xref: /XiangShan/src/main/scala/xiangshan/backend/exu/ExeUnit.scala (revision a63155a6a44b3c7714e55906b55ebf92e0efc125)
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.{FPUCtrlSignals, HasXSParameter, Redirect, XSBundle, XSModule}
12import xiangshan.backend.datapath.WbConfig.{PregWB, _}
13
14class ExeUnitIO(params: ExeUnitParams)(implicit p: Parameters) extends XSBundle {
15  val flush = Flipped(ValidIO(new Redirect()))
16  val in = Flipped(DecoupledIO(new ExuInput(params)))
17  val out = DecoupledIO(new ExuOutput(params))
18  val csrio = if (params.hasCSR) Some(new CSRFileIO) else None
19  val fenceio = if (params.hasFence) Some(new FenceIO) else None
20  val frm = if (params.needSrcFrm) Some(Input(UInt(3.W))) else None
21}
22
23class ExeUnit(exuParams: ExeUnitParams)(implicit p: Parameters) extends LazyModule {
24  lazy val module = new ExeUnitImp(this)(p, exuParams)
25}
26
27class ExeUnitImp(
28  override val wrapper: ExeUnit
29)(implicit
30  p: Parameters, exuParams: ExeUnitParams
31) extends LazyModuleImp(wrapper) with HasXSParameter{
32  private val fuCfgs = exuParams.fuConfigs
33
34  val io = IO(new ExeUnitIO(exuParams))
35
36  val funcUnits = fuCfgs.map(cfg => {
37    assert(cfg.fuGen != null, cfg.name + "Cfg'fuGen is null !!!")
38    val module = cfg.fuGen(p, cfg)
39    module
40  })
41
42  val busy = RegInit(false.B)
43  val robIdx = RegEnable(io.in.bits.robIdx, io.in.fire)
44  when (io.in.fire && io.in.bits.robIdx.needFlush(io.flush)) {
45    busy := false.B
46  }.elsewhen(busy && robIdx.needFlush(io.flush)){
47    busy := false.B
48  }.elsewhen(io.out.fire) {
49    busy := false.B
50  }.elsewhen(io.in.fire) {
51    busy := true.B
52  }
53
54  if (exuParams.latencyCertain){
55    busy := false.B
56  }
57
58  exuParams.wbPortConfigs.map{
59    x => x match {
60      case IntWB(port, priority) => assert((priority == 0) || (priority == 1),
61        s"${exuParams.name}: WbPort must priority=0 or priority=1")
62      case VfWB (port, priority) => assert((priority == 0) || (priority == 1),
63        s"${exuParams.name}: WbPort must priority=0 or priority=1")
64      case _ =>
65    }
66  }
67  val intWbPort = exuParams.getIntWBPort
68  if (intWbPort.isDefined){
69    val sameIntPortExuParam = backendParams.allExuParams.filter(_.getIntWBPort.isDefined)
70      .filter(_.getIntWBPort.get.port == intWbPort.get.port)
71    val samePortOneCertainOneUncertain = sameIntPortExuParam.map(_.latencyCertain).contains(true) && sameIntPortExuParam.map(_.latencyCertain).contains(false)
72    if (samePortOneCertainOneUncertain) sameIntPortExuParam.map(samePort =>
73      samePort.wbPortConfigs.map(
74        x => x match {
75          case IntWB(port, priority) => {
76            if (!samePort.latencyCertain) assert(priority == 1,
77              s"${samePort.name}: IntWbPort $port must latencyCertain priority=0 or latencyUnCertain priority=1")
78            else assert(priority == 0,
79              s"${samePort.name}: IntWbPort $port must latencyCertain priority=0 or latencyUnCertain priority=1")
80          }
81          case _ =>
82        }
83      )
84    )
85  }
86  val vfWbPort = exuParams.getVfWBPort
87  if (vfWbPort.isDefined) {
88    val sameVfPortExuParam = backendParams.allExuParams.filter(_.getVfWBPort.isDefined)
89      .filter(_.getVfWBPort.get.port == vfWbPort.get.port)
90    val samePortOneCertainOneUncertain = sameVfPortExuParam.map(_.latencyCertain).contains(true) && sameVfPortExuParam.map(_.latencyCertain).contains(false)
91    if (samePortOneCertainOneUncertain)  sameVfPortExuParam.map(samePort =>
92      samePort.wbPortConfigs.map(
93        x => x match {
94          case VfWB(port, priority) => {
95            if (!samePort.latencyCertain) assert(priority == 1,
96              s"${samePort.name}: VfWbPort $port must latencyCertain priority=0 or latencyUnCertain priority=1")
97            else assert(priority == 0,
