I notice we have new warnings as a result of CMA being merged, though
thankfully they're just in Kconfig:

warning: (ARM) selects CMA which has unmet direct dependencies (HAVE_DMA_CONTIGUOUS && HAVE_MEMBLOCK && EXPERIMENTAL)

This seems totally weird: you're mandating that ARM must have CMA
selected, but it's an experimental feature?  So you're implying that
the entire ARM kernel becomes totally experimental for the next
release cycle?

I think this needs fixing.