Commit ed4aad50 authored Feb 23, 2017 by Arnaldo Carvalho de Melo

tools include: Provide gcc based cmpxchg fallback for !x86

We've been using an atomic_t implementation subset based on the gcc
builtin functions for a while, now, with refcount.h we need cmpxchg(),
use gcc's __sync_val_compare_and_swap() for that.

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: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-b9zovyxgpa0c4vi3nm0kjo97@git.kernel.org

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

parent 2bcdeadb

tools/include/asm-generic/atomic-gcc.h

+8 −0

Original line number	Diff line number	Diff line
		@@ -60,4 +60,12 @@ static inline int atomic_dec_and_test(atomic_t *v)
		return __sync_sub_and_fetch(&v->counter, 1) == 0;
		}

		#define cmpxchg(ptr, oldval, newval) \
		__sync_val_compare_and_swap(ptr, oldval, newval)

		static inline int atomic_cmpxchg(atomic_t *v, int oldval, int newval)
		{
		return cmpxchg(&(v)->counter, oldval, newval);
		}

		#endif /* __TOOLS_ASM_GENERIC_ATOMIC_H */