Re: [PATCH] wireguard: Kconfig: select CRYPTO_CHACHA_S390

[Jason A. Donenfeld]

On Tue, Jul 05, 2022 at 02:49:19AM +0200, Jason A. Donenfeld wrote:
> Hi Vladis,
> 
> On Mon, Jul 04, 2022 at 09:15:35PM +0200, Vladis Dronov wrote:
> > Select the new implementation of CHACHA20 for S390 when available,
> > it is faster than the generic software implementation.
> > 
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > Link: https://lore.kernel.org/linux-kernel/202207030630.6SZVkrWf-lkp@xxxxxxxxx/
> > Signed-off-by: Vladis Dronov <vdronov@xxxxxxxxxx>
> > ---
> >  drivers/net/Kconfig | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
> > index b2a4f998c180..8c1eeb5a8db8 100644
> > --- a/drivers/net/Kconfig
> > +++ b/drivers/net/Kconfig
> > @@ -94,6 +94,7 @@ config WIREGUARD
> >  	select CRYPTO_CURVE25519_NEON if ARM && KERNEL_MODE_NEON
> >  	select CRYPTO_CHACHA_MIPS if CPU_MIPS32_R2
> >  	select CRYPTO_POLY1305_MIPS if MIPS
> > +	select CRYPTO_CHACHA_S390 if S390
> >  	help
> >  	  WireGuard is a secure, fast, and easy to use replacement for IPSec
> >  	  that uses modern cryptography and clever networking tricks. It's
> > -- 
> > 2.36.1
> 
> Thanks for the patch. Queued up as:
> https://git.zx2c4.com/wireguard-linux/commit/?id=1b4ab028730cd00c144eaa51160865504b780961
> 
> I'll include this in my series to net.git soon.

This actually leads to a minor problem:

  WARNING: unmet direct dependencies detected for CRYPTO_CHACHA_S390
    Depends on [n]: CRYPTO [=y] && CRYPTO_HW [=n] && S390 [=y]

This is of course harmless, since this doesn't *actually* depend on
CRYPTO_HW. In fact, the dependency on CRYPTO_HW is entirely a mistake
here that was repeated a few times. I cleaned this up and fixed it in
this patch:

    https://lore.kernel.org/linux-crypto/20220705014653.111335-1-Jason@xxxxxxxxx/

So hopefully Herbert will take that for 5.19 and then we'll be all set
here.

Jason