[linux-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;

	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, 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;
	}

	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, NULL, &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	90	if (tca[TCA_RATE]) {
22e0f8b9 JF	91	err = gen_replace_estimator(&cl->bstats, NULL,
22e0f8b9 JF	92	&cl->rate_est,
71bcb09a SH	93	qdisc_root_sleeping_lock(sch),
	94	tca[TCA_RATE]);
	95	if (err)
	96	return err;
	97	}
	98
13d2a1d2 PM	99	sch_tree_lock(sch);
	100	if (tb[TCA_DRR_QUANTUM])
	101	cl->quantum = quantum;
	102	sch_tree_unlock(sch);
	103
13d2a1d2 PM	104	return 0;
	105	}
	106
	107	cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
	108	if (cl == NULL)
	109	return -ENOBUFS;
	110
	111	cl->refcnt = 1;
	112	cl->common.classid = classid;
	113	cl->quantum = quantum;
3511c913	114	cl->qdisc = qdisc_create_dflt(sch->dev_queue,
13d2a1d2 PM	115	&pfifo_qdisc_ops, classid);
	116	if (cl->qdisc == NULL)
	117	cl->qdisc = &noop_qdisc;
	118
71bcb09a	119	if (tca[TCA_RATE]) {
22e0f8b9	120	err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est,
71bcb09a SH	121	qdisc_root_sleeping_lock(sch),
	122	tca[TCA_RATE]);
	123	if (err) {
	124	qdisc_destroy(cl->qdisc);
	125	kfree(cl);
	126	return err;
	127	}
	128	}
13d2a1d2 PM	129
	130	sch_tree_lock(sch);
	131	qdisc_class_hash_insert(&q->clhash, &cl->common);
	132	sch_tree_unlock(sch);
	133
	134	qdisc_class_hash_grow(sch, &q->clhash);
	135
	136	*arg = (unsigned long)cl;
	137	return 0;
	138	}
	139
	140	static void drr_destroy_class(struct Qdisc sch, struct drr_class cl)
	141	{
	142	gen_kill_estimator(&cl->bstats, &cl->rate_est);
	143	qdisc_destroy(cl->qdisc);
	144	kfree(cl);
	145	}
	146
	147	static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
	148	{
	149	struct drr_sched *q = qdisc_priv(sch);
	150	struct drr_class cl = (struct drr_class )arg;
	151
	152	if (cl->filter_cnt > 0)
	153	return -EBUSY;
	154
	155	sch_tree_lock(sch);
	156
	157	drr_purge_queue(cl);
	158	qdisc_class_hash_remove(&q->clhash, &cl->common);
	159
7cd0a638 JP	160	BUG_ON(--cl->refcnt == 0);
	161	/*
	162	* This shouldn't happen: we "hold" one cops->get() when called
	163	* from tc_ctl_tclass; the destroy method is done from cops->put().
	164	*/
13d2a1d2 PM	165
	166	sch_tree_unlock(sch);
	167	return 0;
	168	}
	169
	170	static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
	171	{
	172	struct drr_class *cl = drr_find_class(sch, classid);
	173
	174	if (cl != NULL)
	175	cl->refcnt++;
	176
	177	return (unsigned long)cl;
	178	}
	179
	180	static void drr_put_class(struct Qdisc *sch, unsigned long arg)
	181	{
	182	struct drr_class cl = (struct drr_class )arg;
	183
	184	if (--cl->refcnt == 0)
	185	drr_destroy_class(sch, cl);
	186	}
	187
25d8c0d5 JF	188	static struct tcf_proto __rcu *drr_tcf_chain(struct Qdisc sch,
25d8c0d5 JF	189	unsigned long cl)
13d2a1d2 PM	190	{
	191	struct drr_sched *q = qdisc_priv(sch);
	192
	193	if (cl)
	194	return NULL;
	195
	196	return &q->filter_list;
	197	}
	198
	199	static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
	200	u32 classid)
	201	{
	202	struct drr_class *cl = drr_find_class(sch, classid);
	203
	204	if (cl != NULL)
	205	cl->filter_cnt++;
	206
	207	return (unsigned long)cl;
	208	}
	209
	210	static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
	211	{
	212	struct drr_class cl = (struct drr_class )arg;
	213
	214	cl->filter_cnt--;
	215	}
	216
	217	static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
	218	struct Qdisc new, struct Qdisc *old)
	219	{
	220	struct drr_class cl = (struct drr_class )arg;
	221
	222	if (new == NULL) {
3511c913	223	new = qdisc_create_dflt(sch->dev_queue,
13d2a1d2 PM	224	&pfifo_qdisc_ops, cl->common.classid);
	225	if (new == NULL)
	226	new = &noop_qdisc;
	227	}
	228
	229	sch_tree_lock(sch);
	230	drr_purge_queue(cl);
b94c8afc PM	231	*old = cl->qdisc;
b94c8afc PM	232	cl->qdisc = new;
13d2a1d2 PM	233	sch_tree_unlock(sch);
