arch/arm/include/asm/mutex.h

   1 /*
   2  * arch/arm/include/asm/mutex.h
   3  *
   4  * ARM optimized mutex locking primitives
   5  *
   6  * Please look into asm-generic/mutex-xchg.h for a formal definition.
   7  */
   8 #ifndef _ASM_MUTEX_H
   9 #define _ASM_MUTEX_H
  10 /*
  11  * On pre-ARMv6 hardware this results in a swp-based implementation,
  12  * which is the most efficient. For ARMv6+, we have exclusive memory
  13  * accessors and use atomic_dec to avoid the extra xchg operations
  14  * on the locking slowpaths.
  15  */
  16 #if __LINUX_ARM_ARCH__ < 6
  17 #include <asm-generic/mutex-xchg.h>
  18 #else
  19 #include <asm-generic/mutex-dec.h>
  20 #endif
  21 #endif  /* _ASM_MUTEX_H */