xref: /XiangShan/src/main/scala/xiangshan/mem/lsqueue/LSQWrapper.scala (revision b1e920234888fd3e5463ceb2a99c9bdca087f585)
1/***************************************************************************************
2* Copyright (c) 2020-2021 Institute of Computing Technology, Chinese Academy of Sciences
3* Copyright (c) 2020-2021 Peng Cheng Laboratory
4*
5* XiangShan is licensed under Mulan PSL v2.
6* You can use this software according to the terms and conditions of the Mulan PSL v2.
7* You may obtain a copy of Mulan PSL v2 at:
8*          http://license.coscl.org.cn/MulanPSL2
9*
10* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
11* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
12* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
13*
14* See the Mulan PSL v2 for more details.
15***************************************************************************************/
16
17package xiangshan.mem
18
19import org.chipsalliance.cde.config.Parameters
20import chisel3._
21import chisel3.util._
22import utils._
23import utility._
24import xiangshan._
25import xiangshan.backend.Bundles.{DynInst, MemExuOutput}
26import xiangshan.cache._
27import xiangshan.cache.{DCacheLineIO, DCacheWordIO, MemoryOpConstants}
28import xiangshan.cache.mmu.TlbRequestIO
29import xiangshan.mem._
30import xiangshan.backend._
31import xiangshan.backend.rob.RobLsqIO
32
33class ExceptionAddrIO(implicit p: Parameters) extends XSBundle {
34  val isStore = Input(Bool())
35  val vaddr = Output(UInt(VAddrBits.W))
36}
37
38class FwdEntry extends Bundle {
39  val validFast = Bool() // validFast is generated the same cycle with query
40  val valid = Bool() // valid is generated 1 cycle after query request
41  val data = UInt(8.W) // data is generated 1 cycle after query request
42}
43
44// inflight miss block reqs
45class InflightBlockInfo(implicit p: Parameters) extends XSBundle {
46  val block_addr = UInt(PAddrBits.W)
47  val valid = Bool()
48}
49
50class LsqEnqIO(implicit p: Parameters) extends MemBlockBundle {
51  val canAccept = Output(Bool())
52  val needAlloc = Vec(LSQEnqWidth, Input(UInt(2.W)))
53  val req       = Vec(LSQEnqWidth, Flipped(ValidIO(new DynInst)))
54  val resp      = Vec(LSQEnqWidth, Output(new LSIdx))
55}
56
57// Load / Store Queue Wrapper for XiangShan Out of Order LSU
58class LsqWrapper(implicit p: Parameters) extends XSModule with HasDCacheParameters with HasPerfEvents {
59  val io = IO(new Bundle() {
60    val hartId = Input(UInt(8.W))
61    val brqRedirect = Flipped(ValidIO(new Redirect))
62    val enq = new LsqEnqIO
63    val ldu = new Bundle() {
64        val stld_nuke_query = Vec(LoadPipelineWidth, Flipped(new LoadNukeQueryIO)) // from load_s2
65        val ldld_nuke_query = Vec(LoadPipelineWidth, Flipped(new LoadNukeQueryIO)) // from load_s2
66        val ldin = Vec(LoadPipelineWidth, Flipped(Decoupled(new LqWriteBundle))) // from load_s3
67    }
68    val sta = new Bundle() {
69      val storeMaskIn = Vec(StorePipelineWidth, Flipped(Valid(new StoreMaskBundle))) // from store_s0, store mask, send to sq from rs
70      val storeAddrIn = Vec(StorePipelineWidth, Flipped(Valid(new LsPipelineBundle))) // from store_s1
71      val storeAddrInRe = Vec(StorePipelineWidth, Input(new LsPipelineBundle())) // from store_s2
