1package xiangshan.mem 2 3import chisel3._ 4import chisel3.util._ 5import freechips.rocketchip.tile.HasFPUParameters 6import utils._ 7import xiangshan._ 8import xiangshan.cache._ 9import xiangshan.cache.{DCacheLineIO, DCacheWordIO, MemoryOpConstants, TlbRequestIO} 10import xiangshan.backend.LSUOpType 11import xiangshan.mem._ 12import xiangshan.backend.roq.RoqPtr 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 26trait HasLoadHelper { this: XSModule => 27 def rdataHelper(uop: MicroOp, rdata: UInt): UInt = { 28 val fpWen = uop.ctrl.fpWen 29 LookupTree(uop.ctrl.fuOpType, List( 30 LSUOpType.lb -> SignExt(rdata(7, 0) , XLEN), 31 LSUOpType.lh -> SignExt(rdata(15, 0), XLEN), 32 LSUOpType.lw -> Mux(fpWen, rdata, SignExt(rdata(31, 0), XLEN)), 33 LSUOpType.ld -> Mux(fpWen, rdata, SignExt(rdata(63, 0), XLEN)), 34 LSUOpType.lbu -> ZeroExt(rdata(7, 0) , XLEN), 35 LSUOpType.lhu -> ZeroExt(rdata(15, 0), XLEN), 36 LSUOpType.lwu -> ZeroExt(rdata(31, 0), XLEN), 37 )) 38 } 39 40 def fpRdataHelper(uop: MicroOp, rdata: UInt): UInt = { 41 LookupTree(uop.ctrl.fuOpType, List( 42 LSUOpType.lw -> recode(rdata(31, 0), S), 43 LSUOpType.ld -> recode(rdata(63, 0), D) 44 )) 45 } 46} 47 48class LqEnqIO extends XSBundle { 49 val canAccept = Output(Bool()) 50 val sqCanAccept = Input(Bool()) 51 val needAlloc = Vec(RenameWidth, Input(Bool())) 52 val req = Vec(RenameWidth, Flipped(ValidIO(new MicroOp))) 53 val resp = Vec(RenameWidth, Output(new LqPtr)) 54} 55 56// Load Queue 57class LoadQueue extends XSModule 58 with HasDCacheParameters 59 with HasCircularQueuePtrHelper 60 with HasLoadHelper 61{ 62 val io = IO(new Bundle() { 63 val enq = new LqEnqIO 64 val brqRedirect = Input(Valid(new Redirect)) 65 val loadIn = Vec(LoadPipelineWidth, Flipped(Valid(new LsPipelineBundle))) 66 val storeIn = Vec(StorePipelineWidth, Flipped(Valid(new LsPipelineBundle))) // FIXME: Valid() only 67 val ldout = Vec(2, DecoupledIO(new ExuOutput)) // writeback int load 68 val load_s1 = Vec(LoadPipelineWidth, Flipped(new LoadForwardQueryIO)) 69 val commits = Flipped(new RoqCommitIO) 70 val rollback = Output(Valid(new Redirect)) // replay now starts from load instead of store 71 val dcache = new DCacheLineIO 72 val uncache = new DCacheWordIO 73 val roqDeqPtr = Input(new RoqPtr) 74 val exceptionAddr = new ExceptionAddrIO 75 }) 76 77 val uop = Reg(Vec(LoadQueueSize, new MicroOp)) 78 // val data = Reg(Vec(LoadQueueSize, new LsRoqEntry)) 79 val dataModule = Module(new LSQueueData(LoadQueueSize, LoadPipelineWidth)) 80 dataModule.io := DontCare 81 val allocated = RegInit(VecInit(List.fill(LoadQueueSize)(false.B))) // lq entry has been allocated 82 val datavalid = RegInit(VecInit(List.fill(LoadQueueSize)(false.B))) // data is valid 83 val writebacked = RegInit(VecInit(List.fill(LoadQueueSize)(false.B))) // inst has been writebacked to CDB 84 val commited = Reg(Vec(LoadQueueSize, Bool())) // inst has been writebacked to CDB 85 val miss = Reg(Vec(LoadQueueSize, Bool())) // load inst missed, waiting for miss queue to accept miss request 86 val listening = Reg(Vec(LoadQueueSize, Bool())) // waiting for refill result 87 