xref: /XiangShan/src/main/scala/xiangshan/backend/Backend.scala (revision 9b258a00127f32ad428ceb355c633ea860d5df49)
1package xiangshan.backend
2
3import chipsalliance.rocketchip.config.Parameters
4import chisel3._
5import chisel3.util._
6import utils.OptionWrapper
7import freechips.rocketchip.diplomacy.{LazyModule, LazyModuleImp}
8import utility.{PipelineConnect, ZeroExt}
9import xiangshan._
10import xiangshan.backend.Bundles.{DynInst, MemExuInput, MemExuOutput}
11import xiangshan.backend.ctrlblock.CtrlBlock
12import xiangshan.backend.datapath.WbConfig._
13import xiangshan.backend.datapath.{DataPath, NewPipelineConnect, WbDataPath, WbFuBusyTable}
14import xiangshan.backend.exu.ExuBlock
15import xiangshan.backend.fu.vector.Bundles.{VConfig, VType}
16import xiangshan.backend.fu.{FenceIO, FenceToSbuffer, FuConfig, PerfCounterIO}
17import xiangshan.backend.issue.{Scheduler, IntScheduler, MemScheduler, VfScheduler}
18import xiangshan.backend.rob.RobLsqIO
19import xiangshan.frontend.{FtqPtr, FtqRead}
20import xiangshan.mem.{LqPtr, LsqEnqIO, SqPtr}
21
22class Backend(val params: BackendParams)(implicit p: Parameters) extends LazyModule
23  with HasXSParameter {
24
25  /* Only update the idx in mem-scheduler here
26   * Idx in other schedulers can be updated the same way if needed
27   *
28   * Also note that we filter out the 'stData issue-queues' when counting
29   */
30  for ((ibp, idx) <- params.memSchdParams.get.issueBlockParams.filter(iq => iq.StdCnt == 0).zipWithIndex) {
31    ibp.updateIdx(idx)
32  }
33
34  println("[Backend] ExuConfigs:")
35  for (exuCfg <- params.allExuParams) {
36    val fuConfigs = exuCfg.fuConfigs
37    val wbPortConfigs = exuCfg.wbPortConfigs
38    val immType = exuCfg.immType
39
40    println("[Backend]   " +
41      s"${exuCfg.name}: " +
42      s"${ fuConfigs.map(_.name).mkString("fu(s): {", ",", "}") }, " +
43      s"${ wbPortConfigs.mkString("wb: {", ",", "}") }, " +
44      s"${ immType.map(SelImm.mkString(_)).mkString("imm: {", "," , "}") }, " +
45      s"latMax(${exuCfg.latencyValMax}), ${exuCfg.fuLatancySet.mkString("lat: {",",","}")}, ")
46    require(wbPortConfigs.collectFirst { case x: IntWB => x }.nonEmpty ==
47      fuConfigs.map(_.writeIntRf).reduce(_ || _),
48      "int wb port has no priority" )
49    require(wbPortConfigs.collectFirst { case x: VfWB => x }.nonEmpty ==
50      fuConfigs.map(x => x.writeFpRf || x.writeVecRf).reduce(_ || _),
51      "vec wb port has no priority" )
52  }
53
54  for (cfg <- FuConfig.allConfigs) {
55    println(s"[Backend] $cfg")
56  }
57
58  val ctrlBlock = LazyModule(new CtrlBlock(params))
59  val intScheduler = params.intSchdParams.map(x => LazyModule(new Scheduler(x)))
60  val vfScheduler = params.vfSchdParams.map(x => LazyModule(new Scheduler(x)))
61  val memScheduler = params.memSchdParams.map(x => LazyModule(new Scheduler(x)))
62  val dataPath = LazyModule(new DataPath(params))
63  val intExuBlock = params.intSchdParams.map(x => LazyModule(new ExuBlock(x)))
64  val vfExuBlock = params.vfSchdParams.map(x => LazyModule(new ExuBlock(x)))
65  val wbFuBusyTable = LazyModule(new WbFuBusyTable(params))
66
67  lazy val module = new BackendImp(this)
68}
69
