-"""Power ISA Decoder second stage
+# moved to openpower-isa
+# https://git.libre-soc.org/?p=openpower-isa.git;a=summary
+# wildcard imports here ONLY to support migration
-based on Anton Blanchard microwatt decode2.vhdl
-
-Note: OP_TRAP is used for exceptions and interrupts (micro-code style) by
-over-riding the internal opcode when an exception is needed.
-"""
-
-from nmigen import Module, Elaboratable, Signal, Mux, Const, Cat, Repl, Record
-from nmigen.cli import rtlil
-from nmutil.util import sel
-
-from soc.regfile.regfiles import XERRegs
-
-from nmutil.picker import PriorityPicker
-from nmutil.iocontrol import RecordObject
-from nmutil.extend import exts
-
-from soc.experiment.mem_types import LDSTException
-
-from soc.decoder.power_svp64_prefix import SVP64PrefixDecoder
-from soc.decoder.power_svp64_extra import SVP64CRExtra, SVP64RegExtra
-from soc.decoder.power_svp64_rm import SVP64RMModeDecode
-from soc.decoder.power_regspec_map import regspec_decode_read
-from soc.decoder.power_regspec_map import regspec_decode_write
-from soc.decoder.power_decoder import create_pdecode
-from soc.decoder.power_enums import (MicrOp, CryIn, Function,
- CRInSel, CROutSel,
- LdstLen, In1Sel, In2Sel, In3Sel,
- OutSel, SPRfull, SPRreduced,
- RC, LDSTMode,
- SVEXTRA, SVEtype, SVPtype)
-from soc.decoder.decode2execute1 import (Decode2ToExecute1Type, Data,
- Decode2ToOperand)
-from soc.sv.svp64 import SVP64Rec
-from soc.consts import (MSR, SPEC, EXTRA2, EXTRA3, SVP64P, field,
- SPEC_SIZE, SPECb, SPEC_AUG_SIZE, SVP64CROffs)
-
-from soc.regfile.regfiles import FastRegs
-from soc.consts import TT
-from soc.config.state import CoreState
-from soc.regfile.util import spr_to_fast
-
-
-def decode_spr_num(spr):
- return Cat(spr[5:10], spr[0:5])
-
-
-def instr_is_priv(m, op, insn):
- """determines if the instruction is privileged or not
- """
- comb = m.d.comb
- is_priv_insn = Signal(reset_less=True)
- with m.Switch(op):
- with m.Case(MicrOp.OP_ATTN, MicrOp.OP_MFMSR, MicrOp.OP_MTMSRD,
- MicrOp.OP_MTMSR, MicrOp.OP_RFID):
- comb += is_priv_insn.eq(1)
- with m.Case(MicrOp.OP_TLBIE) : comb += is_priv_insn.eq(1)
- with m.Case(MicrOp.OP_MFSPR, MicrOp.OP_MTSPR):
- with m.If(insn[20]): # field XFX.spr[-1] i think
- comb += is_priv_insn.eq(1)
- return is_priv_insn
-
-
-class SPRMap(Elaboratable):
- """SPRMap: maps POWER9 SPR numbers to internal enum values, fast and slow
- """
-
- def __init__(self, regreduce_en):
- self.regreduce_en = regreduce_en
- if regreduce_en:
- SPR = SPRreduced
- else:
- SPR = SPRfull
-
- self.spr_i = Signal(10, reset_less=True)
- self.spr_o = Data(SPR, name="spr_o")
- self.fast_o = Data(3, name="fast_o")
-
- def elaborate(self, platform):
- m = Module()
- if self.regreduce_en:
- SPR = SPRreduced
- else:
- SPR = SPRfull
- with m.Switch(self.spr_i):
- for i, x in enumerate(SPR):
- with m.Case(x.value):
- m.d.comb += self.spr_o.data.eq(i)
- m.d.comb += self.spr_o.ok.eq(1)
- for x, v in spr_to_fast.items():
- with m.Case(x.value):
- m.d.comb += self.fast_o.data.eq(v)
- m.d.comb += self.fast_o.ok.eq(1)
- return m
-
-
-class DecodeA(Elaboratable):
- """DecodeA from instruction
-
- decodes register RA, implicit and explicit CSRs
- """
-
- def __init__(self, dec, regreduce_en):
- self.regreduce_en = regreduce_en
- if self.regreduce_en:
- SPR = SPRreduced
- else:
- SPR = SPRfull
- self.dec = dec
- self.sel_in = Signal(In1Sel, reset_less=True)
- self.insn_in = Signal(32, reset_less=True)
- self.reg_out = Data(5, name="reg_a")
- self.spr_out = Data(SPR, "spr_a")
- self.fast_out = Data(3, "fast_a")
- self.sv_nz = Signal(1)
-
- def elaborate(self, platform):
- m = Module()
- comb = m.d.comb
- op = self.dec.op
- reg = self.reg_out
- m.submodules.sprmap = sprmap = SPRMap(self.regreduce_en)
-
- # select Register A field, if *full 7 bits* are zero (2 more from SVP64)
- ra = Signal(5, reset_less=True)
- comb += ra.eq(self.dec.RA)
- with m.If((self.sel_in == In1Sel.RA) |
- ((self.sel_in == In1Sel.RA_OR_ZERO) &
- ((ra != Const(0, 5)) | (self.sv_nz != Const(0, 1))))):
- comb += reg.data.eq(ra)
- comb += reg.ok.eq(1)
-
- # some Logic/ALU ops have RS as the 3rd arg, but no "RA".
- # moved it to 1st position (in1_sel)... because
- rs = Signal(5, reset_less=True)
- comb += rs.eq(self.dec.RS)
- with m.If(self.sel_in == In1Sel.RS):
- comb += reg.data.eq(rs)
- comb += reg.ok.eq(1)
-
- # decode Fast-SPR based on instruction type
- with m.Switch(op.internal_op):
-
- # BC or BCREG: implicit register (CTR) NOTE: same in DecodeOut
- with m.Case(MicrOp.OP_BC):
- with m.If(~self.dec.BO[2]): # 3.0B p38 BO2=0, use CTR reg
- # constant: CTR
- comb += self.fast_out.data.eq(FastRegs.CTR)
- comb += self.fast_out.ok.eq(1)
- with m.Case(MicrOp.OP_BCREG):
- xo9 = self.dec.FormXL.XO[9] # 3.0B p38 top bit of XO
- xo5 = self.dec.FormXL.XO[5] # 3.0B p38
- with m.If(xo9 & ~xo5):
- # constant: CTR
- comb += self.fast_out.data.eq(FastRegs.CTR)
- comb += self.fast_out.ok.eq(1)
-
- # MFSPR move from SPRs
- with m.Case(MicrOp.OP_MFSPR):
- spr = Signal(10, reset_less=True)
- comb += spr.eq(decode_spr_num(self.dec.SPR)) # from XFX
- comb += sprmap.spr_i.eq(spr)
- comb += self.spr_out.eq(sprmap.spr_o)
- comb += self.fast_out.eq(sprmap.fast_o)
-
- return m
-
-
-class DecodeAImm(Elaboratable):
- """DecodeA immediate from instruction
-
- decodes register RA, whether immediate-zero, implicit and
- explicit CSRs. SVP64 mode requires 2 extra bits
- """
-
- def __init__(self, dec):
- self.dec = dec
- self.sel_in = Signal(In1Sel, reset_less=True)
- self.immz_out = Signal(reset_less=True)
- self.sv_nz = Signal(1) # EXTRA bits from SVP64
-
- def elaborate(self, platform):
- m = Module()
- comb = m.d.comb
-
- # zero immediate requested
- ra = Signal(5, reset_less=True)
- comb += ra.eq(self.dec.RA)
- with m.If((self.sel_in == In1Sel.RA_OR_ZERO) &
- (ra == Const(0, 5)) &
- (self.sv_nz == Const(0, 1))):
- comb += self.immz_out.eq(1)
-
- return m
-
-
-class DecodeB(Elaboratable):
- """DecodeB from instruction
-
- decodes register RB, different forms of immediate (signed, unsigned),
- and implicit SPRs. register B is basically "lane 2" into the CompUnits.
- by industry-standard convention, "lane 2" is where fully-decoded
- immediates are muxed in.
- """
-
- def __init__(self, dec):
- self.dec = dec
- self.sel_in = Signal(In2Sel, reset_less=True)
- self.insn_in = Signal(32, reset_less=True)
- self.reg_out = Data(7, "reg_b")
- self.reg_isvec = Signal(1, name="reg_b_isvec") # TODO: in reg_out
- self.fast_out = Data(3, "fast_b")
-
- def elaborate(self, platform):
- m = Module()
- comb = m.d.comb
- op = self.dec.op
- reg = self.reg_out
-
- # select Register B field
- with m.Switch(self.sel_in):
- with m.Case(In2Sel.RB):
- comb += reg.data.eq(self.dec.RB)
- comb += reg.ok.eq(1)
- with m.Case(In2Sel.RS):
- # for M-Form shiftrot
- comb += reg.data.eq(self.dec.RS)
- comb += reg.ok.eq(1)
-
- # decode SPR2 based on instruction type
- # BCREG implicitly uses LR or TAR for 2nd reg
- # CTR however is already in fast_spr1 *not* 2.
