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/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>
25 struct prio_sched_data {
27 struct tcf_proto __rcu *filter_list;
28 u8 prio2band[TC_PRIO_MAX+1];
29 struct Qdisc *queues[TCQ_PRIO_BANDS];
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;
42 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
43 if (TC_H_MAJ(skb->priority) != sch->handle) {
44 fl = rcu_dereference_bh(q->filter_list);
45 err = tc_classify(skb, fl, &res, false);
46 #ifdef CONFIG_NET_CLS_ACT
50 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
58 return q->queues[q->prio2band[band & TC_PRIO_MAX]];
62 band = TC_H_MIN(band) - 1;
64 return q->queues[q->prio2band[0]];
66 return q->queues[band];
70 prio_enqueue(struct sk_buff *skb, struct Qdisc *sch)
75 qdisc = prio_classify(skb, sch, &ret);
76 #ifdef CONFIG_NET_CLS_ACT
79 if (ret & __NET_XMIT_BYPASS)
80 qdisc_qstats_drop(sch);
86 ret = qdisc_enqueue(skb, qdisc);
87 if (ret == NET_XMIT_SUCCESS) {
89 return NET_XMIT_SUCCESS;
91 if (net_xmit_drop_count(ret))
92 qdisc_qstats_drop(sch);
96 static struct sk_buff *prio_peek(struct Qdisc *sch)
98 struct prio_sched_data *q = qdisc_priv(sch);
101 for (prio = 0; prio < q->bands; prio++) {
102 struct Qdisc *qdisc = q->queues[prio];
103 struct sk_buff *skb = qdisc->ops->peek(qdisc);
110 static struct sk_buff *prio_dequeue(struct Qdisc *sch)
112 struct prio_sched_data *q = qdisc_priv(sch);
115 for (prio = 0; prio < q->bands; prio++) {
116 struct Qdisc *qdisc = q->queues[prio];
117 struct sk_buff *skb = qdisc_dequeue_peeked(qdisc);
119 qdisc_bstats_update(sch, skb);
128 static unsigned int prio_drop(struct Qdisc *sch)
130 struct prio_sched_data *q = qdisc_priv(sch);
135 for (prio = q->bands-1; prio >= 0; prio--) {
136 qdisc = q->queues[prio];
137 if (qdisc->ops->drop && (len = qdisc->ops->drop(qdisc)) != 0) {
147 prio_reset(struct Qdisc *sch)
150 struct prio_sched_data *q = qdisc_priv(sch);
152 for (prio = 0; prio < q->bands; prio++)
153 qdisc_reset(q->queues[prio]);
158 prio_destroy(struct Qdisc *sch)
161 struct prio_sched_data *q = qdisc_priv(sch);
163 tcf_destroy_chain(&q->filter_list);
164 for (prio = 0; prio < q->bands; prio++)
165 qdisc_destroy(q->queues[prio]);
168 static int prio_tune(struct Qdisc *sch, struct nlattr *opt)
170 struct prio_sched_data *q = qdisc_priv(sch);
171 struct tc_prio_qopt *qopt;
174 if (nla_len(opt) < sizeof(*qopt))
176 qopt = nla_data(opt);
178 if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
181 for (i = 0; i <= TC_PRIO_MAX; i++) {
182 if (qopt->priomap[i] >= qopt->bands)
187 q->bands = qopt->bands;
188 memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
190 for (i = q->bands; i < TCQ_PRIO_BANDS; i++) {
191 struct Qdisc *child = q->queues[i];
192 q->queues[i] = &noop_qdisc;
193 if (child != &noop_qdisc) {
194 qdisc_tree_reduce_backlog(child, child->q.qlen, child->qstats.backlog);
195 qdisc_destroy(child);
198 sch_tree_unlock(sch);
200 for (i = 0; i < q->bands; i++) {
201 if (q->queues[i] == &noop_qdisc) {
202 struct Qdisc *child, *old;
204 child = qdisc_create_dflt(sch->dev_queue,
206 TC_H_MAKE(sch->handle, i + 1));
210 q->queues[i] = child;
212 if (old != &noop_qdisc) {
213 qdisc_tree_reduce_backlog(old,
215 old->qstats.backlog);
218 sch_tree_unlock(sch);
225 static int prio_init(struct Qdisc *sch, struct nlattr *opt)
227 struct prio_sched_data *q = qdisc_priv(sch);
230 for (i = 0; i < TCQ_PRIO_BANDS; i++)
231 q->queues[i] = &noop_qdisc;
238 if ((err = prio_tune(sch, opt)) != 0)
244 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
246 struct prio_sched_data *q = qdisc_priv(sch);
247 unsigned char *b = skb_tail_pointer(skb);
248 struct tc_prio_qopt opt;
250 opt.bands = q->bands;
251 memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX + 1);
253 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
254 goto nla_put_failure;
263 static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
266 struct prio_sched_data *q = qdisc_priv(sch);
267 unsigned long band = arg - 1;
272 *old = qdisc_replace(sch, new, &q->queues[band]);
276 static struct Qdisc *
277 prio_leaf(struct Qdisc *sch, unsigned long arg)
279 struct prio_sched_data *q = qdisc_priv(sch);
280 unsigned long band = arg - 1;
282 return q->queues[band];
285 static unsigned long prio_get(struct Qdisc *sch, u32 classid)
287 struct prio_sched_data *q = qdisc_priv(sch);
288 unsigned long band = TC_H_MIN(classid);
290 if (band - 1 >= q->bands)
295 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
297 return prio_get(sch, classid);
301 static void prio_put(struct Qdisc *q, unsigned long cl)
305 static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
308 struct prio_sched_data *q = qdisc_priv(sch);
310 tcm->tcm_handle |= TC_H_MIN(cl);
311 tcm->tcm_info = q->queues[cl-1]->handle;
315 static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
318 struct prio_sched_data *q = qdisc_priv(sch);
321 cl_q = q->queues[cl - 1];
322 if (gnet_stats_copy_basic(d, NULL, &cl_q->bstats) < 0 ||
323 gnet_stats_copy_queue(d, NULL, &cl_q->qstats, cl_q->q.qlen) < 0)
329 static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
331 struct prio_sched_data *q = qdisc_priv(sch);
337 for (prio = 0; prio < q->bands; prio++) {
338 if (arg->count < arg->skip) {
342 if (arg->fn(sch, prio + 1, arg) < 0) {
350 static struct tcf_proto __rcu **prio_find_tcf(struct Qdisc *sch,
353 struct prio_sched_data *q = qdisc_priv(sch);
357 return &q->filter_list;
360 static const struct Qdisc_class_ops prio_class_ops = {
366 .tcf_chain = prio_find_tcf,
367 .bind_tcf = prio_bind,
368 .unbind_tcf = prio_put,
369 .dump = prio_dump_class,
370 .dump_stats = prio_dump_class_stats,
373 static struct Qdisc_ops prio_qdisc_ops __read_mostly = {
375 .cl_ops = &prio_class_ops,
377 .priv_size = sizeof(struct prio_sched_data),
378 .enqueue = prio_enqueue,
379 .dequeue = prio_dequeue,
384 .destroy = prio_destroy,
387 .owner = THIS_MODULE,
390 static int __init prio_module_init(void)
392 return register_qdisc(&prio_qdisc_ops);
395 static void __exit prio_module_exit(void)
397 unregister_qdisc(&prio_qdisc_ops);
400 module_init(prio_module_init)
401 module_exit(prio_module_exit)
403 MODULE_LICENSE("GPL");