xref: /XiangShan/src/main/scala/xiangshan/mem/lsqueue/LSQWrapper.scala (revision 9473e04d5cab97eaf63add958b2392eec3d876a2)
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 LsqWrappper(implicit p: Parameters) extends XSModule with HasDCacheParameters with HasPerfEvents {
57  val io = IO(new Bundle() {
58    val hartId = Input(UInt(8.W))
59    val enq = new LsqEnqIO
60    val brqRedirect = Flipped(ValidIO(new Redirect))
61    val loadPaddrIn = Vec(LoadPipelineWidth, Flipped(Valid(new LqPaddrWriteBundle)))
62    val loadVaddrIn = Vec(LoadPipelineWidth, Flipped(Valid(new LqVaddrWriteBundle)))
63    val replayFast = Vec(LoadPipelineWidth, Flipped(new LoadToLsqFastIO))
64    val replaySlow = Vec(LoadPipelineWidth, Flipped(new LoadToLsqSlowIO))
65    val loadOut = Vec(LoadPipelineWidth, Decoupled(new LsPipelineBundle))
66    val loadIn = Vec(LoadPipelineWidth, Flipped(Valid(new LqWriteBundle)))
67    val storeIn = Vec(StorePipelineWidth, Flipped(Valid(new LsPipelineBundle)))
68    val storeInRe = Vec(StorePipelineWidth, Input(new LsPipelineBundle()))
69    val storeDataIn = Vec(StorePipelineWidth, Flipped(Valid(new ExuOutput))) // store data, send to sq from rs
70    val storeMaskIn = Vec(StorePipelineWidth, Flipped(Valid(new StoreMaskBundle))) // store mask, send to sq from rs
71    val s2_load_data_forwarded = Vec(LoadPipelineWidth, Input(Bool()))
72    val s3_delayed_load_error = Vec(LoadPipelineWidth, Input(Bool()))
73    val s2_dcache_require_replay = Vec(LoadPipelineWidth, Input(Bool()))
74    val s3_replay_from_fetch = Vec(LoadPipelineWidth, Input(Bool()))
75    val sbuffer = Vec(EnsbufferWidth, Decoupled(new DCacheWordReqWithVaddr))
76    val ldout = Vec(LoadPipelineWidth, DecoupledIO(new ExuOutput)) // writeback int load
77    val ldRawDataOut = Vec(LoadPipelineWidth, Output(new LoadDataFromLQBundle))
78    val uncacheOutstanding = Input(Bool())
79    val mmioStout = DecoupledIO(new ExuOutput) // writeback uncached store
80    val forward = Vec(LoadPipelineWidth, Flipped(new PipeLoadForwardQueryIO))
81    val loadViolationQuery = Vec(LoadPipelineWidth, Flipped(new LoadViolationQueryIO))
82    val rob = Flipped(new RobLsqIO)
83    val rollback = Output(Valid(new Redirect))
84    val refill = Flipped(ValidIO(new Refill))
85    val release = Flipped(ValidIO(new Release))
86    val uncache = new UncacheWordIO
87    val exceptionAddr = new ExceptionAddrIO
88    val sqempty = Output(Bool())
89    val issuePtrExt = Output(new SqPtr)
90    val sqFull = Output(Bool())
91    val lqFull = Output(Bool())
92    val lqCancelCnt = Output(UInt(log2Up(LoadQueueSize + 1).W))
93    val sqCancelCnt = Output(UInt(log2Up(StoreQueueSize + 1).W))
94    val sqDeq = Output(UInt(log2Ceil(EnsbufferWidth + 1).W))
95    val trigger = Vec(LoadPipelineWidth, new LqTriggerIO)
96  })
97
98  val loadQueue = Module(new LoadQueue)
99  val storeQueue = Module(new StoreQueue)
100
101  storeQueue.io.hartId := io.hartId
102  storeQueue.io.uncacheOutstanding := io.uncacheOutstanding
103
104  loadQueue.io.storeDataValidVec := storeQueue.io.storeDataValidVec
105
106  dontTouch(loadQueue.io.tlbReplayDelayCycleCtrl)