- with m.If(op.internal_op == MicrOp.OP_BCREG):
- xo9 = self.dec.FormXL.XO[9] # 3.0B p38 top bit of XO
- xo5 = self.dec.FormXL.XO[5] # 3.0B p38
- with m.If(~xo9):
- comb += self.fast_out.data.eq(FastRegs.LR)
- comb += self.fast_out.ok.eq(1)
- with m.Elif(xo5):
- comb += self.fast_out.data.eq(FastRegs.TAR)
- comb += self.fast_out.ok.eq(1)
-
- return m
-
-
-class DecodeBImm(Elaboratable):
- """DecodeB immediate from instruction
- """
- def __init__(self, dec):
- self.dec = dec
- self.sel_in = Signal(In2Sel, reset_less=True)
- self.imm_out = Data(64, "imm_b")
-
- def elaborate(self, platform):
- m = Module()
- comb = m.d.comb
-
- # select Register B Immediate
- with m.Switch(self.sel_in):
- with m.Case(In2Sel.CONST_UI): # unsigned
- comb += self.imm_out.data.eq(self.dec.UI)
- comb += self.imm_out.ok.eq(1)
- with m.Case(In2Sel.CONST_SI): # sign-extended 16-bit
- si = Signal(16, reset_less=True)
- comb += si.eq(self.dec.SI)
- comb += self.imm_out.data.eq(exts(si, 16, 64))
- comb += self.imm_out.ok.eq(1)
- with m.Case(In2Sel.CONST_SI_HI): # sign-extended 16+16=32 bit
- si_hi = Signal(32, reset_less=True)
- comb += si_hi.eq(self.dec.SI << 16)
- comb += self.imm_out.data.eq(exts(si_hi, 32, 64))
- comb += self.imm_out.ok.eq(1)
- with m.Case(In2Sel.CONST_UI_HI): # unsigned
- ui = Signal(16, reset_less=True)
- comb += ui.eq(self.dec.UI)
- comb += self.imm_out.data.eq(ui << 16)
- comb += self.imm_out.ok.eq(1)
- with m.Case(In2Sel.CONST_LI): # sign-extend 24+2=26 bit
- li = Signal(26, reset_less=True)
- comb += li.eq(self.dec.LI << 2)
- comb += self.imm_out.data.eq(exts(li, 26, 64))
- comb += self.imm_out.ok.eq(1)
- with m.Case(In2Sel.CONST_BD): # sign-extend (14+2)=16 bit
- bd = Signal(16, reset_less=True)
- comb += bd.eq(self.dec.BD << 2)
- comb += self.imm_out.data.eq(exts(bd, 16, 64))
- comb += self.imm_out.ok.eq(1)
- with m.Case(In2Sel.CONST_DS): # sign-extended (14+2=16) bit
- ds = Signal(16, reset_less=True)
- comb += ds.eq(self.dec.DS << 2)
- comb += self.imm_out.data.eq(exts(ds, 16, 64))
- comb += self.imm_out.ok.eq(1)
- with m.Case(In2Sel.CONST_M1): # signed (-1)
- comb += self.imm_out.data.eq(~Const(0, 64)) # all 1s
- comb += self.imm_out.ok.eq(1)
- with m.Case(In2Sel.CONST_SH): # unsigned - for shift
- comb += self.imm_out.data.eq(self.dec.sh)
- comb += self.imm_out.ok.eq(1)
- with m.Case(In2Sel.CONST_SH32): # unsigned - for shift
- comb += self.imm_out.data.eq(self.dec.SH32)
- comb += self.imm_out.ok.eq(1)
-
- return m
-
-
-class DecodeC(Elaboratable):
- """DecodeC from instruction
-
- decodes register RC. this is "lane 3" into some CompUnits (not many)
- """
-
- def __init__(self, dec):
- self.dec = dec
- self.sel_in = Signal(In3Sel, reset_less=True)
- self.insn_in = Signal(32, reset_less=True)
- self.reg_out = Data(5, "reg_c")
-
- def elaborate(self, platform):
- m = Module()
- comb = m.d.comb
- op = self.dec.op
- reg = self.reg_out
-
- # select Register C field
- with m.Switch(self.sel_in):
- with m.Case(In3Sel.RB):
- # for M-Form shiftrot
- comb += reg.data.eq(self.dec.RB)
- comb += reg.ok.eq(1)
- with m.Case(In3Sel.RS):
- comb += reg.data.eq(self.dec.RS)
- comb += reg.ok.eq(1)
-
- return m
-
-
-class DecodeOut(Elaboratable):
- """DecodeOut from instruction
-
- decodes output register RA, RT or SPR
- """
-
- def __init__(self, dec, regreduce_en):
- self.regreduce_en = regreduce_en
- if self.regreduce_en:
- SPR = SPRreduced
- else:
- SPR = SPRfull
- self.dec = dec
- self.sel_in = Signal(OutSel, reset_less=True)
- self.insn_in = Signal(32, reset_less=True)
- self.reg_out = Data(5, "reg_o")
- self.spr_out = Data(SPR, "spr_o")
- self.fast_out = Data(3, "fast_o")
-
- def elaborate(self, platform):
- m = Module()
- comb = m.d.comb
- m.submodules.sprmap = sprmap = SPRMap(self.regreduce_en)
- op = self.dec.op
- reg = self.reg_out
-
- # select Register out field
- with m.Switch(self.sel_in):
- with m.Case(OutSel.RT):
- comb += reg.data.eq(self.dec.RT)
- comb += reg.ok.eq(1)
- with m.Case(OutSel.RA):
- comb += reg.data.eq(self.dec.RA)
- comb += reg.ok.eq(1)
- with m.Case(OutSel.SPR):
- spr = Signal(10, reset_less=True)
- comb += spr.eq(decode_spr_num(self.dec.SPR)) # from XFX
- # MFSPR move to SPRs - needs mapping
- with m.If(op.internal_op == MicrOp.OP_MTSPR):
- comb += sprmap.spr_i.eq(spr)
- comb += self.spr_out.eq(sprmap.spr_o)
- comb += self.fast_out.eq(sprmap.fast_o)
-
- # determine Fast Reg
- with m.Switch(op.internal_op):
-
- # BC or BCREG: implicit register (CTR) NOTE: same in DecodeA
- with m.Case(MicrOp.OP_BC, MicrOp.OP_BCREG):
- with m.If(~self.dec.BO[2]): # 3.0B p38 BO2=0, use CTR reg
- # constant: CTR
- comb += self.fast_out.data.eq(FastRegs.CTR)
- comb += self.fast_out.ok.eq(1)
-
- # RFID 1st spr (fast)
- with m.Case(MicrOp.OP_RFID):
- comb += self.fast_out.data.eq(FastRegs.SRR0) # constant: SRR0
- comb += self.fast_out.ok.eq(1)
-
- return m
-
-
-class DecodeOut2(Elaboratable):
- """DecodeOut2 from instruction
-
- decodes output registers (2nd one). note that RA is *implicit* below,
- which now causes problems with SVP64
-
- TODO: SVP64 is a little more complex, here. svp64 allows extending
- by one more destination by having one more EXTRA field. RA-as-src
- is not the same as RA-as-dest. limited in that it's the same first
- 5 bits (from the v3.0B opcode), but still kinda cool. mostly used
- for operations that have src-as-dest: mostly this is LD/ST-with-update
- but there are others.
- """
-
- def __init__(self, dec):
- self.dec = dec
- self.sel_in = Signal(OutSel, reset_less=True)
- self.lk = Signal(reset_less=True)
- self.insn_in = Signal(32, reset_less=True)
- self.reg_out = Data(5, "reg_o2")
- self.fast_out = Data(3, "fast_o2")
-
- def elaborate(self, platform):
- m = Module()
- comb = m.d.comb
- op = self.dec.op
- #m.submodules.svdec = svdec = SVP64RegExtra()
-
- # get the 5-bit reg data before svp64-munging it into 7-bit plus isvec
- #reg = Signal(5, reset_less=True)
-
- if hasattr(self.dec.op, "upd"):
- # update mode LD/ST uses read-reg A also as an output
- with m.If(self.dec.op.upd == LDSTMode.update):
- comb += self.reg_out.data.eq(self.dec.RA)
- comb += self.reg_out.ok.eq(1)
-
- # B, BC or BCREG: potential implicit register (LR) output
- # these give bl, bcl, bclrl, etc.
- with m.Switch(op.internal_op):
-
- # BC* implicit register (LR)
- with m.Case(MicrOp.OP_BC, MicrOp.OP_B, MicrOp.OP_BCREG):
- with m.If(self.lk): # "link" mode
- comb += self.fast_out.data.eq(FastRegs.LR) # constant: LR
- comb += self.fast_out.ok.eq(1)
-
- # RFID 2nd spr (fast)
- with m.Case(MicrOp.OP_RFID):
- comb += self.fast_out.data.eq(FastRegs.SRR1) # constant: SRR1
- comb += self.fast_out.ok.eq(1)
-
- return m
-
-
-class DecodeRC(Elaboratable):
- """DecodeRc from instruction
-
- decodes Record bit Rc
- """
-
- def __init__(self, dec):
- self.dec = dec
- self.sel_in = Signal(RC, reset_less=True)
- self.insn_in = Signal(32, reset_less=True)
- self.rc_out = Data(1, "rc")
-
- def elaborate(self, platform):
- m = Module()
- comb = m.d.comb
-
- # select Record bit out field
- with m.Switch(self.sel_in):
- with m.Case(RC.RC):
- comb += self.rc_out.data.eq(self.dec.Rc)
- comb += self.rc_out.ok.eq(1)
- with m.Case(RC.ONE):
- comb += self.rc_out.data.eq(1)
- comb += self.rc_out.ok.eq(1)
- with m.Case(RC.NONE):
- comb += self.rc_out.data.eq(0)
- comb += self.rc_out.ok.eq(1)
-
- return m
-
-
-class DecodeOE(Elaboratable):
- """DecodeOE from instruction
-
- decodes OE field: uses RC decode detection which might not be good
-
- -- For now, use "rc" in the decode table to decide whether oe exists.
