Commit-ID: ed4aad50ea0384737034b39f952f29cfb2da52ac Gitweb: http://git.kernel.org/tip/ed4aad50ea0384737034b39f952f29cfb2da52ac Author: Arnaldo Carvalho de Melo <a...@redhat.com> AuthorDate: Thu, 23 Feb 2017 15:33:02 -0300 Committer: Arnaldo Carvalho de Melo <a...@redhat.com> 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 <adrian.hun...@intel.com> Cc: David Ahern <dsah...@gmail.com> Cc: Elena Reshetova <elena.reshet...@intel.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Wang Nan <wangn...@huawei.com> Link: http://lkml.kernel.org/n/tip-b9zovyxgpa0c4vi3nm0kj...@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- 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 */
