kernel/include/linux/rwlock_types.h

   1 #ifndef __LINUX_RWLOCK_TYPES_H
   2 #define __LINUX_RWLOCK_TYPES_H
   3
   4 #if !defined(__LINUX_SPINLOCK_TYPES_H)
   5 # error "Do not include directly, include spinlock_types.h"
   6 #endif
   7
   8 /*
   9  * include/linux/rwlock_types.h - generic rwlock type definitions
  10  *                                and initializers
  11  *
  12  * portions Copyright 2005, Red Hat, Inc., Ingo Molnar
  13  * Released under the General Public License (GPL).
  14  */
  15 typedef struct {
  16         arch_rwlock_t raw_lock;
  17 #ifdef CONFIG_GENERIC_LOCKBREAK
  18         unsigned int break_lock;
  19 #endif
  20 #ifdef CONFIG_DEBUG_SPINLOCK
  21         unsigned int magic, owner_cpu;
  22         void *owner;
  23 #endif
  24 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  25         struct lockdep_map dep_map;
  26 #endif
  27 } rwlock_t;
  28
  29 #define RWLOCK_MAGIC            0xdeaf1eed
  30
  31 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  32 # define RW_DEP_MAP_INIT(lockname)      .dep_map = { .name = #lockname }
  33 #else
  34 # define RW_DEP_MAP_INIT(lockname)
  35 #endif
  36
  37 #ifdef CONFIG_DEBUG_SPINLOCK
  38 #define __RW_LOCK_UNLOCKED(lockname)                                    \
  39         (rwlock_t)      {       .raw_lock = __ARCH_RW_LOCK_UNLOCKED,    \
  40                                 .magic = RWLOCK_MAGIC,                  \
  41                                 .owner = SPINLOCK_OWNER_INIT,           \
  42                                 .owner_cpu = -1,                        \
  43                                 RW_DEP_MAP_INIT(lockname) }
  44 #else
  45 #define __RW_LOCK_UNLOCKED(lockname) \
  46         (rwlock_t)      {       .raw_lock = __ARCH_RW_LOCK_UNLOCKED,    \
  47                                 RW_DEP_MAP_INIT(lockname) }
  48 #endif
  49
  50 #define DEFINE_RWLOCK(name) \
  51         rwlock_t name __cacheline_aligned_in_smp = __RW_LOCK_UNLOCKED(name)
  52
  53 #endif /* __LINUX_RWLOCK_TYPES_H */