package coreplex

import Chisel._
import cde.{Parameters, Field}
import junctions._
import uncore.tilelink._
import uncore.coherence._
import uncore.agents._
import uncore.devices._
import uncore.util._
import uncore.converters._
import rocket._
import rocket.Util._
import java.nio.{ByteBuffer,ByteOrder}
import java.nio.file.{Files, Paths}

/** Number of memory channels */
case object NMemoryChannels extends Field[Int]
/** Number of banks per memory channel */
case object NBanksPerMemoryChannel extends Field[Int]
/** Least significant bit of address used for bank partitioning */
case object BankIdLSB extends Field[Int]
/** Function for building some kind of coherence manager agent */
case object BuildL2CoherenceManager extends Field[(Int, Parameters) => CoherenceAgent]
/** Function for building some kind of tile connected to a reset signal */
case object BuildTiles extends Field[Seq[(Bool, Parameters) => Tile]]
/** A string describing on-chip devices, readable by target software */
case object ConfigString extends Field[Array[Byte]]
/** Number of external interrupt sources */
case object NExtInterrupts extends Field[Int]
/** Interrupt controller configuration */
case object PLICKey extends Field[PLICConfig]
/** Number of clock cycles per RTC tick */
case object RTCPeriod extends Field[Int]
/** The file to read the BootROM contents from */
case object BootROMFile extends Field[String]
/** Export an external MMIO slave port */
case object ExportMMIOPort extends Field[Boolean]
/** Expose additional TileLink client ports */
case object NExternalClients extends Field[Int]
/** Extra top-level ports exported from the coreplex */
case object ExtraCoreplexPorts extends Field[Parameters => Bundle]

trait HasCoreplexParameters {
  implicit val p: Parameters
  lazy val nTiles = p(NTiles)
  lazy val nCachedTilePorts = p(NCachedTileLinkPorts)
  lazy val nUncachedTilePorts = p(NUncachedTileLinkPorts)
  lazy val nMemChannels = p(NMemoryChannels)
  lazy val nBanksPerMemChannel = p(NBanksPerMemoryChannel)
  lazy val nBanks = nMemChannels*nBanksPerMemChannel
  lazy val lsb = p(BankIdLSB)
  lazy val innerParams = p.alterPartial({ case TLId => "L1toL2" })
  lazy val outermostParams = p.alterPartial({ case TLId => "Outermost" })
  lazy val outermostMMIOParams = p.alterPartial({ case TLId => "MMIO_Outermost" })
  lazy val nExtClients = p(NExternalClients)
  lazy val exportMMIO = p(ExportMMIOPort)
}

/** Wrapper around everything that isn't a Tile.
  *
  * Usually this is clocked and/or place-and-routed separately from the Tiles.
  */
class Uncore(implicit val p: Parameters) extends Module
    with HasCoreplexParameters {

  val io = new Bundle {
    val mem  = Vec(nMemChannels, new ClientUncachedTileLinkIO()(outermostParams))
    val tiles_cached = Vec(nCachedTilePorts, new ClientTileLinkIO).flip
    val tiles_uncached = Vec(nUncachedTilePorts, new ClientUncachedTileLinkIO).flip
    val ext_uncached = Vec(nExtClients, new ClientUncachedTileLinkIO()(innerParams)).flip
    val prci = Vec(nTiles, new PRCITileIO).asOutput
    val mmio = if (exportMMIO) Some(new ClientUncachedTileLinkIO()(outermostMMIOParams)) else None
    val interrupts = Vec(p(NExtInterrupts), Bool()).asInput
    val debug = new DebugBusIO()(p).flip
  }

  val outmemsys = if (nCachedTilePorts + nUncachedTilePorts > 0)
    Module(new DefaultOuterMemorySystem) // NoC, LLC and SerDes
  else Module(new DummyOuterMemorySystem)
  outmemsys.io.incoherent foreach (_ := false)
  outmemsys.io.tiles_uncached <> io.tiles_uncached
  outmemsys.io.tiles_cached <> io.tiles_cached
  outmemsys.io.ext_uncached <> io.ext_uncached
  io.mem <> outmemsys.io.mem

  buildMMIONetwork(p.alterPartial({case TLId => "L2toMMIO"}))

  def makeBootROM()(implicit p: Parameters) = {
    val romdata = Files.readAllBytes(Paths.get(p(BootROMFile)))
    val rom = ByteBuffer.wrap(romdata)

    rom.order(ByteOrder.LITTLE_ENDIAN)