98              s"${samePort.name}: VfWbPort $port must latencyCertain priority=0 or latencyUnCertain priority=1")
99          }
100          case _ =>
101        }
102      )
103    )
104  }
105  dontTouch(io.out.ready)
106  // rob flush --> funcUnits
107  funcUnits.zipWithIndex.foreach { case (fu, i) =>
108    fu.io.flush <> io.flush
109  }
110
111  def acceptCond(input: ExuInput): Seq[Bool] = {
112    input.params.fuConfigs.map(_.fuSel(input))
113  }
114
115  val in1ToN = Module(new Dispatcher(new ExuInput(exuParams), funcUnits.length, acceptCond))
116
117  // ExeUnit.in <---> Dispatcher.in
118  in1ToN.io.in.valid := io.in.valid && !busy
119  in1ToN.io.in.bits := io.in.bits
120  io.in.ready := !busy && in1ToN.io.in.ready
121
122  // Dispatcher.out <---> FunctionUnits
123  in1ToN.io.out.zip(funcUnits.map(_.io.in)).foreach {
124    case (source: DecoupledIO[ExuInput], sink: DecoupledIO[FuncUnitInput]) =>
125      sink.valid := source.valid
126      source.ready := sink.ready
127
128      sink.bits.data.src.zip(source.bits.src).foreach { case(fuSrc, exuSrc) => fuSrc := exuSrc }
129      sink.bits.data.pc          .foreach(x => x := source.bits.pc.get)
130      sink.bits.data.imm         := source.bits.imm
131      sink.bits.ctrl.fuOpType    := source.bits.fuOpType
132      sink.bits.ctrl.robIdx      := source.bits.robIdx
133      sink.bits.ctrl.pdest       := source.bits.pdest
134      sink.bits.ctrl.rfWen       .foreach(x => x := source.bits.rfWen.get)
135      sink.bits.ctrl.fpWen       .foreach(x => x := source.bits.fpWen.get)
136      sink.bits.ctrl.vecWen      .foreach(x => x := source.bits.vecWen.get)
137      sink.bits.ctrl.flushPipe   .foreach(x => x := source.bits.flushPipe.get)
138      sink.bits.ctrl.preDecode   .foreach(x => x := source.bits.preDecode.get)
139      sink.bits.ctrl.ftqIdx      .foreach(x => x := source.bits.ftqIdx.get)
140      sink.bits.ctrl.ftqOffset   .foreach(x => x := source.bits.ftqOffset.get)
141      sink.bits.ctrl.predictInfo .foreach(x => x := source.bits.predictInfo.get)
142      sink.bits.ctrl.fpu         .foreach(x => x := source.bits.fpu.get)
143      sink.bits.ctrl.vpu         .foreach(x => x := source.bits.vpu.get)
144  }
145
146  private val fuOutValidOH = funcUnits.map(_.io.out.valid)
147  XSError(PopCount(fuOutValidOH) > 1.U, p"fuOutValidOH ${Binary(VecInit(fuOutValidOH).asUInt)} should be one-hot)\n")
148  private val fuOutBitsVec = funcUnits.map(_.io.out.bits)
149  private val fuRedirectVec: Seq[Option[ValidIO[Redirect]]] = funcUnits.map(_.io.out.bits.res.redirect)
150
151  // Assume that one fu can only write int or fp or vec,
152  // otherwise, wenVec should be assigned to wen in fu.
153  private val fuIntWenVec = funcUnits.map(x => x.cfg.writeIntRf.B && x.io.out.bits.ctrl.rfWen.getOrElse(false.B))
154  private val fuFpWenVec  = funcUnits.map(x => x.cfg.writeFpRf.B  && x.io.out.bits.ctrl.fpWen.getOrElse(false.B))
155  private val fuVecWenVec = funcUnits.map(x => x.cfg.writeVecRf.B && x.io.out.bits.ctrl.vecWen.getOrElse(false.B))
156  // FunctionUnits <---> ExeUnit.out
157  io.out.valid := Cat(fuOutValidOH).orR
158  funcUnits.foreach(fu => fu.io.out.ready := io.out.ready)
159
160  // select one fu's result
161  io.out.bits.data := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.res.data))
162  io.out.bits.robIdx := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.ctrl.robIdx))
163  io.out.bits.pdest := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.ctrl.pdest))
164  io.out.bits.intWen.foreach(x => x := Mux1H(fuOutValidOH, fuIntWenVec))
165  io.out.bits.fpWen.foreach(x => x := Mux1H(fuOutValidOH, fuFpWenVec))
166  io.out.bits.vecWen.foreach(x => x := Mux1H(fuOutValidOH, fuVecWenVec))
167  io.out.bits.redirect.foreach(x => x := Mux1H((fuOutValidOH zip fuRedirectVec).filter(_._2.isDefined).map(x => (x._1, x._2.get))))
168  io.out.bits.fflags.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.res.fflags.getOrElse(0.U.asTypeOf(io.out.bits.fflags.get)))))
