Commit cbfbe852 authored by Zhang Rui's avatar Zhang Rui Committed by openeuler-sync-bot
Browse files

x86/topology: Fix duplicated core ID within a package

stable inclusion
from stable-v5.10.154
commit 5bdbccc79c86424fef1960de76abab9e83cfbdc9
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I64YCB

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5bdbccc79c86424fef1960de76abab9e83cfbdc9



--------------------------------

[ Upstream commit 71eac706 ]

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: 7745f03e ("x86/topology: Add CPUID.1F multi-die/package support")
Suggested-by: default avatarLen Brown <len.brown@intel.com>
Signed-off-by: default avatarZhang Rui <rui.zhang@intel.com>
Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: default avatarLen Brown <len.brown@intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20221014090147.1836-5-rui.zhang@intel.com


Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarLipeng Sang <sanglipeng1@jd.com>
(cherry picked from commit d065f1f2)
parent 6c90edfa
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