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 * $FreeBSD$
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. */
48struct 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 */
59void mbq_init(struct mbq *q);
60void mbq_destroy(struct mbq *q);
61void mbq_enqueue(struct mbq *q, struct mbuf *m);
62struct mbuf *mbq_dequeue(struct mbq *q);
63void mbq_purge(struct mbq *q);
64
65/* XXX missing mbq_lock() and mbq_unlock */
66
67void mbq_safe_init(struct mbq *q);
68void mbq_safe_destroy(struct mbq *q);
69void mbq_safe_enqueue(struct mbq *q, struct mbuf *m);
70struct mbuf *mbq_safe_dequeue(struct mbq *q);
71void mbq_safe_purge(struct mbq *q);
72
73static inline unsigned int mbq_len(struct mbq *q)
74{
75    return q->count;
76}
77
78#endif /* __NETMAP_MBQ_H_ */
79