amd64 wakeup: recalculate ssb/rngds mitigations after APICs are woken

[kib]

Summary

APICs are needed to broadcast IPIs for MSR writes.

PR:     270489
Tested by:      dchagin

[dchagin]

sys/amd64/acpica/acpi_wakeup.c

300–301

q just for curiosity: why to not move all of this below intr_resume?

[manu]

Fix the issue for me on my whiskeylake laptop.

Thanks.

[kib]

Move everything after APICs are resumed.

[manu]

Last version still work on my laptop.

[markj]

sys/amd64/acpica/acpi_wakeup.c

299–300

It looks like this comment should move to before the identify_cpu_ext_features() call above.

[kib]

sys/amd64/acpica/acpi_wakeup.c

300–301

I tried to be conservative and recalculate as much as possible right after identify_cpu().

[kib]

Move comment back.

[dchagin]

confirm last ver work on stable/13.2 Intel i5-8265U SSBD, IBPB, MCUOPT

[henrix_camandro.org]

Just FWIW the patch does fix the issue for me too. Thanks a lot everyone!