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 * $FreeBSD$
27 */
28 #ifndef _LINUXKPI_LINUX_WW_MUTEX_H_
29 #define _LINUXKPI_LINUX_WW_MUTEX_H_
30
31 #include <sys/param.h>
32 #include <sys/proc.h>
33 #include <sys/condvar.h>
34 #include <sys/kernel.h>
35
36 #include <linux/mutex.h>
37
38 struct ww_class {
39 const char *mutex_name;
40 };
41
42 struct ww_acquire_ctx {
43 };
44
45 struct ww_mutex {
46 struct mutex base;
47 struct cv condvar;
48 struct ww_acquire_ctx *ctx;
49 };
50
51 #define DEFINE_WW_CLASS(name) \
52 struct ww_class name = { \
53 .mutex_name = mutex_name(#name "_mutex") \
54 }
55
56 #define DEFINE_WW_MUTEX(name, ww_class) \
57 struct ww_mutex name; \
58 static void name##_init(void *arg) \
59 { \
60 ww_mutex_init(&name, &ww_class); \
61 } \
62 SYSINIT(name, SI_SUB_LOCK, SI_ORDER_SECOND, name##_init, NULL)
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 static inline int __must_check
ww_mutex_trylock(struct ww_mutex * lock)74 ww_mutex_trylock(struct ww_mutex *lock)
75 {
76 return (mutex_trylock(&lock->base));
77 }
78
79 extern int linux_ww_mutex_lock_sub(struct ww_mutex *,
80 struct ww_acquire_ctx *, int catch_signal);
81
82 static inline int
ww_mutex_lock(struct ww_mutex * lock,struct ww_acquire_ctx * ctx)83 ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
84 {
85 if (MUTEX_SKIP())
86 return (0);
87 else if ((struct thread *)SX_OWNER(lock->base.sx.sx_lock) == curthread)
88 return (-EALREADY);
89 else
90 return (linux_ww_mutex_lock_sub(lock, ctx, 0));
91 }
92
93 static inline int
ww_mutex_lock_interruptible(struct ww_mutex * lock,struct ww_acquire_ctx * ctx)94 ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
95 {
96 if (MUTEX_SKIP())
97 return (0);
98 else if ((struct thread *)SX_OWNER(lock->base.sx.sx_lock) == curthread)
99 return (-EALREADY);
100 else
101 return (linux_ww_mutex_lock_sub(lock, ctx, 1));
102 }
103
104 extern void linux_ww_mutex_unlock_sub(struct ww_mutex *);
105
106 static inline void
ww_mutex_unlock(struct ww_mutex * lock)107 ww_mutex_unlock(struct ww_mutex *lock)
108 {
109 if (MUTEX_SKIP())
110 return;
111 else
112 linux_ww_mutex_unlock_sub(lock);
113 }
114
115 static inline void
ww_mutex_destroy(struct ww_mutex * lock)116 ww_mutex_destroy(struct ww_mutex *lock)
117 {
118 cv_destroy(&lock->condvar);
119 mutex_destroy(&lock->base);
120 }
121
122 static inline void
ww_acquire_init(struct ww_acquire_ctx * ctx,struct ww_class * ww_class)123 ww_acquire_init(struct ww_acquire_ctx *ctx, struct ww_class *ww_class)
124 {
125 }
126
127 static inline void
ww_mutex_init(struct ww_mutex * lock,struct ww_class * ww_class)128 ww_mutex_init(struct ww_mutex *lock, struct ww_class *ww_class)
129 {
130 linux_mutex_init(&lock->base, ww_class->mutex_name, SX_NOWITNESS);
131 cv_init(&lock->condvar, "lkpi-ww");
132 }
133
134 static inline void
ww_acquire_fini(struct ww_acquire_ctx * ctx)135 ww_acquire_fini(struct ww_acquire_ctx *ctx)
136 {
137 }
138
139 static inline void
ww_acquire_done(struct ww_acquire_ctx * ctx)140 ww_acquire_done(struct ww_acquire_ctx *ctx)
141 {
142 }
143
144 #endif /* _LINUXKPI_LINUX_WW_MUTEX_H_ */
145