Re: [PATCH 04/10] MIPS: Move mips_smp_ipi_init call after prepare_cpus

[Huacai Chen]

Hi, Jiaxun

On Mon, Jun 17, 2024 at 5:03 AM Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> wrote:
>
> This will give platform code a genuine chance to setup
> IPI IRQ in prepare_cpus.
>
> This is the best place for platforms to setup IPI as smp_setup
> is too early for IRQ subsystem.
mips_smp_ipi_init() is an early_initcall() function, why do you say it
is in smp_setup()?


Huacai
>
> Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
> ---
>  arch/mips/kernel/smp.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
> index fe053fe52147..ddf96c28e2f0 100644
> --- a/arch/mips/kernel/smp.c
> +++ b/arch/mips/kernel/smp.c
> @@ -375,7 +375,6 @@ static int __init mips_smp_ipi_init(void)
>
>         return 0;
>  }
> -early_initcall(mips_smp_ipi_init);
>  #endif
>
>  /*
> @@ -460,12 +459,22 @@ void __init smp_cpus_done(unsigned int max_cpus)
>  /* called from main before smp_init() */
>  void __init smp_prepare_cpus(unsigned int max_cpus)
>  {
> +       int rc;
> +
>         init_new_context(current, &init_mm);
>         current_thread_info()->cpu = 0;
>         mp_ops->prepare_cpus(max_cpus);
>         set_cpu_sibling_map(0);
>         set_cpu_core_map(0);
>         calculate_cpu_foreign_map();
> +#ifdef CONFIG_GENERIC_IRQ_IPI
> +       rc = mips_smp_ipi_init();
> +       if (rc) {
> +               pr_err("Failed to initialize IPI - disabling SMP");
> +               init_cpu_present(cpumask_of(0));
> +               return;
> +       }
> +#endif
>  #ifndef CONFIG_HOTPLUG_CPU
>         init_cpu_present(cpu_possible_mask);
>  #endif
>
> --
> 2.43.0
>