72      val vecStoreAddrIn = Vec(StorePipelineWidth, Flipped(Valid(new LsPipelineBundle)))
73    }
74    val std = new Bundle() {
75      val storeDataIn = Vec(StorePipelineWidth, Flipped(Valid(new MemExuOutput))) // from store_s0, store data, send to sq from rs
76    }
77    val ldout = Vec(LoadPipelineWidth, DecoupledIO(new MemExuOutput))
78    val ld_raw_data = Vec(LoadPipelineWidth, Output(new LoadDataFromLQBundle))
79    val replay = Vec(LoadPipelineWidth, Decoupled(new LsPipelineBundle))
80    val sbuffer = Vec(EnsbufferWidth, Decoupled(new DCacheWordReqWithVaddrAndPfFlag))
81    val forward = Vec(LoadPipelineWidth, Flipped(new PipeLoadForwardQueryIO))
82    val rob = Flipped(new RobLsqIO)
83    val rollback = Output(Valid(new Redirect))
84    val release = Flipped(Valid(new Release))
85    val refill = Flipped(Valid(new Refill))
86    val tl_d_channel  = Input(new DcacheToLduForwardIO)
87    val uncacheOutstanding = Input(Bool())
88    val uncache = new UncacheWordIO
89    val mmioStout = DecoupledIO(new MemExuOutput) // writeback uncached store
90    val sqEmpty = Output(Bool())
91    val lq_rep_full = Output(Bool())
92    val sqFull = Output(Bool())
93    val lqFull = Output(Bool())
94    val sqCancelCnt = Output(UInt(log2Up(StoreQueueSize+1).W))
95    val lqCancelCnt = Output(UInt(log2Up(VirtualLoadQueueSize+1).W))
96    val lqDeq = Output(UInt(log2Up(CommitWidth + 1).W))
97    val sqDeq = Output(UInt(log2Ceil(EnsbufferWidth + 1).W))
98    val lqCanAccept = Output(Bool())
99    val sqCanAccept = Output(Bool())
100    val lqDeqPtr = Output(new LqPtr)
101    val sqDeqPtr = Output(new SqPtr)
102    val exceptionAddr = new ExceptionAddrIO
103    val trigger = Vec(LoadPipelineWidth, new LqTriggerIO)
104    val issuePtrExt = Output(new SqPtr)
105    val l2_hint = Input(Valid(new L2ToL1Hint()))
106    val force_write = Output(Bool())
107    val lqEmpty = Output(Bool())
108
109    // vector
110    val vecWriteback = Flipped(ValidIO(new MemExuOutput(isVector = true)))
111    val vecStoreRetire = Flipped(ValidIO(new SqPtr))
112
113    // top-down
114    val debugTopDown = new LoadQueueTopDownIO
115  })
116
117  val loadQueue = Module(new LoadQueue)
118  val storeQueue = Module(new StoreQueue)
119
120  storeQueue.io.hartId := io.hartId
121  storeQueue.io.uncacheOutstanding := io.uncacheOutstanding
122
123
124  dontTouch(loadQueue.io.tlbReplayDelayCycleCtrl)
125  // Todo: imm
126  val tlbReplayDelayCycleCtrl = WireInit(VecInit(Seq(14.U(ReSelectLen.W), 0.U(ReSelectLen.W), 125.U(ReSelectLen.W), 0.U(ReSelectLen.W))))
127  loadQueue.io.tlbReplayDelayCycleCtrl := tlbReplayDelayCycleCtrl
128
129  // io.enq logic
130  // LSQ: send out canAccept when both load queue and store queue are ready
131  // Dispatch: send instructions to LSQ only when they are ready
132  io.enq.canAccept := loadQueue.io.enq.canAccept && storeQueue.io.enq.canAccept
133  io.lqCanAccept := loadQueue.io.enq.canAccept
134  io.sqCanAccept := storeQueue.io.enq.canAccept
135  loadQueue.io.enq.sqCanAccept := storeQueue.io.enq.canAccept
136  storeQueue.io.enq.lqCanAccept := loadQueue.io.enq.canAccept
137  io.lqDeqPtr := loadQueue.io.lqDeqPtr
138  io.sqDeqPtr := storeQueue.io.sqDeqPtr
139  for (i <- io.enq.req.indices) {
140    loadQueue.io.enq.needAlloc(i)      := io.enq.needAlloc(i)(0)
141    loadQueue.io.enq.req(i).valid      := io.enq.needAlloc(i)(0) && io.enq.req(i).valid
