[linux-2.6-block.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;
	unsigned int backlog = cl->qdisc->qstats.backlog;

	qdisc_reset(cl->qdisc);
	qdisc_tree_reduce_backlog(cl->qdisc, len, backlog);
}

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, NULL,
						    &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, NULL, &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;
	}

	*old = qdisc_replace(sch, new, &cl->qdisc);
	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;
	__u32 qlen = cl->qdisc->q.qlen;
	struct tc_drr_stats xstats;

	memset(&xstats, 0, sizeof(xstats));
	if (qlen)
		xstats.deficit = cl->deficit;

	if (gnet_stats_copy_basic(d, NULL, &cl->bstats) < 0 ||
	    gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
	    gnet_stats_copy_queue(d, NULL, &cl->qdisc->qstats, qlen) < 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, false);
	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)
			qdisc_qstats_drop(sch);
		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++;
			qdisc_qstats_drop(sch);
		}
		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 (unlikely(skb == NULL))
				goto out;
			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;
2ccccf5f	56	unsigned int backlog = cl->qdisc->qstats.backlog;
13d2a1d2 PM	57
13d2a1d2 PM	58	qdisc_reset(cl->qdisc);
2ccccf5f	59	qdisc_tree_reduce_backlog(cl->qdisc, len, backlog);
13d2a1d2 PM	60	}
	61
	62	static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
	63	[TCA_DRR_QUANTUM] = { .type = NLA_U32 },
	64	};
	65
	66	static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
	67	struct nlattr *tca, unsigned long arg)
	68	{
	69	struct drr_sched *q = qdisc_priv(sch);
	70	struct drr_class cl = (struct drr_class )*arg;
1844f747	71	struct nlattr *opt = tca[TCA_OPTIONS];
13d2a1d2 PM	72	struct nlattr *tb[TCA_DRR_MAX + 1];
	73	u32 quantum;
	74	int err;
	75
1844f747 JP	76	if (!opt)
	77	return -EINVAL;
	78
	79	err = nla_parse_nested(tb, TCA_DRR_MAX, opt, drr_policy);
13d2a1d2 PM	80	if (err < 0)
	81	return err;
	82
	83	if (tb[TCA_DRR_QUANTUM]) {
	84	quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
	85	if (quantum == 0)
	86	return -EINVAL;
	87	} else
	88	quantum = psched_mtu(qdisc_dev(sch));
	89
	90	if (cl != NULL) {
71bcb09a	91	if (tca[TCA_RATE]) {
22e0f8b9 JF	92	err = gen_replace_estimator(&cl->bstats, NULL,
22e0f8b9 JF	93	&cl->rate_est,
71bcb09a SH	94	qdisc_root_sleeping_lock(sch),
	95	tca[TCA_RATE]);
	96	if (err)
	97	return err;
	98	}
	99
13d2a1d2 PM	100	sch_tree_lock(sch);
	101	if (tb[TCA_DRR_QUANTUM])
	102	cl->quantum = quantum;
	103	sch_tree_unlock(sch);
	104
13d2a1d2 PM	105	return 0;
	106	}
	107
	108	cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
	109	if (cl == NULL)
	110	return -ENOBUFS;
	111
	112	cl->refcnt = 1;
	113	cl->common.classid = classid;
	114	cl->quantum = quantum;
3511c913	115	cl->qdisc = qdisc_create_dflt(sch->dev_queue,
13d2a1d2 PM	116	&pfifo_qdisc_ops, classid);
	117	if (cl->qdisc == NULL)
	118	cl->qdisc = &noop_qdisc;
	119
71bcb09a	120	if (tca[TCA_RATE]) {
22e0f8b9	121	err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est,
71bcb09a SH	122	qdisc_root_sleeping_lock(sch),
	123	tca[TCA_RATE]);
	124	if (err) {
	125	qdisc_destroy(cl->qdisc);
	126	kfree(cl);
	127	return err;
	128	}
	129	}
13d2a1d2 PM	130
	131	sch_tree_lock(sch);
	132	qdisc_class_hash_insert(&q->clhash, &cl->common);
	133	sch_tree_unlock(sch);
	134
	135	qdisc_class_hash_grow(sch, &q->clhash);
	136
	137	*arg = (unsigned long)cl;
	138	return 0;
	139	}
	140
	141	static void drr_destroy_class(struct Qdisc sch, struct drr_class cl)
	142	{
	143	gen_kill_estimator(&cl->bstats, &cl->rate_est);
	144	qdisc_destroy(cl->qdisc);
	145	kfree(cl);
	146	}
	147
	148	static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
	149	{
	150	struct drr_sched *q = qdisc_priv(sch);
	151	struct drr_class cl = (struct drr_class )arg;
	152
	153	if (cl->filter_cnt > 0)
	154	return -EBUSY;
	155
	156	sch_tree_lock(sch);
	157
	158	drr_purge_queue(cl);
	159	qdisc_class_hash_remove(&q->clhash, &cl->common);
	160
7cd0a638 JP	161	BUG_ON(--cl->refcnt == 0);
	162	/*
	163	* This shouldn't happen: we "hold" one cops->get() when called
	164	* from tc_ctl_tclass; the destroy method is done from cops->put().
