xref: /XiangShan/src/main/scala/xiangshan/cache/mmu/TLB.scala (revision 33177a7c6ea22740da90c7bdc8eed306ef2cfda3)
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.internal.naming.chiselName
22import chisel3.util._
23import freechips.rocketchip.util.SRAMAnnotation
24import xiangshan._
25import utils._
26import xiangshan.backend.fu.{PMPChecker, PMPReqBundle}
27import xiangshan.backend.rob.RobPtr
28import xiangshan.backend.fu.util.HasCSRConst
29
30
31@chiselName
32class TLB(Width: Int, q: TLBParameters)(implicit p: Parameters) extends TlbModule with HasCSRConst {
33  val io = IO(new TlbIO(Width, q))
34
35  require(q.superAssociative == "fa")
36  if (q.sameCycle) {
37    require(q.normalAssociative == "fa")
38  }
39
40  val req = io.requestor.map(_.req)
41  val resp = io.requestor.map(_.resp)
42  val ptw = io.ptw
43  val pmp = io.pmp
44
45  val sfence = io.sfence
46  val csr = io.csr
47  val satp = csr.satp
48  val priv = csr.priv
49  val ifecth = if (q.fetchi) true.B else false.B
50  val mode = if (q.useDmode) priv.dmode else priv.imode
51  // val vmEnable = satp.mode === 8.U // && (mode < ModeM) // FIXME: fix me when boot xv6/linux...
52  val vmEnable = if (EnbaleTlbDebug) (satp.mode === 8.U)
53  else (satp.mode === 8.U && (mode < ModeM))
54
55  val reqAddr = req.map(_.bits.vaddr.asTypeOf((new VaBundle).cloneType))
56  val vpn = reqAddr.map(_.vpn)
57  val cmd = req.map(_.bits.cmd)
58  val valid = req.map(_.valid)
59
60  def widthMapSeq[T <: Seq[Data]](f: Int => T) = (0 until Width).map(f)
61
62  def widthMap[T <: Data](f: Int => T) = (0 until Width).map(f)
63
64  // Normal page && Super page
65  val normalPage = TlbStorage(
66    name = "normal",
67    associative = q.normalAssociative,
68    sameCycle = q.sameCycle,
69    ports = Width,
70    nSets = q.normalNSets,
71    nWays = q.normalNWays,
72    sramSinglePort = sramSinglePort,
73    normalPage = true,
74    superPage = false
75  )
76  val superPage = TlbStorage(
77    name = "super",
78    associative = q.superAssociative,
79    sameCycle = q.sameCycle,
80    ports = Width,
81    nSets = q.superNSets,
82    nWays = q.superNWays,
83    sramSinglePort = sramSinglePort,
84    normalPage = q.normalAsVictim,
85    superPage = true,
86  )
87
88
89  for (i <- 0 until Width) {
90    normalPage.r_req_apply(
91      valid = io.requestor(i).req.valid,
92      vpn = vpn(i),
93      i = i
94    )
95    superPage.r_req_apply(
96      valid = io.requestor(i).req.valid,
97      vpn = vpn(i),
98      i = i
99    )
100  }
101
102
103  normalPage.victim.in <> superPage.victim.out
104  normalPage.victim.out <> superPage.victim.in
105  normalPage.sfence <> io.sfence
106  superPage.sfence <> io.sfence
107
108  def TLBNormalRead(i: Int) = {
109    val (normal_hit, normal_ppn, normal_perm, normal_hitVec) = normalPage.r_resp_apply(i)
110    val (super_hit, super_ppn, super_perm, super_hitVec) = superPage.r_resp_apply(i)
111    assert(!(normal_hit && super_hit && vmEnable && RegNext(req(i).valid, init = false.B)))
112
113    val hit = normal_hit || super_hit
114    val ppn = Mux(normal_hit, normal_ppn, super_ppn)
115    val perm = Mux(normal_hit, normal_perm, super_perm)
116
117    val pf = perm.pf && hit
118    val af = perm.af && hit
119    val cmdReg = if (!q.sameCycle) RegNext(cmd(i)) else cmd(i)
120    val validReg = if (!q.sameCycle) RegNext(valid(i)) else valid(i)
121    val offReg = if (!q.sameCycle) RegNext(reqAddr(i).off) else reqAddr(i).off
122    val sizeReg = if (!q.sameCycle) RegNext(req(i).bits.size) else req(i).bits.size
123
124    /** *************** next cycle when two cycle is false******************* */