142    loadQueue.io.enq.req(i).bits       := io.enq.req(i).bits
143    loadQueue.io.enq.req(i).bits.sqIdx := storeQueue.io.enq.resp(i)
144
145    storeQueue.io.enq.needAlloc(i)      := io.enq.needAlloc(i)(1)
146    storeQueue.io.enq.req(i).valid      := io.enq.needAlloc(i)(1) && io.enq.req(i).valid
147    storeQueue.io.enq.req(i).bits       := io.enq.req(i).bits
148    storeQueue.io.enq.req(i).bits       := io.enq.req(i).bits
149    storeQueue.io.enq.req(i).bits.lqIdx := loadQueue.io.enq.resp(i)
150
151    io.enq.resp(i).lqIdx := loadQueue.io.enq.resp(i)
152    io.enq.resp(i).sqIdx := storeQueue.io.enq.resp(i)
153  }
154
155  // store queue wiring
156  storeQueue.io.brqRedirect <> io.brqRedirect
157  storeQueue.io.storeAddrIn <> io.sta.storeAddrIn // from store_s1
158  storeQueue.io.storeAddrInRe <> io.sta.storeAddrInRe // from store_s2
159  storeQueue.io.storeDataIn <> io.std.storeDataIn // from store_s0
160  storeQueue.io.storeMaskIn <> io.sta.storeMaskIn // from store_s0
161  storeQueue.io.sbuffer     <> io.sbuffer
162  storeQueue.io.mmioStout   <> io.mmioStout
163  storeQueue.io.rob         <> io.rob
164  storeQueue.io.exceptionAddr.isStore := DontCare
165  storeQueue.io.sqCancelCnt <> io.sqCancelCnt
166  storeQueue.io.sqDeq       <> io.sqDeq
167  storeQueue.io.sqEmpty     <> io.sqEmpty
168  storeQueue.io.sqFull      <> io.sqFull
169  storeQueue.io.forward     <> io.forward // overlap forwardMask & forwardData, DO NOT CHANGE SEQUENCE
170  storeQueue.io.force_write <> io.force_write
171  storeQueue.io.vecStoreRetire <> io.vecStoreRetire
172
173  /* <------- DANGEROUS: Don't change sequence here ! -------> */
174
175  //  load queue wiring
176  loadQueue.io.redirect            <> io.brqRedirect
177  loadQueue.io.ldu                 <> io.ldu
178  loadQueue.io.ldout               <> io.ldout
179  loadQueue.io.ld_raw_data         <> io.ld_raw_data
180  loadQueue.io.rob                 <> io.rob
181  loadQueue.io.rollback            <> io.rollback
182  loadQueue.io.replay              <> io.replay
183  loadQueue.io.refill              <> io.refill
184  loadQueue.io.tl_d_channel        <> io.tl_d_channel
185  loadQueue.io.release             <> io.release
186  loadQueue.io.trigger             <> io.trigger
187  loadQueue.io.exceptionAddr.isStore := DontCare
188  loadQueue.io.lqCancelCnt         <> io.lqCancelCnt
189  loadQueue.io.sq.stAddrReadySqPtr <> storeQueue.io.stAddrReadySqPtr
190  loadQueue.io.sq.stAddrReadyVec   <> storeQueue.io.stAddrReadyVec
191  loadQueue.io.sq.stDataReadySqPtr <> storeQueue.io.stDataReadySqPtr
192  loadQueue.io.sq.stDataReadyVec   <> storeQueue.io.stDataReadyVec
193  loadQueue.io.sq.stIssuePtr       <> storeQueue.io.stIssuePtr
194  loadQueue.io.sq.sqEmpty          <> storeQueue.io.sqEmpty
195  loadQueue.io.sta.storeAddrIn     <> io.sta.storeAddrIn // store_s1
196  loadQueue.io.sta.vecStoreAddrIn  <> io.sta.vecStoreAddrIn // store_s1
197  loadQueue.io.std.storeDataIn     <> io.std.storeDataIn // store_s0
198  loadQueue.io.lqFull              <> io.lqFull
199  loadQueue.io.lq_rep_full         <> io.lq_rep_full
200  loadQueue.io.lqDeq               <> io.lqDeq
201  loadQueue.io.l2_hint             <> io.l2_hint
202  loadQueue.io.lqEmpty             <> io.lqEmpty
203  loadQueue.io.vecWriteback        <> io.vecWriteback
