1 /*-
2 * Copyright (c) 2017 Mellanox Technologies, Ltd.
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 unmodified, this list of conditions, and the following
10 * disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26 #ifndef _LINUXKPI_LINUX_WW_MUTEX_H_
27 #define _LINUXKPI_LINUX_WW_MUTEX_H_
28
29 #include <sys/param.h>
30 #include <sys/proc.h>
31 #include <sys/condvar.h>
32 #include <sys/kernel.h>
33
34 #include <linux/mutex.h>
35
36 struct ww_class {
37 const char *mutex_name;
38 };
39
40 struct ww_acquire_ctx {
41 };
42
43 struct ww_mutex {
44 struct mutex base;
45 struct cv condvar;
46 struct ww_acquire_ctx *ctx;
47 };
48
49 #define DEFINE_WW_CLASS(name) \
50 struct ww_class name = { \
51 .mutex_name = mutex_name(#name "_mutex") \
52 }
53
54 #define DEFINE_WW_MUTEX(name, ww_class) \
55 struct ww_mutex name; \
56 static void name##_init(void *arg) \
57 { \
58 ww_mutex_init(&name, &ww_class); \
59 } \
60 SYSINIT(name, SI_SUB_LOCK, SI_ORDER_SECOND, name##_init, NULL)
61
62 #define DEFINE_WD_CLASS(name) DEFINE_WW_CLASS(name)
63
64 #define ww_mutex_is_locked(_m) \
65 sx_xlocked(&(_m)->base.sx)
66
67 #define ww_mutex_lock_slow(_m, _x) \
68 ww_mutex_lock(_m, _x)
69
70 #define ww_mutex_lock_slow_interruptible(_m, _x) \
71 ww_mutex_lock_interruptible(_m, _x)
72
73 #if defined(LINUXKPI_VERSION) && LINUXKPI_VERSION >= 51600
74 static inline int __must_check
ww_mutex_trylock(struct ww_mutex * lock,struct ww_acquire_ctx * ctx __unused)75 ww_mutex_trylock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx __unused)
76 #else
77 static inline int __must_check
78 ww_mutex_trylock(struct ww_mutex *lock)
79 #endif
80 {
81 return (mutex_trylock(&lock->base));
82 }
83
84 extern int linux_ww_mutex_lock_sub(struct ww_mutex *,
85 struct ww_acquire_ctx *, int catch_signal);
86
87 static inline int
ww_mutex_lock(struct ww_mutex * lock,struct ww_acquire_ctx * ctx)88 ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
89 {
90 if (MUTEX_SKIP())
91 return (0);
92 else if ((struct thread *)SX_OWNER(lock->base.sx.sx_lock) == curthread)
93 return (-EALREADY);
94 else
95 return (linux_ww_mutex_lock_sub(lock, ctx, 0));
96 }
97
98 static inline int
ww_mutex_lock_interruptible(struct ww_mutex * lock,struct ww_acquire_ctx * ctx)99 ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
100 {
101 if (MUTEX_SKIP())
102 return (0);
103 else if ((struct thread *)SX_OWNER(lock->base.sx.sx_lock) == curthread)
104 return (-EALREADY);
105 else
106 return (linux_ww_mutex_lock_sub(lock, ctx, 1));
107 }
108
109 extern void linux_ww_mutex_unlock_sub(struct ww_mutex *);
110
111 static inline void
ww_mutex_unlock(struct ww_mutex * lock)112 ww_mutex_unlock(struct ww_mutex *lock)
113 {
114 if (MUTEX_SKIP())
115 return;
116 else
117 linux_ww_mutex_unlock_sub(lock);
118 }
119
120 static inline void
ww_mutex_destroy(struct ww_mutex * lock)121 ww_mutex_destroy(struct ww_mutex *lock)
122 {
123 cv_destroy(&lock->condvar);
124 mutex_destroy(&lock->base);
125 }
126
127 static inline void
ww_acquire_init(struct ww_acquire_ctx * ctx,struct ww_class * ww_class)128 ww_acquire_init(struct ww_acquire_ctx *ctx, struct ww_class *ww_class)
129 {
130 }
131
132 static inline void
ww_mutex_init(struct ww_mutex * lock,struct ww_class * ww_class)133 ww_mutex_init(struct ww_mutex *lock, struct ww_class *ww_class)
134 {
135 linux_mutex_init(&lock->base, ww_class->mutex_name, SX_NOWITNESS);
136 cv_init(&lock->condvar, "lkpi-ww");
137 }
138
139 static inline void
ww_acquire_fini(struct ww_acquire_ctx * ctx)140 ww_acquire_fini(struct ww_acquire_ctx *ctx)
141 {
142 }
143
144 static inline void
ww_acquire_done(struct ww_acquire_ctx * ctx)145 ww_acquire_done(struct ww_acquire_ctx *ctx)
146 {
147 }
148
149 #endif /* _LINUXKPI_LINUX_WW_MUTEX_H_ */
150