sys/compat/linuxkpi/common/include/linux/ww_mutex.h

   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 _LINUX_WW_MUTEX_H_
  29 #define _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
  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 *, int catch_signal);
  80
  81 static inline int
  82 ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
  83 {
  84         if (MUTEX_SKIP())
  85                 return (0);
  86         else if ((struct thread *)SX_OWNER(lock->base.sx.sx_lock) == curthread)
  87                 return (-EALREADY);
  88         else
  89                 return (linux_ww_mutex_lock_sub(lock, 0));
  90 }
  91
  92 static inline int
  93 ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
  94 {
  95         if (MUTEX_SKIP())
  96                 return (0);
  97         else if ((struct thread *)SX_OWNER(lock->base.sx.sx_lock) == curthread)
  98                 return (-EALREADY);
  99         else
 100                 return (linux_ww_mutex_lock_sub(lock, 1));
 101 }
 102
 103 extern void linux_ww_mutex_unlock_sub(struct ww_mutex *);
 104
 105 static inline void
 106 ww_mutex_unlock(struct ww_mutex *lock)
 107 {
 108         if (MUTEX_SKIP())
 109                 return;
 110         else
 111                 linux_ww_mutex_unlock_sub(lock);
 112 }
 113
 114 static inline void
 115 ww_mutex_destroy(struct ww_mutex *lock)
 116 {
 117         cv_destroy(&lock->condvar);
 118         mutex_destroy(&lock->base);
 119 }
 120
 121 static inline void
 122 ww_acquire_init(struct ww_acquire_ctx *ctx, struct ww_class *ww_class)
 123 {
 124 }
 125
 126 static inline void
 127 ww_mutex_init(struct ww_mutex *lock, struct ww_class *ww_class)
 128 {
 129         linux_mutex_init(&lock->base, ww_class->mutex_name, SX_NOWITNESS);
 130         cv_init(&lock->condvar, "lkpi-ww");
 131 }
 132
 133 static inline void
 134 ww_acquire_fini(struct ww_acquire_ctx *ctx)
 135 {
 136 }
 137
 138 static inline void
 139 ww_acquire_done(struct ww_acquire_ctx *ctx)
 140 {
 141 }
 142
 143 #endif                                  /* _LINUX_WW_MUTEX_H_ */