xref: /XiangShan/src/main/scala/xiangshan/backend/exu/ExeUnit.scala (revision 8f1fa9b1f65ffa29fe1bf75176395cb8ecde6aa5)
1/***************************************************************************************
2* Copyright (c) 2020-2021 Institute of Computing Technology, Chinese Academy of Sciences
3* Copyright (c) 2020-2021 Peng Cheng Laboratory
4*
5* XiangShan is licensed under Mulan PSL v2.
6* You can use this software according to the terms and conditions of the Mulan PSL v2.
7* You may obtain a copy of Mulan PSL v2 at:
8*          http://license.coscl.org.cn/MulanPSL2
9*
10* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
11* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
12* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
13*
14* See the Mulan PSL v2 for more details.
15***************************************************************************************/
16
17package xiangshan.backend.exu
18
19import org.chipsalliance.cde.config.Parameters
20import chisel3._
21import chisel3.experimental.hierarchy.{Definition, instantiable}
22import chisel3.util._
23import freechips.rocketchip.diplomacy.{LazyModule, LazyModuleImp}
24import utility.DelayN
25import utils._
26import xiangshan.backend.fu.{CSRFileIO, FenceIO, FuncUnitInput}
27import xiangshan.backend.Bundles.{ExuInput, ExuOutput, MemExuInput, MemExuOutput}
28import xiangshan.{FPUCtrlSignals, HasXSParameter, Redirect, XSBundle, XSModule}
29import xiangshan.backend.datapath.WbConfig.{PregWB, _}
30
31class ExeUnitIO(params: ExeUnitParams)(implicit p: Parameters) extends XSBundle {
32  val flush = Flipped(ValidIO(new Redirect()))
33  val in = Flipped(DecoupledIO(new ExuInput(params)))
34  val out = DecoupledIO(new ExuOutput(params))
35  val csrio = if (params.hasCSR) Some(new CSRFileIO) else None
36  val fenceio = if (params.hasFence) Some(new FenceIO) else None
37  val frm = if (params.needSrcFrm) Some(Input(UInt(3.W))) else None
38}
39
40class ExeUnit(exuParams: ExeUnitParams)(implicit p: Parameters) extends LazyModule {
41  override def shouldBeInlined: Boolean = false
42
43  lazy val module = new ExeUnitImp(this)(p, exuParams)
44}
45
46class ExeUnitImp(
47  override val wrapper: ExeUnit
48)(implicit
49  p: Parameters, exuParams: ExeUnitParams
50) extends LazyModuleImp(wrapper) with HasXSParameter{
51  private val fuCfgs = exuParams.fuConfigs
52
53  val io = IO(new ExeUnitIO(exuParams))
54
55  val funcUnits = fuCfgs.map(cfg => {
56    assert(cfg.fuGen != null, cfg.name + "Cfg'fuGen is null !!!")
57    val module = cfg.fuGen(p, cfg)
58    module
59  })
60
61  val busy = RegInit(false.B)
62  val robIdx = RegEnable(io.in.bits.robIdx, io.in.fire)
63  when (io.in.fire && io.in.bits.robIdx.needFlush(io.flush)) {
64    busy := false.B
65  }.elsewhen(busy && robIdx.needFlush(io.flush)){
66    busy := false.B
67  }.elsewhen(io.out.fire) {
68    busy := false.B
69  }.elsewhen(io.in.fire) {
70    busy := true.B
71  }
72
73  if (exuParams.latencyCertain){
74    busy := false.B
75  }
76
77  exuParams.wbPortConfigs.map{
78    x => x match {
79      case IntWB(port, priority) => assert(priority >= 0 && priority <= 2,
80        s"${exuParams.name}: WbPort must priority=0 or priority=1")
81      case VfWB (port, priority) => assert(priority >= 0 && priority <= 2,
82        s"${exuParams.name}: WbPort must priority=0 or priority=1")