169  io.out.bits.wflags.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.ctrl.fpu.getOrElse(0.U.asTypeOf(new FPUCtrlSignals)).wflags)))
170  io.out.bits.vxsat.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.res.vxsat.getOrElse(0.U.asTypeOf(io.out.bits.vxsat.get)))))
171  io.out.bits.exceptionVec.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.ctrl.exceptionVec.getOrElse(0.U.asTypeOf(io.out.bits.exceptionVec.get)))))
172  io.out.bits.flushPipe.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.ctrl.flushPipe.getOrElse(0.U.asTypeOf(io.out.bits.flushPipe.get)))))
173  io.out.bits.replay.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.ctrl.replay.getOrElse(0.U.asTypeOf(io.out.bits.replay.get)))))
174  io.out.bits.predecodeInfo.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.ctrl.preDecode.getOrElse(0.U.asTypeOf(io.out.bits.predecodeInfo.get)))))
175
176  io.csrio.foreach(exuio => funcUnits.foreach(fu => fu.io.csrio.foreach{
177    fuio =>
178      exuio <> fuio
179      fuio.exception := DelayN(exuio.exception, 2)
180  }))
181  io.fenceio.foreach(exuio => funcUnits.foreach(fu => fu.io.fenceio.foreach(fuio => fuio <> exuio)))
182  io.frm.foreach(exuio => funcUnits.foreach(fu => fu.io.frm.foreach(fuio => fuio <> exuio)))
183
184  // debug info
185  io.out.bits.debug     := 0.U.asTypeOf(io.out.bits.debug)
186  io.out.bits.debug.isPerfCnt := funcUnits.map(_.io.csrio.map(_.isPerfCnt)).map(_.getOrElse(false.B)).reduce(_ || _)
187  io.out.bits.debugInfo := 0.U.asTypeOf(io.out.bits.debugInfo)
188}
189
190class DispatcherIO[T <: Data](private val gen: T, n: Int) extends Bundle {
191  val in = Flipped(DecoupledIO(gen))
192
193  val out = Vec(n, DecoupledIO(gen))
194}
195
196class Dispatcher[T <: Data](private val gen: T, n: Int, acceptCond: T => Seq[Bool])
197  (implicit p: Parameters)
198  extends Module {
199
200  val io = IO(new DispatcherIO(gen, n))
201
202  private val acceptVec: Vec[Bool] = VecInit(acceptCond(io.in.bits))
203
204  XSError(io.in.valid && PopCount(acceptVec) > 1.U, s"s[ExeUnit] accept vec should no more than 1, ${Binary(acceptVec.asUInt)} ")
205  XSError(io.in.valid && PopCount(acceptVec) === 0.U, "[ExeUnit] there is a inst not dispatched to any fu")
206
207  io.out.zipWithIndex.foreach { case (out, i) =>
208    out.valid := acceptVec(i) && io.in.valid
209    out.bits := io.in.bits
210  }
211
212  io.in.ready := Mux1H(acceptVec,io.out.map(_.ready))
213}
214
215class MemExeUnitIO (implicit p: Parameters) extends XSBundle {
216  val flush = Flipped(ValidIO(new Redirect()))
217  val in = Flipped(DecoupledIO(new MemExuInput()))
218  val out = DecoupledIO(new MemExuOutput())
219}
220
221class MemExeUnit(exuParams: ExeUnitParams)(implicit p: Parameters) extends XSModule {
222  val io = IO(new MemExeUnitIO)
223  val fu = exuParams.fuConfigs.head.fuGen(p, exuParams.fuConfigs.head)
224  fu.io.flush             := io.flush
225  fu.io.in.valid          := io.in.valid
226  io.in.ready             := fu.io.in.ready
227
228  fu.io.in.bits.ctrl.robIdx    := io.in.bits.uop.robIdx
229  fu.io.in.bits.ctrl.pdest     := io.in.bits.uop.pdest
230  fu.io.in.bits.ctrl.fuOpType  := io.in.bits.uop.fuOpType
231  fu.io.in.bits.data.imm       := io.in.bits.uop.imm
232  fu.io.in.bits.data.src.zip(io.in.bits.src).foreach(x => x._1 := x._2)
233
234  io.out.valid            := fu.io.out.valid
235  fu.io.out.ready         := io.out.ready
236
237  io.out.bits             := 0.U.asTypeOf(io.out.bits) // dontCare other fields
238  io.out.bits.data        := fu.io.out.bits.res.data
239  io.out.bits.uop.robIdx  := fu.io.out.bits.ctrl.robIdx
240  io.out.bits.uop.pdest   := fu.io.out.bits.ctrl.pdest
241  io.out.bits.uop.fuType  := io.in.bits.uop.fuType
242  io.out.bits.uop.fuOpType:= io.in.bits.uop.fuOpType
243  io.out.bits.uop.sqIdx   := io.in.bits.uop.sqIdx
244
245  io.out.bits.debug       := 0.U.asTypeOf(io.out.bits.debug)
246}
247