ID_AA64PFR0_EL1_MASK
cpu_id_aa64pfr0 &= ~ID_AA64PFR0_EL1_MASK;
id &= ~ID_AA64PFR0_EL1_MASK;
#define ID_AA64PFR0_EL1(x) ((x) & ID_AA64PFR0_EL1_MASK)