xref: /XiangShan/src/main/scala/xiangshan/mem/pipeline/HybridUnit.scala (revision a9715d9daab0064634235a9597b254e34fc8d3fa)
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.backend.fu.util.SdtrigExt
33import xiangshan.cache._
34import xiangshan.cache.wpu.ReplayCarry
35import xiangshan.cache.mmu.{TlbCmd, TlbHintReq, TlbReq, TlbRequestIO, TlbResp}
36import xiangshan.mem.mdp._
37
38class HybridUnit(implicit p: Parameters) extends XSModule
39  with HasLoadHelper
40  with HasPerfEvents
41  with HasDCacheParameters
42  with HasCircularQueuePtrHelper
43  with HasVLSUParameters
44  with SdtrigExt
45{
46  val io = IO(new Bundle() {
47    // control
48    val redirect      = Flipped(ValidIO(new Redirect))
49    val csrCtrl       = Flipped(new CustomCSRCtrlIO)
50
51    // flow in
52    val lsin          = Flipped(Decoupled(new MemExuInput))
53
54    // flow out
55    val ldout = DecoupledIO(new MemExuOutput)
56    val stout = DecoupledIO(new MemExuOutput)
57
58    val ldu_io = new Bundle() {
59      // dcache
60      val dcache        = new DCacheLoadIO
61
62      // data path
63      val sbuffer       = new LoadForwardQueryIO
64      val vec_forward   = new LoadForwardQueryIO
65      val lsq           = new LoadToLsqIO
66      val tl_d_channel  = Input(new DcacheToLduForwardIO)
67      val forward_mshr  = Flipped(new LduToMissqueueForwardIO)
68      val refill        = Flipped(ValidIO(new Refill))
69      val tlb_hint      = Flipped(new TlbHintReq)
70      val l2_hint       = Input(Valid(new L2ToL1Hint))
71
72      // fast wakeup
73      val fast_uop = ValidIO(new DynInst) // early wakeup signal generated in load_s1, send to RS in load_s2
74
75      // trigger
76      val trigger = Vec(TriggerNum, new LoadUnitTriggerIO)
77
78      // load to load fast path
79      val l2l_fwd_in    = Input(new LoadToLoadIO)
80      val l2l_fwd_out   = Output(new LoadToLoadIO)
81
82      val ld_fast_match    = Input(Bool())
83      val ld_fast_fuOpType = Input(UInt())
84      val ld_fast_imm      = Input(UInt(12.W))
85
86      // hardware prefetch to l1 cache req
87      val prefetch_req    = Flipped(ValidIO(new L1PrefetchReq))
88
89      // iq cancel
90      val ldCancel = Output(new LoadCancelIO()) // use to cancel the uops waked by this load, and cancel load
91
92      // iq wakeup, use to wakeup consumer uop at load s2
93      val wakeup = ValidIO(new DynInst)
94
95      // load ecc error
96      val s3_dly_ld_err = Output(Bool()) // Note that io.s3_dly_ld_err and io.lsq.s3_dly_ld_err is different
97
98      // schedule error query
99      val stld_nuke_query = Flipped(Vec(StorePipelineWidth, Valid(new StoreNukeQueryIO)))
100
101      // queue-based replay
102      val replay       = Flipped(Decoupled(new LsPipelineBundle))
103      val lq_rep_full  = Input(Bool())
104
105      // misc
106      val s2_ptr_chasing = Output(Bool()) // provide right pc for hw prefetch
107
108      // Load fast replay path
109      val fast_rep_in  = Flipped(Decoupled(new LqWriteBundle))
110      val fast_rep_out = Decoupled(new LqWriteBundle)
111
112      // Load RAR rollback
113      val rollback = Valid(new Redirect)
114
115      // perf
116      val debug_ls         = Output(new DebugLsInfoBundle)
117      val lsTopdownInfo    = Output(new LsTopdownInfo)
118    }
119
120    val stu_io = new Bundle() {
121      val dcache          = new DCacheStoreIO
122      val prefetch_req    = Flipped(DecoupledIO(new StorePrefetchReq))
123      val issue           = Valid(new MemExuInput)
124      val lsq             = ValidIO(new LsPipelineBundle)
125      val lsq_replenish   = Output(new LsPipelineBundle())
126      val stld_nuke_query = Valid(new StoreNukeQueryIO)
127      val st_mask_out     = Valid(new StoreMaskBundle)
128      val debug_ls        = Output(new DebugLsInfoBundle)
129    }
130
131    val vec_stu_io = new Bundle() {
132      val in = Flipped(DecoupledIO(new VecStorePipeBundle()))
133      val isFirstIssue = Input(Bool())
134      val lsq = ValidIO(new LsPipelineBundle())
135      val feedbackSlow = ValidIO(new VSFQFeedback)
136    }
137
138    // prefetch
139    val prefetch_train            = ValidIO(new LdPrefetchTrainBundle()) // provide prefetch info to sms
140    val prefetch_train_l1         = ValidIO(new LdPrefetchTrainBundle()) // provide prefetch info to stream & stride
141    val canAcceptLowConfPrefetch  = Output(Bool())
142    val canAcceptHighConfPrefetch = Output(Bool())
143    val correctMissTrain          = Input(Bool())
144
145    // data path
146    val tlb           = new TlbRequestIO(2)
147    val pmp           = Flipped(new PMPRespBundle()) // arrive same to tlb now
148
149    // rs feedback
150    val feedback_fast = ValidIO(new RSFeedback) // stage 2
151    val feedback_slow = ValidIO(new RSFeedback) // stage 3
152  })
153
154  val StorePrefetchL1Enabled = EnableStorePrefetchAtCommit || EnableStorePrefetchAtIssue || EnableStorePrefetchSPB
155  val s1_ready, s2_ready, s3_ready, sx_can_go = WireInit(false.B)
156
157  // Pipeline
158  // --------------------------------------------------------------------------------
159  // stage 0
160  // --------------------------------------------------------------------------------
161  // generate addr, use addr to query DCache and DTLB
162  val s0_valid         = Wire(Bool())
163  val s0_dcache_ready  = Wire(Bool())
164  val s0_kill          = Wire(Bool())
165  val s0_vaddr         = Wire(UInt(VAddrBits.W))
166  val s0_mask          = Wire(UInt((VLEN/8).W))
167  val s0_uop           = Wire(new DynInst)
168  val s0_has_rob_entry = Wire(Bool())
169  val s0_rsIdx         = Wire(UInt(log2Up(MemIQSizeMax).W))
170  val s0_mshrid        = Wire(UInt())
171  val s0_try_l2l       = Wire(Bool())
172  val s0_rep_carry     = Wire(new ReplayCarry(nWays))
173  val s0_isFirstIssue  = Wire(Bool())
174  val s0_fast_rep      = Wire(Bool())
175  val s0_ld_rep        = Wire(Bool())
176  val s0_l2l_fwd       = Wire(Bool())
177  val s0_sched_idx     = Wire(UInt())
178  val s0_can_go        = s1_ready
179  val s0_fire          = s0_valid && s0_dcache_ready && s0_can_go
180  val s0_out           = Wire(new LqWriteBundle)
181  // vector
182  val s0_isvec = WireInit(false.B)
183  val s0_vecActive = WireInit(true.B)
184  val s0_flowPtr = WireInit(0.U.asTypeOf(new VsFlowPtr))
185  val s0_isLastElem = WireInit(false.B)
186
187  // load flow select/gen
188  // src0: super load replayed by LSQ (cache miss replay) (io.ldu_io.replay)
189  // src1: fast load replay (io.ldu_io.fast_rep_in)
190  // src2: load replayed by LSQ (io.ldu_io.replay)
191  // src3: hardware prefetch from prefetchor (high confidence) (io.prefetch)
192  // src4: int read / software prefetch first issue from RS (io.in)
193  // src5: vec read first issue from RS (TODO)
194  // src6: load try pointchaising when no issued or replayed load (io.fastpath)
195  // src7: hardware prefetch from prefetchor (high confidence) (io.prefetch)
196  // priority: high to low
197  val s0_ld_flow             = FuType.isLoad(s0_uop.fuType) || FuType.isVLoad(s0_uop.fuType)
198  val s0_rep_stall           = io.lsin.valid && isAfter(io.ldu_io.replay.bits.uop.robIdx, io.lsin.bits.uop.robIdx)
199  val s0_super_ld_rep_valid  = io.ldu_io.replay.valid && io.ldu_io.replay.bits.forward_tlDchannel
200  val s0_ld_fast_rep_valid   = io.ldu_io.fast_rep_in.valid
201  val s0_ld_rep_valid        = io.ldu_io.replay.valid && !io.ldu_io.replay.bits.forward_tlDchannel && !s0_rep_stall
202  val s0_high_conf_prf_valid = io.ldu_io.prefetch_req.valid && io.ldu_io.prefetch_req.bits.confidence > 0.U
203  val s0_int_iss_valid       = io.lsin.valid // int flow first issue or software prefetch
204  val s0_vec_iss_valid       = io.vec_stu_io.in.valid
205  val s0_l2l_fwd_valid       = io.ldu_io.l2l_fwd_in.valid && io.ldu_io.ld_fast_match
206  val s0_low_conf_prf_valid  = io.ldu_io.prefetch_req.valid && io.ldu_io.prefetch_req.bits.confidence === 0.U
207  dontTouch(s0_super_ld_rep_valid)
208  dontTouch(s0_ld_fast_rep_valid)
209  dontTouch(s0_ld_rep_valid)
210  dontTouch(s0_high_conf_prf_valid)
211  dontTouch(s0_int_iss_valid)
212  dontTouch(s0_vec_iss_valid)
213  dontTouch(s0_l2l_fwd_valid)
214  dontTouch(s0_low_conf_prf_valid)
215
216  // load flow source ready
217  val s0_super_ld_rep_ready  = WireInit(true.B)
218  val s0_ld_fast_rep_ready   = !s0_super_ld_rep_valid
219  val s0_ld_rep_ready        = !s0_super_ld_rep_valid &&
220                               !s0_ld_fast_rep_valid
221  val s0_high_conf_prf_ready = !s0_super_ld_rep_valid &&
222                               !s0_ld_fast_rep_valid &&
223                               !s0_ld_rep_valid
224
225  val s0_int_iss_ready       = !s0_super_ld_rep_valid &&
226                               !s0_ld_fast_rep_valid &&
227                               !s0_ld_rep_valid &&
228                               !s0_high_conf_prf_valid
229
230  val s0_vec_iss_ready       = !s0_super_ld_rep_valid &&
231                               !s0_ld_fast_rep_valid &&
232                               !s0_ld_rep_valid &&
233                               !s0_high_conf_prf_valid &&
234                               !s0_int_iss_valid
235
236  val s0_l2l_fwd_ready       = !s0_super_ld_rep_valid &&
237                               !s0_ld_fast_rep_valid &&
238                               !s0_ld_rep_valid &&
239                               !s0_high_conf_prf_valid &&
240                               !s0_int_iss_valid &&
241                               !s0_vec_iss_valid
242
243  val s0_low_conf_prf_ready  = !s0_super_ld_rep_valid &&
244                               !s0_ld_fast_rep_valid &&
245                               !s0_ld_rep_valid &&
246                               !s0_high_conf_prf_valid &&
247                               !s0_int_iss_valid &&
248                               !s0_vec_iss_valid &&
249                               !s0_l2l_fwd_valid
250  dontTouch(s0_super_ld_rep_ready)
