x86/acpi/boot: Correct acpi_is_processor_usable() check

The logic in acpi_is_processor_usable() requires the online capable
bit be set for hotpluggable CPUs.  The online capable bit has been
introduced in ACPI 6.3.

However, for ACPI revisions < 6.3 which do not support that bit, CPUs
should be reported as usable, not the other way around.

Reverse the check.

  [ bp: Rewrite commit message. ]

Fixes: e2869bd7af ("x86/acpi/boot: Do not register processors that cannot be onlined for x2APIC")
Suggested-by: Miguel Luis <miguel.luis@oracle.com>
Suggested-by: Boris Ostrovsky <boris.ovstrosky@oracle.com>
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: David R <david@unsolicited.net>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/20230327191026.3454-2-eric.devolder@oracle.com
This commit is contained in:
Eric DeVolder 2023-03-27 15:10:26 -04:00 committed by Borislav Petkov (AMD)
parent a74fabfbd1
commit fed8d8773b

View File

@ -197,7 +197,8 @@ static bool __init acpi_is_processor_usable(u32 lapic_flags)
if (lapic_flags & ACPI_MADT_ENABLED)
return true;
if (acpi_support_online_capable && (lapic_flags & ACPI_MADT_ONLINE_CAPABLE))
if (!acpi_support_online_capable ||
(lapic_flags & ACPI_MADT_ONLINE_CAPABLE))
return true;
return false;