[mirror_ubuntu-jammy-kernel.git] / net / sched / sch_drr.c

/*
 * net/sched/sch_drr.c         Deficit Round Robin scheduler
 *
 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/pkt_sched.h>
#include <net/sch_generic.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>

struct drr_class {
	struct Qdisc_class_common	common;
	unsigned int			refcnt;
	unsigned int			filter_cnt;

	struct gnet_stats_basic_packed		bstats;
	struct gnet_stats_queue		qstats;
	struct gnet_stats_rate_est64	rate_est;
	struct list_head		alist;
	struct Qdisc			*qdisc;

	u32				quantum;
	u32				deficit;
};

struct drr_sched {
	struct list_head		active;
	struct tcf_proto __rcu		*filter_list;
	struct Qdisc_class_hash		clhash;
};

static struct drr_class *drr_find_class(struct Qdisc *sch, u32 classid)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct Qdisc_class_common *clc;

	clc = qdisc_class_find(&q->clhash, classid);
	if (clc == NULL)
		return NULL;
	return container_of(clc, struct drr_class, common);
}

static void drr_purge_queue(struct drr_class *cl)
{
	unsigned int len = cl->qdisc->q.qlen;

	qdisc_reset(cl->qdisc);
	qdisc_tree_decrease_qlen(cl->qdisc, len);
}

static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
	[TCA_DRR_QUANTUM]	= { .type = NLA_U32 },
};

static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
			    struct nlattr **tca, unsigned long *arg)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl = (struct drr_class *)*arg;
	struct nlattr *opt = tca[TCA_OPTIONS];
	struct nlattr *tb[TCA_DRR_MAX + 1];
	u32 quantum;
	int err;

	if (!opt)
		return -EINVAL;

	err = nla_parse_nested(tb, TCA_DRR_MAX, opt, drr_policy);
	if (err < 0)
		return err;

	if (tb[TCA_DRR_QUANTUM]) {
		quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
		if (quantum == 0)
			return -EINVAL;
	} else
		quantum = psched_mtu(qdisc_dev(sch));

	if (cl != NULL) {
		if (tca[TCA_RATE]) {
			err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
						    qdisc_root_sleeping_lock(sch),
						    tca[TCA_RATE]);
			if (err)
				return err;
		}

		sch_tree_lock(sch);
		if (tb[TCA_DRR_QUANTUM])
			cl->quantum = quantum;
		sch_tree_unlock(sch);

		return 0;
	}

	cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
	if (cl == NULL)
		return -ENOBUFS;

	cl->refcnt	   = 1;
	cl->common.classid = classid;
	cl->quantum	   = quantum;
	cl->qdisc	   = qdisc_create_dflt(sch->dev_queue,
					       &pfifo_qdisc_ops, classid);
	if (cl->qdisc == NULL)
		cl->qdisc = &noop_qdisc;

	if (tca[TCA_RATE]) {
		err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
					    qdisc_root_sleeping_lock(sch),
					    tca[TCA_RATE]);
		if (err) {
			qdisc_destroy(cl->qdisc);
			kfree(cl);
			return err;
		}
	}

	sch_tree_lock(sch);
	qdisc_class_hash_insert(&q->clhash, &cl->common);
	sch_tree_unlock(sch);

	qdisc_class_hash_grow(sch, &q->clhash);

	*arg = (unsigned long)cl;
	return 0;
}

static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl)
{
	gen_kill_estimator(&cl->bstats, &cl->rate_est);
	qdisc_destroy(cl->qdisc);
	kfree(cl);
}

static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl = (struct drr_class *)arg;

	if (cl->filter_cnt > 0)
		return -EBUSY;

	sch_tree_lock(sch);

	drr_purge_queue(cl);
	qdisc_class_hash_remove(&q->clhash, &cl->common);

