[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			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 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, NULL);
	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,
						    NULL,
						    qdisc_root_sleeping_running(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->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;
	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) {
			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->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);

	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 drr_sched *q = qdisc_priv(sch);

	if (cl)
		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 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;

	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);
	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,
	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
fceb6435	79	err = nla_parse_nested(tb, TCA_DRR_MAX, opt, drr_policy, NULL);
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,
edb09eb1 ED	94	NULL,
edb09eb1 ED	95	qdisc_root_sleeping_running(sch),
71bcb09a SH	96	tca[TCA_RATE]);
	97	if (err)
	98	return err;
	99	}
	100
13d2a1d2 PM	101	sch_tree_lock(sch);
	102	if (tb[TCA_DRR_QUANTUM])
	103	cl->quantum = quantum;
	104	sch_tree_unlock(sch);
	105
13d2a1d2 PM	106	return 0;
	107	}
	108
	109	cl = kzalloc(sizeof(struct drr_class), GFP_KERNEL);
	110	if (cl == NULL)
	111	return -ENOBUFS;
	112
13d2a1d2 PM	113	cl->common.classid = classid;
13d2a1d2 PM	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;
49b49971 JK	119	else
49b49971 JK	120	qdisc_hash_add(cl->qdisc, true);
13d2a1d2	121
71bcb09a	122	if (tca[TCA_RATE]) {
22e0f8b9	123	err = gen_replace_estimator(&cl->bstats, NULL, &cl->rate_est,
edb09eb1 ED	124	NULL,
edb09eb1 ED	125	qdisc_root_sleeping_running(sch),
71bcb09a SH	126	tca[TCA_RATE]);
	127	if (err) {
	128	qdisc_destroy(cl->qdisc);
	129	kfree(cl);
	130	return err;
	131	}
	132	}
13d2a1d2 PM	133
	134	sch_tree_lock(sch);
	135	qdisc_class_hash_insert(&q->clhash, &cl->common);
	136	sch_tree_unlock(sch);
	137
	138	qdisc_class_hash_grow(sch, &q->clhash);
	139
	140	*arg = (unsigned long)cl;
	141	return 0;
	142	}
	143
	144	static void drr_destroy_class(struct Qdisc sch, struct drr_class cl)
	145	{
1c0d32fd	146	gen_kill_estimator(&cl->rate_est);
13d2a1d2 PM	147	qdisc_destroy(cl->qdisc);
	148	kfree(cl);
	149	}
	150
	151	static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
	152	{
	153	struct drr_sched *q = qdisc_priv(sch);
	154	struct drr_class cl = (struct drr_class )arg;
	155
	156	if (cl->filter_cnt > 0)
	157	return -EBUSY;
	158
	159	sch_tree_lock(sch);
	160
	161	drr_purge_queue(cl);
	162	qdisc_class_hash_remove(&q->clhash, &cl->common);
	163
13d2a1d2	164	sch_tree_unlock(sch);
13d2a1d2	165
143976ce WC	166	drr_destroy_class(sch, cl);
143976ce WC	167	return 0;
13d2a1d2 PM	168	}
13d2a1d2 PM	169
143976ce	170	static unsigned long drr_search_class(struct Qdisc *sch, u32 classid)
13d2a1d2	171	{
143976ce	172	return (unsigned long)drr_find_class(sch, classid);
13d2a1d2 PM	173	}
13d2a1d2 PM	174
