xref: /XiangShan/src/main/scala/xiangshan/mem/pipeline/HybridUnit.scala (revision 195ef4a53ab54326d879e884c4e1568f424f2668)
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 tlb_hint      = Flipped(new TlbHintReq)
69      val l2_hint       = Input(Valid(new L2ToL1Hint))
70
71      // fast wakeup
72      val fast_uop = ValidIO(new DynInst) // early wakeup signal generated in load_s1, send to RS in load_s2
73
74      // trigger
75      val trigger = Vec(TriggerNum, new LoadUnitTriggerIO)
76
77      // load to load fast path
78      val l2l_fwd_in    = Input(new LoadToLoadIO)
79      val l2l_fwd_out   = Output(new LoadToLoadIO)
80
81      val ld_fast_match    = Input(Bool())
82      val ld_fast_fuOpType = Input(UInt())
83      val ld_fast_imm      = Input(UInt(12.W))
84
85      // hardware prefetch to l1 cache req
86      val prefetch_req    = Flipped(ValidIO(new L1PrefetchReq))
87
88      // iq cancel
89      val ldCancel = Output(new LoadCancelIO()) // use to cancel the uops waked by this load, and cancel load
90
91      // iq wakeup, use to wakeup consumer uop at load s2
92      val wakeup = ValidIO(new DynInst)
93
94      // load ecc error
95      val s3_dly_ld_err = Output(Bool()) // Note that io.s3_dly_ld_err and io.lsq.s3_dly_ld_err is different
96
97      // schedule error query
98      val stld_nuke_query = Flipped(Vec(StorePipelineWidth, Valid(new StoreNukeQueryIO)))
99
100      // queue-based replay
101      val replay       = Flipped(Decoupled(new LsPipelineBundle))
102      val lq_rep_full  = Input(Bool())
103
104      // misc
105      val s2_ptr_chasing = Output(Bool()) // provide right pc for hw prefetch
106
107      // Load fast replay path
108      val fast_rep_in  = Flipped(Decoupled(new LqWriteBundle))
109      val fast_rep_out = Decoupled(new LqWriteBundle)
110
111      // Load RAR rollback
112      val rollback = Valid(new Redirect)
113
114      // perf
115      val debug_ls         = Output(new DebugLsInfoBundle)
116      val lsTopdownInfo    = Output(new LsTopdownInfo)
117    }
118
119    val stu_io = new Bundle() {
120      val dcache          = new DCacheStoreIO
121      val prefetch_req    = Flipped(DecoupledIO(new StorePrefetchReq))
122      val issue           = Valid(new MemExuInput)
123      val lsq             = ValidIO(new LsPipelineBundle)
124      val lsq_replenish   = Output(new LsPipelineBundle())
125      val stld_nuke_query = Valid(new StoreNukeQueryIO)
126      val st_mask_out     = Valid(new StoreMaskBundle)
127      val debug_ls        = Output(new DebugLsInfoBundle)
128    }
129
130    val vec_stu_io = new Bundle() {
131      val in = Flipped(DecoupledIO(new VecPipeBundle()))
132      val isFirstIssue = Input(Bool())
133      val lsq = ValidIO(new LsPipelineBundle())
134      val feedbackSlow = ValidIO(new VSFQFeedback)
135    }
136
137    // speculative for gated control
138    val s0_prefetch_spec = Output(Bool())
139    val s1_prefetch_spec = Output(Bool())
140    // prefetch
141    val prefetch_train            = ValidIO(new LdPrefetchTrainBundle()) // provide prefetch info to sms
142    val prefetch_train_l1         = ValidIO(new LdPrefetchTrainBundle()) // provide prefetch info to stream & stride
143    val canAcceptLowConfPrefetch  = Output(Bool())
144    val canAcceptHighConfPrefetch = Output(Bool())
145    val correctMissTrain          = Input(Bool())
146
147    // data path
148    val tlb           = new TlbRequestIO(2)
149    val pmp           = Flipped(new PMPRespBundle()) // arrive same to tlb now
150
151    // rs feedback
152    val feedback_fast = ValidIO(new RSFeedback) // stage 2
153    val feedback_slow = ValidIO(new RSFeedback) // stage 3
154  })
155
156  val StorePrefetchL1Enabled = EnableStorePrefetchAtCommit || EnableStorePrefetchAtIssue || EnableStorePrefetchSPB
157  val s1_ready, s2_ready, s3_ready, sx_can_go = WireInit(false.B)
158
159  // Pipeline
160  // --------------------------------------------------------------------------------
161  // stage 0
162  // --------------------------------------------------------------------------------
163  // generate addr, use addr to query DCache and DTLB
164  val s0_valid         = Wire(Bool())
165  val s0_dcache_ready  = Wire(Bool())
166  val s0_kill          = Wire(Bool())
167  val s0_vaddr         = Wire(UInt(VAddrBits.W))
168  val s0_mask          = Wire(UInt((VLEN/8).W))
169  val s0_uop           = Wire(new DynInst)
170  val s0_has_rob_entry = Wire(Bool())
171  val s0_rsIdx         = Wire(UInt(log2Up(MemIQSizeMax).W))
172  val s0_mshrid        = Wire(UInt())
173  val s0_try_l2l       = Wire(Bool())
174  val s0_rep_carry     = Wire(new ReplayCarry(nWays))
175  val s0_isFirstIssue  = Wire(Bool())
176  val s0_fast_rep      = Wire(Bool())
177  val s0_ld_rep        = Wire(Bool())
178  val s0_l2l_fwd       = Wire(Bool())
179  val s0_sched_idx     = Wire(UInt())
180  val s0_can_go        = s1_ready
181  val s0_fire          = s0_valid && s0_dcache_ready && s0_can_go
182  val s0_out           = Wire(new LqWriteBundle)
183  // vector
184  val s0_isvec = WireInit(false.B)
185  val s0_vecActive = WireInit(true.B)
186  // val s0_flowPtr = WireInit(0.U.asTypeOf(new VsFlowPtr))
187  val s0_isLastElem = WireInit(false.B)
188
189  // load flow select/gen
190  // src0: super load replayed by LSQ (cache miss replay) (io.ldu_io.replay)
191  // src1: fast load replay (io.ldu_io.fast_rep_in)
192  // src2: load replayed by LSQ (io.ldu_io.replay)
193  // src3: hardware prefetch from prefetchor (high confidence) (io.prefetch)
194  // src4: int read / software prefetch first issue from RS (io.in)
195  // src5: vec read first issue from RS (TODO)
196  // src6: load try pointchaising when no issued or replayed load (io.fastpath)
197  // src7: hardware prefetch from prefetchor (high confidence) (io.prefetch)
198  // priority: high to low
199  val s0_ld_flow             = FuType.isLoad(s0_uop.fuType) || FuType.isVLoad(s0_uop.fuType)
200  val s0_rep_stall           = io.lsin.valid && isAfter(io.ldu_io.replay.bits.uop.robIdx, io.lsin.bits.uop.robIdx)
201  val s0_super_ld_rep_valid  = io.ldu_io.replay.valid && io.ldu_io.replay.bits.forward_tlDchannel
202  val s0_ld_fast_rep_valid   = io.ldu_io.fast_rep_in.valid
203  val s0_ld_rep_valid        = io.ldu_io.replay.valid && !io.ldu_io.replay.bits.forward_tlDchannel && !s0_rep_stall
204  val s0_high_conf_prf_valid = io.ldu_io.prefetch_req.valid && io.ldu_io.prefetch_req.bits.confidence > 0.U
205  val s0_int_iss_valid       = io.lsin.valid // int flow first issue or software prefetch
206  val s0_vec_iss_valid       = io.vec_stu_io.in.valid
207  val s0_l2l_fwd_valid       = io.ldu_io.l2l_fwd_in.valid && io.ldu_io.ld_fast_match
208  val s0_low_conf_prf_valid  = io.ldu_io.prefetch_req.valid && io.ldu_io.prefetch_req.bits.confidence === 0.U
209  dontTouch(s0_super_ld_rep_valid)
210  dontTouch(s0_ld_fast_rep_valid)
211  dontTouch(s0_ld_rep_valid)
212  dontTouch(s0_high_conf_prf_valid)
213  dontTouch(s0_int_iss_valid)
214  dontTouch(s0_vec_iss_valid)
215  dontTouch(s0_l2l_fwd_valid)
216  dontTouch(s0_low_conf_prf_valid)
217
218  // load flow source ready
219  val s0_super_ld_rep_ready  = WireInit(true.B)
220  val s0_ld_fast_rep_ready   = !s0_super_ld_rep_valid
221  val s0_ld_rep_ready        = !s0_super_ld_rep_valid &&
222                               !s0_ld_fast_rep_valid
223  val s0_high_conf_prf_ready = !s0_super_ld_rep_valid &&
224                               !s0_ld_fast_rep_valid &&
225                               !s0_ld_rep_valid
226
227  val s0_int_iss_ready       = !s0_super_ld_rep_valid &&
228                               !s0_ld_fast_rep_valid &&
229                               !s0_ld_rep_valid &&
230                               !s0_high_conf_prf_valid
231
232  val s0_vec_iss_ready       = !s0_super_ld_rep_valid &&
233                               !s0_ld_fast_rep_valid &&
234                               !s0_ld_rep_valid &&
235                               !s0_high_conf_prf_valid &&
236                               !s0_int_iss_valid
237
238  val s0_l2l_fwd_ready       = !s0_super_ld_rep_valid &&
239                               !s0_ld_fast_rep_valid &&
240                               !s0_ld_rep_valid &&
241                               !s0_high_conf_prf_valid &&
242                               !s0_int_iss_valid &&
243                               !s0_vec_iss_valid
244
245  val s0_low_conf_prf_ready  = !s0_super_ld_rep_valid &&
246                               !s0_ld_fast_rep_valid &&
247                               !s0_ld_rep_valid &&
248                               !s0_high_conf_prf_valid &&
249                               !s0_int_iss_valid &&
250                               !s0_vec_iss_valid &&
251                               !s0_l2l_fwd_valid
252  dontTouch(s0_super_ld_rep_ready)
253  dontTouch(s0_ld_fast_rep_ready)
254  dontTouch(s0_ld_rep_ready)
255  dontTouch(s0_high_conf_prf_ready)
256  dontTouch(s0_int_iss_ready)
257  dontTouch(s0_vec_iss_ready)
258  dontTouch(s0_l2l_fwd_ready)
259  dontTouch(s0_low_conf_prf_ready)
260
261  // load flow source select (OH)
262  val s0_super_ld_rep_select = s0_super_ld_rep_valid && s0_super_ld_rep_ready
263  val s0_ld_fast_rep_select  = s0_ld_fast_rep_valid && s0_ld_fast_rep_ready
264  val s0_ld_rep_select       = s0_ld_rep_valid && s0_ld_rep_ready
265  val s0_hw_prf_select       = s0_high_conf_prf_ready && s0_high_conf_prf_valid ||
266                               s0_low_conf_prf_ready && s0_low_conf_prf_valid
