Improve boundaryBuffers API | move boundaryBuffers to within-Tile (#3342

) (#3344)

* Add API to force TLBuffers into RocketTile as boundaryBuffers

* Generate boundaryBuffers within the Tile, not the TilePRCIDomain

(cherry picked from commit 3f74d79)

Co-authored-by: Jerry Zhao <jerryz123@berkeley.edu>

src/main/scala/tile/RocketTile.scala

@@ -14,6 +14,7 @@ import freechips.rocketchip.subsystem.TileCrossingParamsLike
 import freechips.rocketchip.util._
 import freechips.rocketchip.prci.{ClockSinkParameters}
 
+case class RocketTileBoundaryBufferParams(force: Boolean = false)
 
 case class RocketTileParams(
     core: RocketCoreParams = RocketCoreParams(),
@@ -26,7 +27,7 @@ case class RocketTileParams(
     beuAddr: Option[BigInt] = None,
     blockerCtrlAddr: Option[BigInt] = None,
     clockSinkParams: ClockSinkParameters = ClockSinkParameters(),
-    boundaryBuffers: Boolean = false // if synthesized with hierarchical PnR, cut feed-throughs?
+    boundaryBuffers: Option[RocketTileBoundaryBufferParams] = None
     ) extends InstantiableTileParams[RocketTile] {
   require(icache.isDefined)
   require(dcache.isDefined)
@@ -104,17 +105,15 @@ class RocketTile private(
 
   override lazy val module = new RocketTileModuleImp(this)
 
-  override def makeMasterBoundaryBuffers(crossing: ClockCrossingType)(implicit p: Parameters) = crossing match {
-    case _: RationalCrossing =>
-      if (!rocketParams.boundaryBuffers) TLBuffer(BufferParams.none)
-      else TLBuffer(BufferParams.none, BufferParams.flow, BufferParams.none, BufferParams.flow, BufferParams(1))
+  override def makeMasterBoundaryBuffers(crossing: ClockCrossingType)(implicit p: Parameters) = (rocketParams.boundaryBuffers, crossing) match {
+    case (Some(RocketTileBoundaryBufferParams(true )), _)                   => TLBuffer()
+    case (Some(RocketTileBoundaryBufferParams(false)), _: RationalCrossing) => TLBuffer(BufferParams.none, BufferParams.flow, BufferParams.none, BufferParams.flow, BufferParams(1))
     case _ => TLBuffer(BufferParams.none)
   }
 
-  override def makeSlaveBoundaryBuffers(crossing: ClockCrossingType)(implicit p: Parameters) = crossing match {
-    case _: RationalCrossing =>
-      if (!rocketParams.boundaryBuffers) TLBuffer(BufferParams.none)
-      else TLBuffer(BufferParams.flow, BufferParams.none, BufferParams.none, BufferParams.none, BufferParams.none)
+  override def makeSlaveBoundaryBuffers(crossing: ClockCrossingType)(implicit p: Parameters) = (rocketParams.boundaryBuffers, crossing) match {
+    case (Some(RocketTileBoundaryBufferParams(true )), _)                   => TLBuffer()
+    case (Some(RocketTileBoundaryBufferParams(false)), _: RationalCrossing) => TLBuffer(BufferParams.flow, BufferParams.none, BufferParams.none, BufferParams.none, BufferParams.none)
     case _ => TLBuffer(BufferParams.none)
   }
 }

src/main/scala/tile/TilePRCIDomain.scala

@@ -93,7 +93,7 @@ abstract class TilePRCIDomain[T <: BaseTile](
   def crossSlavePort(crossingType: ClockCrossingType): TLInwardNode = { DisableMonitors { implicit p => FlipRendering { implicit p =>
     val tlSlaveResetXing = this {
       tile_reset_domain.crossTLIn(tile.slaveNode) :*=
-        tile.makeSlaveBoundaryBuffers(crossingType)
+        tile { tile.makeSlaveBoundaryBuffers(crossingType) }
     }
     val tlSlaveClockXing = this.crossIn(tlSlaveResetXing)
     tlSlaveClockXing(crossingType)
@@ -104,7 +104,7 @@ abstract class TilePRCIDomain[T <: BaseTile](
     */
   def crossMasterPort(crossingType: ClockCrossingType): TLOutwardNode = {
     val tlMasterResetXing = this { DisableMonitors { implicit p =>
-      tile.makeMasterBoundaryBuffers(crossingType) :=*
+      tile { tile.makeMasterBoundaryBuffers(crossingType) } :=*
         tile_reset_domain.crossTLOut(tile.masterNode)
     } }
     val tlMasterClockXing = this.crossOut(tlMasterResetXing)