xref: /XiangShan/src/main/scala/xiangshan/frontend/icache/ICacheMainPipe.scala (revision fe29a7c0f572f909ec49d3d6be38f17de56b8907)
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.frontend.icache
18
19import chipsalliance.rocketchip.config.Parameters
20import chisel3._
21import chisel3.util._
22import freechips.rocketchip.tilelink.ClientStates
23import xiangshan._
24import xiangshan.cache.mmu._
25import utils._
26import utility._
27import xiangshan.backend.fu.{PMPReqBundle, PMPRespBundle}
28import xiangshan.frontend.{FtqICacheInfo, FtqToICacheRequestBundle}
29
30class ICacheMainPipeReq(implicit p: Parameters) extends ICacheBundle
31{
32  val vaddr  = UInt(VAddrBits.W)
33  def vsetIdx = get_idx(vaddr)
34}
35
36class ICacheMainPipeResp(implicit p: Parameters) extends ICacheBundle
37{
38  val vaddr    = UInt(VAddrBits.W)
39  val registerData = UInt(blockBits.W)
40  val sramData = UInt(blockBits.W)
41  val select   = Bool()
42  val paddr    = UInt(PAddrBits.W)
43  val tlbExcp  = new Bundle{
44    val pageFault = Bool()
45    val accessFault = Bool()
46    val mmio = Bool()
47  }
48}
49
50class ICacheMainPipeBundle(implicit p: Parameters) extends ICacheBundle
51{
52  val req  = Flipped(Decoupled(new FtqToICacheRequestBundle))
53  val resp = Vec(PortNumber, ValidIO(new ICacheMainPipeResp))
54}
55
56class ICacheMetaReqBundle(implicit p: Parameters) extends ICacheBundle{
57  val toIMeta       = DecoupledIO(new ICacheReadBundle)
58  val fromIMeta     = Input(new ICacheMetaRespBundle)
59}
60
61class ICacheDataReqBundle(implicit p: Parameters) extends ICacheBundle{
62  val toIData       = DecoupledIO(Vec(partWayNum, new ICacheReadBundle))
63  val fromIData     = Input(new ICacheDataRespBundle)
64}
65
66class ICacheMSHRBundle(implicit p: Parameters) extends ICacheBundle{
67  val toMSHR        = Decoupled(new ICacheMissReq)
68  val fromMSHR      = Flipped(ValidIO(new ICacheMissResp))
69}
70
71class ICachePMPBundle(implicit p: Parameters) extends ICacheBundle{
72  val req  = Valid(new PMPReqBundle())
73  val resp = Input(new PMPRespBundle())
74}
75
76class ICachePerfInfo(implicit p: Parameters) extends ICacheBundle{
77  val only_0_hit     = Bool()
78  val only_0_miss    = Bool()
79  val hit_0_hit_1    = Bool()
80  val hit_0_miss_1   = Bool()
81  val miss_0_hit_1   = Bool()
82  val miss_0_miss_1  = Bool()
83  val hit_0_except_1 = Bool()
84  val miss_0_except_1 = Bool()
85  val except_0       = Bool()
86  val bank_hit       = Vec(2,Bool())
87  val hit            = Bool()
88}
89
90class ICacheMainPipeInterface(implicit p: Parameters) extends ICacheBundle {
91  /*** internal interface ***/
92  val metaArray   = new ICacheMetaReqBundle
93  val dataArray   = new ICacheDataReqBundle
94  val mshr        = Vec(PortNumber, new ICacheMSHRBundle)
95  val errors      = Output(Vec(PortNumber, new L1CacheErrorInfo))
96  /*** outside interface ***/
97  //val fetch       = Vec(PortNumber, new ICacheMainPipeBundle)
98  /* when ftq.valid is high in T + 1 cycle
99   * the ftq component must be valid in T cycle
100   */
101  val fetch       = new ICacheMainPipeBundle
102  val pmp         = Vec(PortNumber, new ICachePMPBundle)
103  val itlb        = Vec(PortNumber, new TlbRequestIO)
104  val respStall   = Input(Bool())
105  val perfInfo = Output(new ICachePerfInfo)
106
107  val prefetchEnable = Output(Bool())
108  val prefetchDisable = Output(Bool())
109  val csr_parity_enable = Input(Bool())
110
111}
112
113class ICacheMainPipe(implicit p: Parameters) extends ICacheModule
114{
115  val io = IO(new ICacheMainPipeInterface)
116
117  /** Input/Output port */
118  val (fromFtq, toIFU)    = (io.fetch.req, io.fetch.resp)
119  val (toMeta, metaResp)  = (io.metaArray.toIMeta, io.metaArray.fromIMeta)
120  val (toData, dataResp)  = (io.dataArray.toIData,  io.dataArray.fromIData)
121  val (toMSHR, fromMSHR)  = (io.mshr.map(_.toMSHR), io.mshr.map(_.fromMSHR))
122  val (toITLB, fromITLB)  = (io.itlb.map(_.req), io.itlb.map(_.resp))