- -- This is not entirely correct architecturally: For mulhd and
- -- mulhdu, the OE field is reserved. It remains to be seen what an
- -- actual POWER9 does if we set it on those instructions, for now we
- -- test that further down when assigning to the multiplier oe input.
- """
-
- def __init__(self, dec):
- self.dec = dec
- self.sel_in = Signal(RC, reset_less=True)
- self.insn_in = Signal(32, reset_less=True)
- self.oe_out = Data(1, "oe")
-
- def elaborate(self, platform):
- m = Module()
- comb = m.d.comb
- op = self.dec.op
-
- with m.Switch(op.internal_op):
-
- # mulhw, mulhwu, mulhd, mulhdu - these *ignore* OE
- # also rotate
- # XXX ARGH! ignoring OE causes incompatibility with microwatt
- # http://lists.libre-soc.org/pipermail/libre-soc-dev/2020-August/000302.html
- with m.Case(MicrOp.OP_MUL_H64, MicrOp.OP_MUL_H32,
- MicrOp.OP_EXTS, MicrOp.OP_CNTZ,
- MicrOp.OP_SHL, MicrOp.OP_SHR, MicrOp.OP_RLC,
- MicrOp.OP_LOAD, MicrOp.OP_STORE,
- MicrOp.OP_RLCL, MicrOp.OP_RLCR,
- MicrOp.OP_EXTSWSLI):
- pass
-
- # all other ops decode OE field
- with m.Default():
- # select OE bit out field
- with m.Switch(self.sel_in):
- with m.Case(RC.RC):
- comb += self.oe_out.data.eq(self.dec.OE)
- comb += self.oe_out.ok.eq(1)
-
- return m
-
-
-class DecodeCRIn(Elaboratable):
- """Decodes input CR from instruction
-
- CR indices - insn fields - (not the data *in* the CR) require only 3
- bits because they refer to CR0-CR7
- """
-
- def __init__(self, dec):
- self.dec = dec
- self.sel_in = Signal(CRInSel, reset_less=True)
- self.insn_in = Signal(32, reset_less=True)
- self.cr_bitfield = Data(3, "cr_bitfield")
- self.cr_bitfield_b = Data(3, "cr_bitfield_b")
- self.cr_bitfield_o = Data(3, "cr_bitfield_o")
- self.whole_reg = Data(8, "cr_fxm")
- self.sv_override = Signal(2, reset_less=True) # do not do EXTRA spec
-
- def elaborate(self, platform):
- m = Module()
- comb = m.d.comb
- op = self.dec.op
- m.submodules.ppick = ppick = PriorityPicker(8, reverse_i=True,
- reverse_o=True)
-
- # zero-initialisation
- comb += self.cr_bitfield.ok.eq(0)
- comb += self.cr_bitfield_b.ok.eq(0)
- comb += self.cr_bitfield_o.ok.eq(0)
- comb += self.whole_reg.ok.eq(0)
- comb += self.sv_override.eq(0)
-
- # select the relevant CR bitfields
- with m.Switch(self.sel_in):
- with m.Case(CRInSel.NONE):
- pass # No bitfield activated
- with m.Case(CRInSel.CR0):
- comb += self.cr_bitfield.data.eq(0) # CR0 (MSB0 numbering)
- comb += self.cr_bitfield.ok.eq(1)
- comb += self.sv_override.eq(1)
- with m.Case(CRInSel.CR1):
- comb += self.cr_bitfield.data.eq(1) # CR1 (MSB0 numbering)
- comb += self.cr_bitfield.ok.eq(1)
- comb += self.sv_override.eq(2)
- with m.Case(CRInSel.BI):
- comb += self.cr_bitfield.data.eq(self.dec.BI[2:5])
- comb += self.cr_bitfield.ok.eq(1)
- with m.Case(CRInSel.BFA):
- comb += self.cr_bitfield.data.eq(self.dec.FormX.BFA)
- comb += self.cr_bitfield.ok.eq(1)
- with m.Case(CRInSel.BA_BB):
- comb += self.cr_bitfield.data.eq(self.dec.BA[2:5])
- comb += self.cr_bitfield.ok.eq(1)
- comb += self.cr_bitfield_b.data.eq(self.dec.BB[2:5])
- comb += self.cr_bitfield_b.ok.eq(1)
- comb += self.cr_bitfield_o.data.eq(self.dec.BT[2:5])
- comb += self.cr_bitfield_o.ok.eq(1)
- with m.Case(CRInSel.BC):
- comb += self.cr_bitfield.data.eq(self.dec.BC[2:5])
- comb += self.cr_bitfield.ok.eq(1)
- with m.Case(CRInSel.WHOLE_REG):
- comb += self.whole_reg.ok.eq(1)
- move_one = Signal(reset_less=True)
- comb += move_one.eq(self.insn_in[20]) # MSB0 bit 11
- with m.If((op.internal_op == MicrOp.OP_MFCR) & move_one):
- # must one-hot the FXM field
- comb += ppick.i.eq(self.dec.FXM)
- comb += self.whole_reg.data.eq(ppick.o)
- with m.Else():
- # otherwise use all of it
- comb += self.whole_reg.data.eq(0xff)
-
- return m
-
-
-class DecodeCROut(Elaboratable):
- """Decodes input CR from instruction
-
- CR indices - insn fields - (not the data *in* the CR) require only 3
- bits because they refer to CR0-CR7
- """
-
- def __init__(self, dec):
- self.dec = dec
- self.rc_in = Signal(reset_less=True)
- self.sel_in = Signal(CROutSel, reset_less=True)
- self.insn_in = Signal(32, reset_less=True)
- self.cr_bitfield = Data(3, "cr_bitfield")
- self.whole_reg = Data(8, "cr_fxm")
- self.sv_override = Signal(2, reset_less=True) # do not do EXTRA spec
-
- def elaborate(self, platform):
- m = Module()
- comb = m.d.comb
- op = self.dec.op
- m.submodules.ppick = ppick = PriorityPicker(8, reverse_i=True,
- reverse_o=True)
-
- comb += self.cr_bitfield.ok.eq(0)
- comb += self.whole_reg.ok.eq(0)
- comb += self.sv_override.eq(0)
-
- # please note these MUST match (setting of cr_bitfield.ok) exactly
- # with write_cr0 below in PowerDecoder2. the reason it's separated
- # is to avoid having duplicate copies of DecodeCROut in multiple
- # PowerDecoderSubsets. register decoding should be a one-off in
- # PowerDecoder2. see https://bugs.libre-soc.org/show_bug.cgi?id=606
-
- with m.Switch(self.sel_in):
- with m.Case(CROutSel.NONE):
- pass # No bitfield activated
- with m.Case(CROutSel.CR0):
- comb += self.cr_bitfield.data.eq(0) # CR0 (MSB0 numbering)
- comb += self.cr_bitfield.ok.eq(self.rc_in) # only when RC=1
- comb += self.sv_override.eq(1)
- with m.Case(CROutSel.CR1):
- comb += self.cr_bitfield.data.eq(1) # CR1 (MSB0 numbering)
- comb += self.cr_bitfield.ok.eq(self.rc_in) # only when RC=1
- comb += self.sv_override.eq(2)
- with m.Case(CROutSel.BF):
- comb += self.cr_bitfield.data.eq(self.dec.FormX.BF)
- comb += self.cr_bitfield.ok.eq(1)
- with m.Case(CROutSel.BT):
- comb += self.cr_bitfield.data.eq(self.dec.FormXL.BT[2:5])
- comb += self.cr_bitfield.ok.eq(1)
- with m.Case(CROutSel.WHOLE_REG):
- comb += self.whole_reg.ok.eq(1)
- move_one = Signal(reset_less=True)
- comb += move_one.eq(self.insn_in[20])
- with m.If((op.internal_op == MicrOp.OP_MTCRF)):
- with m.If(move_one):
- # must one-hot the FXM field
- comb += ppick.i.eq(self.dec.FXM)
- with m.If(ppick.en_o):
- comb += self.whole_reg.data.eq(ppick.o)
- with m.Else():
- comb += self.whole_reg.data.eq(0b00000001) # CR7
- with m.Else():
- comb += self.whole_reg.data.eq(self.dec.FXM)
- with m.Else():
- # otherwise use all of it
- comb += self.whole_reg.data.eq(0xff)
-
- return m
-
-# dictionary of Input Record field names that, if they exist,
-# will need a corresponding CSV Decoder file column (actually, PowerOp)
-# to be decoded (this includes the single bit names)
-record_names = {'insn_type': 'internal_op',
- 'fn_unit': 'function_unit',
- 'rc': 'rc_sel',
- 'oe': 'rc_sel',
- 'zero_a': 'in1_sel',
- 'imm_data': 'in2_sel',
- 'invert_in': 'inv_a',
- 'invert_out': 'inv_out',
- 'rc': 'cr_out',
- 'oe': 'cr_in',
- 'output_carry': 'cry_out',
- 'input_carry': 'cry_in',
- 'is_32bit': 'is_32b',
- 'is_signed': 'sgn',
- 'lk': 'lk',
- 'data_len': 'ldst_len',
- 'byte_reverse': 'br',
- 'sign_extend': 'sgn_ext',
- 'ldst_mode': 'upd',
- }
-
-
-class PowerDecodeSubset(Elaboratable):
- """PowerDecodeSubset: dynamic subset decoder
-
- only fields actually requested are copied over. hence, "subset" (duh).
