xref: /XiangShan/src/main/scala/xiangshan/backend/exu/ExeUnit.scala (revision 6ab6918f8d678bdfe6b2bd2a326acf56cb4325b6)
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 chipsalliance.rocketchip.config.Parameters
21import chisel3._
22import chisel3.experimental.hierarchy.{Definition, instantiable, public}
23import chisel3.util._
24import utils._
25import xiangshan._
26import xiangshan.backend.fu.fpu.{FMA, FPUSubModule}
27import xiangshan.backend.fu.{CSR, FUWithRedirect, Fence, FenceToSbuffer}
28
29class FenceIO(implicit p: Parameters) extends XSBundle {
30  val sfence = Output(new SfenceBundle)
31  val fencei = Output(Bool())
32  val sbuffer = new FenceToSbuffer
33}
34
35@instantiable
36class ExeUnit(config: ExuConfig)(implicit p: Parameters) extends Exu(config) {
37
38  val disableSfence = WireInit(false.B)
39  val csr_frm = WireInit(frm.getOrElse(0.U(3.W)))
40
41  val hasRedirect = config.fuConfigs.zip(functionUnits).filter(_._1.hasRedirect).map(_._2)
42  println(s"${functionUnits} ${hasRedirect} hasRedirect: ${hasRedirect.length}")
43  if (hasRedirect.nonEmpty) {
44    require(hasRedirect.length <= 1)
45    io.out.bits.redirectValid := hasRedirect.head.asInstanceOf[FUWithRedirect].redirectOutValid
46    io.out.bits.redirect := hasRedirect.head.asInstanceOf[FUWithRedirect].redirectOut
47  }
48
49  if (config.fuConfigs.contains(csrCfg)) {
50    val csr = functionUnits.collectFirst{
51      case c: CSR => c
52    }.get
53    csr.csrio <> csrio.get
54    disableSfence := csr.csrio.disableSfence
55    csr_frm := csr.csrio.fpu.frm
56    // setup skip for hpm CSR read
57    io.out.bits.debug.isPerfCnt := RegNext(csr.csrio.isPerfCnt) // TODO: this is dirty
58  }
59
60  if (config.fuConfigs.contains(fenceCfg)) {
61    val fence = functionUnits.collectFirst{
62      case f: Fence => f
63    }.get
64    fenceio.get.sfence <> fence.sfence
65    fenceio.get.fencei <> fence.fencei
66    fenceio.get.sbuffer <> fence.toSbuffer
67    fence.io.out.ready := true.B
68    fence.disableSfence := disableSfence
69  }
70
71  val fpModules = functionUnits.zip(config.fuConfigs.zipWithIndex).filter(_._1.isInstanceOf[FPUSubModule])
72  if (fpModules.nonEmpty) {
73    // frm is from csr/frm (from CSR) or instr_rm (from instruction decoding)
74    val fpSubModules = fpModules.map(_._1.asInstanceOf[FPUSubModule])
75    fpSubModules.foreach(mod => {
76      val instr_rm = mod.io.in.bits.uop.ctrl.fpu.rm
77      mod.rm := Mux(instr_rm =/= 7.U, instr_rm, csr_frm)
78    })
79    // fflags is selected by arbSelReg
80    require(config.hasFastUopOut, "non-fast not implemented")
81    val fflagsSel = fpModules.map{ case (fu, (cfg, i)) =>
82      val fflagsValid = arbSelReg(i)
83      val fflags = fu.asInstanceOf[FPUSubModule].fflags
84      val fflagsBits = if (cfg.fastImplemented) fflags else RegNext(fflags)
85      (fflagsValid, fflagsBits)
86    }
87    io.out.bits.fflags := Mux1H(fflagsSel.map(_._1), fflagsSel.map(_._2))
88  }
89
90  val fmaModules = functionUnits.filter(_.isInstanceOf[FMA]).map(_.asInstanceOf[FMA])
91  if (fmaModules.nonEmpty) {
92    require(fmaModules.length == 1)
93    fmaModules.head.midResult <> fmaMid.get
94  }
95
96  if (config.readIntRf) {
97    val in = io.fromInt
98    val out = io.out
99    XSDebug(in.valid, p"fromInt(${in.valid} ${in.ready}) toInt(${out.valid} ${out.ready})\n")
100    XSDebug(io.redirect.valid, p"Redirect:(${io.redirect.valid}) robIdx:${io.redirect.bits.robIdx}\n")
101    XSDebug(in.valid, p"src1:${Hexadecimal(in.bits.src(0))} src2:${Hexadecimal(in.bits.src(1))} " +
102      p"func:${Binary(in.bits.uop.ctrl.fuOpType)} pc:${Hexadecimal(in.bits.uop.cf.pc)} robIdx:${in.bits.uop.robIdx}\n")
103    XSDebug(out.valid, p"out res:${Hexadecimal(out.bits.data)} robIdx:${out.bits.uop.robIdx}\n")
104  }
105
106}
107
108class AluExeUnit(implicit p: Parameters) extends ExeUnit(AluExeUnitCfg)
109class JumpCSRExeUnit(implicit p: Parameters) extends ExeUnit(JumpCSRExeUnitCfg)
110class JumpExeUnit(implicit p: Parameters) extends ExeUnit(JumpExeUnitCfg)
111class StdExeUnit(implicit p: Parameters) extends ExeUnit(StdExeUnitCfg)
112class FmacExeUnit(implicit p: Parameters) extends ExeUnit(FmacExeUnitCfg)
113class FmiscExeUnit(implicit p: Parameters) extends ExeUnit(FmiscExeUnitCfg)
114
115object ExeUnitDef {
116  def apply(cfg: ExuConfig)(implicit p: Parameters): Definition[ExeUnit] = {
117    cfg match {
118      case JumpExeUnitCfg => Definition(new JumpExeUnit)
119      case AluExeUnitCfg => Definition(new AluExeUnit)
120      case MulDivExeUnitCfg => Definition(new MulDivExeUnit)
121      case JumpCSRExeUnitCfg => Definition(new JumpCSRExeUnit)
122      case FmacExeUnitCfg => Definition(new FmacExeUnit)
123      case FmiscExeUnitCfg => Definition(new FmiscExeUnit)
124      case StdExeUnitCfg => Definition(new StdExeUnit)
125      case _ => {
126        println(s"cannot generate exeUnit from $cfg")
127        null
128      }
129    }
130  }
131}
132
133