xref: /XiangShan/src/main/scala/xiangshan/backend/datapath/WbArbiter.scala (revision 52c49ce8fa92c7541915220ca9dcadc24fc9542e)
1package xiangshan.backend.datapath
2
3import org.chipsalliance.cde.config.Parameters
4import chisel3._
5import chisel3.util._
6import difftest.{DiffFpWriteback, DiffIntWriteback, DifftestModule}
7import utils.XSError
8import xiangshan.backend.BackendParams
9import xiangshan.backend.Bundles.{ExuOutput, WriteBackBundle}
10import xiangshan.backend.datapath.DataConfig.{IntData, VecData}
11import xiangshan.backend.regfile.RfWritePortWithConfig
12import xiangshan.{Redirect, XSBundle, XSModule}
13
14class WbArbiterDispatcherIO[T <: Data](private val gen: T, n: Int) extends Bundle {
15  val in = Flipped(DecoupledIO(gen))
16
17  val out = Vec(n, DecoupledIO(gen))
18}
19
20class WbArbiterDispatcher[T <: Data](private val gen: T, n: Int, acceptCond: T => Seq[Bool])
21                           (implicit p: Parameters)
22  extends Module {
23
24  val io = IO(new WbArbiterDispatcherIO(gen, n))
25
26  private val acceptVec: Vec[Bool] = VecInit(acceptCond(io.in.bits))
27
28  XSError(io.in.valid && PopCount(acceptVec) > 1.U, s"[ExeUnit] accept vec should no more than 1, ${Binary(acceptVec.asUInt)} ")
29
30  io.out.zipWithIndex.foreach { case (out, i) =>
31    out.valid := acceptVec(i) && io.in.valid
32    out.bits := io.in.bits
33  }
34
35  io.in.ready := Cat(io.out.zip(acceptVec).map{ case(out, canAccept) => out.ready && canAccept}).orR
36}
37
38class WbArbiterIO()(implicit p: Parameters, params: WbArbiterParams) extends XSBundle {
39  val flush = Flipped(ValidIO(new Redirect))
40  val in: MixedVec[DecoupledIO[WriteBackBundle]] = Flipped(params.genInput)
41  val out: MixedVec[ValidIO[WriteBackBundle]] = params.genOutput
42
43  def inGroup: Map[Int, Seq[DecoupledIO[WriteBackBundle]]] = in.groupBy(_.bits.params.port).map(x => (x._1, x._2.sortBy(_.bits.params.priority).toSeq))
44}
45
46class WbArbiter(params: WbArbiterParams)(implicit p: Parameters) extends XSModule {
47  val io = IO(new WbArbiterIO()(p, params))
48
49  private val inGroup: Map[Int, Seq[DecoupledIO[WriteBackBundle]]] = io.inGroup
50
51  private val arbiters: Seq[Option[Arbiter[WriteBackBundle]]] = Seq.tabulate(params.numOut) { x => {
52    if (inGroup.contains(x)) {
53      Some(Module(new Arbiter(new WriteBackBundle(inGroup.values.head.head.bits.params, backendParams), inGroup(x).length)))
54    } else {
55      None
56    }
57  }}
58
59  arbiters.zipWithIndex.foreach { case (arb, i) =>
60    if (arb.nonEmpty) {
61      arb.get.io.in.zip(inGroup(i)).foreach { case (arbIn, wbIn) =>
62        arbIn <> wbIn
63      }
64    }
65  }
66
67  io.out.zip(arbiters).foreach { case (wbOut, arb) =>
68    if (arb.nonEmpty) {
69      val arbOut = arb.get.io.out
70      arbOut.ready := true.B
71      wbOut.valid := arbOut.valid
72      wbOut.bits := arbOut.bits
73    } else {
74      wbOut := 0.U.asTypeOf(wbOut)
75    }
76  }
77
78  def getInOutMap: Map[Int, Int] = {
79    (params.wbCfgs.indices zip params.wbCfgs.map(_.port)).toMap
80  }
81}
82
83class WbDataPathIO()(implicit p: Parameters, params: BackendParams) extends XSBundle {
84  val flush = Flipped(ValidIO(new Redirect()))
85
86  val fromTop = new Bundle {
87    val hartId = Input(UInt(8.W))
88  }
89
90  val fromIntExu: MixedVec[MixedVec[DecoupledIO[ExuOutput]]] = Flipped(params.intSchdParams.get.genExuOutputDecoupledBundle)
91
92  val fromVfExu: MixedVec[MixedVec[DecoupledIO[ExuOutput]]] = Flipped(params.vfSchdParams.get.genExuOutputDecoupledBundle)
93
94  val fromMemExu: MixedVec[MixedVec[DecoupledIO[ExuOutput]]] = Flipped(params.memSchdParams.get.genExuOutputDecoupledBundle)
95
96  val oldVdDataFromDataPath = Input(UInt(VLEN.W))
97
98  val oldVdAddrToDataPath = Output(UInt(PhyRegIdxWidth.W))
99
