xref: /XiangShan/src/main/scala/xiangshan/frontend/icache/ICache.scala (revision d7ff19264f2f210248701d414744dd2031dba66c)
1/***************************************************************************************
2* Copyright (c) 2024 Beijing Institute of Open Source Chip (BOSC)
3* Copyright (c) 2020-2024 Institute of Computing Technology, Chinese Academy of Sciences
4* Copyright (c) 2020-2021 Peng Cheng Laboratory
5*
6* XiangShan is licensed under Mulan PSL v2.
7* You can use this software according to the terms and conditions of the Mulan PSL v2.
8* You may obtain a copy of Mulan PSL v2 at:
9*          http://license.coscl.org.cn/MulanPSL2
10*
11* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
12* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
13* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
14*
15* See the Mulan PSL v2 for more details.
16*
17*
18* Acknowledgement
19*
20* This implementation is inspired by several key papers:
21* [1] Glenn Reinman, Brad Calder, and Todd Austin. "[Fetch directed instruction prefetching.]
22* (https://doi.org/10.1109/MICRO.1999.809439)" 32nd Annual ACM/IEEE International Symposium on Microarchitecture
23* (MICRO). 1999.
24***************************************************************************************/
25
26package xiangshan.frontend.icache
27
28import chisel3._
29import chisel3.util._
30import freechips.rocketchip.diplomacy.AddressSet
31import freechips.rocketchip.diplomacy.IdRange
32import freechips.rocketchip.diplomacy.LazyModule
33import freechips.rocketchip.diplomacy.LazyModuleImp
34import freechips.rocketchip.tilelink._
35import freechips.rocketchip.util.BundleFieldBase
36import huancun.AliasField
37import huancun.PrefetchField
38import org.chipsalliance.cde.config.Parameters
39import utility._
40import utility.mbist.MbistPipeline
41import utility.sram.SRAMReadBus
42import utility.sram.SRAMTemplate
43import utility.sram.SRAMWriteBus
44import utils._
45import xiangshan._
46import xiangshan.cache._
47import xiangshan.cache.mmu.TlbRequestIO
48import xiangshan.frontend._
49
50case class ICacheParameters(
51    nSets:               Int = 256,
52    nWays:               Int = 4,
53    rowBits:             Int = 64,
54    nTLBEntries:         Int = 32,
55    tagECC:              Option[String] = None,
56    dataECC:             Option[String] = None,
57    replacer:            Option[String] = Some("random"),
58    PortNumber:          Int = 2,
59    nFetchMshr:          Int = 4,
60    nPrefetchMshr:       Int = 10,
61    nWayLookupSize:      Int = 32,
62    DataCodeUnit:        Int = 64,
63    ICacheDataBanks:     Int = 8,
64    ICacheDataSRAMWidth: Int = 66,
65    // TODO: hard code, need delete
66    partWayNum:          Int = 4,
67    nMMIOs:              Int = 1,
68    blockBytes:          Int = 64,
69    cacheCtrlAddressOpt: Option[AddressSet] = None
70) extends L1CacheParameters {
71
72  val setBytes:     Int         = nSets * blockBytes
73  val aliasBitsOpt: Option[Int] = Option.when(setBytes > pageSize)(log2Ceil(setBytes / pageSize))
74  val reqFields: Seq[BundleFieldBase] = Seq(
75    PrefetchField(),
76    ReqSourceField()
77  ) ++ aliasBitsOpt.map(AliasField)
78  val echoFields: Seq[BundleFieldBase] = Nil
79  def tagCode:    Code                 = Code.fromString(tagECC)
80  def dataCode:   Code                 = Code.fromString(dataECC)
81  def replacement = ReplacementPolicy.fromString(replacer, nWays, nSets)
82}
83
84trait HasICacheParameters extends HasL1CacheParameters with HasInstrMMIOConst with HasIFUConst {
85  val cacheParams: ICacheParameters = icacheParameters
86
87  def ctrlUnitParamsOpt: Option[L1ICacheCtrlParams] = OptionWrapper(
88    cacheParams.cacheCtrlAddressOpt.nonEmpty,
89    L1ICacheCtrlParams(
90      address = cacheParams.cacheCtrlAddressOpt.get,
91      regWidth = XLEN
92    )
93  )
94
95  def ICacheSets:          Int = cacheParams.nSets
96  def ICacheWays:          Int = cacheParams.nWays
97  def PortNumber:          Int = cacheParams.PortNumber
98  def nFetchMshr:          Int = cacheParams.nFetchMshr
99  def nPrefetchMshr:       Int = cacheParams.nPrefetchMshr
100  def nWayLookupSize:      Int = cacheParams.nWayLookupSize
101  def DataCodeUnit:        Int = cacheParams.DataCodeUnit
102  def ICacheDataBanks:     Int = cacheParams.ICacheDataBanks
103  def ICacheDataSRAMWidth: Int = cacheParams.ICacheDataSRAMWidth
104  def partWayNum:          Int = cacheParams.partWayNum
105
106  def ICacheMetaBits:      Int = tagBits // FIXME: unportable: maybe use somemethod to get width
107  def ICacheMetaCodeBits:  Int = 1       // FIXME: unportable: maybe use cacheParams.tagCode.somemethod to get width
108  def ICacheMetaEntryBits: Int = ICacheMetaBits + ICacheMetaCodeBits