251  dontTouch(s0_ld_fast_rep_ready)
252  dontTouch(s0_ld_rep_ready)
253  dontTouch(s0_high_conf_prf_ready)
254  dontTouch(s0_int_iss_ready)
255  dontTouch(s0_vec_iss_ready)
256  dontTouch(s0_l2l_fwd_ready)
257  dontTouch(s0_low_conf_prf_ready)
258
259  // load flow source select (OH)
260  val s0_super_ld_rep_select = s0_super_ld_rep_valid && s0_super_ld_rep_ready
261  val s0_ld_fast_rep_select  = s0_ld_fast_rep_valid && s0_ld_fast_rep_ready
262  val s0_ld_rep_select       = s0_ld_rep_valid && s0_ld_rep_ready
263  val s0_hw_prf_select       = s0_high_conf_prf_ready && s0_high_conf_prf_valid ||
264                               s0_low_conf_prf_ready && s0_low_conf_prf_valid
265  val s0_int_iss_select      = s0_int_iss_ready && s0_int_iss_valid
266  val s0_vec_iss_select      = s0_vec_iss_ready && s0_vec_iss_valid
267  val s0_l2l_fwd_select      = s0_l2l_fwd_ready && s0_l2l_fwd_valid
268  dontTouch(s0_super_ld_rep_select)
269  dontTouch(s0_ld_fast_rep_select)
270  dontTouch(s0_ld_rep_select)
271  dontTouch(s0_hw_prf_select)
272  dontTouch(s0_int_iss_select)
273  dontTouch(s0_vec_iss_select)
274  dontTouch(s0_l2l_fwd_select)
275
276  s0_valid := (s0_super_ld_rep_valid ||
277               s0_ld_fast_rep_valid ||
278               s0_ld_rep_valid ||
279               s0_high_conf_prf_valid ||
280               s0_int_iss_valid ||
281               s0_vec_iss_valid ||
282               s0_l2l_fwd_valid ||
283               s0_low_conf_prf_valid) && !s0_kill
284
285  // which is S0's out is ready and dcache is ready
286  val s0_try_ptr_chasing      = s0_l2l_fwd_select
287  val s0_do_try_ptr_chasing   = s0_try_ptr_chasing && s0_can_go && io.ldu_io.dcache.req.ready
288  val s0_ptr_chasing_vaddr    = io.ldu_io.l2l_fwd_in.data(5, 0) +& io.ldu_io.ld_fast_imm(5, 0)
289  val s0_ptr_chasing_canceled = WireInit(false.B)
290  s0_kill := s0_ptr_chasing_canceled || (s0_out.uop.robIdx.needFlush(io.redirect) && !s0_try_ptr_chasing)
291
292  // prefetch related ctrl signal
293  val s0_prf    = Wire(Bool())
294  val s0_prf_rd = Wire(Bool())
295  val s0_prf_wr = Wire(Bool())
296  val s0_hw_prf = s0_hw_prf_select
297
298  io.canAcceptLowConfPrefetch  := s0_low_conf_prf_ready
299  io.canAcceptHighConfPrefetch := s0_high_conf_prf_ready
300
301  if (StorePrefetchL1Enabled) {
302    s0_dcache_ready := Mux(s0_ld_flow, io.ldu_io.dcache.req.ready, io.stu_io.dcache.req.ready)
303  } else {
304    s0_dcache_ready := Mux(s0_ld_flow, io.ldu_io.dcache.req.ready, true.B)
305  }
306
307  // query DTLB
308  io.tlb.req.valid                   := s0_valid && s0_dcache_ready
309  io.tlb.req.bits.cmd                := Mux(s0_prf,
310                                         Mux(s0_prf_wr, TlbCmd.write, TlbCmd.read),
311                                         Mux(s0_ld_flow, TlbCmd.read, TlbCmd.write)
312                                       )
313  io.tlb.req.bits.vaddr              := Mux(s0_hw_prf_select, io.ldu_io.prefetch_req.bits.paddr, s0_vaddr)
314  io.tlb.req.bits.size               := Mux(s0_isvec, io.vec_stu_io.in.bits.alignedType, LSUOpType.size(s0_uop.fuOpType))
315  io.tlb.req.bits.kill               := s0_kill
316  io.tlb.req.bits.memidx.is_ld       := s0_ld_flow
317  io.tlb.req.bits.memidx.is_st       := !s0_ld_flow
318  io.tlb.req.bits.memidx.idx         := s0_uop.lqIdx.value
319  io.tlb.req.bits.debug.robIdx       := s0_uop.robIdx
320  io.tlb.req.bits.no_translate       := s0_hw_prf_select  // hw b.reqetch addr does not need to be translated
321  io.tlb.req.bits.debug.pc           := s0_uop.pc
322  io.tlb.req.bits.debug.isFirstIssue := s0_isFirstIssue
323
324  // query DCache
325  // for load
326  io.ldu_io.dcache.req.valid             := s0_valid && s0_dcache_ready && s0_ld_flow
327  io.ldu_io.dcache.req.bits.cmd          :=  Mux(s0_prf_rd, MemoryOpConstants.M_PFR,
328                                              Mux(s0_prf_wr, MemoryOpConstants.M_PFW, MemoryOpConstants.M_XRD))
329  io.ldu_io.dcache.req.bits.vaddr        := s0_vaddr
330  io.ldu_io.dcache.req.bits.mask         := s0_mask
331  io.ldu_io.dcache.req.bits.data         := DontCare
332  io.ldu_io.dcache.req.bits.isFirstIssue := s0_isFirstIssue
333  io.ldu_io.dcache.req.bits.instrtype    := Mux(s0_prf, DCACHE_PREFETCH_SOURCE.U, LOAD_SOURCE.U)
334  io.ldu_io.dcache.req.bits.debug_robIdx := s0_uop.robIdx.value
335  io.ldu_io.dcache.req.bits.replayCarry  := s0_rep_carry
336  io.ldu_io.dcache.req.bits.id           := DontCare // TODO: update cache meta
337  io.ldu_io.dcache.pf_source             := Mux(s0_hw_prf_select, io.ldu_io.prefetch_req.bits.pf_source.value, L1_HW_PREFETCH_NULL)
338
339  // for store
340  io.stu_io.dcache.req.valid             := s0_valid && s0_dcache_ready && !s0_ld_flow && !s0_prf
341  io.stu_io.dcache.req.bits.cmd          := MemoryOpConstants.M_PFW
342  io.stu_io.dcache.req.bits.vaddr        := s0_vaddr
343  io.stu_io.dcache.req.bits.instrtype    := Mux(s0_prf, DCACHE_PREFETCH_SOURCE.U, STORE_SOURCE.U)
344
345  // load flow priority mux
346  def fromNullSource() = {
347    s0_vaddr         := 0.U
348    s0_mask          := 0.U
349    s0_uop           := 0.U.asTypeOf(new DynInst)
350    s0_try_l2l       := false.B
351    s0_has_rob_entry := false.B
352    s0_rsIdx         := 0.U
353    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
354    s0_mshrid        := 0.U
355    s0_isFirstIssue  := false.B
356    s0_fast_rep      := false.B
357    s0_ld_rep        := false.B
358    s0_l2l_fwd       := false.B
359    s0_prf           := false.B
360    s0_prf_rd        := false.B
361    s0_prf_wr        := false.B
362    s0_sched_idx     := 0.U
363  }
364
365  def fromFastReplaySource(src: LqWriteBundle) = {
366    s0_vaddr         := src.vaddr
367    s0_mask          := src.mask
368    s0_uop           := src.uop
369    s0_try_l2l       := false.B
370    s0_has_rob_entry := src.hasROBEntry
371    s0_rep_carry     := src.rep_info.rep_carry
372    s0_mshrid        := src.rep_info.mshr_id
373    s0_rsIdx         := src.rsIdx
374    s0_isFirstIssue  := false.B
375    s0_fast_rep      := true.B
376    s0_ld_rep        := src.isLoadReplay
377    s0_l2l_fwd       := false.B
378    s0_prf           := LSUOpType.isPrefetch(src.uop.fuOpType)
379    s0_prf_rd        := src.uop.fuOpType === LSUOpType.prefetch_r
380    s0_prf_wr        := src.uop.fuOpType === LSUOpType.prefetch_w
381    s0_sched_idx     := src.schedIndex
382  }
383
384  def fromNormalReplaySource(src: LsPipelineBundle) = {
385    s0_vaddr         := src.vaddr
386    s0_mask          := genVWmask(src.vaddr, src.uop.fuOpType(1, 0))
387    s0_uop           := src.uop
388    s0_try_l2l       := false.B
389    s0_has_rob_entry := true.B
390    s0_rsIdx         := src.rsIdx
391    s0_rep_carry     := src.replayCarry
392    s0_mshrid        := src.mshrid
393    s0_isFirstIssue  := false.B
394    s0_fast_rep      := false.B
395    s0_ld_rep        := true.B
396    s0_l2l_fwd       := false.B
397    s0_prf           := LSUOpType.isPrefetch(src.uop.fuOpType)
398    s0_prf_rd        := src.uop.fuOpType === LSUOpType.prefetch_r
399    s0_prf_wr        := src.uop.fuOpType === LSUOpType.prefetch_w
400    s0_sched_idx     := src.schedIndex
401  }
402
403  def fromPrefetchSource(src: L1PrefetchReq) = {
404    s0_vaddr         := src.getVaddr()
405    s0_mask          := 0.U
406    s0_uop           := DontCare
407    s0_try_l2l       := false.B
408    s0_has_rob_entry := false.B
409    s0_rsIdx         := 0.U
410    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
411    s0_mshrid        := 0.U
412    s0_isFirstIssue  := false.B
413    s0_fast_rep      := false.B
414    s0_ld_rep        := false.B
415    s0_l2l_fwd       := false.B
416    s0_prf           := true.B
417    s0_prf_rd        := !src.is_store
418    s0_prf_wr        := src.is_store
419    s0_sched_idx     := 0.U
420  }
421
422  def fromIntIssueSource(src: MemExuInput) = {
423    s0_vaddr         := src.src(0) + SignExt(src.uop.imm(11, 0), VAddrBits)
424    s0_mask          := genVWmask(s0_vaddr, src.uop.fuOpType(1,0))
425    s0_uop           := src.uop
426    s0_try_l2l       := false.B
427    s0_has_rob_entry := true.B
428    s0_rsIdx         := src.iqIdx
429    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
430    s0_mshrid        := 0.U
431    s0_isFirstIssue  := true.B
432    s0_fast_rep      := false.B
433    s0_ld_rep        := false.B
434    s0_l2l_fwd       := false.B
435    s0_prf           := LSUOpType.isPrefetch(src.uop.fuOpType)
436    s0_prf_rd        := src.uop.fuOpType === LSUOpType.prefetch_r
437    s0_prf_wr        := src.uop.fuOpType === LSUOpType.prefetch_w
438    s0_sched_idx     := 0.U
439  }
440
441  def fromVecIssueSource(src: VecStorePipeBundle) = {
442    // For now, vector port handles only vector store flows
443    s0_vaddr         := src.vaddr
444    s0_mask          := src.mask
445    s0_uop           := src.uop
446    s0_try_l2l       := false.B
447    s0_has_rob_entry := true.B
448    s0_rsIdx         := 0.U
449    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
450    s0_mshrid        := 0.U
451    s0_isFirstIssue  := src.isFirstIssue
452    s0_fast_rep      := false.B
453    s0_ld_rep        := false.B
454    s0_l2l_fwd       := false.B
455    s0_prf           := false.B
456    s0_prf_rd        := false.B
457    s0_prf_wr        := false.B
458    s0_sched_idx     := 0.U
459
460    s0_isvec         := true.B
461    s0_vecActive           := io.vec_stu_io.in.bits.vecActive
462    s0_flowPtr       := io.vec_stu_io.in.bits.flowPtr
463    s0_isLastElem    := io.vec_stu_io.in.bits.isLastElem
464  }
465
466  def fromLoadToLoadSource(src: LoadToLoadIO) = {
467    s0_vaddr              := Cat(src.data(XLEN-1, 6), s0_ptr_chasing_vaddr(5,0))
468    s0_mask               := genVWmask(s0_vaddr, io.ldu_io.ld_fast_fuOpType(1, 0))
469    // When there's no valid instruction from RS and LSQ, we try the load-to-load forwarding.
