Subject: Re: [PATCH v2 1/3] powerpc/mm: Enable radix GTSE only if supported.

From: Bharata B Rao <[email-masked]>
Date: Mon, 29 Jun 2020 10:01:30 +0530

On Fri, Jun 26, 2020 at 05:55:30PM -0300, Murilo Opsfelder Araújo wrote:
> > diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
> > index bc73abf0bc25..152aa0200cef 100644
> > --- a/arch/powerpc/mm/init_64.c
> > +++ b/arch/powerpc/mm/init_64.c
> > @@ -407,12 +407,15 @@ static void __init early_check_vec5(void)
> >  		if (!(vec5[OV5_INDX(OV5_RADIX_GTSE)] &
> >  						OV5_FEAT(OV5_RADIX_GTSE))) {
> >  			pr_warn("WARNING: Hypervisor doesn't support RADIX with GTSE\n");
> > -		}
> > +			cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE;
> > +		} else
> > +			cur_cpu_spec->mmu_features |= MMU_FTR_GTSE;
> >  		/* Do radix anyway - the hypervisor said we had to */
> >  		cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
> >  	} else if (mmu_supported == OV5_FEAT(OV5_MMU_HASH)) {
> >  		/* Hypervisor only supports hash - disable radix */
> >  		cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
> > +		cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE;
> >  	}
> >  }
> 
> Is this a part of the code where mmu_clear_feature() cannot be used?

Yes, it appears so. Jump label initialization isn't done yet.

Regards,
Bharata.