6529eaba	175	static struct tcf_block drr_tcf_block(struct Qdisc sch, unsigned long cl)
13d2a1d2 PM	176	{
	177	struct drr_sched *q = qdisc_priv(sch);
	178
	179	if (cl)
	180	return NULL;
	181
6529eaba	182	return q->block;
13d2a1d2 PM	183	}
	184
	185	static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent,
	186	u32 classid)
	187	{
	188	struct drr_class *cl = drr_find_class(sch, classid);
	189
	190	if (cl != NULL)
	191	cl->filter_cnt++;
	192
	193	return (unsigned long)cl;
	194	}
	195
	196	static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg)
	197	{
	198	struct drr_class cl = (struct drr_class )arg;
	199
	200	cl->filter_cnt--;
	201	}
	202
	203	static int drr_graft_class(struct Qdisc *sch, unsigned long arg,
	204	struct Qdisc new, struct Qdisc *old)
	205	{
	206	struct drr_class cl = (struct drr_class )arg;
	207
	208	if (new == NULL) {
3511c913	209	new = qdisc_create_dflt(sch->dev_queue,
13d2a1d2 PM	210	&pfifo_qdisc_ops, cl->common.classid);
	211	if (new == NULL)
	212	new = &noop_qdisc;
	213	}
	214
86a7996c	215	*old = qdisc_replace(sch, new, &cl->qdisc);
13d2a1d2 PM	216	return 0;
	217	}
	218
	219	static struct Qdisc drr_class_leaf(struct Qdisc sch, unsigned long arg)
	220	{
	221	struct drr_class cl = (struct drr_class )arg;
	222
	223	return cl->qdisc;
	224	}
	225
	226	static void drr_qlen_notify(struct Qdisc *csh, unsigned long arg)
	227	{
	228	struct drr_class cl = (struct drr_class )arg;
	229
95946658	230	list_del(&cl->alist);
13d2a1d2 PM	231	}
	232
	233	static int drr_dump_class(struct Qdisc *sch, unsigned long arg,
	234	struct sk_buff skb, struct tcmsg tcm)
	235	{
	236	struct drr_class cl = (struct drr_class )arg;
	237	struct nlattr *nest;
	238
	239	tcm->tcm_parent = TC_H_ROOT;
	240	tcm->tcm_handle = cl->common.classid;
	241	tcm->tcm_info = cl->qdisc->handle;
	242
	243	nest = nla_nest_start(skb, TCA_OPTIONS);
	244	if (nest == NULL)
	245	goto nla_put_failure;
1b34ec43 DM	246	if (nla_put_u32(skb, TCA_DRR_QUANTUM, cl->quantum))
1b34ec43 DM	247	goto nla_put_failure;
13d2a1d2 PM	248	return nla_nest_end(skb, nest);
	249
	250	nla_put_failure:
	251	nla_nest_cancel(skb, nest);
	252	return -EMSGSIZE;
	253	}
	254
	255	static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
	256	struct gnet_dump *d)
	257	{
	258	struct drr_class cl = (struct drr_class )arg;
64015853	259	__u32 qlen = cl->qdisc->q.qlen;
13d2a1d2 PM	260	struct tc_drr_stats xstats;
	261
	262	memset(&xstats, 0, sizeof(xstats));
64015853	263	if (qlen)
13d2a1d2 PM	264	xstats.deficit = cl->deficit;
13d2a1d2 PM	265
edb09eb1 ED	266	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
edb09eb1 ED	267	d, NULL, &cl->bstats) < 0 \|\|
1c0d32fd	268	gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 \|\|
b0ab6f92	269	gnet_stats_copy_queue(d, NULL, &cl->qdisc->qstats, qlen) < 0)
13d2a1d2 PM	270	return -1;
	271
	272	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
	273	}
	274
	275	static void drr_walk(struct Qdisc sch, struct qdisc_walker arg)
	276	{
	277	struct drr_sched *q = qdisc_priv(sch);
	278	struct drr_class *cl;
13d2a1d2 PM	279	unsigned int i;
	280
	281	if (arg->stop)
	282	return;
	283
