xref: /XiangShan/src/main/scala/xiangshan/mem/lsqueue/LSQWrapper.scala (revision 3802dba502b91d813c1e563035b876c4e6288166)
1package xiangshan.mem
2
3import chisel3._
4import chisel3.util._
5import utils._
6import xiangshan._
7import xiangshan.cache._
8import xiangshan.cache.{DCacheWordIO, DCacheLineIO, TlbRequestIO, MemoryOpConstants}
9import xiangshan.backend.LSUOpType
10import xiangshan.mem._
11import xiangshan.backend.roq.RoqLsqIO
12
13class ExceptionAddrIO extends XSBundle {
14  val lsIdx = Input(new LSIdx)
15  val isStore = Input(Bool())
16  val vaddr = Output(UInt(VAddrBits.W))
17}
18
19class FwdEntry extends XSBundle {
20  val mask = Vec(8, Bool())
21  val data = Vec(8, UInt(8.W))
22}
23
24// inflight miss block reqs
25class InflightBlockInfo extends XSBundle {
26  val block_addr = UInt(PAddrBits.W)
27  val valid = Bool()
28}
29
30class LsqEnqIO extends XSBundle {
31  val canAccept = Output(Bool())
32  val needAlloc = Vec(RenameWidth, Input(Bool()))
33  val req = Vec(RenameWidth, Flipped(ValidIO(new MicroOp)))
34  val resp = Vec(RenameWidth, Output(new LSIdx))
35}
36
37// Load / Store Queue Wrapper for XiangShan Out of Order LSU
38class LsqWrappper extends XSModule with HasDCacheParameters {
39  val io = IO(new Bundle() {
40    val enq = new LsqEnqIO
41    val brqRedirect = Input(Valid(new Redirect))
42    val loadIn = Vec(LoadPipelineWidth, Flipped(Valid(new LsPipelineBundle)))
43    val storeIn = Vec(StorePipelineWidth, Flipped(Valid(new LsPipelineBundle)))
44    val loadDataForwarded = Vec(LoadPipelineWidth, Input(Bool()))
45    val sbuffer = Vec(StorePipelineWidth, Decoupled(new DCacheWordReq))
46    val ldout = Vec(2, DecoupledIO(new ExuOutput)) // writeback int load
47    val mmioStout = DecoupledIO(new ExuOutput) // writeback uncached store
48    val forward = Vec(LoadPipelineWidth, Flipped(new LoadForwardQueryIO))
49    val roq = Flipped(new RoqLsqIO)
50    val rollback = Output(Valid(new Redirect))
51    val dcache = Flipped(ValidIO(new Refill))
52    val uncache = new DCacheWordIO
53    val exceptionAddr = new ExceptionAddrIO
54    val sqempty = Output(Bool())
55  })
56  val difftestIO = IO(new Bundle() {
57    val fromSQ = new Bundle() {
58      val storeCommit = Output(UInt(2.W))
59      val storeAddr   = Output(Vec(2, UInt(64.W)))
60      val storeData   = Output(Vec(2, UInt(64.W)))
61      val storeMask   = Output(Vec(2, UInt(8.W)))
62    }
63  })
64  difftestIO <> DontCare
65
66  val loadQueue = Module(new LoadQueue)
67  val storeQueue = Module(new StoreQueue)
68
69  // io.enq logic
70  // LSQ: send out canAccept when both load queue and store queue are ready
71  // Dispatch: send instructions to LSQ only when they are ready
72  io.enq.canAccept := loadQueue.io.enq.canAccept && storeQueue.io.enq.canAccept
73  loadQueue.io.enq.sqCanAccept := storeQueue.io.enq.canAccept
74  storeQueue.io.enq.lqCanAccept := loadQueue.io.enq.canAccept
75  for (i <- 0 until RenameWidth) {
76    val isStore = CommitType.lsInstIsStore(io.enq.req(i).bits.ctrl.commitType)
77
78    loadQueue.io.enq.needAlloc(i) := io.enq.needAlloc(i) && !isStore
