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