xref: /XiangShan/src/main/scala/xiangshan/backend/fu/NewCSR/TrapHandleModule.scala (revision 0e43419882c10c4dadc8ba45c790ad5b1c198dad)
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 mideleg = io.in.mideleg.asUInt
17  private val hideleg = io.in.hideleg.asUInt
18  private val medeleg = io.in.medeleg.asUInt
19  private val hedeleg = io.in.hedeleg.asUInt
20  private val mvien = io.in.mvien.asUInt
21  private val hvien = io.in.hvien.asUInt
22
23  private val hasTrap = trapInfo.valid
24  private val hasNMI = hasTrap && trapInfo.bits.nmi
25  private val hasIR = hasTrap && trapInfo.bits.isInterrupt
26  private val hasEX = hasTrap && !trapInfo.bits.isInterrupt
27
28  private val exceptionVec = io.in.trapInfo.bits.trapVec
29  private val intrVec = io.in.trapInfo.bits.intrVec
30  private val hasEXVec = Mux(hasEX, exceptionVec, 0.U)
31  private val hasIRVec = Mux(hasIR, intrVec, 0.U)
32
33  private val interruptGroups: Seq[(Seq[Int], String)] = Seq(
34    InterruptNO.customHighestGroup    -> "customHighest",
35    InterruptNO.localHighGroup        -> "localHigh",
36    InterruptNO.customMiddleHighGroup -> "customMiddleHigh",
37    InterruptNO.interruptDefaultPrio  -> "privArch",
38    InterruptNO.customMiddleLowGroup  -> "customMiddleLow",
39    InterruptNO.localLowGroup         -> "localLow",
40    InterruptNO.customLowestGroup     -> "customLowest",
41  )
42
43  private val filteredIRQs: Seq[UInt] = interruptGroups.map {
44    case (irqGroup, name) => (getMaskFromIRQGroup(irqGroup) & hasIRVec).suggestName(s"filteredIRQs_$name")
45  }
46  private val hasIRQinGroup: Seq[Bool] = interruptGroups.map {
47    case (irqGroup, name) => dontTouch(Cat(filterIRQs(irqGroup, hasIRVec)).orR.suggestName(s"hasIRQinGroup_$name"))
48  }
49
50  private val highestIRQinGroup: Seq[Vec[Bool]] = interruptGroups zip filteredIRQs map {
51    case ((irqGroup: Seq[Int], name), filteredIRQ: UInt) =>
52      produceHighIRInGroup(irqGroup, filteredIRQ).suggestName(s"highestIRQinGroup_$name")
53  }
54
55  private val highestPrioIRVec: Vec[Bool] = MuxCase(
56    0.U.asTypeOf(Vec(64, Bool())),
57    hasIRQinGroup zip highestIRQinGroup map{ case (hasIRQ: Bool, highestIRQ: Vec[Bool]) => hasIRQ -> highestIRQ }
58  )
59  private val highestPrioNMIVec = Wire(Vec(64, Bool()))
60  highestPrioNMIVec.zipWithIndex.foreach { case (irq, i) =>
61    if (NonMaskableIRNO.interruptDefaultPrio.contains(i)) {
62      val higherIRSeq = NonMaskableIRNO.getIRQHigherThan(i)
63      irq := (
64        higherIRSeq.nonEmpty.B && Cat(higherIRSeq.map(num => !hasIRVec(num))).andR ||
65          higherIRSeq.isEmpty.B
66        ) && hasIRVec(i)
67      dontTouch(irq)
68    } else
69      irq := false.B
70  }
71
72  private val highestPrioEXVec = Wire(Vec(64, Bool()))
73  highestPrioEXVec.zipWithIndex.foreach { case (excp, i) =>
74    if (ExceptionNO.priorities.contains(i)) {
75      val higherEXSeq = ExceptionNO.getHigherExcpThan(i)
76      excp := (
77        higherEXSeq.nonEmpty.B && Cat(higherEXSeq.map(num => !hasEXVec(num))).andR ||
78        higherEXSeq.isEmpty.B
79      ) && hasEXVec(i)
80    } else
81      excp := false.B
82  }
83
84  private val highestPrioIR  = highestPrioIRVec.asUInt
85  private val highestPrioNMI = highestPrioNMIVec.asUInt
86  private val highestPrioEX  = highestPrioEXVec.asUInt
87
88
89  private val mIRVec  = dontTouch(WireInit(highestPrioIR))
90  private val hsIRVec = (mIRVec  & mideleg) | (mIRVec  & mvien & ~mideleg)
91  private val vsIRVec = (hsIRVec & hideleg) | (hsIRVec & hvien & ~hideleg)
92
93  private val mEXVec  = highestPrioEX
