xref: /freebsd/sys/dev/netmap/netmap_mbq.c (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
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  * $FreeBSD$
31  */
32 
33 
34 #ifdef linux
35 #include "bsd_glue.h"
36 #elif defined (_WIN32)
37 #include "win_glue.h"
38 #else   /* __FreeBSD__ */
39 #include <sys/param.h>
40 #include <sys/lock.h>
41 #include <sys/mutex.h>
42 #include <sys/systm.h>
43 #include <sys/mbuf.h>
44 #endif  /* __FreeBSD__ */
45 
46 #include "netmap_mbq.h"
47 
48 
49 static inline void __mbq_init(struct mbq *q)
50 {
51     q->head = q->tail = NULL;
52     q->count = 0;
53 }
54 
55 
56 void mbq_safe_init(struct mbq *q)
57 {
58     mtx_init(&q->lock, "mbq", NULL, MTX_SPIN);
59     __mbq_init(q);
60 }
61 
62 
63 void mbq_init(struct mbq *q)
64 {
65     __mbq_init(q);
66 }
67 
68 
69 static inline void __mbq_enqueue(struct mbq *q, struct mbuf *m)
70 {
71     m->m_nextpkt = NULL;
72     if (q->tail) {
73         q->tail->m_nextpkt = m;
74         q->tail = m;
75     } else {
76         q->head = q->tail = m;
77     }
78     q->count++;
79 }
80 
81 
82 void mbq_safe_enqueue(struct mbq *q, struct mbuf *m)
83 {
84     mbq_lock(q);
85     __mbq_enqueue(q, m);
86     mbq_unlock(q);
87 }
88 
89 
90 void mbq_enqueue(struct mbq *q, struct mbuf *m)
91 {
92     __mbq_enqueue(q, m);
93 }
94 
95 
96 static inline struct mbuf *__mbq_dequeue(struct mbq *q)
97 {
98     struct mbuf *ret = NULL;
99 
100     if (q->head) {
101         ret = q->head;
102         q->head = ret->m_nextpkt;
103         if (q->head == NULL) {
104             q->tail = NULL;
105         }
106         q->count--;
107         ret->m_nextpkt = NULL;
108     }
109 
110     return ret;
111 }
112 
113 
114 struct mbuf *mbq_safe_dequeue(struct mbq *q)
115 {
116     struct mbuf *ret;
117 
118     mbq_lock(q);
119     ret =  __mbq_dequeue(q);
120     mbq_unlock(q);
121 
122     return ret;
123 }
124 
125 
126 struct mbuf *mbq_dequeue(struct mbq *q)
127 {
128     return __mbq_dequeue(q);
129 }
130 
131 
132 /* XXX seems pointless to have a generic purge */
133 static void __mbq_purge(struct mbq *q, int safe)
134 {
135     struct mbuf *m;
136 
137     for (;;) {
138         m = safe ? mbq_safe_dequeue(q) : mbq_dequeue(q);
139         if (m) {
140             m_freem(m);
141         } else {
142             break;
143         }
144     }
145 }
146 
147 
148 void mbq_purge(struct mbq *q)
149 {
150     __mbq_purge(q, 0);
151 }
152 
153 
154 void mbq_safe_purge(struct mbq *q)
155 {
156     __mbq_purge(q, 1);
157 }
158 
159 
160 void mbq_safe_fini(struct mbq *q)
161 {
162     mtx_destroy(&q->lock);
163 }
164 
165 
166 void mbq_fini(struct mbq *q)
167 {
168 }
169