[PATCH 2/3] of/fdt: introduce of_scan_flat_dt_subnodes and of_get_flat_dt_phandle

[Benjamin Herrenschmidt]

On Wed, 2017-04-05 at 10:58 -0500, Rob Herring wrote:
> Well, I'd like to avoid expanding usage of flat DT parsing in the
> kernel. But you could just put this function into arch/powerpc and I'd
> never see it, but I like that even less. Mainly, I just wanted to
> raise the point.
> 
> Your argument works until you need that setup in assembly code, then
> you are in the situation that you need to either handle the setup in
> bootloader/firmware or have an simple way to determine that condition.

The main issue is that changing that is a very very invasive change in
an extremely fragile and rather nasty area of code shared by 32 and 64-
bit for which we don't even have easy access to all the machines to
test with anymore :)

It's probably not impossible, but it would delay the new cpu feature
stuff that Nick is making by a lot, probably monthes, making it nearly
impossible to get back into distros etc... 

So while it might be something to consider, I would definitely keep
that as a separate unit of work to do later.

Cheers,
Ben.