This is a note to let you know that I've just added the patch titled
x86/topology: Fix duplicated core ID within a package
to the 5.15-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-topology-fix-duplicated-core-id-within-a-package.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 71eac7063698b7d7b8fafb1683ac24a034541141 Mon Sep 17 00:00:00 2001
From: Zhang Rui <rui.zhang@xxxxxxxxx>
Date: Fri, 14 Oct 2022 17:01:47 +0800
Subject: x86/topology: Fix duplicated core ID within a package
From: Zhang Rui <rui.zhang@xxxxxxxxx>
commit 71eac7063698b7d7b8fafb1683ac24a034541141 upstream.
Today, core ID is assumed to be unique within each package.
But an AlderLake-N platform adds a Module level between core and package,
Linux excludes the unknown modules bits from the core ID, resulting in
duplicate core ID's.
To keep core ID unique within a package, Linux must include all APIC-ID
bits for known or unknown levels above the core and below the package
in the core ID.
It is important to understand that core ID's have always come directly
from the APIC-ID encoding, which comes from the BIOS. Thus there is no
guarantee that they start at 0, or that they are contiguous.
As such, naively using them for array indexes can be problematic.
[ dhansen: un-known -> unknown ]
Fixes: 7745f03eb395 ("x86/topology: Add CPUID.1F multi-die/package support")
Suggested-by: Len Brown <len.brown@xxxxxxxxx>
Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Reviewed-by: Len Brown <len.brown@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20221014090147.1836-5-rui.zhang@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/topology.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kernel/cpu/topology.c
+++ b/arch/x86/kernel/cpu/topology.c
@@ -141,7 +141,7 @@ int detect_extended_topology(struct cpui
sub_index++;
}
- core_select_mask = (~(-1 << core_plus_mask_width)) >> ht_mask_width;
+ core_select_mask = (~(-1 << pkg_mask_width)) >> ht_mask_width;
die_select_mask = (~(-1 << die_plus_mask_width)) >>
core_plus_mask_width;
Patches currently in stable-queue which might be from rui.zhang@xxxxxxxxx are
queue-5.15/x86-topology-fix-multiple-packages-shown-on-a-single-package-system.patch
queue-5.15/hwmon-coretemp-handle-large-core-id-value.patch
queue-5.15/x86-topology-fix-duplicated-core-id-within-a-package.patch