	234	return 0;
	235	}
	236
	237	static struct Qdisc drr_class_leaf(struct Qdisc sch, unsigned long arg)
	238	{
	239	struct drr_class cl = (struct drr_class )arg;
	240
	241	return cl->qdisc;
	242	}
	243
	244	static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
	245	{
	246	struct drr_class cl = (struct drr_class )arg;
	247
	248	if (cl->qdisc->q.qlen == 0)
	249	list_del(&cl->alist);
	250	}
	251
	252	static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
	253	struct sk_buff skb, struct tcmsg tcm)
	254	{
	255	struct drr_class cl = (struct drr_class )arg;
	256	struct nlattr *nest;
	257
	258	tcm->tcm_parent = TC_H_ROOT;
	259	tcm->tcm_handle = cl->common.classid;
	260	tcm->tcm_info = cl->qdisc->handle;
	261
	262	nest = nla_nest_start(skb, TCA_OPTIONS);
	263	if (nest == NULL)
	264	goto nla_put_failure;
1b34ec43 DM	265	if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
1b34ec43 DM	266	goto nla_put_failure;
13d2a1d2 PM	267	return nla_nest_end(skb, nest);
	268
	269	nla_put_failure:
	270	nla_nest_cancel(skb, nest);
	271	return -EMSGSIZE;
	272	}
	273
	274	static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
	275	struct gnet_dump *d)
	276	{
	277	struct drr_class cl = (struct drr_class )arg;
	278	struct tc_drr_stats xstats;
	279
	280	memset(&xstats, 0, sizeof(xstats));
a19d2158	281	if (cl->qdisc->q.qlen) {
13d2a1d2	282	xstats.deficit = cl->deficit;
a19d2158 JP	283	cl->qdisc->qstats.qlen = cl->qdisc->q.qlen;
a19d2158 JP	284	}
13d2a1d2	285
22e0f8b9	286	if (gnet_stats_copy_basic(d, NULL, &cl->bstats) < 0 \|\|
d250a5f9	287	gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 \|\|
13d2a1d2 PM	288	gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
	289	return -1;
	290
	291	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
	292	}
	293
	294	static void drr_walk(struct Qdisc sch, struct qdisc_walker arg)
	295	{
	296	struct drr_sched *q = qdisc_priv(sch);
	297	struct drr_class *cl;
13d2a1d2 PM	298	unsigned int i;
	299
	300	if (arg->stop)
	301	return;
	302
	303	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	304	hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
13d2a1d2 PM	305	if (arg->count < arg->skip) {
	306	arg->count++;
	307	continue;
	308	}
	309	if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
	310	arg->stop = 1;
	311	return;
	312	}
	313	arg->count++;
	314	}
	315	}
	316	}
	317
	318	static struct drr_class drr_classify(struct sk_buff skb, struct Qdisc *sch,
	319	int *qerr)
	320	{
	321	struct drr_sched *q = qdisc_priv(sch);
	322	struct drr_class *cl;
	323	struct tcf_result res;
25d8c0d5	324	struct tcf_proto *fl;
13d2a1d2 PM	325	int result;
	326
	327	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
	328	cl = drr_find_class(sch, skb->priority);
	329	if (cl != NULL)
	330	return cl;
	331	}
	332
	333	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_BYPASS;
25d8c0d5 JF	334	fl = rcu_dereference_bh(q->filter_list);
25d8c0d5 JF	335	result = tc_classify(skb, fl, &res);
13d2a1d2 PM	336	if (result >= 0) {
	337	#ifdef CONFIG_NET_CLS_ACT
	338	switch (result) {
	339	case TC_ACT_QUEUED:
	340	case TC_ACT_STOLEN:
	341	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_STOLEN;
	342	case TC_ACT_SHOT:
	343	return NULL;
	344	}
	345	#endif
	346	cl = (struct drr_class *)res.class;
	347	if (cl == NULL)
	348	cl = drr_find_class(sch, res.classid);
	349	return cl;
	350	}
	351	return NULL;
	352	}
	353
	354	static int drr_enqueue(struct sk_buff skb, struct Qdisc sch)
	355	{
	356	struct drr_sched *q = qdisc_priv(sch);
	357	struct drr_class *cl;
f54ba779	358	int err = 0;
13d2a1d2 PM	359
	360	cl = drr_classify(skb, sch, &err);
	361	if (cl == NULL) {
	362	if (err & __NET_XMIT_BYPASS)
	363	sch->qstats.drops++;
	364	kfree_skb(skb);
	365	return err;
	366	}
	367
13d2a1d2 PM	368	err = qdisc_enqueue(skb, cl->qdisc);
	369	if (unlikely(err != NET_XMIT_SUCCESS)) {
	370	if (net_xmit_drop_count(err)) {
	371	cl->qstats.drops++;
	372	sch->qstats.drops++;
	373	}
	374	return err;
