rocket-chip/uncore/src/package.scala

package object uncore {
import Chisel._
import Node._
import scala.collection.mutable.Stack

//TODO: Remove these Networking classes from the package object once Scala bug
//SI-3439 is resolved.

case class PhysicalNetworkConfiguration(nEndpoints: Int, idBits: Int)

class PhysicalHeader(implicit conf: PhysicalNetworkConfiguration) extends Bundle {
  val src = UFix(width = conf.idBits)
  val dst = UFix(width = conf.idBits)
}

abstract class PhysicalNetworkIO[T <: Data]()(data: => T)(implicit conf: PhysicalNetworkConfiguration) extends Bundle {
  val header = (new PhysicalHeader)
  val payload = data
}

class BasicCrossbarIO[T <: Data]()(data: => T)(implicit conf: PhysicalNetworkConfiguration) extends PhysicalNetworkIO()(data)(conf) {
  override def clone = { new BasicCrossbarIO()(data).asInstanceOf[this.type] }
}

abstract class PhysicalNetwork(conf: PhysicalNetworkConfiguration) extends Component

class LockingRRArbiter[T <: Data](n: Int, count: Int)(data: => T) extends Component {
  val io = new ioArbiter(n)(data)

  val cnt = Reg(resetVal = UFix(0, width = log2Up(count)))
  val cnt_next = cnt + UFix(1)
  val locked = Reg(resetVal = Bool(false))
  val lock_idx = Reg(resetVal = UFix(n))

  if(count > 1){
    when(io.out.valid && io.out.ready) {
      cnt := cnt_next
      when(!locked) {
        locked := Bool(true)
        lock_idx := Vec(io.in.map{ in => in.ready && in.valid}){Bool()}.indexWhere{i: Bool => i} 
      }
      when(cnt_next === UFix(0)) {
        locked := Bool(false)
      }
    }
  } else {
    locked := Bool(false)
    lock_idx := UFix(n)
    cnt := UFix(0)
  }
    

  val last_grant = Reg(resetVal = Bits(0, log2Up(n)))
  val g = ArbiterCtrl((0 until n).map(i => io.in(i).valid && UFix(i) > last_grant) ++ io.in.map(_.valid))
  val grant = (0 until n).map(i => g(i) && UFix(i) > last_grant || g(i+n))
  (0 until n).map(i => io.in(i).ready := Mux(locked, lock_idx === UFix(i), grant(i)) && io.out.ready)

  var choose = Bits(n-1)
  for (i <- n-2 to 0 by -1)
    choose = Mux(io.in(i).valid, Bits(i), choose)
  for (i <- n-1 to 1 by -1)
    choose = Mux(io.in(i).valid && UFix(i) > last_grant, Bits(i), choose)
  choose = Mux(locked, lock_idx, choose)
  when (io.out.valid && io.out.ready) {
    last_grant := choose
  }

  val dvec = Vec(n) { data } 
  (0 until n).map(i => dvec(i) := io.in(i).bits )

  io.out.valid := Mux(locked, io.in(lock_idx).valid, io.in.map(_.valid).foldLeft(Bool(false))( _ || _))
  io.out.bits := dvec(choose)
  io.chosen := choose
}

class BasicCrossbar[T <: Data](count: Int)(data: => T)(implicit conf: PhysicalNetworkConfiguration) extends PhysicalNetwork(conf) {
  val io = new Bundle {
    val in  = Vec(conf.nEndpoints){(new FIFOIO){(new BasicCrossbarIO){data}}}.flip 
    val out = Vec(conf.nEndpoints){(new FIFOIO){(new BasicCrossbarIO){data}}}
  }

  val rdyVecs = List.fill(conf.nEndpoints)(Vec(conf.nEndpoints){Bool()})

  io.out.zip(rdyVecs).zipWithIndex.map{ case ((out, rdys), i) => {
    val rrarb = (new LockingRRArbiter(conf.nEndpoints, count)){io.in(0).bits.clone}
    (rrarb.io.in, io.in, rdys).zipped.map{ case (arb, in, rdy) => {
      arb.valid := in.valid && (in.bits.header.dst === UFix(i)) 
      arb.bits := in.bits
      rdy := arb.ready && (in.bits.header.dst === UFix(i))
    }}
    out <> rrarb.io.out
  }}
  for(i <- 0 until conf.nEndpoints) {
    io.in(i).ready := rdyVecs.map(r => r(i)).reduceLeft(_||_)
  }
}

case class LogicalNetworkConfiguration(nEndpoints: Int, idBits: Int, nMasters: Int, nClients: Int)

abstract class LogicalNetwork[TileLinkType <: Bundle](endpoints: Seq[CoherenceAgentRole])(implicit conf: LogicalNetworkConfiguration) extends Component {
  override val io: Vec[TileLinkType]
  val physicalNetworks: Seq[PhysicalNetwork]
  require(endpoints.length == conf.nEndpoints)
}

class LogicalHeader(implicit conf: LogicalNetworkConfiguration) extends Bundle {
  val src = UFix(width = conf.idBits)
  val dst = UFix(width = conf.idBits)
}

object FIFOedLogicalNetworkIOWrapper {
  def apply[T <: Data](in: FIFOIO[T], src: UFix = UFix(0), dst: UFix = UFix(0))(implicit conf: LogicalNetworkConfiguration) = {
    val shim = (new FIFOedLogicalNetworkIOWrapper(src, dst)){ in.bits.clone }
    shim.io.in.valid := in.valid
    shim.io.in.bits := in.bits
    in.ready := shim.io.in.ready
    shim.io.out
  }
}
class FIFOedLogicalNetworkIOWrapper[T <: Data](src: UFix, dst: UFix)(data: => T)(implicit lconf: LogicalNetworkConfiguration) extends Component {
  val io = new Bundle {
    val in = (new FIFOIO){ data }.flip
    val out = (new FIFOIO){(new LogicalNetworkIO){ data }} 
  }
  io.out.valid := io.in.valid
  io.out.bits.payload := io.in.bits
  io.out.bits.header.dst := dst
  io.out.bits.header.src := src
  io.in.ready := io.out.ready
}

object FIFOedLogicalNetworkIOUnwrapper {
  def apply[T <: Data](in: FIFOIO[LogicalNetworkIO[T]])(implicit conf: LogicalNetworkConfiguration) = {
    val shim = (new FIFOedLogicalNetworkIOUnwrapper){ in.bits.payload.clone }
    shim.io.in.valid := in.valid
    shim.io.in.bits := in.bits
    in.ready := shim.io.in.ready
    shim.io.out
  }
}
class FIFOedLogicalNetworkIOUnwrapper[T <: Data]()(data: => T)(implicit lconf: LogicalNetworkConfiguration) extends Component {
  val io = new Bundle {
    val in = (new FIFOIO){(new LogicalNetworkIO){ data }}.flip
    val out = (new FIFOIO){ data }
  }
  io.out.valid := io.in.valid
  io.out.bits := io.in.bits.payload
  io.in.ready := io.out.ready
}

class LogicalNetworkIO[T <: Data]()(data: => T)(implicit conf: LogicalNetworkConfiguration) extends Bundle {
  val header = new LogicalHeader
  val payload = data
  override def clone = { new LogicalNetworkIO()(data).asInstanceOf[this.type] }
}

}