[M] Change in coreboot[master]: cpu/x86/mp_init.c: Keep track of initial lapic ID inside device_path

[Angel Pons (Code Review)]

Attention is currently required from: Arthur Heymans, Kyösti Mälkki.

Angel Pons has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/64342 )

Change subject: cpu/x86/mp_init.c: Keep track of initial lapic ID inside device_path
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Patch Set 8: Code-Review+1

(5 comments)

File src/arch/x86/cpu.c:

https://review.coreboot.org/c/coreboot/+/64342/comment/61c20097_fe5ebd1a 
PS5, Line 224: 	return NULL;
Given the usage below, maybe it's best to die instead of returning NULL? How important is the CPU cluster device?

https://review.coreboot.org/c/coreboot/+/64342/comment/5e6dfbf7_073733d9 
PS5, Line 233: cpu_cluster()
Can return NULL

https://review.coreboot.org/c/coreboot/+/64342/comment/c3c06e62_97912162 
PS5, Line 254: 	return dev->path.apic.initial_lapicid;
When there are `N` CPU devices (`0` to `N - 1`) and one calls this function with `N` as `logical_cpu`, `dev` would be NULL.

File src/cpu/x86/lapic/lapic_cpu_init.c:

https://review.coreboot.org/c/coreboot/+/64342/comment/111c47f5_dd4ce2e5 
PS8, Line 255: 	cpu_add_map_entry(info->index);
Where is `initial_lapicid` set?

https://review.coreboot.org/c/coreboot/+/64342/comment/24fa51a4_0561677e 
PS8, Line 396: 	cpu_add_map_entry(info->index);
Where is `initial_lapicid` set?