267  val s0_int_iss_select      = s0_int_iss_ready && s0_int_iss_valid
268  val s0_vec_iss_select      = s0_vec_iss_ready && s0_vec_iss_valid
269  val s0_l2l_fwd_select      = s0_l2l_fwd_ready && s0_l2l_fwd_valid
270  dontTouch(s0_super_ld_rep_select)
271  dontTouch(s0_ld_fast_rep_select)
272  dontTouch(s0_ld_rep_select)
273  dontTouch(s0_hw_prf_select)
274  dontTouch(s0_int_iss_select)
275  dontTouch(s0_vec_iss_select)
276  dontTouch(s0_l2l_fwd_select)
277
278  s0_valid := (s0_super_ld_rep_valid ||
279               s0_ld_fast_rep_valid ||
280               s0_ld_rep_valid ||
281               s0_high_conf_prf_valid ||
282               s0_int_iss_valid ||
283               s0_vec_iss_valid ||
284               s0_l2l_fwd_valid ||
285               s0_low_conf_prf_valid) && !s0_kill
286
287  // which is S0's out is ready and dcache is ready
288  val s0_try_ptr_chasing      = s0_l2l_fwd_select
289  val s0_do_try_ptr_chasing   = s0_try_ptr_chasing && s0_can_go && io.ldu_io.dcache.req.ready
290  val s0_ptr_chasing_vaddr    = io.ldu_io.l2l_fwd_in.data(5, 0) +& io.ldu_io.ld_fast_imm(5, 0)
291  val s0_ptr_chasing_canceled = WireInit(false.B)
292  s0_kill := s0_ptr_chasing_canceled || (s0_out.uop.robIdx.needFlush(io.redirect) && !s0_try_ptr_chasing)
293
294  // prefetch related ctrl signal
295  val s0_prf    = Wire(Bool())
296  val s0_prf_rd = Wire(Bool())
297  val s0_prf_wr = Wire(Bool())
298  val s0_hw_prf = s0_hw_prf_select
299
300  io.canAcceptLowConfPrefetch  := s0_low_conf_prf_ready && io.ldu_io.dcache.req.ready
301  io.canAcceptHighConfPrefetch := s0_high_conf_prf_ready && io.ldu_io.dcache.req.ready
302
303  if (StorePrefetchL1Enabled) {
304    s0_dcache_ready := Mux(s0_ld_flow, io.ldu_io.dcache.req.ready, io.stu_io.dcache.req.ready)
305  } else {
306    s0_dcache_ready := Mux(s0_ld_flow, io.ldu_io.dcache.req.ready, true.B)
307  }
308
309  // query DTLB
310  io.tlb.req.valid                   := s0_valid && s0_dcache_ready
311  io.tlb.req.bits.cmd                := Mux(s0_prf,
312                                         Mux(s0_prf_wr, TlbCmd.write, TlbCmd.read),
313                                         Mux(s0_ld_flow, TlbCmd.read, TlbCmd.write)
314                                       )
315  io.tlb.req.bits.vaddr              := Mux(s0_hw_prf_select, io.ldu_io.prefetch_req.bits.paddr, s0_vaddr)
316  io.tlb.req.bits.size               := Mux(s0_isvec, io.vec_stu_io.in.bits.alignedType(1, 0), LSUOpType.size(s0_uop.fuOpType)) // may broken if use it in feature
317  io.tlb.req.bits.kill               := s0_kill
318  io.tlb.req.bits.memidx.is_ld       := s0_ld_flow
319  io.tlb.req.bits.memidx.is_st       := !s0_ld_flow
320  io.tlb.req.bits.memidx.idx         := s0_uop.lqIdx.value
321  io.tlb.req.bits.debug.robIdx       := s0_uop.robIdx
322  io.tlb.req.bits.no_translate       := s0_hw_prf_select  // hw b.reqetch addr does not need to be translated
323  io.tlb.req.bits.debug.pc           := s0_uop.pc
324  io.tlb.req.bits.debug.isFirstIssue := s0_isFirstIssue
325
326  // query DCache
327  // for load
328  io.ldu_io.dcache.req.valid             := s0_valid && s0_dcache_ready && s0_ld_flow
329  io.ldu_io.dcache.req.bits.cmd          :=  Mux(s0_prf_rd, MemoryOpConstants.M_PFR,
330                                              Mux(s0_prf_wr, MemoryOpConstants.M_PFW, MemoryOpConstants.M_XRD))
331  io.ldu_io.dcache.req.bits.vaddr        := s0_vaddr
332  io.ldu_io.dcache.req.bits.mask         := s0_mask
333  io.ldu_io.dcache.req.bits.data         := DontCare
334  io.ldu_io.dcache.req.bits.isFirstIssue := s0_isFirstIssue
335  io.ldu_io.dcache.req.bits.instrtype    := Mux(s0_prf, DCACHE_PREFETCH_SOURCE.U, LOAD_SOURCE.U)
336  io.ldu_io.dcache.req.bits.debug_robIdx := s0_uop.robIdx.value
337  io.ldu_io.dcache.req.bits.replayCarry  := s0_rep_carry
338  io.ldu_io.dcache.req.bits.id           := DontCare // TODO: update cache meta
339  io.ldu_io.dcache.pf_source             := Mux(s0_hw_prf_select, io.ldu_io.prefetch_req.bits.pf_source.value, L1_HW_PREFETCH_NULL)
340  io.ldu_io.dcache.is128Req              := is128Bit(io.vec_stu_io.in.bits.alignedType) && io.vec_stu_io.in.valid && s0_vec_iss_select
341
342  // for store
343  io.stu_io.dcache.req.valid             := s0_valid && s0_dcache_ready && !s0_ld_flow && !s0_prf
344  io.stu_io.dcache.req.bits.cmd          := MemoryOpConstants.M_PFW
345  io.stu_io.dcache.req.bits.vaddr        := s0_vaddr
346  io.stu_io.dcache.req.bits.instrtype    := Mux(s0_prf, DCACHE_PREFETCH_SOURCE.U, STORE_SOURCE.U)
347
348  // load flow priority mux
349  def fromNullSource() = {
350    s0_vaddr         := 0.U
351    s0_mask          := 0.U
352    s0_uop           := 0.U.asTypeOf(new DynInst)
353    s0_try_l2l       := false.B
354    s0_has_rob_entry := false.B
355    s0_rsIdx         := 0.U
356    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
357    s0_mshrid        := 0.U
358    s0_isFirstIssue  := false.B
359    s0_fast_rep      := false.B
360    s0_ld_rep        := false.B
361    s0_l2l_fwd       := false.B
362    s0_prf           := false.B
363    s0_prf_rd        := false.B
364    s0_prf_wr        := false.B
365    s0_sched_idx     := 0.U
366  }
367
368  def fromFastReplaySource(src: LqWriteBundle) = {
369    s0_vaddr         := src.vaddr
370    s0_mask          := src.mask
371    s0_uop           := src.uop
372    s0_try_l2l       := false.B
373    s0_has_rob_entry := src.hasROBEntry
374    s0_rep_carry     := src.rep_info.rep_carry
375    s0_mshrid        := src.rep_info.mshr_id
376    s0_rsIdx         := src.rsIdx
377    s0_isFirstIssue  := false.B
378    s0_fast_rep      := true.B
379    s0_ld_rep        := src.isLoadReplay
380    s0_l2l_fwd       := false.B
381    s0_prf           := LSUOpType.isPrefetch(src.uop.fuOpType)
382    s0_prf_rd        := src.uop.fuOpType === LSUOpType.prefetch_r
383    s0_prf_wr        := src.uop.fuOpType === LSUOpType.prefetch_w
384    s0_sched_idx     := src.schedIndex
385  }
386
387  def fromNormalReplaySource(src: LsPipelineBundle) = {
388    s0_vaddr         := src.vaddr
389    s0_mask          := genVWmask(src.vaddr, src.uop.fuOpType(1, 0))
390    s0_uop           := src.uop
391    s0_try_l2l       := false.B
392    s0_has_rob_entry := true.B
393    s0_rsIdx         := src.rsIdx
394    s0_rep_carry     := src.replayCarry
395    s0_mshrid        := src.mshrid
396    s0_isFirstIssue  := false.B
397    s0_fast_rep      := false.B
398    s0_ld_rep        := true.B
399    s0_l2l_fwd       := false.B
400    s0_prf           := LSUOpType.isPrefetch(src.uop.fuOpType)
401    s0_prf_rd        := src.uop.fuOpType === LSUOpType.prefetch_r
402    s0_prf_wr        := src.uop.fuOpType === LSUOpType.prefetch_w
403    s0_sched_idx     := src.schedIndex
404  }
405
406  def fromPrefetchSource(src: L1PrefetchReq) = {
407    s0_vaddr         := src.getVaddr()
408    s0_mask          := 0.U
409    s0_uop           := DontCare
410    s0_try_l2l       := false.B
411    s0_has_rob_entry := false.B
412    s0_rsIdx         := 0.U
413    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
414    s0_mshrid        := 0.U
415    s0_isFirstIssue  := false.B
416    s0_fast_rep      := false.B
417    s0_ld_rep        := false.B
418    s0_l2l_fwd       := false.B
419    s0_prf           := true.B
420    s0_prf_rd        := !src.is_store
421    s0_prf_wr        := src.is_store
422    s0_sched_idx     := 0.U
423  }
424
425  def fromIntIssueSource(src: MemExuInput) = {
426    s0_vaddr         := src.src(0) + SignExt(src.uop.imm(11, 0), VAddrBits)
427    s0_mask          := genVWmask(s0_vaddr, src.uop.fuOpType(1,0))
428    s0_uop           := src.uop
429    s0_try_l2l       := false.B
430    s0_has_rob_entry := true.B
431    s0_rsIdx         := src.iqIdx
432    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
433    s0_mshrid        := 0.U
434    s0_isFirstIssue  := true.B
435    s0_fast_rep      := false.B
436    s0_ld_rep        := false.B
437    s0_l2l_fwd       := false.B
438    s0_prf           := LSUOpType.isPrefetch(src.uop.fuOpType)
439    s0_prf_rd        := src.uop.fuOpType === LSUOpType.prefetch_r
440    s0_prf_wr        := src.uop.fuOpType === LSUOpType.prefetch_w
441    s0_sched_idx     := 0.U
442  }
443
444  def fromVecIssueSource(src: VecPipeBundle) = {
445    // For now, vector port handles only vector store flows
446    s0_vaddr         := src.vaddr
447    s0_mask          := src.mask
448    s0_uop           := src.uop
449    s0_try_l2l       := false.B
450    s0_has_rob_entry := true.B
451    s0_rsIdx         := 0.U
452    s0_rep_carry     := 0.U.asTypeOf(s0_rep_carry.cloneType)
453    s0_mshrid        := 0.U
454    // s0_isFirstIssue  := src.isFirstIssue
455    s0_fast_rep      := false.B
456    s0_ld_rep        := false.B
457    s0_l2l_fwd       := false.B
458    s0_prf           := false.B
459    s0_prf_rd        := false.B
460    s0_prf_wr        := false.B
461    s0_sched_idx     := 0.U
462
463    s0_isvec         := true.B
464    s0_vecActive           := io.vec_stu_io.in.bits.vecActive
465    // s0_flowPtr       := io.vec_stu_io.in.bits.flowPtr
466    // s0_isLastElem    := io.vec_stu_io.in.bits.isLastElem
467  }
468
469  def fromLoadToLoadSource(src: LoadToLoadIO) = {
470    s0_vaddr              := Cat(src.data(XLEN-1, 6), s0_ptr_chasing_vaddr(5,0))
471    s0_mask               := genVWmask(s0_vaddr, io.ldu_io.ld_fast_fuOpType(1, 0))
472    // When there's no valid instruction from RS and LSQ, we try the load-to-load forwarding.
473    // Assume the pointer chasing is always ld.
