xref: /XiangShan/src/main/scala/xiangshan/backend/exu/ExeUnit.scala (revision ea0f92d8a18e593ddd63d932eaff3d3099c091c0)
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  if(exuParams.latencyValMax.nonEmpty){
52    busy := false.B
53  }
54
55  // rob flush --> funcUnits
56  funcUnits.zipWithIndex.foreach { case (fu, i) =>
57    fu.io.flush <> io.flush
58  }
59
60  def acceptCond(input: ExuInput): Seq[Bool] = {
61    input.params.fuConfigs.map(_.fuSel(input))
62  }
63
64  val in1ToN = Module(new Dispatcher(new ExuInput(exuParams), funcUnits.length, acceptCond))
65
66  // ExeUnit.in <---> Dispatcher.in
67  in1ToN.io.in.valid := io.in.fire()
68  in1ToN.io.in.bits := io.in.bits
69  io.in.ready := !busy
70
71  // Dispatcher.out <---> FunctionUnits
72  in1ToN.io.out.zip(funcUnits.map(_.io.in)).foreach {
73    case (source: DecoupledIO[ExuInput], sink: DecoupledIO[FuncUnitInput]) =>
74      sink.valid := source.valid
75      source.ready := sink.ready
76
77      sink.bits.src.zip(source.bits.src).foreach { case(fuSrc, exuSrc) => fuSrc := exuSrc }
78      sink.bits.fuOpType    := source.bits.fuOpType
79      sink.bits.imm         := source.bits.imm
80      sink.bits.robIdx      := source.bits.robIdx
81      sink.bits.pdest       := source.bits.pdest
82      sink.bits.rfWen       .foreach(x => x := source.bits.rfWen.get)
83      sink.bits.fpWen       .foreach(x => x := source.bits.fpWen.get)
84      sink.bits.vecWen      .foreach(x => x := source.bits.vecWen.get)
85      sink.bits.fpu         .foreach(x => x := source.bits.fpu.get)
86      sink.bits.flushPipe   .foreach(x => x := source.bits.flushPipe.get)
87      sink.bits.pc          .foreach(x => x := source.bits.pc.get)
88      sink.bits.preDecode   .foreach(x => x := source.bits.preDecode.get)
89      sink.bits.ftqIdx      .foreach(x => x := source.bits.ftqIdx.get)
90      sink.bits.ftqOffset   .foreach(x => x := source.bits.ftqOffset.get)
91      sink.bits.predictInfo .foreach(x => x := source.bits.predictInfo.get)
92  }
93
94  private val fuOutValidOH = funcUnits.map(_.io.out.valid)
95  XSError(PopCount(fuOutValidOH) > 1.U, p"fuOutValidOH ${Binary(VecInit(fuOutValidOH).asUInt)} should be one-hot)\n")
96  private val fuOutBitsVec = funcUnits.map(_.io.out.bits)
97  private val fuRedirectVec: Seq[Option[ValidIO[Redirect]]] = funcUnits.map(_.io.out.bits.redirect)
98
99  // Assume that one fu can only write int or fp or vec,
100  // otherwise, wenVec should be assigned to wen in fu.