70class BackendImp(override val wrapper: Backend)(implicit p: Parameters) extends LazyModuleImp(wrapper)
71  with HasXSParameter{
72  implicit private val params = wrapper.params
73  val io = IO(new BackendIO()(p, wrapper.params))
74
75  private val ctrlBlock = wrapper.ctrlBlock.module
76  private val intScheduler = wrapper.intScheduler.get.module
77  private val vfScheduler = wrapper.vfScheduler.get.module
78  private val memScheduler = wrapper.memScheduler.get.module
79  private val dataPath = wrapper.dataPath.module
80  private val intExuBlock = wrapper.intExuBlock.get.module
81  private val vfExuBlock = wrapper.vfExuBlock.get.module
82  private val wbDataPath = Module(new WbDataPath(params))
83  private val wbFuBusyTable = wrapper.wbFuBusyTable.module
84
85  wbFuBusyTable.io.in.intSchdBusyTable := intScheduler.io.wbFuBusyTable
86  wbFuBusyTable.io.in.vfSchdBusyTable := vfScheduler.io.wbFuBusyTable
87  wbFuBusyTable.io.in.memSchdBusyTable := memScheduler.io.wbFuBusyTable
88  intScheduler.io.fromWbFuBusyTable.fuBusyTableRead := wbFuBusyTable.io.out.intRespRead
89  vfScheduler.io.fromWbFuBusyTable.fuBusyTableRead := wbFuBusyTable.io.out.vfRespRead
90  memScheduler.io.fromWbFuBusyTable.fuBusyTableRead := wbFuBusyTable.io.out.memRespRead
91  dataPath.io.wbConfictRead := wbFuBusyTable.io.out.wbConflictRead
92
93  wbDataPath.io.fromIntExu.flatten.filter(x => x.bits.params.writeIntRf)
94
95  private val vconfig = dataPath.io.vconfigReadPort.data
96
97  ctrlBlock.io.fromTop.hartId := io.fromTop.hartId
98  ctrlBlock.io.frontend <> io.frontend
99  ctrlBlock.io.fromWB.wbData <> wbDataPath.io.toCtrlBlock.writeback
100  ctrlBlock.io.fromMem.stIn <> io.mem.stIn
101  ctrlBlock.io.fromMem.violation <> io.mem.memoryViolation
102  ctrlBlock.io.csrCtrl <> intExuBlock.io.csrio.get.customCtrl
103  ctrlBlock.io.robio.csr.intrBitSet := intExuBlock.io.csrio.get.interrupt
104  ctrlBlock.io.robio.csr.trapTarget := intExuBlock.io.csrio.get.trapTarget
105  ctrlBlock.io.robio.csr.isXRet := intExuBlock.io.csrio.get.isXRet
106  ctrlBlock.io.robio.csr.wfiEvent := intExuBlock.io.csrio.get.wfi_event
107  ctrlBlock.io.robio.lsq <> io.mem.robLsqIO
108  ctrlBlock.io.fromDataPath.vtype := vconfig(7, 0).asTypeOf(new VType)
109
110  intScheduler.io.fromTop.hartId := io.fromTop.hartId
111  intScheduler.io.fromCtrlBlock.flush := ctrlBlock.io.toIssueBlock.flush
112  intScheduler.io.fromCtrlBlock.pcVec := ctrlBlock.io.toIssueBlock.pcVec
113  intScheduler.io.fromCtrlBlock.targetVec := ctrlBlock.io.toIssueBlock.targetVec
114  intScheduler.io.fromDispatch.allocPregs <> ctrlBlock.io.toIssueBlock.allocPregs
115  intScheduler.io.fromDispatch.uops <> ctrlBlock.io.toIssueBlock.intUops
116  intScheduler.io.intWriteBack := wbDataPath.io.toIntPreg
117  intScheduler.io.vfWriteBack := 0.U.asTypeOf(intScheduler.io.vfWriteBack)
118  intScheduler.io.fromDataPath := dataPath.io.toIntIQ
119
120  memScheduler.io.fromTop.hartId := io.fromTop.hartId
121  memScheduler.io.fromCtrlBlock.flush := ctrlBlock.io.toIssueBlock.flush
122  memScheduler.io.fromDispatch.allocPregs <> ctrlBlock.io.toIssueBlock.allocPregs
123  memScheduler.io.fromDispatch.uops <> ctrlBlock.io.toIssueBlock.memUops
124  memScheduler.io.intWriteBack := wbDataPath.io.toIntPreg
