xref: /XiangShan/src/main/scala/xiangshan/mem/lsqueue/LSQWrapper.scala (revision 0466583513e4c1ddbbb566b866b8963635acb20f)
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 chipsalliance.rocketchip.config.Parameters
20import chisel3._
21import chisel3.util._
22import utils._
23import utility._
24import xiangshan._
25import xiangshan.cache._
26import xiangshan.cache.{DCacheWordIO, DCacheLineIO, MemoryOpConstants}
27import xiangshan.cache.mmu.{TlbRequestIO}
28import xiangshan.mem._
29import xiangshan.backend.rob.RobLsqIO
30
31class ExceptionAddrIO(implicit p: Parameters) extends XSBundle {
32  val isStore = Input(Bool())
33  val vaddr = Output(UInt(VAddrBits.W))
34}
35
36class FwdEntry extends Bundle {
37  val validFast = Bool() // validFast is generated the same cycle with query
38  val valid = Bool() // valid is generated 1 cycle after query request
39  val data = UInt(8.W) // data is generated 1 cycle after query request
40}
41
42// inflight miss block reqs
43class InflightBlockInfo(implicit p: Parameters) extends XSBundle {
44  val block_addr = UInt(PAddrBits.W)
45  val valid = Bool()
46}
47
48class LsqEnqIO(implicit p: Parameters) extends XSBundle {
49  val canAccept = Output(Bool())
50  val needAlloc = Vec(exuParameters.LsExuCnt, Input(UInt(2.W)))
51  val req       = Vec(exuParameters.LsExuCnt, Flipped(ValidIO(new MicroOp)))
52  val resp      = Vec(exuParameters.LsExuCnt, Output(new LSIdx))
53}
54
55// Load / Store Queue Wrapper for XiangShan Out of Order LSU
56class LsqWrapper(implicit p: Parameters) extends XSModule with HasDCacheParameters with HasPerfEvents {
57  val io = IO(new Bundle() {
58    val hartId = Input(UInt(8.W))
59    val brqRedirect = Flipped(ValidIO(new Redirect))
60    val enq = new LsqEnqIO
61    val ldu = new Bundle() {
62        val stld_nuke_query = Vec(LoadPipelineWidth, Flipped(new LoadNukeQueryIO)) // from load_s2
63        val ldld_nuke_query = Vec(LoadPipelineWidth, Flipped(new LoadNukeQueryIO)) // from load_s2
64        val ldin = Vec(LoadPipelineWidth, Flipped(Decoupled(new LqWriteBundle))) // from load_s3
65    }
66    val sta = new Bundle() {
67      val storeMaskIn = Vec(StorePipelineWidth, Flipped(Valid(new StoreMaskBundle))) // from store_s0, store mask, send to sq from rs
68      val storeAddrIn = Vec(StorePipelineWidth, Flipped(Valid(new LsPipelineBundle))) // from store_s1
69      val storeAddrInRe = Vec(StorePipelineWidth, Input(new LsPipelineBundle())) // from store_s2
70    }
71    val std = new Bundle() {
72      val storeDataIn = Vec(StorePipelineWidth, Flipped(Valid(new ExuOutput))) // from store_s0, store data, send to sq from rs
73    }
74    val ldout = Vec(LoadPipelineWidth, DecoupledIO(new ExuOutput))
75    val ld_raw_data = Vec(LoadPipelineWidth, Output(new LoadDataFromLQBundle))
76    val replay = Vec(LoadPipelineWidth, Decoupled(new LsPipelineBundle))
77    val sbuffer = Vec(EnsbufferWidth, Decoupled(new DCacheWordReqWithVaddr))
78    val forward = Vec(LoadPipelineWidth, Flipped(new PipeLoadForwardQueryIO))
79    val rob = Flipped(new RobLsqIO)
80    val rollback = Output(Valid(new Redirect))
81    val release = Flipped(Valid(new Release))
82    val refill = Flipped(Valid(new Refill))
83    val uncacheOutstanding = Input(Bool())
84    val uncache = new UncacheWordIO
85    val mmioStout = DecoupledIO(new ExuOutput) // writeback uncached store
86    val sqEmpty = Output(Bool())
87    val lq_rep_full = Output(Bool())
88    val sqFull = Output(Bool())
89    val lqFull = Output(Bool())
90    val sqCancelCnt = Output(UInt(log2Up(StoreQueueSize+1).W))