123  val (toPMP,  fromPMP)   = (io.pmp.map(_.req), io.pmp.map(_.resp))
124  io.itlb.foreach(_.req_kill := false.B)
125
126  //Ftq RegNext Register
127  val fromFtqReq = fromFtq.bits.pcMemRead
128
129  /** pipeline control signal */
130  val s1_ready, s2_ready = Wire(Bool())
131  val s0_fire,  s1_fire , s2_fire  = Wire(Bool())
132
133  val missSwitchBit = RegInit(false.B)
134
135  /** replacement status register */
136  val touch_sets = Seq.fill(2)(Wire(Vec(2, UInt(log2Ceil(nSets/2).W))))
137  val touch_ways = Seq.fill(2)(Wire(Vec(2, Valid(UInt(log2Ceil(nWays).W)))) )
138
139  /**
140    ******************************************************************************
141    * ICache Stage 0
142    * - send req to ITLB and wait for tlb miss fixing
143    * - send req to Meta/Data SRAM
144    ******************************************************************************
145    */
146
147  /** s0 control */
148  val s0_valid       = fromFtq.valid
149  val s0_req_vaddr   = (0 until partWayNum + 1).map(i => VecInit(Seq(fromFtqReq(i).startAddr, fromFtqReq(i).nextlineStart)))
150  val s0_req_vsetIdx = (0 until partWayNum + 1).map(i => VecInit(s0_req_vaddr(i).map(get_idx(_))))
151  val s0_only_first  = (0 until partWayNum + 1).map(i => fromFtq.bits.readValid(i) && !fromFtqReq(i).crossCacheline)
152  val s0_double_line = (0 until partWayNum + 1).map(i => fromFtq.bits.readValid(i) &&  fromFtqReq(i).crossCacheline)
153
154  val s0_final_valid        = s0_valid
155  val s0_final_vaddr        = s0_req_vaddr.head
156  val s0_final_vsetIdx      = s0_req_vsetIdx.head
157  val s0_final_only_first   = s0_only_first.head
158  val s0_final_double_line  = s0_double_line.head
159
160  /** SRAM request */
161  //0 -> metaread, 1,2,3 -> data, 3 -> code 4 -> itlb
162  // TODO: it seems like 0,1,2,3 -> dataArray(data); 3 -> dataArray(code); 0 -> metaArray; 4 -> itlb
163  val ftq_req_to_data_doubleline  = s0_double_line.init
164  val ftq_req_to_data_vset_idx    = s0_req_vsetIdx.init
165  val ftq_req_to_data_valid       = fromFtq.bits.readValid.init
166
167  val ftq_req_to_meta_doubleline  = s0_double_line.head
168  val ftq_req_to_meta_vset_idx    = s0_req_vsetIdx.head
169
170  val ftq_req_to_itlb_only_first  = s0_only_first.last
171  val ftq_req_to_itlb_doubleline  = s0_double_line.last
172  val ftq_req_to_itlb_vaddr       = s0_req_vaddr.last
173  val ftq_req_to_itlb_vset_idx    = s0_req_vsetIdx.last
174
175
176  for(i <- 0 until partWayNum) {
177    toData.valid                  := ftq_req_to_data_valid(i) && !missSwitchBit
178    toData.bits(i).isDoubleLine   := ftq_req_to_data_doubleline(i)
179    toData.bits(i).vSetIdx        := ftq_req_to_data_vset_idx(i)
180  }
181
182  toMeta.valid               := s0_valid && !missSwitchBit
183  toMeta.bits.isDoubleLine   := ftq_req_to_meta_doubleline
184  toMeta.bits.vSetIdx        := ftq_req_to_meta_vset_idx
185
186
187  toITLB(0).valid         := s0_valid
188  toITLB(0).bits.size     := 3.U // TODO: fix the size
189  toITLB(0).bits.vaddr    := ftq_req_to_itlb_vaddr(0)
190  toITLB(0).bits.debug.pc := ftq_req_to_itlb_vaddr(0)
191
192  toITLB(1).valid         := s0_valid && ftq_req_to_itlb_doubleline
193  toITLB(1).bits.size     := 3.U // TODO: fix the size
194  toITLB(1).bits.vaddr    := ftq_req_to_itlb_vaddr(1)
195  toITLB(1).bits.debug.pc := ftq_req_to_itlb_vaddr(1)
196
197  toITLB.map{port =>
198    port.bits.cmd                 := TlbCmd.exec
199    port.bits.memidx              := DontCare
200    port.bits.debug.robIdx        := DontCare
201    port.bits.no_translate        := false.B
202    port.bits.debug.isFirstIssue  := DontCare
203  }
204
205  /** ITLB & ICACHE sync case
206   * when icache is not ready, but itlb is ready
207   * because itlb is non-block, then the req will take the port
208   * then itlb will unset the ready?? itlb is wrongly blocked.
209   * Solution: maybe give itlb a signal to tell whether acquire the slot?
