The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

Possible dependencies:

71eac7063698 ("x86/topology: Fix duplicated core ID within a package")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 71eac7063698b7d7b8fafb1683ac24a034541141 Mon Sep 17 00:00:00 2001 From: Zhang Rui rui.zhang@intel.com Date: Fri, 14 Oct 2022 17:01:47 +0800 Subject: [PATCH] x86/topology: Fix duplicated core ID within a package

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@intel.com Signed-off-by: Zhang Rui rui.zhang@intel.com Signed-off-by: Dave Hansen dave.hansen@linux.intel.com Reviewed-by: Len Brown len.brown@intel.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20221014090147.1836-5-rui.zhang@intel.com

diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c index f7592814e5d5..5e868b62a7c4 100644 --- a/arch/x86/kernel/cpu/topology.c +++ b/arch/x86/kernel/cpu/topology.c @@ -141,7 +141,7 @@ int detect_extended_topology(struct cpuinfo_x86 *c) 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;