Re: [PATCH RFC v2] cpu-hotplug: provide prototypes for arch CPU registration

Thomas Gleixner
2023-09-15T19:09:49Z

On Thu, Sep 14 2023 at 15:51, Russell King wrote:
> Provide common prototypes for arch_register_cpu() and
> arch_unregister_cpu(). These are called by acpi_processor.c, with
> weak versions, so the prototype for this is already set. It is
> generally not necessary for function prototypes to be conditional
> on preprocessor macros.
>
> Some architectures (e.g. Loongarch) are missing the prototype for this,
> and rather than add it to Loongarch's asm/cpu.h, lets do the job once
> for everyone.
>
> Since this covers everyone, remove the now unnecessary prototypes in
> asm/cpu.h, and we also need to remove the 'static' from one of ia64's
> arch_register_cpu() definitions.
>
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
> ---
> Spotted during the review of James Morse's patches, I think rather than
> adding prototypes for loongarch to its asm/cpu.h, it would make more
> sense to provide the prototypes in a non-arch specific header file so
> everyone can benefit, rather than having each architecture do its own
> thing.
>
> I'm sending this as RFC as James has yet to comment on my proposal, and
> also to a wider audience, and although it makes a little more work for
> James (to respin his series) it does mean that his series should get a
> little smaller.

And it makes tons of sense.

> See:
> https://lore.kernel.org/r/20230913163823.7880-2-james.morse@arm.com
> https://lore.kernel.org/r/20230913163823.7880-4-james.morse@arm.com
> https://lore.kernel.org/r/20230913163823.7880-23-james.morse@arm.com
>
> v2: lets try not fat-fingering vim.

Yeah. I wondered how you managed to mangle that :)

> arch/ia64/include/asm/cpu.h | 5 -----
> arch/ia64/kernel/topology.c | 2 +-

That's moot as ia64 is queued for removal :)

Thanks,

tglx