125  memScheduler.io.vfWriteBack := wbDataPath.io.toVfPreg
126  memScheduler.io.fromMem.get.scommit := io.mem.sqDeq
127  memScheduler.io.fromMem.get.lcommit := io.mem.lqDeq
128  memScheduler.io.fromMem.get.sqCancelCnt := io.mem.sqCancelCnt
129  memScheduler.io.fromMem.get.lqCancelCnt := io.mem.lqCancelCnt
130  memScheduler.io.fromMem.get.stIssuePtr := io.mem.stIssuePtr
131  memScheduler.io.fromMem.get.memWaitUpdateReq.staIssue.zip(io.mem.stIn).foreach { case (sink, source) =>
132    sink.valid := source.valid
133    sink.bits.uop := 0.U.asTypeOf(sink.bits.uop)
134    sink.bits.uop.robIdx := source.bits.robIdx
135  }
136  memScheduler.io.fromDataPath := dataPath.io.toMemIQ
137  memScheduler.io.fromMem.get.ldaFeedback := io.mem.ldaIqFeedback
138  memScheduler.io.fromMem.get.staFeedback := io.mem.staIqFeedback
139
140  vfScheduler.io.fromTop.hartId := io.fromTop.hartId
141  vfScheduler.io.fromCtrlBlock.flush := ctrlBlock.io.toIssueBlock.flush
142  vfScheduler.io.fromDispatch.allocPregs <> ctrlBlock.io.toIssueBlock.allocPregs
143  vfScheduler.io.fromDispatch.uops <> ctrlBlock.io.toIssueBlock.vfUops
144  vfScheduler.io.intWriteBack := 0.U.asTypeOf(vfScheduler.io.intWriteBack)
145  vfScheduler.io.vfWriteBack := wbDataPath.io.toVfPreg
146  vfScheduler.io.fromDataPath := dataPath.io.toVfIQ
147
148  dataPath.io.flush := ctrlBlock.io.toDataPath.flush
149  dataPath.io.vconfigReadPort.addr := ctrlBlock.io.toDataPath.vtypeAddr
150
151  for (i <- 0 until dataPath.io.fromIntIQ.length) {
152    for (j <- 0 until dataPath.io.fromIntIQ(i).length) {
153      NewPipelineConnect(intScheduler.io.toDataPath(i)(j), dataPath.io.fromIntIQ(i)(j), dataPath.io.fromIntIQ(i)(j).valid,
154        intScheduler.io.toDataPath(i)(j).bits.common.robIdx.needFlush(ctrlBlock.io.toDataPath.flush), Option("intScheduler2DataPathPipe"))
155    }
156  }
157
158  for (i <- 0 until dataPath.io.fromVfIQ.length) {
159    for (j <- 0 until dataPath.io.fromVfIQ(i).length) {
160      NewPipelineConnect(vfScheduler.io.toDataPath(i)(j), dataPath.io.fromVfIQ(i)(j), dataPath.io.fromVfIQ(i)(j).valid,
161        vfScheduler.io.toDataPath(i)(j).bits.common.robIdx.needFlush(ctrlBlock.io.toDataPath.flush), Option("vfScheduler2DataPathPipe"))
162    }
163  }
164
165  for (i <- 0 until dataPath.io.fromMemIQ.length) {
166    for (j <- 0 until dataPath.io.fromMemIQ(i).length) {
167      NewPipelineConnect(memScheduler.io.toDataPath(i)(j), dataPath.io.fromMemIQ(i)(j), dataPath.io.fromMemIQ(i)(j).valid,
168        memScheduler.io.toDataPath(i)(j).bits.common.robIdx.needFlush(ctrlBlock.io.toDataPath.flush), Option("memScheduler2DataPathPipe"))
169    }
170  }
171
172  println(s"[Backend] wbDataPath.io.toIntPreg: ${wbDataPath.io.toIntPreg.size}, dataPath.io.fromIntWb: ${dataPath.io.fromIntWb.size}")
173  println(s"[Backend] wbDataPath.io.toVfPreg: ${wbDataPath.io.toVfPreg.size}, dataPath.io.fromFpWb: ${dataPath.io.fromVfWb.size}")
174  dataPath.io.fromIntWb := wbDataPath.io.toIntPreg
175  dataPath.io.fromVfWb := wbDataPath.io.toVfPreg
176  dataPath.io.debugIntRat := ctrlBlock.io.debug_int_rat
177  dataPath.io.debugFpRat := ctrlBlock.io.debug_fp_rat
178  dataPath.io.debugVecRat := ctrlBlock.io.debug_vec_rat
