[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			filter_cnt;

	struct gnet_stats_basic_packed		bstats;
	struct gnet_stats_queue		qstats;
	struct net_rate_estimator __rcu *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 tcf_block		*block;
	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 netlink_ext_ack *extack)
{
	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) {
		NL_SET_ERR_MSG(extack, "DRR options are required for this operation");
		return -EINVAL;
	}

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

	if (tb[TCA_DRR_QUANTUM]) {
		quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
		if (quantum == 0) {
			NL_SET_ERR_MSG(extack, "Specified DRR quantum cannot be zero");
			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,
						    NULL,
						    qdisc_root_sleeping_running(sch),
						    tca[TCA_RATE]);
			if (err) {
				NL_SET_ERR_MSG(extack, "Failed to replace estimator");
				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->common.classid = classid;
	cl->quantum	   = quantum;
	cl->qdisc	   = qdisc_create_dflt(sch->dev_queue,
					       &pfifo_qdisc_ops, classid,
					       NULL);
	if (cl->qdisc == NULL)
		cl->qdisc = &noop_qdisc;
	else
		qdisc_hash_add(cl->qdisc, true);

	if (tca[TCA_RATE]) {
		err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est,
					    NULL,
					    qdisc_root_sleeping_running(sch),
					    tca[TCA_RATE]);
		if (err) {
			NL_SET_ERR_MSG(extack, "Failed to replace estimator");
			qdisc_put(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->rate_est);
	qdisc_put(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);

	sch_tree_unlock(sch);

	drr_destroy_class(sch, cl);
	return 0;
}

static unsigned long drr_search_class(struct Qdisc *sch, u32 classid)
{
	return (unsigned long)drr_find_class(sch, classid);
}

static struct tcf_block *drr_tcf_block(struct Qdisc *sch, unsigned long cl,
				       struct netlink_ext_ack *extack)
{
	struct drr_sched *q = qdisc_priv(sch);

	if (cl) {
		NL_SET_ERR_MSG(extack, "DRR classid must be zero");
		return NULL;
	}

	return q->block;
}

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 netlink_ext_ack *extack)
{
	struct drr_class *cl = (struct drr_class *)arg;

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

	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(qdisc_root_sleeping_running(sch),
				  d, NULL, &cl->bstats) < 0 ||
	    gnet_stats_copy_rate_est(d, &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 = tcf_classify(skb, fl, &res, false);
	if (result >= 0) {
#ifdef CONFIG_NET_CLS_ACT
		switch (result) {
		case TC_ACT_QUEUED:
		case TC_ACT_STOLEN:
		case TC_ACT_TRAP:
			*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
			/* fall through */
		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 sk_buff **to_free)
{
	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);
		__qdisc_drop(skb, to_free);
		return err;
	}

	err = qdisc_enqueue(skb, cl->qdisc, to_free);
	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;
	}

	qdisc_qstats_backlog_inc(sch, skb);
	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);
			qdisc_qstats_backlog_dec(sch, skb);
			sch->q.qlen--;
			return skb;
		}

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

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

	err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
	if (err)
		return 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->qstats.backlog = 0;
	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_block_put(q->block);