125    val miss = !hit && vmEnable
126    hit.suggestName(s"hit_${i}")
127    miss.suggestName(s"miss_${i}")
128
129    XSDebug(validReg, p"(${i.U}) hit:${hit} miss:${miss} ppn:${Hexadecimal(ppn)} perm:${perm}\n")
130
131    val paddr = Cat(ppn, offReg)
132    val vaddr = SignExt(req(i).bits.vaddr, PAddrBits)
133
134    req(i).ready := resp(i).ready
135    resp(i).valid := validReg
136    resp(i).bits.paddr := Mux(vmEnable, paddr, if (!q.sameCycle) RegNext(vaddr) else vaddr)
137    resp(i).bits.miss := miss
138    resp(i).bits.ptwBack := io.ptw.resp.fire()
139
140    pmp(i).valid := resp(i).valid
141    pmp(i).bits.addr := resp(i).bits.paddr
142    pmp(i).bits.size := sizeReg
143    pmp(i).bits.cmd := cmdReg
144
145    val update = hit && (!perm.a || !perm.d && TlbCmd.isWrite(cmdReg)) // update A/D through exception
146    val modeCheck = !(mode === ModeU && !perm.u || mode === ModeS && perm.u && (!priv.sum || ifecth))
147    val ldPf = !(modeCheck && (perm.r || priv.mxr && perm.x)) && (TlbCmd.isRead(cmdReg) && true.B /* TODO !isAMO*/)
148    val stPf = !(modeCheck && perm.w) && (TlbCmd.isWrite(cmdReg) || false.B /*TODO isAMO. */)
149    val instrPf = !(modeCheck && perm.x) && TlbCmd.isExec(cmdReg)
150    resp(i).bits.excp.pf.ld := (ldPf || update || pf) && vmEnable && hit && !af
151    resp(i).bits.excp.pf.st := (stPf || update || pf) && vmEnable && hit && !af
152    resp(i).bits.excp.pf.instr := (instrPf || update || pf) && vmEnable && hit && !af
153    // NOTE: pf need && with !af, page fault has higher priority than access fault
154    // but ptw may also have access fault, then af happens, the translation is wrong.
155    // In this case, pf has lower priority than af
156
157    // if vmenable, use pre-calcuated pma check result
158    resp(i).bits.mmio := Mux(TlbCmd.isExec(cmdReg), !perm.pi, !perm.pd) && vmEnable && hit
159    resp(i).bits.excp.af.ld := (af || Mux(TlbCmd.isAtom(cmdReg), !perm.pa, !perm.pr) && TlbCmd.isRead(cmdReg)) && vmEnable && hit
160    resp(i).bits.excp.af.st := (af || Mux(TlbCmd.isAtom(cmdReg), !perm.pa, !perm.pw) && TlbCmd.isWrite(cmdReg)) && vmEnable && hit
161    resp(i).bits.excp.af.instr := (af || Mux(TlbCmd.isAtom(cmdReg), false.B, !perm.pe)) && vmEnable && hit
162
163    // if !vmenable, check pma
164    val (pmaMode, accessWidth) = AddressSpace.memmapAddrMatch(resp(i).bits.paddr)
165    when(!vmEnable) {
166      resp(i).bits.mmio := Mux(TlbCmd.isExec(cmdReg), !PMAMode.icache(pmaMode), !PMAMode.dcache(pmaMode))
167      resp(i).bits.excp.af.ld := Mux(TlbCmd.isAtom(cmdReg), !PMAMode.atomic(pmaMode), !PMAMode.read(pmaMode)) && TlbCmd.isRead(cmdReg)
168      resp(i).bits.excp.af.st := Mux(TlbCmd.isAtom(cmdReg), !PMAMode.atomic(pmaMode), !PMAMode.write(pmaMode)) && TlbCmd.isWrite(cmdReg)
169      resp(i).bits.excp.af.instr := Mux(TlbCmd.isAtom(cmdReg), false.B, !PMAMode.execute(pmaMode))
170    }
171
172    (hit, miss, normal_hitVec, super_hitVec, validReg)
173  }
174
175  val readResult = (0 until Width).map(TLBNormalRead(_))
176  val hitVec = readResult.map(_._1)
177  val missVec = readResult.map(_._2)
178  val normalhitVecVec = readResult.map(_._3)
179  val superhitVecVec = readResult.map(_._4)
180  val validRegVec = readResult.map(_._5)
181
182  // replacement
183  def get_access(one_hot: UInt, valid: Bool): Valid[UInt] = {
184    val res = Wire(Valid(UInt(log2Up(one_hot.getWidth).W)))
185    res.valid := Cat(one_hot).orR && valid
186    res.bits := OHToUInt(one_hot)
187    res
188  }
189
190  val normal_refill_idx = if (q.outReplace) {
191    io.replace.normalPage.access.sets := vpn.map(get_idx(_, q.normalNSets))
