xref: /XiangShan/src/main/scala/xiangshan/cache/mmu/Repeater.scala (revision 67ba96b4871c459c09df20e3052738174021a830)
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.cache.mmu
18
19import chipsalliance.rocketchip.config.Parameters
20import chisel3._
21import chisel3.util._
22import xiangshan._
23import xiangshan.cache.{HasDCacheParameters, MemoryOpConstants}
24import utils._
25import utility._
26import freechips.rocketchip.diplomacy.{LazyModule, LazyModuleImp}
27import freechips.rocketchip.tilelink._
28
29class PTWReapterIO(Width: Int)(implicit p: Parameters) extends MMUIOBaseBundle {
30  val tlb = Flipped(new TlbPtwIO(Width))
31  val ptw = new TlbPtwIO
32
33  def apply(tlb: TlbPtwIO, ptw: TlbPtwIO, sfence: SfenceBundle, csr: TlbCsrBundle): Unit = {
34    this.tlb <> tlb
35    this.ptw <> ptw
36    this.sfence <> sfence
37    this.csr <> csr
38  }
39
40  def apply(tlb: TlbPtwIO, sfence: SfenceBundle, csr: TlbCsrBundle): Unit = {
41    this.tlb <> tlb
42    this.sfence <> sfence
43    this.csr <> csr
44  }
45
46}
47
48class PTWRepeater(Width: Int = 1, FenceDelay: Int)(implicit p: Parameters) extends XSModule with HasPtwConst {
49  val io = IO(new PTWReapterIO(Width))
50
51  val req_in = if (Width == 1) {
52    io.tlb.req(0)
53  } else {
54    val arb = Module(new RRArbiter(io.tlb.req(0).bits.cloneType, Width))
55    arb.io.in <> io.tlb.req
56    arb.io.out
57  }
58  val (tlb, ptw, flush) = (io.tlb, io.ptw, DelayN(io.sfence.valid || io.csr.satp.changed, FenceDelay))
59  val req = RegEnable(req_in.bits, req_in.fire())
60  val resp = RegEnable(ptw.resp.bits, ptw.resp.fire())
61  val haveOne = BoolStopWatch(req_in.fire(), tlb.resp.fire() || flush)
62  val sent = BoolStopWatch(ptw.req(0).fire(), req_in.fire() || flush)
63  val recv = BoolStopWatch(ptw.resp.fire() && haveOne, req_in.fire() || flush)
64
65  req_in.ready := !haveOne
66  ptw.req(0).valid := haveOne && !sent
67  ptw.req(0).bits := req
68
69  tlb.resp.bits := resp
70  tlb.resp.valid := haveOne && recv
71  ptw.resp.ready := !recv
72
73  XSPerfAccumulate("req_count", ptw.req(0).fire())
74  XSPerfAccumulate("tlb_req_cycle", BoolStopWatch(req_in.fire(), tlb.resp.fire() || flush))
75  XSPerfAccumulate("ptw_req_cycle", BoolStopWatch(ptw.req(0).fire(), ptw.resp.fire() || flush))
76
77  XSDebug(haveOne, p"haveOne:${haveOne} sent:${sent} recv:${recv} sfence:${flush} req:${req} resp:${resp}")
78  XSDebug(req_in.valid || io.tlb.resp.valid, p"tlb: ${tlb}\n")
79  XSDebug(io.ptw.req(0).valid || io.ptw.resp.valid, p"ptw: ${ptw}\n")
80  assert(!RegNext(recv && io.ptw.resp.valid, init = false.B), "re-receive ptw.resp")
81  XSError(io.ptw.req(0).valid && io.ptw.resp.valid && !flush, "ptw repeater recv resp when sending")
82  XSError(io.ptw.resp.valid && (req.vpn =/= io.ptw.resp.bits.entry.tag), "ptw repeater recv resp with wrong tag")
83  XSError(io.ptw.resp.valid && !io.ptw.resp.ready, "ptw repeater's ptw resp back, but not ready")
84  TimeOutAssert(sent && !recv, timeOutThreshold, "Repeater doesn't recv resp in time")
85}
86
87/* dtlb
88 *
89 */
90
91class PTWRepeaterNB(Width: Int = 1, passReady: Boolean = false, FenceDelay: Int)(implicit p: Parameters) extends XSModule with HasPtwConst {