100  val toIntPreg = Flipped(MixedVec(Vec(params.numPregWb(IntData()),
101    new RfWritePortWithConfig(params.intPregParams.dataCfg, params.intPregParams.addrWidth))))
102
103  val toVfPreg = Flipped(MixedVec(Vec(params.numPregWb(VecData()),
104    new RfWritePortWithConfig(params.vfPregParams.dataCfg, params.vfPregParams.addrWidth))))
105
106  val toCtrlBlock = new Bundle {
107    val writeback: MixedVec[ValidIO[ExuOutput]] = params.genWrite2CtrlBundles
108  }
109}
110
111class WbDataPath(params: BackendParams)(implicit p: Parameters) extends XSModule {
112  val io = IO(new WbDataPathIO()(p, params))
113
114  // split
115  val fromExuPre = (io.fromIntExu ++ io.fromVfExu ++ io.fromMemExu).flatten
116  val fromExuVld: Seq[DecoupledIO[ExuOutput]] = fromExuPre.filter(_.bits.params.hasVLoadFu).toSeq
117  require(fromExuVld.size == 1, "vldCnt should be 1")
118  val vldMgu = Module(new VldMergeUnit(fromExuVld.head.bits.params))
119  vldMgu.io.flush := io.flush
120  vldMgu.io.writeback <> fromExuVld.head
121  vldMgu.io.oldVdReadData := io.oldVdDataFromDataPath
122  io.oldVdAddrToDataPath := vldMgu.io.oldVdReadAddr
123  val fromExuVldAfterMerge: MixedVec[DecoupledIO[ExuOutput]] = WireInit(MixedVecInit(vldMgu.io.writebackAfterMerge))
124  fromExuVldAfterMerge.head <> vldMgu.io.writebackAfterMerge
125  // alias
126  // replace vldu write bundle with vldMdu output bundle
127  val fromExu = (fromExuPre.dropRight(params.VlduCnt) ++ fromExuVldAfterMerge).toSeq //TODO: better implementation
128  val intArbiterInputsWire = WireInit(MixedVecInit(fromExu))
129  val intArbiterInputsWireY = intArbiterInputsWire.filter(_.bits.params.writeIntRf)
130  val intArbiterInputsWireN = intArbiterInputsWire.filterNot(_.bits.params.writeIntRf)
131  val vfArbiterInputsWire = WireInit(MixedVecInit(fromExu))
132  val vfArbiterInputsWireY = vfArbiterInputsWire.filter(_.bits.params.writeVfRf)
133  val vfArbiterInputsWireN = vfArbiterInputsWire.filterNot(_.bits.params.writeVfRf)
134
135  def acceptCond(exuOutput: ExuOutput): Seq[Bool] = {
136    val intWen = if(exuOutput.intWen.isDefined) exuOutput.intWen.get else false.B
137    val fpwen  = if(exuOutput.fpWen.isDefined) exuOutput.fpWen.get else false.B
138    val vecWen = if(exuOutput.vecWen.isDefined) exuOutput.vecWen.get else false.B
139    Seq(intWen, fpwen || vecWen)
140  }
141
142  fromExu.zip(intArbiterInputsWire.zip(vfArbiterInputsWire))map{
143    case (exuOut, (intArbiterInput, vfArbiterInput)) =>
144      val regfilesTypeNum = params.pregParams.size
145      val in1ToN = Module(new WbArbiterDispatcher(new ExuOutput(exuOut.bits.params), regfilesTypeNum, acceptCond))
146      in1ToN.io.in.valid := exuOut.valid
147      in1ToN.io.in.bits := exuOut.bits
148      exuOut.ready := in1ToN.io.in.ready
149      in1ToN.io.out.zip(MixedVecInit(intArbiterInput, vfArbiterInput)).foreach { case (source, sink) =>
150        sink.valid := source.valid
151        sink.bits := source.bits
152        source.ready := sink.ready
153      }
154  }
155  intArbiterInputsWireN.foreach(_.ready := false.B)
156  vfArbiterInputsWireN.foreach(_.ready := false.B)
157
158  println(s"[WbDataPath] write int preg: " +
159    s"IntExu(${io.fromIntExu.flatten.count(_.bits.params.writeIntRf)}) " +
160    s"VfExu(${io.fromVfExu.flatten.count(_.bits.params.writeIntRf)}) " +
161    s"MemExu(${io.fromMemExu.flatten.count(_.bits.params.writeIntRf)})"
162  )
163  println(s"[WbDataPath] write vf preg: " +
164    s"IntExu(${io.fromIntExu.flatten.count(_.bits.params.writeVfRf)}) " +
165    s"VfExu(${io.fromVfExu.flatten.count(_.bits.params.writeVfRf)}) " +
166    s"MemExu(${io.fromMemExu.flatten.count(_.bits.params.writeVfRf)})"
167  )
168
169  // modules
170  private val intWbArbiter = Module(new WbArbiter(params.getIntWbArbiterParams))
171  private val vfWbArbiter = Module(new WbArbiter(params.getVfWbArbiterParams))