	BUG_ON(--cl->refcnt == 0);
	/*
	 * This shouldn't happen: we "hold" one cops->get() when called
	 * from tc_ctl_tclass; the destroy method is done from cops->put().
	 */

	sch_tree_unlock(sch);
	return 0;
}

static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
{
	struct drr_class *cl = drr_find_class(sch, classid);

	if (cl != NULL)
		cl->refcnt++;

	return (unsigned long)cl;
}

static void drr_put_class(struct Qdisc *sch, unsigned long arg)
{
	struct drr_class *cl = (struct drr_class *)arg;

	if (--cl->refcnt == 0)
		drr_destroy_class(sch, cl);
}

static struct tcf_proto __rcu **drr_tcf_chain(struct Qdisc *sch,
					      unsigned long cl)
{
	struct drr_sched *q = qdisc_priv(sch);

	if (cl)
		return NULL;

	return &q->filter_list;
}

static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
				  u32 classid)
{
	struct drr_class *cl = drr_find_class(sch, classid);

	if (cl != NULL)
		cl->filter_cnt++;

	return (unsigned long)cl;
}

static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
{
	struct drr_class *cl = (struct drr_class *)arg;

	cl->filter_cnt--;
}

static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
			   struct Qdisc *new, struct Qdisc **old)
{
	struct drr_class *cl = (struct drr_class *)arg;

	if (new == NULL) {
		new = qdisc_create_dflt(sch->dev_queue,
					&pfifo_qdisc_ops, cl->common.classid);
		if (new == NULL)
			new = &noop_qdisc;
	}

	sch_tree_lock(sch);
	drr_purge_queue(cl);
	*old = cl->qdisc;
	cl->qdisc = new;
	sch_tree_unlock(sch);
	return 0;
}

static struct Qdisc *drr_class_leaf(struct Qdisc *sch, unsigned long arg)
{
	struct drr_class *cl = (struct drr_class *)arg;

	return cl->qdisc;
}

static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
{
	struct drr_class *cl = (struct drr_class *)arg;

	if (cl->qdisc->q.qlen == 0)
		list_del(&cl->alist);
}

static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
			  struct sk_buff *skb, struct tcmsg *tcm)
{
	struct drr_class *cl = (struct drr_class *)arg;
	struct nlattr *nest;

	tcm->tcm_parent	= TC_H_ROOT;
	tcm->tcm_handle	= cl->common.classid;
	tcm->tcm_info	= cl->qdisc->handle;

	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;
	if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
		goto nla_put_failure;
	return nla_nest_end(skb, nest);

nla_put_failure:
	nla_nest_cancel(skb, nest);
	return -EMSGSIZE;
}

static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
				struct gnet_dump *d)
{
	struct drr_class *cl = (struct drr_class *)arg;
	struct tc_drr_stats xstats;

	memset(&xstats, 0, sizeof(xstats));
	if (cl->qdisc->q.qlen) {
		xstats.deficit = cl->deficit;
		cl->qdisc->qstats.qlen = cl->qdisc->q.qlen;
	}

	if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
	    gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
	    gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
		return -1;

	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
}

static void drr_walk(struct Qdisc *sch, struct qdisc_walker *arg)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	unsigned int i;

	if (arg->stop)
		return;

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
			if (arg->count < arg->skip) {
				arg->count++;
				continue;
			}
			if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
				arg->stop = 1;
				return;
			}
			arg->count++;
		}
	}
}

static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
				      int *qerr)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	struct tcf_result res;
	struct tcf_proto *fl;
	int result;

	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
		cl = drr_find_class(sch, skb->priority);
		if (cl != NULL)
			return cl;
	}

