xref: /XiangShan/src/main/scala/xiangshan/backend/fu/NewCSR/TrapHandleModule.scala (revision 94aa21c6009c2f39c5c5dae9c87260c78887efcc)
1package xiangshan.backend.fu.NewCSR
2
3import chisel3._
4import chisel3.util._
5import xiangshan.ExceptionNO
6import xiangshan.backend.fu.NewCSR.CSRBundles.{CauseBundle, PrivState, XtvecBundle}
7import xiangshan.backend.fu.NewCSR.CSRDefines.XtvecMode
8import xiangshan.backend.fu.NewCSR.CSRBundleImplicitCast._
9
10
11class TrapHandleModule extends Module {
12  val io = IO(new TrapHandleIO)
13
14  private val trapInfo = io.in.trapInfo
15  private val privState = io.in.privState
16  private val mstatus  = io.in.mstatus
17  private val vsstatus = io.in.vsstatus
18  private val mnstatus = io.in.mnstatus
19  private val mideleg = io.in.mideleg.asUInt
20  private val hideleg = io.in.hideleg.asUInt
21  private val medeleg = io.in.medeleg.asUInt
22  private val hedeleg = io.in.hedeleg.asUInt
23  private val mvien = io.in.mvien.asUInt
24  private val hvien = io.in.hvien.asUInt
25  private val virtualInterruptIsHvictlInject = io.in.virtualInterruptIsHvictlInject
26
27  private val hasTrap = trapInfo.valid
28  private val hasNMI = hasTrap && trapInfo.bits.nmi
29  private val hasIR = hasTrap && trapInfo.bits.isInterrupt
30  private val hasEX = hasTrap && !trapInfo.bits.isInterrupt
31
32  private val exceptionVec = io.in.trapInfo.bits.trapVec
33  private val intrVec = io.in.trapInfo.bits.intrVec
34  private val hasEXVec = Mux(hasEX, exceptionVec, 0.U)
35  private val hasIRVec = Mux(hasIR, intrVec, 0.U)
36
37  private val irToHS = io.in.trapInfo.bits.irToHS
38  private val irToVS = io.in.trapInfo.bits.irToVS
39
40  private val highestPrioEXVec = Wire(Vec(64, Bool()))
41  highestPrioEXVec.zipWithIndex.foreach { case (excp, i) =>
42    if (ExceptionNO.priorities.contains(i)) {
43      val higherEXSeq = ExceptionNO.getHigherExcpThan(i)
44      excp := (
45        higherEXSeq.nonEmpty.B && Cat(higherEXSeq.map(num => !hasEXVec(num))).andR ||
46        higherEXSeq.isEmpty.B
47      ) && hasEXVec(i)
48    } else
49      excp := false.B
50  }
51
52  private val highestPrioIR  = hasIRVec.asUInt
53  private val highestPrioEX  = highestPrioEXVec.asUInt
54
55  private val mEXVec  = highestPrioEX
56  private val hsEXVec = highestPrioEX & medeleg
57  private val vsEXVec = highestPrioEX & medeleg & hedeleg
58
59  // nmi handle in MMode only and default handler is mtvec
60  private val  mHasIR = hasIR
61  private val hsHasIR = hasIR && irToHS & !hasNMI
62  private val vsHasIR = hasIR && irToVS & !hasNMI
63
64  private val  mHasEX =  mEXVec.orR
65  private val hsHasEX = hsEXVec.orR
66  private val vsHasEX = vsEXVec.orR
67
68  private val  mHasTrap =  mHasEX ||  mHasIR
69  private val hsHasTrap = hsHasEX || hsHasIR
70  private val vsHasTrap = vsHasEX || vsHasIR
71
72  private val handleTrapUnderHS = !privState.isModeM && hsHasTrap
73  private val handleTrapUnderVS = privState.isVirtual && vsHasTrap
74  private val handleTrapUnderM = !handleTrapUnderVS && !handleTrapUnderHS
