microblaze: uaccess: fix put_user and get_user macros
[linux-2.6.git] / net / sched / sch_drr.c
1 /*
2  * net/sched/sch_drr.c         Deficit Round Robin scheduler
3  *
4  * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * version 2 as published by the Free Software Foundation.
9  */
10
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/errno.h>
14 #include <linux/netdevice.h>
15 #include <linux/pkt_sched.h>
16 #include <net/sch_generic.h>
17 #include <net/pkt_sched.h>
18 #include <net/pkt_cls.h>
19
20 struct drr_class {
21         struct Qdisc_class_common       common;
22         unsigned int                    refcnt;
23         unsigned int                    filter_cnt;
24
25         struct gnet_stats_basic_packed          bstats;
26         struct gnet_stats_queue         qstats;
27         struct gnet_stats_rate_est      rate_est;
28         struct list_head                alist;
29         struct Qdisc                    *qdisc;
30
31         u32                             quantum;
32         u32                             deficit;
33 };
34
35 struct drr_sched {
36         struct list_head                active;
37         struct tcf_proto                *filter_list;
38         struct Qdisc_class_hash         clhash;
39 };
40
41 static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid)
42 {
43         struct drr_sched *q = qdisc_priv(sch);
44         struct Qdisc_class_common *clc;
45
46         clc = qdisc_class_find(&q->clhash, classid);
47         if (clc == NULL)
48                 return NULL;
49         return container_of(clc, struct drr_class, common);
50 }
51
52 static void drr_purge_queue(struct drr_class *cl)
53 {
54         unsigned int len = cl->qdisc->q.qlen;
55
56         qdisc_reset(cl->qdisc);
57         qdisc_tree_decrease_qlen(cl->qdisc, len);
58 }
59
60 static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
61         [TCA_DRR_QUANTUM]       = { .type = NLA_U32 },
62 };
63
64 static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
65                             struct nlattr **tca, unsigned long *arg)
66 {
67         struct drr_sched *q = qdisc_priv(sch);
68         struct drr_class *cl = (struct drr_class *)*arg;
69         struct nlattr *opt = tca[TCA_OPTIONS];
70         struct nlattr *tb[TCA_DRR_MAX + 1];
71         u32 quantum;
72         int err;
73
74         if (!opt)
75                 return -EINVAL;
76
77         err = nla_parse_nested(tb, TCA_DRR_MAX, opt, drr_policy);
78         if (err < 0)
79                 return err;
80
81         if (tb[TCA_DRR_QUANTUM]) {
82                 quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
83                 if (quantum == 0)
84                         return -EINVAL;
85         } else
86                 quantum = psched_mtu(qdisc_dev(sch));
87
88         if (cl != NULL) {
89                 if (tca[TCA_RATE]) {
90                         err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
91                                                     qdisc_root_sleeping_lock(sch),
92                                                     tca[TCA_RATE]);
93                         if (err)
94                                 return err;
95                 }
96
97                 sch_tree_lock(sch);
98                 if (tb[TCA_DRR_QUANTUM])
99                         cl->quantum = quantum;
100                 sch_tree_unlock(sch);
101
102                 return 0;
103         }
104
105         cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
106         if (cl == NULL)
107                 return -ENOBUFS;
108
109         cl->refcnt         = 1;
110         cl->common.classid = classid;
111         cl->quantum        = quantum;
112         cl->qdisc          = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
113                                                &pfifo_qdisc_ops, classid);
114         if (cl->qdisc == NULL)
115                 cl->qdisc = &noop_qdisc;
116
117         if (tca[TCA_RATE]) {
118                 err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
119                                             qdisc_root_sleeping_lock(sch),
120                                             tca[TCA_RATE]);
121                 if (err) {
122                         qdisc_destroy(cl->qdisc);
123                         kfree(cl);
124                         return err;
125                 }
126         }
127
128         sch_tree_lock(sch);
129         qdisc_class_hash_insert(&q->clhash, &cl->common);
130         sch_tree_unlock(sch);
131
132         qdisc_class_hash_grow(sch, &q->clhash);
133
134         *arg = (unsigned long)cl;
135         return 0;
136 }
137
138 static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl)
139 {
140         gen_kill_estimator(&cl->bstats, &cl->rate_est);
141         qdisc_destroy(cl->qdisc);
142         kfree(cl);
143 }
144
145 static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
146 {
147         struct drr_sched *q = qdisc_priv(sch);
148         struct drr_class *cl = (struct drr_class *)arg;
149
150         if (cl->filter_cnt > 0)
151                 return -EBUSY;
152
153         sch_tree_lock(sch);
154
155         drr_purge_queue(cl);
156         qdisc_class_hash_remove(&q->clhash, &cl->common);
157
158         BUG_ON(--cl->refcnt == 0);
159         /*
160          * This shouldn't happen: we "hold" one cops->get() when called
161          * from tc_ctl_tclass; the destroy method is done from cops->put().