	165	*/
13d2a1d2 PM	166
	167	sch_tree_unlock(sch);
	168	return 0;
	169	}
	170
	171	static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
	172	{
	173	struct drr_class *cl = drr_find_class(sch, classid);
	174
	175	if (cl != NULL)
	176	cl->refcnt++;
	177
	178	return (unsigned long)cl;
	179	}
	180
	181	static void drr_put_class(struct Qdisc *sch, unsigned long arg)
	182	{
	183	struct drr_class cl = (struct drr_class )arg;
	184
	185	if (--cl->refcnt == 0)
	186	drr_destroy_class(sch, cl);
	187	}
	188
25d8c0d5 JF	189	static struct tcf_proto __rcu *drr_tcf_chain(struct Qdisc sch,
25d8c0d5 JF	190	unsigned long cl)
13d2a1d2 PM	191	{
	192	struct drr_sched *q = qdisc_priv(sch);
	193
	194	if (cl)
	195	return NULL;
	196
	197	return &q->filter_list;
	198	}
	199
	200	static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
	201	u32 classid)
	202	{
	203	struct drr_class *cl = drr_find_class(sch, classid);
	204
	205	if (cl != NULL)
	206	cl->filter_cnt++;
	207
	208	return (unsigned long)cl;
	209	}
	210
	211	static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
	212	{
	213	struct drr_class cl = (struct drr_class )arg;
	214
	215	cl->filter_cnt--;
	216	}
	217
	218	static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
	219	struct Qdisc new, struct Qdisc *old)
	220	{
	221	struct drr_class cl = (struct drr_class )arg;
	222
	223	if (new == NULL) {
3511c913	224	new = qdisc_create_dflt(sch->dev_queue,
13d2a1d2 PM	225	&pfifo_qdisc_ops, cl->common.classid);
	226	if (new == NULL)
	227	new = &noop_qdisc;
	228	}
	229
86a7996c	230	*old = qdisc_replace(sch, new, &cl->qdisc);
13d2a1d2 PM	231	return 0;
	232	}
	233
	234	static struct Qdisc drr_class_leaf(struct Qdisc sch, unsigned long arg)
	235	{
	236	struct drr_class cl = (struct drr_class )arg;
	237
	238	return cl->qdisc;
	239	}
	240
	241	static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
	242	{
	243	struct drr_class cl = (struct drr_class )arg;
	244
	245	if (cl->qdisc->q.qlen == 0)
	246	list_del(&cl->alist);
	247	}
	248
	249	static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
	250	struct sk_buff skb, struct tcmsg tcm)
	251	{
	252	struct drr_class cl = (struct drr_class )arg;
	253	struct nlattr *nest;
	254
	255	tcm->tcm_parent = TC_H_ROOT;
	256	tcm->tcm_handle = cl->common.classid;
	257	tcm->tcm_info = cl->qdisc->handle;
	258
	259	nest = nla_nest_start(skb, TCA_OPTIONS);
	260	if (nest == NULL)
	261	goto nla_put_failure;
1b34ec43 DM	262	if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
1b34ec43 DM	263	goto nla_put_failure;
13d2a1d2 PM	264	return nla_nest_end(skb, nest);
	265
	266	nla_put_failure:
	267	nla_nest_cancel(skb, nest);
	268	return -EMSGSIZE;
	269	}
	270
	271	static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
	272	struct gnet_dump *d)
	273	{
	274	struct drr_class cl = (struct drr_class )arg;
64015853	275	__u32 qlen = cl->qdisc->q.qlen;
13d2a1d2 PM	276	struct tc_drr_stats xstats;
	277
	278	memset(&xstats, 0, sizeof(xstats));
64015853	279	if (qlen)
13d2a1d2 PM	280	xstats.deficit = cl->deficit;
13d2a1d2 PM	281
22e0f8b9	282	if (gnet_stats_copy_basic(d, NULL, &cl->bstats) < 0 \|\|
d250a5f9	283	gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 \|\|
b0ab6f92	284	gnet_stats_copy_queue(d, NULL, &cl->qdisc->qstats, qlen) < 0)
