From 4ccdbecb634b8bc5d49a8f241cb999187e1e1565 Mon Sep 17 00:00:00 2001
From: "Wesley W. Terpstra" <wesley@sifive.com>
Date: Wed, 1 Nov 2017 11:03:45 -0700
Subject: [PATCH] Async covers (#1085)

* cover: support covering cross-product of ready-valid

* tilelink: AsyncCrossing now has covers for all flow control logic
---
 src/main/scala/tilelink/AsyncCrossing.scala | 11 +++++++++++
 src/main/scala/util/Property.scala          |  8 +++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/main/scala/tilelink/AsyncCrossing.scala b/src/main/scala/tilelink/AsyncCrossing.scala
index 6dc65b0f..eb44cc15 100644
--- a/src/main/scala/tilelink/AsyncCrossing.scala
+++ b/src/main/scala/tilelink/AsyncCrossing.scala
@@ -6,6 +6,7 @@ import Chisel._
 import freechips.rocketchip.config.Parameters
 import freechips.rocketchip.diplomacy._
 import freechips.rocketchip.util._
+import freechips.rocketchip.util.property._
 import freechips.rocketchip.coreplex.{CrossingWrapper, AsynchronousCrossing}
 
 class TLAsyncCrossingSource(sync: Int = 3)(implicit p: Parameters) extends LazyModule
@@ -20,11 +21,16 @@ class TLAsyncCrossingSource(sync: Int = 3)(implicit p: Parameters) extends LazyM
 
       out.a <> ToAsyncBundle(in.a, depth, sync)
       in.d <> FromAsyncBundle(out.d, sync)
+      cover(in.a, "TL_ASYNC_CROSSING_SOURCE_A", "MemorySystem;;TLAsyncCrossingSource Channel A")
+      cover(in.d, "TL_ASYNC_CROSSING_SOURCE_D", "MemorySystem;;TLAsyncCrossingSource Channel D")
 
       if (bce) {
         in.b <> FromAsyncBundle(out.b, sync)
         out.c <> ToAsyncBundle(in.c, depth, sync)
         out.e <> ToAsyncBundle(in.e, depth, sync)
+        cover(in.b, "TL_ASYNC_CROSSING_SOURCE_B", "MemorySystem;;TLAsyncCrossingSource Channel B")
+        cover(in.c, "TL_ASYNC_CROSSING_SOURCE_C", "MemorySystem;;TLAsyncCrossingSource Channel C")
+        cover(in.e, "TL_ASYNC_CROSSING_SOURCE_E", "MemorySystem;;TLAsyncCrossingSource Channel E")
       } else {
         in.b.valid := Bool(false)
         in.c.ready := Bool(true)
@@ -48,11 +54,16 @@ class TLAsyncCrossingSink(depth: Int = 8, sync: Int = 3)(implicit p: Parameters)
 
       out.a <> FromAsyncBundle(in.a, sync)
       in.d <> ToAsyncBundle(out.d, depth, sync)
+      cover(out.a, "TL_ASYNC_CROSSING_SINK_A", "MemorySystem;;TLAsyncCrossingSink Channel A")
+      cover(out.d, "TL_ASYNC_CROSSING_SINK_D", "MemorySystem;;TLAsyncCrossingSink Channel D")
 
       if (bce) {
         in.b <> ToAsyncBundle(out.b, depth, sync)
         out.c <> FromAsyncBundle(in.c, sync)
         out.e <> FromAsyncBundle(in.e, sync)
+        cover(out.b, "TL_ASYNC_CROSSING_SINK_B", "MemorySystem;;TLAsyncCrossingSinkChannel B")
+        cover(out.c, "TL_ASYNC_CROSSING_SINK_C", "MemorySystem;;TLAsyncCrossingSink Channel C")
+        cover(out.e, "TL_ASYNC_CROSSING_SINK_E", "MemorySystem;;TLAsyncCrossingSink Channel E")
       } else {
         in.b.widx := UInt(0)
         in.c.ridx := UInt(0)
diff --git a/src/main/scala/util/Property.scala b/src/main/scala/util/Property.scala
index f3c81672..7f020f9b 100644
--- a/src/main/scala/util/Property.scala
+++ b/src/main/scala/util/Property.scala
@@ -4,6 +4,7 @@ package freechips.rocketchip.util.property
 
 import Chisel._
 import chisel3.internal.sourceinfo.{SourceInfo, SourceLine}
+import chisel3.util.{ReadyValidIO}
 import freechips.rocketchip.config.{Field, Parameters}
 
 case object PropertyLibrary extends Field[BasePropertyLibrary](new DefaultPropertyLibrary)
@@ -54,5 +55,10 @@ object cover {
   def apply(cond: Bool, label: String, message: String)(implicit sourceInfo: SourceInfo, p: Parameters): Unit = {
     p(PropertyLibrary).generateProperty(CoverPropertyParameters(cond, label, message))
   }
+  def apply[T <: Data](rv: ReadyValidIO[T], label: String, message: String)(implicit sourceInfo: SourceInfo, p: Parameters): Unit = {
+    apply( rv.valid &&  rv.ready, label + "_FIRE",  message + ": valid and ready")
+    apply( rv.valid && !rv.ready, label + "_STALL", message + ": valid and not ready")
+    apply(!rv.valid &&  rv.ready, label + "_IDLE",  message + ": not valid and ready")
+    apply(!rv.valid && !rv.ready, label + "_FULL",  message + ": not valid and not ready")
+  }
 }
-