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Differential D6060

ensure that initial local apic id is sane on AMD 10h systems
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Authored by avg on Apr 22 2016, 1:30 PM.
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kib
jhb
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rS298736: ensure that initial local apic id is sane on AMD 10h systems
Summary

The initial Local APIC ID is returned by CPUID function 1 (in EBX).
On AMD Family 10h systems the way that ID is built is controlled by
an MSR bit. BKDG instructs BIOS to set it in a certain way, but a BIOS can
be buggy. In that case the ID can confuse tools that use it, e.g. hwloc.
See: https://github.com/open-mpi/hwloc/issues/183

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rS FreeBSD src repository - subversion
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Build 3444: arc lint + arc unit

Event Timeline

avg updated this revision to Diff 15492.Apr 22 2016, 1:30 PM
avg retitled this revision from to ensure that initial local apic id is sane on AMD 10h systems.
avg updated this object.
avg edited the test plan for this revision. (Show Details)
avg added reviewers: jhb, kib.
Herald added a subscriber: imp. · View Herald TranscriptApr 22 2016, 1:30 PM
kib edited edge metadata.EditedApr 22 2016, 2:19 PM

Does the MADT ACPI table content no longer match what CPU reports, in particular, the APIC IDs ?

avg added a comment.Apr 22 2016, 2:42 PM
In D6060#129003, @kib wrote:

Does the MADT ACPI table content no longer match what CPU reports, in particular, the APIC IDs ?

Yes, that's the case. MADT and LAPICs have consistent sane values of 0 -3 on my system, but the IDs reported via CPUID.1 are 0, 0x40, 0x80, 0xc0.

kib added a comment.Apr 22 2016, 2:51 PM
In D6060#129004, @avg wrote:

Yes, that's the case. MADT and LAPICs have consistent sane values of 0 -3 on my system, but the IDs reported via CPUID.1 are 0, 0x40, 0x80, 0xc0.

I suggest to note this in the comment.

kib accepted this revision.Apr 22 2016, 2:51 PM
kib edited edge metadata.
This revision is now accepted and ready to land.Apr 22 2016, 2:51 PM
Closed by commit rS298736: ensure that initial local apic id is sane on AMD 10h systems (authored by avg). · Explain WhyApr 28 2016, 8:30 AM
This revision was automatically updated to reflect the committed changes.

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sys/
amd64/
amd64/
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Diff 15492

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sys/amd64/amd64/initcpu.c

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