libcfs/include/libcfs/linux/linux-lock.h

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright  2008 Sun Microsystems, Inc. All rights reserved
  30  * Use is subject to license terms.
  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 <libcfs/libcfs.h> instead
  46 #endif
  47
  48 #ifndef __KERNEL__
  49 #error This include is only for kernel use.
  50 #endif
  51
  52 #include <linux/smp_lock.h>
  53 #include <linux/mutex.h>
  54
  55 /*
  56  * IMPORTANT !!!!!!!!
  57  *
  58  * All locks' declaration are not guaranteed to be initialized,
  59  * Althought some of they are initialized in Linux. All locks
  60  * declared by CFS_DECL_* should be initialized explicitly.
  61  */
  62
  63 /*
  64  * spin_lock "implementation" (use Linux kernel's primitives)
  65  *
  66  * - spin_lock_init(x)
  67  * - spin_lock(x)
  68  * - spin_lock_bh(x)
  69  * - spin_lock_bh_init(x)
  70  * - spin_unlock(x)
  71  * - spin_unlock_bh(x)
  72  * - spin_trylock(x)
  73  * - spin_is_locked(x)
  74  *
  75  * - spin_lock_irq(x)
  76  * - spin_lock_irqsave(x, f)
  77  * - spin_unlock_irqrestore(x, f)
  78  * - read_lock_irqsave(lock, f)
  79  * - write_lock_irqsave(lock, f)
  80  * - write_unlock_irqrestore(lock, f)
  81  *
  82  * - SPIN_LOCK_UNLOCKED
  83  */
  84
  85 /*
  86  * spinlock "implementation"
  87  */
  88
  89 typedef spinlock_t cfs_spinlock_t;
  90
  91 #define cfs_spin_lock_init(lock)             spin_lock_init(lock)
  92 #define cfs_spin_lock(lock)                  spin_lock(lock)
  93 #define cfs_spin_lock_bh(lock)               spin_lock_bh(lock)
  94 #define cfs_spin_lock_bh_init(lock)          spin_lock_bh_init(lock)
  95 #define cfs_spin_unlock(lock)                spin_unlock(lock)
  96 #define cfs_spin_unlock_bh(lock)             spin_unlock_bh(lock)
  97 #define cfs_spin_trylock(lock)               spin_trylock(lock)
  98 #define cfs_spin_is_locked(lock)             spin_is_locked(lock)
  99
 100 #define cfs_spin_lock_irq(lock)              spin_lock_irq(lock)
 101 #define cfs_spin_unlock_irq(lock)            spin_unlock_irq(lock)
 102 #define cfs_read_lock_irqsave(lock, f)       read_lock_irqsave(lock, f)
 103 #define cfs_write_lock_irqsave(lock, f)      write_lock_irqsave(lock, f)
 104 #define cfs_write_unlock_irqrestore(lock, f) write_unlock_irqrestore(lock, f)
 105 #define cfs_spin_lock_irqsave(lock, f)       spin_lock_irqsave(lock, f)
 106 #define cfs_spin_unlock_irqrestore(lock, f)  spin_unlock_irqrestore(lock, f)
 107
 108 #define CFS_SPIN_LOCK_UNLOCKED               SPIN_LOCK_UNLOCKED
 109
 110 /*
 111  * rw_semaphore "implementation" (use Linux kernel's primitives)
 112  *
 113  * - sema_init(x)
 114  * - init_rwsem(x)
 115  * - down_read(x)
 116  * - up_read(x)
 117  * - down_write(x)
 118  * - up_write(x)
 119  */
 120 typedef struct rw_semaphore cfs_rw_semaphore_t;
 121
 122 #define cfs_sema_init(s, val)     sema_init(s, val)
 123 #define cfs_init_rwsem(s)         init_rwsem(s)
 124 #define cfs_down_read(s)          down_read(s)
 125 #define cfs_down_read_trylock(s)  down_read_trylock(s)
 126 #define cfs_up_read(s)            up_read(s)
 127 #define cfs_down_write(s)         down_write(s)
 128 #define cfs_down_write_trylock(s) down_write_trylock(s)
 129 #define cfs_up_write(s)           up_write(s)
 130
 131 #define cfs_fini_rwsem(s)         do {} while(0)
 132
 133 #define CFS_DECLARE_RWSEM(name)   DECLARE_RWSEM(name)
 134
 135 /*
 136  * semaphore "implementation" (use Linux kernel's primitives)
 137  */
 138 typedef struct semaphore      cfs_semaphore_t;
 139
 140 /*
