Messages in this thread Patch in this message | | | Subject | RE: [patch 1/1] Do not enforce unique IO_APIC_ID for Xeon processors in EM64T mode (x86_64) | Date | Wed, 11 May 2005 11:21:15 -0500 | From | "Protasevich, Natalie" <> |
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> > Looks like the need in the unique id can only be keyed of the local > > APIC id, and probably it is a good idea to keep the NO_IOAPIC_CHECK > > for subarchs that can override the heuristics? > > I prefer not to do that. How about a simple > > if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && > boot_cpu_data.x86 < 15) > /* do uniqueness check */ > else > /* don't do it */ > > ? > > Rationale is that P4s and newer and systems not from Intel > don't have serial APIC busses and don't need this uniqueness check. >
Yes, indeed this looks like the only undisputed (and sufficient) criteria. I tried the below with Xeon box and it worked fine:
--- mpparse.c.orig 2005-05-11 02:10:35.000000000 -0400 +++ mpparse.c 2005-05-11 02:12:31.000000000 -0400 @@ -912,7 +913,15 @@ void __init mp_register_ioapic ( mp_ioapics[idx].mpc_apicaddr = address; set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address); - mp_ioapics[idx].mpc_apicid = io_apic_get_unique_id(idx, id); + if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && (boot_cpu_data.x86 >= 15)) + mp_ioapics[idx].mpc_apicid = id; + else + mp_ioapics[idx].mpc_apicid = io_apic_get_unique_id(idx, id); mp_ioapics[idx].mpc_apicver = io_apic_get_version(idx); /* I am going to test this with Potomacs tonight to be sure, and then can send the final patch. Does the format look OK?
Thanks, --Natalie - 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/
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