Re: [PATCH v1 05/10] powerpc/mm: Do early ioremaps from top to bottom on PPC64 too.

On Tue, Aug 13, 2019 at 08:11:38PM +0000, Christophe Leroy wrote:

Until vmalloc system is up and running, ioremap basically
allocates addresses at the border of the IOREMAP area.

Note that while a few other architectures have a magic hack like powerpc
to make ioremap work before vmalloc, the normal practice would be
to explicitly use early_ioremap.  I guess your change is fine for now,
but it might make sense convert powerpc to the explicit early_ioremap
scheme as well.