[coreboot-gerrit] [S] Change in coreboot[main]: acpi: Enable 64bit ECAM resource

[Nico Huber (Code Review)]

Attention is currently required from: Angel Pons, Arthur Heymans, Cliff Huang, David Milosevic, Lance Zhao, Martin L Roth, Maximilian Brune, Naresh Solanki, Patrick Rudolph, Tim Wawrzynczak.

Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/79096?usp=email )

Change subject: acpi: Enable 64bit ECAM resource
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Patch Set 3:

(1 comment)

File src/acpi/dsdt_top.asl:

https://review.coreboot.org/c/coreboot/+/79096/comment/df3d8ccc_a9750dd2 :
PS3, Line 77: 			MAX1 = (MIN1 + CONFIG_ECAM_MMCONF_LENGTH)
> I'm not sure but this might be something that is often done wrong, too. […]

I looked around in our tree and the only code that would seem to agree with
this is for NHLT devices, e.g. `soc/intel/alderlake/acpi/pch_hda.asl`.
However, digging more into the spec, it contradicts itself. In Table 6.44
it says for Len > 0, MinFixed, MaxFixed: "Fixed size, fixed location
resource descriptor. _GRA must be 0 and _LEN must be (_MAX - _MIN +1).".
I think that is more likely to be correct. When it says "highest possible
base address" that might just be a copy-paste error. And I seem to
remember now that we stumbled over this before.

This would make it `MIN1 + CONFIG_ECAM_MMCONF_LENGTH - 1` then.