LXR linux/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 */
  22