	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,
	.find		= drr_search_class,
	.tcf_block	= drr_tcf_block,
	.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,
	.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;
13d2a1d2 PM	23	unsigned int filter_cnt;
13d2a1d2 PM	24
c1a8f1f1	25	struct gnet_stats_basic_packed bstats;
13d2a1d2	26	struct gnet_stats_queue qstats;
1c0d32fd	27	struct net_rate_estimator __rcu *rate_est;
13d2a1d2 PM	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;
25d8c0d5	37	struct tcf_proto __rcu *filter_list;
6529eaba	38	struct tcf_block *block;
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,
793d81d6 AA	67	struct nlattr *tca, unsigned long arg,
793d81d6 AA	68	struct netlink_ext_ack *extack)
13d2a1d2 PM	69	{
	70	struct drr_sched *q = qdisc_priv(sch);
	71	struct drr_class cl = (struct drr_class )*arg;
1844f747	72	struct nlattr *opt = tca[TCA_OPTIONS];
13d2a1d2 PM	73	struct nlattr *tb[TCA_DRR_MAX + 1];
	74	u32 quantum;
	75	int err;
	76
a7c31693 AA	77	if (!opt) {
a7c31693 AA	78	NL_SET_ERR_MSG(extack, "DRR options are required for this operation");
1844f747	79	return -EINVAL;
a7c31693	80	}
1844f747	81
a7c31693	82	err = nla_parse_nested(tb, TCA_DRR_MAX, opt, drr_policy, extack);
13d2a1d2 PM	83	if (err < 0)
	84	return err;
	85
	86	if (tb[TCA_DRR_QUANTUM]) {
	87	quantum = nla_get_u32(tb[TCA_DRR_QUANTUM]);
a7c31693 AA	88	if (quantum == 0) {
a7c31693 AA	89	NL_SET_ERR_MSG(extack, "Specified DRR quantum cannot be zero");
13d2a1d2	90	return -EINVAL;
a7c31693	91	}
13d2a1d2 PM	92	} else
	93	quantum = psched_mtu(qdisc_dev(sch));
	94
	95	if (cl != NULL) {
71bcb09a	96	if (tca[TCA_RATE]) {
22e0f8b9 JF	97	err = gen_replace_estimator(&cl->bstats, NULL,
22e0f8b9 JF	98	&cl->rate_est,
edb09eb1 ED	99	NULL,
edb09eb1 ED	100	qdisc_root_sleeping_running(sch),
71bcb09a	101	tca[TCA_RATE]);
a7c31693 AA	102	if (err) {
a7c31693 AA	103	NL_SET_ERR_MSG(extack, "Failed to replace estimator");
71bcb09a	104	return err;
a7c31693	105	}
71bcb09a SH	106	}
71bcb09a SH	107
13d2a1d2 PM	108	sch_tree_lock(sch);
	109	if (tb[TCA_DRR_QUANTUM])
	110	cl->quantum = quantum;
	111	sch_tree_unlock(sch);
	112
13d2a1d2 PM	113	return 0;
	114	}
	115
	116	cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
	117	if (cl == NULL)
	118	return -ENOBUFS;
	119
13d2a1d2 PM	120	cl->common.classid = classid;
13d2a1d2 PM	121	cl->quantum = quantum;
3511c913	122	cl->qdisc = qdisc_create_dflt(sch->dev_queue,
a38a9882 AA	123	&pfifo_qdisc_ops, classid,
a38a9882 AA	124	NULL);
13d2a1d2 PM	125	if (cl->qdisc == NULL)
13d2a1d2 PM	126	cl->qdisc = &noop_qdisc;
49b49971 JK	127	else
49b49971 JK	128	qdisc_hash_add(cl->qdisc, true);
13d2a1d2	129
71bcb09a	130	if (tca[TCA_RATE]) {
22e0f8b9	131	err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est,
edb09eb1 ED	132	NULL,
edb09eb1 ED	133	qdisc_root_sleeping_running(sch),
71bcb09a SH	134	tca[TCA_RATE]);
71bcb09a SH	135	if (err) {
a7c31693	136	NL_SET_ERR_MSG(extack, "Failed to replace estimator");
86bd446b	137	qdisc_put(cl->qdisc);
71bcb09a SH	138	kfree(cl);
	139	return err;
	140	}
	141	}
13d2a1d2 PM	142
	143	sch_tree_lock(sch);
	144	qdisc_class_hash_insert(&q->clhash, &cl->common);
	145	sch_tree_unlock(sch);
	146
	147	qdisc_class_hash_grow(sch, &q->clhash);
	148
	149	*arg = (unsigned long)cl;
	150	return 0;
	151	}
	152
	153	static void drr_destroy_class(struct Qdisc sch, struct drr_class cl)
	154	{
