From e5fd91f1ef340da553f7a79da9540c3db711c937 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Tue, 8 Sep 2015 01:01:14 -0300 Subject: Linux-libre 4.2-gnu --- tools/arch/x86/include/asm/atomic.h | 65 +++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 tools/arch/x86/include/asm/atomic.h (limited to 'tools/arch/x86/include/asm/atomic.h') diff --git a/tools/arch/x86/include/asm/atomic.h b/tools/arch/x86/include/asm/atomic.h new file mode 100644 index 000000000..059e33e94 --- /dev/null +++ b/tools/arch/x86/include/asm/atomic.h @@ -0,0 +1,65 @@ +#ifndef _TOOLS_LINUX_ASM_X86_ATOMIC_H +#define _TOOLS_LINUX_ASM_X86_ATOMIC_H + +#include +#include +#include "rmwcc.h" + +#define LOCK_PREFIX "\n\tlock; " + +/* + * Atomic operations that C can't guarantee us. Useful for + * resource counting etc.. + */ + +#define ATOMIC_INIT(i) { (i) } + +/** + * atomic_read - read atomic variable + * @v: pointer of type atomic_t + * + * Atomically reads the value of @v. + */ +static inline int atomic_read(const atomic_t *v) +{ + return ACCESS_ONCE((v)->counter); +} + +/** + * atomic_set - set atomic variable + * @v: pointer of type atomic_t + * @i: required value + * + * Atomically sets the value of @v to @i. + */ +static inline void atomic_set(atomic_t *v, int i) +{ + v->counter = i; +} + +/** + * atomic_inc - increment atomic variable + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1. + */ +static inline void atomic_inc(atomic_t *v) +{ + asm volatile(LOCK_PREFIX "incl %0" + : "+m" (v->counter)); +} + +/** + * atomic_dec_and_test - decrement and test + * @v: pointer of type atomic_t + * + * Atomically decrements @v by 1 and + * returns true if the result is 0, or false for all other + * cases. + */ +static inline int atomic_dec_and_test(atomic_t *v) +{ + GEN_UNARY_RMWcc(LOCK_PREFIX "decl", v->counter, "%0", "e"); +} + +#endif /* _TOOLS_LINUX_ASM_X86_ATOMIC_H */ -- cgit v1.2.3-54-g00ecf