xref: /XiangShan/src/main/scala/xiangshan/mem/pipeline/HybridUnit.scala (revision 60bd4d3c479c667a9be115b0e6eb174a7695071f)
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.ExceptionNO._
25import xiangshan._
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.rob.RobPtr
31import xiangshan.backend.fu._
32import xiangshan.cache._
33import xiangshan.cache.wpu.ReplayCarry
34import xiangshan.cache.mmu.{TlbCmd, TlbReq, TlbRequestIO, TlbResp}
35import xiangshan.mem.mdp._
36
37class HybridUnit(implicit p: Parameters) extends XSModule
38  with HasLoadHelper
39  with HasPerfEvents
40  with HasDCacheParameters
41  with HasCircularQueuePtrHelper
42  with HasVLSUParameters
43{
44  val io = IO(new Bundle() {
45    // control
46    val redirect      = Flipped(ValidIO(new Redirect))
47    val csrCtrl       = Flipped(new CustomCSRCtrlIO)
48
49    // flow in
50    val lsin          = Flipped(Decoupled(new MemExuInput))
51
52    // flow out
53    val ldout = DecoupledIO(new MemExuOutput)
54    val stout = DecoupledIO(new MemExuOutput)
55
56    val ldu_io = new Bundle() {
57      // dcache
58      val dcache        = new DCacheLoadIO
59
60      // data path
61      val sbuffer       = new LoadForwardQueryIO
62      val vec_forward   = new LoadForwardQueryIO
63      val lsq           = new LoadToLsqIO
64      val tl_d_channel  = Input(new DcacheToLduForwardIO)
65      val forward_mshr  = Flipped(new LduToMissqueueForwardIO)
66      val refill        = Flipped(ValidIO(new Refill))
67      val l2_hint       = Input(Valid(new L2ToL1Hint))
68
69      // fast wakeup
70      val fast_uop = ValidIO(new DynInst) // early wakeup signal generated in load_s1, send to RS in load_s2
71
72      // trigger
73      val trigger = Vec(3, new LoadUnitTriggerIO)
74
75      // load to load fast path
76      val l2l_fwd_in    = Input(new LoadToLoadIO)
77      val l2l_fwd_out   = Output(new LoadToLoadIO)
78
79      val ld_fast_match    = Input(Bool())
80      val ld_fast_fuOpType = Input(UInt())
81      val ld_fast_imm      = Input(UInt(12.W))
82
83      // hardware prefetch to l1 cache req
84      val prefetch_req    = Flipped(ValidIO(new L1PrefetchReq))
85
86      // iq cancel
87      val ldCancel = Output(new LoadCancelIO()) // use to cancel the uops waked by this load, and cancel load
88
89      // load ecc error
90      val s3_dly_ld_err = Output(Bool()) // Note that io.s3_dly_ld_err and io.lsq.s3_dly_ld_err is different
91
92      // schedule error query
93      val stld_nuke_query = Flipped(Vec(StorePipelineWidth, Valid(new StoreNukeQueryIO)))
94
95      // queue-based replay
96      val replay       = Flipped(Decoupled(new LsPipelineBundle))
97      val lq_rep_full  = Input(Bool())
98
99      // misc
100      val s2_ptr_chasing = Output(Bool()) // provide right pc for hw prefetch
101
102      // Load fast replay path
103      val fast_rep_in  = Flipped(Decoupled(new LqWriteBundle))
104      val fast_rep_out = Decoupled(new LqWriteBundle)
105
106      // perf
107      val debug_ls         = Output(new DebugLsInfoBundle)
108      val lsTopdownInfo    = Output(new LsTopdownInfo)
109    }
110
111    val stu_io = new Bundle() {
112      val dcache          = new DCacheStoreIO
113      val prefetch_req    = Flipped(DecoupledIO(new StorePrefetchReq))
114      val issue           = Valid(new MemExuInput)
115      val lsq             = ValidIO(new LsPipelineBundle)
116      val lsq_replenish   = Output(new LsPipelineBundle())
117      val stld_nuke_query = Valid(new StoreNukeQueryIO)
118      val st_mask_out     = Valid(new StoreMaskBundle)
119      val debug_ls        = Output(new DebugLsInfoBundle)
120    }
121
122    val vec_stu_io = new Bundle() {
123      val in = Flipped(DecoupledIO(new VecStorePipeBundle()))
124      val isFirstIssue = Input(Bool())
125      val lsq = ValidIO(new LsPipelineBundle())
126      val feedbackSlow = ValidIO(new VSFQFeedback)
127    }
128
129    // prefetch
130    val prefetch_train            = ValidIO(new LdPrefetchTrainBundle()) // provide prefetch info to sms
131    val prefetch_train_l1         = ValidIO(new LdPrefetchTrainBundle()) // provide prefetch info to stream & stride
132    val canAcceptLowConfPrefetch  = Output(Bool())
133    val canAcceptHighConfPrefetch = Output(Bool())
134    val correctMissTrain          = Input(Bool())
135
136    // data path
137    val tlb           = new TlbRequestIO(2)
138    val pmp           = Flipped(new PMPRespBundle()) // arrive same to tlb now
139
140    // rs feedback
141    val feedback_fast = ValidIO(new RSFeedback) // stage 2
142    val feedback_slow = ValidIO(new RSFeedback) // stage 3
143  })
144
145  val StorePrefetchL1Enabled = EnableStorePrefetchAtCommit || EnableStorePrefetchAtIssue || EnableStorePrefetchSPB
146  val s1_ready, s2_ready, s3_ready, sx_can_go = WireInit(false.B)
147
148  // Pipeline
149  // --------------------------------------------------------------------------------
150  // stage 0
151  // --------------------------------------------------------------------------------
152  // generate addr, use addr to query DCache and DTLB
153  val s0_valid         = Wire(Bool())
154  val s0_dcache_ready  = Wire(Bool())
155  val s0_kill          = Wire(Bool())
156  val s0_vaddr         = Wire(UInt(VAddrBits.W))
157  val s0_mask          = Wire(UInt((VLEN/8).W))
158  val s0_uop           = Wire(new DynInst)
159  val s0_has_rob_entry = Wire(Bool())
160  val s0_rsIdx         = Wire(UInt(log2Up(MemIQSizeMax).W))
161  val s0_mshrid        = Wire(UInt())
162  val s0_try_l2l       = Wire(Bool())
163  val s0_rep_carry     = Wire(new ReplayCarry(nWays))
164  val s0_isFirstIssue  = Wire(Bool())
165  val s0_fast_rep      = Wire(Bool())
166  val s0_ld_rep        = Wire(Bool())
167  val s0_l2l_fwd       = Wire(Bool())
168  val s0_sched_idx     = Wire(UInt())
169  val s0_deqPortIdx    = Wire(UInt(log2Ceil(LoadPipelineWidth).W))
170  val s0_can_go        = s1_ready
171  val s0_fire          = s0_valid && s0_dcache_ready && s0_can_go
172  val s0_out           = Wire(new LqWriteBundle)
173  // vector
174  val s0_isvec = WireInit(false.B)
175  val s0_exp = WireInit(true.B)
176  val s0_flowPtr = WireInit(0.U.asTypeOf(new VsFlowPtr))
177
178  // load flow select/gen
179  // src0: super load replayed by LSQ (cache miss replay) (io.ldu_io.replay)
180  // src1: fast load replay (io.ldu_io.fast_rep_in)
181  // src2: load replayed by LSQ (io.ldu_io.replay)
182  // src3: hardware prefetch from prefetchor (high confidence) (io.prefetch)
183  // src4: int read / software prefetch first issue from RS (io.in)
184  // src5: vec read first issue from RS (TODO)
185  // src6: load try pointchaising when no issued or replayed load (io.fastpath)
186  // src7: hardware prefetch from prefetchor (high confidence) (io.prefetch)
187  // priority: high to low
188  val s0_ld_flow             = FuType.isLoad(s0_uop.fuType) || FuType.isVLoad(s0_uop.fuType)
189  val s0_rep_stall           = io.lsin.valid && isAfter(io.ldu_io.replay.bits.uop.robIdx, io.lsin.bits.uop.robIdx)
190  val s0_super_ld_rep_valid  = io.ldu_io.replay.valid && io.ldu_io.replay.bits.forward_tlDchannel
191  val s0_ld_fast_rep_valid   = io.ldu_io.fast_rep_in.valid
192  val s0_ld_rep_valid        = io.ldu_io.replay.valid && !io.ldu_io.replay.bits.forward_tlDchannel && !s0_rep_stall
193  val s0_high_conf_prf_valid = io.ldu_io.prefetch_req.valid && io.ldu_io.prefetch_req.bits.confidence > 0.U
194  val s0_int_iss_valid       = io.lsin.valid // int flow first issue or software prefetch
195  val s0_vec_iss_valid       = io.vec_stu_io.in.valid
196  val s0_l2l_fwd_valid       = io.ldu_io.l2l_fwd_in.valid && io.ldu_io.ld_fast_match
197  val s0_low_conf_prf_valid  = io.ldu_io.prefetch_req.valid && io.ldu_io.prefetch_req.bits.confidence === 0.U
198  dontTouch(s0_super_ld_rep_valid)
199  dontTouch(s0_ld_fast_rep_valid)
200  dontTouch(s0_ld_rep_valid)
201  dontTouch(s0_high_conf_prf_valid)
202  dontTouch(s0_int_iss_valid)
203  dontTouch(s0_vec_iss_valid)
204  dontTouch(s0_l2l_fwd_valid)
205  dontTouch(s0_low_conf_prf_valid)
206
207  // load flow source ready
208  val s0_super_ld_rep_ready  = WireInit(true.B)
209  val s0_ld_fast_rep_ready   = !s0_super_ld_rep_valid
210  val s0_ld_rep_ready        = !s0_super_ld_rep_valid &&
211                               !s0_ld_fast_rep_valid
212  val s0_high_conf_prf_ready = !s0_super_ld_rep_valid &&
213                               !s0_ld_fast_rep_valid &&
214                               !s0_ld_rep_valid
215
216  val s0_int_iss_ready       = !s0_super_ld_rep_valid &&
217                               !s0_ld_fast_rep_valid &&
218                               !s0_ld_rep_valid &&
219                               !s0_high_conf_prf_valid
220
221  val s0_vec_iss_ready       = !s0_super_ld_rep_valid &&
222                               !s0_ld_fast_rep_valid &&
223                               !s0_ld_rep_valid &&
224                               !s0_high_conf_prf_valid &&
225                               !s0_int_iss_valid
226
227  val s0_l2l_fwd_ready       = !s0_super_ld_rep_valid &&
228                               !s0_ld_fast_rep_valid &&
229                               !s0_ld_rep_valid &&
230                               !s0_high_conf_prf_valid &&
231                               !s0_int_iss_valid &&
232                               !s0_vec_iss_valid
233
234  val s0_low_conf_prf_ready  = !s0_super_ld_rep_valid &&
235                               !s0_ld_fast_rep_valid &&
236                               !s0_ld_rep_valid &&
237                               !s0_high_conf_prf_valid &&
238                               !s0_int_iss_valid &&
239                               !s0_vec_iss_valid &&
240                               !s0_l2l_fwd_valid
241  dontTouch(s0_super_ld_rep_ready)
242  dontTouch(s0_ld_fast_rep_ready)
243  dontTouch(s0_ld_rep_ready)
244  dontTouch(s0_high_conf_prf_ready)
245  dontTouch(s0_int_iss_ready)
