On Wed, Jun 07, 2023 at 02:53:51PM -0400, Olivier Dion wrote:
> If configured to use atomic builtins, use them for implementing the
> CMM_LOAD_SHARED and CMM_STORE_SHARED macros.
>
> Change-Id: I3eaaaaf0d26c47aced6e94b40fd59c7b8baa6272
> Co-authored-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> Signed-off-by: Olivier Dion <od...@efficios.com>
> ---
> include/urcu/system.h | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/include/urcu/system.h b/include/urcu/system.h
> index faae390..f184aad 100644
> --- a/include/urcu/system.h
> +++ b/include/urcu/system.h
> @@ -19,9 +19,28 @@
> * all copies or substantial portions of the Software.
> */
>
> +#include <urcu/config.h>
> #include <urcu/compiler.h>
> #include <urcu/arch.h>
>
> +#ifdef CONFIG_RCU_USE_ATOMIC_BUILTINS
> +
> +#define CMM_LOAD_SHARED(x) \
> + __atomic_load_n(&(x), __ATOMIC_RELAXED)
> +
> +#define _CMM_LOAD_SHARED(x) CMM_LOAD_SHARED(x)
> +
> +#define CMM_STORE_SHARED(x, v) \
> + __extension__ \
> + ({ \
> + __typeof__(v) _v = (v); \
> + __atomic_store_n(&(x), _v, __ATOMIC_RELAXED); \
> + _v; \
> + })
> +
> +#define _CMM_STORE_SHARED(x, v) CMM_STORE_SHARED(x, v)
Same question here on loss of volatile semantics.
Thanx, Paul
> +
> +#else
> /*
> * Identify a shared load. A cmm_smp_rmc() or cmm_smp_mc() should come
> * before the load.
> @@ -56,4 +75,6 @@
> _v = _v; /* Work around clang "unused result" */ \
> })
>
> +#endif /* CONFIG_RCU_USE_ATOMIC_BUILTINS */
> +
> #endif /* _URCU_SYSTEM_H */
> --
> 2.40.1
>
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