x86: keep the /proc/meminfo page count correct
[linux-2.6/libata-dev.git] / net / sched / sch_prio.c
blob504a78cdb718bb7dd7ba05e60feb1f5fd2e89ea3
1 /*
2 * net/sched/sch_prio.c Simple 3-band priority "scheduler".
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.
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 * Fixes: 19990609: J Hadi Salim <hadi@nortelnetworks.com>:
11 * Init -- EINVAL when opt undefined
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>
24 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];
33 static struct Qdisc *
34 prio_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
36 struct prio_sched_data *q = qdisc_priv(sch);
37 u32 band = skb->priority;
38 struct tcf_result res;
39 int err;
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;
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]];
58 band = res.classid;
60 band = TC_H_MIN(band) - 1;
61 if (band >= q->bands)
62 return q->queues[q->prio2band[0]];
64 return q->queues[band];
67 static int
68 prio_enqueue(struct sk_buff *skb, struct Qdisc *sch)
70 struct Qdisc *qdisc;
71 int ret;
73 qdisc = prio_classify(skb, sch, &ret);
74 #ifdef CONFIG_NET_CLS_ACT
75 if (qdisc == NULL) {
77 if (ret & __NET_XMIT_BYPASS)
78 sch->qstats.drops++;
79 kfree_skb(skb);
80 return ret;
82 #endif
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;
91 if (net_xmit_drop_count(ret))
92 sch->qstats.drops++;
93 return ret;
97 static int
98 prio_requeue(struct sk_buff *skb, struct Qdisc* sch)
100 struct Qdisc *qdisc;
101 int ret;
103 qdisc = prio_classify(skb, sch, &ret);
104 #ifdef CONFIG_NET_CLS_ACT
105 if (qdisc == NULL) {
106 if (ret & __NET_XMIT_BYPASS)
107 sch->qstats.drops++;
108 kfree_skb(skb);
109 return ret;
111 #endif
113 if ((ret = qdisc->ops->requeue(skb, qdisc)) == NET_XMIT_SUCCESS) {
114 sch->q.qlen++;
115 sch->qstats.requeues++;
116 return NET_XMIT_SUCCESS;
118 if (net_xmit_drop_count(ret))
119 sch->qstats.drops++;
120 return ret;
124 static struct sk_buff *prio_dequeue(struct Qdisc* sch)
126 struct prio_sched_data *q = qdisc_priv(sch);
127 int prio;
129 for (prio = 0; prio < q->bands; prio++) {
130 struct Qdisc *qdisc = q->queues[prio];
131 struct sk_buff *skb = qdisc->dequeue(qdisc);
132 if (skb) {
133 sch->q.qlen--;
134 return skb;
137 return NULL;
141 static unsigned int prio_drop(struct Qdisc* sch)
143 struct prio_sched_data *q = qdisc_priv(sch);
144 int prio;
145 unsigned int len;
146 struct Qdisc *qdisc;
148 for (prio = q->bands-1; prio >= 0; prio--) {
149 qdisc = q->queues[prio];
150 if (qdisc->ops->drop && (len = qdisc->ops->drop(qdisc)) != 0) {
151 sch->q.qlen--;
152 return len;
155 return 0;
159 static void
160 prio_reset(struct Qdisc* sch)
162 int prio;
163 struct prio_sched_data *q = qdisc_priv(sch);
165 for (prio=0; prio<q->bands; prio++)
166 qdisc_reset(q->queues[prio]);
167 sch->q.qlen = 0;
170 static void
171 prio_destroy(struct Qdisc* sch)
173 int prio;
174 struct prio_sched_data *q = qdisc_priv(sch);
176 tcf_destroy_chain(&q->filter_list);
177 for (prio=0; prio<q->bands; prio++)
178 qdisc_destroy(q->queues[prio]);
181 static int prio_tune(struct Qdisc *sch, struct nlattr *opt)
183 struct prio_sched_data *q = qdisc_priv(sch);
184 struct tc_prio_qopt *qopt;
185 int i;
187 if (nla_len(opt) < sizeof(*qopt))
188 return -EINVAL;
189 qopt = nla_data(opt);
191 if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
192 return -EINVAL;
194 for (i=0; i<=TC_PRIO_MAX; i++) {
195 if (qopt->priomap[i] >= qopt->bands)
196 return -EINVAL;
199 sch_tree_lock(sch);
200 q->bands = qopt->bands;
201 memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
203 for (i=q->bands; i<TCQ_PRIO_BANDS; i++) {
204 struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc);
205 if (child != &noop_qdisc) {
206 qdisc_tree_decrease_qlen(child, child->q.qlen);
207 qdisc_destroy(child);
210 sch_tree_unlock(sch);
212 for (i=0; i<q->bands; i++) {
213 if (q->queues[i] == &noop_qdisc) {
214 struct Qdisc *child;
215 child = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
216 &pfifo_qdisc_ops,
217 TC_H_MAKE(sch->handle, i + 1));
218 if (child) {
219 sch_tree_lock(sch);
220 child = xchg(&q->queues[i], child);
222 if (child != &noop_qdisc) {
223 qdisc_tree_decrease_qlen(child,
224 child->q.qlen);
225 qdisc_destroy(child);
227 sch_tree_unlock(sch);
231 return 0;
234 static int prio_init(struct Qdisc *sch, struct nlattr *opt)
236 struct prio_sched_data *q = qdisc_priv(sch);