- """
- def __init__(self, dec, opkls=None, fn_name=None, final=False, state=None,
- svp64_en=True, regreduce_en=False):
-
- self.svp64_en = svp64_en
- self.regreduce_en = regreduce_en
- if svp64_en:
- self.sv_rm = SVP64Rec(name="dec_svp64") # SVP64 RM field
- self.sv_a_nz = Signal(1)
- self.final = final
- self.opkls = opkls
- self.fn_name = fn_name
- if opkls is None:
- opkls = Decode2ToOperand
- self.do = opkls(fn_name)
- col_subset = self.get_col_subset(self.do)
-
- # only needed for "main" PowerDecode2
- if not self.final:
- self.e = Decode2ToExecute1Type(name=self.fn_name, do=self.do,
- regreduce_en=regreduce_en)
-
- # create decoder if one not already given
- if dec is None:
- dec = create_pdecode(name=fn_name, col_subset=col_subset,
- row_subset=self.rowsubsetfn)
- self.dec = dec
-
- # state information needed by the Decoder
- if state is None:
- state = CoreState("dec2")
- self.state = state
-
- def get_col_subset(self, do):
- subset = { 'cr_in', 'cr_out', 'rc_sel'} # needed, non-optional
- for k, v in record_names.items():
- if hasattr(do, k):
- subset.add(v)
- print ("get_col_subset", self.fn_name, do.fields, subset)
- return subset
-
- def rowsubsetfn(self, opcode, row):
- """select per-Function-Unit subset of opcodes to be processed
-
- normally this just looks at the "unit" column. MMU is different
- in that it processes specific SPR set/get operations that the SPR
- pipeline should not.
- """
- return (row['unit'] == self.fn_name or
- # sigh a dreadful hack: MTSPR and MFSPR need to be processed
- # by the MMU pipeline so we direct those opcodes to MMU **AND**
- # SPR pipelines, then selectively weed out the SPRs that should
- # or should not not go to each pipeline, further down.
- # really this should be done by modifying the CSV syntax
- # to support multiple tasks (unit column multiple entries)
- # see https://bugs.libre-soc.org/show_bug.cgi?id=310
- (self.fn_name == 'MMU' and row['unit'] == 'SPR' and
- row['internal op'] in ['OP_MTSPR', 'OP_MFSPR'])
- )
-
- def ports(self):
- ports = self.dec.ports() + self.e.ports()
- if self.svp64_en:
- ports += self.sv_rm.ports()
- return ports
-
- def needs_field(self, field, op_field):
- if self.final:
- do = self.do
- else:
- do = self.e_tmp.do
- return hasattr(do, field) and self.op_get(op_field) is not None
-
- def do_copy(self, field, val, final=False):
- if final or self.final:
- do = self.do
- else:
- do = self.e_tmp.do
- if hasattr(do, field) and val is not None:
- return getattr(do, field).eq(val)
- return []
-
- def op_get(self, op_field):
- return getattr(self.dec.op, op_field, None)
-
- def elaborate(self, platform):
- if self.regreduce_en:
- SPR = SPRreduced
- else:
- SPR = SPRfull
- m = Module()
- comb = m.d.comb
- state = self.state
- op, do = self.dec.op, self.do
- msr, cia = state.msr, state.pc
- # fill in for a normal instruction (not an exception)
- # copy over if non-exception, non-privileged etc. is detected
- if not self.final:
- if self.fn_name is None:
- name = "tmp"
- else:
- name = self.fn_name + "tmp"
- self.e_tmp = Decode2ToExecute1Type(name=name, opkls=self.opkls,
- regreduce_en=self.regreduce_en)
-
- # set up submodule decoders
- m.submodules.dec = self.dec
- m.submodules.dec_rc = self.dec_rc = dec_rc = DecodeRC(self.dec)
- m.submodules.dec_oe = dec_oe = DecodeOE(self.dec)
-
- # copy instruction through...
- for i in [do.insn, dec_rc.insn_in, dec_oe.insn_in, ]:
- comb += i.eq(self.dec.opcode_in)
-
- # ...and subdecoders' input fields
- comb += dec_rc.sel_in.eq(op.rc_sel)
- comb += dec_oe.sel_in.eq(op.rc_sel) # XXX should be OE sel
-
- # copy "state" over
- comb += self.do_copy("msr", msr)
- comb += self.do_copy("cia", cia)
-
- # set up instruction type
- # no op: defaults to OP_ILLEGAL
- internal_op = self.op_get("internal_op")
- comb += self.do_copy("insn_type", internal_op)
-
- # function unit for decoded instruction: requires minor redirect
- # for SPR set/get
- fn = self.op_get("function_unit")
- spr = Signal(10, reset_less=True)
- comb += spr.eq(decode_spr_num(self.dec.SPR)) # from XFX
-
- # Microwatt doesn't implement the partition table
- # instead has PRTBL register (SPR) to point to process table
- is_spr_mv = Signal()
- is_mmu_spr = Signal()
- comb += is_spr_mv.eq((internal_op == MicrOp.OP_MTSPR) |
- (internal_op == MicrOp.OP_MFSPR))
- comb += is_mmu_spr.eq((spr == SPR.DSISR.value) |
- (spr == SPR.DAR.value) |
- (spr == SPR.PRTBL.value) |
- (spr == SPR.PIDR.value))
- # MMU must receive MMU SPRs
- with m.If(is_spr_mv & (fn == Function.SPR) & is_mmu_spr):
- comb += self.do_copy("fn_unit", Function.NONE)
- comb += self.do_copy("insn_type", MicrOp.OP_ILLEGAL)
- # SPR pipe must *not* receive MMU SPRs
- with m.Elif(is_spr_mv & (fn == Function.MMU) & ~is_mmu_spr):
- comb += self.do_copy("fn_unit", Function.NONE)
- comb += self.do_copy("insn_type", MicrOp.OP_ILLEGAL)
- # all others ok
- with m.Else():
- comb += self.do_copy("fn_unit", fn)
-
- # immediates
- if self.needs_field("zero_a", "in1_sel"):
- m.submodules.dec_ai = dec_ai = DecodeAImm(self.dec)
- comb += dec_ai.sv_nz.eq(self.sv_a_nz)
- comb += dec_ai.sel_in.eq(op.in1_sel)
- comb += self.do_copy("zero_a", dec_ai.immz_out) # RA==0 detected
- if self.needs_field("imm_data", "in2_sel"):
- m.submodules.dec_bi = dec_bi = DecodeBImm(self.dec)
- comb += dec_bi.sel_in.eq(op.in2_sel)
- comb += self.do_copy("imm_data", dec_bi.imm_out) # imm in RB
-
- # rc and oe out
- comb += self.do_copy("rc", dec_rc.rc_out)
- comb += self.do_copy("oe", dec_oe.oe_out)
-
- # CR in/out - note: these MUST match with what happens in
- # DecodeCROut!
- rc_out = self.dec_rc.rc_out.data
- with m.Switch(op.cr_out):
- with m.Case(CROutSel.CR0, CROutSel.CR1):
- comb += self.do_copy("write_cr0", rc_out) # only when RC=1
- with m.Case(CROutSel.BF, CROutSel.BT):
- comb += self.do_copy("write_cr0", 1)
-
- comb += self.do_copy("input_cr", self.op_get("cr_in")) # CR in
- comb += self.do_copy("output_cr", self.op_get("cr_out")) # CR out
-
- # decoded/selected instruction flags
- comb += self.do_copy("data_len", self.op_get("ldst_len"))
- comb += self.do_copy("invert_in", self.op_get("inv_a"))
- comb += self.do_copy("invert_out", self.op_get("inv_out"))
- comb += self.do_copy("input_carry", self.op_get("cry_in"))
- comb += self.do_copy("output_carry", self.op_get("cry_out"))
- comb += self.do_copy("is_32bit", self.op_get("is_32b"))
- comb += self.do_copy("is_signed", self.op_get("sgn"))
- lk = self.op_get("lk")
- if lk is not None:
- with m.If(lk):
- comb += self.do_copy("lk", self.dec.LK) # XXX TODO: accessor
-
- comb += self.do_copy("byte_reverse", self.op_get("br"))
- comb += self.do_copy("sign_extend", self.op_get("sgn_ext"))
- comb += self.do_copy("ldst_mode", self.op_get("upd")) # LD/ST mode
-
- return m
-
-
-class PowerDecode2(PowerDecodeSubset):
- """PowerDecode2: the main instruction decoder.
-
- whilst PowerDecode is responsible for decoding the actual opcode, this
- module encapsulates further specialist, sparse information and
- expansion of fields that is inconvenient to have in the CSV files.
- for example: the encoding of the immediates, which are detected
- and expanded out to their full value from an annotated (enum)
- representation.
-
- implicit register usage is also set up, here. for example: OP_BC
- requires implicitly reading CTR, OP_RFID requires implicitly writing
- to SRR1 and so on.