13d2a1d2 PM	285	return -1;
	286
	287	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
	288	}
	289
	290	static void drr_walk(struct Qdisc sch, struct qdisc_walker arg)
	291	{
	292	struct drr_sched *q = qdisc_priv(sch);
	293	struct drr_class *cl;
13d2a1d2 PM	294	unsigned int i;
	295
	296	if (arg->stop)
	297	return;
	298
	299	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	300	hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
13d2a1d2 PM	301	if (arg->count < arg->skip) {
	302	arg->count++;
	303	continue;
	304	}
	305	if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
	306	arg->stop = 1;
	307	return;
	308	}
	309	arg->count++;
	310	}
	311	}
	312	}
	313
	314	static struct drr_class drr_classify(struct sk_buff skb, struct Qdisc *sch,
	315	int *qerr)
	316	{
	317	struct drr_sched *q = qdisc_priv(sch);
	318	struct drr_class *cl;
	319	struct tcf_result res;
25d8c0d5	320	struct tcf_proto *fl;
13d2a1d2 PM	321	int result;
	322
	323	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
	324	cl = drr_find_class(sch, skb->priority);
	325	if (cl != NULL)
	326	return cl;
	327	}
	328
	329	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_BYPASS;
25d8c0d5	330	fl = rcu_dereference_bh(q->filter_list);
3b3ae880	331	result = tc_classify(skb, fl, &res, false);
13d2a1d2 PM	332	if (result >= 0) {
	333	#ifdef CONFIG_NET_CLS_ACT
	334	switch (result) {
	335	case TC_ACT_QUEUED:
	336	case TC_ACT_STOLEN:
	337	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_STOLEN;
	338	case TC_ACT_SHOT:
	339	return NULL;
	340	}
	341	#endif
	342	cl = (struct drr_class *)res.class;
	343	if (cl == NULL)
	344	cl = drr_find_class(sch, res.classid);
	345	return cl;
	346	}
	347	return NULL;
	348	}
	349
	350	static int drr_enqueue(struct sk_buff skb, struct Qdisc sch)
	351	{
	352	struct drr_sched *q = qdisc_priv(sch);
	353	struct drr_class *cl;
f54ba779	354	int err = 0;
13d2a1d2 PM	355
	356	cl = drr_classify(skb, sch, &err);
	357	if (cl == NULL) {
	358	if (err & __NET_XMIT_BYPASS)
25331d6c	359	qdisc_qstats_drop(sch);
13d2a1d2 PM	360	kfree_skb(skb);
	361	return err;
	362	}
	363
13d2a1d2 PM	364	err = qdisc_enqueue(skb, cl->qdisc);
	365	if (unlikely(err != NET_XMIT_SUCCESS)) {
	366	if (net_xmit_drop_count(err)) {
	367	cl->qstats.drops++;
25331d6c	368	qdisc_qstats_drop(sch);
13d2a1d2 PM	369	}
	370	return err;
	371	}
	372
	373	if (cl->qdisc->q.qlen == 1) {
	374	list_add_tail(&cl->alist, &q->active);
	375	cl->deficit = cl->quantum;
	376	}
	377
13d2a1d2 PM	378	sch->q.qlen++;
	379	return err;
	380	}
	381
	382	static struct sk_buff drr_dequeue(struct Qdisc sch)
	383	{
	384	struct drr_sched *q = qdisc_priv(sch);
	385	struct drr_class *cl;
	386	struct sk_buff *skb;
	387	unsigned int len;
	388
3f0947c3 PM	389	if (list_empty(&q->active))
	390	goto out;
	391	while (1) {
13d2a1d2 PM	392	cl = list_first_entry(&q->active, struct drr_class, alist);
13d2a1d2 PM	393	skb = cl->qdisc->ops->peek(cl->qdisc);
6e765a00 FW	394	if (skb == NULL) {
6e765a00 FW	395	qdisc_warn_nonwc(__func__, cl->qdisc);
3f0947c3	396	goto out;
6e765a00	397	}
13d2a1d2 PM	398
	399	len = qdisc_pkt_len(skb);
	400	if (len <= cl->deficit) {
	401	cl->deficit -= len;
	402	skb = qdisc_dequeue_peeked(cl->qdisc);
df3eb6cd BH	403	if (unlikely(skb == NULL))
df3eb6cd BH	404	goto out;
