xref: /XiangShan/src/main/scala/xiangshan/mem/lsqueue/LoadQueue.scala (revision 3fae98ac4fa4aeb3c8ed035932edb8a13ce11e3c)
1package xiangshan.mem
2
3import chisel3._
4import chisel3.util._
5import utils._
6import xiangshan._
7import xiangshan.cache._
8import xiangshan.cache.{DCacheWordIO, DCacheLineIO, TlbRequestIO, MemoryOpConstants}
9import xiangshan.backend.LSUOpType
10import xiangshan.mem._
11import xiangshan.backend.roq.RoqPtr
12import xiangshan.backend.fu.fpu.boxF32ToF64
13
14
15class LqPtr extends CircularQueuePtr(LqPtr.LoadQueueSize) { }
16
17object LqPtr extends HasXSParameter {
18  def apply(f: Bool, v: UInt): LqPtr = {
19    val ptr = Wire(new LqPtr)
20    ptr.flag := f
21    ptr.value := v
22    ptr
23  }
24}
25
26
27// Load Queue
28class LoadQueue extends XSModule with HasDCacheParameters with HasCircularQueuePtrHelper {
29  val io = IO(new Bundle() {
30    val dp1Req = Vec(RenameWidth, Flipped(DecoupledIO(new MicroOp)))
31    val lqReady = Output(Vec(RenameWidth, Bool()))
32    val sqReady = Input(Vec(RenameWidth, Bool()))
33    val lqIdxs = Output(Vec(RenameWidth, new LqPtr)) // LSIdx will be assembled in LSQWrapper
34    val brqRedirect = Input(Valid(new Redirect))
35    val loadIn = Vec(LoadPipelineWidth, Flipped(Valid(new LsPipelineBundle)))
36    val storeIn = Vec(StorePipelineWidth, Flipped(Valid(new LsPipelineBundle))) // FIXME: Valid() only
37    val ldout = Vec(2, DecoupledIO(new ExuOutput)) // writeback load
38    val forward = Vec(LoadPipelineWidth, Flipped(new LoadForwardQueryIO))
39    val commits = Flipped(Vec(CommitWidth, Valid(new RoqCommit)))
40    val rollback = Output(Valid(new Redirect)) // replay now starts from load instead of store
41    val dcache = new DCacheLineIO
42    val uncache = new DCacheWordIO
43    val roqDeqPtr = Input(new RoqPtr)
44    val exceptionAddr = new ExceptionAddrIO
45    // val refill = Flipped(Valid(new DCacheLineReq ))
46  })
47
48  val uop = Reg(Vec(LoadQueueSize, new MicroOp))
49  // val data = Reg(Vec(LoadQueueSize, new LsRoqEntry))
50  val dataModule = Module(new LSQueueData(LoadQueueSize, LoadPipelineWidth))
51  dataModule.io := DontCare
52  val allocated = RegInit(VecInit(List.fill(LoadQueueSize)(false.B))) // lq entry has been allocated
53  val valid = RegInit(VecInit(List.fill(LoadQueueSize)(false.B))) // data is valid
54  val writebacked = RegInit(VecInit(List.fill(LoadQueueSize)(false.B))) // inst has been writebacked to CDB
55  val commited = Reg(Vec(LoadQueueSize, Bool())) // inst has been writebacked to CDB
56  val miss = Reg(Vec(LoadQueueSize, Bool())) // load inst missed, waiting for miss queue to accept miss request
57  val listening = Reg(Vec(LoadQueueSize, Bool())) // waiting for refill result
58  val pending = Reg(Vec(LoadQueueSize, Bool())) // mmio pending: inst is an mmio inst, it will not be executed until it reachs the end of roq
59
60  val ringBufferHeadExtended = RegInit(0.U.asTypeOf(new LqPtr))
61  val ringBufferTailExtended = RegInit(0.U.asTypeOf(new LqPtr))
62  val ringBufferHead = ringBufferHeadExtended.value
63  val ringBufferTail = ringBufferTailExtended.value
64  val ringBufferSameFlag = ringBufferHeadExtended.flag === ringBufferTailExtended.flag
65  val ringBufferEmpty = ringBufferHead === ringBufferTail && ringBufferSameFlag