246  dontTouch(s0_vec_iss_ready)
247  dontTouch(s0_l2l_fwd_ready)
248  dontTouch(s0_low_conf_prf_ready)
249
250  // load flow source select (OH)
251  val s0_super_ld_rep_select = s0_super_ld_rep_valid && s0_super_ld_rep_ready
252  val s0_ld_fast_rep_select  = s0_ld_fast_rep_valid && s0_ld_fast_rep_ready
253  val s0_ld_rep_select       = s0_ld_rep_valid && s0_ld_rep_ready
254  val s0_hw_prf_select       = s0_high_conf_prf_ready && s0_high_conf_prf_valid ||
255                               s0_low_conf_prf_ready && s0_low_conf_prf_valid
256  val s0_int_iss_select      = s0_int_iss_ready && s0_int_iss_valid
257  val s0_vec_iss_select      = s0_vec_iss_ready && s0_vec_iss_valid
258  val s0_l2l_fwd_select      = s0_l2l_fwd_ready && s0_l2l_fwd_valid
259  dontTouch(s0_super_ld_rep_select)
260  dontTouch(s0_ld_fast_rep_select)
261  dontTouch(s0_ld_rep_select)
262  dontTouch(s0_hw_prf_select)
263  dontTouch(s0_int_iss_select)
264  dontTouch(s0_vec_iss_select)
265  dontTouch(s0_l2l_fwd_select)
266
267  s0_valid := (s0_super_ld_rep_valid ||
268               s0_ld_fast_rep_valid ||
269               s0_ld_rep_valid ||
270               s0_high_conf_prf_valid ||
271               s0_int_iss_valid ||
272               s0_vec_iss_valid ||
273               s0_l2l_fwd_valid ||
274               s0_low_conf_prf_valid) && !s0_kill
275
276  // which is S0's out is ready and dcache is ready
277  val s0_try_ptr_chasing      = s0_l2l_fwd_select
278  val s0_do_try_ptr_chasing   = s0_try_ptr_chasing && s0_can_go && io.ldu_io.dcache.req.ready
279  val s0_ptr_chasing_vaddr    = io.ldu_io.l2l_fwd_in.data(5, 0) +& io.ldu_io.ld_fast_imm(5, 0)
280  val s0_ptr_chasing_canceled = WireInit(false.B)
281  s0_kill := s0_ptr_chasing_canceled || (s0_out.uop.robIdx.needFlush(io.redirect) && !s0_try_ptr_chasing)
282
283  // prefetch related ctrl signal
284  val s0_prf    = Wire(Bool())
285  val s0_prf_rd = Wire(Bool())
286  val s0_prf_wr = Wire(Bool())
287  val s0_hw_prf = s0_hw_prf_select
288
289  io.canAcceptLowConfPrefetch  := s0_low_conf_prf_ready
290  io.canAcceptHighConfPrefetch := s0_high_conf_prf_ready
291
292  if (StorePrefetchL1Enabled) {
293    s0_dcache_ready := Mux(s0_ld_flow, io.ldu_io.dcache.req.ready, io.stu_io.dcache.req.ready)
294  } else {
295    s0_dcache_ready := Mux(s0_ld_flow, io.ldu_io.dcache.req.ready, true.B)
296  }
297
298  // query DTLB
299  io.tlb.req.valid                   := s0_valid && s0_dcache_ready
300  io.tlb.req.bits.cmd                := Mux(s0_prf,
301                                         Mux(s0_prf_wr, TlbCmd.write, TlbCmd.read),
302                                         Mux(s0_ld_flow, TlbCmd.read, TlbCmd.write)
303                                       )
304  io.tlb.req.bits.vaddr              := Mux(s0_hw_prf_select, io.ldu_io.prefetch_req.bits.paddr, s0_vaddr)
305  io.tlb.req.bits.size               := Mux(s0_isvec, io.vec_stu_io.in.bits.alignedType, LSUOpType.size(s0_uop.fuOpType))
306  io.tlb.req.bits.kill               := s0_kill
307  io.tlb.req.bits.memidx.is_ld       := s0_ld_flow
308  io.tlb.req.bits.memidx.is_st       := !s0_ld_flow
309  io.tlb.req.bits.memidx.idx         := s0_uop.lqIdx.value
310  io.tlb.req.bits.debug.robIdx       := s0_uop.robIdx
311  io.tlb.req.bits.no_translate       := s0_hw_prf_select  // hw b.reqetch addr does not need to be translated
312  io.tlb.req.bits.debug.pc           := s0_uop.pc
313  io.tlb.req.bits.debug.isFirstIssue := s0_isFirstIssue
314
315  // query DCache
316  // for load
317  io.ldu_io.dcache.req.valid             := s0_valid && s0_dcache_ready && s0_ld_flow
318  io.ldu_io.dcache.req.bits.cmd          :=  Mux(s0_prf_rd, MemoryOpConstants.M_PFR,
319                                              Mux(s0_prf_wr, MemoryOpConstants.M_PFW, MemoryOpConstants.M_XRD))
320  io.ldu_io.dcache.req.bits.vaddr        := s0_vaddr
321  io.ldu_io.dcache.req.bits.mask         := s0_mask
322  io.ldu_io.dcache.req.bits.data         := DontCare
323  io.ldu_io.dcache.req.bits.isFirstIssue := s0_isFirstIssue
324  io.ldu_io.dcache.req.bits.instrtype    := Mux(s0_prf, DCACHE_PREFETCH_SOURCE.U, LOAD_SOURCE.U)
325  io.ldu_io.dcache.req.bits.debug_robIdx := s0_uop.robIdx.value
326  io.ldu_io.dcache.req.bits.replayCarry  := s0_rep_carry
327  io.ldu_io.dcache.req.bits.id           := DontCare // TODO: update cache meta
328  io.ldu_io.dcache.pf_source             := Mux(s0_hw_prf_select, io.ldu_io.prefetch_req.bits.pf_source.value, L1_HW_PREFETCH_NULL)
329
330  // for store
331  io.stu_io.dcache.req.valid             := s0_valid && s0_dcache_ready && !s0_ld_flow && !s0_prf
332  io.stu_io.dcache.req.bits.cmd          := MemoryOpConstants.M_PFW
333  io.stu_io.dcache.req.bits.vaddr        := s0_vaddr
334  io.stu_io.dcache.req.bits.instrtype    := Mux(s0_prf, DCACHE_PREFETCH_SOURCE.U, STORE_SOURCE.U)
335
336  // load flow priority mux
337  def fromNullSource() = {
338    s0_vaddr         := 0.U
339    s0_mask          := 0.U
340    s0_uop           := 0.U.asTypeOf(new DynInst)
341    s0_try_l2l       := false.B
342    s0_has_rob_entry := false.B
343    s0_rsIdx         := 0.U
344    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
345    s0_mshrid        := 0.U
346    s0_isFirstIssue  := false.B
347    s0_fast_rep      := false.B
348    s0_ld_rep        := false.B
349    s0_l2l_fwd       := false.B
350    s0_prf           := false.B
351    s0_prf_rd        := false.B
352    s0_prf_wr        := false.B
353    s0_sched_idx     := 0.U
354    s0_deqPortIdx    := 0.U
355  }
356
357  def fromFastReplaySource(src: LqWriteBundle) = {
358    s0_vaddr         := src.vaddr
359    s0_mask          := src.mask
360    s0_uop           := src.uop
361    s0_try_l2l       := false.B
362    s0_has_rob_entry := src.hasROBEntry
363    s0_rep_carry     := src.rep_info.rep_carry
364    s0_mshrid        := src.rep_info.mshr_id
365    s0_rsIdx         := src.rsIdx
366    s0_isFirstIssue  := false.B
367    s0_fast_rep      := true.B
368    s0_ld_rep        := src.isLoadReplay
369    s0_l2l_fwd       := false.B
370    s0_prf           := LSUOpType.isPrefetch(src.uop.fuOpType)
371    s0_prf_rd        := src.uop.fuOpType === LSUOpType.prefetch_r
372    s0_prf_wr        := src.uop.fuOpType === LSUOpType.prefetch_w
373    s0_sched_idx     := src.schedIndex
374    s0_deqPortIdx    := src.deqPortIdx
375  }
376
377  def fromNormalReplaySource(src: LsPipelineBundle) = {
378    s0_vaddr         := src.vaddr
379    s0_mask          := genVWmask(src.vaddr, src.uop.fuOpType(1, 0))
380    s0_uop           := src.uop
381    s0_try_l2l       := false.B
382    s0_has_rob_entry := true.B
383    s0_rsIdx         := src.rsIdx
384    s0_rep_carry     := src.replayCarry
385    s0_mshrid        := src.mshrid
386    s0_isFirstIssue  := false.B
387    s0_fast_rep      := false.B
388    s0_ld_rep        := true.B
389    s0_l2l_fwd       := false.B
390    s0_prf           := LSUOpType.isPrefetch(src.uop.fuOpType)
391    s0_prf_rd        := src.uop.fuOpType === LSUOpType.prefetch_r
392    s0_prf_wr        := src.uop.fuOpType === LSUOpType.prefetch_w
393    s0_sched_idx     := src.schedIndex
394    s0_deqPortIdx    := src.deqPortIdx
395  }
396
397  def fromPrefetchSource(src: L1PrefetchReq) = {
398    s0_vaddr         := src.getVaddr()
399    s0_mask          := 0.U
400    s0_uop           := DontCare
401    s0_try_l2l       := false.B
402    s0_has_rob_entry := false.B
403    s0_rsIdx         := 0.U
404    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
405    s0_mshrid        := 0.U
406    s0_isFirstIssue  := false.B
407    s0_fast_rep      := false.B
408    s0_ld_rep        := false.B
409    s0_l2l_fwd       := false.B
410    s0_prf           := true.B
411    s0_prf_rd        := !src.is_store
412    s0_prf_wr        := src.is_store
413    s0_sched_idx     := 0.U
414    s0_deqPortIdx    := 0.U
415  }
416
417  def fromIntIssueSource(src: MemExuInput) = {
418    s0_vaddr         := src.src(0) + SignExt(src.uop.imm(11, 0), VAddrBits)
419    s0_mask          := genVWmask(s0_vaddr, src.uop.fuOpType(1,0))
420    s0_uop           := src.uop
421    s0_try_l2l       := false.B
422    s0_has_rob_entry := true.B
423    s0_rsIdx         := src.iqIdx
424    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
425    s0_mshrid        := 0.U
426    s0_isFirstIssue  := true.B
427    s0_fast_rep      := false.B
428    s0_ld_rep        := false.B
429    s0_l2l_fwd       := false.B
430    s0_prf           := LSUOpType.isPrefetch(src.uop.fuOpType)
431    s0_prf_rd        := src.uop.fuOpType === LSUOpType.prefetch_r
432    s0_prf_wr        := src.uop.fuOpType === LSUOpType.prefetch_w
433    s0_sched_idx     := 0.U
434    s0_deqPortIdx    := src.deqPortIdx
435  }
436
437  def fromVecIssueSource(src: VecStorePipeBundle) = {
438    // For now, vector port handles only vector store flows
439    s0_vaddr         := src.vaddr
440    s0_mask          := src.mask
441    s0_uop           := src.uop
442    s0_try_l2l       := false.B
443    s0_has_rob_entry := true.B
444    s0_rsIdx         := 0.U
445    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
446    s0_mshrid        := 0.U
447    s0_isFirstIssue  := src.isFirstIssue
448    s0_fast_rep      := false.B
449    s0_ld_rep        := false.B
450    s0_l2l_fwd       := false.B
451    s0_prf           := false.B
452    s0_prf_rd        := false.B
453    s0_prf_wr        := false.B
454    s0_sched_idx     := 0.U
455
456    s0_isvec         := true.B
457    s0_exp           := io.vec_stu_io.in.bits.exp
458    s0_flowPtr       := io.vec_stu_io.in.bits.flowPtr
459    s0_deqPortIdx    := 0.U
460  }
461
462  def fromLoadToLoadSource(src: LoadToLoadIO) = {
463    s0_vaddr              := Cat(src.data(XLEN-1, 6), s0_ptr_chasing_vaddr(5,0))
464    s0_mask               := genVWmask(s0_vaddr, io.ldu_io.ld_fast_fuOpType(1, 0))
465    // When there's no valid instruction from RS and LSQ, we try the load-to-load forwarding.
