powerpc/mm: Add a parameter to disable 1TB segs

[Michael Neuling]

On Mon, 2016-07-04 at 16:09 +1000, Michael Ellerman wrote:
> On Mon, 2016-04-07 at 00:44:04 UTC, Oliver O'Halloran wrote:
> > 
> > This patch adds the kernel command line parameter "no_tb_segs" which
> > forces the kernel to use 256MB rather than 1TB segments. Forcing the
> > use
> > of 256MB segments makes it considerably easier to test code that
> > depends
> > on an SLB miss occurring.
> That's a fairly awful name :)
> 
> Can you call it "disable_1T_segments" ?
> 
> 
> It should also be mentioned in Documentation/kernel-parameters.txt, with
> emphasis that it's a debug option and powerpc only.

To that end, should we add "powerpc_" at the start of the option?

Mikey