xref: /XiangShan/src/main/scala/xiangshan/backend/exu/ExeUnit.scala (revision 8891a219bbc84f568e1d134854d8d5ed86d6d560)
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 csr_frm = WireInit(frm.getOrElse(0.U(3.W)))
41
42  val hasRedirect = config.fuConfigs.zip(functionUnits).filter(_._1.hasRedirect).map(_._2)
43  println(s"${functionUnits} ${hasRedirect} hasRedirect: ${hasRedirect.length}")
44  if (hasRedirect.nonEmpty) {
45    require(hasRedirect.length <= 1)
46    io.out.bits.redirectValid := hasRedirect.head.asInstanceOf[FUWithRedirect].redirectOutValid
47    io.out.bits.redirect := hasRedirect.head.asInstanceOf[FUWithRedirect].redirectOut
48  }
49
50  if (config.fuConfigs.contains(csrCfg)) {
51    val csr = functionUnits.collectFirst{
52      case c: CSR => c
53    }.get
54    csr.csrio <> csrio.get
55    csrio.get.tlb := DelayN(csr.csrio.tlb, 2)
56    csrio.get.customCtrl := DelayN(csr.csrio.customCtrl, 2)
57    csrio.get.trapTarget := RegNext(csr.csrio.trapTarget)
58    csr.csrio.exception := DelayN(csrio.get.exception, 2)
59    disableSfence := csr.csrio.disableSfence
60    csr_frm := csr.csrio.fpu.frm
61    // setup skip for hpm CSR read
62    io.out.bits.debug.isPerfCnt := RegNext(csr.csrio.isPerfCnt) // TODO: this is dirty
63  }
64
65  if (config.fuConfigs.contains(fenceCfg)) {
66    val fence = functionUnits.collectFirst{
67      case f: Fence => f
68    }.get
69    fenceio.get.sfence <> fence.sfence
70    fenceio.get.fencei <> fence.fencei
71    fenceio.get.sbuffer <> fence.toSbuffer
72    fence.io.out.ready := true.B
73    fence.disableSfence := disableSfence
74  }
75
76  val fpModules = functionUnits.zip(config.fuConfigs.zipWithIndex).filter(_._1.isInstanceOf[FPUSubModule])
77  if (fpModules.nonEmpty) {
78    // frm is from csr/frm (from CSR) or instr_rm (from instruction decoding)
79    val fpSubModules = fpModules.map(_._1.asInstanceOf[FPUSubModule])
80    fpSubModules.foreach(mod => {
81      val instr_rm = mod.io.in.bits.uop.ctrl.fpu.rm
82      mod.rm := Mux(instr_rm =/= 7.U, instr_rm, csr_frm)
83    })
84    // fflags is selected by arbSelReg
85    require(config.hasFastUopOut, "non-fast not implemented")
86    val fflagsSel = fpModules.map{ case (fu, (cfg, i)) =>
87      val fflagsValid = arbSelReg(i)
88      val fflags = fu.asInstanceOf[FPUSubModule].fflags
89      val fflagsBits = if (cfg.fastImplemented) fflags else RegNext(fflags)
90      (fflagsValid, fflagsBits)
91    }
92    io.out.bits.fflags := Mux1H(fflagsSel.map(_._1), fflagsSel.map(_._2))
93  }
94
95  val fmaModules = functionUnits.filter(_.isInstanceOf[FMA]).map(_.asInstanceOf[FMA])
96  if (fmaModules.nonEmpty) {
97    require(fmaModules.length == 1)
98    fmaModules.head.midResult <> fmaMid.get
99  }
100
101  if (config.readIntRf) {
102    val in = io.fromInt
103    val out = io.out
104    XSDebug(in.valid, p"fromInt(${in.valid} ${in.ready}) toInt(${out.valid} ${out.ready})\n")
105    XSDebug(io.redirect.valid, p"Redirect:(${io.redirect.valid}) robIdx:${io.redirect.bits.robIdx}\n")
106    XSDebug(in.valid, p"src1:${Hexadecimal(in.bits.src(0))} src2:${Hexadecimal(in.bits.src(1))} " +
107      p"func:${Binary(in.bits.uop.ctrl.fuOpType)} pc:${Hexadecimal(in.bits.uop.cf.pc)} robIdx:${in.bits.uop.robIdx}\n")
108    XSDebug(out.valid, p"out res:${Hexadecimal(out.bits.data)} robIdx:${out.bits.uop.robIdx}\n")
109  }
110
111}
112
113class AluExeUnit(implicit p: Parameters) extends ExeUnit(AluExeUnitCfg)
114class JumpCSRExeUnit(implicit p: Parameters) extends ExeUnit(JumpCSRExeUnitCfg)
115class JumpExeUnit(implicit p: Parameters) extends ExeUnit(JumpExeUnitCfg)
116class StdExeUnit(implicit p: Parameters) extends ExeUnit(StdExeUnitCfg)
117class FmacExeUnit(implicit p: Parameters) extends ExeUnit(FmacExeUnitCfg)
118class FmiscExeUnit(implicit p: Parameters) extends ExeUnit(FmiscExeUnitCfg)
119
120object ExeUnitDef {
121  val defMap = new scala.collection.mutable.HashMap[ExuConfig, Definition[ExeUnit]]()
122
123  def apply(cfg: ExuConfig)(implicit p: Parameters): Definition[ExeUnit] = {
124    cfg match {
125      case JumpExeUnitCfg => defMap.getOrElseUpdate(cfg, Definition(new JumpExeUnit))
126      case AluExeUnitCfg => defMap.getOrElseUpdate(cfg, Definition(new AluExeUnit))
127      case MulDivExeUnitCfg => defMap.getOrElseUpdate(cfg, Definition(new MulDivExeUnit))
128      // TODO: CSR should also use instance. We need to fix difftest.
129      // We should not call DifftestModule in Definition/Instance for now.
130      case JumpCSRExeUnitCfg => Definition(new JumpCSRExeUnit)
131      case FmacExeUnitCfg => defMap.getOrElseUpdate(cfg, Definition(new FmacExeUnit))
132      case FmiscExeUnitCfg => defMap.getOrElseUpdate(cfg, Definition(new FmiscExeUnit))
133      case StdExeUnitCfg => defMap.getOrElseUpdate(cfg, Definition(new StdExeUnit))
134      case _ => {
135        println(s"cannot generate exeUnit from $cfg")
136        null
137      }
138    }
139  }
140}
141