Re: APIC version and 8-bit APIC IDs
From: Martin Wilck (martin.wilck_at_fujitsu-siemens.com)
Date: 08/31/05
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Date: Wed, 31 Aug 2005 16:27:40 +0200 To: linux-kernel@vger.kernel.org
Hi Maciej,
> It actually depends on the APIC type, rather than the CPU. E.g. with
> Pentium systems the width of the ID is either 4 bits or 8 bits,
> depending on whether the integrated or an external 82489DX APIC is
> used. This should be able to be determined by the APIC version; for
> v <= 0xf the ID is 8-bit and for v >= 0x10 it used to be 4-bit. Now
> you only need to determine what is the value of v above 0x10 that
> makes the ID 8-bit again.
That would be v>=0x14 for Intel. But that is wrong for AMD CPUs. The
actual Dual-Core Athlon CPUs we have report an APIC version of 0x10.
Please refer to the start of this thread.
Anyway, I understand that you agree this does not belong into the
subarch code?
Regards
Martin
-- Martin Wilck Phone: +49 5251 8 15113 Fujitsu Siemens Computers Fax: +49 5251 8 20409 Heinz-Nixdorf-Ring 1 mailto:Martin.Wilck@Fujitsu-Siemens.com D-33106 Paderborn http://www.fujitsu-siemens.com/primergy - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
- Previous message: Dr. David Alan Gilbert: "Re: Where is the performance bottleneck?"
- In reply to: Maciej W. Rozycki: "Re: APIC version and 8-bit APIC IDs"
- Next in thread: Andi Kleen: "Re: APIC version and 8-bit APIC IDs"
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