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
28 struct tcf_proto *filter_list;
29 u8 prio2band[TC_PRIO_MAX+1];
30 struct Qdisc *queues[TCQ_PRIO_BANDS];
35 prio_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
37 struct prio_sched_data *q = qdisc_priv(sch);
38 u32 band = skb->priority;
39 struct tcf_result res;
42 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
43 if (TC_H_MAJ(skb->priority) != sch->handle) {
44 err = tc_classify(skb, q->filter_list, &res);
45 #ifdef CONFIG_NET_CLS_ACT
49 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
54 if (!q->filter_list || err < 0) {
57 return q->queues[q->prio2band[band&TC_PRIO_MAX]];
61 band = TC_H_MIN(band) - 1;
63 return q->queues[q->prio2band[0]];
65 return q->queues[band];
69 prio_enqueue(struct sk_buff *skb, struct Qdisc *sch)
74 qdisc = prio_classify(skb, sch, &ret);
75 #ifdef CONFIG_NET_CLS_ACT
78 if (ret & __NET_XMIT_BYPASS)
85 ret = qdisc_enqueue(skb, qdisc);
86 if (ret == NET_XMIT_SUCCESS) {
87 sch->bstats.bytes += qdisc_pkt_len(skb);
88 sch->bstats.packets++;
90 return NET_XMIT_SUCCESS;
92 if (net_xmit_drop_count(ret))
97 static struct sk_buff *prio_peek(struct Qdisc *sch)
99 struct prio_sched_data *q = qdisc_priv(sch);
102 for (prio = 0; prio < q->bands; prio++) {
103 struct Qdisc *qdisc = q->queues[prio];
104 struct sk_buff *skb = qdisc->ops->peek(qdisc);
111 static struct sk_buff *prio_dequeue(struct Qdisc* sch)
113 struct prio_sched_data *q = qdisc_priv(sch);
116 for (prio = 0; prio < q->bands; prio++) {
117 struct Qdisc *qdisc = q->queues[prio];
118 struct sk_buff *skb = qdisc->dequeue(qdisc);
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_decrease_qlen(child, child->q.qlen);
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;
203 child = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
205 TC_H_MAKE(sch->handle, i + 1));
209 q->queues[i] = child;
211 if (old != &noop_qdisc) {
212 qdisc_tree_decrease_qlen(old,
216 sch_tree_unlock(sch);
223 static int prio_init(struct Qdisc *sch, struct nlattr *opt)
225 struct prio_sched_data *q = qdisc_priv(sch);
228 for (i=0; i<TCQ_PRIO_BANDS; i++)
229 q->queues[i] = &noop_qdisc;
236 if ((err= prio_tune(sch, opt)) != 0)
242 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
244 struct prio_sched_data *q = qdisc_priv(sch);
245 unsigned char *b = skb_tail_pointer(skb);
246 struct tc_prio_qopt opt;
248 opt.bands = q->bands;
249 memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX+1);
251 NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
260 static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
263 struct prio_sched_data *q = qdisc_priv(sch);
264 unsigned long band = arg - 1;
270 *old = q->queues[band];
271 q->queues[band] = new;
272 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
274 sch_tree_unlock(sch);
279 static struct Qdisc *
280 prio_leaf(struct Qdisc *sch, unsigned long arg)
282 struct prio_sched_data *q = qdisc_priv(sch);
283 unsigned long band = arg - 1;
285 return q->queues[band];
288 static unsigned long prio_get(struct Qdisc *sch, u32 classid)
290 struct prio_sched_data *q = qdisc_priv(sch);
291 unsigned long band = TC_H_MIN(classid);
293 if (band - 1 >= q->bands)
298 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
300 return prio_get(sch, classid);
304 static void prio_put(struct Qdisc *q, unsigned long cl)
308 static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
311 struct prio_sched_data *q = qdisc_priv(sch);
313 tcm->tcm_handle |= TC_H_MIN(cl);
314 tcm->tcm_info = q->queues[cl-1]->handle;
318 static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
321 struct prio_sched_data *q = qdisc_priv(sch);
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)
333 static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
335 struct prio_sched_data *q = qdisc_priv(sch);
341 for (prio = 0; prio < q->bands; prio++) {
342 if (arg->count < arg->skip) {
346 if (arg->fn(sch, prio+1, arg) < 0) {
354 static struct tcf_proto ** prio_find_tcf(struct Qdisc *sch, unsigned long cl)
356 struct prio_sched_data *q = qdisc_priv(sch);
360 return &q->filter_list;
363 static const struct Qdisc_class_ops prio_class_ops = {
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,
376 static struct Qdisc_ops prio_qdisc_ops __read_mostly = {
378 .cl_ops = &prio_class_ops,
380 .priv_size = sizeof(struct prio_sched_data),
381 .enqueue = prio_enqueue,
382 .dequeue = prio_dequeue,
387 .destroy = prio_destroy,
390 .owner = THIS_MODULE,
393 static int __init prio_module_init(void)
395 return register_qdisc(&prio_qdisc_ops);
398 static void __exit prio_module_exit(void)
400 unregister_qdisc(&prio_qdisc_ops);
403 module_init(prio_module_init)
404 module_exit(prio_module_exit)
406 MODULE_LICENSE("GPL");