xref: /XiangShan/src/main/scala/xiangshan/mem/pipeline/HybridUnit.scala (revision c41f725a91c55e75c95c55b4bb0d2649f43e4c83)
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.mem
18
19import org.chipsalliance.cde.config.Parameters
20import chisel3._
21import chisel3.util._
22import utils._
23import utility._
24import xiangshan._
25import xiangshan.ExceptionNO._
26import xiangshan.backend.Bundles.{DynInst, MemExuInput, MemExuOutput}
27import xiangshan.backend.fu.PMPRespBundle
28import xiangshan.backend.fu.FuConfig._
29import xiangshan.backend.ctrlblock.{DebugLsInfoBundle, LsTopdownInfo}
30import xiangshan.backend.fu.NewCSR._
31import xiangshan.backend.rob.RobPtr
32import xiangshan.backend.fu._
33import xiangshan.backend.fu.util.SdtrigExt
34import xiangshan.mem.mdp._
35import xiangshan.mem.Bundles._
36import xiangshan.cache._
37import xiangshan.cache.wpu.ReplayCarry
38import xiangshan.cache.mmu.{TlbCmd, TlbHintReq, TlbReq, TlbRequestIO, TlbResp}
39
40class HybridUnit(implicit p: Parameters) extends XSModule
41  with HasLoadHelper
42  with HasPerfEvents
43  with HasDCacheParameters
44  with HasCircularQueuePtrHelper
45  with HasVLSUParameters
46  with SdtrigExt
47{
48  val io = IO(new Bundle() {
49    // control
50    val redirect      = Flipped(ValidIO(new Redirect))
51    val csrCtrl       = Flipped(new CustomCSRCtrlIO)
52
53    // flow in
54    val lsin          = Flipped(Decoupled(new MemExuInput))
55
56    // flow out
57    val ldout = DecoupledIO(new MemExuOutput)
58    val stout = DecoupledIO(new MemExuOutput)
59
60    val ldu_io = new Bundle() {
61      // dcache
62      val dcache        = new DCacheLoadIO
63
64      // data path
65      val sbuffer       = new LoadForwardQueryIO
66      val ubuffer       = new LoadForwardQueryIO
67      val vec_forward   = new LoadForwardQueryIO
68      val lsq           = new LoadToLsqIO
69      val tl_d_channel  = Input(new DcacheToLduForwardIO)
70      val forward_mshr  = Flipped(new LduToMissqueueForwardIO)
71      val tlb_hint      = Flipped(new TlbHintReq)
72      val l2_hint       = Input(Valid(new L2ToL1Hint))
73
74      // fast wakeup
75      val fast_uop = ValidIO(new DynInst) // early wakeup signal generated in load_s1, send to RS in load_s2
76
77      // trigger
78      val trigger = Vec(TriggerNum, new LoadUnitTriggerIO)
79
80      // load to load fast path
81      val l2l_fwd_in    = Input(new LoadToLoadIO)
82      val l2l_fwd_out   = Output(new LoadToLoadIO)
83
84      val ld_fast_match    = Input(Bool())
85      val ld_fast_fuOpType = Input(UInt())
86      val ld_fast_imm      = Input(UInt(12.W))
87
88      // hardware prefetch to l1 cache req
89      val prefetch_req    = Flipped(ValidIO(new L1PrefetchReq))
90
91      // iq cancel
92      val ldCancel = Output(new LoadCancelIO()) // use to cancel the uops waked by this load, and cancel load
93
94      // iq wakeup, use to wakeup consumer uop at load s2
95      val wakeup = ValidIO(new DynInst)
96
97      // load ecc error
98      val s3_dly_ld_err = Output(Bool()) // Note that io.s3_dly_ld_err and io.lsq.s3_dly_ld_err is different
99
100      // schedule error query
101      val stld_nuke_query = Flipped(Vec(StorePipelineWidth, Valid(new StoreNukeQueryIO)))
102
103      // queue-based replay
104      val replay       = Flipped(Decoupled(new LsPipelineBundle))
105      val lq_rep_full  = Input(Bool())
106
107      // misc
108      val s2_ptr_chasing = Output(Bool()) // provide right pc for hw prefetch
109
110      // Load fast replay path
111      val fast_rep_in  = Flipped(Decoupled(new LqWriteBundle))
112      val fast_rep_out = Decoupled(new LqWriteBundle)
113
114      // Load RAR rollback
115      val rollback = Valid(new Redirect)
116
117      // perf
118      val debug_ls         = Output(new DebugLsInfoBundle)
119      val lsTopdownInfo    = Output(new LsTopdownInfo)
120    }
121
122    val stu_io = new Bundle() {
123      val dcache          = new DCacheStoreIO
124      val prefetch_req    = Flipped(DecoupledIO(new StorePrefetchReq))
125      val issue           = Valid(new MemExuInput)
126      val lsq             = ValidIO(new LsPipelineBundle)
127      val lsq_replenish   = Output(new LsPipelineBundle())
128      val stld_nuke_query = Valid(new StoreNukeQueryIO)
129      val st_mask_out     = Valid(new StoreMaskBundle)
130      val debug_ls        = Output(new DebugLsInfoBundle)
131    }
132
133    val vec_stu_io = new Bundle() {
134      val in = Flipped(DecoupledIO(new VecPipeBundle()))
135      val isFirstIssue = Input(Bool())
136      val lsq = ValidIO(new LsPipelineBundle())
137      val feedbackSlow = ValidIO(new VSFQFeedback)
138    }
139
140    // speculative for gated control
141    val s0_prefetch_spec = Output(Bool())
142    val s1_prefetch_spec = Output(Bool())
143    // prefetch
144    val prefetch_train            = ValidIO(new LdPrefetchTrainBundle()) // provide prefetch info to sms
145    val prefetch_train_l1         = ValidIO(new LdPrefetchTrainBundle()) // provide prefetch info to stream & stride
146    val canAcceptLowConfPrefetch  = Output(Bool())
147    val canAcceptHighConfPrefetch = Output(Bool())
148    val correctMissTrain          = Input(Bool())
149
150    // data path
151    val tlb           = new TlbRequestIO(2)
152    val pmp           = Flipped(new PMPRespBundle()) // arrive same to tlb now
153
154    // rs feedback
155    val feedback_fast = ValidIO(new RSFeedback) // stage 2
156    val feedback_slow = ValidIO(new RSFeedback) // stage 3
157
158    // for store trigger
159    val fromCsrTrigger = Input(new CsrTriggerBundle)
160  })
161
162  val StorePrefetchL1Enabled = EnableStorePrefetchAtCommit || EnableStorePrefetchAtIssue || EnableStorePrefetchSPB
163  val s1_ready, s2_ready, s3_ready, sx_can_go = WireInit(false.B)
164
165  // Pipeline
166  // --------------------------------------------------------------------------------
167  // stage 0
168  // --------------------------------------------------------------------------------
169  // generate addr, use addr to query DCache and DTLB
170  val s0_valid         = Wire(Bool())
171  val s0_dcache_ready  = Wire(Bool())
172  val s0_kill          = Wire(Bool())
173  val s0_vaddr         = Wire(UInt(VAddrBits.W))
174  val s0_mask          = Wire(UInt((VLEN/8).W))
175  val s0_uop           = Wire(new DynInst)
176  val s0_has_rob_entry = Wire(Bool())
177  val s0_mshrid        = Wire(UInt())
178  val s0_try_l2l       = Wire(Bool())
179  val s0_rep_carry     = Wire(new ReplayCarry(nWays))
180  val s0_isFirstIssue  = Wire(Bool())
181  val s0_fast_rep      = Wire(Bool())
182  val s0_ld_rep        = Wire(Bool())
183  val s0_l2l_fwd       = Wire(Bool())
184  val s0_sched_idx     = Wire(UInt())
185  val s0_can_go        = s1_ready
186  val s0_fire          = s0_valid && s0_dcache_ready && s0_can_go
187  val s0_out           = Wire(new LqWriteBundle)
188  // vector
189  val s0_isvec = WireInit(false.B)
190  val s0_vecActive = WireInit(true.B)
191  // val s0_flowPtr = WireInit(0.U.asTypeOf(new VsFlowPtr))
192  val s0_isLastElem = WireInit(false.B)
193
194  // load flow select/gen
195  // src0: super load replayed by LSQ (cache miss replay) (io.ldu_io.replay)
196  // src1: fast load replay (io.ldu_io.fast_rep_in)
197  // src2: load replayed by LSQ (io.ldu_io.replay)
198  // src3: hardware prefetch from prefetchor (high confidence) (io.prefetch)
199  // src4: int read / software prefetch first issue from RS (io.in)
200  // src5: vec read first issue from RS (TODO)
201  // src6: load try pointchaising when no issued or replayed load (io.fastpath)
202  // src7: hardware prefetch from prefetchor (high confidence) (io.prefetch)
203  // priority: high to low
204  val s0_ld_flow             = FuType.isLoad(s0_uop.fuType) || FuType.isVLoad(s0_uop.fuType)
205  val s0_rep_stall           = io.lsin.valid && isAfter(io.ldu_io.replay.bits.uop.robIdx, io.lsin.bits.uop.robIdx)
206  private val SRC_NUM = 8
207  private val Seq(
208    super_rep_idx, fast_rep_idx, lsq_rep_idx, high_pf_idx,
209    int_iss_idx, vec_iss_idx, l2l_fwd_idx, low_pf_idx
210  ) = (0 until SRC_NUM).toSeq
211  // load flow source valid
212  val s0_src_valid_vec = WireInit(VecInit(Seq(
213    io.ldu_io.replay.valid && io.ldu_io.replay.bits.forward_tlDchannel,
214    io.ldu_io.fast_rep_in.valid,
215    io.ldu_io.replay.valid && !io.ldu_io.replay.bits.forward_tlDchannel && !s0_rep_stall,
216    io.ldu_io.prefetch_req.valid && io.ldu_io.prefetch_req.bits.confidence > 0.U,
217    io.lsin.valid, // int flow first issue or software prefetch
218    io.vec_stu_io.in.valid,
219    io.ldu_io.l2l_fwd_in.valid && io.ldu_io.ld_fast_match,
220    io.ldu_io.prefetch_req.valid && io.ldu_io.prefetch_req.bits.confidence === 0.U,
221  )))
222  // load flow source ready
223  val s0_src_ready_vec = Wire(Vec(SRC_NUM, Bool()))
224  s0_src_ready_vec(0) := true.B
225  for(i <- 1 until SRC_NUM){
226    s0_src_ready_vec(i) := !s0_src_valid_vec.take(i).reduce(_ || _)
227  }
228  // load flow source select (OH)
