atomic.h: add atomic64 cmpxchg, xchg and add_unless to mips

Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/asm-mips/atomic.h

@@ -306,8 +306,8 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
 	return result;
 }
 
-#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
-#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
+#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
+#define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))
 
 /**
  * atomic_add_unless - add unless the number is a given value
@@ -320,7 +320,7 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
  */
 #define atomic_add_unless(v, a, u)				\
 ({								\
-	int c, old;						\
+	__typeof__((v)->counter) c, old;			\
 	c = atomic_read(v);					\
 	while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
 		c = old;					\
@@ -681,6 +681,29 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
 	return result;
 }
 
+#define atomic64_cmpxchg(v, o, n) \
+	(((__typeof__((v)->counter)))cmpxchg(&((v)->counter), (o), (n)))
+#define atomic64_xchg(v, new) (xchg(&((v)->counter), (new)))
+
+/**
+ * atomic64_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic64_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, so long as it was not @u.
+ * Returns non-zero if @v was not @u, and zero otherwise.
+ */
+#define atomic64_add_unless(v, a, u)				\
+({								\
+	__typeof__((v)->counter) c, old;			\
+	c = atomic_read(v);					\
+	while (c != (u) && (old = atomic64_cmpxchg((v), c, c + (a))) != c) \
+		c = old;					\
+	c != (u);						\
+})
+#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
+
 #define atomic64_dec_return(v) atomic64_sub_return(1,(v))
 #define atomic64_inc_return(v) atomic64_add_return(1,(v))