xref: /XiangShan/src/main/scala/xiangshan/mem/pipeline/StoreUnit.scala (revision b56f947ea6e9fe50fd06047a225356a808f2a3b1)
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.mem
18
19import chipsalliance.rocketchip.config.Parameters
20import chisel3._
21import chisel3.util._
22import utils._
23import xiangshan.ExceptionNO._
24import xiangshan._
25import xiangshan.backend.fu.PMPRespBundle
26import xiangshan.cache.mmu.{TlbCmd, TlbReq, TlbRequestIO, TlbResp}
27
28// Store Pipeline Stage 0
29// Generate addr, use addr to query DCache and DTLB
30class StoreUnit_S0(implicit p: Parameters) extends XSModule {
31  val io = IO(new Bundle() {
32    val in = Flipped(Decoupled(new ExuInput))
33    val rsIdx = Input(UInt(log2Up(IssQueSize).W))
34    val isFirstIssue = Input(Bool())
35    val out = Decoupled(new LsPipelineBundle)
36    val dtlbReq = DecoupledIO(new TlbReq)
37  })
38
39  // send req to dtlb
40  // val saddr = io.in.bits.src(0) + SignExt(io.in.bits.uop.ctrl.imm(11,0), VAddrBits)
41  val imm12 = WireInit(io.in.bits.uop.ctrl.imm(11,0))
42  val saddr_lo = io.in.bits.src(0)(11,0) + Cat(0.U(1.W), imm12)
43  val saddr_hi = Mux(saddr_lo(12),
44    Mux(imm12(11), io.in.bits.src(0)(VAddrBits-1, 12), io.in.bits.src(0)(VAddrBits-1, 12)+1.U),
45    Mux(imm12(11), io.in.bits.src(0)(VAddrBits-1, 12)+SignExt(1.U, VAddrBits-12), io.in.bits.src(0)(VAddrBits-1, 12)),
46  )
47  val saddr = Cat(saddr_hi, saddr_lo(11,0))
48
49  io.dtlbReq.bits.vaddr := saddr
50  io.dtlbReq.valid := io.in.valid
51  io.dtlbReq.bits.cmd := TlbCmd.write
52  io.dtlbReq.bits.size := LSUOpType.size(io.in.bits.uop.ctrl.fuOpType)
53  io.dtlbReq.bits.kill := DontCare
54  io.dtlbReq.bits.debug.robIdx := io.in.bits.uop.robIdx
55  io.dtlbReq.bits.debug.pc := io.in.bits.uop.cf.pc
56  io.dtlbReq.bits.debug.isFirstIssue := io.isFirstIssue
57
58  io.out.bits := DontCare
59  io.out.bits.vaddr := saddr
60
61  // Now data use its own io
62  // io.out.bits.data := genWdata(io.in.bits.src(1), io.in.bits.uop.ctrl.fuOpType(1,0))
63  io.out.bits.data := io.in.bits.src(1) // FIXME: remove data from pipeline
64  io.out.bits.uop := io.in.bits.uop
65  io.out.bits.miss := DontCare
66  io.out.bits.rsIdx := io.rsIdx
67  io.out.bits.mask := genWmask(io.out.bits.vaddr, io.in.bits.uop.ctrl.fuOpType(1,0))
68  io.out.bits.isFirstIssue := io.isFirstIssue
69  io.out.bits.wlineflag := io.in.bits.uop.ctrl.fuOpType === LSUOpType.cbo_zero
70  io.out.valid := io.in.valid
71  io.in.ready := io.out.ready
72
73  // exception check
74  val addrAligned = LookupTree(io.in.bits.uop.ctrl.fuOpType(1,0), List(
75    "b00".U   -> true.B,              //b
76    "b01".U   -> (io.out.bits.vaddr(0) === 0.U),   //h
77    "b10".U   -> (io.out.bits.vaddr(1,0) === 0.U), //w
78    "b11".U   -> (io.out.bits.vaddr(2,0) === 0.U)  //d
79  ))
80  io.out.bits.uop.cf.exceptionVec(storeAddrMisaligned) := !addrAligned
81
82  XSPerfAccumulate("in_valid", io.in.valid)
83  XSPerfAccumulate("in_fire", io.in.fire)
84  XSPerfAccumulate("in_fire_first_issue", io.in.fire && io.isFirstIssue)
85  XSPerfAccumulate("addr_spec_success", io.out.fire() && saddr(VAddrBits-1, 12) === io.in.bits.src(0)(VAddrBits-1, 12))
86  XSPerfAccumulate("addr_spec_failed", io.out.fire() && saddr(VAddrBits-1, 12) =/= io.in.bits.src(0)(VAddrBits-1, 12))
87  XSPerfAccumulate("addr_spec_success_once", io.out.fire() && saddr(VAddrBits-1, 12) === io.in.bits.src(0)(VAddrBits-1, 12) && io.isFirstIssue)
