xref: /XiangShan/src/main/scala/xiangshan/backend/fu/NewCSR/TrapHandleModule.scala (revision 3113cca92d7dc15709ce8496d6684a5490a284c2)
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 highestPrioNMIVec = Wire(Vec(64, Bool()))
38  highestPrioNMIVec.zipWithIndex.foreach { case (irq, i) =>
39    if (NonMaskableIRNO.interruptDefaultPrio.contains(i)) {
40      val higherIRSeq = NonMaskableIRNO.getIRQHigherThan(i)
41      irq := (
42        higherIRSeq.nonEmpty.B && Cat(higherIRSeq.map(num => !hasIRVec(num))).andR ||
43          higherIRSeq.isEmpty.B
44        ) && hasIRVec(i)
45      dontTouch(irq)
46    } else
47      irq := false.B
48  }
49
50  private val highestPrioEXVec = Wire(Vec(64, Bool()))
51  highestPrioEXVec.zipWithIndex.foreach { case (excp, i) =>
52    if (ExceptionNO.priorities.contains(i)) {
53      val higherEXSeq = ExceptionNO.getHigherExcpThan(i)
54      excp := (
55        higherEXSeq.nonEmpty.B && Cat(higherEXSeq.map(num => !hasEXVec(num))).andR ||
56        higherEXSeq.isEmpty.B
57      ) && hasEXVec(i)
58    } else
59      excp := false.B
60  }
61
62  private val highestPrioIR  = hasIRVec.asUInt
63  private val highestPrioNMI = highestPrioNMIVec.asUInt
64  private val highestPrioEX  = highestPrioEXVec.asUInt
65
66
67  private val mIRVec  = dontTouch(WireInit(highestPrioIR))
68  private val hsIRVec = (mIRVec  & mideleg) | (mIRVec  & mvien & ~mideleg)
69  private val vsIRVec = (hsIRVec & hideleg) | (hsIRVec & hvien & ~hideleg)
70
71  private val mEXVec  = highestPrioEX
72  private val hsEXVec = highestPrioEX & medeleg
73  private val vsEXVec = highestPrioEX & medeleg & hedeleg
74
75  // nmi handle in MMode only and default handler is mtvec
76  private val  mHasIR =  mIRVec.orR
77  private val hsHasIR = hsIRVec.orR & !hasNMI
78  private val vsHasIR = (vsIRVec.orR || hasIR && virtualInterruptIsHvictlInject) & !hasNMI
79
80  private val  mHasEX =  mEXVec.orR
81  private val hsHasEX = hsEXVec.orR
82  private val vsHasEX = vsEXVec.orR
83
84  private val  mHasTrap =  mHasEX ||  mHasIR
85  private val hsHasTrap = hsHasEX || hsHasIR
86  private val vsHasTrap = vsHasEX || vsHasIR
87
88  private val handleTrapUnderHS = !privState.isModeM && hsHasTrap
89  private val handleTrapUnderVS = privState.isVirtual && vsHasTrap
90  private val handleTrapUnderM = !handleTrapUnderVS && !handleTrapUnderHS
91
92  // Todo: support more interrupt and exception
93  private val exceptionRegular = OHToUInt(highestPrioEX)
94  private val interruptNO = OHToUInt(Mux(hasNMI, highestPrioNMI, highestPrioIR))
95  private val exceptionNO = Mux(trapInfo.bits.singleStep, ExceptionNO.breakPoint.U, exceptionRegular)
96
97  private val causeNO = Mux(hasIR, interruptNO, exceptionNO)
98
99  // sm/ssdbltrp
100  private val m_EX_DT  = handleTrapUnderM  && mstatus.MDT.asBool  && hasTrap
101  private val s_EX_DT  = handleTrapUnderHS && mstatus.SDT.asBool  && hasTrap
102  private val vs_EX_DT = handleTrapUnderVS && vsstatus.SDT.asBool && hasTrap
103
104  private val dbltrpToMN = m_EX_DT && mnstatus.NMIE.asBool // NMI not allow double trap
105  private val hasDTExcp  = m_EX_DT || s_EX_DT || vs_EX_DT
106
107  private val trapToHS = handleTrapUnderHS && !s_EX_DT && !vs_EX_DT
108  private val traptoVS = handleTrapUnderVS && !vs_EX_DT
109
110  private val xtvec = MuxCase(io.in.mtvec, Seq(
111    traptoVS -> io.in.vstvec,
112    trapToHS -> io.in.stvec
113  ))
114  private val pcFromXtvec = Cat(xtvec.addr.asUInt + Mux(xtvec.mode === XtvecMode.Vectored && hasIR, interruptNO(5, 0), 0.U), 0.U(2.W))
115
116  io.out.entryPrivState := MuxCase(default = PrivState.ModeM, mapping = Seq(
117    traptoVS -> PrivState.ModeVS,
118    trapToHS -> PrivState.ModeHS,
119  ))
120
121  io.out.causeNO.Interrupt := hasIR
122  io.out.causeNO.ExceptionCode := causeNO
123  io.out.pcFromXtvec := pcFromXtvec
124  io.out.hasDTExcp := hasDTExcp
125  io.out.dbltrpToMN := dbltrpToMN
126
127}
128
129class TrapHandleIO extends Bundle {
130  val in = Input(new Bundle {
131    val trapInfo = ValidIO(new Bundle {
132      val trapVec = UInt(64.W)
133      val nmi = Bool()
134      val intrVec = UInt(64.W)
135      val isInterrupt = Bool()
136      val singleStep = Bool()
137    })
138    val privState = new PrivState
139    val mstatus = new MstatusBundle
140    val vsstatus = new SstatusBundle
141    val mnstatus = new MnstatusBundle
142    val mideleg = new MidelegBundle
143    val medeleg = new MedelegBundle
144    val hideleg = new HidelegBundle
145    val hedeleg = new HedelegBundle
146    val mvien = new MvienBundle
147    val hvien = new HvienBundle
148    // trap vector
149    val mtvec = Input(new XtvecBundle)
150    val stvec = Input(new XtvecBundle)
151    val vstvec = Input(new XtvecBundle)
152    // virtual interrupt is hvictl inject
153    val virtualInterruptIsHvictlInject = Input(Bool())
154  })
155
156  val out = new Bundle {
157    val entryPrivState = new PrivState
158    val causeNO = new CauseBundle
159    val dbltrpToMN = Bool()
160    val hasDTExcp = Bool()
161    val pcFromXtvec = UInt()
162  }
163}