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: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 Signed-off-by:
Sasha Levin <sashal@kernel.org> Signed-off-by:
Lipeng Sang <sanglipeng1@jd.com>
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