xref: /XiangShan/src/main/scala/xiangshan/mem/pipeline/StoreUnit.scala (revision c6d439803a044ea209139672b25e35fe8d7f4aa0)
1/***************************************************************************************
2* Copyright (c) 2020-2021 Institute of Computing Technology, Chinese Academy of Sciences
3*
4* XiangShan is licensed under Mulan PSL v2.
5* You can use this software according to the terms and conditions of the Mulan PSL v2.
6* You may obtain a copy of Mulan PSL v2 at:
7*          http://license.coscl.org.cn/MulanPSL2
8*
9* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
10* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
11* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
12*
13* See the Mulan PSL v2 for more details.
14***************************************************************************************/
15
16package xiangshan.mem
17
18import chipsalliance.rocketchip.config.Parameters
19import chisel3._
20import chisel3.util._
21import utils._
22import xiangshan._
23import xiangshan.backend.decode.ImmUnion
24import xiangshan.cache._
25
26// Store Pipeline Stage 0
27// Generate addr, use addr to query DCache and DTLB
28class StoreUnit_S0(implicit p: Parameters) extends XSModule {
29  val io = IO(new Bundle() {
30    val in = Flipped(Decoupled(new ExuInput))
31    val rsIdx = Input(UInt(log2Up(IssQueSize).W))
32    val isFirstIssue = Input(Bool())
33    val out = Decoupled(new LsPipelineBundle)
34    val dtlbReq = DecoupledIO(new TlbReq)
35  })
36
37  // send req to dtlb
38  // val saddr = io.in.bits.src(0) + SignExt(io.in.bits.uop.ctrl.imm(11,0), VAddrBits)
39  val imm12 = WireInit(io.in.bits.uop.ctrl.imm(11,0))
40  val saddr_lo = io.in.bits.src(0)(11,0) + Cat(0.U(1.W), imm12)
41  val saddr_hi = Mux(saddr_lo(12),
42    Mux(imm12(11), io.in.bits.src(0)(VAddrBits-1, 12), io.in.bits.src(0)(VAddrBits-1, 12)+1.U),
43    Mux(imm12(11), io.in.bits.src(0)(VAddrBits-1, 12)+SignExt(1.U, VAddrBits-12), io.in.bits.src(0)(VAddrBits-1, 12)),
44  )
45  val saddr = Cat(saddr_hi, saddr_lo(11,0))
46
47  io.dtlbReq.bits.vaddr := saddr
48  io.dtlbReq.valid := io.in.valid
49  io.dtlbReq.bits.cmd := TlbCmd.write
50  io.dtlbReq.bits.roqIdx := io.in.bits.uop.roqIdx
51  io.dtlbReq.bits.debug.pc := io.in.bits.uop.cf.pc
52  io.dtlbReq.bits.debug.isFirstIssue := io.isFirstIssue
53
54  io.out.bits := DontCare
55  io.out.bits.vaddr := saddr
56
57  // Now data use its own io
58  // io.out.bits.data := genWdata(io.in.bits.src(1), io.in.bits.uop.ctrl.fuOpType(1,0))
59  io.out.bits.data := io.in.bits.src(1) // FIXME: remove data from pipeline
60  io.out.bits.uop := io.in.bits.uop
61  io.out.bits.miss := DontCare
62  io.out.bits.rsIdx := io.rsIdx
63  io.out.bits.mask := genWmask(io.out.bits.vaddr, io.in.bits.uop.ctrl.fuOpType(1,0))
64  io.out.valid := io.in.valid
65  io.in.ready := io.out.ready
66
67  // exception check
68  val addrAligned = LookupTree(io.in.bits.uop.ctrl.fuOpType(1,0), List(
69    "b00".U   -> true.B,              //b
70    "b01".U   -> (io.out.bits.vaddr(0) === 0.U),   //h
71    "b10".U   -> (io.out.bits.vaddr(1,0) === 0.U), //w
72    "b11".U   -> (io.out.bits.vaddr(2,0) === 0.U)  //d
73  ))
74  io.out.bits.uop.cf.exceptionVec(storeAddrMisaligned) := !addrAligned
75
76  XSPerfAccumulate("addr_spec_success", io.out.fire() && saddr(VAddrBits-1, 12) === io.in.bits.src(0)(VAddrBits-1, 12))
77  XSPerfAccumulate("addr_spec_failed", io.out.fire() && saddr(VAddrBits-1, 12) =/= io.in.bits.src(0)(VAddrBits-1, 12))
78  XSPerfAccumulate("addr_spec_success_once", io.out.fire() && saddr(VAddrBits-1, 12) === io.in.bits.src(0)(VAddrBits-1, 12) && io.isFirstIssue)
79  XSPerfAccumulate("addr_spec_failed_once", io.out.fire() && saddr(VAddrBits-1, 12) =/= io.in.bits.src(0)(VAddrBits-1, 12) && io.isFirstIssue)
80}
81
82// Load Pipeline Stage 1
83// TLB resp (send paddr to dcache)
84class StoreUnit_S1(implicit p: Parameters) extends XSModule {
85  val io = IO(new Bundle() {
86    val in = Flipped(Decoupled(new LsPipelineBundle))
87    val out = Decoupled(new LsPipelineBundle)
88    val lsq = ValidIO(new LsPipelineBundle)
89    val dtlbResp = Flipped(DecoupledIO(new TlbResp))
90    val rsFeedback = ValidIO(new RSFeedback)
91  })
92
93  val s1_paddr = io.dtlbResp.bits.paddr
94  val s1_tlb_miss = io.dtlbResp.bits.miss
95  val s1_mmio = io.dtlbResp.bits.mmio
96  val s1_exception = selectStore(io.out.bits.uop.cf.exceptionVec, false).asUInt.orR
97
98  io.in.ready := true.B
99
100  io.dtlbResp.ready := true.B // TODO: why dtlbResp needs a ready?