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 88 89 val debug_mmio = Reg(Vec(LoadQueueSize, Bool())) // mmio: inst is an mmio inst 90 91 val enqPtrExt = RegInit(VecInit((0 until RenameWidth).map(_.U.asTypeOf(new LqPtr)))) 92 val deqPtrExt = RegInit(0.U.asTypeOf(new LqPtr)) 93 val validCounter = RegInit(0.U(log2Ceil(LoadQueueSize + 1).W)) 94 val allowEnqueue = RegInit(true.B) 95 96 val enqPtr = enqPtrExt(0).value 97 val deqPtr = deqPtrExt.value 98 val sameFlag = enqPtrExt(0).flag === deqPtrExt.flag 99 val isEmpty = enqPtr === deqPtr && sameFlag 100 val isFull = enqPtr === deqPtr && !sameFlag 101 val allowIn = !isFull 102 103 val loadCommit = (0 until CommitWidth).map(i => io.commits.valid(i) && !io.commits.isWalk && io.commits.info(i).commitType === CommitType.LOAD) 104 val mcommitIdx = (0 until CommitWidth).map(i => io.commits.info(i).lqIdx.value) 105 106 val deqMask = UIntToMask(deqPtr, LoadQueueSize) 107 val enqMask = UIntToMask(enqPtr, LoadQueueSize) 108 109 /** 110 * Enqueue at dispatch 111 * 112 * Currently, LoadQueue only allows enqueue when #emptyEntries > RenameWidth(EnqWidth) 113 */ 114 io.enq.canAccept := allowEnqueue 115 116 for (i <- 0 until RenameWidth) { 117 val offset = if (i == 0) 0.U else PopCount(io.enq.needAlloc.take(i)) 118 val lqIdx = enqPtrExt(offset) 119 val index = lqIdx.value 120 when (io.enq.req(i).valid && io.enq.canAccept && io.enq.sqCanAccept && !io.brqRedirect.valid) { 121 uop(index) := io.enq.req(i).bits 122 allocated(index) := true.B 123 datavalid(index) := false.B 124 writebacked(index) := false.B 125 commited(index) := false.B 126 miss(index) := false.B 127 listening(index) := false.B 128 pending(index) := false.B 129 } 130 io.enq.resp(i) := lqIdx 131 } 132 XSDebug(p"(ready, valid): ${io.enq.canAccept}, ${Binary(Cat(io.enq.req.map(_.valid)))}\n") 133 134 /** 135 * Writeback load from load units 136 * 137 * Most load instructions writeback to regfile at the same time. 138 * However, 139 * (1) For an mmio instruction with exceptions, it writes back to ROB immediately. 140 * (2) For an mmio instruction without exceptions, it does not write back. 141 * The mmio instruction will be sent to lower level when it reaches ROB's head. 142 * After uncache response, it will write back through arbiter with loadUnit. 143 * (3) For cache misses, it is marked miss and sent to dcache later. 144 * After cache refills, it will write back through arbiter with loadUnit. 145 */ 146 for (i <- 0 until LoadPipelineWidth) { 147 dataModule.io.wb(i).wen := false.B 148 when(io.loadIn(i).fire()) { 149 when(io.loadIn(i).bits.miss) { 150 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", 151 io.loadIn(i).bits.uop.lqIdx.asUInt, 152 io.loadIn(i).bits.uop.cf.pc, 153 io.loadIn(i).bits.vaddr, 154 io.loadIn(i).bits.paddr, 155 io.loadIn(i).bits.data, 156 io.loadIn(i).bits.mask, 157 io.loadIn(i).bits.forwardData.asUInt, 158 io.loadIn(i).bits.forwardMask.asUInt, 159 io.loadIn(i).bits.mmio, 160 io.loadIn(i).bits.rollback, 161 io.loadIn(i).bits.uop.cf.exceptionVec.asUInt 162 ) 163 }.otherwise { 164 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", 165 