xref: /XiangShan/src/main/scala/xiangshan/backend/exu/ExeUnit.scala (revision ef6723f9795e8222d080df5d74a2a307c1e68a86)
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.backend.exu
18
19
20import org.chipsalliance.cde.config.Parameters
21import chisel3._
22import chisel3.experimental.hierarchy.{Definition, instantiable}
23import chisel3.util._
24import utils._
25import utility._
26import xiangshan._
27import xiangshan.backend.fu.fpu.{FMA, FPUSubModule}
28import xiangshan.backend.fu.{CSR, FUWithRedirect, Fence, FenceToSbuffer}
29
30class FenceIO(implicit p: Parameters) extends XSBundle {
31  val sfence = Output(new SfenceBundle)
32  val fencei = Output(Bool())
33  val sbuffer = new FenceToSbuffer
34}
35
36@instantiable
37class ExeUnit(config: ExuConfig)(implicit p: Parameters) extends Exu(config) {
38
39  val disableSfence = WireInit(false.B)
40  val disableHfenceg = WireInit(false.B)
41  val disableHfencev = WireInit(false.B)
42  val virtMode = WireInit(false.B)
43  val csr_frm = WireInit(frm.getOrElse(0.U(3.W)))
44
45  val hasRedirect = config.fuConfigs.zip(functionUnits).filter(_._1.hasRedirect).map(_._2)
46  println(s"${functionUnits} ${hasRedirect} hasRedirect: ${hasRedirect.length}")
47  if (hasRedirect.nonEmpty) {
48    require(hasRedirect.length <= 1)
49    io.out.bits.redirectValid := hasRedirect.head.asInstanceOf[FUWithRedirect].redirectOutValid
50    io.out.bits.redirect := hasRedirect.head.asInstanceOf[FUWithRedirect].redirectOut
51  }
52
53  if (config.fuConfigs.contains(csrCfg)) {
54    val csr = functionUnits.collectFirst{
55      case c: CSR => c
56    }.get
57    csr.csrio <> csrio.get
58    csrio.get.tlb := DelayN(csr.csrio.tlb, 2)
59    csrio.get.customCtrl := DelayN(csr.csrio.customCtrl, 2)
60    csrio.get.trapTarget := RegNext(csr.csrio.trapTarget)
61    csr.csrio.exception := DelayN(csrio.get.exception, 2)
62    disableSfence := csr.csrio.disableSfence
63    disableHfenceg := csr.csrio.disableHfenceg
64    disableHfencev := csr.csrio.disableHfencev
65    virtMode := csr.csrio.customCtrl.virtMode
66    csr_frm := csr.csrio.fpu.frm
67    // setup skip for hpm CSR read
68    io.out.bits.debug.isPerfCnt := RegNext(csr.csrio.isPerfCnt) // TODO: this is dirty
69  }
70
71  if (config.fuConfigs.contains(fenceCfg)) {
72    val fence = functionUnits.collectFirst{
73      case f: Fence => f
74    }.get
75    fenceio.get.sfence <> fence.sfence
76    fenceio.get.fencei <> fence.fencei
77    fenceio.get.sbuffer <> fence.toSbuffer
78    fence.io.out.ready := true.B
79    fence.disableSfence := disableSfence
80    fence.disableHfenceg := disableHfenceg
81    fence.disableHfencev := disableHfencev
82    fence.virtMode := virtMode
83  }
84
85  val fpModules = functionUnits.zip(config.fuConfigs.zipWithIndex).filter(_._1.isInstanceOf[FPUSubModule])
86  if (fpModules.nonEmpty) {
87    // frm is from csr/frm (from CSR) or instr_rm (from instruction decoding)
88    val fpSubModules = fpModules.map(_._1.asInstanceOf[FPUSubModule])
89    fpSubModules.foreach(mod => {
