From d3547a6193bc2203e253c7f3868f52ec32a17b31 Mon Sep 17 00:00:00 2001
From: "Wesley W. Terpstra" <wesley@sifive.com>
Date: Fri, 30 Sep 2016 01:49:46 -0700
Subject: [PATCH] tilelink2: Isolation gate insertion module

---
 .../scala/uncore/tilelink2/Isolation.scala    | 60 +++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 src/main/scala/uncore/tilelink2/Isolation.scala

diff --git a/src/main/scala/uncore/tilelink2/Isolation.scala b/src/main/scala/uncore/tilelink2/Isolation.scala
new file mode 100644
index 00000000..e5dda00f
--- /dev/null
+++ b/src/main/scala/uncore/tilelink2/Isolation.scala
@@ -0,0 +1,60 @@
+// See LICENSE for license details.
+
+package uncore.tilelink2
+
+import Chisel._
+import chisel3.internal.sourceinfo.SourceInfo
+
+class TLIsolation(f: UInt => UInt) extends LazyModule
+{
+  val node = TLAsyncIdentityNode()
+
+  lazy val module = new LazyModuleImp(this) {
+    val io = new Bundle {
+      val in  = node.bundleIn
+      val out = node.bundleOut
+    }
+
+    def ISO[T <: Data](x: T): T = x.fromBits(f(x.asUInt))
+
+    ((io.in zip io.out) zip (node.edgesIn zip node.edgesOut)) foreach { case ((in, out), (edgeIn, edgeOut)) =>
+
+      out.a.mem := ISO(in.a.mem)
+      out.a.widx := ISO(in.a.widx)
+      in.a.ridx := ISO(out.a.ridx)
+      out.d.ridx := ISO(in.d.ridx)
+      in.d.widx := ISO(out.d.widx)
+      in.d.mem := ISO(out.d.mem)
+
+      if (edgeOut.manager.base.anySupportAcquire && edgeOut.client.base.anySupportProbe) {
+        in.b.widx := ISO(out.b.widx)
+        in.c.ridx := ISO(out.c.ridx)
+        in.e.ridx := ISO(out.e.ridx)
+        out.b.ridx := ISO(in.b.ridx)
+        out.c.widx := ISO(in.c.widx)
+        out.e.widx := ISO(in.e.widx)
+        in.b.mem := ISO(out.b.mem)
+        out.c.mem := ISO(in.c.mem)
+        out.e.mem := ISO(in.e.mem)
+      } else {
+        in.b.widx := UInt(0)
+        in.c.ridx := UInt(0)
+        in.e.ridx := UInt(0)
+        out.b.ridx := UInt(0)
+        out.c.widx := UInt(0)
+        out.e.widx := UInt(0)
+      }
+    }
+  }
+}
+
+object TLIsolation
+{
+  // applied to the TL source node; y.node := TLIsolation()(x.node)
+  // f should insert an isolation gate between the input UInt and its result
+  def apply(f: UInt => UInt)(x: TLAsyncOutwardNode)(implicit sourceInfo: SourceInfo): TLAsyncOutwardNode = {
+    val iso = LazyModule(new TLIsolation(f))
+    iso.node := x
+    iso.node
+  }
+}