	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
	fl = rcu_dereference_bh(q->filter_list);
	result = tc_classify(skb, fl, &res);
	if (result >= 0) {
#ifdef CONFIG_NET_CLS_ACT
		switch (result) {
		case TC_ACT_QUEUED:
		case TC_ACT_STOLEN:
			*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
		case TC_ACT_SHOT:
			return NULL;
		}
#endif
		cl = (struct drr_class *)res.class;
		if (cl == NULL)
			cl = drr_find_class(sch, res.classid);
		return cl;
	}
	return NULL;
}

static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	int err = 0;

	cl = drr_classify(skb, sch, &err);
	if (cl == NULL) {
		if (err & __NET_XMIT_BYPASS)
			sch->qstats.drops++;
		kfree_skb(skb);
		return err;
	}

	err = qdisc_enqueue(skb, cl->qdisc);
	if (unlikely(err != NET_XMIT_SUCCESS)) {
		if (net_xmit_drop_count(err)) {
			cl->qstats.drops++;
			sch->qstats.drops++;
		}
		return err;
	}

	if (cl->qdisc->q.qlen == 1) {
		list_add_tail(&cl->alist, &q->active);
		cl->deficit = cl->quantum;
	}

	sch->q.qlen++;
	return err;
}

static struct sk_buff *drr_dequeue(struct Qdisc *sch)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	struct sk_buff *skb;
	unsigned int len;

	if (list_empty(&q->active))
		goto out;
	while (1) {
		cl = list_first_entry(&q->active, struct drr_class, alist);
		skb = cl->qdisc->ops->peek(cl->qdisc);
		if (skb == NULL) {
			qdisc_warn_nonwc(__func__, cl->qdisc);
			goto out;
		}

		len = qdisc_pkt_len(skb);
		if (len <= cl->deficit) {
			cl->deficit -= len;
			skb = qdisc_dequeue_peeked(cl->qdisc);
			if (cl->qdisc->q.qlen == 0)
				list_del(&cl->alist);

			bstats_update(&cl->bstats, skb);
			qdisc_bstats_update(sch, skb);
			sch->q.qlen--;
			return skb;
		}

		cl->deficit += cl->quantum;
		list_move_tail(&cl->alist, &q->active);
	}
out:
	return NULL;
}

static unsigned int drr_drop(struct Qdisc *sch)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	unsigned int len;

	list_for_each_entry(cl, &q->active, alist) {
		if (cl->qdisc->ops->drop) {
			len = cl->qdisc->ops->drop(cl->qdisc);
			if (len > 0) {
				sch->q.qlen--;
				if (cl->qdisc->q.qlen == 0)
					list_del(&cl->alist);
				return len;
			}
		}
	}
	return 0;
}

static int drr_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
{
	struct drr_sched *q = qdisc_priv(sch);
	int err;

	err = qdisc_class_hash_init(&q->clhash);
	if (err < 0)
		return err;
	INIT_LIST_HEAD(&q->active);
	return 0;
}

static void drr_reset_qdisc(struct Qdisc *sch)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	unsigned int i;

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
			if (cl->qdisc->q.qlen)
				list_del(&cl->alist);
			qdisc_reset(cl->qdisc);
		}
	}
	sch->q.qlen = 0;
}

static void drr_destroy_qdisc(struct Qdisc *sch)
{
	struct drr_sched *q = qdisc_priv(sch);
	struct drr_class *cl;
	struct hlist_node *next;
	unsigned int i;

	tcf_destroy_chain(&q->filter_list);

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
					  common.hnode)
			drr_destroy_class(sch, cl);
	}
	qdisc_class_hash_destroy(&q->clhash);
}

static const struct Qdisc_class_ops drr_class_ops = {
	.change		= drr_change_class,
	.delete		= drr_delete_class,
	.get		= drr_get_class,
	.put		= drr_put_class,
	.tcf_chain	= drr_tcf_chain,
	.bind_tcf	= drr_bind_tcf,
	.unbind_tcf	= drr_unbind_tcf,
	.graft		= drr_graft_class,
	.leaf		= drr_class_leaf,
	.qlen_notify	= drr_qlen_notify,
	.dump		= drr_dump_class,
	.dump_stats	= drr_dump_class_stats,
	.walk		= drr_walk,
};