	284	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	285	hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
13d2a1d2 PM	286	if (arg->count < arg->skip) {
	287	arg->count++;
	288	continue;
	289	}
	290	if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
	291	arg->stop = 1;
	292	return;
	293	}
	294	arg->count++;
	295	}
	296	}
	297	}
	298
	299	static struct drr_class drr_classify(struct sk_buff skb, struct Qdisc *sch,
	300	int *qerr)
	301	{
	302	struct drr_sched *q = qdisc_priv(sch);
	303	struct drr_class *cl;
	304	struct tcf_result res;
25d8c0d5	305	struct tcf_proto *fl;
13d2a1d2 PM	306	int result;
	307
	308	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0) {
	309	cl = drr_find_class(sch, skb->priority);
	310	if (cl != NULL)
	311	return cl;
	312	}
	313
	314	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_BYPASS;
25d8c0d5	315	fl = rcu_dereference_bh(q->filter_list);
87d83093	316	result = tcf_classify(skb, fl, &res, false);
13d2a1d2 PM	317	if (result >= 0) {
	318	#ifdef CONFIG_NET_CLS_ACT
	319	switch (result) {
	320	case TC_ACT_QUEUED:
	321	case TC_ACT_STOLEN:
e25ea21f	322	case TC_ACT_TRAP:
13d2a1d2	323	*qerr = NET_XMIT_SUCCESS \| __NET_XMIT_STOLEN;
f3ae608e	324	/* fall through */
13d2a1d2 PM	325	case TC_ACT_SHOT:
	326	return NULL;
	327	}
	328	#endif
	329	cl = (struct drr_class *)res.class;
	330	if (cl == NULL)
	331	cl = drr_find_class(sch, res.classid);
	332	return cl;
	333	}
	334	return NULL;
	335	}
	336
520ac30f ED	337	static int drr_enqueue(struct sk_buff skb, struct Qdisc sch,
520ac30f ED	338	struct sk_buff **to_free)
13d2a1d2 PM	339	{
	340	struct drr_sched *q = qdisc_priv(sch);
	341	struct drr_class *cl;
f54ba779	342	int err = 0;
13d2a1d2 PM	343
	344	cl = drr_classify(skb, sch, &err);
	345	if (cl == NULL) {
	346	if (err & __NET_XMIT_BYPASS)
25331d6c	347	qdisc_qstats_drop(sch);
520ac30f	348	__qdisc_drop(skb, to_free);
13d2a1d2 PM	349	return err;
	350	}
	351
520ac30f	352	err = qdisc_enqueue(skb, cl->qdisc, to_free);
13d2a1d2 PM	353	if (unlikely(err != NET_XMIT_SUCCESS)) {
	354	if (net_xmit_drop_count(err)) {
	355	cl->qstats.drops++;
25331d6c	356	qdisc_qstats_drop(sch);
13d2a1d2 PM	357	}
	358	return err;
	359	}
	360
	361	if (cl->qdisc->q.qlen == 1) {
	362	list_add_tail(&cl->alist, &q->active);
	363	cl->deficit = cl->quantum;
	364	}
	365
6a73b571	366	qdisc_qstats_backlog_inc(sch, skb);
13d2a1d2 PM	367	sch->q.qlen++;
	368	return err;
	369	}
	370
	371	static struct sk_buff drr_dequeue(struct Qdisc sch)
	372	{
	373	struct drr_sched *q = qdisc_priv(sch);
	374	struct drr_class *cl;
	375	struct sk_buff *skb;
	376	unsigned int len;
	377
3f0947c3 PM	378	if (list_empty(&q->active))
	379	goto out;
	380	while (1) {
13d2a1d2 PM	381	cl = list_first_entry(&q->active, struct drr_class, alist);
13d2a1d2 PM	382	skb = cl->qdisc->ops->peek(cl->qdisc);
6e765a00 FW	383	if (skb == NULL) {
6e765a00 FW	384	qdisc_warn_nonwc(__func__, cl->qdisc);
3f0947c3	385	goto out;
6e765a00	386	}
13d2a1d2 PM	387
	388	len = qdisc_pkt_len(skb);
	389	if (len <= cl->deficit) {
	390	cl->deficit -= len;
	391	skb = qdisc_dequeue_peeked(cl->qdisc);
df3eb6cd BH	392	if (unlikely(skb == NULL))