 141  * rwlock_t "implementation" (use Linux kernel's primitives)
 142  *
 143  * - rwlock_init(x)
 144  * - read_lock(x)
 145  * - read_unlock(x)
 146  * - write_lock(x)
 147  * - write_unlock(x)
 148  * - write_lock_bh(x)
 149  * - write_unlock_bh(x)
 150  *
 151  * - RW_LOCK_UNLOCKED
 152  */
 153 typedef rwlock_t cfs_rwlock_t;
 154
 155 #define cfs_rwlock_init(lock)                  rwlock_init(lock)
 156 #define cfs_read_lock(lock)                    read_lock(lock)
 157 #define cfs_read_unlock(lock)                  read_unlock(lock)
 158 #define cfs_read_unlock_irqrestore(lock,flags) \
 159         read_unlock_irqrestore(lock, flags)
 160 #define cfs_write_lock(lock)                   write_lock(lock)
 161 #define cfs_write_unlock(lock)                 write_unlock(lock)
 162 #define cfs_write_lock_bh(lock)                write_lock_bh(lock)
 163 #define cfs_write_unlock_bh(lock)              write_unlock_bh(lock)
 164
 165 #define CFS_RW_LOCK_UNLOCKED                   RW_LOCK_UNLOCKED
 166
 167 /*
 168  * completion "implementation" (use Linux kernel's primitives)
 169  *
 170  * - DECLARE_COMPLETION(work)
 171  * - INIT_COMPLETION(c)
 172  * - COMPLETION_INITIALIZER(work)
 173  * - init_completion(c)
 174  * - complete(c)
 175  * - wait_for_completion(c)
 176  * - wait_for_completion_interruptible(c)
 177  * - fini_completion(c)
 178  */
 179 typedef struct completion cfs_completion_t;
 180
 181 #define CFS_DECLARE_COMPLETION(work)             DECLARE_COMPLETION(work)
 182 #define CFS_INIT_COMPLETION(c)                   INIT_COMPLETION(c)
 183 #define CFS_COMPLETION_INITIALIZER(work)         COMPLETION_INITIALIZER(work)
 184 #define cfs_init_completion(c)                   init_completion(c)
 185 #define cfs_complete(c)                          complete(c)
 186 #define cfs_wait_for_completion(c)               wait_for_completion(c)
 187 #define cfs_wait_for_completion_interruptible(c) \
 188         wait_for_completion_interruptible(c)
 189 #define cfs_complete_and_exit(c, code)           complete_and_exit(c, code)
 190 #define cfs_fini_completion(c)                   do { } while (0)
 191
 192 /*
 193  * mutex "implementation" (use Linux kernel's primitives)
 194  *
 195  * - DECLARE_MUTEX(name)
 196  * - mutex_init(x)
 197  * - init_mutex(x)
 198  * - init_mutex_locked(x)
 199  * - init_MUTEX_LOCKED(x)
 200  * - mutex_up(x)
 201  * - mutex_down(x)
 202  * - up(x)
 203  * - down(x)
 204  * - mutex_down_trylock(x)
 205  * - mutex_lock(x)
 206  * - mutex_unlock(x)
 207  */
 208 typedef struct mutex cfs_mutex_t;
 209
 210 #define CFS_DEFINE_MUTEX(name)             DEFINE_MUTEX(name)
 211 #define CFS_DECLARE_MUTEX(name)            DECLARE_MUTEX(name)
 212
 213 #define cfs_mutex_init(x)                   mutex_init(x)
 214 #define cfs_init_mutex(x)                   init_MUTEX(x)
 215 #define cfs_init_mutex_locked(x)            init_MUTEX_LOCKED(x)
 216 #define cfs_mutex_up(x)                     up(x)
 217 #define cfs_mutex_down(x)                   down(x)
 218 #define cfs_up(x)                           up(x)
 219 #define cfs_down(x)                         down(x)
 220 #define cfs_mutex_down_trylock(x)           down_trylock(x)
 221 #define cfs_mutex_lock(x)                   mutex_lock(x)
 222 #define cfs_mutex_unlock(x)                 mutex_unlock(x)
 223 #define cfs_mutex_trylock(x)                mutex_trylock(x)
 224
 225 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,16)
 226
 227 /**************************************************************************
 228  *
 229  * Mutex interface from newer Linux kernels.