static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
	.cl_ops		= &drr_class_ops,
	.id		= "drr",
	.priv_size	= sizeof(struct drr_sched),
	.enqueue	= drr_enqueue,
	.dequeue	= drr_dequeue,
	.peek		= qdisc_peek_dequeued,
	.drop		= drr_drop,
	.init		= drr_init_qdisc,
	.reset		= drr_reset_qdisc,
	.destroy	= drr_destroy_qdisc,
	.owner		= THIS_MODULE,
};

static int __init drr_init(void)
{
	return register_qdisc(&drr_qdisc_ops);
}

static void __exit drr_exit(void)
{
	unregister_qdisc(&drr_qdisc_ops);
}

module_init(drr_init);
module_exit(drr_exit);
MODULE_LICENSE("GPL");
Commit	Line	Data
13d2a1d2 PM	1	/*
	2	* net/sched/sch_drr.c Deficit Round Robin scheduler
	3	*
	4	* Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* version 2 as published by the Free Software Foundation.
	9	*/
	10
	11	#include <linux/module.h>
5a0e3ad6	12	#include <linux/slab.h>
13d2a1d2 PM	13	#include <linux/init.h>
	14	#include <linux/errno.h>
	15	#include <linux/netdevice.h>
	16	#include <linux/pkt_sched.h>
	17	#include <net/sch_generic.h>
	18	#include <net/pkt_sched.h>
	19	#include <net/pkt_cls.h>
	20
	21	struct drr_class {
	22	struct Qdisc_class_common common;
	23	unsigned int refcnt;
	24	unsigned int filter_cnt;
	25
c1a8f1f1	26	struct gnet_stats_basic_packed bstats;
13d2a1d2	27	struct gnet_stats_queue qstats;
45203a3b	28	struct gnet_stats_rate_est64 rate_est;
13d2a1d2 PM	29	struct list_head alist;
	30	struct Qdisc *qdisc;
	31
	32	u32 quantum;
	33	u32 deficit;
	34	};
	35
	36	struct drr_sched {
	37	struct list_head active;
25d8c0d5	38	struct tcf_proto __rcu *filter_list;
13d2a1d2 PM	39	struct Qdisc_class_hash clhash;
	40	};
	41
	42	static struct drr_class drr_find_class(struct Qdisc sch, u32 classid)
	43	{
	44	struct drr_sched *q = qdisc_priv(sch);
	45	struct Qdisc_class_common *clc;
	46
	47	clc = qdisc_class_find(&q->clhash, classid);
	48	if (clc == NULL)
	49	return NULL;
	50	return container_of(clc, struct drr_class, common);
	51	}
	52
	53	static void drr_purge_queue(struct drr_class *cl)
	54	{
	55	unsigned int len = cl->qdisc->q.qlen;
	56
	57	qdisc_reset(cl->qdisc);
	58	qdisc_tree_decrease_qlen(cl->qdisc, len);
	59	}
	60
	61	static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
	62	[TCA_DRR_QUANTUM] = { .type = NLA_U32 },
	63	};
	64
	65	static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
	66	struct nlattr *tca, unsigned long arg)
	67	{
	68	struct drr_sched *q = qdisc_priv(sch);
	69	struct drr_class cl = (struct drr_class )*arg;
1844f747	70	struct nlattr *opt = tca[TCA_OPTIONS];
13d2a1d2 PM	71	struct nlattr *tb[TCA_DRR_MAX + 1];
	72	u32 quantum;
	73	int err;
	74
1844f747 JP	75	if (!opt)
	76	return -EINVAL;
	77
	78	err = nla_parse_nested(tb, TCA_DRR_MAX, opt, drr_policy);
13d2a1d2 PM	79	if (err < 0)
	80	return err;
	81
	82	if (tb[TCA_DRR_QUANTUM]) {
	83	quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
	84	if (quantum == 0)
	85	return -EINVAL;
	86	} else
	87	quantum = psched_mtu(qdisc_dev(sch));