229  val s0_src_select_vec = WireInit(VecInit((0 until SRC_NUM).map{i => s0_src_valid_vec(i) && s0_src_ready_vec(i)}))
230  val s0_hw_prf_select = s0_src_select_vec(high_pf_idx) || s0_src_select_vec(low_pf_idx)
231
232  if (backendParams.debugEn){
233    dontTouch(s0_src_valid_vec)
234    dontTouch(s0_src_ready_vec)
235    dontTouch(s0_src_select_vec)
236  }
237
238  s0_valid := s0_src_valid_vec.reduce(_ || _) && !s0_kill
239
240  // which is S0's out is ready and dcache is ready
241  val s0_try_ptr_chasing      = s0_src_select_vec(l2l_fwd_idx)
242  val s0_do_try_ptr_chasing   = s0_try_ptr_chasing && s0_can_go && io.ldu_io.dcache.req.ready
243  val s0_ptr_chasing_vaddr    = io.ldu_io.l2l_fwd_in.data(5, 0) +& io.ldu_io.ld_fast_imm(5, 0)
244  val s0_ptr_chasing_canceled = WireInit(false.B)
245  s0_kill := s0_ptr_chasing_canceled || (s0_out.uop.robIdx.needFlush(io.redirect) && !s0_try_ptr_chasing)
246
247  // prefetch related ctrl signal
248  val s0_prf    = Wire(Bool())
249  val s0_prf_rd = Wire(Bool())
250  val s0_prf_wr = Wire(Bool())
251  val s0_hw_prf = s0_hw_prf_select
252
253  io.canAcceptLowConfPrefetch  := s0_src_ready_vec(low_pf_idx) && io.ldu_io.dcache.req.ready
254  io.canAcceptHighConfPrefetch := s0_src_ready_vec(high_pf_idx) && io.ldu_io.dcache.req.ready
255
256  if (StorePrefetchL1Enabled) {
257    s0_dcache_ready := Mux(s0_ld_flow, io.ldu_io.dcache.req.ready, io.stu_io.dcache.req.ready)
258  } else {
259    s0_dcache_ready := Mux(s0_ld_flow, io.ldu_io.dcache.req.ready, true.B)
260  }
261
262  // query DTLB
263  io.tlb.req.valid                   := s0_valid && s0_dcache_ready
264  io.tlb.req.bits.cmd                := Mux(s0_prf,
265                                         Mux(s0_prf_wr, TlbCmd.write, TlbCmd.read),
266                                         Mux(s0_ld_flow, TlbCmd.read, TlbCmd.write)
267                                       )
268  io.tlb.req.bits.vaddr              := Mux(s0_hw_prf_select, io.ldu_io.prefetch_req.bits.paddr, s0_vaddr)
269  io.tlb.req.bits.size               := Mux(s0_isvec, io.vec_stu_io.in.bits.alignedType(1, 0), LSUOpType.size(s0_uop.fuOpType)) // may broken if use it in feature
270  io.tlb.req.bits.kill               := s0_kill
271  io.tlb.req.bits.memidx.is_ld       := s0_ld_flow
272  io.tlb.req.bits.memidx.is_st       := !s0_ld_flow
273  io.tlb.req.bits.memidx.idx         := s0_uop.lqIdx.value
274  io.tlb.req.bits.debug.robIdx       := s0_uop.robIdx
275  io.tlb.req.bits.no_translate       := s0_hw_prf_select  // hw b.reqetch addr does not need to be translated
276  io.tlb.req.bits.debug.pc           := s0_uop.pc
277  io.tlb.req.bits.debug.isFirstIssue := s0_isFirstIssue
278
279  // query DCache
280  // for load
281  io.ldu_io.dcache.req.valid             := s0_valid && s0_dcache_ready && s0_ld_flow
282  io.ldu_io.dcache.req.bits.cmd          :=  Mux(s0_prf_rd, MemoryOpConstants.M_PFR,
283                                              Mux(s0_prf_wr, MemoryOpConstants.M_PFW, MemoryOpConstants.M_XRD))
284  io.ldu_io.dcache.req.bits.vaddr        := s0_vaddr
285  io.ldu_io.dcache.req.bits.mask         := s0_mask
286  io.ldu_io.dcache.req.bits.data         := DontCare
287  io.ldu_io.dcache.req.bits.isFirstIssue := s0_isFirstIssue
288  io.ldu_io.dcache.req.bits.instrtype    := Mux(s0_prf, DCACHE_PREFETCH_SOURCE.U, LOAD_SOURCE.U)
289  io.ldu_io.dcache.req.bits.debug_robIdx := s0_uop.robIdx.value
290  io.ldu_io.dcache.req.bits.replayCarry  := s0_rep_carry
291  io.ldu_io.dcache.req.bits.id           := DontCare // TODO: update cache meta
292  io.ldu_io.dcache.pf_source             := Mux(s0_hw_prf_select, io.ldu_io.prefetch_req.bits.pf_source.value, L1_HW_PREFETCH_NULL)
293  io.ldu_io.dcache.is128Req              := is128Bit(io.vec_stu_io.in.bits.alignedType) && io.vec_stu_io.in.valid && s0_src_select_vec(vec_iss_idx)
294
295  // for store
296  io.stu_io.dcache.req.valid             := s0_valid && s0_dcache_ready && !s0_ld_flow && !s0_prf
297  io.stu_io.dcache.req.bits.cmd          := MemoryOpConstants.M_PFW
298  io.stu_io.dcache.req.bits.vaddr        := s0_vaddr
299  io.stu_io.dcache.req.bits.instrtype    := Mux(s0_prf, DCACHE_PREFETCH_SOURCE.U, STORE_SOURCE.U)
300
301  // load flow priority mux
302  def fromNullSource() = {
303    s0_vaddr         := 0.U
304    s0_mask          := 0.U
305    s0_uop           := 0.U.asTypeOf(new DynInst)
306    s0_try_l2l       := false.B
307    s0_has_rob_entry := false.B
308    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
309    s0_mshrid        := 0.U
310    s0_isFirstIssue  := false.B
311    s0_fast_rep      := false.B
312    s0_ld_rep        := false.B
313    s0_l2l_fwd       := false.B
314    s0_prf           := false.B
315    s0_prf_rd        := false.B
316    s0_prf_wr        := false.B
317    s0_sched_idx     := 0.U
318  }
319
320  def fromFastReplaySource(src: LqWriteBundle) = {
321    s0_vaddr         := src.vaddr
322    s0_mask          := src.mask
323    s0_uop           := src.uop
324    s0_try_l2l       := false.B
325    s0_has_rob_entry := src.hasROBEntry
326    s0_rep_carry     := src.rep_info.rep_carry
327    s0_mshrid        := src.rep_info.mshr_id
328    s0_isFirstIssue  := false.B
329    s0_fast_rep      := true.B
330    s0_ld_rep        := src.isLoadReplay
331    s0_l2l_fwd       := false.B
332    s0_prf           := LSUOpType.isPrefetch(src.uop.fuOpType)
333    s0_prf_rd        := src.uop.fuOpType === LSUOpType.prefetch_r
334    s0_prf_wr        := src.uop.fuOpType === LSUOpType.prefetch_w
335    s0_sched_idx     := src.schedIndex
336  }
337
338  def fromNormalReplaySource(src: LsPipelineBundle) = {
339    s0_vaddr         := src.vaddr
340    s0_mask          := genVWmask(src.vaddr, src.uop.fuOpType(1, 0))
341    s0_uop           := src.uop
342    s0_try_l2l       := false.B
343    s0_has_rob_entry := true.B
344    s0_rep_carry     := src.replayCarry
345    s0_mshrid        := src.mshrid
346    s0_isFirstIssue  := false.B
347    s0_fast_rep      := false.B
348    s0_ld_rep        := true.B
349    s0_l2l_fwd       := false.B
350    s0_prf           := LSUOpType.isPrefetch(src.uop.fuOpType)
351    s0_prf_rd        := src.uop.fuOpType === LSUOpType.prefetch_r
352    s0_prf_wr        := src.uop.fuOpType === LSUOpType.prefetch_w
353    s0_sched_idx     := src.schedIndex
354  }
355
356  def fromPrefetchSource(src: L1PrefetchReq) = {
357    s0_vaddr         := src.getVaddr()
358    s0_mask          := 0.U
359    s0_uop           := DontCare
360    s0_try_l2l       := false.B
361    s0_has_rob_entry := false.B
362    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
363    s0_mshrid        := 0.U
364    s0_isFirstIssue  := false.B
365    s0_fast_rep      := false.B
366    s0_ld_rep        := false.B
367    s0_l2l_fwd       := false.B
368    s0_prf           := true.B
369    s0_prf_rd        := !src.is_store
370    s0_prf_wr        := src.is_store
371    s0_sched_idx     := 0.U
372  }
373
374  def fromIntIssueSource(src: MemExuInput) = {
375    s0_vaddr         := src.src(0) + SignExt(src.uop.imm(11, 0), VAddrBits)
376    s0_mask          := genVWmask(s0_vaddr, src.uop.fuOpType(1,0))
377    s0_uop           := src.uop
378    s0_try_l2l       := false.B
379    s0_has_rob_entry := true.B
380    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
381    s0_mshrid        := 0.U
382    s0_isFirstIssue  := true.B
383    s0_fast_rep      := false.B
384    s0_ld_rep        := false.B
385    s0_l2l_fwd       := false.B
386    s0_prf           := LSUOpType.isPrefetch(src.uop.fuOpType)
387    s0_prf_rd        := src.uop.fuOpType === LSUOpType.prefetch_r
388    s0_prf_wr        := src.uop.fuOpType === LSUOpType.prefetch_w
389    s0_sched_idx     := 0.U
390  }
391
392  def fromVecIssueSource(src: VecPipeBundle) = {
393    // For now, vector port handles only vector store flows
394    s0_vaddr         := src.vaddr
395    s0_mask          := src.mask
396    s0_uop           := src.uop
397    s0_try_l2l       := false.B
398    s0_has_rob_entry := true.B
399    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
400    s0_mshrid        := 0.U
401    // s0_isFirstIssue  := src.isFirstIssue
402    s0_fast_rep      := false.B
403    s0_ld_rep        := false.B
404    s0_l2l_fwd       := false.B
405    s0_prf           := false.B
406    s0_prf_rd        := false.B
407    s0_prf_wr        := false.B
408    s0_sched_idx     := 0.U
409
410    s0_isvec         := true.B
411    s0_vecActive           := io.vec_stu_io.in.bits.vecActive
412    // s0_flowPtr       := io.vec_stu_io.in.bits.flowPtr
413    // s0_isLastElem    := io.vec_stu_io.in.bits.isLastElem
414  }
415
416  def fromLoadToLoadSource(src: LoadToLoadIO) = {
417    s0_vaddr              := Cat(src.data(XLEN-1, 6), s0_ptr_chasing_vaddr(5,0))
418    s0_mask               := genVWmask(s0_vaddr, io.ldu_io.ld_fast_fuOpType(1, 0))
419    // When there's no valid instruction from RS and LSQ, we try the load-to-load forwarding.
420    // Assume the pointer chasing is always ld.