466    // Assume the pointer chasing is always ld.
467    s0_uop.fuOpType  := io.ldu_io.ld_fast_fuOpType
468    s0_try_l2l            := true.B
469    // we dont care s0_isFirstIssue and s0_rsIdx and s0_sqIdx and s0_deqPortIdx in S0 when trying pointchasing
470    // because these signals will be updated in S1
471    s0_has_rob_entry      := false.B
472    s0_rsIdx              := 0.U
473    s0_mshrid             := 0.U
474    s0_rep_carry          := 0.U.asTypeOf(s0_rep_carry.cloneType)
475    s0_isFirstIssue       := true.B
476    s0_fast_rep           := false.B
477    s0_ld_rep             := false.B
478    s0_l2l_fwd            := true.B
479    s0_prf                := false.B
480    s0_prf_rd             := false.B
481    s0_prf_wr             := false.B
482    s0_sched_idx          := 0.U
483    s0_deqPortIdx         := 0.U
484  }
485
486  // set default
487  s0_uop := DontCare
488  when (s0_super_ld_rep_select)      { fromNormalReplaySource(io.ldu_io.replay.bits)     }
489  .elsewhen (s0_ld_fast_rep_select)  { fromFastReplaySource(io.ldu_io.fast_rep_in.bits)  }
490  .elsewhen (s0_ld_rep_select)       { fromNormalReplaySource(io.ldu_io.replay.bits)     }
491  .elsewhen (s0_hw_prf_select)       { fromPrefetchSource(io.ldu_io.prefetch_req.bits)   }
492  .elsewhen (s0_int_iss_select)      { fromIntIssueSource(io.lsin.bits)                  }
493  .elsewhen (s0_vec_iss_select)      { fromVecIssueSource(io.vec_stu_io.in.bits)         }
494  .otherwise {
495    if (EnableLoadToLoadForward) {
496      fromLoadToLoadSource(io.ldu_io.l2l_fwd_in)
497    } else {
498      fromNullSource()
499    }
500  }
501
502  // address align check
503  val s0_addr_aligned = LookupTree(Mux(s0_isvec, io.vec_stu_io.in.bits.alignedType, s0_uop.fuOpType(1, 0)), List(
504    "b00".U   -> true.B,                   //b
505    "b01".U   -> (s0_vaddr(0)    === 0.U), //h
506    "b10".U   -> (s0_vaddr(1, 0) === 0.U), //w
507    "b11".U   -> (s0_vaddr(2, 0) === 0.U)  //d
508  ))
509
510  // accept load flow if dcache ready (tlb is always ready)
511  // TODO: prefetch need writeback to loadQueueFlag
512  s0_out               := DontCare
513  s0_out.rsIdx         := s0_rsIdx
514  s0_out.vaddr         := s0_vaddr
515  s0_out.mask          := s0_mask
516  s0_out.uop           := s0_uop
517  s0_out.isFirstIssue  := s0_isFirstIssue
518  s0_out.hasROBEntry   := s0_has_rob_entry
519  s0_out.isPrefetch    := s0_prf
520  s0_out.isHWPrefetch  := s0_hw_prf
521  s0_out.isFastReplay  := s0_fast_rep
522  s0_out.isLoadReplay  := s0_ld_rep
523  s0_out.isFastPath    := s0_l2l_fwd
524  s0_out.mshrid        := s0_mshrid
525  s0_out.isvec         := s0_isvec
526  s0_out.exp           := s0_exp
527  s0_out.sflowPtr      := s0_flowPtr
528  s0_out.uop.exceptionVec(loadAddrMisaligned)  := !s0_addr_aligned && s0_ld_flow
529  s0_out.uop.exceptionVec(storeAddrMisaligned) := !s0_addr_aligned && !s0_ld_flow
530  s0_out.forward_tlDchannel := s0_super_ld_rep_select
531  when(io.tlb.req.valid && s0_isFirstIssue) {
532    s0_out.uop.debugInfo.tlbFirstReqTime := GTimer()
533  }.otherwise{
534    s0_out.uop.debugInfo.tlbFirstReqTime := s0_uop.debugInfo.tlbFirstReqTime
535  }
536  s0_out.schedIndex     := s0_sched_idx
537  s0_out.deqPortIdx     := s0_deqPortIdx
538
539  // load fast replay
540  io.ldu_io.fast_rep_in.ready := (s0_can_go && io.ldu_io.dcache.req.ready && s0_ld_fast_rep_ready)
541
542  // load flow source ready
543  // cache missed load has highest priority
544  // always accept cache missed load flow from load replay queue
545  io.ldu_io.replay.ready := (s0_can_go && io.ldu_io.dcache.req.ready && (s0_ld_rep_ready && !s0_rep_stall || s0_super_ld_rep_select))
546
547  // accept load flow from rs when:
548  // 1) there is no lsq-replayed load
549  // 2) there is no fast replayed load
550  // 3) there is no high confidence prefetch request
551  io.lsin.ready := (s0_can_go &&
552                    Mux(FuType.isLoad(io.lsin.bits.uop.fuType), io.ldu_io.dcache.req.ready,
553                    (if (StorePrefetchL1Enabled) io.stu_io.dcache.req.ready else true.B)) && s0_int_iss_ready)
554  io.vec_stu_io.in.ready := s0_can_go && io.ldu_io.dcache.req.ready && s0_vec_iss_ready
555
556
557  // for hw prefetch load flow feedback, to be added later
558  // io.prefetch_in.ready := s0_hw_prf_select
559
560  // dcache replacement extra info
561  // TODO: should prefetch load update replacement?
562  io.ldu_io.dcache.replacementUpdated := Mux(s0_ld_rep_select || s0_super_ld_rep_select, io.ldu_io.replay.bits.replacementUpdated, false.B)
563
564  io.stu_io.prefetch_req.ready := s1_ready && io.stu_io.dcache.req.ready && !io.lsin.valid
565
566  // load debug
567  XSDebug(io.ldu_io.dcache.req.fire && s0_ld_flow,
568    p"[DCACHE LOAD REQ] pc ${Hexadecimal(s0_uop.pc)}, vaddr ${Hexadecimal(s0_vaddr)}\n"
569  )
570  XSDebug(s0_valid && s0_ld_flow,
571    p"S0: pc ${Hexadecimal(s0_out.uop.pc)}, lqIdx ${Hexadecimal(s0_out.uop.lqIdx.asUInt)}, " +
572    p"vaddr ${Hexadecimal(s0_out.vaddr)}, mask ${Hexadecimal(s0_out.mask)}\n")
573
574  // store debug
575  XSDebug(io.stu_io.dcache.req.fire && !s0_ld_flow,
576    p"[DCACHE STORE REQ] pc ${Hexadecimal(s0_uop.pc)}, vaddr ${Hexadecimal(s0_vaddr)}\n"
577  )
578  XSDebug(s0_valid && !s0_ld_flow,
579    p"S0: pc ${Hexadecimal(s0_out.uop.pc)}, sqIdx ${Hexadecimal(s0_out.uop.sqIdx.asUInt)}, " +
580    p"vaddr ${Hexadecimal(s0_out.vaddr)}, mask ${Hexadecimal(s0_out.mask)}\n")
581
582
583  // Pipeline
584  // --------------------------------------------------------------------------------
585  // stage 1
586  // --------------------------------------------------------------------------------
587  // TLB resp (send paddr to dcache)
588  val s1_valid      = RegInit(false.B)
589  val s1_in         = Wire(new LqWriteBundle)
590  val s1_out        = Wire(new LqWriteBundle)
591  val s1_kill       = Wire(Bool())
592  val s1_can_go     = s2_ready
593  val s1_fire       = s1_valid && !s1_kill && s1_can_go
594  val s1_ld_flow    = RegNext(s0_ld_flow)
595  val s1_isvec      = RegEnable(s0_out.isvec, false.B, s0_fire)
596
597  s1_ready := !s1_valid || s1_kill || s2_ready
598  when (s0_fire) { s1_valid := true.B }
599  .elsewhen (s1_fire) { s1_valid := false.B }
600  .elsewhen (s1_kill) { s1_valid := false.B }
601  s1_in   := RegEnable(s0_out, s0_fire)
602
603  val s1_fast_rep_dly_err = RegNext(io.ldu_io.fast_rep_in.bits.delayedLoadError)
604  val s1_fast_rep_kill    = s1_fast_rep_dly_err && s1_in.isFastReplay
605  val s1_l2l_fwd_dly_err  = RegNext(io.ldu_io.l2l_fwd_in.dly_ld_err)
606  val s1_l2l_fwd_kill     = s1_l2l_fwd_dly_err && s1_in.isFastPath
607  val s1_late_kill        = s1_fast_rep_kill || s1_l2l_fwd_kill
608  val s1_vaddr_hi         = Wire(UInt())
609  val s1_vaddr_lo         = Wire(UInt())
610  val s1_vaddr            = Wire(UInt())
611  val s1_paddr_dup_lsu    = Wire(UInt())
612  val s1_paddr_dup_dcache = Wire(UInt())
613  val s1_ld_exception     = ExceptionNO.selectByFu(s1_out.uop.exceptionVec, LduCfg).asUInt.orR   // af & pf exception were modified below.
614  val s1_st_exception     = ExceptionNO.selectByFu(s1_out.uop.exceptionVec, StaCfg).asUInt.orR   // af & pf exception were modified below.
