1 /*
2 * Copyright (C) 2013-2014 Vincenzo Maffione. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26 /*
27 * $FreeBSD: stable/10/sys/dev/netmap/netmap_mbq.h 270252 2014-08-20 23:34:36Z luigi $
28 */
29
30
31 #ifndef __NETMAP_MBQ_H__
32 #define __NETMAP_MBQ_H__
33
34 /*
35 * These function implement an mbuf tailq with an optional lock.
36 * The base functions act ONLY ON THE QUEUE, whereas the "safe"
37 * variants (mbq_safe_*) also handle the lock.
38 */
39
40 /* XXX probably rely on a previous definition of SPINLOCK_T */
41 #ifdef linux
42 #define SPINLOCK_T safe_spinlock_t
43 #else
44 #define SPINLOCK_T struct mtx
45 #endif
46
47 /* A FIFO queue of mbufs with an optional lock. */
48 struct mbq {
49 struct mbuf *head;
50 struct mbuf *tail;
51 int count;
52 SPINLOCK_T lock;
53 };
54
55 /* XXX "destroy" does not match "init" as a name.
56 * We should also clarify whether init can be used while
57 * holding a lock, and whether mbq_safe_destroy() is a NOP.
58 */
59 void mbq_init(struct mbq *q);
60 void mbq_destroy(struct mbq *q);
61 void mbq_enqueue(struct mbq *q, struct mbuf *m);
62 struct mbuf *mbq_dequeue(struct mbq *q);
63 void mbq_purge(struct mbq *q);
64
65 static inline void
mbq_lock(struct mbq * q)66 mbq_lock(struct mbq *q)
67 {
68 mtx_lock_spin(&q->lock);
69 }
70
71 static inline void
mbq_unlock(struct mbq * q)72 mbq_unlock(struct mbq *q)
73 {
74 mtx_unlock_spin(&q->lock);
75 }
76
77
78 void mbq_safe_init(struct mbq *q);
79 void mbq_safe_destroy(struct mbq *q);
80 void mbq_safe_enqueue(struct mbq *q, struct mbuf *m);
81 struct mbuf *mbq_safe_dequeue(struct mbq *q);
82 void mbq_safe_purge(struct mbq *q);
83
mbq_len(struct mbq * q)84 static inline unsigned int mbq_len(struct mbq *q)
85 {
86 return q->count;
87 }
88
89 #endif /* __NETMAP_MBQ_H_ */
90