/* * 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 *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; int err; *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; err = tc_classify(skb, q->filter_list, &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) sch->qstats.drops++; 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)) sch->qstats.drops++; 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_decrease_qlen(child, child->q.qlen); 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_decrease_qlen(old, old->q.qlen); 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; sch_tree_lock(sch); *old = q->queues[band]; q->queues[band] = new; qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); qdisc_reset(*old); sch_tree_unlock(sch); 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]; cl_q->qstats.qlen = cl_q->q.qlen; if (gnet_stats_copy_basic(d, &cl_q->bstats) < 0 || gnet_stats_copy_queue(d, &cl_q->qstats) < 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 **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");