Re: [RFC][PATCH 1/5] mm: Rework {set,clear,mm}_tlb_flush_pending()

From: Peter Zijlstra
Date: Wed Aug 02 2017 - 11:46:27 EST

On Wed, Aug 02, 2017 at 11:57:04PM +1000, Benjamin Herrenschmidt wrote:
> On Wed, 2017-08-02 at 10:11 +0200, Peter Zijlstra wrote:
> > which should be completely ordered against anything prior and anything
> > following, and is I think the behaviour we want from TLB flushes in
> > general, but is very much not provided by a number of architectures
> > afaict.
> >
> > Ah, found the hash-64 code, yes that's good too. The hash32 code lives
> > in asm and confuses me, it has a bunch of SYNC, SYNC_601 and isync in.
> > The nohash variant seems to do a isync after tlbwe, but again no clue.
> Doing some archeology ? :-)

I thought ppc32 is still a popular platform for embedded, and not
actually knowing what kind of mmu those sport (if one at all of course),
I just looked at all of them.

Also, I'd been looking at all arch tlb invalidate code in any case :-)
(and yes my head hurts because of it)