421    s0_uop.fuOpType  := io.ldu_io.ld_fast_fuOpType
422    s0_try_l2l            := true.B
423    // we dont care s0_isFirstIssue and s0_rsIdx and s0_sqIdx in S0 when trying pointchasing
424    // because these signals will be updated in S1
425    s0_has_rob_entry      := false.B
426    s0_mshrid             := 0.U
427    s0_rep_carry          := 0.U.asTypeOf(s0_rep_carry.cloneType)
428    s0_isFirstIssue       := true.B
429    s0_fast_rep           := false.B
430    s0_ld_rep             := false.B
431    s0_l2l_fwd            := true.B
432    s0_prf                := false.B
433    s0_prf_rd             := false.B
434    s0_prf_wr             := false.B
435    s0_sched_idx          := 0.U
436  }
437
438  // set default
439  s0_uop := DontCare
440  when (s0_src_select_vec(super_rep_idx)) { fromNormalReplaySource(io.ldu_io.replay.bits)     }
441  .elsewhen (s0_src_select_vec(fast_rep_idx)) { fromFastReplaySource(io.ldu_io.fast_rep_in.bits)  }
442  .elsewhen (s0_src_select_vec(lsq_rep_idx)) { fromNormalReplaySource(io.ldu_io.replay.bits)     }
443  .elsewhen (s0_hw_prf_select) { fromPrefetchSource(io.ldu_io.prefetch_req.bits)   }
444  .elsewhen (s0_src_select_vec(int_iss_idx)) { fromIntIssueSource(io.lsin.bits)                  }
445  .elsewhen (s0_src_select_vec(vec_iss_idx)) { fromVecIssueSource(io.vec_stu_io.in.bits)         }
446  .otherwise {
447    if (EnableLoadToLoadForward) {
448      fromLoadToLoadSource(io.ldu_io.l2l_fwd_in)
449    } else {
450      fromNullSource()
451    }
452  }
453
454  // address align check
455  val s0_addr_aligned = LookupTree(Mux(s0_isvec, io.vec_stu_io.in.bits.alignedType(1,0), s0_uop.fuOpType(1, 0)), List(
456    "b00".U   -> true.B,                   //b
457    "b01".U   -> (s0_vaddr(0)    === 0.U), //h
458    "b10".U   -> (s0_vaddr(1, 0) === 0.U), //w
459    "b11".U   -> (s0_vaddr(2, 0) === 0.U)  //d
460  ))// may broken if use it in feature
461
462  // accept load flow if dcache ready (tlb is always ready)
463  // TODO: prefetch need writeback to loadQueueFlag
464  s0_out               := DontCare
465  s0_out.vaddr         := s0_vaddr
466  s0_out.mask          := s0_mask
467  s0_out.uop           := s0_uop
468  s0_out.isFirstIssue  := s0_isFirstIssue
469  s0_out.hasROBEntry   := s0_has_rob_entry
470  s0_out.isPrefetch    := s0_prf
471  s0_out.isHWPrefetch  := s0_hw_prf
472  s0_out.isFastReplay  := s0_fast_rep
473  s0_out.isLoadReplay  := s0_ld_rep
474  s0_out.isFastPath    := s0_l2l_fwd
475  s0_out.mshrid        := s0_mshrid
476  s0_out.isvec         := s0_isvec
477  s0_out.isLastElem    := s0_isLastElem
478  s0_out.vecActive           := s0_vecActive
479  // s0_out.sflowPtr      := s0_flowPtr
480  s0_out.uop.exceptionVec(loadAddrMisaligned)  := !s0_addr_aligned && s0_ld_flow
481  s0_out.uop.exceptionVec(storeAddrMisaligned) := !s0_addr_aligned && !s0_ld_flow
482  s0_out.forward_tlDchannel := s0_src_select_vec(super_rep_idx)
483  when(io.tlb.req.valid && s0_isFirstIssue) {
484    s0_out.uop.debugInfo.tlbFirstReqTime := GTimer()
485  }.otherwise{
486    s0_out.uop.debugInfo.tlbFirstReqTime := s0_uop.debugInfo.tlbFirstReqTime
487  }
488  s0_out.schedIndex     := s0_sched_idx
489
490  // load fast replay
491  io.ldu_io.fast_rep_in.ready := (s0_can_go && io.ldu_io.dcache.req.ready && s0_src_ready_vec(fast_rep_idx))
492
493  // load flow source ready
494  // cache missed load has highest priority
495  // always accept cache missed load flow from load replay queue
496  io.ldu_io.replay.ready := (s0_can_go && io.ldu_io.dcache.req.ready && (s0_src_ready_vec(lsq_rep_idx) && !s0_rep_stall || s0_src_select_vec(super_rep_idx)))
497
498  // accept load flow from rs when:
499  // 1) there is no lsq-replayed load
500  // 2) there is no fast replayed load
501  // 3) there is no high confidence prefetch request
502  io.lsin.ready := (s0_can_go &&
503                    Mux(FuType.isLoad(io.lsin.bits.uop.fuType), io.ldu_io.dcache.req.ready,
504                    (if (StorePrefetchL1Enabled) io.stu_io.dcache.req.ready else true.B)) && s0_src_ready_vec(int_iss_idx))
505  io.vec_stu_io.in.ready := s0_can_go && io.ldu_io.dcache.req.ready && s0_src_ready_vec(vec_iss_idx)
506
507
508  // for hw prefetch load flow feedback, to be added later
509  // io.prefetch_in.ready := s0_hw_prf_select
510
511  // dcache replacement extra info
512  // TODO: should prefetch load update replacement?
513  io.ldu_io.dcache.replacementUpdated := Mux(s0_src_select_vec(lsq_rep_idx) || s0_src_select_vec(super_rep_idx), io.ldu_io.replay.bits.replacementUpdated, false.B)
514
515  io.stu_io.prefetch_req.ready := s1_ready && io.stu_io.dcache.req.ready && !io.lsin.valid
516
517  // load debug
518  XSDebug(io.ldu_io.dcache.req.fire && s0_ld_flow,
519    p"[DCACHE LOAD REQ] pc ${Hexadecimal(s0_uop.pc)}, vaddr ${Hexadecimal(s0_vaddr)}\n"
520  )
521  XSDebug(s0_valid && s0_ld_flow,
522    p"S0: pc ${Hexadecimal(s0_out.uop.pc)}, lqIdx ${Hexadecimal(s0_out.uop.lqIdx.asUInt)}, " +
523    p"vaddr ${Hexadecimal(s0_out.vaddr)}, mask ${Hexadecimal(s0_out.mask)}\n")
524
525  // store debug
526  XSDebug(io.stu_io.dcache.req.fire && !s0_ld_flow,
527    p"[DCACHE STORE REQ] pc ${Hexadecimal(s0_uop.pc)}, vaddr ${Hexadecimal(s0_vaddr)}\n"
528  )
529  XSDebug(s0_valid && !s0_ld_flow,
530    p"S0: pc ${Hexadecimal(s0_out.uop.pc)}, sqIdx ${Hexadecimal(s0_out.uop.sqIdx.asUInt)}, " +
531    p"vaddr ${Hexadecimal(s0_out.vaddr)}, mask ${Hexadecimal(s0_out.mask)}\n")
532
533
534  // Pipeline
535  // --------------------------------------------------------------------------------
536  // stage 1
537  // --------------------------------------------------------------------------------
538  // TLB resp (send paddr to dcache)
539  val s1_valid      = RegInit(false.B)
540  val s1_in         = Wire(new LqWriteBundle)
541  val s1_out        = Wire(new LqWriteBundle)
542  val s1_kill       = Wire(Bool())
543  val s1_can_go     = s2_ready
544  val s1_fire       = s1_valid && !s1_kill && s1_can_go
545  val s1_ld_flow    = RegNext(s0_ld_flow)
546  val s1_isvec      = RegEnable(s0_out.isvec, false.B, s0_fire)
547  val s1_isLastElem = RegEnable(s0_out.isLastElem, false.B, s0_fire)
548
549  s1_ready := !s1_valid || s1_kill || s2_ready
550  when (s0_fire) { s1_valid := true.B }
551  .elsewhen (s1_fire) { s1_valid := false.B }
552  .elsewhen (s1_kill) { s1_valid := false.B }
553  s1_in   := RegEnable(s0_out, s0_fire)
554
555  val s1_fast_rep_dly_err = RegNext(io.ldu_io.fast_rep_in.bits.delayedLoadError)
556  val s1_fast_rep_kill    = s1_fast_rep_dly_err && s1_in.isFastReplay
557  val s1_l2l_fwd_dly_err  = RegNext(io.ldu_io.l2l_fwd_in.dly_ld_err)
558  val s1_l2l_fwd_kill     = s1_l2l_fwd_dly_err && s1_in.isFastPath
559  val s1_late_kill        = s1_fast_rep_kill || s1_l2l_fwd_kill
560  val s1_vaddr_hi         = Wire(UInt())
561  val s1_vaddr_lo         = Wire(UInt())
562  val s1_vaddr            = Wire(UInt())
563  val s1_paddr_dup_lsu    = Wire(UInt())
564  val s1_paddr_dup_dcache = Wire(UInt())
565  val s1_ld_exception     = ExceptionNO.selectByFu(s1_out.uop.exceptionVec, LduCfg).asUInt.orR   // af & pf exception were modified below.
566  val s1_st_exception     = ExceptionNO.selectByFu(s1_out.uop.exceptionVec, StaCfg).asUInt.orR   // af & pf exception were modified below.
567  val s1_exception        = (s1_ld_flow && s1_ld_exception) || (!s1_ld_flow && s1_st_exception)
568  val s1_tlb_miss         = io.tlb.resp.bits.miss
569  val s1_prf              = s1_in.isPrefetch
570  val s1_hw_prf           = s1_in.isHWPrefetch
571  val s1_sw_prf           = s1_prf && !s1_hw_prf
572  val s1_tlb_memidx       = io.tlb.resp.bits.memidx
573
574  // mmio cbo decoder
575  val s1_mmio_cbo  = (s1_in.uop.fuOpType === LSUOpType.cbo_clean ||
576                      s1_in.uop.fuOpType === LSUOpType.cbo_flush ||
577                      s1_in.uop.fuOpType === LSUOpType.cbo_inval) && !s1_ld_flow && !s1_prf
578  val s1_mmio = s1_mmio_cbo
579
580  s1_vaddr_hi         := s1_in.vaddr(VAddrBits - 1, 6)
581  s1_vaddr_lo         := s1_in.vaddr(5, 0)
582  s1_vaddr            := Cat(s1_vaddr_hi, s1_vaddr_lo)
583  s1_paddr_dup_lsu    := io.tlb.resp.bits.paddr(0)
584  s1_paddr_dup_dcache := io.tlb.resp.bits.paddr(1)
585
586  when (s1_tlb_memidx.is_ld && io.tlb.resp.valid && !s1_tlb_miss &&
587        s1_tlb_memidx.idx === s1_in.uop.lqIdx.value && s1_ld_flow) {
588    // printf("Load idx = %d\n", s1_tlb_memidx.idx)
589    s1_out.uop.debugInfo.tlbRespTime := GTimer()
590  } .elsewhen(s1_tlb_memidx.is_st && io.tlb.resp.valid && !s1_tlb_miss &&
591              s1_tlb_memidx.idx === s1_out.uop.sqIdx.value && !s1_ld_flow) {
592    // printf("Store idx = %d\n", s1_tlb_memidx.idx)
593    s1_out.uop.debugInfo.tlbRespTime := GTimer()
594  }
595
596  io.tlb.req_kill   := s1_kill
597  io.tlb.resp.ready := true.B
598
599  io.ldu_io.dcache.s1_paddr_dup_lsu    <> s1_paddr_dup_lsu
600  io.ldu_io.dcache.s1_paddr_dup_dcache <> s1_paddr_dup_dcache
601  io.ldu_io.dcache.s1_kill             := s1_kill || s1_tlb_miss || s1_exception
602  io.ldu_io.dcache.s1_kill_data_read   := s1_kill || s1_tlb_miss
603
604  // store to load forwarding
605  io.ldu_io.sbuffer.valid := s1_valid && !(s1_exception || s1_tlb_miss || s1_kill || s1_fast_rep_kill || s1_prf || !s1_ld_flow)
606  io.ldu_io.sbuffer.vaddr := s1_vaddr
607  io.ldu_io.sbuffer.paddr := s1_paddr_dup_lsu
608  io.ldu_io.sbuffer.uop   := s1_in.uop
609  io.ldu_io.sbuffer.sqIdx := s1_in.uop.sqIdx
610  io.ldu_io.sbuffer.mask  := s1_in.mask
611  io.ldu_io.sbuffer.pc    := s1_in.uop.pc // FIXME: remove it
612
613  io.ldu_io.ubuffer.valid := s1_valid && !(s1_exception || s1_tlb_miss || s1_kill || s1_fast_rep_kill || s1_prf || !s1_ld_flow)
614  io.ldu_io.ubuffer.vaddr := s1_vaddr
615  io.ldu_io.ubuffer.paddr := s1_paddr_dup_lsu
616  io.ldu_io.ubuffer.uop   := s1_in.uop
617  io.ldu_io.ubuffer.sqIdx := s1_in.uop.sqIdx
618  io.ldu_io.ubuffer.mask  := s1_in.mask
619  io.ldu_io.ubuffer.pc    := s1_in.uop.pc // FIXME: remove it
620
621  io.ldu_io.vec_forward.valid := s1_valid && !(s1_exception || s1_tlb_miss || s1_kill || s1_fast_rep_kill || s1_prf || !s1_ld_flow)
622  io.ldu_io.vec_forward.vaddr := s1_vaddr
623  io.ldu_io.vec_forward.paddr := s1_paddr_dup_lsu
624  io.ldu_io.vec_forward.uop   := s1_in.uop
625  io.ldu_io.vec_forward.sqIdx := s1_in.uop.sqIdx
626  io.ldu_io.vec_forward.mask  := s1_in.mask
627  io.ldu_io.vec_forward.pc    := s1_in.uop.pc // FIXME: remove it
628
629  io.ldu_io.lsq.forward.valid     := s1_valid && !(s1_exception || s1_tlb_miss || s1_kill || s1_fast_rep_kill || s1_prf || !s1_ld_flow)
630  io.ldu_io.lsq.forward.vaddr     := s1_vaddr
631  io.ldu_io.lsq.forward.paddr     := s1_paddr_dup_lsu
632  io.ldu_io.lsq.forward.uop       := s1_in.uop
633  io.ldu_io.lsq.forward.sqIdx     := s1_in.uop.sqIdx
634  io.ldu_io.lsq.forward.sqIdxMask := 0.U
635  io.ldu_io.lsq.forward.mask      := s1_in.mask
636  io.ldu_io.lsq.forward.pc        := s1_in.uop.pc // FIXME: remove it
637
638  // st-ld violation query
639  val s1_nuke = VecInit((0 until StorePipelineWidth).map(w => {
640                       io.ldu_io.stld_nuke_query(w).valid && // query valid
641                       isAfter(s1_in.uop.robIdx, io.ldu_io.stld_nuke_query(w).bits.robIdx) && // older store
642                       // TODO: Fix me when vector instruction
643                       (s1_paddr_dup_lsu(PAddrBits-1, 3) === io.ldu_io.stld_nuke_query(w).bits.paddr(PAddrBits-1, 3)) && // paddr match
644                       (s1_in.mask & io.ldu_io.stld_nuke_query(w).bits.mask).orR // data mask contain
645                      })).asUInt.orR && !s1_tlb_miss && s1_ld_flow
646
647  s1_out                   := s1_in
648  s1_out.vaddr             := s1_vaddr
649  s1_out.paddr             := s1_paddr_dup_lsu
650  s1_out.tlbMiss           := s1_tlb_miss
651  s1_out.ptwBack           := io.tlb.resp.bits.ptwBack
652  s1_out.rep_info.debug    := s1_in.uop.debugInfo
653  s1_out.rep_info.nuke     := s1_nuke && !s1_sw_prf
654  s1_out.lateKill          := s1_late_kill
655
656  // store trigger
657  val storeTrigger = Module(new MemTrigger(MemType.STORE))
658  storeTrigger.io.fromCsrTrigger.tdataVec             := io.fromCsrTrigger.tdataVec
659  storeTrigger.io.fromCsrTrigger.tEnableVec           := io.fromCsrTrigger.tEnableVec
660  storeTrigger.io.fromCsrTrigger.triggerCanRaiseBpExp := io.fromCsrTrigger.triggerCanRaiseBpExp
661  storeTrigger.io.fromCsrTrigger.debugMode            := io.fromCsrTrigger.debugMode
662  storeTrigger.io.fromLoadStore.vaddr                 := s1_vaddr
663  storeTrigger.io.fromLoadStore.isVectorUnitStride    := s1_in.isvec && s1_in.is128bit
664  storeTrigger.io.fromLoadStore.mask                  := s1_in.mask
665
666  when (s1_ld_flow) {
667    when (!s1_late_kill) {
668      // current ori test will cause the case of ldest == 0, below will be modifeid in the future.