109
110  def ICacheDataBits: Int = blockBits / ICacheDataBanks
111  def ICacheDataCodeSegs: Int =
112    math.ceil(ICacheDataBits / DataCodeUnit).toInt // split data to segments for ECC checking
113  def ICacheDataCodeBits: Int =
114    ICacheDataCodeSegs * 1 // FIXME: unportable: maybe use cacheParams.dataCode.somemethod to get width
115  def ICacheDataEntryBits: Int = ICacheDataBits + ICacheDataCodeBits
116  def ICacheBankVisitNum:  Int = 32 * 8 / ICacheDataBits + 1
117  def highestIdxBit:       Int = log2Ceil(nSets) - 1
118
119  require((ICacheDataBanks >= 2) && isPow2(ICacheDataBanks))
120  require(ICacheDataSRAMWidth >= ICacheDataEntryBits)
121  require(isPow2(ICacheSets), s"nSets($ICacheSets) must be pow2")
122  require(isPow2(ICacheWays), s"nWays($ICacheWays) must be pow2")
123
124  def generatePipeControl(lastFire: Bool, thisFire: Bool, thisFlush: Bool, lastFlush: Bool): Bool = {
125    val valid = RegInit(false.B)
126    when(thisFlush)(valid := false.B)
127      .elsewhen(lastFire && !lastFlush)(valid := true.B)
128      .elsewhen(thisFire)(valid := false.B)
129    valid
130  }
131
132  def ResultHoldBypass[T <: Data](data: T, valid: Bool): T =
133    Mux(valid, data, RegEnable(data, valid))
134
135  def ResultHoldBypass[T <: Data](data: T, init: T, valid: Bool): T =
136    Mux(valid, data, RegEnable(data, init, valid))
137
138  def holdReleaseLatch(valid: Bool, release: Bool, flush: Bool): Bool = {
139    val bit = RegInit(false.B)
140    when(flush)(bit := false.B)
141      .elsewhen(valid && !release)(bit := true.B)
142      .elsewhen(release)(bit := false.B)
143    bit || valid
144  }
145
146  def blockCounter(block: Bool, flush: Bool, threshold: Int): Bool = {
147    val counter = RegInit(0.U(log2Up(threshold + 1).W))
148    when(block)(counter := counter + 1.U)
149    when(flush)(counter := 0.U)
150    counter > threshold.U
151  }
152
153  def InitQueue[T <: Data](entry: T, size: Int): Vec[T] =
154    RegInit(VecInit(Seq.fill(size)(0.U.asTypeOf(entry.cloneType))))
155
156  def getBankSel(blkOffset: UInt, valid: Bool = true.B): Vec[UInt] = {
157    val bankIdxLow  = (Cat(0.U(1.W), blkOffset) >> log2Ceil(blockBytes / ICacheDataBanks)).asUInt
158    val bankIdxHigh = ((Cat(0.U(1.W), blkOffset) + 32.U) >> log2Ceil(blockBytes / ICacheDataBanks)).asUInt
159    val bankSel     = VecInit((0 until ICacheDataBanks * 2).map(i => (i.U >= bankIdxLow) && (i.U <= bankIdxHigh)))
160    assert(
161      !valid || PopCount(bankSel) === ICacheBankVisitNum.U,
162      "The number of bank visits must be %d, but bankSel=0x%x",
163      ICacheBankVisitNum.U,
164      bankSel.asUInt
165    )
166    bankSel.asTypeOf(UInt((ICacheDataBanks * 2).W)).asTypeOf(Vec(2, UInt(ICacheDataBanks.W)))
167  }
168
169  def getLineSel(blkOffset: UInt): Vec[Bool] = {
170    val bankIdxLow = (blkOffset >> log2Ceil(blockBytes / ICacheDataBanks)).asUInt
171    val lineSel    = VecInit((0 until ICacheDataBanks).map(i => i.U < bankIdxLow))
172    lineSel
173  }
174
175  def getBlkAddr(addr:        UInt): UInt = (addr >> blockOffBits).asUInt
176  def getPhyTagFromBlk(addr:  UInt): UInt = (addr >> (pgUntagBits - blockOffBits)).asUInt
177  def getIdxFromBlk(addr:     UInt): UInt = addr(idxBits - 1, 0)
178  def getPaddrFromPtag(vaddr: UInt, ptag: UInt): UInt = Cat(ptag, vaddr(pgUntagBits - 1, 0))
179  def getPaddrFromPtag(vaddrVec: Vec[UInt], ptagVec: Vec[UInt]): Vec[UInt] =
180    VecInit((vaddrVec zip ptagVec).map { case (vaddr, ptag) => getPaddrFromPtag(vaddr, ptag) })
181}
182
183trait HasICacheECCHelper extends HasICacheParameters {
184  def encodeMetaECC(meta: UInt, poison: Bool = false.B): UInt = {
185    require(meta.getWidth == ICacheMetaBits)
186    val code = cacheParams.tagCode.encode(meta, poison) >> ICacheMetaBits
187    code.asTypeOf(UInt(ICacheMetaCodeBits.W))
188  }
189
190  def encodeDataECC(data: UInt, poison: Bool = false.B): UInt = {
191    require(data.getWidth == ICacheDataBits)
192    val datas = data.asTypeOf(Vec(ICacheDataCodeSegs, UInt((ICacheDataBits / ICacheDataCodeSegs).W)))
193    val codes = VecInit(datas.map(cacheParams.dataCode.encode(_, poison) >> (ICacheDataBits / ICacheDataCodeSegs)))
194    codes.asTypeOf(UInt(ICacheDataCodeBits.W))
195  }
196}
197
198abstract class ICacheBundle(implicit p: Parameters) extends XSBundle
199    with HasICacheParameters
200
201abstract class ICacheModule(implicit p: Parameters) extends XSModule
202    with HasICacheParameters
203
204abstract class ICacheArray(implicit p: Parameters) extends XSModule
205    with HasICacheParameters
206
207class ICacheMetadata(implicit p: Parameters) extends ICacheBundle {
208  val tag: UInt = UInt(tagBits.W)
209}
210
211object ICacheMetadata {
