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

[Mark Brown]

On Mon, May 10, 2021 at 03:57:11PM +0100, Dave P Martin wrote:

> > +.macro sve_flush_ffr
> >  		_sve_wrffr	0

> This doesn't flush the FFR as advertised, but writes whatever happens to
> be in P0 to the FFR.

Oh, bother - the way the macros work mean the argument isn't super clear
there, it looks like it writes an immediate value, and then of course
the generated code looks identical.  Will fix.

> Thinking about it, is there ever a situation when we would want to flush
> the P-regs and not the FFR (or vice-versa)?  I can't see where we would
> want to do that myself.

> 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.
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