vppinfra: add atomic macros for __sync builtins

This is first part of addition of atomic macros with only macros for
__sync builtins.

- Based on earlier patch by Damjan (https://gerrit.fd.io/r/#/c/10729/)
Additionally
- clib_atomic_release macro added and used in the absence
of any memory barrier.
- clib_atomic_bool_cmp_and_swap added

Change-Id: Ie4e48c1e184a652018d1d0d87c4be80ddd180a3b
Original-patch-by: Damjan Marion <damarion@cisco.com>
Signed-off-by: Sirshak Das <sirshak.das@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Ola Liljedahl <ola.liljedahl@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/vnet/util/refcount.h b/src/vnet/util/refcount.h
index ea92148dafa..873ab6def69 100644
--- a/src/vnet/util/refcount.h
+++ b/src/vnet/util/refcount.h
@@ -52,14 +52,14 @@ typedef struct {
 static_always_inline
 void vlib_refcount_lock (volatile u32 *counter_lock)
 {
-  while (__sync_lock_test_and_set (counter_lock, 1))
+  while (clib_atomic_test_and_set (counter_lock))
     ;
 }
 
 static_always_inline
 void vlib_refcount_unlock (volatile u32 *counter_lock)
 {
-  *counter_lock = 0;
+  clib_atomic_release(counter_lock);
 }
 
 void __vlib_refcount_resize(vlib_refcount_per_cpu_t *per_cpu, u32 size);