locking,arch: Rewrite generic atomic support

Rewrite generic atomic support to only require cmpxchg(), generate all
other primitives from that.

Furthermore reduce the endless repetition for all these primitives to
a few CPP macros. This way we get more for less lines.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140508135852.940119622@infradead.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 16 insertions, 4 deletions

diff --git a/include/asm-generic/atomic64.h b/include/asm-generic/atomic64.h
index b18ce4f9ee3d..30ad9c86cebb 100644
--- a/include/asm-generic/atomic64.h
+++ b/include/asm-generic/atomic64.h
@@ -20,10 +20,22 @@ typedef struct {
 
 extern long long atomic64_read(const atomic64_t *v);
 extern void      atomic64_set(atomic64_t *v, long long i);
-extern void      atomic64_add(long long a, atomic64_t *v);
-extern long long atomic64_add_return(long long a, atomic64_t *v);
-extern void      atomic64_sub(long long a, atomic64_t *v);
-extern long long atomic64_sub_return(long long a, atomic64_t *v);
+
+#define ATOMIC64_OP(op)                                                 \
+extern void      atomic64_##op(long long a, atomic64_t *v);
+
+#define ATOMIC64_OP_RETURN(op)                                          \
+extern long long atomic64_##op##_return(long long a, atomic64_t *v);
+
+#define ATOMIC64_OPS(op)        ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op)
+
+ATOMIC64_OPS(add)
+ATOMIC64_OPS(sub)
+
+#undef ATOMIC64_OPS
+#undef ATOMIC64_OP_RETURN
+#undef ATOMIC64_OP
+
 extern long long atomic64_dec_if_positive(atomic64_t *v);
 extern long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n);
 extern long long atomic64_xchg(atomic64_t *v, long long new);