212  def apply(tag: Bits)(implicit p: Parameters): ICacheMetadata = {
213    val meta = Wire(new ICacheMetadata)
214    meta.tag := tag
215    meta
216  }
217}
218
219class ICacheMetaArrayIO(implicit p: Parameters) extends ICacheBundle {
220  val write:    DecoupledIO[ICacheMetaWriteBundle] = Flipped(DecoupledIO(new ICacheMetaWriteBundle))
221  val read:     DecoupledIO[ICacheReadBundle]      = Flipped(DecoupledIO(new ICacheReadBundle))
222  val readResp: ICacheMetaRespBundle               = Output(new ICacheMetaRespBundle)
223  val flush:    Vec[Valid[ICacheMetaFlushBundle]]  = Vec(PortNumber, Flipped(ValidIO(new ICacheMetaFlushBundle)))
224  val flushAll: Bool                               = Input(Bool())
225}
226
227class ICacheMetaArray(implicit p: Parameters) extends ICacheArray with HasICacheECCHelper {
228  class ICacheMetaEntry(implicit p: Parameters) extends ICacheBundle {
229    val meta: ICacheMetadata = new ICacheMetadata
230    val code: UInt           = UInt(ICacheMetaCodeBits.W)
231  }
232
233  private object ICacheMetaEntry {
234    def apply(meta: ICacheMetadata, poison: Bool)(implicit p: Parameters): ICacheMetaEntry = {
235      val entry = Wire(new ICacheMetaEntry)
236      entry.meta := meta
237      entry.code := encodeMetaECC(meta.asUInt, poison)
238      entry
239    }
240  }
241
242  // sanity check
243  require(ICacheMetaEntryBits == (new ICacheMetaEntry).getWidth)
244
245  val io: ICacheMetaArrayIO = IO(new ICacheMetaArrayIO)
246
247  private val port_0_read_0 = io.read.valid && !io.read.bits.vSetIdx(0)(0)
248  private val port_0_read_1 = io.read.valid && io.read.bits.vSetIdx(0)(0)
249  private val port_1_read_1 = io.read.valid && io.read.bits.vSetIdx(1)(0) && io.read.bits.isDoubleLine
250  private val port_1_read_0 = io.read.valid && !io.read.bits.vSetIdx(1)(0) && io.read.bits.isDoubleLine
251
252  private val port_0_read_0_reg = RegEnable(port_0_read_0, 0.U.asTypeOf(port_0_read_0), io.read.fire)
253  private val port_0_read_1_reg = RegEnable(port_0_read_1, 0.U.asTypeOf(port_0_read_1), io.read.fire)
254  private val port_1_read_1_reg = RegEnable(port_1_read_1, 0.U.asTypeOf(port_1_read_1), io.read.fire)
255  private val port_1_read_0_reg = RegEnable(port_1_read_0, 0.U.asTypeOf(port_1_read_0), io.read.fire)
256
257  private val bank_0_idx = Mux(port_0_read_0, io.read.bits.vSetIdx(0), io.read.bits.vSetIdx(1))
258  private val bank_1_idx = Mux(port_0_read_1, io.read.bits.vSetIdx(0), io.read.bits.vSetIdx(1))
259
260  private val write_bank_0 = io.write.valid && !io.write.bits.bankIdx
261  private val write_bank_1 = io.write.valid && io.write.bits.bankIdx
262
263  private val write_meta_bits = ICacheMetaEntry(
264    meta = ICacheMetadata(
265      tag = io.write.bits.phyTag
266    ),
267    poison = io.write.bits.poison
268  )
269
270  private val tagArrays = (0 until PortNumber) map { bank =>
271    val tagArray = Module(new SRAMTemplate(
272      new ICacheMetaEntry(),
273      set = nSets / PortNumber,
274      way = nWays,
275      shouldReset = true,
276      holdRead = true,
277      singlePort = true,
278      withClockGate = true,
279      hasMbist = hasMbist
280    ))
281
282    // meta connection
283    if (bank == 0) {
284      tagArray.io.r.req.valid := port_0_read_0 || port_1_read_0
285      tagArray.io.r.req.bits.apply(setIdx = bank_0_idx(highestIdxBit, 1))
286      tagArray.io.w.req.valid := write_bank_0
287      tagArray.io.w.req.bits.apply(
288        data = write_meta_bits,
289        setIdx = io.write.bits.virIdx(highestIdxBit, 1),
290        waymask = io.write.bits.waymask
291      )
292    } else {
293      tagArray.io.r.req.valid := port_0_read_1 || port_1_read_1
294      tagArray.io.r.req.bits.apply(setIdx = bank_1_idx(highestIdxBit, 1))
295      tagArray.io.w.req.valid := write_bank_1
296      tagArray.io.w.req.bits.apply(
297        data = write_meta_bits,
298        setIdx = io.write.bits.virIdx(highestIdxBit, 1),
299        waymask = io.write.bits.waymask
300      )
301    }
302
303    tagArray
304  }
305  private val mbistPl = MbistPipeline.PlaceMbistPipeline(1, "MbistPipeIcacheTag", hasMbist)
306
307  private val read_set_idx_next = RegEnable(io.read.bits.vSetIdx, 0.U.asTypeOf(io.read.bits.vSetIdx), io.read.fire)
308  private val valid_array       = RegInit(VecInit(Seq.fill(nWays)(0.U(nSets.W))))
309  private val valid_metas       = Wire(Vec(PortNumber, Vec(nWays, Bool())))
310  // valid read
311  (0 until PortNumber).foreach(i =>
312    (0 until nWays).foreach(way =>
313      valid_metas(i)(way) := valid_array(way)(read_set_idx_next(i))
314    )
315  )
316  io.readResp.entryValid := valid_metas
317
318  io.read.ready := !io.write.valid && !io.flush.map(_.valid).reduce(_ || _) && !io.flushAll &&