179  dataPath.io.debugVconfigRat := ctrlBlock.io.debug_vconfig_rat
180
181  intExuBlock.io.flush := ctrlBlock.io.toExuBlock.flush
182  for (i <- 0 until intExuBlock.io.in.length) {
183    for (j <- 0 until intExuBlock.io.in(i).length) {
184      NewPipelineConnect(dataPath.io.toIntExu(i)(j), intExuBlock.io.in(i)(j), intExuBlock.io.in(i)(j).fire,
185        Mux(dataPath.io.toIntExu(i)(j).fire,
186          dataPath.io.toIntExu(i)(j).bits.robIdx.needFlush(ctrlBlock.io.toExuBlock.flush),
187          intExuBlock.io.in(i)(j).bits.robIdx.needFlush(ctrlBlock.io.toExuBlock.flush)))
188    }
189  }
190
191  private val csrio = intExuBlock.io.csrio.get
192  csrio.hartId := io.fromTop.hartId
193  csrio.perf.retiredInstr <> ctrlBlock.io.robio.csr.perfinfo.retiredInstr
194  csrio.perf.ctrlInfo <> ctrlBlock.io.perfInfo.ctrlInfo
195  csrio.perf.perfEventsCtrl <> ctrlBlock.getPerf
196  csrio.fpu.fflags := ctrlBlock.io.robio.csr.fflags
197  csrio.fpu.isIllegal := false.B // Todo: remove it
198  csrio.fpu.dirty_fs := ctrlBlock.io.robio.csr.dirty_fs
199  csrio.vpu <> 0.U.asTypeOf(csrio.vpu) // Todo
200
201  val debugVconfig = dataPath.io.debugVconfig.asTypeOf(new VConfig)
202  val debugVtype = VType.toVtypeStruct(debugVconfig.vtype).asUInt
203  val debugVl = debugVconfig.vl
204  csrio.vpu.set_vxsat := ctrlBlock.io.robio.csr.vxsat
205  csrio.vpu.set_vstart.valid := ctrlBlock.io.robio.csr.vcsrFlag
206  csrio.vpu.set_vstart.bits := 0.U
207  csrio.vpu.set_vtype.valid := ctrlBlock.io.robio.csr.vcsrFlag
208  csrio.vpu.set_vtype.bits := ZeroExt(debugVtype, XLEN)
209  csrio.vpu.set_vl.valid := ctrlBlock.io.robio.csr.vcsrFlag
210  csrio.vpu.set_vl.bits := ZeroExt(debugVl, XLEN)
211  csrio.exception := ctrlBlock.io.robio.exception
212  csrio.memExceptionVAddr := io.mem.exceptionVAddr
213  csrio.externalInterrupt := io.fromTop.externalInterrupt
214  csrio.distributedUpdate(0) := io.mem.csrDistributedUpdate
215  csrio.distributedUpdate(1) := io.frontendCsrDistributedUpdate
216  csrio.perf <> io.perf
217  private val fenceio = intExuBlock.io.fenceio.get
218  fenceio.disableSfence := csrio.disableSfence
219  io.fenceio <> fenceio
220
221  vfExuBlock.io.flush := ctrlBlock.io.toExuBlock.flush
222  for (i <- 0 until vfExuBlock.io.in.size) {
223    for (j <- 0 until vfExuBlock.io.in(i).size) {
224      NewPipelineConnect(dataPath.io.toFpExu(i)(j), vfExuBlock.io.in(i)(j), vfExuBlock.io.in(i)(j).fire,
225        Mux(dataPath.io.toFpExu(i)(j).fire,
226          dataPath.io.toFpExu(i)(j).bits.robIdx.needFlush(ctrlBlock.io.toExuBlock.flush),
227          vfExuBlock.io.in(i)(j).bits.robIdx.needFlush(ctrlBlock.io.toExuBlock.flush)))
228    }
229  }
230  vfExuBlock.io.frm.foreach(_ := csrio.fpu.frm)
231
232  wbDataPath.io.flush := ctrlBlock.io.redirect
233  wbDataPath.io.fromTop.hartId := io.fromTop.hartId
234  wbDataPath.io.fromIntExu <> intExuBlock.io.out
235  wbDataPath.io.fromVfExu <> vfExuBlock.io.out
236  wbDataPath.io.fromMemExu.flatten.zip(io.mem.writeBack).foreach { case (sink, source) =>
237    sink.valid := source.valid
238    source.ready := sink.ready
239    sink.bits.data   := source.bits.data
240    sink.bits.pdest  := source.bits.uop.pdest
241    sink.bits.robIdx := source.bits.uop.robIdx
