[lttng-dev] [PATCH 04/11] urcu/arch/generic: Use atomic builtins if configured

[Olivier Dion]

If configured to use atomic builtins, implement SMP memory barriers in
term of atomic builtins if the architecture does not implement its own
version.

Change-Id: Iddc4283606e0fce572e104d2d3f03b5c0d9926fb
Co-authored-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
Signed-off-by: Olivier Dion <odion at efficios.com>
---
 include/urcu/arch/generic.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/include/urcu/arch/generic.h b/include/urcu/arch/generic.h
index be6e41e..e292c70 100644
--- a/include/urcu/arch/generic.h
+++ b/include/urcu/arch/generic.h
@@ -43,6 +43,14 @@ extern "C" {
  * GCC builtins) as well as cmm_rmb and cmm_wmb (defaulting to cmm_mb).
  */
 
+#ifdef CONFIG_RCU_USE_ATOMIC_BUILTINS
+
+# ifndef cmm_smp_mb
+#  define cmm_smp_mb() __atomic_thread_fence(__ATOMIC_SEQ_CST)
+# endif
+
+#endif	/* CONFIG_RCU_USE_ATOMIC_BUILTINS */
+
 #ifndef cmm_mb
 #define cmm_mb()    __sync_synchronize()
 #endif
-- 
2.39.2