474    s0_uop.fuOpType  := io.ldu_io.ld_fast_fuOpType
475    s0_try_l2l            := true.B
476    // we dont care s0_isFirstIssue and s0_rsIdx and s0_sqIdx in S0 when trying pointchasing
477    // because these signals will be updated in S1
478    s0_has_rob_entry      := false.B
479    s0_rsIdx              := 0.U
480    s0_mshrid             := 0.U
481    s0_rep_carry          := 0.U.asTypeOf(s0_rep_carry.cloneType)
482    s0_isFirstIssue       := true.B
483    s0_fast_rep           := false.B
484    s0_ld_rep             := false.B
485    s0_l2l_fwd            := true.B
486    s0_prf                := false.B
487    s0_prf_rd             := false.B
488    s0_prf_wr             := false.B
489    s0_sched_idx          := 0.U
490  }
491
492  // set default
493  s0_uop := DontCare
494  when (s0_super_ld_rep_select)      { fromNormalReplaySource(io.ldu_io.replay.bits)     }
495  .elsewhen (s0_ld_fast_rep_select)  { fromFastReplaySource(io.ldu_io.fast_rep_in.bits)  }
496  .elsewhen (s0_ld_rep_select)       { fromNormalReplaySource(io.ldu_io.replay.bits)     }
497  .elsewhen (s0_hw_prf_select)       { fromPrefetchSource(io.ldu_io.prefetch_req.bits)   }
498  .elsewhen (s0_int_iss_select)      { fromIntIssueSource(io.lsin.bits)                  }
499  .elsewhen (s0_vec_iss_select)      { fromVecIssueSource(io.vec_stu_io.in.bits)         }
500  .otherwise {
501    if (EnableLoadToLoadForward) {
502      fromLoadToLoadSource(io.ldu_io.l2l_fwd_in)
503    } else {
504      fromNullSource()
505    }
506  }
507
508  // address align check
509  val s0_addr_aligned = LookupTree(Mux(s0_isvec, io.vec_stu_io.in.bits.alignedType(1,0), s0_uop.fuOpType(1, 0)), List(
510    "b00".U   -> true.B,                   //b
511    "b01".U   -> (s0_vaddr(0)    === 0.U), //h
512    "b10".U   -> (s0_vaddr(1, 0) === 0.U), //w
513    "b11".U   -> (s0_vaddr(2, 0) === 0.U)  //d
514  ))// may broken if use it in feature
515
516  // accept load flow if dcache ready (tlb is always ready)
517  // TODO: prefetch need writeback to loadQueueFlag
518  s0_out               := DontCare
519  s0_out.rsIdx         := s0_rsIdx
520  s0_out.vaddr         := s0_vaddr
521  s0_out.mask          := s0_mask
522  s0_out.uop           := s0_uop
523  s0_out.isFirstIssue  := s0_isFirstIssue
524  s0_out.hasROBEntry   := s0_has_rob_entry
525  s0_out.isPrefetch    := s0_prf
526  s0_out.isHWPrefetch  := s0_hw_prf
527  s0_out.isFastReplay  := s0_fast_rep
528  s0_out.isLoadReplay  := s0_ld_rep
529  s0_out.isFastPath    := s0_l2l_fwd
530  s0_out.mshrid        := s0_mshrid
531  s0_out.isvec         := s0_isvec
532  s0_out.isLastElem    := s0_isLastElem
533  s0_out.vecActive           := s0_vecActive
534  // s0_out.sflowPtr      := s0_flowPtr
535  s0_out.uop.exceptionVec(loadAddrMisaligned)  := !s0_addr_aligned && s0_ld_flow
536  s0_out.uop.exceptionVec(storeAddrMisaligned) := !s0_addr_aligned && !s0_ld_flow
537  s0_out.forward_tlDchannel := s0_super_ld_rep_select
538  when(io.tlb.req.valid && s0_isFirstIssue) {
539    s0_out.uop.debugInfo.tlbFirstReqTime := GTimer()
540  }.otherwise{
541    s0_out.uop.debugInfo.tlbFirstReqTime := s0_uop.debugInfo.tlbFirstReqTime
542  }
543  s0_out.schedIndex     := s0_sched_idx
544
545  // load fast replay
546  io.ldu_io.fast_rep_in.ready := (s0_can_go && io.ldu_io.dcache.req.ready && s0_ld_fast_rep_ready)
547
548  // load flow source ready
549  // cache missed load has highest priority
550  // always accept cache missed load flow from load replay queue
551  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))
552
553  // accept load flow from rs when:
554  // 1) there is no lsq-replayed load
555  // 2) there is no fast replayed load
556  // 3) there is no high confidence prefetch request
557  io.lsin.ready := (s0_can_go &&
558                    Mux(FuType.isLoad(io.lsin.bits.uop.fuType), io.ldu_io.dcache.req.ready,
559                    (if (StorePrefetchL1Enabled) io.stu_io.dcache.req.ready else true.B)) && s0_int_iss_ready)
560  io.vec_stu_io.in.ready := s0_can_go && io.ldu_io.dcache.req.ready && s0_vec_iss_ready
561
562
563  // for hw prefetch load flow feedback, to be added later
564  // io.prefetch_in.ready := s0_hw_prf_select
565
566  // dcache replacement extra info
567  // TODO: should prefetch load update replacement?
568  io.ldu_io.dcache.replacementUpdated := Mux(s0_ld_rep_select || s0_super_ld_rep_select, io.ldu_io.replay.bits.replacementUpdated, false.B)
569
570  io.stu_io.prefetch_req.ready := s1_ready && io.stu_io.dcache.req.ready && !io.lsin.valid
571
572  // load debug
573  XSDebug(io.ldu_io.dcache.req.fire && s0_ld_flow,
574    p"[DCACHE LOAD REQ] pc ${Hexadecimal(s0_uop.pc)}, vaddr ${Hexadecimal(s0_vaddr)}\n"
575  )
576  XSDebug(s0_valid && s0_ld_flow,
577    p"S0: pc ${Hexadecimal(s0_out.uop.pc)}, lqIdx ${Hexadecimal(s0_out.uop.lqIdx.asUInt)}, " +
578    p"vaddr ${Hexadecimal(s0_out.vaddr)}, mask ${Hexadecimal(s0_out.mask)}\n")
579
580  // store debug
581  XSDebug(io.stu_io.dcache.req.fire && !s0_ld_flow,
582    p"[DCACHE STORE REQ] pc ${Hexadecimal(s0_uop.pc)}, vaddr ${Hexadecimal(s0_vaddr)}\n"
583  )
584  XSDebug(s0_valid && !s0_ld_flow,
585    p"S0: pc ${Hexadecimal(s0_out.uop.pc)}, sqIdx ${Hexadecimal(s0_out.uop.sqIdx.asUInt)}, " +
586    p"vaddr ${Hexadecimal(s0_out.vaddr)}, mask ${Hexadecimal(s0_out.mask)}\n")
587
588
589  // Pipeline
590  // --------------------------------------------------------------------------------
591  // stage 1
592  // --------------------------------------------------------------------------------
593  // TLB resp (send paddr to dcache)
594  val s1_valid      = RegInit(false.B)
595  val s1_in         = Wire(new LqWriteBundle)
596  val s1_out        = Wire(new LqWriteBundle)
597  val s1_kill       = Wire(Bool())
598  val s1_can_go     = s2_ready
599  val s1_fire       = s1_valid && !s1_kill && s1_can_go
600  val s1_ld_flow    = RegNext(s0_ld_flow)
601  val s1_isvec      = RegEnable(s0_out.isvec, false.B, s0_fire)
602  val s1_isLastElem = RegEnable(s0_out.isLastElem, false.B, s0_fire)
603
604  s1_ready := !s1_valid || s1_kill || s2_ready
605  when (s0_fire) { s1_valid := true.B }
606  .elsewhen (s1_fire) { s1_valid := false.B }
607  .elsewhen (s1_kill) { s1_valid := false.B }
608  s1_in   := RegEnable(s0_out, s0_fire)
609
610  val s1_fast_rep_dly_err = RegNext(io.ldu_io.fast_rep_in.bits.delayedLoadError)
611  val s1_fast_rep_kill    = s1_fast_rep_dly_err && s1_in.isFastReplay
612  val s1_l2l_fwd_dly_err  = RegNext(io.ldu_io.l2l_fwd_in.dly_ld_err)
613  val s1_l2l_fwd_kill     = s1_l2l_fwd_dly_err && s1_in.isFastPath
614  val s1_late_kill        = s1_fast_rep_kill || s1_l2l_fwd_kill
615  val s1_vaddr_hi         = Wire(UInt())
616  val s1_vaddr_lo         = Wire(UInt())
617  val s1_vaddr            = Wire(UInt())
618  val s1_paddr_dup_lsu    = Wire(UInt())
619  val s1_paddr_dup_dcache = Wire(UInt())
620  val s1_ld_exception     = ExceptionNO.selectByFu(s1_out.uop.exceptionVec, LduCfg).asUInt.orR   // af & pf exception were modified below.
621  val s1_st_exception     = ExceptionNO.selectByFu(s1_out.uop.exceptionVec, StaCfg).asUInt.orR   // af & pf exception were modified below.