192    io.replace.normalPage.access.touch_ways := normalhitVecVec.zipWithIndex.map{ case (hv, i) => get_access(hv,
193      validRegVec(i))}
194    io.replace.normalPage.chosen_set := get_idx(io.ptw.resp.bits.entry.tag, q.normalNSets)
195    io.replace.normalPage.refillIdx
196  } else if (q.normalAssociative == "fa") {
197    val re = ReplacementPolicy.fromString(q.normalReplacer, q.normalNWays)
198    re.access(normalhitVecVec.zipWithIndex.map{ case (hv, i) => get_access(hv, validRegVec(i))})
199    re.way
200  } else { // set-acco && plru
201    val re = ReplacementPolicy.fromString(q.normalReplacer, q.normalNSets, q.normalNWays)
202    re.access(vpn.map(get_idx(_, q.normalNSets)), normalhitVecVec.zipWithIndex.map{ case (hv, i) => get_access(hv,
203      validRegVec(i))})
204    re.way(get_idx(io.ptw.resp.bits.entry.tag, q.normalNSets))
205  }
206
207  val super_refill_idx = if (q.outReplace) {
208    io.replace.superPage.access.sets := vpn.map(get_idx(_, q.normalNSets))
209    io.replace.superPage.access.touch_ways := superhitVecVec.zipWithIndex.map{ case (hv, i) => get_access(hv,
210      validRegVec(i))}
211    io.replace.superPage.chosen_set := DontCare
212    io.replace.superPage.refillIdx
213  } else {
214    val re = ReplacementPolicy.fromString(q.superReplacer, q.superNWays)
215    re.access(superhitVecVec.zipWithIndex.map{ case (hv, i) => get_access(hv, validRegVec(i))})
216    re.way
217  }
218
219  val refill = ptw.resp.fire() && !sfence.valid
220  normalPage.w_apply(
221    valid = { if (q.normalAsVictim) false.B
222    else refill && ptw.resp.bits.entry.level.get === 2.U },
223    wayIdx = normal_refill_idx,
224    data = ptw.resp.bits
225  )
226  superPage.w_apply(
227    valid = { if (q.normalAsVictim) refill
228    else refill && ptw.resp.bits.entry.level.get =/= 2.U },
229    wayIdx = super_refill_idx,
230    data = ptw.resp.bits
231  )
232
233  for (i <- 0 until Width) {
234    io.ptw.req(i).valid := validRegVec(i) && missVec(i) && !RegNext(refill)
235    io.ptw.req(i).bits.vpn := RegNext(reqAddr(i).vpn)
236  }
237  io.ptw.resp.ready := true.B
238
239  if (!q.shouldBlock) {
240    for (i <- 0 until Width) {
241      XSPerfAccumulate("first_access" + Integer.toString(i, 10), validRegVec(i) && vmEnable && RegNext(req(i).bits.debug.isFirstIssue))
242      XSPerfAccumulate("access" + Integer.toString(i, 10), validRegVec(i) && vmEnable)
243    }
244    for (i <- 0 until Width) {
245      XSPerfAccumulate("first_miss" + Integer.toString(i, 10), validRegVec(i) && vmEnable && missVec(i) && RegNext(req(i).bits.debug.isFirstIssue))
246      XSPerfAccumulate("miss" + Integer.toString(i, 10), validRegVec(i) && vmEnable && missVec(i))
247    }
248  } else {
249    // NOTE: ITLB is blocked, so every resp will be valid only when hit
250    // every req will be ready only when hit
251    for (i <- 0 until Width) {
252      XSPerfAccumulate(s"access${i}", io.requestor(i).req.fire() && vmEnable)
253      XSPerfAccumulate(s"miss${i}", ptw.req(i).fire())
254    }
255
256  }
257  //val reqCycleCnt = Reg(UInt(16.W))
258  //reqCycleCnt := reqCycleCnt + BoolStopWatch(ptw.req(0).fire(), ptw.resp.fire || sfence.valid)
259  //XSPerfAccumulate("ptw_req_count", ptw.req.fire())
260  //XSPerfAccumulate("ptw_req_cycle", Mux(ptw.resp.fire(), reqCycleCnt, 0.U))
261  XSPerfAccumulate("ptw_resp_count", ptw.resp.fire())
262  XSPerfAccumulate("ptw_resp_pf_count", ptw.resp.fire() && ptw.resp.bits.pf)
263
264  // Log
265  for(i <- 0 until Width) {
266    XSDebug(req(i).valid, p"req(${i.U}): (${req(i).valid} ${req(i).ready}) ${req(i).bits}\n")
267    XSDebug(resp(i).valid, p"resp(${i.U}): (${resp(i).valid} ${resp(i).ready}) ${resp(i).bits}\n")
