Change in coreboot[master]: soc/intel/{adl,tgl,jsl}: Add smihandler_soc_disable_busmaster

[Kane Chen (Code Review)]

Attention is currently required from: Furquan Shaikh, Kane Chen, Karthik Ramasubramanian.
Hello build bot (Jenkins), Furquan Shaikh, Kane Chen, Tim Wawrzynczak, Patrick Rudolph, Karthik Ramasubramanian,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/52873

to look at the new patch set (#6).

Change subject: soc/intel/{adl,tgl,jsl}: Add smihandler_soc_disable_busmaster
......................................................................

soc/intel/{adl,tgl,jsl}: Add smihandler_soc_disable_busmaster

If a power button SMI is triggered between where it is currently
enabled and before FSP-S exits, when the SMI handler disables
bus mastering for all devices, it inadvertently also disables
the PMC's I/O decoding, so the register write to actually go into
S5 does not succeed, and the system hangs.

This can be solved by skipping the PMC when disabling bus
mastering in the SMI handler, for which a callback,
smihandler_soc_disable_busmaster is provided.

BUG=b:186194102, b:186815114
TEST=Power on the system and pressing power button repeatedly doesn't
     cause the system hang during shutdown.

Change-Id: I1cf5cf91ebad4a49df6679e01fc88ff60c81526c
Signed-off-by: Kane Chen 
---
M src/soc/intel/alderlake/smihandler.c
M src/soc/intel/jasperlake/smihandler.c
M src/soc/intel/tigerlake/smihandler.c
3 files changed, 24 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/73/52873/6