[deliverable/linux.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/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_est	rate_est;
	struct list_head		alist;
	struct Qdisc			*qdisc;

	u32				quantum;
	u32				deficit;
};

struct drr_sched {
	struct list_head		active;
	struct tcf_proto		*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(qdisc_dev(sch), 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 **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(qdisc_dev(sch), 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;
	NLA_PUT_U32(skb, TCA_DRR_QUANTUM, cl->quantum);
	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;
	struct hlist_node *n;
	unsigned int i;

	if (arg->stop)
		return;

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry(cl, n, &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;
	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;
	result = tc_classify(skb, q->filter_list, &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;
	unsigned int len;
	int err;

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

	len = qdisc_pkt_len(skb);
	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;
	}

	cl->bstats.packets++;
	cl->bstats.bytes += len;
	sch->bstats.packets++;
	sch->bstats.bytes += len;

	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)
			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);
			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;
	struct hlist_node *n;
	unsigned int i;

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry(cl, n, &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 *n, *next;
	unsigned int i;

	tcf_destroy_chain(&q->filter_list);

	for (i = 0; i < q->clhash.hashsize; i++) {
		hlist_for_each_entry_safe(cl, n, 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>
	12	#include <linux/init.h>
	13	#include <linux/errno.h>
	14	#include <linux/netdevice.h>
	15	#include <linux/pkt_sched.h>
	16	#include <net/sch_generic.h>
	17	#include <net/pkt_sched.h>
	18	#include <net/pkt_cls.h>
	19
	20	struct drr_class {
	21	struct Qdisc_class_common common;
	22	unsigned int refcnt;
	23	unsigned int filter_cnt;
	24
c1a8f1f1	25	struct gnet_stats_basic_packed bstats;
13d2a1d2 PM	26	struct gnet_stats_queue qstats;
	27	struct gnet_stats_rate_est rate_est;
	28	struct list_head alist;
	29	struct Qdisc *qdisc;
	30
	31	u32 quantum;
	32	u32 deficit;
	33	};
	34
	35	struct drr_sched {
	36	struct list_head active;
	37	struct tcf_proto *filter_list;
	38	struct Qdisc_class_hash clhash;
	39	};
	40
	41	static struct drr_class drr_find_class(struct Qdisc sch, u32 classid)
	42	{
	43	struct drr_sched *q = qdisc_priv(sch);
	44	struct Qdisc_class_common *clc;
	45
	46	clc = qdisc_class_find(&q->clhash, classid);
	47	if (clc == NULL)
	48	return NULL;
	49	return container_of(clc, struct drr_class, common);
	50	}
	51
	52	static void drr_purge_queue(struct drr_class *cl)
	53	{
	54	unsigned int len = cl->qdisc->q.qlen;
	55
	56	qdisc_reset(cl->qdisc);
	57	qdisc_tree_decrease_qlen(cl->qdisc, len);
	58	}
	59
	60	static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
	61	[TCA_DRR_QUANTUM] = { .type = NLA_U32 },
	62	};
	63
	64	static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
	65	struct nlattr *tca, unsigned long arg)
	66	{
	67	struct drr_sched *q = qdisc_priv(sch);
	68	struct drr_class cl = (struct drr_class )*arg;
1844f747	69	struct nlattr *opt = tca[TCA_OPTIONS];
13d2a1d2 PM	70	struct nlattr *tb[TCA_DRR_MAX + 1];
	71	u32 quantum;
	72	int err;
	73
1844f747 JP	74	if (!opt)
	75	return -EINVAL;
	76
	77	err = nla_parse_nested(tb, TCA_DRR_MAX, opt, drr_policy);
13d2a1d2 PM	78	if (err < 0)
	79	return err;
	80
	81	if (tb[TCA_DRR_QUANTUM]) {
	82	quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
	83	if (quantum == 0)
	84	return -EINVAL;
	85	} else
	86	quantum = psched_mtu(qdisc_dev(sch));
	87
	88	if (cl != NULL) {
71bcb09a SH	89	if (tca[TCA_RATE]) {
	90	err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
	91	qdisc_root_sleeping_lock(sch),
	92	tca[TCA_RATE]);
	93	if (err)
	94	return err;
	95	}
	96
13d2a1d2 PM	97	sch_tree_lock(sch);
	98	if (tb[TCA_DRR_QUANTUM])
	99	cl->quantum = quantum;
	100	sch_tree_unlock(sch);
	101
13d2a1d2 PM	102	return 0;