-
- in addition, PowerDecoder2 is responsible for detecting whether
- instructions are illegal (or privileged) or not, and instead of
- just leaving at that, *replacing* the instruction to execute with
- a suitable alternative (trap).
-
- LDSTExceptions are done the cycle _after_ they're detected (after
- they come out of LDSTCompUnit). basically despite the instruction
- being decoded, the results of the decode are completely ignored
- and "exception.happened" used to set the "actual" instruction to
- "OP_TRAP". the LDSTException data structure gets filled in,
- in the CompTrapOpSubset and that's what it fills in SRR.
-
- to make this work, TestIssuer must notice "exception.happened"
- after the (failed) LD/ST and copies the LDSTException info from
- the output, into here (PowerDecoder2). without incrementing PC.
- """
-
- def __init__(self, dec, opkls=None, fn_name=None, final=False,
- state=None, svp64_en=True, regreduce_en=False):
- super().__init__(dec, opkls, fn_name, final, state, svp64_en,
- regreduce_en=False)
- self.exc = LDSTException("dec2_exc")
-
- if self.svp64_en:
- self.cr_out_isvec = Signal(1, name="cr_out_isvec")
- self.cr_in_isvec = Signal(1, name="cr_in_isvec")
- self.cr_in_b_isvec = Signal(1, name="cr_in_b_isvec")
- self.cr_in_o_isvec = Signal(1, name="cr_in_o_isvec")
- self.in1_isvec = Signal(1, name="reg_a_isvec")
- self.in2_isvec = Signal(1, name="reg_b_isvec")
- self.in3_isvec = Signal(1, name="reg_c_isvec")
- self.o_isvec = Signal(1, name="reg_o_isvec")
- self.o2_isvec = Signal(1, name="reg_o2_isvec")
- self.no_in_vec = Signal(1, name="no_in_vec") # no inputs vector
- self.no_out_vec = Signal(1, name="no_out_vec") # no outputs vector
- self.loop_continue = Signal(1, name="loop_continue")
- self.rm_dec = SVP64RMModeDecode("svp64_rm_dec")
- else:
- self.no_in_vec = Const(1, 1)
- self.no_out_vec = Const(1, 1)
- self.loop_continue = Const(0, 1)
-
- def get_col_subset(self, opkls):
- subset = super().get_col_subset(opkls)
- subset.add("asmcode")
- subset.add("in1_sel")
- subset.add("in2_sel")
- subset.add("in3_sel")
- subset.add("out_sel")
- if self.svp64_en:
- subset.add("sv_in1")
- subset.add("sv_in2")
- subset.add("sv_in3")
- subset.add("sv_out")
- subset.add("sv_out2")
- subset.add("sv_cr_in")
- subset.add("sv_cr_out")
- subset.add("SV_Etype")
- subset.add("SV_Ptype")
- subset.add("lk")
- subset.add("internal_op")
- subset.add("form")
- return subset
-
- def elaborate(self, platform):
- m = super().elaborate(platform)
- comb = m.d.comb
- state = self.state
- e_out, op, do_out = self.e, self.dec.op, self.e.do
- dec_spr, msr, cia, ext_irq = state.dec, state.msr, state.pc, state.eint
- rc_out = self.dec_rc.rc_out.data
- e = self.e_tmp
- do = e.do
-
- # fill in for a normal instruction (not an exception)
- # copy over if non-exception, non-privileged etc. is detected
-
- # set up submodule decoders
- m.submodules.dec_a = dec_a = DecodeA(self.dec, self.regreduce_en)
- m.submodules.dec_b = dec_b = DecodeB(self.dec)
- m.submodules.dec_c = dec_c = DecodeC(self.dec)
- m.submodules.dec_o = dec_o = DecodeOut(self.dec, self.regreduce_en)
- m.submodules.dec_o2 = dec_o2 = DecodeOut2(self.dec)
- m.submodules.dec_cr_in = self.dec_cr_in = DecodeCRIn(self.dec)
- m.submodules.dec_cr_out = self.dec_cr_out = DecodeCROut(self.dec)
- comb += dec_a.sv_nz.eq(self.sv_a_nz)
-
- if self.svp64_en:
- # and SVP64 Extra decoders
- m.submodules.crout_svdec = crout_svdec = SVP64CRExtra()
- m.submodules.crin_svdec = crin_svdec = SVP64CRExtra()
- m.submodules.crin_svdec_b = crin_svdec_b = SVP64CRExtra()
- m.submodules.crin_svdec_o = crin_svdec_o = SVP64CRExtra()
- m.submodules.in1_svdec = in1_svdec = SVP64RegExtra()
- m.submodules.in2_svdec = in2_svdec = SVP64RegExtra()
- m.submodules.in3_svdec = in3_svdec = SVP64RegExtra()
- m.submodules.o_svdec = o_svdec = SVP64RegExtra()
- m.submodules.o2_svdec = o2_svdec = SVP64RegExtra()
-
- # debug access to crout_svdec (used in get_pdecode_cr_out)
- self.crout_svdec = crout_svdec
-
- # and SVP64 RM mode decoder
- m.submodules.sv_rm_dec = rm_dec = self.rm_dec
-
- # get the 5-bit reg data before svp64-munging it into 7-bit plus isvec
- reg = Signal(5, reset_less=True)
-
- # copy instruction through...
- for i in [do.insn, dec_a.insn_in, dec_b.insn_in,
- self.dec_cr_in.insn_in, self.dec_cr_out.insn_in,
- dec_c.insn_in, dec_o.insn_in, dec_o2.insn_in]:
- comb += i.eq(self.dec.opcode_in)
-
- # CR setup
- comb += self.dec_cr_in.sel_in.eq(op.cr_in)
- comb += self.dec_cr_out.sel_in.eq(op.cr_out)
- comb += self.dec_cr_out.rc_in.eq(rc_out)
-
- # CR register info
- comb += self.do_copy("read_cr_whole", self.dec_cr_in.whole_reg)
- comb += self.do_copy("write_cr_whole", self.dec_cr_out.whole_reg)
-
- # ...and subdecoders' input fields
- comb += dec_a.sel_in.eq(op.in1_sel)
- comb += dec_b.sel_in.eq(op.in2_sel)
- comb += dec_c.sel_in.eq(op.in3_sel)
- comb += dec_o.sel_in.eq(op.out_sel)
- comb += dec_o2.sel_in.eq(op.out_sel)
- if hasattr(do, "lk"):
- comb += dec_o2.lk.eq(do.lk)
-
- if self.svp64_en:
- # now do the SVP64 munging. op.SV_Etype and op.sv_in1 comes from
- # PowerDecoder which in turn comes from LDST-RM*.csv and RM-*.csv
- # which in turn were auto-generated by sv_analysis.py
- extra = self.sv_rm.extra # SVP64 extra bits 10:18
-
- #######
- # CR out
- comb += crout_svdec.idx.eq(op.sv_cr_out) # SVP64 CR out
- comb += self.cr_out_isvec.eq(crout_svdec.isvec)
-
- #######
- # CR in - selection slightly different due to shared CR field sigh
- cr_a_idx = Signal(SVEXTRA)
- cr_b_idx = Signal(SVEXTRA)
-
- # these change slightly, when decoding BA/BB. really should have
- # their own separate CSV column: sv_cr_in1 and sv_cr_in2, but hey
- comb += cr_a_idx.eq(op.sv_cr_in)
- comb += cr_b_idx.eq(SVEXTRA.NONE)
- with m.If(op.sv_cr_in == SVEXTRA.Idx_1_2.value):
- comb += cr_a_idx.eq(SVEXTRA.Idx1)
- comb += cr_b_idx.eq(SVEXTRA.Idx2)
-
- comb += self.cr_in_isvec.eq(crin_svdec.isvec)
- comb += self.cr_in_b_isvec.eq(crin_svdec_b.isvec)
- comb += self.cr_in_o_isvec.eq(crin_svdec_o.isvec)
-
- # indices are slightly different, BA/BB mess sorted above
- comb += crin_svdec.idx.eq(cr_a_idx) # SVP64 CR in A
- comb += crin_svdec_b.idx.eq(cr_b_idx) # SVP64 CR in B
- comb += crin_svdec_o.idx.eq(op.sv_cr_out) # SVP64 CR out
-
- # get SVSTATE srcstep (TODO: elwidth etc.) needed below
- srcstep = Signal.like(self.state.svstate.srcstep)
- dststep = Signal.like(self.state.svstate.dststep)
- comb += srcstep.eq(self.state.svstate.srcstep)
- comb += dststep.eq(self.state.svstate.dststep)
-
- # registers a, b, c and out and out2 (LD/ST EA)
- for to_reg, fromreg, svdec, out in (
- (e.read_reg1, dec_a.reg_out, in1_svdec, False),
- (e.read_reg2, dec_b.reg_out, in2_svdec, False),
- (e.read_reg3, dec_c.reg_out, in3_svdec, False),
- (e.write_reg, dec_o.reg_out, o_svdec, True),
- (e.write_ea, dec_o2.reg_out, o2_svdec, True)):
- comb += svdec.extra.eq(extra) # EXTRA field of SVP64 RM
- comb += svdec.etype.eq(op.SV_Etype) # EXTRA2/3 for this insn
- comb += svdec.reg_in.eq(fromreg.data) # 3-bit (CR0/BC/BFA)
- comb += to_reg.ok.eq(fromreg.ok)
- # detect if Vectorised: add srcstep/dststep if yes.
