We currently run with 4k page size and 3 levels of page table which gives us a
38 bit address space. This is too small to fit Seattle's RAM.

We can either switch to 64k pages and 2 levels which would give us a
performance boost plus 42bits of VA space or move to 48bit VA space on 4k
pages, disabling SMMU support.

The only drawback of the 64k page support is that we'd lose compat support with
armv7 binaries. However, binutils 2.25 is changing segment offsets so that
32bit binaries would effectively run with 64k page size.

The best way forward IMHO would be to enable CONFIG_COMPAT for 64k page size
and tell anyone who needs to run 32bit code to use Factory as the base.