[linux-2.6-block.git] / net / sched / sch_red.c

/*
 * net/sched/sch_red.c	Random Early Detection queue.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 * Changes:
 * J Hadi Salim 980914:	computation fixes
 * Alexey Makarenko <makar@phoenix.kharkov.ua> 990814: qave on idle link was calculated incorrectly.
 * J Hadi Salim 980816:  ECN support
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
#include <net/inet_ecn.h>
#include <net/red.h>


/*	Parameters, settable by user:
	-----------------------------

	limit		- bytes (must be > qth_max + burst)

	Hard limit on queue length, should be chosen >qth_max
	to allow packet bursts. This parameter does not
	affect the algorithms behaviour and can be chosen
	arbitrarily high (well, less than ram size)
	Really, this limit will never be reached
	if RED works correctly.
 */

struct red_sched_data {
	u32			limit;		/* HARD maximal queue length */
	unsigned char		flags;
	struct timer_list	adapt_timer;
	struct Qdisc		*sch;
	struct red_parms	parms;
	struct red_vars		vars;
	struct red_stats	stats;
	struct Qdisc		*qdisc;
};

static inline int red_use_ecn(struct red_sched_data *q)
{
	return q->flags & TC_RED_ECN;
}

static inline int red_use_harddrop(struct red_sched_data *q)
{
	return q->flags & TC_RED_HARDDROP;
}

static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch,
		       struct sk_buff **to_free)
{
	struct red_sched_data *q = qdisc_priv(sch);
	struct Qdisc *child = q->qdisc;
	int ret;

	q->vars.qavg = red_calc_qavg(&q->parms,
				     &q->vars,
				     child->qstats.backlog);

	if (red_is_idling(&q->vars))
		red_end_of_idle_period(&q->vars);

	switch (red_action(&q->parms, &q->vars, q->vars.qavg)) {
	case RED_DONT_MARK:
		break;

	case RED_PROB_MARK:
		qdisc_qstats_overlimit(sch);
		if (!red_use_ecn(q) || !INET_ECN_set_ce(skb)) {
			q->stats.prob_drop++;
			goto congestion_drop;
		}

		q->stats.prob_mark++;
		break;

	case RED_HARD_MARK:
		qdisc_qstats_overlimit(sch);
		if (red_use_harddrop(q) || !red_use_ecn(q) ||
		    !INET_ECN_set_ce(skb)) {
			q->stats.forced_drop++;
			goto congestion_drop;
		}

		q->stats.forced_mark++;
		break;
	}

	ret = qdisc_enqueue(skb, child, to_free);
	if (likely(ret == NET_XMIT_SUCCESS)) {
		qdisc_qstats_backlog_inc(sch, skb);
		sch->q.qlen++;
	} else if (net_xmit_drop_count(ret)) {
		q->stats.pdrop++;
		qdisc_qstats_drop(sch);
	}
	return ret;

congestion_drop:
	qdisc_drop(skb, sch, to_free);
	return NET_XMIT_CN;
}

static struct sk_buff *red_dequeue(struct Qdisc *sch)
{
	struct sk_buff *skb;
	struct red_sched_data *q = qdisc_priv(sch);
	struct Qdisc *child = q->qdisc;

	skb = child->dequeue(child);
	if (skb) {
		qdisc_bstats_update(sch, skb);
		qdisc_qstats_backlog_dec(sch, skb);
		sch->q.qlen--;
	} else {
		if (!red_is_idling(&q->vars))
			red_start_of_idle_period(&q->vars);
	}
	return skb;
}

static struct sk_buff *red_peek(struct Qdisc *sch)
{
	struct red_sched_data *q = qdisc_priv(sch);
	struct Qdisc *child = q->qdisc;

	return child->ops->peek(child);
}

static void red_reset(struct Qdisc *sch)
{
	struct red_sched_data *q = qdisc_priv(sch);

	qdisc_reset(q->qdisc);
	sch->qstats.backlog = 0;
	sch->q.qlen = 0;
	red_restart(&q->vars);
}

static int red_offload(struct Qdisc *sch, bool enable)
{
	struct red_sched_data *q = qdisc_priv(sch);
	struct net_device *dev = qdisc_dev(sch);
	struct tc_red_qopt_offload opt = {
		.handle = sch->handle,
		.parent = sch->parent,
	};
	int err;

