blob: 0e6f34bd9a683725f568f6485df4314f2c9a32ab [file] [log] [blame]
/*
* 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) {
new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
TC_H_MAKE(sch->handle, arg), extack);
if (!new)
new = &noop_qdisc;
else
qdisc_hash_add(new, true);
}
*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, cl_q->cpu_bstats, &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");