pkt_sched: Remove qdisc->ops->requeue() etc.
[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         struct tcf_proto *filter_list;
28         u8  prio2band[TC_PRIO_MAX+1];
29         struct Qdisc *queues[TCQ_PRIO_BANDS];
30 };
31
32
33 static struct Qdisc *
34 prio_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
35 {
36         struct prio_sched_data *q = qdisc_priv(sch);
37         u32 band = skb->priority;
38         struct tcf_result res;
39         int err;
40
41         *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
42         if (TC_H_MAJ(skb->priority) != sch->handle) {
43                 err = tc_classify(skb, q->filter_list, &res);
44 #ifdef CONFIG_NET_CLS_ACT
45                 switch (err) {
46                 case TC_ACT_STOLEN:
47                 case TC_ACT_QUEUED:
48                         *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
49                 case TC_ACT_SHOT:
50                         return NULL;
51                 }
52 #endif
53                 if (!q->filter_list || err < 0) {
54                         if (TC_H_MAJ(band))
55                                 band = 0;
56                         return q->queues[q->prio2band[band&TC_PRIO_MAX]];
57                 }
58                 band = res.classid;
59         }
60         band = TC_H_MIN(band) - 1;
61         if (band >= q->bands)
62                 return q->queues[q->prio2band[0]];
63
64         return q->queues[band];
65 }
66
67 static int
68 prio_enqueue(struct sk_buff *skb, struct Qdisc *sch)
69 {
70         struct Qdisc *qdisc;
71         int ret;
72
73         qdisc = prio_classify(skb, sch, &ret);
74 #ifdef CONFIG_NET_CLS_ACT
75         if (qdisc == NULL) {
76
77                 if (ret & __NET_XMIT_BYPASS)
78                         sch->qstats.drops++;
79                 kfree_skb(skb);
80                 return ret;
81         }
82 #endif
83
84         ret = qdisc_enqueue(skb, qdisc);
85         if (ret == NET_XMIT_SUCCESS) {
86                 sch->bstats.bytes += qdisc_pkt_len(skb);
87                 sch->bstats.packets++;
88                 sch->q.qlen++;
89                 return NET_XMIT_SUCCESS;
90         }
91         if (net_xmit_drop_count(ret))
92                 sch->qstats.drops++;
93         return ret;
94 }
95
96 static struct sk_buff *prio_peek(struct Qdisc *sch)
97 {
98         struct prio_sched_data *q = qdisc_priv(sch);
99         int prio;
100
101         for (prio = 0; prio < q->bands; prio++) {
102                 struct Qdisc *qdisc = q->queues[prio];
103                 struct sk_buff *skb = qdisc->ops->peek(qdisc);
104                 if (skb)
105                         return skb;
106         }
107         return NULL;
108 }
109
110 static struct sk_buff *prio_dequeue(struct Qdisc* sch)
111 {
112         struct prio_sched_data *q = qdisc_priv(sch);
113         int prio;
114
115         for (prio = 0; prio < q->bands; prio++) {
116                 struct Qdisc *qdisc = q->queues[prio];
117                 struct sk_buff *skb = qdisc->dequeue(qdisc);
118                 if (skb) {
119                         sch->q.qlen--;
120                         return skb;
121                 }
122         }
123         return NULL;
124
125 }
126
127 static unsigned int prio_drop(struct Qdisc* sch)
128 {
129         struct prio_sched_data *q = qdisc_priv(sch);
130         int prio;
131         unsigned int len;
132         struct Qdisc *qdisc;
133
134         for (prio = q->bands-1; prio >= 0; prio--) {
135                 qdisc = q->queues[prio];
136                 if (qdisc->ops->drop && (len = qdisc->ops->drop(qdisc)) != 0) {
137                         sch->q.qlen--;
138                         return len;
139                 }
140         }
141         return 0;
142 }
143
144
145 static void
146 prio_reset(struct Qdisc* sch)
147 {
148         int prio;
149         struct prio_sched_data *q = qdisc_priv(sch);
150
151         for (prio=0; prio<q->bands; prio++)
152                 qdisc_reset(q->queues[prio]);
153         sch->q.qlen = 0;
154 }
155
156 static void
157 prio_destroy(struct Qdisc* sch)
158 {
159         int prio;
160         struct prio_sched_data *q = qdisc_priv(sch);
161
162         tcf_destroy_chain(&q->filter_list);
163         for (prio=0; prio<q->bands; prio++)
164                 qdisc_destroy(q->queues[prio]);