107  val tlbReplayDelayCycleCtrl = WireInit(VecInit(Seq(11.U(ReSelectLen.W), 50.U(ReSelectLen.W), 30.U(ReSelectLen.W), 10.U(ReSelectLen.W))))
108  loadQueue.io.tlbReplayDelayCycleCtrl := tlbReplayDelayCycleCtrl
109
110  // io.enq logic
111  // LSQ: send out canAccept when both load queue and store queue are ready
112  // Dispatch: send instructions to LSQ only when they are ready
113  io.enq.canAccept := loadQueue.io.enq.canAccept && storeQueue.io.enq.canAccept
114  loadQueue.io.enq.sqCanAccept := storeQueue.io.enq.canAccept
115  storeQueue.io.enq.lqCanAccept := loadQueue.io.enq.canAccept
116  for (i <- io.enq.req.indices) {
117    loadQueue.io.enq.needAlloc(i)      := io.enq.needAlloc(i)(0)
118    loadQueue.io.enq.req(i).valid      := io.enq.needAlloc(i)(0) && io.enq.req(i).valid
119    loadQueue.io.enq.req(i).bits       := io.enq.req(i).bits
120    loadQueue.io.enq.req(i).bits.sqIdx := storeQueue.io.enq.resp(i)
121
122    storeQueue.io.enq.needAlloc(i)      := io.enq.needAlloc(i)(1)
123    storeQueue.io.enq.req(i).valid      := io.enq.needAlloc(i)(1) && io.enq.req(i).valid
124    storeQueue.io.enq.req(i).bits       := io.enq.req(i).bits
125    storeQueue.io.enq.req(i).bits       := io.enq.req(i).bits
126    storeQueue.io.enq.req(i).bits.lqIdx := loadQueue.io.enq.resp(i)
127
128    io.enq.resp(i).lqIdx := loadQueue.io.enq.resp(i)
129    io.enq.resp(i).sqIdx := storeQueue.io.enq.resp(i)
130  }
131
132  // load queue wiring
133  loadQueue.io.brqRedirect <> io.brqRedirect
134  loadQueue.io.loadPaddrIn <> io.loadPaddrIn
135  loadQueue.io.loadOut <> io.loadOut
136  loadQueue.io.loadVaddrIn <> io.loadVaddrIn
137  loadQueue.io.replayFast <> io.replayFast
138  loadQueue.io.replaySlow <> io.replaySlow
139  loadQueue.io.loadIn <> io.loadIn
140  loadQueue.io.storeIn <> io.storeIn
141  loadQueue.io.s2_load_data_forwarded <> io.s2_load_data_forwarded
142  loadQueue.io.s3_delayed_load_error <> io.s3_delayed_load_error
143  loadQueue.io.s2_dcache_require_replay <> io.s2_dcache_require_replay
144  loadQueue.io.s3_replay_from_fetch <> io.s3_replay_from_fetch
145  loadQueue.io.ldout <> io.ldout
146  loadQueue.io.ldRawDataOut <> io.ldRawDataOut
147  loadQueue.io.rob <> io.rob
148  loadQueue.io.rollback <> io.rollback
149  loadQueue.io.refill <> io.refill
150  loadQueue.io.release <> io.release
151  loadQueue.io.trigger <> io.trigger
152  loadQueue.io.exceptionAddr.isStore := DontCare
153  loadQueue.io.lqCancelCnt <> io.lqCancelCnt
154
155  // store queue wiring
156  // storeQueue.io <> DontCare
157  storeQueue.io.brqRedirect <> io.brqRedirect
158  storeQueue.io.storeIn <> io.storeIn
159  storeQueue.io.storeInRe <> io.storeInRe
160  storeQueue.io.storeDataIn <> io.storeDataIn
161  storeQueue.io.storeMaskIn <> io.storeMaskIn
162  storeQueue.io.sbuffer <> io.sbuffer
163  storeQueue.io.mmioStout <> io.mmioStout
164  storeQueue.io.rob <> io.rob
165  storeQueue.io.exceptionAddr.isStore := DontCare
166  storeQueue.io.issuePtrExt <> io.issuePtrExt
167  storeQueue.io.sqCancelCnt <> io.sqCancelCnt
168  storeQueue.io.sqDeq <> io.sqDeq
169
170  loadQueue.io.load_s1 <> io.forward