66  val ringBufferFull = ringBufferHead === ringBufferTail && !ringBufferSameFlag
67  val ringBufferAllowin = !ringBufferFull
68
69  val loadCommit = (0 until CommitWidth).map(i => io.commits(i).valid && !io.commits(i).bits.isWalk && io.commits(i).bits.uop.ctrl.commitType === CommitType.LOAD)
70  val mcommitIdx = (0 until CommitWidth).map(i => io.commits(i).bits.uop.lqIdx.value)
71
72  val tailMask = (((1.U((LoadQueueSize + 1).W)) << ringBufferTail).asUInt - 1.U)(LoadQueueSize - 1, 0)
73  val headMask = (((1.U((LoadQueueSize + 1).W)) << ringBufferHead).asUInt - 1.U)(LoadQueueSize - 1, 0)
74  val enqDeqMask1 = tailMask ^ headMask
75  val enqDeqMask = Mux(ringBufferSameFlag, enqDeqMask1, ~enqDeqMask1)
76
77  // Enqueue at dispatch
78  val emptyEntries = LoadQueueSize.U - distanceBetween(ringBufferHeadExtended, ringBufferTailExtended)
79  XSDebug("(ready, valid): ")
80  for (i <- 0 until RenameWidth) {
81    val offset = if (i == 0) 0.U else PopCount((0 until i).map(io.dp1Req(_).valid))
82    val lqIdx = ringBufferHeadExtended + offset
83    val index = lqIdx.value
84    when(io.dp1Req(i).fire()) {
85      uop(index) := io.dp1Req(i).bits
86      allocated(index) := true.B
87      valid(index) := false.B
88      writebacked(index) := false.B
89      commited(index) := false.B
90      miss(index) := false.B
91      listening(index) := false.B
92      pending(index) := false.B
93    }
94    val numTryEnqueue = offset +& io.dp1Req(i).valid
95    io.lqReady(i) := numTryEnqueue <= emptyEntries
96    io.dp1Req(i).ready := io.lqReady(i) && io.sqReady(i)
97    io.lqIdxs(i) := lqIdx
98    XSDebug(false, true.B, "(%d, %d) ", io.dp1Req(i).ready, io.dp1Req(i).valid)
99  }
100  XSDebug(false, true.B, "\n")
101
102  val firedDispatch = VecInit((0 until CommitWidth).map(io.dp1Req(_).fire())).asUInt
103  when(firedDispatch.orR) {
104    ringBufferHeadExtended := ringBufferHeadExtended + PopCount(firedDispatch)
105    XSInfo("dispatched %d insts to lq\n", PopCount(firedDispatch))
106  }
107
108  // writeback load
109  (0 until LoadPipelineWidth).map(i => {
110    dataModule.io.wb(i).wen := false.B
111    when(io.loadIn(i).fire()) {
112      when(io.loadIn(i).bits.miss) {
113        XSInfo(io.loadIn(i).valid, "load miss write to lq idx %d pc 0x%x vaddr %x paddr %x data %x mask %x forwardData %x forwardMask: %x mmio %x roll %x exc %x\n",
114          io.loadIn(i).bits.uop.lqIdx.asUInt,
115          io.loadIn(i).bits.uop.cf.pc,
116          io.loadIn(i).bits.vaddr,
117          io.loadIn(i).bits.paddr,
118          io.loadIn(i).bits.data,
119          io.loadIn(i).bits.mask,
120          io.loadIn(i).bits.forwardData.asUInt,
121          io.loadIn(i).bits.forwardMask.asUInt,
122          io.loadIn(i).bits.mmio,
123          io.loadIn(i).bits.rollback,
124          io.loadIn(i).bits.uop.cf.exceptionVec.asUInt
125          )
126        }.otherwise {
127          XSInfo(io.loadIn(i).valid, "load hit write to cbd lqidx %d pc 0x%x vaddr %x paddr %x data %x mask %x forwardData %x forwardMask: %x mmio %x roll %x exc %x\n",
128          io.loadIn(i).bits.uop.lqIdx.asUInt,
129          io.loadIn(i).bits.uop.cf.pc,
130          io.loadIn(i).bits.vaddr,
131          io.loadIn(i).bits.paddr,
132          io.loadIn(i).bits.data,
133          io.loadIn(i).bits.mask,
