From: Eric DeVolder <eric.devolder@oracle.com>
Date: Mon, 27 Mar 2023 19:10:26 +0000 (-0400)
Subject: x86/acpi/boot: Correct acpi_is_processor_usable() check
X-Git-Tag: v6.6.7~3150^2~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=fed8d8773b8ea68ad99d9eee8c8343bef9da2c2c;p=platform%2Fkernel%2Flinux-starfive.git

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: e2869bd7af60 ("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
---

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 7292184..0dac4ab 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -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;