319    tagArrays.map(_.io.r.req.ready).reduce(_ && _)
320
321  // valid write
322  private val way_num = OHToUInt(io.write.bits.waymask)
323  when(io.write.valid) {
324    valid_array(way_num) := valid_array(way_num).bitSet(io.write.bits.virIdx, true.B)
325  }
326
327  XSPerfAccumulate("meta_refill_num", io.write.valid)
328
329  io.readResp.metas <> DontCare
330  io.readResp.codes <> DontCare
331  private val readMetaEntries = tagArrays.map(port => port.io.r.resp.asTypeOf(Vec(nWays, new ICacheMetaEntry())))
332  private val readMetas       = readMetaEntries.map(_.map(_.meta))
333  private val readCodes       = readMetaEntries.map(_.map(_.code))
334
335  // TEST: force ECC to fail by setting readCodes to 0
336  if (ICacheForceMetaECCError) {
337    readCodes.foreach(_.foreach(_ := 0.U))
338  }
339
340  when(port_0_read_0_reg) {
341    io.readResp.metas(0) := readMetas(0)
342    io.readResp.codes(0) := readCodes(0)
343  }.elsewhen(port_0_read_1_reg) {
344    io.readResp.metas(0) := readMetas(1)
345    io.readResp.codes(0) := readCodes(1)
346  }
347
348  when(port_1_read_0_reg) {
349    io.readResp.metas(1) := readMetas(0)
350    io.readResp.codes(1) := readCodes(0)
351  }.elsewhen(port_1_read_1_reg) {
352    io.readResp.metas(1) := readMetas(1)
353    io.readResp.codes(1) := readCodes(1)
354  }
355
356  io.write.ready := true.B // TODO : has bug ? should be !io.cacheOp.req.valid
357
358  /*
359   * flush logic
360   */
361  // flush standalone set (e.g. flushed by mainPipe before doing re-fetch)
362  when(io.flush.map(_.valid).reduce(_ || _)) {
363    (0 until nWays).foreach { w =>
364      valid_array(w) := (0 until PortNumber).map { i =>
365        Mux(
366          // check if set `virIdx` in way `w` is requested to be flushed by port `i`
367          io.flush(i).valid && io.flush(i).bits.waymask(w),
368          valid_array(w).bitSet(io.flush(i).bits.virIdx, false.B),
369          valid_array(w)
370        )
371      }.reduce(_ & _)
372    }
373  }
374
375  // flush all (e.g. fence.i)
376  when(io.flushAll) {
377    (0 until nWays).foreach(w => valid_array(w) := 0.U)
378  }
379
380  // PERF: flush counter
381  XSPerfAccumulate("flush", io.flush.map(_.valid).reduce(_ || _))
382  XSPerfAccumulate("flush_all", io.flushAll)
383}
384
385class ICacheDataArrayIO(implicit p: Parameters) extends ICacheBundle {
386  val write:    DecoupledIO[ICacheDataWriteBundle] = Flipped(DecoupledIO(new ICacheDataWriteBundle))
387  val read:     Vec[DecoupledIO[ICacheReadBundle]] = Flipped(Vec(partWayNum, DecoupledIO(new ICacheReadBundle)))
388  val readResp: ICacheDataRespBundle               = Output(new ICacheDataRespBundle)
389}
390
391class ICacheDataArray(implicit p: Parameters) extends ICacheArray with HasICacheECCHelper {
392  class ICacheDataEntry(implicit p: Parameters) extends ICacheBundle {
393    val data: UInt = UInt(ICacheDataBits.W)
394    val code: UInt = UInt(ICacheDataCodeBits.W)
395  }
396
397  private object ICacheDataEntry {
398    def apply(data: UInt, poison: Bool)(implicit p: Parameters): ICacheDataEntry = {
399      val entry = Wire(new ICacheDataEntry)
400      entry.data := data
401      entry.code := encodeDataECC(data, poison)
402      entry
403    }
404  }
405
406  val io: ICacheDataArrayIO = IO(new ICacheDataArrayIO)
407
408  /**
409    ******************************************************************************
410    * data array
411    ******************************************************************************
412    */
413  private val writeDatas   = io.write.bits.data.asTypeOf(Vec(ICacheDataBanks, UInt(ICacheDataBits.W)))
414  private val writeEntries = writeDatas.map(ICacheDataEntry(_, io.write.bits.poison).asUInt)
415
416  // io.read() are copies to control fan-out, we can simply use .head here
417  private val bankSel  = getBankSel(io.read.head.bits.blkOffset, io.read.head.valid)
418  private val lineSel  = getLineSel(io.read.head.bits.blkOffset)
419  private val waymasks = io.read.head.bits.waymask
420  private val masks    = Wire(Vec(nWays, Vec(ICacheDataBanks, Bool())))
421  (0 until nWays).foreach { way =>
422    (0 until ICacheDataBanks).foreach { bank =>
423      masks(way)(bank) := Mux(
424        lineSel(bank),
425        waymasks(1)(way) && bankSel(1)(bank).asBool,
426        waymasks(0)(way) && bankSel(0)(bank).asBool
427      )
428    }
429  }
430
431  private val dataArrays = (0 until nWays).map { way =>
432    val banks = (0 until ICacheDataBanks).map { bank =>
433      val sramBank = Module(new SRAMTemplateWithFixedWidth(
434        UInt(ICacheDataEntryBits.W),
435        set = nSets,
436        width = ICacheDataSRAMWidth,
437        shouldReset = true,
438        holdRead = true,
439        singlePort = true,
