On Thu, Oct 6, 2016 at 1:06 AM, Dou Liyang <douly.fnst@xxxxxxxxxxxxxx> wrote:
> I seem to remember that in x2APIC Spec the x2APIC ID may be at 255 or
> greater.
Good to know. Maybe later when one package have more cores like 30 cores etc.
> If we do that judgment, it may be affect x2APIC's work in some other places.
>
> I saw the MADT, the main reason may be that we define 0xff to acpi_id
> in LAPIC mode.
> As you said, it was like:
> [ 42.107902] ACPI: LAPIC (acpi_id[0xff] lapic_id[0xff] disabled)
> [ 42.120125] ACPI: LAPIC (acpi_id[0xff] lapic_id[0xff] disabled)
> [ 42.132361] ACPI: LAPIC (acpi_id[0xff] lapic_id[0xff] disabled)
> ...
>
> How about doing the acpi_id check when we parse it in
> acpi_parse_lapic().
>
> 8<----------------
>
> --- a/arch/x86/kernel/acpi/boot.c
> +++ b/arch/x86/kernel/acpi/boot.c
> @@ -233,6 +233,11 @@ acpi_parse_lapic(struct acpi_subtable_header * header,
> const unsigned long end)
>
> acpi_table_print_madt_entry(header);
>
> + if (processor->id >= 255) {
> + ++disabled_cpus;
> + return -EINVAL;
> + }
> +
> /*
> * We need to register disabled CPU as well to permit
> * counting disabled CPUs. This allows us to size
Yes, that should work. but should do the same thing for x2apic
in acpi_parse_x2apic should have
> + if (processor->local_apic_id == -1) {
> + ++disabled_cpus;
> + return -EINVAL;
> + }
that is the reason why i want to extend acpi_register_lapic()
to take extra disabled_id (one is 0xff and another is 0xffffffff)
so could save some lines.
Thanks
Yinghai
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