669      // af & pf exception were modified
670      s1_out.uop.exceptionVec(loadPageFault)       := io.tlb.resp.bits.excp(0).pf.ld
671      s1_out.uop.exceptionVec(loadGuestPageFault)  := io.tlb.resp.bits.excp(0).gpf.ld
672      s1_out.uop.exceptionVec(loadAccessFault)     := io.tlb.resp.bits.excp(0).af.ld
673    } .otherwise {
674      s1_out.uop.exceptionVec(loadAddrMisaligned)  := false.B
675      s1_out.uop.exceptionVec(loadAccessFault)     := s1_late_kill
676    }
677  } .otherwise {
678    s1_out.uop.exceptionVec(storePageFault)        := io.tlb.resp.bits.excp(0).pf.st
679    s1_out.uop.exceptionVec(storeGuestPageFault)   := io.tlb.resp.bits.excp(0).gpf.st
680    s1_out.uop.exceptionVec(storeAccessFault)      := io.tlb.resp.bits.excp(0).af.st
681    s1_out.uop.trigger                             := storeTrigger.io.toLoadStore.triggerAction
682    s1_out.uop.exceptionVec(breakPoint)            := TriggerAction.isExp(storeTrigger.io.toLoadStore.triggerAction)
683  }
684
685  // load trigger
686  val loadTrigger = Module(new MemTrigger(MemType.LOAD))
687  loadTrigger.io.fromCsrTrigger.tdataVec             := io.fromCsrTrigger.tdataVec
688  loadTrigger.io.fromCsrTrigger.tEnableVec           := io.fromCsrTrigger.tEnableVec
689  loadTrigger.io.fromCsrTrigger.triggerCanRaiseBpExp := io.fromCsrTrigger.triggerCanRaiseBpExp
690  loadTrigger.io.fromCsrTrigger.debugMode            := io.fromCsrTrigger.debugMode
691  loadTrigger.io.fromLoadStore.vaddr                 := s1_vaddr
692  loadTrigger.io.fromLoadStore.isVectorUnitStride    := s1_in.isvec && s1_in.is128bit
693  loadTrigger.io.fromLoadStore.mask                  := s1_in.mask
694
695  when (s1_ld_flow) {
696    s1_out.uop.exceptionVec(breakPoint) := TriggerAction.isExp(loadTrigger.io.toLoadStore.triggerAction)
697    s1_out.uop.trigger := loadTrigger.io.toLoadStore.triggerAction
698  }
699
700  // pointer chasing
701  val s1_try_ptr_chasing       = RegNext(s0_do_try_ptr_chasing, false.B)
702  val s1_ptr_chasing_vaddr     = RegEnable(s0_ptr_chasing_vaddr, s0_do_try_ptr_chasing)
703  val s1_fu_op_type_not_ld     = WireInit(false.B)
704  val s1_not_fast_match        = WireInit(false.B)
705  val s1_addr_mismatch         = WireInit(false.B)
706  val s1_addr_misaligned       = WireInit(false.B)
707  val s1_ptr_chasing_canceled  = WireInit(false.B)
708  val s1_cancel_ptr_chasing    = WireInit(false.B)
709
710  s1_kill := s1_late_kill ||
711             s1_cancel_ptr_chasing ||
712             s1_in.uop.robIdx.needFlush(io.redirect) ||
713             RegEnable(s0_kill, false.B, io.lsin.valid || io.ldu_io.replay.valid || io.ldu_io.l2l_fwd_in.valid || io.ldu_io.fast_rep_in.valid || io.vec_stu_io.in.valid)
714
715  if (EnableLoadToLoadForward) {
716    // Sometimes, we need to cancel the load-load forwarding.
717    // These can be put at S0 if timing is bad at S1.
718    // Case 0: CACHE_SET(base + offset) != CACHE_SET(base) (lowest 6-bit addition has an overflow)
719    s1_addr_mismatch      := s1_ptr_chasing_vaddr(6) || RegEnable(io.ldu_io.ld_fast_imm(11, 6).orR, s0_do_try_ptr_chasing)
720    // Case 1: the address is misaligned, kill s1
721    s1_addr_misaligned    := LookupTree(s1_in.uop.fuOpType(1, 0), List(
722                             "b00".U   -> false.B,                  //b
723                             "b01".U   -> (s1_vaddr(0)    =/= 0.U), //h
724                             "b10".U   -> (s1_vaddr(1, 0) =/= 0.U), //w
725                             "b11".U   -> (s1_vaddr(2, 0) =/= 0.U)  //d
726                          ))
727    // Case 2: this load-load uop is cancelled
728    s1_ptr_chasing_canceled := !io.lsin.valid || FuType.isStore(io.lsin.bits.uop.fuType)
729
730    when (s1_try_ptr_chasing) {
731      s1_cancel_ptr_chasing := s1_addr_mismatch || s1_addr_misaligned || s1_ptr_chasing_canceled
732
733      s1_in.uop           := io.lsin.bits.uop
734      s1_in.isFirstIssue  := io.lsin.bits.isFirstIssue
735      s1_vaddr_lo         := s1_ptr_chasing_vaddr(5, 0)
736      s1_paddr_dup_lsu    := Cat(io.tlb.resp.bits.paddr(0)(PAddrBits - 1, 6), s1_vaddr_lo)
737      s1_paddr_dup_dcache := Cat(io.tlb.resp.bits.paddr(0)(PAddrBits - 1, 6), s1_vaddr_lo)
738
739      // recored tlb time when get the data to ensure the correctness of the latency calculation (although it should not record in here, because it does not use tlb)
740      s1_in.uop.debugInfo.tlbFirstReqTime := GTimer()
741      s1_in.uop.debugInfo.tlbRespTime     := GTimer()
742    }
743    when (!s1_cancel_ptr_chasing) {
744      s0_ptr_chasing_canceled := s1_try_ptr_chasing && !io.ldu_io.replay.fire && !io.ldu_io.fast_rep_in.fire && !(s0_src_valid_vec(high_pf_idx) && io.canAcceptHighConfPrefetch)
745      when (s1_try_ptr_chasing) {
746        io.lsin.ready := true.B
747      }
748    }
749  }
750
751  // pre-calcuate sqIdx mask in s0, then send it to lsq in s1 for forwarding
752  val s1_sqIdx_mask = RegNext(UIntToMask(s0_out.uop.sqIdx.value, StoreQueueSize))
753  // to enable load-load, sqIdxMask must be calculated based on lsin.uop
754  // If the timing here is not OK, load-load forwarding has to be disabled.
755  // Or we calculate sqIdxMask at RS??
