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

   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
 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
 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_ */