1 /*-
2 * Copyright (c) 2020 The FreeBSD Foundation
3 *
4 * This software was developed by Emmanuel Vadot under sponsorship
5 * from the FreeBSD Foundation.
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 #ifndef _LINUXKPI_LINUX_REFCOUNT_H
30 #define _LINUXKPI_LINUX_REFCOUNT_H
31
32 #include <linux/atomic.h>
33 #include <linux/spinlock.h>
34
35 typedef atomic_t refcount_t;
36
37 static inline void
refcount_set(refcount_t * ref,unsigned int i)38 refcount_set(refcount_t *ref, unsigned int i)
39 {
40 atomic_set(ref, i);
41 }
42
43 static inline void
refcount_inc(refcount_t * ref)44 refcount_inc(refcount_t *ref)
45 {
46 atomic_inc(ref);
47 }
48
49 static inline bool
refcount_inc_not_zero(refcount_t * ref)50 refcount_inc_not_zero(refcount_t *ref)
51 {
52 return (atomic_inc_not_zero(ref));
53 }
54
55 static inline void
refcount_dec(refcount_t * ref)56 refcount_dec(refcount_t *ref)
57 {
58 atomic_dec(ref);
59 }
60
61 static inline unsigned int
refcount_read(refcount_t * ref)62 refcount_read(refcount_t *ref)
63 {
64 return atomic_read(ref);
65 }
66
67 static inline bool
refcount_dec_and_lock_irqsave(refcount_t * ref,spinlock_t * lock,unsigned long * flags)68 refcount_dec_and_lock_irqsave(refcount_t *ref, spinlock_t *lock,
69 unsigned long *flags)
70 {
71 if (atomic_dec_and_test(ref) == true) {
72 spin_lock_irqsave(lock, flags);
73 return (true);
74 }
75 return (false);
76 }
77
78 static inline bool
refcount_dec_and_test(refcount_t * r)79 refcount_dec_and_test(refcount_t *r)
80 {
81
82 return (atomic_dec_and_test(r));
83 }
84
85 #endif /* __LINUXKPI_LINUX_REFCOUNT_H__ */
86