xref: /freebsd-12.1/sys/dev/netmap/netmap_mbq.c (revision cfbe5d01) 
1 /*
2  * Copyright (C) 2013 Vincenzo Maffione. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *   1. Redistributions of source code must retain the above copyright
8  *      notice, this list of conditions and the following disclaimer.
9  *   2. Redistributions in binary form must reproduce the above copyright
10  *      notice, this list of conditions and the following disclaimer in the
11  *      documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 /*
27  * $FreeBSD$
28  */
29 
30 
31 #ifdef linux
32 #include "bsd_glue.h"
33 #else   /* __FreeBSD__ */
34 #include <sys/param.h>
35 #include <sys/lock.h>
36 #include <sys/mutex.h>
37 #include <sys/systm.h>
38 #include <sys/mbuf.h>
39 #endif  /* __FreeBSD__ */
40 
41 #include "netmap_mbq.h"
42 
43 
44 static inline void __mbq_init(struct mbq *q)
45 {
46     q->head = q->tail = NULL;
47     q->count = 0;
48 }
49 
50 void mbq_safe_init(struct mbq *q)
51 {
52     mtx_init(&q->lock, "mbq", NULL, MTX_SPIN);
53     __mbq_init(q);
54 }
55 
56 void mbq_init(struct mbq *q)
57 {
58     __mbq_init(q);
59 }
60 
61 static inline void __mbq_enqueue(struct mbq *q, struct mbuf *m)
62 {
63     m->m_nextpkt = NULL;
64     if (q->tail) {
65         q->tail->m_nextpkt = m;
66         q->tail = m;
67     } else {
68         q->head = q->tail = m;
69     }
70     q->count++;
71 }
72 
73 void mbq_safe_enqueue(struct mbq *q, struct mbuf *m)
74 {
75     mtx_lock(&q->lock);
76     __mbq_enqueue(q, m);
77     mtx_unlock(&q->lock);
78 }
79 
80 void mbq_enqueue(struct mbq *q, struct mbuf *m)
81 {
82     __mbq_enqueue(q, m);
83 }
84 
85 static inline struct mbuf *__mbq_dequeue(struct mbq *q)
86 {
87     struct mbuf *ret = NULL;
88 
89     if (q->head) {
90         ret = q->head;
91         q->head = ret->m_nextpkt;
92         if (q->head == NULL) {
93             q->tail = NULL;
94         }
95         q->count--;
96         ret->m_nextpkt = NULL;
97     }
98 
99     return ret;
100 }
101 
102 struct mbuf *mbq_safe_dequeue(struct mbq *q)
103 {
104     struct mbuf *ret;
105 
106     mtx_lock(&q->lock);
107     ret =  __mbq_dequeue(q);
108     mtx_unlock(&q->lock);
109 
110     return ret;
111 }
112 
113 struct mbuf *mbq_dequeue(struct mbq *q)
114 {
115     return __mbq_dequeue(q);
116 }
117 
118 /* XXX seems pointless to have a generic purge */
119 static void __mbq_purge(struct mbq *q, int safe)
120 {
121     struct mbuf *m;
122 
123     for (;;) {
124         m = safe ? mbq_safe_dequeue(q) : mbq_dequeue(q);
125         if (m) {
126             m_freem(m);
127         } else {
128             break;
129         }
130     }
131 }
132 
133 void mbq_purge(struct mbq *q)
134 {
135     __mbq_purge(q, 0);
136 }
137 
138 void mbq_safe_purge(struct mbq *q)
139 {
140     __mbq_purge(q, 1);
141 }
142 
143 void mbq_safe_destroy(struct mbq *q)
144 {
145     mtx_destroy(&q->lock);
146 }
147 
148 
149 void mbq_destroy(struct mbq *q)
150 {
151 }
152 
153