io.loadIn(i).bits.uop.lqIdx.asUInt, 166 io.loadIn(i).bits.uop.cf.pc, 167 io.loadIn(i).bits.vaddr, 168 io.loadIn(i).bits.paddr, 169 io.loadIn(i).bits.data, 170 io.loadIn(i).bits.mask, 171 io.loadIn(i).bits.forwardData.asUInt, 172 io.loadIn(i).bits.forwardMask.asUInt, 173 io.loadIn(i).bits.mmio, 174 io.loadIn(i).bits.rollback, 175 io.loadIn(i).bits.uop.cf.exceptionVec.asUInt 176 ) 177 } 178 val loadWbIndex = io.loadIn(i).bits.uop.lqIdx.value 179 datavalid(loadWbIndex) := !io.loadIn(i).bits.miss && !io.loadIn(i).bits.mmio 180 writebacked(loadWbIndex) := !io.loadIn(i).bits.miss && !io.loadIn(i).bits.mmio 181 182 val loadWbData = Wire(new LsqEntry) 183 loadWbData.paddr := io.loadIn(i).bits.paddr 184 loadWbData.vaddr := io.loadIn(i).bits.vaddr 185 loadWbData.mask := io.loadIn(i).bits.mask 186 loadWbData.data := io.loadIn(i).bits.data // for mmio / misc / debug 187 loadWbData.fwdMask := io.loadIn(i).bits.forwardMask 188 loadWbData.fwdData := io.loadIn(i).bits.forwardData 189 loadWbData.exception := io.loadIn(i).bits.uop.cf.exceptionVec.asUInt 190 dataModule.io.wbWrite(i, loadWbIndex, loadWbData) 191 dataModule.io.wb(i).wen := true.B 192 193 debug_mmio(loadWbIndex) := io.loadIn(i).bits.mmio 194 195 val dcacheMissed = io.loadIn(i).bits.miss && !io.loadIn(i).bits.mmio 196 miss(loadWbIndex) := dcacheMissed && !io.loadIn(i).bits.uop.cf.exceptionVec.asUInt.orR 197 listening(loadWbIndex) := dcacheMissed 198 pending(loadWbIndex) := io.loadIn(i).bits.mmio && !io.loadIn(i).bits.uop.cf.exceptionVec.asUInt.orR 199 } 200 } 201 202 /** 203 * Cache miss request 204 * 205 * (1) writeback: miss 206 * (2) send to dcache: listing 207 * (3) dcache response: datavalid 208 * (4) writeback to ROB: writeback 209 */ 210 val inflightReqs = RegInit(VecInit(Seq.fill(cfg.nLoadMissEntries)(0.U.asTypeOf(new InflightBlockInfo)))) 211 val inflightReqFull = inflightReqs.map(req => req.valid).reduce(_&&_) 212 val reqBlockIndex = PriorityEncoder(~VecInit(inflightReqs.map(req => req.valid)).asUInt) 213 214 val missRefillSelVec = VecInit( 215 (0 until LoadQueueSize).map{ i => 216 val inflight = inflightReqs.map(req => req.valid && req.block_addr === get_block_addr(dataModule.io.rdata(i).paddr)).reduce(_||_) 217 allocated(i) && miss(i) && !inflight 218 }) 219 220 val missRefillSel = getFirstOne(missRefillSelVec, deqMask) 221 val missRefillBlockAddr = get_block_addr(dataModule.io.rdata(missRefillSel).paddr) 222 io.dcache.req.valid := missRefillSelVec.asUInt.orR 223 io.dcache.req.bits.cmd := MemoryOpConstants.M_XRD 224 io.dcache.req.bits.addr := missRefillBlockAddr 225 io.dcache.req.bits.data := DontCare 226 io.dcache.req.bits.mask := DontCare 227 228 io.dcache.req.bits.meta.id := DontCare 229 io.dcache.req.bits.meta.vaddr := DontCare // dataModule.io.rdata(missRefillSel).vaddr 230 io.dcache.req.bits.meta.paddr := missRefillBlockAddr 231 io.dcache.req.bits.meta.uop := uop(missRefillSel) 232 io.dcache.req.bits.meta.mmio := false.B // mmio(missRefillSel) 233 io.dcache.req.bits.meta.tlb_miss := false.B 234 io.dcache.req.bits.meta.mask := DontCare 235 io.dcache.req.bits.meta.replay := false.B 236 237 io.dcache.resp.ready := true.B 238 239 assert(!