blob: fd0591903c8a93b9a1712ded0041a41efa47aa33 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/types.h>
14#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/errno.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/skbuff.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <net/pkt_sched.h>
18
19/* 1 band FIFO pseudo-"scheduler" */
20
21struct fifo_sched_data
22{
Thomas Graf6fc8e842005-06-18 22:58:00 -070023 u32 limit;
Linus Torvalds1da177e2005-04-16 15:20:36 -070024};
25
Thomas Graf6fc8e842005-06-18 22:58:00 -070026static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc* sch)
Linus Torvalds1da177e2005-04-16 15:20:36 -070027{
28 struct fifo_sched_data *q = qdisc_priv(sch);
29
Thomas Grafaaae3012005-06-18 22:57:42 -070030 if (likely(sch->qstats.backlog + skb->len <= q->limit))
31 return qdisc_enqueue_tail(skb, sch);
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
Thomas Grafaaae3012005-06-18 22:57:42 -070033 return qdisc_reshape_fail(skb, sch);
Linus Torvalds1da177e2005-04-16 15:20:36 -070034}
35
Thomas Graf6fc8e842005-06-18 22:58:00 -070036static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc* sch)
Linus Torvalds1da177e2005-04-16 15:20:36 -070037{
38 struct fifo_sched_data *q = qdisc_priv(sch);
39
Thomas Grafaaae3012005-06-18 22:57:42 -070040 if (likely(skb_queue_len(&sch->q) < q->limit))
41 return qdisc_enqueue_tail(skb, sch);
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
Thomas Grafaaae3012005-06-18 22:57:42 -070043 return qdisc_reshape_fail(skb, sch);
Linus Torvalds1da177e2005-04-16 15:20:36 -070044}
45
46static int fifo_init(struct Qdisc *sch, struct rtattr *opt)
47{
48 struct fifo_sched_data *q = qdisc_priv(sch);
49
50 if (opt == NULL) {
Thomas Graf6fc8e842005-06-18 22:58:00 -070051 u32 limit = sch->dev->tx_queue_len ? : 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
53 if (sch->ops == &bfifo_qdisc_ops)
Thomas Graf6fc8e842005-06-18 22:58:00 -070054 limit *= sch->dev->mtu;
55
56 q->limit = limit;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 } else {
58 struct tc_fifo_qopt *ctl = RTA_DATA(opt);
Thomas Graf6fc8e842005-06-18 22:58:00 -070059
60 if (RTA_PAYLOAD(opt) < sizeof(*ctl))
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 return -EINVAL;
Thomas Graf6fc8e842005-06-18 22:58:00 -070062
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 q->limit = ctl->limit;
64 }
Thomas Graf6fc8e842005-06-18 22:58:00 -070065
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 return 0;
67}
68
69static int fifo_dump(struct Qdisc *sch, struct sk_buff *skb)
70{
71 struct fifo_sched_data *q = qdisc_priv(sch);
Thomas Graf6fc8e842005-06-18 22:58:00 -070072 struct tc_fifo_qopt opt = { .limit = q->limit };
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 return skb->len;
76
77rtattr_failure:
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 return -1;
79}
80
Eric Dumazet20fea082007-11-14 01:44:41 -080081struct Qdisc_ops pfifo_qdisc_ops __read_mostly = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 .id = "pfifo",
83 .priv_size = sizeof(struct fifo_sched_data),
84 .enqueue = pfifo_enqueue,
Thomas Grafaaae3012005-06-18 22:57:42 -070085 .dequeue = qdisc_dequeue_head,
86 .requeue = qdisc_requeue,
87 .drop = qdisc_queue_drop,
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 .init = fifo_init,
Thomas Grafaaae3012005-06-18 22:57:42 -070089 .reset = qdisc_reset_queue,
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 .change = fifo_init,
91 .dump = fifo_dump,
92 .owner = THIS_MODULE,
93};
Patrick McHardy62e3ba12008-01-22 22:10:23 -080094EXPORT_SYMBOL(pfifo_qdisc_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
Eric Dumazet20fea082007-11-14 01:44:41 -080096struct Qdisc_ops bfifo_qdisc_ops __read_mostly = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 .id = "bfifo",
98 .priv_size = sizeof(struct fifo_sched_data),
99 .enqueue = bfifo_enqueue,
Thomas Grafaaae3012005-06-18 22:57:42 -0700100 .dequeue = qdisc_dequeue_head,
101 .requeue = qdisc_requeue,
102 .drop = qdisc_queue_drop,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 .init = fifo_init,
Thomas Grafaaae3012005-06-18 22:57:42 -0700104 .reset = qdisc_reset_queue,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 .change = fifo_init,
106 .dump = fifo_dump,
107 .owner = THIS_MODULE,
108};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109EXPORT_SYMBOL(bfifo_qdisc_ops);