df3eb6cd BH	393	goto out;
13d2a1d2 PM	394	if (cl->qdisc->q.qlen == 0)
13d2a1d2 PM	395	list_del(&cl->alist);
2dd875ff ED	396
2dd875ff ED	397	bstats_update(&cl->bstats, skb);
9190b3b3	398	qdisc_bstats_update(sch, skb);
6a73b571	399	qdisc_qstats_backlog_dec(sch, skb);
13d2a1d2 PM	400	sch->q.qlen--;
	401	return skb;
	402	}
	403
	404	cl->deficit += cl->quantum;
13d2a1d2 PM	405	list_move_tail(&cl->alist, &q->active);
13d2a1d2 PM	406	}
3f0947c3	407	out:
13d2a1d2 PM	408	return NULL;
	409	}
	410
e63d7dfd AA	411	static int drr_init_qdisc(struct Qdisc sch, struct nlattr opt,
e63d7dfd AA	412	struct netlink_ext_ack *extack)
13d2a1d2 PM	413	{
	414	struct drr_sched *q = qdisc_priv(sch);
	415	int err;
	416
69d78ef2	417	err = tcf_block_get(&q->block, &q->filter_list, sch);
6529eaba JP	418	if (err)
6529eaba JP	419	return err;
13d2a1d2 PM	420	err = qdisc_class_hash_init(&q->clhash);
	421	if (err < 0)
	422	return err;
	423	INIT_LIST_HEAD(&q->active);
	424	return 0;
	425	}
	426
	427	static void drr_reset_qdisc(struct Qdisc *sch)
	428	{
	429	struct drr_sched *q = qdisc_priv(sch);
	430	struct drr_class *cl;
13d2a1d2 PM	431	unsigned int i;
	432
	433	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	434	hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
13d2a1d2 PM	435	if (cl->qdisc->q.qlen)
	436	list_del(&cl->alist);
	437	qdisc_reset(cl->qdisc);
	438	}
	439	}
6a73b571	440	sch->qstats.backlog = 0;
13d2a1d2 PM	441	sch->q.qlen = 0;
	442	}
	443
	444	static void drr_destroy_qdisc(struct Qdisc *sch)
	445	{
	446	struct drr_sched *q = qdisc_priv(sch);
	447	struct drr_class *cl;
b67bfe0d	448	struct hlist_node *next;
13d2a1d2 PM	449	unsigned int i;
13d2a1d2 PM	450
6529eaba	451	tcf_block_put(q->block);
13d2a1d2 PM	452
13d2a1d2 PM	453	for (i = 0; i < q->clhash.hashsize; i++) {
b67bfe0d	454	hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
13d2a1d2 PM	455	common.hnode)
	456	drr_destroy_class(sch, cl);
	457	}
	458	qdisc_class_hash_destroy(&q->clhash);
	459	}
	460
	461	static const struct Qdisc_class_ops drr_class_ops = {
	462	.change = drr_change_class,
	463	.delete = drr_delete_class,
143976ce	464	.find = drr_search_class,
6529eaba	465	.tcf_block = drr_tcf_block,
13d2a1d2 PM	466	.bind_tcf = drr_bind_tcf,
	467	.unbind_tcf = drr_unbind_tcf,
	468	.graft = drr_graft_class,
	469	.leaf = drr_class_leaf,
	470	.qlen_notify = drr_qlen_notify,
	471	.dump = drr_dump_class,
	472	.dump_stats = drr_dump_class_stats,
	473	.walk = drr_walk,
	474	};
	475
	476	static struct Qdisc_ops drr_qdisc_ops __read_mostly = {
	477	.cl_ops = &drr_class_ops,
	478	.id = "drr",
	479	.priv_size = sizeof(struct drr_sched),
	480	.enqueue = drr_enqueue,
	481	.dequeue = drr_dequeue,
	482	.peek = qdisc_peek_dequeued,
13d2a1d2 PM	483	.init = drr_init_qdisc,
	484	.reset = drr_reset_qdisc,
	485	.destroy = drr_destroy_qdisc,
	486	.owner = THIS_MODULE,
	487	};
	488
	489	static int __init drr_init(void)
	490	{
	491	return register_qdisc(&drr_qdisc_ops);
	492	}
	493
	494	static void __exit drr_exit(void)
	495	{
	496	unregister_qdisc(&drr_qdisc_ops);
	497	}
	498
	499	module_init(drr_init);
	500	module_exit(drr_exit);
	501	MODULE_LICENSE("GPL");