Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * net/sched/sch_fifo.c The simplest FIFO queue. | |
4 | * | |
1da177e4 LT |
5 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
6 | */ | |
7 | ||
1da177e4 | 8 | #include <linux/module.h> |
5a0e3ad6 | 9 | #include <linux/slab.h> |
1da177e4 LT |
10 | #include <linux/types.h> |
11 | #include <linux/kernel.h> | |
1da177e4 | 12 | #include <linux/errno.h> |
1da177e4 | 13 | #include <linux/skbuff.h> |
1da177e4 | 14 | #include <net/pkt_sched.h> |
aaca9408 | 15 | #include <net/pkt_cls.h> |
1da177e4 LT |
16 | |
17 | /* 1 band FIFO pseudo-"scheduler" */ | |
18 | ||
520ac30f ED |
19 | static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch, |
20 | struct sk_buff **to_free) | |
1da177e4 | 21 | { |
d276055c | 22 | if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <= sch->limit)) |
aaae3013 | 23 | return qdisc_enqueue_tail(skb, sch); |
1da177e4 | 24 | |
520ac30f | 25 | return qdisc_drop(skb, sch, to_free); |
1da177e4 LT |
26 | } |
27 | ||
520ac30f ED |
28 | static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch, |
29 | struct sk_buff **to_free) | |
1da177e4 | 30 | { |
97d0678f | 31 | if (likely(sch->q.qlen < sch->limit)) |
aaae3013 | 32 | return qdisc_enqueue_tail(skb, sch); |
1da177e4 | 33 | |
520ac30f | 34 | return qdisc_drop(skb, sch, to_free); |
1da177e4 LT |
35 | } |
36 | ||
520ac30f ED |
37 | static int pfifo_tail_enqueue(struct sk_buff *skb, struct Qdisc *sch, |
38 | struct sk_buff **to_free) | |
57dbb2d8 | 39 | { |
6c0d54f1 ED |
40 | unsigned int prev_backlog; |
41 | ||
97d0678f | 42 | if (likely(sch->q.qlen < sch->limit)) |
57dbb2d8 HPP |
43 | return qdisc_enqueue_tail(skb, sch); |
44 | ||
6c0d54f1 | 45 | prev_backlog = sch->qstats.backlog; |
57dbb2d8 | 46 | /* queue full, remove one skb to fulfill the limit */ |
520ac30f | 47 | __qdisc_queue_drop_head(sch, &sch->q, to_free); |
25331d6c | 48 | qdisc_qstats_drop(sch); |
57dbb2d8 HPP |
49 | qdisc_enqueue_tail(skb, sch); |
50 | ||
6c0d54f1 | 51 | qdisc_tree_reduce_backlog(sch, 0, prev_backlog - sch->qstats.backlog); |
57dbb2d8 HPP |
52 | return NET_XMIT_CN; |
53 | } | |
54 | ||
aaca9408 PM |
55 | static void fifo_offload_init(struct Qdisc *sch) |
56 | { | |
57 | struct net_device *dev = qdisc_dev(sch); | |
58 | struct tc_fifo_qopt_offload qopt; | |
59 | ||
60 | if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) | |
61 | return; | |
62 | ||
63 | qopt.command = TC_FIFO_REPLACE; | |
64 | qopt.handle = sch->handle; | |
65 | qopt.parent = sch->parent; | |
66 | dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_FIFO, &qopt); | |
67 | } | |
68 | ||
69 | static void fifo_offload_destroy(struct Qdisc *sch) | |
70 | { | |
71 | struct net_device *dev = qdisc_dev(sch); | |
72 | struct tc_fifo_qopt_offload qopt; | |
73 | ||
74 | if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) | |
75 | return; | |
76 | ||
77 | qopt.command = TC_FIFO_DESTROY; | |
78 | qopt.handle = sch->handle; | |
79 | qopt.parent = sch->parent; | |
80 | dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_FIFO, &qopt); | |
81 | } | |
82 | ||
83 | static int fifo_offload_dump(struct Qdisc *sch) | |
84 | { | |