134          io.loadIn(i).bits.forwardData.asUInt,
135          io.loadIn(i).bits.forwardMask.asUInt,
136          io.loadIn(i).bits.mmio,
137          io.loadIn(i).bits.rollback,
138          io.loadIn(i).bits.uop.cf.exceptionVec.asUInt
139          )
140        }
141        val loadWbIndex = io.loadIn(i).bits.uop.lqIdx.value
142        valid(loadWbIndex) := !io.loadIn(i).bits.miss && !io.loadIn(i).bits.mmio
143        writebacked(loadWbIndex) := !io.loadIn(i).bits.miss && !io.loadIn(i).bits.mmio
144        allocated(loadWbIndex) := !io.loadIn(i).bits.uop.cf.exceptionVec.asUInt.orR
145
146        val loadWbData = Wire(new LsqEntry)
147        loadWbData.paddr := io.loadIn(i).bits.paddr
148        loadWbData.vaddr := io.loadIn(i).bits.vaddr
149        loadWbData.mask := io.loadIn(i).bits.mask
150        loadWbData.data := io.loadIn(i).bits.data // for mmio / misc / debug
151        loadWbData.mmio := io.loadIn(i).bits.mmio
152        loadWbData.fwdMask := io.loadIn(i).bits.forwardMask
153        loadWbData.fwdData := io.loadIn(i).bits.forwardData
154        loadWbData.exception := io.loadIn(i).bits.uop.cf.exceptionVec.asUInt
155        dataModule.io.wbWrite(i, loadWbIndex, loadWbData)
156        dataModule.io.wb(i).wen := true.B
157
158        val dcacheMissed = io.loadIn(i).bits.miss && !io.loadIn(i).bits.mmio
159        miss(loadWbIndex) := dcacheMissed
160        listening(loadWbIndex) := dcacheMissed
161        pending(loadWbIndex) := io.loadIn(i).bits.mmio
162      }
163    })
164
165  // cache miss request
166  val inflightReqs = RegInit(VecInit(Seq.fill(cfg.nLoadMissEntries)(0.U.asTypeOf(new InflightBlockInfo))))
167  val inflightReqFull = inflightReqs.map(req => req.valid).reduce(_&&_)
168  val reqBlockIndex = PriorityEncoder(~VecInit(inflightReqs.map(req => req.valid)).asUInt)
169
170  val missRefillSelVec = VecInit(
171    (0 until LoadQueueSize).map{ i =>
172      val inflight = inflightReqs.map(req => req.valid && req.block_addr === get_block_addr(dataModule.io.rdata(i).paddr)).reduce(_||_)
173      allocated(i) && miss(i) && !inflight
174    })
175
176  val missRefillSel = getFirstOne(missRefillSelVec, tailMask)
177  val missRefillBlockAddr = get_block_addr(dataModule.io.rdata(missRefillSel).paddr)
178  io.dcache.req.valid := missRefillSelVec.asUInt.orR
179  io.dcache.req.bits.cmd := MemoryOpConstants.M_XRD
180  io.dcache.req.bits.addr := missRefillBlockAddr
181  io.dcache.req.bits.data := DontCare
182  io.dcache.req.bits.mask := DontCare
183
184  io.dcache.req.bits.meta.id       := DontCare
185  io.dcache.req.bits.meta.vaddr    := DontCare // dataModule.io.rdata(missRefillSel).vaddr
186  io.dcache.req.bits.meta.paddr    := missRefillBlockAddr
187  io.dcache.req.bits.meta.uop      := uop(missRefillSel)
188  io.dcache.req.bits.meta.mmio     := false.B // dataModule.io.rdata(missRefillSel).mmio
189  io.dcache.req.bits.meta.tlb_miss := false.B
190  io.dcache.req.bits.meta.mask     := DontCare
191  io.dcache.req.bits.meta.replay   := false.B
192
193  io.dcache.resp.ready := true.B
194
195  assert(!(dataModule.io.rdata(missRefillSel).mmio && io.dcache.req.valid))
196
197  when(io.dcache.req.fire()) {
198    miss(missRefillSel) := false.B
199    listening(missRefillSel) := true.B
200
201    // mark this block as inflight
