| /* |
| * Copyright (c) 2008, Intel Corporation. |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms and conditions of the GNU General Public License, |
| * version 2, as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| * more details. |
| * |
| * You should have received a copy of the GNU General Public License along with |
| * this program; if not, see <http://www.gnu.org/licenses/>. |
| * |
| * Author: Alexander Duyck <alexander.h.duyck@intel.com> |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/string.h> |
| #include <linux/errno.h> |
| #include <linux/skbuff.h> |
| #include <net/netlink.h> |
| #include <net/pkt_sched.h> |
| |
| |
| struct multiq_sched_data { |
| u16 bands; |
| u16 max_bands; |
| u16 curband; |
| struct tcf_proto __rcu *filter_list; |
| struct Qdisc **queues; |
| }; |
| |
| |
| static struct Qdisc * |
| multiq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr) |
| { |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| u32 band; |
| struct tcf_result res; |
| struct tcf_proto *fl = rcu_dereference_bh(q->filter_list); |
| int err; |
| |
| *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; |
| err = tc_classify(skb, fl, &res); |
| #ifdef CONFIG_NET_CLS_ACT |
| switch (err) { |
| case TC_ACT_STOLEN: |
| case TC_ACT_QUEUED: |
| *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; |
| case TC_ACT_SHOT: |
| return NULL; |
| } |
| #endif |
| band = skb_get_queue_mapping(skb); |
| |
| if (band >= q->bands) |
| return q->queues[0]; |
| |
| return q->queues[band]; |
| } |
| |
| static int |
| multiq_enqueue(struct sk_buff *skb, struct Qdisc *sch) |
| { |
| struct Qdisc *qdisc; |
| int ret; |
| |
| qdisc = multiq_classify(skb, sch, &ret); |
| #ifdef CONFIG_NET_CLS_ACT |
| if (qdisc == NULL) { |
| |
| if (ret & __NET_XMIT_BYPASS) |
| qdisc_qstats_drop(sch); |
| kfree_skb(skb); |
| return ret; |
| } |
| #endif |
| |
| ret = qdisc_enqueue(skb, qdisc); |
| if (ret == NET_XMIT_SUCCESS) { |
| sch->q.qlen++; |
| return NET_XMIT_SUCCESS; |
| } |
| if (net_xmit_drop_count(ret)) |
| qdisc_qstats_drop(sch); |
| return ret; |
| } |
| |
| static struct sk_buff *multiq_dequeue(struct Qdisc *sch) |
| { |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| struct Qdisc *qdisc; |
| struct sk_buff *skb; |
| int band; |
| |
| for (band = 0; band < q->bands; band++) { |
| /* cycle through bands to ensure fairness */ |
| q->curband++; |
| if (q->curband >= q->bands) |
| q->curband = 0; |
| |
| /* Check that target subqueue is available before |
| * pulling an skb to avoid head-of-line blocking. |
| */ |
| if (!netif_xmit_stopped( |
| netdev_get_tx_queue(qdisc_dev(sch), q->curband))) { |
| qdisc = q->queues[q->curband]; |
| skb = qdisc->dequeue(qdisc); |
| if (skb) { |
| qdisc_bstats_update(sch, skb); |
| sch->q.qlen--; |
| return skb; |
| } |
| } |
| } |
| return NULL; |
| |
| } |
| |
| static struct sk_buff *multiq_peek(struct Qdisc *sch) |
| { |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| unsigned int curband = q->curband; |
| struct Qdisc *qdisc; |
| struct sk_buff *skb; |
| int band; |
| |
| for (band = 0; band < q->bands; band++) { |
| /* cycle through bands to ensure fairness */ |
| curband++; |
| if (curband >= q->bands) |
| curband = 0; |
| |
| /* Check that target subqueue is available before |
| * pulling an skb to avoid head-of-line blocking. |
| */ |
| if (!netif_xmit_stopped( |
| netdev_get_tx_queue(qdisc_dev(sch), curband))) { |
