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References: <20231102002453.1299195-1-william@wkennington.com> <20231102101009.15104-1-william@wkennington.com>
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From:   William Kennington <william@wkennington.com>
Date:   Fri, 1 Dec 2023 15:51:35 -0800
Message-ID: <CAD_4BXgmCdc_H-XfmGnW3fa6H=cbONma6QzUiofNVZWJtcBwOg@mail.gmail.com>
Subject: Re: [PATCH v2] ARM: npcm: Add CPU hotplug callbacks for kexec support
To:     tmaimon77@gmail.com, tali.perry1@gmail.com, avifishman70@gmail.com
Cc:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        openbmc@lists.ozlabs.org, Brian Ma <chma0@nuvoton.com>
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On Thu, Nov 2, 2023 at 3:10=E2=80=AFAM William A. Kennington III
<william@wkennington.com> wrote:
>
> From: Brian Ma <chma0@nuvoton.com>
>
> Add callbacks required for kexec to function. The NPCM7xx does
> not expose controls for powering down CPU cores, so just wait in idle
> loop.
>
> Signed-off-by: Brian Ma <chma0@nuvoton.com>
> Signed-off-by: William A. Kennington III <william@wkennington.com>
> ---
>  arch/arm/mach-npcm/platsmp.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/arch/arm/mach-npcm/platsmp.c b/arch/arm/mach-npcm/platsmp.c
> index 41891d3aa124..6cc7b5894f08 100644
> --- a/arch/arm/mach-npcm/platsmp.c
> +++ b/arch/arm/mach-npcm/platsmp.c
> @@ -69,10 +69,27 @@ static void __init npcm7xx_smp_prepare_cpus(unsigned =
int max_cpus)
>
>         iounmap(scu_base);
>  }
> +#ifdef CONFIG_HOTPLUG_CPU
> +static void npcm7xx_cpu_die(unsigned int cpu)
> +{
> +       while (1)
> +               cpu_do_idle();
> +}
> +
> +static int npcm7xx_cpu_kill(unsigned int l_cpu)
> +{
> +       return 1;
> +}
> +#endif
> +
>
>  static struct smp_operations npcm7xx_smp_ops __initdata =3D {
>         .smp_prepare_cpus =3D npcm7xx_smp_prepare_cpus,
>         .smp_boot_secondary =3D npcm7xx_smp_boot_secondary,
> +#ifdef CONFIG_HOTPLUG_CPU
> +       .cpu_die                        =3D npcm7xx_cpu_die,
> +       .cpu_kill                       =3D npcm7xx_cpu_kill,
> +#endif
>  };
>
>  CPU_METHOD_OF_DECLARE(npcm7xx_smp, "nuvoton,npcm750-smp", &npcm7xx_smp_o=
ps);
> --
> 2.42.0.820.g83a721a137-goog
>'

Mind taking another look? This should be updated accordingly.