From befc54a444b7ddbe61c4d456c8a2981fd40d221f Mon Sep 17 00:00:00 2001
From: Charles Papon <charles.papon.90@gmail.com>
Date: Fri, 21 Feb 2020 13:28:29 +0100
Subject: [PATCH] No more Fetcher flush() API as it can now be done via the
 decoder.flushNext

---
 src/main/scala/vexriscv/Services.scala            |  1 -
 src/main/scala/vexriscv/ip/InstructionCache.scala |  2 +-
 src/main/scala/vexriscv/plugin/DebugPlugin.scala  |  1 -
 src/main/scala/vexriscv/plugin/Fetcher.scala      | 15 +++++++--------
 4 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/src/main/scala/vexriscv/Services.scala b/src/main/scala/vexriscv/Services.scala
index 09cd098..4b0aeca 100644
--- a/src/main/scala/vexriscv/Services.scala
+++ b/src/main/scala/vexriscv/Services.scala
@@ -13,7 +13,6 @@ trait JumpService{
 
 trait IBusFetcher{
   def haltIt() : Unit
-  def flushIt() : Unit
   def incoming() : Bool
   def pcValid(stage : Stage) : Bool
   def getInjectionPort() : Stream[Bits]
diff --git a/src/main/scala/vexriscv/ip/InstructionCache.scala b/src/main/scala/vexriscv/ip/InstructionCache.scala
index 0a809c6..4df0f79 100644
--- a/src/main/scala/vexriscv/ip/InstructionCache.scala
+++ b/src/main/scala/vexriscv/ip/InstructionCache.scala
@@ -114,7 +114,7 @@ case class InstructionCacheCpuFetch(p : InstructionCacheConfig) extends Bundle w
   val mmuBus  = MemoryTranslatorBus()
   val physicalAddress = UInt(p.addressWidth bits)
   val cacheMiss, error, mmuRefilling, mmuException, isUser  = ifGen(!p.twoCycleCache)(Bool)
-  val haltIt  = Bool
+  val haltIt  = Bool() //Used to wait on the MMU rsp busy
 
   override def asMaster(): Unit = {
     out(isValid, isStuck, isRemoved, pc)
diff --git a/src/main/scala/vexriscv/plugin/DebugPlugin.scala b/src/main/scala/vexriscv/plugin/DebugPlugin.scala
index 1b0084b..a1051d7 100644
--- a/src/main/scala/vexriscv/plugin/DebugPlugin.scala
+++ b/src/main/scala/vexriscv/plugin/DebugPlugin.scala
@@ -201,7 +201,6 @@ class DebugPlugin(val debugClockDomain : ClockDomain, hardwareBreakpointCount :
         execute.arbitration.haltByOther := True
         busReadDataReg := execute.input(PC).asBits
         when(stagesFromExecute.tail.map(_.arbitration.isValid).orR === False){
-          iBusFetcher.flushIt()
           iBusFetcher.haltIt()
           execute.arbitration.flushIt   := True
           execute.arbitration.flushNext := True
diff --git a/src/main/scala/vexriscv/plugin/Fetcher.scala b/src/main/scala/vexriscv/plugin/Fetcher.scala
index 0c61fa1..ec40773 100644
--- a/src/main/scala/vexriscv/plugin/Fetcher.scala
+++ b/src/main/scala/vexriscv/plugin/Fetcher.scala
@@ -32,7 +32,6 @@ abstract class IBusFetcherImpl(val resetVector : BigInt,
 //  assert(!(cmdToRspStageCount == 1 && !injectorStage))
   assert(!(compressedGen && !decodePcGen))
   var fetcherHalt : Bool = null
-  var fetcherflushIt : Bool = null
   var pcValids : Vec[Bool] = null
   def pcValid(stage : Stage) = pcValids(pipeline.indexOf(stage))
   var incomingInstruction : Bool = null
@@ -47,8 +46,6 @@ abstract class IBusFetcherImpl(val resetVector : BigInt,
   var predictionJumpInterface : Flow[UInt] = null
 
   override def haltIt(): Unit = fetcherHalt := True
-  override def flushIt(): Unit = fetcherflushIt := True
-
   case class JumpInfo(interface :  Flow[UInt], stage: Stage, priority : Int)
   val jumpInfos = ArrayBuffer[JumpInfo]()
   override def createJumpInterface(stage: Stage, priority : Int = 0): Flow[UInt] = {
@@ -62,7 +59,6 @@ abstract class IBusFetcherImpl(val resetVector : BigInt,
 //  var decodeExceptionPort : Flow[ExceptionCause] = null
   override def setup(pipeline: VexRiscv): Unit = {
     fetcherHalt = False
-    fetcherflushIt = False
     incomingInstruction = False
     if(resetVector == null) externalResetVector = in(UInt(32 bits).setName("externalResetVector"))
 
@@ -91,13 +87,16 @@ abstract class IBusFetcherImpl(val resetVector : BigInt,
     s == IBUS_RSP || s == DECOMPRESSOR
   }
 
-  def getFlushAt(s : Any, lastCond : Boolean = true): Bool = {
-    if(isDrivingDecode(s) && lastCond)  pipeline.decode.arbitration.isRemoved else fetcherflushIt
-  }
+
 
   class FetchArea(pipeline : VexRiscv) extends Area {
     import pipeline._
     import pipeline.config._
+    val fetcherflushIt = stages.map(_.arbitration.flushNext).orR
+
+    def getFlushAt(s : Any, lastCond : Boolean = true): Bool = {
+      if(isDrivingDecode(s) && lastCond)  pipeline.decode.arbitration.isRemoved else fetcherflushIt
+    }
 
     //Arbitrate jump requests into pcLoad
     val jump = new Area {
@@ -113,7 +112,7 @@ abstract class IBusFetcherImpl(val resetVector : BigInt,
       pcLoad.payload := MuxOH(OHMasking.first(valids.asBits), pcs)
     }
 
-    fetcherflushIt setWhen(stages.map(_.arbitration.flushNext).orR)
+
 
     //The fetchPC pcReg can also be use for the second stage of the fetch
     //When the fetcherHalt is set and the pipeline isn't stalled,, the pc is propagated to to the pcReg, which allow