94  private val hsEXVec = highestPrioEX & medeleg
95  private val vsEXVec = highestPrioEX & medeleg & hedeleg
96
97  // nmi handle in MMode only and default handler is mtvec
98  private val  mHasIR =  mIRVec.orR
99  private val hsHasIR = hsIRVec.orR & !hasNMI
100  private val vsHasIR = vsIRVec.orR & !hasNMI
101
102  private val  mHasEX =  mEXVec.orR
103  private val hsHasEX = hsEXVec.orR
104  private val vsHasEX = vsEXVec.orR
105
106  private val  mHasTrap =  mHasEX ||  mHasIR
107  private val hsHasTrap = hsHasEX || hsHasIR
108  private val vsHasTrap = vsHasEX || vsHasIR
109
110  private val handleTrapUnderHS = !privState.isModeM && hsHasTrap
111  private val handleTrapUnderVS = privState.isVirtual && vsHasTrap
112
113  // Todo: support more interrupt and exception
114  private val exceptionRegular = OHToUInt(highestPrioEX)
115  private val interruptNO = OHToUInt(Mux(hasNMI, highestPrioNMI, highestPrioIR))
116  private val exceptionNO = Mux(trapInfo.bits.singleStep, ExceptionNO.breakPoint.U, exceptionRegular)
117
118  private val causeNO = Mux(hasIR, interruptNO, exceptionNO)
119
120  private val xtvec = MuxCase(io.in.mtvec, Seq(
121    handleTrapUnderVS -> io.in.vstvec,
122    handleTrapUnderHS -> io.in.stvec
123  ))
124  private val pcFromXtvec = Cat(xtvec.addr.asUInt + Mux(xtvec.mode === XtvecMode.Vectored && hasIR, interruptNO(5, 0), 0.U), 0.U(2.W))
125
126  io.out.entryPrivState := MuxCase(default = PrivState.ModeM, mapping = Seq(
127    handleTrapUnderVS -> PrivState.ModeVS,
128    handleTrapUnderHS -> PrivState.ModeHS,
129  ))
130
131  io.out.causeNO.Interrupt := hasIR
132  io.out.causeNO.ExceptionCode := causeNO
133  io.out.pcFromXtvec := pcFromXtvec
134
135  def filterIRQs(group: Seq[Int], originIRQ: UInt): Seq[Bool] = {
136    group.map(irqNum => originIRQ(irqNum))
137  }
138
139  def getIRQHigherThanInGroup(group: Seq[Int])(irq: Int): Seq[Int] = {
140    val idx = group.indexOf(irq, 0)
141    require(idx != -1, s"The irq($irq) does not exists in IntPriority Seq")
142    group.slice(0, idx)
143  }
144
145  def getMaskFromIRQGroup(group: Seq[Int]): UInt = {
146    group.map(irq => BigInt(1) << irq).reduce(_ | _).U
147  }
148
149  def produceHighIRInGroup(irqGroup: Seq[Int], filteredIRVec: UInt): Vec[Bool] = {
150    val irVec = Wire(Vec(64, Bool()))
151    irVec.zipWithIndex.foreach { case (irq, i) =>
152      if (irqGroup.contains(i)) {
153        val higherIRSeq: Seq[Int] = getIRQHigherThanInGroup(irqGroup)(i)
154        irq := (
155          higherIRSeq.nonEmpty.B && Cat(higherIRSeq.map(num => !filteredIRVec(num))).andR ||
156            higherIRSeq.isEmpty.B
157          ) && filteredIRVec(i)
158      } else
159        irq := false.B
160    }
161    irVec
162  }
163}
164
165class TrapHandleIO extends Bundle {
166  val in = Input(new Bundle {
167    val trapInfo = ValidIO(new Bundle {
168      val trapVec = UInt(64.W)
169      val nmi = Bool()
170      val intrVec = UInt(64.W)
171      val isInterrupt = Bool()
172      val singleStep = Bool()
173    })
174    val privState = new PrivState
175    val mideleg = new MidelegBundle
176    val medeleg = new MedelegBundle
177    val hideleg = new HidelegBundle
178    val hedeleg = new HedelegBundle
179    val mvien = new MvienBundle
180    val hvien = new HvienBundle
181    // trap vector
182    val mtvec = Input(new XtvecBundle)
183    val stvec = Input(new XtvecBundle)
184    val vstvec = Input(new XtvecBundle)
185  })
186
187  val out = new Bundle {
188    val entryPrivState = new PrivState
189    val causeNO = new CauseBundle
190    val pcFromXtvec = UInt()
191  }
192}