arm64: cpufeature: Add support for the MPAM v0.1 architecture version
According to the MPAM spec [1], the supported architecture versions are
v1.0, v1.1 and v0.1. MPAM versions v0.1 and v1.1 are functionally
identical, but v0.1 additionally supports the FORCE_NS feature.
ID_AA64PR | ID_AA64PR | MPAM Extension | Notes
F0_EL1. | F1_EL1. | Architecture |
MPAM | MPAM_frac | version |
---------------------------------------------------------------------------
0b0000 | 0b0001 | v0.1 | MPAM v0.1 is implemented.
| | | MPAM v0.1 is the same as MPAM v1.1
| | | with FORCE_NS which is
| | | incompatible with MPAM v1.0.
---------------------------------------------------------------------------
0b0001 | 0b0000 | v1.0 | MPAM v1.0 is implemented.
---------------------------------------------------------------------------
0b0001 | 0b0001 | v1.1 | MPAM v1.1 is implemented.
| | | MPAM v1.1 includes all features of
| | | MPAM v1.0.
| | | It must not include FORCE_NS.
FORCE_NS is a feature that operates in EL3 mode. Consequently, the current
Linux MPAM driver is also compatible with MPAM v0.1. To support v0.1, the
existing driver which only checks ID_AA64PFR0_EL1.MPAM for the major
version needs to examine ID_AA64PFR1_EL1.MPAM_frac for the minor version
as well.