[PATCH] powerpc: Fix HAVE_HARDLOCKUP_DETECTOR_ARCH build configuration

[Christophe Leroy]

Le 27/03/2021 à 10:49, Chen Huang a écrit :
> When compiling the powerpc with the SMP disabled, it shows the issue:
> 
> arch/powerpc/kernel/watchdog.c: In function ‘watchdog_smp_panic’:
> arch/powerpc/kernel/watchdog.c:177:4: error: implicit declaration of function ‘smp_send_nmi_ipi’; did you mean ‘smp_send_stop’? [-Werror=implicit-function-declaration]
>    177 |    smp_send_nmi_ipi(c, wd_lockup_ipi, 1000000);
>        |    ^~~~~~~~~~~~~~~~
>        |    smp_send_stop
> cc1: all warnings being treated as errors
> make[2]: *** [scripts/Makefile.build:273: arch/powerpc/kernel/watchdog.o] Error 1
> make[1]: *** [scripts/Makefile.build:534: arch/powerpc/kernel] Error 2
> make: *** [Makefile:1980: arch/powerpc] Error 2
> make: *** Waiting for unfinished jobs....
> 
> We found that powerpc used ipi to implement hardlockup watchdog, so the
> HAVE_HARDLOCKUP_DETECTOR_ARCH should depend on the SMP.
> 
> Fixes: 2104180a5369 ("powerpc/64s: implement arch-specific hardlockup watchdog")
> Reported-by: Hulk Robot <hulkci at huawei.com>
> Signed-off-by: Chen Huang <chenhuang5 at huawei.com>
> ---
>   arch/powerpc/Kconfig | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 764df010baee..2d4f37b117ce 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -225,7 +225,7 @@ config PPC
>   	select HAVE_LIVEPATCH			if HAVE_DYNAMIC_FTRACE_WITH_REGS
>   	select HAVE_MOD_ARCH_SPECIFIC
>   	select HAVE_NMI				if PERF_EVENTS || (PPC64 && PPC_BOOK3S)
> -	select HAVE_HARDLOCKUP_DETECTOR_ARCH	if (PPC64 && PPC_BOOK3S)
> +	select HAVE_HARDLOCKUP_DETECTOR_ARCH	if PPC64 && PPC_BOOK3S && SMP

While modifying this line, you should restore the alphabetic order by moving it up.

You can use PPC_BOOK3S_64 instead of PPC64 && PPC_BOOK3S

>   	select HAVE_OPTPROBES			if PPC64
>   	select HAVE_PERF_EVENTS
>   	select HAVE_PERF_EVENTS_NMI		if PPC64
>