On Wed, Jul 06, 2016 at 10:28:57AM -0700, Geoff Levand wrote:
> On Wed, 2016-07-06 at 16:52 +0900, AKASHI Takahiro wrote:
> > --- a/arch/arm64/include/asm/smp.h
> > +++ b/arch/arm64/include/asm/smp.h
> > @@ -136,6 +136,10 @@ static inline void cpu_panic_kernel(void)
> > */
> > bool cpus_are_stuck_in_kernel(void);
> >
> > +#ifdef CONFIG_KEXEC_CORE
> > +extern void smp_send_crash_stop(void);
> > +#endif
>
> It seems this could be simplified by removing these
> conditionals, then move the conditionals that are
> around the smp_send_crash_stop definition to inside
> that definition.
OK.
> > diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
> > index 62ff3c0..51e0b73 100644
> > --- a/arch/arm64/kernel/smp.c
> > +++ b/arch/arm64/kernel/smp.c
> > @@ -800,6 +803,28 @@ static void ipi_cpu_stop(unsigned int cpu)
> > > > > cpu_relax();
> > }
> >
> > +#ifdef CONFIG_KEXEC_CORE
> > +static atomic_t waiting_for_crash_ipi;
> > +
> > +static void ipi_cpu_crash_stop(unsigned int cpu, struct pt_regs *regs)
> > +{
> > +> > crash_save_cpu(regs, cpu);
> > +
> > +> > atomic_dec(&waiting_for_crash_ipi);
> > +
> > +> > local_irq_disable();
> > +
> > +#ifdef CONFIG_HOTPLUG_CPU
> > +> > if (cpu_ops[cpu]->cpu_die)
> > +> > > cpu_ops[cpu]->cpu_die(cpu);
> > +#endif
> > +
> > +> > /* just in case */
> > +> > while (1)
> > +> > > wfi();
> > +}
> > +#endif
>
> /*
> > * Main handler for inter-processor interrupts
> > */
> > @@ -830,6 +855,14 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
> > > > > irq_exit();
> > > > > break;
> >
> > +#ifdef CONFIG_KEXEC_CORE
> > +> > case IPI_CPU_CRASH_STOP:
> > +> > > irq_enter();
> > +> > > ipi_cpu_crash_stop(cpu, regs);
> > +
> > +> > > unreachable();
> > +#endif
>
> It seems like you could simplifiy with something like:
>
> case IPI_CPU_CRASH_STOP:
> if (IS_ENABLED(CONFIG_KEXEC_CORE) {
> irq_enter();
> ipi_cpu_crash_stop(cpu, regs);
> unreachable();
> }
OK, I will take this.
> Then move the CONFIG_KEXEC_CORE conditional around
> ipi_cpu_crash_stop to just around crash_save_cpu().
Yeah, we can do that, but I added these conditionals just because
the kernel size can be reduced (a bit, obviously) if kexec is
not needed.
So instead of removing the conditional around ipi_cpu_crash_stop(),
an empty definition will be added for !CONFIG_KEXEC_CORE.
Thanks,
-Takahiro AKASHI
> -Geoff
