| /* |
| * net/sched/sch_prio.c Simple 3-band priority "scheduler". |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
| * Fixes: 19990609: J Hadi Salim <hadi@nortelnetworks.com>: |
| * Init -- EINVAL when opt undefined |
| */ |
| |
| #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> |
| #include <net/pkt_cls.h> |
| |
| struct prio_sched_data { |
| int bands; |
| struct tcf_proto __rcu *filter_list; |
| struct tcf_block *block; |
| u8 prio2band[TC_PRIO_MAX+1]; |
| struct Qdisc *queues[TCQ_PRIO_BANDS]; |
| }; |
| |
| |
| static struct Qdisc * |
| prio_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr) |
| { |
| struct prio_sched_data *q = qdisc_priv(sch); |
| u32 band = skb->priority; |
| struct tcf_result res; |
| struct tcf_proto *fl; |
| int err; |
| |
| *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; |
| if (TC_H_MAJ(skb->priority) != sch->handle) { |
| fl = rcu_dereference_bh(q->filter_list); |
| err = tcf_classify(skb, fl, &res, false); |
| #ifdef CONFIG_NET_CLS_ACT |
| switch (err) { |
| case TC_ACT_STOLEN: |
| case TC_ACT_QUEUED: |
| case TC_ACT_TRAP: |
| *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; |
| /* fall through */ |
| case TC_ACT_SHOT: |
| return NULL; |
| } |
| #endif |
| if (!fl || err < 0) { |
| if (TC_H_MAJ(band)) |
| band = 0; |
| return q->queues[q->prio2band[band & TC_PRIO_MAX]]; |
| } |
| band = res.classid; |
| } |
| band = TC_H_MIN(band) - 1; |
| if (band >= q->bands) |
| return q->queues[q->prio2band[0]]; |
| |
| return q->queues[band]; |
| } |
| |
| static int |
| prio_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) |
| { |
| struct Qdisc *qdisc; |
| int ret; |
| |
| qdisc = prio_classify(skb, sch, &ret); |
| #ifdef CONFIG_NET_CLS_ACT |
| if (qdisc == NULL) { |
| |
| if (ret & __NET_XMIT_BYPASS) |
| qdisc_qstats_drop(sch); |
| __qdisc_drop(skb, to_free); |
| return ret; |
| } |
| #endif |
| |
| ret = qdisc_enqueue(skb, qdisc, to_free); |
| if (ret == NET_XMIT_SUCCESS) { |
| qdisc_qstats_backlog_inc(sch, skb); |
| sch->q.qlen++; |
| return NET_XMIT_SUCCESS; |
| } |
| if (net_xmit_drop_count(ret)) |
| qdisc_qstats_drop(sch); |
| return ret; |
| } |
| |
| static struct sk_buff *prio_peek(struct Qdisc *sch) |
| { |
| struct prio_sched_data *q = qdisc_priv(sch); |
| int prio; |
| |
| for (prio = 0; prio < q->bands; prio++) { |
| struct Qdisc *qdisc = q->queues[prio]; |
| struct sk_buff *skb = qdisc->ops->peek(qdisc); |
| if (skb) |
| return skb; |
| } |
| return NULL; |
| } |
| |
| static struct sk_buff *prio_dequeue(struct Qdisc *sch) |
| { |
| struct prio_sched_data *q = qdisc_priv(sch); |
| int prio; |
| |
| for (prio = 0; prio < q->bands; prio++) { |
| struct Qdisc *qdisc = q->queues[prio]; |
| struct sk_buff *skb = qdisc_dequeue_peeked(qdisc); |
| if (skb) { |
| qdisc_bstats_update(sch, skb); |
| qdisc_qstats_backlog_dec(sch, skb); |
| sch->q.qlen--; |
| return skb; |
| } |
| } |
| return NULL; |
| |
| } |
| |
| static void |
| prio_reset(struct Qdisc *sch) |
| { |
| int prio; |
| struct prio_sched_data *q = qdisc_priv(sch); |
| |
| for (prio = 0; prio < q->bands; prio++) |
| qdisc_reset(q->queues[prio]); |
| sch->qstats.backlog = 0; |
| sch->q.qlen = 0; |
| } |
| |
| static int prio_offload(struct Qdisc *sch, struct tc_prio_qopt *qopt) |
| { |
| struct net_device *dev = qdisc_dev(sch); |
| struct tc_prio_qopt_offload opt = { |
| .handle = sch->handle, |
| .parent = sch->parent, |
| }; |
| |
| if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) |
| return -EOPNOTSUPP; |
| |
| if (qopt) { |
| opt.command = TC_PRIO_REPLACE; |
| opt.replace_params.bands = qopt->bands; |
| memcpy(&opt.replace_params.priomap, qopt->priomap, |
| TC_PRIO_MAX + 1); |
| opt.replace_params.qstats = &sch->qstats; |