202    inflightReqs(reqBlockIndex).valid := true.B
203    inflightReqs(reqBlockIndex).block_addr := missRefillBlockAddr
204    assert(!inflightReqs(reqBlockIndex).valid)
205  }
206
207  when(io.dcache.resp.fire()) {
208    val inflight = inflightReqs.map(req => req.valid && req.block_addr === get_block_addr(io.dcache.resp.bits.meta.paddr)).reduce(_||_)
209    assert(inflight)
210    for (i <- 0 until cfg.nLoadMissEntries) {
211      when (inflightReqs(i).valid && inflightReqs(i).block_addr === get_block_addr(io.dcache.resp.bits.meta.paddr)) {
212        inflightReqs(i).valid := false.B
213      }
214    }
215  }
216
217
218  when(io.dcache.req.fire()){
219    XSDebug("miss req: pc:0x%x roqIdx:%d lqIdx:%d (p)addr:0x%x vaddr:0x%x\n",
220      io.dcache.req.bits.meta.uop.cf.pc, io.dcache.req.bits.meta.uop.roqIdx.asUInt, io.dcache.req.bits.meta.uop.lqIdx.asUInt,
221      io.dcache.req.bits.addr, io.dcache.req.bits.meta.vaddr
222    )
223  }
224
225  when(io.dcache.resp.fire()){
226    XSDebug("miss resp: pc:0x%x roqIdx:%d lqIdx:%d (p)addr:0x%x data %x\n",
227      io.dcache.resp.bits.meta.uop.cf.pc, io.dcache.resp.bits.meta.uop.roqIdx.asUInt, io.dcache.resp.bits.meta.uop.lqIdx.asUInt,
228      io.dcache.resp.bits.meta.paddr, io.dcache.resp.bits.data
229    )
230  }
231
232  // Refill 64 bit in a cycle
233  // Refill data comes back from io.dcache.resp
234  dataModule.io.refill.dcache := io.dcache.resp.bits
235
236  (0 until LoadQueueSize).map(i => {
237    val blockMatch = get_block_addr(dataModule.io.rdata(i).paddr) === io.dcache.resp.bits.meta.paddr
238    dataModule.io.refill.wen(i) := false.B
239    when(allocated(i) && listening(i) && blockMatch && io.dcache.resp.fire()) {
240      dataModule.io.refill.wen(i) := true.B
241      valid(i) := true.B
242      listening(i) := false.B
243    }
244  })
245
246  // writeback up to 2 missed load insts to CDB
247  // just randomly pick 2 missed load (data refilled), write them back to cdb
248  val loadWbSelVec = VecInit((0 until LoadQueueSize).map(i => {
249    allocated(i) && valid(i) && !writebacked(i)
250  })).asUInt() // use uint instead vec to reduce verilog lines
251  val loadWbSel = Wire(Vec(StorePipelineWidth, UInt(log2Up(LoadQueueSize).W)))
252  val loadWbSelV= Wire(Vec(StorePipelineWidth, Bool()))
253  val lselvec0 = PriorityEncoderOH(loadWbSelVec)
254  val lselvec1 = PriorityEncoderOH(loadWbSelVec & (~lselvec0).asUInt)
255  loadWbSel(0) := OHToUInt(lselvec0)
256  loadWbSelV(0):= lselvec0.orR
257  loadWbSel(1) := OHToUInt(lselvec1)
258  loadWbSelV(1) := lselvec1.orR
259  (0 until StorePipelineWidth).map(i => {
260    // data select
261    val rdata = dataModule.io.rdata(loadWbSel(i)).data
262    val func = uop(loadWbSel(i)).ctrl.fuOpType
263    val raddr = dataModule.io.rdata(loadWbSel(i)).paddr
264    val rdataSel = LookupTree(raddr(2, 0), List(
265      "b000".U -> rdata(63, 0),
266      "b001".U -> rdata(63, 8),
267      "b010".U -> rdata(63, 16),
268      "b011".U -> rdata(63, 24),
269      "b100".U -> rdata(63, 32),
270      "b101".U -> rdata(63, 40),
271      "b110".U -> rdata(63, 48),
272      "b111".U -> rdata(63, 56)
273    ))
274    val rdataPartialLoad = LookupTree(func, List(
275        LSUOpType.lb   -> SignExt(rdataSel(7, 0) , XLEN),
276        LSUOpType.lh   -> SignExt(rdataSel(15, 0), XLEN),
