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authorArnaldo Carvalho de Melo <acme@redhat.com>2017-02-22 16:55:43 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2017-03-03 19:07:13 -0300
commit8a73615df3b8973df2de1455c00e9169522d8257 (patch)
tree1920f5e43fda4eac0c8769ae5fb483057113116e /tools/arch
parent3337e682d9f3043bb0b925d976558ed5c41b0a09 (diff)
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tools arch x86: Introduce atomic_cmpxchg()
Will be used by atomic_cmpxchg_relaxed(), in turn used by refcount.h. 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: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-kdmovd3l4gw5b1w31ypr6ddv@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/arch')
-rw-r--r--tools/arch/x86/include/asm/atomic.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/tools/arch/x86/include/asm/atomic.h b/tools/arch/x86/include/asm/atomic.h
index 059e33e94260..328eeceec709 100644
--- a/tools/arch/x86/include/asm/atomic.h
+++ b/tools/arch/x86/include/asm/atomic.h
@@ -7,6 +7,8 @@
#define LOCK_PREFIX "\n\tlock; "
+#include <asm/cmpxchg.h>
+
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
@@ -62,4 +64,9 @@ static inline int atomic_dec_and_test(atomic_t *v)
GEN_UNARY_RMWcc(LOCK_PREFIX "decl", v->counter, "%0", "e");
}
+static __always_inline int atomic_cmpxchg(atomic_t *v, int old, int new)
+{
+ return cmpxchg(&v->counter, old, new);
+}
+
#endif /* _TOOLS_LINUX_ASM_X86_ATOMIC_H */