Re: [pm:bleeding-edge 47/48] drivers/acpi/processor_idle.c:548:7: error: implicit declaration of function 'wakeup_cpu0'

[Vitaly Kuznetsov <vkuznets@redhat.com>]

kernel test robot <lkp@intel.com> writes:

> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git bleeding-edge
> head:   a70fdf61936ab0200d31bebea4b44bb67454ce07
> commit: 5f5e49e999acd8556e694e841d63226d21e409d9 [47/48] ACPI: processor: Fix CPU0 wakeup in acpi_idle_play_dead()
> config: x86_64-randconfig-a013-20210329 (attached as .config)
> compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 2a28d1d3b7bf2062288b46af34e33ccc543a99fa)
> reproduce (this is a W=1 build):
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # install x86_64 cross compiling tool for clang build
>         # apt-get install binutils-x86-64-linux-gnu
>         # https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/commit/?id=5f5e49e999acd8556e694e841d63226d21e409d9
>         git remote add pm https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git
>         git fetch --no-tags pm bleeding-edge
>         git checkout 5f5e49e999acd8556e694e841d63226d21e409d9
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> All errors (new ones prefixed by >>):
>
>>> drivers/acpi/processor_idle.c:548:7: error: implicit declaration of function 'wakeup_cpu0' [-Werror,-Wimplicit-function-declaration]
>                    if (wakeup_cpu0())
>                        ^

Sigh,

This one is under CONFIG_SMP in arch/x86/include/asm/smp.h

>>> drivers/acpi/processor_idle.c:549:4: error: implicit declaration of function 'start_cpu0' [-Werror,-Wimplicit-function-declaration]
>                            start_cpu0();

This one is under CONFIG_HOTPLUG_CPU0 (which obviously depends on
CONFIG_SMP)

I think we can put the whole block under #ifdef CONFIG_HOTPLUG_CPU0 as
it makes zero sense otherwise. I'll send a follow-up patch.

>                            ^
>    drivers/acpi/processor_idle.c:1103:12: warning: no previous prototype for function 'acpi_processor_ffh_lpi_probe' [-Wmissing-prototypes]
>    int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
>               ^
>    drivers/acpi/processor_idle.c:1103:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
>    int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
>    ^
>    static 
>    drivers/acpi/processor_idle.c:1108:12: warning: no previous prototype for function 'acpi_processor_ffh_lpi_enter' [-Wmissing-prototypes]
>    int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
>               ^
>    drivers/acpi/processor_idle.c:1108:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
>    int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
>    ^
>    static 
>    2 warnings and 2 errors generated.
>
>
> vim +/wakeup_cpu0 +548 drivers/acpi/processor_idle.c
>
>    524	
>    525	/**
>    526	 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
>    527	 * @dev: the target CPU
>    528	 * @index: the index of suggested state
>    529	 */
>    530	static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
>    531	{
>    532		struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
>    533	
>    534		ACPI_FLUSH_CPU_CACHE();
>    535	
>    536		while (1) {
>    537	
>    538			if (cx->entry_method == ACPI_CSTATE_HALT)
>    539				safe_halt();
>    540			else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
>    541				inb(cx->address);
>    542				wait_for_freeze();
>    543			} else
>    544				return -ENODEV;
>    545	
>    546	#ifdef CONFIG_X86
>    547			/* If NMI wants to wake up CPU0, start CPU0. */
>  > 548			if (wakeup_cpu0())
>  > 549				start_cpu0();
>    550	#endif
>    551		}
>    552	
>    553		/* Never reached */
>    554		return 0;
>    555	}
>    556	
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

-- 
Vitaly