277        LSUOpType.lw   -> SignExt(rdataSel(31, 0), XLEN),
278        LSUOpType.ld   -> SignExt(rdataSel(63, 0), XLEN),
279        LSUOpType.lbu  -> ZeroExt(rdataSel(7, 0) , XLEN),
280        LSUOpType.lhu  -> ZeroExt(rdataSel(15, 0), XLEN),
281        LSUOpType.lwu  -> ZeroExt(rdataSel(31, 0), XLEN),
282        LSUOpType.flw  -> boxF32ToF64(rdataSel(31, 0))
283    ))
284    io.ldout(i).bits.uop := uop(loadWbSel(i))
285    io.ldout(i).bits.uop.cf.exceptionVec := dataModule.io.rdata(loadWbSel(i)).exception.asBools
286    io.ldout(i).bits.uop.lqIdx := loadWbSel(i).asTypeOf(new LqPtr)
287    io.ldout(i).bits.data := rdataPartialLoad
288    io.ldout(i).bits.redirectValid := false.B
289    io.ldout(i).bits.redirect := DontCare
290    io.ldout(i).bits.brUpdate := DontCare
291    io.ldout(i).bits.debug.isMMIO := dataModule.io.rdata(loadWbSel(i)).mmio
292    io.ldout(i).bits.fflags := DontCare
293    io.ldout(i).valid := loadWbSelVec(loadWbSel(i)) && loadWbSelV(i)
294    when(io.ldout(i).fire()) {
295      writebacked(loadWbSel(i)) := true.B
296      XSInfo("load miss write to cbd roqidx %d lqidx %d pc 0x%x paddr %x data %x mmio %x\n",
297        io.ldout(i).bits.uop.roqIdx.asUInt,
298        io.ldout(i).bits.uop.lqIdx.asUInt,
299        io.ldout(i).bits.uop.cf.pc,
300        dataModule.io.rdata(loadWbSel(i)).paddr,
301        dataModule.io.rdata(loadWbSel(i)).data,
302        dataModule.io.rdata(loadWbSel(i)).mmio
303      )
304    }
305  })
306
307  // move tailPtr
308  // allocatedMask: dequeuePtr can go to the next 1-bit
309  val allocatedMask = VecInit((0 until LoadQueueSize).map(i => allocated(i) || !enqDeqMask(i)))
310  // find the first one from deqPtr (ringBufferTail)
311  val nextTail1 = getFirstOneWithFlag(allocatedMask, tailMask, ringBufferTailExtended.flag)
312  val nextTail = Mux(Cat(allocatedMask).orR, nextTail1, ringBufferHeadExtended)
313  ringBufferTailExtended := nextTail
314
315  // When load commited, mark it as !allocated, this entry will be recycled later
316  (0 until CommitWidth).map(i => {
317    when(loadCommit(i)) {
318      allocated(mcommitIdx(i)) := false.B
319      XSDebug("load commit %d: idx %d %x\n", i.U, mcommitIdx(i), uop(mcommitIdx(i)).cf.pc)
320    }
321  })
322
323  // rollback check
324  val rollback = Wire(Vec(StorePipelineWidth, Valid(new Redirect)))
325
326  def getFirstOne(mask: Vec[Bool], startMask: UInt) = {
327    val length = mask.length
328    val highBits = (0 until length).map(i => mask(i) & ~startMask(i))
329    val highBitsUint = Cat(highBits.reverse)
330    PriorityEncoder(Mux(highBitsUint.orR(), highBitsUint, mask.asUInt))
331  }
332
333  def getFirstOneWithFlag(mask: Vec[Bool], startMask: UInt, startFlag: Bool) = {
334    val length = mask.length
335    val highBits = (0 until length).map(i => mask(i) & ~startMask(i))
336    val highBitsUint = Cat(highBits.reverse)
337    val changeDirection = !highBitsUint.orR()
338    val index = PriorityEncoder(Mux(!changeDirection, highBitsUint, mask.asUInt))
339    LqPtr(startFlag ^ changeDirection, index)
340  }
341
342  def getOldestInTwo(valid: Seq[Bool], uop: Seq[MicroOp]) = {
343    assert(valid.length == uop.length)
344    assert(valid.length == 2)
345    Mux(valid(0) && valid(1),
346      Mux(isAfter(uop(0).roqIdx, uop(1).roqIdx), uop(1), uop(0)),