	103	}
	104
	105	cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
	106	if (cl == NULL)
	107	return -ENOBUFS;
	108
	109	cl->refcnt = 1;
	110	cl->common.classid = classid;
	111	cl->quantum = quantum;
	112	cl->qdisc = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
	113	&pfifo_qdisc_ops, classid);
	114	if (cl->qdisc == NULL)
	115	cl->qdisc = &noop_qdisc;
	116
71bcb09a SH	117	if (tca[TCA_RATE]) {
	118	err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
	119	qdisc_root_sleeping_lock(sch),
	120	tca[TCA_RATE]);
	121	if (err) {
	122	qdisc_destroy(cl->qdisc);
	123	kfree(cl);
	124	return err;
	125	}
	126	}
13d2a1d2 PM	127
	128	sch_tree_lock(sch);
	129	qdisc_class_hash_insert(&q->clhash, &cl->common);
	130	sch_tree_unlock(sch);
	131
	132	qdisc_class_hash_grow(sch, &q->clhash);
	133
	134	*arg = (unsigned long)cl;
	135	return 0;
	136	}
	137
	138	static void drr_destroy_class(struct Qdisc sch, struct drr_class cl)
	139	{
	140	gen_kill_estimator(&cl->bstats, &cl->rate_est);
	141	qdisc_destroy(cl->qdisc);
	142	kfree(cl);
	143	}
	144
	145	static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
	146	{
	147	struct drr_sched *q = qdisc_priv(sch);
	148	struct drr_class cl = (struct drr_class )arg;
	149
	150	if (cl->filter_cnt > 0)
	151	return -EBUSY;
	152
	153	sch_tree_lock(sch);
	154
	155	drr_purge_queue(cl);
	156	qdisc_class_hash_remove(&q->clhash, &cl->common);
	157
7cd0a638 JP	158	BUG_ON(--cl->refcnt == 0);
	159	/*
	160	* This shouldn't happen: we "hold" one cops->get() when called
	161	* from tc_ctl_tclass; the destroy method is done from cops->put().
	162	*/
13d2a1d2 PM	163
	164	sch_tree_unlock(sch);
	165	return 0;
	166	}
	167
	168	static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
	169	{
	170	struct drr_class *cl = drr_find_class(sch, classid);
	171
	172	if (cl != NULL)
	173	cl->refcnt++;
	174
	175	return (unsigned long)cl;
	176	}
	177
	178	static void drr_put_class(struct Qdisc *sch, unsigned long arg)
	179	{
	180	struct drr_class cl = (struct drr_class )arg;
	181
	182	if (--cl->refcnt == 0)
	183	drr_destroy_class(sch, cl);
	184	}
	185
	186	static struct tcf_proto *drr_tcf_chain(struct Qdisc sch, unsigned long cl)
	187	{
	188	struct drr_sched *q = qdisc_priv(sch);
	189
	190	if (cl)
	191	return NULL;
	192
	193	return &q->filter_list;
	194	}
	195
	196	static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
	197	u32 classid)
	198	{
	199	struct drr_class *cl = drr_find_class(sch, classid);
	200
	201	if (cl != NULL)
	202	cl->filter_cnt++;
	203
	204	return (unsigned long)cl;
	205	}
	206
	207	static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
	208	{
	209	struct drr_class cl = (struct drr_class )arg;
	210
	211	cl->filter_cnt--;
	212	}
	213
	214	static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
	215	struct Qdisc new, struct Qdisc *old)
	216	{
	217	struct drr_class cl = (struct drr_class )arg;
	218
	219	if (new == NULL) {
	220	new = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
	221	&pfifo_qdisc_ops, cl->common.classid);
	222	if (new == NULL)
	223	new = &noop_qdisc;
	224	}
	225
	226	sch_tree_lock(sch);
227	drr_purge_queue(cl);
b94c8afc PM	228	*old = cl->qdisc;
b94c8afc PM	229	cl->qdisc = new;
13d2a1d2 PM	230	sch_tree_unlock(sch);
	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;
	262	NLA_PUT_U32(skb, TCA_DRR_QUANTUM, cl->quantum);
	263	return nla_nest_end(skb, nest);
	264
	265	nla_put_failure:
	266	nla_nest_cancel(skb, nest);
	267	return -EMSGSIZE;
	268	}
	269
	270	static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
	271	struct gnet_dump *d)
	272	{
	273	struct drr_class cl = (struct drr_class )arg;
	274	struct tc_drr_stats xstats;
	275
	276	memset(&xstats, 0, sizeof(xstats));
a19d2158	277	if (cl->qdisc->q.qlen) {
13d2a1d2	278	xstats.deficit = cl->deficit;
a19d2158 JP	279	cl->qdisc->qstats.qlen = cl->qdisc->q.qlen;
a19d2158 JP	280	}
13d2a1d2 PM	281
13d2a1d2 PM	282	if (gnet_stats_copy_basic(d, &cl->bstats) < 0 \|\|
d250a5f9	283	gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 \|\|
13d2a1d2 PM	284	gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
	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;
	294	struct hlist_node *n;
	295	unsigned int i;
