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 * 69 mbq_peek(struct mbq *q) 70 { 71 return q->head; 72 } 73 74 static inline void 75 mbq_lock(struct mbq *q) 76 { 77 mtx_lock_spin(&q->lock); 78 } 79 80 static inline void 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 93 static inline unsigned int mbq_len(struct mbq *q) 94 { 95 return q->count; 96 } 97 98 #endif /* _NET_NETMAP_MBQ_H_ */ 99