210   */
211
212  val itlb_can_go    = toITLB(0).ready && toITLB(1).ready
213  val icache_can_go  = toData.ready && toMeta.ready
214  val pipe_can_go    = !missSwitchBit && s1_ready
215  val s0_can_go      = itlb_can_go && icache_can_go && pipe_can_go
216  val s0_fetch_fire  = s0_valid && s0_can_go
217  s0_fire        := s0_fetch_fire
218  toITLB.map{port => port.bits.kill := !icache_can_go || !pipe_can_go}
219
220  //TODO: fix GTimer() condition
221  fromFtq.ready := s0_can_go
222
223  /**
224    ******************************************************************************
225    * ICache Stage 1
226    * - get tlb resp data (exceptiong info and physical addresses)
227    * - get Meta/Data SRAM read responses (latched for pipeline stop)
228    * - tag compare/hit check
229    ******************************************************************************
230    */
231
232  /** s1 control */
233
234  val s1_valid = generatePipeControl(lastFire = s0_fire, thisFire = s1_fire, thisFlush = false.B, lastFlush = false.B)
235
236  val s1_req_vaddr   = RegEnable(s0_final_vaddr, s0_fire)
237  val s1_req_vsetIdx = RegEnable(s0_final_vsetIdx, s0_fire)
238  val s1_only_first  = RegEnable(s0_final_only_first, s0_fire)
239  val s1_double_line = RegEnable(s0_final_double_line, s0_fire)
240
241  /** tlb response latch for pipeline stop */
242  val tlb_back = fromITLB.map(_.fire())
243  val tlb_need_back = VecInit((0 until PortNumber).map(i => ValidHold(s0_fire && toITLB(i).fire(), s1_fire, false.B)))
244  val tlb_already_recv = RegInit(VecInit(Seq.fill(PortNumber)(false.B)))
245  val tlb_ready_recv = VecInit((0 until PortNumber).map(i => RegNext(s0_fire, false.B) || (s1_valid && !tlb_already_recv(i))))
246  val tlb_resp_valid = Wire(Vec(2, Bool()))
247  for (i <- 0 until PortNumber) {
248    tlb_resp_valid(i) := tlb_already_recv(i) || (tlb_ready_recv(i) && tlb_back(i))
249    when (tlb_already_recv(i) && s1_fire) {
250      tlb_already_recv(i) := false.B
251    }
252    when (tlb_back(i) && tlb_ready_recv(i) && !s1_fire) {
253      tlb_already_recv(i) := true.B
254    }
255    fromITLB(i).ready := tlb_ready_recv(i)
256  }
257  assert(RegNext(Cat((0 until PortNumber).map(i => tlb_need_back(i) || !tlb_resp_valid(i))).andR(), true.B),
258    "when tlb should not back, tlb should not resp valid")
259  assert(RegNext(!s1_valid || Cat(tlb_need_back).orR, true.B), "when s1_valid, need at least one tlb_need_back")
260  assert(RegNext(s1_valid || !Cat(tlb_need_back).orR, true.B), "when !s1_valid, all the tlb_need_back should be false")
261  assert(RegNext(s1_valid || !Cat(tlb_already_recv).orR, true.B), "when !s1_valid, should not tlb_already_recv")
262  assert(RegNext(s1_valid || !Cat(tlb_resp_valid).orR, true.B), "when !s1_valid, should not tlb_resp_valid")
263
264  val tlbRespPAddr = VecInit((0 until PortNumber).map(i => ResultHoldBypass(valid = tlb_back(i), data = fromITLB(i).bits.paddr(0))))
265  val tlbExcpPF = VecInit((0 until PortNumber).map(i => ResultHoldBypass(valid = tlb_back(i), data = fromITLB(i).bits.excp(0).pf.instr) && tlb_need_back(i)))
266  val tlbExcpAF = VecInit((0 until PortNumber).map(i => ResultHoldBypass(valid = tlb_back(i), data = fromITLB(i).bits.excp(0).af.instr) && tlb_need_back(i)))
267  val tlbExcp = VecInit((0 until PortNumber).map(i => tlbExcpPF(i) || tlbExcpPF(i)))
268
269  val tlbRespAllValid = Cat((0 until PortNumber).map(i => !tlb_need_back(i) || tlb_resp_valid(i))).andR
270  s1_ready := s2_ready && tlbRespAllValid  || !s1_valid
271  s1_fire  := s1_valid && tlbRespAllValid && s2_ready
272
273  /** s1 hit check/tag compare */
274  val s1_req_paddr              = tlbRespPAddr
275  val s1_req_ptags              = VecInit(s1_req_paddr.map(get_phy_tag(_)))
276
277  val s1_meta_ptags              = ResultHoldBypass(data = metaResp.tags, valid = RegNext(s0_fire))
278//  val s1_meta_cohs               = ResultHoldBypass(data = metaResp.cohs, valid = RegNext(s0_fire))
279  val s1_meta_valids             = ResultHoldBypass(data = metaResp.entryValid, valid = RegNext(s0_fire))
280  val s1_meta_errors             = ResultHoldBypass(data = metaResp.errors, valid = RegNext(s0_fire))
281
282  val s1_data_cacheline          = ResultHoldBypass(data = dataResp.datas, valid = RegNext(s0_fire))
283  val s1_data_errorBits          = ResultHoldBypass(data = dataResp.codes, valid = RegNext(s0_fire))
284
285  val s1_tag_eq_vec        = VecInit((0 until PortNumber).map( p => VecInit((0 until nWays).map( w =>  s1_meta_ptags(p)(w) ===  s1_req_ptags(p) ))))
286  val s1_tag_match_vec     = VecInit((0 until PortNumber).map( k => VecInit(s1_tag_eq_vec(k).zipWithIndex.map{ case(way_tag_eq, w) => way_tag_eq && s1_meta_valids(k)(w) /*s1_meta_cohs(k)(w).isValid()*/})))
287  val s1_tag_match         = VecInit(s1_tag_match_vec.map(vector => ParallelOR(vector)))
288
289  val s1_port_hit          = VecInit(Seq(s1_tag_match(0) && s1_valid  && !tlbExcp(0),  s1_tag_match(1) && s1_valid && s1_double_line && !tlbExcp(1) ))
290  val s1_bank_miss         = VecInit(Seq(!s1_tag_match(0) && s1_valid && !tlbExcp(0), !s1_tag_match(1) && s1_valid && s1_double_line && !tlbExcp(1) ))
291  val s1_hit               = (s1_port_hit(0) && s1_port_hit(1)) || (!s1_double_line && s1_port_hit(0))
292
293  /** choose victim cacheline */
294  val replacers       = Seq.fill(PortNumber)(ReplacementPolicy.fromString(cacheParams.replacer,nWays,nSets/PortNumber))
295  val s1_victim_oh    = ResultHoldBypass(data = VecInit(replacers.zipWithIndex.map{case (replacer, i) => UIntToOH(replacer.way(s1_req_vsetIdx(i)))}), valid = RegNext(s0_fire))
296
297
298  when(s1_fire){
299    assert(PopCount(s1_tag_match_vec(0)) <= 1.U && (PopCount(s1_tag_match_vec(1)) <= 1.U || !s1_double_line),