- # to_reg is 7-bits, outs get dststep added, ins get srcstep
- with m.If(svdec.isvec):
- step = dststep if out else srcstep
- comb += to_reg.data.eq(step+svdec.reg_out)
- with m.Else():
- comb += to_reg.data.eq(svdec.reg_out)
-
- comb += in1_svdec.idx.eq(op.sv_in1) # SVP64 reg #1 (in1_sel)
- comb += in2_svdec.idx.eq(op.sv_in2) # SVP64 reg #2 (in2_sel)
- comb += in3_svdec.idx.eq(op.sv_in3) # SVP64 reg #3 (in3_sel)
- comb += o_svdec.idx.eq(op.sv_out) # SVP64 output (out_sel)
- comb += o2_svdec.idx.eq(op.sv_out2) # SVP64 output (implicit)
- # XXX TODO - work out where this should come from. the problem is
- # that LD-with-update is implied (computed from "is instruction in
- # "update mode" rather than specified cleanly as its own CSV column
-
- # output reg-is-vectorised (and when no in/out is vectorised)
- comb += self.in1_isvec.eq(in1_svdec.isvec)
- comb += self.in2_isvec.eq(in2_svdec.isvec)
- comb += self.in3_isvec.eq(in3_svdec.isvec)
- comb += self.o_isvec.eq(o_svdec.isvec)
- comb += self.o2_isvec.eq(o2_svdec.isvec)
- # TODO add SPRs here. must be True when *all* are scalar
- l = map(lambda svdec: svdec.isvec, [in1_svdec, in2_svdec, in3_svdec,
- crin_svdec, crin_svdec_b, crin_svdec_o])
- comb += self.no_in_vec.eq(~Cat(*l).bool()) # all input scalar
- l = map(lambda svdec: svdec.isvec, [o2_svdec, o_svdec, crout_svdec])
- comb += self.no_out_vec.eq(~Cat(*l).bool()) # all output scalar
- # now create a general-purpose "test" as to whether looping
- # should continue. this doesn't include predication bit-tests
- loop = self.loop_continue
- with m.Switch(op.SV_Ptype):
- with m.Case(SVPtype.P2.value):
- # twin-predication
- # TODO: *and cache-inhibited LD/ST!*
- comb += loop.eq(~(self.no_in_vec | self.no_out_vec))
- with m.Case(SVPtype.P1.value):
- # single-predication, test relies on dest only
- comb += loop.eq(~self.no_out_vec)
- with m.Default():
- # not an SV operation, no looping
- comb += loop.eq(0)
-
- # condition registers (CR)
- for to_reg, cr, name, svdec, out in (
- (e.read_cr1, self.dec_cr_in, "cr_bitfield", crin_svdec, 0),
- (e.read_cr2, self.dec_cr_in, "cr_bitfield_b", crin_svdec_b, 0),
- (e.read_cr3, self.dec_cr_in, "cr_bitfield_o", crin_svdec_o, 0),
- (e.write_cr, self.dec_cr_out, "cr_bitfield", crout_svdec, 1)):
- fromreg = getattr(cr, name)
- comb += svdec.extra.eq(extra) # EXTRA field of SVP64 RM
- comb += svdec.etype.eq(op.SV_Etype) # EXTRA2/3 for this insn
- comb += svdec.cr_in.eq(fromreg.data) # 3-bit (CR0/BC/BFA)
- with m.If(svdec.isvec):
- # check if this is CR0 or CR1: treated differently
- # (does not "listen" to EXTRA2/3 spec for a start)
- # also: the CRs start from completely different locations
- step = dststep if out else srcstep
- with m.If(cr.sv_override == 1): # CR0
- offs = SVP64CROffs.CR0
- comb += to_reg.data.eq(step+offs)
- with m.Elif(cr.sv_override == 2): # CR1
- offs = SVP64CROffs.CR1
- comb += to_reg.data.eq(step+1)
- with m.Else():
- comb += to_reg.data.eq(step+svdec.cr_out) # 7-bit out
- with m.Else():
- comb += to_reg.data.eq(svdec.cr_out) # 7-bit output
- comb += to_reg.ok.eq(fromreg.ok)
-
- # sigh must determine if RA is nonzero (7 bit)
- comb += self.sv_a_nz.eq(e.read_reg1.data != Const(0, 7))
- else:
- # connect up to/from read/write GPRs
- for to_reg, fromreg in ((e.read_reg1, dec_a.reg_out),
- (e.read_reg2, dec_b.reg_out),
- (e.read_reg3, dec_c.reg_out),
- (e.write_reg, dec_o.reg_out),
- (e.write_ea, dec_o2.reg_out)):
- comb += to_reg.data.eq(fromreg.data)
- comb += to_reg.ok.eq(fromreg.ok)
-
- # connect up to/from read/write CRs
- for to_reg, cr, name in (
- (e.read_cr1, self.dec_cr_in, "cr_bitfield", ),
- (e.read_cr2, self.dec_cr_in, "cr_bitfield_b", ),
- (e.read_cr3, self.dec_cr_in, "cr_bitfield_o", ),
- (e.write_cr, self.dec_cr_out, "cr_bitfield", )):
- fromreg = getattr(cr, name)
- comb += to_reg.data.eq(fromreg.data)
- comb += to_reg.ok.eq(fromreg.ok)
-
- # SPRs out
- comb += e.read_spr1.eq(dec_a.spr_out)
- comb += e.write_spr.eq(dec_o.spr_out)
-
- # Fast regs out
- comb += e.read_fast1.eq(dec_a.fast_out)
- comb += e.read_fast2.eq(dec_b.fast_out)
- comb += e.write_fast1.eq(dec_o.fast_out)
- comb += e.write_fast2.eq(dec_o2.fast_out)
-
- if self.svp64_en:
- # connect up SVP64 RM Mode decoding
- fn = self.op_get("function_unit")
- comb += rm_dec.fn_in.eq(fn) # decode needs to know if LD/ST type
- comb += rm_dec.ptype_in.eq(op.SV_Ptype) # Single/Twin predicated
- comb += rm_dec.rc_in.eq(rc_out) # Rc=1
- comb += rm_dec.rm_in.eq(self.sv_rm) # SVP64 RM mode
-
- # sigh this is exactly the sort of thing for which the
- # decoder is designed to not need. MTSPR, MFSPR and others need
- # access to the XER bits. however setting e.oe is not appropriate
- with m.If(op.internal_op == MicrOp.OP_MFSPR):
- comb += e.xer_in.eq(0b111) # SO, CA, OV
- with m.If(op.internal_op == MicrOp.OP_CMP):
- comb += e.xer_in.eq(1<<XERRegs.SO) # SO
- with m.If(op.internal_op == MicrOp.OP_MTSPR):
- comb += e.xer_out.eq(1)
-
- # set the trapaddr to 0x700 for a td/tw/tdi/twi operation
- with m.If(op.internal_op == MicrOp.OP_TRAP):
- # *DO NOT* call self.trap here. that would reset absolutely
- # everything including destroying read of RA and RB.
- comb += self.do_copy("trapaddr", 0x70) # strip first nibble
-
- ####################
- # ok so the instruction's been decoded, blah blah, however
- # now we need to determine if it's actually going to go ahead...
- # *or* if in fact it's a privileged operation, whether there's
- # an external interrupt, etc. etc. this is a simple priority
- # if-elif-elif sequence. decrement takes highest priority,
- # EINT next highest, privileged operation third.
-
- # check if instruction is privileged
- is_priv_insn = instr_is_priv(m, op.internal_op, e.do.insn)
-
- # different IRQ conditions
- ext_irq_ok = Signal()
- dec_irq_ok = Signal()
- priv_ok = Signal()
- illeg_ok = Signal()
- exc = self.exc
-
- comb += ext_irq_ok.eq(ext_irq & msr[MSR.EE]) # v3.0B p944 (MSR.EE)
- comb += dec_irq_ok.eq(dec_spr[63] & msr[MSR.EE]) # 6.5.11 p1076
- comb += priv_ok.eq(is_priv_insn & msr[MSR.PR])
- comb += illeg_ok.eq(op.internal_op == MicrOp.OP_ILLEGAL)
-
- # LD/ST exceptions. TestIssuer copies the exception info at us
- # after a failed LD/ST.
- with m.If(exc.happened):
- with m.If(exc.alignment):
- self.trap(m, TT.PRIV, 0x600)
- with m.Elif(exc.instr_fault):
- with m.If(exc.segment_fault):
- self.trap(m, TT.PRIV, 0x480)
- with m.Else():
- # pass exception info to trap to create SRR1
- self.trap(m, TT.MEMEXC, 0x400, exc)
- with m.Else():
- with m.If(exc.segment_fault):
- self.trap(m, TT.PRIV, 0x380)
- with m.Else():
- self.trap(m, TT.PRIV, 0x300)
-
- # decrement counter (v3.0B p1099): TODO 32-bit version (MSR.LPCR)
- with m.Elif(dec_irq_ok):
- self.trap(m, TT.DEC, 0x900) # v3.0B 6.5 p1065
-
- # external interrupt? only if MSR.EE set
- with m.Elif(ext_irq_ok):
- self.trap(m, TT.EINT, 0x500)
-
- # privileged instruction trap
- with m.Elif(priv_ok):
- self.trap(m, TT.PRIV, 0x700)
-
- # illegal instruction must redirect to trap. this is done by
- # *overwriting* the decoded instruction and starting again.
