PowerPC POWER10 updates to dcbf, sync and wait instructions

[Alan Modra]

On Mon, May 18, 2020 at 04:40:24PM -0500, Peter Bergner wrote:
> On 5/18/20 3:03 PM, Tulio Magno Quites Machado Filho wrote:
> > Power ISA 3.1 states the following (page 1038):
> > 
> >     The encodings for dcbfps, dcbstps, plwsync, and phwsync were chosen to
> >     enable software developed to control updates to persistent storage on
> >     processors that comply with Version 3.1 and subsequent versions of the
> >     architecture to run compatibly on the POWER9 processor.
> > 
> > So, I think these instructions should be available on POWER9 too.
> [snip]
> > Likewise here.
> > Power ISA 3.1, page 1087, figure 5 better describes how they're executed on
> > earlier processors.
> 
> I don't think this is saying we should enable the new mnemonics on POWER9,
> but rather if one of these is assembled for POWER10, that they'll run on
> POWER9 just fine.  Ditto for the sync insns.
> 
> Alan or Bill,
> 
> How do you read those paragraphs?

With the same conclusion as you do.

-- 
Alan Modra
Australia Development Lab, IBM