440        withClockGate = false, // enable signal timing is bad, no gating here
441        hasMbist = hasMbist
442      ))
443
444      // read
445      sramBank.io.r.req.valid := io.read(bank % 4).valid && masks(way)(bank)
446      sramBank.io.r.req.bits.apply(setIdx =
447        Mux(lineSel(bank), io.read(bank % 4).bits.vSetIdx(1), io.read(bank % 4).bits.vSetIdx(0))
448      )
449      // write
450      sramBank.io.w.req.valid := io.write.valid && io.write.bits.waymask(way).asBool
451      sramBank.io.w.req.bits.apply(
452        data = writeEntries(bank),
453        setIdx = io.write.bits.virIdx,
454        // waymask is invalid when way of SRAMTemplate <= 1
455        waymask = 0.U
456      )
457      sramBank
458    }
459    MbistPipeline.PlaceMbistPipeline(1, s"MbistPipeIcacheDataWay${way}", hasMbist)
460    banks
461  }
462
463  /**
464    ******************************************************************************
465    * read logic
466    ******************************************************************************
467    */
468  private val masksReg = RegEnable(masks, 0.U.asTypeOf(masks), io.read(0).valid)
469  private val readDataWithCode = (0 until ICacheDataBanks).map { bank =>
470    Mux1H(VecInit(masksReg.map(_(bank))).asTypeOf(UInt(nWays.W)), dataArrays.map(_(bank).io.r.resp.asUInt))
471  }
472  private val readEntries = readDataWithCode.map(_.asTypeOf(new ICacheDataEntry()))
473  private val readDatas   = VecInit(readEntries.map(_.data))
474  private val readCodes   = VecInit(readEntries.map(_.code))
475
476  // TEST: force ECC to fail by setting readCodes to 0
477  if (ICacheForceDataECCError) {
478    readCodes.foreach(_ := 0.U)
479  }
480
481  /**
482    ******************************************************************************
483    * IO
484    ******************************************************************************
485    */
486  io.readResp.datas := readDatas
487  io.readResp.codes := readCodes
488  io.write.ready    := true.B
489  io.read.foreach(_.ready := !io.write.valid)
490}
491
492class ICacheReplacerIO(implicit p: Parameters) extends ICacheBundle {
493  val touch:  Vec[Valid[ReplacerTouch]] = Vec(PortNumber, Flipped(ValidIO(new ReplacerTouch)))
494  val victim: ReplacerVictim            = Flipped(new ReplacerVictim)
495}
496
497class ICacheReplacer(implicit p: Parameters) extends ICacheModule {
498  val io: ICacheReplacerIO = IO(new ICacheReplacerIO)
499
500  private val replacers =
501    Seq.fill(PortNumber)(ReplacementPolicy.fromString(cacheParams.replacer, nWays, nSets / PortNumber))
502
503  // touch
504  private val touch_sets = Seq.fill(PortNumber)(Wire(Vec(PortNumber, UInt(log2Ceil(nSets / PortNumber).W))))
505  private val touch_ways = Seq.fill(PortNumber)(Wire(Vec(PortNumber, Valid(UInt(wayBits.W)))))
506  (0 until PortNumber).foreach { i =>
507    touch_sets(i)(0) := Mux(
508      io.touch(i).bits.vSetIdx(0),
509      io.touch(1).bits.vSetIdx(highestIdxBit, 1),
510      io.touch(0).bits.vSetIdx(highestIdxBit, 1)
511    )
512    touch_ways(i)(0).bits  := Mux(io.touch(i).bits.vSetIdx(0), io.touch(1).bits.way, io.touch(0).bits.way)
513    touch_ways(i)(0).valid := Mux(io.touch(i).bits.vSetIdx(0), io.touch(1).valid, io.touch(0).valid)
514  }
515
516  // victim
517  io.victim.way := Mux(
518    io.victim.vSetIdx.bits(0),
519    replacers(1).way(io.victim.vSetIdx.bits(highestIdxBit, 1)),
520    replacers(0).way(io.victim.vSetIdx.bits(highestIdxBit, 1))
521  )
522
523  // touch the victim in next cycle
524  private val victim_vSetIdx_reg =
525    RegEnable(io.victim.vSetIdx.bits, 0.U.asTypeOf(io.victim.vSetIdx.bits), io.victim.vSetIdx.valid)
526  private val victim_way_reg = RegEnable(io.victim.way, 0.U.asTypeOf(io.victim.way), io.victim.vSetIdx.valid)
527  (0 until PortNumber).foreach { i =>
528    touch_sets(i)(1)       := victim_vSetIdx_reg(highestIdxBit, 1)
529    touch_ways(i)(1).bits  := victim_way_reg
530    touch_ways(i)(1).valid := RegNext(io.victim.vSetIdx.valid) && (victim_vSetIdx_reg(0) === i.U)
531  }
532
533  ((replacers zip touch_sets) zip touch_ways).foreach { case ((r, s), w) => r.access(s, w) }
534}
535
536class ICacheIO(implicit p: Parameters) extends ICacheBundle {
537  val hartId: UInt = Input(UInt(hartIdLen.W))
538  // FTQ
539  val fetch:       ICacheMainPipeBundle = new ICacheMainPipeBundle
540  val ftqPrefetch: FtqToPrefetchIO      = Flipped(new FtqToPrefetchIO)
541  // memblock
542  val softPrefetch: Vec[Valid[SoftIfetchPrefetchBundle]] =
543    Vec(backendParams.LduCnt, Flipped(Valid(new SoftIfetchPrefetchBundle)))
544  // IFU
545  val stop:  Bool = Input(Bool())
546  val toIFU: Bool = Output(Bool())
547  // PMP: mainPipe & prefetchPipe need PortNumber each
