For those managing to get their hands on a recently released Loongson 3A4000/3B4000 or even older Loongson 3 MIPS64 processors, improving the support is on the way with the upcoming Linux 5.7 kernel.
Queued as part of the MIPS architecture work for Linux 5.7 are a number of Loongson improvements, in particular for the Loongson 3 series.
The Loongson processors are pretty much impossible to come by outside of China, and gained some fame as the platform of choice for Richard Stallman.