(debug_mmio(missRefillSel) && io.dcache.req.valid)) 240 241 when(io.dcache.req.fire()) { 242 miss(missRefillSel) := false.B 243 listening(missRefillSel) := true.B 244 245 // mark this block as inflight 246 inflightReqs(reqBlockIndex).valid := true.B 247 inflightReqs(reqBlockIndex).block_addr := missRefillBlockAddr 248 assert(!inflightReqs(reqBlockIndex).valid) 249 } 250 251 when(io.dcache.resp.fire()) { 252 val inflight = inflightReqs.map(req => req.valid && req.block_addr === get_block_addr(io.dcache.resp.bits.meta.paddr)).reduce(_||_) 253 assert(inflight) 254 for (i <- 0 until cfg.nLoadMissEntries) { 255 when (inflightReqs(i).valid && inflightReqs(i).block_addr === get_block_addr(io.dcache.resp.bits.meta.paddr)) { 256 inflightReqs(i).valid := false.B 257 } 258 } 259 } 260 261 262 when(io.dcache.req.fire()){ 263 XSDebug("miss req: pc:0x%x roqIdx:%d lqIdx:%d (p)addr:0x%x vaddr:0x%x\n", 264 io.dcache.req.bits.meta.uop.cf.pc, io.dcache.req.bits.meta.uop.roqIdx.asUInt, io.dcache.req.bits.meta.uop.lqIdx.asUInt, 265 io.dcache.req.bits.addr, io.dcache.req.bits.meta.vaddr 266 ) 267 } 268 269 when(io.dcache.resp.fire()){ 270 XSDebug("miss resp: pc:0x%x roqIdx:%d lqIdx:%d (p)addr:0x%x data %x\n", 271 io.dcache.resp.bits.meta.uop.cf.pc, io.dcache.resp.bits.meta.uop.roqIdx.asUInt, io.dcache.resp.bits.meta.uop.lqIdx.asUInt, 272 io.dcache.resp.bits.meta.paddr, io.dcache.resp.bits.data 273 ) 274 } 275 276 // Refill 64 bit in a cycle 277 // Refill data comes back from io.dcache.resp 278 dataModule.io.refill.dcache := io.dcache.resp.bits 279 280 (0 until LoadQueueSize).map(i => { 281 val blockMatch = get_block_addr(dataModule.io.rdata(i).paddr) === io.dcache.resp.bits.meta.paddr 282 dataModule.io.refill.wen(i) := false.B 283 when(allocated(i) && listening(i) && blockMatch && io.dcache.resp.fire()) { 284 dataModule.io.refill.wen(i) := true.B 285 datavalid(i) := true.B 286 listening(i) := false.B 287 } 288 }) 289 290 // writeback up to 2 missed load insts to CDB 291 // just randomly pick 2 missed load (data refilled), write them back to cdb 292 val loadWbSelVec = VecInit((0 until LoadQueueSize).map(i => { 293 allocated(i) && datavalid(i) && !writebacked(i) 294 })).asUInt() // use uint instead vec to reduce verilog lines 295 val loadWbSel = Wire(Vec(StorePipelineWidth, UInt(log2Up(LoadQueueSize).W))) 296 val loadWbSelV= Wire(Vec(StorePipelineWidth, Bool())) 297 val lselvec0 = PriorityEncoderOH(loadWbSelVec) 298 val lselvec1 = PriorityEncoderOH(loadWbSelVec & (~lselvec0).asUInt) 299 loadWbSel(0) := OHToUInt(lselvec0) 300 loadWbSelV(0):= lselvec0.orR 301 loadWbSel(1) := OHToUInt(lselvec1) 302 loadWbSelV(1) := lselvec1.orR 303 (0 until StorePipelineWidth).map(i => { 304 // data select 305 val rdata = dataModule.io.rdata(loadWbSel(i)).data 306 val seluop = uop(loadWbSel(i)) 307 val func = seluop.ctrl.fuOpType 308 val raddr = dataModule.io.rdata(loadWbSel(i)).paddr 309 val rdataSel = LookupTree(raddr(2, 0), List( 310 "b000".U -> rdata(63, 0), 311 "b001".U -> rdata(63, 8), 312 "b010".U -> rdata(63, 16), 313 "b011".U -> rdata(63, 24), 314 "b100".U -> rdata(63, 32), 315 "b101".U -> rdata(63, 40), 316 "b110".U -> rdata(63, 48), 317 "b111".U -> rdata(63, 56) 318 )) 319 val rdataPartialLoad = rdataHelper(seluop, rdataSel) 320 321 val validWb = loadWbSelVec(loadWbSel(i)) && loadWbSelV(i) 322 323 // writeback missed int/fp load 324 // 325 // Int load writeback will finish (if not blocked) in one cycle 326 io.ldout(i).bits.uop := seluop 327 io.ldout(i).bits.uop.cf.exceptionVec := dataModule.io.rdata(loadWbSel(i)).exception.asBools 328 io.ldout(i).bits.uop.lqIdx := loadWbSel(i).asTypeOf(new LqPtr) 329 io.ldout(i).bits.data := rdataPartialLoad 330 io.ldout(i).bits.redirectValid := false.B 331 io.ldout(i).bits.redirect := DontCare 332 io.ldout(i).bits.brUpdate := DontCare 333 io.ldout(i).bits.debug.isMMIO := debug_mmio(loadWbSel(i)) 334 io.ldout(i).bits.fflags := DontCare 335 io.ldout(i).valid := validWb 336 337 when(io.ldout(i).fire()){ 338 writebacked(loadWbSel(i)) := true.B 339 } 340 341 when(io.ldout(i).fire()) { 342 XSInfo("int load miss write to cbd roqidx %d lqidx %d pc 0x%x paddr %x data %x mmio %x\n", 343 io.ldout(i).bits.uop.roqIdx.asUInt, 344 io.ldout(i).bits.uop.lqIdx.asUInt, 345 io.ldout(i).bits.uop.cf.pc, 346 dataModule.io.rdata(loadWbSel(i)).paddr, 347 dataModule.io.rdata(loadWbSel(i)).data, 348 debug_mmio(loadWbSel(i)) 349 ) 350 } 351 352 }) 353 354 /** 355 * Load commits 356 * 357 * When load commited, mark it as !allocated and move deqPtrExt forward. 358 */ 359 (0 until CommitWidth).map(i => { 360 when(loadCommit(i)) { 361 allocated(mcommitIdx(i)) := false.B 362 XSDebug("load commit %d: idx %d %x\n", i.U, mcommitIdx(i), uop(mcommitIdx(i)).cf.pc) 363 } 364 }) 365 366 def getFirstOne(mask: Vec[Bool], startMask: UInt) = { 367 val length = mask.length 368 val highBits = (0 until length).map(i => mask(i) & ~startMask(i)) 369 val highBitsUint = Cat(highBits.reverse) 370 PriorityEncoder(Mux(highBitsUint.orR(), highBitsUint, mask.asUInt)) 371 } 372 373 def getOldestInTwo(valid: Seq[Bool], uop: Seq[MicroOp]) = { 374 assert(valid.length == uop.length) 375 assert(valid.length == 2) 376 Mux(valid(0) && valid(1), 377 Mux(isAfter(uop(0).roqIdx, uop(1).roqIdx), uop(1), uop(0)), 378 Mux(valid(0) && !valid(1), uop(0), uop(1))) 379 } 380 381 def getAfterMask(valid: Seq[Bool], uop: Seq[MicroOp]) = { 382 assert(valid.length == uop.length) 383 val length = valid.length 384 (0 until length).map(i => { 385 (0 until length).map(j => { 386 Mux(valid(i) && valid(j), 387 isAfter(uop(i).roqIdx, uop(j).roqIdx), 388 Mux(!valid(i), true.B, false.B)) 389 }) 390 }) 391 } 392 393 /** 394 * Memory violation detection 395 * 396 * When store writes back, it searches LoadQueue for younger load instructions 397 * with the same load physical address. They loaded wrong data and need re-execution. 398 * 399 * Cycle 0: Store Writeback 400 * Generate match vector for store address with rangeMask(stPtr, enqPtr). 401 * Besides, load instructions in LoadUnit_S1 and S2 are also checked. 402 * Cycle 1: Redirect Generation 403 * There're three possible types of violations. Choose the oldest load. 404 * Set io.redirect according to the detected violation. 