xref: /XiangShan/src/main/scala/xiangshan/mem/pipeline/StoreUnit.scala (revision 49272fa467f97c3293eb9ed685e99ecf79691182)
1package xiangshan.mem
2
3import chisel3._
4import chisel3.util._
5import utils._
6import xiangshan._
7import xiangshan.cache._
8
9// Store Pipeline Stage 0
10// Generate addr, use addr to query DCache and DTLB
11class StoreUnit_S0 extends XSModule {
12  val io = IO(new Bundle() {
13    val in = Flipped(Decoupled(new ExuInput))
14    val out = Decoupled(new LsPipelineBundle)
15    val dtlbReq = DecoupledIO(new TlbReq)
16  })
17
18  // send req to dtlb
19  val saddr = io.in.bits.src1 + io.in.bits.uop.ctrl.imm
20
21  io.dtlbReq.bits.vaddr := saddr
22  io.dtlbReq.valid := io.in.valid
23  io.dtlbReq.bits.cmd := TlbCmd.write
24  io.dtlbReq.bits.roqIdx := io.in.bits.uop.roqIdx
25  io.dtlbReq.bits.debug.pc := io.in.bits.uop.cf.pc
26
27  io.out.bits := DontCare
28  io.out.bits.vaddr := saddr
29
30  io.out.bits.data := genWdata(io.in.bits.src2, io.in.bits.uop.ctrl.fuOpType(1,0))
31  io.out.bits.uop := io.in.bits.uop
32  io.out.bits.miss := DontCare
33  io.out.bits.mask := genWmask(io.out.bits.vaddr, io.in.bits.uop.ctrl.fuOpType(1,0))
34  io.out.valid := io.in.valid
35  io.in.ready := io.out.ready
36
37  // exception check
38  val addrAligned = LookupTree(io.in.bits.uop.ctrl.fuOpType(1,0), List(
39    "b00".U   -> true.B,              //b
40    "b01".U   -> (io.out.bits.vaddr(0) === 0.U),   //h
41    "b10".U   -> (io.out.bits.vaddr(1,0) === 0.U), //w
42    "b11".U   -> (io.out.bits.vaddr(2,0) === 0.U)  //d
43  ))
44  io.out.bits.uop.cf.exceptionVec(storeAddrMisaligned) := !addrAligned
45
46}
47
48// Load Pipeline Stage 1
49// TLB resp (send paddr to dcache)
50class StoreUnit_S1 extends XSModule {
51  val io = IO(new Bundle() {
52    val in = Flipped(Decoupled(new LsPipelineBundle))
53    val out = Decoupled(new LsPipelineBundle)
54    // val fp_out = Decoupled(new LsPipelineBundle)
55    val lsq = ValidIO(new LsPipelineBundle)
56    val dtlbResp = Flipped(DecoupledIO(new TlbResp))
57    val tlbFeedback = ValidIO(new TlbFeedback)
58  })
59
60  val s1_paddr = io.dtlbResp.bits.paddr
61  val s1_tlb_miss = io.dtlbResp.bits.miss
62
63  io.in.ready := true.B
64
65  io.dtlbResp.ready := true.B // TODO: why dtlbResp needs a ready?
66
67  // Send TLB feedback to store issue queue
68  io.tlbFeedback.valid := io.in.valid
69  io.tlbFeedback.bits.hit := !s1_tlb_miss
70  io.tlbFeedback.bits.roqIdx := io.in.bits.uop.roqIdx
71  XSDebug(io.tlbFeedback.valid,
72    "S1 Store: tlbHit: %d roqIdx: %d\n",
73    io.tlbFeedback.bits.hit,
74    io.tlbFeedback.bits.roqIdx.asUInt
75  )
76
77  // get paddr from dtlb, check if rollback is needed
78  // writeback store inst to lsq
79  io.lsq.valid := io.in.valid && !s1_tlb_miss// TODO: && ! FP
80  io.lsq.bits := io.in.bits
81  io.lsq.bits.paddr := s1_paddr
82  io.lsq.bits.miss := false.B
83  io.lsq.bits.mmio := AddressSpace.isMMIO(s1_paddr)
84  io.lsq.bits.uop.cf.exceptionVec(storePageFault) := io.dtlbResp.bits.excp.pf.st
85
86  // mmio inst with exception will be writebacked immediately
87  val hasException = io.out.bits.uop.cf.exceptionVec.asUInt.orR
88  io.out.valid := io.in.valid && (!io.out.bits.mmio || hasException) && !s1_tlb_miss
89  io.out.bits := io.lsq.bits
90
91  // if fp
92  // io.fp_out.valid := ...
93  // io.fp_out.bits := ...
94
95}
96
97class StoreUnit_S2 extends XSModule {
98  val io = IO(new Bundle() {
99    val in = Flipped(Decoupled(new LsPipelineBundle))
100    val stout = DecoupledIO(new ExuOutput) // writeback store
101  })
102
103  io.in.ready := true.B
104
105  io.stout.valid := io.in.valid
106  io.stout.bits.uop := io.in.bits.uop
107  io.stout.bits.data := DontCare
108  io.stout.bits.redirectValid := false.B
109  io.stout.bits.redirect := DontCare
110  io.stout.bits.brUpdate := DontCare
111  io.stout.bits.debug.isMMIO := io.in.bits.mmio
112  io.stout.bits.fflags := DontCare
113
114}
115
116class StoreUnit extends XSModule {
117  val io = IO(new Bundle() {
118    val stin = Flipped(Decoupled(new ExuInput))
119    val redirect = Flipped(ValidIO(new Redirect))
120    val tlbFeedback = ValidIO(new TlbFeedback)
121    val dtlb = new TlbRequestIO()
122    val lsq = ValidIO(new LsPipelineBundle)
123    val stout = DecoupledIO(new ExuOutput) // writeback store
124  })
125
126  val store_s0 = Module(new StoreUnit_S0)
127  val store_s1 = Module(new StoreUnit_S1)
128  val store_s2 = Module(new StoreUnit_S2)
129
130  store_s0.io.in <> io.stin
131  store_s0.io.dtlbReq <> io.dtlb.req
132
133  PipelineConnect(store_s0.io.out, store_s1.io.in, true.B, store_s0.io.out.bits.uop.roqIdx.needFlush(io.redirect))
134
135  store_s1.io.lsq <> io.lsq // send result to sq
136  store_s1.io.dtlbResp <> io.dtlb.resp
137  store_s1.io.tlbFeedback <> io.tlbFeedback
138
139  PipelineConnect(store_s1.io.out, store_s2.io.in, true.B, store_s1.io.out.bits.uop.roqIdx.needFlush(io.redirect))
140
141  store_s2.io.stout <> io.stout
142
143  private def printPipeLine(pipeline: LsPipelineBundle, cond: Bool, name: String): Unit = {
144    XSDebug(cond,
145      p"$name" + p" pc ${Hexadecimal(pipeline.uop.cf.pc)} " +
146        p"addr ${Hexadecimal(pipeline.vaddr)} -> ${Hexadecimal(pipeline.paddr)} " +
147        p"op ${Binary(pipeline.uop.ctrl.fuOpType)} " +
148        p"data ${Hexadecimal(pipeline.data)} " +
149        p"mask ${Hexadecimal(pipeline.mask)}\n"
150    )
151  }
152
153  printPipeLine(store_s0.io.out.bits, store_s0.io.out.valid, "S0")
154  printPipeLine(store_s1.io.out.bits, store_s1.io.out.valid, "S1")
155
156}
157