X-Git-Url: https://git.libre-soc.org/?p=soc.git;a=blobdiff_plain;f=src%2Fsoc%2Fdecoder%2Fpower_decoder2.py;h=220258e0a7e5e9faab40572e3ec842578b8e0603;hp=e24de8a30e2d2f766828b5b535a64bbeba442548;hb=63aeeaa31a60065b03421d3a5497327078d0b0e8;hpb=18cd7c75da484e6dd68eb97bd74d26cdbaef0f8a diff --git a/src/soc/decoder/power_decoder2.py b/src/soc/decoder/power_decoder2.py index e24de8a3..220258e0 100644 --- a/src/soc/decoder/power_decoder2.py +++ b/src/soc/decoder/power_decoder2.py @@ -14,14 +14,19 @@ 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_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, SPR, RC, LDSTMode) -from soc.decoder.decode2execute1 import Decode2ToExecute1Type, Data + OutSel, SPR, RC, LDSTMode, + SVEXTRA, SVEtype) +from soc.decoder.decode2execute1 import (Decode2ToExecute1Type, Data, + Decode2ToOperand) +from soc.sv.svp64 import SVP64Rec from soc.consts import MSR from soc.regfile.regfiles import FastRegs @@ -74,6 +79,77 @@ class SPRMap(Elaboratable): return m +class SVP64RegExtra(Elaboratable): + """SVP64RegExtra - decodes SVP64 Extra fields to determine reg extension + + incoming 5-bit GPR/FP is turned into a 7-bit and marked as scalar/vector + depending on info in one of the positions in the EXTRA field. + + designed so that "no change" to the 5-bit register number occurs if + SV either does not apply or the relevant EXTRA2/3 field bits are zero. + + see https://libre-soc.org/openpower/sv/svp64/ + """ + def __init__(self): + self.extra = Signal(10, reset_less=True) + self.etype = Signal(SVEtype, reset_less=True) # 2 or 3 bits + self.idx = Signal(SVEXTRA, reset_less=True) # which part of extra + self.reg_in = Signal(5) # incoming reg number (5 bits, RA, RB) + self.reg_out = Signal(7) # extra-augmented output (7 bits) + self.isvec = Signal(1) # reg is marked as vector if true + + def elaborate(self, platform): + m = Module() + comb = m.d.comb + + # first get the spec. if not changed it's "scalar identity behaviour" + # which is zero which is ok. + spec = Signal(3) + + # back in the LDSTRM-* and RM-* files generated by sv_analysis.py + # we marked every op with an Etype: EXTRA2 or EXTRA3, and also said + # which of the 4 (or 3 for EXTRA3) sub-fields of bits 10:18 contain + # the register-extension information. extract those how + with m.Switch(self.etype): + # 2-bit index selection mode + with m.Case(SVEtype.EXTRA2): + with m.Switch(self.idx): + with m.Case(SVEXTRA.Idx0): # 1st 2 bits + comb += spec[1:3].eq(self.extra[0:2]) + with m.Case(SVEXTRA.Idx1): # 2nd 2 bits + comb += spec[1:3].eq(self.extra[2:4]) + with m.Case(SVEXTRA.Idx2): # 3rd 2 bits + comb += spec[1:3].eq(self.extra[4:6]) + with m.Case(SVEXTRA.Idx3): # 4th 2 bits + comb += spec[1:3].eq(self.extra[6:8]) + # 3-bit index selection mode + with m.Case(SVEtype.EXTRA3): + with m.Switch(self.idx): + with m.Case(SVEXTRA.Idx0): # 1st 3 bits + comb += spec.eq(self.extra[0:3]) + with m.Case(SVEXTRA.Idx1): # 2nd 3 bits + comb += spec.eq(self.extra[3:6]) + with m.Case(SVEXTRA.Idx2): # 3rd 3 bits + comb += spec.eq(self.extra[6:9]) + # cannot fit more than 9 bits so there is no 4th thing + + # now decode it. bit 2 is "scalar/vector". note that spec could be zero + # from above, which (by design) has the effect of "no change", below. + + # simple: isvec is top bit of spec + comb += self.isvec.eq(spec[2]) + + # decode vector differently from scalar + with m.If(self.isvec): + # Vector: shifted up, extra in LSBs (RA << 2) | spec[0:1] + comb += self.reg_out.eq(Cat(spec[:2], self.reg_in)) + with m.Else(): + # Scalar: not shifted up, extra in MSBs RA | (spec[0:1] << 5) + comb += self.reg_out.eq(Cat(self.reg_in, spec[:2])) + + return m + + class DecodeA(Elaboratable): """DecodeA from instruction @@ -82,16 +158,23 @@ class DecodeA(Elaboratable): def __init__(self, dec): self.dec = dec + self.sv_rm = SVP64Rec() # SVP64 RM field 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.reg_out = Data(7, name="reg_a") + self.reg_isvec = Signal(1, name="reg_a_isvec") # TODO: in reg_out self.spr_out = Data(SPR, "spr_a") self.fast_out = Data(3, "fast_a") def elaborate(self, platform): m = Module() comb = m.d.comb + op = self.dec.op m.submodules.sprmap = sprmap = SPRMap() + 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) # select Register A field ra = Signal(5, reset_less=True) @@ -99,16 +182,32 @@ class DecodeA(Elaboratable): with m.If((self.sel_in == In1Sel.RA) | ((self.sel_in == In1Sel.RA_OR_ZERO) & (ra != Const(0, 5)))): - comb += self.reg_out.data.eq(ra) + comb += reg.eq(ra) comb += self.reg_out.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 += self.reg_out.data.eq(self.dec.RS) + comb += reg.eq(rs) comb += self.reg_out.ok.eq(1) + # 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 + comb += svdec.extra.eq(extra) # EXTRA field of SVP64 RM + comb += svdec.etype.eq(op.SV_Etype) # EXTRA2/3 for this insn + comb += svdec.idx.eq(op.sv_in1) # SVP64 reg #1 (matches in1_sel) + comb += svdec.reg_in.eq(reg) # 5-bit (RA, RS) + + # outputs: 7-bit reg number and whether it's vectorised + comb += self.reg_out.data.eq(svdec.reg_out) + comb += self.reg_isvec.eq(svdec.isvec) + # decode Fast-SPR based on instruction type - op = self.dec.op with m.Switch(op.internal_op): # BC or BCREG: implicit register (CTR) NOTE: same in DecodeOut @@ -172,6 +271,7 @@ class DecodeB(Elaboratable): def __init__(self, dec): self.dec = dec + self.sv_rm = SVP64Rec() # SVP64 RM field self.sel_in = Signal(In2Sel, reset_less=True) self.insn_in = Signal(32, reset_less=True) self.reg_out = Data(5, "reg_b") @@ -276,6 +376,7 @@ class DecodeC(Elaboratable): def __init__(self, dec): self.dec = dec + self.sv_rm = SVP64Rec() # SVP64 RM field self.sel_in = Signal(In3Sel, reset_less=True) self.insn_in = Signal(32, reset_less=True) self.reg_out = Data(5, "reg_c") @@ -305,6 +406,7 @@ class DecodeOut(Elaboratable): def __init__(self, dec): self.dec = dec + self.sv_rm = SVP64Rec() # SVP64 RM field self.sel_in = Signal(OutSel, reset_less=True) self.insn_in = Signal(32, reset_less=True) self.reg_out = Data(5, "reg_o") @@ -359,6 +461,7 @@ class DecodeOut2(Elaboratable): def __init__(self, dec): self.dec = dec + self.sv_rm = SVP64Rec() # SVP64 RM field self.sel_in = Signal(OutSel, reset_less=True) self.lk = Signal(reset_less=True) self.insn_in = Signal(32, reset_less=True) @@ -482,6 +585,7 @@ class DecodeCRIn(Elaboratable): def __init__(self, dec): self.dec = dec + self.sv_rm = SVP64Rec() # SVP64 RM field self.sel_in = Signal(CRInSel, reset_less=True) self.insn_in = Signal(32, reset_less=True) self.cr_bitfield = Data(3, "cr_bitfield") @@ -546,6 +650,7 @@ class DecodeCROut(Elaboratable): def __init__(self, dec): self.dec = dec + self.sv_rm = SVP64Rec() # SVP64 RM field self.rc_in = Signal(reset_less=True) self.sel_in = Signal(CROutSel, reset_less=True) self.insn_in = Signal(32, reset_less=True) @@ -617,20 +722,28 @@ record_names = {'insn_type': 'internal_op', '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): - def __init__(self, dec, opkls=None, fn_name=None, - final=False, state=None): - + self.sv_rm = SVP64Rec(name="dec_svp64") # SVP64 RM field self.final = final self.opkls = opkls self.fn_name = fn_name - self.e = Decode2ToExecute1Type(name=self.fn_name, opkls=self.opkls) - col_subset = self.get_col_subset(self.e.do) + 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) + # 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) @@ -653,18 +766,18 @@ class PowerDecodeSubset(Elaboratable): return row['unit'] == self.fn_name def ports(self): - return self.dec.ports() + self.e.ports() + return self.dec.ports() + self.e.ports() + self.sv_rm.ports() def needs_field(self, field, op_field): if self.final: - do = self.e.do + 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.e.do + do = self.do else: do = self.e_tmp.do if hasattr(do, field) and val is not None: @@ -678,20 +791,17 @@ class PowerDecodeSubset(Elaboratable): m = Module() comb = m.d.comb state = self.state - e_out, op, do_out = self.e, self.dec.op, self.e.do + 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 self.final: - e = self.e - else: + if not self.final: if self.fn_name is None: name = "tmp" else: name = self.fn_name + "tmp" - self.e_tmp = e = Decode2ToExecute1Type(name=name, opkls=self.opkls) - do = e.do + self.e_tmp = Decode2ToExecute1Type(name=name, opkls=self.opkls) # set up submodule decoders m.submodules.dec = self.dec @@ -710,6 +820,8 @@ class PowerDecodeSubset(Elaboratable): comb += dec_rc.sel_in.eq(op.rc_sel) comb += dec_oe.sel_in.eq(op.rc_sel) # XXX should be OE sel comb += self.dec_cr_in.sel_in.eq(op.cr_in) + comb += self.dec_cr_in.sv_rm.eq(self.sv_rm) + comb += self.dec_cr_out.sv_rm.eq(self.sv_rm) comb += self.dec_cr_out.sel_in.eq(op.cr_out) comb += self.dec_cr_out.rc_in.eq(dec_rc.rc_out.data) @@ -717,10 +829,24 @@ class PowerDecodeSubset(Elaboratable): comb += self.do_copy("msr", msr) comb += self.do_copy("cia", cia) - # set up instruction, pick fn unit + # set up instruction type # no op: defaults to OP_ILLEGAL comb += self.do_copy("insn_type", self.op_get("internal_op")) - comb += self.do_copy("fn_unit", self.op_get("function_unit")) + + # 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 + + # for first test only forward SPRs 18 and 19 to MMU, when + # operation is MTSPR or MFSPR. TODO: add other MMU SPRs + 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))): + comb += self.do_copy("fn_unit", Function.MMU) + with m.Else(): + comb += self.do_copy("fn_unit",fn) # immediates if self.needs_field("zero_a", "in1_sel"): @@ -782,14 +908,36 @@ class PowerDecode2(PowerDecodeSubset): 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): + super().__init__(dec, opkls, fn_name, final, state) + self.exc = LDSTException("dec2_exc") + 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") + subset.add("sv_in1") + subset.add("sv_in2") + subset.add("sv_in3") + subset.add("sv_out") + subset.add("SV_Etype") + subset.add("SV_Ptype") subset.add("lk") subset.add("internal_op") subset.add("form") @@ -819,6 +967,11 @@ class PowerDecode2(PowerDecodeSubset): dec_c.insn_in, dec_o.insn_in, dec_o2.insn_in]: comb += i.eq(self.dec.opcode_in) + # ... and svp64 rm + for i in [dec_a.insn_in, dec_b.insn_in, + dec_c.insn_in, dec_o.insn_in, dec_o2.insn_in]: + comb += i.eq(self.sv_rm) + # ...and subdecoders' input fields comb += dec_a.sel_in.eq(op.in1_sel) comb += dec_b.sel_in.eq(op.in2_sel) @@ -829,11 +982,14 @@ class PowerDecode2(PowerDecodeSubset): comb += dec_o2.lk.eq(do.lk) # registers a, b, c and out and out2 (LD/ST EA) - comb += e.read_reg1.eq(dec_a.reg_out) - comb += e.read_reg2.eq(dec_b.reg_out) - comb += e.read_reg3.eq(dec_c.reg_out) - comb += e.write_reg.eq(dec_o.reg_out) - comb += e.write_ea.eq(dec_o2.reg_out) + 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) # SPRs out comb += e.read_spr1.eq(dec_a.spr_out) @@ -883,14 +1039,32 @@ class PowerDecode2(PowerDecodeSubset): 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]) # v3.0B 6.5.11 p1076 + 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.If(dec_irq_ok): + with m.Elif(dec_irq_ok): self.trap(m, TT.DEC, 0x900) # v3.0B 6.5 p1065 # external interrupt? only if MSR.EE set @@ -936,9 +1110,13 @@ class PowerDecode2(PowerDecodeSubset): 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): + def trap(self, m, traptype, trapaddr, exc=None): """trap: this basically "rewrites" the decoded instruction as a trap """ comb = m.d.comb @@ -951,6 +1129,7 @@ class PowerDecode2(PowerDecodeSubset): 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"