[PATCH] frv: add atomic64_add_unless()

[Sudip Mukherjee]

The build of frv allmodconfig was failing with the error:
lib/atomic64_test.c:209:9: error:
	implicit declaration of function 'atomic64_add_unless'

All the atomic64 operations were defined in frv, but
atomic64_add_unless() was not done.
Implement atomic64_add_unless() as done in other arch.

Signed-off-by: Sudip Mukherjee <sudip.mukherjee@xxxxxxxxxxxxxxx>
---

build log of next-20170118 is at:
https://travis-ci.org/sudipm-mukherjee/parport/jobs/192936474

There is also two more errors about redefinition. I will prepare
separate patch for that.

 arch/frv/include/asm/atomic.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/frv/include/asm/atomic.h b/arch/frv/include/asm/atomic.h
index 1c2a5e2..994ed3d 100644
--- a/arch/frv/include/asm/atomic.h
+++ b/arch/frv/include/asm/atomic.h
@@ -161,6 +161,22 @@ static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
 	return c;
 }
 
+static inline int atomic64_add_unless(atomic64_t *v, long long i, long long u)
+{
+	long long c, old;
+
+	c = atomic64_read(v);
+	for (;;) {
+		if (unlikely(c == u))
+			break;
+		old = atomic64_cmpxchg(v, c, c + i);
+		if (likely(old == c))
+			break;
+		c = old;
+	}
+	return c != u;
+}
+
 #define ATOMIC_OP(op)							\
 static inline int atomic_fetch_##op(int i, atomic_t *v)			\
 {									\
-- 
2.7.4