Re: [PATCH v2] powerpc: Move arch_trigger_cpumask_backtrace from nmi.h to irq.h

[Michael Ellerman <mpe@ellerman.id.au>]

Douglas Anderson <dianders@chromium.org> writes:
> The powerpc architecture was the only one that defined
> arch_trigger_cpumask_backtrace() in asm/nmi.h instead of
> asm/irq.h. Move it to be consistent.
>
> This fixes compile time errors introduced by commit 7ca8fe94aa92
> ("watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH"). That commit
> caused <asm/nmi.h> to stop being included if the hardlockup detector
> wasn't enabled. The specific errors were:
>   error: implicit declaration of function ‘nmi_cpu_backtrace’
>   error: implicit declaration of function ‘nmi_trigger_cpumask_backtrace’
>
> NOTE: when moving this into irq.h, we also change the guards from just
> checking if "CONFIG_NMI_IPI" is defined to also checking if
> "CONFIG_PPC_BOOK3S_64" is defined. This matches the code in
> arch/powerpc/kernel/stacktrace.c. Previously this worked because
> <asm.nmi.h> was included if "CONFIG_HAVE_HARDLOCKUP_DETECTOR_ARCH" was
> defined. For powerpc that's only selected if "CONFIG_PPC_BOOK3S_64" is
> defined.
>
> Fixes: 7ca8fe94aa92 ("watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH")
> Reported-by: Michael Ellerman <mpe@ellerman.id.au>
> Closes: https://lore.kernel.org/r/871qi5otdh.fsf@mail.lhotse
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
> I'd expect that this would land in Andrew Morton's tree along with the
> other lockup detector stuff.
>
> Changes in v2:
> - Change the guards to include CONFIG_PPC_BOOK3S_64.

Thanks, this fixes all the build errors AFAICS.

Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)

cheers

>  arch/powerpc/include/asm/irq.h | 6 ++++++
>  arch/powerpc/include/asm/nmi.h | 6 ------
>  2 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
> index 94dffa1dd223..f257cacb49a9 100644
> --- a/arch/powerpc/include/asm/irq.h
> +++ b/arch/powerpc/include/asm/irq.h
> @@ -53,5 +53,11 @@ void __do_IRQ(struct pt_regs *regs);
>  
>  int irq_choose_cpu(const struct cpumask *mask);
>  
> +#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_NMI_IPI)
> +extern void arch_trigger_cpumask_backtrace(const cpumask_t *mask,
> +					   bool exclude_self);
> +#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
> +#endif
> +
>  #endif /* _ASM_IRQ_H */
>  #endif /* __KERNEL__ */
> diff --git a/arch/powerpc/include/asm/nmi.h b/arch/powerpc/include/asm/nmi.h
> index ce25318c3902..49a75340c3e0 100644
> --- a/arch/powerpc/include/asm/nmi.h
> +++ b/arch/powerpc/include/asm/nmi.h
> @@ -9,12 +9,6 @@ void watchdog_hardlockup_set_timeout_pct(u64 pct);
>  static inline void watchdog_hardlockup_set_timeout_pct(u64 pct) {}
>  #endif
>  
> -#ifdef CONFIG_NMI_IPI
> -extern void arch_trigger_cpumask_backtrace(const cpumask_t *mask,
> -					   bool exclude_self);
> -#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
> -#endif
> -
>  extern void hv_nmi_check_nonrecoverable(struct pt_regs *regs);
>  
>  #endif /* _ASM_NMI_H */
> -- 
> 2.41.0.162.gfafddb0af9-goog