	375	}
	376
	377	if (cl->qdisc->q.qlen == 1) {
	378	list_add_tail(&cl->alist, &q->active);
	379	cl->deficit = cl->quantum;
	380	}
	381
13d2a1d2 PM	382	sch->q.qlen++;
	383	return err;
	384	}
	385
	386	static struct sk_buff drr_dequeue(struct Qdisc sch)
	387	{
	388	struct drr_sched *q = qdisc_priv(sch);
	389	struct drr_class *cl;
	390	struct sk_buff *skb;
	391	unsigned int len;
	392
3f0947c3 PM	393	if (list_empty(&q->active))
	394	goto out;
	395	while (1) {
13d2a1d2 PM	396	cl = list_first_entry(&q->active, struct drr_class, alist);
13d2a1d2 PM	397	skb = cl->qdisc->ops->peek(cl->qdisc);
6e765a00 FW	398	if (skb == NULL) {
6e765a00 FW	399	qdisc_warn_nonwc(__func__, cl->qdisc);
3f0947c3	400	goto out;
6e765a00	401	}
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);
2dd875ff ED	409
2dd875ff ED	410	bstats_update(&cl->bstats, skb);
9190b3b3	411	qdisc_bstats_update(sch, skb);
13d2a1d2 PM	412	sch->q.qlen--;
	413	return skb;
	414	}
	415
	416	cl->deficit += cl->quantum;
13d2a1d2 PM	417	list_move_tail(&cl->alist, &q->active);
13d2a1d2 PM	418	}
3f0947c3	419	out:
13d2a1d2 PM	420	return NULL;
	421	}
	422
	423	static unsigned int drr_drop(struct Qdisc *sch)
	424	{
	425	struct drr_sched *q = qdisc_priv(sch);
	426	struct drr_class *cl;
	427	unsigned int len;
	428
	429	list_for_each_entry(cl, &q->active, alist) {
	430	if (cl->qdisc->ops->drop) {
	431	len = cl->qdisc->ops->drop(cl->qdisc);
	432	if (len > 0) {
98aa9c80	433	sch->q.qlen--;
13d2a1d2 PM	434	if (cl->qdisc->q.qlen == 0)
	435	list_del(&cl->alist);
	436	return len;
	437	}
	438	}
	439	}
	440	return 0;
	441	}
	442
	443	static int drr_init_qdisc(struct Qdisc sch, struct nlattr opt)
	444	{
	445	struct drr_sched *q = qdisc_priv(sch);
	446	int err;
	447
	448	err = qdisc_class_hash_init(&q->clhash);
	449	if (err < 0)
	450	return err;
	451	INIT_LIST_HEAD(&q->active);
	452	return 0;
	453	}
	454
	455	static void drr_reset_qdisc(struct Qdisc *sch)
	456	{
	457	struct drr_sched *q = qdisc_priv(sch);
	458	struct drr_class *cl;
13d2a1d2 PM	459	unsigned int i;
	460
	461	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	462	hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
13d2a1d2 PM	463	if (cl->qdisc->q.qlen)
	464	list_del(&cl->alist);
	465	qdisc_reset(cl->qdisc);
	466	}
	467	}
	468	sch->q.qlen = 0;
	469	}
	470
	471	static void drr_destroy_qdisc(struct Qdisc *sch)
	472	{
	473	struct drr_sched *q = qdisc_priv(sch);
	474	struct drr_class *cl;
b67bfe0d	475	struct hlist_node *next;
13d2a1d2 PM	476	unsigned int i;
	477
	478	tcf_destroy_chain(&q->filter_list);
	479
	480	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	481	hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
13d2a1d2 PM	482	common.hnode)
	483	drr_destroy_class(sch, cl);
	484	}
	485	qdisc_class_hash_destroy(&q->clhash);
	486	}
	487
	488	static const struct Qdisc_class_ops drr_class_ops = {
	489	.change = drr_change_class,
	490	.delete = drr_delete_class,
	491	.get = drr_get_class,
	492	.put = drr_put_class,
	493	.tcf_chain = drr_tcf_chain,
	494	.bind_tcf = drr_bind_tcf,
	495	.unbind_tcf = drr_unbind_tcf,
	496	.graft = drr_graft_class,
	497	.leaf = drr_class_leaf,
	498	.qlen_notify = drr_qlen_notify,
	499	.dump = drr_dump_class,
	500	.dump_stats = drr_dump_class_stats,
	501	.walk = drr_walk,
	502	};
	503
	504	static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
	505	.cl_ops = &drr_class_ops,
	506	.id = "drr",
	507	.priv_size = sizeof(struct drr_sched),
	508	.enqueue = drr_enqueue,
	509	.dequeue = drr_dequeue,
	510	.peek = qdisc_peek_dequeued,
	511	.drop = drr_drop,
	512	.init = drr_init_qdisc,
	513	.reset = drr_reset_qdisc,
	514	.destroy = drr_destroy_qdisc,
	515	.owner = THIS_MODULE,
	516	};
	517
	518	static int __init drr_init(void)
	519	{
	520	return register_qdisc(&drr_qdisc_ops);
	521	}
	522
	523	static void __exit drr_exit(void)
	524	{
	525	unregister_qdisc(&drr_qdisc_ops);
	526	}
	527
	528	module_init(drr_init);
	529	module_exit(drr_exit);
	530	MODULE_LICENSE("GPL");