[linux-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.limit = q->limit;
		opt.set.is_ecn = red_use_ecn(q);
		opt.set.is_harddrop = red_use_harddrop(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_put(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 Qdisc *old_child = NULL, *child = NULL;
	struct red_sched_data *q = qdisc_priv(sch);
	struct nlattr *tb[TCA_RED_MAX + 1];
	struct tc_red_qopt *ctl;
	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_flush_backlog(q->qdisc);
		old_child = 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);

	if (old_child)
		qdisc_put(old_child);
	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_offload hw_stats = {
		.command = TC_RED_STATS,
		.handle = sch->handle,
		.parent = sch->parent,
		{
			.stats.bstats = &sch->bstats,
			.stats.qstats = &sch->qstats,
		},
	};

	return qdisc_offload_dump_helper(sch, 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;

	err = red_dump_offload_stats(sch);
	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 void red_graft_offload(struct Qdisc *sch,
			      struct Qdisc *new, struct Qdisc *old,
			      struct netlink_ext_ack *extack)
{
	struct tc_red_qopt_offload graft_offload = {
		.handle		= sch->handle,
		.parent		= sch->parent,
		.child_handle	= new->handle,
		.command	= TC_RED_GRAFT,
	};

	qdisc_offload_graft_helper(qdisc_dev(sch), sch, new, old,
				   TC_SETUP_QDISC_RED, &graft_offload, extack);
}

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);

