[PATCH 5/9] riscv: Fix set up of cpu hotplug callbacks

[Alexandre Ghiti]

On 07/02/2025 17:19, Andrew Jones wrote:
> CPU hotplug callbacks should be set up even if we detected all
> current cpus emulate misaligned accesses, since we want to
> ensure our expectations of all cpus emulating is maintained.
>
> Fixes: 6e5ce7f2eae3 ("riscv: Decouple emulated unaligned accesses from access speed")
> Fixes: e7c9d66e313b ("RISC-V: Report vector unaligned access speed hwprobe")
> Signed-off-by: Andrew Jones <ajones at ventanamicro.com>
> ---
>   arch/riscv/kernel/unaligned_access_speed.c | 27 +++++++++++-----------
>   1 file changed, 13 insertions(+), 14 deletions(-)
>
> diff --git a/arch/riscv/kernel/unaligned_access_speed.c b/arch/riscv/kernel/unaligned_access_speed.c
> index 780f1c5f512a..c9d3237649bb 100644
> --- a/arch/riscv/kernel/unaligned_access_speed.c
> +++ b/arch/riscv/kernel/unaligned_access_speed.c
> @@ -247,13 +247,6 @@ static void __init check_unaligned_access_speed_all_cpus(void)
>   	/* Check core 0. */
>   	smp_call_on_cpu(0, check_unaligned_access, bufs[0], true);
>   
> -	/*
> -	 * Setup hotplug callbacks for any new CPUs that come online or go
> -	 * offline.
> -	 */
> -	cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "riscv:online",
> -				  riscv_online_cpu, riscv_offline_cpu);
> -
>   out:
>   	for_each_cpu(cpu, cpu_online_mask) {
>   		if (bufs[cpu])
> @@ -383,13 +376,6 @@ static int __init vec_check_unaligned_access_speed_all_cpus(void *unused __alway
>   {
>   	schedule_on_each_cpu(check_vector_unaligned_access);
>   
> -	/*
> -	 * Setup hotplug callbacks for any new CPUs that come online or go
> -	 * offline.
> -	 */
> -	cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "riscv:online",
> -				  riscv_online_cpu_vec, NULL);
> -
>   	return 0;
>   }
>   #else /* CONFIG_RISCV_PROBE_VECTOR_UNALIGNED_ACCESS */
> @@ -415,6 +401,19 @@ static int __init check_unaligned_access_all_cpus(void)
>   			    NULL, "vec_check_unaligned_access_speed_all_cpus");
>   	}
>   
> +	/*
> +	 * Setup hotplug callbacks for any new CPUs that come online or go
> +	 * offline.
> +	 */
> +#ifdef CONFIG_RISCV_PROBE_UNALIGNED_ACCESS
> +	cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "riscv:online",
> +				  riscv_online_cpu, riscv_offline_cpu);
> +#endif
> +#ifdef CONFIG_RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
> +	cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "riscv:online",
> +				  riscv_online_cpu_vec, NULL);
> +#endif
> +
>   	return 0;
>   }
>   

Reviewed-by: Alexandre Ghiti <alexghiti at rivosinc.com>

Thanks,

Alex