92  val io = IO(new PTWReapterIO(Width))
93
94  val req_in = if (Width == 1) {
95    io.tlb.req(0)
96  } else {
97    val arb = Module(new RRArbiter(io.tlb.req(0).bits.cloneType, Width))
98    arb.io.in <> io.tlb.req
99    arb.io.out
100  }
101  val (tlb, ptw, flush) = (io.tlb, io.ptw, DelayN(io.sfence.valid || io.csr.satp.changed, FenceDelay))
102  /* sent: tlb -> repeater -> ptw
103   * recv: ptw -> repeater -> tlb
104   * different from PTWRepeater
105   */
106
107  // tlb -> repeater -> ptw
108  val req = RegEnable(req_in.bits, req_in.fire())
109  val sent = BoolStopWatch(req_in.fire(), ptw.req(0).fire() || flush)
110  req_in.ready := !sent || { if (passReady) ptw.req(0).ready else false.B }
111  ptw.req(0).valid := sent
112  ptw.req(0).bits := req
113
114  // ptw -> repeater -> tlb
115  val resp = RegEnable(ptw.resp.bits, ptw.resp.fire())
116  val recv = BoolStopWatch(ptw.resp.fire(), tlb.resp.fire() || flush)
117  ptw.resp.ready := !recv || { if (passReady) tlb.resp.ready else false.B }
118  tlb.resp.valid := recv
119  tlb.resp.bits := resp
120
121  XSPerfAccumulate("req", req_in.fire())
122  XSPerfAccumulate("resp", tlb.resp.fire())
123  if (!passReady) {
124    XSPerfAccumulate("req_blank", req_in.valid && sent && ptw.req(0).ready)
125    XSPerfAccumulate("resp_blank", ptw.resp.valid && recv && tlb.resp.ready)
126    XSPerfAccumulate("req_blank_ignore_ready", req_in.valid && sent)
127    XSPerfAccumulate("resp_blank_ignore_ready", ptw.resp.valid && recv)
128  }
129  XSDebug(req_in.valid || io.tlb.resp.valid, p"tlb: ${tlb}\n")
130  XSDebug(io.ptw.req(0).valid || io.ptw.resp.valid, p"ptw: ${ptw}\n")
131}
132
133class PTWFilterIO(Width: Int)(implicit p: Parameters) extends MMUIOBaseBundle {
134  val tlb = Flipped(new VectorTlbPtwIO(Width))
135  val ptw = new TlbPtwIO()
136
137  def apply(tlb: VectorTlbPtwIO, ptw: TlbPtwIO, sfence: SfenceBundle, csr: TlbCsrBundle): Unit = {
138    this.tlb <> tlb
139    this.ptw <> ptw
140    this.sfence <> sfence
141    this.csr <> csr
142  }
143
144  def apply(tlb: VectorTlbPtwIO, sfence: SfenceBundle, csr: TlbCsrBundle): Unit = {
145    this.tlb <> tlb
146    this.sfence <> sfence
147    this.csr <> csr
148  }
149
150}
151
152class PTWFilter(Width: Int, Size: Int, FenceDelay: Int)(implicit p: Parameters) extends XSModule with HasPtwConst {
153  require(Size >= Width)
154
155  val io = IO(new PTWFilterIO(Width))
156
157  val v = RegInit(VecInit(Seq.fill(Size)(false.B)))
158  val ports = Reg(Vec(Size, Vec(Width, Bool()))) // record which port(s) the entry come from, may not able to cover all the ports
159  val vpn = Reg(Vec(Size, UInt(vpnLen.W)))
160  val enqPtr = RegInit(0.U(log2Up(Size).W)) // Enq
161  val issPtr = RegInit(0.U(log2Up(Size).W)) // Iss to Ptw
162  val deqPtr = RegInit(0.U(log2Up(Size).W)) // Deq
163  val mayFullDeq = RegInit(false.B)
164  val mayFullIss = RegInit(false.B)
165  val counter = RegInit(0.U(log2Up(Size+1).W))
166
167  val flush = DelayN(io.sfence.valid || io.csr.satp.changed, FenceDelay)
168  val tlb_req = WireInit(io.tlb.req) // NOTE: tlb_req is not io.tlb.req, see below codes, just use cloneType
169  tlb_req.suggestName("tlb_req")
170
171  val inflight_counter = RegInit(0.U(log2Up(Size + 1).W))
