xref: /XiangShan/src/main/scala/xiangshan/mem/pipeline/StoreUnit.scala (revision d479a3a838f93713e8d569af098b6da7fc3c5905)
1package xiangshan.mem
2
3import chisel3._
4import chisel3.util._
5import utils._
6import xiangshan._
7import xiangshan.backend.decode.ImmUnion
8import xiangshan.cache._
9
10// Store Pipeline Stage 0
11// Generate addr, use addr to query DCache and DTLB
12class StoreUnit_S0 extends XSModule {
13  val io = IO(new Bundle() {
14    val in = Flipped(Decoupled(new ExuInput))
15    val rsIdx = Input(UInt(log2Up(IssQueSize).W))
16    val out = Decoupled(new LsPipelineBundle)
17    val dtlbReq = DecoupledIO(new TlbReq)
18  })
19
20  // send req to dtlb
21  // val saddr = io.in.bits.src1 + SignExt(io.in.bits.uop.ctrl.imm(11,0), VAddrBits)
22  val imm12 = WireInit(io.in.bits.uop.ctrl.imm(11,0))
23  val saddr_lo = io.in.bits.src1(11,0) + Cat(0.U(1.W), imm12)
24  val saddr_hi = Mux(saddr_lo(12),
25    Mux(imm12(11), io.in.bits.src1(VAddrBits-1, 12), io.in.bits.src1(VAddrBits-1, 12)+1.U),
26    Mux(imm12(11), io.in.bits.src1(VAddrBits-1, 12)+SignExt(1.U, VAddrBits-12), io.in.bits.src1(VAddrBits-1, 12)),
27  )
28  val saddr = Cat(saddr_hi, saddr_lo(11,0))
29
30  io.dtlbReq.bits.vaddr := saddr
31  io.dtlbReq.valid := io.in.valid
32  io.dtlbReq.bits.cmd := TlbCmd.write
33  io.dtlbReq.bits.roqIdx := io.in.bits.uop.roqIdx
34  io.dtlbReq.bits.debug.pc := io.in.bits.uop.cf.pc
35
36  io.out.bits := DontCare
37  io.out.bits.vaddr := saddr
38
39  io.out.bits.data := genWdata(io.in.bits.src2, io.in.bits.uop.ctrl.fuOpType(1,0))
40  io.out.bits.uop := io.in.bits.uop
41  io.out.bits.miss := DontCare
42  io.out.bits.rsIdx := io.rsIdx
43  io.out.bits.mask := genWmask(io.out.bits.vaddr, io.in.bits.uop.ctrl.fuOpType(1,0))
44  io.out.valid := io.in.valid
45  io.in.ready := io.out.ready
46
47  // exception check
48  val addrAligned = LookupTree(io.in.bits.uop.ctrl.fuOpType(1,0), List(
49    "b00".U   -> true.B,              //b
50    "b01".U   -> (io.out.bits.vaddr(0) === 0.U),   //h
51    "b10".U   -> (io.out.bits.vaddr(1,0) === 0.U), //w
52    "b11".U   -> (io.out.bits.vaddr(2,0) === 0.U)  //d
53  ))
54  io.out.bits.uop.cf.exceptionVec(storeAddrMisaligned) := !addrAligned
55
56}
57
58// Load Pipeline Stage 1
59// TLB resp (send paddr to dcache)
60class StoreUnit_S1 extends XSModule {
61  val io = IO(new Bundle() {
62    val in = Flipped(Decoupled(new LsPipelineBundle))
63    val out = Decoupled(new LsPipelineBundle)
64    val lsq = ValidIO(new LsPipelineBundle)
65    val dtlbResp = Flipped(DecoupledIO(new TlbResp))
66    val tlbFeedback = ValidIO(new TlbFeedback)
67  })
68
69  val s1_paddr = io.dtlbResp.bits.paddr
70  val s1_tlb_miss = io.dtlbResp.bits.miss
71  val s1_mmio = io.dtlbResp.bits.mmio
72  val s1_exception = selectStore(io.out.bits.uop.cf.exceptionVec, false).asUInt.orR
73
74  io.in.ready := true.B
75
76  io.dtlbResp.ready := true.B // TODO: why dtlbResp needs a ready?
