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;
61 return q->queues[q->prio2band[band & TC_PRIO_MAX]];
65 band = TC_H_MIN(band) - 1;
67 return q->queues[q->prio2band[0]];
69 return q->queues[band];
73 prio_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
78 qdisc = prio_classify(skb, sch, &ret);
79 #ifdef CONFIG_NET_CLS_ACT
82 if (ret & __NET_XMIT_BYPASS)
83 qdisc_qstats_drop(sch);
84 __qdisc_drop(skb, to_free);
89 ret = qdisc_enqueue(skb, qdisc, to_free);
90 if (ret == NET_XMIT_SUCCESS) {
91 qdisc_qstats_backlog_inc(sch, skb);
93 return NET_XMIT_SUCCESS;
95 if (net_xmit_drop_count(ret))
96 qdisc_qstats_drop(sch);
100 static struct sk_buff *prio_peek(struct Qdisc *sch)
102 struct prio_sched_data *q = qdisc_priv(sch);
105 for (prio = 0; prio < q->bands; prio++) {
106 struct Qdisc *qdisc = q->queues[prio];
107 struct sk_buff *skb = qdisc->ops->peek(qdisc);
114 static struct sk_buff *prio_dequeue(struct Qdisc *sch)
116 struct prio_sched_data *q = qdisc_priv(sch);
119 for (prio = 0; prio < q->bands; prio++) {
120 struct Qdisc *qdisc = q->queues[prio];
121 struct sk_buff *skb = qdisc_dequeue_peeked(qdisc);
123 qdisc_bstats_update(sch, skb);
124 qdisc_qstats_backlog_dec(sch, skb);
134 prio_reset(struct Qdisc *sch)
137 struct prio_sched_data *q = qdisc_priv(sch);
139 for (prio = 0; prio < q->bands; prio++)
140 qdisc_reset(q->queues[prio]);
141 sch->qstats.backlog = 0;
145 static int prio_offload(struct Qdisc *sch, bool enable)
147 struct prio_sched_data *q = qdisc_priv(sch);
148 struct net_device *dev = qdisc_dev(sch);
149 struct tc_prio_qopt_offload opt = {
150 .handle = sch->handle,
151 .parent = sch->parent,
154 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
158 opt.command = TC_PRIO_REPLACE;
159 opt.replace_params.bands = q->bands;
160 memcpy(&opt.replace_params.priomap, q->prio2band,
162 opt.replace_params.qstats = &sch->qstats;
164 opt.command = TC_PRIO_DESTROY;
167 return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_PRIO, &opt);
171 prio_destroy(struct Qdisc *sch)
174 struct prio_sched_data *q = qdisc_priv(sch);
176 tcf_block_put(q->block);
177 prio_offload(sch, false);
178 for (prio = 0; prio < q->bands; prio++)
179 qdisc_destroy(q->queues[prio]);
182 static int prio_tune(struct Qdisc *sch, struct nlattr *opt,
183 struct netlink_ext_ack *extack)
185 struct prio_sched_data *q = qdisc_priv(sch);
186 struct Qdisc *queues[TCQ_PRIO_BANDS];
187 int oldbands = q->bands, i;
188 struct tc_prio_qopt *qopt;
190 if (nla_len(opt) < sizeof(*qopt))
192 qopt = nla_data(opt);
194 if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
197 for (i = 0; i <= TC_PRIO_MAX; i++) {
198 if (qopt->priomap[i] >= qopt->bands)
202 /* Before commit, make sure we can allocate all new qdiscs */
203 for (i = oldbands; i < qopt->bands; i++) {
204 queues[i] = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
205 TC_H_MAKE(sch->handle, i + 1),
209 qdisc_destroy(queues[--i]);
215 q->bands = qopt->bands;
216 memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
218 for (i = q->bands; i < oldbands; i++) {
219 struct Qdisc *child = q->queues[i];
221 qdisc_tree_reduce_backlog(child, child->q.qlen,
222 child->qstats.backlog);
223 qdisc_destroy(child);
226 for (i = oldbands; i < q->bands; i++) {
227 q->queues[i] = queues[i];
228 if (q->queues[i] != &noop_qdisc)
229 qdisc_hash_add(q->queues[i], true);
232 sch_tree_unlock(sch);