300      "Multiple hit in main pipe, port0:is=%d,ptag=0x%x,vidx=0x%x,vaddr=0x%x port1:is=%d,ptag=0x%x,vidx=0x%x,vaddr=0x%x ",
301      PopCount(s1_tag_match_vec(0)) > 1.U,s1_req_ptags(0), get_idx(s1_req_vaddr(0)), s1_req_vaddr(0),
302      PopCount(s1_tag_match_vec(1)) > 1.U && s1_double_line, s1_req_ptags(1), get_idx(s1_req_vaddr(1)), s1_req_vaddr(1))
303  }
304
305  ((replacers zip touch_sets) zip touch_ways).map{case ((r, s),w) => r.access(s,w)}
306
307
308  /** <PERF> replace victim way number */
309
310  (0 until nWays).map{ w =>
311    XSPerfAccumulate("line_0_hit_way_" + Integer.toString(w, 10),  s1_fire && s1_port_hit(0) && OHToUInt(s1_tag_match_vec(0))  === w.U)
312  }
313
314  (0 until nWays).map{ w =>
315    XSPerfAccumulate("line_0_victim_way_" + Integer.toString(w, 10),  s1_fire && !s1_port_hit(0) && OHToUInt(s1_victim_oh(0))  === w.U)
316  }
317
318  (0 until nWays).map{ w =>
319    XSPerfAccumulate("line_1_hit_way_" + Integer.toString(w, 10),  s1_fire && s1_double_line && s1_port_hit(1) && OHToUInt(s1_tag_match_vec(1))  === w.U)
320  }
321
322  (0 until nWays).map{ w =>
323    XSPerfAccumulate("line_1_victim_way_" + Integer.toString(w, 10),  s1_fire && s1_double_line && !s1_port_hit(1) && OHToUInt(s1_victim_oh(1))  === w.U)
324  }
325
326  /**
327    ******************************************************************************
328    * ICache Stage 2
329    * - send request to MSHR if ICache miss
330    * - generate secondary miss status/data registers
331    * - response to IFU
332    ******************************************************************************
333    */
334
335  /** s2 control */
336  val s2_fetch_finish = Wire(Bool())
337
338  val s2_valid          = generatePipeControl(lastFire = s1_fire, thisFire = s2_fire, thisFlush = false.B, lastFlush = false.B)
339  val s2_miss_available = Wire(Bool())
340
341  s2_ready      := (s2_valid && s2_fetch_finish && !io.respStall) || (!s2_valid && s2_miss_available)
342  s2_fire       := s2_valid && s2_fetch_finish && !io.respStall
343
344  /** s2 data */
345  val mmio = fromPMP.map(port => port.mmio) // TODO: handle it
346
347  val (s2_req_paddr , s2_req_vaddr)   = (RegEnable(s1_req_paddr, s1_fire), RegEnable(s1_req_vaddr, s1_fire))
348  val s2_req_vsetIdx  = RegEnable(s1_req_vsetIdx, s1_fire)
349  val s2_req_ptags    = RegEnable(s1_req_ptags, s1_fire)
350  val s2_only_first   = RegEnable(s1_only_first, s1_fire)
351  val s2_double_line  = RegEnable(s1_double_line, s1_fire)
352  val s2_hit          = RegEnable(s1_hit   , s1_fire)
353  val s2_port_hit     = RegEnable(s1_port_hit, s1_fire)
354  val s2_bank_miss    = RegEnable(s1_bank_miss, s1_fire)
355  val s2_waymask      = RegEnable(s1_victim_oh, s1_fire)
356//  val s2_victim_coh   = RegEnable(s1_victim_coh, s1_fire)
357  val s2_tag_match_vec = RegEnable(s1_tag_match_vec, s1_fire)
358
359  assert(RegNext(!s2_valid || s2_req_paddr(0)(11,0) === s2_req_vaddr(0)(11,0), true.B))
360
361  /** status imply that s2 is a secondary miss (no need to resend miss request) */
362  val sec_meet_vec = Wire(Vec(2, Bool()))
363  val s2_fixed_hit_vec = VecInit((0 until 2).map(i => s2_port_hit(i) || sec_meet_vec(i)))
364  val s2_fixed_hit = (s2_valid && s2_fixed_hit_vec(0) && s2_fixed_hit_vec(1) && s2_double_line) || (s2_valid && s2_fixed_hit_vec(0) && !s2_double_line)
365
366  val s2_meta_errors    = RegEnable(s1_meta_errors,    s1_fire)
367  val s2_data_errorBits = RegEnable(s1_data_errorBits, s1_fire)
368  val s2_data_cacheline = RegEnable(s1_data_cacheline, s1_fire)
369
370  val s2_data_errors    = Wire(Vec(PortNumber,Vec(nWays, Bool())))
371
372  (0 until PortNumber).map{ i =>
373    val read_datas = s2_data_cacheline(i).asTypeOf(Vec(nWays,Vec(dataCodeUnitNum, UInt(dataCodeUnit.W))))
374    val read_codes = s2_data_errorBits(i).asTypeOf(Vec(nWays,Vec(dataCodeUnitNum, UInt(dataCodeBits.W))))
375    val data_full_wayBits = VecInit((0 until nWays).map( w =>
376                                  VecInit((0 until dataCodeUnitNum).map(u =>
377                                        Cat(read_codes(w)(u), read_datas(w)(u))))))
378    val data_error_wayBits = VecInit((0 until nWays).map( w =>
379                                  VecInit((0 until dataCodeUnitNum).map(u =>
380                                       cacheParams.dataCode.decode(data_full_wayBits(w)(u)).error ))))
381    if(i == 0){
382      (0 until nWays).map{ w =>
383        s2_data_errors(i)(w) := RegNext(RegNext(s1_fire)) && RegNext(data_error_wayBits(w)).reduce(_||_)
384      }
385    } else {
386      (0 until nWays).map{ w =>
387        s2_data_errors(i)(w) := RegNext(RegNext(s1_fire)) && RegNext(RegNext(s1_double_line)) && RegNext(data_error_wayBits(w)).reduce(_||_)
388      }
389    }
390  }
391
392  val s2_parity_meta_error  = VecInit((0 until PortNumber).map(i => s2_meta_errors(i).reduce(_||_) && io.csr_parity_enable))
393  val s2_parity_data_error  = VecInit((0 until PortNumber).map(i => s2_data_errors(i).reduce(_||_) && io.csr_parity_enable))
394  val s2_parity_error       = VecInit((0 until PortNumber).map(i => RegNext(s2_parity_meta_error(i)) || s2_parity_data_error(i)))
395
396  for(i <- 0 until PortNumber){
397    io.errors(i).valid            := RegNext(s2_parity_error(i) && RegNext(RegNext(s1_fire)))
398    io.errors(i).report_to_beu    := RegNext(s2_parity_error(i) && RegNext(RegNext(s1_fire)))
399    io.errors(i).paddr            := RegNext(RegNext(s2_req_paddr(i)))
400    io.errors(i).source           := DontCare
401    io.errors(i).source.tag       := RegNext(RegNext(s2_parity_meta_error(i)))
402    io.errors(i).source.data      := RegNext(s2_parity_data_error(i))