85 | struct tc_fifo_qopt_offload qopt; | |
86 | ||
87 | qopt.command = TC_FIFO_STATS; | |
88 | qopt.handle = sch->handle; | |
89 | qopt.parent = sch->parent; | |
90 | qopt.stats.bstats = &sch->bstats; | |
91 | qopt.stats.qstats = &sch->qstats; | |
92 | ||
93 | return qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_FIFO, &qopt); | |
94 | } | |
95 | ||
96 | static int __fifo_init(struct Qdisc *sch, struct nlattr *opt, | |
97 | struct netlink_ext_ack *extack) | |
1da177e4 | 98 | { |
23624935 ED |
99 | bool bypass; |
100 | bool is_bfifo = sch->ops == &bfifo_qdisc_ops; | |
1da177e4 LT |
101 | |
102 | if (opt == NULL) { | |
348e3435 | 103 | u32 limit = qdisc_dev(sch)->tx_queue_len; |
1da177e4 | 104 | |
23624935 | 105 | if (is_bfifo) |
6473990c | 106 | limit *= psched_mtu(qdisc_dev(sch)); |
6fc8e84f | 107 | |
d276055c | 108 | sch->limit = limit; |
1da177e4 | 109 | } else { |
1e90474c | 110 | struct tc_fifo_qopt *ctl = nla_data(opt); |
6fc8e84f | 111 | |
1e90474c | 112 | if (nla_len(opt) < sizeof(*ctl)) |
1da177e4 | 113 | return -EINVAL; |
6fc8e84f | 114 | |
d276055c | 115 | sch->limit = ctl->limit; |
1da177e4 | 116 | } |
6fc8e84f | 117 | |
23624935 | 118 | if (is_bfifo) |
d276055c | 119 | bypass = sch->limit >= psched_mtu(qdisc_dev(sch)); |
23624935 | 120 | else |
d276055c | 121 | bypass = sch->limit >= 1; |
23624935 ED |
122 | |
123 | if (bypass) | |
124 | sch->flags |= TCQ_F_CAN_BYPASS; | |
125 | else | |
126 | sch->flags &= ~TCQ_F_CAN_BYPASS; | |
aaca9408 | 127 | |
1da177e4 LT |
128 | return 0; |
129 | } | |
130 | ||
aaca9408 PM |
131 | static int fifo_init(struct Qdisc *sch, struct nlattr *opt, |
132 | struct netlink_ext_ack *extack) | |
133 | { | |
134 | int err; | |
135 | ||
136 | err = __fifo_init(sch, opt, extack); | |
137 | if (err) | |
138 | return err; | |
139 | ||
140 | fifo_offload_init(sch); | |
141 | return 0; | |
142 | } | |
143 | ||
144 | static int fifo_hd_init(struct Qdisc *sch, struct nlattr *opt, | |
145 | struct netlink_ext_ack *extack) | |
146 | { | |
147 | return __fifo_init(sch, opt, extack); | |
148 | } | |
149 | ||
150 | static void fifo_destroy(struct Qdisc *sch) | |
151 | { | |
152 | fifo_offload_destroy(sch); | |
153 | } | |
154 | ||
155 | static int __fifo_dump(struct Qdisc *sch, struct sk_buff *skb) | |
1da177e4 | 156 | { |
d276055c | 157 | struct tc_fifo_qopt opt = { .limit = sch->limit }; |
1da177e4 | 158 | |
1b34ec43 DM |
159 | if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) |
160 | goto nla_put_failure; | |
1da177e4 LT |
161 | return skb->len; |
162 | ||
1e90474c | 163 | nla_put_failure: |
1da177e4 LT |
164 | return -1; |
165 | } | |
166 | ||
aaca9408 PM |
167 | static int fifo_dump(struct Qdisc *sch, struct sk_buff *skb) |
168 | { | |
169 | int err; | |
170 | ||
171 | err = fifo_offload_dump(sch); | |
172 | if (err) | |
173 | return err; | |
174 | ||
175 | return __fifo_dump(sch, skb); | |
176 | } | |
177 | ||
178 | static int fifo_hd_dump(struct Qdisc *sch, struct sk_buff *skb) | |
179 | { | |
180 | return __fifo_dump(sch, skb); | |
181 | } | |
182 | ||
20fea08b | 183 | struct Qdisc_ops pfifo_qdisc_ops __read_mostly = { |
1da177e4 | 184 | .id = "pfifo", |
d276055c | 185 | .priv_size = 0, |