172  val inflight_full = inflight_counter === Size.U
173  when (io.ptw.req(0).fire() =/= io.ptw.resp.fire()) {
174    inflight_counter := Mux(io.ptw.req(0).fire(), inflight_counter + 1.U, inflight_counter - 1.U)
175  }
176
177  val canEnqueue = Wire(Bool()) // NOTE: actually enqueue
178  val ptwResp = RegEnable(io.ptw.resp.bits, io.ptw.resp.fire())
179  val ptwResp_OldMatchVec = vpn.zip(v).map{ case (pi, vi) =>
180    vi && io.ptw.resp.bits.entry.hit(pi, io.csr.satp.asid, true, true)}
181  val ptwResp_valid = RegNext(io.ptw.resp.fire() && Cat(ptwResp_OldMatchVec).orR, init = false.B)
182  val oldMatchVec_early = io.tlb.req.map(a => vpn.zip(v).map{ case (pi, vi) => vi && pi === a.bits.vpn})
183  val lastReqMatchVec_early = io.tlb.req.map(a => tlb_req.map{ b => b.valid && b.bits.vpn === a.bits.vpn && canEnqueue})
184  val newMatchVec_early = io.tlb.req.map(a => io.tlb.req.map(b => a.bits.vpn === b.bits.vpn))
185
186  (0 until Width) foreach { i =>
187    tlb_req(i).valid := RegNext(io.tlb.req(i).valid &&
188      !(ptwResp_valid && ptwResp.entry.hit(io.tlb.req(i).bits.vpn, 0.U, true, true)) &&
189      !Cat(lastReqMatchVec_early(i)).orR,
190      init = false.B)
191    tlb_req(i).bits := RegEnable(io.tlb.req(i).bits, io.tlb.req(i).valid)
192  }
193
194  val oldMatchVec = oldMatchVec_early.map(a => RegNext(Cat(a).orR))
195  val newMatchVec = (0 until Width).map(i => (0 until Width).map(j =>
196    RegNext(newMatchVec_early(i)(j)) && tlb_req(j).valid
197  ))
198  val ptwResp_newMatchVec = tlb_req.map(a =>
199    ptwResp_valid && ptwResp.entry.hit(a.bits.vpn, 0.U, allType = true, true))
200
201  val oldMatchVec2 = (0 until Width).map(i => oldMatchVec_early(i).map(RegNext(_)).map(_ & tlb_req(i).valid))
202  val update_ports = v.indices.map(i => oldMatchVec2.map(j => j(i)))
203  val ports_init = (0 until Width).map(i => (1 << i).U(Width.W))
204  val filter_ports = (0 until Width).map(i => ParallelMux(newMatchVec(i).zip(ports_init).drop(i)))
205  val resp_vector = RegEnable(ParallelMux(ptwResp_OldMatchVec zip ports), io.ptw.resp.fire())
206
207  def canMerge(index: Int) : Bool = {
208    ptwResp_newMatchVec(index) || oldMatchVec(index) ||
209    Cat(newMatchVec(index).take(index)).orR
210  }
211
212  def filter_req() = {
213    val reqs =  tlb_req.indices.map{ i =>
214      val req = Wire(ValidIO(new PtwReq()))
215      val merge = canMerge(i)
216      req.bits := tlb_req(i).bits
217      req.valid := !merge && tlb_req(i).valid
218      req
219    }
220    reqs
221  }
222
223  val reqs = filter_req()
224  val req_ports = filter_ports
225  val isFull = enqPtr === deqPtr && mayFullDeq
226  val isEmptyDeq = enqPtr === deqPtr && !mayFullDeq
227  val isEmptyIss = enqPtr === issPtr && !mayFullIss
228  val accumEnqNum = (0 until Width).map(i => PopCount(reqs.take(i).map(_.valid)))
229  val enqPtrVecInit = VecInit((0 until Width).map(i => enqPtr + i.U))
230  val enqPtrVec = VecInit((0 until Width).map(i => enqPtrVecInit(accumEnqNum(i))))
231  val enqNum = PopCount(reqs.map(_.valid))
232  canEnqueue := counter +& enqNum <= Size.U
233
234  // the req may recv false ready, but actually received. Filter and TLB will handle it.