470    // Assume the pointer chasing is always ld.
471    s0_uop.fuOpType  := io.ldu_io.ld_fast_fuOpType
472    s0_try_l2l            := true.B
473    // we dont care s0_isFirstIssue and s0_rsIdx and s0_sqIdx in S0 when trying pointchasing
474    // because these signals will be updated in S1
475    s0_has_rob_entry      := false.B
476    s0_rsIdx              := 0.U
477    s0_mshrid             := 0.U
478    s0_rep_carry          := 0.U.asTypeOf(s0_rep_carry.cloneType)
479    s0_isFirstIssue       := true.B
480    s0_fast_rep           := false.B
481    s0_ld_rep             := false.B
482    s0_l2l_fwd            := true.B
483    s0_prf                := false.B
484    s0_prf_rd             := false.B
485    s0_prf_wr             := false.B
486    s0_sched_idx          := 0.U
487  }
488
489  // set default
490  s0_uop := DontCare
491  when (s0_super_ld_rep_select)      { fromNormalReplaySource(io.ldu_io.replay.bits)     }
492  .elsewhen (s0_ld_fast_rep_select)  { fromFastReplaySource(io.ldu_io.fast_rep_in.bits)  }
493  .elsewhen (s0_ld_rep_select)       { fromNormalReplaySource(io.ldu_io.replay.bits)     }
494  .elsewhen (s0_hw_prf_select)       { fromPrefetchSource(io.ldu_io.prefetch_req.bits)   }
495  .elsewhen (s0_int_iss_select)      { fromIntIssueSource(io.lsin.bits)                  }
496  .elsewhen (s0_vec_iss_select)      { fromVecIssueSource(io.vec_stu_io.in.bits)         }
497  .otherwise {
498    if (EnableLoadToLoadForward) {
499      fromLoadToLoadSource(io.ldu_io.l2l_fwd_in)
500    } else {
501      fromNullSource()
502    }
503  }
504
505  // address align check
506  val s0_addr_aligned = LookupTree(Mux(s0_isvec, io.vec_stu_io.in.bits.alignedType, s0_uop.fuOpType(1, 0)), List(
507    "b00".U   -> true.B,                   //b
508    "b01".U   -> (s0_vaddr(0)    === 0.U), //h
509    "b10".U   -> (s0_vaddr(1, 0) === 0.U), //w
510    "b11".U   -> (s0_vaddr(2, 0) === 0.U)  //d
511  ))
512
513  // accept load flow if dcache ready (tlb is always ready)
514  // TODO: prefetch need writeback to loadQueueFlag
515  s0_out               := DontCare
516  s0_out.rsIdx         := s0_rsIdx
517  s0_out.vaddr         := s0_vaddr
518  s0_out.mask          := s0_mask
519  s0_out.uop           := s0_uop
520  s0_out.isFirstIssue  := s0_isFirstIssue
521  s0_out.hasROBEntry   := s0_has_rob_entry
522  s0_out.isPrefetch    := s0_prf
523  s0_out.isHWPrefetch  := s0_hw_prf
524  s0_out.isFastReplay  := s0_fast_rep
525  s0_out.isLoadReplay  := s0_ld_rep
526  s0_out.isFastPath    := s0_l2l_fwd
527  s0_out.mshrid        := s0_mshrid
528  s0_out.isvec         := s0_isvec
529  s0_out.isLastElem    := s0_isLastElem
530  s0_out.vecActive           := s0_vecActive
531  s0_out.sflowPtr      := s0_flowPtr
532  s0_out.uop.exceptionVec(loadAddrMisaligned)  := !s0_addr_aligned && s0_ld_flow
533  s0_out.uop.exceptionVec(storeAddrMisaligned) := !s0_addr_aligned && !s0_ld_flow
534  s0_out.forward_tlDchannel := s0_super_ld_rep_select
535  when(io.tlb.req.valid && s0_isFirstIssue) {
536    s0_out.uop.debugInfo.tlbFirstReqTime := GTimer()
537  }.otherwise{
538    s0_out.uop.debugInfo.tlbFirstReqTime := s0_uop.debugInfo.tlbFirstReqTime
539  }
540  s0_out.schedIndex     := s0_sched_idx
541
542  // load fast replay
543  io.ldu_io.fast_rep_in.ready := (s0_can_go && io.ldu_io.dcache.req.ready && s0_ld_fast_rep_ready)
544
545  // load flow source ready
546  // cache missed load has highest priority
547  // always accept cache missed load flow from load replay queue
548  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))
549
550  // accept load flow from rs when:
551  // 1) there is no lsq-replayed load
552  // 2) there is no fast replayed load
553  // 3) there is no high confidence prefetch request
554  io.lsin.ready := (s0_can_go &&
555                    Mux(FuType.isLoad(io.lsin.bits.uop.fuType), io.ldu_io.dcache.req.ready,
556                    (if (StorePrefetchL1Enabled) io.stu_io.dcache.req.ready else true.B)) && s0_int_iss_ready)
557  io.vec_stu_io.in.ready := s0_can_go && io.ldu_io.dcache.req.ready && s0_vec_iss_ready
558
559
560  // for hw prefetch load flow feedback, to be added later
561  // io.prefetch_in.ready := s0_hw_prf_select
562
563  // dcache replacement extra info
564  // TODO: should prefetch load update replacement?
565  io.ldu_io.dcache.replacementUpdated := Mux(s0_ld_rep_select || s0_super_ld_rep_select, io.ldu_io.replay.bits.replacementUpdated, false.B)
566
567  io.stu_io.prefetch_req.ready := s1_ready && io.stu_io.dcache.req.ready && !io.lsin.valid
568
569  // load debug
570  XSDebug(io.ldu_io.dcache.req.fire && s0_ld_flow,
571    p"[DCACHE LOAD REQ] pc ${Hexadecimal(s0_uop.pc)}, vaddr ${Hexadecimal(s0_vaddr)}\n"
572  )
573  XSDebug(s0_valid && s0_ld_flow,
574    p"S0: pc ${Hexadecimal(s0_out.uop.pc)}, lqIdx ${Hexadecimal(s0_out.uop.lqIdx.asUInt)}, " +
575    p"vaddr ${Hexadecimal(s0_out.vaddr)}, mask ${Hexadecimal(s0_out.mask)}\n")
576
577  // store debug
578  XSDebug(io.stu_io.dcache.req.fire && !s0_ld_flow,
579    p"[DCACHE STORE REQ] pc ${Hexadecimal(s0_uop.pc)}, vaddr ${Hexadecimal(s0_vaddr)}\n"
580  )
581  XSDebug(s0_valid && !s0_ld_flow,
582    p"S0: pc ${Hexadecimal(s0_out.uop.pc)}, sqIdx ${Hexadecimal(s0_out.uop.sqIdx.asUInt)}, " +
583    p"vaddr ${Hexadecimal(s0_out.vaddr)}, mask ${Hexadecimal(s0_out.mask)}\n")
584
585
586  // Pipeline
587  // --------------------------------------------------------------------------------
588  // stage 1
589  // --------------------------------------------------------------------------------
590  // TLB resp (send paddr to dcache)
591  val s1_valid      = RegInit(false.B)
592  val s1_in         = Wire(new LqWriteBundle)
593  val s1_out        = Wire(new LqWriteBundle)
594  val s1_kill       = Wire(Bool())
595  val s1_can_go     = s2_ready
596  val s1_fire       = s1_valid && !s1_kill && s1_can_go
597  val s1_ld_flow    = RegNext(s0_ld_flow)
598  val s1_isvec      = RegEnable(s0_out.isvec, false.B, s0_fire)
599  val s1_isLastElem = RegEnable(s0_out.isLastElem, false.B, s0_fire)
600
601  s1_ready := !s1_valid || s1_kill || s2_ready
602  when (s0_fire) { s1_valid := true.B }
603  .elsewhen (s1_fire) { s1_valid := false.B }
604  .elsewhen (s1_kill) { s1_valid := false.B }
605  s1_in   := RegEnable(s0_out, s0_fire)
606
607  val s1_fast_rep_dly_err = RegNext(io.ldu_io.fast_rep_in.bits.delayedLoadError)
608  val s1_fast_rep_kill    = s1_fast_rep_dly_err && s1_in.isFastReplay
609  val s1_l2l_fwd_dly_err  = RegNext(io.ldu_io.l2l_fwd_in.dly_ld_err)
610  val s1_l2l_fwd_kill     = s1_l2l_fwd_dly_err && s1_in.isFastPath
611  val s1_late_kill        = s1_fast_rep_kill || s1_l2l_fwd_kill
612  val s1_vaddr_hi         = Wire(UInt())
613  val s1_vaddr_lo         = Wire(UInt())
614  val s1_vaddr            = Wire(UInt())
615  val s1_paddr_dup_lsu    = Wire(UInt())
616  val s1_paddr_dup_dcache = Wire(UInt())
617  val s1_ld_exception     = ExceptionNO.selectByFu(s1_out.uop.exceptionVec, LduCfg).asUInt.orR   // af & pf exception were modified below.
618  val s1_st_exception     = ExceptionNO.selectByFu(s1_out.uop.exceptionVec, StaCfg).asUInt.orR   // af & pf exception were modified below.
