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Linux 3.8-rc7
[cris-mirror.git] / net / sched / sch_prio.c
blob79359b69ad8d6fcf35b6937673d4ae332bbf5158
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/slab.h>
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/string.h>
19 #include <linux/errno.h>
20 #include <linux/skbuff.h>
21 #include <net/netlink.h>
22 #include <net/pkt_sched.h>
23
24
25 struct prio_sched_data {
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->q.qlen++;
87 return NET_XMIT_SUCCESS;
88 }
89 if (net_xmit_drop_count(ret))
90 sch->qstats.drops++;
91 return ret;
92 }
93
94 static struct sk_buff *prio_peek(struct Qdisc *sch)
95 {
96 struct prio_sched_data *q = qdisc_priv(sch);
97 int prio;
98
99 for (prio = 0; prio < q->bands; prio++) {
100 struct Qdisc *qdisc = q->queues[prio];
101 struct sk_buff *skb = qdisc->ops->peek(qdisc);
102 if (skb)
103 return skb;
104 }
105 return NULL;
106 }
107
108 static struct sk_buff *prio_dequeue(struct Qdisc *sch)
109 {
110 struct prio_sched_data *q = qdisc_priv(sch);
111 int prio;
112
113 for (prio = 0; prio < q->bands; prio++) {
114 struct Qdisc *qdisc = q->queues[prio];
115 struct sk_buff *skb = qdisc_dequeue_peeked(qdisc);
116 if (skb) {
117 qdisc_bstats_update(sch, skb);
118 sch->q.qlen--;
119 return skb;
120 }
121 }
122 return NULL;
123
124 }
125
126 static unsigned int prio_drop(struct Qdisc *sch)
127 {
128 struct prio_sched_data *q = qdisc_priv(sch);
129 int prio;
130 unsigned int len;
131 struct Qdisc *qdisc;
132
133 for (prio = q->bands-1; prio >= 0; prio--) {
134 qdisc = q->queues[prio];
135 if (qdisc->ops->drop && (len = qdisc->ops->drop(qdisc)) != 0) {
136 sch->q.qlen--;
137 return len;
138 }
139 }
140 return 0;
141 }
142
143
144 static void
145 prio_reset(struct Qdisc *sch)
146 {
147 int prio;
148 struct prio_sched_data *q = qdisc_priv(sch);
149
150 for (prio = 0; prio < q->bands; prio++)
151 qdisc_reset(q->queues[prio]);
152 sch->q.qlen = 0;
153 }
154
155 static void
156 prio_destroy(struct Qdisc *sch)
157 {
158 int prio;
159 struct prio_sched_data *q = qdisc_priv(sch);
160
161 tcf_destroy_chain(&q->filter_list);
162 for (prio = 0; prio < q->bands; prio++)
163 qdisc_destroy(q->queues[prio]);
164 }
165
166 static int prio_tune(struct Qdisc *sch, struct nlattr *opt)
167 {
168 struct prio_sched_data *q = qdisc_priv(sch);
169 struct tc_prio_qopt *qopt;
170 int i;
171
172 if (nla_len(opt) < sizeof(*qopt))
173 return -EINVAL;
174 qopt = nla_data(opt);
175
176 if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
177 return -EINVAL;
178
179 for (i = 0; i <= TC_PRIO_MAX; i++) {
180 if (qopt->priomap[i] >= qopt->bands)
181 return -EINVAL;
182 }
183
184 sch_tree_lock(sch);
185 q->bands = qopt->bands;
186 memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
187
188 for (i = q->bands; i < TCQ_PRIO_BANDS; i++) {
189 struct Qdisc *child = q->queues[i];
190 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, *old;
201
202 child = qdisc_create_dflt(sch->dev_queue,
203 &pfifo_qdisc_ops,
204 TC_H_MAKE(sch->handle, i + 1));
205 if (child) {
206 sch_tree_lock(sch);
207 old = q->queues[i];
208 q->queues[i] = child;
209
210 if (old != &noop_qdisc) {
211 qdisc_tree_decrease_qlen(old,
212 old->q.qlen);
213 qdisc_destroy(old);
214 }
215 sch_tree_unlock(sch);
216 }
217 }
218 }
219 return 0;
220 }
221
222 static int prio_init(struct Qdisc *sch, struct nlattr *opt)
223 {
224 struct prio_sched_data *q = qdisc_priv(sch);
225 int i;
226
227 for (i = 0; i < TCQ_PRIO_BANDS; i++)
228 q->queues[i] = &noop_qdisc;
229
230 if (opt == NULL) {
231 return -EINVAL;
232 } else {
233 int err;
234