| } else { |
| opt.command = TC_PRIO_DESTROY; |
| } |
| |
| return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_PRIO, &opt); |
| } |
| |
| static void |
| prio_destroy(struct Qdisc *sch) |
| { |
| int prio; |
| struct prio_sched_data *q = qdisc_priv(sch); |
| |
| tcf_block_put(q->block); |
| prio_offload(sch, NULL); |
| for (prio = 0; prio < q->bands; prio++) |
| qdisc_put(q->queues[prio]); |
| } |
| |
| static int prio_tune(struct Qdisc *sch, struct nlattr *opt, |
| struct netlink_ext_ack *extack) |
| { |
| struct prio_sched_data *q = qdisc_priv(sch); |
| struct Qdisc *queues[TCQ_PRIO_BANDS]; |
| int oldbands = q->bands, i; |
| struct tc_prio_qopt *qopt; |
| |
| if (nla_len(opt) < sizeof(*qopt)) |
| return -EINVAL; |
| qopt = nla_data(opt); |
| |
| if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2) |
| return -EINVAL; |
| |
| for (i = 0; i <= TC_PRIO_MAX; i++) { |
| if (qopt->priomap[i] >= qopt->bands) |
| return -EINVAL; |
| } |
| |
| /* Before commit, make sure we can allocate all new qdiscs */ |
| for (i = oldbands; i < qopt->bands; i++) { |
| queues[i] = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, |
| TC_H_MAKE(sch->handle, i + 1), |
| extack); |
| if (!queues[i]) { |
| while (i > oldbands) |
| qdisc_put(queues[--i]); |
| return -ENOMEM; |
| } |
| } |
| |
| prio_offload(sch, qopt); |
| sch_tree_lock(sch); |
| q->bands = qopt->bands; |
| memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1); |
| |
| for (i = q->bands; i < oldbands; i++) { |
| struct Qdisc *child = q->queues[i]; |
| |
| qdisc_tree_reduce_backlog(child, child->q.qlen, |
| child->qstats.backlog); |
| qdisc_put(child); |
| } |
| |
| for (i = oldbands; i < q->bands; i++) { |
| q->queues[i] = queues[i]; |
| if (q->queues[i] != &noop_qdisc) |
| qdisc_hash_add(q->queues[i], true); |
| } |
| |
| sch_tree_unlock(sch); |
| return 0; |
| } |
| |
| static int prio_init(struct Qdisc *sch, struct nlattr *opt, |
| struct netlink_ext_ack *extack) |
| { |
| struct prio_sched_data *q = qdisc_priv(sch); |
| int err; |
| |
| if (!opt) |
| return -EINVAL; |
| |
| err = tcf_block_get(&q->block, &q->filter_list, sch, extack); |
| if (err) |
| return err; |
| |
| return prio_tune(sch, opt, extack); |
| } |
| |
| static int prio_dump_offload(struct Qdisc *sch) |
| { |
| struct net_device *dev = qdisc_dev(sch); |
| struct tc_prio_qopt_offload hw_stats = { |
| .command = TC_PRIO_STATS, |
| .handle = sch->handle, |
| .parent = sch->parent, |
| { |
| .stats = { |
| .bstats = &sch->bstats, |
| .qstats = &sch->qstats, |
| }, |
| }, |
| }; |
| int err; |
| |
| sch->flags &= ~TCQ_F_OFFLOADED; |
| if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) |
| return 0; |
| |
| err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_PRIO, |
| &hw_stats); |
| if (err == -EOPNOTSUPP) |
| return 0; |
| |
| if (!err) |
| sch->flags |= TCQ_F_OFFLOADED; |
| |
| return err; |
| } |
| |
| static int prio_dump(struct Qdisc *sch, struct sk_buff *skb) |
| { |
| struct prio_sched_data *q = qdisc_priv(sch); |
| unsigned char *b = skb_tail_pointer(skb); |
| struct tc_prio_qopt opt; |
| int err; |
| |
| opt.bands = q->bands; |
| memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX + 1); |
| |
| err = prio_dump_offload(sch); |
| if (err) |
| goto nla_put_failure; |
| |
| 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 prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, |
| struct Qdisc **old, struct netlink_ext_ack *extack) |
| { |
| struct prio_sched_data *q = qdisc_priv(sch); |
| struct tc_prio_qopt_offload graft_offload; |
| struct net_device *dev = qdisc_dev(sch); |
| unsigned long band = arg - 1; |
| bool any_qdisc_is_offloaded; |
| int err; |
| |
| if (new == NULL) |