	88
	89	if (cl != NULL) {
71bcb09a SH	90	if (tca[TCA_RATE]) {
	91	err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
	92	qdisc_root_sleeping_lock(sch),
	93	tca[TCA_RATE]);
	94	if (err)
	95	return err;
	96	}
	97
13d2a1d2 PM	98	sch_tree_lock(sch);
	99	if (tb[TCA_DRR_QUANTUM])
	100	cl->quantum = quantum;
	101	sch_tree_unlock(sch);
	102
13d2a1d2 PM	103	return 0;
	104	}
	105
	106	cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
	107	if (cl == NULL)
	108	return -ENOBUFS;
	109
	110	cl->refcnt = 1;
	111	cl->common.classid = classid;
	112	cl->quantum = quantum;
3511c913	113	cl->qdisc = qdisc_create_dflt(sch->dev_queue,
13d2a1d2 PM	114	&pfifo_qdisc_ops, classid);
	115	if (cl->qdisc == NULL)
	116	cl->qdisc = &noop_qdisc;
	117
71bcb09a SH	118	if (tca[TCA_RATE]) {
	119	err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
	120	qdisc_root_sleeping_lock(sch),
	121	tca[TCA_RATE]);
	122	if (err) {
	123	qdisc_destroy(cl->qdisc);
	124	kfree(cl);
	125	return err;
	126	}
	127	}
13d2a1d2 PM	128
	129	sch_tree_lock(sch);
	130	qdisc_class_hash_insert(&q->clhash, &cl->common);
	131	sch_tree_unlock(sch);
	132
	133	qdisc_class_hash_grow(sch, &q->clhash);
	134
	135	*arg = (unsigned long)cl;
	136	return 0;
	137	}
	138
	139	static void drr_destroy_class(struct Qdisc sch, struct drr_class cl)
	140	{
	141	gen_kill_estimator(&cl->bstats, &cl->rate_est);
	142	qdisc_destroy(cl->qdisc);
	143	kfree(cl);
	144	}
	145
	146	static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
	147	{
	148	struct drr_sched *q = qdisc_priv(sch);
	149	struct drr_class cl = (struct drr_class )arg;
	150
	151	if (cl->filter_cnt > 0)
	152	return -EBUSY;
	153
	154	sch_tree_lock(sch);
	155
	156	drr_purge_queue(cl);
	157	qdisc_class_hash_remove(&q->clhash, &cl->common);
	158
7cd0a638 JP	159	BUG_ON(--cl->refcnt == 0);
	160	/*
	161	* This shouldn't happen: we "hold" one cops->get() when called
	162	* from tc_ctl_tclass; the destroy method is done from cops->put().
	163	*/
13d2a1d2 PM	164
	165	sch_tree_unlock(sch);
	166	return 0;
	167	}
	168
	169	static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
	170	{
	171	struct drr_class *cl = drr_find_class(sch, classid);
	172
	173	if (cl != NULL)
	174	cl->refcnt++;
	175
	176	return (unsigned long)cl;
	177	}
	178
	179	static void drr_put_class(struct Qdisc *sch, unsigned long arg)
	180	{
	181	struct drr_class cl = (struct drr_class )arg;
	182
	183	if (--cl->refcnt == 0)
	184	drr_destroy_class(sch, cl);
	185	}
	186
25d8c0d5 JF	187	static struct tcf_proto __rcu *drr_tcf_chain(struct Qdisc sch,
25d8c0d5 JF	188	unsigned long cl)
13d2a1d2 PM	189	{
	190	struct drr_sched *q = qdisc_priv(sch);
	191
	192	if (cl)
	193	return NULL;
	194
	195	return &q->filter_list;
	196	}
	197
	198	static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
	199	u32 classid)
	200	{
	201	struct drr_class *cl = drr_find_class(sch, classid);
	202
	203	if (cl != NULL)
	204	cl->filter_cnt++;