	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
		return -EOPNOTSUPP;

	if (enable) {
		opt.command = TC_RED_REPLACE;
		opt.set.min = q->parms.qth_min >> q->parms.Wlog;
		opt.set.max = q->parms.qth_max >> q->parms.Wlog;
		opt.set.probability = q->parms.max_P;
		opt.set.is_ecn = red_use_ecn(q);
	} else {
		opt.command = TC_RED_DESTROY;
	}

	err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED, &opt);

	if (!err && enable)
		sch->flags |= TCQ_F_OFFLOADED;
	else
		sch->flags &= ~TCQ_F_OFFLOADED;

	return err;
}

static void red_destroy(struct Qdisc *sch)
{
	struct red_sched_data *q = qdisc_priv(sch);

	del_timer_sync(&q->adapt_timer);
	red_offload(sch, false);
	qdisc_destroy(q->qdisc);
}

static const struct nla_policy red_policy[TCA_RED_MAX + 1] = {
	[TCA_RED_PARMS]	= { .len = sizeof(struct tc_red_qopt) },
	[TCA_RED_STAB]	= { .len = RED_STAB_SIZE },
	[TCA_RED_MAX_P] = { .type = NLA_U32 },
};

static int red_change(struct Qdisc *sch, struct nlattr *opt)
{
	struct red_sched_data *q = qdisc_priv(sch);
	struct nlattr *tb[TCA_RED_MAX + 1];
	struct tc_red_qopt *ctl;
	struct Qdisc *child = NULL;
	int err;
	u32 max_P;

	if (opt == NULL)
		return -EINVAL;

	err = nla_parse_nested(tb, TCA_RED_MAX, opt, red_policy, NULL);
	if (err < 0)
		return err;

	if (tb[TCA_RED_PARMS] == NULL ||
	    tb[TCA_RED_STAB] == NULL)
		return -EINVAL;

	max_P = tb[TCA_RED_MAX_P] ? nla_get_u32(tb[TCA_RED_MAX_P]) : 0;

	ctl = nla_data(tb[TCA_RED_PARMS]);
	if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog))
		return -EINVAL;

	if (ctl->limit > 0) {
		child = fifo_create_dflt(sch, &bfifo_qdisc_ops, ctl->limit);
		if (IS_ERR(child))
			return PTR_ERR(child);
	}

	if (child != &noop_qdisc)
		qdisc_hash_add(child, true);
	sch_tree_lock(sch);
	q->flags = ctl->flags;
	q->limit = ctl->limit;
	if (child) {
		qdisc_tree_reduce_backlog(q->qdisc, q->qdisc->q.qlen,
					  q->qdisc->qstats.backlog);
		qdisc_destroy(q->qdisc);
		q->qdisc = child;
	}

	red_set_parms(&q->parms,
		      ctl->qth_min, ctl->qth_max, ctl->Wlog,
		      ctl->Plog, ctl->Scell_log,
		      nla_data(tb[TCA_RED_STAB]),
		      max_P);
	red_set_vars(&q->vars);

	del_timer(&q->adapt_timer);
	if (ctl->flags & TC_RED_ADAPTATIVE)
		mod_timer(&q->adapt_timer, jiffies + HZ/2);

	if (!q->qdisc->q.qlen)
		red_start_of_idle_period(&q->vars);

	sch_tree_unlock(sch);
	red_offload(sch, true);
	return 0;
}

static inline void red_adaptative_timer(struct timer_list *t)
{
	struct red_sched_data *q = from_timer(q, t, adapt_timer);
	struct Qdisc *sch = q->sch;
	spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch));

	spin_lock(root_lock);
	red_adaptative_algo(&q->parms, &q->vars);
	mod_timer(&q->adapt_timer, jiffies + HZ/2);
	spin_unlock(root_lock);
}

static int red_init(struct Qdisc *sch, struct nlattr *opt,
		    struct netlink_ext_ack *extack)
{
	struct red_sched_data *q = qdisc_priv(sch);

	q->qdisc = &noop_qdisc;
	q->sch = sch;
	timer_setup(&q->adapt_timer, red_adaptative_timer, 0);
	return red_change(sch, opt);
}

static int red_dump_offload_stats(struct Qdisc *sch, struct tc_red_qopt *opt)
{
	struct net_device *dev = qdisc_dev(sch);
	struct tc_red_qopt_offload hw_stats = {
		.command = TC_RED_STATS,
		.handle = sch->handle,
		.parent = sch->parent,
		{
			.stats.bstats = &sch->bstats,
			.stats.qstats = &sch->qstats,
		},
	};

