Tobias, the SPR names/numbers are in sprs.csv.  you can find the appropriate
names from running soc/decoder/power_enums.py, it deliberately prints out
the SPRs after reading sprs.csv

also remember spaces, and also to use SPR.DSISR.value (etc)

        SPR_PID   = 48  # TODO read docs for POWER9
        # Microwatt doesn't implement the partition table
        # instead has PRTBL register (SPR) to point to process table
        SPR_PRTBL = 720 # see common.vhdl in microwatt, not in POWER9
        with m.If(((self.dec.op.internal_op == MicrOp.OP_MTSPR) |
                   (self.dec.op.internal_op == MicrOp.OP_MFSPR)) &
                  ((spr == SPR.DSISR) | (spr == SPR.DAR)
                   | (spr==SPR_PRTBL) | (spr==SPR_PID))):
            comb += self.do_copy("fn_unit", Function.MMU)
        with m.Else():