233 prio_offload(sch, true);
237 static int prio_init(struct Qdisc *sch, struct nlattr *opt,
238 struct netlink_ext_ack *extack)
240 struct prio_sched_data *q = qdisc_priv(sch);
246 err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
250 return prio_tune(sch, opt, extack);
253 static int prio_dump_offload(struct Qdisc *sch)
255 struct net_device *dev = qdisc_dev(sch);
256 struct tc_prio_qopt_offload hw_stats = {
257 .command = TC_PRIO_STATS,
258 .handle = sch->handle,
259 .parent = sch->parent,
262 .bstats = &sch->bstats,
263 .qstats = &sch->qstats,
269 sch->flags &= ~TCQ_F_OFFLOADED;
270 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
273 err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_PRIO,
275 if (err == -EOPNOTSUPP)
279 sch->flags |= TCQ_F_OFFLOADED;
284 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
286 struct prio_sched_data *q = qdisc_priv(sch);
287 unsigned char *b = skb_tail_pointer(skb);
288 struct tc_prio_qopt opt;
291 opt.bands = q->bands;
292 memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX + 1);
294 err = prio_dump_offload(sch);
296 goto nla_put_failure;
298 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
299 goto nla_put_failure;
308 static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
309 struct Qdisc **old, struct netlink_ext_ack *extack)
311 struct prio_sched_data *q = qdisc_priv(sch);
312 unsigned long band = arg - 1;
317 *old = qdisc_replace(sch, new, &q->queues[band]);
321 static struct Qdisc *
322 prio_leaf(struct Qdisc *sch, unsigned long arg)
324 struct prio_sched_data *q = qdisc_priv(sch);
325 unsigned long band = arg - 1;
327 return q->queues[band];
330 static unsigned long prio_find(struct Qdisc *sch, u32 classid)
332 struct prio_sched_data *q = qdisc_priv(sch);
333 unsigned long band = TC_H_MIN(classid);
335 if (band - 1 >= q->bands)
340 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
342 return prio_find(sch, classid);
346 static void prio_unbind(struct Qdisc *q, unsigned long cl)
350 static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
353 struct prio_sched_data *q = qdisc_priv(sch);
355 tcm->tcm_handle |= TC_H_MIN(cl);
356 tcm->tcm_info = q->queues[cl-1]->handle;
360 static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
363 struct prio_sched_data *q = qdisc_priv(sch);
366 cl_q = q->queues[cl - 1];
367 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
368 d, NULL, &cl_q->bstats) < 0 ||
369 gnet_stats_copy_queue(d, NULL, &cl_q->qstats, cl_q->q.qlen) < 0)
375 static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
377 struct prio_sched_data *q = qdisc_priv(sch);
383 for (prio = 0; prio < q->bands; prio++) {
384 if (arg->count < arg->skip) {
388 if (arg->fn(sch, prio + 1, arg) < 0) {
396 static struct tcf_block *prio_tcf_block(struct Qdisc *sch, unsigned long cl,
397 struct netlink_ext_ack *extack)
399 struct prio_sched_data *q = qdisc_priv(sch);
406 static const struct Qdisc_class_ops prio_class_ops = {
411 .tcf_block = prio_tcf_block,
412 .bind_tcf = prio_bind,
413 .unbind_tcf = prio_unbind,
414 .dump = prio_dump_class,
415 .dump_stats = prio_dump_class_stats,
418 static struct Qdisc_ops prio_qdisc_ops __read_mostly = {
420 .cl_ops = &prio_class_ops,
422 .priv_size = sizeof(struct prio_sched_data),
423 .enqueue = prio_enqueue,
424 .dequeue = prio_dequeue,
428 .destroy = prio_destroy,
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");