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, 36 insertions, 47 deletions

diff --git a/lib/atomic64.c b/lib/atomic64.c
index 08a4f068e61e..1298c05ef528 100644
--- a/lib/atomic64.c
+++ b/lib/atomic64.c
@@ -70,53 +70,42 @@ void atomic64_set(atomic64_t *v, long long i)
 }
 EXPORT_SYMBOL(atomic64_set);
 
-void atomic64_add(long long a, atomic64_t *v)
-{
-        unsigned long flags;
-        raw_spinlock_t *lock = lock_addr(v);
-
-        raw_spin_lock_irqsave(lock, flags);
-        v->counter += a;
-        raw_spin_unlock_irqrestore(lock, flags);
-}
-EXPORT_SYMBOL(atomic64_add);
-
-long long atomic64_add_return(long long a, atomic64_t *v)
-{
-        unsigned long flags;
-        raw_spinlock_t *lock = lock_addr(v);
-        long long val;
-
-        raw_spin_lock_irqsave(lock, flags);
-        val = v->counter += a;
-        raw_spin_unlock_irqrestore(lock, flags);
-        return val;
-}
-EXPORT_SYMBOL(atomic64_add_return);
-
-void atomic64_sub(long long a, atomic64_t *v)
-{
-        unsigned long flags;
-        raw_spinlock_t *lock = lock_addr(v);
-
-        raw_spin_lock_irqsave(lock, flags);
-        v->counter -= a;
-        raw_spin_unlock_irqrestore(lock, flags);
-}
-EXPORT_SYMBOL(atomic64_sub);
-
-long long atomic64_sub_return(long long a, atomic64_t *v)
-{
-        unsigned long flags;
-        raw_spinlock_t *lock = lock_addr(v);
-        long long val;
-
-        raw_spin_lock_irqsave(lock, flags);
-        val = v->counter -= a;
-        raw_spin_unlock_irqrestore(lock, flags);
-        return val;
-}
-EXPORT_SYMBOL(atomic64_sub_return);
+#define ATOMIC64_OP(op, c_op)                                           \
+void atomic64_##op(long long a, atomic64_t *v)                          \
+{                                                                       \
+        unsigned long flags;                                            \
+        raw_spinlock_t *lock = lock_addr(v);                            \
+                                                                        \
+        raw_spin_lock_irqsave(lock, flags);                             \
+        v->counter c_op a;                                              \
+        raw_spin_unlock_irqrestore(lock, flags);                        \
+}                                                                       \
+EXPORT_SYMBOL(atomic64_##op);
+
+#define ATOMIC64_OP_RETURN(op, c_op)                                    \
+long long atomic64_##op##_return(long long a, atomic64_t *v)            \
+{                                                                       \
+        unsigned long flags;                                            \
+        raw_spinlock_t *lock = lock_addr(v);                            \
+        long long val;                                                  \
+                                                                        \
+        raw_spin_lock_irqsave(lock, flags);                             \
+        val = (v->counter c_op a);                                      \
+        raw_spin_unlock_irqrestore(lock, flags);                        \
+        return val;                                                     \
+}                                                                       \
+EXPORT_SYMBOL(atomic64_##op##_return);
+
+#define ATOMIC64_OPS(op, c_op)                                          \
+        ATOMIC64_OP(op, c_op)                                           \
+        ATOMIC64_OP_RETURN(op, c_op)
+
+ATOMIC64_OPS(add, +=)
+ATOMIC64_OPS(sub, -=)
+
+#undef ATOMIC64_OPS
+#undef ATOMIC64_OP_RETURN
+#undef ATOMIC64_OP
 
 long long atomic64_dec_if_positive(atomic64_t *v)
 {