soc/amd/picasso/include/iomap: add comment about ACPI IO assignment

Finally figured out why ACPI_GPE0_BLK only being 4 bytes after
ACPI_CPU_CONTROL won't work and its due to the CPU trapping 8 IO
addresses from ACPI_CPU_CONTROL on for C state control. This is set up
in set_cstate_io_addr by writing the ACPI_CPU_CONTROL value into
MSR_CSTATE_ADDRESS.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: Iedf53bbdae6ca65224601aad5cd1163df4b54131
Reviewed-on: https://review.coreboot.org/c/coreboot/+/73423
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Fred Reitberger <reitbergerfred@gmail.com>

0 files changed, 0 insertions, 0 deletions