1/*
2 * Copyright (C) 2013-2014 Vincenzo Maffione
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *   1. Redistributions of source code must retain the above copyright
9 *      notice, this list of conditions and the following disclaimer.
10 *   2. Redistributions in binary form must reproduce the above copyright
11 *      notice, this list of conditions and the following disclaimer in the
12 *      documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27/*
28 * $FreeBSD: stable/11/sys/dev/netmap/netmap_mbq.c 341477 2018-12-04 17:40:56Z vmaffione $
29 */
30
31
32#ifdef linux
33#include "bsd_glue.h"
34#elif defined (_WIN32)
35#include "win_glue.h"
36#else   /* __FreeBSD__ */
37#include <sys/param.h>
38#include <sys/lock.h>
39#include <sys/mutex.h>
40#include <sys/systm.h>
41#include <sys/mbuf.h>
42#endif  /* __FreeBSD__ */
43
44#include "netmap_mbq.h"
45
46
47static inline void __mbq_init(struct mbq *q)
48{
49    q->head = q->tail = NULL;
50    q->count = 0;
51}
52
53
54void mbq_safe_init(struct mbq *q)
55{
56    mtx_init(&q->lock, "mbq", NULL, MTX_SPIN);
57    __mbq_init(q);
58}
59
60
61void mbq_init(struct mbq *q)
62{
63    __mbq_init(q);
64}
65
66
67static inline void __mbq_enqueue(struct mbq *q, struct mbuf *m)
68{
69    m->m_nextpkt = NULL;
70    if (q->tail) {
71        q->tail->m_nextpkt = m;
72        q->tail = m;
73    } else {
74        q->head = q->tail = m;
75    }
76    q->count++;
77}
78
79
80void mbq_safe_enqueue(struct mbq *q, struct mbuf *m)
81{
82    mbq_lock(q);
83    __mbq_enqueue(q, m);
84    mbq_unlock(q);
85}
86
87
88void mbq_enqueue(struct mbq *q, struct mbuf *m)
89{
90    __mbq_enqueue(q, m);
91}
92
93
94static inline struct mbuf *__mbq_dequeue(struct mbq *q)
95{
96    struct mbuf *ret = NULL;
97
98    if (q->head) {
99        ret = q->head;
100        q->head = ret->m_nextpkt;
101        if (q->head == NULL) {
102            q->tail = NULL;
103        }
104        q->count--;
105        ret->m_nextpkt = NULL;
106    }
107
108    return ret;
109}
110
111
112struct mbuf *mbq_safe_dequeue(struct mbq *q)
113{
114    struct mbuf *ret;
115
116    mbq_lock(q);
117    ret =  __mbq_dequeue(q);
118    mbq_unlock(q);
119
120    return ret;
121}
122
123
124struct mbuf *mbq_dequeue(struct mbq *q)
125{
126    return __mbq_dequeue(q);
127}
128
129
130/* XXX seems pointless to have a generic purge */
131static void __mbq_purge(struct mbq *q, int safe)
132{
133    struct mbuf *m;
134
135    for (;;) {
136        m = safe ? mbq_safe_dequeue(q) : mbq_dequeue(q);
137        if (m) {
138            m_freem(m);
139        } else {
140            break;
141        }
142    }
143}
144
145
146void mbq_purge(struct mbq *q)
147{
148    __mbq_purge(q, 0);
149}
150
151
152void mbq_safe_purge(struct mbq *q)
153{
154    __mbq_purge(q, 1);
155}
156
157
158void mbq_safe_fini(struct mbq *q)
159{
160    mtx_destroy(&q->lock);
161}
162
163
164void mbq_fini(struct mbq *q)
165{
166}
167