403    io.errors(i).source.l2        := false.B
404    io.errors(i).opType           := DontCare
405    io.errors(i).opType.fetch     := true.B
406  }
407  XSError(s2_parity_error.reduce(_||_) && RegNext(RegNext(s1_fire)), "ICache has parity error in MainPaipe!")
408
409
410  /** exception and pmp logic **/
411  //PMP Result
412  val s2_tlb_need_back = VecInit((0 until PortNumber).map(i => ValidHold(tlb_need_back(i) && s1_fire, s2_fire, false.B)))
413  val pmpExcpAF = Wire(Vec(PortNumber, Bool()))
414  pmpExcpAF(0)  := fromPMP(0).instr && s2_tlb_need_back(0)
415  pmpExcpAF(1)  := fromPMP(1).instr && s2_double_line && s2_tlb_need_back(1)
416  //exception information
417  //short delay exception signal
418  val s2_except_pf        = RegEnable(tlbExcpPF, s1_fire)
419  val s2_except_tlb_af    = RegEnable(tlbExcpAF, s1_fire)
420  //long delay exception signal
421  val s2_except_pmp_af    =  DataHoldBypass(pmpExcpAF, RegNext(s1_fire))
422  // val s2_except_parity_af =  VecInit(s2_parity_error(i) && RegNext(RegNext(s1_fire))                      )
423
424  val s2_except    = VecInit((0 until 2).map{i => s2_except_pf(i) || s2_except_tlb_af(i)})
425  val s2_has_except = s2_valid && (s2_except_tlb_af.reduce(_||_) || s2_except_pf.reduce(_||_))
426  //MMIO
427  val s2_mmio      = DataHoldBypass(io.pmp(0).resp.mmio && !s2_except_tlb_af(0) && !s2_except_pmp_af(0) && !s2_except_pf(0), RegNext(s1_fire)).asBool() && s2_valid
428
429  //send physical address to PMP
430  io.pmp.zipWithIndex.map { case (p, i) =>
431    p.req.valid := s2_valid && !missSwitchBit
432    p.req.bits.addr := s2_req_paddr(i)
433    p.req.bits.size := 3.U // TODO
434    p.req.bits.cmd := TlbCmd.exec
435  }
436
437  /*** cacheline miss logic ***/
438  val wait_idle :: wait_queue_ready :: wait_send_req  :: wait_two_resp :: wait_0_resp :: wait_1_resp :: wait_one_resp ::wait_finish :: wait_pmp_except :: Nil = Enum(9)
439  val wait_state = RegInit(wait_idle)
440
441  val port_miss_fix  = VecInit(Seq(fromMSHR(0).fire() && !s2_port_hit(0),   fromMSHR(1).fire() && s2_double_line && !s2_port_hit(1) ))
442
443  // secondary miss record registers
444  class MissSlot(implicit p: Parameters) extends  ICacheBundle {
445    val m_vSetIdx   = UInt(idxBits.W)
446    val m_pTag      = UInt(tagBits.W)
447    val m_data      = UInt(blockBits.W)
448    val m_corrupt   = Bool()
449  }
450
451  val missSlot    = Seq.fill(2)(RegInit(0.U.asTypeOf(new MissSlot)))
452  val m_invalid :: m_valid :: m_refilled :: m_flushed :: m_wait_sec_miss :: m_check_final ::Nil = Enum(6)
453  val missStateQueue = RegInit(VecInit(Seq.fill(2)(m_invalid)) )
454  val reservedRefillData = Wire(Vec(2, UInt(blockBits.W)))
455
456  s2_miss_available :=  VecInit(missStateQueue.map(entry => entry === m_invalid  || entry === m_wait_sec_miss)).reduce(_&&_)
457
458  val fix_sec_miss     = Wire(Vec(4, Bool()))
459  val sec_meet_0_miss = fix_sec_miss(0) || fix_sec_miss(2)
460  val sec_meet_1_miss = fix_sec_miss(1) || fix_sec_miss(3)
461  sec_meet_vec := VecInit(Seq(sec_meet_0_miss,sec_meet_1_miss ))
462
463  /*** miss/hit pattern: <Control Signal> only raise at the first cycle of s2_valid ***/
464  val cacheline_0_hit  = (s2_port_hit(0) || sec_meet_0_miss)
465  val cacheline_0_miss = !s2_port_hit(0) && !sec_meet_0_miss
466
467  val cacheline_1_hit  = (s2_port_hit(1) || sec_meet_1_miss)
468  val cacheline_1_miss = !s2_port_hit(1) && !sec_meet_1_miss
469
470  val  only_0_miss      = RegNext(s1_fire) && cacheline_0_miss && !s2_double_line && !s2_has_except && !s2_mmio
471  val  only_0_hit       = RegNext(s1_fire) && cacheline_0_hit  && !s2_double_line && !s2_mmio
472  val  hit_0_hit_1      = RegNext(s1_fire) && cacheline_0_hit  && cacheline_1_hit  && s2_double_line && !s2_mmio
473  val  hit_0_miss_1     = RegNext(s1_fire) && cacheline_0_hit  && cacheline_1_miss && s2_double_line  && !s2_has_except && !s2_mmio
474  val  miss_0_hit_1     = RegNext(s1_fire) && cacheline_0_miss && cacheline_1_hit && s2_double_line  && !s2_has_except && !s2_mmio
475  val  miss_0_miss_1    = RegNext(s1_fire) && cacheline_0_miss && cacheline_1_miss && s2_double_line  && !s2_has_except && !s2_mmio
476
