Commit-ID: ed4aad50ea0384737034b39f952f29cfb2da52ac Gitweb: http://git.kernel.org/tip/ed4aad50ea0384737034b39f952f29cfb2da52ac Author: Arnaldo Carvalho de Melo <[email protected]> AuthorDate: Thu, 23 Feb 2017 15:33:02 -0300 Committer: Arnaldo Carvalho de Melo <[email protected]> CommitDate: Fri, 3 Mar 2017 19:07:14 -0300
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 <[email protected]> Cc: David Ahern <[email protected]> Cc: Elena Reshetova <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Wang Nan <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- tools/include/asm-generic/atomic-gcc.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/tools/include/asm-generic/atomic-gcc.h b/tools/include/asm-generic/atomic-gcc.h index 2ba78c9..5e9738f 100644 --- a/tools/include/asm-generic/atomic-gcc.h +++ b/tools/include/asm-generic/atomic-gcc.h @@ -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 */