- # (note: the same goes for interrupts and for privileged operations,
- # just with different trapaddr and traptype)
- with m.Elif(illeg_ok):
- # illegal instruction trap
- self.trap(m, TT.ILLEG, 0x700)
-
- # no exception, just copy things to the output
- with m.Else():
- comb += e_out.eq(e)
-
- ####################
- # follow-up after trap/irq to set up SRR0/1
-
- # trap: (note e.insn_type so this includes OP_ILLEGAL) set up fast regs
- # Note: OP_SC could actually be modified to just be a trap
- with m.If((do_out.insn_type == MicrOp.OP_TRAP) |
- (do_out.insn_type == MicrOp.OP_SC)):
- # TRAP write fast1 = SRR0
- comb += e_out.write_fast1.data.eq(FastRegs.SRR0) # constant: SRR0
- comb += e_out.write_fast1.ok.eq(1)
- # TRAP write fast2 = SRR1
- comb += e_out.write_fast2.data.eq(FastRegs.SRR1) # constant: SRR1
- comb += e_out.write_fast2.ok.eq(1)
-
- # RFID: needs to read SRR0/1
- with m.If(do_out.insn_type == MicrOp.OP_RFID):
- # TRAP read fast1 = SRR0
- comb += e_out.read_fast1.data.eq(FastRegs.SRR0) # constant: SRR0
- comb += e_out.read_fast1.ok.eq(1)
- # TRAP read fast2 = SRR1
- comb += e_out.read_fast2.data.eq(FastRegs.SRR1) # constant: SRR1
- comb += e_out.read_fast2.ok.eq(1)
-
- # annoying simulator bug
- if hasattr(e_out, "asmcode") and hasattr(self.dec.op, "asmcode"):
- comb += e_out.asmcode.eq(self.dec.op.asmcode)
-
- return m
-
- def trap(self, m, traptype, trapaddr, exc=None):
- """trap: this basically "rewrites" the decoded instruction as a trap
- """
- comb = m.d.comb
- op, e = self.dec.op, self.e
- comb += e.eq(0) # reset eeeeeverything
-
- # start again
- comb += self.do_copy("insn", self.dec.opcode_in, True)
- comb += self.do_copy("insn_type", MicrOp.OP_TRAP, True)
- comb += self.do_copy("fn_unit", Function.TRAP, True)
- comb += self.do_copy("trapaddr", trapaddr >> 4, True) # bottom 4 bits
- comb += self.do_copy("traptype", traptype, True) # request type
- comb += self.do_copy("ldst_exc", exc, True) # request type
- comb += self.do_copy("msr", self.state.msr, True) # copy of MSR "state"
- comb += self.do_copy("cia", self.state.pc, True) # copy of PC "state"
-
-
-
-def get_rdflags(e, cu):
- rdl = []
- for idx in range(cu.n_src):
- regfile, regname, _ = cu.get_in_spec(idx)
- rdflag, read = regspec_decode_read(e, regfile, regname)
- rdl.append(rdflag)
- print("rdflags", rdl)
- return Cat(*rdl)
-
-
-if __name__ == '__main__':
- pdecode = create_pdecode()
- dec2 = PowerDecode2(pdecode)
- vl = rtlil.convert(dec2, ports=dec2.ports() + pdecode.ports())
- with open("dec2.il", "w") as f:
- f.write(vl)
+from openpower.decoder.power_decoder2 import *
-# SPDX-License: LGPLv3+
-# Copyright (C) 2020, 2021 Luke Kenneth Casson Leighton <lkcl@lkcl.net>
-# Copyright (C) 2020, Michael Nolan
+# moved to openpower-isa
+# https://git.libre-soc.org/?p=openpower-isa.git;a=summary
+# wildcard imports here ONLY to support migration
-"""Enums used in OpenPOWER ISA decoding
-
-Note: for SV, from v3.1B p12:
-
- The designated SPR sandbox consists of non-privileged SPRs 704-719 and
- privileged SPRs 720-735.
-
-Note: the option exists to select a much shorter list of SPRs, to reduce
-regfile size in HDL. this is SPRreduced and the supported list is in
-get_spr_enum
-"""
-
-from enum import Enum, unique
-import csv
-import os
-from os.path import dirname, join
-from collections import namedtuple
-
-
-def find_wiki_dir():
- filedir = os.path.dirname(os.path.abspath(__file__))
- basedir = dirname(dirname(dirname(filedir)))
- tabledir = join(basedir, 'libreriscv')
- tabledir = join(tabledir, 'openpower')
- return join(tabledir, 'isatables')
-
-
-def find_wiki_file(name):
- filedir = os.path.dirname(os.path.abspath(__file__))
- basedir = dirname(dirname(dirname(filedir)))
- tabledir = join(basedir, 'libreriscv')
- tabledir = join(tabledir, 'openpower')
- tabledir = join(tabledir, 'isatables')
-
- return join(find_wiki_dir(), name)
-
-
-def get_csv(name):
- file_path = find_wiki_file(name)
- with open(file_path, 'r') as csvfile:
- reader = csv.DictReader(csvfile)
- return list(reader)
-
-
-# names of the fields in the tables that don't correspond to an enum
-single_bit_flags = ['inv A', 'inv out',
- 'cry out', 'BR', 'sgn ext', 'rsrv', '32b',
- 'sgn', 'lk', 'sgl pipe']
-
-# default values for fields in the table
-default_values = {'unit': "NONE", 'internal op': "OP_ILLEGAL",
- 'in1': "RA", 'in2': 'NONE', 'in3': 'NONE', 'out': 'NONE',
- 'CR in': 'NONE',
- 'ldst len': 'NONE',
- 'upd': '0',
- 'rc': 'NONE', 'cry in': 'ZERO', 'form': 'NONE'}
-
-
-def get_signal_name(name):
- if name[0].isdigit():
- name = "is_" + name
- return name.lower().replace(' ', '_')
-
-# this corresponds to which Function Unit (pipeline-with-Reservation-Stations)
-# is to process and guard the operation. they are roughly divided by having
-# the same register input/output signature (X-Form, etc.)
-
-
-@unique
-class Function(Enum):
- NONE = 0
- ALU = 1 << 1
- LDST = 1 << 2
- SHIFT_ROT = 1 << 3
- LOGICAL = 1 << 4
- BRANCH = 1 << 5
- CR = 1 << 6
- TRAP = 1 << 7
- MUL = 1 << 8
- DIV = 1 << 9
- SPR = 1 << 10
- MMU = 1 << 11
- SV = 1 << 12 # Simple-V https://libre-soc.org/openpower/sv
- VL = 1 << 13 # setvl
-
-
-@unique
-class Form(Enum):
- NONE = 0
- I = 1
- B = 2
- SC = 3
- D = 4
- DS = 5
- DQ = 6
- DX = 7
- X = 8
- XL = 9
- XFX = 10
- XFL = 11
- XX1 = 12
- XX2 = 13
- XX3 = 14
- XX4 = 15
- XS = 16
- XO = 17
- A = 18
- M = 19
- MD = 20
- MDS = 21
- VA = 22
- VC = 23
- VX = 24
- EVX = 25
- EVS = 26
- Z22 = 27
- Z23 = 28
- SVL = 29 # Simple-V for setvl instruction
-
-# Simple-V svp64 fields https://libre-soc.org/openpower/sv/svp64/
-
-
-@unique
-class SVPtype(Enum):
- NONE = 0
- P1 = 1
- P2 = 2
-
-
-@unique
-class SVEtype(Enum):
- NONE = 0
- EXTRA2 = 1
- EXTRA3 = 2
-
-
-@unique
-class SVEXTRA(Enum):
- NONE = 0
- Idx0 = 1
- Idx1 = 2
- Idx2 = 3
- Idx3 = 4
- Idx_1_2 = 5 # due to weird BA/BB for crops
-
-
-@unique
-class SVP64PredMode(Enum):
- ALWAYS = 0
- INT = 1
- CR = 2
-
-
-@unique
-class SVP64PredInt(Enum):
- ALWAYS = 0
- R3_UNARY = 1
- R3 = 2
- R3_N = 3
- R10 = 4
- R10_N = 5
- R30 = 6
- R30_N = 7
-
-
-@unique
-class SVP64PredCR(Enum):
- LT = 0
- GE = 1
- GT = 2
- LE = 3
- EQ = 4
- NE = 5
- SO = 6
- NS = 7
-
-
-@unique
-class SVP64RMMode(Enum):
- NORMAL = 0
- MAPREDUCE = 1
- FFIRST = 2
- SATURATE = 3
- PREDRES = 4
-
-
-@unique
-class SVP64width(Enum):
- DEFAULT = 0
- EW_32 = 1
- EW_16 = 2
- EW_8 = 3
-
-
-@unique
-class SVP64subvl(Enum):
- VEC1 = 0
- VEC2 = 1
- VEC3 = 2
- VEC4 = 3
