2 * net/sched/sch_prio.c Simple 3-band priority "scheduler".
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.
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 * Fixes: 19990609: J Hadi Salim <hadi@nortelnetworks.com>:
11 * Init -- EINVAL when opt undefined
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/string.h>
19 #include <linux/errno.h>
20 #include <linux/skbuff.h>
21 #include <net/netlink.h>
22 #include <net/pkt_sched.h>
23 #include <net/pkt_cls.h>
25 struct prio_sched_data
{
27 struct tcf_proto __rcu
*filter_list
;
28 struct tcf_block
*block
;
29 u8 prio2band
[TC_PRIO_MAX
+1];
30 struct Qdisc
*queues
[TCQ_PRIO_BANDS
];
35 prio_classify(struct sk_buff
*skb
, struct Qdisc
*sch
, int *qerr
)
37 struct prio_sched_data
*q
= qdisc_priv(sch
);
38 u32 band
= skb
->priority
;
39 struct tcf_result res
;
43 *qerr
= NET_XMIT_SUCCESS
| __NET_XMIT_BYPASS
;
44 if (TC_H_MAJ(skb
->priority
) != sch
->handle
) {
45 fl
= rcu_dereference_bh(q
->filter_list
);
46 err
= tcf_classify(skb
, fl
, &res
, false);
47 #ifdef CONFIG_NET_CLS_ACT
52 *qerr
= NET_XMIT_SUCCESS
| __NET_XMIT_STOLEN
;
61 return q
->queues
[q
->prio2band
[band
& TC_PRIO_MAX
]];
65 band
= TC_H_MIN(band
) - 1;
67 return q
->queues
[q
->prio2band
[0]];
69 return q
->queues
[band
];
73 prio_enqueue(struct sk_buff
*skb
, struct Qdisc
*sch
, struct sk_buff
**to_free
)
78 qdisc
= prio_classify(skb
, sch
, &ret
);
79 #ifdef CONFIG_NET_CLS_ACT
82 if (ret
& __NET_XMIT_BYPASS
)
83 qdisc_qstats_drop(sch
);
84 __qdisc_drop(skb
, to_free
);
89 ret
= qdisc_enqueue(skb
, qdisc
, to_free
);
90 if (ret
== NET_XMIT_SUCCESS
) {
91 qdisc_qstats_backlog_inc(sch
, skb
);
93 return NET_XMIT_SUCCESS
;
95 if (net_xmit_drop_count(ret
))
96 qdisc_qstats_drop(sch
);
100 static struct sk_buff
*prio_peek(struct Qdisc
*sch
)
102 struct prio_sched_data
*q
= qdisc_priv(sch
);
105 for (prio
= 0; prio
< q
->bands
; prio
++) {
106 struct Qdisc
*qdisc
= q
->queues
[prio
];
107 struct sk_buff
*skb
= qdisc
->ops
->peek(qdisc
);
114 static struct sk_buff
*prio_dequeue(struct Qdisc
*sch
)
116 struct prio_sched_data
*q
= qdisc_priv(sch
);
119 for (prio
= 0; prio
< q
->bands
; prio
++) {
120 struct Qdisc
*qdisc
= q
->queues
[prio
];
121 struct sk_buff
*skb
= qdisc_dequeue_peeked(qdisc
);
123 qdisc_bstats_update(sch
, skb
);
124 qdisc_qstats_backlog_dec(sch
, skb
);
134 prio_reset(struct Qdisc
*sch
)
137 struct prio_sched_data
*q
= qdisc_priv(sch
);
139 for (prio
= 0; prio
< q
->bands
; prio
++)
140 qdisc_reset(q
->queues
[prio
]);
141 sch
->qstats
.backlog
= 0;
146 prio_destroy(struct Qdisc
*sch
)
149 struct prio_sched_data
*q
= qdisc_priv(sch
);
151 tcf_block_put(q
->block
);
152 for (prio
= 0; prio
< q
->bands
; prio
++)
153 qdisc_destroy(q
->queues
[prio
]);
156 static int prio_tune(struct Qdisc
*sch
, struct nlattr
*opt
)
158 struct prio_sched_data
*q
= qdisc_priv(sch
);
159 struct Qdisc
*queues
[TCQ_PRIO_BANDS
];
160 int oldbands
= q
->bands
, i
;
161 struct tc_prio_qopt
*qopt
;
163 if (nla_len(opt
) < sizeof(*qopt
))
165 qopt
= nla_data(opt
);
167 if (qopt
->bands
> TCQ_PRIO_BANDS
|| qopt
->bands
< 2)
170 for (i
= 0; i
<= TC_PRIO_MAX
; i
++) {
171 if (qopt
->priomap
[i
] >= qopt
->bands
)
175 /* Before commit, make sure we can allocate all new qdiscs */
176 for (i
= oldbands
; i
< qopt
->bands
; i
++) {
177 queues
[i
] = qdisc_create_dflt(sch
->dev_queue
, &pfifo_qdisc_ops
,
178 TC_H_MAKE(sch
->handle
, i
+ 1));
181 qdisc_destroy(queues
[--i
]);
187 q
->bands
= qopt
->bands
;
188 memcpy(q
->prio2band
, qopt
->priomap
