Add cmpxchg64 and cmpxchg64_local to x86_64

Make sure that at least cmpxchg64_local is available on all architectures to use
for unsigned long long values.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Andi Kleen <ak@muc.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 16 insertions, 6 deletions

diff --git a/include/asm-x86/cmpxchg_64.h b/include/asm-x86/cmpxchg_64.h
index 5e182062e6e..56f5b41e071 100644
--- a/include/asm-x86/cmpxchg_64.h
+++ b/include/asm-x86/cmpxchg_64.h
@@ -124,11 +124,21 @@ static inline unsigned long __cmpxchg_local(volatile void *ptr,
         return old;
 }
 
-#define cmpxchg(ptr,o,n)\
-        ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
-                                        (unsigned long)(n),sizeof(*(ptr))))
-#define cmpxchg_local(ptr,o,n)\
-        ((__typeof__(*(ptr)))__cmpxchg_local((ptr),(unsigned long)(o),\
-                                        (unsigned long)(n),sizeof(*(ptr))))
+#define cmpxchg(ptr, o, n)                                              \
+        ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o),       \
+                                        (unsigned long)(n), sizeof(*(ptr))))
+#define cmpxchg64(ptr, o, n)                                            \
+  ({                                                                    \
+        BUILD_BUG_ON(sizeof(*(ptr)) != 8);                              \
+        cmpxchg((ptr), (o), (n));                                       \
+  })
+#define cmpxchg_local(ptr, o, n)                                        \
+        ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
+                                        (unsigned long)(n), sizeof(*(ptr))))
+#define cmpxchg64_local(ptr, o, n)                                      \
+  ({                                                                    \
+        BUILD_BUG_ON(sizeof(*(ptr)) != 8);                              \
+        cmpxchg_local((ptr), (o), (n));                                 \
+  })
 
 #endif