477  val  hit_0_except_1   = RegNext(s1_fire) && s2_double_line &&  !s2_except(0) && s2_except(1)  &&  cacheline_0_hit
478  val  miss_0_except_1  = RegNext(s1_fire) && s2_double_line &&  !s2_except(0) && s2_except(1)  &&  cacheline_0_miss
479  val  except_0         = RegNext(s1_fire) && s2_except(0)
480
481  def holdReleaseLatch(valid: Bool, release: Bool, flush: Bool): Bool ={
482    val bit = RegInit(false.B)
483    when(flush)                   { bit := false.B  }
484    .elsewhen(valid && !release)  { bit := true.B   }
485    .elsewhen(release)            { bit := false.B  }
486    bit || valid
487  }
488
489  /*** miss/hit pattern latch: <Control Signal> latch the miss/hit patter if pipeline stop ***/
490  val  miss_0_hit_1_latch     =   holdReleaseLatch(valid = miss_0_hit_1,    release = s2_fire,      flush = false.B)
491  val  miss_0_miss_1_latch    =   holdReleaseLatch(valid = miss_0_miss_1,   release = s2_fire,      flush = false.B)
492  val  only_0_miss_latch      =   holdReleaseLatch(valid = only_0_miss,     release = s2_fire,      flush = false.B)
493  val  hit_0_miss_1_latch     =   holdReleaseLatch(valid = hit_0_miss_1,    release = s2_fire,      flush = false.B)
494
495  val  miss_0_except_1_latch  =   holdReleaseLatch(valid = miss_0_except_1, release = s2_fire,      flush = false.B)
496  val  except_0_latch          =   holdReleaseLatch(valid = except_0,    release = s2_fire,      flush = false.B)
497  val  hit_0_except_1_latch         =    holdReleaseLatch(valid = hit_0_except_1,    release = s2_fire,      flush = false.B)
498
499  val only_0_hit_latch        = holdReleaseLatch(valid = only_0_hit,   release = s2_fire,      flush = false.B)
500  val hit_0_hit_1_latch        = holdReleaseLatch(valid = hit_0_hit_1,   release = s2_fire,      flush = false.B)
501
502
503  /*** secondary miss judgment ***/
504
505  def waitSecondComeIn(missState: UInt): Bool = (missState === m_wait_sec_miss)
506
507  def getMissSituat(slotNum : Int, missNum : Int ) :Bool =  {
508    RegNext(s1_fire) &&
509    RegNext(missSlot(slotNum).m_vSetIdx === s1_req_vsetIdx(missNum)) &&
510    RegNext(missSlot(slotNum).m_pTag  === s1_req_ptags(missNum)) &&
511    !s2_port_hit(missNum)  &&
512    waitSecondComeIn(missStateQueue(slotNum))
513  }
514
515  val miss_0_s2_0 =   getMissSituat(slotNum = 0, missNum = 0)
516  val miss_0_s2_1 =   getMissSituat(slotNum = 0, missNum = 1)
517  val miss_1_s2_0 =   getMissSituat(slotNum = 1, missNum = 0)
518  val miss_1_s2_1 =   getMissSituat(slotNum = 1, missNum = 1)
519
520  val miss_0_s2_0_latch =   holdReleaseLatch(valid = miss_0_s2_0,    release = s2_fire,      flush = false.B)
521  val miss_0_s2_1_latch =   holdReleaseLatch(valid = miss_0_s2_1,    release = s2_fire,      flush = false.B)
522  val miss_1_s2_0_latch =   holdReleaseLatch(valid = miss_1_s2_0,    release = s2_fire,      flush = false.B)
523  val miss_1_s2_1_latch =   holdReleaseLatch(valid = miss_1_s2_1,    release = s2_fire,      flush = false.B)
524
525
526  val slot_0_solve = fix_sec_miss(0) || fix_sec_miss(1)
527  val slot_1_solve = fix_sec_miss(2) || fix_sec_miss(3)
528  val slot_slove   = VecInit(Seq(slot_0_solve, slot_1_solve))
529
530  fix_sec_miss   := VecInit(Seq(miss_0_s2_0_latch, miss_0_s2_1_latch, miss_1_s2_0_latch, miss_1_s2_1_latch))
531
532  /*** reserved data for secondary miss ***/
533
534  reservedRefillData(0) := DataHoldBypass(data = missSlot(0).m_data, valid = miss_0_s2_0 || miss_0_s2_1)
535  reservedRefillData(1) := DataHoldBypass(data = missSlot(1).m_data, valid = miss_1_s2_0 || miss_1_s2_1)
536
537  /*** miss state machine ***/
538
539  //deal with not-cache-hit pmp af
540  val only_pmp_af = Wire(Vec(2, Bool()))
541  only_pmp_af(0) := s2_except_pmp_af(0) && cacheline_0_miss && !s2_except(0) && s2_valid
542  only_pmp_af(1) := s2_except_pmp_af(1) && cacheline_1_miss && !s2_except(1) && s2_valid && s2_double_line
543
544  switch(wait_state){
545    is(wait_idle){
546      when(only_pmp_af(0) || only_pmp_af(1) || s2_mmio){
547        //should not send req to MissUnit when there is an access exception in PMP
548        //But to avoid using pmp exception in control signal (like s2_fire), should delay 1 cycle.