615  val s1_exception        = (s1_ld_flow && s1_ld_exception) || (!s1_ld_flow && s1_st_exception)
616  val s1_tlb_miss         = io.tlb.resp.bits.miss
617  val s1_prf              = s1_in.isPrefetch
618  val s1_hw_prf           = s1_in.isHWPrefetch
619  val s1_sw_prf           = s1_prf && !s1_hw_prf
620  val s1_tlb_memidx       = io.tlb.resp.bits.memidx
621
622  // mmio cbo decoder
623  val s1_mmio_cbo  = (s1_in.uop.fuOpType === LSUOpType.cbo_clean ||
624                      s1_in.uop.fuOpType === LSUOpType.cbo_flush ||
625                      s1_in.uop.fuOpType === LSUOpType.cbo_inval) && !s1_ld_flow && !s1_prf
626  val s1_mmio = s1_mmio_cbo
627
628  s1_vaddr_hi         := s1_in.vaddr(VAddrBits - 1, 6)
629  s1_vaddr_lo         := s1_in.vaddr(5, 0)
630  s1_vaddr            := Cat(s1_vaddr_hi, s1_vaddr_lo)
631  s1_paddr_dup_lsu    := io.tlb.resp.bits.paddr(0)
632  s1_paddr_dup_dcache := io.tlb.resp.bits.paddr(1)
633
634  when (s1_tlb_memidx.is_ld && io.tlb.resp.valid && !s1_tlb_miss &&
635        s1_tlb_memidx.idx === s1_in.uop.lqIdx.value && s1_ld_flow) {
636    // printf("Load idx = %d\n", s1_tlb_memidx.idx)
637    s1_out.uop.debugInfo.tlbRespTime := GTimer()
638  } .elsewhen(s1_tlb_memidx.is_st && io.tlb.resp.valid && !s1_tlb_miss &&
639              s1_tlb_memidx.idx === s1_out.uop.sqIdx.value && !s1_ld_flow) {
640    // printf("Store idx = %d\n", s1_tlb_memidx.idx)
641    s1_out.uop.debugInfo.tlbRespTime := GTimer()
642  }
643
644  io.tlb.req_kill   := s1_kill
645  io.tlb.resp.ready := true.B
646
647  io.ldu_io.dcache.s1_paddr_dup_lsu    <> s1_paddr_dup_lsu
648  io.ldu_io.dcache.s1_paddr_dup_dcache <> s1_paddr_dup_dcache
649  io.ldu_io.dcache.s1_kill             := s1_kill || s1_tlb_miss || s1_exception
650
651  // store to load forwarding
652  io.ldu_io.sbuffer.valid := s1_valid && !(s1_exception || s1_tlb_miss || s1_kill || s1_fast_rep_kill || s1_prf || !s1_ld_flow)
653  io.ldu_io.sbuffer.vaddr := s1_vaddr
654  io.ldu_io.sbuffer.paddr := s1_paddr_dup_lsu
655  io.ldu_io.sbuffer.uop   := s1_in.uop
656  io.ldu_io.sbuffer.sqIdx := s1_in.uop.sqIdx
657  io.ldu_io.sbuffer.mask  := s1_in.mask
658  io.ldu_io.sbuffer.pc    := s1_in.uop.pc // FIXME: remove it
659
660  io.ldu_io.vec_forward.valid := s1_valid && !(s1_exception || s1_tlb_miss || s1_kill || s1_fast_rep_kill || s1_prf || !s1_ld_flow)
661  io.ldu_io.vec_forward.vaddr := s1_vaddr
662  io.ldu_io.vec_forward.paddr := s1_paddr_dup_lsu
663  io.ldu_io.vec_forward.uop   := s1_in.uop
664  io.ldu_io.vec_forward.sqIdx := s1_in.uop.sqIdx
665  io.ldu_io.vec_forward.mask  := s1_in.mask
666  io.ldu_io.vec_forward.pc    := s1_in.uop.pc // FIXME: remove it
667
668  io.ldu_io.lsq.forward.valid     := s1_valid && !(s1_exception || s1_tlb_miss || s1_kill || s1_fast_rep_kill || s1_prf || !s1_ld_flow)
669  io.ldu_io.lsq.forward.vaddr     := s1_vaddr
670  io.ldu_io.lsq.forward.paddr     := s1_paddr_dup_lsu
671  io.ldu_io.lsq.forward.uop       := s1_in.uop
672  io.ldu_io.lsq.forward.sqIdx     := s1_in.uop.sqIdx
673  io.ldu_io.lsq.forward.sqIdxMask := 0.U
674  io.ldu_io.lsq.forward.mask      := s1_in.mask
675  io.ldu_io.lsq.forward.pc        := s1_in.uop.pc // FIXME: remove it
676
677  // st-ld violation query
678  val s1_nuke = VecInit((0 until StorePipelineWidth).map(w => {
679                       io.ldu_io.stld_nuke_query(w).valid && // query valid
680                       isAfter(s1_in.uop.robIdx, io.ldu_io.stld_nuke_query(w).bits.robIdx) && // older store
681                       // TODO: Fix me when vector instruction
682                       (s1_paddr_dup_lsu(PAddrBits-1, 3) === io.ldu_io.stld_nuke_query(w).bits.paddr(PAddrBits-1, 3)) && // paddr match
683                       (s1_in.mask & io.ldu_io.stld_nuke_query(w).bits.mask).orR // data mask contain
684                      })).asUInt.orR && !s1_tlb_miss && s1_ld_flow
685
686  s1_out                   := s1_in
687  s1_out.vaddr             := s1_vaddr
688  s1_out.paddr             := s1_paddr_dup_lsu
689  s1_out.tlbMiss           := s1_tlb_miss
690  s1_out.ptwBack           := io.tlb.resp.bits.ptwBack
691  s1_out.rsIdx             := s1_in.rsIdx
692  s1_out.rep_info.debug    := s1_in.uop.debugInfo
693  s1_out.rep_info.nuke     := s1_nuke && !s1_sw_prf
694  s1_out.lateKill          := s1_late_kill
695
696  when (s1_ld_flow) {
697    when (!s1_late_kill) {
698      // current ori test will cause the case of ldest == 0, below will be modifeid in the future.
699      // af & pf exception were modified
700      s1_out.uop.exceptionVec(loadPageFault)   := io.tlb.resp.bits.excp(0).pf.ld
701      s1_out.uop.exceptionVec(loadAccessFault) := io.tlb.resp.bits.excp(0).af.ld
702    } .otherwise {
703      s1_out.uop.exceptionVec(loadAddrMisaligned) := false.B
704      s1_out.uop.exceptionVec(loadAccessFault)    := s1_late_kill
705    }
706  } .otherwise {
707    s1_out.uop.exceptionVec(storePageFault)   := io.tlb.resp.bits.excp(0).pf.st
708    s1_out.uop.exceptionVec(storeAccessFault) := io.tlb.resp.bits.excp(0).af.st
709  }
710
711  // pointer chasing
712  val s1_try_ptr_chasing       = RegNext(s0_do_try_ptr_chasing, false.B)
713  val s1_ptr_chasing_vaddr     = RegEnable(s0_ptr_chasing_vaddr, s0_do_try_ptr_chasing)
714  val s1_fu_op_type_not_ld     = WireInit(false.B)
715  val s1_not_fast_match        = WireInit(false.B)
716  val s1_addr_mismatch         = WireInit(false.B)
717  val s1_addr_misaligned       = WireInit(false.B)
718  val s1_ptr_chasing_canceled  = WireInit(false.B)
719  val s1_cancel_ptr_chasing    = WireInit(false.B)
720
721  s1_kill := s1_late_kill ||
722             s1_cancel_ptr_chasing ||
723             s1_in.uop.robIdx.needFlush(io.redirect) ||
724             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)
725
726  if (EnableLoadToLoadForward) {
727    // Sometimes, we need to cancel the load-load forwarding.
728    // These can be put at S0 if timing is bad at S1.
729    // Case 0: CACHE_SET(base + offset) != CACHE_SET(base) (lowest 6-bit addition has an overflow)
730    s1_addr_mismatch      := s1_ptr_chasing_vaddr(6) || RegEnable(io.ldu_io.ld_fast_imm(11, 6).orR, s0_do_try_ptr_chasing)
731    // Case 1: the address is misaligned, kill s1
732    s1_addr_misaligned    := LookupTree(s1_in.uop.fuOpType(1, 0), List(
733                             "b00".U   -> false.B,                  //b
734                             "b01".U   -> (s1_vaddr(0)    =/= 0.U), //h
735                             "b10".U   -> (s1_vaddr(1, 0) =/= 0.U), //w
736                             "b11".U   -> (s1_vaddr(2, 0) =/= 0.U)  //d
737                          ))
738    // Case 2: this load-load uop is cancelled
739    s1_ptr_chasing_canceled := !io.lsin.valid || FuType.isStore(io.lsin.bits.uop.fuType)
740
741    when (s1_try_ptr_chasing) {
742      s1_cancel_ptr_chasing := s1_addr_mismatch || s1_addr_misaligned || s1_ptr_chasing_canceled
743
744      s1_in.uop           := io.lsin.bits.uop
745      s1_in.rsIdx         := io.lsin.bits.iqIdx
746      s1_in.isFirstIssue  := io.lsin.bits.isFirstIssue
747      s1_vaddr_lo         := s1_ptr_chasing_vaddr(5, 0)
748      s1_paddr_dup_lsu    := Cat(io.tlb.resp.bits.paddr(0)(PAddrBits - 1, 6), s1_vaddr_lo)
749      s1_paddr_dup_dcache := Cat(io.tlb.resp.bits.paddr(0)(PAddrBits - 1, 6), s1_vaddr_lo)
750
751      // 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)
752      s1_in.uop.debugInfo.tlbFirstReqTime := GTimer()
753      s1_in.uop.debugInfo.tlbRespTime     := GTimer()
754    }
755    when (!s1_cancel_ptr_chasing) {
756      s0_ptr_chasing_canceled := s1_try_ptr_chasing && !io.ldu_io.replay.fire && !io.ldu_io.fast_rep_in.fire
757      when (s1_try_ptr_chasing) {
758        io.lsin.ready := true.B
759      }
760    }
761  }
762
763  // pre-calcuate sqIdx mask in s0, then send it to lsq in s1 for forwarding
764  val s1_sqIdx_mask = RegNext(UIntToMask(s0_out.uop.sqIdx.value, StoreQueueSize))
765  // to enable load-load, sqIdxMask must be calculated based on lsin.uop
766  // If the timing here is not OK, load-load forwarding has to be disabled.
767  // Or we calculate sqIdxMask at RS??
