]> git.baikalelectronics.ru Git - kernel.git/commit
x86/topology: Fix duplicated core ID within a package
authorZhang Rui <rui.zhang@intel.com>
Fri, 14 Oct 2022 09:01:47 +0000 (17:01 +0800)
committerDave Hansen <dave.hansen@linux.intel.com>
Mon, 17 Oct 2022 18:58:52 +0000 (11:58 -0700)
commitd143e215dce4690dc762f214474ada4ccac41ad2
tree0687f2222519f4578f0df80a2096271edcb43fb3
parentca22de20b0cb1c212510dd673b5de0d002733b9d
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: a22998b5d3de ("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
arch/x86/kernel/cpu/topology.c