619  val s1_exception        = (s1_ld_flow && s1_ld_exception) || (!s1_ld_flow && s1_st_exception)
620  val s1_tlb_miss         = io.tlb.resp.bits.miss
621  val s1_prf              = s1_in.isPrefetch
622  val s1_hw_prf           = s1_in.isHWPrefetch
623  val s1_sw_prf           = s1_prf && !s1_hw_prf
624  val s1_tlb_memidx       = io.tlb.resp.bits.memidx
625
626  // mmio cbo decoder
627  val s1_mmio_cbo  = (s1_in.uop.fuOpType === LSUOpType.cbo_clean ||
628                      s1_in.uop.fuOpType === LSUOpType.cbo_flush ||
629                      s1_in.uop.fuOpType === LSUOpType.cbo_inval) && !s1_ld_flow && !s1_prf
630  val s1_mmio = s1_mmio_cbo
631
632  s1_vaddr_hi         := s1_in.vaddr(VAddrBits - 1, 6)
633  s1_vaddr_lo         := s1_in.vaddr(5, 0)
634  s1_vaddr            := Cat(s1_vaddr_hi, s1_vaddr_lo)
635  s1_paddr_dup_lsu    := io.tlb.resp.bits.paddr(0)
636  s1_paddr_dup_dcache := io.tlb.resp.bits.paddr(1)
637
638  when (s1_tlb_memidx.is_ld && io.tlb.resp.valid && !s1_tlb_miss &&
639        s1_tlb_memidx.idx === s1_in.uop.lqIdx.value && s1_ld_flow) {
640    // printf("Load idx = %d\n", s1_tlb_memidx.idx)
641    s1_out.uop.debugInfo.tlbRespTime := GTimer()
642  } .elsewhen(s1_tlb_memidx.is_st && io.tlb.resp.valid && !s1_tlb_miss &&
643              s1_tlb_memidx.idx === s1_out.uop.sqIdx.value && !s1_ld_flow) {
644    // printf("Store idx = %d\n", s1_tlb_memidx.idx)
645    s1_out.uop.debugInfo.tlbRespTime := GTimer()
646  }
647
648  io.tlb.req_kill   := s1_kill
649  io.tlb.resp.ready := true.B
650
651  io.ldu_io.dcache.s1_paddr_dup_lsu    <> s1_paddr_dup_lsu
652  io.ldu_io.dcache.s1_paddr_dup_dcache <> s1_paddr_dup_dcache
653  io.ldu_io.dcache.s1_kill             := s1_kill || s1_tlb_miss || s1_exception
654
655  // store to load forwarding
656  io.ldu_io.sbuffer.valid := s1_valid && !(s1_exception || s1_tlb_miss || s1_kill || s1_fast_rep_kill || s1_prf || !s1_ld_flow)
657  io.ldu_io.sbuffer.vaddr := s1_vaddr
658  io.ldu_io.sbuffer.paddr := s1_paddr_dup_lsu
659  io.ldu_io.sbuffer.uop   := s1_in.uop
660  io.ldu_io.sbuffer.sqIdx := s1_in.uop.sqIdx
661  io.ldu_io.sbuffer.mask  := s1_in.mask
662  io.ldu_io.sbuffer.pc    := s1_in.uop.pc // FIXME: remove it
663
664  io.ldu_io.vec_forward.valid := s1_valid && !(s1_exception || s1_tlb_miss || s1_kill || s1_fast_rep_kill || s1_prf || !s1_ld_flow)
665  io.ldu_io.vec_forward.vaddr := s1_vaddr
666  io.ldu_io.vec_forward.paddr := s1_paddr_dup_lsu
667  io.ldu_io.vec_forward.uop   := s1_in.uop
668  io.ldu_io.vec_forward.sqIdx := s1_in.uop.sqIdx
669  io.ldu_io.vec_forward.mask  := s1_in.mask
670  io.ldu_io.vec_forward.pc    := s1_in.uop.pc // FIXME: remove it
671
672  io.ldu_io.lsq.forward.valid     := s1_valid && !(s1_exception || s1_tlb_miss || s1_kill || s1_fast_rep_kill || s1_prf || !s1_ld_flow)
673  io.ldu_io.lsq.forward.vaddr     := s1_vaddr
674  io.ldu_io.lsq.forward.paddr     := s1_paddr_dup_lsu
675  io.ldu_io.lsq.forward.uop       := s1_in.uop
676  io.ldu_io.lsq.forward.sqIdx     := s1_in.uop.sqIdx
677  io.ldu_io.lsq.forward.sqIdxMask := 0.U
678  io.ldu_io.lsq.forward.mask      := s1_in.mask
679  io.ldu_io.lsq.forward.pc        := s1_in.uop.pc // FIXME: remove it
680
681  // st-ld violation query
682  val s1_nuke = VecInit((0 until StorePipelineWidth).map(w => {
683                       io.ldu_io.stld_nuke_query(w).valid && // query valid
684                       isAfter(s1_in.uop.robIdx, io.ldu_io.stld_nuke_query(w).bits.robIdx) && // older store
685                       // TODO: Fix me when vector instruction
686                       (s1_paddr_dup_lsu(PAddrBits-1, 3) === io.ldu_io.stld_nuke_query(w).bits.paddr(PAddrBits-1, 3)) && // paddr match
687                       (s1_in.mask & io.ldu_io.stld_nuke_query(w).bits.mask).orR // data mask contain
688                      })).asUInt.orR && !s1_tlb_miss && s1_ld_flow
689
690  s1_out                   := s1_in
691  s1_out.vaddr             := s1_vaddr
692  s1_out.paddr             := s1_paddr_dup_lsu
693  s1_out.tlbMiss           := s1_tlb_miss
694  s1_out.ptwBack           := io.tlb.resp.bits.ptwBack
695  s1_out.rsIdx             := s1_in.rsIdx
696  s1_out.rep_info.debug    := s1_in.uop.debugInfo
697  s1_out.rep_info.nuke     := s1_nuke && !s1_sw_prf
698  s1_out.lateKill          := s1_late_kill
699
700  when (s1_ld_flow) {
701    when (!s1_late_kill) {
702      // current ori test will cause the case of ldest == 0, below will be modifeid in the future.
703      // af & pf exception were modified
704      s1_out.uop.exceptionVec(loadPageFault)   := io.tlb.resp.bits.excp(0).pf.ld
705      s1_out.uop.exceptionVec(loadAccessFault) := io.tlb.resp.bits.excp(0).af.ld
706    } .otherwise {
707      s1_out.uop.exceptionVec(loadAddrMisaligned) := false.B
708      s1_out.uop.exceptionVec(loadAccessFault)    := s1_late_kill
709    }
710  } .otherwise {
711    s1_out.uop.exceptionVec(storePageFault)   := io.tlb.resp.bits.excp(0).pf.st
712    s1_out.uop.exceptionVec(storeAccessFault) := io.tlb.resp.bits.excp(0).af.st
713  }
714
715  // pointer chasing
716  val s1_try_ptr_chasing       = RegNext(s0_do_try_ptr_chasing, false.B)
717  val s1_ptr_chasing_vaddr     = RegEnable(s0_ptr_chasing_vaddr, s0_do_try_ptr_chasing)
718  val s1_fu_op_type_not_ld     = WireInit(false.B)
719  val s1_not_fast_match        = WireInit(false.B)
720  val s1_addr_mismatch         = WireInit(false.B)
721  val s1_addr_misaligned       = WireInit(false.B)
722  val s1_ptr_chasing_canceled  = WireInit(false.B)
723  val s1_cancel_ptr_chasing    = WireInit(false.B)
724
725  s1_kill := s1_late_kill ||
726             s1_cancel_ptr_chasing ||
727             s1_in.uop.robIdx.needFlush(io.redirect) ||
728             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)
729
730  if (EnableLoadToLoadForward) {
731    // Sometimes, we need to cancel the load-load forwarding.
732    // These can be put at S0 if timing is bad at S1.
733    // Case 0: CACHE_SET(base + offset) != CACHE_SET(base) (lowest 6-bit addition has an overflow)
734    s1_addr_mismatch      := s1_ptr_chasing_vaddr(6) || RegEnable(io.ldu_io.ld_fast_imm(11, 6).orR, s0_do_try_ptr_chasing)
735    // Case 1: the address is misaligned, kill s1
736    s1_addr_misaligned    := LookupTree(s1_in.uop.fuOpType(1, 0), List(
737                             "b00".U   -> false.B,                  //b
738                             "b01".U   -> (s1_vaddr(0)    =/= 0.U), //h
739                             "b10".U   -> (s1_vaddr(1, 0) =/= 0.U), //w
740                             "b11".U   -> (s1_vaddr(2, 0) =/= 0.U)  //d
741                          ))
742    // Case 2: this load-load uop is cancelled
743    s1_ptr_chasing_canceled := !io.lsin.valid || FuType.isStore(io.lsin.bits.uop.fuType)
744
745    when (s1_try_ptr_chasing) {
746      s1_cancel_ptr_chasing := s1_addr_mismatch || s1_addr_misaligned || s1_ptr_chasing_canceled
747
748      s1_in.uop           := io.lsin.bits.uop
749      s1_in.rsIdx         := io.lsin.bits.iqIdx
750      s1_in.isFirstIssue  := io.lsin.bits.isFirstIssue
751      s1_vaddr_lo         := s1_ptr_chasing_vaddr(5, 0)
752      s1_paddr_dup_lsu    := Cat(io.tlb.resp.bits.paddr(0)(PAddrBits - 1, 6), s1_vaddr_lo)
753      s1_paddr_dup_dcache := Cat(io.tlb.resp.bits.paddr(0)(PAddrBits - 1, 6), s1_vaddr_lo)
754
755      // 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)
756      s1_in.uop.debugInfo.tlbFirstReqTime := GTimer()
757      s1_in.uop.debugInfo.tlbRespTime     := GTimer()
758    }
759    when (!s1_cancel_ptr_chasing) {
760      s0_ptr_chasing_canceled := s1_try_ptr_chasing && !io.ldu_io.replay.fire && !io.ldu_io.fast_rep_in.fire
761      when (s1_try_ptr_chasing) {
762        io.lsin.ready := true.B
763      }
764    }
765  }
766
767  // pre-calcuate sqIdx mask in s0, then send it to lsq in s1 for forwarding
768  val s1_sqIdx_mask = RegNext(UIntToMask(s0_out.uop.sqIdx.value, StoreQueueSize))
769  // to enable load-load, sqIdxMask must be calculated based on lsin.uop
770  // If the timing here is not OK, load-load forwarding has to be disabled.
771  // Or we calculate sqIdxMask at RS??