 230  *
 231  * this augments compatibility interface from include/linux/mutex.h
 232  *
 233  **************************************************************************/
 234
 235 static inline void cfs_mutex_destroy(cfs_mutex_t *lock)
 236 {
 237 }
 238
 239 /*
 240  * This is for use in assertions _only_, i.e., this function should always
 241  * return 1.
 242  *
 243  * \retval 1 mutex is locked.
 244  *
 245  * \retval 0 mutex is not locked. This should never happen.
 246  */
 247 static inline int cfs_mutex_is_locked(cfs_mutex_t *lock)
 248 {
 249         return 1;
 250 }
 251 #else /* LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16) */
 252 #define cfs_mutex_destroy(x)    mutex_destroy(x)
 253 #define cfs_mutex_is_locked(x)  mutex_is_locked(x)
 254 #endif /* LINUX_VERSION_CODE < KERNEL_VERSION(2,6,16) */
 255
 256 /*
 257  * Kernel locking primitives
 258  *
 259  * - lock_kernel
 260  * - unlock_kernel
 261  */
 262 #define cfs_lock_kernel()      lock_kernel()
 263 #define cfs_unlock_kernel()    unlock_kernel()
 264
 265 #ifndef lockdep_set_class
 266
 267 /**************************************************************************
 268  *
 269  * Lockdep "implementation". Also see liblustre.h
 270  *
 271  **************************************************************************/
 272
 273 typedef struct cfs_lock_class_key {
 274         ;
 275 } cfs_lock_class_key_t;
 276
 277 #define cfs_lockdep_set_class(lock, key) \
 278         do { (void)sizeof (lock);(void)sizeof (key); } while (0)
 279 /* This has to be a macro, so that `subclass' can be undefined in kernels that
 280  * do not support lockdep. */
 281
 282
 283 static inline void cfs_lockdep_off(void)
 284 {
 285 }
 286
 287 static inline void cfs_lockdep_on(void)
 288 {
 289 }
 290 #else
 291 typedef struct lock_class_key cfs_lock_class_key_t;
 292
 293 #define cfs_lockdep_set_class(lock, key) lockdep_set_class(lock, key)
 294 #define cfs_lockdep_off()                lockdep_off()
 295 #define cfs_lockdep_on()                 lockdep_on()
 296 #endif /* lockdep_set_class */
 297
 298 #ifndef CONFIG_DEBUG_LOCK_ALLOC
 299 #ifndef mutex_lock_nested
 300 #define cfs_mutex_lock_nested(mutex, subclass) mutex_lock(mutex)
 301 #else
 302 #define cfs_mutex_lock_nested(mutex, subclass) \
 303         mutex_lock_nested(mutex, subclass)
 304 #endif
 305
 306 #ifndef spin_lock_nested
 307 #define cfs_spin_lock_nested(lock, subclass) spin_lock(lock)
 308 #else
 309 #define cfs_spin_lock_nested(lock, subclass) spin_lock_nested(lock, subclass)
 310 #endif
 311
 312 #ifndef down_read_nested
 313 #define cfs_down_read_nested(lock, subclass) down_read(lock)
 314 #else
 315 #define cfs_down_read_nested(lock, subclass) down_read_nested(lock, subclass)
 316 #endif
 317
 318 #ifndef down_write_nested
 319 #define cfs_down_write_nested(lock, subclass) down_write(lock)
 320 #else
 321 #define cfs_down_write_nested(lock, subclass) down_write_nested(lock, subclass)
 322 #endif
 323 #endif /* CONFIG_DEBUG_LOCK_ALLOC */
 324
 325
 326 #endif /* __LIBCFS_LINUX_CFS_LOCK_H__ */