Re: [PATCH V3 6/6] crypto/nx: Add P9 NX support for 842 compression engine

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Tue, 2017-08-29 at 09:58 -0400, Dan Streetman wrote:
> > +
> > +       ret = -EINVAL;
> > +       if (coproc && coproc->vas.rxwin) {
> > +               wmem->txwin = nx842_alloc_txwin(coproc);
> 
> this is wrong.  the workmem is scratch memory that's valid only for
> the duration of a single operation.
> 
> do you actually need a txwin per crypto transform?  or do you need a
> txwin per coprocessor?  or txwin per processor?  either per-coproc or
> per-cpu should be created at driver init and held separately
> (globally) instead of a per-transform txwin.  I really don't see why
> you would need a txwin per transform, because the coproc should not
> care how many different transforms there are.

We should only need a single window for the whole kernel really, plus
one per user process who wants direct access but that's not relevant
here.

Cheers,
Ben.