768  io.ldu_io.lsq.forward.sqIdxMask := s1_sqIdx_mask
769  if (EnableLoadToLoadForward) {
770    when (s1_try_ptr_chasing) {
771      io.ldu_io.lsq.forward.sqIdxMask := UIntToMask(io.lsin.bits.uop.sqIdx.value, StoreQueueSize)
772    }
773  }
774
775  io.ldu_io.forward_mshr.valid  := s1_valid && s1_out.forward_tlDchannel && s1_ld_flow
776  io.ldu_io.forward_mshr.mshrid := s1_out.mshrid
777  io.ldu_io.forward_mshr.paddr  := s1_out.paddr
778
779  io.stu_io.dcache.s1_kill := s1_tlb_miss || s1_exception || s1_mmio || s1_in.uop.robIdx.needFlush(io.redirect)
780  io.stu_io.dcache.s1_paddr := s1_paddr_dup_dcache
781
782
783  // load debug
784  XSDebug(s1_valid && s1_ld_flow,
785    p"S1: pc ${Hexadecimal(s1_out.uop.pc)}, lId ${Hexadecimal(s1_out.uop.lqIdx.asUInt)}, tlb_miss ${io.tlb.resp.bits.miss}, " +
786    p"paddr ${Hexadecimal(s1_out.paddr)}, mmio ${s1_out.mmio}\n")
787
788  // store debug
789  XSDebug(s1_valid && !s1_ld_flow,
790    p"S1: pc ${Hexadecimal(s1_out.uop.pc)}, lId ${Hexadecimal(s1_out.uop.sqIdx.asUInt)}, tlb_miss ${io.tlb.resp.bits.miss}, " +
791    p"paddr ${Hexadecimal(s1_out.paddr)}, mmio ${s1_out.mmio}\n")
792
793  // store out
794  io.stu_io.lsq.valid         := s1_valid && !s1_ld_flow && !s1_prf && !s1_isvec
795  io.stu_io.lsq.bits          := s1_out
796  io.stu_io.lsq.bits.miss     := s1_tlb_miss
797
798  io.vec_stu_io.lsq.valid     := s1_valid && !s1_ld_flow && !s1_prf && s1_isvec
799  io.vec_stu_io.lsq.bits          := s1_out
800  io.vec_stu_io.lsq.bits.miss     := s1_tlb_miss
801
802  io.stu_io.st_mask_out.valid       := s1_valid && !s1_ld_flow && !s1_prf
803  io.stu_io.st_mask_out.bits.mask   := s1_out.mask
804  io.stu_io.st_mask_out.bits.sqIdx  := s1_out.uop.sqIdx
805
806  io.stu_io.issue.valid       := s1_valid && !s1_tlb_miss && !s1_ld_flow && !s1_prf && !s1_isvec
807  io.stu_io.issue.bits        := RegEnable(io.lsin.bits, io.lsin.fire)
808
809  // st-ld violation dectect request
810  io.stu_io.stld_nuke_query.valid       := s1_valid && !s1_tlb_miss && !s1_ld_flow && !s1_prf
811  io.stu_io.stld_nuke_query.bits.robIdx := s1_in.uop.robIdx
812  io.stu_io.stld_nuke_query.bits.paddr  := s1_paddr_dup_lsu
813  io.stu_io.stld_nuke_query.bits.mask   := s1_in.mask
814
815  // Pipeline
816  // --------------------------------------------------------------------------------
817  // stage 2
818  // --------------------------------------------------------------------------------
819  // s2: DCache resp
820  val s2_valid  = RegInit(false.B)
821  val s2_in     = Wire(new LqWriteBundle)
822  val s2_out    = Wire(new LqWriteBundle)
823  val s2_kill   = Wire(Bool())
824  val s2_can_go = s3_ready
825  val s2_fire   = s2_valid && !s2_kill && s2_can_go
826  val s2_isvec  = RegEnable(s1_isvec, false.B, s1_fire)
827  val s2_exp    = RegEnable(s1_out.exp, true.B, s1_fire)
828  val s2_paddr  = RegEnable(s1_paddr_dup_lsu, s1_fire)
829
830  s2_kill := s2_in.uop.robIdx.needFlush(io.redirect)
831  s2_ready := !s2_valid || s2_kill || s3_ready
832  when (s1_fire) { s2_valid := true.B }
833  .elsewhen (s2_fire) { s2_valid := false.B }
834  .elsewhen (s2_kill) { s2_valid := false.B }
835  s2_in := RegEnable(s1_out, s1_fire)
836
837  val s2_pmp = WireInit(io.pmp)
838
839  val s2_prf    = s2_in.isPrefetch
840  val s2_hw_prf = s2_in.isHWPrefetch
841  val s2_ld_flow  = RegEnable(s1_ld_flow, s1_fire)
842
843  // exception that may cause load addr to be invalid / illegal
844  // if such exception happen, that inst and its exception info
845  // will be force writebacked to rob
846  val s2_exception_vec = WireInit(s2_in.uop.exceptionVec)
847  when (s2_ld_flow) {
848    when (!s2_in.lateKill) {
849      s2_exception_vec(loadAccessFault) := (s2_in.uop.exceptionVec(loadAccessFault) || s2_pmp.ld) && s2_exp
850      // soft prefetch will not trigger any exception (but ecc error interrupt may be triggered)
851      when (s2_prf || s2_in.tlbMiss) {
852        s2_exception_vec := 0.U.asTypeOf(s2_exception_vec.cloneType)
853      }
854    }
855  } .otherwise {
856    s2_exception_vec(storeAccessFault) := s2_in.uop.exceptionVec(storeAccessFault) || s2_pmp.st
857    when (s2_prf || s2_in.tlbMiss) {
858      s2_exception_vec := 0.U.asTypeOf(s2_exception_vec.cloneType)
859    }
860  }
861  val s2_ld_exception = ExceptionNO.selectByFu(s2_exception_vec, LduCfg).asUInt.orR && s2_ld_flow
862  val s2_st_exception = ExceptionNO.selectByFu(s2_exception_vec, StaCfg).asUInt.orR && !s2_ld_flow
863  val s2_exception    = s2_ld_exception || s2_st_exception
864
865  val (s2_fwd_frm_d_chan, s2_fwd_data_frm_d_chan) = io.ldu_io.tl_d_channel.forward(s1_valid && s1_out.forward_tlDchannel, s1_out.mshrid, s1_out.paddr)
866  val (s2_fwd_data_valid, s2_fwd_frm_mshr, s2_fwd_data_frm_mshr) = io.ldu_io.forward_mshr.forward()
867  val s2_fwd_frm_d_chan_or_mshr = s2_fwd_data_valid && (s2_fwd_frm_d_chan || s2_fwd_frm_mshr)
868
869  // writeback access fault caused by ecc error / bus error
870  // * ecc data error is slow to generate, so we will not use it until load stage 3
871  // * in load stage 3, an extra signal io.load_error will be used to
872  val s2_actually_mmio = s2_pmp.mmio
873  val s2_ld_mmio       = !s2_prf &&
874                          s2_actually_mmio &&
875                         !s2_exception &&
876                         !s2_in.tlbMiss &&
877                         s2_ld_flow
878  val s2_st_mmio       = !s2_prf &&
879                          (RegNext(s1_mmio) || s2_pmp.mmio) &&
880                         !s2_exception &&
881                         !s2_in.tlbMiss &&
882                         !s2_ld_flow
883  val s2_st_atomic     = !s2_prf &&
884                          (RegNext(s1_mmio) || s2_pmp.atomic) &&
885                         !s2_exception &&
886                         !s2_in.tlbMiss &&
887                         !s2_ld_flow
888  val s2_full_fwd      = Wire(Bool())
889  val s2_mem_amb       = s2_in.uop.storeSetHit &&
890                         io.ldu_io.lsq.forward.addrInvalid
891
892  val s2_tlb_miss      = s2_in.tlbMiss
893  val s2_fwd_fail      = io.ldu_io.lsq.forward.dataInvalid || io.ldu_io.vec_forward.dataInvalid
894  val s2_dcache_miss   = io.ldu_io.dcache.resp.bits.miss &&
895                         !s2_fwd_frm_d_chan_or_mshr &&
896                         !s2_full_fwd
897
898  val s2_mq_nack       = io.ldu_io.dcache.s2_mq_nack &&
899                         !s2_fwd_frm_d_chan_or_mshr &&
900                         !s2_full_fwd
901
902  val s2_bank_conflict = io.ldu_io.dcache.s2_bank_conflict &&
903                         !s2_fwd_frm_d_chan_or_mshr &&
904                         !s2_full_fwd
905
906  val s2_wpu_pred_fail = io.ldu_io.dcache.s2_wpu_pred_fail &&
907                        !s2_fwd_frm_d_chan_or_mshr &&
908                        !s2_full_fwd
909
910  val s2_rar_nack      = io.ldu_io.lsq.ldld_nuke_query.req.valid &&
911                         !io.ldu_io.lsq.ldld_nuke_query.req.ready
912
913  val s2_raw_nack      = io.ldu_io.lsq.stld_nuke_query.req.valid &&
914                         !io.ldu_io.lsq.stld_nuke_query.req.ready
915
916  // st-ld violation query
917  //  NeedFastRecovery Valid when
918  //  1. Fast recovery query request Valid.
919  //  2. Load instruction is younger than requestors(store instructions).
920  //  3. Physical address match.
921  //  4. Data contains.
922  val s2_nuke = VecInit((0 until StorePipelineWidth).map(w => {
923                        io.ldu_io.stld_nuke_query(w).valid && // query valid
924                        isAfter(s2_in.uop.robIdx, io.ldu_io.stld_nuke_query(w).bits.robIdx) && // older store
925                        // TODO: Fix me when vector instruction
926                        (s2_in.paddr(PAddrBits-1, 3) === io.ldu_io.stld_nuke_query(w).bits.paddr(PAddrBits-1, 3)) && // paddr match
927                        (s2_in.mask & io.ldu_io.stld_nuke_query(w).bits.mask).orR // data mask contain
928                      })).asUInt.orR && s2_ld_flow || s2_in.rep_info.nuke
929
930  val s2_cache_handled   = io.ldu_io.dcache.resp.bits.handled
931  val s2_cache_tag_error = RegNext(io.csrCtrl.cache_error_enable) &&
932                           io.ldu_io.dcache.resp.bits.tag_error
933
934  val s2_troublem        = !s2_exception &&
935                           !s2_ld_mmio &&
936                           !s2_prf &&
937                           !s2_in.lateKill &&
938                           s2_ld_flow
939
940  io.ldu_io.dcache.resp.ready := true.B
941  io.stu_io.dcache.resp.ready := true.B
942  val s2_dcache_should_resp = !(s2_in.tlbMiss || s2_exception || s2_ld_mmio || s2_prf || s2_in.lateKill) && s2_ld_flow
943  assert(!(s2_valid && (s2_dcache_should_resp && !io.ldu_io.dcache.resp.valid)), "DCache response got lost")
944
945  // fast replay require
946  val s2_dcache_fast_rep = (s2_mq_nack || !s2_dcache_miss && (s2_bank_conflict || s2_wpu_pred_fail))
947  val s2_nuke_fast_rep   = !s2_mq_nack &&
948                           !s2_dcache_miss &&
949                           !s2_bank_conflict &&
950                           !s2_wpu_pred_fail &&
951                           !s2_rar_nack &&
952                           !s2_raw_nack &&
