Re: [PATCH v5 3/5] arm64: smp: Allocate and setup IPI as NMI

From: Sumit Garg <sumit.garg@linaro.org>
To: Marc Zyngier <maz@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Jason Cooper <jason@lakedaemon.net>,
	Mark Rutland <mark.rutland@arm.com>,
	julien.thierry.kdev@gmail.com,
	Douglas Anderson <dianders@chromium.org>,
	Daniel Thompson <daniel.thompson@linaro.org>,
	Jason Wessel <jason.wessel@windriver.com>,
	Masayoshi Mizuma <msys.mizuma@gmail.com>,
	ito-yuichi@fujitsu.com, kgdb-bugreport@lists.sourceforge.net,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v5 3/5] arm64: smp: Allocate and setup IPI as NMI
Date: Tue, 20 Oct 2020 12:46:51 +0530	[thread overview]
Message-ID: <CAFA6WYODXzOoH=NiurikiK6wepsdfmnmUd4BzEJnguaSGzW7GQ@mail.gmail.com> (raw)
In-Reply-To: <1c68b74251dc72b0cd74706280ea96f7@kernel.org>

On Mon, 19 Oct 2020 at 17:29, Marc Zyngier <maz@kernel.org> wrote:
>
> On 2020-10-14 12:12, Sumit Garg wrote:
> > Allocate an unused IPI that can be turned as NMI using ipi_nmi
> > framework.
>
> This doesn't do any allocation, as far as I can see. It relies on
> the initial grant from the interrupt controller to be larger than
> what the kernel currently uses.
>

Okay, will update the commit message as s/Allocate/Assign/.

-Sumit

> > Also, invoke corresponding NMI setup/teardown APIs.
> >
> > Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
> > ---
> >  arch/arm64/kernel/smp.c | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >
> > diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
> > index 82e75fc..129ebfb 100644
> > --- a/arch/arm64/kernel/smp.c
> > +++ b/arch/arm64/kernel/smp.c
> > @@ -43,6 +43,7 @@
> >  #include <asm/daifflags.h>
> >  #include <asm/kvm_mmu.h>
> >  #include <asm/mmu_context.h>
> > +#include <asm/nmi.h>
> >  #include <asm/numa.h>
> >  #include <asm/processor.h>
> >  #include <asm/smp_plat.h>
> > @@ -962,6 +963,8 @@ static void ipi_setup(int cpu)
> >
> >       for (i = 0; i < nr_ipi; i++)
> >               enable_percpu_irq(ipi_irq_base + i, 0);
> > +
> > +     ipi_nmi_setup(cpu);
> >  }
> >
> >  #ifdef CONFIG_HOTPLUG_CPU
> > @@ -974,6 +977,8 @@ static void ipi_teardown(int cpu)
> >
> >       for (i = 0; i < nr_ipi; i++)
> >               disable_percpu_irq(ipi_irq_base + i);
> > +
> > +     ipi_nmi_teardown(cpu);
> >  }
> >  #endif
> >
> > @@ -995,6 +1000,9 @@ void __init set_smp_ipi_range(int ipi_base, int n)
> >               irq_set_status_flags(ipi_base + i, IRQ_HIDDEN);
> >       }
> >
> > +     if (n > nr_ipi)
> > +             set_smp_ipi_nmi(ipi_base + nr_ipi);
> > +
> >       ipi_irq_base = ipi_base;
> >
> >       /* Setup the boot CPU immediately */
>
> Thanks,
>
>          M.
> --
> Jazz is not dead. It just smells funny...