It is a Chinese MIPS-based Arch

re "China has invested too much on mips64 (instead of arm) to switch" - this doesn't seem uniform across different Chinese companies, and loong still seems fairly niche there as far as I can make out from talking to people. Huawei are still all in on Arm, although they no longer have access to more recent Arm versions so they are continuing to develop the ones they had licenses for. Risc-V is also being developed elsewhere.