237 int i;
239 for (i=0; i<TCQ_PRIO_BANDS; i++)
240 q->queues[i] = &noop_qdisc;
242 if (opt == NULL) {
243 return -EINVAL;
244 } else {
245 int err;
247 if ((err= prio_tune(sch, opt)) != 0)
248 return err;
250 return 0;
253 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
255 struct prio_sched_data *q = qdisc_priv(sch);
256 unsigned char *b = skb_tail_pointer(skb);
257 struct tc_prio_qopt opt;
259 opt.bands = q->bands;
260 memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX+1);
262 NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
264 return skb->len;
266 nla_put_failure:
267 nlmsg_trim(skb, b);
268 return -1;
271 static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
272 struct Qdisc **old)
274 struct prio_sched_data *q = qdisc_priv(sch);
275 unsigned long band = arg - 1;
277 if (band >= q->bands)
278 return -EINVAL;
280 if (new == NULL)
281 new = &noop_qdisc;
283 sch_tree_lock(sch);
284 *old = q->queues[band];
285 q->queues[band] = new;
286 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
287 qdisc_reset(*old);
288 sch_tree_unlock(sch);
290 return 0;
293 static struct Qdisc *
294 prio_leaf(struct Qdisc *sch, unsigned long arg)
296 struct prio_sched_data *q = qdisc_priv(sch);
297 unsigned long band = arg - 1;
299 if (band >= q->bands)
300 return NULL;
302 return q->queues[band];
305 static unsigned long prio_get(struct Qdisc *sch, u32 classid)
307 struct prio_sched_data *q = qdisc_priv(sch);
308 unsigned long band = TC_H_MIN(classid);
310 if (band - 1 >= q->bands)
311 return 0;
312 return band;
315 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
317 return prio_get(sch, classid);
321 static void prio_put(struct Qdisc *q, unsigned long cl)
323 return;
326 static int prio_change(struct Qdisc *sch, u32 handle, u32 parent, struct nlattr **tca, unsigned long *arg)
328 unsigned long cl = *arg;
329 struct prio_sched_data *q = qdisc_priv(sch);
331 if (cl - 1 > q->bands)
332 return -ENOENT;
333 return 0;
336 static int prio_delete(struct Qdisc *sch, unsigned long cl)
338 struct prio_sched_data *q = qdisc_priv(sch);
339 if (cl - 1 > q->bands)
340 return -ENOENT;
341 return 0;
345 static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
346 struct tcmsg *tcm)
348 struct prio_sched_data *q = qdisc_priv(sch);
350 if (cl - 1 > q->bands)
351 return -ENOENT;
352 tcm->tcm_handle |= TC_H_MIN(cl);
353 if (q->queues[cl-1])
354 tcm->tcm_info = q->queues[cl-1]->handle;
355 return 0;
358 static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
359 struct gnet_dump *d)
361 struct prio_sched_data *q = qdisc_priv(sch);
362 struct Qdisc *cl_q;
364 cl_q = q->queues[cl - 1];
365 if (gnet_stats_copy_basic(d, &cl_q->bstats) < 0 ||
366 gnet_stats_copy_queue(d, &cl_q->qstats) < 0)
367 return -1;
369 return 0;
372 static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
374 struct prio_sched_data *q = qdisc_priv(sch);
375 int prio;
377 if (arg->stop)
378 return;
380 for (prio = 0; prio < q->bands; prio++) {
381 if (arg->count < arg->skip) {
382 arg->count++;
383 continue;
385 if (arg->fn(sch, prio+1, arg) < 0) {
386 arg->stop = 1;
387 break;
389 arg->count++;
393 static struct tcf_proto ** prio_find_tcf(struct Qdisc *sch, unsigned long cl)
395 struct prio_sched_data *q = qdisc_priv(sch);
397 if (cl)
398 return NULL;
399 return &q->filter_list;
402 static const struct Qdisc_class_ops prio_class_ops = {
403 .graft = prio_graft,
404 .leaf = prio_leaf,
405 .get = prio_get,
406 .put = prio_put,
407 .change = prio_change,
408 .delete = prio_delete,
409 .walk = prio_walk,
410 .tcf_chain = prio_find_tcf,
411 .bind_tcf = prio_bind,
412 .unbind_tcf = prio_put,
413 .dump = prio_dump_class,
414 .dump_stats = prio_dump_class_stats,
417 static struct Qdisc_ops prio_qdisc_ops __read_mostly = {
418 .next = NULL,
419 .cl_ops = &prio_class_ops,
420 .id = "prio",
421 .priv_size = sizeof(struct prio_sched_data),
422 .enqueue = prio_enqueue,
423 .dequeue = prio_dequeue,
424 .requeue = prio_requeue,
425 .drop = prio_drop,
426 .init = prio_init,
427 .reset = prio_reset,
428 .destroy = prio_destroy,
429 .change = prio_tune,
430 .dump = prio_dump,
431 .owner = THIS_MODULE,
434 static int __init prio_module_init(void)
436 return register_qdisc(&prio_qdisc_ops);
439 static void __exit prio_module_exit(void)
441 unregister_qdisc(&prio_qdisc_ops);
444 module_init(prio_module_init)
445 module_exit(prio_module_exit)
447 MODULE_LICENSE("GPL");