165 }
166
167 static int prio_tune(struct Qdisc *sch, struct nlattr *opt)
168 {
169         struct prio_sched_data *q = qdisc_priv(sch);
170         struct tc_prio_qopt *qopt;
171         int i;
172
173         if (nla_len(opt) < sizeof(*qopt))
174                 return -EINVAL;
175         qopt = nla_data(opt);
176
177         if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
178                 return -EINVAL;
179
180         for (i=0; i<=TC_PRIO_MAX; i++) {
181                 if (qopt->priomap[i] >= qopt->bands)
182                         return -EINVAL;
183         }
184
185         sch_tree_lock(sch);
186         q->bands = qopt->bands;
187         memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
188
189         for (i=q->bands; i<TCQ_PRIO_BANDS; i++) {
190                 struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc);
191                 if (child != &noop_qdisc) {
192                         qdisc_tree_decrease_qlen(child, child->q.qlen);
193                         qdisc_destroy(child);
194                 }
195         }
196         sch_tree_unlock(sch);
197
198         for (i=0; i<q->bands; i++) {
199                 if (q->queues[i] == &noop_qdisc) {
200                         struct Qdisc *child;
201                         child = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
202                                                   &pfifo_qdisc_ops,
203                                                   TC_H_MAKE(sch->handle, i + 1));
204                         if (child) {
205                                 sch_tree_lock(sch);
206                                 child = xchg(&q->queues[i], child);
207
208                                 if (child != &noop_qdisc) {
209                                         qdisc_tree_decrease_qlen(child,
210                                                                  child->q.qlen);
211                                         qdisc_destroy(child);
212                                 }
213                                 sch_tree_unlock(sch);
214                         }
215                 }
216         }
217         return 0;
218 }
219
220 static int prio_init(struct Qdisc *sch, struct nlattr *opt)
221 {
222         struct prio_sched_data *q = qdisc_priv(sch);
223         int i;
224
225         for (i=0; i<TCQ_PRIO_BANDS; i++)
226                 q->queues[i] = &noop_qdisc;
227
228         if (opt == NULL) {
229                 return -EINVAL;
230         } else {
231                 int err;
232
233                 if ((err= prio_tune(sch, opt)) != 0)
234                         return err;
235         }
236         return 0;
237 }
238
239 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
240 {
241         struct prio_sched_data *q = qdisc_priv(sch);
242         unsigned char *b = skb_tail_pointer(skb);
243         struct tc_prio_qopt opt;
244
245         opt.bands = q->bands;
246         memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX+1);
247
248         NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
249
250         return skb->len;
251
252 nla_put_failure:
253         nlmsg_trim(skb, b);
254         return -1;
255 }
256
257 static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
258                       struct Qdisc **old)
259 {
260         struct prio_sched_data *q = qdisc_priv(sch);
261         unsigned long band = arg - 1;
262
263         if (band >= q->bands)
264                 return -EINVAL;
265
266         if (new == NULL)
267                 new = &noop_qdisc;
268
269         sch_tree_lock(sch);
270         *old = q->queues[band];
271         q->queues[band] = new;
272         qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
273         qdisc_reset(*old);
274         sch_tree_unlock(sch);
275
276         return 0;
277 }
278
279 static struct Qdisc *
280 prio_leaf(struct Qdisc *sch, unsigned long arg)
281 {
282         struct prio_sched_data *q = qdisc_priv(sch);
283         unsigned long band = arg - 1;
284
285         if (band >= q->bands)
286                 return NULL;
287
288         return q->queues[band];
289 }
290
291 static unsigned long prio_get(struct Qdisc *sch, u32 classid)
292 {
293         struct prio_sched_data *q = qdisc_priv(sch);
294         unsigned long band = TC_H_MIN(classid);
295
