[coreboot-gerrit] Change in coreboot[master]: Rename MMCONF Kconfigs to ECAM_MMCONF

[Furquan Shaikh (Code Review)]

Attention is currently required from: Raul Rangel, Mariusz Szafrański, Jonathan Zhang, Paul Menzel, Stefan Reinauer, Kyösti Mälkki, Andrey Petrov, Patrick Rudolph, Nico Huber, Anjaneya "Reddy" Chagam, Johnny Lin, Suresh Bellampalli, Morgan Jang, Michal Motyl, Alexander Couzens, Felix Held, Shelley Chen, Lance Zhao, Jason Glenesk, Martin Roth, Damien Zammit, Lee Leahy, Marshall Dawson, Tim Wawrzynczak, Vanessa Eusebio, Huang Jin.
Furquan Shaikh has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/57333 )

Change subject: Rename MMCONF Kconfigs to ECAM_MMCONF
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Patch Set 5:

(2 comments)

Commit Message:

https://review.coreboot.org/c/coreboot/+/57333/comment/aa444f1b_5c470e16 
PS4, Line 9: the MMCONF Kconfigs only use the Enhanced Configuration
           : Access mechanism (ECAM) method
> The IO/MMIO distinction seems x86 specific to me, where we have two mechanisms concurrently.

Agreed.
> I'd say all other platforms simply need to implement some PCI OPS, without any special notion. They can use `device/pci_mmio_ops.h` for this, but don't have to.

All other platforms need (some kind of) MMIO ops. How the config window mapping works is specific to the platform. If the platform follows PCI spec, then it uses ECAM and hence has the config window mapping all devices. Other platforms might have some kind of translation unit to setup the decoding for the required device and then access that at maybe some fixed address. So at the top-level the MMIO ops can stay the same, but they can allow the platforms to map and provide the address to use for performing read/write config.

Patchset:

PS5:
> Can we please back up a little and discuss this on the mailing list first? […]

+1. I think it would be good to outline the entire effort required for enabling PCI config access for non-x86 platforms and solidify on the design. It can act as good reference for both the author and the reviewers. I had talked to Shelley about this last week and she was planning to upload something to gerrit for this.