756  io.ldu_io.lsq.forward.sqIdxMask := s1_sqIdx_mask
757  if (EnableLoadToLoadForward) {
758    when (s1_try_ptr_chasing) {
759      io.ldu_io.lsq.forward.sqIdxMask := UIntToMask(io.lsin.bits.uop.sqIdx.value, StoreQueueSize)
760    }
761  }
762
763  io.ldu_io.forward_mshr.valid  := s1_valid && s1_out.forward_tlDchannel && s1_ld_flow
764  io.ldu_io.forward_mshr.mshrid := s1_out.mshrid
765  io.ldu_io.forward_mshr.paddr  := s1_out.paddr
766
767  io.ldu_io.wakeup.valid := s0_fire && s0_ld_flow && (s0_src_select_vec(super_rep_idx) || s0_src_select_vec(fast_rep_idx) || s0_src_select_vec(lsq_rep_idx) || s0_src_select_vec(int_iss_idx))
768  io.ldu_io.wakeup.bits := s0_uop
769
770  io.stu_io.dcache.s1_kill := s1_tlb_miss || s1_exception || s1_mmio || s1_in.uop.robIdx.needFlush(io.redirect)
771  io.stu_io.dcache.s1_paddr := s1_paddr_dup_dcache
772
773
774  // load debug
775  XSDebug(s1_valid && s1_ld_flow,
776    p"S1: pc ${Hexadecimal(s1_out.uop.pc)}, lId ${Hexadecimal(s1_out.uop.lqIdx.asUInt)}, tlb_miss ${io.tlb.resp.bits.miss}, " +
777    p"paddr ${Hexadecimal(s1_out.paddr)}, mmio ${s1_out.mmio}\n")
778
779  // store debug
780  XSDebug(s1_valid && !s1_ld_flow,
781    p"S1: pc ${Hexadecimal(s1_out.uop.pc)}, lId ${Hexadecimal(s1_out.uop.sqIdx.asUInt)}, tlb_miss ${io.tlb.resp.bits.miss}, " +
782    p"paddr ${Hexadecimal(s1_out.paddr)}, mmio ${s1_out.mmio}\n")
783
784  // store out
785  io.stu_io.lsq.valid         := s1_valid && !s1_ld_flow && !s1_prf && !s1_isvec
786  io.stu_io.lsq.bits          := s1_out
787  io.stu_io.lsq.bits.miss     := s1_tlb_miss
788
789  io.vec_stu_io.lsq.valid     := s1_valid && !s1_ld_flow && !s1_prf && s1_isvec
790  io.vec_stu_io.lsq.bits          := s1_out
791  io.vec_stu_io.lsq.bits.miss     := s1_tlb_miss
792  io.vec_stu_io.lsq.bits.isLastElem := s1_isLastElem
793
794  io.stu_io.st_mask_out.valid       := s1_valid && !s1_ld_flow && !s1_prf
795  io.stu_io.st_mask_out.bits.mask   := s1_out.mask
796  io.stu_io.st_mask_out.bits.sqIdx  := s1_out.uop.sqIdx
797
798  io.stu_io.issue.valid       := s1_valid && !s1_tlb_miss && !s1_ld_flow && !s1_prf && !s1_isvec
799  io.stu_io.issue.bits        := RegEnable(io.lsin.bits, io.lsin.fire)
800
801  // st-ld violation dectect request
802  io.stu_io.stld_nuke_query.valid       := s1_valid && !s1_tlb_miss && !s1_ld_flow && !s1_prf
803  io.stu_io.stld_nuke_query.bits.robIdx := s1_in.uop.robIdx
804  io.stu_io.stld_nuke_query.bits.paddr  := s1_paddr_dup_lsu
805  io.stu_io.stld_nuke_query.bits.mask   := s1_in.mask
806
807  // Pipeline
808  // --------------------------------------------------------------------------------
809  // stage 2
810  // --------------------------------------------------------------------------------
811  // s2: DCache resp
812  val s2_valid  = RegInit(false.B)
813  val s2_in     = Wire(new LqWriteBundle)
814  val s2_out    = Wire(new LqWriteBundle)
815  val s2_kill   = Wire(Bool())
816  val s2_can_go = s3_ready
817  val s2_fire   = s2_valid && !s2_kill && s2_can_go
818  val s2_isvec  = RegEnable(s1_isvec, false.B, s1_fire)
819  val s2_vecActive    = RegEnable(s1_out.vecActive, true.B, s1_fire)
820  val s2_paddr  = RegEnable(s1_paddr_dup_lsu, s1_fire)
821
822  s2_kill := s2_in.uop.robIdx.needFlush(io.redirect)
823  s2_ready := !s2_valid || s2_kill || s3_ready
824  when (s1_fire) { s2_valid := true.B }
825  .elsewhen (s2_fire) { s2_valid := false.B }
826  .elsewhen (s2_kill) { s2_valid := false.B }
827  s2_in := RegEnable(s1_out, s1_fire)
828
829  val s2_pmp = WireInit(io.pmp)
830
831  val s2_prf    = s2_in.isPrefetch
832  val s2_hw_prf = s2_in.isHWPrefetch
833  val s2_ld_flow  = RegEnable(s1_ld_flow, s1_fire)
834
835  // exception that may cause load addr to be invalid / illegal
836  // if such exception happen, that inst and its exception info
837  // will be force writebacked to rob
838  val s2_exception_vec = WireInit(s2_in.uop.exceptionVec)
839  when (s2_ld_flow) {
840    when (!s2_in.lateKill) {
841      s2_exception_vec(loadAccessFault) := s2_vecActive && (
842        s2_in.uop.exceptionVec(loadAccessFault) || s2_pmp.ld ||
843          s2_fwd_frm_d_chan && s2_d_corrupt ||
844          s2_fwd_frm_mshr && s2_mshr_corrupt
845      )
846      // soft prefetch will not trigger any exception (but ecc error interrupt may be triggered)
847      when (s2_prf || s2_in.tlbMiss) {
848        s2_exception_vec := 0.U.asTypeOf(s2_exception_vec.cloneType)
849      }
850    }
851  } .otherwise {
852    s2_exception_vec(storeAccessFault) := s2_in.uop.exceptionVec(storeAccessFault) || s2_pmp.st
853    when (s2_prf || s2_in.tlbMiss) {
854      s2_exception_vec := 0.U.asTypeOf(s2_exception_vec.cloneType)
855    }
856  }
857  val s2_ld_exception = ExceptionNO.selectByFu(s2_exception_vec, LduCfg).asUInt.orR && s2_ld_flow
858  val s2_st_exception = ExceptionNO.selectByFu(s2_exception_vec, StaCfg).asUInt.orR && !s2_ld_flow
859  val s2_exception    = s2_ld_exception || s2_st_exception
860
861  val (s2_fwd_frm_d_chan, s2_fwd_data_frm_d_chan, s2_d_corrupt) = io.ldu_io.tl_d_channel.forward(s1_valid && s1_out.forward_tlDchannel, s1_out.mshrid, s1_out.paddr)
862  val (s2_fwd_data_valid, s2_fwd_frm_mshr, s2_fwd_data_frm_mshr, s2_mshr_corrupt) = io.ldu_io.forward_mshr.forward()
863  val s2_fwd_frm_d_chan_or_mshr = s2_fwd_data_valid && (s2_fwd_frm_d_chan || s2_fwd_frm_mshr)
864
865  // writeback access fault caused by ecc error / bus error
866  // * ecc data error is slow to generate, so we will not use it until load stage 3
867  // * in load stage 3, an extra signal io.load_error will be used to
868  val s2_actually_mmio = s2_pmp.mmio
869  val s2_ld_mmio       = !s2_prf &&
870                          s2_actually_mmio &&
871                         !s2_exception &&
872                         !s2_in.tlbMiss &&
873                         s2_ld_flow
874  val s2_st_mmio       = !s2_prf &&
875                          (RegNext(s1_mmio) || s2_pmp.mmio) &&
876                         !s2_exception &&
877                         !s2_in.tlbMiss &&
878                         !s2_ld_flow
879  val s2_st_atomic     = !s2_prf &&
880                          (RegNext(s1_mmio) || s2_pmp.atomic) &&
881                         !s2_exception &&
882                         !s2_in.tlbMiss &&
883                         !s2_ld_flow
884  val s2_full_fwd      = Wire(Bool())
885  val s2_mem_amb       = s2_in.uop.storeSetHit &&
886                         io.ldu_io.lsq.forward.addrInvalid
887
888  val s2_tlb_miss      = s2_in.tlbMiss
889  val s2_fwd_fail      = io.ldu_io.lsq.forward.dataInvalid || io.ldu_io.vec_forward.dataInvalid
890  val s2_dcache_miss   = io.ldu_io.dcache.resp.bits.miss &&
891                         !s2_fwd_frm_d_chan_or_mshr &&
892                         !s2_full_fwd
893
894  val s2_mq_nack       = io.ldu_io.dcache.s2_mq_nack &&
895                         !s2_fwd_frm_d_chan_or_mshr &&
896                         !s2_full_fwd
897
898  val s2_bank_conflict = io.ldu_io.dcache.s2_bank_conflict &&
899                         !s2_fwd_frm_d_chan_or_mshr &&
900                         !s2_full_fwd
901
902  val s2_wpu_pred_fail = io.ldu_io.dcache.s2_wpu_pred_fail &&
903                        !s2_fwd_frm_d_chan_or_mshr &&
904                        !s2_full_fwd
905
906  val s2_rar_nack      = io.ldu_io.lsq.ldld_nuke_query.req.valid &&
907                         !io.ldu_io.lsq.ldld_nuke_query.req.ready
908
909  val s2_raw_nack      = io.ldu_io.lsq.stld_nuke_query.req.valid &&
910                         !io.ldu_io.lsq.stld_nuke_query.req.ready
911
912  // st-ld violation query
913  //  NeedFastRecovery Valid when
914  //  1. Fast recovery query request Valid.
915  //  2. Load instruction is younger than requestors(store instructions).
916  //  3. Physical address match.
917  //  4. Data contains.
918  val s2_nuke = VecInit((0 until StorePipelineWidth).map(w => {
919                        io.ldu_io.stld_nuke_query(w).valid && // query valid
920                        isAfter(s2_in.uop.robIdx, io.ldu_io.stld_nuke_query(w).bits.robIdx) && // older store
921                        // TODO: Fix me when vector instruction
922                        (s2_in.paddr(PAddrBits-1, 3) === io.ldu_io.stld_nuke_query(w).bits.paddr(PAddrBits-1, 3)) && // paddr match
923                        (s2_in.mask & io.ldu_io.stld_nuke_query(w).bits.mask).orR // data mask contain
924                      })).asUInt.orR && s2_ld_flow || s2_in.rep_info.nuke
925
926  val s2_cache_handled   = io.ldu_io.dcache.resp.bits.handled
927  val s2_cache_tag_error = RegNext(io.csrCtrl.cache_error_enable) &&
928                           io.ldu_io.dcache.resp.bits.tag_error
929
930  val s2_troublem        = !s2_exception &&
931                           !s2_ld_mmio &&
932                           !s2_prf &&
933                           !s2_in.lateKill &&
934                           s2_ld_flow
935
936  io.ldu_io.dcache.resp.ready := true.B
937  io.stu_io.dcache.resp.ready := true.B
938  val s2_dcache_should_resp = !(s2_in.tlbMiss || s2_exception || s2_ld_mmio || s2_prf || s2_in.lateKill) && s2_ld_flow
939  assert(!(s2_valid && (s2_dcache_should_resp && !io.ldu_io.dcache.resp.valid)), "DCache response got lost")
940
941  // fast replay require
942  val s2_dcache_fast_rep = (s2_mq_nack || !s2_dcache_miss && (s2_bank_conflict || s2_wpu_pred_fail))
943  val s2_nuke_fast_rep   = !s2_mq_nack &&
944                           !s2_dcache_miss &&
945                           !s2_bank_conflict &&
946                           !s2_wpu_pred_fail &&
947                           !s2_rar_nack &&