83      case _ =>
84    }
85  }
86  val intWbPort = exuParams.getIntWBPort
87  if (intWbPort.isDefined){
88    val sameIntPortExuParam = backendParams.allExuParams.filter(_.getIntWBPort.isDefined)
89      .filter(_.getIntWBPort.get.port == intWbPort.get.port)
90    val samePortOneCertainOneUncertain = sameIntPortExuParam.map(_.latencyCertain).contains(true) && sameIntPortExuParam.map(_.latencyCertain).contains(false)
91    if (samePortOneCertainOneUncertain) sameIntPortExuParam.map(samePort =>
92      samePort.wbPortConfigs.map(
93        x => x match {
94          case IntWB(port, priority) => {
95            if (!samePort.latencyCertain) assert(priority == 1,
96              s"${samePort.name}: IntWbPort $port must latencyCertain priority=0 or latencyUnCertain priority=1")
97            else assert(priority == 0,
98              s"${samePort.name}: IntWbPort $port must latencyCertain priority=0 or latencyUnCertain priority=1")
99          }
100          case _ =>
101        }
102      )
103    )
104  }
105  val vfWbPort = exuParams.getVfWBPort
106  if (vfWbPort.isDefined) {
107    val sameVfPortExuParam = backendParams.allExuParams.filter(_.getVfWBPort.isDefined)
108      .filter(_.getVfWBPort.get.port == vfWbPort.get.port)
109    val samePortOneCertainOneUncertain = sameVfPortExuParam.map(_.latencyCertain).contains(true) && sameVfPortExuParam.map(_.latencyCertain).contains(false)
110    if (samePortOneCertainOneUncertain)  sameVfPortExuParam.map(samePort =>
111      samePort.wbPortConfigs.map(
112        x => x match {
113          case VfWB(port, priority) => {
114            if (!samePort.latencyCertain) assert(priority == 1,
115              s"${samePort.name}: VfWbPort $port must latencyCertain priority=0 or latencyUnCertain priority=1")
116            else assert(priority == 0,
117              s"${samePort.name}: VfWbPort $port must latencyCertain priority=0 or latencyUnCertain priority=1")
118          }
119          case _ =>
120        }
121      )
122    )
123  }
124  dontTouch(io.out.ready)
125  // rob flush --> funcUnits
126  funcUnits.zipWithIndex.foreach { case (fu, i) =>
127    fu.io.flush <> io.flush
128  }
129
130  def acceptCond(input: ExuInput): Seq[Bool] = {
131    input.params.fuConfigs.map(_.fuSel(input))
132  }
133
134  val in1ToN = Module(new Dispatcher(new ExuInput(exuParams), funcUnits.length, acceptCond))
135
136  // ExeUnit.in <---> Dispatcher.in
137  in1ToN.io.in.valid := io.in.valid && !busy
138  in1ToN.io.in.bits := io.in.bits
139  io.in.ready := !busy && in1ToN.io.in.ready
140
141  // Dispatcher.out <---> FunctionUnits
142  in1ToN.io.out.zip(funcUnits.map(_.io.in)).foreach {
143    case (source: DecoupledIO[ExuInput], sink: DecoupledIO[FuncUnitInput]) =>
144      sink.valid := source.valid
145      source.ready := sink.ready
146
147      sink.bits.data.src.zip(source.bits.src).foreach { case(fuSrc, exuSrc) => fuSrc := exuSrc }
148      sink.bits.data.pc          .foreach(x => x := source.bits.pc.get)
149      sink.bits.data.imm         := source.bits.imm
150      sink.bits.ctrl.fuOpType    := source.bits.fuOpType
151      sink.bits.ctrl.robIdx      := source.bits.robIdx
152      sink.bits.ctrl.pdest       := source.bits.pdest
153      sink.bits.ctrl.rfWen       .foreach(x => x := source.bits.rfWen.get)