1da177e4 | 186 | .enqueue = pfifo_enqueue, |
aaae3013 | 187 | .dequeue = qdisc_dequeue_head, |
48a8f519 | 188 | .peek = qdisc_peek_head, |
1da177e4 | 189 | .init = fifo_init, |
aaca9408 | 190 | .destroy = fifo_destroy, |
aaae3013 | 191 | .reset = qdisc_reset_queue, |
2030721c | 192 | .change = fifo_init, |
1da177e4 LT |
193 | .dump = fifo_dump, |
194 | .owner = THIS_MODULE, | |
195 | }; | |
62e3ba1b | 196 | EXPORT_SYMBOL(pfifo_qdisc_ops); |
1da177e4 | 197 | |
20fea08b | 198 | struct Qdisc_ops bfifo_qdisc_ops __read_mostly = { |
1da177e4 | 199 | .id = "bfifo", |
d276055c | 200 | .priv_size = 0, |
1da177e4 | 201 | .enqueue = bfifo_enqueue, |
aaae3013 | 202 | .dequeue = qdisc_dequeue_head, |
48a8f519 | 203 | .peek = qdisc_peek_head, |
1da177e4 | 204 | .init = fifo_init, |
aaca9408 | 205 | .destroy = fifo_destroy, |
aaae3013 | 206 | .reset = qdisc_reset_queue, |
2030721c | 207 | .change = fifo_init, |
1da177e4 LT |
208 | .dump = fifo_dump, |
209 | .owner = THIS_MODULE, | |
210 | }; | |
1da177e4 | 211 | EXPORT_SYMBOL(bfifo_qdisc_ops); |
fb0305ce | 212 | |
57dbb2d8 HPP |
213 | struct Qdisc_ops pfifo_head_drop_qdisc_ops __read_mostly = { |
214 | .id = "pfifo_head_drop", | |
d276055c | 215 | .priv_size = 0, |
57dbb2d8 HPP |
216 | .enqueue = pfifo_tail_enqueue, |
217 | .dequeue = qdisc_dequeue_head, | |
218 | .peek = qdisc_peek_head, | |
aaca9408 | 219 | .init = fifo_hd_init, |
57dbb2d8 | 220 | .reset = qdisc_reset_queue, |
aaca9408 PM |
221 | .change = fifo_hd_init, |
222 | .dump = fifo_hd_dump, | |
57dbb2d8 HPP |
223 | .owner = THIS_MODULE, |
224 | }; | |
225 | ||
fb0305ce PM |
226 | /* Pass size change message down to embedded FIFO */ |
227 | int fifo_set_limit(struct Qdisc *q, unsigned int limit) | |
228 | { | |
229 | struct nlattr *nla; | |
230 | int ret = -ENOMEM; | |
231 | ||
232 | /* Hack to avoid sending change message to non-FIFO */ | |
233 | if (strncmp(q->ops->id + 1, "fifo", 4) != 0) | |
234 | return 0; | |
235 | ||
560ee196 ED |
236 | if (!q->ops->change) |
237 | return 0; | |
238 | ||
fb0305ce PM |
239 | nla = kmalloc(nla_attr_size(sizeof(struct tc_fifo_qopt)), GFP_KERNEL); |
240 | if (nla) { | |
241 | nla->nla_type = RTM_NEWQDISC; | |
242 | nla->nla_len = nla_attr_size(sizeof(struct tc_fifo_qopt)); | |
243 | ((struct tc_fifo_qopt *)nla_data(nla))->limit = limit; | |
244 | ||
2030721c | 245 | ret = q->ops->change(q, nla, NULL); |
fb0305ce PM |
246 | kfree(nla); |
247 | } | |
248 | return ret; | |
249 | } | |
250 | EXPORT_SYMBOL(fifo_set_limit); | |
251 | ||
252 | struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops, | |
a38a9882 AA |
253 | unsigned int limit, |
254 | struct netlink_ext_ack *extack) | |
fb0305ce PM |
255 | { |
256 | struct Qdisc *q; | |
257 | int err = -ENOMEM; | |
258 | ||
a38a9882 AA |
259 | q = qdisc_create_dflt(sch->dev_queue, ops, TC_H_MAKE(sch->handle, 1), |
260 | extack); | |
fb0305ce PM |
261 | if (q) { |
262 | err = fifo_set_limit(q, limit); | |
263 | if (err < 0) { | |
86bd446b | 264 | qdisc_put(q); |
fb0305ce PM |
265 | q = NULL; |
266 | } | |
267 | } | |
268 | ||
269 | return q ? : ERR_PTR(err); | |
270 | } | |
271 | EXPORT_SYMBOL(fifo_create_dflt); |