772  io.ldu_io.lsq.forward.sqIdxMask := s1_sqIdx_mask
773  if (EnableLoadToLoadForward) {
774    when (s1_try_ptr_chasing) {
775      io.ldu_io.lsq.forward.sqIdxMask := UIntToMask(io.lsin.bits.uop.sqIdx.value, StoreQueueSize)
776    }
777  }
778
779  io.ldu_io.forward_mshr.valid  := s1_valid && s1_out.forward_tlDchannel && s1_ld_flow
780  io.ldu_io.forward_mshr.mshrid := s1_out.mshrid
781  io.ldu_io.forward_mshr.paddr  := s1_out.paddr
782
783  io.ldu_io.wakeup.valid := s0_fire && s0_ld_flow && (s0_super_ld_rep_select || s0_ld_fast_rep_select || s0_ld_rep_select || s0_int_iss_select)
784  io.ldu_io.wakeup.bits := s0_uop
785
786  io.stu_io.dcache.s1_kill := s1_tlb_miss || s1_exception || s1_mmio || s1_in.uop.robIdx.needFlush(io.redirect)
787  io.stu_io.dcache.s1_paddr := s1_paddr_dup_dcache
788
789
790  // load debug
791  XSDebug(s1_valid && s1_ld_flow,
792    p"S1: pc ${Hexadecimal(s1_out.uop.pc)}, lId ${Hexadecimal(s1_out.uop.lqIdx.asUInt)}, tlb_miss ${io.tlb.resp.bits.miss}, " +
793    p"paddr ${Hexadecimal(s1_out.paddr)}, mmio ${s1_out.mmio}\n")
794
795  // store debug
796  XSDebug(s1_valid && !s1_ld_flow,
797    p"S1: pc ${Hexadecimal(s1_out.uop.pc)}, lId ${Hexadecimal(s1_out.uop.sqIdx.asUInt)}, tlb_miss ${io.tlb.resp.bits.miss}, " +
798    p"paddr ${Hexadecimal(s1_out.paddr)}, mmio ${s1_out.mmio}\n")
799
800  // store out
801  io.stu_io.lsq.valid         := s1_valid && !s1_ld_flow && !s1_prf && !s1_isvec
802  io.stu_io.lsq.bits          := s1_out
803  io.stu_io.lsq.bits.miss     := s1_tlb_miss
804
805  io.vec_stu_io.lsq.valid     := s1_valid && !s1_ld_flow && !s1_prf && s1_isvec
806  io.vec_stu_io.lsq.bits          := s1_out
807  io.vec_stu_io.lsq.bits.miss     := s1_tlb_miss
808  io.vec_stu_io.lsq.bits.isLastElem := s1_isLastElem
809
810  io.stu_io.st_mask_out.valid       := s1_valid && !s1_ld_flow && !s1_prf
811  io.stu_io.st_mask_out.bits.mask   := s1_out.mask
812  io.stu_io.st_mask_out.bits.sqIdx  := s1_out.uop.sqIdx
813
814  io.stu_io.issue.valid       := s1_valid && !s1_tlb_miss && !s1_ld_flow && !s1_prf && !s1_isvec
815  io.stu_io.issue.bits        := RegEnable(io.lsin.bits, io.lsin.fire)
816
817  // st-ld violation dectect request
818  io.stu_io.stld_nuke_query.valid       := s1_valid && !s1_tlb_miss && !s1_ld_flow && !s1_prf
819  io.stu_io.stld_nuke_query.bits.robIdx := s1_in.uop.robIdx
820  io.stu_io.stld_nuke_query.bits.paddr  := s1_paddr_dup_lsu
821  io.stu_io.stld_nuke_query.bits.mask   := s1_in.mask
822
823  // Pipeline
824  // --------------------------------------------------------------------------------
825  // stage 2
826  // --------------------------------------------------------------------------------
827  // s2: DCache resp
828  val s2_valid  = RegInit(false.B)
829  val s2_in     = Wire(new LqWriteBundle)
830  val s2_out    = Wire(new LqWriteBundle)
831  val s2_kill   = Wire(Bool())
832  val s2_can_go = s3_ready
833  val s2_fire   = s2_valid && !s2_kill && s2_can_go
834  val s2_isvec  = RegEnable(s1_isvec, false.B, s1_fire)
835  val s2_vecActive    = RegEnable(s1_out.vecActive, true.B, s1_fire)
836  val s2_paddr  = RegEnable(s1_paddr_dup_lsu, s1_fire)
837
838  s2_kill := s2_in.uop.robIdx.needFlush(io.redirect)
839  s2_ready := !s2_valid || s2_kill || s3_ready
840  when (s1_fire) { s2_valid := true.B }
841  .elsewhen (s2_fire) { s2_valid := false.B }
842  .elsewhen (s2_kill) { s2_valid := false.B }
843  s2_in := RegEnable(s1_out, s1_fire)
844
845  val s2_pmp = WireInit(io.pmp)
846
847  val s2_prf    = s2_in.isPrefetch
848  val s2_hw_prf = s2_in.isHWPrefetch
849  val s2_ld_flow  = RegEnable(s1_ld_flow, s1_fire)
850
851  // exception that may cause load addr to be invalid / illegal
852  // if such exception happen, that inst and its exception info
853  // will be force writebacked to rob
854  val s2_exception_vec = WireInit(s2_in.uop.exceptionVec)
855  when (s2_ld_flow) {
856    when (!s2_in.lateKill) {
857      s2_exception_vec(loadAccessFault) := (s2_in.uop.exceptionVec(loadAccessFault) || s2_pmp.ld) && s2_vecActive
858      // soft prefetch will not trigger any exception (but ecc error interrupt may be triggered)
859      when (s2_prf || s2_in.tlbMiss) {
860        s2_exception_vec := 0.U.asTypeOf(s2_exception_vec.cloneType)
861      }
862    }
863  } .otherwise {
864    s2_exception_vec(storeAccessFault) := s2_in.uop.exceptionVec(storeAccessFault) || s2_pmp.st
865    when (s2_prf || s2_in.tlbMiss) {
866      s2_exception_vec := 0.U.asTypeOf(s2_exception_vec.cloneType)
867    }
868  }
869  val s2_ld_exception = ExceptionNO.selectByFu(s2_exception_vec, LduCfg).asUInt.orR && s2_ld_flow
870  val s2_st_exception = ExceptionNO.selectByFu(s2_exception_vec, StaCfg).asUInt.orR && !s2_ld_flow
871  val s2_exception    = s2_ld_exception || s2_st_exception
872
873  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)
874  val (s2_fwd_data_valid, s2_fwd_frm_mshr, s2_fwd_data_frm_mshr) = io.ldu_io.forward_mshr.forward()
875  val s2_fwd_frm_d_chan_or_mshr = s2_fwd_data_valid && (s2_fwd_frm_d_chan || s2_fwd_frm_mshr)
876
877  // writeback access fault caused by ecc error / bus error
878  // * ecc data error is slow to generate, so we will not use it until load stage 3
879  // * in load stage 3, an extra signal io.load_error will be used to
880  val s2_actually_mmio = s2_pmp.mmio
881  val s2_ld_mmio       = !s2_prf &&
882                          s2_actually_mmio &&
883                         !s2_exception &&
884                         !s2_in.tlbMiss &&
885                         s2_ld_flow
886  val s2_st_mmio       = !s2_prf &&
887                          (RegNext(s1_mmio) || s2_pmp.mmio) &&
888                         !s2_exception &&
889                         !s2_in.tlbMiss &&
890                         !s2_ld_flow
891  val s2_st_atomic     = !s2_prf &&
892                          (RegNext(s1_mmio) || s2_pmp.atomic) &&
893                         !s2_exception &&
894                         !s2_in.tlbMiss &&
895                         !s2_ld_flow
896  val s2_full_fwd      = Wire(Bool())
897  val s2_mem_amb       = s2_in.uop.storeSetHit &&
898                         io.ldu_io.lsq.forward.addrInvalid
899
900  val s2_tlb_miss      = s2_in.tlbMiss
901  val s2_fwd_fail      = io.ldu_io.lsq.forward.dataInvalid || io.ldu_io.vec_forward.dataInvalid
902  val s2_dcache_miss   = io.ldu_io.dcache.resp.bits.miss &&
903                         !s2_fwd_frm_d_chan_or_mshr &&
904                         !s2_full_fwd
905
906  val s2_mq_nack       = io.ldu_io.dcache.s2_mq_nack &&
907                         !s2_fwd_frm_d_chan_or_mshr &&
908                         !s2_full_fwd
909
910  val s2_bank_conflict = io.ldu_io.dcache.s2_bank_conflict &&
911                         !s2_fwd_frm_d_chan_or_mshr &&
912                         !s2_full_fwd
913
914  val s2_wpu_pred_fail = io.ldu_io.dcache.s2_wpu_pred_fail &&
915                        !s2_fwd_frm_d_chan_or_mshr &&
916                        !s2_full_fwd
917
918  val s2_rar_nack      = io.ldu_io.lsq.ldld_nuke_query.req.valid &&
919                         !io.ldu_io.lsq.ldld_nuke_query.req.ready
920
921  val s2_raw_nack      = io.ldu_io.lsq.stld_nuke_query.req.valid &&
922                         !io.ldu_io.lsq.stld_nuke_query.req.ready
923
924  // st-ld violation query
925  //  NeedFastRecovery Valid when
926  //  1. Fast recovery query request Valid.
927  //  2. Load instruction is younger than requestors(store instructions).
928  //  3. Physical address match.
929  //  4. Data contains.
930  val s2_nuke = VecInit((0 until StorePipelineWidth).map(w => {
931                        io.ldu_io.stld_nuke_query(w).valid && // query valid
932                        isAfter(s2_in.uop.robIdx, io.ldu_io.stld_nuke_query(w).bits.robIdx) && // older store
933                        // TODO: Fix me when vector instruction
934                        (s2_in.paddr(PAddrBits-1, 3) === io.ldu_io.stld_nuke_query(w).bits.paddr(PAddrBits-1, 3)) && // paddr match
935                        (s2_in.mask & io.ldu_io.stld_nuke_query(w).bits.mask).orR // data mask contain
936                      })).asUInt.orR && s2_ld_flow || s2_in.rep_info.nuke
937
938  val s2_cache_handled   = io.ldu_io.dcache.resp.bits.handled
939  val s2_cache_tag_error = RegNext(io.csrCtrl.cache_error_enable) &&
940                           io.ldu_io.dcache.resp.bits.tag_error
941
942  val s2_troublem        = !s2_exception &&
943                           !s2_ld_mmio &&
944                           !s2_prf &&
945                           !s2_in.lateKill &&
946                           s2_ld_flow
947
948  io.ldu_io.dcache.resp.ready := true.B
949  io.stu_io.dcache.resp.ready := true.B
950  val s2_dcache_should_resp = !(s2_in.tlbMiss || s2_exception || s2_ld_mmio || s2_prf || s2_in.lateKill) && s2_ld_flow
951  assert(!(s2_valid && (s2_dcache_should_resp && !io.ldu_io.dcache.resp.valid)), "DCache response got lost")
952
953  // fast replay require
954  val s2_dcache_fast_rep = (s2_mq_nack || !s2_dcache_miss && (s2_bank_conflict || s2_wpu_pred_fail))
955  val s2_nuke_fast_rep   = !s2_mq_nack &&
956                           !s2_dcache_miss &&
957                           !s2_bank_conflict &&
958                           !s2_wpu_pred_fail &&
959                           !s2_rar_nack &&
960                           !s2_raw_nack &&
961                           s2_nuke
962
963  val s2_fast_rep = !s2_mem_amb &&