162          */
163
164         sch_tree_unlock(sch);
165         return 0;
166 }
167
168 static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
169 {
170         struct drr_class *cl = drr_find_class(sch, classid);
171
172         if (cl != NULL)
173                 cl->refcnt++;
174
175         return (unsigned long)cl;
176 }
177
178 static void drr_put_class(struct Qdisc *sch, unsigned long arg)
179 {
180         struct drr_class *cl = (struct drr_class *)arg;
181
182         if (--cl->refcnt == 0)
183                 drr_destroy_class(sch, cl);
184 }
185
186 static struct tcf_proto **drr_tcf_chain(struct Qdisc *sch, unsigned long cl)
187 {
188         struct drr_sched *q = qdisc_priv(sch);
189
190         if (cl)
191                 return NULL;
192
193         return &q->filter_list;
194 }
195
196 static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
197                                   u32 classid)
198 {
199         struct drr_class *cl = drr_find_class(sch, classid);
200
201         if (cl != NULL)
202                 cl->filter_cnt++;
203
204         return (unsigned long)cl;
205 }
206
207 static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
208 {
209         struct drr_class *cl = (struct drr_class *)arg;
210
211         cl->filter_cnt--;
212 }
213
214 static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
215                            struct Qdisc *new, struct Qdisc **old)
216 {
217         struct drr_class *cl = (struct drr_class *)arg;
218
219         if (new == NULL) {
220                 new = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
221                                         &pfifo_qdisc_ops, cl->common.classid);
222                 if (new == NULL)
223                         new = &noop_qdisc;
224         }
225
226         sch_tree_lock(sch);
227         drr_purge_queue(cl);
228         *old = cl->qdisc;
229         cl->qdisc = new;
230         sch_tree_unlock(sch);
231         return 0;
232 }
233
234 static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg)
235 {
236         struct drr_class *cl = (struct drr_class *)arg;
237
238         return cl->qdisc;
239 }
240
241 static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
242 {
243         struct drr_class *cl = (struct drr_class *)arg;
244
245         if (cl->qdisc->q.qlen == 0)
246                 list_del(&cl->alist);
247 }
248
249 static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
250                           struct sk_buff *skb, struct tcmsg *tcm)
251 {
252         struct drr_class *cl = (struct drr_class *)arg;
253         struct nlattr *nest;
254
255         tcm->tcm_parent = TC_H_ROOT;
256         tcm->tcm_handle = cl->common.classid;
257         tcm->tcm_info   = cl->qdisc->handle;
258
259         nest = nla_nest_start(skb, TCA_OPTIONS);
260         if (nest == NULL)
261                 goto nla_put_failure;
262         NLA_PUT_U32(skb, TCA_DRR_QUANTUM, cl->quantum);
263         return nla_nest_end(skb, nest);
264
265 nla_put_failure:
266         nla_nest_cancel(skb, nest);
267         return -EMSGSIZE;
268 }
269
270 static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
271                                 struct gnet_dump *d)
272 {
273         struct drr_class *cl = (struct drr_class *)arg;
274         struct tc_drr_stats xstats;
275
276         memset(&xstats, 0, sizeof(xstats));
277         if (cl->qdisc->q.qlen) {
278                 xstats.deficit = cl->deficit;
279                 cl->qdisc->qstats.qlen = cl->qdisc->q.qlen;
280         }
281
282         if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
283             gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
284             gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
285                 return -1;
286
287         return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
288 }
289
290 static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
291 {
292         struct drr_sched *q = qdisc_priv(sch);
293         struct drr_class *cl;