242    sink.bits.intWen.foreach(_ := source.bits.uop.rfWen)
243    sink.bits.fpWen.foreach(_ := source.bits.uop.fpWen)
244    sink.bits.vecWen.foreach(_ := source.bits.uop.vecWen)
245    sink.bits.exceptionVec.foreach(_ := source.bits.uop.exceptionVec)
246    sink.bits.flushPipe.foreach(_ := source.bits.uop.flushPipe)
247    sink.bits.replay.foreach(_ := source.bits.uop.replayInst)
248    sink.bits.debug := source.bits.debug
249    sink.bits.debugInfo := 0.U.asTypeOf(sink.bits.debugInfo)
250    sink.bits.lqIdx.foreach(_ := source.bits.uop.lqIdx)
251    sink.bits.sqIdx.foreach(_ := source.bits.uop.sqIdx)
252    sink.bits.ftqIdx.foreach(_ := source.bits.uop.ftqPtr)
253    sink.bits.ftqOffset.foreach(_ := source.bits.uop.ftqOffset)
254  }
255
256  // to mem
257  io.mem.redirect := ctrlBlock.io.redirect
258  io.mem.issueUops.zip(dataPath.io.toMemExu.flatten).foreach { case (sink, source) =>
259    sink.valid := source.valid
260    source.ready := sink.ready
261    sink.bits.iqIdx         := source.bits.iqIdx
262    sink.bits.isFirstIssue  := source.bits.isFirstIssue
263    sink.bits.uop           := 0.U.asTypeOf(sink.bits.uop)
264    sink.bits.src           := 0.U.asTypeOf(sink.bits.src)
265    sink.bits.src.zip(source.bits.src).foreach { case (l, r) => l := r}
266    sink.bits.uop.fuType    := source.bits.fuType
267    sink.bits.uop.fuOpType  := source.bits.fuOpType
268    sink.bits.uop.imm       := source.bits.imm
269    sink.bits.uop.robIdx    := source.bits.robIdx
270    sink.bits.uop.pdest     := source.bits.pdest
271    sink.bits.uop.rfWen     := source.bits.rfWen.getOrElse(false.B)
272    sink.bits.uop.fpWen     := source.bits.fpWen.getOrElse(false.B)
273    sink.bits.uop.vecWen    := source.bits.vecWen.getOrElse(false.B)
274    sink.bits.uop.flushPipe := source.bits.flushPipe.getOrElse(false.B)
275    sink.bits.uop.pc        := source.bits.pc.getOrElse(0.U)
276    sink.bits.uop.lqIdx     := source.bits.lqIdx.getOrElse(0.U.asTypeOf(new LqPtr))
277    sink.bits.uop.sqIdx     := source.bits.sqIdx.getOrElse(0.U.asTypeOf(new SqPtr))
278    sink.bits.uop.ftqPtr    := source.bits.ftqIdx.getOrElse(0.U.asTypeOf(new FtqPtr))
279    sink.bits.uop.ftqOffset := source.bits.ftqOffset.getOrElse(0.U)
280  }
281  io.mem.loadFastMatch := memScheduler.io.toMem.get.loadFastMatch.map(_.fastMatch)
282  io.mem.loadFastImm := memScheduler.io.toMem.get.loadFastMatch.map(_.fastImm)
283  io.mem.tlbCsr := csrio.tlb
284  io.mem.csrCtrl := csrio.customCtrl
285  io.mem.sfence := fenceio.sfence
286  io.mem.isStoreException := CommitType.lsInstIsStore(ctrlBlock.io.robio.exception.bits.commitType)
287  require(io.mem.loadPcRead.size == params.LduCnt)
288  io.mem.loadPcRead.zipWithIndex.foreach { case (loadPcRead, i) =>
289    loadPcRead.data := ctrlBlock.io.memLdPcRead(i).data
290    ctrlBlock.io.memLdPcRead(i).ptr := loadPcRead.ptr
291    ctrlBlock.io.memLdPcRead(i).offset := loadPcRead.offset
292  }
293  // mem io
294  io.mem.lsqEnqIO <> memScheduler.io.memIO.get.lsqEnqIO
295  io.mem.robLsqIO <> ctrlBlock.io.robio.lsq
296  io.mem.toSbuffer <> fenceio.sbuffer
297
298  io.frontendSfence := fenceio.sfence
299  io.frontendTlbCsr := csrio.tlb
300  io.frontendCsrCtrl := csrio.customCtrl