154      sink.bits.ctrl.fpWen       .foreach(x => x := source.bits.fpWen.get)
155      sink.bits.ctrl.vecWen      .foreach(x => x := source.bits.vecWen.get)
156      sink.bits.ctrl.flushPipe   .foreach(x => x := source.bits.flushPipe.get)
157      sink.bits.ctrl.preDecode   .foreach(x => x := source.bits.preDecode.get)
158      sink.bits.ctrl.ftqIdx      .foreach(x => x := source.bits.ftqIdx.get)
159      sink.bits.ctrl.ftqOffset   .foreach(x => x := source.bits.ftqOffset.get)
160      sink.bits.ctrl.predictInfo .foreach(x => x := source.bits.predictInfo.get)
161      sink.bits.ctrl.fpu         .foreach(x => x := source.bits.fpu.get)
162      sink.bits.ctrl.vpu         .foreach(x => x := source.bits.vpu.get)
163      sink.bits.perfDebugInfo    := source.bits.perfDebugInfo
164  }
165
166  private val fuOutValidOH = funcUnits.map(_.io.out.valid)
167  XSError(PopCount(fuOutValidOH) > 1.U, p"fuOutValidOH ${Binary(VecInit(fuOutValidOH).asUInt)} should be one-hot)\n")
168  private val fuOutBitsVec = funcUnits.map(_.io.out.bits)
169  private val fuRedirectVec: Seq[Option[ValidIO[Redirect]]] = funcUnits.map(_.io.out.bits.res.redirect)
170
171  // Assume that one fu can only write int or fp or vec,
172  // otherwise, wenVec should be assigned to wen in fu.
173  private val fuIntWenVec = funcUnits.map(x => x.cfg.writeIntRf.B && x.io.out.bits.ctrl.rfWen.getOrElse(false.B))
174  private val fuFpWenVec  = funcUnits.map(x => x.cfg.writeFpRf.B  && x.io.out.bits.ctrl.fpWen.getOrElse(false.B))
175  private val fuVecWenVec = funcUnits.map(x => x.cfg.writeVecRf.B && x.io.out.bits.ctrl.vecWen.getOrElse(false.B))
176  // FunctionUnits <---> ExeUnit.out
177  io.out.valid := Cat(fuOutValidOH).orR
178  funcUnits.foreach(fu => fu.io.out.ready := io.out.ready)
179
180  // select one fu's result
181  io.out.bits.data := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.res.data))
182  io.out.bits.robIdx := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.ctrl.robIdx))
183  io.out.bits.pdest := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.ctrl.pdest))
184  io.out.bits.intWen.foreach(x => x := Mux1H(fuOutValidOH, fuIntWenVec))
185  io.out.bits.fpWen.foreach(x => x := Mux1H(fuOutValidOH, fuFpWenVec))
186  io.out.bits.vecWen.foreach(x => x := Mux1H(fuOutValidOH, fuVecWenVec))
187  io.out.bits.redirect.foreach(x => x := Mux1H((fuOutValidOH zip fuRedirectVec).filter(_._2.isDefined).map(x => (x._1, x._2.get))))
188  io.out.bits.fflags.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.res.fflags.getOrElse(0.U.asTypeOf(io.out.bits.fflags.get)))))
189  io.out.bits.wflags.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.ctrl.fpu.getOrElse(0.U.asTypeOf(new FPUCtrlSignals)).wflags)))
190  io.out.bits.vxsat.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.res.vxsat.getOrElse(0.U.asTypeOf(io.out.bits.vxsat.get)))))
191  io.out.bits.exceptionVec.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.ctrl.exceptionVec.getOrElse(0.U.asTypeOf(io.out.bits.exceptionVec.get)))))
192  io.out.bits.flushPipe.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.ctrl.flushPipe.getOrElse(0.U.asTypeOf(io.out.bits.flushPipe.get)))))
193  io.out.bits.replay.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.ctrl.replay.getOrElse(0.U.asTypeOf(io.out.bits.replay.get)))))
