[PATCH 2/6] arm64: Allow mismatched 32-bit EL0 support

[Will Deacon]

On Wed, Oct 28, 2020 at 11:18:10AM +0000, Catalin Marinas wrote:
> On Tue, Oct 27, 2020 at 09:51:14PM +0000, Will Deacon wrote:
> > +bool system_has_mismatched_32bit_el0(void)
> > +{
> > +	u64 reg;
> > +	unsigned int fld;
> > +
> > +	if (!__allow_mismatched_32bit_el0)
> > +		return false;
> > +
> > +	reg = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
> > +	fld = cpuid_feature_extract_unsigned_field(reg, ID_AA64PFR0_EL0_SHIFT);
> > +	return fld == ID_AA64PFR0_EL0_64BIT_ONLY;
> > +}
> 
> Same here, this reports true even if no 32-bit is available (I have yet
> to go through the other patches to see how this function is used).

Same deal, really. We need to report true to deal with late-onlining.

Will