include/linux/rwlock_types.h

   1 #ifndef __LINUX_RWLOCK_TYPES_H
   2 #define __LINUX_RWLOCK_TYPES_H
   3
   4 /*
   5  * include/linux/rwlock_types.h - generic rwlock type definitions
   6  *                                and initializers
   7  *
   8  * portions Copyright 2005, Red Hat, Inc., Ingo Molnar
   9  * Released under the General Public License (GPL).
  10  */
  11 typedef struct {
  12         arch_rwlock_t raw_lock;
  13 #ifdef CONFIG_GENERIC_LOCKBREAK
  14         unsigned int break_lock;
  15 #endif
  16 #ifdef CONFIG_DEBUG_SPINLOCK
  17         unsigned int magic, owner_cpu;
  18         void *owner;
  19 #endif
  20 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  21         struct lockdep_map dep_map;
  22 #endif
  23 } rwlock_t;
  24
  25 #define RWLOCK_MAGIC            0xdeaf1eed
  26
  27 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  28 # define RW_DEP_MAP_INIT(lockname)      .dep_map = { .name = #lockname }
  29 #else
  30 # define RW_DEP_MAP_INIT(lockname)
  31 #endif
  32
  33 #ifdef CONFIG_DEBUG_SPINLOCK
  34 #define __RW_LOCK_UNLOCKED(lockname)                                    \
  35         (rwlock_t)      {       .raw_lock = __ARCH_RW_LOCK_UNLOCKED,    \
  36                                 .magic = RWLOCK_MAGIC,                  \
  37                                 .owner = SPINLOCK_OWNER_INIT,           \
  38                                 .owner_cpu = -1,                        \
  39                                 RW_DEP_MAP_INIT(lockname) }
  40 #else
  41 #define __RW_LOCK_UNLOCKED(lockname) \
  42         (rwlock_t)      {       .raw_lock = __ARCH_RW_LOCK_UNLOCKED,    \
  43                                 RW_DEP_MAP_INIT(lockname) }
  44 #endif
  45
  46 /*
  47  * RW_LOCK_UNLOCKED defeat lockdep state tracking and is hence
  48  * deprecated.
  49  *
  50  * Please use DEFINE_RWLOCK() or __RW_LOCK_UNLOCKED() as appropriate.
  51  */
  52 #define RW_LOCK_UNLOCKED        __RW_LOCK_UNLOCKED(old_style_rw_init)
  53
  54 #define DEFINE_RWLOCK(x)        rwlock_t x = __RW_LOCK_UNLOCKED(x)
  55
  56 #endif /* __LINUX_RWLOCK_TYPES_H */