294         struct hlist_node *n;
295         unsigned int i;
296
297         if (arg->stop)
298                 return;
299
300         for (i = 0; i < q->clhash.hashsize; i++) {
301                 hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
302                         if (arg->count < arg->skip) {
303                                 arg->count++;
304                                 continue;
305                         }
306                         if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
307                                 arg->stop = 1;
308                                 return;
309                         }
310                         arg->count++;
311                 }
312         }
313 }
314
315 static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
316                                       int *qerr)
317 {
318         struct drr_sched *q = qdisc_priv(sch);
319         struct drr_class *cl;
320         struct tcf_result res;
321         int result;
322
323         if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
324                 cl = drr_find_class(sch, skb->priority);
325                 if (cl != NULL)
326                         return cl;
327         }
328
329         *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
330         result = tc_classify(skb, q->filter_list, &res);
331         if (result >= 0) {
332 #ifdef CONFIG_NET_CLS_ACT
333                 switch (result) {
334                 case TC_ACT_QUEUED:
335                 case TC_ACT_STOLEN:
336                         *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
337                 case TC_ACT_SHOT:
338                         return NULL;
339                 }
340 #endif
341                 cl = (struct drr_class *)res.class;
342                 if (cl == NULL)
343                         cl = drr_find_class(sch, res.classid);
344                 return cl;
345         }
346         return NULL;
347 }
348
349 static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch)
350 {
351         struct drr_sched *q = qdisc_priv(sch);
352         struct drr_class *cl;
353         unsigned int len;
354         int err;
355
356         cl = drr_classify(skb, sch, &err);
357         if (cl == NULL) {
358                 if (err & __NET_XMIT_BYPASS)
359                         sch->qstats.drops++;
360                 kfree_skb(skb);
361                 return err;
362         }
363
364         len = qdisc_pkt_len(skb);
365         err = qdisc_enqueue(skb, cl->qdisc);
366         if (unlikely(err != NET_XMIT_SUCCESS)) {
367                 if (net_xmit_drop_count(err)) {
368                         cl->qstats.drops++;
369                         sch->qstats.drops++;
370                 }
371                 return err;
372         }
373
374         if (cl->qdisc->q.qlen == 1) {
375                 list_add_tail(&cl->alist, &q->active);
376                 cl->deficit = cl->quantum;
377         }
378
379         cl->bstats.packets++;
380         cl->bstats.bytes += len;
381         sch->bstats.packets++;
382         sch->bstats.bytes += len;
383
384         sch->q.qlen++;
385         return err;
386 }
387
388 static struct sk_buff *drr_dequeue(struct Qdisc *sch)
389 {
390         struct drr_sched *q = qdisc_priv(sch);
391         struct drr_class *cl;
392         struct sk_buff *skb;
393         unsigned int len;
394
395         if (list_empty(&q->active))
396                 goto out;
397         while (1) {
398                 cl = list_first_entry(&q->active, struct drr_class, alist);
399                 skb = cl->qdisc->ops->peek(cl->qdisc);
400                 if (skb == NULL)
401                         goto out;
402
403                 len = qdisc_pkt_len(skb);
404                 if (len <= cl->deficit) {
405                         cl->deficit -= len;
406                         skb = qdisc_dequeue_peeked(cl->qdisc);
407                         if (cl->qdisc->q.qlen == 0)
408                                 list_del(&cl->alist);