548  val pmp: Vec[ICachePMPBundle] = Vec(2 * PortNumber, new ICachePMPBundle)
549  // iTLB
550  val itlb:          Vec[TlbRequestIO] = Vec(PortNumber, new TlbRequestIO)
551  val itlbFlushPipe: Bool              = Bool()
552  // backend/BEU
553  val error: Valid[L1CacheErrorInfo] = ValidIO(new L1CacheErrorInfo)
554  // backend/CSR
555  val csr_pf_enable: Bool = Input(Bool())
556  // flush
557  val fencei: Bool = Input(Bool())
558  val flush:  Bool = Input(Bool())
559
560  // perf
561  val perfInfo: ICachePerfInfo = Output(new ICachePerfInfo)
562}
563
564class ICache()(implicit p: Parameters) extends LazyModule with HasICacheParameters {
565  override def shouldBeInlined: Boolean = false
566
567  val clientParameters: TLMasterPortParameters = TLMasterPortParameters.v1(
568    Seq(TLMasterParameters.v1(
569      name = "icache",
570      sourceId = IdRange(0, cacheParams.nFetchMshr + cacheParams.nPrefetchMshr + 1)
571    )),
572    requestFields = cacheParams.reqFields,
573    echoFields = cacheParams.echoFields
574  )
575
576  val clientNode: TLClientNode = TLClientNode(Seq(clientParameters))
577
578  val ctrlUnitOpt: Option[ICacheCtrlUnit] = ctrlUnitParamsOpt.map(params => LazyModule(new ICacheCtrlUnit(params)))
579
580  lazy val module: ICacheImp = new ICacheImp(this)
581}
582
583class ICacheImp(outer: ICache) extends LazyModuleImp(outer) with HasICacheParameters with HasPerfEvents {
584  val io: ICacheIO = IO(new ICacheIO)
585
586  println("ICache:")
587  println("  TagECC: " + cacheParams.tagECC)
588  println("  DataECC: " + cacheParams.dataECC)
589  println("  ICacheSets: " + cacheParams.nSets)
590  println("  ICacheWays: " + cacheParams.nWays)
591  println("  PortNumber: " + cacheParams.PortNumber)
592  println("  nFetchMshr: " + cacheParams.nFetchMshr)
593  println("  nPrefetchMshr: " + cacheParams.nPrefetchMshr)
594  println("  nWayLookupSize: " + cacheParams.nWayLookupSize)
595  println("  DataCodeUnit: " + cacheParams.DataCodeUnit)
596  println("  ICacheDataBanks: " + cacheParams.ICacheDataBanks)
597  println("  ICacheDataSRAMWidth: " + cacheParams.ICacheDataSRAMWidth)
598
599  val (bus, edge) = outer.clientNode.out.head
600
601  private val metaArray  = Module(new ICacheMetaArray)
602  private val dataArray  = Module(new ICacheDataArray)
603  private val mainPipe   = Module(new ICacheMainPipe)
604  private val missUnit   = Module(new ICacheMissUnit(edge))
605  private val replacer   = Module(new ICacheReplacer)
606  private val prefetcher = Module(new IPrefetchPipe)
607  private val wayLookup  = Module(new WayLookup)
608
609  private val ecc_enable = if (outer.ctrlUnitOpt.nonEmpty) outer.ctrlUnitOpt.get.module.io.ecc_enable else true.B
610
611  // dataArray io
612  if (outer.ctrlUnitOpt.nonEmpty) {
613    val ctrlUnit = outer.ctrlUnitOpt.get.module
614    when(ctrlUnit.io.injecting) {
615      dataArray.io.write <> ctrlUnit.io.dataWrite
616      missUnit.io.data_write.ready := false.B
617    }.otherwise {
618      ctrlUnit.io.dataWrite.ready := false.B
619      dataArray.io.write <> missUnit.io.data_write
620    }
621  } else {
622    dataArray.io.write <> missUnit.io.data_write
623  }
624  dataArray.io.read <> mainPipe.io.dataArray.toIData
625  mainPipe.io.dataArray.fromIData := dataArray.io.readResp
626
627  // metaArray io
628  metaArray.io.flushAll := io.fencei
629  metaArray.io.flush <> mainPipe.io.metaArrayFlush
630  if (outer.ctrlUnitOpt.nonEmpty) {
631    val ctrlUnit = outer.ctrlUnitOpt.get.module
632    when(ctrlUnit.io.injecting) {
633      metaArray.io.write <> ctrlUnit.io.metaWrite
634      metaArray.io.read <> ctrlUnit.io.metaRead
635      missUnit.io.meta_write.ready         := false.B
636      prefetcher.io.metaRead.toIMeta.ready := false.B
637    }.otherwise {
638      ctrlUnit.io.metaWrite.ready := false.B
639      ctrlUnit.io.metaRead.ready  := false.B
640      metaArray.io.write <> missUnit.io.meta_write
641      metaArray.io.read <> prefetcher.io.metaRead.toIMeta
642    }
643    ctrlUnit.io.metaReadResp := metaArray.io.readResp
644  } else {
645    metaArray.io.write <> missUnit.io.meta_write
646    metaArray.io.read <> prefetcher.io.metaRead.toIMeta
647  }
648  prefetcher.io.metaRead.fromIMeta := metaArray.io.readResp
649
650  prefetcher.io.flush         := io.flush
651  prefetcher.io.csr_pf_enable := io.csr_pf_enable
652  prefetcher.io.ecc_enable    := ecc_enable
653  prefetcher.io.MSHRResp      := missUnit.io.fetch_resp
654  prefetcher.io.flushFromBpu  := io.ftqPrefetch.flushFromBpu
655  // cache softPrefetch
656  private val softPrefetchValid = RegInit(false.B)
657  private val softPrefetch      = RegInit(0.U.asTypeOf(new IPrefetchReq))
658  /* FIXME:
659   * If there is already a pending softPrefetch request, it will be overwritten.
