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C/C++ Source or Header  |  2006-08-11  |  8.3 KB  |  247 lines
  1. #ifndef __LINUX_SPINLOCK_H
  2. #define __LINUX_SPINLOCK_H
  3.  
  4. /*
  5.  * include/linux/spinlock.h - generic spinlock/rwlock declarations
  6.  *
  7.  * here's the role of the various spinlock/rwlock related include files:
  8.  *
  9.  * on SMP builds:
  10.  *
  11.  *  asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
  12.  *                        initializers
  13.  *
  14.  *  linux/spinlock_types.h:
  15.  *                        defines the generic type and initializers
  16.  *
  17.  *  asm/spinlock.h:       contains the __raw_spin_*()/etc. lowlevel
  18.  *                        implementations, mostly inline assembly code
  19.  *
  20.  *   (also included on UP-debug builds:)
  21.  *
  22.  *  linux/spinlock_api_smp.h:
  23.  *                        contains the prototypes for the _spin_*() APIs.
  24.  *
  25.  *  linux/spinlock.h:     builds the final spin_*() APIs.
  26.  *
  27.  * on UP builds:
  28.  *
  29.  *  linux/spinlock_type_up.h:
  30.  *                        contains the generic, simplified UP spinlock type.
  31.  *                        (which is an empty structure on non-debug builds)
  32.  *
  33.  *  linux/spinlock_types.h:
  34.  *                        defines the generic type and initializers
  35.  *
  36.  *  linux/spinlock_up.h:
  37.  *                        contains the __raw_spin_*()/etc. version of UP
  38.  *                        builds. (which are NOPs on non-debug, non-preempt
  39.  *                        builds)
  40.  *
  41.  *   (included on UP-non-debug builds:)
  42.  *
  43.  *  linux/spinlock_api_up.h:
  44.  *                        builds the _spin_*() APIs.
  45.  *
  46.  *  linux/spinlock.h:     builds the final spin_*() APIs.
  47.  */
  48.  
  49. #include <linux/preempt.h>
  50. #include <linux/linkage.h>
  51. #include <linux/compiler.h>
  52. #include <linux/thread_info.h>
  53. #include <linux/kernel.h>
  54. #include <linux/stringify.h>
  55.  
  56. #include <asm/system.h>
  57.  
  58. /*
  59.  * Must define these before including other files, inline functions need them
  60.  */
  61. #define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME
  62.  
  63. #define LOCK_SECTION_START(extra)               \
  64.         ".subsection 1\n\t"                     \
  65.         extra                                   \
  66.         ".ifndef " LOCK_SECTION_NAME "\n\t"     \
  67.         LOCK_SECTION_NAME ":\n\t"               \
  68.         ".endif\n"
  69.  
  70. #define LOCK_SECTION_END                        \
  71.         ".previous\n\t"
  72.  
  73. #define __lockfunc fastcall __attribute__((section(".spinlock.text")))
  74.  
  75. /*
  76.  * Pull the raw_spinlock_t and raw_rwlock_t definitions:
  77.  */
  78. #include <linux/spinlock_types.h>
  79.  
  80. extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
  81.  
  82. /*
  83.  * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
  84.  */
  85. #if defined(CONFIG_SMP)
  86. # include <asm/spinlock.h>
  87. #else
  88. # include <linux/spinlock_up.h>
  89. #endif
  90.  
  91. #define spin_lock_init(lock)    do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0)
  92. #define rwlock_init(lock)    do { *(lock) = RW_LOCK_UNLOCKED; } while (0)
  93.  
  94. #define spin_is_locked(lock)    __raw_spin_is_locked(&(lock)->raw_lock)
  95.  
  96. /**
  97.  * spin_unlock_wait - wait until the spinlock gets unlocked
  98.  * @lock: the spinlock in question.
  99.  */
  100. #define spin_unlock_wait(lock)    __raw_spin_unlock_wait(&(lock)->raw_lock)
  101.  
  102. /*
  103.  * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
  104.  */
  105. #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
  106. # include <linux/spinlock_api_smp.h>
  107. #else
  108. # include <linux/spinlock_api_up.h>
  109. #endif
  110.  
  111. #ifdef CONFIG_DEBUG_SPINLOCK
  112.  extern void _raw_spin_lock(spinlock_t *lock);
  113. #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
  114.  extern int _raw_spin_trylock(spinlock_t *lock);
  115.  extern void _raw_spin_unlock(spinlock_t *lock);
  116.  
  117.  extern void _raw_read_lock(rwlock_t *lock);
  118.  extern int _raw_read_trylock(rwlock_t *lock);
  119.  extern void _raw_read_unlock(rwlock_t *lock);
  120.  extern void _raw_write_lock(rwlock_t *lock);
  121.  extern int _raw_write_trylock(rwlock_t *lock);
  122.  extern void _raw_write_unlock(rwlock_t *lock);
  123. #else
  124. # define _raw_spin_unlock(lock)        __raw_spin_unlock(&(lock)->raw_lock)
  125. # define _raw_spin_trylock(lock)    __raw_spin_trylock(&(lock)->raw_lock)
  126. # define _raw_spin_lock(lock)        __raw_spin_lock(&(lock)->raw_lock)
  127. # define _raw_spin_lock_flags(lock, flags) \
  128.         __raw_spin_lock_flags(&(lock)->raw_lock, *(flags))
  129. # define _raw_read_lock(rwlock)        __raw_read_lock(&(rwlock)->raw_lock)
  130. # define _raw_write_lock(rwlock)    __raw_write_lock(&(rwlock)->raw_lock)
  131. # define _raw_read_unlock(rwlock)    __raw_read_unlock(&(rwlock)->raw_lock)
  132. # define _raw_write_unlock(rwlock)    __raw_write_unlock(&(rwlock)->raw_lock)
  133. # define _raw_read_trylock(rwlock)    __raw_read_trylock(&(rwlock)->raw_lock)
  134. # define _raw_write_trylock(rwlock)    __raw_write_trylock(&(rwlock)->raw_lock)
  135. #endif
  136.  