964                    !s2_tlb_miss &&
965                    !s2_fwd_fail &&
966                    (s2_dcache_fast_rep || s2_nuke_fast_rep) &&
967                    s2_troublem
968
969  // need allocate new entry
970  val s2_can_query = !s2_mem_amb &&
971                     !s2_tlb_miss  &&
972                     !s2_fwd_fail &&
973                     !s2_dcache_fast_rep &&
974                     s2_troublem
975
976  val s2_data_fwded = s2_dcache_miss && (s2_full_fwd || s2_cache_tag_error)
977
978  // ld-ld violation require
979  io.ldu_io.lsq.ldld_nuke_query.req.valid           := s2_valid && s2_can_query
980  io.ldu_io.lsq.ldld_nuke_query.req.bits.uop        := s2_in.uop
981  io.ldu_io.lsq.ldld_nuke_query.req.bits.mask       := s2_in.mask
982  io.ldu_io.lsq.ldld_nuke_query.req.bits.paddr      := s2_in.paddr
983  io.ldu_io.lsq.ldld_nuke_query.req.bits.data_valid := Mux(s2_full_fwd || s2_fwd_data_valid, true.B, !s2_dcache_miss)
984
985  // st-ld violation require
986  io.ldu_io.lsq.stld_nuke_query.req.valid           := s2_valid && s2_can_query
987  io.ldu_io.lsq.stld_nuke_query.req.bits.uop        := s2_in.uop
988  io.ldu_io.lsq.stld_nuke_query.req.bits.mask       := s2_in.mask
989  io.ldu_io.lsq.stld_nuke_query.req.bits.paddr      := s2_in.paddr
990  io.ldu_io.lsq.stld_nuke_query.req.bits.data_valid := Mux(s2_full_fwd || s2_fwd_data_valid, true.B, !s2_dcache_miss)
991
992  // merge forward result
993  // lsq has higher priority than sbuffer
994  val s2_fwd_mask = Wire(Vec((VLEN/8), Bool()))
995  val s2_fwd_data = Wire(Vec((VLEN/8), UInt(8.W)))
996  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
997  // generate XLEN/8 Muxs
998  for (i <- 0 until VLEN / 8) {
999    s2_fwd_mask(i) := io.ldu_io.lsq.forward.forwardMask(i) || io.ldu_io.sbuffer.forwardMask(i) || io.ldu_io.vec_forward.forwardMask(i)
1000    s2_fwd_data(i) := Mux(
1001      io.ldu_io.lsq.forward.forwardMask(i),
1002      io.ldu_io.lsq.forward.forwardData(i),
1003      Mux(
1004        io.ldu_io.vec_forward.forwardMask(i),
1005        io.ldu_io.vec_forward.forwardData(i),
1006        io.ldu_io.sbuffer.forwardData(i)
1007      )
1008    )
1009  }
1010
1011  XSDebug(s2_fire && s2_ld_flow, "[FWD LOAD RESP] pc %x fwd %x(%b) + %x(%b)\n",
1012    s2_in.uop.pc,
1013    io.ldu_io.lsq.forward.forwardData.asUInt, io.ldu_io.lsq.forward.forwardMask.asUInt,
1014    s2_in.forwardData.asUInt, s2_in.forwardMask.asUInt
1015  )
1016
1017  //
1018  s2_out                  := s2_in
1019  s2_out.data             := 0.U // data will be generated in load s3
1020  s2_out.uop.fpWen        := s2_in.uop.fpWen && !s2_exception && s2_ld_flow
1021  s2_out.mmio             := s2_ld_mmio || s2_st_mmio
1022  s2_out.atomic           := s2_st_atomic
1023  s2_out.uop.flushPipe    := false.B
1024  s2_out.uop.exceptionVec := s2_exception_vec
1025  s2_out.forwardMask      := s2_fwd_mask
1026  s2_out.forwardData      := s2_fwd_data
1027  s2_out.handledByMSHR    := s2_cache_handled
1028  s2_out.miss             := s2_dcache_miss && s2_troublem
1029  s2_out.feedbacked       := io.feedback_fast.valid && !io.feedback_fast.bits.hit
1030
1031  // Generate replay signal caused by:
1032  // * st-ld violation check
1033  // * tlb miss
1034  // * dcache replay
1035  // * forward data invalid
1036  // * dcache miss
1037  s2_out.rep_info.mem_amb         := s2_mem_amb && s2_troublem
1038  s2_out.rep_info.tlb_miss        := s2_tlb_miss && s2_troublem
1039  s2_out.rep_info.fwd_fail        := s2_fwd_fail && s2_troublem
1040  s2_out.rep_info.dcache_rep      := s2_mq_nack && s2_troublem
1041  s2_out.rep_info.dcache_miss     := s2_dcache_miss && s2_troublem
1042  s2_out.rep_info.bank_conflict   := s2_bank_conflict && s2_troublem
1043  s2_out.rep_info.wpu_fail        := s2_wpu_pred_fail && s2_troublem
1044  s2_out.rep_info.rar_nack        := s2_rar_nack && s2_troublem
1045  s2_out.rep_info.raw_nack        := s2_raw_nack && s2_troublem
1046  s2_out.rep_info.nuke            := s2_nuke && s2_troublem
1047  s2_out.rep_info.full_fwd        := s2_data_fwded
1048  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)
1049  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)
1050  s2_out.rep_info.rep_carry       := io.ldu_io.dcache.resp.bits.replayCarry
1051  s2_out.rep_info.mshr_id         := io.ldu_io.dcache.resp.bits.mshr_id
1052  s2_out.rep_info.last_beat       := s2_in.paddr(log2Up(refillBytes))
1053  s2_out.rep_info.debug           := s2_in.uop.debugInfo
1054  s2_out.rep_info.tlb_id          := io.ldu_io.tlb_hint.id
1055  s2_out.rep_info.tlb_full        := io.ldu_io.tlb_hint.full
1056
1057  // if forward fail, replay this inst from fetch
1058  val debug_fwd_fail_rep = s2_fwd_fail && !s2_troublem && !s2_in.tlbMiss
1059  // if ld-ld violation is detected, replay from this inst from fetch
1060  val debug_ldld_nuke_rep = false.B // s2_ldld_violation && !s2_ld_mmio && !s2_is_prefetch && !s2_in.tlbMiss
1061  // io.out.bits.uop.replayInst := false.B
1062
1063  // to be removed
1064  val s2_ld_need_fb = !s2_in.isLoadReplay &&      // already feedbacked
1065                      io.ldu_io.lq_rep_full &&           // LoadQueueReplay is full
1066                      s2_out.rep_info.need_rep && // need replay
1067                      !s2_exception &&            // no exception is triggered
1068                      !s2_hw_prf &&               // not hardware prefetch
1069                      !s2_isvec
1070  val s2_st_need_fb = !s2_ld_flow && !s2_hw_prf && !s2_isvec
1071  io.feedback_fast.valid                 := s2_valid && (s2_ld_need_fb || s2_st_need_fb)
1072  io.feedback_fast.bits.hit              := Mux(s2_ld_flow, false.B, !s2_tlb_miss)
1073  io.feedback_fast.bits.flushState       := s2_in.ptwBack
1074  io.feedback_fast.bits.robIdx           := s2_in.uop.robIdx
1075  io.feedback_fast.bits.sourceType       := Mux(s2_ld_flow, RSFeedbackType.lrqFull, RSFeedbackType.tlbMiss)
1076  io.feedback_fast.bits.dataInvalidSqIdx := DontCare
1077
1078  val s2_vec_feedback = Wire(Valid(new VSFQFeedback))
1079  s2_vec_feedback.valid := s2_valid && !s2_ld_flow && !s2_hw_prf && s2_isvec
1080  s2_vec_feedback.bits.flowPtr := s2_out.sflowPtr
1081  s2_vec_feedback.bits.hit := !s2_tlb_miss
1082  s2_vec_feedback.bits.sourceType := RSFeedbackType.tlbMiss
1083  s2_vec_feedback.bits.paddr := s2_paddr
1084  s2_vec_feedback.bits.mmio := s2_st_mmio
1085  s2_vec_feedback.bits.atomic := s2_st_mmio
1086  s2_vec_feedback.bits.exceptionVec := s2_exception_vec
1087
1088  io.stu_io.lsq_replenish := s2_out
1089  io.stu_io.lsq_replenish.miss := io.ldu_io.dcache.resp.fire && io.ldu_io.dcache.resp.bits.miss
1090
1091  io.ldu_io.ldCancel.ld1Cancel := false.B
1092
1093  // fast wakeup
1094  io.ldu_io.fast_uop.valid := RegNext(
1095    !io.ldu_io.dcache.s1_disable_fast_wakeup &&
1096    s1_valid &&
1097    !s1_kill &&
1098    !io.tlb.resp.bits.miss &&
1099    !io.ldu_io.lsq.forward.dataInvalidFast
1100  ) && (s2_valid && !s2_out.rep_info.need_rep && !s2_ld_mmio && s2_ld_flow) && !s2_isvec
1101  io.ldu_io.fast_uop.bits := RegNext(s1_out.uop)
1102
1103  //
1104  io.ldu_io.s2_ptr_chasing                    := RegEnable(s1_try_ptr_chasing && !s1_cancel_ptr_chasing, false.B, s1_fire)
1105
1106  // prefetch train
1107  io.prefetch_train.valid              := s2_valid && !s2_actually_mmio && !s2_in.tlbMiss
1108  io.prefetch_train.bits.fromLsPipelineBundle(s2_in)
1109  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?
1110  io.prefetch_train.bits.meta_prefetch := Mux(s2_ld_flow, io.ldu_io.dcache.resp.bits.meta_prefetch, false.B)
1111  io.prefetch_train.bits.meta_access   := Mux(s2_ld_flow, io.ldu_io.dcache.resp.bits.meta_access, false.B)
1112
1113  io.prefetch_train_l1.valid              := s2_valid && !s2_actually_mmio && s2_ld_flow
1114  io.prefetch_train_l1.bits.fromLsPipelineBundle(s2_in)
1115  io.prefetch_train_l1.bits.miss          := io.ldu_io.dcache.resp.bits.miss
1116  io.prefetch_train_l1.bits.meta_prefetch := io.ldu_io.dcache.resp.bits.meta_prefetch
1117  io.prefetch_train_l1.bits.meta_access   := io.ldu_io.dcache.resp.bits.meta_access
1118  if (env.FPGAPlatform){
1119    io.ldu_io.dcache.s0_pc := DontCare
1120    io.ldu_io.dcache.s1_pc := DontCare
1121    io.ldu_io.dcache.s2_pc := DontCare
1122  }else{
1123    io.ldu_io.dcache.s0_pc := s0_out.uop.pc
1124    io.ldu_io.dcache.s1_pc := s1_out.uop.pc
1125    io.ldu_io.dcache.s2_pc := s2_out.uop.pc
1126  }
1127  io.ldu_io.dcache.s2_kill := s2_pmp.ld  || s2_actually_mmio || s2_kill
1128  io.stu_io.dcache.s2_kill := s2_pmp.st || s2_actually_mmio || s2_kill
1129  io.stu_io.dcache.s2_pc := s2_out.uop.pc
1130
1131  val s1_ld_left_fire = s1_valid && !s1_kill && s2_ready && s1_ld_flow
1132  val s2_ld_valid_dup = RegInit(0.U(6.W))
1133  s2_ld_valid_dup := 0x0.U(6.W)
1134  when (s1_ld_left_fire && !s1_out.isHWPrefetch && s1_ld_flow) { s2_ld_valid_dup := 0x3f.U(6.W) }
1135  when (s1_kill || s1_out.isHWPrefetch || !s1_ld_flow) { s2_ld_valid_dup := 0x0.U(6.W) }
1136  assert(RegNext((s2_valid === s2_ld_valid_dup(0)) || RegNext(s1_out.isHWPrefetch) || RegNext(!s1_ld_flow)))
1137
1138  // Pipeline
1139  // --------------------------------------------------------------------------------
1140  // stage 3
1141  // --------------------------------------------------------------------------------
1142  // writeback and update load queue
1143  val s3_valid        = RegNext(s2_valid && !s2_out.isHWPrefetch && !s2_out.uop.robIdx.needFlush(io.redirect))
