Commit 8a73615d authored Feb 22, 2017 by Arnaldo Carvalho de Melo

tools arch x86: Introduce atomic_cmpxchg()

Will be used by atomic_cmpxchg_relaxed(), in turn used by refcount.h.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Elena Reshetova <elena.reshetova@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-kdmovd3l4gw5b1w31ypr6ddv@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 3337e682

tools/arch/x86/include/asm/atomic.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -7,6 +7,8 @@

		#define LOCK_PREFIX "\n\tlock; "

		#include <asm/cmpxchg.h>

		/*
		* Atomic operations that C can't guarantee us. Useful for
		* resource counting etc..
		@@ -62,4 +64,9 @@ static inline int atomic_dec_and_test(atomic_t *v)
		GEN_UNARY_RMWcc(LOCK_PREFIX "decl", v->counter, "%0", "e");
		}

		static __always_inline int atomic_cmpxchg(atomic_t *v, int old, int new)
		{
		return cmpxchg(&v->counter, old, new);
		}

		#endif /* _TOOLS_LINUX_ASM_X86_ATOMIC_H */