	red_graft_offload(sch, new, *old, extack);
	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;
c0b7490b	169	opt.set.limit = q->limit;
602f3baf	170	opt.set.is_ecn = red_use_ecn(q);
190852a5	171	opt.set.is_harddrop = red_use_harddrop(q);
416ef9b1	172	opt.set.qstats = &sch->qstats;
602f3baf NF	173	} else {
	174	opt.command = TC_RED_DESTROY;
	175	}
	176
8234af2d	177	return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED, &opt);
602f3baf NF	178	}
602f3baf NF	179
f38c39d6 PM	180	static void red_destroy(struct Qdisc *sch)
	181	{
	182	struct red_sched_data *q = qdisc_priv(sch);
8af2a218 ED	183
8af2a218 ED	184	del_timer_sync(&q->adapt_timer);
602f3baf	185	red_offload(sch, false);
86bd446b	186	qdisc_put(q->qdisc);
f38c39d6 PM	187	}
f38c39d6 PM	188
27a3421e PM	189	static const struct nla_policy red_policy[TCA_RED_MAX + 1] = {
	190	[TCA_RED_PARMS] = { .len = sizeof(struct tc_red_qopt) },
	191	[TCA_RED_STAB] = { .len = RED_STAB_SIZE },
a73ed26b	192	[TCA_RED_MAX_P] = { .type = NLA_U32 },
27a3421e PM	193	};
27a3421e PM	194
2030721c AA	195	static int red_change(struct Qdisc sch, struct nlattr opt,
2030721c AA	196	struct netlink_ext_ack *extack)
1da177e4	197	{
0c8d13ac	198	struct Qdisc old_child = NULL, child = NULL;
1da177e4	199	struct red_sched_data *q = qdisc_priv(sch);
1e90474c	200	struct nlattr *tb[TCA_RED_MAX + 1];
1da177e4	201	struct tc_red_qopt *ctl;
cee63723	202	int err;
a73ed26b	203	u32 max_P;
1da177e4	204
cee63723	205	if (opt == NULL)
dba051f3 TG	206	return -EINVAL;
dba051f3 TG	207
fceb6435	208	err = nla_parse_nested(tb, TCA_RED_MAX, opt, red_policy, NULL);
cee63723 PM	209	if (err < 0)
	210	return err;
	211
1e90474c	212	if (tb[TCA_RED_PARMS] == NULL \|\|
27a3421e	213	tb[TCA_RED_STAB] == NULL)
1da177e4 LT	214	return -EINVAL;
1da177e4 LT	215
a73ed26b ED	216	max_P = tb[TCA_RED_MAX_P] ? nla_get_u32(tb[TCA_RED_MAX_P]) : 0;
a73ed26b ED	217
1e90474c	218	ctl = nla_data(tb[TCA_RED_PARMS]);
8afa10cb NF	219	if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog))
8afa10cb NF	220	return -EINVAL;
1da177e4	221
f38c39d6	222	if (ctl->limit > 0) {
a38a9882 AA	223	child = fifo_create_dflt(sch, &bfifo_qdisc_ops, ctl->limit,
a38a9882 AA	224	extack);
fb0305ce PM	225	if (IS_ERR(child))
fb0305ce PM	226	return PTR_ERR(child);
f38c39d6	227
44a63b13	228	/* child is fifo, no need to check for noop_qdisc */
49b49971	229	qdisc_hash_add(child, true);
44a63b13 PA	230	}
44a63b13 PA	231
1da177e4 LT	232	sch_tree_lock(sch);
1da177e4 LT	233	q->flags = ctl->flags;
1da177e4	234	q->limit = ctl->limit;
5e50da01	235	if (child) {
e5f0e8f8	236	qdisc_tree_flush_backlog(q->qdisc);
0c8d13ac	237	old_child = q->qdisc;
b94c8afc	238	q->qdisc = child;
5e50da01	239	}
1da177e4	240
eeca6688 ED	241	red_set_parms(&q->parms,
eeca6688 ED	242	ctl->qth_min, ctl->qth_max, ctl->Wlog,
a73ed26b ED	243	ctl->Plog, ctl->Scell_log,
	244	nla_data(tb[TCA_RED_STAB]),
	245	max_P);
eeca6688	246	red_set_vars(&q->vars);
6b31b28a	247
8af2a218 ED	248	del_timer(&q->adapt_timer);
	249	if (ctl->flags & TC_RED_ADAPTATIVE)
	250	mod_timer(&q->adapt_timer, jiffies + HZ/2);
	251
1ee5fa1e	252	if (!q->qdisc->q.qlen)
eeca6688	253	red_start_of_idle_period(&q->vars);
dba051f3	254
1da177e4	255	sch_tree_unlock(sch);
0c8d13ac	256
602f3baf	257	red_offload(sch, true);
0c8d13ac JK	258
	259	if (old_child)
	260	qdisc_put(old_child);
1da177e4 LT	261	return 0;
	262	}
	263
cdeabbb8	264	static inline void red_adaptative_timer(struct timer_list *t)
8af2a218	265	{
cdeabbb8 KC	266	struct red_sched_data *q = from_timer(q, t, adapt_timer);
cdeabbb8 KC	267	struct Qdisc *sch = q->sch;
8af2a218 ED	268	spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch));
	269
	270	spin_lock(root_lock);
eeca6688	271	red_adaptative_algo(&q->parms, &q->vars);
8af2a218 ED	272	mod_timer(&q->adapt_timer, jiffies + HZ/2);
	273	spin_unlock(root_lock);
	274	}
	275
e63d7dfd AA	276	static int red_init(struct Qdisc sch, struct nlattr opt,
e63d7dfd AA	277	struct netlink_ext_ack *extack)
1da177e4	278	{
f38c39d6 PM	279	struct red_sched_data *q = qdisc_priv(sch);
	280
	281	q->qdisc = &noop_qdisc;
cdeabbb8 KC	282	q->sch = sch;
cdeabbb8 KC	283	timer_setup(&q->adapt_timer, red_adaptative_timer, 0);
2030721c	284	return red_change(sch, opt, extack);
1da177e4 LT	285	}
1da177e4 LT	286
dad54c0f	287	static int red_dump_offload_stats(struct Qdisc *sch)
602f3baf	288	{
602f3baf	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	};
8234af2d	298
b592843c	299	return qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_RED, &hw_stats);
602f3baf NF	300	}
602f3baf NF	301
1da177e4 LT	302	static int red_dump(struct Qdisc sch, struct sk_buff skb)
	303	{
	304	struct red_sched_data *q = qdisc_priv(sch);
1e90474c	305	struct nlattr *opts = NULL;
6b31b28a TG	306	struct tc_red_qopt opt = {
	307	.limit = q->limit,
