xref: /XiangShan/src/main/scala/xiangshan/backend/exu/ExeUnit.scala (revision 7000dd3d435504b327112f0f41179a57712858af)
1package xiangshan.backend.exu
2
3import chipsalliance.rocketchip.config.Parameters
4import chisel3._
5import chisel3.util._
6import freechips.rocketchip.diplomacy.{LazyModule, LazyModuleImp}
7import utility.DelayN
8import utils._
9import xiangshan.backend.fu.{CSRFileIO, FenceIO, FuncUnitInput}
10import xiangshan.backend.Bundles.{ExuInput, ExuOutput, MemExuInput, MemExuOutput}
11import xiangshan.{Redirect, XSBundle, XSModule}
12
13class ExeUnitIO(params: ExeUnitParams)(implicit p: Parameters) extends XSBundle {
14  val flush = Flipped(ValidIO(new Redirect()))
15  val in = Flipped(DecoupledIO(new ExuInput(params)))
16  val out = DecoupledIO(new ExuOutput(params))
17  val csrio = if (params.hasCSR) Some(new CSRFileIO) else None
18  val fenceio = if (params.hasFence) Some(new FenceIO) else None
19  val frm = if (params.needSrcFrm) Some(Input(UInt(3.W))) else None
20}
21
22class ExeUnit(exuParams: ExeUnitParams)(implicit p: Parameters) extends LazyModule {
23  lazy val module = new ExeUnitImp(this)(p, exuParams)
24}
25
26class ExeUnitImp(
27  override val wrapper: ExeUnit
28)(implicit
29  p: Parameters, exuParams: ExeUnitParams
30) extends LazyModuleImp(wrapper) {
31  private val fuCfgs = exuParams.fuConfigs
32
33  val io = IO(new ExeUnitIO(exuParams))
34
35  val funcUnits = fuCfgs.map(cfg => {
36    val module = cfg.fuGen(p, cfg)
37    module
38  })
39
40  val busy = RegInit(false.B)
41  val robIdx = RegEnable(io.in.bits.robIdx, io.in.fire)
42  when (io.in.fire && io.in.bits.robIdx.needFlush(io.flush)) {
43    busy := false.B
44  }.elsewhen(busy && robIdx.needFlush(io.flush)){
45    busy := false.B
46  }.elsewhen(io.out.fire) {
47    busy := false.B
48  }.elsewhen(io.in.fire) {
49    busy := true.B
50  }
51
52  // rob flush --> funcUnits
53  funcUnits.zipWithIndex.foreach { case (fu, i) =>
54    fu.io.flush <> io.flush
55  }
56
57  def acceptCond(input: ExuInput): Seq[Bool] = {
58    input.params.fuConfigs.map(_.fuSel(input))
59  }
60
61  val in1ToN = Module(new Dispatcher(new ExuInput(exuParams), funcUnits.length, acceptCond))
62
63  // ExeUnit.in <---> Dispatcher.in
64  in1ToN.io.in.valid := io.in.valid && !busy
65  in1ToN.io.in.bits := io.in.bits
66  io.in.ready := !busy
67
68  // Dispatcher.out <---> FunctionUnits
69  in1ToN.io.out.zip(funcUnits.map(_.io.in)).foreach {
70    case (source: DecoupledIO[ExuInput], sink: DecoupledIO[FuncUnitInput]) =>
71      sink.valid := source.valid
72      source.ready := sink.ready
73
74      sink.bits.src.zip(source.bits.src).foreach { case(fuSrc, exuSrc) => fuSrc := exuSrc }
75      sink.bits.fuOpType    := source.bits.fuOpType
76      sink.bits.imm         := source.bits.imm
77      sink.bits.robIdx      := source.bits.robIdx
78      sink.bits.pdest       := source.bits.pdest
79      sink.bits.rfWen       .foreach(x => x := source.bits.rfWen.get)
80      sink.bits.fpWen       .foreach(x => x := source.bits.fpWen.get)
81      sink.bits.vecWen      .foreach(x => x := source.bits.vecWen.get)
82      sink.bits.fpu         .foreach(x => x := source.bits.fpu.get)
83      sink.bits.flushPipe   .foreach(x => x := source.bits.flushPipe.get)
84      sink.bits.pc          .foreach(x => x := source.bits.pc.get)
85      sink.bits.preDecode   .foreach(x => x := source.bits.preDecode.get)
86      sink.bits.ftqIdx      .foreach(x => x := source.bits.ftqIdx.get)
87      sink.bits.ftqOffset   .foreach(x => x := source.bits.ftqOffset.get)
88      sink.bits.predictInfo .foreach(x => x := source.bits.predictInfo.get)
89  }
90
91  private val fuOutValidOH = funcUnits.map(_.io.out.valid)
92  private val fuOutBitsVec = funcUnits.map(_.io.out.bits)
93  private val fuRedirectVec: Seq[Option[ValidIO[Redirect]]] = funcUnits.map(_.io.out.bits.redirect)
94
95  // Assume that one fu can only write int or fp or vec,
96  // otherwise, wenVec should be assigned to wen in fu.