1c0d32fd	155	gen_kill_estimator(&cl->rate_est);
86bd446b	156	qdisc_put(cl->qdisc);
13d2a1d2 PM	157	kfree(cl);
	158	}
	159
	160	static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
	161	{
	162	struct drr_sched *q = qdisc_priv(sch);
	163	struct drr_class cl = (struct drr_class )arg;
	164
	165	if (cl->filter_cnt > 0)
	166	return -EBUSY;
	167
	168	sch_tree_lock(sch);
	169
	170	drr_purge_queue(cl);
	171	qdisc_class_hash_remove(&q->clhash, &cl->common);
	172
13d2a1d2	173	sch_tree_unlock(sch);
13d2a1d2	174
143976ce WC	175	drr_destroy_class(sch, cl);
143976ce WC	176	return 0;
13d2a1d2 PM	177	}
13d2a1d2 PM	178
143976ce	179	static unsigned long drr_search_class(struct Qdisc *sch, u32 classid)
13d2a1d2	180	{
143976ce	181	return (unsigned long)drr_find_class(sch, classid);
13d2a1d2 PM	182	}
13d2a1d2 PM	183
cbaacc4e AA	184	static struct tcf_block drr_tcf_block(struct Qdisc sch, unsigned long cl,
cbaacc4e AA	185	struct netlink_ext_ack *extack)
13d2a1d2 PM	186	{
	187	struct drr_sched *q = qdisc_priv(sch);
	188
a7c31693 AA	189	if (cl) {
a7c31693 AA	190	NL_SET_ERR_MSG(extack, "DRR classid must be zero");
13d2a1d2	191	return NULL;
a7c31693	192	}
13d2a1d2	193
6529eaba	194	return q->block;
13d2a1d2 PM	195	}
	196
	197	static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
	198	u32 classid)
	199	{
	200	struct drr_class *cl = drr_find_class(sch, classid);
	201
	202	if (cl != NULL)
	203	cl->filter_cnt++;
	204
	205	return (unsigned long)cl;
	206	}
	207
	208	static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
	209	{
	210	struct drr_class cl = (struct drr_class )arg;
	211
	212	cl->filter_cnt--;
	213	}
	214
	215	static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
653d6fd6 AA	216	struct Qdisc new, struct Qdisc *old,
653d6fd6 AA	217	struct netlink_ext_ack *extack)
13d2a1d2 PM	218	{
	219	struct drr_class cl = (struct drr_class )arg;
	220
	221	if (new == NULL) {
a38a9882 AA	222	new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
a38a9882 AA	223	cl->common.classid, NULL);
13d2a1d2 PM	224	if (new == NULL)
	225	new = &noop_qdisc;
	226	}
	227
86a7996c	228	*old = qdisc_replace(sch, new, &cl->qdisc);
13d2a1d2 PM	229	return 0;
	230	}
	231
	232	static struct Qdisc drr_class_leaf(struct Qdisc sch, unsigned long arg)
	233	{
	234	struct drr_class cl = (struct drr_class )arg;
	235
	236	return cl->qdisc;
	237	}
	238
	239	static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
	240	{
	241	struct drr_class cl = (struct drr_class )arg;
	242
95946658	243	list_del(&cl->alist);
13d2a1d2 PM	244	}
	245
	246	static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
	247	struct sk_buff skb, struct tcmsg tcm)
	248	{
	249	struct drr_class cl = (struct drr_class )arg;
	250	struct nlattr *nest;
	251
	252	tcm->tcm_parent = TC_H_ROOT;
	253	tcm->tcm_handle = cl->common.classid;
	254	tcm->tcm_info = cl->qdisc->handle;
	255
	256	nest = nla_nest_start(skb, TCA_OPTIONS);
	257	if (nest == NULL)
	258	goto nla_put_failure;
1b34ec43 DM	259	if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
1b34ec43 DM	260	goto nla_put_failure;
13d2a1d2 PM	261	return nla_nest_end(skb, nest);
	262
	263	nla_put_failure:
	264	nla_nest_cancel(skb, nest);
	265	return -EMSGSIZE;
	266	}
	267
	268	static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
	269	struct gnet_dump *d)
	270	{
	271	struct drr_class cl = (struct drr_class )arg;
64015853	272	__u32 qlen = cl->qdisc->q.qlen;