405 */ 406 io.load_s1 := DontCare 407 def detectRollback(i: Int) = { 408 val startIndex = io.storeIn(i).bits.uop.lqIdx.value 409 val lqIdxMask = UIntToMask(startIndex, LoadQueueSize) 410 val xorMask = lqIdxMask ^ enqMask 411 val sameFlag = io.storeIn(i).bits.uop.lqIdx.flag === enqPtrExt(0).flag 412 val toEnqPtrMask = Mux(sameFlag, xorMask, ~xorMask) 413 414 // check if load already in lq needs to be rolledback 415 val lqViolationVec = RegNext(VecInit((0 until LoadQueueSize).map(j => { 416 val addrMatch = allocated(j) && 417 io.storeIn(i).bits.paddr(PAddrBits - 1, 3) === dataModule.io.rdata(j).paddr(PAddrBits - 1, 3) 418 val entryNeedCheck = toEnqPtrMask(j) && addrMatch && (datavalid(j) || listening(j) || miss(j)) 419 // TODO: update refilled data 420 val violationVec = (0 until 8).map(k => dataModule.io.rdata(j).mask(k) && io.storeIn(i).bits.mask(k)) 421 Cat(violationVec).orR() && entryNeedCheck 422 }))) 423 val lqViolation = lqViolationVec.asUInt().orR() 424 val lqViolationIndex = getFirstOne(lqViolationVec, RegNext(lqIdxMask)) 425 val lqViolationUop = uop(lqViolationIndex) 426 // lqViolationUop.lqIdx.flag := deqMask(lqViolationIndex) ^ deqPtrExt.flag 427 // lqViolationUop.lqIdx.value := lqViolationIndex 428 XSDebug(lqViolation, p"${Binary(Cat(lqViolationVec))}, $startIndex, $lqViolationIndex\n") 429 430 // when l/s writeback to roq together, check if rollback is needed 431 val wbViolationVec = RegNext(VecInit((0 until LoadPipelineWidth).map(j => { 432 io.loadIn(j).valid && 433 isAfter(io.loadIn(j).bits.uop.roqIdx, io.storeIn(i).bits.uop.roqIdx) && 434 io.storeIn(i).bits.paddr(PAddrBits - 1, 3) === io.loadIn(j).bits.paddr(PAddrBits - 1, 3) && 435 (io.storeIn(i).bits.mask & io.loadIn(j).bits.mask).orR 436 }))) 437 val wbViolation = wbViolationVec.asUInt().orR() 438 val wbViolationUop = getOldestInTwo(wbViolationVec, RegNext(VecInit(io.loadIn.map(_.bits.uop)))) 439 XSDebug(wbViolation, p"${Binary(Cat(wbViolationVec))}, $wbViolationUop\n") 440 441 // check if rollback is needed for load in l1 442 val l1ViolationVec = RegNext(VecInit((0 until LoadPipelineWidth).map(j => { 443 io.load_s1(j).valid && // L1 valid 444 isAfter(io.load_s1(j).uop.roqIdx, io.storeIn(i).bits.uop.roqIdx) && 445 io.storeIn(i).bits.paddr(PAddrBits - 1, 3) === io.load_s1(j).paddr(PAddrBits - 1, 3) && 446 (io.storeIn(i).bits.mask & io.load_s1(j).mask).orR 447 }))) 448 val l1Violation = l1ViolationVec.asUInt().orR() 449 val l1ViolationUop = getOldestInTwo(l1ViolationVec, RegNext(VecInit(io.load_s1.map(_.uop)))) 450 XSDebug(l1Violation, p"${Binary(Cat(l1ViolationVec))}, $l1ViolationUop\n") 451 452 val rollbackValidVec = Seq(lqViolation, wbViolation, l1Violation) 453 val rollbackUopVec = Seq(lqViolationUop, wbViolationUop, l1ViolationUop) 454 455 val mask = getAfterMask(rollbackValidVec, rollbackUopVec) 456 val oneAfterZero = mask(1)(0) 457 val rollbackUop = Mux(oneAfterZero && mask(2)(0), 458 rollbackUopVec(0), 459 Mux(!oneAfterZero && mask(2)(1), rollbackUopVec(1), rollbackUopVec(2))) 460 461 XSDebug( 462 l1Violation, 463 "need rollback (l4 load) pc %x roqidx %d target %x\n", 