locking/atomic, arch/tile: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()
Implement FETCH-OP atomic primitives, these are very similar to the
existing OP-RETURN primitives we already have, except they return the
value of the atomic variable _before_ modification.
This is especially useful for irreversible operations -- such as
bitops (because it becomes impossible to reconstruct the state prior
to modification).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/tile/include/asm/atomic.h b/arch/tile/include/asm/atomic.h
index 9fc0107..9807030 100644
--- a/arch/tile/include/asm/atomic.h
+++ b/arch/tile/include/asm/atomic.h
@@ -46,6 +46,10 @@
*/
#define atomic_sub_return(i, v) atomic_add_return((int)(-(i)), (v))
+#define atomic_fetch_sub(i, v) atomic_fetch_add(-(int)(i), (v))
+
+#define atomic_fetch_or atomic_fetch_or
+
/**
* atomic_sub - subtract integer from atomic variable
* @i: integer value to subtract