622  val s1_exception        = (s1_ld_flow && s1_ld_exception) || (!s1_ld_flow && s1_st_exception)
623  val s1_tlb_miss         = io.tlb.resp.bits.miss
624  val s1_prf              = s1_in.isPrefetch
625  val s1_hw_prf           = s1_in.isHWPrefetch
626  val s1_sw_prf           = s1_prf && !s1_hw_prf
627  val s1_tlb_memidx       = io.tlb.resp.bits.memidx
628
629  // mmio cbo decoder
630  val s1_mmio_cbo  = (s1_in.uop.fuOpType === LSUOpType.cbo_clean ||
631                      s1_in.uop.fuOpType === LSUOpType.cbo_flush ||
632                      s1_in.uop.fuOpType === LSUOpType.cbo_inval) && !s1_ld_flow && !s1_prf
633  val s1_mmio = s1_mmio_cbo
634
635  s1_vaddr_hi         := s1_in.vaddr(VAddrBits - 1, 6)
636  s1_vaddr_lo         := s1_in.vaddr(5, 0)
637  s1_vaddr            := Cat(s1_vaddr_hi, s1_vaddr_lo)
638  s1_paddr_dup_lsu    := io.tlb.resp.bits.paddr(0)
639  s1_paddr_dup_dcache := io.tlb.resp.bits.paddr(1)
640
641  when (s1_tlb_memidx.is_ld && io.tlb.resp.valid && !s1_tlb_miss &&
642        s1_tlb_memidx.idx === s1_in.uop.lqIdx.value && s1_ld_flow) {
643    // printf("Load idx = %d\n", s1_tlb_memidx.idx)
644    s1_out.uop.debugInfo.tlbRespTime := GTimer()
645  } .elsewhen(s1_tlb_memidx.is_st && io.tlb.resp.valid && !s1_tlb_miss &&
646              s1_tlb_memidx.idx === s1_out.uop.sqIdx.value && !s1_ld_flow) {
647    // printf("Store idx = %d\n", s1_tlb_memidx.idx)
648    s1_out.uop.debugInfo.tlbRespTime := GTimer()
649  }
650
651  io.tlb.req_kill   := s1_kill
652  io.tlb.resp.ready := true.B
653
654  io.ldu_io.dcache.s1_paddr_dup_lsu    <> s1_paddr_dup_lsu
655  io.ldu_io.dcache.s1_paddr_dup_dcache <> s1_paddr_dup_dcache
656  io.ldu_io.dcache.s1_kill             := s1_kill || s1_tlb_miss || s1_exception
657
658  // store to load forwarding
659  io.ldu_io.sbuffer.valid := s1_valid && !(s1_exception || s1_tlb_miss || s1_kill || s1_fast_rep_kill || s1_prf || !s1_ld_flow)
660  io.ldu_io.sbuffer.vaddr := s1_vaddr
661  io.ldu_io.sbuffer.paddr := s1_paddr_dup_lsu
662  io.ldu_io.sbuffer.uop   := s1_in.uop
663  io.ldu_io.sbuffer.sqIdx := s1_in.uop.sqIdx
664  io.ldu_io.sbuffer.mask  := s1_in.mask
665  io.ldu_io.sbuffer.pc    := s1_in.uop.pc // FIXME: remove it
666
667  io.ldu_io.vec_forward.valid := s1_valid && !(s1_exception || s1_tlb_miss || s1_kill || s1_fast_rep_kill || s1_prf || !s1_ld_flow)
668  io.ldu_io.vec_forward.vaddr := s1_vaddr
669  io.ldu_io.vec_forward.paddr := s1_paddr_dup_lsu
670  io.ldu_io.vec_forward.uop   := s1_in.uop
671  io.ldu_io.vec_forward.sqIdx := s1_in.uop.sqIdx
672  io.ldu_io.vec_forward.mask  := s1_in.mask
673  io.ldu_io.vec_forward.pc    := s1_in.uop.pc // FIXME: remove it
674
675  io.ldu_io.lsq.forward.valid     := s1_valid && !(s1_exception || s1_tlb_miss || s1_kill || s1_fast_rep_kill || s1_prf || !s1_ld_flow)
676  io.ldu_io.lsq.forward.vaddr     := s1_vaddr
677  io.ldu_io.lsq.forward.paddr     := s1_paddr_dup_lsu
678  io.ldu_io.lsq.forward.uop       := s1_in.uop
679  io.ldu_io.lsq.forward.sqIdx     := s1_in.uop.sqIdx
680  io.ldu_io.lsq.forward.sqIdxMask := 0.U
681  io.ldu_io.lsq.forward.mask      := s1_in.mask
682  io.ldu_io.lsq.forward.pc        := s1_in.uop.pc // FIXME: remove it
683
684  // st-ld violation query
685  val s1_nuke = VecInit((0 until StorePipelineWidth).map(w => {
686                       io.ldu_io.stld_nuke_query(w).valid && // query valid
687                       isAfter(s1_in.uop.robIdx, io.ldu_io.stld_nuke_query(w).bits.robIdx) && // older store
688                       // TODO: Fix me when vector instruction
689                       (s1_paddr_dup_lsu(PAddrBits-1, 3) === io.ldu_io.stld_nuke_query(w).bits.paddr(PAddrBits-1, 3)) && // paddr match
690                       (s1_in.mask & io.ldu_io.stld_nuke_query(w).bits.mask).orR // data mask contain
691                      })).asUInt.orR && !s1_tlb_miss && s1_ld_flow
692
693  s1_out                   := s1_in
694  s1_out.vaddr             := s1_vaddr
695  s1_out.paddr             := s1_paddr_dup_lsu
696  s1_out.tlbMiss           := s1_tlb_miss
697  s1_out.ptwBack           := io.tlb.resp.bits.ptwBack
698  s1_out.rsIdx             := s1_in.rsIdx
699  s1_out.rep_info.debug    := s1_in.uop.debugInfo
700  s1_out.rep_info.nuke     := s1_nuke && !s1_sw_prf
701  s1_out.lateKill          := s1_late_kill
702
703  when (s1_ld_flow) {
704    when (!s1_late_kill) {
705      // current ori test will cause the case of ldest == 0, below will be modifeid in the future.
706      // af & pf exception were modified
707      s1_out.uop.exceptionVec(loadPageFault)       := io.tlb.resp.bits.excp(0).pf.ld
708      s1_out.uop.exceptionVec(loadGuestPageFault)  := io.tlb.resp.bits.excp(0).gpf.ld
709      s1_out.uop.exceptionVec(loadAccessFault)     := io.tlb.resp.bits.excp(0).af.ld
710    } .otherwise {
711      s1_out.uop.exceptionVec(loadAddrMisaligned)  := false.B
712      s1_out.uop.exceptionVec(loadAccessFault)     := s1_late_kill
713    }
714  } .otherwise {
715    s1_out.uop.exceptionVec(storePageFault)        := io.tlb.resp.bits.excp(0).pf.st
716    s1_out.uop.exceptionVec(storeGuestPageFault)   := io.tlb.resp.bits.excp(0).gpf.st
717    s1_out.uop.exceptionVec(storeAccessFault)      := io.tlb.resp.bits.excp(0).af.st
718  }
719
720  // pointer chasing
721  val s1_try_ptr_chasing       = RegNext(s0_do_try_ptr_chasing, false.B)
722  val s1_ptr_chasing_vaddr     = RegEnable(s0_ptr_chasing_vaddr, s0_do_try_ptr_chasing)
723  val s1_fu_op_type_not_ld     = WireInit(false.B)
724  val s1_not_fast_match        = WireInit(false.B)
725  val s1_addr_mismatch         = WireInit(false.B)
726  val s1_addr_misaligned       = WireInit(false.B)
727  val s1_ptr_chasing_canceled  = WireInit(false.B)
728  val s1_cancel_ptr_chasing    = WireInit(false.B)
729
730  s1_kill := s1_late_kill ||
731             s1_cancel_ptr_chasing ||
732             s1_in.uop.robIdx.needFlush(io.redirect) ||
733             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)
734
735  if (EnableLoadToLoadForward) {
736    // Sometimes, we need to cancel the load-load forwarding.
737    // These can be put at S0 if timing is bad at S1.
738    // Case 0: CACHE_SET(base + offset) != CACHE_SET(base) (lowest 6-bit addition has an overflow)
739    s1_addr_mismatch      := s1_ptr_chasing_vaddr(6) || RegEnable(io.ldu_io.ld_fast_imm(11, 6).orR, s0_do_try_ptr_chasing)
740    // Case 1: the address is misaligned, kill s1
741    s1_addr_misaligned    := LookupTree(s1_in.uop.fuOpType(1, 0), List(
742                             "b00".U   -> false.B,                  //b
743                             "b01".U   -> (s1_vaddr(0)    =/= 0.U), //h
744                             "b10".U   -> (s1_vaddr(1, 0) =/= 0.U), //w
745                             "b11".U   -> (s1_vaddr(2, 0) =/= 0.U)  //d
746                          ))
747    // Case 2: this load-load uop is cancelled
748    s1_ptr_chasing_canceled := !io.lsin.valid || FuType.isStore(io.lsin.bits.uop.fuType)
749
750    when (s1_try_ptr_chasing) {
751      s1_cancel_ptr_chasing := s1_addr_mismatch || s1_addr_misaligned || s1_ptr_chasing_canceled
752
753      s1_in.uop           := io.lsin.bits.uop
754      s1_in.rsIdx         := io.lsin.bits.iqIdx
755      s1_in.isFirstIssue  := io.lsin.bits.isFirstIssue
756      s1_vaddr_lo         := s1_ptr_chasing_vaddr(5, 0)
757      s1_paddr_dup_lsu    := Cat(io.tlb.resp.bits.paddr(0)(PAddrBits - 1, 6), s1_vaddr_lo)
758      s1_paddr_dup_dcache := Cat(io.tlb.resp.bits.paddr(0)(PAddrBits - 1, 6), s1_vaddr_lo)
759
760      // 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)
761      s1_in.uop.debugInfo.tlbFirstReqTime := GTimer()
762      s1_in.uop.debugInfo.tlbRespTime     := GTimer()
763    }
764    when (!s1_cancel_ptr_chasing) {
765      s0_ptr_chasing_canceled := s1_try_ptr_chasing && !io.ldu_io.replay.fire && !io.ldu_io.fast_rep_in.fire && !(s0_high_conf_prf_valid && io.canAcceptHighConfPrefetch)
766      when (s1_try_ptr_chasing) {
767        io.lsin.ready := true.B
768      }
769    }
770  }
771
772  // pre-calcuate sqIdx mask in s0, then send it to lsq in s1 for forwarding
773  val s1_sqIdx_mask = RegNext(UIntToMask(s0_out.uop.sqIdx.value, StoreQueueSize))
774  // to enable load-load, sqIdxMask must be calculated based on lsin.uop
775  // If the timing here is not OK, load-load forwarding has to be disabled.
776  // Or we calculate sqIdxMask at RS??
777  io.ldu_io.lsq.forward.sqIdxMask := s1_sqIdx_mask
778  if (EnableLoadToLoadForward) {
779    when (s1_try_ptr_chasing) {
780      io.ldu_io.lsq.forward.sqIdxMask := UIntToMask(io.lsin.bits.uop.sqIdx.value, StoreQueueSize)
781    }
782  }
783
784  io.ldu_io.forward_mshr.valid  := s1_valid && s1_out.forward_tlDchannel && s1_ld_flow
785  io.ldu_io.forward_mshr.mshrid := s1_out.mshrid
786  io.ldu_io.forward_mshr.paddr  := s1_out.paddr
787
788  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)
789  io.ldu_io.wakeup.bits := s0_uop
790
791  io.stu_io.dcache.s1_kill := s1_tlb_miss || s1_exception || s1_mmio || s1_in.uop.robIdx.needFlush(io.redirect)
792  io.stu_io.dcache.s1_paddr := s1_paddr_dup_dcache
793
794
795  // load debug
796  XSDebug(s1_valid && s1_ld_flow,