268  }
269
270  XSDebug(sfence.valid, p"Sfence: ${sfence}\n")
271  XSDebug(ParallelOR(valid)|| ptw.resp.valid, p"CSR: ${csr}\n")
272  XSDebug(ParallelOR(valid) || ptw.resp.valid, p"vmEnable:${vmEnable} hit:${Binary(VecInit(hitVec).asUInt)} miss:${Binary(VecInit(missVec).asUInt)}\n")
273  for (i <- ptw.req.indices) {
274    XSDebug(ptw.req(i).fire(), p"PTW req:${ptw.req(i).bits}\n")
275  }
276  XSDebug(ptw.resp.valid, p"PTW resp:${ptw.resp.bits} (v:${ptw.resp.valid}r:${ptw.resp.ready}) \n")
277
278  println(s"${q.name}: normal page: ${q.normalNWays} ${q.normalAssociative} ${q.normalReplacer.get} super page: ${q.superNWays} ${q.superAssociative} ${q.superReplacer.get}")
279
280//   // NOTE: just for simple tlb debug, comment it after tlb's debug
281  // assert(!io.ptw.resp.valid || io.ptw.resp.bits.entry.tag === io.ptw.resp.bits.entry.ppn, "Simple tlb debug requires vpn === ppn")
282}
283
284class TlbReplace(Width: Int, q: TLBParameters)(implicit p: Parameters) extends TlbModule {
285  val io = IO(new TlbReplaceIO(Width, q))
286
287  if (q.normalAssociative == "fa") {
288    val re = ReplacementPolicy.fromString(q.normalReplacer, q.normalNWays)
289    re.access(io.normalPage.access.touch_ways)
290    io.normalPage.refillIdx := re.way
291  } else { // set-acco && plru
292    val re = ReplacementPolicy.fromString(q.normalReplacer, q.normalNSets, q.normalNWays)
293    re.access(io.normalPage.access.sets, io.normalPage.access.touch_ways)
294    io.normalPage.refillIdx := { if (q.normalNWays == 1) 0.U else re.way(io.normalPage.chosen_set) }
295  }
296
297  if (q.superAssociative == "fa") {
298    val re = ReplacementPolicy.fromString(q.superReplacer, q.superNWays)
299    re.access(io.superPage.access.touch_ways)
300    io.superPage.refillIdx := re.way
301  } else { // set-acco && plru
302    val re = ReplacementPolicy.fromString(q.superReplacer, q.superNSets, q.superNWays)
303    re.access(io.superPage.access.sets, io.superPage.access.touch_ways)
304    io.superPage.refillIdx := { if (q.superNWays == 1) 0.U else re.way(io.superPage.chosen_set) }
305  }
306}
307
308object TLB {
309  def apply
310  (
311    in: Seq[BlockTlbRequestIO],
312    sfence: SfenceBundle,
313    csr: TlbCsrBundle,
314    width: Int,
315    shouldBlock: Boolean,
316    q: TLBParameters
317  )(implicit p: Parameters) = {
318    require(in.length == width)
319
320    val tlb = Module(new TLB(width, q))
321
322    tlb.io.sfence <> sfence
323    tlb.io.csr <> csr
324    tlb.suggestName(s"tlb_${q.name}")
325
326    if (!shouldBlock) { // dtlb
327      for (i <- 0 until width) {
328        tlb.io.requestor(i) <> in(i)
329        // tlb.io.requestor(i).req.valid := in(i).req.valid
330        // tlb.io.requestor(i).req.bits := in(i).req.bits
331        // in(i).req.ready := tlb.io.requestor(i).req.ready
332
333        // in(i).resp.valid := tlb.io.requestor(i).resp.valid
334        // in(i).resp.bits := tlb.io.requestor(i).resp.bits
335        // tlb.io.requestor(i).resp.ready := in(i).resp.ready
336      }
337    } else { // itlb
338      //require(width == 1)
339      (0 until width).map{ i =>
340        tlb.io.requestor(i).req.valid := in(i).req.valid
341        tlb.io.requestor(i).req.bits := in(i).req.bits
342        in(i).req.ready := !tlb.io.requestor(i).resp.bits.miss && in(i).resp.ready && tlb.io.requestor(i).req.ready
343
344        in(i).resp.valid := tlb.io.requestor(i).resp.valid && !tlb.io.requestor(i).resp.bits.miss
345        in(i).resp.bits := tlb.io.requestor(i).resp.bits
346        tlb.io.requestor(i).resp.ready := in(i).resp.ready
347      }
348    }
349
350    tlb.io.ptw
351  }
352}
353