[PATCH v1 1/3] arm64/sve: Split _sve_flush macro into separate Z, P and FFR flushes

[Dave Martin]

On Mon, May 10, 2021 at 05:19:58PM +0100, Mark Brown wrote:
> On Mon, May 10, 2021 at 04:47:23PM +0100, Dave Martin wrote:
> > On Mon, May 10, 2021 at 04:22:53PM +0100, Mark Brown wrote:
> > > On Mon, May 10, 2021 at 03:57:11PM +0100, Dave P Martin wrote:
> 
> > > > If not, can we keep these combined?  We could either keep the name
> > > > sve_flush_p (since the FFR is a predicate register, if a weird kind of
> > > > one), or go with something more descriptive such as sve_flush_p_and_ffr.
> 
> > > Not right now but I do expect to build on this in the not too distant
> > > future.
> 
> > OK, but due to the fact that we need to dirty a P-register in order to
> > zero the FFR, these still don't feel like independent operations.
> 
> Indeed, like I said I got confused by the way the macros end up being
> written when I originally wrote this.
> 
> > Can we control the clearing of the FFR (or not) with an argument to a
> > combined macro?
> 
> It's an option, I'm poking around with how to do it.

OK, if we keep the P-reg and FFR flushing as a single macro for now and
extend it later, I'd be happy with that.

Cheers
---Dave