171  storeQueue.io.forward <> io.forward // overlap forwardMask & forwardData, DO NOT CHANGE SEQUENCE
172
173  loadQueue.io.loadViolationQuery <> io.loadViolationQuery
174
175  storeQueue.io.sqempty <> io.sqempty
176
177  // rob commits for lsq is delayed for two cycles, which causes the delayed update for deqPtr in lq/sq
178  // s0: commit
179  // s1:               exception find
180  // s2:               exception triggered
181  // s3: ptr updated & new address
182  // address will be used at the next cycle after exception is triggered
183  io.exceptionAddr.vaddr := Mux(RegNext(io.exceptionAddr.isStore), storeQueue.io.exceptionAddr.vaddr, loadQueue.io.exceptionAddr.vaddr)
184
185  // naive uncache arbiter
186  val s_idle :: s_load :: s_store :: Nil = Enum(3)
187  val pendingstate = RegInit(s_idle)
188
189  switch(pendingstate){
190    is(s_idle){
191      when(io.uncache.req.fire() && !io.uncacheOutstanding){
192        pendingstate := Mux(loadQueue.io.uncache.req.valid, s_load,
193                          Mux(io.uncacheOutstanding, s_idle, s_store))
194      }
195    }
196    is(s_load){
197      when(io.uncache.resp.fire()){
198        pendingstate := s_idle
199      }
200    }
201    is(s_store){
202      when(io.uncache.resp.fire()){
203        pendingstate := s_idle
204      }
205    }
206  }
207
208  loadQueue.io.uncache := DontCare
209  storeQueue.io.uncache := DontCare
210  loadQueue.io.uncache.resp.valid := false.B
211  storeQueue.io.uncache.resp.valid := false.B
212  when(loadQueue.io.uncache.req.valid){
213    io.uncache.req <> loadQueue.io.uncache.req
214  }.otherwise{
215    io.uncache.req <> storeQueue.io.uncache.req
216  }
217  when (io.uncacheOutstanding) {
218    io.uncache.resp <> loadQueue.io.uncache.resp
219  } .otherwise {
220    when(pendingstate === s_load){
221      io.uncache.resp <> loadQueue.io.uncache.resp
222    }.otherwise{
223      io.uncache.resp <> storeQueue.io.uncache.resp
224    }
225  }
226
227
228  assert(!(loadQueue.io.uncache.req.valid && storeQueue.io.uncache.req.valid))
229  assert(!(loadQueue.io.uncache.resp.valid && storeQueue.io.uncache.resp.valid))
230  when (!io.uncacheOutstanding) {
231    assert(!((loadQueue.io.uncache.resp.valid || storeQueue.io.uncache.resp.valid) && pendingstate === s_idle))
232  }
233
234  io.lqFull := loadQueue.io.lqFull
235  io.sqFull := storeQueue.io.sqFull
236
237  val perfEvents = Seq(loadQueue, storeQueue).flatMap(_.getPerfEvents)
238  generatePerfEvent()
239}
240
241class LsqEnqCtrl(implicit p: Parameters) extends XSModule {
242  val io = IO(new Bundle {
243    val redirect = Flipped(ValidIO(new Redirect))
244    // to dispatch
245    val enq = new LsqEnqIO
246    // from rob
247    val lcommit = Input(UInt(log2Up(CommitWidth + 1).W))
248    // from `memBlock.io.sqDeq`
249    val scommit = Input(UInt(log2Ceil(EnsbufferWidth + 1).W))
250    // from/tp lsq
251    val lqCancelCnt = Input(UInt(log2Up(LoadQueueSize + 1).W))
252    val sqCancelCnt = Input(UInt(log2Up(StoreQueueSize + 1).W))
253    val enqLsq = Flipped(new LsqEnqIO)
254  })
255
256  val lqPtr = RegInit(0.U.asTypeOf(new LqPtr))