	if (!(sch->flags & TCQ_F_OFFLOADED))
		return 0;

	return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED,
					     &hw_stats);
}

static int red_dump(struct Qdisc *sch, struct sk_buff *skb)
{
	struct red_sched_data *q = qdisc_priv(sch);
	struct nlattr *opts = NULL;
	struct tc_red_qopt opt = {
		.limit		= q->limit,
		.flags		= q->flags,
		.qth_min	= q->parms.qth_min >> q->parms.Wlog,
		.qth_max	= q->parms.qth_max >> q->parms.Wlog,
		.Wlog		= q->parms.Wlog,
		.Plog		= q->parms.Plog,
		.Scell_log	= q->parms.Scell_log,
	};
	int err;

	sch->qstats.backlog = q->qdisc->qstats.backlog;
	err = red_dump_offload_stats(sch, &opt);
	if (err)
		goto nla_put_failure;

	opts = nla_nest_start(skb, TCA_OPTIONS);
	if (opts == NULL)
		goto nla_put_failure;
	if (nla_put(skb, TCA_RED_PARMS, sizeof(opt), &opt) ||
	    nla_put_u32(skb, TCA_RED_MAX_P, q->parms.max_P))
		goto nla_put_failure;
	return nla_nest_end(skb, opts);

nla_put_failure:
	nla_nest_cancel(skb, opts);
	return -EMSGSIZE;
}

static int red_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
{
	struct red_sched_data *q = qdisc_priv(sch);
	struct net_device *dev = qdisc_dev(sch);
	struct tc_red_xstats st = {
		.early	= q->stats.prob_drop + q->stats.forced_drop,
		.pdrop	= q->stats.pdrop,
		.other	= q->stats.other,
		.marked	= q->stats.prob_mark + q->stats.forced_mark,
	};

	if (sch->flags & TCQ_F_OFFLOADED) {
		struct red_stats hw_stats = {0};
		struct tc_red_qopt_offload hw_stats_request = {
			.command = TC_RED_XSTATS,
			.handle = sch->handle,
			.parent = sch->parent,
			{
				.xstats = &hw_stats,
			},
		};
		if (!dev->netdev_ops->ndo_setup_tc(dev,
						   TC_SETUP_QDISC_RED,
						   &hw_stats_request)) {
			st.early += hw_stats.prob_drop + hw_stats.forced_drop;
			st.pdrop += hw_stats.pdrop;
			st.other += hw_stats.other;
			st.marked += hw_stats.prob_mark + hw_stats.forced_mark;
		}
	}

	return gnet_stats_copy_app(d, &st, sizeof(st));
}

static int red_dump_class(struct Qdisc *sch, unsigned long cl,
			  struct sk_buff *skb, struct tcmsg *tcm)
{
	struct red_sched_data *q = qdisc_priv(sch);

	tcm->tcm_handle |= TC_H_MIN(1);
	tcm->tcm_info = q->qdisc->handle;
	return 0;
}

static int red_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
		     struct Qdisc **old)
{
	struct red_sched_data *q = qdisc_priv(sch);

	if (new == NULL)
		new = &noop_qdisc;

	*old = qdisc_replace(sch, new, &q->qdisc);
	return 0;
}

static struct Qdisc *red_leaf(struct Qdisc *sch, unsigned long arg)
{
	struct red_sched_data *q = qdisc_priv(sch);
	return q->qdisc;
}

static unsigned long red_find(struct Qdisc *sch, u32 classid)
{
	return 1;
}

static void red_walk(struct Qdisc *sch, struct qdisc_walker *walker)
{
	if (!walker->stop) {
		if (walker->count >= walker->skip)
			if (walker->fn(sch, 1, walker) < 0) {
				walker->stop = 1;
				return;
			}
		walker->count++;
	}
}

static const struct Qdisc_class_ops red_class_ops = {
	.graft		=	red_graft,
	.leaf		=	red_leaf,
	.find		=	red_find,
	.walk		=	red_walk,
	.dump		=	red_dump_class,
};