953                           s2_nuke
954
955  val s2_fast_rep = !s2_mem_amb &&
956                    !s2_tlb_miss &&
957                    !s2_fwd_fail &&
958                    (s2_dcache_fast_rep || s2_nuke_fast_rep) &&
959                    s2_troublem
960
961  // need allocate new entry
962  val s2_can_query = !s2_mem_amb &&
963                     !s2_tlb_miss  &&
964                     !s2_fwd_fail &&
965                     !s2_dcache_fast_rep &&
966                     s2_troublem
967
968  val s2_data_fwded = s2_dcache_miss && (s2_full_fwd || s2_cache_tag_error)
969
970  // ld-ld violation require
971  io.ldu_io.lsq.ldld_nuke_query.req.valid           := s2_valid && s2_can_query
972  io.ldu_io.lsq.ldld_nuke_query.req.bits.uop        := s2_in.uop
973  io.ldu_io.lsq.ldld_nuke_query.req.bits.mask       := s2_in.mask
974  io.ldu_io.lsq.ldld_nuke_query.req.bits.paddr      := s2_in.paddr
975  io.ldu_io.lsq.ldld_nuke_query.req.bits.data_valid := Mux(s2_full_fwd || s2_fwd_data_valid, true.B, !s2_dcache_miss)
976
977  // st-ld violation require
978  io.ldu_io.lsq.stld_nuke_query.req.valid           := s2_valid && s2_can_query
979  io.ldu_io.lsq.stld_nuke_query.req.bits.uop        := s2_in.uop
980  io.ldu_io.lsq.stld_nuke_query.req.bits.mask       := s2_in.mask
981  io.ldu_io.lsq.stld_nuke_query.req.bits.paddr      := s2_in.paddr
982  io.ldu_io.lsq.stld_nuke_query.req.bits.data_valid := Mux(s2_full_fwd || s2_fwd_data_valid, true.B, !s2_dcache_miss)
983
984  // merge forward result
985  // lsq has higher priority than sbuffer
986  val s2_fwd_mask = Wire(Vec((VLEN/8), Bool()))
987  val s2_fwd_data = Wire(Vec((VLEN/8), UInt(8.W)))
988  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
989  // generate XLEN/8 Muxs
990  for (i <- 0 until VLEN / 8) {
991    s2_fwd_mask(i) := io.ldu_io.lsq.forward.forwardMask(i) || io.ldu_io.sbuffer.forwardMask(i) || io.ldu_io.vec_forward.forwardMask(i)
992    s2_fwd_data(i) := Mux(
993      io.ldu_io.lsq.forward.forwardMask(i),
994      io.ldu_io.lsq.forward.forwardData(i),
995      Mux(
996        io.ldu_io.vec_forward.forwardMask(i),
997        io.ldu_io.vec_forward.forwardData(i),
998        io.ldu_io.sbuffer.forwardData(i)
999      )
1000    )
1001  }
1002
1003  XSDebug(s2_fire && s2_ld_flow, "[FWD LOAD RESP] pc %x fwd %x(%b) + %x(%b)\n",
1004    s2_in.uop.pc,
1005    io.ldu_io.lsq.forward.forwardData.asUInt, io.ldu_io.lsq.forward.forwardMask.asUInt,
1006    s2_in.forwardData.asUInt, s2_in.forwardMask.asUInt
1007  )
1008
1009  //
1010  s2_out                  := s2_in
1011  s2_out.data             := 0.U // data will be generated in load s3
1012  s2_out.uop.fpWen        := s2_in.uop.fpWen && !s2_exception && s2_ld_flow
1013  s2_out.mmio             := s2_ld_mmio || s2_st_mmio
1014  s2_out.atomic           := s2_st_atomic
1015  s2_out.uop.flushPipe    := false.B
1016  s2_out.uop.exceptionVec := s2_exception_vec
1017  s2_out.forwardMask      := s2_fwd_mask
1018  s2_out.forwardData      := s2_fwd_data
1019  s2_out.handledByMSHR    := s2_cache_handled
1020  s2_out.miss             := s2_dcache_miss && s2_troublem
1021  s2_out.feedbacked       := io.feedback_fast.valid && !io.feedback_fast.bits.hit
1022
1023  // Generate replay signal caused by:
1024  // * st-ld violation check
1025  // * tlb miss
1026  // * dcache replay
1027  // * forward data invalid
1028  // * dcache miss
1029  s2_out.rep_info.mem_amb         := s2_mem_amb && s2_troublem
1030  s2_out.rep_info.tlb_miss        := s2_tlb_miss && s2_troublem
1031  s2_out.rep_info.fwd_fail        := s2_fwd_fail && s2_troublem
1032  s2_out.rep_info.dcache_rep      := s2_mq_nack && s2_troublem
1033  s2_out.rep_info.dcache_miss     := s2_dcache_miss && s2_troublem
1034  s2_out.rep_info.bank_conflict   := s2_bank_conflict && s2_troublem
1035  s2_out.rep_info.wpu_fail        := s2_wpu_pred_fail && s2_troublem
1036  s2_out.rep_info.rar_nack        := s2_rar_nack && s2_troublem
1037  s2_out.rep_info.raw_nack        := s2_raw_nack && s2_troublem
1038  s2_out.rep_info.nuke            := s2_nuke && s2_troublem
1039  s2_out.rep_info.full_fwd        := s2_data_fwded
1040  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)
1041  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)
1042  s2_out.rep_info.rep_carry       := io.ldu_io.dcache.resp.bits.replayCarry
1043  s2_out.rep_info.mshr_id         := io.ldu_io.dcache.resp.bits.mshr_id
1044  s2_out.rep_info.last_beat       := s2_in.paddr(log2Up(refillBytes))
1045  s2_out.rep_info.debug           := s2_in.uop.debugInfo
1046
1047  // if forward fail, replay this inst from fetch
1048  val debug_fwd_fail_rep = s2_fwd_fail && !s2_troublem && !s2_in.tlbMiss
1049  // if ld-ld violation is detected, replay from this inst from fetch
1050  val debug_ldld_nuke_rep = false.B // s2_ldld_violation && !s2_ld_mmio && !s2_is_prefetch && !s2_in.tlbMiss
1051  // io.out.bits.uop.replayInst := false.B
1052
1053  // to be removed
1054  val s2_ld_need_fb = !s2_in.isLoadReplay &&      // already feedbacked
1055                      io.ldu_io.lq_rep_full &&           // LoadQueueReplay is full
1056                      s2_out.rep_info.need_rep && // need replay
1057                      !s2_exception &&            // no exception is triggered
1058                      !s2_hw_prf &&               // not hardware prefetch
1059                      !s2_isvec
1060  val s2_st_need_fb = !s2_ld_flow && !s2_hw_prf && !s2_isvec
1061  io.feedback_fast.valid                 := s2_valid && (s2_ld_need_fb || s2_st_need_fb)
1062  io.feedback_fast.bits.hit              := Mux(s2_ld_flow, false.B, !s2_tlb_miss)
1063  io.feedback_fast.bits.flushState       := s2_in.ptwBack
1064  io.feedback_fast.bits.robIdx           := s2_in.uop.robIdx
1065  io.feedback_fast.bits.sourceType       := Mux(s2_ld_flow, RSFeedbackType.lrqFull, RSFeedbackType.tlbMiss)
1066  io.feedback_fast.bits.dataInvalidSqIdx := DontCare
1067
1068  val s2_vec_feedback = Wire(Valid(new VSFQFeedback))
1069  s2_vec_feedback.valid := s2_valid && !s2_ld_flow && !s2_hw_prf && s2_isvec
1070  s2_vec_feedback.bits.flowPtr := s2_out.sflowPtr
1071  s2_vec_feedback.bits.hit := !s2_tlb_miss
1072  s2_vec_feedback.bits.sourceType := RSFeedbackType.tlbMiss
1073  s2_vec_feedback.bits.paddr := s2_paddr
1074
1075  io.stu_io.lsq_replenish := s2_out
1076  io.stu_io.lsq_replenish.miss := io.ldu_io.dcache.resp.fire && io.ldu_io.dcache.resp.bits.miss
1077
1078  io.ldu_io.ldCancel.ld1Cancel.valid := s2_valid && (
1079    (s2_out.rep_info.need_rep && s2_out.isFirstIssue) ||                // exe fail and issued from IQ
1080    s2_ld_mmio                                                             // is mmio
1081  ) && s2_ld_flow
1082  io.ldu_io.ldCancel.ld1Cancel.bits := s2_out.deqPortIdx
1083
1084  // fast wakeup
1085  io.ldu_io.fast_uop.valid := RegNext(
1086    !io.ldu_io.dcache.s1_disable_fast_wakeup &&
1087    s1_valid &&
1088    !s1_kill &&
1089    !io.tlb.resp.bits.miss &&
1090    !io.ldu_io.lsq.forward.dataInvalidFast
1091  ) && (s2_valid && !s2_out.rep_info.need_rep && !s2_ld_mmio && s2_ld_flow) && !s2_isvec
1092  io.ldu_io.fast_uop.bits := RegNext(s1_out.uop)
1093
1094  //
1095  io.ldu_io.s2_ptr_chasing                    := RegEnable(s1_try_ptr_chasing && !s1_cancel_ptr_chasing, false.B, s1_fire)
1096
1097  // prefetch train
1098  io.prefetch_train.valid              := s2_valid && !s2_actually_mmio && !s2_in.tlbMiss
1099  io.prefetch_train.bits.fromLsPipelineBundle(s2_in)
1100  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?
1101  io.prefetch_train.bits.meta_prefetch := Mux(s2_ld_flow, io.ldu_io.dcache.resp.bits.meta_prefetch, false.B)
1102  io.prefetch_train.bits.meta_access   := Mux(s2_ld_flow, io.ldu_io.dcache.resp.bits.meta_access, false.B)
1103
1104  io.prefetch_train_l1.valid              := s2_valid && !s2_actually_mmio && s2_ld_flow
1105  io.prefetch_train_l1.bits.fromLsPipelineBundle(s2_in)
1106  io.prefetch_train_l1.bits.miss          := io.ldu_io.dcache.resp.bits.miss
1107  io.prefetch_train_l1.bits.meta_prefetch := io.ldu_io.dcache.resp.bits.meta_prefetch
1108  io.prefetch_train_l1.bits.meta_access   := io.ldu_io.dcache.resp.bits.meta_access
1109  if (env.FPGAPlatform){
1110    io.ldu_io.dcache.s0_pc := DontCare
1111    io.ldu_io.dcache.s1_pc := DontCare
1112    io.ldu_io.dcache.s2_pc := DontCare
1113  }else{
1114    io.ldu_io.dcache.s0_pc := s0_out.uop.pc
1115    io.ldu_io.dcache.s1_pc := s1_out.uop.pc
1116    io.ldu_io.dcache.s2_pc := s2_out.uop.pc
1117  }
1118  io.ldu_io.dcache.s2_kill := s2_pmp.ld  || s2_actually_mmio || s2_kill
1119  io.stu_io.dcache.s2_kill := s2_pmp.st || s2_actually_mmio || s2_kill
1120  io.stu_io.dcache.s2_pc := s2_out.uop.pc
1121
1122  val s1_ld_left_fire = s1_valid && !s1_kill && s2_ready && s1_ld_flow
1123  val s2_ld_valid_dup = RegInit(0.U(6.W))
1124  s2_ld_valid_dup := 0x0.U(6.W)
1125  when (s1_ld_left_fire && !s1_out.isHWPrefetch && s1_ld_flow) { s2_ld_valid_dup := 0x3f.U(6.W) }
1126  when (s1_kill || s1_out.isHWPrefetch || !s1_ld_flow) { s2_ld_valid_dup := 0x0.U(6.W) }
1127  assert(RegNext((s2_valid === s2_ld_valid_dup(0)) || RegNext(s1_out.isHWPrefetch) || RegNext(!s1_ld_flow)))
1128
1129  // Pipeline