88  XSPerfAccumulate("addr_spec_failed_once", io.out.fire() && saddr(VAddrBits-1, 12) =/= io.in.bits.src(0)(VAddrBits-1, 12) && io.isFirstIssue)
89}
90
91// Store Pipeline Stage 1
92// TLB resp (send paddr to dcache)
93class StoreUnit_S1(implicit p: Parameters) extends XSModule {
94  val io = IO(new Bundle() {
95    val in = Flipped(Decoupled(new LsPipelineBundle))
96    val out = Decoupled(new LsPipelineBundle)
97    val lsq = ValidIO(new LsPipelineBundle())
98    val dtlbResp = Flipped(DecoupledIO(new TlbResp))
99    val rsFeedback = ValidIO(new RSFeedback)
100  })
101
102  // mmio cbo decoder
103  val is_mmio_cbo = io.in.bits.uop.ctrl.fuOpType === LSUOpType.cbo_clean ||
104    io.in.bits.uop.ctrl.fuOpType === LSUOpType.cbo_flush ||
105    io.in.bits.uop.ctrl.fuOpType === LSUOpType.cbo_inval
106
107  val s1_paddr = io.dtlbResp.bits.paddr
108  val s1_tlb_miss = io.dtlbResp.bits.miss
109  val s1_mmio = is_mmio_cbo
110  val s1_exception = ExceptionNO.selectByFu(io.out.bits.uop.cf.exceptionVec, staCfg).asUInt.orR
111
112  io.in.ready := true.B
113
114  io.dtlbResp.ready := true.B // TODO: why dtlbResp needs a ready?
115
116  // Send TLB feedback to store issue queue
117  // Store feedback is generated in store_s1, sent to RS in store_s2
118  io.rsFeedback.valid := io.in.valid
119  io.rsFeedback.bits.hit := !s1_tlb_miss
120  io.rsFeedback.bits.flushState := io.dtlbResp.bits.ptwBack
121  io.rsFeedback.bits.rsIdx := io.in.bits.rsIdx
122  io.rsFeedback.bits.sourceType := RSFeedbackType.tlbMiss
123  XSDebug(io.rsFeedback.valid,
124    "S1 Store: tlbHit: %d robIdx: %d\n",
125    io.rsFeedback.bits.hit,
126    io.rsFeedback.bits.rsIdx
127  )
128  io.rsFeedback.bits.dataInvalidSqIdx := DontCare
129
130  // get paddr from dtlb, check if rollback is needed
131  // writeback store inst to lsq
132  io.out.valid := io.in.valid && !s1_tlb_miss
133  io.out.bits := io.in.bits
134  io.out.bits.paddr := s1_paddr
135  io.out.bits.miss := false.B
136  io.out.bits.mmio := s1_mmio
137  io.out.bits.uop.cf.exceptionVec(storePageFault) := io.dtlbResp.bits.excp.pf.st
138  io.out.bits.uop.cf.exceptionVec(storeAccessFault) := io.dtlbResp.bits.excp.af.st
139
140  io.lsq.valid := io.in.valid
141  io.lsq.bits := io.out.bits
142  io.lsq.bits.miss := s1_tlb_miss
143
144  // mmio inst with exception will be writebacked immediately
145  // io.out.valid := io.in.valid && (!io.out.bits.mmio || s1_exception) && !s1_tlb_miss
146
147  XSPerfAccumulate("in_valid", io.in.valid)
148  XSPerfAccumulate("in_fire", io.in.fire)
149  XSPerfAccumulate("in_fire_first_issue", io.in.fire && io.in.bits.isFirstIssue)
150  XSPerfAccumulate("tlb_miss", io.in.fire && s1_tlb_miss)
151  XSPerfAccumulate("tlb_miss_first_issue", io.in.fire && s1_tlb_miss && io.in.bits.isFirstIssue)
152}
153
154class StoreUnit_S2(implicit p: Parameters) extends XSModule {
155  val io = IO(new Bundle() {
156    val in = Flipped(Decoupled(new LsPipelineBundle))
157    val pmpResp = Flipped(new PMPRespBundle)
158    val static_pm = Input(Valid(Bool()))
159    val out = Decoupled(new LsPipelineBundle)
160  })
161  val pmp = WireInit(io.pmpResp)
162  when (io.static_pm.valid) {
163    pmp.ld := false.B
164    pmp.st := false.B
165    pmp.instr := false.B
166    pmp.mmio := io.static_pm.bits
167  }
168
169  val s2_exception = ExceptionNO.selectByFu(io.out.bits.uop.cf.exceptionVec, staCfg).asUInt.orR
170  val is_mmio = io.in.bits.mmio || pmp.mmio
171
172  io.in.ready := true.B