91    val lqCancelCnt = Output(UInt(log2Up(VirtualLoadQueueSize+1).W))
92    val lqDeq = Output(UInt(log2Up(CommitWidth + 1).W))
93    val sqDeq = Output(UInt(log2Ceil(EnsbufferWidth + 1).W))
94    val lqCanAccept = Output(Bool())
95    val sqCanAccept = Output(Bool())
96    val exceptionAddr = new ExceptionAddrIO
97    val trigger = Vec(LoadPipelineWidth, new LqTriggerIO)
98    val issuePtrExt = Output(new SqPtr)
99    val l2_hint = Input(Valid(new L2ToL1Hint()))
100    val force_write = Output(Bool())
101  })
102
103  val loadQueue = Module(new LoadQueue)
104  val storeQueue = Module(new StoreQueue)
105
106  storeQueue.io.hartId := io.hartId
107  storeQueue.io.uncacheOutstanding := io.uncacheOutstanding
108
109
110  dontTouch(loadQueue.io.tlbReplayDelayCycleCtrl)
111  val tlbReplayDelayCycleCtrl = WireInit(VecInit(Seq(14.U(ReSelectLen.W), 0.U(ReSelectLen.W), 125.U(ReSelectLen.W), 0.U(ReSelectLen.W))))
112  loadQueue.io.tlbReplayDelayCycleCtrl := tlbReplayDelayCycleCtrl
113
114  // io.enq logic
115  // LSQ: send out canAccept when both load queue and store queue are ready
116  // Dispatch: send instructions to LSQ only when they are ready
117  io.enq.canAccept := loadQueue.io.enq.canAccept && storeQueue.io.enq.canAccept
118  io.lqCanAccept := loadQueue.io.enq.canAccept
119  io.sqCanAccept := storeQueue.io.enq.canAccept
120  loadQueue.io.enq.sqCanAccept := storeQueue.io.enq.canAccept
121  storeQueue.io.enq.lqCanAccept := loadQueue.io.enq.canAccept
122  for (i <- io.enq.req.indices) {
123    loadQueue.io.enq.needAlloc(i)      := io.enq.needAlloc(i)(0)
124    loadQueue.io.enq.req(i).valid      := io.enq.needAlloc(i)(0) && io.enq.req(i).valid
125    loadQueue.io.enq.req(i).bits       := io.enq.req(i).bits
126    loadQueue.io.enq.req(i).bits.sqIdx := storeQueue.io.enq.resp(i)
127
128    storeQueue.io.enq.needAlloc(i)      := io.enq.needAlloc(i)(1)
129    storeQueue.io.enq.req(i).valid      := io.enq.needAlloc(i)(1) && io.enq.req(i).valid
130    storeQueue.io.enq.req(i).bits       := io.enq.req(i).bits
131    storeQueue.io.enq.req(i).bits       := io.enq.req(i).bits
132    storeQueue.io.enq.req(i).bits.lqIdx := loadQueue.io.enq.resp(i)
133
134    io.enq.resp(i).lqIdx := loadQueue.io.enq.resp(i)
135    io.enq.resp(i).sqIdx := storeQueue.io.enq.resp(i)
136  }
137
138  // store queue wiring
139  storeQueue.io.brqRedirect <> io.brqRedirect
140  storeQueue.io.storeAddrIn <> io.sta.storeAddrIn // from store_s1
141  storeQueue.io.storeAddrInRe <> io.sta.storeAddrInRe // from store_s2
142  storeQueue.io.storeDataIn <> io.std.storeDataIn // from store_s0
143  storeQueue.io.storeMaskIn <> io.sta.storeMaskIn // from store_s0
144  storeQueue.io.sbuffer     <> io.sbuffer
145  storeQueue.io.mmioStout   <> io.mmioStout
146  storeQueue.io.rob         <> io.rob
147  storeQueue.io.exceptionAddr.isStore := DontCare
148  storeQueue.io.sqCancelCnt <> io.sqCancelCnt
149  storeQueue.io.sqDeq       <> io.sqDeq
150  storeQueue.io.sqEmpty     <> io.sqEmpty
151  storeQueue.io.sqFull      <> io.sqFull
152  storeQueue.io.forward     <> io.forward // overlap forwardMask & forwardData, DO NOT CHANGE SEQUENCE
153  storeQueue.io.force_write <> io.force_write
154
155  /* <------- DANGEROUS: Don't change sequence here ! -------> */
156
157  //  load queue wiring
158  loadQueue.io.redirect            <> io.brqRedirect
159  loadQueue.io.ldu                 <> io.ldu
160  loadQueue.io.ldout               <> io.ldout
161  loadQueue.io.ld_raw_data         <> io.ld_raw_data
162  loadQueue.io.rob                 <> io.rob
163  loadQueue.io.rollback            <> io.rollback