    // for now, have the reset vector jump straight to memory
    val resetToMemDist = p(GlobalAddrMap)("mem").start - p(ResetVector)
    require(resetToMemDist == (resetToMemDist.toInt >> 12 << 12))
    val configStringAddr = p(ResetVector).toInt + rom.capacity

    require(rom.getInt(12) == 0,
      "Config string address position should not be occupied by code")
    rom.putInt(12, configStringAddr)
    rom.array() ++ p(ConfigString).toSeq
  }

  def buildMMIONetwork(implicit p: Parameters) = {
    val ioAddrMap = p(GlobalAddrMap).subMap("io")

    val mmioNetwork = Module(new TileLinkRecursiveInterconnect(1, ioAddrMap))
    mmioNetwork.io.in.head <> outmemsys.io.mmio

    val plic = Module(new PLIC(p(PLICKey)))
    plic.io.tl <> mmioNetwork.port("int:plic")
    for (i <- 0 until io.interrupts.size) {
      val gateway = Module(new LevelGateway)
      gateway.io.interrupt := io.interrupts(i)
      plic.io.devices(i) <> gateway.io.plic
    }

    val debugModule = Module(new DebugModule)
    debugModule.io.tl <> mmioNetwork.port("int:debug")
    debugModule.io.db <> io.debug

    val prci = Module(new PRCI)
    prci.io.tl <> mmioNetwork.port("int:prci")
    io.prci := prci.io.tiles
    prci.io.rtcTick := Counter(p(RTCPeriod)).inc() // placeholder for real RTC

    for (i <- 0 until nTiles) {
      prci.io.interrupts(i).meip := plic.io.harts(plic.cfg.context(i, 'M'))
      if (p(UseVM))
        prci.io.interrupts(i).seip := plic.io.harts(plic.cfg.context(i, 'S'))
      prci.io.interrupts(i).debug := debugModule.io.debugInterrupts(i)

      io.prci(i).reset := reset
    }

    val bootROM = Module(new ROMSlave(makeBootROM()))
    bootROM.io <> mmioNetwork.port("int:bootrom")

    io.mmio.map { ext => ext <> mmioNetwork.port("ext") }
  }
}

abstract class OuterMemorySystem(implicit val p: Parameters)
    extends Module with HasCoreplexParameters {
  val io = new Bundle {
    val tiles_cached = Vec(nCachedTilePorts, new ClientTileLinkIO).flip
    val tiles_uncached = Vec(nUncachedTilePorts, new ClientUncachedTileLinkIO).flip
    val ext_uncached = Vec(nExtClients, new ClientUncachedTileLinkIO()(innerParams)).flip
    val incoherent = Vec(nCachedTilePorts, Bool()).asInput
    val mem  = Vec(nMemChannels, new ClientUncachedTileLinkIO()(outermostParams))
    val mmio = new ClientUncachedTileLinkIO()(p.alterPartial({case TLId => "L2toMMIO"}))
  }
}

/** Use in place of OuterMemorySystem if there are no clients to connect. */
class DummyOuterMemorySystem(implicit p: Parameters) extends OuterMemorySystem()(p) {
  require(nCachedTilePorts + nUncachedTilePorts + nExtClients == 0)

  io.mem.foreach { tl =>
    tl.acquire.valid := Bool(false)
    tl.grant.ready := Bool(false)
  }

  io.mmio.acquire.valid := Bool(false)
  io.mmio.grant.ready := Bool(false)
}

/** The whole outer memory hierarchy, including a NoC, some kind of coherence
  * manager agent, and a converter from TileLink to MemIO.
  */ 
class DefaultOuterMemorySystem(implicit p: Parameters) extends OuterMemorySystem()(p) {
  // Create a simple L1toL2 NoC between the tiles and the banks of outer memory
  // Cached ports are first in client list, making sharerToClientId just an indentity function
  // addrToBank is sed to hash physical addresses (of cache blocks) to banks (and thereby memory channels)
  def sharerToClientId(sharerId: UInt) = sharerId
  def addrToBank(addr: UInt): UInt = {
    val isMemory = p(GlobalAddrMap).isInRegion("mem", addr << log2Up(p(CacheBlockBytes)))
    Mux(isMemory,
      if (nBanks > 1) addr(lsb + log2Up(nBanks) - 1, lsb) else UInt(0),
      UInt(nBanks))
  }
  val preBuffering = TileLinkDepths(1,1,2,2,0)
  val l1tol2net = Module(new PortedTileLinkCrossbar(addrToBank, sharerToClientId, preBuffering))