-
-
-@unique
-class SVP64sat(Enum):
- NONE = 0
- SIGNED = 1
- UNSIGNED = 2
-
-
-# supported instructions: make sure to keep up-to-date with CSV files
-# just like everything else
-_insns = [
- "NONE", "add", "addc", "addco", "adde", "addeo", "addi", "addic", "addic.",
- "addis", "addme", "addmeo", "addo", "addze", "addzeo", "and", "andc",
- "andi.", "andis.", "attn", "b", "bc", "bcctr", "bclr", "bctar",
- "bpermd", "cmp", "cmpb", "cmpeqb", "cmpi", "cmpl", "cmpli", "cmprb",
- "cntlzd", "cntlzw", "cnttzd", "cnttzw", "crand", "crandc", "creqv",
- "crnand", "crnor", "cror", "crorc", "crxor", "darn", "dcbf", "dcbst",
- "dcbt", "dcbtst", "dcbz", "divd", "divde", "divdeo", "divdeu",
- "divdeuo", "divdo", "divdu", "divduo", "divw", "divwe", "divweo",
- "divweu", "divweuo", "divwo", "divwu", "divwuo", "eqv", "extsb",
- "extsh", "extsw", "extswsli", "hrfid", "icbi", "icbt", "isel", "isync",
- "lbarx", "lbz", "lbzu", "lbzux", "lbzx", "ld", "ldarx", "ldbrx",
- "ldu", "ldux", "ldx", "lha", "lharx", "lhau", "lhaux", "lhax",
- "lhbrx", "lhz", "lhzu", "lhzux", "lhzx", "lwa", "lwarx", "lwaux",
- "lwax", "lwbrx", "lwz", "lwzcix", "lwzu", "lwzux", "lwzx", "mcrf", "mcrxr",
- "mcrxrx", "mfcr/mfocrf", "mfmsr", "mfspr", "modsd", "modsw", "modud",
- "moduw", "mtcrf/mtocrf", "mtmsr", "mtmsrd", "mtspr", "mulhd", "mulhdu",
- "mulhw", "mulhwu", "mulld", "mulldo", "mulli", "mullw", "mullwo",
- "nand", "neg", "nego", "nop", "nor", "or", "orc", "ori", "oris",
- "popcntb", "popcntd", "popcntw", "prtyd", "prtyw", "rfid", "rldcl",
- "rldcr", "rldic", "rldicl", "rldicr", "rldimi", "rlwimi", "rlwinm",
- "rlwnm", "setb",
- "setvl", # https://libre-soc.org/openpower/sv/setvl
- "sim_cfg", "slbia", "sld", "slw", "srad", "sradi", "sraw",
- "srawi", "srd", "srw", "stb", "stbcix", "stbcx", "stbu", "stbux", "stbx",
- "std", "stdbrx", "stdcx", "stdu", "stdux", "stdx", "sth", "sthbrx", "sthcx",
- "sthu", "sthux", "sthx", "stw", "stwbrx", "stwcx", "stwu", "stwux",
- "stwx", "subf", "subfc", "subfco", "subfe", "subfeo", "subfic",
- "subfme", "subfmeo", "subfo", "subfze", "subfzeo", "sync", "td",
- "tdi", "tlbie", "tlbiel", "tw", "twi", "xor", "xori", "xoris",
-]
-
-# two-way lookup of instruction-to-index and vice-versa
-insns = {}
-asmidx = {}
-for i, insn in enumerate(_insns):
- insns[i] = insn
- asmidx[insn] = i
-
-# Internal Operation numbering. Add new opcodes here (FPADD, FPMUL etc.)
-
-
-@unique
-class MicrOp(Enum):
- OP_ILLEGAL = 0 # important that this is zero (see power_decoder.py)
- OP_NOP = 1
- OP_ADD = 2
- OP_ADDPCIS = 3
- OP_AND = 4
- OP_ATTN = 5
- OP_B = 6
- OP_BC = 7
- OP_BCREG = 8
- OP_BPERM = 9
- OP_CMP = 10
- OP_CMPB = 11
- OP_CMPEQB = 12
- OP_CMPRB = 13
- OP_CNTZ = 14
- OP_CRAND = 15
- OP_CRANDC = 16
- OP_CREQV = 17
- OP_CRNAND = 18
- OP_CRNOR = 19
- OP_CROR = 20
- OP_CRORC = 21
- OP_CRXOR = 22
- OP_DARN = 23
- OP_DCBF = 24
- OP_DCBST = 25
- OP_DCBT = 26
- OP_DCBTST = 27
- OP_DCBZ = 28
- OP_DIV = 29
- OP_DIVE = 30
- OP_EXTS = 31
- OP_EXTSWSLI = 32
- OP_ICBI = 33
- OP_ICBT = 34
- OP_ISEL = 35
- OP_ISYNC = 36
- OP_LOAD = 37
- OP_STORE = 38
- OP_MADDHD = 39
- OP_MADDHDU = 40
- OP_MADDLD = 41
- OP_MCRF = 42
- OP_MCRXR = 43
- OP_MCRXRX = 44
- OP_MFCR = 45
- OP_MFSPR = 46
- OP_MOD = 47
- OP_MTCRF = 48
- OP_MTSPR = 49
- OP_MUL_L64 = 50
- OP_MUL_H64 = 51
- OP_MUL_H32 = 52
- OP_OR = 53
- OP_POPCNT = 54
- OP_PRTY = 55
- OP_RLC = 56
- OP_RLCL = 57
- OP_RLCR = 58
- OP_SETB = 59
- OP_SHL = 60
- OP_SHR = 61
- OP_SYNC = 62
- OP_TRAP = 63
- OP_XOR = 67
- OP_SIM_CONFIG = 68
- OP_CROP = 69
- OP_RFID = 70
- OP_MFMSR = 71
- OP_MTMSRD = 72
- OP_SC = 73
- OP_MTMSR = 74
- OP_TLBIE = 75
- OP_SETVL = 76
-
-
-@unique
-class In1Sel(Enum):
- NONE = 0
- RA = 1
- RA_OR_ZERO = 2
- SPR = 3
- RS = 4 # for some ALU/Logical operations
-
-
-@unique
-class In2Sel(Enum):
- NONE = 0
- RB = 1
- CONST_UI = 2
- CONST_SI = 3
- CONST_UI_HI = 4
- CONST_SI_HI = 5
- CONST_LI = 6
- CONST_BD = 7
- CONST_DS = 8
- CONST_M1 = 9
- CONST_SH = 10
- CONST_SH32 = 11
- SPR = 12
- RS = 13 # for shiftrot (M-Form)
-
-
-@unique
-class In3Sel(Enum):
- NONE = 0
- RS = 1
- RB = 2 # for shiftrot (M-Form)
-
-
-@unique
-class OutSel(Enum):
- NONE = 0
- RT = 1
- RA = 2
- SPR = 3
- RT_OR_ZERO = 4
-
-
-@unique
-class LdstLen(Enum):
- NONE = 0
- is1B = 1
- is2B = 2
- is4B = 4
- is8B = 8
-
-
-@unique
-class LDSTMode(Enum):
- NONE = 0
- update = 1
- cix = 2
- cx = 3
-
-
-@unique
-class RC(Enum):
- NONE = 0
- ONE = 1
- RC = 2
-
-
-@unique
-class CryIn(Enum):
- ZERO = 0
- ONE = 1
- CA = 2
- # TODO OV = 3
-
-
-@unique
-class CRInSel(Enum):
- NONE = 0
- CR0 = 1
- BI = 2
- BFA = 3
- BA_BB = 4
- BC = 5
- WHOLE_REG = 6
- CR1 = 7
-
-
-@unique
-class CROutSel(Enum):
- NONE = 0
- CR0 = 1
- BF = 2
- BT = 3
- WHOLE_REG = 4
- CR1 = 5
-
-
-# SPRs - Special-Purpose Registers. See V3.0B Figure 18 p971 and
-# http://libre-riscv.org/openpower/isatables/sprs.csv
-# http://bugs.libre-riscv.org/show_bug.cgi?id=261
-
-def get_spr_enum(full_file):
- """get_spr_enum - creates an Enum of SPRs, dynamically
- has the option to reduce the enum to a much shorter list.
- this saves drastically on the size of the regfile
- """
- short_list = {'PIDR', 'DAR', 'PRTBL', 'DSISR', 'SVSRR0', 'SVSTATE',
- 'SPRG0_priv', 'SPRG1_priv', 'SPRG2_priv', 'SPRG3_priv',
- 'SPRG3'
- }
- spr_csv = []
- for row in get_csv("sprs.csv"):
- if full_file or row['SPR'] in short_list:
- spr_csv.append(row)
-
- spr_info = namedtuple('spr_info', 'SPR priv_mtspr priv_mfspr length idx')
- spr_dict = {}
- spr_byname = {}
- for row in spr_csv:
- info = spr_info(SPR=row['SPR'], priv_mtspr=row['priv_mtspr'],
- priv_mfspr=row['priv_mfspr'], length=int(row['len']),
- idx=int(row['Idx']))
- spr_dict[int(row['Idx'])] = info
- spr_byname[row['SPR']] = info
- fields = [(row['SPR'], int(row['Idx'])) for row in spr_csv]
- SPR = Enum('SPR', fields)
- return SPR, spr_dict, spr_byname
-
-SPRfull, spr_dict, spr_byname = get_spr_enum(full_file=True)
-SPRreduced, _, _ = get_spr_enum(full_file=False)
-
-XER_bits = {
- 'SO': 32,
- 'OV': 33,
- 'CA': 34,
- 'OV32': 44,
- 'CA32': 45
-}
-
-if __name__ == '__main__':
- # find out what the heck is in SPR enum :)
- print("sprs full", len(SPRfull))
- print(dir(SPRfull))
- print("sprs reduced", len(SPRreduced))
- print(dir(SPRreduced))
- print(dir(Enum))
- print(SPRfull.__members__['TAR'])
- for x in SPRfull:
- print(x, x.value, str(x), x.name)
-
- print("function", Function.ALU.name)
+from openpower.decoder.power_enums import *
projects / soc.git / commitdiff