797    p"S1: pc ${Hexadecimal(s1_out.uop.pc)}, lId ${Hexadecimal(s1_out.uop.lqIdx.asUInt)}, tlb_miss ${io.tlb.resp.bits.miss}, " +
798    p"paddr ${Hexadecimal(s1_out.paddr)}, mmio ${s1_out.mmio}\n")
799
800  // store debug
801  XSDebug(s1_valid && !s1_ld_flow,
802    p"S1: pc ${Hexadecimal(s1_out.uop.pc)}, lId ${Hexadecimal(s1_out.uop.sqIdx.asUInt)}, tlb_miss ${io.tlb.resp.bits.miss}, " +
803    p"paddr ${Hexadecimal(s1_out.paddr)}, mmio ${s1_out.mmio}\n")
804
805  // store out
806  io.stu_io.lsq.valid         := s1_valid && !s1_ld_flow && !s1_prf && !s1_isvec
807  io.stu_io.lsq.bits          := s1_out
808  io.stu_io.lsq.bits.miss     := s1_tlb_miss
809
810  io.vec_stu_io.lsq.valid     := s1_valid && !s1_ld_flow && !s1_prf && s1_isvec
811  io.vec_stu_io.lsq.bits          := s1_out
812  io.vec_stu_io.lsq.bits.miss     := s1_tlb_miss
813  io.vec_stu_io.lsq.bits.isLastElem := s1_isLastElem
814
815  io.stu_io.st_mask_out.valid       := s1_valid && !s1_ld_flow && !s1_prf
816  io.stu_io.st_mask_out.bits.mask   := s1_out.mask
817  io.stu_io.st_mask_out.bits.sqIdx  := s1_out.uop.sqIdx
818
819  io.stu_io.issue.valid       := s1_valid && !s1_tlb_miss && !s1_ld_flow && !s1_prf && !s1_isvec
820  io.stu_io.issue.bits        := RegEnable(io.lsin.bits, io.lsin.fire)
821
822  // st-ld violation dectect request
823  io.stu_io.stld_nuke_query.valid       := s1_valid && !s1_tlb_miss && !s1_ld_flow && !s1_prf
824  io.stu_io.stld_nuke_query.bits.robIdx := s1_in.uop.robIdx
825  io.stu_io.stld_nuke_query.bits.paddr  := s1_paddr_dup_lsu
826  io.stu_io.stld_nuke_query.bits.mask   := s1_in.mask
827
828  // Pipeline
829  // --------------------------------------------------------------------------------
830  // stage 2
831  // --------------------------------------------------------------------------------
832  // s2: DCache resp
833  val s2_valid  = RegInit(false.B)
834  val s2_in     = Wire(new LqWriteBundle)
835  val s2_out    = Wire(new LqWriteBundle)
836  val s2_kill   = Wire(Bool())
837  val s2_can_go = s3_ready
838  val s2_fire   = s2_valid && !s2_kill && s2_can_go
839  val s2_isvec  = RegEnable(s1_isvec, false.B, s1_fire)
840  val s2_vecActive    = RegEnable(s1_out.vecActive, true.B, s1_fire)
841  val s2_paddr  = RegEnable(s1_paddr_dup_lsu, s1_fire)
842
843  s2_kill := s2_in.uop.robIdx.needFlush(io.redirect)
844  s2_ready := !s2_valid || s2_kill || s3_ready
845  when (s1_fire) { s2_valid := true.B }
846  .elsewhen (s2_fire) { s2_valid := false.B }
847  .elsewhen (s2_kill) { s2_valid := false.B }
848  s2_in := RegEnable(s1_out, s1_fire)
849
850  val s2_pmp = WireInit(io.pmp)
851
852  val s2_prf    = s2_in.isPrefetch
853  val s2_hw_prf = s2_in.isHWPrefetch
854  val s2_ld_flow  = RegEnable(s1_ld_flow, s1_fire)
855
856  // exception that may cause load addr to be invalid / illegal
857  // if such exception happen, that inst and its exception info
858  // will be force writebacked to rob
859  val s2_exception_vec = WireInit(s2_in.uop.exceptionVec)
860  when (s2_ld_flow) {
861    when (!s2_in.lateKill) {
862      s2_exception_vec(loadAccessFault) := (s2_in.uop.exceptionVec(loadAccessFault) || s2_pmp.ld) && s2_vecActive
863      // soft prefetch will not trigger any exception (but ecc error interrupt may be triggered)
864      when (s2_prf || s2_in.tlbMiss) {
865        s2_exception_vec := 0.U.asTypeOf(s2_exception_vec.cloneType)
866      }
867    }
868  } .otherwise {
869    s2_exception_vec(storeAccessFault) := s2_in.uop.exceptionVec(storeAccessFault) || s2_pmp.st
870    when (s2_prf || s2_in.tlbMiss) {
871      s2_exception_vec := 0.U.asTypeOf(s2_exception_vec.cloneType)
872    }
873  }
874  val s2_ld_exception = ExceptionNO.selectByFu(s2_exception_vec, LduCfg).asUInt.orR && s2_ld_flow
875  val s2_st_exception = ExceptionNO.selectByFu(s2_exception_vec, StaCfg).asUInt.orR && !s2_ld_flow
876  val s2_exception    = s2_ld_exception || s2_st_exception
877
878  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)
879  val (s2_fwd_data_valid, s2_fwd_frm_mshr, s2_fwd_data_frm_mshr) = io.ldu_io.forward_mshr.forward()
880  val s2_fwd_frm_d_chan_or_mshr = s2_fwd_data_valid && (s2_fwd_frm_d_chan || s2_fwd_frm_mshr)
881
882  // writeback access fault caused by ecc error / bus error
883  // * ecc data error is slow to generate, so we will not use it until load stage 3
884  // * in load stage 3, an extra signal io.load_error will be used to
885  val s2_actually_mmio = s2_pmp.mmio
886  val s2_ld_mmio       = !s2_prf &&
887                          s2_actually_mmio &&
888                         !s2_exception &&
889                         !s2_in.tlbMiss &&
890                         s2_ld_flow
891  val s2_st_mmio       = !s2_prf &&
892                          (RegNext(s1_mmio) || s2_pmp.mmio) &&
893                         !s2_exception &&
894                         !s2_in.tlbMiss &&
895                         !s2_ld_flow
896  val s2_st_atomic     = !s2_prf &&
897                          (RegNext(s1_mmio) || s2_pmp.atomic) &&
898                         !s2_exception &&
899                         !s2_in.tlbMiss &&
900                         !s2_ld_flow
901  val s2_full_fwd      = Wire(Bool())
902  val s2_mem_amb       = s2_in.uop.storeSetHit &&
903                         io.ldu_io.lsq.forward.addrInvalid
904
905  val s2_tlb_miss      = s2_in.tlbMiss
906  val s2_fwd_fail      = io.ldu_io.lsq.forward.dataInvalid || io.ldu_io.vec_forward.dataInvalid
907  val s2_dcache_miss   = io.ldu_io.dcache.resp.bits.miss &&
908                         !s2_fwd_frm_d_chan_or_mshr &&
909                         !s2_full_fwd
910
911  val s2_mq_nack       = io.ldu_io.dcache.s2_mq_nack &&
912                         !s2_fwd_frm_d_chan_or_mshr &&
913                         !s2_full_fwd
914
915  val s2_bank_conflict = io.ldu_io.dcache.s2_bank_conflict &&
916                         !s2_fwd_frm_d_chan_or_mshr &&
917                         !s2_full_fwd
918
919  val s2_wpu_pred_fail = io.ldu_io.dcache.s2_wpu_pred_fail &&
920                        !s2_fwd_frm_d_chan_or_mshr &&
921                        !s2_full_fwd
922
923  val s2_rar_nack      = io.ldu_io.lsq.ldld_nuke_query.req.valid &&
924                         !io.ldu_io.lsq.ldld_nuke_query.req.ready
925
926  val s2_raw_nack      = io.ldu_io.lsq.stld_nuke_query.req.valid &&
927                         !io.ldu_io.lsq.stld_nuke_query.req.ready
928
929  // st-ld violation query
930  //  NeedFastRecovery Valid when
931  //  1. Fast recovery query request Valid.
932  //  2. Load instruction is younger than requestors(store instructions).
933  //  3. Physical address match.
934  //  4. Data contains.
935  val s2_nuke = VecInit((0 until StorePipelineWidth).map(w => {
936                        io.ldu_io.stld_nuke_query(w).valid && // query valid
937                        isAfter(s2_in.uop.robIdx, io.ldu_io.stld_nuke_query(w).bits.robIdx) && // older store
938                        // TODO: Fix me when vector instruction
939                        (s2_in.paddr(PAddrBits-1, 3) === io.ldu_io.stld_nuke_query(w).bits.paddr(PAddrBits-1, 3)) && // paddr match
940                        (s2_in.mask & io.ldu_io.stld_nuke_query(w).bits.mask).orR // data mask contain
941                      })).asUInt.orR && s2_ld_flow || s2_in.rep_info.nuke
942
943  val s2_cache_handled   = io.ldu_io.dcache.resp.bits.handled
944  val s2_cache_tag_error = RegNext(io.csrCtrl.cache_error_enable) &&
945                           io.ldu_io.dcache.resp.bits.tag_error
946
947  val s2_troublem        = !s2_exception &&
948                           !s2_ld_mmio &&
949                           !s2_prf &&
950                           !s2_in.lateKill &&
951                           s2_ld_flow
952
953  io.ldu_io.dcache.resp.ready := true.B
954  io.stu_io.dcache.resp.ready := true.B
955  val s2_dcache_should_resp = !(s2_in.tlbMiss || s2_exception || s2_ld_mmio || s2_prf || s2_in.lateKill) && s2_ld_flow
956  assert(!(s2_valid && (s2_dcache_should_resp && !io.ldu_io.dcache.resp.valid)), "DCache response got lost")
957
958  // fast replay require
959  val s2_dcache_fast_rep = (s2_mq_nack || !s2_dcache_miss && (s2_bank_conflict || s2_wpu_pred_fail))
960  val s2_nuke_fast_rep   = !s2_mq_nack &&
961                           !s2_dcache_miss &&
962                           !s2_bank_conflict &&
963                           !s2_wpu_pred_fail &&
964                           !s2_rar_nack &&
965                           !s2_raw_nack &&
966                           s2_nuke
967
968  val s2_fast_rep = !s2_mem_amb &&
969                    !s2_tlb_miss &&
970                    !s2_fwd_fail &&
971                    (s2_dcache_fast_rep || s2_nuke_fast_rep) &&
972                    s2_troublem
973
974  // need allocate new entry
975  val s2_can_query = !s2_mem_amb &&
976                     !s2_tlb_miss  &&
977                     !s2_fwd_fail &&
978                     !s2_dcache_fast_rep &&
979                     s2_troublem
980
981  val s2_data_fwded = s2_dcache_miss && (s2_full_fwd || s2_cache_tag_error)
982
983  // ld-ld violation require
984  io.ldu_io.lsq.ldld_nuke_query.req.valid           := s2_valid && s2_can_query
