THIS_MODULE,
501 };
502
503 static struct Qdisc_ops rr_qdisc_ops __read_mostly = {
504         .next           =       NULL,
505         .cl_ops         =       &prio_class_ops,
506         .id             =       "rr",
507         .priv_size      =       sizeof(struct prio_sched_data),
508         .enqueue        =       prio_enqueue,
509         .dequeue        =       rr_dequeue,
510         .requeue        =       prio_requeue,
511         .drop           =       prio_drop,
512         .init           =       prio_init,
513         .reset          =       prio_reset,
514         .destroy        =       prio_destroy,
515         .change         =       prio_tune,
516         .dump           =       prio_dump,
517         .owner          =       THIS_MODULE,
518 };
519
520 static int __init prio_module_init(void)
521 {
522         int err;
523
524         err = register_qdisc(&prio_qdisc_ops);
525         if (err < 0)
526                 return err;
527         err = register_qdisc(&rr_qdisc_ops);
528         if (err < 0)
529                 unregister_qdisc(&prio_qdisc_ops);
530         return err;
531 }
532
533 static void __exit prio_module_exit(void)
534 {
535         unregister_qdisc(&prio_qdisc_ops);
536         unregister_qdisc(&rr_qdisc_ops);
537 }
538
539 module_init(prio_module_init)
540 module_exit(prio_module_exit)
541
542 MODULE_LICENSE("GPL");
543 MODULE_ALIAS("sch_rr");