	205
	206	return (unsigned long)cl;
	207	}
	208
	209	static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
	210	{
	211	struct drr_class cl = (struct drr_class )arg;
	212
	213	cl->filter_cnt--;
	214	}
	215
	216	static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
	217	struct Qdisc new, struct Qdisc *old)
	218	{
	219	struct drr_class cl = (struct drr_class )arg;
	220
	221	if (new == NULL) {
3511c913	222	new = qdisc_create_dflt(sch->dev_queue,
13d2a1d2 PM	223	&pfifo_qdisc_ops, cl->common.classid);
	224	if (new == NULL)
	225	new = &noop_qdisc;
	226	}
	227
	228	sch_tree_lock(sch);
	229	drr_purge_queue(cl);
b94c8afc PM	230	*old = cl->qdisc;
b94c8afc PM	231	cl->qdisc = new;
13d2a1d2 PM	232	sch_tree_unlock(sch);
	233	return 0;
	234	}
	235
	236	static struct Qdisc drr_class_leaf(struct Qdisc sch, unsigned long arg)
	237	{
	238	struct drr_class cl = (struct drr_class )arg;
	239
	240	return cl->qdisc;
	241	}
	242
	243	static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
	244	{
	245	struct drr_class cl = (struct drr_class )arg;
	246
	247	if (cl->qdisc->q.qlen == 0)
	248	list_del(&cl->alist);
	249	}
	250
	251	static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
	252	struct sk_buff skb, struct tcmsg tcm)
	253	{
	254	struct drr_class cl = (struct drr_class )arg;
	255	struct nlattr *nest;
	256
	257	tcm->tcm_parent = TC_H_ROOT;
	258	tcm->tcm_handle = cl->common.classid;
	259	tcm->tcm_info = cl->qdisc->handle;
	260
	261	nest = nla_nest_start(skb, TCA_OPTIONS);
	262	if (nest == NULL)
	263	goto nla_put_failure;
1b34ec43 DM	264	if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
1b34ec43 DM	265	goto nla_put_failure;
13d2a1d2 PM	266	return nla_nest_end(skb, nest);
	267
	268	nla_put_failure:
	269	nla_nest_cancel(skb, nest);
	270	return -EMSGSIZE;
	271	}
	272
	273	static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
	274	struct gnet_dump *d)
	275	{
	276	struct drr_class cl = (struct drr_class )arg;
	277	struct tc_drr_stats xstats;
	278
	279	memset(&xstats, 0, sizeof(xstats));
a19d2158	280	if (cl->qdisc->q.qlen) {
13d2a1d2	281	xstats.deficit = cl->deficit;
a19d2158 JP	282	cl->qdisc->qstats.qlen = cl->qdisc->q.qlen;
a19d2158 JP	283	}
13d2a1d2 PM	284
13d2a1d2 PM	285	if (gnet_stats_copy_basic(d, &cl->bstats) < 0 \|\|
d250a5f9	286	gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 \|\|
13d2a1d2 PM	287	gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
	288	return -1;
	289
	290	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
	291	}
	292
	293	static void drr_walk(struct Qdisc sch, struct qdisc_walker arg)
	294	{
	295	struct drr_sched *q = qdisc_priv(sch);
	296	struct drr_class *cl;
13d2a1d2 PM	297	unsigned int i;
	298
	299	if (arg->stop)
	300	return;
	301
	302	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	303	hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
13d2a1d2 PM	304	if (arg->count < arg->skip) {
	305	arg->count++;
	306	continue;