, TC_PRIO_MAX
+1);
190 for (i
= q
->bands
; i
< oldbands
; i
++) {
191 struct Qdisc
*child
= q
->queues
[i
];
193 qdisc_tree_reduce_backlog(child
, child
->q
.qlen
,
194 child
->qstats
.backlog
);
195 qdisc_destroy(child
);
198 for (i
= oldbands
; i
< q
->bands
; i
++) {
199 q
->queues
[i
] = queues
[i
];
200 if (q
->queues
[i
] != &noop_qdisc
)
201 qdisc_hash_add(q
->queues
[i
], true);
204 sch_tree_unlock(sch
);
208 static int prio_init(struct Qdisc
*sch
, struct nlattr
*opt
)
210 struct prio_sched_data
*q
= qdisc_priv(sch
);
216 err
= tcf_block_get(&q
->block
, &q
->filter_list
, sch
);
220 return prio_tune(sch
, opt
);
223 static int prio_dump(struct Qdisc
*sch
, struct sk_buff
*skb
)
225 struct prio_sched_data
*q
= qdisc_priv(sch
);
226 unsigned char *b
= skb_tail_pointer(skb
);
227 struct tc_prio_qopt opt
;
229 opt
.bands
= q
->bands
;
230 memcpy(&opt
.priomap
, q
->prio2band
, TC_PRIO_MAX
+ 1);
232 if (nla_put(skb
, TCA_OPTIONS
, sizeof(opt
), &opt
))
233 goto nla_put_failure
;
242 static int prio_graft(struct Qdisc
*sch
, unsigned long arg
, struct Qdisc
*new,
245 struct prio_sched_data
*q
= qdisc_priv(sch
);
246 unsigned long band
= arg
- 1;
251 *old
= qdisc_replace(sch
, new, &q
->queues
[band
]);
255 static struct Qdisc
*
256 prio_leaf(struct Qdisc
*sch
, unsigned long arg
)
258 struct prio_sched_data
*q
= qdisc_priv(sch
);
259 unsigned long band
= arg
- 1;
261 return q
->queues
[band
];
264 static unsigned long prio_find(struct Qdisc
*sch
, u32 classid
)
266 struct prio_sched_data
*q
= qdisc_priv(sch
);
267 unsigned long band
= TC_H_MIN(classid
);
269 if (band
- 1 >= q
->bands
)
274 static unsigned long prio_bind(struct Qdisc
*sch
, unsigned long parent
, u32 classid
)
276 return prio_find(sch
, classid
);
280 static void prio_unbind(struct Qdisc
*q
, unsigned long cl
)
284 static int prio_dump_class(struct Qdisc
*sch
, unsigned long cl
, struct sk_buff
*skb
,
287 struct prio_sched_data
*q
= qdisc_priv(sch
);
289 tcm
->tcm_handle
|= TC_H_MIN(cl
);
290 tcm
->tcm_info
= q
->queues
[cl
-1]->handle
;
294 static int prio_dump_class_stats(struct Qdisc
*sch
, unsigned long cl
,
297 struct prio_sched_data
*q
= qdisc_priv(sch
);
300 cl_q
= q
->queues
[cl
- 1];
301 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch
),
302 d
, NULL
, &cl_q
->bstats
) < 0 ||
303 gnet_stats_copy_queue(d
, NULL
, &cl_q
->qstats
, cl_q
->q
.qlen
) < 0)
309 static void prio_walk(struct Qdisc
*sch
, struct qdisc_walker
*arg
)
311 struct prio_sched_data
*q
= qdisc_priv(sch
);
317 for (prio
= 0; prio
< q
->bands
; prio
++) {
318 if (arg
->count
< arg
->skip
) {
322 if (arg
->fn(sch
, prio
+ 1, arg
) < 0) {
330 static struct tcf_block
*prio_tcf_block(struct Qdisc
*sch
, unsigned long cl
)
332 struct prio_sched_data
*q
= qdisc_priv(sch
);
339 static const struct Qdisc_class_ops prio_class_ops
= {
344 .tcf_block
= prio_tcf_block
,
345 .bind_tcf
= prio_bind
,
346 .unbind_tcf
= prio_unbind
,
347 .dump
= prio_dump_class
,
348 .dump_stats
= prio_dump_class_stats
,
351 static struct Qdisc_ops prio_qdisc_ops __read_mostly
= {
353 .cl_ops
= &prio_class_ops
,
355 .priv_size
= sizeof(struct prio_sched_data
),
356 .enqueue
= prio_enqueue
,
357 .dequeue
= prio_dequeue
,
361 .destroy
= prio_destroy
,
364 .owner
= THIS_MODULE
,
367 static int __init
prio_module_init(void)
369 return register_qdisc(&prio_qdisc_ops
);
372 static void __exit
prio_module_exit(void)
374 unregister_qdisc(&prio_qdisc_ops
);
377 module_init(prio_module_init
)
378 module_exit(prio_module_exit
)
380 MODULE_LICENSE("GPL");