> From: Alex Bennée <[email protected]> > Sent: Friday, September 29, 2023 3:27 PM > To: Salil Mehta <[email protected]> > Cc: [email protected]; [email protected]; [email protected]; jean- > [email protected]; Jonathan Cameron <[email protected]>; > [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; > [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > zhukeqian <[email protected]>; wangxiongfeng (C) > <[email protected]>; wangyanan (Y) <[email protected]>; > [email protected]; [email protected]; [email protected]; Linuxarm > <[email protected]> > Subject: Re: [PATCH 3/9] hw/acpi: Add ACPI CPU hotplug init stub > > > Salil Mehta <[email protected]> writes: > > > ACPI CPU hotplug related initialization should only happen if > > ACPI_CPU_HOTPLUG > > support has been enabled for particular architecture. Add > > cpu_hotplug_hw_init() > > stub to avoid compilation break. > > When does the compilation break? It's usually ok to include stubs with > that commit.
To be specific. it is not a compilation break but linking error. Support of ACPI_CPU_HOTPLUG is optional. This flag is defined in architecture specific Kconfig. Function cpu_hotplug_hw_init() is part of the hw/acpi/cpu.c which gets compiled only when a particular architecture defines ACPI_CPU_HOTPLUG flag. ACPI GED framework support for CPU Hotplug is not specific to any architecture. acpi_ged_initfn() calls cpu_hotplug_hw_init() when GED device gets created. This functions gets called irrespective of the fact CPU Hotplug is supported or not. If ACPI_CPU_HOTPLUG is not enabled then presence of cpu_hotplug_hw_init() will cause linking error without the presence of stub. Thanks Salil. > > Signed-off-by: Salil Mehta <[email protected]> > > --- > > hw/acpi/acpi-cpu-hotplug-stub.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/hw/acpi/acpi-cpu-hotplug-stub.c b/hw/acpi/acpi-cpu-hotplug- > stub.c > > index 3fc4b14c26..c6c61bb9cd 100644 > > --- a/hw/acpi/acpi-cpu-hotplug-stub.c > > +++ b/hw/acpi/acpi-cpu-hotplug-stub.c > > @@ -19,6 +19,12 @@ void legacy_acpi_cpu_hotplug_init(MemoryRegion > *parent, Object *owner, > > return; > > } > > > > +void cpu_hotplug_hw_init(MemoryRegion *as, Object *owner, > > + CPUHotplugState *state, hwaddr base_addr) > > +{ > > + return; > > +} > > + > > void acpi_cpu_ospm_status(CPUHotplugState *cpu_st, ACPIOSTInfoList > ***list) > > { > > return; > > > -- > Alex Bennée > Virtualisation Tech Lead @ Linaro
