[M] Change in coreboot[master]: UNTESTED acpi: Add ECAM region below PNP0C02 device in SSDT

[Arthur Heymans (Code Review)]

Attention is currently required from: Angel Pons, Jeff Daly, Lance Zhao, Matt DeVillier, Nico Huber, Sean Rhodes, Tim Wawrzynczak, Vanessa Eusebio.

Hello Angel Pons, Felix Held, Jeff Daly, Lance Zhao, Matt DeVillier, Nico Huber, Sean Rhodes, Tim Wawrzynczak, Vanessa Eusebio, build bot (Jenkins),

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

https://review.coreboot.org/c/coreboot/+/75729?usp=email

to look at the new patch set (#3).

Change subject: UNTESTED acpi: Add ECAM region below PNP0C02 device in SSDT
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UNTESTED acpi: Add ECAM region below PNP0C02 device in SSDT

From the Linux documentation (Documentation/PCI/acpi-info.rst):
[6] PCI Firmware 3.2, sec 4.1.2:
    If the operating system does not natively comprehend reserving the
    MMCFG region, the MMCFG region must be reserved by firmware.  The
    address range reported in the MCFG table or by _CBA method (see Section
    4.1.3) must be reserved by declaring a motherboard resource.  For most
    systems, the motherboard resource would appear at the root of the ACPI
    namespace (under _SB) in a node with a _HID of EISAID (PNP0C02), and
    the resources in this case should not be claimed in the root PCI bus’s
    _CRS.  The resources can optionally be returned in Int15 E820 or
    EFIGetMemoryMap as reserved memory but must always be reported through
    ACPI as a motherboard resource.

So in order for the OS to use ECAM MMCONF over legacy PCI IO
configuration, a PNP0C02 HId device needs to reserve this region.
Instead of having this code in each DSDT, add this via SSDT on all
platforms with CONFIG_ECAM_MMCONF_SUPPORT.

As no AMD platforms has this defined in DSDT this fixes Linux using
legacy PCI IO configuration over MMCONF. Tianocore messes with e820
table so that Linux in such a way that it prevents Linux from using PCIe
ECAM. This change fixes that problem.

Signed-off-by: Arthur Heymans 
Change-Id: I852e393726a1b086cf582f4d2d707e7cde05cbf4
---
M src/acpi/acpi.c
M src/northbridge/intel/gm45/acpi/gm45.asl
M src/northbridge/intel/haswell/acpi/hostbridge.asl
M src/northbridge/intel/i945/acpi/i945.asl
M src/northbridge/intel/ironlake/acpi/ironlake.asl
M src/northbridge/intel/pineview/acpi/pineview.asl
M src/northbridge/intel/sandybridge/acpi/sandybridge.asl
M src/northbridge/intel/x4x/acpi/x4x.asl
M src/soc/intel/apollolake/acpi/northbridge.asl
M src/soc/intel/baytrail/acpi/southcluster.asl
M src/soc/intel/braswell/acpi/southcluster.asl
M src/soc/intel/common/block/acpi/acpi/northbridge.asl
M src/soc/intel/denverton_ns/acpi/northcluster.asl
M src/soc/intel/skylake/acpi/systemagent.asl
14 files changed, 38 insertions(+), 45 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/29/75729/3