[PATCH] powerpc/64: set DSCR default initially from SPR

[Michael Ellerman]

Nicholas Piggin <npiggin at gmail.com> writes:

> Take the DSCR value set by firmware as the dscr_default value,
> rather than zero.
>
> POWER9 recommends DSCR default to a non-zero value.
>
> From: Nicholas Piggin <npiggin at gmail.com>
> ---
> This has a problem that OS which set the DSCR to non-default
> then kexec to Linux will be used as our default. I send a
> corresponding patch to skiboot which resets SPRs in opal_reinit_cpus
> which will make this do the right thing in that case.

That doesn't work for pseries etc.

We should reset it in the kexec down path.

cheers