13d2a1d2 PM	273	struct tc_drr_stats xstats;
	274
	275	memset(&xstats, 0, sizeof(xstats));
64015853	276	if (qlen)
13d2a1d2 PM	277	xstats.deficit = cl->deficit;
13d2a1d2 PM	278
edb09eb1 ED	279	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
edb09eb1 ED	280	d, NULL, &cl->bstats) < 0 \|\|
1c0d32fd	281	gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 \|\|
b0ab6f92	282	gnet_stats_copy_queue(d, NULL, &cl->qdisc->qstats, qlen) < 0)
13d2a1d2 PM	283	return -1;
	284
	285	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
	286	}
	287
	288	static void drr_walk(struct Qdisc sch, struct qdisc_walker arg)
	289	{
	290	struct drr_sched *q = qdisc_priv(sch);
	291	struct drr_class *cl;
13d2a1d2 PM	292	unsigned int i;
	293
	294	if (arg->stop)
	295	return;
	296
	297	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	298	hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
13d2a1d2 PM	299	if (arg->count < arg->skip) {
	300	arg->count++;
	301	continue;
	302	}
	303	if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
	304	arg->stop = 1;
	305	return;
	306	}
	307	arg->count++;
	308	}
	309	}
	310	}
	311
	312	static struct drr_class drr_classify(struct sk_buff skb, struct Qdisc *sch,
	313	int *qerr)
	314	{
	315	struct drr_sched *q = qdisc_priv(sch);
	316	struct drr_class *cl;
	317	struct tcf_result res;
25d8c0d5	318	struct tcf_proto *fl;
13d2a1d2 PM	319	int result;
	320
	321	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
	322	cl = drr_find_class(sch, skb->priority);
	323	if (cl != NULL)
	324	return cl;
	325	}
	326
	327	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_BYPASS;
25d8c0d5	328	fl = rcu_dereference_bh(q->filter_list);
87d83093	329	result = tcf_classify(skb, fl, &res, false);
13d2a1d2 PM	330	if (result >= 0) {
	331	#ifdef CONFIG_NET_CLS_ACT
	332	switch (result) {
	333	case TC_ACT_QUEUED:
	334	case TC_ACT_STOLEN:
e25ea21f	335	case TC_ACT_TRAP:
13d2a1d2	336	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_STOLEN;
f3ae608e	337	/* fall through */
13d2a1d2 PM	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
520ac30f ED	350	static int drr_enqueue(struct sk_buff skb, struct Qdisc sch,
520ac30f ED	351	struct sk_buff **to_free)
13d2a1d2 PM	352	{
	353	struct drr_sched *q = qdisc_priv(sch);
	354	struct drr_class *cl;
f54ba779	355	int err = 0;
13d2a1d2 PM	356
	357	cl = drr_classify(skb, sch, &err);
	358	if (cl == NULL) {
	359	if (err & __NET_XMIT_BYPASS)
25331d6c	360	qdisc_qstats_drop(sch);
520ac30f	361	__qdisc_drop(skb, to_free);
13d2a1d2 PM	362	return err;
	363	}
	364
520ac30f	365	err = qdisc_enqueue(skb, cl->qdisc, to_free);
13d2a1d2 PM	366	if (unlikely(err != NET_XMIT_SUCCESS)) {
	367	if (net_xmit_drop_count(err)) {
	368	cl->qstats.drops++;
25331d6c	369	qdisc_qstats_drop(sch);
13d2a1d2 PM	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
6a73b571	379	qdisc_qstats_backlog_inc(sch, skb);
13d2a1d2 PM	380	sch->q.qlen++;
	381	return err;
	382	}
	383
	384	static struct sk_buff drr_dequeue(struct Qdisc sch)
	385	{
	386	struct drr_sched *q = qdisc_priv(sch);
	387	struct drr_class *cl;
	388	struct sk_buff *skb;
	389	unsigned int len;
	390
3f0947c3 PM	391	if (list_empty(&q->active))
	392	goto out;
	393	while (1) {
13d2a1d2 PM	394	cl = list_first_entry(&q->active, struct drr_class, alist);
13d2a1d2 PM	395	skb = cl->qdisc->ops->peek(cl->qdisc);
6e765a00 FW	396	if (skb == NULL) {
6e765a00 FW	397	qdisc_warn_nonwc(__func__, cl->qdisc);