985  io.ldu_io.lsq.ldld_nuke_query.req.bits.uop        := s2_in.uop
986  io.ldu_io.lsq.ldld_nuke_query.req.bits.mask       := s2_in.mask
987  io.ldu_io.lsq.ldld_nuke_query.req.bits.paddr      := s2_in.paddr
988  io.ldu_io.lsq.ldld_nuke_query.req.bits.data_valid := Mux(s2_full_fwd || s2_fwd_data_valid, true.B, !s2_dcache_miss)
989
990  // st-ld violation require
991  io.ldu_io.lsq.stld_nuke_query.req.valid           := s2_valid && s2_can_query
992  io.ldu_io.lsq.stld_nuke_query.req.bits.uop        := s2_in.uop
993  io.ldu_io.lsq.stld_nuke_query.req.bits.mask       := s2_in.mask
994  io.ldu_io.lsq.stld_nuke_query.req.bits.paddr      := s2_in.paddr
995  io.ldu_io.lsq.stld_nuke_query.req.bits.data_valid := Mux(s2_full_fwd || s2_fwd_data_valid, true.B, !s2_dcache_miss)
996
997  // merge forward result
998  // lsq has higher priority than sbuffer
999  val s2_fwd_mask = Wire(Vec((VLEN/8), Bool()))
1000  val s2_fwd_data = Wire(Vec((VLEN/8), UInt(8.W)))
1001  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
1002  // generate XLEN/8 Muxs
1003  for (i <- 0 until VLEN / 8) {
1004    s2_fwd_mask(i) := io.ldu_io.lsq.forward.forwardMask(i) || io.ldu_io.sbuffer.forwardMask(i) || io.ldu_io.vec_forward.forwardMask(i)
1005    s2_fwd_data(i) := Mux(
1006      io.ldu_io.lsq.forward.forwardMask(i),
1007      io.ldu_io.lsq.forward.forwardData(i),
1008      Mux(
1009        io.ldu_io.vec_forward.forwardMask(i),
1010        io.ldu_io.vec_forward.forwardData(i),
1011        io.ldu_io.sbuffer.forwardData(i)
1012      )
1013    )
1014  }
1015
1016  XSDebug(s2_fire && s2_ld_flow, "[FWD LOAD RESP] pc %x fwd %x(%b) + %x(%b)\n",
1017    s2_in.uop.pc,
1018    io.ldu_io.lsq.forward.forwardData.asUInt, io.ldu_io.lsq.forward.forwardMask.asUInt,
1019    s2_in.forwardData.asUInt, s2_in.forwardMask.asUInt
1020  )
1021
1022  //
1023  s2_out                  := s2_in
1024  s2_out.data             := 0.U // data will be generated in load s3
1025  s2_out.uop.fpWen        := s2_in.uop.fpWen && !s2_exception && s2_ld_flow
1026  s2_out.mmio             := s2_ld_mmio || s2_st_mmio
1027  s2_out.atomic           := s2_st_atomic
1028  s2_out.uop.flushPipe    := false.B
1029  s2_out.uop.exceptionVec := s2_exception_vec
1030  s2_out.forwardMask      := s2_fwd_mask
1031  s2_out.forwardData      := s2_fwd_data
1032  s2_out.handledByMSHR    := s2_cache_handled
1033  s2_out.miss             := s2_dcache_miss && s2_troublem
1034  s2_out.feedbacked       := io.feedback_fast.valid && !io.feedback_fast.bits.hit
1035
1036  // Generate replay signal caused by:
1037  // * st-ld violation check
1038  // * tlb miss
1039  // * dcache replay
1040  // * forward data invalid
1041  // * dcache miss
1042  s2_out.rep_info.mem_amb         := s2_mem_amb && s2_troublem
1043  s2_out.rep_info.tlb_miss        := s2_tlb_miss && s2_troublem
1044  s2_out.rep_info.fwd_fail        := s2_fwd_fail && s2_troublem
1045  s2_out.rep_info.dcache_rep      := s2_mq_nack && s2_troublem
1046  s2_out.rep_info.dcache_miss     := s2_dcache_miss && s2_troublem
1047  s2_out.rep_info.bank_conflict   := s2_bank_conflict && s2_troublem
1048  s2_out.rep_info.wpu_fail        := s2_wpu_pred_fail && s2_troublem
1049  s2_out.rep_info.rar_nack        := s2_rar_nack && s2_troublem
1050  s2_out.rep_info.raw_nack        := s2_raw_nack && s2_troublem
1051  s2_out.rep_info.nuke            := s2_nuke && s2_troublem
1052  s2_out.rep_info.full_fwd        := s2_data_fwded
1053  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)
1054  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)
1055  s2_out.rep_info.rep_carry       := io.ldu_io.dcache.resp.bits.replayCarry
1056  s2_out.rep_info.mshr_id         := io.ldu_io.dcache.resp.bits.mshr_id
1057  s2_out.rep_info.last_beat       := s2_in.paddr(log2Up(refillBytes))
1058  s2_out.rep_info.debug           := s2_in.uop.debugInfo
1059  s2_out.rep_info.tlb_id          := io.ldu_io.tlb_hint.id
1060  s2_out.rep_info.tlb_full        := io.ldu_io.tlb_hint.full
1061
1062  // if forward fail, replay this inst from fetch
1063  val debug_fwd_fail_rep = s2_fwd_fail && !s2_troublem && !s2_in.tlbMiss
1064  // if ld-ld violation is detected, replay from this inst from fetch
1065  val debug_ldld_nuke_rep = false.B // s2_ldld_violation && !s2_ld_mmio && !s2_is_prefetch && !s2_in.tlbMiss
1066  // io.out.bits.uop.replayInst := false.B
1067
1068  // to be removed
1069  val s2_ld_need_fb = !s2_in.isLoadReplay &&      // already feedbacked
1070                      io.ldu_io.lq_rep_full &&           // LoadQueueReplay is full
1071                      s2_out.rep_info.need_rep && // need replay
1072                      !s2_exception &&            // no exception is triggered
1073                      !s2_hw_prf &&               // not hardware prefetch
1074                      !s2_isvec
1075  val s2_st_need_fb = !s2_ld_flow && !s2_hw_prf && !s2_isvec
1076  io.feedback_fast.valid                 := s2_valid && (s2_ld_need_fb || s2_st_need_fb)
1077  io.feedback_fast.bits.hit              := Mux(s2_ld_flow, false.B, !s2_tlb_miss)
1078  io.feedback_fast.bits.flushState       := s2_in.ptwBack
1079  io.feedback_fast.bits.robIdx           := s2_in.uop.robIdx
1080  io.feedback_fast.bits.sourceType       := Mux(s2_ld_flow, RSFeedbackType.lrqFull, RSFeedbackType.tlbMiss)
1081  io.feedback_fast.bits.dataInvalidSqIdx := DontCare
1082
1083  val s2_vec_feedback = Wire(Valid(new VSFQFeedback))
1084  s2_vec_feedback.valid := s2_valid && !s2_ld_flow && !s2_hw_prf && s2_isvec
1085  // s2_vec_feedback.bits.flowPtr := s2_out.sflowPtr
1086  s2_vec_feedback.bits.hit := !s2_tlb_miss
1087  s2_vec_feedback.bits.sourceType := RSFeedbackType.tlbMiss
1088  s2_vec_feedback.bits.paddr := s2_paddr
1089  s2_vec_feedback.bits.mmio := s2_st_mmio
1090  s2_vec_feedback.bits.atomic := s2_st_mmio
1091  s2_vec_feedback.bits.exceptionVec := s2_exception_vec
1092
1093  io.stu_io.lsq_replenish := s2_out
1094  io.stu_io.lsq_replenish.miss := io.ldu_io.dcache.resp.fire && io.ldu_io.dcache.resp.bits.miss
1095
1096  io.ldu_io.ldCancel.ld1Cancel := false.B
1097
1098  // fast wakeup
1099  io.ldu_io.fast_uop.valid := RegNext(
1100    !io.ldu_io.dcache.s1_disable_fast_wakeup &&
1101    s1_valid &&
1102    !s1_kill &&
1103    !io.tlb.resp.bits.miss &&
1104    !io.ldu_io.lsq.forward.dataInvalidFast
1105  ) && (s2_valid && !s2_out.rep_info.need_rep && !s2_ld_mmio && s2_ld_flow) && !s2_isvec
1106  io.ldu_io.fast_uop.bits := RegNext(s1_out.uop)
1107
1108  //
1109  io.ldu_io.s2_ptr_chasing                    := RegEnable(s1_try_ptr_chasing && !s1_cancel_ptr_chasing, false.B, s1_fire)
1110
1111  // prefetch train
1112  io.s0_prefetch_spec := s0_fire
1113  io.s1_prefetch_spec := s1_fire
1114  io.prefetch_train.valid              := s2_valid && !s2_actually_mmio && !s2_in.tlbMiss
1115  io.prefetch_train.bits.fromLsPipelineBundle(s2_in)
1116  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?
1117  io.prefetch_train.bits.meta_prefetch := Mux(s2_ld_flow, io.ldu_io.dcache.resp.bits.meta_prefetch, false.B)
1118  io.prefetch_train.bits.meta_access   := Mux(s2_ld_flow, io.ldu_io.dcache.resp.bits.meta_access, false.B)
1119
1120  io.prefetch_train_l1.valid              := s2_valid && !s2_actually_mmio && s2_ld_flow
1121  io.prefetch_train_l1.bits.fromLsPipelineBundle(s2_in)
1122  io.prefetch_train_l1.bits.miss          := io.ldu_io.dcache.resp.bits.miss
1123  io.prefetch_train_l1.bits.meta_prefetch := io.ldu_io.dcache.resp.bits.meta_prefetch
1124  io.prefetch_train_l1.bits.meta_access   := io.ldu_io.dcache.resp.bits.meta_access
1125  if (env.FPGAPlatform){
1126    io.ldu_io.dcache.s0_pc := DontCare
1127    io.ldu_io.dcache.s1_pc := DontCare
1128    io.ldu_io.dcache.s2_pc := DontCare
1129  }else{
1130    io.ldu_io.dcache.s0_pc := s0_out.uop.pc
1131    io.ldu_io.dcache.s1_pc := s1_out.uop.pc
1132    io.ldu_io.dcache.s2_pc := s2_out.uop.pc
1133  }
1134  io.ldu_io.dcache.s2_kill := s2_pmp.ld  || s2_actually_mmio || s2_kill
1135  io.stu_io.dcache.s2_kill := s2_pmp.st || s2_actually_mmio || s2_kill
1136  io.stu_io.dcache.s2_pc := s2_out.uop.pc
1137
1138  val s1_ld_left_fire = s1_valid && !s1_kill && s2_ready && s1_ld_flow
1139  val s2_ld_valid_dup = RegInit(0.U(6.W))
1140  s2_ld_valid_dup := 0x0.U(6.W)
1141  when (s1_ld_left_fire && !s1_out.isHWPrefetch && s1_ld_flow) { s2_ld_valid_dup := 0x3f.U(6.W) }
1142  when (s1_kill || s1_out.isHWPrefetch || !s1_ld_flow) { s2_ld_valid_dup := 0x0.U(6.W) }
1143  assert(RegNext((s2_valid === s2_ld_valid_dup(0)) || RegNext(s1_out.isHWPrefetch) || RegNext(!s1_ld_flow)))
1144
1145  // Pipeline
1146  // --------------------------------------------------------------------------------
1147  // stage 3
1148  // --------------------------------------------------------------------------------
1149  // writeback and update load queue
1150  val s3_valid        = RegNext(s2_valid && !s2_out.isHWPrefetch && !s2_out.uop.robIdx.needFlush(io.redirect))
1151  val s3_in           = RegEnable(s2_out, s2_fire)
1152  val s3_out          = Wire(Valid(new MemExuOutput))
1153  val s3_dcache_rep   = RegEnable(s2_dcache_fast_rep && s2_troublem, false.B, s2_fire)