296         if (band - 1 >= q->bands)
297                 return 0;
298         return band;
299 }
300
301 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
302 {
303         return prio_get(sch, classid);
304 }
305
306
307 static void prio_put(struct Qdisc *q, unsigned long cl)
308 {
309         return;
310 }
311
312 static int prio_change(struct Qdisc *sch, u32 handle, u32 parent, struct nlattr **tca, unsigned long *arg)
313 {
314         unsigned long cl = *arg;
315         struct prio_sched_data *q = qdisc_priv(sch);
316
317         if (cl - 1 > q->bands)
318                 return -ENOENT;
319         return 0;
320 }
321
322 static int prio_delete(struct Qdisc *sch, unsigned long cl)
323 {
324         struct prio_sched_data *q = qdisc_priv(sch);
325         if (cl - 1 > q->bands)
326                 return -ENOENT;
327         return 0;
328 }
329
330
331 static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
332                            struct tcmsg *tcm)
333 {
334         struct prio_sched_data *q = qdisc_priv(sch);
335
336         if (cl - 1 > q->bands)
337                 return -ENOENT;
338         tcm->tcm_handle |= TC_H_MIN(cl);
339         if (q->queues[cl-1])
340                 tcm->tcm_info = q->queues[cl-1]->handle;
341         return 0;
342 }
343
344 static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
345                                  struct gnet_dump *d)
346 {
347         struct prio_sched_data *q = qdisc_priv(sch);
348         struct Qdisc *cl_q;
349
350         cl_q = q->queues[cl - 1];
351         if (gnet_stats_copy_basic(d, &cl_q->bstats) < 0 ||
352             gnet_stats_copy_queue(d, &cl_q->qstats) < 0)
353                 return -1;
354
355         return 0;
356 }
357
358 static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
359 {
360         struct prio_sched_data *q = qdisc_priv(sch);
361         int prio;
362
363         if (arg->stop)
364                 return;
365
366         for (prio = 0; prio < q->bands; prio++) {
367                 if (arg->count < arg->skip) {
368                         arg->count++;
369                         continue;
370                 }
371                 if (arg->fn(sch, prio+1, arg) < 0) {
372                         arg->stop = 1;
373                         break;
374                 }
375                 arg->count++;
376         }
377 }
378
379 static struct tcf_proto ** prio_find_tcf(struct Qdisc *sch, unsigned long cl)
380 {
381         struct prio_sched_data *q = qdisc_priv(sch);
382
383         if (cl)
384                 return NULL;
385         return &q->filter_list;
386 }
387
388 static const struct Qdisc_class_ops prio_class_ops = {
389         .graft          =       prio_graft,
390         .leaf           =       prio_leaf,
391         .get            =       prio_get,
392         .put            =       prio_put,
393         .change         =       prio_change,
394         .delete         =       prio_delete,
395         .walk           =       prio_walk,
396         .tcf_chain      =       prio_find_tcf,
397         .bind_tcf       =       prio_bind,
398         .unbind_tcf     =       prio_put,
399         .dump           =       prio_dump_class,
400         .dump_stats     =       prio_dump_class_stats,
401 };
402
403 static struct Qdisc_ops prio_qdisc_ops __read_mostly = {
404         .next           =       NULL,
405         .cl_ops         =       &prio_class_ops,
406         .id             =       "prio",
407         .priv_size      =       sizeof(struct prio_sched_data),
408         .enqueue        =       prio_enqueue,
409         .dequeue        =       prio_dequeue,
410         .peek           =       prio_peek,
411         .drop           =       prio_drop,
412         .init           =       prio_init,
413         .reset          =       prio_reset,
414         .destroy        =       prio_destroy,
415         .change         =       prio_tune,
416         .dump           =       prio_dump,
417         .owner          =       THIS_MODULE,
418 };
419
420 static int __init prio_module_init(void)
421 {
422         return register_qdisc(&prio_qdisc_ops);
423 }
424
425 static void __exit prio_module_exit(void)
426 {
427         unregister_qdisc(&prio_qdisc_ops);
428 }
429
430 module_init(prio_module_init)
431 module_exit(prio_module_exit)
432
433 MODULE_LICENSE("GPL");