235  val enqNum_fake = PopCount(io.tlb.req.map(_.valid))
236  val canEnqueue_fake = counter +& enqNum_fake <= Size.U
237  io.tlb.req.map(_.ready := canEnqueue_fake) // NOTE: just drop un-fire reqs
238
239  // tlb req flushed by ptw resp: last ptw resp && current ptw resp
240  // the flushed tlb req will fakely enq, with a false valid
241  val tlb_req_flushed = reqs.map(a => io.ptw.resp.valid && io.ptw.resp.bits.entry.hit(a.bits.vpn, 0.U, true, true))
242
243  io.tlb.resp.valid := ptwResp_valid
244  io.tlb.resp.bits.data := ptwResp
245  io.tlb.resp.bits.vector := resp_vector
246
247  val issue_valid = v(issPtr) && !isEmptyIss && !inflight_full
248  val issue_filtered = ptwResp_valid && ptwResp.entry.hit(io.ptw.req(0).bits.vpn, io.csr.satp.asid, allType=true, ignoreAsid=true)
249  val issue_fire_fake = issue_valid && (io.ptw.req(0).ready || (issue_filtered && false.B /*timing-opt*/))
250  io.ptw.req(0).valid := issue_valid && !issue_filtered
251  io.ptw.req(0).bits.vpn := vpn(issPtr)
252  io.ptw.resp.ready := true.B
253
254  reqs.zipWithIndex.map{
255    case (req, i) =>
256      when (req.valid && canEnqueue) {
257        v(enqPtrVec(i)) := !tlb_req_flushed(i)
258        vpn(enqPtrVec(i)) := req.bits.vpn
259        ports(enqPtrVec(i)) := req_ports(i).asBools
260      }
261  }
262  for (i <- ports.indices) {
263    when (v(i)) {
264      ports(i) := ports(i).zip(update_ports(i)).map(a => a._1 || a._2)
265    }
266  }
267
268  val do_enq = canEnqueue && Cat(reqs.map(_.valid)).orR
269  val do_deq = (!v(deqPtr) && !isEmptyDeq)
270  val do_iss = issue_fire_fake || (!v(issPtr) && !isEmptyIss)
271  when (do_enq) {
272    enqPtr := enqPtr + enqNum
273  }
274  when (do_deq) {
275    deqPtr := deqPtr + 1.U
276  }
277  when (do_iss) {
278    issPtr := issPtr + 1.U
279  }
280  when (issue_fire_fake && issue_filtered) { // issued but is filtered
281    v(issPtr) := false.B
282  }
283  when (do_enq =/= do_deq) {
284    mayFullDeq := do_enq
285  }
286  when (do_enq =/= do_iss) {
287    mayFullIss := do_enq
288  }
289
290  when (io.ptw.resp.fire()) {
291    v.zip(ptwResp_OldMatchVec).map{ case (vi, mi) => when (mi) { vi := false.B }}
292  }
293
294  counter := counter - do_deq + Mux(do_enq, enqNum, 0.U)
295  assert(counter <= Size.U, "counter should be no more than Size")
296  assert(inflight_counter <= Size.U, "inflight should be no more than Size")
297  when (counter === 0.U) {
298    assert(!io.ptw.req(0).fire(), "when counter is 0, should not req")
299    assert(isEmptyDeq && isEmptyIss, "when counter is 0, should be empty")
300  }
301  when (counter === Size.U) {
302    assert(mayFullDeq, "when counter is Size, should be full")
303  }
304
305  when (flush) {
306    v.map(_ := false.B)
307    deqPtr := 0.U
308    enqPtr := 0.U
309    issPtr := 0.U
310    ptwResp_valid := false.B
311    mayFullDeq := false.B
312    mayFullIss := false.B
313    counter := 0.U