| qdisc = q->queues[curband]; |
| skb = qdisc->ops->peek(qdisc); |
| if (skb) |
| return skb; |
| } |
| } |
| return NULL; |
| |
| } |
| |
| static unsigned int multiq_drop(struct Qdisc *sch) |
| { |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| int band; |
| unsigned int len; |
| struct Qdisc *qdisc; |
| |
| for (band = q->bands - 1; band >= 0; band--) { |
| qdisc = q->queues[band]; |
| if (qdisc->ops->drop) { |
| len = qdisc->ops->drop(qdisc); |
| if (len != 0) { |
| sch->q.qlen--; |
| return len; |
| } |
| } |
| } |
| return 0; |
| } |
| |
| |
| static void |
| multiq_reset(struct Qdisc *sch) |
| { |
| u16 band; |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| |
| for (band = 0; band < q->bands; band++) |
| qdisc_reset(q->queues[band]); |
| sch->q.qlen = 0; |
| q->curband = 0; |
| } |
| |
| static void |
| multiq_destroy(struct Qdisc *sch) |
| { |
| int band; |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| |
| tcf_destroy_chain(&q->filter_list); |
| for (band = 0; band < q->bands; band++) |
| qdisc_destroy(q->queues[band]); |
| |
| kfree(q->queues); |
| } |
| |
| static int multiq_tune(struct Qdisc *sch, struct nlattr *opt) |
| { |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| struct tc_multiq_qopt *qopt; |
| int i; |
| |
| if (!netif_is_multiqueue(qdisc_dev(sch))) |
| return -EOPNOTSUPP; |
| if (nla_len(opt) < sizeof(*qopt)) |
| return -EINVAL; |
| |
| qopt = nla_data(opt); |
| |
| qopt->bands = qdisc_dev(sch)->real_num_tx_queues; |
| |
| sch_tree_lock(sch); |
| q->bands = qopt->bands; |
| for (i = q->bands; i < q->max_bands; i++) { |
| if (q->queues[i] != &noop_qdisc) { |
| struct Qdisc *child = q->queues[i]; |
| q->queues[i] = &noop_qdisc; |
| qdisc_tree_reduce_backlog(child, child->q.qlen, |
| child->qstats.backlog); |
| qdisc_destroy(child); |
| } |
| } |
| |
| sch_tree_unlock(sch); |
| |
| for (i = 0; i < q->bands; i++) { |
| if (q->queues[i] == &noop_qdisc) { |
| struct Qdisc *child, *old; |
| child = qdisc_create_dflt(sch->dev_queue, |
| &pfifo_qdisc_ops, |
| TC_H_MAKE(sch->handle, |
| i + 1)); |
| if (child) { |
| sch_tree_lock(sch); |
| old = q->queues[i]; |
| q->queues[i] = child; |
| |
| if (old != &noop_qdisc) { |
| qdisc_tree_reduce_backlog(old, |
| old->q.qlen, |
| old->qstats.backlog); |
| qdisc_destroy(old); |
| } |
| sch_tree_unlock(sch); |
| } |
| } |
| } |
| return 0; |
| } |
| |
| static int multiq_init(struct Qdisc *sch, struct nlattr *opt) |
| { |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| int i, err; |
| |
| q->queues = NULL; |
| |
| if (opt == NULL) |
| return -EINVAL; |
| |
| q->max_bands = qdisc_dev(sch)->num_tx_queues; |
| |
| q->queues = kcalloc(q->max_bands, sizeof(struct Qdisc *), GFP_KERNEL); |
| if (!q->queues) |
| return -ENOBUFS; |
| for (i = 0; i < q->max_bands; i++) |
| q->queues[i] = &noop_qdisc; |
| |
| err = multiq_tune(sch, opt); |
| |
| if (err) |
| kfree(q->queues); |
| |
| return err; |
| } |
| |
| static int multiq_dump(struct Qdisc *sch, struct sk_buff *skb) |
| { |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| unsigned char *b = skb_tail_pointer(skb); |
| struct tc_multiq_qopt opt; |
| |
| opt.bands = q->bands; |
| opt.max_bands = q->max_bands; |
| |
| if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) |
| goto nla_put_failure; |
| |
| return skb->len; |
| |
| nla_put_failure: |
| nlmsg_trim(skb, b); |
| return -1; |
| } |
| |
