[v2] ARM: npcm: Add CPU hotplug callbacks for kexec support

[PATCH v2] ARM: npcm: Add CPU hotplug callbacks for kexec support

Posted by William A. Kennington III 2 years, 1 month ago

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 = {
 	.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

Re: [PATCH v2] ARM: npcm: Add CPU hotplug callbacks for kexec support

Posted by William Kennington 2 years ago

On Thu, Nov 2, 2023 at 3:10 AM 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 = {
>         .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
>'

Mind taking another look? This should be updated accordingly.

Re: [PATCH v2] ARM: npcm: Add CPU hotplug callbacks for kexec support

Posted by Tomer Maimon 2 years ago

Hi William,

On Sat, 2 Dec 2023 at 01:51, William Kennington <william@wkennington.com> wrote:
>
> On Thu, Nov 2, 2023 at 3:10 AM 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 = {
> >         .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
> >'
>
> Mind taking another look? This should be updated accordingly.

Reviewed-by: Tomer Maimon <tmaimon77@gmail.com>

Best regards,

Tomer