101  private val fuIntWenVec = funcUnits.map(_.cfg.writeIntRf.B)
102  private val fuFpWenVec = funcUnits.map(_.cfg.writeFpRf.B)
103  private val fuVecWenVec = funcUnits.map(_.cfg.writeVecRf.B)
104  // FunctionUnits <---> ExeUnit.out
105  io.out.valid := Cat(fuOutValidOH).orR
106  funcUnits.foreach(fu => fu.io.out.ready := io.out.ready)
107
108  // select one fu's result
109  io.out.bits.data := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.data))
110  io.out.bits.robIdx := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.robIdx))
111  io.out.bits.pdest := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.pdest))
112  io.out.bits.intWen.foreach(x => x := Mux1H(fuOutValidOH, fuIntWenVec))
113  io.out.bits.fpWen.foreach(x => x := Mux1H(fuOutValidOH, fuFpWenVec))
114  io.out.bits.vecWen.foreach(x => x := Mux1H(fuOutValidOH, fuVecWenVec))
115  io.out.bits.redirect.foreach(x => x := Mux1H((fuOutValidOH zip fuRedirectVec).filter(_._2.isDefined).map(x => (x._1, x._2.get))))
116  io.out.bits.fflags.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.fflags.getOrElse(0.U.asTypeOf(io.out.bits.fflags.get)))))
117  io.out.bits.exceptionVec.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.exceptionVec.getOrElse(0.U.asTypeOf(io.out.bits.exceptionVec.get)))))
118  io.out.bits.flushPipe.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.flushPipe.getOrElse(0.U.asTypeOf(io.out.bits.flushPipe.get)))))
119  io.out.bits.replay.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.replay.getOrElse(0.U.asTypeOf(io.out.bits.replay.get)))))
120  io.out.bits.predecodeInfo.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.preDecode.getOrElse(0.U.asTypeOf(io.out.bits.predecodeInfo.get)))))
121
122  io.csrio.foreach(exuio => funcUnits.foreach(fu => fu.io.csrio.foreach{
123    fuio =>
124      exuio <> fuio
125      fuio.exception := DelayN(exuio.exception, 2)
126  }))
127  io.fenceio.foreach(exuio => funcUnits.foreach(fu => fu.io.fenceio.foreach(fuio => fuio <> exuio)))
128  io.frm.foreach(exuio => funcUnits.foreach(fu => fu.io.frm.foreach(fuio => fuio <> exuio)))
129
130  // debug info
131  io.out.bits.debug     := 0.U.asTypeOf(io.out.bits.debug)
132  io.out.bits.debugInfo := 0.U.asTypeOf(io.out.bits.debugInfo)
133}
134
135class DispatcherIO[T <: Data](private val gen: T, n: Int) extends Bundle {
136  val in = Flipped(DecoupledIO(gen))
137
138  val out = Vec(n, DecoupledIO(gen))
139}
140
141class Dispatcher[T <: Data](private val gen: T, n: Int, acceptCond: T => Seq[Bool])
142  (implicit p: Parameters)
143  extends Module {
144
145  val io = IO(new DispatcherIO(gen, n))
146
147  private val acceptVec: Vec[Bool] = VecInit(acceptCond(io.in.bits))
148
149  XSError(io.in.valid && PopCount(acceptVec) > 1.U, s"s[ExeUnit] accept vec should no more than 1, ${Binary(acceptVec.asUInt)} ")
150  XSError(io.in.valid && PopCount(acceptVec) === 0.U, "[ExeUnit] there is a inst not dispatched to any fu")
151
152  io.out.zipWithIndex.foreach { case (out, i) =>
153    out.valid := acceptVec(i) && io.in.valid && out.ready
154    out.bits := io.in.bits
155  }
156
157  io.in.ready := Cat(io.out.map(_.ready)).orR
158}
159
160class MemExeUnitIO (implicit p: Parameters) extends XSBundle {
161  val flush = Flipped(ValidIO(new Redirect()))
162  val in = Flipped(DecoupledIO(new MemExuInput()))
163  val out = DecoupledIO(new MemExuOutput())
164}
165
166class MemExeUnit(exuParams: ExeUnitParams)(implicit p: Parameters) extends XSModule {
167  val io = IO(new MemExeUnitIO)
168  val fu = exuParams.fuConfigs.head.fuGen(p, exuParams.fuConfigs.head)
169  fu.io.flush             := io.flush
170  fu.io.in.valid          := io.in.valid
171  io.in.ready             := fu.io.in.ready
172
173  fu.io.in.bits.robIdx    := io.in.bits.uop.robIdx
174  fu.io.in.bits.pdest     := io.in.bits.uop.pdest
175  fu.io.in.bits.fuOpType  := io.in.bits.uop.fuOpType
176  fu.io.in.bits.imm       := io.in.bits.uop.imm
177  fu.io.in.bits.src.zip(io.in.bits.src).foreach(x => x._1 := x._2)
178
179  io.out.valid            := fu.io.out.valid
180  fu.io.out.ready         := io.out.ready
181
182  io.out.bits             := 0.U.asTypeOf(io.out.bits) // dontCare other fields
183  io.out.bits.data        := fu.io.out.bits.data
184  io.out.bits.uop.robIdx  := fu.io.out.bits.robIdx
185  io.out.bits.uop.pdest   := fu.io.out.bits.pdest
186  io.out.bits.uop.fuType  := io.in.bits.uop.fuType
187  io.out.bits.uop.fuOpType:= io.in.bits.uop.fuOpType
188  io.out.bits.uop.sqIdx   := io.in.bits.uop.sqIdx
189
190  io.out.bits.debug       := 0.U.asTypeOf(io.out.bits.debug)
191}
192