1130  // --------------------------------------------------------------------------------
1131  // stage 3
1132  // --------------------------------------------------------------------------------
1133  // writeback and update load queue
1134  val s3_valid        = RegNext(s2_valid && !s2_out.isHWPrefetch && !s2_out.uop.robIdx.needFlush(io.redirect))
1135  val s3_in           = RegEnable(s2_out, s2_fire)
1136  val s3_out          = Wire(Valid(new MemExuOutput))
1137  val s3_dcache_rep   = RegEnable(s2_dcache_fast_rep && s2_troublem, false.B, s2_fire)
1138  val s3_ld_valid_dup = RegEnable(s2_ld_valid_dup, s2_fire)
1139  val s3_fast_rep     = Wire(Bool())
1140  val s3_ld_flow      = RegNext(s2_ld_flow)
1141  val s3_troublem     = RegNext(s2_troublem)
1142  val s3_kill         = s3_in.uop.robIdx.needFlush(io.redirect)
1143  val s3_isvec        = RegNext(s2_isvec)
1144  s3_ready := !s3_valid || s3_kill || sx_can_go
1145
1146  // forwrad last beat
1147  val (s3_fwd_frm_d_chan, s3_fwd_data_frm_d_chan) = io.ldu_io.tl_d_channel.forward(s2_valid && s2_out.forward_tlDchannel, s2_out.mshrid, s2_out.paddr)
1148  val s3_fwd_data_valid = RegEnable(s2_fwd_data_valid, false.B, s2_valid)
1149  val s3_fwd_frm_d_chan_valid = (s3_fwd_frm_d_chan && s3_fwd_data_valid) && s3_ld_flow
1150
1151
1152  // s3 load fast replay
1153  io.ldu_io.fast_rep_out.valid := s3_valid &&
1154                                  s3_fast_rep &&
1155                                  !s3_in.uop.robIdx.needFlush(io.redirect) &&
1156                                  s3_ld_flow &&
1157                                  !s3_isvec
1158  io.ldu_io.fast_rep_out.bits := s3_in
1159
1160  io.ldu_io.lsq.ldin.valid := s3_valid &&
1161                              (!s3_fast_rep || !io.ldu_io.fast_rep_out.ready) &&
1162                              !s3_in.feedbacked &&
1163                              !s3_in.lateKill &&
1164                              s3_ld_flow &&
1165                              !s3_isvec
1166  io.ldu_io.lsq.ldin.bits := s3_in
1167  io.ldu_io.lsq.ldin.bits.miss := s3_in.miss && !s3_fwd_frm_d_chan_valid
1168
1169  /* <------- DANGEROUS: Don't change sequence here ! -------> */
1170  io.ldu_io.lsq.ldin.bits.data_wen_dup := s3_ld_valid_dup.asBools
1171  io.ldu_io.lsq.ldin.bits.replacementUpdated := io.ldu_io.dcache.resp.bits.replacementUpdated
1172  io.ldu_io.lsq.ldin.bits.missDbUpdated := RegNext(s2_fire && s2_in.hasROBEntry && !s2_in.tlbMiss && !s2_in.missDbUpdated)
1173
1174  val s3_dly_ld_err =
1175    if (EnableAccurateLoadError) {
1176      (s3_in.lateKill || io.ldu_io.dcache.resp.bits.error_delayed) && RegNext(io.csrCtrl.cache_error_enable)
1177    } else {
1178      WireInit(false.B)
1179    }
1180  io.ldu_io.s3_dly_ld_err := false.B // s3_dly_ld_err && s3_valid
1181  io.ldu_io.fast_rep_out.bits.delayedLoadError := s3_dly_ld_err
1182  io.ldu_io.lsq.ldin.bits.dcacheRequireReplay  := s3_dcache_rep
1183
1184  val s3_vp_match_fail = RegNext(io.ldu_io.lsq.forward.matchInvalid || io.ldu_io.sbuffer.matchInvalid) && s3_troublem
1185  val s3_ldld_rep_inst =
1186      io.ldu_io.lsq.ldld_nuke_query.resp.valid &&
1187      io.ldu_io.lsq.ldld_nuke_query.resp.bits.rep_frm_fetch &&
1188      RegNext(io.csrCtrl.ldld_vio_check_enable)
1189
1190  val s3_rep_info = WireInit(s3_in.rep_info)
1191  s3_rep_info.dcache_miss   := s3_in.rep_info.dcache_miss && !s3_fwd_frm_d_chan_valid && s3_troublem
1192  val s3_rep_frm_fetch = s3_vp_match_fail || s3_ldld_rep_inst
1193  val s3_sel_rep_cause = PriorityEncoderOH(s3_rep_info.cause.asUInt)
1194  val s3_force_rep     = s3_sel_rep_cause(LoadReplayCauses.C_TM) &&
1195                         !s3_in.uop.exceptionVec(loadAddrMisaligned) &&
1196                         s3_troublem
1197
1198  val s3_ld_exception = ExceptionNO.selectByFu(s3_in.uop.exceptionVec, LduCfg).asUInt.orR && s3_ld_flow
1199  val s3_st_exception = ExceptionNO.selectByFu(s3_in.uop.exceptionVec, StaCfg).asUInt.orR && !s3_ld_flow
1200  val s3_exception    = s3_ld_exception || s3_st_exception
1201  when ((s3_ld_exception || s3_dly_ld_err || s3_rep_frm_fetch) && !s3_force_rep) {
1202    io.ldu_io.lsq.ldin.bits.rep_info.cause := 0.U.asTypeOf(s3_rep_info.cause.cloneType)
1203  } .otherwise {
1204    io.ldu_io.lsq.ldin.bits.rep_info.cause := VecInit(s3_sel_rep_cause.asBools)
1205  }
1206
1207  // Int flow, if hit, will be writebacked at s3
1208  s3_out.valid                := s3_valid &&
1209                                (!s3_ld_flow && !s3_in.feedbacked || !io.ldu_io.lsq.ldin.bits.rep_info.need_rep) && !s3_in.mmio
1210  s3_out.bits.uop             := s3_in.uop
1211  s3_out.bits.uop.exceptionVec(loadAccessFault) := (s3_dly_ld_err  || s3_in.uop.exceptionVec(loadAccessFault)) && s3_ld_flow
1212  s3_out.bits.uop.replayInst := s3_rep_frm_fetch
1213  s3_out.bits.data            := s3_in.data
1214  s3_out.bits.debug.isMMIO    := s3_in.mmio
1215  s3_out.bits.debug.isPerfCnt := false.B
1216  s3_out.bits.debug.paddr     := s3_in.paddr
1217  s3_out.bits.debug.vaddr     := s3_in.vaddr
1218
1219  when (s3_force_rep) {
1220    s3_out.bits.uop.exceptionVec := 0.U.asTypeOf(s3_in.uop.exceptionVec.cloneType)
1221  }
1222
1223  /* <------- DANGEROUS: Don't change sequence here ! -------> */
1224  io.ldu_io.lsq.ldin.bits.uop := s3_out.bits.uop
1225
1226  val s3_revoke = s3_exception || io.ldu_io.lsq.ldin.bits.rep_info.need_rep
1227  io.ldu_io.lsq.ldld_nuke_query.revoke := s3_revoke
1228  io.ldu_io.lsq.stld_nuke_query.revoke := s3_revoke
1229
1230  // feedback slow
1231  s3_fast_rep := RegNext(s2_fast_rep) &&
1232                 !s3_in.feedbacked &&
1233                 !s3_in.lateKill &&
1234                 !s3_rep_frm_fetch &&
1235                 !s3_exception
1236
1237  val s3_fb_no_waiting = !s3_in.isLoadReplay && !(s3_fast_rep && io.ldu_io.fast_rep_out.ready) && !s3_in.feedbacked
1238
1239  //
1240  io.feedback_slow.valid                 := s3_valid && !s3_in.uop.robIdx.needFlush(io.redirect) && s3_fb_no_waiting && s3_ld_flow
1241  io.feedback_slow.bits.hit              := !io.ldu_io.lsq.ldin.bits.rep_info.need_rep || io.ldu_io.lsq.ldin.ready
1242  io.feedback_slow.bits.flushState       := s3_in.ptwBack
1243  io.feedback_slow.bits.robIdx           := s3_in.uop.robIdx
1244  io.feedback_slow.bits.sourceType       := RSFeedbackType.lrqFull
1245  io.feedback_slow.bits.dataInvalidSqIdx := DontCare
1246
1247  io.vec_stu_io.feedbackSlow.valid := RegNext(s2_vec_feedback.valid && !s2_out.uop.robIdx.needFlush(io.redirect))
1248  io.vec_stu_io.feedbackSlow.bits := RegNext(s2_vec_feedback.bits)
1249
1250  io.ldu_io.ldCancel.ld2Cancel.valid := s3_valid && (
1251    (io.ldu_io.lsq.ldin.bits.rep_info.need_rep && s3_in.isFirstIssue) ||
1252    s3_in.mmio
1253  ) && s3_ld_flow
1254  io.ldu_io.ldCancel.ld2Cancel.bits := s3_in.deqPortIdx
1255
1256  // data from dcache hit
1257  val s3_ld_raw_data_frm_cache = Wire(new LoadDataFromDcacheBundle)
1258  s3_ld_raw_data_frm_cache.respDcacheData       := io.ldu_io.dcache.resp.bits.data_delayed
1259  s3_ld_raw_data_frm_cache.forwardMask          := RegEnable(s2_fwd_mask, s2_valid)
1260  s3_ld_raw_data_frm_cache.forwardData          := RegEnable(s2_fwd_data, s2_valid)
1261  s3_ld_raw_data_frm_cache.uop                  := RegEnable(s2_out.uop, s2_valid)
1262  s3_ld_raw_data_frm_cache.addrOffset           := RegEnable(s2_out.paddr(3, 0), s2_valid)
1263  s3_ld_raw_data_frm_cache.forward_D            := RegEnable(s2_fwd_frm_d_chan, false.B, s2_valid) || s3_fwd_frm_d_chan_valid
1264  s3_ld_raw_data_frm_cache.forwardData_D        := Mux(s3_fwd_frm_d_chan_valid, s3_fwd_data_frm_d_chan, RegEnable(s2_fwd_data_frm_d_chan, s2_valid))
1265  s3_ld_raw_data_frm_cache.forward_mshr         := RegEnable(s2_fwd_frm_mshr, false.B, s2_valid)
1266  s3_ld_raw_data_frm_cache.forwardData_mshr     := RegEnable(s2_fwd_data_frm_mshr, s2_valid)
1267  s3_ld_raw_data_frm_cache.forward_result_valid := RegEnable(s2_fwd_data_valid, false.B, s2_valid)
1268
1269  val s3_merged_data_frm_cache = s3_ld_raw_data_frm_cache.mergedData()
1270  val s3_picked_data_frm_cache = LookupTree(s3_ld_raw_data_frm_cache.addrOffset, List(
1271    "b0000".U -> s3_merged_data_frm_cache(63,    0),
1272    "b0001".U -> s3_merged_data_frm_cache(63,    8),
1273    "b0010".U -> s3_merged_data_frm_cache(63,   16),
1274    "b0011".U -> s3_merged_data_frm_cache(63,   24),
1275    "b0100".U -> s3_merged_data_frm_cache(63,   32),
1276    "b0101".U -> s3_merged_data_frm_cache(63,   40),
1277    "b0110".U -> s3_merged_data_frm_cache(63,   48),
1278    "b0111".U -> s3_merged_data_frm_cache(63,   56),
1279    "b1000".U -> s3_merged_data_frm_cache(127,  64),
1280    "b1001".U -> s3_merged_data_frm_cache(127,  72),
1281    "b1010".U -> s3_merged_data_frm_cache(127,  80),
1282    "b1011".U -> s3_merged_data_frm_cache(127,  88),
1283    "b1100".U -> s3_merged_data_frm_cache(127,  96),
1284    "b1101".U -> s3_merged_data_frm_cache(127, 104),
1285    "b1110".U -> s3_merged_data_frm_cache(127, 112),
1286    "b1111".U -> s3_merged_data_frm_cache(127, 120)
1287  ))
1288  val s3_ld_data_frm_cache = rdataHelper(s3_ld_raw_data_frm_cache.uop, s3_picked_data_frm_cache)
1289
1290  // FIXME: add 1 cycle delay ?