164  loadQueue.io.replay              <> io.replay
165  loadQueue.io.refill              <> io.refill
166  loadQueue.io.release             <> io.release
167  loadQueue.io.trigger             <> io.trigger
168  loadQueue.io.exceptionAddr.isStore := DontCare
169  loadQueue.io.lqCancelCnt         <> io.lqCancelCnt
170  loadQueue.io.sq.stAddrReadySqPtr <> storeQueue.io.stAddrReadySqPtr
171  loadQueue.io.sq.stAddrReadyVec   <> storeQueue.io.stAddrReadyVec
172  loadQueue.io.sq.stDataReadySqPtr <> storeQueue.io.stDataReadySqPtr
173  loadQueue.io.sq.stDataReadyVec   <> storeQueue.io.stDataReadyVec
174  loadQueue.io.sq.stIssuePtr       <> storeQueue.io.stIssuePtr
175  loadQueue.io.sq.sqEmpty          <> storeQueue.io.sqEmpty
176  loadQueue.io.sta.storeAddrIn     <> io.sta.storeAddrIn // store_s1
177  loadQueue.io.std.storeDataIn     <> io.std.storeDataIn // store_s0
178  loadQueue.io.lqFull              <> io.lqFull
179  loadQueue.io.lq_rep_full         <> io.lq_rep_full
180  loadQueue.io.lqDeq               <> io.lqDeq
181  loadQueue.io.l2_hint             <> io.l2_hint
182
183  // rob commits for lsq is delayed for two cycles, which causes the delayed update for deqPtr in lq/sq
184  // s0: commit
185  // s1:               exception find
186  // s2:               exception triggered
187  // s3: ptr updated & new address
188  // address will be used at the next cycle after exception is triggered
189  io.exceptionAddr.vaddr := Mux(RegNext(io.exceptionAddr.isStore), storeQueue.io.exceptionAddr.vaddr, loadQueue.io.exceptionAddr.vaddr)
190  io.issuePtrExt := storeQueue.io.stAddrReadySqPtr
191
192  // naive uncache arbiter
193  val s_idle :: s_load :: s_store :: Nil = Enum(3)
194  val pendingstate = RegInit(s_idle)
195
196  switch(pendingstate){
197    is(s_idle){
198      when(io.uncache.req.fire() && !io.uncacheOutstanding){
199        pendingstate := Mux(loadQueue.io.uncache.req.valid, s_load,
200                          Mux(io.uncacheOutstanding, s_idle, s_store))
201      }
202    }
203    is(s_load){
204      when(io.uncache.resp.fire()){
205        pendingstate := s_idle
206      }
207    }
208    is(s_store){
209      when(io.uncache.resp.fire()){
210        pendingstate := s_idle
211      }
212    }
213  }
214
215  loadQueue.io.uncache := DontCare
216  storeQueue.io.uncache := DontCare
217  loadQueue.io.uncache.resp.valid := false.B
218  storeQueue.io.uncache.resp.valid := false.B
219  when(loadQueue.io.uncache.req.valid){
220    io.uncache.req <> loadQueue.io.uncache.req
221  }.otherwise{
222    io.uncache.req <> storeQueue.io.uncache.req
223  }
224  when (io.uncacheOutstanding) {
225    io.uncache.resp <> loadQueue.io.uncache.resp
226  } .otherwise {
227    when(pendingstate === s_load){
228      io.uncache.resp <> loadQueue.io.uncache.resp
229    }.otherwise{
230      io.uncache.resp <> storeQueue.io.uncache.resp
231    }
232  }
233
234
235  assert(!(loadQueue.io.uncache.req.valid && storeQueue.io.uncache.req.valid))
236  assert(!(loadQueue.io.uncache.resp.valid && storeQueue.io.uncache.resp.valid))
237  when (!io.uncacheOutstanding) {
238    assert(!((loadQueue.io.uncache.resp.valid || storeQueue.io.uncache.resp.valid) && pendingstate === s_idle))
239  }
240
241
242  val perfEvents = Seq(loadQueue, storeQueue).flatMap(_.getPerfEvents)
243  generatePerfEvent()
244}
245
246class LsqEnqCtrl(implicit p: Parameters) extends XSModule {
247  val io = IO(new Bundle {
248    val redirect = Flipped(ValidIO(new Redirect))
249    // to dispatch
250    val enq = new LsqEnqIO
251    // from `memBlock.io.lqDeq
