It does not serve any purpose now, the io apic id is not seen by software, and some Intel documents claim that the register is implemented for FUD reasons. More, renumbering seems to not work on new Intel machines which actually have mismatched MADT and hw IDs. On older machines where separate APIC bus existed, unique numbering of all APICs was required for bus arbitration to work, but it is no longer true (that machines were SMP from pre-Pentium IV era). When matching PCIe IOAPIC device against MADT-enumerated IOAPICs, compare io_apic_id from BAR against io_apic_id read from the MADT-pointed register page. Reviewed by: jhb Tested by: flo (previous version), pho MFC after: 2 weeks Differential revision: https://reviews.freebsd.org/D23965 |
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acpica | ||
bios | ||
conf | ||
cpufreq | ||
include | ||
iommu | ||
isa | ||
pci | ||
x86 | ||
xen |