235 if ((err = prio_tune(sch, opt)) != 0)
236 return err;
237 }
238 return 0;
239 }
240
241 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
242 {
243 struct prio_sched_data *q = qdisc_priv(sch);
244 unsigned char *b = skb_tail_pointer(skb);
245 struct tc_prio_qopt opt;
246
247 opt.bands = q->bands;
248 memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX + 1);
249
250 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
251 goto nla_put_failure;
252
253 return skb->len;
254
255 nla_put_failure:
256 nlmsg_trim(skb, b);
257 return -1;
258 }
259
260 static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
261 struct Qdisc **old)
262 {
263 struct prio_sched_data *q = qdisc_priv(sch);
264 unsigned long band = arg - 1;
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 return q->queues[band];
286 }
287
288 static unsigned long prio_get(struct Qdisc *sch, u32 classid)
289 {
290 struct prio_sched_data *q = qdisc_priv(sch);
291 unsigned long band = TC_H_MIN(classid);
292
293 if (band - 1 >= q->bands)
294 return 0;
295 return band;
296 }
297
298 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
299 {
300 return prio_get(sch, classid);
301 }
302
303
304 static void prio_put(struct Qdisc *q, unsigned long cl)
305 {
306 }
307
308 static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
309 struct tcmsg *tcm)
310 {
311 struct prio_sched_data *q = qdisc_priv(sch);
312
313 tcm->tcm_handle |= TC_H_MIN(cl);
314 tcm->tcm_info = q->queues[cl-1]->handle;
315 return 0;
316 }
317
318 static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
319 struct gnet_dump *d)
320 {
321 struct prio_sched_data *q = qdisc_priv(sch);
322 struct Qdisc *cl_q;
323
324 cl_q = q->queues[cl - 1];
325 cl_q->qstats.qlen = cl_q->q.qlen;
326 if (gnet_stats_copy_basic(d, &cl_q->bstats) < 0 ||
327 gnet_stats_copy_queue(d, &cl_q->qstats) < 0)
328 return -1;
329
330 return 0;
331 }
332
333 static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
334 {
335 struct prio_sched_data *q = qdisc_priv(sch);
336 int prio;
337
338 if (arg->stop)
339 return;
340
341 for (prio = 0; prio < q->bands; prio++) {
342 if (arg->count < arg->skip) {
343 arg->count++;
344 continue;
345 }
346 if (arg->fn(sch, prio + 1, arg) < 0) {
347 arg->stop = 1;
348 break;
349 }
350 arg->count++;
351 }
352 }
353
354 static struct tcf_proto **prio_find_tcf(struct Qdisc *sch, unsigned long cl)
355 {
356 struct prio_sched_data *q = qdisc_priv(sch);
357
358 if (cl)
359 return NULL;
360 return &q->filter_list;
361 }
362
363 static const struct Qdisc_class_ops prio_class_ops = {
364 .graft = prio_graft,
365 .leaf = prio_leaf,
366 .get = prio_get,
367 .put = prio_put,
368 .walk = prio_walk,
369 .tcf_chain = prio_find_tcf,
370 .bind_tcf = prio_bind,
371 .unbind_tcf = prio_put,
372 .dump = prio_dump_class,
373 .dump_stats = prio_dump_class_stats,
374 };
375
376 static struct Qdisc_ops prio_qdisc_ops __read_mostly = {
377 .next = NULL,
378 .cl_ops = &prio_class_ops,
379 .id = "prio",
380 .priv_size = sizeof(struct prio_sched_data),
381 .enqueue = prio_enqueue,
382 .dequeue = prio_dequeue,
383 .peek = prio_peek,
384 .drop = prio_drop,
385 .init = prio_init,
386 .reset = prio_reset,
387 .destroy = prio_destroy,
388 .change = prio_tune,
389 .dump = prio_dump,
390 .owner = THIS_MODULE,
391 };
392
393 static int __init prio_module_init(void)
394 {
395 return register_qdisc(&prio_qdisc_ops);
396 }
397
398 static void __exit prio_module_exit(void)
399 {
400 unregister_qdisc(&prio_qdisc_ops);
401 }
402
403 module_init(prio_module_init)
404 module_exit(prio_module_exit)
405
406 MODULE_LICENSE("GPL");
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