2 * Copyright (c) 2008, Intel Corporation.
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, see <http://www.gnu.org/licenses/>.
16 * Author: Alexander Duyck <alexander.h.duyck@intel.com>
19 #include <linux/module.h>
20 #include <linux/slab.h>
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/string.h>
24 #include <linux/errno.h>
25 #include <linux/skbuff.h>
26 #include <net/netlink.h>
27 #include <net/pkt_sched.h>
30 struct multiq_sched_data {
34 struct tcf_proto __rcu *filter_list;
35 struct Qdisc **queues;
40 multiq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
42 struct multiq_sched_data *q = qdisc_priv(sch);
44 struct tcf_result res;
45 struct tcf_proto *fl = rcu_dereference_bh(q->filter_list);
48 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
49 err = tc_classify(skb, fl, &res, false);
50 #ifdef CONFIG_NET_CLS_ACT
54 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
59 band = skb_get_queue_mapping(skb);
64 return q->queues[band];
68 multiq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
73 qdisc = multiq_classify(skb, sch, &ret);
74 #ifdef CONFIG_NET_CLS_ACT
77 if (ret & __NET_XMIT_BYPASS)
78 qdisc_qstats_drop(sch);
84 ret = qdisc_enqueue(skb, qdisc);
85 if (ret == NET_XMIT_SUCCESS) {
87 return NET_XMIT_SUCCESS;
89 if (net_xmit_drop_count(ret))
90 qdisc_qstats_drop(sch);
94 static struct sk_buff *multiq_dequeue(struct Qdisc *sch)
96 struct multiq_sched_data *q = qdisc_priv(sch);
101 for (band = 0; band < q->bands; band++) {
102 /* cycle through bands to ensure fairness */
104 if (q->curband >= q->bands)
107 /* Check that target subqueue is available before
108 * pulling an skb to avoid head-of-line blocking.
110 if (!netif_xmit_stopped(
111 netdev_get_tx_queue(qdisc_dev(sch), q->curband))) {
112 qdisc = q->queues[q->curband];
113 skb = qdisc->dequeue(qdisc);
115 qdisc_bstats_update(sch, skb);
125 static struct sk_buff *multiq_peek(struct Qdisc *sch)
127 struct multiq_sched_data *q = qdisc_priv(sch);
128 unsigned int curband = q->curband;
133 for (band = 0; band < q->bands; band++) {
134 /* cycle through bands to ensure fairness */
136 if (curband >= q->bands)
139 /* Check that target subqueue is available before
140 * pulling an skb to avoid head-of-line blocking.
142 if (!netif_xmit_stopped(
143 netdev_get_tx_queue(qdisc_dev(sch), curband))) {
144 qdisc = q->queues[curband];
145 skb = qdisc->ops->peek(qdisc);
154 static unsigned int multiq_drop(struct Qdisc *sch)
156 struct multiq_sched_data *q = qdisc_priv(sch);
161 for (band = q->bands - 1; band >= 0; band--) {
162 qdisc = q->queues[band];
163 if (qdisc->ops->drop) {
164 len = qdisc->ops->drop(qdisc);
176 multiq_reset(struct Qdisc *sch)
179 struct multiq_sched_data *q = qdisc_priv(sch);
181 for (band = 0; band < q->bands; band++)
182 qdisc_reset(q->queues[band]);
188 multiq_destroy(struct Qdisc *sch)
191 struct multiq_sched_data *q = qdisc_priv(sch);
193 tcf_destroy_chain(&q->filter_list);
194 for (band = 0; band < q->bands; band++)
195 qdisc_destroy(q->queues[band]);
200 static int multiq_tune(struct Qdisc *sch, struct nlattr *opt)
202 struct multiq_sched_data *q = qdisc_priv(sch);
203 struct tc_multiq_qopt *qopt;
206 if (!netif_is_multiqueue(qdisc_dev(sch)))
208 if (nla_len(opt) < sizeof(*qopt))
211 qopt = nla_data(opt);
213 qopt->bands = qdisc_dev(sch)->real_num_tx_queues;
216 q->bands = qopt->bands;
217 for (i = q->bands; i < q->max_bands; i++) {
218 if (q->queues[i] != &noop_qdisc) {
219 struct Qdisc *child = q->queues[i];
220 q->queues[i] = &noop_qdisc;
221 qdisc_tree_reduce_backlog(child, child->q.qlen,
222 child->qstats.backlog);
223 qdisc_destroy(child);
