#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 multiq_sched_data {
u16 bands;
u16 max_bands;
u16 curband;
struct tcf_proto __rcu *filter_list;
struct tcf_block *block;
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 = tcf_classify(skb, NULL, 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;
fallthrough;
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 sk_buff **to_free)
{
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);
__qdisc_drop(skb, to_free);
return ret;
}
#endif
ret = qdisc_enqueue(skb, qdisc, to_free);
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++) {
q->curband++;
if (q->curband >= q->bands)
q->curband = 0;
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++) {
curband++;
if (curband >= q->bands)
curband = 0;
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 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]);
q->curband = 0;
}
static void
multiq_destroy(struct Qdisc *sch)
{
int band;
struct multiq_sched_data *q = qdisc_priv(sch);
tcf_block_put(q->block);
for (band = 0; band < q->bands; band++)
qdisc_put(q->queues[band]);
kfree(q->queues);
}
static int multiq_tune(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
struct multiq_sched_data *q = qdisc_priv(sch);
struct tc_multiq_qopt *qopt;
struct Qdisc **removed;
int i, n_removed = 0;
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;
removed = kmalloc(sizeof(*removed) * (q->max_bands - qopt->bands),
GFP_KERNEL);
if (!removed)
return -ENOMEM;
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_purge_queue(child);
removed[n_removed++] = child;
}
}
sch_tree_unlock(sch);
for (i = 0; i < n_removed; i++)
qdisc_put(removed[i]);
kfree(removed);
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), extack);
if (child) {
sch_tree_lock(sch);
old = q->queues[i];
q->queues[i] = child;
if (child != &noop_qdisc)
qdisc_hash_add(child, true);
if (old != &noop_qdisc)
qdisc_purge_queue(old);
sch_tree_unlock(sch);
qdisc_put(old);
}
}
}
return 0;
}
static int multiq_init(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
struct multiq_sched_data *q = qdisc_priv(sch);
int i, err;
q->queues = NULL;
if (!opt)
return -EINVAL;
err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
if (err)
return err;
q->max_bands = qdisc_dev(sch)->num_tx_queues;
q->queues = kzalloc_objs(struct Qdisc *, q->max_bands);
if (!q->queues)
return -ENOBUFS;
for (i = 0; i < q->max_bands; i++)
q->queues[i] = &noop_qdisc;
return multiq_tune(sch, opt, extack);
}
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 netlink_ext_ack *extack)
{
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_find(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_find(sch, classid);
}
static void multiq_unbind(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, cl_q->cpu_bstats, &cl_q->bstats, true) < 0 ||
qdisc_qstats_copy(d, cl_q) < 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 (!tc_qdisc_stats_dump(sch, band + 1, arg))
break;
}
}
static struct tcf_block *multiq_tcf_block(struct Qdisc *sch, unsigned long cl,
struct netlink_ext_ack *extack)
{
struct multiq_sched_data *q = qdisc_priv(sch);
if (cl)
return NULL;
return q->block;
}
static const struct Qdisc_class_ops multiq_class_ops = {
.graft = multiq_graft,
.leaf = multiq_leaf,
.find = multiq_find,
.walk = multiq_walk,
.tcf_block = multiq_tcf_block,
.bind_tcf = multiq_bind,
.unbind_tcf = multiq_unbind,
.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,
.init = multiq_init,
.reset = multiq_reset,
.destroy = multiq_destroy,
.change = multiq_tune,
.dump = multiq_dump,
.owner = THIS_MODULE,
};
MODULE_ALIAS_NET_SCH("multiq");
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");
MODULE_DESCRIPTION("Multi queue to hardware queue mapping qdisc");
