The above patch fixes the issue for me (on 32-bit mipsel), but would need some further testing.
I wrote:
> Fixes: 51061b8876a3 ("MIPS: math-emu: Fix prefx detection and COP1X function
> field definition")
but I realized this has been broken by
commit 919af8b96c89 ("MIPS: Make definitions of MIPSInst_FMA_{FUNC,FMTM}
consistent with MIPS64 manual")
in v5.12 which modified the MIPSInst_FMA_FFMT macro without updating the users.
