2 * Copyright (c) 2020 The FreeBSD Foundation
4 * This software was developed by Emmanuel Vadot under sponsorship
5 * from the FreeBSD Foundation.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
31 #ifndef _LINUX_REFCOUNT_H
32 #define _LINUX_REFCOUNT_H
34 #include <linux/atomic.h>
36 struct refcount_linux {
39 typedef struct refcount_linux refcount_t;
42 refcount_set(refcount_t *ref, unsigned int i)
44 atomic_set(&ref->value, i);
48 refcount_inc(refcount_t *ref)
50 atomic_inc(&ref->value);
54 refcount_inc_not_zero(refcount_t *ref)
56 return (atomic_inc_not_zero(&ref->value));
60 refcount_dec(refcount_t *ref)
62 atomic_dec(&ref->value);
65 static inline unsigned int
66 refcount_read(refcount_t *ref)
68 return atomic_read(&ref->value);
72 refcount_dec_and_lock_irqsave(refcount_t *ref, spinlock_t *lock,
75 if (atomic_dec_and_test(&ref->value) == true) {
76 spin_lock_irqsave(lock, flags);
82 #endif /* __LINUX_REFCOUNT_H__ */