3f0947c3	398	goto out;
6e765a00	399	}
13d2a1d2 PM	400
	401	len = qdisc_pkt_len(skb);
	402	if (len <= cl->deficit) {
	403	cl->deficit -= len;
	404	skb = qdisc_dequeue_peeked(cl->qdisc);
df3eb6cd BH	405	if (unlikely(skb == NULL))
df3eb6cd BH	406	goto out;
13d2a1d2 PM	407	if (cl->qdisc->q.qlen == 0)
13d2a1d2 PM	408	list_del(&cl->alist);
2dd875ff ED	409
2dd875ff ED	410	bstats_update(&cl->bstats, skb);
9190b3b3	411	qdisc_bstats_update(sch, skb);
6a73b571	412	qdisc_qstats_backlog_dec(sch, skb);
13d2a1d2 PM	413	sch->q.qlen--;
	414	return skb;
	415	}
	416
	417	cl->deficit += cl->quantum;
13d2a1d2 PM	418	list_move_tail(&cl->alist, &q->active);
13d2a1d2 PM	419	}
3f0947c3	420	out:
13d2a1d2 PM	421	return NULL;
	422	}
	423
e63d7dfd AA	424	static int drr_init_qdisc(struct Qdisc sch, struct nlattr opt,
e63d7dfd AA	425	struct netlink_ext_ack *extack)
13d2a1d2 PM	426	{
	427	struct drr_sched *q = qdisc_priv(sch);
	428	int err;
	429
8d1a77f9	430	err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
6529eaba JP	431	if (err)
6529eaba JP	432	return err;
13d2a1d2 PM	433	err = qdisc_class_hash_init(&q->clhash);
	434	if (err < 0)
	435	return err;
	436	INIT_LIST_HEAD(&q->active);
	437	return 0;
	438	}
	439
	440	static void drr_reset_qdisc(struct Qdisc *sch)
	441	{
	442	struct drr_sched *q = qdisc_priv(sch);
	443	struct drr_class *cl;
13d2a1d2 PM	444	unsigned int i;
	445
	446	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	447	hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
13d2a1d2 PM	448	if (cl->qdisc->q.qlen)
	449	list_del(&cl->alist);
	450	qdisc_reset(cl->qdisc);
	451	}
	452	}
6a73b571	453	sch->qstats.backlog = 0;
13d2a1d2 PM	454	sch->q.qlen = 0;
	455	}
	456
	457	static void drr_destroy_qdisc(struct Qdisc *sch)
	458	{
	459	struct drr_sched *q = qdisc_priv(sch);
	460	struct drr_class *cl;
b67bfe0d	461	struct hlist_node *next;
13d2a1d2 PM	462	unsigned int i;
13d2a1d2 PM	463
6529eaba	464	tcf_block_put(q->block);
13d2a1d2 PM	465
13d2a1d2 PM	466	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	467	hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
13d2a1d2 PM	468	common.hnode)
	469	drr_destroy_class(sch, cl);
	470	}
	471	qdisc_class_hash_destroy(&q->clhash);
	472	}
	473
	474	static const struct Qdisc_class_ops drr_class_ops = {
	475	.change = drr_change_class,
	476	.delete = drr_delete_class,
143976ce	477	.find = drr_search_class,
6529eaba	478	.tcf_block = drr_tcf_block,
13d2a1d2 PM	479	.bind_tcf = drr_bind_tcf,
	480	.unbind_tcf = drr_unbind_tcf,
	481	.graft = drr_graft_class,
	482	.leaf = drr_class_leaf,
	483	.qlen_notify = drr_qlen_notify,
	484	.dump = drr_dump_class,
	485	.dump_stats = drr_dump_class_stats,
	486	.walk = drr_walk,
	487	};
	488
	489	static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
	490	.cl_ops = &drr_class_ops,
	491	.id = "drr",
	492	.priv_size = sizeof(struct drr_sched),
	493	.enqueue = drr_enqueue,
	494	.dequeue = drr_dequeue,
	495	.peek = qdisc_peek_dequeued,
13d2a1d2 PM	496	.init = drr_init_qdisc,
	497	.reset = drr_reset_qdisc,
	498	.destroy = drr_destroy_qdisc,
	499	.owner = THIS_MODULE,
	500	};
	501
	502	static int __init drr_init(void)
	503	{
	504	return register_qdisc(&drr_qdisc_ops);
	505	}
	506
	507	static void __exit drr_exit(void)
	508	{
	509	unregister_qdisc(&drr_qdisc_ops);
	510	}
	511
	512	module_init(drr_init);
	513	module_exit(drr_exit);
	514	MODULE_LICENSE("GPL");