660   * Also, if there are multiple softPrefetch requests in the same cycle, only the first one will be accepted.
661   * We should implement a softPrefetchQueue (like ibuffer, multi-in, single-out) to solve this.
662   * However, the impact on performance still needs to be assessed.
663   * Considering that the frequency of prefetch.i may not be high, let's start with a temporary dummy solution.
664   */
665  when(io.softPrefetch.map(_.valid).reduce(_ || _)) {
666    softPrefetchValid := true.B
667    softPrefetch.fromSoftPrefetch(MuxCase(
668      0.U.asTypeOf(new SoftIfetchPrefetchBundle),
669      io.softPrefetch.map(req => req.valid -> req.bits)
670    ))
671  }.elsewhen(prefetcher.io.req.fire) {
672    softPrefetchValid := false.B
673  }
674  // pass ftqPrefetch
675  private val ftqPrefetch = WireInit(0.U.asTypeOf(new IPrefetchReq))
676  ftqPrefetch.fromFtqICacheInfo(io.ftqPrefetch.req.bits)
677  // software prefetch has higher priority
678  prefetcher.io.req.valid                 := softPrefetchValid || io.ftqPrefetch.req.valid
679  prefetcher.io.req.bits                  := Mux(softPrefetchValid, softPrefetch, ftqPrefetch)
680  prefetcher.io.req.bits.backendException := io.ftqPrefetch.backendException
681  io.ftqPrefetch.req.ready                := prefetcher.io.req.ready && !softPrefetchValid
682
683  missUnit.io.hartId := io.hartId
684  missUnit.io.fencei := io.fencei
685  missUnit.io.flush  := io.flush
686  missUnit.io.fetch_req <> mainPipe.io.mshr.req
687  missUnit.io.prefetch_req <> prefetcher.io.MSHRReq
688  missUnit.io.mem_grant.valid := false.B
689  missUnit.io.mem_grant.bits  := DontCare
690  missUnit.io.mem_grant <> bus.d
691
692  mainPipe.io.flush      := io.flush
693  mainPipe.io.respStall  := io.stop
694  mainPipe.io.ecc_enable := ecc_enable
695  mainPipe.io.hartId     := io.hartId
696  mainPipe.io.mshr.resp  := missUnit.io.fetch_resp
697  mainPipe.io.fetch.req <> io.fetch.req
698  mainPipe.io.wayLookupRead <> wayLookup.io.read
699
700  wayLookup.io.flush := io.flush
701  wayLookup.io.write <> prefetcher.io.wayLookupWrite
702  wayLookup.io.update := missUnit.io.fetch_resp
703
704  replacer.io.touch <> mainPipe.io.touch
705  replacer.io.victim <> missUnit.io.victim
706
707  io.pmp(0) <> mainPipe.io.pmp(0)
708  io.pmp(1) <> mainPipe.io.pmp(1)
709  io.pmp(2) <> prefetcher.io.pmp(0)
710  io.pmp(3) <> prefetcher.io.pmp(1)
711
712  io.itlb(0) <> prefetcher.io.itlb(0)
713  io.itlb(1) <> prefetcher.io.itlb(1)
714  io.itlbFlushPipe := prefetcher.io.itlbFlushPipe
715
716  // notify IFU that Icache pipeline is available
717  io.toIFU    := mainPipe.io.fetch.req.ready
718  io.perfInfo := mainPipe.io.perfInfo
719
720  io.fetch.resp <> mainPipe.io.fetch.resp
721  io.fetch.topdownIcacheMiss := mainPipe.io.fetch.topdownIcacheMiss
722  io.fetch.topdownItlbMiss   := mainPipe.io.fetch.topdownItlbMiss
723
724  bus.b.ready := false.B
725  bus.c.valid := false.B
726  bus.c.bits  := DontCare
727  bus.e.valid := false.B
728  bus.e.bits  := DontCare
729
730  bus.a <> missUnit.io.mem_acquire
731
732  // Parity error port
733  private val errors       = mainPipe.io.errors
734  private val errors_valid = errors.map(e => e.valid).reduce(_ | _)
735  io.error.bits <> RegEnable(
736    PriorityMux(errors.map(e => e.valid -> e.bits)),
737    0.U.asTypeOf(errors(0).bits),
738    errors_valid
739  )
740  io.error.valid := RegNext(errors_valid, false.B)
741
742  XSPerfAccumulate(
743    "softPrefetch_drop_not_ready",
744    io.softPrefetch.map(_.valid).reduce(_ || _) && softPrefetchValid && !prefetcher.io.req.fire
745  )
746  XSPerfAccumulate("softPrefetch_drop_multi_req", PopCount(io.softPrefetch.map(_.valid)) > 1.U)
747  XSPerfAccumulate("softPrefetch_block_ftq", softPrefetchValid && io.ftqPrefetch.req.valid)
748
749  val perfEvents: Seq[(String, Bool)] = Seq(
750    ("icache_miss_cnt  ", false.B),
751    ("icache_miss_penalty", BoolStopWatch(start = false.B, stop = false.B || false.B, startHighPriority = true))
752  )
753  generatePerfEvent()
754}
755
756//class ICachePartWayReadBundle[T <: Data](gen: T, pWay: Int)(implicit p: Parameters)
757//    extends ICacheBundle {
758//  val req = Flipped(Vec(
759//    PortNumber,
760//    Decoupled(new Bundle {
761//      val ridx = UInt((log2Ceil(nSets) - 1).W)
762//    })
763//  ))
764//  val resp = Output(new Bundle {