347      Mux(valid(0) && !valid(1), uop(0), uop(1)))
348  }
349
350  def getAfterMask(valid: Seq[Bool], uop: Seq[MicroOp]) = {
351    assert(valid.length == uop.length)
352    val length = valid.length
353    (0 until length).map(i => {
354      (0 until length).map(j => {
355        Mux(valid(i) && valid(j),
356          isAfter(uop(i).roqIdx, uop(j).roqIdx),
357          Mux(!valid(i), true.B, false.B))
358      })
359    })
360  }
361
362  def rangeMask(start: LqPtr, end: LqPtr): UInt = {
363    val startMask = (1.U((LoadQueueSize + 1).W) << start.value).asUInt - 1.U
364    val endMask = (1.U((LoadQueueSize + 1).W) << end.value).asUInt - 1.U
365    val xorMask = startMask(LoadQueueSize - 1, 0) ^ endMask(LoadQueueSize - 1, 0)
366    Mux(start.flag === end.flag, xorMask, ~xorMask)
367  }
368
369  // ignore data forward
370  (0 until LoadPipelineWidth).foreach(i => {
371    io.forward(i).forwardMask := DontCare
372    io.forward(i).forwardData := DontCare
373  })
374
375  // store backward query and rollback
376  //  val needCheck = Seq.fill(8)(WireInit(true.B))
377  (0 until StorePipelineWidth).foreach(i => {
378    rollback(i) := DontCare
379
380    when(io.storeIn(i).valid) {
381      val startIndex = io.storeIn(i).bits.uop.lqIdx.value
382      val lqIdxMask = ((1.U((LoadQueueSize + 1).W) << startIndex).asUInt - 1.U)(LoadQueueSize - 1, 0)
383      val xorMask = lqIdxMask ^ headMask
384      val sameFlag = io.storeIn(i).bits.uop.lqIdx.flag === ringBufferHeadExtended.flag
385      val toEnqPtrMask = Mux(sameFlag, xorMask, ~xorMask)
386
387      // check if load already in lq needs to be rolledback
388      val lqViolationVec = VecInit((0 until LoadQueueSize).map(j => {
389        val addrMatch = allocated(j) &&
390          io.storeIn(i).bits.paddr(PAddrBits - 1, 3) === dataModule.io.rdata(j).paddr(PAddrBits - 1, 3)
391        val entryNeedCheck = toEnqPtrMask(j) && addrMatch && (valid(j) || listening(j) || miss(j))
392        // TODO: update refilled data
393        val violationVec = (0 until 8).map(k => dataModule.io.rdata(j).mask(k) && io.storeIn(i).bits.mask(k))
394        Cat(violationVec).orR() && entryNeedCheck
395      }))
396      val lqViolation = lqViolationVec.asUInt().orR()
397      val lqViolationIndex = getFirstOne(lqViolationVec, lqIdxMask)
398      val lqViolationUop = uop(lqViolationIndex)
399      XSDebug(lqViolation, p"${Binary(Cat(lqViolationVec))}, $startIndex, $lqViolationIndex\n")
400
401      // when l/s writeback to roq together, check if rollback is needed
402      val wbViolationVec = VecInit((0 until LoadPipelineWidth).map(j => {
403        io.loadIn(j).valid &&
404          isAfter(io.loadIn(j).bits.uop.roqIdx, io.storeIn(i).bits.uop.roqIdx) &&
405          io.storeIn(i).bits.paddr(PAddrBits - 1, 3) === io.loadIn(j).bits.paddr(PAddrBits - 1, 3) &&
406          (io.storeIn(i).bits.mask & io.loadIn(j).bits.mask).orR
407      }))
408      val wbViolation = wbViolationVec.asUInt().orR()
409      val wbViolationUop = getOldestInTwo(wbViolationVec, io.loadIn.map(_.bits.uop))
410      XSDebug(wbViolation, p"${Binary(Cat(wbViolationVec))}, $wbViolationUop\n")
411
412      // check if rollback is needed for load in l1
413      val l1ViolationVec = VecInit((0 until LoadPipelineWidth).map(j => {
