1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (C) 2013-2014 Vincenzo Maffione
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 /*
30 */
31
32
33 #ifndef _NET_NETMAP_MBQ_H__
34 #define _NET_NETMAP_MBQ_H__
35
36 /*
37 * These function implement an mbuf tailq with an optional lock.
38 * The base functions act ONLY ON THE QUEUE, whereas the "safe"
39 * variants (mbq_safe_*) also handle the lock.
40 */
41
42 /* XXX probably rely on a previous definition of SPINLOCK_T */
43 #ifdef linux
44 #define SPINLOCK_T safe_spinlock_t
45 #elif defined (_WIN32)
46 #define SPINLOCK_T win_spinlock_t
47 #else
48 #define SPINLOCK_T struct mtx
49 #endif
50
51 /* A FIFO queue of mbufs with an optional lock. */
52 struct mbq {
53 struct mbuf *head;
54 struct mbuf *tail;
55 int count;
56 SPINLOCK_T lock;
57 };
58
59 /* We should clarify whether init can be used while
60 * holding a lock, and whether mbq_safe_destroy() is a NOP.
61 */
62 void mbq_init(struct mbq *q);
63 void mbq_fini(struct mbq *q);
64 void mbq_enqueue(struct mbq *q, struct mbuf *m);
65 struct mbuf *mbq_dequeue(struct mbq *q);
66 void mbq_purge(struct mbq *q);
67
68 static inline struct mbuf *
mbq_peek(struct mbq * q)69 mbq_peek(struct mbq *q)
70 {
71 return q->head;
72 }
73
74 static inline void
mbq_lock(struct mbq * q)75 mbq_lock(struct mbq *q)
76 {
77 mtx_lock_spin(&q->lock);
78 }
79
80 static inline void
mbq_unlock(struct mbq * q)81 mbq_unlock(struct mbq *q)
82 {
83 mtx_unlock_spin(&q->lock);
84 }
85
86
87 void mbq_safe_init(struct mbq *q);
88 void mbq_safe_fini(struct mbq *q);
89 void mbq_safe_enqueue(struct mbq *q, struct mbuf *m);
90 struct mbuf *mbq_safe_dequeue(struct mbq *q);
91 void mbq_safe_purge(struct mbq *q);
92
mbq_len(struct mbq * q)93 static inline unsigned int mbq_len(struct mbq *q)
94 {
95 return q->count;
96 }
97
98 #endif /* _NET_NETMAP_MBQ_H_ */
99