409                         sch->q.qlen--;
410                         return skb;
411                 }
412
413                 cl->deficit += cl->quantum;
414                 list_move_tail(&cl->alist, &q->active);
415         }
416 out:
417         return NULL;
418 }
419
420 static unsigned int drr_drop(struct Qdisc *sch)
421 {
422         struct drr_sched *q = qdisc_priv(sch);
423         struct drr_class *cl;
424         unsigned int len;
425
426         list_for_each_entry(cl, &q->active, alist) {
427                 if (cl->qdisc->ops->drop) {
428                         len = cl->qdisc->ops->drop(cl->qdisc);
429                         if (len > 0) {
430                                 sch->q.qlen--;
431                                 if (cl->qdisc->q.qlen == 0)
432                                         list_del(&cl->alist);
433                                 return len;
434                         }
435                 }
436         }
437         return 0;
438 }
439
440 static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
441 {
442         struct drr_sched *q = qdisc_priv(sch);
443         int err;
444
445         err = qdisc_class_hash_init(&q->clhash);
446         if (err < 0)
447                 return err;
448         INIT_LIST_HEAD(&q->active);
449         return 0;
450 }
451
452 static void drr_reset_qdisc(struct Qdisc *sch)
453 {
454         struct drr_sched *q = qdisc_priv(sch);
455         struct drr_class *cl;
456         struct hlist_node *n;
457         unsigned int i;
458
459         for (i = 0; i < q->clhash.hashsize; i++) {
460                 hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
461                         if (cl->qdisc->q.qlen)
462                                 list_del(&cl->alist);
463                         qdisc_reset(cl->qdisc);
464                 }
465         }
466         sch->q.qlen = 0;
467 }
468
469 static void drr_destroy_qdisc(struct Qdisc *sch)
470 {
471         struct drr_sched *q = qdisc_priv(sch);
472         struct drr_class *cl;
473         struct hlist_node *n, *next;
474         unsigned int i;
475
476         tcf_destroy_chain(&q->filter_list);
477
478         for (i = 0; i < q->clhash.hashsize; i++) {
479                 hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[i],
480                                           common.hnode)
481                         drr_destroy_class(sch, cl);
482         }
483         qdisc_class_hash_destroy(&q->clhash);
484 }
485
486 static const struct Qdisc_class_ops drr_class_ops = {
487         .change         = drr_change_class,
488         .delete         = drr_delete_class,
489         .get            = drr_get_class,
490         .put            = drr_put_class,
491         .tcf_chain      = drr_tcf_chain,
492         .bind_tcf       = drr_bind_tcf,
493         .unbind_tcf     = drr_unbind_tcf,
494         .graft          = drr_graft_class,
495         .leaf           = drr_class_leaf,
496         .qlen_notify    = drr_qlen_notify,
497         .dump           = drr_dump_class,
498         .dump_stats     = drr_dump_class_stats,
499         .walk           = drr_walk,
500 };
501
502 static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
503         .cl_ops         = &drr_class_ops,
504         .id             = "drr",
505         .priv_size      = sizeof(struct drr_sched),
506         .enqueue        = drr_enqueue,
507         .dequeue        = drr_dequeue,
508         .peek           = qdisc_peek_dequeued,
509         .drop           = drr_drop,
510         .init           = drr_init_qdisc,
511         .reset          = drr_reset_qdisc,
512         .destroy        = drr_destroy_qdisc,
513         .owner          = THIS_MODULE,
514 };
515
516 static int __init drr_init(void)
517 {
518         return register_qdisc(&drr_qdisc_ops);
519 }
520
521 static void __exit drr_exit(void)
522 {
523         unregister_qdisc(&drr_qdisc_ops);
524 }
525
526 module_init(drr_init);
527 module_exit(drr_exit);
528 MODULE_LICENSE("GPL");