static struct Qdisc_ops red_qdisc_ops __read_mostly = {
	.id		=	"red",
	.priv_size	=	sizeof(struct red_sched_data),
	.cl_ops		=	&red_class_ops,
	.enqueue	=	red_enqueue,
	.dequeue	=	red_dequeue,
	.peek		=	red_peek,
	.init		=	red_init,
	.reset		=	red_reset,
	.destroy	=	red_destroy,
	.change		=	red_change,
	.dump		=	red_dump,
	.dump_stats	=	red_dump_stats,
	.owner		=	THIS_MODULE,
};

static int __init red_module_init(void)
{
	return register_qdisc(&red_qdisc_ops);
}

static void __exit red_module_exit(void)
{
	unregister_qdisc(&red_qdisc_ops);
}

module_init(red_module_init)
module_exit(red_module_exit)

MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* net/sched/sch_red.c Random Early Detection queue.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation; either version
	7	* 2 of the License, or (at your option) any later version.
	8	*
	9	* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
	10	*
	11	* Changes:
dba051f3	12	* J Hadi Salim 980914: computation fixes
1da177e4	13	* Alexey Makarenko <makar@phoenix.kharkov.ua> 990814: qave on idle link was calculated incorrectly.
dba051f3	14	* J Hadi Salim 980816: ECN support
1da177e4 LT	15	*/
1da177e4 LT	16
1da177e4	17	#include <linux/module.h>
1da177e4 LT	18	#include <linux/types.h>
1da177e4 LT	19	#include <linux/kernel.h>
1da177e4	20	#include <linux/skbuff.h>
1da177e4	21	#include <net/pkt_sched.h>
602f3baf	22	#include <net/pkt_cls.h>
1da177e4	23	#include <net/inet_ecn.h>
6b31b28a	24	#include <net/red.h>
1da177e4 LT	25
1da177e4 LT	26
6b31b28a	27	/* Parameters, settable by user:
1da177e4 LT	28	-----------------------------
	29
	30	limit - bytes (must be > qth_max + burst)
	31
	32	Hard limit on queue length, should be chosen >qth_max
	33	to allow packet bursts. This parameter does not
	34	affect the algorithms behaviour and can be chosen
	35	arbitrarily high (well, less than ram size)
	36	Really, this limit will never be reached
	37	if RED works correctly.
1da177e4 LT	38	*/
1da177e4 LT	39
cc7ec456	40	struct red_sched_data {
6b31b28a TG	41	u32 limit; /* HARD maximal queue length */
6b31b28a TG	42	unsigned char flags;
8af2a218	43	struct timer_list adapt_timer;
cdeabbb8	44	struct Qdisc *sch;
6b31b28a	45	struct red_parms parms;
eeca6688	46	struct red_vars vars;
6b31b28a	47	struct red_stats stats;
f38c39d6	48	struct Qdisc *qdisc;
1da177e4 LT	49	};
1da177e4 LT	50
6b31b28a	51	static inline int red_use_ecn(struct red_sched_data *q)
1da177e4	52	{
6b31b28a	53	return q->flags & TC_RED_ECN;
1da177e4 LT	54	}
1da177e4 LT	55
bdc450a0 TG	56	static inline int red_use_harddrop(struct red_sched_data *q)
	57	{
	58	return q->flags & TC_RED_HARDDROP;
	59	}
	60
520ac30f ED	61	static int red_enqueue(struct sk_buff skb, struct Qdisc sch,
520ac30f ED	62	struct sk_buff **to_free)
1da177e4 LT	63	{
1da177e4 LT	64	struct red_sched_data *q = qdisc_priv(sch);
f38c39d6 PM	65	struct Qdisc *child = q->qdisc;
f38c39d6 PM	66	int ret;
1da177e4	67
eeca6688 ED	68	q->vars.qavg = red_calc_qavg(&q->parms,
	69	&q->vars,
	70	child->qstats.backlog);
1da177e4	71
eeca6688 ED	72	if (red_is_idling(&q->vars))