| static int multiq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, |
| struct Qdisc **old) |
| { |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| unsigned long band = arg - 1; |
| |
| if (new == NULL) |
| new = &noop_qdisc; |
| |
| *old = qdisc_replace(sch, new, &q->queues[band]); |
| return 0; |
| } |
| |
| static struct Qdisc * |
| multiq_leaf(struct Qdisc *sch, unsigned long arg) |
| { |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| unsigned long band = arg - 1; |
| |
| return q->queues[band]; |
| } |
| |
| static unsigned long multiq_get(struct Qdisc *sch, u32 classid) |
| { |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| unsigned long band = TC_H_MIN(classid); |
| |
| if (band - 1 >= q->bands) |
| return 0; |
| return band; |
| } |
| |
| static unsigned long multiq_bind(struct Qdisc *sch, unsigned long parent, |
| u32 classid) |
| { |
| return multiq_get(sch, classid); |
| } |
| |
| |
| static void multiq_put(struct Qdisc *q, unsigned long cl) |
| { |
| } |
| |
| static int multiq_dump_class(struct Qdisc *sch, unsigned long cl, |
| struct sk_buff *skb, struct tcmsg *tcm) |
| { |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| |
| tcm->tcm_handle |= TC_H_MIN(cl); |
| tcm->tcm_info = q->queues[cl - 1]->handle; |
| return 0; |
| } |
| |
| static int multiq_dump_class_stats(struct Qdisc *sch, unsigned long cl, |
| struct gnet_dump *d) |
| { |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| struct Qdisc *cl_q; |
| |
| cl_q = q->queues[cl - 1]; |
| if (gnet_stats_copy_basic(d, NULL, &cl_q->bstats) < 0 || |
| gnet_stats_copy_queue(d, NULL, &cl_q->qstats, cl_q->q.qlen) < 0) |
| return -1; |
| |
| return 0; |
| } |
| |
| static void multiq_walk(struct Qdisc *sch, struct qdisc_walker *arg) |
| { |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| int band; |
| |
| if (arg->stop) |
| return; |
| |
| for (band = 0; band < q->bands; band++) { |
| if (arg->count < arg->skip) { |
| arg->count++; |
| continue; |
| } |
| if (arg->fn(sch, band + 1, arg) < 0) { |
| arg->stop = 1; |
| break; |
| } |
| arg->count++; |
| } |
| } |
| |
| static struct tcf_proto __rcu **multiq_find_tcf(struct Qdisc *sch, |
| unsigned long cl) |
| { |
| struct multiq_sched_data *q = qdisc_priv(sch); |
| |
| if (cl) |
| return NULL; |
| return &q->filter_list; |
| } |
| |
| static const struct Qdisc_class_ops multiq_class_ops = { |
| .graft = multiq_graft, |
| .leaf = multiq_leaf, |
| .get = multiq_get, |
| .put = multiq_put, |
| .walk = multiq_walk, |
| .tcf_chain = multiq_find_tcf, |
| .bind_tcf = multiq_bind, |
| .unbind_tcf = multiq_put, |
| .dump = multiq_dump_class, |
| .dump_stats = multiq_dump_class_stats, |
| }; |
| |
| static struct Qdisc_ops multiq_qdisc_ops __read_mostly = { |
| .next = NULL, |
| .cl_ops = &multiq_class_ops, |
| .id = "multiq", |
| .priv_size = sizeof(struct multiq_sched_data), |
| .enqueue = multiq_enqueue, |
| .dequeue = multiq_dequeue, |
| .peek = multiq_peek, |
| .drop = multiq_drop, |
| .init = multiq_init, |
| .reset = multiq_reset, |
| .destroy = multiq_destroy, |
| .change = multiq_tune, |
| .dump = multiq_dump, |
| .owner = THIS_MODULE, |
| }; |
| |
| static int __init multiq_module_init(void) |
| { |
| return register_qdisc(&multiq_qdisc_ops); |
| } |
| |
| static void __exit multiq_module_exit(void) |
| { |
| unregister_qdisc(&multiq_qdisc_ops); |
| } |
| |
| module_init(multiq_module_init) |
| module_exit(multiq_module_exit) |
| |
| MODULE_LICENSE("GPL"); |