948                           !s2_raw_nack &&
949                           s2_nuke
950
951  val s2_fast_rep = !s2_mem_amb &&
952                    !s2_tlb_miss &&
953                    !s2_fwd_fail &&
954                    (s2_dcache_fast_rep || s2_nuke_fast_rep) &&
955                    s2_troublem
956
957  // need allocate new entry
958  val s2_can_query = !s2_mem_amb &&
959                     !s2_tlb_miss  &&
960                     !s2_fwd_fail &&
961                     !s2_dcache_fast_rep &&
962                     s2_troublem
963
964  val s2_data_fwded = s2_dcache_miss && (s2_full_fwd || s2_cache_tag_error)
965
966  // ld-ld violation require
967  io.ldu_io.lsq.ldld_nuke_query.req.valid           := s2_valid && s2_can_query
968  io.ldu_io.lsq.ldld_nuke_query.req.bits.uop        := s2_in.uop
969  io.ldu_io.lsq.ldld_nuke_query.req.bits.mask       := s2_in.mask
970  io.ldu_io.lsq.ldld_nuke_query.req.bits.paddr      := s2_in.paddr
971  io.ldu_io.lsq.ldld_nuke_query.req.bits.data_valid := Mux(s2_full_fwd || s2_fwd_data_valid, true.B, !s2_dcache_miss)
972
973  // st-ld violation require
974  io.ldu_io.lsq.stld_nuke_query.req.valid           := s2_valid && s2_can_query
975  io.ldu_io.lsq.stld_nuke_query.req.bits.uop        := s2_in.uop
976  io.ldu_io.lsq.stld_nuke_query.req.bits.mask       := s2_in.mask
977  io.ldu_io.lsq.stld_nuke_query.req.bits.paddr      := s2_in.paddr
978  io.ldu_io.lsq.stld_nuke_query.req.bits.data_valid := Mux(s2_full_fwd || s2_fwd_data_valid, true.B, !s2_dcache_miss)
979
980  // merge forward result
981  // lsq has higher priority than sbuffer
982  val s2_fwd_mask = Wire(Vec((VLEN/8), Bool()))
983  val s2_fwd_data = Wire(Vec((VLEN/8), UInt(8.W)))
984  s2_full_fwd := ((~s2_fwd_mask.asUInt).asUInt & s2_in.mask) === 0.U && !io.ldu_io.lsq.forward.dataInvalid && !io.ldu_io.vec_forward.dataInvalid
985  // generate XLEN/8 Muxs
986  for (i <- 0 until VLEN / 8) {
987    s2_fwd_mask(i) := io.ldu_io.lsq.forward.forwardMask(i) || io.ldu_io.sbuffer.forwardMask(i) || io.ldu_io.vec_forward.forwardMask(i) || io.ldu_io.ubuffer.forwardMask(i)
988    s2_fwd_data(i) :=
989      Mux(io.ldu_io.lsq.forward.forwardMask(i), io.ldu_io.lsq.forward.forwardData(i),
990      Mux(io.ldu_io.vec_forward.forwardMask(i), io.ldu_io.vec_forward.forwardData(i),
991      Mux(io.ldu_io.ubuffer.forwardMask(i), io.ldu_io.ubuffer.forwardData(i),
992      io.ldu_io.sbuffer.forwardData(i))))
993  }
994
995  XSDebug(s2_fire && s2_ld_flow, "[FWD LOAD RESP] pc %x fwd %x(%b) + %x(%b)\n",
996    s2_in.uop.pc,
997    io.ldu_io.lsq.forward.forwardData.asUInt, io.ldu_io.lsq.forward.forwardMask.asUInt,
998    s2_in.forwardData.asUInt, s2_in.forwardMask.asUInt
999  )
1000
1001  //
1002  s2_out                  := s2_in
1003  s2_out.data             := 0.U // data will be generated in load s3
1004  s2_out.uop.fpWen        := s2_in.uop.fpWen && !s2_exception && s2_ld_flow
1005  s2_out.mmio             := s2_ld_mmio || s2_st_mmio
1006  s2_out.atomic           := s2_st_atomic
1007  s2_out.uop.flushPipe    := false.B
1008  s2_out.uop.exceptionVec := s2_exception_vec
1009  s2_out.forwardMask      := s2_fwd_mask
1010  s2_out.forwardData      := s2_fwd_data
1011  s2_out.handledByMSHR    := s2_cache_handled
1012  s2_out.miss             := s2_dcache_miss && s2_troublem
1013  s2_out.feedbacked       := io.feedback_fast.valid && !io.feedback_fast.bits.hit
1014
1015  // Generate replay signal caused by:
1016  // * st-ld violation check
1017  // * tlb miss
1018  // * dcache replay
1019  // * forward data invalid
1020  // * dcache miss
1021  s2_out.rep_info.mem_amb         := s2_mem_amb && s2_troublem
1022  s2_out.rep_info.tlb_miss        := s2_tlb_miss && s2_troublem
1023  s2_out.rep_info.fwd_fail        := s2_fwd_fail && s2_troublem
1024  s2_out.rep_info.dcache_rep      := s2_mq_nack && s2_troublem
1025  s2_out.rep_info.dcache_miss     := s2_dcache_miss && s2_troublem
1026  s2_out.rep_info.bank_conflict   := s2_bank_conflict && s2_troublem
1027  s2_out.rep_info.wpu_fail        := s2_wpu_pred_fail && s2_troublem
1028  s2_out.rep_info.rar_nack        := s2_rar_nack && s2_troublem
1029  s2_out.rep_info.raw_nack        := s2_raw_nack && s2_troublem
1030  s2_out.rep_info.nuke            := s2_nuke && s2_troublem
1031  s2_out.rep_info.full_fwd        := s2_data_fwded
1032  s2_out.rep_info.data_inv_sq_idx := Mux(io.ldu_io.vec_forward.dataInvalid, s2_out.uop.sqIdx, io.ldu_io.lsq.forward.dataInvalidSqIdx)
1033  s2_out.rep_info.addr_inv_sq_idx := Mux(io.ldu_io.vec_forward.addrInvalid, s2_out.uop.sqIdx, io.ldu_io.lsq.forward.addrInvalidSqIdx)
1034  s2_out.rep_info.rep_carry       := io.ldu_io.dcache.resp.bits.replayCarry
1035  s2_out.rep_info.mshr_id         := io.ldu_io.dcache.resp.bits.mshr_id
1036  s2_out.rep_info.last_beat       := s2_in.paddr(log2Up(refillBytes))
1037  s2_out.rep_info.debug           := s2_in.uop.debugInfo
1038  s2_out.rep_info.tlb_id          := io.ldu_io.tlb_hint.id
1039  s2_out.rep_info.tlb_full        := io.ldu_io.tlb_hint.full
1040
1041  // if forward fail, replay this inst from fetch
1042  val debug_fwd_fail_rep = s2_fwd_fail && !s2_troublem && !s2_in.tlbMiss
1043  // if ld-ld violation is detected, replay from this inst from fetch
1044  val debug_ldld_nuke_rep = false.B // s2_ldld_violation && !s2_ld_mmio && !s2_is_prefetch && !s2_in.tlbMiss
1045  // io.out.bits.uop.replayInst := false.B
1046
1047  // to be removed
1048  val s2_ld_need_fb = !s2_in.isLoadReplay &&      // already feedbacked
1049                      io.ldu_io.lq_rep_full &&           // LoadQueueReplay is full
1050                      s2_out.rep_info.need_rep && // need replay
1051                      !s2_exception &&            // no exception is triggered
1052                      !s2_hw_prf &&               // not hardware prefetch
1053                      !s2_isvec
1054  val s2_st_need_fb = !s2_ld_flow && !s2_hw_prf && !s2_isvec
1055  io.feedback_fast.valid                 := s2_valid && (s2_ld_need_fb || s2_st_need_fb)
1056  io.feedback_fast.bits.hit              := Mux(s2_ld_flow, false.B, !s2_tlb_miss)
1057  io.feedback_fast.bits.flushState       := s2_in.ptwBack
1058  io.feedback_fast.bits.robIdx           := s2_in.uop.robIdx
1059  io.feedback_fast.bits.sourceType       := Mux(s2_ld_flow, RSFeedbackType.lrqFull, RSFeedbackType.tlbMiss)
1060  io.feedback_fast.bits.dataInvalidSqIdx := DontCare
1061
1062  val s2_vec_feedback = Wire(Valid(new VSFQFeedback))
1063  s2_vec_feedback.valid := s2_valid && !s2_ld_flow && !s2_hw_prf && s2_isvec
1064  // s2_vec_feedback.bits.flowPtr := s2_out.sflowPtr
1065  s2_vec_feedback.bits.hit := !s2_tlb_miss
1066  s2_vec_feedback.bits.sourceType := RSFeedbackType.tlbMiss
1067  s2_vec_feedback.bits.paddr := s2_paddr
1068  s2_vec_feedback.bits.mmio := s2_st_mmio
1069  s2_vec_feedback.bits.atomic := s2_st_mmio
1070  s2_vec_feedback.bits.exceptionVec := s2_exception_vec
1071
1072  io.stu_io.lsq_replenish := s2_out
1073  io.stu_io.lsq_replenish.miss := io.ldu_io.dcache.resp.fire && io.ldu_io.dcache.resp.bits.miss
1074
1075  io.ldu_io.ldCancel.ld1Cancel := false.B
1076
1077  // fast wakeup
1078  io.ldu_io.fast_uop.valid := RegNext(
1079    !io.ldu_io.dcache.s1_disable_fast_wakeup &&
1080    s1_valid &&
1081    !s1_kill &&
1082    !io.tlb.resp.bits.miss &&
1083    !io.ldu_io.lsq.forward.dataInvalidFast
1084  ) && (s2_valid && !s2_out.rep_info.need_rep && !s2_ld_mmio && s2_ld_flow) && !s2_isvec
1085  io.ldu_io.fast_uop.bits := RegNext(s1_out.uop)
1086
1087  //
1088  io.ldu_io.s2_ptr_chasing                    := RegEnable(s1_try_ptr_chasing && !s1_cancel_ptr_chasing, false.B, s1_fire)
1089
1090  // prefetch train
1091  io.s0_prefetch_spec := s0_fire
1092  io.s1_prefetch_spec := s1_fire
1093  io.prefetch_train.valid              := s2_valid && !s2_actually_mmio && !s2_in.tlbMiss
1094  io.prefetch_train.bits.fromLsPipelineBundle(s2_in)
1095  io.prefetch_train.bits.miss          := Mux(s2_ld_flow, io.ldu_io.dcache.resp.bits.miss, io.stu_io.dcache.resp.bits.miss) // TODO: use trace with bank conflict?
1096  io.prefetch_train.bits.meta_prefetch := Mux(s2_ld_flow, io.ldu_io.dcache.resp.bits.meta_prefetch, false.B)
1097  io.prefetch_train.bits.meta_access   := Mux(s2_ld_flow, io.ldu_io.dcache.resp.bits.meta_access, false.B)
1098
1099  io.prefetch_train_l1.valid              := s2_valid && !s2_actually_mmio && s2_ld_flow
1100  io.prefetch_train_l1.bits.fromLsPipelineBundle(s2_in)
1101  io.prefetch_train_l1.bits.miss          := io.ldu_io.dcache.resp.bits.miss
1102  io.prefetch_train_l1.bits.meta_prefetch := io.ldu_io.dcache.resp.bits.meta_prefetch
1103  io.prefetch_train_l1.bits.meta_access   := io.ldu_io.dcache.resp.bits.meta_access
1104  if (env.FPGAPlatform){
1105    io.ldu_io.dcache.s0_pc := DontCare
1106    io.ldu_io.dcache.s1_pc := DontCare
1107    io.ldu_io.dcache.s2_pc := DontCare
1108  }else{
1109    io.ldu_io.dcache.s0_pc := s0_out.uop.pc
1110    io.ldu_io.dcache.s1_pc := s1_out.uop.pc
1111    io.ldu_io.dcache.s2_pc := s2_out.uop.pc
1112  }
1113  io.ldu_io.dcache.s2_kill := s2_pmp.ld  || s2_actually_mmio || s2_kill
1114  io.stu_io.dcache.s2_kill := s2_pmp.st || s2_actually_mmio || s2_kill
1115  io.stu_io.dcache.s2_pc := s2_out.uop.pc
1116
1117  val s1_ld_left_fire = s1_valid && !s1_kill && s2_ready && s1_ld_flow
1118  val s2_ld_valid_dup = RegInit(0.U(6.W))
1119  s2_ld_valid_dup := 0x0.U(6.W)
1120  when (s1_ld_left_fire && !s1_out.isHWPrefetch && s1_ld_flow) { s2_ld_valid_dup := 0x3f.U(6.W) }
1121  when (s1_kill || s1_out.isHWPrefetch || !s1_ld_flow) { s2_ld_valid_dup := 0x0.U(6.W) }
