From a74fabfbd1b7013045afc8cc541e6cab3360ccb5 Mon Sep 17 00:00:00 2001
From: Mario Limonciello <mario.limonciello@amd.com>
Date: Wed, 29 Mar 2023 12:45:35 -0500
Subject: [PATCH] x86/ACPI/boot: Use FADT version to check support for online capable
Git-commit: a74fabfbd1b7013045afc8cc541e6cab3360ccb5
Patch-mainline: v6.3-rc6
References: git-fixes
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@oracle.com>
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/943d2445-84df-d939-f578-5d8240d342cc@unsolicited.net
Acked-by: Takashi Iwai <tiwai@suse.de>
---
arch/x86/kernel/acpi/boot.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 1c38174b5f01..729218462404 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -146,7 +146,11 @@ static int __init acpi_parse_madt(struct acpi_table_header *table)
pr_debug("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,
--
2.35.3