[linux-block.git] / net / sched / sch_fifo.c

/*
 * net/sched/sch_fifo.c	The simplest FIFO 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>
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <net/pkt_sched.h>

/* 1 band FIFO pseudo-"scheduler" */

struct fifo_sched_data
{
	u32 limit;
};

static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc* sch)
{
	struct fifo_sched_data *q = qdisc_priv(sch);

	if (likely(sch->qstats.backlog + skb->len <= q->limit))
		return qdisc_enqueue_tail(skb, sch);

	return qdisc_reshape_fail(skb, sch);
}

static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc* sch)
{
	struct fifo_sched_data *q = qdisc_priv(sch);

	if (likely(skb_queue_len(&sch->q) < q->limit))
		return qdisc_enqueue_tail(skb, sch);

	return qdisc_reshape_fail(skb, sch);
}

static int fifo_init(struct Qdisc *sch, struct rtattr *opt)
{
	struct fifo_sched_data *q = qdisc_priv(sch);

	if (opt == NULL) {
		u32 limit = sch->dev->tx_queue_len ? : 1;

		if (sch->ops == &bfifo_qdisc_ops)
			limit *= sch->dev->mtu;

		q->limit = limit;
	} else {
		struct tc_fifo_qopt *ctl = RTA_DATA(opt);

		if (RTA_PAYLOAD(opt) < sizeof(*ctl))
			return -EINVAL;

		q->limit = ctl->limit;
	}

	return 0;
}

static int fifo_dump(struct Qdisc *sch, struct sk_buff *skb)
{
	struct fifo_sched_data *q = qdisc_priv(sch);
	struct tc_fifo_qopt opt = { .limit = q->limit };

	RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
	return skb->len;

rtattr_failure:
	return -1;
}

struct Qdisc_ops pfifo_qdisc_ops = {
	.id		=	"pfifo",
	.priv_size	=	sizeof(struct fifo_sched_data),
	.enqueue	=	pfifo_enqueue,
	.dequeue	=	qdisc_dequeue_head,
	.requeue	=	qdisc_requeue,
	.drop		=	qdisc_queue_drop,
	.init		=	fifo_init,
	.reset		=	qdisc_reset_queue,
	.change		=	fifo_init,
	.dump		=	fifo_dump,
	.owner		=	THIS_MODULE,
};

struct Qdisc_ops bfifo_qdisc_ops = {
	.id		=	"bfifo",
	.priv_size	=	sizeof(struct fifo_sched_data),
	.enqueue	=	bfifo_enqueue,
	.dequeue	=	qdisc_dequeue_head,
	.requeue	=	qdisc_requeue,
	.drop		=	qdisc_queue_drop,
	.init		=	fifo_init,
	.reset		=	qdisc_reset_queue,
	.change		=	fifo_init,
	.dump		=	fifo_dump,
	.owner		=	THIS_MODULE,
};

EXPORT_SYMBOL(bfifo_qdisc_ops);
EXPORT_SYMBOL(pfifo_qdisc_ops);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* net/sched/sch_fifo.c The simplest FIFO 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
1da177e4	12	#include <linux/module.h>
1da177e4 LT	13	#include <linux/types.h>
1da177e4 LT	14	#include <linux/kernel.h>
1da177e4	15	#include <linux/errno.h>
1da177e4	16	#include <linux/skbuff.h>
1da177e4 LT	17	#include <net/pkt_sched.h>
	18
	19	/* 1 band FIFO pseudo-"scheduler" */
	20
	21	struct fifo_sched_data
	22	{
6fc8e84f	23	u32 limit;
1da177e4 LT	24	};
1da177e4 LT	25
6fc8e84f	26	static int bfifo_enqueue(struct sk_buff skb, struct Qdisc sch)
1da177e4 LT	27	{
	28	struct fifo_sched_data *q = qdisc_priv(sch);
	29
aaae3013 TG	30	if (likely(sch->qstats.backlog + skb->len <= q->limit))
aaae3013 TG	31	return qdisc_enqueue_tail(skb, sch);
1da177e4	32
aaae3013	33	return qdisc_reshape_fail(skb, sch);
1da177e4 LT	34	}
1da177e4 LT	35
6fc8e84f	36	static int pfifo_enqueue(struct sk_buff skb, struct Qdisc sch)
1da177e4 LT	37	{
	38	struct fifo_sched_data *q = qdisc_priv(sch);
	39
aaae3013 TG	40	if (likely(skb_queue_len(&sch->q) < q->limit))
aaae3013 TG	41	return qdisc_enqueue_tail(skb, sch);
1da177e4	42
aaae3013	43	return qdisc_reshape_fail(skb, sch);
1da177e4 LT	44	}
	45
	46	static int fifo_init(struct Qdisc sch, struct rtattr opt)
	47	{
	48	struct fifo_sched_data *q = qdisc_priv(sch);
	49
	50	if (opt == NULL) {
6fc8e84f	51	u32 limit = sch->dev->tx_queue_len ? : 1;
1da177e4 LT	52
1da177e4 LT	53	if (sch->ops == &bfifo_qdisc_ops)
6fc8e84f TG	54	limit *= sch->dev->mtu;
	55
	56	q->limit = limit;
1da177e4 LT	57	} else {
1da177e4 LT	58	struct tc_fifo_qopt *ctl = RTA_DATA(opt);
6fc8e84f TG	59
6fc8e84f TG	60	if (RTA_PAYLOAD(opt) < sizeof(*ctl))
1da177e4	61	return -EINVAL;
6fc8e84f	62
1da177e4 LT	63	q->limit = ctl->limit;
1da177e4 LT	64	}
6fc8e84f	65
1da177e4 LT	66	return 0;
	67	}
	68
	69	static int fifo_dump(struct Qdisc sch, struct sk_buff skb)
	70	{
	71	struct fifo_sched_data *q = qdisc_priv(sch);
6fc8e84f	72	struct tc_fifo_qopt opt = { .limit = q->limit };
1da177e4	73
1da177e4	74	RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
1da177e4 LT	75	return skb->len;
	76
	77	rtattr_failure:
1da177e4 LT	78	return -1;
	79	}
	80
	81	struct Qdisc_ops pfifo_qdisc_ops = {
1da177e4 LT	82	.id = "pfifo",
	83	.priv_size = sizeof(struct fifo_sched_data),
	84	.enqueue = pfifo_enqueue,
aaae3013 TG	85	.dequeue = qdisc_dequeue_head,
	86	.requeue = qdisc_requeue,
	87	.drop = qdisc_queue_drop,
1da177e4	88	.init = fifo_init,
aaae3013	89	.reset = qdisc_reset_queue,
1da177e4 LT	90	.change = fifo_init,
	91	.dump = fifo_dump,
	92	.owner = THIS_MODULE,
	93	};
	94
	95	struct Qdisc_ops bfifo_qdisc_ops = {
1da177e4 LT	96	.id = "bfifo",
	97	.priv_size = sizeof(struct fifo_sched_data),
	98	.enqueue = bfifo_enqueue,
aaae3013 TG	99	.dequeue = qdisc_dequeue_head,
	100	.requeue = qdisc_requeue,
	101	.drop = qdisc_queue_drop,
1da177e4	102	.init = fifo_init,
aaae3013	103	.reset = qdisc_reset_queue,
1da177e4 LT	104	.change = fifo_init,
	105	.dump = fifo_dump,
	106	.owner = THIS_MODULE,
	107	};
	108
	109	EXPORT_SYMBOL(bfifo_qdisc_ops);
	110	EXPORT_SYMBOL(pfifo_qdisc_ops);