| new = &noop_qdisc; |
| |
| *old = qdisc_replace(sch, new, &q->queues[band]); |
| |
| if (!tc_can_offload(dev)) |
| return 0; |
| |
| graft_offload.handle = sch->handle; |
| graft_offload.parent = sch->parent; |
| graft_offload.graft_params.band = band; |
| graft_offload.graft_params.child_handle = new->handle; |
| graft_offload.command = TC_PRIO_GRAFT; |
| |
| err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_PRIO, |
| &graft_offload); |
| |
| /* Don't report error if the graft is part of destroy operation. */ |
| if (err && new != &noop_qdisc) { |
| /* Don't report error if the parent, the old child and the new |
| * one are not offloaded. |
| */ |
| any_qdisc_is_offloaded = sch->flags & TCQ_F_OFFLOADED; |
| any_qdisc_is_offloaded |= new->flags & TCQ_F_OFFLOADED; |
| if (*old) |
| any_qdisc_is_offloaded |= (*old)->flags & |
| TCQ_F_OFFLOADED; |
| |
| if (any_qdisc_is_offloaded) |
| NL_SET_ERR_MSG(extack, "Offloading graft operation failed."); |
| } |
| |
| return 0; |
| } |
| |
| static struct Qdisc * |
| prio_leaf(struct Qdisc *sch, unsigned long arg) |
| { |
| struct prio_sched_data *q = qdisc_priv(sch); |
| unsigned long band = arg - 1; |
| |
| return q->queues[band]; |
| } |
| |
| static unsigned long prio_find(struct Qdisc *sch, u32 classid) |
| { |
| struct prio_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 prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid) |
| { |
| return prio_find(sch, classid); |
| } |
| |
| |
| static void prio_unbind(struct Qdisc *q, unsigned long cl) |
| { |
| } |
| |
| static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb, |
| struct tcmsg *tcm) |
| { |
| struct prio_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 prio_dump_class_stats(struct Qdisc *sch, unsigned long cl, |
| struct gnet_dump *d) |
| { |
| struct prio_sched_data *q = qdisc_priv(sch); |
| struct Qdisc *cl_q; |
| |
| cl_q = q->queues[cl - 1]; |
| if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), |
| 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 prio_walk(struct Qdisc *sch, struct qdisc_walker *arg) |
| { |
| struct prio_sched_data *q = qdisc_priv(sch); |
| int prio; |
| |
| if (arg->stop) |
| return; |
| |
| for (prio = 0; prio < q->bands; prio++) { |
| if (arg->count < arg->skip) { |
| arg->count++; |
| continue; |
| } |
| if (arg->fn(sch, prio + 1, arg) < 0) { |
| arg->stop = 1; |
| break; |
| } |
| arg->count++; |
| } |
| } |
| |
| static struct tcf_block *prio_tcf_block(struct Qdisc *sch, unsigned long cl, |
| struct netlink_ext_ack *extack) |
| { |
| struct prio_sched_data *q = qdisc_priv(sch); |
| |
| if (cl) |
| return NULL; |
| return q->block; |
| } |
| |
| static const struct Qdisc_class_ops prio_class_ops = { |
| .graft = prio_graft, |
| .leaf = prio_leaf, |
| .find = prio_find, |
| .walk = prio_walk, |
| .tcf_block = prio_tcf_block, |
| .bind_tcf = prio_bind, |
| .unbind_tcf = prio_unbind, |
| .dump = prio_dump_class, |
| .dump_stats = prio_dump_class_stats, |
| }; |
| |
| static struct Qdisc_ops prio_qdisc_ops __read_mostly = { |
| .next = NULL, |
| .cl_ops = &prio_class_ops, |
| .id = "prio", |
| .priv_size = sizeof(struct prio_sched_data), |
| .enqueue = prio_enqueue, |
| .dequeue = prio_dequeue, |
| .peek = prio_peek, |
| .init = prio_init, |
| .reset = prio_reset, |
| .destroy = prio_destroy, |
| .change = prio_tune, |
| .dump = prio_dump, |
| .owner = THIS_MODULE, |
| }; |
| |
| static int __init prio_module_init(void) |
| { |
| return register_qdisc(&prio_qdisc_ops); |
| } |
| |
| static void __exit prio_module_exit(void) |
| { |
| unregister_qdisc(&prio_qdisc_ops); |
| } |
| |
| module_init(prio_module_init) |
| module_exit(prio_module_exit) |
| |
| MODULE_LICENSE("GPL"); |