204
205  // rob commits for lsq is delayed for two cycles, which causes the delayed update for deqPtr in lq/sq
206  // s0: commit
207  // s1:               exception find
208  // s2:               exception triggered
209  // s3: ptr updated & new address
210  // address will be used at the next cycle after exception is triggered
211  io.exceptionAddr.vaddr := Mux(RegNext(io.exceptionAddr.isStore), storeQueue.io.exceptionAddr.vaddr, loadQueue.io.exceptionAddr.vaddr)
212  io.issuePtrExt := storeQueue.io.stAddrReadySqPtr
213
214  // naive uncache arbiter
215  val s_idle :: s_load :: s_store :: Nil = Enum(3)
216  val pendingstate = RegInit(s_idle)
217
218  switch(pendingstate){
219    is(s_idle){
220      when(io.uncache.req.fire && !io.uncacheOutstanding){
221        pendingstate := Mux(loadQueue.io.uncache.req.valid, s_load,
222                          Mux(io.uncacheOutstanding, s_idle, s_store))
223      }
224    }
225    is(s_load){
226      when(io.uncache.resp.fire){
227        pendingstate := s_idle
228      }
229    }
230    is(s_store){
231      when(io.uncache.resp.fire){
232        pendingstate := s_idle
233      }
234    }
235  }
236
237  loadQueue.io.uncache := DontCare
238  storeQueue.io.uncache := DontCare
239  loadQueue.io.uncache.req.ready := false.B
240  storeQueue.io.uncache.req.ready := false.B
241  loadQueue.io.uncache.resp.valid := false.B
242  storeQueue.io.uncache.resp.valid := false.B
243  when(loadQueue.io.uncache.req.valid){
244    io.uncache.req <> loadQueue.io.uncache.req
245  }.otherwise{
246    io.uncache.req <> storeQueue.io.uncache.req
247  }
248  when (io.uncacheOutstanding) {
249    io.uncache.resp <> loadQueue.io.uncache.resp
250  } .otherwise {
251    when(pendingstate === s_load){
252      io.uncache.resp <> loadQueue.io.uncache.resp
253    }.otherwise{
254      io.uncache.resp <> storeQueue.io.uncache.resp
255    }
256  }
257
258  loadQueue.io.debugTopDown <> io.debugTopDown
259
260  assert(!(loadQueue.io.uncache.req.valid && storeQueue.io.uncache.req.valid))
261  assert(!(loadQueue.io.uncache.resp.valid && storeQueue.io.uncache.resp.valid))
262  when (!io.uncacheOutstanding) {
263    assert(!((loadQueue.io.uncache.resp.valid || storeQueue.io.uncache.resp.valid) && pendingstate === s_idle))
264  }
265
266
267  val perfEvents = Seq(loadQueue, storeQueue).flatMap(_.getPerfEvents)
268  generatePerfEvent()
269}
270
271class LsqEnqCtrl(implicit p: Parameters) extends XSModule {
272  val io = IO(new Bundle {
273    val redirect = Flipped(ValidIO(new Redirect))
274    // to dispatch
275    val enq = new LsqEnqIO
276    // from `memBlock.io.lqDeq
277    val lcommit = Input(UInt(log2Up(CommitWidth + 1).W))
278    // from `memBlock.io.sqDeq`
279    val scommit = Input(UInt(log2Ceil(EnsbufferWidth + 1).W))
280    // from/tp lsq
281    val lqCancelCnt = Input(UInt(log2Up(VirtualLoadQueueSize + 1).W))
282    val sqCancelCnt = Input(UInt(log2Up(StoreQueueSize + 1).W))
283    val enqLsq = Flipped(new LsqEnqIO)
284  })
285
286  val lqPtr = RegInit(0.U.asTypeOf(new LqPtr))
287  val sqPtr = RegInit(0.U.asTypeOf(new SqPtr))
288  val lqCounter = RegInit(VirtualLoadQueueSize.U(log2Up(VirtualLoadQueueSize + 1).W))
289  val sqCounter = RegInit(StoreQueueSize.U(log2Up(StoreQueueSize + 1).W))
290  val canAccept = RegInit(false.B)
291
