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

James Puthukattukaran
2022-12-09T03:18:48Z

Extending the patch commit aa06e20f1be628186f0c2dcec09ea0009eb69778 to be
included for acpi_parse_x2apic as well. There is a check for invalid apicid.
However, there are BIOSes with madt verison >= 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>
---
arch/x86/kernel/acpi/boot.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 907cc98b1938..6dc46909bd9a 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -208,7 +208,14 @@ 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 &&
+ !(processor->lapic_flags & ACPI_MADT_ENABLED) &&
+ !(processor->lapic_flags & ACPI_MADT_ONLINE_CAPABLE))
+ return 0;
+
+ /* for systems older than madt version 5, ignore invalid ID */
if (apic_id == 0xffffffff)
return 0;

--
2.31.1