1package xiangshan.backend.fu.NewCSR 2 3import chisel3._ 4import chisel3.util._ 5import chisel3.util.experimental.decode.TruthTable 6import freechips.rocketchip.rocket.CSRs 7import xiangshan.backend.fu.NewCSR.CSRBundles.{Counteren, PrivState} 8import xiangshan.backend.fu.NewCSR.CSRDefines._ 9 10class CSRPermitModule extends Module { 11 val io = IO(new CSRPermitIO) 12 13 private val (ren, wen, addr, privState, debugMode) = ( 14 io.in.csrAccess.ren, 15 io.in.csrAccess.wen, 16 io.in.csrAccess.addr, 17 io.in.privState, 18 io.in.debugMode 19 ) 20 21 private val csrAccess = WireInit(ren || wen) 22 23 private val (mret, sret) = ( 24 io.in.mret, 25 io.in.sret, 26 ) 27 28 private val (tsr, vtsr) = ( 29 io.in.status.tsr, 30 io.in.status.vtsr, 31 ) 32 33 private val (tw, vtw) = ( 34 io.in.status.tw, 35 io.in.status.vtw 36 ) 37 38 private val (tvm, vtvm) = ( 39 io.in.status.tvm, 40 io.in.status.vtvm, 41 ) 42 43 private val csrIsCustom = io.in.csrIsCustom 44 45 private val (mcounteren, hcounteren, scounteren) = ( 46 io.in.status.mcounteren, 47 io.in.status.hcounteren, 48 io.in.status.scounteren, 49 ) 50 51 private val (mcounterenTM, hcounterenTM) = ( 52 mcounteren(1), 53 hcounteren(1), 54 ) 55 56 private val (menvcfg, henvcfg) = ( 57 io.in.status.menvcfg, 58 io.in.status.henvcfg, 59 ) 60 61 private val (menvcfgSTCE, henvcfgSTCE) = ( 62 menvcfg(63), 63 henvcfg(63), 64 ) 65 66 private val (sFSIsOff, sVSIsOff, sOrVsFSIsOff, sOrVsVSIsOff) = ( 67 io.in.status.mstatusFSOff, 68 io.in.status.mstatusVSOff, 69 io.in.status.mstatusFSOff || io.in.status.vsstatusFSOff, 70 io.in.status.mstatusVSOff || io.in.status.vsstatusVSOff, 71 ) 72 73 private val csrIsRO = addr(11, 10) === "b11".U 74 private val csrIsUnpriv = addr(9, 8) === "b00".U 75 private val csrIsHPM = addr >= CSRs.cycle.U && addr <= CSRs.hpmcounter31.U 76 private val csrIsFp = Seq(CSRs.fflags, CSRs.frm, CSRs.fcsr).map(_.U === addr).reduce(_ || _) 77 private val csrIsVec = Seq(CSRs.vstart, CSRs.vxsat, CSRs.vxrm, CSRs.vcsr, CSRs.vl, CSRs.vtype, CSRs.vlenb).map(_.U === addr).reduce(_ || _) 78 private val csrIsWritableVec = Seq(CSRs.vstart, CSRs.vxsat, CSRs.vxrm, CSRs.vcsr).map(_.U === addr).reduce(_ || _) 79 private val counterAddr = addr(4, 0) // 32 counters 80 81 private val accessTable = TruthTable(Seq( 82 // V PRVM ADDR 83 BitPat("b0__00___00") -> BitPat.Y(), // HU access U 84 BitPat("b1__00___00") -> BitPat.Y(), // VU access U 85 BitPat("b0__01___00") -> BitPat.Y(), // HS access U 86 BitPat("b0__01___01") -> BitPat.Y(), // HS access S 87 BitPat("b0__01___10") -> BitPat.Y(), // HS access H 88 BitPat("b1__01___00") -> BitPat.Y(), // VS access U 89 BitPat("b1__01___01") -> BitPat.Y(), // VS access S 90 BitPat("b0__11___00") -> BitPat.Y(), // M access HU 91 BitPat("b0__11___01") -> BitPat.Y(), // M access HS 92 BitPat("b0__11___10") -> BitPat.Y(), // M access H 93 BitPat("b0__11___11") -> BitPat.Y(), // M access M 94 ), BitPat.N()) 95 96 private val regularPrivilegeLegal = chisel3.util.experimental.decode.decoder( 97 privState.V.asUInt ## privState.PRVM.asUInt ## addr(9, 8), 98 accessTable 99 ).asBool 100 101 private val isDebugReg = addr(11, 4) === "h7b".U 102 private val privilegeLegal = Mux(isDebugReg, debugMode, regularPrivilegeLegal || debugMode) 103 104 private val rwIllegal = csrIsRO && wen 105 106 private val mret_EX_II = mret && !privState.isModeM 107 private val mret_EX_VI = false.B 108 private val mretIllegal = mret_EX_II || mret_EX_VI 109 110 private val sret_EX_II = sret && (privState.isModeHU || privState.isModeHS && tsr) 111 private val sret_EX_VI = sret && (privState.isModeVU || privState.isModeVS && vtsr) 112 private val sretIllegal = sret_EX_II || sret_EX_VI 113 114 private val rwSatp_EX_II = csrAccess && privState.isModeHS && tvm && (addr === CSRs.satp.U || addr === CSRs.hgatp.U) 115 private val rwSatp_EX_VI = csrAccess && privState.isModeVS && vtvm && (addr === CSRs.satp.U) 116 117 private val rwCustom_EX_II = csrAccess && privState.isModeVS && csrIsCustom 118 119 private val accessHPM = ren && csrIsHPM 120 private val accessHPM_EX_II = accessHPM && ( 121 !privState.isModeM && !mcounteren(counterAddr) || 122 privState.isModeHU && !scounteren(counterAddr) 123 ) 124 private val accessHPM_EX_VI = accessHPM && mcounteren(counterAddr) && ( 125 privState.isModeVS && !hcounteren(counterAddr) || 126 privState.isModeVU && (!hcounteren(counterAddr) || !scounteren(counterAddr)) 127 ) 128 129 private val rwStimecmp_EX_II = csrAccess && ((privState.isModeHS && !mcounterenTM || !privState.isModeM && !menvcfgSTCE) && addr === CSRs.vstimecmp.U || 130 ((privState.isModeHS || privState.isModeVS) && !mcounterenTM || !privState.isModeM && !menvcfgSTCE) && addr === CSRs.stimecmp.U) 131 private val rwStimecmp_EX_VI = csrAccess && privState.isModeVS && (mcounterenTM && !hcounterenTM || menvcfgSTCE && !henvcfgSTCE) && addr === CSRs.stimecmp.U 132 133 private val fsEffectiveOff = sFSIsOff && !privState.isVirtual || sOrVsFSIsOff && privState.isVirtual 134 private val vsEffectiveOff = sVSIsOff && !privState.isVirtual || sOrVsVSIsOff && privState.isVirtual 135 136 private val fpOff_EX_II = csrAccess && csrIsFp && fsEffectiveOff 137 private val vecOff_EX_II = csrAccess && csrIsVec && vsEffectiveOff 138 139 private val fpVec_EX_II = fpOff_EX_II || vecOff_EX_II 140 141 private val csrAccessIllegal = (!privilegeLegal || rwIllegal) 142 143 io.out.illegal := csrAccess && csrAccessIllegal 144 145 // Todo: check correct 146 io.out.EX_II := io.out.illegal && !privState.isVirtual || mret_EX_II || sret_EX_II || rwSatp_EX_II || accessHPM_EX_II || rwStimecmp_EX_II || rwCustom_EX_II || fpVec_EX_II 147 io.out.EX_VI := io.out.illegal && privState.isVirtual || mret_EX_VI || sret_EX_VI || rwSatp_EX_VI || accessHPM_EX_VI || rwStimecmp_EX_VI 148 149 io.out.hasLegalWen := wen && !csrAccessIllegal 150 io.out.hasLegalMret := mret && !mretIllegal 151 io.out.hasLegalSret := sret && !sretIllegal 152 153 io.out.hasLegalWriteFcsr := wen && csrIsFp && !fsEffectiveOff 154 io.out.hasLegalWriteVcsr := wen && csrIsWritableVec && !vsEffectiveOff 155 156 dontTouch(regularPrivilegeLegal) 157} 158 159class CSRPermitIO extends Bundle { 160 val in = Input(new Bundle { 161 val csrAccess = new Bundle { 162 val ren = Bool() 163 val wen = Bool() 164 val addr = UInt(12.W) 165 } 166 val privState = new PrivState 167 val debugMode = Bool() 168 val mret = Bool() 169 val sret = Bool() 170 val csrIsCustom = Bool() 171 val status = new Bundle { 172 // Trap SRET 173 val tsr = Bool() 174 // Virtual Trap SRET 175 val vtsr = Bool() 176 // Timeout Wait 177 val tw = Bool() 178 // Virtual Timeout Wait 179 val vtw = Bool() 180 // Trap Virtual Memory 181 val tvm = Bool() 182 // Virtual Trap Virtual Memory 183 val vtvm = Bool() 184 // Machine level counter enable, access PMC from the level less than M will trap EX_II 185 val mcounteren = UInt(32.W) 186 // Hypervisor level counter enable. 187 // Accessing PMC from VS/VU level will trap EX_VI, if m[x]=1 && h[x]=0 188 val hcounteren = UInt(32.W) 189 // Supervisor level counter enable. 190 // Accessing PMC from **HU level** will trap EX_II, if s[x]=0 191 // Accessing PMC from **VU level** will trap EX_VI, if m[x]=1 && h[x]=1 && s[x]=0 192 val scounteren = UInt(32.W) 193 // Machine environment configuration register. 194 // Accessing stimecmp or vstimecmp from **Non-M level** will trap EX_II, if menvcfg.STCE=0 195 val menvcfg = UInt(64.W) 196 // Hypervisor environment configuration register. 197 // Accessing vstimecmp from ** V level** will trap EX_VI, if menvcfg.STCE=1 && henvcfg.STCE=0 198 val henvcfg = UInt(64.W) 199 200 val mstatusFSOff = Bool() 201 val vsstatusFSOff = Bool() 202 val mstatusVSOff = Bool() 203 val vsstatusVSOff = Bool() 204 } 205 }) 206 207 val out = Output(new Bundle { 208 val hasLegalWen = Bool() 209 val hasLegalMret = Bool() 210 val hasLegalSret = Bool() 211 val hasLegalWriteFcsr = Bool() 212 val hasLegalWriteVcsr = Bool() 213 // Todo: split illegal into EX_II and EX_VI 214 val illegal = Bool() 215 val EX_II = Bool() 216 val EX_VI = Bool() 217 }) 218} 219