549        //NOTE: pmp exception cache line also could hit in ICache, but the result is meaningless. Just give the exception signals.
550        wait_state := wait_finish
551      }.elsewhen(miss_0_except_1_latch){
552        wait_state :=  Mux(toMSHR(0).ready, wait_queue_ready ,wait_idle )
553      }.elsewhen( only_0_miss_latch  || miss_0_hit_1_latch){
554        wait_state :=  Mux(toMSHR(0).ready, wait_queue_ready ,wait_idle )
555      }.elsewhen(hit_0_miss_1_latch){
556        wait_state :=  Mux(toMSHR(1).ready, wait_queue_ready ,wait_idle )
557      }.elsewhen( miss_0_miss_1_latch ){
558        wait_state := Mux(toMSHR(0).ready && toMSHR(1).ready, wait_queue_ready ,wait_idle)
559      }
560    }
561
562    is(wait_queue_ready){
563      wait_state := wait_send_req
564    }
565
566    is(wait_send_req) {
567      when(miss_0_except_1_latch || only_0_miss_latch || hit_0_miss_1_latch || miss_0_hit_1_latch){
568        wait_state :=  wait_one_resp
569      }.elsewhen( miss_0_miss_1_latch ){
570        wait_state := wait_two_resp
571      }
572    }
573
574    is(wait_one_resp) {
575      when( (miss_0_except_1_latch ||only_0_miss_latch || miss_0_hit_1_latch) && fromMSHR(0).fire()){
576        wait_state := wait_finish
577      }.elsewhen( hit_0_miss_1_latch && fromMSHR(1).fire()){
578        wait_state := wait_finish
579      }
580    }
581
582    is(wait_two_resp) {
583      when(fromMSHR(0).fire() && fromMSHR(1).fire()){
584        wait_state := wait_finish
585      }.elsewhen( !fromMSHR(0).fire() && fromMSHR(1).fire() ){
586        wait_state := wait_0_resp
587      }.elsewhen(fromMSHR(0).fire() && !fromMSHR(1).fire()){
588        wait_state := wait_1_resp
589      }
590    }
591
592    is(wait_0_resp) {
593      when(fromMSHR(0).fire()){
594        wait_state := wait_finish
595      }
596    }
597
598    is(wait_1_resp) {
599      when(fromMSHR(1).fire()){
600        wait_state := wait_finish
601      }
602    }
603
604    is(wait_finish) {when(s2_fire) {wait_state := wait_idle }
605    }
606  }
607
608
609  /*** send request to MissUnit ***/
610
611  (0 until 2).map { i =>
612    if(i == 1) toMSHR(i).valid   := (hit_0_miss_1_latch || miss_0_miss_1_latch) && wait_state === wait_queue_ready && !s2_mmio
613        else     toMSHR(i).valid := (only_0_miss_latch || miss_0_hit_1_latch || miss_0_miss_1_latch || miss_0_except_1_latch) && wait_state === wait_queue_ready && !s2_mmio
614    toMSHR(i).bits.paddr    := s2_req_paddr(i)
615    toMSHR(i).bits.vaddr    := s2_req_vaddr(i)
616    toMSHR(i).bits.waymask  := s2_waymask(i)
617
618
619    when(toMSHR(i).fire() && missStateQueue(i) === m_invalid){
620      missStateQueue(i)     := m_valid
621      missSlot(i).m_vSetIdx := s2_req_vsetIdx(i)
622      missSlot(i).m_pTag    := get_phy_tag(s2_req_paddr(i))
623    }
624
625    when(fromMSHR(i).fire() && missStateQueue(i) === m_valid ){
626      missStateQueue(i)         := m_refilled
627      missSlot(i).m_data        := fromMSHR(i).bits.data
628      missSlot(i).m_corrupt     := fromMSHR(i).bits.corrupt
629    }
630
631
632    when(s2_fire && missStateQueue(i) === m_refilled){
633      missStateQueue(i)     := m_wait_sec_miss
634    }
635
636    /*** Only the first cycle to check whether meet the secondary miss ***/
637    when(missStateQueue(i) === m_wait_sec_miss){
638      /*** The seondary req has been fix by this slot and another also hit || the secondary req for other cacheline and hit ***/
639      when((slot_slove(i) && s2_fire) || (!slot_slove(i) && s2_fire) ) {
640        missStateQueue(i)     := m_invalid
641      }
642      /*** The seondary req has been fix by this slot but another miss/f3 not ready || the seondary req for other cacheline and miss ***/
643      .elsewhen((slot_slove(i) && !s2_fire && s2_valid) ||  (s2_valid && !slot_slove(i) && !s2_fire) ){
644        missStateQueue(i)     := m_check_final
645      }
646    }
647
648    when(missStateQueue(i) === m_check_final && toMSHR(i).fire()){
649      missStateQueue(i)     :=  m_valid
650      missSlot(i).m_vSetIdx := s2_req_vsetIdx(i)
651      missSlot(i).m_pTag    := get_phy_tag(s2_req_paddr(i))
652    }.elsewhen(missStateQueue(i) === m_check_final) {
653      missStateQueue(i)     :=  m_invalid
654    }
655  }
656
657  io.prefetchEnable := false.B
658  io.prefetchDisable := false.B