eeca6688 ED	73	red_end_of_idle_period(&q->vars);
1da177e4	74
eeca6688	75	switch (red_action(&q->parms, &q->vars, q->vars.qavg)) {
cc7ec456 ED	76	case RED_DONT_MARK:
	77	break;
	78
	79	case RED_PROB_MARK:
25331d6c	80	qdisc_qstats_overlimit(sch);
cc7ec456 ED	81	if (!red_use_ecn(q) \|\| !INET_ECN_set_ce(skb)) {
	82	q->stats.prob_drop++;
	83	goto congestion_drop;
	84	}
	85
	86	q->stats.prob_mark++;
	87	break;
	88
	89	case RED_HARD_MARK:
25331d6c	90	qdisc_qstats_overlimit(sch);
cc7ec456 ED	91	if (red_use_harddrop(q) \|\| !red_use_ecn(q) \|\|
	92	!INET_ECN_set_ce(skb)) {
	93	q->stats.forced_drop++;
	94	goto congestion_drop;
	95	}
	96
	97	q->stats.forced_mark++;
	98	break;
1da177e4 LT	99	}
1da177e4 LT	100
520ac30f	101	ret = qdisc_enqueue(skb, child, to_free);
f38c39d6	102	if (likely(ret == NET_XMIT_SUCCESS)) {
d7f4f332	103	qdisc_qstats_backlog_inc(sch, skb);
f38c39d6	104	sch->q.qlen++;
378a2f09	105	} else if (net_xmit_drop_count(ret)) {
f38c39d6	106	q->stats.pdrop++;
25331d6c	107	qdisc_qstats_drop(sch);
f38c39d6 PM	108	}
f38c39d6 PM	109	return ret;
6b31b28a TG	110
6b31b28a TG	111	congestion_drop:
520ac30f	112	qdisc_drop(skb, sch, to_free);
1da177e4 LT	113	return NET_XMIT_CN;
	114	}
	115
cc7ec456	116	static struct sk_buff red_dequeue(struct Qdisc sch)
1da177e4 LT	117	{
	118	struct sk_buff *skb;
	119	struct red_sched_data *q = qdisc_priv(sch);
f38c39d6	120	struct Qdisc *child = q->qdisc;
1da177e4	121
f38c39d6	122	skb = child->dequeue(child);
9190b3b3 ED	123	if (skb) {
9190b3b3 ED	124	qdisc_bstats_update(sch, skb);
d7f4f332	125	qdisc_qstats_backlog_dec(sch, skb);
f38c39d6	126	sch->q.qlen--;
9190b3b3	127	} else {
eeca6688 ED	128	if (!red_is_idling(&q->vars))
eeca6688 ED	129	red_start_of_idle_period(&q->vars);
9190b3b3	130	}
9e178ff2	131	return skb;
1da177e4 LT	132	}
1da177e4 LT	133
cc7ec456	134	static struct sk_buff red_peek(struct Qdisc sch)
8e3af978 JP	135	{
	136	struct red_sched_data *q = qdisc_priv(sch);
	137	struct Qdisc *child = q->qdisc;
	138
	139	return child->ops->peek(child);
	140	}
	141
cc7ec456	142	static void red_reset(struct Qdisc *sch)
1da177e4 LT	143	{
	144	struct red_sched_data *q = qdisc_priv(sch);
	145
f38c39d6	146	qdisc_reset(q->qdisc);
d7f4f332	147	sch->qstats.backlog = 0;
f38c39d6	148	sch->q.qlen = 0;
eeca6688	149	red_restart(&q->vars);
1da177e4 LT	150	}
1da177e4 LT	151
602f3baf NF	152	static int red_offload(struct Qdisc *sch, bool enable)
	153	{
	154	struct red_sched_data *q = qdisc_priv(sch);
	155	struct net_device *dev = qdisc_dev(sch);
	156	struct tc_red_qopt_offload opt = {
	157	.handle = sch->handle,
	158	.parent = sch->parent,
	159	};
428a68af	160	int err;
602f3baf NF	161
	162	if (!tc_can_offload(dev) \|\| !dev->netdev_ops->ndo_setup_tc)
	163	return -EOPNOTSUPP;
	164
	165	if (enable) {
	166	opt.command = TC_RED_REPLACE;
	167	opt.set.min = q->parms.qth_min >> q->parms.Wlog;
	168	opt.set.max = q->parms.qth_max >> q->parms.Wlog;
	169	opt.set.probability = q->parms.max_P;
	170	opt.set.is_ecn = red_use_ecn(q);
	171	} else {
	172	opt.command = TC_RED_DESTROY;
	173	}