	308	.flags = q->flags,
	309	.qth_min = q->parms.qth_min >> q->parms.Wlog,
	310	.qth_max = q->parms.qth_max >> q->parms.Wlog,
	311	.Wlog = q->parms.Wlog,
	312	.Plog = q->parms.Plog,
	313	.Scell_log = q->parms.Scell_log,
	314	};
602f3baf	315	int err;
1da177e4	316
dad54c0f	317	err = red_dump_offload_stats(sch);
602f3baf NF	318	if (err)
	319	goto nla_put_failure;
	320
1e90474c PM	321	opts = nla_nest_start(skb, TCA_OPTIONS);
	322	if (opts == NULL)
	323	goto nla_put_failure;
1b34ec43 DM	324	if (nla_put(skb, TCA_RED_PARMS, sizeof(opt), &opt) \|\|
	325	nla_put_u32(skb, TCA_RED_MAX_P, q->parms.max_P))
	326	goto nla_put_failure;
1e90474c	327	return nla_nest_end(skb, opts);
1da177e4	328
1e90474c	329	nla_put_failure:
bc3ed28c TG	330	nla_nest_cancel(skb, opts);
bc3ed28c TG	331	return -EMSGSIZE;
1da177e4 LT	332	}
	333
	334	static int red_dump_stats(struct Qdisc sch, struct gnet_dump d)
	335	{
	336	struct red_sched_data *q = qdisc_priv(sch);
602f3baf	337	struct net_device *dev = qdisc_dev(sch);
f8253df5	338	struct tc_red_xstats st = {0};
6b31b28a	339
428a68af	340	if (sch->flags & TCQ_F_OFFLOADED) {
602f3baf	341	struct tc_red_qopt_offload hw_stats_request = {
ee9d3429	342	.command = TC_RED_XSTATS,
602f3baf NF	343	.handle = sch->handle,
602f3baf NF	344	.parent = sch->parent,
ee9d3429	345	{
f8253df5	346	.xstats = &q->stats,
ee9d3429	347	},
602f3baf	348	};
f8253df5 NF	349	dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED,
f8253df5 NF	350	&hw_stats_request);
602f3baf	351	}
f8253df5 NF	352	st.early = q->stats.prob_drop + q->stats.forced_drop;
	353	st.pdrop = q->stats.pdrop;
	354	st.other = q->stats.other;
	355	st.marked = q->stats.prob_mark + q->stats.forced_mark;
602f3baf	356
6b31b28a	357	return gnet_stats_copy_app(d, &st, sizeof(st));
1da177e4 LT	358	}
1da177e4 LT	359
f38c39d6 PM	360	static int red_dump_class(struct Qdisc *sch, unsigned long cl,
	361	struct sk_buff skb, struct tcmsg tcm)
	362	{
	363	struct red_sched_data *q = qdisc_priv(sch);
	364
f38c39d6 PM	365	tcm->tcm_handle \|= TC_H_MIN(1);
	366	tcm->tcm_info = q->qdisc->handle;
	367	return 0;
	368	}
	369
bf2a752b JK	370	static void red_graft_offload(struct Qdisc *sch,
	371	struct Qdisc new, struct Qdisc old,
	372	struct netlink_ext_ack *extack)
	373	{
	374	struct tc_red_qopt_offload graft_offload = {
	375	.handle = sch->handle,
	376	.parent = sch->parent,
	377	.child_handle = new->handle,
	378	.command = TC_RED_GRAFT,
	379	};
	380
	381	qdisc_offload_graft_helper(qdisc_dev(sch), sch, new, old,
	382	TC_SETUP_QDISC_RED, &graft_offload, extack);
	383	}
	384
f38c39d6	385	static int red_graft(struct Qdisc sch, unsigned long arg, struct Qdisc new,
653d6fd6	386	struct Qdisc *old, struct netlink_ext_ack extack)
f38c39d6 PM	387	{
	388	struct red_sched_data *q = qdisc_priv(sch);
	389
	390	if (new == NULL)
	391	new = &noop_qdisc;
	392
86a7996c	393	*old = qdisc_replace(sch, new, &q->qdisc);
bf2a752b JK	394
bf2a752b JK	395	red_graft_offload(sch, new, *old, extack);
f38c39d6 PM	396	return 0;
	397	}
	398
	399	static struct Qdisc red_leaf(struct Qdisc sch, unsigned long arg)
	400	{
	401	struct red_sched_data *q = qdisc_priv(sch);
	402	return q->qdisc;
	403	}
	404
143976ce	405	static unsigned long red_find(struct Qdisc *sch, u32 classid)
f38c39d6 PM	406	{
	407	return 1;
	408	}
	409
f38c39d6 PM	410	static void red_walk(struct Qdisc sch, struct qdisc_walker walker)
	411	{
	412	if (!walker->stop) {
	413	if (walker->count >= walker->skip)
	414	if (walker->fn(sch, 1, walker) < 0) {
	415	walker->stop = 1;
	416	return;
	417	}
	418	walker->count++;
	419	}
	420	}
	421
20fea08b	422	static const struct Qdisc_class_ops red_class_ops = {
f38c39d6 PM	423	.graft = red_graft,
f38c39d6 PM	424	.leaf = red_leaf,
143976ce	425	.find = red_find,
f38c39d6	426	.walk = red_walk,
f38c39d6 PM	427	.dump = red_dump_class,
	428	};
	429
20fea08b	430	static struct Qdisc_ops red_qdisc_ops __read_mostly = {
1da177e4 LT	431	.id = "red",
1da177e4 LT	432	.priv_size = sizeof(struct red_sched_data),
f38c39d6	433	.cl_ops = &red_class_ops,
1da177e4 LT	434	.enqueue = red_enqueue,
1da177e4 LT	435	.dequeue = red_dequeue,
8e3af978	436	.peek = red_peek,
1da177e4 LT	437	.init = red_init,
1da177e4 LT	438	.reset = red_reset,
f38c39d6	439	.destroy = red_destroy,
1da177e4 LT	440	.change = red_change,
	441	.dump = red_dump,
	442	.dump_stats = red_dump_stats,
	443	.owner = THIS_MODULE,
	444	};
	445
	446	static int __init red_module_init(void)
	447	{
	448	return register_qdisc(&red_qdisc_ops);
	449	}
dba051f3 TG	450
dba051f3 TG	451	static void __exit red_module_exit(void)
1da177e4 LT	452	{
	453	unregister_qdisc(&red_qdisc_ops);
	454	}
dba051f3	455
1da177e4 LT	456	module_init(red_module_init)
1da177e4 LT	457	module_exit(red_module_exit)
dba051f3	458
1da177e4	459	MODULE_LICENSE("GPL");