Re: [PATCH v2 12/24] powerpc/cpu: Mark start_secondary_resume() __noreturn

From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Josh Poimboeuf <jpoimboe@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: "jgross@suse.com" <jgross@suse.com>,
	"richard.henderson@linaro.org" <richard.henderson@linaro.org>,
	"ink@jurassic.park.msu.ru" <ink@jurassic.park.msu.ru>,
	"mattst88@gmail.com" <mattst88@gmail.com>,
	"linux-alpha@vger.kernel.org" <linux-alpha@vger.kernel.org>,
	"linux@armlinux.org.uk" <linux@armlinux.org.uk>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
	"will@kernel.org" <will@kernel.org>,
	"guoren@kernel.org" <guoren@kernel.org>,
	"linux-csky@vger.kernel.org" <linux-csky@vger.kernel.org>,
	"linux-ia64@vger.kernel.org" <linux-ia64@vger.kernel.org>,
	"chenhuacai@kernel.org" <chenhuacai@kernel.org>,
	"kernel@xen0n.name" <kernel@xen0n.name>,
	"loongarch@lists.linux.dev" <loongarch@lists.linux.dev>,
	"f.fainelli@gmail.com" <f.fainelli@gmail.com>,
	"bcm-kernel-feedback-list@broadcom.com"
	<bcm-kernel-feedback-list@broadcom.com>,
	"tsbogend@alpha.franken.de" <tsbogend@alpha.franken.de>,
	"linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org>,
	"jiaxun.yang@flygoat.com" <jiaxun.yang@flygoat.com>,
	"mpe@ellerman.id.au" <mpe@ellerman.id.au>,
	"npiggin@gmail.com" <npiggin@gmail.com>,
	"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
	"ysato@users.sourceforge.jp" <ysato@users.sourceforge.jp>,
	"dalias@libc.org" <dalias@libc.org>,
	"linux-sh@vger.kernel.org" <linux-sh@vger.kernel.org>,
	"davem@davemloft.net" <davem@davemloft.net>,
	"sparclinux@vger.kernel.org" <sparclinux@vger.kernel.org>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"mingo@redhat.com" <mingo@redhat.com>,
	"bp@alien8.de" <bp@alien8.de>,
	"dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
	"x86@kernel.org" <x86@kernel.org>,
	"hpa@zytor.com" <hpa@zytor.com>,
	"chris@zankel.net" <chris@zankel.net>,
	"jcmvbkbc@gmail.com" <jcmvbkbc@gmail.com>,
	"linux-xtensa@linux-xtensa.org" <linux-xtensa@linux-xtensa.org>,
	"peterz@infradead.org" <peterz@infradead.org>,
	"juri.lelli@redhat.com" <juri.lelli@redhat.com>,
	"vincent.guittot@linaro.org" <vincent.guittot@linaro.org>,
	"dietmar.eggemann@arm.com" <dietmar.eggemann@arm.com>,
	"rostedt@goodmis.org" <rostedt@goodmis.org>,
	"bsegall@google.com" <bsegall@google.com>,
	"mgorman@suse.de" <mgorman@suse.de>,
	"bristot@redhat.com" <bristot@redhat.com>,
	"vschneid@redhat.com" <vschneid@redhat.com>,
	"paulmck@kernel.org" <paulmck@kernel.org>
Subject: Re: [PATCH v2 12/24] powerpc/cpu: Mark start_secondary_resume() __noreturn
Date: Tue, 14 Feb 2023 07:19:27 +0000	[thread overview]
Message-ID: <3a1be09c-b9fd-a473-0819-81a4ebdf34cc@csgroup.eu> (raw)
In-Reply-To: <b6b2141f832d8cd8ade65f190d04b011cda5f9bb.1676358308.git.jpoimboe@kernel.org>

Le 14/02/2023 à 08:05, Josh Poimboeuf a écrit :
> start_secondary_resume() doesn't return.  Annotate it as such.  By
> extension this also makes arch_cpu_idle_dead() noreturn.
> 
> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>

> ---
>   arch/powerpc/include/asm/smp.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
> index f63505d74932..cfd42ca8765c 100644
> --- a/arch/powerpc/include/asm/smp.h
> +++ b/arch/powerpc/include/asm/smp.h
> @@ -66,7 +66,7 @@ void start_secondary(void *unused);
>   extern int smp_send_nmi_ipi(int cpu, void (*fn)(struct pt_regs *), u64 delay_us);
>   extern int smp_send_safe_nmi_ipi(int cpu, void (*fn)(struct pt_regs *), u64 delay_us);
>   extern void smp_send_debugger_break(void);
> -extern void start_secondary_resume(void);
> +extern void __noreturn start_secondary_resume(void);

Would have been a good opportunity to drop the pointless 'extern' keyword.

Checkpatch reports:

CHECK: extern prototypes should be avoided in .h files
#19: FILE: arch/powerpc/include/asm/smp.h:69:
+extern void __noreturn start_secondary_resume(void);

>   extern void smp_generic_give_timebase(void);
>   extern void smp_generic_take_timebase(void);
>   