	174
428a68af YM	175	err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED, &opt);
	176
	177	if (!err && enable)
	178	sch->flags \|= TCQ_F_OFFLOADED;
	179	else
	180	sch->flags &= ~TCQ_F_OFFLOADED;
	181
	182	return err;
602f3baf NF	183	}
602f3baf NF	184
f38c39d6 PM	185	static void red_destroy(struct Qdisc *sch)
	186	{
	187	struct red_sched_data *q = qdisc_priv(sch);
8af2a218 ED	188
8af2a218 ED	189	del_timer_sync(&q->adapt_timer);
602f3baf	190	red_offload(sch, false);
f38c39d6 PM	191	qdisc_destroy(q->qdisc);
	192	}
	193
27a3421e PM	194	static const struct nla_policy red_policy[TCA_RED_MAX + 1] = {
	195	[TCA_RED_PARMS] = { .len = sizeof(struct tc_red_qopt) },
	196	[TCA_RED_STAB] = { .len = RED_STAB_SIZE },
a73ed26b	197	[TCA_RED_MAX_P] = { .type = NLA_U32 },
27a3421e PM	198	};
27a3421e PM	199
1e90474c	200	static int red_change(struct Qdisc sch, struct nlattr opt)
1da177e4 LT	201	{
1da177e4 LT	202	struct red_sched_data *q = qdisc_priv(sch);
1e90474c	203	struct nlattr *tb[TCA_RED_MAX + 1];
1da177e4	204	struct tc_red_qopt *ctl;
f38c39d6	205	struct Qdisc *child = NULL;
cee63723	206	int err;
a73ed26b	207	u32 max_P;
1da177e4	208
cee63723	209	if (opt == NULL)
dba051f3 TG	210	return -EINVAL;
dba051f3 TG	211
fceb6435	212	err = nla_parse_nested(tb, TCA_RED_MAX, opt, red_policy, NULL);
cee63723 PM	213	if (err < 0)
	214	return err;
	215
1e90474c	216	if (tb[TCA_RED_PARMS] == NULL \|\|
27a3421e	217	tb[TCA_RED_STAB] == NULL)
1da177e4 LT	218	return -EINVAL;
1da177e4 LT	219
a73ed26b ED	220	max_P = tb[TCA_RED_MAX_P] ? nla_get_u32(tb[TCA_RED_MAX_P]) : 0;
a73ed26b ED	221
1e90474c	222	ctl = nla_data(tb[TCA_RED_PARMS]);
8afa10cb NF	223	if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog))
8afa10cb NF	224	return -EINVAL;
1da177e4	225
f38c39d6	226	if (ctl->limit > 0) {
fb0305ce PM	227	child = fifo_create_dflt(sch, &bfifo_qdisc_ops, ctl->limit);
	228	if (IS_ERR(child))
	229	return PTR_ERR(child);
f38c39d6 PM	230	}
f38c39d6 PM	231
49b49971 JK	232	if (child != &noop_qdisc)
49b49971 JK	233	qdisc_hash_add(child, true);
1da177e4 LT	234	sch_tree_lock(sch);
1da177e4 LT	235	q->flags = ctl->flags;
1da177e4	236	q->limit = ctl->limit;
5e50da01	237	if (child) {
2ccccf5f WC	238	qdisc_tree_reduce_backlog(q->qdisc, q->qdisc->q.qlen,
2ccccf5f WC	239	q->qdisc->qstats.backlog);
b94c8afc PM	240	qdisc_destroy(q->qdisc);
b94c8afc PM	241	q->qdisc = child;
5e50da01	242	}
1da177e4	243
eeca6688 ED	244	red_set_parms(&q->parms,
eeca6688 ED	245	ctl->qth_min, ctl->qth_max, ctl->Wlog,
a73ed26b ED	246	ctl->Plog, ctl->Scell_log,
	247	nla_data(tb[TCA_RED_STAB]),
	248	max_P);
eeca6688	249	red_set_vars(&q->vars);
6b31b28a	250
8af2a218 ED	251	del_timer(&q->adapt_timer);
	252	if (ctl->flags & TC_RED_ADAPTATIVE)
	253	mod_timer(&q->adapt_timer, jiffies + HZ/2);
	254
1ee5fa1e	255	if (!q->qdisc->q.qlen)
eeca6688	256	red_start_of_idle_period(&q->vars);
dba051f3	257
1da177e4	258	sch_tree_unlock(sch);
602f3baf	259	red_offload(sch, true);
1da177e4 LT	260	return 0;
	261	}
	262
cdeabbb8	263	static inline void red_adaptative_timer(struct timer_list *t)