414        io.forward(j).valid && // L4 valid\
415          isAfter(io.forward(j).uop.roqIdx, io.storeIn(i).bits.uop.roqIdx) &&
416          io.storeIn(i).bits.paddr(PAddrBits - 1, 3) === io.forward(j).paddr(PAddrBits - 1, 3) &&
417          (io.storeIn(i).bits.mask & io.forward(j).mask).orR
418      }))
419      val l1Violation = l1ViolationVec.asUInt().orR()
420      val l1ViolationUop = getOldestInTwo(l1ViolationVec, io.forward.map(_.uop))
421      XSDebug(l1Violation, p"${Binary(Cat(l1ViolationVec))}, $l1ViolationUop\n")
422
423      val rollbackValidVec = Seq(lqViolation, wbViolation, l1Violation)
424      val rollbackUopVec = Seq(lqViolationUop, wbViolationUop, l1ViolationUop)
425      rollback(i).valid := Cat(rollbackValidVec).orR
426      val mask = getAfterMask(rollbackValidVec, rollbackUopVec)
427      val oneAfterZero = mask(1)(0)
428      val rollbackUop = Mux(oneAfterZero && mask(2)(0),
429        rollbackUopVec(0),
430        Mux(!oneAfterZero && mask(2)(1), rollbackUopVec(1), rollbackUopVec(2)))
431      rollback(i).bits.roqIdx := rollbackUop.roqIdx - 1.U
432
433      rollback(i).bits.isReplay := true.B
434      rollback(i).bits.isMisPred := false.B
435      rollback(i).bits.isException := false.B
436      rollback(i).bits.isFlushPipe := false.B
437
438      XSDebug(
439        l1Violation,
440        "need rollback (l4 load) pc %x roqidx %d target %x\n",
441        io.storeIn(i).bits.uop.cf.pc, io.storeIn(i).bits.uop.roqIdx.asUInt, l1ViolationUop.roqIdx.asUInt
442      )
443      XSDebug(
444        lqViolation,
445        "need rollback (ld wb before store) pc %x roqidx %d target %x\n",
446        io.storeIn(i).bits.uop.cf.pc, io.storeIn(i).bits.uop.roqIdx.asUInt, lqViolationUop.roqIdx.asUInt
447      )
448      XSDebug(
449        wbViolation,
450        "need rollback (ld/st wb together) pc %x roqidx %d target %x\n",
451        io.storeIn(i).bits.uop.cf.pc, io.storeIn(i).bits.uop.roqIdx.asUInt, wbViolationUop.roqIdx.asUInt
452      )
453    }.otherwise {
454      rollback(i).valid := false.B
455    }
456  })
457
458  def rollbackSel(a: Valid[Redirect], b: Valid[Redirect]): ValidIO[Redirect] = {
459    Mux(
460      a.valid,
461      Mux(
462        b.valid,
463        Mux(isAfter(a.bits.roqIdx, b.bits.roqIdx), b, a), // a,b both valid, sel oldest
464        a // sel a
465      ),
466      b // sel b
467    )
468  }
469
470  io.rollback := ParallelOperation(rollback, rollbackSel)
471
472  // Memory mapped IO / other uncached operations
473
474  // setup misc mem access req
475  // mask / paddr / data can be get from lq.data
476  val commitType = io.commits(0).bits.uop.ctrl.commitType
477  io.uncache.req.valid := pending(ringBufferTail) && allocated(ringBufferTail) &&
478    commitType === CommitType.LOAD &&
479    io.roqDeqPtr === uop(ringBufferTail).roqIdx &&
480    !io.commits(0).bits.isWalk
481
482  io.uncache.req.bits.cmd  := MemoryOpConstants.M_XRD
483  io.uncache.req.bits.addr := dataModule.io.rdata(ringBufferTail).paddr
484  io.uncache.req.bits.data := dataModule.io.rdata(ringBufferTail).data
485  io.uncache.req.bits.mask := dataModule.io.rdata(ringBufferTail).mask
486
487  io.uncache.req.bits.meta.id       := DontCare // TODO: // FIXME
488  io.uncache.req.bits.meta.vaddr    := DontCare
