LXR linux/drivers/staging/lustre/include/linux/libcfs/linux/linux-lock.h

   1/*
   2 * GPL HEADER START
   3 *
   4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License version 2 only,
   8 * as published by the Free Software Foundation.
   9 *
  10 * This program is distributed in the hope that it will be useful, but
  11 * WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 * General Public License version 2 for more details (a copy is included
  14 * in the LICENSE file that accompanied this code).
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * version 2 along with this program; If not, see
  18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19 *
  20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21 * CA 95054 USA or visit www.sun.com if you need additional information or
  22 * have any questions.
  23 *
  24 * GPL HEADER END
  25 */
  26/*
  27 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  28 * Use is subject to license terms.
  29 *
  30 * Copyright (c) 2012, Intel Corporation.
  31 */
  32/*
  33 * This file is part of Lustre, http://www.lustre.org/
  34 * Lustre is a trademark of Sun Microsystems, Inc.
  35 *
  36 * libcfs/include/libcfs/linux/linux-lock.h
  37 *
  38 * Basic library routines.
  39 */
  40
  41#ifndef __LIBCFS_LINUX_CFS_LOCK_H__
  42#define __LIBCFS_LINUX_CFS_LOCK_H__
  43
  44#ifndef __LIBCFS_LIBCFS_H__
  45#error Do not #include this file directly. #include <linux/libcfs/libcfs.h> instead
  46#endif
  47
  48
  49#include <linux/mutex.h>
  50
  51/*
  52 * IMPORTANT !!!!!!!!
  53 *
  54 * All locks' declaration are not guaranteed to be initialized,
  55 * Althought some of they are initialized in Linux. All locks
  56 * declared by CFS_DECL_* should be initialized explicitly.
  57 */
  58
  59/*
  60 * spin_lock "implementation" (use Linux kernel's primitives)
  61 *
  62 * - spin_lock_init(x)
  63 * - spin_lock(x)
  64 * - spin_lock_bh(x)
  65 * - spin_lock_bh_init(x)
  66 * - spin_unlock(x)
  67 * - spin_unlock_bh(x)
  68 * - spin_trylock(x)
  69 * - spin_is_locked(x)
  70 *
  71 * - spin_lock_irq(x)
  72 * - spin_lock_irqsave(x, f)
  73 * - spin_unlock_irqrestore(x, f)
  74 * - read_lock_irqsave(lock, f)
  75 * - write_lock_irqsave(lock, f)
  76 * - write_unlock_irqrestore(lock, f)
  77 */
  78
  79/*
  80 * spinlock "implementation"
  81 */
  82
  83
  84
  85
  86/*
  87 * rw_semaphore "implementation" (use Linux kernel's primitives)
  88 *
  89 * - sema_init(x)
  90 * - init_rwsem(x)
  91 * - down_read(x)
  92 * - up_read(x)
  93 * - down_write(x)
  94 * - up_write(x)
  95 */
  96
  97
  98#define fini_rwsem(s)           do {} while (0)
  99
 100
 101/*
 102 * rwlock_t "implementation" (use Linux kernel's primitives)
 103 *
 104 * - rwlock_init(x)
 105 * - read_lock(x)
 106 * - read_unlock(x)
 107 * - write_lock(x)
 108 * - write_unlock(x)
 109 * - write_lock_bh(x)
 110 * - write_unlock_bh(x)
 111 *
 112 * - RW_LOCK_UNLOCKED
 113 */
 114
 115
 116#ifndef DEFINE_RWLOCK
 117#define DEFINE_RWLOCK(lock)     rwlock_t lock = __RW_LOCK_UNLOCKED(lock)
 118#endif
 119
 120/*
 121 * completion "implementation" (use Linux kernel's primitives)
 122 *
 123 * - DECLARE_COMPLETION(work)
 124 * - INIT_COMPLETION(c)
 125 * - COMPLETION_INITIALIZER(work)
 126 * - init_completion(c)
 127 * - complete(c)
 128 * - wait_for_completion(c)
 129 * - wait_for_completion_interruptible(c)
 130 * - fini_completion(c)
 131 */
 132#define fini_completion(c) do { } while (0)
 133
 134/*
 135 * semaphore "implementation" (use Linux kernel's primitives)
 136 * - DEFINE_SEMAPHORE(name)
 137 * - sema_init(sem, val)
 138 * - up(sem)
 139 * - down(sem)
 140 * - down_interruptible(sem)
 141 * - down_trylock(sem)
 142 */
 143
 144/*
 145 * mutex "implementation" (use Linux kernel's primitives)
 146 *
 147 * - DEFINE_MUTEX(name)
 148 * - mutex_init(x)
 149 * - mutex_lock(x)
 150 * - mutex_unlock(x)
 151 * - mutex_trylock(x)
 152 * - mutex_is_locked(x)
 153 * - mutex_destroy(x)
 154 */
 155
 156#ifndef lockdep_set_class
 157
 158/**************************************************************************
 159 *
 160 * Lockdep "implementation". Also see liblustre.h
 161 *
 162 **************************************************************************/
 163
 164struct lock_class_key {
 165        ;
 166};
 167
 168#define lockdep_set_class(lock, key) \
 169        do { (void)sizeof(lock); (void)sizeof(key); } while (0)
 170/* This has to be a macro, so that `subclass' can be undefined in kernels
 171 * that do not support lockdep. */
 172
 173
 174static inline void lockdep_off(void)
 175{
 176}
 177
 178static inline void lockdep_on(void)
 179{
 180}
 181#else
 182
 183#endif /* lockdep_set_class */
 184
 185#ifndef CONFIG_DEBUG_LOCK_ALLOC
 186#ifndef mutex_lock_nested
 187#define mutex_lock_nested(mutex, subclass) mutex_lock(mutex)
 188#endif
 189
 190#ifndef spin_lock_nested
 191#define spin_lock_nested(lock, subclass) spin_lock(lock)
 192#endif
 193
 194#ifndef down_read_nested
 195#define down_read_nested(lock, subclass) down_read(lock)
 196#endif
 197
 198#ifndef down_write_nested
 199#define down_write_nested(lock, subclass) down_write(lock)
 200#endif
 201#endif /* CONFIG_DEBUG_LOCK_ALLOC */
 202
 203
 204#endif /* __LIBCFS_LINUX_CFS_LOCK_H__ */
 205