Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:5 as permitted sender) client-ip=2620:137:e000::3:5;
MIME-Version: 1.0
References: <20231102002453.1299195-1-william@wkennington.com> <20231102005321.1303809-1-william@wkennington.com>
In-Reply-To: <20231102005321.1303809-1-william@wkennington.com>
From:   Tomer Maimon <tmaimon77@gmail.com>
Date:   Thu, 2 Nov 2023 10:38:36 +0200
Message-ID: <CAP6Zq1ig9hadeWATYVgzZkhmsU3qe6Se+hwU6rSjvnGr0OmvMA@mail.gmail.com>
Subject: Re: [PATCH RESEND] ARM: npcm: Add CPU hotplug callbacks for kexec support
To:     william@wkennington.com
Cc:     tali.perry1@gmail.com, avifishman70@gmail.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        openbmc@lists.ozlabs.org, Brian Ma <chma0@nuvoton.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hi William,


On Thu, 2 Nov 2023 at 02:53, <william@wkennington.com> wrote:
>
> From: Brian Ma <chma0@nuvoton.com>
>
> Add callbacks required for kexec to function. The NPCM7xx/NPCN8xx does
> not expose controls for powering down CPU cores, so just wait in idle
> loop.
This patch is related only to NPCM7xx please modify NPCM7xx/NPCN8xx to NPCM7xx.
>
> 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 = {
>         .smp_prepare_cpus = npcm7xx_smp_prepare_cpus,
>         .smp_boot_secondary = npcm7xx_smp_boot_secondary,
> +#ifdef CONFIG_HOTPLUG_CPU
> +       .cpu_die                        = npcm7xx_cpu_die,
> +       .cpu_kill                       = npcm7xx_cpu_kill,
> +#endif
>  };
>
>  CPU_METHOD_OF_DECLARE(npcm7xx_smp, "nuvoton,npcm750-smp", &npcm7xx_smp_ops);
> --
> 2.42.0.820.g83a721a137-goog
>

Best regards,

Tomer