1/*
2 * Copyright (C) 2013-2014 Vincenzo Maffione
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *   1. Redistributions of source code must retain the above copyright
9 *      notice, this list of conditions and the following disclaimer.
10 *   2. Redistributions in binary form must reproduce the above copyright
11 *      notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27/*
28 * $FreeBSD: stable/11/sys/dev/netmap/netmap_mbq.h 341477 2018-12-04 17:40:56Z vmaffione $
29 */
30
31
32#ifndef _NET_NETMAP_MBQ_H__
33#define _NET_NETMAP_MBQ_H__
34
35/*
36 * These function implement an mbuf tailq with an optional lock.
37 * The base functions act ONLY ON THE QUEUE, whereas the "safe"
38 * variants (mbq_safe_*) also handle the lock.
39 */
40
41/* XXX probably rely on a previous definition of SPINLOCK_T */
42#ifdef linux
43#define SPINLOCK_T  safe_spinlock_t
44#elif defined (_WIN32)
45#define SPINLOCK_T 	win_spinlock_t
46#else
47#define SPINLOCK_T  struct mtx
48#endif
49
50/* A FIFO queue of mbufs with an optional lock. */
51struct mbq {
52    struct mbuf *head;
53    struct mbuf *tail;
54    int count;
55    SPINLOCK_T lock;
56};
57
58/* We should clarify whether init can be used while
59 * holding a lock, and whether mbq_safe_destroy() is a NOP.
60 */
61void mbq_init(struct mbq *q);
62void mbq_fini(struct mbq *q);
63void mbq_enqueue(struct mbq *q, struct mbuf *m);
64struct mbuf *mbq_dequeue(struct mbq *q);
65void mbq_purge(struct mbq *q);
66
67static inline struct mbuf *
68mbq_peek(struct mbq *q)
69{
70	return q->head;
71}
72
73static inline void
74mbq_lock(struct mbq *q)
75{
76	mtx_lock_spin(&q->lock);
77}
78
79static inline void
80mbq_unlock(struct mbq *q)
81{
82	mtx_unlock_spin(&q->lock);
83}
84
85
86void mbq_safe_init(struct mbq *q);
87void mbq_safe_fini(struct mbq *q);
88void mbq_safe_enqueue(struct mbq *q, struct mbuf *m);
89struct mbuf *mbq_safe_dequeue(struct mbq *q);
90void mbq_safe_purge(struct mbq *q);
91
92static inline unsigned int mbq_len(struct mbq *q)
93{
94    return q->count;
95}
96
97#endif /* _NET_NETMAP_MBQ_H_ */
98