1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 * $FreeBSD$ 31 */ 32 33 34 #ifndef _NET_NETMAP_MBQ_H__ 35 #define _NET_NETMAP_MBQ_H__ 36 37 /* 38 * These function implement an mbuf tailq with an optional lock. 39 * The base functions act ONLY ON THE QUEUE, whereas the "safe" 40 * variants (mbq_safe_*) also handle the lock. 41 */ 42 43 /* XXX probably rely on a previous definition of SPINLOCK_T */ 44 #ifdef linux 45 #define SPINLOCK_T safe_spinlock_t 46 #elif defined (_WIN32) 47 #define SPINLOCK_T win_spinlock_t 48 #else 49 #define SPINLOCK_T struct mtx 50 #endif 51 52 /* A FIFO queue of mbufs with an optional lock. */ 53 struct mbq { 54 struct mbuf *head; 55 struct mbuf *tail; 56 int count; 57 SPINLOCK_T lock; 58 }; 59 60 /* We should clarify whether init can be used while 61 * holding a lock, and whether mbq_safe_destroy() is a NOP. 62 */ 63 void mbq_init(struct mbq *q); 64 void mbq_fini(struct mbq *q); 65 void mbq_enqueue(struct mbq *q, struct mbuf *m); 66 struct mbuf *mbq_dequeue(struct mbq *q); 67 void mbq_purge(struct mbq *q); 68 69 static inline struct mbuf * 70 mbq_peek(struct mbq *q) 71 { 72 return q->head; 73 } 74 75 static inline void 76 mbq_lock(struct mbq *q) 77 { 78 mtx_lock_spin(&q->lock); 79 } 80 81 static inline void 82 mbq_unlock(struct mbq *q) 83 { 84 mtx_unlock_spin(&q->lock); 85 } 86 87 88 void mbq_safe_init(struct mbq *q); 89 void mbq_safe_fini(struct mbq *q); 90 void mbq_safe_enqueue(struct mbq *q, struct mbuf *m); 91 struct mbuf *mbq_safe_dequeue(struct mbq *q); 92 void mbq_safe_purge(struct mbq *q); 93 94 static inline unsigned int mbq_len(struct mbq *q) 95 { 96 return q->count; 97 } 98 99 #endif /* _NET_NETMAP_MBQ_H_ */ 100