1154  val s3_ld_valid_dup = RegEnable(s2_ld_valid_dup, s2_fire)
1155  val s3_fast_rep     = Wire(Bool())
1156  val s3_ld_flow      = RegNext(s2_ld_flow)
1157  val s3_troublem     = RegNext(s2_troublem)
1158  val s3_kill         = s3_in.uop.robIdx.needFlush(io.redirect)
1159  val s3_isvec        = RegNext(s2_isvec)
1160  s3_ready := !s3_valid || s3_kill || sx_can_go
1161
1162  // forwrad last beat
1163  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)
1164  val s3_fwd_data_valid = RegEnable(s2_fwd_data_valid, false.B, s2_valid)
1165  val s3_fwd_frm_d_chan_valid = (s3_fwd_frm_d_chan && s3_fwd_data_valid) && s3_ld_flow
1166
1167
1168  // s3 load fast replay
1169  io.ldu_io.fast_rep_out.valid := s3_valid &&
1170                                  s3_fast_rep &&
1171                                  !s3_in.uop.robIdx.needFlush(io.redirect) &&
1172                                  s3_ld_flow &&
1173                                  !s3_isvec
1174  io.ldu_io.fast_rep_out.bits := s3_in
1175
1176  io.ldu_io.lsq.ldin.valid := s3_valid &&
1177                              (!s3_fast_rep || !io.ldu_io.fast_rep_out.ready) &&
1178                              !s3_in.feedbacked &&
1179                              !s3_in.lateKill &&
1180                              s3_ld_flow
1181  io.ldu_io.lsq.ldin.bits := s3_in
1182  io.ldu_io.lsq.ldin.bits.miss := s3_in.miss && !s3_fwd_frm_d_chan_valid
1183
1184  /* <------- DANGEROUS: Don't change sequence here ! -------> */
1185  io.ldu_io.lsq.ldin.bits.data_wen_dup := s3_ld_valid_dup.asBools
1186  io.ldu_io.lsq.ldin.bits.replacementUpdated := io.ldu_io.dcache.resp.bits.replacementUpdated
1187  io.ldu_io.lsq.ldin.bits.missDbUpdated := RegNext(s2_fire && s2_in.hasROBEntry && !s2_in.tlbMiss && !s2_in.missDbUpdated)
1188
1189  val s3_dly_ld_err =
1190    if (EnableAccurateLoadError) {
1191      (s3_in.lateKill || io.ldu_io.dcache.resp.bits.error_delayed) && RegNext(io.csrCtrl.cache_error_enable)
1192    } else {
1193      WireInit(false.B)
1194    }
1195  io.ldu_io.s3_dly_ld_err := false.B // s3_dly_ld_err && s3_valid
1196  io.ldu_io.fast_rep_out.bits.delayedLoadError := s3_dly_ld_err
1197  io.ldu_io.lsq.ldin.bits.dcacheRequireReplay  := s3_dcache_rep
1198
1199  val s3_vp_match_fail = RegNext(io.ldu_io.lsq.forward.matchInvalid || io.ldu_io.sbuffer.matchInvalid) && s3_troublem
1200  val s3_ldld_rep_inst =
1201      io.ldu_io.lsq.ldld_nuke_query.resp.valid &&
1202      io.ldu_io.lsq.ldld_nuke_query.resp.bits.rep_frm_fetch &&
1203      RegNext(io.csrCtrl.ldld_vio_check_enable)
1204
1205  val s3_rep_info = WireInit(s3_in.rep_info)
1206  s3_rep_info.dcache_miss   := s3_in.rep_info.dcache_miss && !s3_fwd_frm_d_chan_valid && s3_troublem
1207  val s3_rep_frm_fetch = s3_vp_match_fail
1208  val s3_flushPipe = s3_ldld_rep_inst
1209  val s3_sel_rep_cause = PriorityEncoderOH(s3_rep_info.cause.asUInt)
1210  val s3_force_rep     = s3_sel_rep_cause(LoadReplayCauses.C_TM) &&
1211                         !s3_in.uop.exceptionVec(loadAddrMisaligned) &&
1212                         s3_troublem
1213
1214  val s3_ld_exception = ExceptionNO.selectByFu(s3_in.uop.exceptionVec, LduCfg).asUInt.orR && s3_ld_flow
1215  val s3_st_exception = ExceptionNO.selectByFu(s3_in.uop.exceptionVec, StaCfg).asUInt.orR && !s3_ld_flow
1216  val s3_exception    = s3_ld_exception || s3_st_exception
1217  when ((s3_ld_exception || s3_dly_ld_err || s3_rep_frm_fetch) && !s3_force_rep) {
1218    io.ldu_io.lsq.ldin.bits.rep_info.cause := 0.U.asTypeOf(s3_rep_info.cause.cloneType)
1219  } .otherwise {
1220    io.ldu_io.lsq.ldin.bits.rep_info.cause := VecInit(s3_sel_rep_cause.asBools)
1221  }
1222
1223  // Int flow, if hit, will be writebacked at s3
1224  s3_out.valid                := s3_valid &&
1225                                (!s3_ld_flow && !s3_in.feedbacked || !io.ldu_io.lsq.ldin.bits.rep_info.need_rep) && !s3_in.mmio
1226  s3_out.bits.uop             := s3_in.uop
1227  s3_out.bits.uop.exceptionVec(loadAccessFault) := (s3_dly_ld_err  || s3_in.uop.exceptionVec(loadAccessFault)) && s3_ld_flow
1228  s3_out.bits.uop.replayInst := s3_rep_frm_fetch
1229  s3_out.bits.data            := s3_in.data
1230  s3_out.bits.debug.isMMIO    := s3_in.mmio
1231  s3_out.bits.debug.isPerfCnt := false.B
1232  s3_out.bits.debug.paddr     := s3_in.paddr
1233  s3_out.bits.debug.vaddr     := s3_in.vaddr
1234
1235  when (s3_force_rep) {
1236    s3_out.bits.uop.exceptionVec := 0.U.asTypeOf(s3_in.uop.exceptionVec.cloneType)
1237  }
1238
1239  io.ldu_io.rollback.valid := s3_valid && (s3_rep_frm_fetch || s3_flushPipe) && !s3_exception && s3_ld_flow
1240  io.ldu_io.rollback.bits             := DontCare
1241  io.ldu_io.rollback.bits.isRVC       := s3_out.bits.uop.preDecodeInfo.isRVC
1242  io.ldu_io.rollback.bits.robIdx      := s3_out.bits.uop.robIdx
1243  io.ldu_io.rollback.bits.ftqIdx      := s3_out.bits.uop.ftqPtr
1244  io.ldu_io.rollback.bits.ftqOffset   := s3_out.bits.uop.ftqOffset
1245  io.ldu_io.rollback.bits.level       := Mux(s3_rep_frm_fetch, RedirectLevel.flush, RedirectLevel.flushAfter)
1246  io.ldu_io.rollback.bits.cfiUpdate.target := s3_out.bits.uop.pc
1247  io.ldu_io.rollback.bits.debug_runahead_checkpoint_id := s3_out.bits.uop.debugInfo.runahead_checkpoint_id
1248  /* <------- DANGEROUS: Don't change sequence here ! -------> */
1249  io.ldu_io.lsq.ldin.bits.uop := s3_out.bits.uop
1250
1251  val s3_revoke = s3_exception || io.ldu_io.lsq.ldin.bits.rep_info.need_rep
1252  io.ldu_io.lsq.ldld_nuke_query.revoke := s3_revoke
1253  io.ldu_io.lsq.stld_nuke_query.revoke := s3_revoke
1254
1255  // feedback slow
1256  s3_fast_rep := RegNext(s2_fast_rep) &&
1257                 !s3_in.feedbacked &&
1258                 !s3_in.lateKill &&
1259                 !s3_rep_frm_fetch &&
1260                 !s3_exception
1261
1262  val s3_fb_no_waiting = !s3_in.isLoadReplay && !(s3_fast_rep && io.ldu_io.fast_rep_out.ready) && !s3_in.feedbacked
1263
1264  //
1265  io.feedback_slow.valid                 := s3_valid && !s3_in.uop.robIdx.needFlush(io.redirect) && s3_fb_no_waiting && s3_ld_flow
1266  io.feedback_slow.bits.hit              := !io.ldu_io.lsq.ldin.bits.rep_info.need_rep || io.ldu_io.lsq.ldin.ready
1267  io.feedback_slow.bits.flushState       := s3_in.ptwBack
1268  io.feedback_slow.bits.robIdx           := s3_in.uop.robIdx
1269  io.feedback_slow.bits.sourceType       := RSFeedbackType.lrqFull
1270  io.feedback_slow.bits.dataInvalidSqIdx := DontCare
1271
1272  io.vec_stu_io.feedbackSlow.valid := RegNext(s2_vec_feedback.valid && !s2_out.uop.robIdx.needFlush(io.redirect))
1273  io.vec_stu_io.feedbackSlow.bits := RegNext(s2_vec_feedback.bits)
1274
1275  io.ldu_io.ldCancel.ld2Cancel := s3_valid && s3_ld_flow && (                          // is load
1276    io.ldu_io.lsq.ldin.bits.rep_info.need_rep || s3_in.mmio                            // exe fail or is mmio
1277  )
1278
1279  // data from dcache hit
1280  val s3_ld_raw_data_frm_cache = Wire(new LoadDataFromDcacheBundle)
1281  s3_ld_raw_data_frm_cache.respDcacheData       := io.ldu_io.dcache.resp.bits.data_delayed
1282  s3_ld_raw_data_frm_cache.forwardMask          := RegEnable(s2_fwd_mask, s2_valid)
1283  s3_ld_raw_data_frm_cache.forwardData          := RegEnable(s2_fwd_data, s2_valid)
1284  s3_ld_raw_data_frm_cache.uop                  := RegEnable(s2_out.uop, s2_valid)
1285  s3_ld_raw_data_frm_cache.addrOffset           := RegEnable(s2_out.paddr(3, 0), s2_valid)
1286  s3_ld_raw_data_frm_cache.forward_D            := RegEnable(s2_fwd_frm_d_chan, false.B, s2_valid) || s3_fwd_frm_d_chan_valid
1287  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))
1288  s3_ld_raw_data_frm_cache.forward_mshr         := RegEnable(s2_fwd_frm_mshr, false.B, s2_valid)
1289  s3_ld_raw_data_frm_cache.forwardData_mshr     := RegEnable(s2_fwd_data_frm_mshr, s2_valid)
1290  s3_ld_raw_data_frm_cache.forward_result_valid := RegEnable(s2_fwd_data_valid, false.B, s2_valid)
1291
1292  val s3_merged_data_frm_cache = s3_ld_raw_data_frm_cache.mergedData()
1293  val s3_picked_data_frm_cache = LookupTree(s3_ld_raw_data_frm_cache.addrOffset, List(
1294    "b0000".U -> s3_merged_data_frm_cache(63,    0),
1295    "b0001".U -> s3_merged_data_frm_cache(63,    8),
1296    "b0010".U -> s3_merged_data_frm_cache(63,   16),
1297    "b0011".U -> s3_merged_data_frm_cache(63,   24),
1298    "b0100".U -> s3_merged_data_frm_cache(63,   32),
1299    "b0101".U -> s3_merged_data_frm_cache(63,   40),
1300    "b0110".U -> s3_merged_data_frm_cache(63,   48),
1301    "b0111".U -> s3_merged_data_frm_cache(63,   56),
1302    "b1000".U -> s3_merged_data_frm_cache(127,  64),
1303    "b1001".U -> s3_merged_data_frm_cache(127,  72),
1304    "b1010".U -> s3_merged_data_frm_cache(127,  80),
1305    "b1011".U -> s3_merged_data_frm_cache(127,  88),
1306    "b1100".U -> s3_merged_data_frm_cache(127,  96),
1307    "b1101".U -> s3_merged_data_frm_cache(127, 104),
1308    "b1110".U -> s3_merged_data_frm_cache(127, 112),
1309    "b1111".U -> s3_merged_data_frm_cache(127, 120)
1310  ))
1311  val s3_ld_data_frm_cache = rdataHelper(s3_ld_raw_data_frm_cache.uop, s3_picked_data_frm_cache)
1312
1313  // FIXME: add 1 cycle delay ?
