skylake: Work around issue in ACPI interpreter

There appears to be an issue that is causing this particular bit of
ACPI code to be incorrectly interpreted by the kernel and the IASL
disassembler.

Ensuring the PCRB() method is defined in the DSDT before any uses of
it appears to fix the problem, but that relies on specific ordering
of the ASL files included by pch.asl and may break again in the future
if the includes were re-ordered.  (they are alphabetic now)

So in this case to work around the issue unroll the function call so
the admittedly messy calculation is reduced to a constant when compiled.

Note this issue was observed with both iasl-20130117 and
iasl-20150717.

ACPICA bug: https://bugs.acpica.org/show_bug.cgi?id=1201

BUG=chrome-os-partner:45760
BRANCH=none
TEST=verify disassembled AML is correct

Change-Id: I7b6a3b792f79755db0ea7b9f2ef6ee7f5000e018
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: ecacc340d6e1068ea649f0859657bb3208695730
Original-Change-Id: I232523f5b6ce290da6e7d99405a53b9437b10e0d
Original-Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/302167
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/11721
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
1 file changed