Re: [PATCH RFC v3 05/21] ACPI: Rename ACPI_HOTPLUG_CPU to include 'present'

Jonathan Cameron
2023-12-14T17:41:10Z

On Wed, 13 Dec 2023 12:49:37 +0000
Russell King (Oracle) <rmk+kernel@armlinux.org.uk> wrote:

> From: James Morse <james.morse@arm.com>
>
> 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@arm.com>
> Tested-by: Miguel Luis <miguel.luis@oracle.com>
> Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com>
> Tested-by: Jianyong Wu <jianyong.wu@arm.com>
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Formatting nitpick inline. Either way FWIW:
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> 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