8af2a218	264	{
cdeabbb8 KC	265	struct red_sched_data *q = from_timer(q, t, adapt_timer);
cdeabbb8 KC	266	struct Qdisc *sch = q->sch;
8af2a218 ED	267	spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch));
	268
	269	spin_lock(root_lock);
eeca6688	270	red_adaptative_algo(&q->parms, &q->vars);
8af2a218 ED	271	mod_timer(&q->adapt_timer, jiffies + HZ/2);
	272	spin_unlock(root_lock);
	273	}
	274
e63d7dfd AA	275	static int red_init(struct Qdisc sch, struct nlattr opt,
e63d7dfd AA	276	struct netlink_ext_ack *extack)
1da177e4	277	{
f38c39d6 PM	278	struct red_sched_data *q = qdisc_priv(sch);
	279
	280	q->qdisc = &noop_qdisc;
cdeabbb8 KC	281	q->sch = sch;
cdeabbb8 KC	282	timer_setup(&q->adapt_timer, red_adaptative_timer, 0);
1da177e4 LT	283	return red_change(sch, opt);
	284	}
	285
428a68af	286	static int red_dump_offload_stats(struct Qdisc sch, struct tc_red_qopt opt)
602f3baf NF	287	{
	288	struct net_device *dev = qdisc_dev(sch);
	289	struct tc_red_qopt_offload hw_stats = {
ee9d3429	290	.command = TC_RED_STATS,
602f3baf NF	291	.handle = sch->handle,
602f3baf NF	292	.parent = sch->parent,
ee9d3429 AM	293	{
	294	.stats.bstats = &sch->bstats,
	295	.stats.qstats = &sch->qstats,
	296	},
602f3baf	297	};
602f3baf	298
428a68af	299	if (!(sch->flags & TCQ_F_OFFLOADED))
602f3baf NF	300	return 0;
602f3baf NF	301
428a68af YM	302	return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED,
428a68af YM	303	&hw_stats);
602f3baf NF	304	}
602f3baf NF	305
1da177e4 LT	306	static int red_dump(struct Qdisc sch, struct sk_buff skb)
	307	{
	308	struct red_sched_data *q = qdisc_priv(sch);
1e90474c	309	struct nlattr *opts = NULL;
6b31b28a TG	310	struct tc_red_qopt opt = {
	311	.limit = q->limit,
	312	.flags = q->flags,
	313	.qth_min = q->parms.qth_min >> q->parms.Wlog,
	314	.qth_max = q->parms.qth_max >> q->parms.Wlog,
	315	.Wlog = q->parms.Wlog,
	316	.Plog = q->parms.Plog,
	317	.Scell_log = q->parms.Scell_log,
	318	};
602f3baf	319	int err;
1da177e4	320
0dfb33a0	321	sch->qstats.backlog = q->qdisc->qstats.backlog;
428a68af	322	err = red_dump_offload_stats(sch, &opt);
602f3baf NF	323	if (err)
	324	goto nla_put_failure;
	325
1e90474c PM	326	opts = nla_nest_start(skb, TCA_OPTIONS);
	327	if (opts == NULL)
	328	goto nla_put_failure;
1b34ec43 DM	329	if (nla_put(skb, TCA_RED_PARMS, sizeof(opt), &opt) \|\|
	330	nla_put_u32(skb, TCA_RED_MAX_P, q->parms.max_P))
	331	goto nla_put_failure;
1e90474c	332	return nla_nest_end(skb, opts);
1da177e4	333
1e90474c	334	nla_put_failure:
bc3ed28c TG	335	nla_nest_cancel(skb, opts);
bc3ed28c TG	336	return -EMSGSIZE;
1da177e4 LT	337	}
	338
	339	static int red_dump_stats(struct Qdisc sch, struct gnet_dump d)
	340	{
	341	struct red_sched_data *q = qdisc_priv(sch);
602f3baf	342	struct net_device *dev = qdisc_dev(sch);
6b31b28a TG	343	struct tc_red_xstats st = {
	344	.early = q->stats.prob_drop + q->stats.forced_drop,
	345	.pdrop = q->stats.pdrop,
	346	.other = q->stats.other,
	347	.marked = q->stats.prob_mark + q->stats.forced_mark,
	348	};
	349
428a68af	350	if (sch->flags & TCQ_F_OFFLOADED) {
