On Fri, Dec 16, 2022 at 7:36 PM James Puthukattukaran
<james.puthukattukaran@xxxxxxxxxx> wrote:
>
> Extending commit aa06e20f1be6 ("x86/ACPI: Don't add CPUs that are not
> online capable") to include acpi_parse_x2apic as well. There is a check
> for invalid apicid; however, there are BIOS FW with madt version >= 5
> support that do not bother setting apic id to an invalid value since they
> assume the OS will check the enabled and online capable flags.
>
> Signed-off-by: James Puthukattukaran<james.puthukattukaran@xxxxxxxxxx>
> Reported-by: Benjamin Fuller<ben.fuller@xxxxxxxxxx>
>
> v2 : use 'enabled' local variable. Also fix checkpatch.pl catches
> ---
> arch/x86/kernel/acpi/boot.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
> index 907cc98b1938..35d8c8654b42 100644
> --- a/arch/x86/kernel/acpi/boot.c
> +++ b/arch/x86/kernel/acpi/boot.c
> @@ -208,7 +208,16 @@ acpi_parse_x2apic(union acpi_subtable_headers *header, const unsigned long end)
> apic_id = processor->local_apic_id;
> enabled = processor->lapic_flags & ACPI_MADT_ENABLED;
>
> - /* Ignore invalid ID */
> +
> + /* don't register processors that can not be onlined */
> + if (acpi_support_online_capable &&
> + !enabled &&
Is the line break before the "enabled" check necessary?
I think it would be better to check "enabled" first anyway.
> + !(processor->lapic_flags & ACPI_MADT_ONLINE_CAPABLE))
> + return 0;
> +
> + /* for systems older than madt version 5 (does not have
> + * ACPI_MADT_ONLINE_CAPABLE defined), ignore invalid ID
> + */
The formatting of the above comment doesn't follow the kernel coding
style for multi-line comments.
> if (apic_id == 0xffffffff)
> return 0;
>
> --