79    loadQueue.io.enq.req(i).valid  := !isStore && io.enq.req(i).valid
80    loadQueue.io.enq.req(i).bits  := io.enq.req(i).bits
81
82    storeQueue.io.enq.needAlloc(i) := io.enq.needAlloc(i) && isStore
83    storeQueue.io.enq.req(i).valid :=  isStore && io.enq.req(i).valid
84    storeQueue.io.enq.req(i).bits := io.enq.req(i).bits
85
86    io.enq.resp(i).lqIdx := loadQueue.io.enq.resp(i)
87    io.enq.resp(i).sqIdx := storeQueue.io.enq.resp(i)
88  }
89
90  // load queue wiring
91  loadQueue.io.brqRedirect <> io.brqRedirect
92  loadQueue.io.loadIn <> io.loadIn
93  loadQueue.io.storeIn <> io.storeIn
94  loadQueue.io.loadDataForwarded <> io.loadDataForwarded
95  loadQueue.io.ldout <> io.ldout
96  loadQueue.io.roq <> io.roq
97  loadQueue.io.rollback <> io.rollback
98  loadQueue.io.dcache <> io.dcache
99  loadQueue.io.exceptionAddr.lsIdx := io.exceptionAddr.lsIdx
100  loadQueue.io.exceptionAddr.isStore := DontCare
101
102  // store queue wiring
103  // storeQueue.io <> DontCare
104  storeQueue.io.brqRedirect <> io.brqRedirect
105  storeQueue.io.storeIn <> io.storeIn
106  storeQueue.io.sbuffer <> io.sbuffer
107  storeQueue.io.mmioStout <> io.mmioStout
108  storeQueue.io.roq <> io.roq
109  storeQueue.io.exceptionAddr.lsIdx := io.exceptionAddr.lsIdx
110  storeQueue.io.exceptionAddr.isStore := DontCare
111
112  loadQueue.io.load_s1 <> io.forward
113  storeQueue.io.forward <> io.forward // overlap forwardMask & forwardData, DO NOT CHANGE SEQUENCE
114
115  storeQueue.io.sqempty <> io.sqempty
116
117  if (env.DualCoreDifftest) {
118    difftestIO.fromSQ <> storeQueue.difftestIO
119  }
120
121  io.exceptionAddr.vaddr := Mux(io.exceptionAddr.isStore, storeQueue.io.exceptionAddr.vaddr, loadQueue.io.exceptionAddr.vaddr)
122
123  // naive uncache arbiter
124  val s_idle :: s_load :: s_store :: Nil = Enum(3)
125  val pendingstate = RegInit(s_idle)
126
127  switch(pendingstate){
128    is(s_idle){
129      when(io.uncache.req.fire()){
130        pendingstate := Mux(loadQueue.io.uncache.req.valid, s_load, s_store)
131      }
132    }
133    is(s_load){
134      when(io.uncache.resp.fire()){
135        pendingstate := s_idle
136      }
137    }
138    is(s_store){
139      when(io.uncache.resp.fire()){
140        pendingstate := s_idle
141      }
142    }
143  }
144
145  loadQueue.io.uncache := DontCare
146  storeQueue.io.uncache := DontCare
147  loadQueue.io.uncache.resp.valid := false.B
148  storeQueue.io.uncache.resp.valid := false.B
149  when(loadQueue.io.uncache.req.valid){
150    io.uncache.req <> loadQueue.io.uncache.req
151  }.otherwise{
152    io.uncache.req <> storeQueue.io.uncache.req
153  }
154  when(pendingstate === s_load){
155    io.uncache.resp <> loadQueue.io.uncache.resp
156  }.otherwise{
157    io.uncache.resp <> storeQueue.io.uncache.resp
158  }
159
160  assert(!(loadQueue.io.uncache.req.valid && storeQueue.io.uncache.req.valid))
161  assert(!(loadQueue.io.uncache.resp.valid && storeQueue.io.uncache.resp.valid))
162  assert(!((loadQueue.io.uncache.resp.valid || storeQueue.io.uncache.resp.valid) && pendingstate === s_idle))
163
164}
165