From fed1f53afadba00baccf2469cad1f3186cc31eff Mon Sep 17 00:00:00 2001
From: "Wesley W. Terpstra" <wesley@sifive.com>
Date: Fri, 19 May 2017 16:09:57 -0700
Subject: [PATCH] tilelink2: add a TLSplitter to be used for the ISP port

---
 .../scala/uncore/tilelink2/Splitter.scala     | 118 ++++++++++++++++++
 1 file changed, 118 insertions(+)
 create mode 100644 src/main/scala/uncore/tilelink2/Splitter.scala

diff --git a/src/main/scala/uncore/tilelink2/Splitter.scala b/src/main/scala/uncore/tilelink2/Splitter.scala
new file mode 100644
index 00000000..6a0a4503
--- /dev/null
+++ b/src/main/scala/uncore/tilelink2/Splitter.scala
@@ -0,0 +1,118 @@
+// See LICENSE.SiFive for license details.
+
+package uncore.tilelink2
+
+import Chisel._
+import config._
+import diplomacy._
+
+class TLSplitter(policy: TLArbiter.Policy = TLArbiter.lowestIndexFirst)(implicit p: Parameters) extends LazyModule
+{
+  val node = TLSplitterNode(
+    clientFn  = { case SplitterArg(newSize, ports) =>
+      if (newSize == 0) Nil else
+      Seq.fill(newSize / ports.size) { ports }.flatten
+    },
+    managerFn = { case SplitterArg(newSize, ports) =>
+      if (newSize == 0) Nil else
+      ports.grouped(newSize).toList.transpose.map { seq =>
+        val fifoIdFactory = TLXbar.relabeler()
+        val outputIdRanges = TLXbar.mapOutputIds(seq)
+        seq(0).copy(
+          minLatency = seq.map(_.minLatency).min,
+          endSinkId = outputIdRanges.map(_.map(_.end).getOrElse(0)).max,
+          managers = ManagerUnification(seq.zipWithIndex.flatMap { case (port, i) =>
+            require (port.beatBytes == seq(0).beatBytes,
+              s"Splitter data widths don't match: ${port.managers.map(_.name)} has ${port.beatBytes}B vs ${seq(0).managers.map(_.name)} has ${seq(0).beatBytes}B")
+            val fifoIdMapper = fifoIdFactory()
+            port.managers map { manager => manager.copy(
+              fifoId = manager.fifoId.map(fifoIdMapper(_))
+            )}
+          })
+        )
+      }
+    })
+
+  lazy val module = new LazyModuleImp(this) {
+    val io = new Bundle {
+      val in  = node.bundleIn
+      val out = node.bundleOut
+    }
+
+    def group[T](x: Seq[T]) =
+      if (x.isEmpty) Nil else x.grouped(node.edgesIn.size).toList.transpose
+
+    ((node.edgesIn zip io.in) zip (group(node.edgesOut) zip group(io.out))) foreach {
+      case ((edgeIn, io_in), (edgesOut, io_out)) =>
+
+      // Grab the port ID mapping
+      val outputIdRanges = TLXbar.mapOutputIds(edgesOut.map(_.manager))
+
+      // Find a good mask for address decoding
+      val port_addrs = edgesOut.map(_.manager.managers.map(_.address).flatten)
+      val routingMask = AddressDecoder(port_addrs)
+      val route_addrs = port_addrs.map(_.map(_.widen(~routingMask)).distinct)
+      val outputPorts = route_addrs.map(seq => (addr: UInt) => seq.map(_.contains(addr)).reduce(_ || _))
+
+      // We need an intermediate size of bundle with the widest possible identifiers
+      val wide_bundle = TLBundleParameters.union(Seq(io_in.params) ++ io_out.map(_.params))
+
+      // Transform input bundle sources (sinks use global namespace on both sides)
+      val in = Wire(TLBundle(wide_bundle))
+      in.a <> io_in.a
+      io_in.d <> in.d
+
+      if (edgeIn.client.anySupportProbe && edgesOut.exists(_.manager.anySupportAcquireB)) {
+        in.c <> io_in.c
+        in.e <> io_in.e
+        io_in.b <> in.b
+      } else {
+        in.c.valid := Bool(false)
+        in.e.valid := Bool(false)
+        in.b.ready := Bool(false)
+        io_in.c.ready := Bool(true)
+        io_in.e.ready := Bool(true)
+        io_in.b.valid := Bool(false)
+      }
+
+      // Handle size = 1 gracefully (Chisel3 empty range is broken)
+      def trim(id: UInt, size: Int) = if (size <= 1) UInt(0) else id(log2Ceil(size)-1, 0)
+
+      // Transform output bundle sinks (sources use global namespace on both sides)
+      val out = Wire(Vec(io_out.size, TLBundle(wide_bundle)))
+      for (i <- 0 until out.size) {
+        val r = outputIdRanges(i)
+
+        io_out(i).a <> out(i).a
+        out(i).d <> io_out(i).d
+        out(i).d.bits.sink := io_out(i).d.bits.sink | UInt(r.map(_.start).getOrElse(0))
+
+        if (edgesOut(i).manager.anySupportAcquireB && edgeIn.client.anySupportProbe) {
+          io_out(i).c <> out(i).c
+          io_out(i).e <> out(i).e
+          out(i).b <> io_out(i).b
+          io_out(i).e.bits.sink := trim(out(i).e.bits.sink, r.map(_.size).getOrElse(0))
+        } else {
+          out(i).c.ready := Bool(false)
+          out(i).e.ready := Bool(false)
+          out(i).b.valid := Bool(false)
+          io_out(i).c.valid := Bool(false)
+          io_out(i).e.valid := Bool(false)
+          io_out(i).b.ready := Bool(true)
+        }
+      }
+
+      val requestA = Vec(outputPorts.map { o => o(in.a.bits.address) })
+      val requestC = Vec(outputPorts.map { o => o(in.c.bits.address) })
+      val requestE = Vec(outputIdRanges.map { o => o.map(_.contains(in.e.bits.sink)).getOrElse(Bool(false)) })
+      (out.map(_.a) zip TLXbar.fanout(in.a, requestA)) foreach { case (o, i) => o <> i }
+      (out.map(_.c) zip TLXbar.fanout(in.c, requestC)) foreach { case (o, i) => o <> i }
+      (out.map(_.e) zip TLXbar.fanout(in.e, requestE)) foreach { case (o, i) => o <> i }
+
+      val beatsB = Vec((out zip edgesOut) map { case (o, e) => e.numBeats1(o.b.bits) })
+      val beatsD = Vec((out zip edgesOut) map { case (o, e) => e.numBeats1(o.d.bits) })
+      TLArbiter(policy)(in.b, (beatsB zip out.map(_.b)):_*)
+      TLArbiter(policy)(in.d, (beatsD zip out.map(_.d)):_*)
+    }
+  }
+}