101
102  // Send TLB feedback to store issue queue
103  io.rsFeedback.valid := io.in.valid
104  io.rsFeedback.bits.hit := !s1_tlb_miss
105  io.rsFeedback.bits.flushState := io.dtlbResp.bits.ptwBack
106  io.rsFeedback.bits.rsIdx := io.in.bits.rsIdx
107  io.rsFeedback.bits.sourceType := RSFeedbackType.tlbMiss
108  XSDebug(io.rsFeedback.valid,
109    "S1 Store: tlbHit: %d roqIdx: %d\n",
110    io.rsFeedback.bits.hit,
111    io.rsFeedback.bits.rsIdx
112  )
113
114
115  // get paddr from dtlb, check if rollback is needed
116  // writeback store inst to lsq
117  io.lsq.valid := io.in.valid && !s1_tlb_miss
118  io.lsq.bits := io.in.bits
119  io.lsq.bits.paddr := s1_paddr
120  io.lsq.bits.miss := false.B
121  io.lsq.bits.mmio := s1_mmio && !s1_exception
122  io.lsq.bits.uop.cf.exceptionVec(storePageFault) := io.dtlbResp.bits.excp.pf.st
123  io.lsq.bits.uop.cf.exceptionVec(storeAccessFault) := io.dtlbResp.bits.excp.af.st
124
125  // mmio inst with exception will be writebacked immediately
126  io.out.valid := io.in.valid && (!io.out.bits.mmio || s1_exception) && !s1_tlb_miss
127  io.out.bits := io.lsq.bits
128}
129
130class StoreUnit_S2(implicit p: Parameters) extends XSModule {
131  val io = IO(new Bundle() {
132    val in = Flipped(Decoupled(new LsPipelineBundle))
133    val out = Decoupled(new LsPipelineBundle)
134  })
135
136  io.in.ready := true.B
137  io.out.bits := io.in.bits
138  io.out.valid := io.in.valid
139
140}
141
142class StoreUnit_S3(implicit p: Parameters) extends XSModule {
143  val io = IO(new Bundle() {
144    val in = Flipped(Decoupled(new LsPipelineBundle))
145    val stout = DecoupledIO(new ExuOutput) // writeback store
146  })
147
148  io.in.ready := true.B
149
150  io.stout.valid := io.in.valid
151  io.stout.bits.uop := io.in.bits.uop
152  io.stout.bits.data := DontCare
153  io.stout.bits.redirectValid := false.B
154  io.stout.bits.redirect := DontCare
155  io.stout.bits.debug.isMMIO := io.in.bits.mmio
156  io.stout.bits.debug.paddr := DontCare
157  io.stout.bits.debug.isPerfCnt := false.B
158  io.stout.bits.fflags := DontCare
159
160}
161
162class StoreUnit(implicit p: Parameters) extends XSModule {
163  val io = IO(new Bundle() {
164    val stin = Flipped(Decoupled(new ExuInput))
165    val redirect = Flipped(ValidIO(new Redirect))
166    val flush = Input(Bool())
167    val rsFeedback = ValidIO(new RSFeedback)
168    val dtlb = new TlbRequestIO()
169    val rsIdx = Input(UInt(log2Up(IssQueSize).W))
170    val isFirstIssue = Input(Bool())
171    val lsq = ValidIO(new LsPipelineBundle)
172    val stout = DecoupledIO(new ExuOutput) // writeback store
173  })
174
175  val store_s0 = Module(new StoreUnit_S0)
176  val store_s1 = Module(new StoreUnit_S1)
177  val store_s2 = Module(new StoreUnit_S2)
178  val store_s3 = Module(new StoreUnit_S3)
179
180  store_s0.io.in <> io.stin
181  store_s0.io.dtlbReq <> io.dtlb.req
182  store_s0.io.rsIdx := io.rsIdx
183  store_s0.io.isFirstIssue := io.isFirstIssue
184
185  PipelineConnect(store_s0.io.out, store_s1.io.in, true.B, store_s0.io.out.bits.uop.roqIdx.needFlush(io.redirect, io.flush))
186
187  store_s1.io.lsq <> io.lsq // send result to sq
188  store_s1.io.dtlbResp <> io.dtlb.resp
189  store_s1.io.rsFeedback <> io.rsFeedback
190
191  PipelineConnect(store_s1.io.out, store_s2.io.in, true.B, store_s1.io.out.bits.uop.roqIdx.needFlush(io.redirect, io.flush))
192
193  PipelineConnect(store_s2.io.out, store_s3.io.in, true.B, store_s2.io.out.bits.uop.roqIdx.needFlush(io.redirect, io.flush))
194
195  store_s3.io.stout <> io.stout
196
197  private def printPipeLine(pipeline: LsPipelineBundle, cond: Bool, name: String): Unit = {
198    XSDebug(cond,
199      p"$name" + p" pc ${Hexadecimal(pipeline.uop.cf.pc)} " +
200        p"addr ${Hexadecimal(pipeline.vaddr)} -> ${Hexadecimal(pipeline.paddr)} " +
201        p"op ${Binary(pipeline.uop.ctrl.fuOpType)} " +
202        p"data ${Hexadecimal(pipeline.data)} " +
203        p"mask ${Hexadecimal(pipeline.mask)}\n"
204    )
205  }
206
207  printPipeLine(store_s0.io.out.bits, store_s0.io.out.valid, "S0")
208  printPipeLine(store_s1.io.out.bits, store_s1.io.out.valid, "S1")
209
210}
211