On Wed, 13 Dec 2023 12:49:37 +0000 Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> wrote: > From: James Morse <james.morse@xxxxxxx> > > The code behind ACPI_HOTPLUG_CPU allows a not-present CPU to become > present. This isn't the only use of HOTPLUG_CPU. On arm64 and riscv > CPUs can be taken offline as a power saving measure. > > On arm64 an offline CPU may be disabled by firmware, preventing it from > being brought back online, but it remains present throughout. > > Adding code to prevent user-space trying to online these disabled CPUs > needs some additional terminology. > > Rename the Kconfig symbol CONFIG_ACPI_HOTPLUG_PRESENT_CPU to reflect > that it makes possible CPUs present. > > HOTPLUG_CPU is untouched as this is only about the ACPI mechanism. > > Signed-off-by: James Morse <james.morse@xxxxxxx> > Tested-by: Miguel Luis <miguel.luis@xxxxxxxxxx> > Tested-by: Vishnu Pajjuri <vishnu@xxxxxxxxxxxxxxxxxxxxxx> > Tested-by: Jianyong Wu <jianyong.wu@xxxxxxx> > Signed-off-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> Formatting nitpick inline. Either way FWIW: Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> > diff --git a/include/linux/acpi.h b/include/linux/acpi.h > index 4db54e928b36..36071bc11acd 100644 > --- a/include/linux/acpi.h > +++ b/include/linux/acpi.h > #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC > int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr); > @@ -629,7 +629,7 @@ static inline u32 acpi_osc_ctx_get_cxl_control(struct acpi_osc_context *context) > #define ACPI_GSB_ACCESS_ATTRIB_RAW_PROCESS 0x0000000F > > /* Enable _OST when all relevant hotplug operations are enabled */ > -#if defined(CONFIG_ACPI_HOTPLUG_CPU) && \ > +#if defined(CONFIG_ACPI_HOTPLUG_PRESENT_CPU) && \ Trivial but I think there is a tab to many before that \ > defined(CONFIG_ACPI_HOTPLUG_MEMORY) && \ > defined(CONFIG_ACPI_CONTAINER) > #define ACPI_HOTPLUG_OST
