tree 281bf0b1e50bfe0d3f5e72c193e182d54d785c2d
parent c8007f727bbaa562107dd3e60a473403c22faee2
author Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> 1501491119 +0200
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1511508959 +0100

x86/cpu/amd: Derive L3 shared_cpu_map from cpu_llc_shared_mask

commit 2b83809a5e6d619a780876fcaf68cdc42b50d28c upstream.

For systems with X86_FEATURE_TOPOEXT, current logic uses the APIC ID
to calculate shared_cpu_map. However, APIC IDs are not guaranteed to
be contiguous for cores across different L3s (e.g. family17h system
w/ downcore configuration). This breaks the logic, and results in an
incorrect L3 shared_cpu_map.

Instead, always use the previously calculated cpu_llc_shared_mask of
each CPU to derive the L3 shared_cpu_map.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170731085159.9455-3-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>