489  io.uncache.req.bits.meta.paddr    := dataModule.io.rdata(ringBufferTail).paddr
490  io.uncache.req.bits.meta.uop      := uop(ringBufferTail)
491  io.uncache.req.bits.meta.mmio     := true.B // dataModule.io.rdata(ringBufferTail).mmio
492  io.uncache.req.bits.meta.tlb_miss := false.B
493  io.uncache.req.bits.meta.mask     := dataModule.io.rdata(ringBufferTail).mask
494  io.uncache.req.bits.meta.replay   := false.B
495
496  io.uncache.resp.ready := true.B
497
498  when(io.uncache.req.fire()){
499    pending(ringBufferTail) := false.B
500  }
501
502  dataModule.io.uncache.wen := false.B
503  when(io.uncache.resp.fire()){
504    valid(ringBufferTail) := true.B
505    dataModule.io.uncacheWrite(ringBufferTail, io.uncache.resp.bits.data(XLEN-1, 0))
506    dataModule.io.uncache.wen := true.B
507    // TODO: write back exception info
508  }
509
510  when(io.uncache.req.fire()){
511    XSDebug("uncache req: pc %x addr %x data %x op %x mask %x\n",
512      uop(ringBufferTail).cf.pc,
513      io.uncache.req.bits.addr,
514      io.uncache.req.bits.data,
515      io.uncache.req.bits.cmd,
516      io.uncache.req.bits.mask
517    )
518  }
519
520  when(io.uncache.resp.fire()){
521    XSDebug("uncache resp: data %x\n", io.dcache.resp.bits.data)
522  }
523
524  // Read vaddr for mem exception
525  io.exceptionAddr.vaddr := dataModule.io.rdata(io.exceptionAddr.lsIdx.lqIdx.value).vaddr
526
527  // misprediction recovery / exception redirect
528  // invalidate lq term using robIdx
529  val needCancel = Wire(Vec(LoadQueueSize, Bool()))
530  for (i <- 0 until LoadQueueSize) {
531    needCancel(i) := uop(i).roqIdx.needFlush(io.brqRedirect) && allocated(i) && !commited(i)
532    when(needCancel(i)) {
533      when(io.brqRedirect.bits.isReplay){
534        valid(i) := false.B
535        writebacked(i) := false.B
536        listening(i) := false.B
537        miss(i) := false.B
538        pending(i) := false.B
539      }.otherwise{
540        allocated(i) := false.B
541      }
542    }
543  }
544  when (io.brqRedirect.valid && io.brqRedirect.bits.isMisPred) {
545    ringBufferHeadExtended := ringBufferHeadExtended - PopCount(needCancel)
546  }
547
548  // assert(!io.rollback.valid)
549  when(io.rollback.valid) {
550    XSDebug("Mem rollback: pc %x roqidx %d\n", io.rollback.bits.pc, io.rollback.bits.roqIdx.asUInt)
551  }
552
553  // debug info
554  XSDebug("head %d:%d tail %d:%d\n", ringBufferHeadExtended.flag, ringBufferHead, ringBufferTailExtended.flag, ringBufferTail)
555
556  def PrintFlag(flag: Bool, name: String): Unit = {
557    when(flag) {
558      XSDebug(false, true.B, name)
559    }.otherwise {
560      XSDebug(false, true.B, " ")
561    }
562  }
563
564  for (i <- 0 until LoadQueueSize) {
565    if (i % 4 == 0) XSDebug("")
566    XSDebug(false, true.B, "%x [%x] ", uop(i).cf.pc, dataModule.io.rdata(i).paddr)
567    PrintFlag(allocated(i), "a")
568    PrintFlag(allocated(i) && valid(i), "v")
569    PrintFlag(allocated(i) && writebacked(i), "w")
570    PrintFlag(allocated(i) && commited(i), "c")
571    PrintFlag(allocated(i) && miss(i), "m")
572    PrintFlag(allocated(i) && listening(i), "l")
573    PrintFlag(allocated(i) && pending(i), "p")
574    XSDebug(false, true.B, " ")
575    if (i % 4 == 3 || i == LoadQueueSize - 1) XSDebug(false, true.B, "\n")
576  }
577
578}
579