[POWERPC] atomic.h: Add atomic64 cmpxchg, xchg and add_unless to powerpc

atomic.h : Add atomic64 cmpxchg, xchg and add_unless to powerpc

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 39 insertions, 1 deletions

diff --git a/include/asm-powerpc/atomic.h b/include/asm-powerpc/atomic.h
index f038e33e6d48..2ce4b6b7b348 100644
--- a/include/asm-powerpc/atomic.h
+++ b/include/asm-powerpc/atomic.h
@@ -165,7 +165,8 @@ static __inline__ int atomic_dec_return(atomic_t *v)
         return t;
 }
 
-#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
+#define atomic_cmpxchg(v, o, n) \
+        ((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 
 /**
@@ -413,6 +414,43 @@ static __inline__ long atomic64_dec_if_positive(atomic64_t *v)
         return t;
 }
 
+#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.
+ */
+static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
+{
+        long t;
+
+        __asm__ __volatile__ (
+        LWSYNC_ON_SMP
+"1:     ldarx   %0,0,%1         # atomic_add_unless\n\
+        cmpd    0,%0,%3 \n\
+        beq-    2f \n\
+        add     %0,%2,%0 \n"
+"       stdcx.  %0,0,%1 \n\
+        bne-    1b \n"
+        ISYNC_ON_SMP
+"       subf    %0,%2,%0 \n\
+2:"
+        : "=&r" (t)
+        : "r" (&v->counter), "r" (a), "r" (u)
+        : "cc", "memory");
+
+        return t != u;
+}
+
+#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
+
 #endif /* __powerpc64__ */
 
 #include <asm-generic/atomic.h>