314    inflight_counter := 0.U
315  }
316
317  // perf
318  XSPerfAccumulate("tlb_req_count", PopCount(Cat(io.tlb.req.map(_.valid))))
319  XSPerfAccumulate("tlb_req_count_filtered", Mux(do_enq, accumEnqNum(Width - 1), 0.U))
320  XSPerfAccumulate("ptw_req_count", io.ptw.req(0).fire())
321  XSPerfAccumulate("ptw_req_cycle", inflight_counter)
322  XSPerfAccumulate("tlb_resp_count", io.tlb.resp.fire())
323  XSPerfAccumulate("ptw_resp_count", io.ptw.resp.fire())
324  XSPerfAccumulate("inflight_cycle", !isEmptyDeq)
325  for (i <- 0 until Size + 1) {
326    XSPerfAccumulate(s"counter${i}", counter === i.U)
327  }
328
329  for (i <- 0 until Size) {
330    TimeOutAssert(v(i), timeOutThreshold, s"Filter ${i} doesn't recv resp in time")
331  }
332}
333
334object PTWRepeater {
335  def apply(fenceDelay: Int,
336    tlb: TlbPtwIO,
337    sfence: SfenceBundle,
338    csr: TlbCsrBundle
339  )(implicit p: Parameters) = {
340    val width = tlb.req.size
341    val repeater = Module(new PTWRepeater(width, fenceDelay))
342    repeater.io.apply(tlb, sfence, csr)
343    repeater
344  }
345
346  def apply(fenceDelay: Int,
347    tlb: TlbPtwIO,
348    ptw: TlbPtwIO,
349    sfence: SfenceBundle,
350    csr: TlbCsrBundle
351  )(implicit p: Parameters) = {
352    val width = tlb.req.size
353    val repeater = Module(new PTWRepeater(width, fenceDelay))
354    repeater.io.apply(tlb, ptw, sfence, csr)
355    repeater
356  }
357}
358
359object PTWRepeaterNB {
360  def apply(passReady: Boolean, fenceDelay: Int,
361    tlb: TlbPtwIO,
362    sfence: SfenceBundle,
363    csr: TlbCsrBundle
364  )(implicit p: Parameters) = {
365    val width = tlb.req.size
366    val repeater = Module(new PTWRepeaterNB(width, passReady,fenceDelay))
367    repeater.io.apply(tlb, sfence, csr)
368    repeater
369  }
370
371  def apply(passReady: Boolean, fenceDelay: Int,
372    tlb: TlbPtwIO,
373    ptw: TlbPtwIO,
374    sfence: SfenceBundle,
375    csr: TlbCsrBundle
376  )(implicit p: Parameters) = {
377    val width = tlb.req.size
378    val repeater = Module(new PTWRepeaterNB(width, passReady, fenceDelay))
379    repeater.io.apply(tlb, ptw, sfence, csr)
380    repeater
381  }
382}
383
384object PTWFilter {
385  def apply(fenceDelay: Int,
386    tlb: VectorTlbPtwIO,
387    ptw: TlbPtwIO,
388    sfence: SfenceBundle,
389    csr: TlbCsrBundle,
390    size: Int
391  )(implicit p: Parameters) = {
392    val width = tlb.req.size
393    val filter = Module(new PTWFilter(width, size, fenceDelay))
394    filter.io.apply(tlb, ptw, sfence, csr)
395    filter
396  }
397
398  def apply(fenceDelay: Int,
399    tlb: VectorTlbPtwIO,
400    sfence: SfenceBundle,
401    csr: TlbCsrBundle,
402    size: Int
403  )(implicit p: Parameters) = {
404    val width = tlb.req.size
405    val filter = Module(new PTWFilter(width, size, fenceDelay))
406    filter.io.apply(tlb, sfence, csr)
407    filter
408  }
409
410}
411