257  val sqPtr = RegInit(0.U.asTypeOf(new SqPtr))
258  val lqCounter = RegInit(LoadQueueSize.U(log2Up(LoadQueueSize + 1).W))
259  val sqCounter = RegInit(StoreQueueSize.U(log2Up(StoreQueueSize + 1).W))
260  val canAccept = RegInit(false.B)
261
262  val loadEnqNumber = PopCount(io.enq.req.zip(io.enq.needAlloc).map(x => x._1.valid && x._2(0)))
263  val storeEnqNumber = PopCount(io.enq.req.zip(io.enq.needAlloc).map(x => x._1.valid && x._2(1)))
264
265  // How to update ptr and counter:
266  // (1) by default, updated according to enq/commit
267  // (2) when redirect and dispatch queue is empty, update according to lsq
268  val t1_redirect = RegNext(io.redirect.valid)
269  val t2_redirect = RegNext(t1_redirect)
270  val t2_update = t2_redirect && !VecInit(io.enq.needAlloc.map(_.orR)).asUInt.orR
271  val t3_update = RegNext(t2_update)
272  val t3_lqCancelCnt = RegNext(io.lqCancelCnt)
273  val t3_sqCancelCnt = RegNext(io.sqCancelCnt)
274  when (t3_update) {
275    lqPtr := lqPtr - t3_lqCancelCnt
276    lqCounter := lqCounter + io.lcommit + t3_lqCancelCnt
277    sqPtr := sqPtr - t3_sqCancelCnt
278    sqCounter := sqCounter + io.scommit + t3_sqCancelCnt
279  }.elsewhen (!io.redirect.valid && io.enq.canAccept) {
280    lqPtr := lqPtr + loadEnqNumber
281    lqCounter := lqCounter + io.lcommit - loadEnqNumber
282    sqPtr := sqPtr + storeEnqNumber
283    sqCounter := sqCounter + io.scommit - storeEnqNumber
284  }.otherwise {
285    lqCounter := lqCounter + io.lcommit
286    sqCounter := sqCounter + io.scommit
287  }
288
289
290  val maxAllocate = Seq(exuParameters.LduCnt, exuParameters.StuCnt).max
291  val ldCanAccept = lqCounter >= loadEnqNumber +& maxAllocate.U
292  val sqCanAccept = sqCounter >= storeEnqNumber +& maxAllocate.U
293  // It is possible that t3_update and enq are true at the same clock cycle.
294  // For example, if redirect.valid lasts more than one clock cycle,
295  // after the last redirect, new instructions may enter but previously redirect
296  // has not been resolved (updated according to the cancel count from LSQ).
297  // To solve the issue easily, we block enqueue when t3_update, which is RegNext(t2_update).
298  io.enq.canAccept := RegNext(ldCanAccept && sqCanAccept && !t2_update)
299  val lqOffset = Wire(Vec(io.enq.resp.length, UInt(log2Up(maxAllocate + 1).W)))
300  val sqOffset = Wire(Vec(io.enq.resp.length, UInt(log2Up(maxAllocate + 1).W)))
301  for ((resp, i) <- io.enq.resp.zipWithIndex) {
302    lqOffset(i) := PopCount(io.enq.needAlloc.take(i).map(a => a(0)))
303    resp.lqIdx := lqPtr + lqOffset(i)
304    sqOffset(i) := PopCount(io.enq.needAlloc.take(i).map(a => a(1)))
305    resp.sqIdx := sqPtr + sqOffset(i)
306  }
307
308  io.enqLsq.needAlloc := RegNext(io.enq.needAlloc)
309  io.enqLsq.req.zip(io.enq.req).zip(io.enq.resp).foreach{ case ((toLsq, enq), resp) =>
310    val do_enq = enq.valid && !io.redirect.valid && io.enq.canAccept
311    toLsq.valid := RegNext(do_enq)
312    toLsq.bits := RegEnable(enq.bits, do_enq)
313    toLsq.bits.lqIdx := RegEnable(resp.lqIdx, do_enq)
314    toLsq.bits.sqIdx := RegEnable(resp.sqIdx, do_enq)
315  }
316
317}
318