1144  val s3_in           = RegEnable(s2_out, s2_fire)
1145  val s3_out          = Wire(Valid(new MemExuOutput))
1146  val s3_dcache_rep   = RegEnable(s2_dcache_fast_rep && s2_troublem, false.B, s2_fire)
1147  val s3_ld_valid_dup = RegEnable(s2_ld_valid_dup, s2_fire)
1148  val s3_fast_rep     = Wire(Bool())
1149  val s3_ld_flow      = RegNext(s2_ld_flow)
1150  val s3_troublem     = RegNext(s2_troublem)
1151  val s3_kill         = s3_in.uop.robIdx.needFlush(io.redirect)
1152  val s3_isvec        = RegNext(s2_isvec)
1153  s3_ready := !s3_valid || s3_kill || sx_can_go
1154
1155  // forwrad last beat
1156  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)
1157  val s3_fwd_data_valid = RegEnable(s2_fwd_data_valid, false.B, s2_valid)
1158  val s3_fwd_frm_d_chan_valid = (s3_fwd_frm_d_chan && s3_fwd_data_valid) && s3_ld_flow
1159
1160
1161  // s3 load fast replay
1162  io.ldu_io.fast_rep_out.valid := s3_valid &&
1163                                  s3_fast_rep &&
1164                                  !s3_in.uop.robIdx.needFlush(io.redirect) &&
1165                                  s3_ld_flow &&
1166                                  !s3_isvec
1167  io.ldu_io.fast_rep_out.bits := s3_in
1168
1169  io.ldu_io.lsq.ldin.valid := s3_valid &&
1170                              (!s3_fast_rep || !io.ldu_io.fast_rep_out.ready) &&
1171                              !s3_in.feedbacked &&
1172                              !s3_in.lateKill &&
1173                              s3_ld_flow
1174  io.ldu_io.lsq.ldin.bits := s3_in
1175  io.ldu_io.lsq.ldin.bits.miss := s3_in.miss && !s3_fwd_frm_d_chan_valid
1176
1177  /* <------- DANGEROUS: Don't change sequence here ! -------> */
1178  io.ldu_io.lsq.ldin.bits.data_wen_dup := s3_ld_valid_dup.asBools
1179  io.ldu_io.lsq.ldin.bits.replacementUpdated := io.ldu_io.dcache.resp.bits.replacementUpdated
1180  io.ldu_io.lsq.ldin.bits.missDbUpdated := RegNext(s2_fire && s2_in.hasROBEntry && !s2_in.tlbMiss && !s2_in.missDbUpdated)
1181
1182  val s3_dly_ld_err =
1183    if (EnableAccurateLoadError) {
1184      (s3_in.lateKill || io.ldu_io.dcache.resp.bits.error_delayed) && RegNext(io.csrCtrl.cache_error_enable)
1185    } else {
1186      WireInit(false.B)
1187    }
1188  io.ldu_io.s3_dly_ld_err := false.B // s3_dly_ld_err && s3_valid
1189  io.ldu_io.fast_rep_out.bits.delayedLoadError := s3_dly_ld_err
1190  io.ldu_io.lsq.ldin.bits.dcacheRequireReplay  := s3_dcache_rep
1191
1192  val s3_vp_match_fail = RegNext(io.ldu_io.lsq.forward.matchInvalid || io.ldu_io.sbuffer.matchInvalid) && s3_troublem
1193  val s3_ldld_rep_inst =
1194      io.ldu_io.lsq.ldld_nuke_query.resp.valid &&
1195      io.ldu_io.lsq.ldld_nuke_query.resp.bits.rep_frm_fetch &&
1196      RegNext(io.csrCtrl.ldld_vio_check_enable)
1197
1198  val s3_rep_info = WireInit(s3_in.rep_info)
1199  s3_rep_info.dcache_miss   := s3_in.rep_info.dcache_miss && !s3_fwd_frm_d_chan_valid && s3_troublem
1200  val s3_rep_frm_fetch = s3_vp_match_fail
1201  val s3_flushPipe = s3_ldld_rep_inst
1202  val s3_sel_rep_cause = PriorityEncoderOH(s3_rep_info.cause.asUInt)
1203  val s3_force_rep     = s3_sel_rep_cause(LoadReplayCauses.C_TM) &&
1204                         !s3_in.uop.exceptionVec(loadAddrMisaligned) &&
1205                         s3_troublem
1206
1207  val s3_ld_exception = ExceptionNO.selectByFu(s3_in.uop.exceptionVec, LduCfg).asUInt.orR && s3_ld_flow
1208  val s3_st_exception = ExceptionNO.selectByFu(s3_in.uop.exceptionVec, StaCfg).asUInt.orR && !s3_ld_flow
1209  val s3_exception    = s3_ld_exception || s3_st_exception
1210  when ((s3_ld_exception || s3_dly_ld_err || s3_rep_frm_fetch) && !s3_force_rep) {
1211    io.ldu_io.lsq.ldin.bits.rep_info.cause := 0.U.asTypeOf(s3_rep_info.cause.cloneType)
1212  } .otherwise {
1213    io.ldu_io.lsq.ldin.bits.rep_info.cause := VecInit(s3_sel_rep_cause.asBools)
1214  }
1215
1216  // Int flow, if hit, will be writebacked at s3
1217  s3_out.valid                := s3_valid &&
1218                                (!s3_ld_flow && !s3_in.feedbacked || !io.ldu_io.lsq.ldin.bits.rep_info.need_rep) && !s3_in.mmio
1219  s3_out.bits.uop             := s3_in.uop
1220  s3_out.bits.uop.exceptionVec(loadAccessFault) := (s3_dly_ld_err  || s3_in.uop.exceptionVec(loadAccessFault)) && s3_ld_flow
1221  s3_out.bits.uop.replayInst := s3_rep_frm_fetch
1222  s3_out.bits.data            := s3_in.data
1223  s3_out.bits.debug.isMMIO    := s3_in.mmio
1224  s3_out.bits.debug.isPerfCnt := false.B
1225  s3_out.bits.debug.paddr     := s3_in.paddr
1226  s3_out.bits.debug.vaddr     := s3_in.vaddr
1227
1228  when (s3_force_rep) {
1229    s3_out.bits.uop.exceptionVec := 0.U.asTypeOf(s3_in.uop.exceptionVec.cloneType)
1230  }
1231
1232  io.ldu_io.rollback.valid := s3_valid && (s3_rep_frm_fetch || s3_flushPipe) && !s3_exception && s3_ld_flow
1233  io.ldu_io.rollback.bits             := DontCare
1234  io.ldu_io.rollback.bits.isRVC       := s3_out.bits.uop.preDecodeInfo.isRVC
1235  io.ldu_io.rollback.bits.robIdx      := s3_out.bits.uop.robIdx
1236  io.ldu_io.rollback.bits.ftqIdx      := s3_out.bits.uop.ftqPtr
1237  io.ldu_io.rollback.bits.ftqOffset   := s3_out.bits.uop.ftqOffset
1238  io.ldu_io.rollback.bits.level       := Mux(s3_rep_frm_fetch, RedirectLevel.flush, RedirectLevel.flushAfter)
1239  io.ldu_io.rollback.bits.cfiUpdate.target := s3_out.bits.uop.pc
1240  io.ldu_io.rollback.bits.debug_runahead_checkpoint_id := s3_out.bits.uop.debugInfo.runahead_checkpoint_id
1241  /* <------- DANGEROUS: Don't change sequence here ! -------> */
1242  io.ldu_io.lsq.ldin.bits.uop := s3_out.bits.uop
1243
1244  val s3_revoke = s3_exception || io.ldu_io.lsq.ldin.bits.rep_info.need_rep
1245  io.ldu_io.lsq.ldld_nuke_query.revoke := s3_revoke
1246  io.ldu_io.lsq.stld_nuke_query.revoke := s3_revoke
1247
1248  // feedback slow
1249  s3_fast_rep := RegNext(s2_fast_rep) &&
1250                 !s3_in.feedbacked &&
1251                 !s3_in.lateKill &&
1252                 !s3_rep_frm_fetch &&
1253                 !s3_exception
1254
1255  val s3_fb_no_waiting = !s3_in.isLoadReplay && !(s3_fast_rep && io.ldu_io.fast_rep_out.ready) && !s3_in.feedbacked
1256
1257  //
1258  io.feedback_slow.valid                 := s3_valid && !s3_in.uop.robIdx.needFlush(io.redirect) && s3_fb_no_waiting && s3_ld_flow
1259  io.feedback_slow.bits.hit              := !io.ldu_io.lsq.ldin.bits.rep_info.need_rep || io.ldu_io.lsq.ldin.ready
1260  io.feedback_slow.bits.flushState       := s3_in.ptwBack
1261  io.feedback_slow.bits.robIdx           := s3_in.uop.robIdx
1262  io.feedback_slow.bits.sourceType       := RSFeedbackType.lrqFull
1263  io.feedback_slow.bits.dataInvalidSqIdx := DontCare
1264
1265  io.vec_stu_io.feedbackSlow.valid := RegNext(s2_vec_feedback.valid && !s2_out.uop.robIdx.needFlush(io.redirect))
1266  io.vec_stu_io.feedbackSlow.bits := RegNext(s2_vec_feedback.bits)
1267
1268  io.ldu_io.ldCancel.ld2Cancel := s3_valid && s3_ld_flow && (                          // is load
1269    io.ldu_io.lsq.ldin.bits.rep_info.need_rep || s3_in.mmio                            // exe fail or is mmio
1270  )
1271
1272  // data from dcache hit
1273  val s3_ld_raw_data_frm_cache = Wire(new LoadDataFromDcacheBundle)
1274  s3_ld_raw_data_frm_cache.respDcacheData       := io.ldu_io.dcache.resp.bits.data_delayed
1275  s3_ld_raw_data_frm_cache.forwardMask          := RegEnable(s2_fwd_mask, s2_valid)
1276  s3_ld_raw_data_frm_cache.forwardData          := RegEnable(s2_fwd_data, s2_valid)
1277  s3_ld_raw_data_frm_cache.uop                  := RegEnable(s2_out.uop, s2_valid)
1278  s3_ld_raw_data_frm_cache.addrOffset           := RegEnable(s2_out.paddr(3, 0), s2_valid)
1279  s3_ld_raw_data_frm_cache.forward_D            := RegEnable(s2_fwd_frm_d_chan, false.B, s2_valid) || s3_fwd_frm_d_chan_valid
1280  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))
1281  s3_ld_raw_data_frm_cache.forward_mshr         := RegEnable(s2_fwd_frm_mshr, false.B, s2_valid)
1282  s3_ld_raw_data_frm_cache.forwardData_mshr     := RegEnable(s2_fwd_data_frm_mshr, s2_valid)
1283  s3_ld_raw_data_frm_cache.forward_result_valid := RegEnable(s2_fwd_data_valid, false.B, s2_valid)
1284
1285  val s3_merged_data_frm_cache = s3_ld_raw_data_frm_cache.mergedData()
1286  val s3_picked_data_frm_cache = LookupTree(s3_ld_raw_data_frm_cache.addrOffset, List(
1287    "b0000".U -> s3_merged_data_frm_cache(63,    0),
1288    "b0001".U -> s3_merged_data_frm_cache(63,    8),
1289    "b0010".U -> s3_merged_data_frm_cache(63,   16),
1290    "b0011".U -> s3_merged_data_frm_cache(63,   24),
1291    "b0100".U -> s3_merged_data_frm_cache(63,   32),
1292    "b0101".U -> s3_merged_data_frm_cache(63,   40),
1293    "b0110".U -> s3_merged_data_frm_cache(63,   48),
1294    "b0111".U -> s3_merged_data_frm_cache(63,   56),
1295    "b1000".U -> s3_merged_data_frm_cache(127,  64),
1296    "b1001".U -> s3_merged_data_frm_cache(127,  72),
1297    "b1010".U -> s3_merged_data_frm_cache(127,  80),
1298    "b1011".U -> s3_merged_data_frm_cache(127,  88),
1299    "b1100".U -> s3_merged_data_frm_cache(127,  96),
1300    "b1101".U -> s3_merged_data_frm_cache(127, 104),
1301    "b1110".U -> s3_merged_data_frm_cache(127, 112),
1302    "b1111".U -> s3_merged_data_frm_cache(127, 120)
1303  ))
1304  val s3_ld_data_frm_cache = rdataHelper(s3_ld_raw_data_frm_cache.uop, s3_picked_data_frm_cache)
1305
1306  // FIXME: add 1 cycle delay ?
