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> |
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 | }; |
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 | ||
0abf77e5 | 30 | if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <= q->limit)) |
aaae3013 | 31 | return qdisc_enqueue_tail(skb, sch); |
1da177e4 | 32 | |
aaae3013 | 33 | return qdisc_reshape_fail(skb, sch); |
1da177e4 LT |
34 | } |
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)) |
41 | return qdisc_enqueue_tail(skb, sch); | |
1da177e4 | 42 | |
aaae3013 | 43 | return qdisc_reshape_fail(skb, sch); |
1da177e4 LT |
44 | } |
45 | ||
1e90474c | 46 | static int fifo_init(struct Qdisc *sch, struct nlattr *opt) |
1da177e4 LT |
47 | { |
48 | struct fifo_sched_data *q = qdisc_priv(sch); | |
49 | ||
50 | if (opt == NULL) { | |
5ce2d488 | 51 | u32 limit = qdisc_dev(sch)->tx_queue_len ? : 1; |
1da177e4 LT |
52 | |
53 | if (sch->ops == &bfifo_qdisc_ops) | |
5ce2d488 | 54 | limit *= qdisc_dev(sch)->mtu; |
6fc8e84f TG |
55 | |
56 | q->limit = limit; | |
1da177e4 | 57 | } else { |
1e90474c | 58 | struct tc_fifo_qopt *ctl = nla_data(opt); |
6fc8e84f | 59 | |
1e90474c | 60 | if (nla_len(opt) < sizeof(*ctl)) |
1da177e4 | 61 | return -EINVAL; |
6fc8e84f | 62 | |
1da177e4 LT |
63 | q->limit = ctl->limit; |
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 | |
1e90474c | 74 | NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); |
1da177e4 LT |
75 | return skb->len; |
76 | ||
1e90474c | 77 | nla_put_failure: |
1da177e4 LT |
78 | return -1; |
79 | } | |
80 | ||
20fea08b | 81 | struct Qdisc_ops pfifo_qdisc_ops __read_mostly = { |
1da177e4 LT |
82 | .id = "pfifo", |
83 | .priv_size = sizeof(struct fifo_sched_data), | |
84 | .enqueue = pfifo_enqueue, | |
aaae3013 | 85 | .dequeue = qdisc_dequeue_head, |
48a8f519 | 86 | .peek = qdisc_peek_head, |
aaae3013 | 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 | }; | |
62e3ba1b | 94 | EXPORT_SYMBOL(pfifo_qdisc_ops); |
1da177e4 | 95 | |
20fea08b | 96 | struct Qdisc_ops bfifo_qdisc_ops __read_mostly = { |
1da177e4 LT |
97 | .id = "bfifo", |
98 | .priv_size = sizeof(struct fifo_sched_data), | |
99 | .enqueue = bfifo_enqueue, | |
aaae3013 | 100 | .dequeue = qdisc_dequeue_head, |
48a8f519 | 101 | .peek = qdisc_peek_head, |
aaae3013 | 102 | .drop = qdisc_queue_drop, |
1da177e4 | 103 | .init = fifo_init, |
aaae3013 | 104 | .reset = qdisc_reset_queue, |
1da177e4 LT |
105 | .change = fifo_init, |
106 | .dump = fifo_dump, | |
107 | .owner = THIS_MODULE, | |
108 | }; | |
1da177e4 | 109 | EXPORT_SYMBOL(bfifo_qdisc_ops); |
fb0305ce PM |
110 | |
111 | /* Pass size change message down to embedded FIFO */ | |
112 | int fifo_set_limit(struct Qdisc *q, unsigned int limit) | |
113 | { | |
114 | struct nlattr *nla; | |
115 | int ret = -ENOMEM; | |
116 | ||
117 | /* Hack to avoid sending change message to non-FIFO */ | |
118 | if (strncmp(q->ops->id + 1, "fifo", 4) != 0) | |
119 | return 0; | |
120 | ||
121 | nla = kmalloc(nla_attr_size(sizeof(struct tc_fifo_qopt)), GFP_KERNEL); | |
122 | if (nla) { | |
123 | nla->nla_type = RTM_NEWQDISC; | |
124 | nla->nla_len = nla_attr_size(sizeof(struct tc_fifo_qopt)); | |
125 | ((struct tc_fifo_qopt *)nla_data(nla))->limit = limit; | |
126 | ||
127 | ret = q->ops->change(q, nla); | |
128 | kfree(nla); | |
129 | } | |
130 | return ret; | |
131 | } | |
132 | EXPORT_SYMBOL(fifo_set_limit); | |
133 | ||
134 | struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops, | |
135 | unsigned int limit) | |
136 | { | |
137 | struct Qdisc *q; | |
138 | int err = -ENOMEM; | |
139 | ||
5ce2d488 | 140 | q = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue, |
bb949fbd | 141 | ops, TC_H_MAKE(sch->handle, 1)); |
fb0305ce PM |
142 | if (q) { |
143 | err = fifo_set_limit(q, limit); | |
144 | if (err < 0) { | |
145 | qdisc_destroy(q); | |
146 | q = NULL; | |
147 | } | |
148 | } | |
149 | ||
150 | return q ? : ERR_PTR(err); | |
151 | } | |
152 | EXPORT_SYMBOL(fifo_create_dflt); |