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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>
This commit is contained in:
Arnaldo Carvalho de Melo 2017-02-23 15:33:02 -03:00
parent 2bcdeadbc0
commit ed4aad50ea
1 changed files with 8 additions and 0 deletions
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8
tools/include/asm-generic/atomic-gcc.h
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@ -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 */