227 sch_tree_unlock(sch);
229 for (i = 0; i < q->bands; i++) {
230 if (q->queues[i] == &noop_qdisc) {
231 struct Qdisc *child, *old;
232 child = qdisc_create_dflt(sch->dev_queue,
234 TC_H_MAKE(sch->handle,
239 q->queues[i] = child;
241 if (old != &noop_qdisc) {
242 qdisc_tree_reduce_backlog(old,
244 old->qstats.backlog);
247 sch_tree_unlock(sch);
254 static int multiq_init(struct Qdisc *sch, struct nlattr *opt)
256 struct multiq_sched_data *q = qdisc_priv(sch);
264 q->max_bands = qdisc_dev(sch)->num_tx_queues;
266 q->queues = kcalloc(q->max_bands, sizeof(struct Qdisc *), GFP_KERNEL);
269 for (i = 0; i < q->max_bands; i++)
270 q->queues[i] = &noop_qdisc;
272 err = multiq_tune(sch, opt);
280 static int multiq_dump(struct Qdisc *sch, struct sk_buff *skb)
282 struct multiq_sched_data *q = qdisc_priv(sch);
283 unsigned char *b = skb_tail_pointer(skb);
284 struct tc_multiq_qopt opt;
286 opt.bands = q->bands;
287 opt.max_bands = q->max_bands;
289 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
290 goto nla_put_failure;
299 static int multiq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
302 struct multiq_sched_data *q = qdisc_priv(sch);
303 unsigned long band = arg - 1;
308 *old = qdisc_replace(sch, new, &q->queues[band]);
312 static struct Qdisc *
313 multiq_leaf(struct Qdisc *sch, unsigned long arg)
315 struct multiq_sched_data *q = qdisc_priv(sch);
316 unsigned long band = arg - 1;
318 return q->queues[band];
321 static unsigned long multiq_get(struct Qdisc *sch, u32 classid)
323 struct multiq_sched_data *q = qdisc_priv(sch);
324 unsigned long band = TC_H_MIN(classid);
326 if (band - 1 >= q->bands)
331 static unsigned long multiq_bind(struct Qdisc *sch, unsigned long parent,
334 return multiq_get(sch, classid);
338 static void multiq_put(struct Qdisc *q, unsigned long cl)
342 static int multiq_dump_class(struct Qdisc *sch, unsigned long cl,
343 struct sk_buff *skb, struct tcmsg *tcm)
345 struct multiq_sched_data *q = qdisc_priv(sch);
347 tcm->tcm_handle |= TC_H_MIN(cl);
348 tcm->tcm_info = q->queues[cl - 1]->handle;
352 static int multiq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
355 struct multiq_sched_data *q = qdisc_priv(sch);
358 cl_q = q->queues[cl - 1];
359 if (gnet_stats_copy_basic(d, NULL, &cl_q->bstats) < 0 ||
360 gnet_stats_copy_queue(d, NULL, &cl_q->qstats, cl_q->q.qlen) < 0)
366 static void multiq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
368 struct multiq_sched_data *q = qdisc_priv(sch);
374 for (band = 0; band < q->bands; band++) {
375 if (arg->count < arg->skip) {
379 if (arg->fn(sch, band + 1, arg) < 0) {
387 static struct tcf_proto __rcu **multiq_find_tcf(struct Qdisc *sch,
390 struct multiq_sched_data *q = qdisc_priv(sch);
394 return &q->filter_list;
397 static const struct Qdisc_class_ops multiq_class_ops = {
398 .graft = multiq_graft,
403 .tcf_chain = multiq_find_tcf,
404 .bind_tcf = multiq_bind,
405 .unbind_tcf = multiq_put,
406 .dump = multiq_dump_class,
407 .dump_stats = multiq_dump_class_stats,
410 static struct Qdisc_ops multiq_qdisc_ops __read_mostly = {
412 .cl_ops = &multiq_class_ops,
414 .priv_size = sizeof(struct multiq_sched_data),
415 .enqueue = multiq_enqueue,
416 .dequeue = multiq_dequeue,
420 .reset = multiq_reset,
421 .destroy = multiq_destroy,
422 .change = multiq_tune,
424 .owner = THIS_MODULE,
427 static int __init multiq_module_init(void)
429 return register_qdisc(&multiq_qdisc_ops);
432 static void __exit multiq_module_exit(void)
434 unregister_qdisc(&multiq_qdisc_ops);
437 module_init(multiq_module_init)
438 module_exit(multiq_module_exit)
440 MODULE_LICENSE("GPL");