From 29e8d76446e876be21833a3c3bb2f7c6d1a709b4 Mon Sep 17 00:00:00 2001 From: Eric DeVolder Date: Mon, 27 Mar 2023 15:10:26 -0400 Subject: [PATCH] x86/acpi/boot: Correct acpi_is_processor_usable() check commit fed8d8773b8ea68ad99d9eee8c8343bef9da2c2c upstream. 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 Suggested-by: Boris Ostrovsky Signed-off-by: Eric DeVolder Signed-off-by: Borislav Petkov (AMD) Tested-by: David R Cc: Link: https://lore.kernel.org/r/20230327191026.3454-2-eric.devolder@oracle.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/acpi/boot.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 518bda5..ee45e0e 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -193,7 +193,8 @@ 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; -- 2.7.4