	296
	297	if (arg->stop)
	298	return;
	299
	300	for (i = 0; i < q->clhash.hashsize; i++) {
	301	hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
	302	if (arg->count < arg->skip) {
	303	arg->count++;
	304	continue;
	305	}
	306	if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
	307	arg->stop = 1;
	308	return;
	309	}
	310	arg->count++;
	311	}
	312	}
	313	}
	314
	315	static struct drr_class drr_classify(struct sk_buff skb, struct Qdisc *sch,
	316	int *qerr)
	317	{
	318	struct drr_sched *q = qdisc_priv(sch);
	319	struct drr_class *cl;
	320	struct tcf_result res;
	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;
	330	result = tc_classify(skb, q->filter_list, &res);
	331	if (result >= 0) {
	332	#ifdef CONFIG_NET_CLS_ACT
	333	switch (result) {
	334	case TC_ACT_QUEUED:
	335	case TC_ACT_STOLEN:
	336	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_STOLEN;
	337	case TC_ACT_SHOT:
	338	return NULL;
	339	}
	340	#endif
	341	cl = (struct drr_class *)res.class;
	342	if (cl == NULL)
	343	cl = drr_find_class(sch, res.classid);
	344	return cl;
	345	}
	346	return NULL;
	347	}
348
349	static int drr_enqueue(struct sk_buff skb, struct Qdisc sch)
350	{
351	struct drr_sched *q = qdisc_priv(sch);
352	struct drr_class *cl;
353	unsigned int len;
354	int err;
355
356	cl = drr_classify(skb, sch, &err);
357	if (cl == NULL) {
358	if (err & __NET_XMIT_BYPASS)
359	sch->qstats.drops++;
360	kfree_skb(skb);
361	return err;
362	}
363
364	len = qdisc_pkt_len(skb);
365	err = qdisc_enqueue(skb, cl->qdisc);
366	if (unlikely(err != NET_XMIT_SUCCESS)) {
367	if (net_xmit_drop_count(err)) {
368	cl->qstats.drops++;
369	sch->qstats.drops++;
370	}
371	return err;
372	}
373
374	if (cl->qdisc->q.qlen == 1) {
375	list_add_tail(&cl->alist, &q->active);
376	cl->deficit = cl->quantum;
377	}
378
379	cl->bstats.packets++;
380	cl->bstats.bytes += len;
381	sch->bstats.packets++;
382	sch->bstats.bytes += len;
383
384	sch->q.qlen++;
385	return err;
386	}
387
388	static struct sk_buff drr_dequeue(struct Qdisc sch)
389	{
390	struct drr_sched *q = qdisc_priv(sch);
391	struct drr_class *cl;
392	struct sk_buff *skb;
393	unsigned int len;
394
3f0947c3 PM	395	if (list_empty(&q->active))
	396	goto out;
	397	while (1) {
13d2a1d2 PM	398	cl = list_first_entry(&q->active, struct drr_class, alist);
	399	skb = cl->qdisc->ops->peek(cl->qdisc);
	400	if (skb == NULL)
3f0947c3	401	goto out;
13d2a1d2 PM	402
	403	len = qdisc_pkt_len(skb);
	404	if (len <= cl->deficit) {
	405	cl->deficit -= len;
	406	skb = qdisc_dequeue_peeked(cl->qdisc);
	407	if (cl->qdisc->q.qlen == 0)
	408	list_del(&cl->alist);
	409	sch->q.qlen--;
	410	return skb;
	411	}
	412
	413	cl->deficit += cl->quantum;
13d2a1d2 PM	414	list_move_tail(&cl->alist, &q->active);
13d2a1d2 PM	415	}
3f0947c3	416	out:
13d2a1d2 PM	417	return NULL;
	418	}
	419
	420	static unsigned int drr_drop(struct Qdisc *sch)
	421	{
	422	struct drr_sched *q = qdisc_priv(sch);
	423	struct drr_class *cl;
	424	unsigned int len;
	425
	426	list_for_each_entry(cl, &q->active, alist) {
	427	if (cl->qdisc->ops->drop) {
	428	len = cl->qdisc->ops->drop(cl->qdisc);
	429	if (len > 0) {
98aa9c80	430	sch->q.qlen--;
13d2a1d2 PM	431	if (cl->qdisc->q.qlen == 0)
	432	list_del(&cl->alist);
	433	return len;
	434	}
	435	}
	436	}
	437	return 0;
	438	}
	439
	440	static int drr_init_qdisc(struct Qdisc sch, struct nlattr opt)
	441	{
	442	struct drr_sched *q = qdisc_priv(sch);
	443	int err;
	444
	445	err = qdisc_class_hash_init(&q->clhash);
	446	if (err < 0)
	447	return err;
	448	INIT_LIST_HEAD(&q->active);
	449	return 0;
	450	}
	451
	452	static void drr_reset_qdisc(struct Qdisc *sch)
	453	{
	454	struct drr_sched *q = qdisc_priv(sch);
	455	struct drr_class *cl;
	456	struct hlist_node *n;
	457	unsigned int i;
	458
	459	for (i = 0; i < q->clhash.hashsize; i++) {
	460	hlist_for_each_entry(cl, n, &q->clhash.hash[i], common.hnode) {
	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;
	473	struct hlist_node n, next;
	474	unsigned int i;
	475
	476	tcf_destroy_chain(&q->filter_list);
	477
	478	for (i = 0; i < q->clhash.hashsize; i++) {
	479	hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[i],
	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");