194  io.out.bits.predecodeInfo.foreach(x => x := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.ctrl.preDecode.getOrElse(0.U.asTypeOf(io.out.bits.predecodeInfo.get)))))
195
196  io.csrio.foreach(exuio => funcUnits.foreach(fu => fu.io.csrio.foreach{
197    fuio =>
198      exuio <> fuio
199      fuio.exception := DelayN(exuio.exception, 2)
200  }))
201  io.fenceio.foreach(exuio => funcUnits.foreach(fu => fu.io.fenceio.foreach(fuio => fuio <> exuio)))
202  io.frm.foreach(exuio => funcUnits.foreach(fu => fu.io.frm.foreach(fuio => fuio <> exuio)))
203
204  // debug info
205  io.out.bits.debug     := 0.U.asTypeOf(io.out.bits.debug)
206  io.out.bits.debug.isPerfCnt := funcUnits.map(_.io.csrio.map(_.isPerfCnt)).map(_.getOrElse(false.B)).reduce(_ || _)
207  io.out.bits.debugInfo := Mux1H(fuOutValidOH, fuOutBitsVec.map(_.perfDebugInfo))
208}
209
210class DispatcherIO[T <: Data](private val gen: T, n: Int) extends Bundle {
211  val in = Flipped(DecoupledIO(gen))
212
213  val out = Vec(n, DecoupledIO(gen))
214}
215
216class Dispatcher[T <: Data](private val gen: T, n: Int, acceptCond: T => Seq[Bool])
217  (implicit p: Parameters)
218  extends Module {
219
220  val io = IO(new DispatcherIO(gen, n))
221
222  private val acceptVec: Vec[Bool] = VecInit(acceptCond(io.in.bits))
223
224  XSError(io.in.valid && PopCount(acceptVec) > 1.U, s"s[ExeUnit] accept vec should no more than 1, ${Binary(acceptVec.asUInt)} ")
225  XSError(io.in.valid && PopCount(acceptVec) === 0.U, "[ExeUnit] there is a inst not dispatched to any fu")
226
227  io.out.zipWithIndex.foreach { case (out, i) =>
228    out.valid := acceptVec(i) && io.in.valid
229    out.bits := io.in.bits
230  }
231
232  io.in.ready := Mux1H(acceptVec,io.out.map(_.ready))
233}
234
235class MemExeUnitIO (implicit p: Parameters) extends XSBundle {
236  val flush = Flipped(ValidIO(new Redirect()))
237  val in = Flipped(DecoupledIO(new MemExuInput()))
238  val out = DecoupledIO(new MemExuOutput())
239}
240
241class MemExeUnit(exuParams: ExeUnitParams)(implicit p: Parameters) extends XSModule {
242  val io = IO(new MemExeUnitIO)
243  val fu = exuParams.fuConfigs.head.fuGen(p, exuParams.fuConfigs.head)
244  fu.io.flush             := io.flush
245  fu.io.in.valid          := io.in.valid
246  io.in.ready             := fu.io.in.ready
247
248  fu.io.in.bits.ctrl.robIdx    := io.in.bits.uop.robIdx
249  fu.io.in.bits.ctrl.pdest     := io.in.bits.uop.pdest
250  fu.io.in.bits.ctrl.fuOpType  := io.in.bits.uop.fuOpType
251  fu.io.in.bits.data.imm       := io.in.bits.uop.imm
252  fu.io.in.bits.data.src.zip(io.in.bits.src).foreach(x => x._1 := x._2)
253  fu.io.in.bits.perfDebugInfo := io.in.bits.uop.debugInfo
254
255  io.out.valid            := fu.io.out.valid
256  fu.io.out.ready         := io.out.ready
257
258  io.out.bits             := 0.U.asTypeOf(io.out.bits) // dontCare other fields
259  io.out.bits.data        := fu.io.out.bits.res.data
260  io.out.bits.uop.robIdx  := fu.io.out.bits.ctrl.robIdx
261  io.out.bits.uop.pdest   := fu.io.out.bits.ctrl.pdest
262  io.out.bits.uop.fuType  := io.in.bits.uop.fuType
263  io.out.bits.uop.fuOpType:= io.in.bits.uop.fuOpType
264  io.out.bits.uop.sqIdx   := io.in.bits.uop.sqIdx
265  io.out.bits.uop.debugInfo := fu.io.out.bits.perfDebugInfo
266
267  io.out.bits.debug       := 0.U.asTypeOf(io.out.bits.debug)
268}
269