659  when(toMSHR.map(_.valid).reduce(_||_)){
660    missSwitchBit := true.B
661    io.prefetchEnable := true.B
662  }.elsewhen(missSwitchBit && s2_fetch_finish){
663    missSwitchBit := false.B
664    io.prefetchDisable := true.B
665  }
666
667
668  val miss_all_fix       =  wait_state === wait_finish
669
670  s2_fetch_finish        := ((s2_valid && s2_fixed_hit) || miss_all_fix || hit_0_except_1_latch || except_0_latch)
671
672  /** update replacement status register: 0 is hit access/ 1 is miss access */
673  (touch_ways zip touch_sets).zipWithIndex.map{ case((t_w,t_s), i) =>
674    t_s(0)         := s2_req_vsetIdx(i)
675    t_w(0).valid   := s2_valid && s2_port_hit(i)
676    t_w(0).bits    := OHToUInt(s2_tag_match_vec(i))
677
678    t_s(1)         := s2_req_vsetIdx(i)
679    t_w(1).valid   := s2_valid && !s2_port_hit(i)
680    t_w(1).bits    := OHToUInt(s2_waymask(i))
681  }
682
683  //** use hit one-hot select data
684  val s2_hit_datas    = VecInit(s2_data_cacheline.zipWithIndex.map { case(bank, i) =>
685    val port_hit_data = Mux1H(s2_tag_match_vec(i).asUInt, bank)
686    port_hit_data
687  })
688
689  val s2_register_datas       = Wire(Vec(2, UInt(blockBits.W)))
690
691  s2_register_datas.zipWithIndex.map{case(bank,i) =>
692    // if(i == 0) bank := Mux(s2_port_hit(i), s2_hit_datas(i), Mux(miss_0_s2_0_latch,reservedRefillData(0), Mux(miss_1_s2_0_latch,reservedRefillData(1), missSlot(0).m_data)))
693    // else    bank    := Mux(s2_port_hit(i), s2_hit_datas(i), Mux(miss_0_s2_1_latch,reservedRefillData(0), Mux(miss_1_s2_1_latch,reservedRefillData(1), missSlot(1).m_data)))
694    if(i == 0) bank := Mux(miss_0_s2_0_latch,reservedRefillData(0), Mux(miss_1_s2_0_latch,reservedRefillData(1), missSlot(0).m_data))
695    else    bank    := Mux(miss_0_s2_1_latch,reservedRefillData(0), Mux(miss_1_s2_1_latch,reservedRefillData(1), missSlot(1).m_data))
696  }
697
698  /** response to IFU */
699
700  (0 until PortNumber).map{ i =>
701    if(i ==0) toIFU(i).valid          := s2_fire
702       else   toIFU(i).valid          := s2_fire && s2_double_line
703    //when select is high, use sramData. Otherwise, use registerData.
704    toIFU(i).bits.registerData  := s2_register_datas(i)
705    toIFU(i).bits.sramData  := s2_hit_datas(i)
706    toIFU(i).bits.select    := s2_port_hit(i)
707    toIFU(i).bits.paddr     := s2_req_paddr(i)
708    toIFU(i).bits.vaddr     := s2_req_vaddr(i)
709    toIFU(i).bits.tlbExcp.pageFault     := s2_except_pf(i)
710    toIFU(i).bits.tlbExcp.accessFault   := s2_except_tlb_af(i) || missSlot(i).m_corrupt || s2_except_pmp_af(i)
711    toIFU(i).bits.tlbExcp.mmio          := s2_mmio
712
713    when(RegNext(s2_fire && missSlot(i).m_corrupt)){
714      io.errors(i).valid            := true.B
715      io.errors(i).report_to_beu    := false.B // l2 should have report that to bus error unit, no need to do it again
716      io.errors(i).paddr            := RegNext(s2_req_paddr(i))
717      io.errors(i).source.tag       := false.B
718      io.errors(i).source.data      := false.B
719      io.errors(i).source.l2        := true.B
720    }
721  }
722
723  io.perfInfo.only_0_hit    := only_0_hit_latch
724  io.perfInfo.only_0_miss   := only_0_miss_latch
725  io.perfInfo.hit_0_hit_1   := hit_0_hit_1_latch
726  io.perfInfo.hit_0_miss_1  := hit_0_miss_1_latch
727  io.perfInfo.miss_0_hit_1  := miss_0_hit_1_latch
728  io.perfInfo.miss_0_miss_1 := miss_0_miss_1_latch
729  io.perfInfo.hit_0_except_1 := hit_0_except_1_latch
730  io.perfInfo.miss_0_except_1 := miss_0_except_1_latch
731  io.perfInfo.except_0      := except_0_latch
732  io.perfInfo.bank_hit(0)   := only_0_miss_latch  || hit_0_hit_1_latch || hit_0_miss_1_latch || hit_0_except_1_latch
733  io.perfInfo.bank_hit(1)   := miss_0_hit_1_latch || hit_0_hit_1_latch
734  io.perfInfo.hit           := hit_0_hit_1_latch || only_0_hit_latch || hit_0_except_1_latch || except_0_latch
735
736  /** <PERF> fetch bubble generated by icache miss*/
737
738  XSPerfAccumulate("icache_bubble_s2_miss",    s2_valid && !s2_fetch_finish )
739
740  val tlb_miss_vec = VecInit((0 until PortNumber).map(i => toITLB(i).valid && s0_can_go && fromITLB(i).bits.miss))
741  val tlb_has_miss = tlb_miss_vec.reduce(_ || _)
742  XSPerfAccumulate("icache_bubble_s0_tlb_miss",    s0_valid && tlb_has_miss )
743}
744