173  io.out.bits := io.in.bits
174  io.out.bits.mmio := is_mmio && !s2_exception
175  io.out.bits.uop.cf.exceptionVec(storeAccessFault) := io.in.bits.uop.cf.exceptionVec(storeAccessFault) || pmp.st
176  io.out.valid := io.in.valid && (!is_mmio || s2_exception)
177}
178
179class StoreUnit_S3(implicit p: Parameters) extends XSModule {
180  val io = IO(new Bundle() {
181    val in = Flipped(Decoupled(new LsPipelineBundle))
182    val stout = DecoupledIO(new ExuOutput) // writeback store
183  })
184
185  io.in.ready := true.B
186
187  io.stout.valid := io.in.valid
188  io.stout.bits.uop := io.in.bits.uop
189  io.stout.bits.data := DontCare
190  io.stout.bits.redirectValid := false.B
191  io.stout.bits.redirect := DontCare
192  io.stout.bits.debug.isMMIO := io.in.bits.mmio
193  io.stout.bits.debug.paddr := io.in.bits.paddr
194  io.stout.bits.debug.vaddr := io.in.bits.vaddr
195  io.stout.bits.debug.isPerfCnt := false.B
196  io.stout.bits.fflags := DontCare
197
198}
199
200class StoreUnit(implicit p: Parameters) extends XSModule {
201  val io = IO(new Bundle() {
202    val stin = Flipped(Decoupled(new ExuInput))
203    val redirect = Flipped(ValidIO(new Redirect))
204    val feedbackSlow = ValidIO(new RSFeedback)
205    val tlb = new TlbRequestIO()
206    val pmp = Flipped(new PMPRespBundle())
207    val rsIdx = Input(UInt(log2Up(IssQueSize).W))
208    val isFirstIssue = Input(Bool())
209    val lsq = ValidIO(new LsPipelineBundle)
210    val lsq_replenish = Output(new LsPipelineBundle())
211    val stout = DecoupledIO(new ExuOutput) // writeback store
212  })
213
214  val store_s0 = Module(new StoreUnit_S0)
215  val store_s1 = Module(new StoreUnit_S1)
216  val store_s2 = Module(new StoreUnit_S2)
217  val store_s3 = Module(new StoreUnit_S3)
218
219  store_s0.io.in <> io.stin
220  store_s0.io.dtlbReq <> io.tlb.req
221  store_s0.io.rsIdx := io.rsIdx
222  store_s0.io.isFirstIssue := io.isFirstIssue
223
224  PipelineConnect(store_s0.io.out, store_s1.io.in, true.B, store_s0.io.out.bits.uop.robIdx.needFlush(io.redirect))
225
226
227  store_s1.io.dtlbResp <> io.tlb.resp
228  io.lsq <> store_s1.io.lsq
229
230  PipelineConnect(store_s1.io.out, store_s2.io.in, true.B, store_s1.io.out.bits.uop.robIdx.needFlush(io.redirect))
231
232  // feedback tlb miss to RS in store_s2
233  io.feedbackSlow.bits := RegNext(store_s1.io.rsFeedback.bits)
234  io.feedbackSlow.valid := RegNext(store_s1.io.rsFeedback.valid && !store_s1.io.out.bits.uop.robIdx.needFlush(io.redirect))
235
236  store_s2.io.pmpResp <> io.pmp
237  store_s2.io.static_pm := RegNext(io.tlb.resp.bits.static_pm)
238  io.lsq_replenish := store_s2.io.out.bits // mmio and exception
239  PipelineConnect(store_s2.io.out, store_s3.io.in, true.B, store_s2.io.out.bits.uop.robIdx.needFlush(io.redirect))
240
241  store_s3.io.stout <> io.stout
242
243  private def printPipeLine(pipeline: LsPipelineBundle, cond: Bool, name: String): Unit = {
244    XSDebug(cond,
245      p"$name" + p" pc ${Hexadecimal(pipeline.uop.cf.pc)} " +
246        p"addr ${Hexadecimal(pipeline.vaddr)} -> ${Hexadecimal(pipeline.paddr)} " +
247        p"op ${Binary(pipeline.uop.ctrl.fuOpType)} " +
248        p"data ${Hexadecimal(pipeline.data)} " +
249        p"mask ${Hexadecimal(pipeline.mask)}\n"
250    )
251  }
252
253  printPipeLine(store_s0.io.out.bits, store_s0.io.out.valid, "S0")
254  printPipeLine(store_s1.io.out.bits, store_s1.io.out.valid, "S1")
255}
256