77
78  // Send TLB feedback to store issue queue
79  io.tlbFeedback.valid := io.in.valid
80  io.tlbFeedback.bits.hit := !s1_tlb_miss
81  io.tlbFeedback.bits.flushState := io.dtlbResp.bits.ptwBack
82  io.tlbFeedback.bits.rsIdx := io.in.bits.rsIdx
83  XSDebug(io.tlbFeedback.valid,
84    "S1 Store: tlbHit: %d roqIdx: %d\n",
85    io.tlbFeedback.bits.hit,
86    io.tlbFeedback.bits.rsIdx
87  )
88
89
90  // get paddr from dtlb, check if rollback is needed
91  // writeback store inst to lsq
92  io.lsq.valid := io.in.valid && !s1_tlb_miss
93  io.lsq.bits := io.in.bits
94  io.lsq.bits.paddr := s1_paddr
95  io.lsq.bits.miss := false.B
96  io.lsq.bits.mmio := s1_mmio && !s1_exception
97  io.lsq.bits.uop.cf.exceptionVec(storePageFault) := io.dtlbResp.bits.excp.pf.st
98  io.lsq.bits.uop.cf.exceptionVec(storeAccessFault) := io.dtlbResp.bits.excp.af.st
99
100  // mmio inst with exception will be writebacked immediately
101  io.out.valid := io.in.valid && (!io.out.bits.mmio || s1_exception) && !s1_tlb_miss
102  io.out.bits := io.lsq.bits
103}
104
105class StoreUnit_S2 extends XSModule {
106  val io = IO(new Bundle() {
107    val in = Flipped(Decoupled(new LsPipelineBundle))
108    val out = Decoupled(new LsPipelineBundle)
109  })
110
111  io.in.ready := true.B
112  io.out.bits := io.in.bits
113  io.out.valid := io.in.valid
114
115}
116
117class StoreUnit_S3 extends XSModule {
118  val io = IO(new Bundle() {
119    val in = Flipped(Decoupled(new LsPipelineBundle))
120    val stout = DecoupledIO(new ExuOutput) // writeback store
121  })
122
123  io.in.ready := true.B
124
125  io.stout.valid := io.in.valid
126  io.stout.bits.uop := io.in.bits.uop
127  io.stout.bits.data := DontCare
128  io.stout.bits.redirectValid := false.B
129  io.stout.bits.redirect := DontCare
130  io.stout.bits.debug.isMMIO := io.in.bits.mmio
131  io.stout.bits.debug.paddr := DontCare
132  io.stout.bits.debug.isPerfCnt := false.B
133  io.stout.bits.fflags := DontCare
134
135}
136
137class StoreUnit extends XSModule {
138  val io = IO(new Bundle() {
139    val stin = Flipped(Decoupled(new ExuInput))
140    val redirect = Flipped(ValidIO(new Redirect))
141    val flush = Input(Bool())
142    val tlbFeedback = ValidIO(new TlbFeedback)
143    val dtlb = new TlbRequestIO()
144    val rsIdx = Input(UInt(log2Up(IssQueSize).W))
145    val lsq = ValidIO(new LsPipelineBundle)
146    val stout = DecoupledIO(new ExuOutput) // writeback store
147  })
148
149  val store_s0 = Module(new StoreUnit_S0)
150  val store_s1 = Module(new StoreUnit_S1)
151  val store_s2 = Module(new StoreUnit_S2)
152  val store_s3 = Module(new StoreUnit_S3)
153
154  store_s0.io.in <> io.stin
155  store_s0.io.dtlbReq <> io.dtlb.req
156  store_s0.io.rsIdx := io.rsIdx
157
158  PipelineConnect(store_s0.io.out, store_s1.io.in, true.B, store_s0.io.out.bits.uop.roqIdx.needFlush(io.redirect, io.flush))
159
160  store_s1.io.lsq <> io.lsq // send result to sq
161  store_s1.io.dtlbResp <> io.dtlb.resp
162  store_s1.io.tlbFeedback <> io.tlbFeedback
163
164  PipelineConnect(store_s1.io.out, store_s2.io.in, true.B, store_s1.io.out.bits.uop.roqIdx.needFlush(io.redirect, io.flush))
165
166  PipelineConnect(store_s2.io.out, store_s3.io.in, true.B, store_s2.io.out.bits.uop.roqIdx.needFlush(io.redirect, io.flush))
167
168  store_s3.io.stout <> io.stout
169
170  private def printPipeLine(pipeline: LsPipelineBundle, cond: Bool, name: String): Unit = {
171    XSDebug(cond,
172      p"$name" + p" pc ${Hexadecimal(pipeline.uop.cf.pc)} " +
173        p"addr ${Hexadecimal(pipeline.vaddr)} -> ${Hexadecimal(pipeline.paddr)} " +
174        p"op ${Binary(pipeline.uop.ctrl.fuOpType)} " +
175        p"data ${Hexadecimal(pipeline.data)} " +
176        p"mask ${Hexadecimal(pipeline.mask)}\n"
177    )
178  }
179
180  printPipeLine(store_s0.io.out.bits, store_s0.io.out.valid, "S0")
181  printPipeLine(store_s1.io.out.bits, store_s1.io.out.valid, "S1")
182
183}
184