602f3baf NF	351	struct red_stats hw_stats = {0};
602f3baf NF	352	struct tc_red_qopt_offload hw_stats_request = {
ee9d3429	353	.command = TC_RED_XSTATS,
602f3baf NF	354	.handle = sch->handle,
602f3baf NF	355	.parent = sch->parent,
ee9d3429 AM	356	{
	357	.xstats = &hw_stats,
	358	},
602f3baf NF	359	};
	360	if (!dev->netdev_ops->ndo_setup_tc(dev,
	361	TC_SETUP_QDISC_RED,
	362	&hw_stats_request)) {
	363	st.early += hw_stats.prob_drop + hw_stats.forced_drop;
	364	st.pdrop += hw_stats.pdrop;
	365	st.other += hw_stats.other;
	366	st.marked += hw_stats.prob_mark + hw_stats.forced_mark;
	367	}
	368	}
	369
6b31b28a	370	return gnet_stats_copy_app(d, &st, sizeof(st));
1da177e4 LT	371	}
1da177e4 LT	372
f38c39d6 PM	373	static int red_dump_class(struct Qdisc *sch, unsigned long cl,
	374	struct sk_buff skb, struct tcmsg tcm)
	375	{
	376	struct red_sched_data *q = qdisc_priv(sch);
	377
f38c39d6 PM	378	tcm->tcm_handle \|= TC_H_MIN(1);
	379	tcm->tcm_info = q->qdisc->handle;
	380	return 0;
	381	}
	382
	383	static int red_graft(struct Qdisc sch, unsigned long arg, struct Qdisc new,
	384	struct Qdisc **old)
	385	{
	386	struct red_sched_data *q = qdisc_priv(sch);
	387
	388	if (new == NULL)
	389	new = &noop_qdisc;
	390
86a7996c	391	*old = qdisc_replace(sch, new, &q->qdisc);
f38c39d6 PM	392	return 0;
	393	}
	394
	395	static struct Qdisc red_leaf(struct Qdisc sch, unsigned long arg)
	396	{
	397	struct red_sched_data *q = qdisc_priv(sch);
	398	return q->qdisc;
	399	}
	400
143976ce	401	static unsigned long red_find(struct Qdisc *sch, u32 classid)
f38c39d6 PM	402	{
	403	return 1;
	404	}
	405
f38c39d6 PM	406	static void red_walk(struct Qdisc sch, struct qdisc_walker walker)
	407	{
	408	if (!walker->stop) {
	409	if (walker->count >= walker->skip)
	410	if (walker->fn(sch, 1, walker) < 0) {
	411	walker->stop = 1;
	412	return;
	413	}
	414	walker->count++;
	415	}
	416	}
	417
20fea08b	418	static const struct Qdisc_class_ops red_class_ops = {
f38c39d6 PM	419	.graft = red_graft,
f38c39d6 PM	420	.leaf = red_leaf,
143976ce	421	.find = red_find,
f38c39d6	422	.walk = red_walk,
f38c39d6 PM	423	.dump = red_dump_class,
	424	};
	425
20fea08b	426	static struct Qdisc_ops red_qdisc_ops __read_mostly = {
1da177e4 LT	427	.id = "red",
1da177e4 LT	428	.priv_size = sizeof(struct red_sched_data),
f38c39d6	429	.cl_ops = &red_class_ops,
1da177e4 LT	430	.enqueue = red_enqueue,
1da177e4 LT	431	.dequeue = red_dequeue,
8e3af978	432	.peek = red_peek,
1da177e4 LT	433	.init = red_init,
1da177e4 LT	434	.reset = red_reset,
f38c39d6	435	.destroy = red_destroy,
1da177e4 LT	436	.change = red_change,
	437	.dump = red_dump,
	438	.dump_stats = red_dump_stats,
	439	.owner = THIS_MODULE,
	440	};
	441
	442	static int __init red_module_init(void)
	443	{
	444	return register_qdisc(&red_qdisc_ops);
	445	}
dba051f3 TG	446
dba051f3 TG	447	static void __exit red_module_exit(void)
1da177e4 LT	448	{
	449	unregister_qdisc(&red_qdisc_ops);
	450	}
dba051f3	451
1da177e4 LT	452	module_init(red_module_init)
1da177e4 LT	453	module_exit(red_module_exit)
dba051f3	454
1da177e4	455	MODULE_LICENSE("GPL");