97  private val fuIntWenVec = funcUnits.map(_.cfg.writeIntRf.B)
98  private val fuFpWenVec = funcUnits.map(_.cfg.writeFpRf.B)
99  private val fuVecWenVec = funcUnits.map(_.cfg.writeVecRf.B)
100  // FunctionUnits <---> ExeUnit.out
101  io.out.valid := Cat(fuOutValidOH).orR
102  funcUnits.foreach(fu => fu.io.out.ready := io.out.ready)
103
104  // select one fu's result
105  io.out.bits.data := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.data))
106  io.out.bits.robIdx := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.robIdx))
107  io.out.bits.pdest := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.pdest))
108  io.out.bits.intWen.foreach(x => x := Mux1H(fuOutValidOH, fuIntWenVec))
109  io.out.bits.fpWen.foreach(x => x := Mux1H(fuOutValidOH, fuFpWenVec))
110  io.out.bits.vecWen.foreach(x => x := Mux1H(fuOutValidOH, fuVecWenVec))
111  io.out.bits.redirect.foreach(x => x := Mux1H((fuOutValidOH zip fuRedirectVec).filter(_._2.isDefined).map(x => (x._1, x._2.get))))
112  io.out.bits.fflags.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.fflags.getOrElse(0.U.asTypeOf(io.out.bits.fflags.get)))))
113  io.out.bits.exceptionVec.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.exceptionVec.getOrElse(0.U.asTypeOf(io.out.bits.exceptionVec.get)))))
114  io.out.bits.flushPipe.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.flushPipe.getOrElse(0.U.asTypeOf(io.out.bits.flushPipe.get)))))
115  io.out.bits.replay.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.replay.getOrElse(0.U.asTypeOf(io.out.bits.replay.get)))))
116  io.out.bits.predecodeInfo.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.preDecode.getOrElse(0.U.asTypeOf(io.out.bits.predecodeInfo.get)))))
117
118  io.csrio.foreach(exuio => funcUnits.foreach(fu => fu.io.csrio.foreach{
119    fuio =>
120      exuio <> fuio
121      fuio.exception := DelayN(exuio.exception, 2)
122  }))
123  io.fenceio.foreach(exuio => funcUnits.foreach(fu => fu.io.fenceio.foreach(fuio => fuio <> exuio)))
124  io.frm.foreach(exuio => funcUnits.foreach(fu => fu.io.frm.foreach(fuio => fuio <> exuio)))
125
126  // debug info
127  io.out.bits.debug     := 0.U.asTypeOf(io.out.bits.debug)
128  io.out.bits.debugInfo := 0.U.asTypeOf(io.out.bits.debugInfo)
129}
130
131class DispatcherIO[T <: Data](private val gen: T, n: Int) extends Bundle {
132  val in = Flipped(DecoupledIO(gen))
133
134  val out = Vec(n, DecoupledIO(gen))
135}
136
137class Dispatcher[T <: Data](private val gen: T, n: Int, acceptCond: T => Seq[Bool])
138  (implicit p: Parameters)
139  extends Module {
140
141  val io = IO(new DispatcherIO(gen, n))
142
143  private val acceptVec: Vec[Bool] = VecInit(acceptCond(io.in.bits))
144
145  XSError(io.in.valid && PopCount(acceptVec) > 1.U, s"s[ExeUnit] accept vec should no more than 1, ${Binary(acceptVec.asUInt)} ")
146  XSError(io.in.valid && PopCount(acceptVec) === 0.U, "[ExeUnit] there is a inst not dispatched to any fu")
147
148  io.out.zipWithIndex.foreach { case (out, i) =>
149    out.valid := acceptVec(i) && io.in.valid && out.ready
150    out.bits := io.in.bits
151  }
152
153  io.in.ready := Cat(io.out.map(_.ready)).orR
154}
155
156class MemExeUnitIO (implicit p: Parameters) extends XSBundle {
157  val flush = Flipped(ValidIO(new Redirect()))
158  val in = Flipped(DecoupledIO(new MemExuInput()))
159  val out = DecoupledIO(new MemExuOutput())
160}
161
162class MemExeUnit(exuParams: ExeUnitParams)(implicit p: Parameters) extends XSModule {
163  val io = IO(new MemExeUnitIO)
164  val fu = exuParams.fuConfigs.head.fuGen(p, exuParams.fuConfigs.head)
165  fu.io.flush             := io.flush
166  fu.io.in.valid          := io.in.valid
167  io.in.ready             := fu.io.in.ready
168
169  fu.io.in.bits.robIdx    := io.in.bits.uop.robIdx
170  fu.io.in.bits.pdest     := io.in.bits.uop.pdest
171  fu.io.in.bits.fuOpType  := io.in.bits.uop.fuOpType
172  fu.io.in.bits.imm       := io.in.bits.uop.imm
173  fu.io.in.bits.src.zip(io.in.bits.src).foreach(x => x._1 := x._2)
174
175  io.out.valid            := fu.io.out.valid
176  fu.io.out.ready         := io.out.ready
177
178  io.out.bits             := 0.U.asTypeOf(io.out.bits) // dontCare other fields
179  io.out.bits.data        := fu.io.out.bits.data
180  io.out.bits.uop.robIdx  := fu.io.out.bits.robIdx
181  io.out.bits.uop.pdest   := fu.io.out.bits.pdest
182  io.out.bits.uop.fuType  := io.in.bits.uop.fuType
183  io.out.bits.uop.fuOpType:= io.in.bits.uop.fuOpType
184  io.out.bits.uop.sqIdx   := io.in.bits.uop.sqIdx
185
186  io.out.bits.debug       := 0.U.asTypeOf(io.out.bits.debug)
187}
188