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