765//    val rdata = Vec(PortNumber, Vec(pWay, gen))
766//  })
767//}
768
769//class ICacheWriteBundle[T <: Data](gen: T, pWay: Int)(implicit p: Parameters)
770//    extends ICacheBundle {
771//  val wdata    = gen
772//  val widx     = UInt((log2Ceil(nSets) - 1).W)
773//  val wbankidx = Bool()
774//  val wmask    = Vec(pWay, Bool())
775//}
776
777//class ICachePartWayArray[T <: Data](gen: T, pWay: Int)(implicit p: Parameters) extends ICacheArray {
778//
779//  // including part way data
780//  val io = IO {
781//    new Bundle {
782//      val read  = new ICachePartWayReadBundle(gen, pWay)
783//      val write = Flipped(ValidIO(new ICacheWriteBundle(gen, pWay)))
784//    }
785//  }
786//
787//  io.read.req.map(_.ready := !io.write.valid)
788//
789//  val srams = (0 until PortNumber) map { bank =>
790//    val sramBank = Module(new SRAMTemplate(
791//      gen,
792//      set = nSets / 2,
793//      way = pWay,
794//      shouldReset = true,
795//      holdRead = true,
796//      singlePort = true,
797//      withClockGate = true
798//    ))
799//
800//    sramBank.io.r.req.valid := io.read.req(bank).valid
801//    sramBank.io.r.req.bits.apply(setIdx = io.read.req(bank).bits.ridx)
802//
803//    if (bank == 0) sramBank.io.w.req.valid := io.write.valid && !io.write.bits.wbankidx
804//    else sramBank.io.w.req.valid           := io.write.valid && io.write.bits.wbankidx
805//    sramBank.io.w.req.bits.apply(
806//      data = io.write.bits.wdata,
807//      setIdx = io.write.bits.widx,
808//      waymask = io.write.bits.wmask.asUInt
809//    )
810//
811//    sramBank
812//  }
813//
814//  io.read.req.map(_.ready := !io.write.valid && srams.map(_.io.r.req.ready).reduce(_ && _))
815//
816//  io.read.resp.rdata := VecInit(srams.map(bank => bank.io.r.resp.asTypeOf(Vec(pWay, gen))))
817//
818//}
819
820class SRAMTemplateWithFixedWidthIO[T <: Data](gen: T, set: Int, way: Int) extends Bundle {
821  val r: SRAMReadBus[T]  = Flipped(new SRAMReadBus(gen, set, way))
822  val w: SRAMWriteBus[T] = Flipped(new SRAMWriteBus(gen, set, way))
823}
824
825// Automatically partition the SRAM based on the width of the data and the desired width.
826// final SRAM width = width * way
827class SRAMTemplateWithFixedWidth[T <: Data](
828    gen:           T,
829    set:           Int,
830    width:         Int,
831    way:           Int = 1,
832    shouldReset:   Boolean = false,
833    holdRead:      Boolean = false,
834    singlePort:    Boolean = false,
835    bypassWrite:   Boolean = false,
836    withClockGate: Boolean = false,
837    hasMbist:      Boolean = false
838) extends Module {
839
840  private val dataBits  = gen.getWidth
841  private val bankNum   = math.ceil(dataBits.toDouble / width.toDouble).toInt
842  private val totalBits = bankNum * width
843
844  val io: SRAMTemplateWithFixedWidthIO[T] = IO(new SRAMTemplateWithFixedWidthIO(gen, set, way))
845
846  private val wordType = UInt(width.W)
847  private val writeDatas = (0 until bankNum).map { bank =>
848    VecInit((0 until way).map { i =>
849      io.w.req.bits.data(i).asTypeOf(UInt(totalBits.W)).asTypeOf(Vec(bankNum, wordType))(bank)
850    })
851  }
852
853  private val srams = (0 until bankNum) map { bank =>
854    val sramBank = Module(new SRAMTemplate(
855      wordType,
856      set = set,
857      way = way,
858      shouldReset = shouldReset,
859      holdRead = holdRead,
860      singlePort = singlePort,
861      bypassWrite = bypassWrite,
862      withClockGate = withClockGate,
863      hasMbist = hasMbist
864    ))
865    // read req
866    sramBank.io.r.req.valid       := io.r.req.valid
867    sramBank.io.r.req.bits.setIdx := io.r.req.bits.setIdx
868
869    // write req
870    sramBank.io.w.req.valid       := io.w.req.valid
871    sramBank.io.w.req.bits.setIdx := io.w.req.bits.setIdx
872    sramBank.io.w.req.bits.data   := writeDatas(bank)
873    sramBank.io.w.req.bits.waymask.foreach(_ := io.w.req.bits.waymask.get)
874
875    sramBank
876  }
877
878  io.r.req.ready := !io.w.req.valid
879  (0 until way).foreach { i =>
880    io.r.resp.data(i) := VecInit((0 until bankNum).map(bank =>
881      srams(bank).io.r.resp.data(i)
882    )).asTypeOf(UInt(totalBits.W))(dataBits - 1, 0).asTypeOf(gen.cloneType)
883  }
884
885  io.r.req.ready := srams.head.io.r.req.ready
886  io.w.req.ready := srams.head.io.w.req.ready
887}
888