292  val loadEnqVec = io.enq.req.zip(io.enq.needAlloc).map(x => x._1.valid && x._2(0))
293  val storeEnqVec = io.enq.req.zip(io.enq.needAlloc).map(x => x._1.valid && x._2(1))
294  val loadEnqNumber = PopCount(loadEnqVec)
295  val storeEnqNumber = PopCount(storeEnqVec)
296  val isLastUopVec = io.enq.req.map(_.bits.lastUop)
297  val lqAllocNumber = PopCount(loadEnqVec.zip(isLastUopVec).map(x => x._1 && x._2))
298  val sqAllocNumber = PopCount(storeEnqVec.zip(isLastUopVec).map(x => x._1 && x._2))
299
300  // How to update ptr and counter:
301  // (1) by default, updated according to enq/commit
302  // (2) when redirect and dispatch queue is empty, update according to lsq
303  val t1_redirect = RegNext(io.redirect.valid)
304  val t2_redirect = RegNext(t1_redirect)
305  val t2_update = t2_redirect && !VecInit(io.enq.needAlloc.map(_.orR)).asUInt.orR
306  val t3_update = RegNext(t2_update)
307  val t3_lqCancelCnt = RegNext(io.lqCancelCnt)
308  val t3_sqCancelCnt = RegNext(io.sqCancelCnt)
309  when (t3_update) {
310    lqPtr := lqPtr - t3_lqCancelCnt
311    lqCounter := lqCounter + io.lcommit + t3_lqCancelCnt
312    sqPtr := sqPtr - t3_sqCancelCnt
313    sqCounter := sqCounter + io.scommit + t3_sqCancelCnt
314  }.elsewhen (!io.redirect.valid && io.enq.canAccept) {
315    lqPtr := lqPtr + lqAllocNumber
316    lqCounter := lqCounter + io.lcommit - lqAllocNumber
317    sqPtr := sqPtr + sqAllocNumber
318    sqCounter := sqCounter + io.scommit - sqAllocNumber
319  }.otherwise {
320    lqCounter := lqCounter + io.lcommit
321    sqCounter := sqCounter + io.scommit
322  }
323
324
325  val maxAllocate = backendParams.LdExuCnt max backendParams.StaExuCnt
326  val ldCanAccept = lqCounter >= lqAllocNumber +& maxAllocate.U
327  val sqCanAccept = sqCounter >= sqAllocNumber +& maxAllocate.U
328  // It is possible that t3_update and enq are true at the same clock cycle.
329  // For example, if redirect.valid lasts more than one clock cycle,
330  // after the last redirect, new instructions may enter but previously redirect
331  // has not been resolved (updated according to the cancel count from LSQ).
332  // To solve the issue easily, we block enqueue when t3_update, which is RegNext(t2_update).
333  io.enq.canAccept := RegNext(ldCanAccept && sqCanAccept && !t2_update)
334  val lqOffset = Wire(Vec(io.enq.resp.length, UInt(log2Up(maxAllocate + 1).W)))
335  val sqOffset = Wire(Vec(io.enq.resp.length, UInt(log2Up(maxAllocate + 1).W)))
336  for ((resp, i) <- io.enq.resp.zipWithIndex) {
337    lqOffset(i) := PopCount(io.enq.needAlloc.zip(isLastUopVec).take(i).map(x => x._1(0) && x._2))
338    resp.lqIdx := lqPtr + lqOffset(i)
339    sqOffset(i) := PopCount(io.enq.needAlloc.zip(isLastUopVec).take(i).map(x => x._1(1) && x._2))
340    resp.sqIdx := sqPtr + sqOffset(i)
341  }
342
343  io.enqLsq.needAlloc := RegNext(VecInit(io.enq.needAlloc.zip(io.enq.req).map(x => x._1 & Fill(2, x._2.bits.lastUop))))
344  io.enqLsq.req.zip(io.enq.req).zip(io.enq.resp).foreach{ case ((toLsq, enq), resp) =>
345    val do_enq = enq.valid && !io.redirect.valid && io.enq.canAccept && enq.bits.lastUop
346    toLsq.valid := RegNext(do_enq)
347    toLsq.bits := RegEnable(enq.bits, do_enq)
348    toLsq.bits.lqIdx := RegEnable(resp.lqIdx, do_enq)
349    toLsq.bits.sqIdx := RegEnable(resp.sqIdx, do_enq)
350  }
351
352}