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>
23 #include <net/pkt_cls.h>
25 struct prio_sched_data {
27 struct tcf_proto __rcu *filter_list;
28 struct tcf_block *block;
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;
43 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
44 if (TC_H_MAJ(skb->priority) != sch->handle) {
45 fl = rcu_dereference_bh(q->filter_list);
46 err = tcf_classify(skb, fl, &res, false);
47 #ifdef CONFIG_NET_CLS_ACT
52 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
60 return q->queues[q->prio2band[band & TC_PRIO_MAX]];
64 band = TC_H_MIN(band) - 1;
66 return q->queues[q->prio2band[0]];
68 return q->queues[band];
72 prio_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
77 qdisc = prio_classify(skb, sch, &ret);
78 #ifdef CONFIG_NET_CLS_ACT
81 if (ret & __NET_XMIT_BYPASS)
82 qdisc_qstats_drop(sch);
88 ret = qdisc_enqueue(skb, qdisc, to_free);
89 if (ret == NET_XMIT_SUCCESS) {
90 qdisc_qstats_backlog_inc(sch, skb);
92 return NET_XMIT_SUCCESS;
94 if (net_xmit_drop_count(ret))
95 qdisc_qstats_drop(sch);
99 static struct sk_buff *prio_peek(struct Qdisc *sch)
101 struct prio_sched_data *q = qdisc_priv(sch);
104 for (prio = 0; prio < q->bands; prio++) {
105 struct Qdisc *qdisc = q->queues[prio];
106 struct sk_buff *skb = qdisc->ops->peek(qdisc);
113 static struct sk_buff *prio_dequeue(struct Qdisc *sch)
115 struct prio_sched_data *q = qdisc_priv(sch);
118 for (prio = 0; prio < q->bands; prio++) {
119 struct Qdisc *qdisc = q->queues[prio];
120 struct sk_buff *skb = qdisc_dequeue_peeked(qdisc);
122 qdisc_bstats_update(sch, skb);
123 qdisc_qstats_backlog_dec(sch, skb);
133 prio_reset(struct Qdisc *sch)
136 struct prio_sched_data *q = qdisc_priv(sch);
138 for (prio = 0; prio < q->bands; prio++)
139 qdisc_reset(q->queues[prio]);
140 sch->qstats.backlog = 0;
145 prio_destroy(struct Qdisc *sch)
148 struct prio_sched_data *q = qdisc_priv(sch);
150 tcf_block_put(q->block);
151 for (prio = 0; prio < q->bands; prio++)
152 qdisc_destroy(q->queues[prio]);
155 static int prio_tune(struct Qdisc *sch, struct nlattr *opt)
157 struct prio_sched_data *q = qdisc_priv(sch);
158 struct Qdisc *queues[TCQ_PRIO_BANDS];
159 int oldbands = q->bands, i;
160 struct tc_prio_qopt *qopt;
162 if (nla_len(opt) < sizeof(*qopt))
164 qopt = nla_data(opt);
166 if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
169 for (i = 0; i <= TC_PRIO_MAX; i++) {
170 if (qopt->priomap[i] >= qopt->bands)
174 /* Before commit, make sure we can allocate all new qdiscs */
175 for (i = oldbands; i < qopt->bands; i++) {
176 queues[i] = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
177 TC_H_MAKE(sch->handle, i + 1));
180 qdisc_destroy(queues[--i]);
186 q->bands = qopt->bands;
187 memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
189 for (i = q->bands; i < oldbands; i++) {
190 struct Qdisc *child = q->queues[i];
192 qdisc_tree_reduce_backlog(child, child->q.qlen,
193 child->qstats.backlog);
194 qdisc_destroy(child);
197 for (i = oldbands; i < q->bands; i++) {
198 q->queues[i] = queues[i];
199 if (q->queues[i] != &noop_qdisc)
200 qdisc_hash_add(q->queues[i], true);
203 sch_tree_unlock(sch);
207 static int prio_init(struct Qdisc *sch, struct nlattr *opt)
209 struct prio_sched_data *q = qdisc_priv(sch);
215 err = tcf_block_get(&q->block, &q->filter_list);
219 return prio_tune(sch, opt);
222 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
224 struct prio_sched_data *q = qdisc_priv(sch);
225 unsigned char *b = skb_tail_pointer(skb);
226 struct tc_prio_qopt opt;
228 opt.bands = q->bands;
229 memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX + 1);
231 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
232 goto nla_put_failure;
241 static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
244 struct prio_sched_data *q = qdisc_priv(sch);
245 unsigned long band = arg - 1;
250 *old = qdisc_replace(sch, new, &q->queues[band]);
254 static struct Qdisc *
255 prio_leaf(struct Qdisc *sch, unsigned long arg)
257 struct prio_sched_data *q = qdisc_priv(sch);
258 unsigned long band = arg - 1;
260 return q->queues[band];
263 static unsigned long prio_get(struct Qdisc *sch, u32 classid)
265 struct prio_sched_data *q = qdisc_priv(sch);
266 unsigned long band = TC_H_MIN(classid);
268 if (band - 1 >= q->bands)
273 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
275 return prio_get(sch, classid);
279 static void prio_put(struct Qdisc *q, unsigned long cl)
283 static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
286 struct prio_sched_data *q = qdisc_priv(sch);
288 tcm->tcm_handle |= TC_H_MIN(cl);
289 tcm->tcm_info = q->queues[cl-1]->handle;
293 static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
296 struct prio_sched_data *q = qdisc_priv(sch);
299 cl_q = q->queues[cl - 1];
300 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
301 d, NULL, &cl_q->bstats) < 0 ||
302 gnet_stats_copy_queue(d, NULL, &cl_q->qstats, cl_q->q.qlen) < 0)
308 static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
310 struct prio_sched_data *q = qdisc_priv(sch);
316 for (prio = 0; prio < q->bands; prio++) {
317 if (arg->count < arg->skip) {
321 if (arg->fn(sch, prio + 1, arg) < 0) {
329 static struct tcf_block *prio_tcf_block(struct Qdisc *sch, unsigned long cl)
331 struct prio_sched_data *q = qdisc_priv(sch);
338 static const struct Qdisc_class_ops prio_class_ops = {
344 .tcf_block = prio_tcf_block,
345 .bind_tcf = prio_bind,
346 .unbind_tcf = prio_put,
347 .dump = prio_dump_class,
348 .dump_stats = prio_dump_class_stats,
351 static struct Qdisc_ops prio_qdisc_ops __read_mostly = {
353 .cl_ops = &prio_class_ops,
355 .priv_size = sizeof(struct prio_sched_data),
356 .enqueue = prio_enqueue,
357 .dequeue = prio_dequeue,
361 .destroy = prio_destroy,
364 .owner = THIS_MODULE,
367 static int __init prio_module_init(void)
369 return register_qdisc(&prio_qdisc_ops);
372 static void __exit prio_module_exit(void)
374 unregister_qdisc(&prio_qdisc_ops);
377 module_init(prio_module_init)
378 module_exit(prio_module_exit)
380 MODULE_LICENSE("GPL");