	307	}
	308	if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
	309	arg->stop = 1;
	310	return;
	311	}
	312	arg->count++;
	313	}
	314	}
	315	}
	316
	317	static struct drr_class drr_classify(struct sk_buff skb, struct Qdisc *sch,
	318	int *qerr)
	319	{
	320	struct drr_sched *q = qdisc_priv(sch);
	321	struct drr_class *cl;
	322	struct tcf_result res;
25d8c0d5	323	struct tcf_proto *fl;
13d2a1d2 PM	324	int result;
	325
	326	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
	327	cl = drr_find_class(sch, skb->priority);
	328	if (cl != NULL)
	329	return cl;
	330	}
	331
	332	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_BYPASS;
25d8c0d5 JF	333	fl = rcu_dereference_bh(q->filter_list);
25d8c0d5 JF	334	result = tc_classify(skb, fl, &res);
13d2a1d2 PM	335	if (result >= 0) {
	336	#ifdef CONFIG_NET_CLS_ACT
	337	switch (result) {
	338	case TC_ACT_QUEUED:
	339	case TC_ACT_STOLEN:
	340	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_STOLEN;
	341	case TC_ACT_SHOT:
	342	return NULL;
	343	}
	344	#endif
	345	cl = (struct drr_class *)res.class;
	346	if (cl == NULL)
	347	cl = drr_find_class(sch, res.classid);
	348	return cl;
	349	}
	350	return NULL;
	351	}
	352
	353	static int drr_enqueue(struct sk_buff skb, struct Qdisc sch)
	354	{
	355	struct drr_sched *q = qdisc_priv(sch);
	356	struct drr_class *cl;
f54ba779	357	int err = 0;
13d2a1d2 PM	358
	359	cl = drr_classify(skb, sch, &err);
	360	if (cl == NULL) {
	361	if (err & __NET_XMIT_BYPASS)
	362	sch->qstats.drops++;
	363	kfree_skb(skb);
	364	return err;
	365	}
	366
13d2a1d2 PM	367	err = qdisc_enqueue(skb, cl->qdisc);
	368	if (unlikely(err != NET_XMIT_SUCCESS)) {
	369	if (net_xmit_drop_count(err)) {
	370	cl->qstats.drops++;
	371	sch->qstats.drops++;
	372	}
	373	return err;
	374	}
	375
	376	if (cl->qdisc->q.qlen == 1) {
	377	list_add_tail(&cl->alist, &q->active);
	378	cl->deficit = cl->quantum;
	379	}
	380
13d2a1d2 PM	381	sch->q.qlen++;
	382	return err;
	383	}
	384
	385	static struct sk_buff drr_dequeue(struct Qdisc sch)
	386	{
	387	struct drr_sched *q = qdisc_priv(sch);
	388	struct drr_class *cl;
	389	struct sk_buff *skb;
	390	unsigned int len;
	391
3f0947c3 PM	392	if (list_empty(&q->active))
	393	goto out;
	394	while (1) {
13d2a1d2 PM	395	cl = list_first_entry(&q->active, struct drr_class, alist);
13d2a1d2 PM	396	skb = cl->qdisc->ops->peek(cl->qdisc);
6e765a00 FW	397	if (skb == NULL) {
6e765a00 FW	398	qdisc_warn_nonwc(__func__, cl->qdisc);
3f0947c3	399	goto out;
6e765a00	400	}
13d2a1d2 PM	401
	402	len = qdisc_pkt_len(skb);
	403	if (len <= cl->deficit) {
	404	cl->deficit -= len;
	405	skb = qdisc_dequeue_peeked(cl->qdisc);
	406	if (cl->qdisc->q.qlen == 0)
	407	list_del(&cl->alist);
2dd875ff ED	408
2dd875ff ED	409	bstats_update(&cl->bstats, skb);
9190b3b3	410	qdisc_bstats_update(sch, skb);
13d2a1d2 PM	411	sch->q.qlen--;
	412	return skb;
	413	}
	414
	415	cl->deficit += cl->quantum;
13d2a1d2 PM	416	list_move_tail(&cl->alist, &q->active);