1122  assert(RegNext((s2_valid === s2_ld_valid_dup(0)) || RegNext(s1_out.isHWPrefetch) || RegNext(!s1_ld_flow)))
1123
1124  // Pipeline
1125  // --------------------------------------------------------------------------------
1126  // stage 3
1127  // --------------------------------------------------------------------------------
1128  // writeback and update load queue
1129  val s3_valid        = RegNext(s2_valid && !s2_out.isHWPrefetch && !s2_out.uop.robIdx.needFlush(io.redirect))
1130  val s3_in           = RegEnable(s2_out, s2_fire)
1131  val s3_out          = Wire(Valid(new MemExuOutput))
1132  val s3_dcache_rep   = RegEnable(s2_dcache_fast_rep && s2_troublem, false.B, s2_fire)
1133  val s3_ld_valid_dup = RegEnable(s2_ld_valid_dup, s2_fire)
1134  val s3_fast_rep     = Wire(Bool())
1135  val s3_ld_flow      = RegNext(s2_ld_flow)
1136  val s3_troublem     = RegNext(s2_troublem)
1137  val s3_kill         = s3_in.uop.robIdx.needFlush(io.redirect)
1138  val s3_isvec        = RegNext(s2_isvec)
1139  s3_ready := !s3_valid || s3_kill || sx_can_go
1140
1141  // s3 load fast replay
1142  io.ldu_io.fast_rep_out.valid := s3_valid &&
1143                                  s3_fast_rep &&
1144                                  !s3_in.uop.robIdx.needFlush(io.redirect) &&
1145                                  s3_ld_flow &&
1146                                  !s3_isvec
1147  io.ldu_io.fast_rep_out.bits := s3_in
1148
1149  io.ldu_io.lsq.ldin.valid := s3_valid &&
1150                              (!s3_fast_rep || !io.ldu_io.fast_rep_out.ready) &&
1151                              !s3_in.feedbacked &&
1152                              !s3_in.lateKill &&
1153                              s3_ld_flow
1154  io.ldu_io.lsq.ldin.bits := s3_in
1155  io.ldu_io.lsq.ldin.bits.miss := s3_in.miss
1156
1157  /* <------- DANGEROUS: Don't change sequence here ! -------> */
1158  io.ldu_io.lsq.ldin.bits.data_wen_dup := s3_ld_valid_dup.asBools
1159  io.ldu_io.lsq.ldin.bits.replacementUpdated := io.ldu_io.dcache.resp.bits.replacementUpdated
1160  io.ldu_io.lsq.ldin.bits.missDbUpdated := RegNext(s2_fire && s2_in.hasROBEntry && !s2_in.tlbMiss && !s2_in.missDbUpdated)
1161
1162  val s3_dly_ld_err =
1163    if (EnableAccurateLoadError) {
1164      (s3_in.lateKill || io.ldu_io.dcache.resp.bits.error_delayed) && RegNext(io.csrCtrl.cache_error_enable)
1165    } else {
1166      WireInit(false.B)
1167    }
1168  io.ldu_io.s3_dly_ld_err := false.B // s3_dly_ld_err && s3_valid
1169  io.ldu_io.fast_rep_out.bits.delayedLoadError := s3_dly_ld_err
1170  io.ldu_io.lsq.ldin.bits.dcacheRequireReplay  := s3_dcache_rep
1171
1172  val s3_vp_match_fail = RegNext(io.ldu_io.lsq.forward.matchInvalid || io.ldu_io.sbuffer.matchInvalid || io.ldu_io.ubuffer.matchInvalid) && s3_troublem
1173  val s3_ldld_rep_inst =
1174      io.ldu_io.lsq.ldld_nuke_query.resp.valid &&
1175      io.ldu_io.lsq.ldld_nuke_query.resp.bits.rep_frm_fetch &&
1176      RegNext(io.csrCtrl.ldld_vio_check_enable)
1177
1178  val s3_rep_info = WireInit(s3_in.rep_info)
1179  s3_rep_info.dcache_miss   := s3_in.rep_info.dcache_miss && s3_troublem
1180  val s3_rep_frm_fetch = s3_vp_match_fail
1181  val s3_flushPipe = s3_ldld_rep_inst
1182  val s3_sel_rep_cause = PriorityEncoderOH(s3_rep_info.cause.asUInt)
1183  val s3_force_rep     = s3_sel_rep_cause(LoadReplayCauses.C_TM) &&
1184                         !s3_in.uop.exceptionVec(loadAddrMisaligned) &&
1185                         s3_troublem
1186
1187  val s3_ld_exception = ExceptionNO.selectByFu(s3_in.uop.exceptionVec, LduCfg).asUInt.orR && s3_ld_flow
1188  val s3_st_exception = ExceptionNO.selectByFu(s3_in.uop.exceptionVec, StaCfg).asUInt.orR && !s3_ld_flow
1189  val s3_exception    = s3_ld_exception || s3_st_exception
1190  when ((s3_ld_exception || s3_dly_ld_err || s3_rep_frm_fetch) && !s3_force_rep) {
1191    io.ldu_io.lsq.ldin.bits.rep_info.cause := 0.U.asTypeOf(s3_rep_info.cause.cloneType)
1192  } .otherwise {
1193    io.ldu_io.lsq.ldin.bits.rep_info.cause := VecInit(s3_sel_rep_cause.asBools)
1194  }
1195
1196  // Int flow, if hit, will be writebacked at s3
1197  s3_out.valid                := s3_valid &&
1198                                (!s3_ld_flow && !s3_in.feedbacked || !io.ldu_io.lsq.ldin.bits.rep_info.need_rep) && !s3_in.mmio
1199  s3_out.bits.uop             := s3_in.uop
1200  s3_out.bits.uop.exceptionVec(loadAccessFault) := (s3_dly_ld_err  || s3_in.uop.exceptionVec(loadAccessFault)) && s3_ld_flow
1201  s3_out.bits.uop.replayInst := s3_rep_frm_fetch
1202  s3_out.bits.data            := s3_in.data
1203  s3_out.bits.debug.isMMIO    := s3_in.mmio
1204  s3_out.bits.debug.isNC      := s3_in.nc
1205  s3_out.bits.debug.isPerfCnt := false.B
1206  s3_out.bits.debug.paddr     := s3_in.paddr
1207  s3_out.bits.debug.vaddr     := s3_in.vaddr
1208
1209  when (s3_force_rep) {
1210    s3_out.bits.uop.exceptionVec := 0.U.asTypeOf(s3_in.uop.exceptionVec.cloneType)
1211  }
1212
1213  io.ldu_io.rollback.valid := s3_valid && (s3_rep_frm_fetch || s3_flushPipe) && !s3_exception && s3_ld_flow
1214  io.ldu_io.rollback.bits             := DontCare
1215  io.ldu_io.rollback.bits.isRVC       := s3_out.bits.uop.preDecodeInfo.isRVC
1216  io.ldu_io.rollback.bits.robIdx      := s3_out.bits.uop.robIdx
1217  io.ldu_io.rollback.bits.ftqIdx      := s3_out.bits.uop.ftqPtr
1218  io.ldu_io.rollback.bits.ftqOffset   := s3_out.bits.uop.ftqOffset
1219  io.ldu_io.rollback.bits.level       := Mux(s3_rep_frm_fetch, RedirectLevel.flush, RedirectLevel.flushAfter)
1220  io.ldu_io.rollback.bits.cfiUpdate.target := s3_out.bits.uop.pc
1221  io.ldu_io.rollback.bits.debug_runahead_checkpoint_id := s3_out.bits.uop.debugInfo.runahead_checkpoint_id
1222  /* <------- DANGEROUS: Don't change sequence here ! -------> */
1223  io.ldu_io.lsq.ldin.bits.uop := s3_out.bits.uop
1224
1225  val s3_revoke = s3_exception || io.ldu_io.lsq.ldin.bits.rep_info.need_rep
1226  io.ldu_io.lsq.ldld_nuke_query.revoke := s3_revoke
1227  io.ldu_io.lsq.stld_nuke_query.revoke := s3_revoke
1228
1229  // feedback slow
1230  s3_fast_rep := RegNext(s2_fast_rep) &&
1231                 !s3_in.feedbacked &&
1232                 !s3_in.lateKill &&
1233                 !s3_rep_frm_fetch &&
1234                 !s3_exception
1235
1236  val s3_fb_no_waiting = !s3_in.isLoadReplay && !(s3_fast_rep && io.ldu_io.fast_rep_out.ready) && !s3_in.feedbacked
1237
1238  //
1239  io.feedback_slow.valid                 := s3_valid && !s3_in.uop.robIdx.needFlush(io.redirect) && s3_fb_no_waiting && s3_ld_flow
1240  io.feedback_slow.bits.hit              := !io.ldu_io.lsq.ldin.bits.rep_info.need_rep || io.ldu_io.lsq.ldin.ready
1241  io.feedback_slow.bits.flushState       := s3_in.ptwBack
1242  io.feedback_slow.bits.robIdx           := s3_in.uop.robIdx
1243  io.feedback_slow.bits.sourceType       := RSFeedbackType.lrqFull
1244  io.feedback_slow.bits.dataInvalidSqIdx := DontCare
1245
1246  io.vec_stu_io.feedbackSlow.valid := RegNext(s2_vec_feedback.valid && !s2_out.uop.robIdx.needFlush(io.redirect))
1247  io.vec_stu_io.feedbackSlow.bits := RegNext(s2_vec_feedback.bits)
1248
1249  io.ldu_io.ldCancel.ld2Cancel := s3_valid && s3_ld_flow && (                          // is load
1250    io.ldu_io.lsq.ldin.bits.rep_info.need_rep || s3_in.mmio                            // exe fail or is mmio
1251  )
1252
1253  // data from dcache hit
1254  val s3_ld_raw_data_frm_cache = Wire(new LoadDataFromDcacheBundle)
1255  s3_ld_raw_data_frm_cache.respDcacheData       := io.ldu_io.dcache.resp.bits.data
1256  s3_ld_raw_data_frm_cache.forward_D            := s2_fwd_frm_d_chan
1257  s3_ld_raw_data_frm_cache.forwardData_D        := s2_fwd_data_frm_d_chan
1258  s3_ld_raw_data_frm_cache.forward_mshr         := s2_fwd_frm_mshr
1259  s3_ld_raw_data_frm_cache.forwardData_mshr     := s2_fwd_data_frm_mshr
1260  s3_ld_raw_data_frm_cache.forward_result_valid := s2_fwd_data_valid
1261
1262  s3_ld_raw_data_frm_cache.forwardMask          := RegEnable(s2_fwd_mask, s2_valid)
1263  s3_ld_raw_data_frm_cache.forwardData          := RegEnable(s2_fwd_data, s2_valid)
1264  s3_ld_raw_data_frm_cache.uop                  := RegEnable(s2_out.uop, s2_valid)
1265  s3_ld_raw_data_frm_cache.addrOffset           := RegEnable(s2_out.paddr(3, 0), s2_valid)
1266
1267  val s3_merged_data_frm_tlD   = RegEnable(s3_ld_raw_data_frm_cache.mergeTLData(), s2_valid)
1268  val s3_merged_data_frm_cache = s3_ld_raw_data_frm_cache.mergeLsqFwdData(s3_merged_data_frm_tlD)
1269  val s3_picked_data_frm_cache = LookupTree(s3_ld_raw_data_frm_cache.addrOffset, List(
1270    "b0000".U -> s3_merged_data_frm_cache(63,    0),
1271    "b0001".U -> s3_merged_data_frm_cache(63,    8),
1272    "b0010".U -> s3_merged_data_frm_cache(63,   16),
1273    "b0011".U -> s3_merged_data_frm_cache(63,   24),
1274    "b0100".U -> s3_merged_data_frm_cache(63,   32),
1275    "b0101".U -> s3_merged_data_frm_cache(63,   40),
1276    "b0110".U -> s3_merged_data_frm_cache(63,   48),
1277    "b0111".U -> s3_merged_data_frm_cache(63,   56),
1278    "b1000".U -> s3_merged_data_frm_cache(127,  64),
1279    "b1001".U -> s3_merged_data_frm_cache(127,  72),
1280    "b1010".U -> s3_merged_data_frm_cache(127,  80),
1281    "b1011".U -> s3_merged_data_frm_cache(127,  88),
1282    "b1100".U -> s3_merged_data_frm_cache(127,  96),
1283    "b1101".U -> s3_merged_data_frm_cache(127, 104),
1284    "b1110".U -> s3_merged_data_frm_cache(127, 112),
1285    "b1111".U -> s3_merged_data_frm_cache(127, 120)
1286  ))
1287  val s3_ld_data_frm_cache = rdataHelper(s3_ld_raw_data_frm_cache.uop, s3_picked_data_frm_cache)
1288
1289  // FIXME: add 1 cycle delay ?
