Re: [PATCH v3] x86/ACPI: Ignore CPUs that are not online capable for x2apic, entries as well

[James Puthukattukaran <james.puthukattukaran@oracle.com>]

Adding others that I missed on my first email. 

James

On 12/22/22 13:26, James Puthukattukaran 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@oracle.com>
> Reported-by: Benjamin Fuller<ben.fuller@oracle.com>
> 
> v2 : use 'enabled' local variable. Also fix checkpatch.pl catches
> v3 : updates as per Rafael's comments
> ---
>  arch/x86/kernel/acpi/boot.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
> index 907cc98b1938..cf2509f9de31 100644
> --- a/arch/x86/kernel/acpi/boot.c
> +++ b/arch/x86/kernel/acpi/boot.c
> @@ -208,7 +208,15 @@ 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 (!enabled && acpi_support_online_capable &&
> +	    !(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
> +	 */
>  	if (apic_id == 0xffffffff)
>  		return 0;
>