172  println(s"[WbDataPath] int preg write back port num: ${intWbArbiter.io.out.size}, active port: ${intWbArbiter.io.inGroup.keys.toSeq.sorted}")
173  println(s"[WbDataPath] vf preg write back port num: ${vfWbArbiter.io.out.size}, active port: ${vfWbArbiter.io.inGroup.keys.toSeq.sorted}")
174
175  // module assign
176  intWbArbiter.io.flush <> io.flush
177  require(intWbArbiter.io.in.size == intArbiterInputsWireY.size, s"intWbArbiter input size: ${intWbArbiter.io.in.size}, all vf wb size: ${intArbiterInputsWireY.size}")
178  intWbArbiter.io.in.zip(intArbiterInputsWireY).foreach { case (arbiterIn, in) =>
179    arbiterIn.valid := in.valid && in.bits.intWen.get
180    in.ready := arbiterIn.ready
181    arbiterIn.bits.fromExuOutput(in.bits)
182  }
183  private val intWbArbiterOut = intWbArbiter.io.out
184
185  vfWbArbiter.io.flush <> io.flush
186  require(vfWbArbiter.io.in.size == vfArbiterInputsWireY.size, s"vfWbArbiter input size: ${vfWbArbiter.io.in.size}, all vf wb size: ${vfArbiterInputsWireY.size}")
187  vfWbArbiter.io.in.zip(vfArbiterInputsWireY).foreach { case (arbiterIn, in) =>
188    arbiterIn.valid := in.valid && (in.bits.fpWen.getOrElse(false.B) || in.bits.vecWen.getOrElse(false.B))
189    in.ready := arbiterIn.ready
190    arbiterIn.bits.fromExuOutput(in.bits)
191  }
192
193  private val vfWbArbiterOut = vfWbArbiter.io.out
194
195  private val intExuInputs = io.fromIntExu.flatten.toSeq
196  private val intExuWBs = WireInit(MixedVecInit(intExuInputs))
197  private val vfExuInputs = io.fromVfExu.flatten.toSeq
198  private val vfExuWBs = WireInit(MixedVecInit(vfExuInputs))
199  private val memExuInputs = io.fromMemExu.flatten.toSeq
200  private val memExuWBs = WireInit(MixedVecInit(memExuInputs))
201
202  // only fired port can write back to ctrl block
203  (intExuWBs zip intExuInputs).foreach { case (wb, input) => wb.valid := input.fire }
204  (vfExuWBs zip vfExuInputs).foreach { case (wb, input) => wb.valid := input.fire }
205  (memExuWBs zip memExuInputs).foreach { case (wb, input) => wb.valid := input.fire }
206
207  // the ports not writting back pregs are always ready
208  // the ports set highest priority are always ready
209  (intExuInputs ++ vfExuInputs ++ memExuInputs).foreach( x =>
210    if (x.bits.params.hasNoDataWB || x.bits.params.isHighestWBPriority) x.ready := true.B
211  )
212
213  // io assign
214  private val toIntPreg: MixedVec[RfWritePortWithConfig] = MixedVecInit(intWbArbiterOut.map(x => x.bits.asIntRfWriteBundle(x.fire)).toSeq)
215  private val toVfPreg: MixedVec[RfWritePortWithConfig] = MixedVecInit(vfWbArbiterOut.map(x => x.bits.asVfRfWriteBundle(x.fire)).toSeq)
216
217  private val wb2Ctrl = intExuWBs ++ vfExuWBs ++ memExuWBs
218
219  io.toIntPreg := toIntPreg
220  io.toVfPreg := toVfPreg
221  io.toCtrlBlock.writeback.zip(wb2Ctrl).foreach { case (sink, source) =>
222    sink.valid := source.valid
223    sink.bits := source.bits
224    source.ready := true.B
225  }
226
227  if (env.EnableDifftest || env.AlwaysBasicDiff) {
228    intWbArbiterOut.foreach(out => {
229      val difftest = DifftestModule(new DiffIntWriteback(IntPhyRegs))
230      difftest.coreid := io.fromTop.hartId
231      difftest.valid := out.fire && out.bits.rfWen
232      difftest.address := out.bits.pdest
233      difftest.data := out.bits.data
234    })
235  }
236
237  if (env.EnableDifftest || env.AlwaysBasicDiff) {
238    vfWbArbiterOut.foreach(out => {
239      val difftest = DifftestModule(new DiffFpWriteback(VfPhyRegs))
240      difftest.coreid := io.fromTop.hartId
241      difftest.valid := out.fire // all fp instr will write fp rf
242      difftest.address := out.bits.pdest
243      difftest.data := out.bits.data
244    })
245  }
246
247}
248
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252