  // Create point(s) of coherence serialization
  val managerEndpoints = List.tabulate(nBanks){id => p(BuildL2CoherenceManager)(id, p)}
  managerEndpoints.foreach { _.incoherent := io.incoherent }

  val mmioManager = Module(new MMIOTileLinkManager()(p.alterPartial({
    case TLId => "L1toL2"
    case InnerTLId => "L1toL2"
    case OuterTLId => "L2toMMIO"
  })))

  io.mmio.acquire <> Queue(mmioManager.io.outer.acquire, 1)
  mmioManager.io.outer.grant <> Queue(io.mmio.grant, 1)

  // Wire the tiles to the TileLink client ports of the L1toL2 network,
  // and coherence manager(s) to the other side
  l1tol2net.io.clients_cached <> io.tiles_cached
  l1tol2net.io.clients_uncached <> io.tiles_uncached ++ io.ext_uncached
  l1tol2net.io.managers <> managerEndpoints.map(_.innerTL) :+ mmioManager.io.inner

  // Create a converter between TileLinkIO and MemIO for each channel
  val outerTLParams = p.alterPartial({ case TLId => "L2toMC" })
  val backendBuffering = TileLinkDepths(0,0,0,0,0)

  // TODO: the code to print this stuff should live somewhere else
  println("Generated Address Map")
  for (entry <- p(GlobalAddrMap).flatten) {
    val name = entry.name
    val start = entry.region.start
    val end = entry.region.start + entry.region.size - 1
    println(f"\t$name%s $start%x - $end%x")
  }
  println("Generated Configuration String")
  println(new String(p(ConfigString)))

  val mem_ic = Module(new TileLinkMemoryInterconnect(nBanksPerMemChannel, nMemChannels)(outermostParams))

  for ((bank, icPort) <- managerEndpoints zip mem_ic.io.in) {
    val unwrap = Module(new ClientTileLinkIOUnwrapper()(outerTLParams))
    unwrap.io.in <> ClientTileLinkEnqueuer(bank.outerTL, backendBuffering)(outerTLParams)
    TileLinkWidthAdapter(icPort, unwrap.io.out)
  }

  io.mem <> mem_ic.io.out
}

abstract class Coreplex(implicit val p: Parameters) extends Module
    with HasCoreplexParameters {
  class CoreplexIO(implicit val p: Parameters) extends Bundle {
    val mem  = Vec(nMemChannels, new ClientUncachedTileLinkIO()(outermostParams))
    val ext_clients = Vec(nExtClients, new ClientUncachedTileLinkIO()(innerParams)).flip
    val mmio = if(p(ExportMMIOPort)) Some(new ClientUncachedTileLinkIO()(outermostMMIOParams)) else None
    val interrupts = Vec(p(NExtInterrupts), Bool()).asInput
    val debug = new DebugBusIO()(p).flip
    val extra = p(ExtraCoreplexPorts)(p)
    val success: Option[Bool] = if (hasSuccessFlag) Some(Bool(OUTPUT)) else None
  }

  def hasSuccessFlag: Boolean = false
  val io = new CoreplexIO
}

class DefaultCoreplex(topParams: Parameters) extends Coreplex()(topParams) {
  // Build an Uncore and a set of Tiles
  val tileResets = Wire(Vec(nTiles, Bool()))
  val tileList = p(BuildTiles).zip(tileResets).map {
    case (tile, rst) => tile(rst, p)
  }
  val nCachedPorts = tileList.map(tile => tile.io.cached.size).reduce(_ + _)
  val nUncachedPorts = tileList.map(tile => tile.io.uncached.size).reduce(_ + _)

  val innerTLParams = p.alterPartial({
    case HastiId => "TL"
    case TLId => "L1toL2"
    case NCachedTileLinkPorts => nCachedPorts
    case NUncachedTileLinkPorts => nUncachedPorts
  })

  val uncore = Module(new Uncore()(innerTLParams))

  (uncore.io.prci, tileResets, tileList).zipped.foreach {
    case (prci, rst, tile) =>
      rst := prci.reset
      tile.io.prci <> prci
  }

  // Connect the uncore to the tile memory ports, HostIO and MemIO
  uncore.io.tiles_cached <> tileList.map(_.io.cached).flatten
  uncore.io.tiles_uncached <> tileList.map(_.io.uncached).flatten
  uncore.io.interrupts <> io.interrupts
  uncore.io.debug <> io.debug
  uncore.io.ext_uncached <> io.ext_clients
  if (exportMMIO) { io.mmio.get <> uncore.io.mmio.get }
  io.mem <> uncore.io.mem
}

class GroundTestCoreplex(topParams: Parameters) extends DefaultCoreplex(topParams) {
  override def hasSuccessFlag = true
  io.success.get := tileList.flatMap(_.io.elements get "success").map(_.asInstanceOf[Bool]).reduce(_&&_)
}