From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Hi,
These patches aim to remove CONFIG_HOLES_IN_ZONE and essentially hardwire
pfn_valid_within() to 1.
The idea is to mark NOMAP pages as reserved in the memory map and restore
the intended semantics of pfn_valid() to designate availability of struct
page for a pfn.
With this the core mm will be able to cope with the fact that it cannot use
NOMAP pages and the holes created by NOMAP ranges within MAX_ORDER blocks
will be treated correctly even without the need for pfn_valid_within.
The patches are boot tested on qemu-system-aarch64.
I beleive it would be best to route these via mmotm tree.