1307  io.ldout.bits      := s3_out.bits
1308  io.ldout.bits.data := s3_ld_data_frm_cache
1309  io.ldout.valid     := s3_out.valid && !s3_out.bits.uop.robIdx.needFlush(io.redirect) && s3_ld_flow && !s3_isvec
1310
1311  // for uncache
1312  io.ldu_io.lsq.uncache.ready := true.B
1313
1314  // fast load to load forward
1315  if (EnableLoadToLoadForward) {
1316    io.ldu_io.l2l_fwd_out.valid      := s3_out.valid && !s3_in.lateKill && s3_ld_flow
1317    io.ldu_io.l2l_fwd_out.data       := s3_ld_data_frm_cache
1318    io.ldu_io.l2l_fwd_out.dly_ld_err := s3_dly_ld_err // ecc delayed error
1319  } else {
1320    io.ldu_io.l2l_fwd_out.valid      := false.B
1321    io.ldu_io.l2l_fwd_out.data       := DontCare
1322    io.ldu_io.l2l_fwd_out.dly_ld_err := DontCare
1323  }
1324
1325  // hybrid unit writeback to rob
1326  // delay params
1327  val SelectGroupSize   = RollbackGroupSize
1328  val lgSelectGroupSize = log2Ceil(SelectGroupSize)
1329  val TotalSelectCycles = scala.math.ceil(log2Ceil(LoadQueueRAWSize).toFloat / lgSelectGroupSize).toInt + 1
1330  val TotalDelayCycles  = TotalSelectCycles - 2
1331
1332  // writeback
1333  val sx_valid = Wire(Vec(TotalDelayCycles + 1, Bool()))
1334  val sx_ready = Wire(Vec(TotalDelayCycles + 1, Bool()))
1335  val sx_in    = Wire(Vec(TotalDelayCycles + 1, new MemExuOutput))
1336
1337  sx_can_go := sx_ready.head
1338  for (i <- 0 until TotalDelayCycles + 1) {
1339    if (i == 0) {
1340      sx_valid(i) := s3_valid &&
1341                    !s3_ld_flow &&
1342                    !s3_in.feedbacked &&
1343                    !s3_in.mmio
1344      sx_in(i)    := s3_out.bits
1345      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))
1346    } else {
1347      val cur_kill   = sx_in(i).uop.robIdx.needFlush(io.redirect)
1348      val cur_can_go = (if (i == TotalDelayCycles) io.stout.ready else sx_ready(i+1))
1349      val cur_fire   = sx_valid(i) && !cur_kill && cur_can_go
1350      val prev_fire  = sx_valid(i-1) && !sx_in(i-1).uop.robIdx.needFlush(io.redirect) && sx_ready(i)
1351
1352      sx_ready(i) := !sx_valid(i) || cur_kill || (if (i == TotalDelayCycles) io.stout.ready else sx_ready(i+1))
1353      val sx_valid_can_go = prev_fire || cur_fire || cur_kill
1354      sx_valid(i) := RegEnable(Mux(prev_fire, true.B, false.B), sx_valid_can_go)
1355      sx_in(i) := RegEnable(sx_in(i-1), prev_fire)
1356    }
1357  }
1358
1359  val sx_last_valid = sx_valid.takeRight(1).head
1360  val sx_last_ready = sx_ready.takeRight(1).head
1361  val sx_last_in    = sx_in.takeRight(1).head
1362
1363  sx_last_ready  := !sx_last_valid || sx_last_in.uop.robIdx.needFlush(io.redirect) || io.stout.ready
1364  io.stout.valid := sx_last_valid && !sx_last_in.uop.robIdx.needFlush(io.redirect) && FuType.isStore(sx_last_in.uop.fuType)
1365  io.stout.bits  := sx_last_in
1366
1367   // trigger
1368  val ld_trigger = FuType.isLoad(io.ldout.bits.uop.fuType)
1369  val last_valid_data = RegEnable(io.ldout.bits.data, io.stout.fire)
1370  val hit_ld_addr_trig_hit_vec = Wire(Vec(TriggerNum, Bool()))
1371  val lq_ld_addr_trig_hit_vec = RegNext(io.ldu_io.lsq.trigger.lqLoadAddrTriggerHitVec)
1372  (0 until TriggerNum).map{i => {
1373    val tdata2    = RegNext(RegNext(io.ldu_io.trigger(i).tdata2))
1374    val matchType = RegNext(RegNext(io.ldu_io.trigger(i).matchType))
1375    val tEnable   = RegNext(RegNext(io.ldu_io.trigger(i).tEnable))
1376
1377    hit_ld_addr_trig_hit_vec(i)        := TriggerCmp(RegNext(s3_in.vaddr), tdata2, matchType, tEnable)
1378    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))
1379    io.ldu_io.trigger(i).lastDataHit   := TriggerCmp(last_valid_data, tdata2, matchType, tEnable)
1380  }}
1381  io.ldu_io.lsq.trigger.hitLoadAddrTriggerHitVec := hit_ld_addr_trig_hit_vec
1382
1383  // FIXME: please move this part to LoadQueueReplay
1384  io.ldu_io.debug_ls := DontCare
1385  io.stu_io.debug_ls := DontCare
1386  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
1387  io.stu_io.debug_ls.s1_robIdx := s1_in.uop.robIdx.value
1388
1389 // Topdown
1390  io.ldu_io.lsTopdownInfo.s1.robIdx          := s1_in.uop.robIdx.value
1391  io.ldu_io.lsTopdownInfo.s1.vaddr_valid     := s1_valid && s1_in.hasROBEntry
1392  io.ldu_io.lsTopdownInfo.s1.vaddr_bits      := s1_vaddr
1393  io.ldu_io.lsTopdownInfo.s2.robIdx          := s2_in.uop.robIdx.value
1394  io.ldu_io.lsTopdownInfo.s2.paddr_valid     := s2_fire && s2_in.hasROBEntry && !s2_in.tlbMiss
1395  io.ldu_io.lsTopdownInfo.s2.paddr_bits      := s2_in.paddr
1396  io.ldu_io.lsTopdownInfo.s2.first_real_miss := io.ldu_io.dcache.resp.bits.real_miss
1397  io.ldu_io.lsTopdownInfo.s2.cache_miss_en   := s2_fire && s2_in.hasROBEntry && !s2_in.tlbMiss && !s2_in.missDbUpdated
1398
1399  // perf cnt
1400  XSPerfAccumulate("s0_in_valid",                  io.lsin.valid)
1401  XSPerfAccumulate("s0_in_block",                  io.lsin.valid && !io.lsin.fire)
1402  XSPerfAccumulate("s0_in_fire_first_issue",       s0_valid && s0_isFirstIssue)
1403  XSPerfAccumulate("s0_lsq_fire_first_issue",      io.ldu_io.replay.fire)
1404  XSPerfAccumulate("s0_ldu_fire_first_issue",      io.lsin.fire && s0_isFirstIssue)
1405  XSPerfAccumulate("s0_fast_replay_issue",         io.ldu_io.fast_rep_in.fire)
1406  XSPerfAccumulate("s0_stall_out",                 s0_valid && !s0_can_go)
1407  XSPerfAccumulate("s0_stall_ld_dcache",           s0_valid && !io.ldu_io.dcache.req.ready)
1408  XSPerfAccumulate("s0_stall_st_dcache",           s0_valid && !io.stu_io.dcache.req.ready)
1409  XSPerfAccumulate("s0_addr_spec_success",         s0_fire && s0_vaddr(VAddrBits-1, 12) === io.lsin.bits.src(0)(VAddrBits-1, 12))
1410  XSPerfAccumulate("s0_addr_spec_failed",          s0_fire && s0_vaddr(VAddrBits-1, 12) =/= io.lsin.bits.src(0)(VAddrBits-1, 12))
1411  XSPerfAccumulate("s0_addr_spec_success_once",    s0_fire && s0_vaddr(VAddrBits-1, 12) === io.lsin.bits.src(0)(VAddrBits-1, 12) && s0_isFirstIssue)
1412  XSPerfAccumulate("s0_addr_spec_failed_once",     s0_fire && s0_vaddr(VAddrBits-1, 12) =/= io.lsin.bits.src(0)(VAddrBits-1, 12) && s0_isFirstIssue)
1413  XSPerfAccumulate("s0_forward_tl_d_channel",      s0_out.forward_tlDchannel)
1414  XSPerfAccumulate("s0_hardware_prefetch_fire",    s0_fire && s0_hw_prf_select)
1415  XSPerfAccumulate("s0_software_prefetch_fire",    s0_fire && s0_prf && s0_int_iss_select)
1416  XSPerfAccumulate("s0_hardware_prefetch_blocked", io.ldu_io.prefetch_req.valid && !s0_hw_prf_select)
1417  XSPerfAccumulate("s0_hardware_prefetch_total",   io.ldu_io.prefetch_req.valid)
1418
1419  XSPerfAccumulate("s1_in_valid",                  s1_valid)
1420  XSPerfAccumulate("s1_in_fire",                   s1_fire)
1421  XSPerfAccumulate("s1_in_fire_first_issue",       s1_fire && s1_in.isFirstIssue)
1422  XSPerfAccumulate("s1_tlb_miss",                  s1_fire && s1_tlb_miss)
1423  XSPerfAccumulate("s1_tlb_miss_first_issue",      s1_fire && s1_tlb_miss && s1_in.isFirstIssue)
1424  XSPerfAccumulate("s1_stall_out",                 s1_valid && !s1_can_go)
1425  XSPerfAccumulate("s1_late_kill",                 s1_valid && s1_fast_rep_kill)
1426
1427  XSPerfAccumulate("s2_in_valid",                  s2_valid)
1428  XSPerfAccumulate("s2_in_fire",                   s2_fire)
1429  XSPerfAccumulate("s2_in_fire_first_issue",       s2_fire && s2_in.isFirstIssue)
1430  XSPerfAccumulate("s2_dcache_miss",               s2_fire && io.ldu_io.dcache.resp.bits.miss)
1431  XSPerfAccumulate("s2_dcache_miss_first_issue",   s2_fire && io.ldu_io.dcache.resp.bits.miss && s2_in.isFirstIssue)
1432  XSPerfAccumulate("s2_dcache_real_miss_first_issue",   s2_fire && io.ldu_io.dcache.resp.bits.miss && s2_in.isFirstIssue)
1433  XSPerfAccumulate("s2_full_forward",              s2_fire && s2_full_fwd)
1434  XSPerfAccumulate("s2_dcache_miss_full_forward",  s2_fire && s2_dcache_miss)
1435  XSPerfAccumulate("s2_fwd_frm_d_can",             s2_valid && s2_fwd_frm_d_chan)
1436  XSPerfAccumulate("s2_fwd_frm_d_chan_or_mshr",    s2_valid && s2_fwd_frm_d_chan_or_mshr)
1437  XSPerfAccumulate("s2_stall_out",                 s2_fire && !s2_can_go)
1438  XSPerfAccumulate("s2_prefetch",                  s2_fire && s2_prf)
1439  XSPerfAccumulate("s2_prefetch_ignored",          s2_fire && s2_prf && s2_mq_nack) // ignore prefetch for mshr full / miss req port conflict
1440  XSPerfAccumulate("s2_prefetch_miss",             s2_fire && s2_prf && io.ldu_io.dcache.resp.bits.miss) // prefetch req miss in l1
1441  XSPerfAccumulate("s2_prefetch_hit",              s2_fire && s2_prf && !io.ldu_io.dcache.resp.bits.miss) // prefetch req hit in l1
1442  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
1443  XSPerfAccumulate("s2_forward_req",               s2_fire && s2_in.forward_tlDchannel)
1444  XSPerfAccumulate("s2_successfully_forward_channel_D", s2_fire && s2_fwd_frm_d_chan && s2_fwd_data_valid)
1445  XSPerfAccumulate("s2_successfully_forward_mshr",      s2_fire && s2_fwd_frm_mshr && s2_fwd_data_valid)
1446
1447  XSPerfAccumulate("s3_fwd_frm_d_chan",            s3_valid && s3_fwd_frm_d_chan_valid)
1448
1449  XSPerfAccumulate("load_to_load_forward",                      s1_try_ptr_chasing && !s1_ptr_chasing_canceled)
1450  XSPerfAccumulate("load_to_load_forward_try",                  s1_try_ptr_chasing)
1451  XSPerfAccumulate("load_to_load_forward_fail",                 s1_cancel_ptr_chasing)
1452  XSPerfAccumulate("load_to_load_forward_fail_cancelled",       s1_cancel_ptr_chasing && s1_ptr_chasing_canceled)
1453  XSPerfAccumulate("load_to_load_forward_fail_wakeup_mismatch", s1_cancel_ptr_chasing && !s1_ptr_chasing_canceled && s1_not_fast_match)
1454  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)
1455  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)
1456  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)
1457
1458  // bug lyq: some signals in perfEvents are no longer suitable for the current MemBlock design
1459  // hardware performance counter
1460  val perfEvents = Seq(
1461    ("load_s0_in_fire         ", s0_fire                                                        ),
1462    ("load_to_load_forward    ", s1_fire && s1_try_ptr_chasing && !s1_ptr_chasing_canceled      ),
1463    ("stall_dcache            ", s0_valid && s0_can_go && !io.ldu_io.dcache.req.ready           ),
1464    ("load_s1_in_fire         ", s0_fire                                                        ),
1465    ("load_s1_tlb_miss        ", s1_fire && io.tlb.resp.bits.miss                               ),
1466    ("load_s2_in_fire         ", s1_fire                                                        ),
1467    ("load_s2_dcache_miss     ", s2_fire && io.ldu_io.dcache.resp.bits.miss                     ),
1468  )
1469  generatePerfEvent()
1470}