[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,
	};

	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);
		opt.set.qstats = &sch->qstats;
	} else {
		opt.command = TC_RED_DESTROY;
	}

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

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 netlink_ext_ack *extack)
{
	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,
					 extack);
		if (IS_ERR(child))
			return PTR_ERR(child);

		/* child is fifo, no need to check for 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, extack);
}

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,
		},
	};
	int err;

	sch->flags &= ~TCQ_F_OFFLOADED;

	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
		return 0;

	err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED,
					    &hw_stats);
	if (err == -EOPNOTSUPP)
		return 0;

	if (!err)
		sch->flags |= TCQ_F_OFFLOADED;

	return err;
}

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;

	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 = {0};

	if (sch->flags & TCQ_F_OFFLOADED) {
		struct tc_red_qopt_offload hw_stats_request = {
			.command = TC_RED_XSTATS,
			.handle = sch->handle,
			.parent = sch->parent,
			{
				.xstats = &q->stats,
			},
		};
		dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED,
					      &hw_stats_request);
	}
	st.early = q->stats.prob_drop + q->stats.forced_drop;
	st.pdrop = q->stats.pdrop;
	st.other = q->stats.other;
	st.marked = q->stats.prob_mark + q->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 netlink_ext_ack *extack)
{
	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	};
	160
	161	if (!tc_can_offload(dev) \|\| !dev->netdev_ops->ndo_setup_tc)
	162	return -EOPNOTSUPP;
	163
	164	if (enable) {
	165	opt.command = TC_RED_REPLACE;
	166	opt.set.min = q->parms.qth_min >> q->parms.Wlog;
	167	opt.set.max = q->parms.qth_max >> q->parms.Wlog;
	168	opt.set.probability = q->parms.max_P;
	169	opt.set.is_ecn = red_use_ecn(q);
416ef9b1	170	opt.set.qstats = &sch->qstats;
602f3baf NF	171	} else {
	172	opt.command = TC_RED_DESTROY;
	173	}
	174
8234af2d	175	return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED, &opt);
602f3baf NF	176	}
602f3baf NF	177
f38c39d6 PM	178	static void red_destroy(struct Qdisc *sch)
	179	{
	180	struct red_sched_data *q = qdisc_priv(sch);
8af2a218 ED	181
8af2a218 ED	182	del_timer_sync(&q->adapt_timer);
602f3baf	183	red_offload(sch, false);
f38c39d6 PM	184	qdisc_destroy(q->qdisc);
	185	}
	186
27a3421e PM	187	static const struct nla_policy red_policy[TCA_RED_MAX + 1] = {
	188	[TCA_RED_PARMS] = { .len = sizeof(struct tc_red_qopt) },
	189	[TCA_RED_STAB] = { .len = RED_STAB_SIZE },
a73ed26b	190	[TCA_RED_MAX_P] = { .type = NLA_U32 },
27a3421e PM	191	};
27a3421e PM	192
2030721c AA	193	static int red_change(struct Qdisc sch, struct nlattr opt,
2030721c AA	194	struct netlink_ext_ack *extack)
1da177e4 LT	195	{
1da177e4 LT	196	struct red_sched_data *q = qdisc_priv(sch);
1e90474c	197	struct nlattr *tb[TCA_RED_MAX + 1];
1da177e4	198	struct tc_red_qopt *ctl;
f38c39d6	199	struct Qdisc *child = NULL;
cee63723	200	int err;
a73ed26b	201	u32 max_P;
1da177e4	202
cee63723	203	if (opt == NULL)
dba051f3 TG	204	return -EINVAL;
dba051f3 TG	205
fceb6435	206	err = nla_parse_nested(tb, TCA_RED_MAX, opt, red_policy, NULL);
cee63723 PM	207	if (err < 0)
	208	return err;
	209
1e90474c	210	if (tb[TCA_RED_PARMS] == NULL \|\|
27a3421e	211	tb[TCA_RED_STAB] == NULL)
1da177e4 LT	212	return -EINVAL;
1da177e4 LT	213
a73ed26b ED	214	max_P = tb[TCA_RED_MAX_P] ? nla_get_u32(tb[TCA_RED_MAX_P]) : 0;
a73ed26b ED	215
1e90474c	216	ctl = nla_data(tb[TCA_RED_PARMS]);
8afa10cb NF	217	if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog))
8afa10cb NF	218	return -EINVAL;
1da177e4	219