90      val instr_rm = mod.io.in.bits.uop.ctrl.fpu.rm
91      mod.rm := Mux(instr_rm =/= 7.U, instr_rm, csr_frm)
92    })
93    // fflags is selected by arbSelReg
94    require(config.hasFastUopOut, "non-fast not implemented")
95    val fflagsSel = fpModules.map{ case (fu, (cfg, i)) =>
96      val fflagsValid = arbSelReg(i)
97      val fflags = fu.asInstanceOf[FPUSubModule].fflags
98      val fflagsBits = if (cfg.fastImplemented) fflags else RegNext(fflags)
99      (fflagsValid, fflagsBits)
100    }
101    io.out.bits.fflags := Mux1H(fflagsSel.map(_._1), fflagsSel.map(_._2))
102  }
103
104  val fmaModules = functionUnits.filter(_.isInstanceOf[FMA]).map(_.asInstanceOf[FMA])
105  if (fmaModules.nonEmpty) {
106    require(fmaModules.length == 1)
107    fmaModules.head.midResult <> fmaMid.get
108  }
109
110  if (config.readIntRf) {
111    val in = io.fromInt
112    val out = io.out
113    XSDebug(in.valid, p"fromInt(${in.valid} ${in.ready}) toInt(${out.valid} ${out.ready})\n")
114    XSDebug(io.redirect.valid, p"Redirect:(${io.redirect.valid}) robIdx:${io.redirect.bits.robIdx}\n")
115    XSDebug(in.valid, p"src1:${Hexadecimal(in.bits.src(0))} src2:${Hexadecimal(in.bits.src(1))} " +
116      p"func:${Binary(in.bits.uop.ctrl.fuOpType)} pc:${Hexadecimal(in.bits.uop.cf.pc)} robIdx:${in.bits.uop.robIdx}\n")
117    XSDebug(out.valid, p"out res:${Hexadecimal(out.bits.data)} robIdx:${out.bits.uop.robIdx}\n")
118  }
119
120}
121
122class AluExeUnit(implicit p: Parameters) extends ExeUnit(AluExeUnitCfg)
123class JumpCSRExeUnit(implicit p: Parameters) extends ExeUnit(JumpCSRExeUnitCfg)
124class JumpExeUnit(implicit p: Parameters) extends ExeUnit(JumpExeUnitCfg)
125class StdExeUnit(implicit p: Parameters) extends ExeUnit(StdExeUnitCfg)
126class FmacExeUnit(implicit p: Parameters) extends ExeUnit(FmacExeUnitCfg)
127class FmiscExeUnit(implicit p: Parameters) extends ExeUnit(FmiscExeUnitCfg)
128
129object ExeUnitDef {
130  val defMap = new scala.collection.mutable.HashMap[ExuConfig, Definition[ExeUnit]]()
131
132  def apply(cfg: ExuConfig)(implicit p: Parameters): Definition[ExeUnit] = {
133    cfg match {
134      case JumpExeUnitCfg => defMap.getOrElseUpdate(cfg, Definition(new JumpExeUnit))
135      case AluExeUnitCfg => defMap.getOrElseUpdate(cfg, Definition(new AluExeUnit))
136      case MulDivExeUnitCfg => defMap.getOrElseUpdate(cfg, Definition(new MulDivExeUnit))
137      // TODO: CSR should also use instance. We need to fix difftest.
138      // We should not call DifftestModule in Definition/Instance for now.
139      case JumpCSRExeUnitCfg => Definition(new JumpCSRExeUnit)
140      case FmacExeUnitCfg => defMap.getOrElseUpdate(cfg, Definition(new FmacExeUnit))
141      case FmiscExeUnitCfg => defMap.getOrElseUpdate(cfg, Definition(new FmiscExeUnit))
142      case StdExeUnitCfg => defMap.getOrElseUpdate(cfg, Definition(new StdExeUnit))
143      case _ => {
144        println(s"cannot generate exeUnit from $cfg")
145        null
146      }
147    }
148  }
149}
150