1290  io.ldout.bits      := s3_out.bits
1291  io.ldout.bits.data := s3_ld_data_frm_cache
1292  io.ldout.valid     := s3_out.valid && !s3_out.bits.uop.robIdx.needFlush(io.redirect) && s3_ld_flow && !s3_isvec
1293
1294  // for uncache
1295  io.ldu_io.lsq.uncache.ready := true.B
1296
1297  // fast load to load forward
1298  if (EnableLoadToLoadForward) {
1299    io.ldu_io.l2l_fwd_out.valid      := s3_out.valid && !s3_in.lateKill && s3_ld_flow
1300    io.ldu_io.l2l_fwd_out.data       := s3_ld_data_frm_cache
1301    io.ldu_io.l2l_fwd_out.dly_ld_err := s3_dly_ld_err // ecc delayed error
1302  } else {
1303    io.ldu_io.l2l_fwd_out.valid      := false.B
1304    io.ldu_io.l2l_fwd_out.data       := DontCare
1305    io.ldu_io.l2l_fwd_out.dly_ld_err := DontCare
1306  }
1307
1308  // hybrid unit writeback to rob
1309  // delay params
1310  val SelectGroupSize   = RollbackGroupSize
1311  val lgSelectGroupSize = log2Ceil(SelectGroupSize)
1312  val TotalSelectCycles = scala.math.ceil(log2Ceil(LoadQueueRAWSize).toFloat / lgSelectGroupSize).toInt + 1
1313  val TotalDelayCycles  = TotalSelectCycles - 2
1314
1315  // writeback
1316  val sx_valid = Wire(Vec(TotalDelayCycles + 1, Bool()))
1317  val sx_ready = Wire(Vec(TotalDelayCycles + 1, Bool()))
1318  val sx_in    = Wire(Vec(TotalDelayCycles + 1, new MemExuOutput))
1319
1320  sx_can_go := sx_ready.head
1321  for (i <- 0 until TotalDelayCycles + 1) {
1322    if (i == 0) {
1323      sx_valid(i) := s3_valid &&
1324                    !s3_ld_flow &&
1325                    !s3_in.feedbacked &&
1326                    !s3_in.mmio
1327      sx_in(i)    := s3_out.bits
1328      sx_ready(i) := !s3_valid(i) || sx_in(i).uop.robIdx.needFlush(io.redirect) || (if (TotalDelayCycles == 0) io.stout.ready else sx_ready(i+1))
1329    } else {
1330      val cur_kill   = sx_in(i).uop.robIdx.needFlush(io.redirect)
1331      val cur_can_go = (if (i == TotalDelayCycles) io.stout.ready else sx_ready(i+1))
1332      val cur_fire   = sx_valid(i) && !cur_kill && cur_can_go
1333      val prev_fire  = sx_valid(i-1) && !sx_in(i-1).uop.robIdx.needFlush(io.redirect) && sx_ready(i)
1334
1335      sx_ready(i) := !sx_valid(i) || cur_kill || (if (i == TotalDelayCycles) io.stout.ready else sx_ready(i+1))
1336      val sx_valid_can_go = prev_fire || cur_fire || cur_kill
1337      sx_valid(i) := RegEnable(Mux(prev_fire, true.B, false.B), sx_valid_can_go)
1338      sx_in(i) := RegEnable(sx_in(i-1), prev_fire)
1339    }
1340  }
1341
1342  val sx_last_valid = sx_valid.takeRight(1).head
1343  val sx_last_ready = sx_ready.takeRight(1).head
1344  val sx_last_in    = sx_in.takeRight(1).head
1345
1346  sx_last_ready  := !sx_last_valid || sx_last_in.uop.robIdx.needFlush(io.redirect) || io.stout.ready
1347  io.stout.valid := sx_last_valid && !sx_last_in.uop.robIdx.needFlush(io.redirect) && FuType.isStore(sx_last_in.uop.fuType)
1348  io.stout.bits  := sx_last_in
1349
1350  // FIXME: please move this part to LoadQueueReplay
1351  io.ldu_io.debug_ls := DontCare
1352  io.stu_io.debug_ls := DontCare
1353  io.stu_io.debug_ls.s1_isTlbFirstMiss := io.tlb.resp.valid && io.tlb.resp.bits.miss && io.tlb.resp.bits.debug.isFirstIssue && !s1_in.isHWPrefetch && !s1_ld_flow
1354  io.stu_io.debug_ls.s1_robIdx := s1_in.uop.robIdx.value
1355
1356 // Topdown
1357  io.ldu_io.lsTopdownInfo.s1.robIdx          := s1_in.uop.robIdx.value
1358  io.ldu_io.lsTopdownInfo.s1.vaddr_valid     := s1_valid && s1_in.hasROBEntry
1359  io.ldu_io.lsTopdownInfo.s1.vaddr_bits      := s1_vaddr
1360  io.ldu_io.lsTopdownInfo.s2.robIdx          := s2_in.uop.robIdx.value
1361  io.ldu_io.lsTopdownInfo.s2.paddr_valid     := s2_fire && s2_in.hasROBEntry && !s2_in.tlbMiss
1362  io.ldu_io.lsTopdownInfo.s2.paddr_bits      := s2_in.paddr
1363  io.ldu_io.lsTopdownInfo.s2.first_real_miss := io.ldu_io.dcache.resp.bits.real_miss
1364  io.ldu_io.lsTopdownInfo.s2.cache_miss_en   := s2_fire && s2_in.hasROBEntry && !s2_in.tlbMiss && !s2_in.missDbUpdated
1365
1366  // perf cnt
1367  XSPerfAccumulate("s0_in_valid",                  io.lsin.valid)
1368  XSPerfAccumulate("s0_in_block",                  io.lsin.valid && !io.lsin.fire)
1369  XSPerfAccumulate("s0_in_fire_first_issue",       s0_valid && s0_isFirstIssue)
1370  XSPerfAccumulate("s0_lsq_fire_first_issue",      io.ldu_io.replay.fire)
1371  XSPerfAccumulate("s0_ldu_fire_first_issue",      io.lsin.fire && s0_isFirstIssue)
1372  XSPerfAccumulate("s0_fast_replay_issue",         io.ldu_io.fast_rep_in.fire)
1373  XSPerfAccumulate("s0_stall_out",                 s0_valid && !s0_can_go)
1374  XSPerfAccumulate("s0_stall_ld_dcache",           s0_valid && !io.ldu_io.dcache.req.ready)
1375  XSPerfAccumulate("s0_stall_st_dcache",           s0_valid && !io.stu_io.dcache.req.ready)
1376  XSPerfAccumulate("s0_addr_spec_success",         s0_fire && s0_vaddr(VAddrBits-1, 12) === io.lsin.bits.src(0)(VAddrBits-1, 12))
1377  XSPerfAccumulate("s0_addr_spec_failed",          s0_fire && s0_vaddr(VAddrBits-1, 12) =/= io.lsin.bits.src(0)(VAddrBits-1, 12))
1378  XSPerfAccumulate("s0_addr_spec_success_once",    s0_fire && s0_vaddr(VAddrBits-1, 12) === io.lsin.bits.src(0)(VAddrBits-1, 12) && s0_isFirstIssue)
1379  XSPerfAccumulate("s0_addr_spec_failed_once",     s0_fire && s0_vaddr(VAddrBits-1, 12) =/= io.lsin.bits.src(0)(VAddrBits-1, 12) && s0_isFirstIssue)
1380  XSPerfAccumulate("s0_forward_tl_d_channel",      s0_out.forward_tlDchannel)
1381  XSPerfAccumulate("s0_hardware_prefetch_fire",    s0_fire && s0_hw_prf_select)
1382  XSPerfAccumulate("s0_software_prefetch_fire",    s0_fire && s0_prf && s0_src_select_vec(int_iss_idx))
1383  XSPerfAccumulate("s0_hardware_prefetch_blocked", io.ldu_io.prefetch_req.valid && !s0_hw_prf_select)
1384  XSPerfAccumulate("s0_hardware_prefetch_total",   io.ldu_io.prefetch_req.valid)
1385
1386  XSPerfAccumulate("s1_in_valid",                  s1_valid)
1387  XSPerfAccumulate("s1_in_fire",                   s1_fire)
1388  XSPerfAccumulate("s1_in_fire_first_issue",       s1_fire && s1_in.isFirstIssue)
1389  XSPerfAccumulate("s1_tlb_miss",                  s1_fire && s1_tlb_miss)
1390  XSPerfAccumulate("s1_tlb_miss_first_issue",      s1_fire && s1_tlb_miss && s1_in.isFirstIssue)
1391  XSPerfAccumulate("s1_stall_out",                 s1_valid && !s1_can_go)
1392  XSPerfAccumulate("s1_late_kill",                 s1_valid && s1_fast_rep_kill)
1393
1394  XSPerfAccumulate("s2_in_valid",                  s2_valid)
1395  XSPerfAccumulate("s2_in_fire",                   s2_fire)
1396  XSPerfAccumulate("s2_in_fire_first_issue",       s2_fire && s2_in.isFirstIssue)
1397  XSPerfAccumulate("s2_dcache_miss",               s2_fire && io.ldu_io.dcache.resp.bits.miss)
1398  XSPerfAccumulate("s2_dcache_miss_first_issue",   s2_fire && io.ldu_io.dcache.resp.bits.miss && s2_in.isFirstIssue)
1399  XSPerfAccumulate("s2_dcache_real_miss_first_issue",   s2_fire && io.ldu_io.dcache.resp.bits.miss && s2_in.isFirstIssue)
1400  XSPerfAccumulate("s2_full_forward",              s2_fire && s2_full_fwd)
1401  XSPerfAccumulate("s2_dcache_miss_full_forward",  s2_fire && s2_dcache_miss)
1402  XSPerfAccumulate("s2_fwd_frm_d_can",             s2_valid && s2_fwd_frm_d_chan)
1403  XSPerfAccumulate("s2_fwd_frm_d_chan_or_mshr",    s2_valid && s2_fwd_frm_d_chan_or_mshr)
1404  XSPerfAccumulate("s2_stall_out",                 s2_fire && !s2_can_go)
1405  XSPerfAccumulate("s2_prefetch",                  s2_fire && s2_prf)
1406  XSPerfAccumulate("s2_prefetch_ignored",          s2_fire && s2_prf && io.ldu_io.dcache.s2_mq_nack) // ignore prefetch for mshr full / miss req port conflict
1407  XSPerfAccumulate("s2_prefetch_miss",             s2_fire && s2_prf && io.ldu_io.dcache.resp.bits.miss) // prefetch req miss in l1
1408  XSPerfAccumulate("s2_prefetch_hit",              s2_fire && s2_prf && !io.ldu_io.dcache.resp.bits.miss) // prefetch req hit in l1
1409  XSPerfAccumulate("s2_prefetch_accept",           s2_fire && s2_prf && io.ldu_io.dcache.resp.bits.miss && !io.ldu_io.dcache.s2_mq_nack) // prefetch a missed line in l1, and l1 accepted it
1410  XSPerfAccumulate("s2_forward_req",               s2_fire && s2_in.forward_tlDchannel)
1411  XSPerfAccumulate("s2_successfully_forward_channel_D", s2_fire && s2_fwd_frm_d_chan && s2_fwd_data_valid)
1412  XSPerfAccumulate("s2_successfully_forward_mshr",      s2_fire && s2_fwd_frm_mshr && s2_fwd_data_valid)
1413
1414  XSPerfAccumulate("load_to_load_forward",                      s1_try_ptr_chasing && !s1_ptr_chasing_canceled)
1415  XSPerfAccumulate("load_to_load_forward_try",                  s1_try_ptr_chasing)
1416  XSPerfAccumulate("load_to_load_forward_fail",                 s1_cancel_ptr_chasing)
1417  XSPerfAccumulate("load_to_load_forward_fail_cancelled",       s1_cancel_ptr_chasing && s1_ptr_chasing_canceled)
1418  XSPerfAccumulate("load_to_load_forward_fail_wakeup_mismatch", s1_cancel_ptr_chasing && !s1_ptr_chasing_canceled && s1_not_fast_match)
1419  XSPerfAccumulate("load_to_load_forward_fail_op_not_ld",       s1_cancel_ptr_chasing && !s1_ptr_chasing_canceled && !s1_not_fast_match && s1_fu_op_type_not_ld)
1420  XSPerfAccumulate("load_to_load_forward_fail_addr_align",      s1_cancel_ptr_chasing && !s1_ptr_chasing_canceled && !s1_not_fast_match && !s1_fu_op_type_not_ld && s1_addr_misaligned)
1421  XSPerfAccumulate("load_to_load_forward_fail_set_mismatch",    s1_cancel_ptr_chasing && !s1_ptr_chasing_canceled && !s1_not_fast_match && !s1_fu_op_type_not_ld && !s1_addr_misaligned && s1_addr_mismatch)
1422
1423  // bug lyq: some signals in perfEvents are no longer suitable for the current MemBlock design
1424  // hardware performance counter
1425  val perfEvents = Seq(
1426    ("load_s0_in_fire         ", s0_fire                                                        ),
1427    ("load_to_load_forward    ", s1_fire && s1_try_ptr_chasing && !s1_ptr_chasing_canceled      ),
1428    ("stall_dcache            ", s0_valid && s0_can_go && !io.ldu_io.dcache.req.ready           ),
1429    ("load_s1_in_fire         ", s0_fire                                                        ),
1430    ("load_s1_tlb_miss        ", s1_fire && io.tlb.resp.bits.miss                               ),
1431    ("load_s2_in_fire         ", s1_fire                                                        ),
1432    ("load_s2_dcache_miss     ", s2_fire && io.ldu_io.dcache.resp.bits.miss                     ),
1433  )
1434  generatePerfEvent()
1435}
1436