464 io.storeIn(i).bits.uop.cf.pc, io.storeIn(i).bits.uop.roqIdx.asUInt, l1ViolationUop.roqIdx.asUInt 465 ) 466 XSDebug( 467 lqViolation, 468 "need rollback (ld wb before store) pc %x roqidx %d target %x\n", 469 io.storeIn(i).bits.uop.cf.pc, io.storeIn(i).bits.uop.roqIdx.asUInt, lqViolationUop.roqIdx.asUInt 470 ) 471 XSDebug( 472 wbViolation, 473 "need rollback (ld/st wb together) pc %x roqidx %d target %x\n", 474 io.storeIn(i).bits.uop.cf.pc, io.storeIn(i).bits.uop.roqIdx.asUInt, wbViolationUop.roqIdx.asUInt 475 ) 476 477 (RegNext(io.storeIn(i).valid) && Cat(rollbackValidVec).orR, rollbackUop) 478 } 479 480 // rollback check 481 val rollback = Wire(Vec(StorePipelineWidth, Valid(new MicroOp))) 482 for (i <- 0 until StorePipelineWidth) { 483 val detectedRollback = detectRollback(i) 484 rollback(i).valid := detectedRollback._1 485 rollback(i).bits := detectedRollback._2 486 } 487 488 def rollbackSel(a: Valid[MicroOp], b: Valid[MicroOp]): ValidIO[MicroOp] = { 489 Mux( 490 a.valid, 491 Mux( 492 b.valid, 493 Mux(isAfter(a.bits.roqIdx, b.bits.roqIdx), b, a), // a,b both valid, sel oldest 494 a // sel a 495 ), 496 b // sel b 497 ) 498 } 499 500 val rollbackSelected = ParallelOperation(rollback, rollbackSel) 501 val lastCycleRedirect = RegNext(io.brqRedirect) 502 503 // Note that we use roqIdx - 1.U to flush the load instruction itself. 504 // Thus, here if last cycle's roqIdx equals to this cycle's roqIdx, it still triggers the redirect. 505 io.rollback.valid := rollbackSelected.valid && 506 (!lastCycleRedirect.valid || !isAfter(rollbackSelected.bits.roqIdx, lastCycleRedirect.bits.roqIdx)) && 507 !(lastCycleRedirect.valid && lastCycleRedirect.bits.isUnconditional()) 508 509 io.rollback.bits.roqIdx := rollbackSelected.bits.roqIdx 510 io.rollback.bits.level := RedirectLevel.flush 511 io.rollback.bits.interrupt := DontCare 512 io.rollback.bits.pc := DontCare 513 io.rollback.bits.target := rollbackSelected.bits.cf.pc 514 io.rollback.bits.brTag := rollbackSelected.bits.brTag 515 516 when(io.rollback.valid) { 517 XSDebug("Mem rollback: pc %x roqidx %d\n", io.rollback.bits.pc, io.rollback.bits.roqIdx.asUInt) 518 } 519 520 /** 521 * Memory mapped IO / other uncached operations 522 * 523 */ 524 io.uncache.req.valid := pending(deqPtr) && allocated(deqPtr) && 525 io.commits.info(0).commitType === CommitType.LOAD && 526 io.roqDeqPtr === uop(deqPtr).roqIdx && 527 !io.commits.isWalk 528 529 io.uncache.req.bits.cmd := MemoryOpConstants.M_XRD 530 io.uncache.req.bits.addr := dataModule.io.rdata(deqPtr).paddr 531 io.uncache.req.bits.data := dataModule.io.rdata(deqPtr).data 532 io.uncache.req.bits.mask := dataModule.io.rdata(deqPtr).mask 533 534 io.uncache.req.bits.meta.id := DontCare 535 io.uncache.req.bits.meta.vaddr := DontCare 536 io.uncache.req.bits.meta.paddr := dataModule.io.rdata(deqPtr).paddr 537 io.uncache.req.bits.meta.uop := uop(deqPtr) 538 io.uncache.req.bits.meta.mmio := true.B 539 io.uncache.req.bits.meta.tlb_miss := false.B 540 io.uncache.req.bits.meta.mask := dataModule.io.rdata(deqPtr).mask 541 io.uncache.req.bits.meta.replay := false.B 542 543 io.uncache.resp.ready := true.B 544 545 when (io.uncache.req.fire()) { 546 pending(deqPtr) := false.B 547 548 XSDebug("uncache req: pc %x addr %x data %x op %x mask %x\n", 549 uop(deqPtr).cf.pc, 550 io.uncache.req.bits.addr, 551 io.uncache.req.bits.data, 552 io.uncache.req.bits.cmd, 553 io.uncache.req.bits.mask 554 ) 555 } 556 557 dataModule.io.uncache.wen := false.B 558 when(io.uncache.resp.fire()){ 559 datavalid(deqPtr) := true.B 560 dataModule.io.uncacheWrite(deqPtr, io.uncache.resp.bits.data(XLEN-1, 0)) 561 dataModule.io.uncache.wen := true.B 562 563 XSDebug("uncache resp: data %x\n", io.dcache.resp.bits.data) 564 } 565 566 // Read vaddr for mem exception 567 io.exceptionAddr.vaddr := dataModule.io.rdata(io.exceptionAddr.lsIdx.lqIdx.value).vaddr 568 569 // misprediction recovery / exception redirect 570 // invalidate lq term using robIdx 571 val needCancel = Wire(Vec(LoadQueueSize, Bool())) 572 for (i <- 0 until LoadQueueSize) { 573 needCancel(i) := uop(i).roqIdx.needFlush(io.brqRedirect) && allocated(i) && !commited(i) 574 when (needCancel(i)) { 575 allocated(i) := false.B 576 } 577 } 578 579 /** 580 * update pointers 581 */ 582 val lastCycleCancelCount = PopCount(RegNext(needCancel)) 583 // when io.brqRedirect.valid, we don't allow eneuque even though it may fire. 584 val enqNumber = Mux(io.enq.canAccept && io.enq.sqCanAccept && !io.brqRedirect.valid, PopCount(io.enq.req.map(_.valid)), 0.U) 585 when (lastCycleRedirect.valid) { 586 // we recover the pointers in the next cycle after redirect 587 enqPtrExt := VecInit(enqPtrExt.map(_ - lastCycleCancelCount)) 588 }.otherwise { 589 enqPtrExt := VecInit(enqPtrExt.map(_ + enqNumber)) 590 } 591 592 val commitCount = PopCount(loadCommit) 593 deqPtrExt := deqPtrExt + commitCount 594 595 val lastLastCycleRedirect = RegNext(lastCycleRedirect.valid) 596 val trueValidCounter = distanceBetween(enqPtrExt(0), deqPtrExt) 597 validCounter := Mux(lastLastCycleRedirect, 598 trueValidCounter, 599 validCounter + enqNumber - commitCount 600 ) 601 602 allowEnqueue := Mux(io.brqRedirect.valid, 603 false.B, 604 Mux(lastLastCycleRedirect, 605 trueValidCounter <= (LoadQueueSize - RenameWidth).U, 606 validCounter + enqNumber <= (LoadQueueSize - RenameWidth).U 607 ) 608 ) 609 610 // debug info 611 XSDebug("enqPtrExt %d:%d deqPtrExt %d:%d\n", enqPtrExt(0).flag, enqPtr, deqPtrExt.flag, deqPtr) 612 613 def PrintFlag(flag: Bool, name: String): Unit = { 614 when(flag) { 615 XSDebug(false, true.B, name) 616 }.otherwise { 617 XSDebug(false, true.B, " ") 618 } 619 } 620 621 for (i <- 0 until LoadQueueSize) { 622 if (i % 4 == 0) XSDebug("") 623 XSDebug(false, true.B, "%x [%x] ", uop(i).cf.pc, dataModule.io.rdata(i).paddr) 624 PrintFlag(allocated(i), "a") 625 PrintFlag(allocated(i) && datavalid(i), "v") 626 PrintFlag(allocated(i) && writebacked(i), "w") 627 PrintFlag(allocated(i) && commited(i), "c") 628 PrintFlag(allocated(i) && miss(i), "m") 629 PrintFlag(allocated(i) && listening(i), "l") 630 PrintFlag(allocated(i) && pending(i), "p") 631 XSDebug(false, true.B, " ") 632 if (i % 4 == 3 || i == LoadQueueSize - 1) XSDebug(false, true.B, "\n") 633 } 634 635} 636