On Fri, Aug 29, 2025 at 01:07:32AM -0700, Ankur Arora wrote:
> diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h
> index f5801b0ba9e9..9b29abc212db 100644
> --- a/arch/arm64/include/asm/barrier.h
> +++ b/arch/arm64/include/asm/barrier.h
> @@ -219,6 +219,28 @@ do { \
> (typeof(*ptr))VAL; \
> })
>
> +extern bool arch_timer_evtstrm_available(void);
In theory, this doesn't work if CONFIG_ARM_ARCH_TIMER is disabled,
though that's not the case for arm64. Maybe add a short comment that's
re-declared here to avoid include dependencies.
> +
> +#define smp_cond_load_relaxed_timewait(ptr, cond_expr, time_check_expr) \
> +({ \
> + typeof(ptr) __PTR = (ptr); \
> + __unqual_scalar_typeof(*ptr) VAL; \
> + bool __wfe = arch_timer_evtstrm_available(); \
> + \
> + for (;;) { \
> + VAL = READ_ONCE(*__PTR); \
> + if (cond_expr) \
> + break; \
> + if (time_check_expr) \
> + break; \
> + if (likely(__wfe)) \
> + __cmpwait_relaxed(__PTR, VAL); \
> + else \
> + cpu_relax(); \
> + } \
> + (typeof(*ptr)) VAL; \
> +})
> +
> #include <asm-generic/barrier.h>
>
> #endif /* __ASSEMBLY__ */
Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