252    val lcommit = Input(UInt(log2Up(CommitWidth + 1).W))
253    // from `memBlock.io.sqDeq`
254    val scommit = Input(UInt(log2Ceil(EnsbufferWidth + 1).W))
255    // from/tp lsq
256    val lqCancelCnt = Input(UInt(log2Up(VirtualLoadQueueSize + 1).W))
257    val sqCancelCnt = Input(UInt(log2Up(StoreQueueSize + 1).W))
258    val enqLsq = Flipped(new LsqEnqIO)
259  })
260
261  val lqPtr = RegInit(0.U.asTypeOf(new LqPtr))
262  val sqPtr = RegInit(0.U.asTypeOf(new SqPtr))
263  val lqCounter = RegInit(VirtualLoadQueueSize.U(log2Up(VirtualLoadQueueSize + 1).W))
264  val sqCounter = RegInit(StoreQueueSize.U(log2Up(StoreQueueSize + 1).W))
265  val canAccept = RegInit(false.B)
266
267  val loadEnqNumber = PopCount(io.enq.req.zip(io.enq.needAlloc).map(x => x._1.valid && x._2(0)))
268  val storeEnqNumber = PopCount(io.enq.req.zip(io.enq.needAlloc).map(x => x._1.valid && x._2(1)))
269
270  // How to update ptr and counter:
271  // (1) by default, updated according to enq/commit
272  // (2) when redirect and dispatch queue is empty, update according to lsq
273  val t1_redirect = RegNext(io.redirect.valid)
274  val t2_redirect = RegNext(t1_redirect)
275  val t2_update = t2_redirect && !VecInit(io.enq.needAlloc.map(_.orR)).asUInt.orR
276  val t3_update = RegNext(t2_update)
277  val t3_lqCancelCnt = RegNext(io.lqCancelCnt)
278  val t3_sqCancelCnt = RegNext(io.sqCancelCnt)
279  when (t3_update) {
280    lqPtr := lqPtr - t3_lqCancelCnt
281    lqCounter := lqCounter + io.lcommit + t3_lqCancelCnt
282    sqPtr := sqPtr - t3_sqCancelCnt
283    sqCounter := sqCounter + io.scommit + t3_sqCancelCnt
284  }.elsewhen (!io.redirect.valid && io.enq.canAccept) {
285    lqPtr := lqPtr + loadEnqNumber
286    lqCounter := lqCounter + io.lcommit - loadEnqNumber
287    sqPtr := sqPtr + storeEnqNumber
288    sqCounter := sqCounter + io.scommit - storeEnqNumber
289  }.otherwise {
290    lqCounter := lqCounter + io.lcommit
291    sqCounter := sqCounter + io.scommit
292  }
293
294
295  val maxAllocate = Seq(exuParameters.LduCnt, exuParameters.StuCnt).max
296  val ldCanAccept = lqCounter >= loadEnqNumber +& maxAllocate.U
297  val sqCanAccept = sqCounter >= storeEnqNumber +& maxAllocate.U
298  // It is possible that t3_update and enq are true at the same clock cycle.
299  // For example, if redirect.valid lasts more than one clock cycle,
300  // after the last redirect, new instructions may enter but previously redirect
301  // has not been resolved (updated according to the cancel count from LSQ).
302  // To solve the issue easily, we block enqueue when t3_update, which is RegNext(t2_update).
303  io.enq.canAccept := RegNext(ldCanAccept && sqCanAccept && !t2_update)
304  val lqOffset = Wire(Vec(io.enq.resp.length, UInt(log2Up(maxAllocate + 1).W)))
305  val sqOffset = Wire(Vec(io.enq.resp.length, UInt(log2Up(maxAllocate + 1).W)))
306  for ((resp, i) <- io.enq.resp.zipWithIndex) {
307    lqOffset(i) := PopCount(io.enq.needAlloc.take(i).map(a => a(0)))
308    resp.lqIdx := lqPtr + lqOffset(i)
309    sqOffset(i) := PopCount(io.enq.needAlloc.take(i).map(a => a(1)))
310    resp.sqIdx := sqPtr + sqOffset(i)
311  }
312
313  io.enqLsq.needAlloc := RegNext(io.enq.needAlloc)
314  io.enqLsq.req.zip(io.enq.req).zip(io.enq.resp).foreach{ case ((toLsq, enq), resp) =>
315    val do_enq = enq.valid && !io.redirect.valid && io.enq.canAccept
316    toLsq.valid := RegNext(do_enq)
317    toLsq.bits := RegEnable(enq.bits, do_enq)
318    toLsq.bits.lqIdx := RegEnable(resp.lqIdx, do_enq)
319    toLsq.bits.sqIdx := RegEnable(resp.sqIdx, do_enq)
320  }
321
322}