75
76  // Todo: support more interrupt and exception
77  private val exceptionRegular = OHToUInt(highestPrioEX)
78  private val interruptNO = highestPrioIR
79  private val exceptionNO = Mux(trapInfo.bits.singleStep, ExceptionNO.breakPoint.U, exceptionRegular)
80
81  private val causeNO = Mux(hasIR, interruptNO, exceptionNO)
82
83  // sm/ssdbltrp
84  private val m_EX_DT  = handleTrapUnderM  && mstatus.MDT.asBool  && hasTrap
85  private val s_EX_DT  = handleTrapUnderHS && mstatus.SDT.asBool  && hasTrap
86  private val vs_EX_DT = handleTrapUnderVS && vsstatus.SDT.asBool && hasTrap
87
88  private val dbltrpToMN = m_EX_DT && mnstatus.NMIE.asBool // NMI not allow double trap
89  private val hasDTExcp  = m_EX_DT || s_EX_DT || vs_EX_DT
90
91  private val trapToHS = handleTrapUnderHS && !s_EX_DT && !vs_EX_DT
92  private val traptoVS = handleTrapUnderVS && !vs_EX_DT
93
94  private val xtvec = MuxCase(io.in.mtvec, Seq(
95    traptoVS -> io.in.vstvec,
96    trapToHS -> io.in.stvec
97  ))
98  private val adjustinterruptNO = Mux(
99    InterruptNO.getVS.map(_.U === interruptNO).reduce(_ || _) && vsHasIR,
100    interruptNO - 1.U, // map VSSIP, VSTIP, VSEIP to SSIP, STIP, SEIP
101    interruptNO,
102  )
103  private val pcFromXtvec = Cat(xtvec.addr.asUInt + Mux(xtvec.mode === XtvecMode.Vectored && hasIR, adjustinterruptNO(5, 0), 0.U), 0.U(2.W))
104
105  io.out.entryPrivState := MuxCase(default = PrivState.ModeM, mapping = Seq(
106    traptoVS -> PrivState.ModeVS,
107    trapToHS -> PrivState.ModeHS,
108  ))
109
110  io.out.causeNO.Interrupt := hasIR
111  io.out.causeNO.ExceptionCode := causeNO
112  io.out.pcFromXtvec := pcFromXtvec
113  io.out.hasDTExcp := hasDTExcp
114  io.out.dbltrpToMN := dbltrpToMN
115
116}
117
118class TrapHandleIO extends Bundle {
119  val in = Input(new Bundle {
120    val trapInfo = ValidIO(new Bundle {
121      val trapVec = UInt(64.W)
122      val nmi = Bool()
123      val intrVec = UInt(8.W)
124      val isInterrupt = Bool()
125      val singleStep = Bool()
126      // trap to x mode
127      val irToHS = Bool()
128      val irToVS = Bool()
129    })
130    val privState = new PrivState
131    val mstatus = new MstatusBundle
132    val vsstatus = new SstatusBundle
133    val mnstatus = new MnstatusBundle
134    val mideleg = new MidelegBundle
135    val medeleg = new MedelegBundle
136    val hideleg = new HidelegBundle
137    val hedeleg = new HedelegBundle
138    val mvien = new MvienBundle
139    val hvien = new HvienBundle
140    // trap vector
141    val mtvec = Input(new XtvecBundle)
142    val stvec = Input(new XtvecBundle)
143    val vstvec = Input(new XtvecBundle)
144    // virtual interrupt is hvictl inject
145    val virtualInterruptIsHvictlInject = Input(Bool())
146  })
147
148  val out = new Bundle {
149    val entryPrivState = new PrivState
150    val causeNO = new CauseBundle
151    val dbltrpToMN = Bool()
152    val hasDTExcp = Bool()
153    val pcFromXtvec = UInt()
154  }
155}