f38c39d6	220	if (ctl->limit > 0) {
a38a9882 AA	221	child = fifo_create_dflt(sch, &bfifo_qdisc_ops, ctl->limit,
a38a9882 AA	222	extack);
fb0305ce PM	223	if (IS_ERR(child))
fb0305ce PM	224	return PTR_ERR(child);
f38c39d6	225
44a63b13	226	/* child is fifo, no need to check for noop_qdisc */
49b49971	227	qdisc_hash_add(child, true);
44a63b13 PA	228	}
44a63b13 PA	229
1da177e4 LT	230	sch_tree_lock(sch);
1da177e4 LT	231	q->flags = ctl->flags;
1da177e4	232	q->limit = ctl->limit;
5e50da01	233	if (child) {
2ccccf5f WC	234	qdisc_tree_reduce_backlog(q->qdisc, q->qdisc->q.qlen,
2ccccf5f WC	235	q->qdisc->qstats.backlog);
b94c8afc PM	236	qdisc_destroy(q->qdisc);
b94c8afc PM	237	q->qdisc = child;
5e50da01	238	}
1da177e4	239
eeca6688 ED	240	red_set_parms(&q->parms,
eeca6688 ED	241	ctl->qth_min, ctl->qth_max, ctl->Wlog,
a73ed26b ED	242	ctl->Plog, ctl->Scell_log,
	243	nla_data(tb[TCA_RED_STAB]),
	244	max_P);
eeca6688	245	red_set_vars(&q->vars);
6b31b28a	246
8af2a218 ED	247	del_timer(&q->adapt_timer);
	248	if (ctl->flags & TC_RED_ADAPTATIVE)
	249	mod_timer(&q->adapt_timer, jiffies + HZ/2);
	250
1ee5fa1e	251	if (!q->qdisc->q.qlen)
eeca6688	252	red_start_of_idle_period(&q->vars);
dba051f3	253
1da177e4	254	sch_tree_unlock(sch);
602f3baf	255	red_offload(sch, true);
1da177e4 LT	256	return 0;
	257	}
	258
cdeabbb8	259	static inline void red_adaptative_timer(struct timer_list *t)
8af2a218	260	{
cdeabbb8 KC	261	struct red_sched_data *q = from_timer(q, t, adapt_timer);
cdeabbb8 KC	262	struct Qdisc *sch = q->sch;
8af2a218 ED	263	spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch));
	264
	265	spin_lock(root_lock);
eeca6688	266	red_adaptative_algo(&q->parms, &q->vars);
8af2a218 ED	267	mod_timer(&q->adapt_timer, jiffies + HZ/2);
	268	spin_unlock(root_lock);
	269	}
	270
e63d7dfd AA	271	static int red_init(struct Qdisc sch, struct nlattr opt,
e63d7dfd AA	272	struct netlink_ext_ack *extack)
1da177e4	273	{
f38c39d6 PM	274	struct red_sched_data *q = qdisc_priv(sch);
	275
	276	q->qdisc = &noop_qdisc;
cdeabbb8 KC	277	q->sch = sch;
cdeabbb8 KC	278	timer_setup(&q->adapt_timer, red_adaptative_timer, 0);
2030721c	279	return red_change(sch, opt, extack);
1da177e4 LT	280	}
1da177e4 LT	281
428a68af	282	static int red_dump_offload_stats(struct Qdisc sch, struct tc_red_qopt opt)
602f3baf NF	283	{
	284	struct net_device *dev = qdisc_dev(sch);
	285	struct tc_red_qopt_offload hw_stats = {
ee9d3429	286	.command = TC_RED_STATS,
602f3baf NF	287	.handle = sch->handle,
602f3baf NF	288	.parent = sch->parent,
ee9d3429 AM	289	{
	290	.stats.bstats = &sch->bstats,
	291	.stats.qstats = &sch->qstats,
	292	},
602f3baf	293	};
8234af2d NF	294	int err;
	295
	296	sch->flags &= ~TCQ_F_OFFLOADED;
602f3baf	297
8234af2d NF	298	if (!tc_can_offload(dev) \|\| !dev->netdev_ops->ndo_setup_tc)
	299	return 0;
	300
	301	err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED,
	302	&hw_stats);
	303	if (err == -EOPNOTSUPP)
602f3baf NF	304	return 0;
602f3baf NF	305
8234af2d NF	306	if (!err)
	307	sch->flags \|= TCQ_F_OFFLOADED;
	308
	309	return err;
602f3baf NF	310	}
602f3baf NF	311
1da177e4 LT	312	static int red_dump(struct Qdisc sch, struct sk_buff skb)
	313	{
	314	struct red_sched_data *q = qdisc_priv(sch);
1e90474c	315	struct nlattr *opts = NULL;
6b31b28a TG	316	struct tc_red_qopt opt = {
	317	.limit = q->limit,
	318	.flags = q->flags,
	319	.qth_min = q->parms.qth_min >> q->parms.Wlog,
	320	.qth_max = q->parms.qth_max >> q->parms.Wlog,
	321	.Wlog = q->parms.Wlog,
	322	.Plog = q->parms.Plog,
	323	.Scell_log = q->parms.Scell_log,
	324	};
602f3baf	325	int err;
1da177e4	326
428a68af	327	err = red_dump_offload_stats(sch, &opt);
602f3baf NF	328	if (err)
	329	goto nla_put_failure;
	330
1e90474c PM	331	opts = nla_nest_start(skb, TCA_OPTIONS);
	332	if (opts == NULL)
