1 /*-
2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * Copyright (c) 2013-2017 Mellanox Technologies, Ltd.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice unmodified, this list of conditions, and the following
13 * disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * $FreeBSD$
30 */
31 #ifndef _LINUX_SPINLOCK_H_
32 #define _LINUX_SPINLOCK_H_
33
34 #include <sys/param.h>
35 #include <sys/kernel.h>
36 #include <sys/lock.h>
37 #include <sys/mutex.h>
38 #include <sys/kdb.h>
39
40 #include <linux/compiler.h>
41 #include <linux/rwlock.h>
42 #include <linux/bottom_half.h>
43
44 typedef struct {
45 struct mtx m;
46 } spinlock_t;
47
48 /*
49 * By defining CONFIG_SPIN_SKIP LinuxKPI spinlocks and asserts will be
50 * skipped during panic(). By default it is disabled due to
51 * performance reasons.
52 */
53 #ifdef CONFIG_SPIN_SKIP
54 #define SPIN_SKIP(void) unlikely(SCHEDULER_STOPPED() || kdb_active)
55 #else
56 #define SPIN_SKIP(void) 0
57 #endif
58
59 #define spin_lock(_l) do { \
60 if (SPIN_SKIP()) \
61 break; \
62 mtx_lock(&(_l)->m); \
63 local_bh_disable(); \
64 } while (0)
65
66 #define spin_lock_bh(_l) do { \
67 spin_lock(_l); \
68 } while (0)
69
70 #define spin_lock_irq(_l) do { \
71 spin_lock(_l); \
72 } while (0)
73
74 #define spin_unlock(_l) do { \
75 if (SPIN_SKIP()) \
76 break; \
77 local_bh_enable(); \
78 mtx_unlock(&(_l)->m); \
79 } while (0)
80
81 #define spin_unlock_bh(_l) do { \
82 spin_unlock(_l); \
83 } while (0)
84
85 #define spin_unlock_irq(_l) do { \
86 spin_unlock(_l); \
87 } while (0)
88
89 #define spin_trylock(_l) ({ \
90 int __ret; \
91 if (SPIN_SKIP()) { \
92 __ret = 1; \
93 } else { \
94 __ret = mtx_trylock(&(_l)->m); \
95 if (likely(__ret != 0)) \
96 local_bh_disable(); \
97 } \
98 __ret; \
99 })
100
101 #define spin_trylock_irq(_l) \
102 spin_trylock(_l)
103
104 #define spin_lock_nested(_l, _n) do { \
105 if (SPIN_SKIP()) \
106 break; \
107 mtx_lock_flags(&(_l)->m, MTX_DUPOK); \
108 local_bh_disable(); \
109 } while (0)
110
111 #define spin_lock_irqsave(_l, flags) do { \
112 (flags) = 0; \
113 spin_lock(_l); \
114 } while (0)
115
116 #define spin_lock_irqsave_nested(_l, flags, _n) do { \
117 (flags) = 0; \
118 spin_lock_nested(_l, _n); \
119 } while (0)
120
121 #define spin_unlock_irqrestore(_l, flags) do { \
122 spin_unlock(_l); \
123 } while (0)
124
125 #ifdef WITNESS_ALL
126 /* NOTE: the maximum WITNESS name is 64 chars */
127 #define __spin_lock_name(name, file, line) \
128 (((const char *){file ":" #line "-" name}) + \
129 (sizeof(file) > 16 ? sizeof(file) - 16 : 0))
130 #else
131 #define __spin_lock_name(name, file, line) name
132 #endif
133 #define _spin_lock_name(...) __spin_lock_name(__VA_ARGS__)
134 #define spin_lock_name(name) _spin_lock_name(name, __FILE__, __LINE__)
135
136 #define spin_lock_init(lock) linux_spin_lock_init(lock, spin_lock_name("lnxspin"))
137
138 static inline void
linux_spin_lock_init(spinlock_t * lock,const char * name)139 linux_spin_lock_init(spinlock_t *lock, const char *name)
140 {
141
142 memset(lock, 0, sizeof(*lock));
143 mtx_init(&lock->m, name, NULL, MTX_DEF | MTX_NOWITNESS);
144 }
145
146 static inline void
spin_lock_destroy(spinlock_t * lock)147 spin_lock_destroy(spinlock_t *lock)
148 {
149
150 mtx_destroy(&lock->m);
151 }
152
153 #define DEFINE_SPINLOCK(lock) \
154 spinlock_t lock; \
155 MTX_SYSINIT(lock, &(lock).m, spin_lock_name("lnxspin"), MTX_DEF)
156
157 #define assert_spin_locked(_l) do { \
158 if (SPIN_SKIP()) \
159 break; \
160 mtx_assert(&(_l)->m, MA_OWNED); \
161 } while (0)
162
163 #endif /* _LINUX_SPINLOCK_H_ */
164