13d2a1d2 PM	417	}
3f0947c3	418	out:
13d2a1d2 PM	419	return NULL;
	420	}
	421
	422	static unsigned int drr_drop(struct Qdisc *sch)
	423	{
	424	struct drr_sched *q = qdisc_priv(sch);
	425	struct drr_class *cl;
	426	unsigned int len;
	427
	428	list_for_each_entry(cl, &q->active, alist) {
	429	if (cl->qdisc->ops->drop) {
	430	len = cl->qdisc->ops->drop(cl->qdisc);
	431	if (len > 0) {
98aa9c80	432	sch->q.qlen--;
13d2a1d2 PM	433	if (cl->qdisc->q.qlen == 0)
	434	list_del(&cl->alist);
	435	return len;
	436	}
	437	}
	438	}
	439	return 0;
	440	}
	441
	442	static int drr_init_qdisc(struct Qdisc sch, struct nlattr opt)
	443	{
	444	struct drr_sched *q = qdisc_priv(sch);
	445	int err;
	446
	447	err = qdisc_class_hash_init(&q->clhash);
	448	if (err < 0)
	449	return err;
	450	INIT_LIST_HEAD(&q->active);
	451	return 0;
	452	}
	453
	454	static void drr_reset_qdisc(struct Qdisc *sch)
	455	{
	456	struct drr_sched *q = qdisc_priv(sch);
	457	struct drr_class *cl;
13d2a1d2 PM	458	unsigned int i;
	459
	460	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	461	hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
13d2a1d2 PM	462	if (cl->qdisc->q.qlen)
	463	list_del(&cl->alist);
	464	qdisc_reset(cl->qdisc);
	465	}
	466	}
	467	sch->q.qlen = 0;
	468	}
	469
	470	static void drr_destroy_qdisc(struct Qdisc *sch)
	471	{
	472	struct drr_sched *q = qdisc_priv(sch);
	473	struct drr_class *cl;
b67bfe0d	474	struct hlist_node *next;
13d2a1d2 PM	475	unsigned int i;
	476
	477	tcf_destroy_chain(&q->filter_list);
	478
	479	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	480	hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
13d2a1d2 PM	481	common.hnode)
	482	drr_destroy_class(sch, cl);
	483	}
	484	qdisc_class_hash_destroy(&q->clhash);
	485	}
	486
	487	static const struct Qdisc_class_ops drr_class_ops = {
	488	.change = drr_change_class,
	489	.delete = drr_delete_class,
	490	.get = drr_get_class,
	491	.put = drr_put_class,
	492	.tcf_chain = drr_tcf_chain,
	493	.bind_tcf = drr_bind_tcf,
	494	.unbind_tcf = drr_unbind_tcf,
	495	.graft = drr_graft_class,
	496	.leaf = drr_class_leaf,
	497	.qlen_notify = drr_qlen_notify,
	498	.dump = drr_dump_class,
	499	.dump_stats = drr_dump_class_stats,
	500	.walk = drr_walk,
	501	};
	502
	503	static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
	504	.cl_ops = &drr_class_ops,
	505	.id = "drr",
	506	.priv_size = sizeof(struct drr_sched),
	507	.enqueue = drr_enqueue,
	508	.dequeue = drr_dequeue,
	509	.peek = qdisc_peek_dequeued,
	510	.drop = drr_drop,
	511	.init = drr_init_qdisc,
	512	.reset = drr_reset_qdisc,
	513	.destroy = drr_destroy_qdisc,
	514	.owner = THIS_MODULE,
	515	};
	516
	517	static int __init drr_init(void)
	518	{
	519	return register_qdisc(&drr_qdisc_ops);
	520	}
	521
	522	static void __exit drr_exit(void)
	523	{
	524	unregister_qdisc(&drr_qdisc_ops);
	525	}
	526
	527	module_init(drr_init);
	528	module_exit(drr_exit);
	529	MODULE_LICENSE("GPL");