	333	goto nla_put_failure;
1b34ec43 DM	334	if (nla_put(skb, TCA_RED_PARMS, sizeof(opt), &opt) \|\|
	335	nla_put_u32(skb, TCA_RED_MAX_P, q->parms.max_P))
	336	goto nla_put_failure;
1e90474c	337	return nla_nest_end(skb, opts);
1da177e4	338
1e90474c	339	nla_put_failure:
bc3ed28c TG	340	nla_nest_cancel(skb, opts);
bc3ed28c TG	341	return -EMSGSIZE;
1da177e4 LT	342	}
	343
	344	static int red_dump_stats(struct Qdisc sch, struct gnet_dump d)
	345	{
	346	struct red_sched_data *q = qdisc_priv(sch);
602f3baf	347	struct net_device *dev = qdisc_dev(sch);
f8253df5	348	struct tc_red_xstats st = {0};
6b31b28a	349
428a68af	350	if (sch->flags & TCQ_F_OFFLOADED) {
602f3baf	351	struct tc_red_qopt_offload hw_stats_request = {
ee9d3429	352	.command = TC_RED_XSTATS,
602f3baf NF	353	.handle = sch->handle,
602f3baf NF	354	.parent = sch->parent,
ee9d3429	355	{
f8253df5	356	.xstats = &q->stats,
ee9d3429	357	},
602f3baf	358	};
f8253df5 NF	359	dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED,
f8253df5 NF	360	&hw_stats_request);
602f3baf	361	}
f8253df5 NF	362	st.early = q->stats.prob_drop + q->stats.forced_drop;
	363	st.pdrop = q->stats.pdrop;
	364	st.other = q->stats.other;
	365	st.marked = q->stats.prob_mark + q->stats.forced_mark;
602f3baf	366
6b31b28a	367	return gnet_stats_copy_app(d, &st, sizeof(st));
1da177e4 LT	368	}
1da177e4 LT	369
f38c39d6 PM	370	static int red_dump_class(struct Qdisc *sch, unsigned long cl,
	371	struct sk_buff skb, struct tcmsg tcm)
	372	{
	373	struct red_sched_data *q = qdisc_priv(sch);
	374
f38c39d6 PM	375	tcm->tcm_handle \|= TC_H_MIN(1);
	376	tcm->tcm_info = q->qdisc->handle;
	377	return 0;
	378	}
	379
	380	static int red_graft(struct Qdisc sch, unsigned long arg, struct Qdisc new,
653d6fd6	381	struct Qdisc *old, struct netlink_ext_ack extack)
f38c39d6 PM	382	{
	383	struct red_sched_data *q = qdisc_priv(sch);
	384
	385	if (new == NULL)
	386	new = &noop_qdisc;
	387
86a7996c	388	*old = qdisc_replace(sch, new, &q->qdisc);
f38c39d6 PM	389	return 0;
	390	}
	391
	392	static struct Qdisc red_leaf(struct Qdisc sch, unsigned long arg)
	393	{
	394	struct red_sched_data *q = qdisc_priv(sch);
	395	return q->qdisc;
	396	}
	397
143976ce	398	static unsigned long red_find(struct Qdisc *sch, u32 classid)
f38c39d6 PM	399	{
	400	return 1;
	401	}
	402
f38c39d6 PM	403	static void red_walk(struct Qdisc sch, struct qdisc_walker walker)
	404	{
	405	if (!walker->stop) {
	406	if (walker->count >= walker->skip)
	407	if (walker->fn(sch, 1, walker) < 0) {
	408	walker->stop = 1;
	409	return;
	410	}
	411	walker->count++;
	412	}
	413	}
	414
20fea08b	415	static const struct Qdisc_class_ops red_class_ops = {
f38c39d6 PM	416	.graft = red_graft,
f38c39d6 PM	417	.leaf = red_leaf,
143976ce	418	.find = red_find,
f38c39d6	419	.walk = red_walk,
f38c39d6 PM	420	.dump = red_dump_class,
	421	};
	422
20fea08b	423	static struct Qdisc_ops red_qdisc_ops __read_mostly = {
1da177e4 LT	424	.id = "red",
1da177e4 LT	425	.priv_size = sizeof(struct red_sched_data),
f38c39d6	426	.cl_ops = &red_class_ops,
1da177e4 LT	427	.enqueue = red_enqueue,
1da177e4 LT	428	.dequeue = red_dequeue,
8e3af978	429	.peek = red_peek,
1da177e4 LT	430	.init = red_init,
1da177e4 LT	431	.reset = red_reset,
f38c39d6	432	.destroy = red_destroy,
1da177e4 LT	433	.change = red_change,
	434	.dump = red_dump,
	435	.dump_stats = red_dump_stats,
	436	.owner = THIS_MODULE,
	437	};
	438
	439	static int __init red_module_init(void)
	440	{
	441	return register_qdisc(&red_qdisc_ops);
	442	}
dba051f3 TG	443
dba051f3 TG	444	static void __exit red_module_exit(void)
1da177e4 LT	445	{
	446	unregister_qdisc(&red_qdisc_ops);
	447	}
dba051f3	448
1da177e4 LT	449	module_init(red_module_init)
1da177e4 LT	450	module_exit(red_module_exit)
dba051f3	451
1da177e4	452	MODULE_LICENSE("GPL");