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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2017-02-23 19:33:02 +0100 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2017-03-03 23:07:14 +0100 |
| commit | ed4aad50ea0384737034b39f952f29cfb2da52ac (patch) | |
| tree | 1603e24ea3afad82d27138c65b3d8ece9e9497f1 /tools/include/asm-generic | |
| parent | tools include: Introduce atomic_cmpxchg_{relaxed,release}() (diff) | |
| download | linux-ed4aad50ea0384737034b39f952f29cfb2da52ac.tar.xz linux-ed4aad50ea0384737034b39f952f29cfb2da52ac.zip | |
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>
Diffstat (limited to 'tools/include/asm-generic')
| -rw-r--r-- | tools/include/asm-generic/atomic-gcc.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/tools/include/asm-generic/atomic-gcc.h b/tools/include/asm-generic/atomic-gcc.h index 2ba78c9f5701..5e9738f97bf3 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 */ |