13d2a1d2 PM	405	if (cl->qdisc->q.qlen == 0)
13d2a1d2 PM	406	list_del(&cl->alist);
2dd875ff ED	407
2dd875ff ED	408	bstats_update(&cl->bstats, skb);
9190b3b3	409	qdisc_bstats_update(sch, skb);
13d2a1d2 PM	410	sch->q.qlen--;
	411	return skb;
	412	}
	413
	414	cl->deficit += cl->quantum;
13d2a1d2 PM	415	list_move_tail(&cl->alist, &q->active);
13d2a1d2 PM	416	}
3f0947c3	417	out:
13d2a1d2 PM	418	return NULL;
	419	}
	420
	421	static unsigned int drr_drop(struct Qdisc *sch)
	422	{
	423	struct drr_sched *q = qdisc_priv(sch);
	424	struct drr_class *cl;
	425	unsigned int len;
	426
	427	list_for_each_entry(cl, &q->active, alist) {
	428	if (cl->qdisc->ops->drop) {
	429	len = cl->qdisc->ops->drop(cl->qdisc);
	430	if (len > 0) {
98aa9c80	431	sch->q.qlen--;
13d2a1d2 PM	432	if (cl->qdisc->q.qlen == 0)
	433	list_del(&cl->alist);
	434	return len;
	435	}
	436	}
	437	}
	438	return 0;
	439	}
	440
	441	static int drr_init_qdisc(struct Qdisc sch, struct nlattr opt)
	442	{
	443	struct drr_sched *q = qdisc_priv(sch);
	444	int err;
	445
	446	err = qdisc_class_hash_init(&q->clhash);
	447	if (err < 0)
	448	return err;
	449	INIT_LIST_HEAD(&q->active);
	450	return 0;
	451	}
	452
	453	static void drr_reset_qdisc(struct Qdisc *sch)
	454	{
	455	struct drr_sched *q = qdisc_priv(sch);
	456	struct drr_class *cl;
13d2a1d2 PM	457	unsigned int i;
	458
	459	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	460	hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
13d2a1d2 PM	461	if (cl->qdisc->q.qlen)
	462	list_del(&cl->alist);
	463	qdisc_reset(cl->qdisc);
	464	}
	465	}
	466	sch->q.qlen = 0;
	467	}
	468
	469	static void drr_destroy_qdisc(struct Qdisc *sch)
	470	{
	471	struct drr_sched *q = qdisc_priv(sch);
	472	struct drr_class *cl;
b67bfe0d	473	struct hlist_node *next;
13d2a1d2 PM	474	unsigned int i;
	475
	476	tcf_destroy_chain(&q->filter_list);
	477
	478	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	479	hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
13d2a1d2 PM	480	common.hnode)
	481	drr_destroy_class(sch, cl);
	482	}
	483	qdisc_class_hash_destroy(&q->clhash);
	484	}
	485
	486	static const struct Qdisc_class_ops drr_class_ops = {
	487	.change = drr_change_class,
	488	.delete = drr_delete_class,
	489	.get = drr_get_class,
	490	.put = drr_put_class,
	491	.tcf_chain = drr_tcf_chain,
	492	.bind_tcf = drr_bind_tcf,
	493	.unbind_tcf = drr_unbind_tcf,
	494	.graft = drr_graft_class,
	495	.leaf = drr_class_leaf,
	496	.qlen_notify = drr_qlen_notify,
	497	.dump = drr_dump_class,
	498	.dump_stats = drr_dump_class_stats,
	499	.walk = drr_walk,
	500	};
	501
	502	static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
	503	.cl_ops = &drr_class_ops,
	504	.id = "drr",
	505	.priv_size = sizeof(struct drr_sched),
	506	.enqueue = drr_enqueue,
	507	.dequeue = drr_dequeue,
	508	.peek = qdisc_peek_dequeued,
	509	.drop = drr_drop,
	510	.init = drr_init_qdisc,
	511	.reset = drr_reset_qdisc,
	512	.destroy = drr_destroy_qdisc,
	513	.owner = THIS_MODULE,
	514	};
	515
	516	static int __init drr_init(void)
	517	{
	518	return register_qdisc(&drr_qdisc_ops);
	519	}
	520
	521	static void __exit drr_exit(void)
	522	{
	523	unregister_qdisc(&drr_qdisc_ops);
	524	}
	525
	526	module_init(drr_init);
	527	module_exit(drr_exit);
	528	MODULE_LICENSE("GPL");