Messages in this thread | | | From | (Eric W. Biederman) | Date | Sat, 12 Jul 2008 00:02:54 -0700 | Subject | Re: [patch 00/26] x64, x2apic/intr-remap: Interrupt-remapping and x2apic support |
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"Yinghai Lu" <yhlu.kernel@gmail.com> writes:
> On Fri, Jul 11, 2008 at 8:52 PM, Eric W. Biederman > <ebiederm@xmission.com> wrote: >> "Yinghai Lu" <yhlu.kernel@gmail.com> writes: >> >>> 1. wonder if x2apic can be use with uniprocessor. >>> >>> in APIC_init_uniprocessor, it will try to enable x2apic, but later >>> >>> apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid)); >>> >>> but SET_APIC_ID is still for xapic version. so need to GET_APIC_ID, >>> SET_APIC_ID for different >>> genapic like 32bit. >>> >>> 2 check_x2apic is called in setup_arch, but it only set apic_ops, >>> and genapic still not changed, aka apic_flat... >>> wonder if you need to call setup_apic_routing to set genapic. >>> >>> otherwise read_apic_id could have use the one from apic_flat....need >>> to shift...... >>> >>> 3.or move read_apic_id to apic_ops intead...together with GET_APIC_ID too. >>> but 32bit version seems like to put GET_APIC_ID with genapic... >>> >>> which one is better? 2 or 3 >> >> Z finish untangle SMP support from apic initialization and move the apic >> initialization up into init_IRQ. >> >> That is better but is likely the wrong short term approach. > > plan to add get_apic_id(x) into 64bit genapic, and will use > #define GET_APIC_ID(x) genapic->get_apic_id(x) > #define read_apic_id() GET_APIC_ID(apic_read(APIC_ID)) > > so it is identical to 32bit, and we smooth the merging of 32/64 apic code > > also read the x2APIC spec pdf, it doesn't say anything about interrupt > remapping...need to be used with x2apic...
Clustered logical mode won't work as it requires > 16 bits of apicid. So only flat physical mode will work.
Eric
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