1314  io.ldout.bits      := s3_out.bits
1315  io.ldout.bits.data := s3_ld_data_frm_cache
1316  io.ldout.valid     := s3_out.valid && !s3_out.bits.uop.robIdx.needFlush(io.redirect) && s3_ld_flow && !s3_isvec
1317
1318  // for uncache
1319  io.ldu_io.lsq.uncache.ready := true.B
1320
1321  // fast load to load forward
1322  if (EnableLoadToLoadForward) {
1323    io.ldu_io.l2l_fwd_out.valid      := s3_out.valid && !s3_in.lateKill && s3_ld_flow
1324    io.ldu_io.l2l_fwd_out.data       := s3_ld_data_frm_cache
1325    io.ldu_io.l2l_fwd_out.dly_ld_err := s3_dly_ld_err // ecc delayed error
1326  } else {
1327    io.ldu_io.l2l_fwd_out.valid      := false.B
1328    io.ldu_io.l2l_fwd_out.data       := DontCare
1329    io.ldu_io.l2l_fwd_out.dly_ld_err := DontCare
1330  }
1331
1332  // hybrid unit writeback to rob
1333  // delay params
1334  val SelectGroupSize   = RollbackGroupSize
1335  val lgSelectGroupSize = log2Ceil(SelectGroupSize)
1336  val TotalSelectCycles = scala.math.ceil(log2Ceil(LoadQueueRAWSize).toFloat / lgSelectGroupSize).toInt + 1
1337  val TotalDelayCycles  = TotalSelectCycles - 2
1338
1339  // writeback
1340  val sx_valid = Wire(Vec(TotalDelayCycles + 1, Bool()))
1341  val sx_ready = Wire(Vec(TotalDelayCycles + 1, Bool()))
1342  val sx_in    = Wire(Vec(TotalDelayCycles + 1, new MemExuOutput))
1343
1344  sx_can_go := sx_ready.head
1345  for (i <- 0 until TotalDelayCycles + 1) {
1346    if (i == 0) {
1347      sx_valid(i) := s3_valid &&
1348                    !s3_ld_flow &&
1349                    !s3_in.feedbacked &&
1350                    !s3_in.mmio
1351      sx_in(i)    := s3_out.bits
1352      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))
1353    } else {
1354      val cur_kill   = sx_in(i).uop.robIdx.needFlush(io.redirect)
1355      val cur_can_go = (if (i == TotalDelayCycles) io.stout.ready else sx_ready(i+1))
1356      val cur_fire   = sx_valid(i) && !cur_kill && cur_can_go
1357      val prev_fire  = sx_valid(i-1) && !sx_in(i-1).uop.robIdx.needFlush(io.redirect) && sx_ready(i)
1358
1359      sx_ready(i) := !sx_valid(i) || cur_kill || (if (i == TotalDelayCycles) io.stout.ready else sx_ready(i+1))
1360      val sx_valid_can_go = prev_fire || cur_fire || cur_kill
1361      sx_valid(i) := RegEnable(Mux(prev_fire, true.B, false.B), sx_valid_can_go)
1362      sx_in(i) := RegEnable(sx_in(i-1), prev_fire)
1363    }
1364  }
1365
1366  val sx_last_valid = sx_valid.takeRight(1).head
1367  val sx_last_ready = sx_ready.takeRight(1).head
1368  val sx_last_in    = sx_in.takeRight(1).head
1369
1370  sx_last_ready  := !sx_last_valid || sx_last_in.uop.robIdx.needFlush(io.redirect) || io.stout.ready
1371  io.stout.valid := sx_last_valid && !sx_last_in.uop.robIdx.needFlush(io.redirect) && FuType.isStore(sx_last_in.uop.fuType)
1372  io.stout.bits  := sx_last_in
1373
1374   // trigger
1375  val ld_trigger = FuType.isLoad(io.ldout.bits.uop.fuType)
1376  val last_valid_data = RegEnable(io.ldout.bits.data, io.stout.fire)
1377  val hit_ld_addr_trig_hit_vec = Wire(Vec(TriggerNum, Bool()))
1378  val lq_ld_addr_trig_hit_vec = RegNext(io.ldu_io.lsq.trigger.lqLoadAddrTriggerHitVec)
1379  (0 until TriggerNum).map{i => {
1380    val tdata2    = RegNext(RegNext(io.ldu_io.trigger(i).tdata2))
1381    val matchType = RegNext(RegNext(io.ldu_io.trigger(i).matchType))
1382    val tEnable   = RegNext(RegNext(io.ldu_io.trigger(i).tEnable))
1383
1384    hit_ld_addr_trig_hit_vec(i)        := TriggerCmp(RegNext(s3_in.vaddr), tdata2, matchType, tEnable)
1385    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))
1386  }}
1387  io.ldu_io.lsq.trigger.hitLoadAddrTriggerHitVec := hit_ld_addr_trig_hit_vec
1388
1389  // FIXME: please move this part to LoadQueueReplay
1390  io.ldu_io.debug_ls := DontCare
1391  io.stu_io.debug_ls := DontCare
1392  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
1393  io.stu_io.debug_ls.s1_robIdx := s1_in.uop.robIdx.value
1394
1395 // Topdown
1396  io.ldu_io.lsTopdownInfo.s1.robIdx          := s1_in.uop.robIdx.value
1397  io.ldu_io.lsTopdownInfo.s1.vaddr_valid     := s1_valid && s1_in.hasROBEntry
1398  io.ldu_io.lsTopdownInfo.s1.vaddr_bits      := s1_vaddr
1399  io.ldu_io.lsTopdownInfo.s2.robIdx          := s2_in.uop.robIdx.value
1400  io.ldu_io.lsTopdownInfo.s2.paddr_valid     := s2_fire && s2_in.hasROBEntry && !s2_in.tlbMiss
1401  io.ldu_io.lsTopdownInfo.s2.paddr_bits      := s2_in.paddr
1402  io.ldu_io.lsTopdownInfo.s2.first_real_miss := io.ldu_io.dcache.resp.bits.real_miss
1403  io.ldu_io.lsTopdownInfo.s2.cache_miss_en   := s2_fire && s2_in.hasROBEntry && !s2_in.tlbMiss && !s2_in.missDbUpdated
1404
1405  // perf cnt
1406  XSPerfAccumulate("s0_in_valid",                  io.lsin.valid)
1407  XSPerfAccumulate("s0_in_block",                  io.lsin.valid && !io.lsin.fire)
1408  XSPerfAccumulate("s0_in_fire_first_issue",       s0_valid && s0_isFirstIssue)
1409  XSPerfAccumulate("s0_lsq_fire_first_issue",      io.ldu_io.replay.fire)
1410  XSPerfAccumulate("s0_ldu_fire_first_issue",      io.lsin.fire && s0_isFirstIssue)
1411  XSPerfAccumulate("s0_fast_replay_issue",         io.ldu_io.fast_rep_in.fire)
1412  XSPerfAccumulate("s0_stall_out",                 s0_valid && !s0_can_go)
1413  XSPerfAccumulate("s0_stall_ld_dcache",           s0_valid && !io.ldu_io.dcache.req.ready)
1414  XSPerfAccumulate("s0_stall_st_dcache",           s0_valid && !io.stu_io.dcache.req.ready)
1415  XSPerfAccumulate("s0_addr_spec_success",         s0_fire && s0_vaddr(VAddrBits-1, 12) === io.lsin.bits.src(0)(VAddrBits-1, 12))
1416  XSPerfAccumulate("s0_addr_spec_failed",          s0_fire && s0_vaddr(VAddrBits-1, 12) =/= io.lsin.bits.src(0)(VAddrBits-1, 12))
1417  XSPerfAccumulate("s0_addr_spec_success_once",    s0_fire && s0_vaddr(VAddrBits-1, 12) === io.lsin.bits.src(0)(VAddrBits-1, 12) && s0_isFirstIssue)
1418  XSPerfAccumulate("s0_addr_spec_failed_once",     s0_fire && s0_vaddr(VAddrBits-1, 12) =/= io.lsin.bits.src(0)(VAddrBits-1, 12) && s0_isFirstIssue)
1419  XSPerfAccumulate("s0_forward_tl_d_channel",      s0_out.forward_tlDchannel)
1420  XSPerfAccumulate("s0_hardware_prefetch_fire",    s0_fire && s0_hw_prf_select)
1421  XSPerfAccumulate("s0_software_prefetch_fire",    s0_fire && s0_prf && s0_int_iss_select)
1422  XSPerfAccumulate("s0_hardware_prefetch_blocked", io.ldu_io.prefetch_req.valid && !s0_hw_prf_select)
1423  XSPerfAccumulate("s0_hardware_prefetch_total",   io.ldu_io.prefetch_req.valid)
1424
1425  XSPerfAccumulate("s1_in_valid",                  s1_valid)
1426  XSPerfAccumulate("s1_in_fire",                   s1_fire)
1427  XSPerfAccumulate("s1_in_fire_first_issue",       s1_fire && s1_in.isFirstIssue)
1428  XSPerfAccumulate("s1_tlb_miss",                  s1_fire && s1_tlb_miss)
1429  XSPerfAccumulate("s1_tlb_miss_first_issue",      s1_fire && s1_tlb_miss && s1_in.isFirstIssue)
1430  XSPerfAccumulate("s1_stall_out",                 s1_valid && !s1_can_go)
1431  XSPerfAccumulate("s1_late_kill",                 s1_valid && s1_fast_rep_kill)
1432
1433  XSPerfAccumulate("s2_in_valid",                  s2_valid)
1434  XSPerfAccumulate("s2_in_fire",                   s2_fire)
1435  XSPerfAccumulate("s2_in_fire_first_issue",       s2_fire && s2_in.isFirstIssue)
1436  XSPerfAccumulate("s2_dcache_miss",               s2_fire && io.ldu_io.dcache.resp.bits.miss)
1437  XSPerfAccumulate("s2_dcache_miss_first_issue",   s2_fire && io.ldu_io.dcache.resp.bits.miss && s2_in.isFirstIssue)
1438  XSPerfAccumulate("s2_dcache_real_miss_first_issue",   s2_fire && io.ldu_io.dcache.resp.bits.miss && s2_in.isFirstIssue)
1439  XSPerfAccumulate("s2_full_forward",              s2_fire && s2_full_fwd)
1440  XSPerfAccumulate("s2_dcache_miss_full_forward",  s2_fire && s2_dcache_miss)
1441  XSPerfAccumulate("s2_fwd_frm_d_can",             s2_valid && s2_fwd_frm_d_chan)
1442  XSPerfAccumulate("s2_fwd_frm_d_chan_or_mshr",    s2_valid && s2_fwd_frm_d_chan_or_mshr)
1443  XSPerfAccumulate("s2_stall_out",                 s2_fire && !s2_can_go)
1444  XSPerfAccumulate("s2_prefetch",                  s2_fire && s2_prf)
1445  XSPerfAccumulate("s2_prefetch_ignored",          s2_fire && s2_prf && io.ldu_io.dcache.s2_mq_nack) // ignore prefetch for mshr full / miss req port conflict
1446  XSPerfAccumulate("s2_prefetch_miss",             s2_fire && s2_prf && io.ldu_io.dcache.resp.bits.miss) // prefetch req miss in l1
1447  XSPerfAccumulate("s2_prefetch_hit",              s2_fire && s2_prf && !io.ldu_io.dcache.resp.bits.miss) // prefetch req hit in l1
1448  XSPerfAccumulate("s2_prefetch_accept",           s2_fire && s2_prf && io.ldu_io.dcache.resp.bits.miss && !io.ldu_io.dcache.s2_mq_nack) // prefetch a missed line in l1, and l1 accepted it
1449  XSPerfAccumulate("s2_forward_req",               s2_fire && s2_in.forward_tlDchannel)
1450  XSPerfAccumulate("s2_successfully_forward_channel_D", s2_fire && s2_fwd_frm_d_chan && s2_fwd_data_valid)
1451  XSPerfAccumulate("s2_successfully_forward_mshr",      s2_fire && s2_fwd_frm_mshr && s2_fwd_data_valid)
1452
1453  XSPerfAccumulate("s3_fwd_frm_d_chan",            s3_valid && s3_fwd_frm_d_chan_valid)
1454
1455  XSPerfAccumulate("load_to_load_forward",                      s1_try_ptr_chasing && !s1_ptr_chasing_canceled)
1456  XSPerfAccumulate("load_to_load_forward_try",                  s1_try_ptr_chasing)
1457  XSPerfAccumulate("load_to_load_forward_fail",                 s1_cancel_ptr_chasing)
1458  XSPerfAccumulate("load_to_load_forward_fail_cancelled",       s1_cancel_ptr_chasing && s1_ptr_chasing_canceled)
1459  XSPerfAccumulate("load_to_load_forward_fail_wakeup_mismatch", s1_cancel_ptr_chasing && !s1_ptr_chasing_canceled && s1_not_fast_match)
1460  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)
1461  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)
1462  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)
1463
1464  // bug lyq: some signals in perfEvents are no longer suitable for the current MemBlock design
1465  // hardware performance counter
1466  val perfEvents = Seq(
1467    ("load_s0_in_fire         ", s0_fire                                                        ),
1468    ("load_to_load_forward    ", s1_fire && s1_try_ptr_chasing && !s1_ptr_chasing_canceled      ),
1469    ("stall_dcache            ", s0_valid && s0_can_go && !io.ldu_io.dcache.req.ready           ),
1470    ("load_s1_in_fire         ", s0_fire                                                        ),
1471    ("load_s1_tlb_miss        ", s1_fire && io.tlb.resp.bits.miss                               ),
1472    ("load_s2_in_fire         ", s1_fire                                                        ),
1473    ("load_s2_dcache_miss     ", s2_fire && io.ldu_io.dcache.resp.bits.miss                     ),
1474  )
1475  generatePerfEvent()
1476}