1291  io.ldout.bits      := s3_out.bits
1292  io.ldout.bits.data := s3_ld_data_frm_cache
1293  io.ldout.valid     := s3_out.valid && !s3_out.bits.uop.robIdx.needFlush(io.redirect) && s3_ld_flow && !s3_isvec
1294
1295  // for uncache
1296  io.ldu_io.lsq.uncache.ready := true.B
1297
1298  // fast load to load forward
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
1303  // hybrid unit writeback to rob
1304  // delay params
1305  val SelectGroupSize   = RollbackGroupSize
1306  val lgSelectGroupSize = log2Ceil(SelectGroupSize)
1307  val TotalSelectCycles = scala.math.ceil(log2Ceil(LoadQueueRAWSize).toFloat / lgSelectGroupSize).toInt + 1
1308  val TotalDelayCycles  = TotalSelectCycles - 2
1309
1310  // writeback
1311  val sx_valid = Wire(Vec(TotalDelayCycles + 1, Bool()))
1312  val sx_ready = Wire(Vec(TotalDelayCycles + 1, Bool()))
1313  val sx_in    = Wire(Vec(TotalDelayCycles + 1, new MemExuOutput))
1314
1315  sx_can_go := sx_ready.head
1316  for (i <- 0 until TotalDelayCycles + 1) {
1317    if (i == 0) {
1318      sx_valid(i) := s3_valid &&
1319                    !s3_ld_flow &&
1320                    !s3_in.feedbacked &&
1321                    !s3_in.mmio
1322      sx_in(i)    := s3_out.bits
1323      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))
1324    } else {
1325      val cur_kill   = sx_in(i).uop.robIdx.needFlush(io.redirect)
1326      val cur_can_go = (if (i == TotalDelayCycles) io.stout.ready else sx_ready(i+1))
1327      val cur_fire   = sx_valid(i) && !cur_kill && cur_can_go
1328      val prev_fire  = sx_valid(i-1) && !sx_in(i-1).uop.robIdx.needFlush(io.redirect) && sx_ready(i)
1329
1330      sx_ready(i) := !sx_valid(i) || cur_kill || (if (i == TotalDelayCycles) io.stout.ready else sx_ready(i+1))
1331      val sx_valid_can_go = prev_fire || cur_fire || cur_kill
1332      sx_valid(i) := RegEnable(Mux(prev_fire, true.B, false.B), sx_valid_can_go)
1333      sx_in(i) := RegEnable(sx_in(i-1), prev_fire)
1334    }
1335  }
1336
1337  val sx_last_valid = sx_valid.takeRight(1).head
1338  val sx_last_ready = sx_ready.takeRight(1).head
1339  val sx_last_in    = sx_in.takeRight(1).head
1340
1341  sx_last_ready  := !sx_last_valid || sx_last_in.uop.robIdx.needFlush(io.redirect) || io.stout.ready
1342  io.stout.valid := sx_last_valid && !sx_last_in.uop.robIdx.needFlush(io.redirect) && FuType.isStore(sx_last_in.uop.fuType)
1343  io.stout.bits  := sx_last_in
1344
1345   // trigger
1346  val ld_trigger = FuType.isLoad(io.ldout.bits.uop.fuType)
1347  val last_valid_data = RegEnable(io.ldout.bits.data, io.stout.fire)
1348  val hit_ld_addr_trig_hit_vec = Wire(Vec(3, Bool()))
1349  val lq_ld_addr_trig_hit_vec = RegNext(io.ldu_io.lsq.trigger.lqLoadAddrTriggerHitVec)
1350  (0 until 3).map{i => {
1351    val tdata2    = RegNext(RegNext(io.ldu_io.trigger(i).tdata2))
1352    val matchType = RegNext(RegNext(io.ldu_io.trigger(i).matchType))
1353    val tEnable   = RegNext(RegNext(io.ldu_io.trigger(i).tEnable))
1354
1355    hit_ld_addr_trig_hit_vec(i)        := TriggerCmp(RegNext(s3_in.vaddr), tdata2, matchType, tEnable)
1356    io.ldu_io.trigger(i).addrHit       := Mux(io.ldout.valid && ld_trigger, hit_ld_addr_trig_hit_vec(i), lq_ld_addr_trig_hit_vec(i))
1357    io.ldu_io.trigger(i).lastDataHit   := TriggerCmp(last_valid_data, tdata2, matchType, tEnable)
1358  }}
1359  io.ldu_io.lsq.trigger.hitLoadAddrTriggerHitVec := hit_ld_addr_trig_hit_vec
1360
1361  // FIXME: please move this part to LoadQueueReplay
1362  io.ldu_io.debug_ls := DontCare
1363  io.stu_io.debug_ls := DontCare
1364  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
1365  io.stu_io.debug_ls.s1_robIdx := s1_in.uop.robIdx.value
1366
1367 // Topdown
1368  io.ldu_io.lsTopdownInfo.s1.robIdx          := s1_in.uop.robIdx.value
1369  io.ldu_io.lsTopdownInfo.s1.vaddr_valid     := s1_valid && s1_in.hasROBEntry
1370  io.ldu_io.lsTopdownInfo.s1.vaddr_bits      := s1_vaddr
1371  io.ldu_io.lsTopdownInfo.s2.robIdx          := s2_in.uop.robIdx.value
1372  io.ldu_io.lsTopdownInfo.s2.paddr_valid     := s2_fire && s2_in.hasROBEntry && !s2_in.tlbMiss
1373  io.ldu_io.lsTopdownInfo.s2.paddr_bits      := s2_in.paddr
1374  io.ldu_io.lsTopdownInfo.s2.first_real_miss := io.ldu_io.dcache.resp.bits.real_miss
1375  io.ldu_io.lsTopdownInfo.s2.cache_miss_en   := s2_fire && s2_in.hasROBEntry && !s2_in.tlbMiss && !s2_in.missDbUpdated
1376
1377  // perf cnt
1378  XSPerfAccumulate("s0_in_valid",                  io.lsin.valid)
1379  XSPerfAccumulate("s0_in_block",                  io.lsin.valid && !io.lsin.fire)
1380  XSPerfAccumulate("s0_in_fire_first_issue",       s0_valid && s0_isFirstIssue)
1381  XSPerfAccumulate("s0_lsq_fire_first_issue",      io.ldu_io.replay.fire)
1382  XSPerfAccumulate("s0_ldu_fire_first_issue",      io.lsin.fire && s0_isFirstIssue)
1383  XSPerfAccumulate("s0_fast_replay_issue",         io.ldu_io.fast_rep_in.fire)
1384  XSPerfAccumulate("s0_stall_out",                 s0_valid && !s0_can_go)
1385  XSPerfAccumulate("s0_stall_ld_dcache",           s0_valid && !io.ldu_io.dcache.req.ready)
1386  XSPerfAccumulate("s0_stall_st_dcache",           s0_valid && !io.stu_io.dcache.req.ready)
1387  XSPerfAccumulate("s0_addr_spec_success",         s0_fire && s0_vaddr(VAddrBits-1, 12) === io.lsin.bits.src(0)(VAddrBits-1, 12))
1388  XSPerfAccumulate("s0_addr_spec_failed",          s0_fire && s0_vaddr(VAddrBits-1, 12) =/= io.lsin.bits.src(0)(VAddrBits-1, 12))
1389  XSPerfAccumulate("s0_addr_spec_success_once",    s0_fire && s0_vaddr(VAddrBits-1, 12) === io.lsin.bits.src(0)(VAddrBits-1, 12) && s0_isFirstIssue)
1390  XSPerfAccumulate("s0_addr_spec_failed_once",     s0_fire && s0_vaddr(VAddrBits-1, 12) =/= io.lsin.bits.src(0)(VAddrBits-1, 12) && s0_isFirstIssue)
1391  XSPerfAccumulate("s0_forward_tl_d_channel",      s0_out.forward_tlDchannel)
1392  XSPerfAccumulate("s0_hardware_prefetch_fire",    s0_fire && s0_hw_prf_select)
1393  XSPerfAccumulate("s0_software_prefetch_fire",    s0_fire && s0_prf && s0_int_iss_select)
1394  XSPerfAccumulate("s0_hardware_prefetch_blocked", io.ldu_io.prefetch_req.valid && !s0_hw_prf_select)
1395  XSPerfAccumulate("s0_hardware_prefetch_total",   io.ldu_io.prefetch_req.valid)
1396
1397  XSPerfAccumulate("s1_in_valid",                  s1_valid)
1398  XSPerfAccumulate("s1_in_fire",                   s1_fire)
1399  XSPerfAccumulate("s1_in_fire_first_issue",       s1_fire && s1_in.isFirstIssue)
1400  XSPerfAccumulate("s1_tlb_miss",                  s1_fire && s1_tlb_miss)
1401  XSPerfAccumulate("s1_tlb_miss_first_issue",      s1_fire && s1_tlb_miss && s1_in.isFirstIssue)
1402  XSPerfAccumulate("s1_stall_out",                 s1_valid && !s1_can_go)
1403  XSPerfAccumulate("s1_late_kill",                 s1_valid && s1_fast_rep_kill)
1404
1405  XSPerfAccumulate("s2_in_valid",                  s2_valid)
1406  XSPerfAccumulate("s2_in_fire",                   s2_fire)
1407  XSPerfAccumulate("s2_in_fire_first_issue",       s2_fire && s2_in.isFirstIssue)
1408  XSPerfAccumulate("s2_dcache_miss",               s2_fire && io.ldu_io.dcache.resp.bits.miss)
1409  XSPerfAccumulate("s2_dcache_miss_first_issue",   s2_fire && io.ldu_io.dcache.resp.bits.miss && s2_in.isFirstIssue)
1410  XSPerfAccumulate("s2_dcache_real_miss_first_issue",   s2_fire && io.ldu_io.dcache.resp.bits.miss && s2_in.isFirstIssue)
1411  XSPerfAccumulate("s2_full_forward",              s2_fire && s2_full_fwd)
1412  XSPerfAccumulate("s2_dcache_miss_full_forward",  s2_fire && s2_dcache_miss)
1413  XSPerfAccumulate("s2_fwd_frm_d_can",             s2_valid && s2_fwd_frm_d_chan)
1414  XSPerfAccumulate("s2_fwd_frm_d_chan_or_mshr",    s2_valid && s2_fwd_frm_d_chan_or_mshr)
1415  XSPerfAccumulate("s2_stall_out",                 s2_fire && !s2_can_go)
1416  XSPerfAccumulate("s2_prefetch",                  s2_fire && s2_prf)
1417  XSPerfAccumulate("s2_prefetch_ignored",          s2_fire && s2_prf && s2_mq_nack) // ignore prefetch for mshr full / miss req port conflict
1418  XSPerfAccumulate("s2_prefetch_miss",             s2_fire && s2_prf && io.ldu_io.dcache.resp.bits.miss) // prefetch req miss in l1
1419  XSPerfAccumulate("s2_prefetch_hit",              s2_fire && s2_prf && !io.ldu_io.dcache.resp.bits.miss) // prefetch req hit in l1
1420  XSPerfAccumulate("s2_prefetch_accept",           s2_fire && s2_prf && io.ldu_io.dcache.resp.bits.miss && !s2_mq_nack) // prefetch a missed line in l1, and l1 accepted it
1421  XSPerfAccumulate("s2_forward_req",               s2_fire && s2_in.forward_tlDchannel)
1422  XSPerfAccumulate("s2_successfully_forward_channel_D", s2_fire && s2_fwd_frm_d_chan && s2_fwd_data_valid)
1423  XSPerfAccumulate("s2_successfully_forward_mshr",      s2_fire && s2_fwd_frm_mshr && s2_fwd_data_valid)
1424
1425  XSPerfAccumulate("s3_fwd_frm_d_chan",            s3_valid && s3_fwd_frm_d_chan_valid)
1426
1427  XSPerfAccumulate("load_to_load_forward",                      s1_try_ptr_chasing && !s1_ptr_chasing_canceled)
1428  XSPerfAccumulate("load_to_load_forward_try",                  s1_try_ptr_chasing)
1429  XSPerfAccumulate("load_to_load_forward_fail",                 s1_cancel_ptr_chasing)
1430  XSPerfAccumulate("load_to_load_forward_fail_cancelled",       s1_cancel_ptr_chasing && s1_ptr_chasing_canceled)
1431  XSPerfAccumulate("load_to_load_forward_fail_wakeup_mismatch", s1_cancel_ptr_chasing && !s1_ptr_chasing_canceled && s1_not_fast_match)
1432  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)
1433  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)
1434  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)
1435
1436  // bug lyq: some signals in perfEvents are no longer suitable for the current MemBlock design
1437  // hardware performance counter
1438  val perfEvents = Seq(
1439    ("load_s0_in_fire         ", s0_fire                                                        ),
1440    ("load_to_load_forward    ", s1_fire && s1_try_ptr_chasing && !s1_ptr_chasing_canceled      ),
1441    ("stall_dcache            ", s0_valid && s0_can_go && !io.ldu_io.dcache.req.ready           ),
1442    ("load_s1_in_fire         ", s0_fire                                                        ),
1443    ("load_s1_tlb_miss        ", s1_fire && io.tlb.resp.bits.miss                               ),
1444    ("load_s2_in_fire         ", s1_fire                                                        ),
1445    ("load_s2_dcache_miss     ", s2_fire && io.ldu_io.dcache.resp.bits.miss                     ),
1446  )
1447  generatePerfEvent()
1448}