301
302  io.tlb <> csrio.tlb
303
304  io.csrCustomCtrl := csrio.customCtrl
305
306  dontTouch(memScheduler.io)
307  dontTouch(io.mem)
308  dontTouch(dataPath.io.toMemExu)
309  dontTouch(wbDataPath.io.fromMemExu)
310}
311
312class BackendMemIO(implicit p: Parameters, params: BackendParams) extends XSBundle {
313  // params alias
314  private val LoadQueueSize = VirtualLoadQueueSize
315  // In/Out // Todo: split it into one-direction bundle
316  val lsqEnqIO = Flipped(new LsqEnqIO)
317  val robLsqIO = new RobLsqIO
318  val toSbuffer = new FenceToSbuffer
319  val ldaIqFeedback = Vec(params.LduCnt, Flipped(new MemRSFeedbackIO))
320  val staIqFeedback = Vec(params.StaCnt, Flipped(new MemRSFeedbackIO))
321  val loadPcRead = Vec(params.LduCnt, Flipped(new FtqRead(UInt(VAddrBits.W))))
322
323  // Input
324  val writeBack = MixedVec(Seq.fill(params.LduCnt + params.StaCnt * 2)(Flipped(DecoupledIO(new MemExuOutput()))) ++ Seq.fill(params.VlduCnt)(Flipped(DecoupledIO(new MemExuOutput(true)))))
325
326  val s3_delayed_load_error = Input(Vec(LoadPipelineWidth, Bool()))
327  val stIn = Input(Vec(params.StaCnt, ValidIO(new DynInst())))
328  val memoryViolation = Flipped(ValidIO(new Redirect))
329  val exceptionVAddr = Input(UInt(VAddrBits.W))
330  val sqDeq = Input(UInt(log2Ceil(EnsbufferWidth + 1).W))
331  val lqDeq = Input(UInt(log2Up(CommitWidth + 1).W))
332
333  val lqCancelCnt = Input(UInt(log2Up(VirtualLoadQueueSize + 1).W))
334  val sqCancelCnt = Input(UInt(log2Up(StoreQueueSize + 1).W))
335
336  val otherFastWakeup = Flipped(Vec(params.LduCnt + 2 * params.StaCnt, ValidIO(new DynInst)))
337  val stIssuePtr = Input(new SqPtr())
338
339  val csrDistributedUpdate = Flipped(new DistributedCSRUpdateReq)
340
341  // Output
342  val redirect = ValidIO(new Redirect)   // rob flush MemBlock
343  val issueUops = MixedVec(Seq.fill(params.LduCnt + params.StaCnt * 2)(DecoupledIO(new MemExuInput())) ++ Seq.fill(params.VlduCnt)(DecoupledIO(new MemExuInput(true))))
344  val loadFastMatch = Vec(params.LduCnt, Output(UInt(params.LduCnt.W)))
345  val loadFastImm   = Vec(params.LduCnt, Output(UInt(12.W))) // Imm_I
346
347  val tlbCsr = Output(new TlbCsrBundle)
348  val csrCtrl = Output(new CustomCSRCtrlIO)
349  val sfence = Output(new SfenceBundle)
350  val isStoreException = Output(Bool())
351}
352
353class BackendIO(implicit p: Parameters, params: BackendParams) extends XSBundle {
354  val fromTop = new Bundle {
355    val hartId = Input(UInt(8.W))
356    val externalInterrupt = new ExternalInterruptIO
357  }
358
359  val toTop = new Bundle {
360    val cpuHalted = Output(Bool())
361  }
362
363  val fenceio = new FenceIO
364  // Todo: merge these bundles into BackendFrontendIO
365  val frontend = Flipped(new FrontendToCtrlIO)
366  val frontendSfence = Output(new SfenceBundle)
367  val frontendCsrCtrl = Output(new CustomCSRCtrlIO)
368  val frontendTlbCsr = Output(new TlbCsrBundle)
369  // distributed csr write
370  val frontendCsrDistributedUpdate = Flipped(new DistributedCSRUpdateReq)
371
372  val mem = new BackendMemIO
373
374  val perf = Input(new PerfCounterIO)
375
376  val tlb = Output(new TlbCsrBundle)
377
378  val csrCustomCtrl = Output(new CustomCSRCtrlIO)
379}
380