[PATCH] powerpc/mm/hash: Always clear UPRT and Host Radix bits when setting up CPU

[Michael Ellerman]

"Aneesh Kumar K.V" <aneesh.kumar at linux.vnet.ibm.com> writes:

> We will set LPCR with correct value for radix during int. This make sure we
> start with a sanitized value of LPCR. In case of kexec, cpus can have LPCR
> value based on the previous translation mode we were running.
>
> Fixes: fe036a0605d60 ("powerpc/64/kexec: Fix MMU cleanup on radix")
> Cc: stable at vger.kernel.org # v4.9+
> Acked-by: Michael Neuling <mikey at neuling.org>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>

I can merge this, but the proper fix is to set a sensible value on the
kexec down path.

That way you can kexec into an older kernel, which doesn't have this
fix. For this specific case maybe that's not really an issue, because
this is Power9 only and there aren't any old kernels that are expected
to work.

cheers