  137. #define read_can_lock(rwlock)        __raw_read_can_lock(&(rwlock)->raw_lock)
  138. #define write_can_lock(rwlock)        __raw_write_can_lock(&(rwlock)->raw_lock)
  139.  
  140. /*
  141.  * Define the various spin_lock and rw_lock methods.  Note we define these
  142.  * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
  143.  * methods are defined as nops in the case they are not required.
  144.  */
  145. #define spin_trylock(lock)        __cond_lock(_spin_trylock(lock))
  146. #define read_trylock(lock)        __cond_lock(_read_trylock(lock))
  147. #define write_trylock(lock)        __cond_lock(_write_trylock(lock))
  148.  
  149. #define spin_lock(lock)            _spin_lock(lock)
  150. #define write_lock(lock)        _write_lock(lock)
  151. #define read_lock(lock)            _read_lock(lock)
  152.  
  153. #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
  154. #define spin_lock_irqsave(lock, flags)    flags = _spin_lock_irqsave(lock)
  155. #define read_lock_irqsave(lock, flags)    flags = _read_lock_irqsave(lock)
  156. #define write_lock_irqsave(lock, flags)    flags = _write_lock_irqsave(lock)
  157. #else
  158. #define spin_lock_irqsave(lock, flags)    _spin_lock_irqsave(lock, flags)
  159. #define read_lock_irqsave(lock, flags)    _read_lock_irqsave(lock, flags)
  160. #define write_lock_irqsave(lock, flags)    _write_lock_irqsave(lock, flags)
  161. #endif
  162.  
  163. #define spin_lock_irq(lock)        _spin_lock_irq(lock)
  164. #define spin_lock_bh(lock)        _spin_lock_bh(lock)
  165.  
  166. #define read_lock_irq(lock)        _read_lock_irq(lock)
  167. #define read_lock_bh(lock)        _read_lock_bh(lock)
  168.  
  169. #define write_lock_irq(lock)        _write_lock_irq(lock)
  170. #define write_lock_bh(lock)        _write_lock_bh(lock)
  171.  
  172. /*
  173.  * We inline the unlock functions in the nondebug case:
  174.  */
  175. #if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || !defined(CONFIG_SMP)
  176. # define spin_unlock(lock)        _spin_unlock(lock)
  177. # define read_unlock(lock)        _read_unlock(lock)
  178. # define write_unlock(lock)        _write_unlock(lock)
  179. #else
  180. # define spin_unlock(lock)        __raw_spin_unlock(&(lock)->raw_lock)
  181. # define read_unlock(lock)        __raw_read_unlock(&(lock)->raw_lock)
  182. # define write_unlock(lock)        __raw_write_unlock(&(lock)->raw_lock)
  183. #endif
  184.  
  185. #if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || !defined(CONFIG_SMP)
  186. # define spin_unlock_irq(lock)        _spin_unlock_irq(lock)
  187. # define read_unlock_irq(lock)        _read_unlock_irq(lock)
  188. # define write_unlock_irq(lock)        _write_unlock_irq(lock)
  189. #else
  190. # define spin_unlock_irq(lock) \
  191.     do { __raw_spin_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
  192. # define read_unlock_irq(lock) \
  193.     do { __raw_read_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
  194. # define write_unlock_irq(lock) \
  195.     do { __raw_write_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
  196. #endif
  197.  
  198. #define spin_unlock_irqrestore(lock, flags) \
  199.                     _spin_unlock_irqrestore(lock, flags)
  200. #define spin_unlock_bh(lock)        _spin_unlock_bh(lock)
  201.  
  202. #define read_unlock_irqrestore(lock, flags) \
  203.                     _read_unlock_irqrestore(lock, flags)
  204. #define read_unlock_bh(lock)        _read_unlock_bh(lock)
  205.  
  206. #define write_unlock_irqrestore(lock, flags) \
  207.                     _write_unlock_irqrestore(lock, flags)
  208. #define write_unlock_bh(lock)        _write_unlock_bh(lock)
  209.  
  210. #define spin_trylock_bh(lock)        __cond_lock(_spin_trylock_bh(lock))
  211.  
  212. #define spin_trylock_irq(lock) \
  213. ({ \
  214.     local_irq_disable(); \
  215.     _spin_trylock(lock) ? \
  216.     1 : ({ local_irq_enable(); 0;  }); \
  217. })
  218.  
  219. #define spin_trylock_irqsave(lock, flags) \
  220. ({ \
  221.     local_irq_save(flags); \
  222.     _spin_trylock(lock) ? \
  223.     1 : ({ local_irq_restore(flags); 0; }); \
  224. })
  225.  
  226. /*
  227.  * Pull the atomic_t declaration:
  228.  * (asm-mips/atomic.h needs above definitions)
  229.  */
  230. #include <asm/atomic.h>
  231. /**
  232.  * atomic_dec_and_lock - lock on reaching reference count zero
  233.  * @atomic: the atomic counter
  234.  * @lock: the spinlock in question
  235.  */
  236. extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
  237. #define atomic_dec_and_lock(atomic, lock) \
  238.         __cond_lock(_atomic_dec_and_lock(atomic, lock))
  239.  
  240. /**
  241.  * spin_can_lock - would spin_trylock() succeed?
  242.  * @lock: the spinlock in question.
  243.  */
  244. #define spin_can_lock(lock)    (!spin_is_locked(lock))
  245.  
  246. #endif /* __LINUX_SPINLOCK_H */
  247.