From 28b635e7215412958592d337a0442d422fbbc867 Mon Sep 17 00:00:00 2001
From: Henry Cook <henry@sifive.com>
Date: Wed, 20 Sep 2017 18:53:44 -0700
Subject: [PATCH] tile: add halt_and_catch_fire signal

for unrecoverable / fatal errors
---
 src/main/scala/tile/RocketTile.scala | 17 ++++++++++++++++-
 src/main/scala/util/Misc.scala       |  4 ++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/main/scala/tile/RocketTile.scala b/src/main/scala/tile/RocketTile.scala
index f36dbdc0..106dac84 100644
--- a/src/main/scala/tile/RocketTile.scala
+++ b/src/main/scala/tile/RocketTile.scala
@@ -20,6 +20,7 @@ case class RocketTileParams(
     dataScratchpadBytes: Int = 0,
     boundaryBuffers: Boolean = false,
     trace: Boolean = false,
+    hcfOnUncorrectable: Boolean = false,
     name: Option[String] = Some("tile"),
     externalMasterBuffers: Int = 0,
     externalSlaveBuffers: Int = 0) extends TileParams {
@@ -131,6 +132,7 @@ class RocketTile(val rocketParams: RocketTileParams, val hartid: Int)(implicit p
 class RocketTileBundle(outer: RocketTile) extends BaseTileBundle(outer)
     with HasExternalInterruptsBundle
     with CanHaveScratchpadBundle
+    with CanHaltAndCatchFire
 
 class RocketTileModule(outer: RocketTile) extends BaseTileModule(outer, () => new RocketTileBundle(outer))
     with HasExternalInterruptsModule
@@ -138,9 +140,12 @@ class RocketTileModule(outer: RocketTile) extends BaseTileModule(outer, () => ne
     with CanHaveScratchpadModule {
 
   val core = Module(p(BuildCore)(outer.p))
+  val uncorrectable = RegInit(Bool(false))
+
   decodeCoreInterrupts(core.io.interrupts) // Decode the interrupt vector
   core.io.hartid := io.hartid // Pass through the hartid
   io.trace.foreach { _ := core.io.trace }
+  io.halt_and_catch_fire := (if(outer.rocketParams.hcfOnUncorrectable) uncorrectable else false.B)
   outer.frontend.module.io.cpu <> core.io.imem
   outer.frontend.module.io.reset_vector := io.reset_vector
   outer.frontend.module.io.hartid := io.hartid
@@ -154,6 +159,12 @@ class RocketTileModule(outer: RocketTile) extends BaseTileModule(outer, () => ne
   core.io.rocc.busy := roccCore.busy
   core.io.rocc.interrupt := roccCore.interrupt
 
+  when(!uncorrectable) { uncorrectable :=
+    List(outer.frontend.module.io.errors, outer.dcache.module.io.errors)
+      .flatMap { e => e.uncorrectable.map(_.valid) }
+      .reduceOption(_||_)
+      .getOrElse(false.B)
+  }
 
   // TODO eliminate this redundancy
   val h = dcachePorts.size
@@ -207,7 +218,10 @@ abstract class RocketTileWrapper(rtp: RocketTileParams, hartid: Int)(implicit p:
   }
 
   lazy val module = new LazyModuleImp(this) {
-    val io = new CoreBundle with HasExternallyDrivenTileConstants with CanHaveInstructionTracePort {
+    val io = new CoreBundle
+        with HasExternallyDrivenTileConstants
+        with CanHaveInstructionTracePort
+        with CanHaltAndCatchFire {
       val master = masterNode.bundleOut
       val slave = slaveNode.bundleIn
       val outputInterrupts = intOutputNode.map(_.bundleOut)
@@ -219,6 +233,7 @@ abstract class RocketTileWrapper(rtp: RocketTileParams, hartid: Int)(implicit p:
     rocket.module.io.hartid := io.hartid
     rocket.module.io.reset_vector := io.reset_vector
     io.trace.foreach { _ := rocket.module.io.trace.get }
+    io.halt_and_catch_fire := rocket.module.io.halt_and_catch_fire
   }
 }
 
diff --git a/src/main/scala/util/Misc.scala b/src/main/scala/util/Misc.scala
index 16fb4f98..39469330 100644
--- a/src/main/scala/util/Misc.scala
+++ b/src/main/scala/util/Misc.scala
@@ -26,6 +26,10 @@ trait Clocked extends Bundle {
   val reset = Bool()  
 }
 
+trait CanHaltAndCatchFire extends Bundle {
+  val halt_and_catch_fire = Bool(OUTPUT)
+}
+
 object DecoupledHelper {
   def apply(rvs: Bool*) = new DecoupledHelper(rvs)
 }