This is a note to let you know that I've just added the patch titled
x86/ACPI/boot: Use FADT version to check support for online capable
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-acpi-boot-use-fadt-version-to-check-support-for-.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit cf8da7f357c25cfa1fb0b78c3ad744e071e8d798
Author: Mario Limonciello <mario.limonciello@xxxxxxx>
Date: Wed Mar 29 12:45:35 2023 -0500
x86/ACPI/boot: Use FADT version to check support for online capable
[ Upstream commit a74fabfbd1b7013045afc8cc541e6cab3360ccb5 ]
ACPI 6.3 introduced the online capable bit, and also introduced MADT
version 5.
Latter was used to distinguish whether the offset storing online capable
could be used. However ACPI 6.2b has MADT version "45" which is for
an errata version of the ACPI 6.2 spec. This means that the Linux code
for detecting availability of MADT will mistakenly flag ACPI 6.2b as
supporting online capable which is inaccurate as it's an ACPI 6.3 feature.
Instead use the FADT major and minor revision fields to distinguish this.
[ bp: Massage. ]
Fixes: aa06e20f1be6 ("x86/ACPI: Don't add CPUs that are not online capable")
Reported-by: Eric DeVolder <eric.devolder@xxxxxxxxxx>
Reported-by: Borislav Petkov <bp@xxxxxxxxx>
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Cc: <stable@xxxxxxxxxx>
Link: https://lore.kernel.org/r/943d2445-84df-d939-f578-5d8240d342cc@xxxxxxxxxxxxxxx
Stable-dep-of: 128b0c9781c9 ("x86/i8259: Skip probing when ACPI/MADT advertises PCAT compatibility")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 7840e650f452a..2f7f72b6f1235 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -141,7 +141,11 @@ static int __init acpi_parse_madt(struct acpi_table_header *table)
printk(KERN_DEBUG PREFIX "Local APIC address 0x%08x\n",
madt->address);
}
- if (madt->header.revision >= 5)
+
+ /* ACPI 6.3 and newer support the online capable bit. */
+ if (acpi_gbl_FADT.header.revision > 6 ||
+ (acpi_gbl_FADT.header.revision == 6 &&
+ acpi_gbl_FADT.minor_revision >= 3))
acpi_support_online_capable = true;
default_acpi_madt_oem_check(madt->header.oem_id,
