rocketchip: move memory channel Xbar from coreplex to rocketchip

We want to keep the banks split in the outer SoC if there is an L3.
Furthermore, each channel might go to different memory subsystems,
like DDR/HMC/Zero, from rocketchip.

src/main/scala/rocketchip/BaseTop.scala

@@ -35,6 +35,7 @@ trait TopNetwork extends HasPeripheryParameters {
   val peripheryBus = LazyModule(new TLXbar)
   val intBus = LazyModule(new IntXbar)
   val l2 = LazyModule(new TLBuffer)
+  val mem = Seq.fill(p(coreplex.BankedL2Config).nMemoryChannels) { LazyModule(new TLXbar) }
 
   peripheryBus.node :=
     TLBuffer()(

src/main/scala/rocketchip/Periphery.scala

@@ -72,28 +72,21 @@ trait PeripheryExtInterruptsModule {
 
 /////
 
-trait PeripheryNoMem extends TopNetwork {
-  private val channels = p(BankedL2Config).nMemoryChannels
-  require (channels == 0)
-  val mem = Seq()
-}
-
-/////
-
 trait PeripheryMasterAXI4Mem {
   this: TopNetwork =>
   val module: PeripheryMasterAXI4MemModule
 
   private val config = p(ExtMem)
   private val channels = p(BankedL2Config).nMemoryChannels
+  private val lineBytes = p(CacheBlockBytes)
 
-  val mem_axi4 = AXI4BlindOutputNode(Seq.tabulate(channels) { i =>
-    val c_size = config.size/channels
-    val c_base = config.base + c_size*i
+  val mem_axi4 = AXI4BlindOutputNode(Seq.tabulate(channels) { channel =>
+    val base = AddressSet(config.base, config.size-1)
+    val filter = AddressSet(channel * lineBytes, ~((channels-1) * lineBytes))
 
     AXI4SlavePortParameters(
       slaves = Seq(AXI4SlaveParameters(
-        address       = List(AddressSet(c_base, c_size-1)),
+        address       = base.intersect(filter).toList,
         regionType    = RegionType.UNCACHED,   // cacheable
         executable    = true,
         supportsWrite = TransferSizes(1, 256), // The slave supports 1-256 byte transfers
@@ -102,10 +95,13 @@ trait PeripheryMasterAXI4Mem {
       beatBytes = config.beatBytes)
   })
 
-  val mem = Seq.fill(channels) {
-    val converter = LazyModule(new TLToAXI4(config.idBits))
-    mem_axi4 := AXI4Buffer()(converter.node)
-    converter.node
+  private val converter = LazyModule(new TLToAXI4(config.idBits))
+  private val buffer = LazyModule(new AXI4Buffer)
+
+  mem foreach { case xbar =>
+    converter.node := xbar.node
+    buffer.node := converter.node
+    mem_axi4 := buffer.node
   }
 }
 

src/main/scala/rocketchip/RocketPlexMaster.scala

@@ -12,14 +12,15 @@ import coreplex._
 
 trait RocketPlexMaster extends TopNetwork {
   val module: RocketPlexMasterModule
-  val mem: Seq[TLInwardNode]
 
   val coreplex = LazyModule(new DefaultCoreplex)
 
   coreplex.l2in :=* l2.node
   socBus.node := coreplex.mmio
   coreplex.mmioInt := intBus.intnode
-  mem.foreach { _ := coreplex.mem }
+
+  require (mem.size == coreplex.mem.size)
+  (mem zip coreplex.mem) foreach { case (xbar, channel) => xbar.node :=* channel }
 }
 
 trait RocketPlexMasterBundle extends TopNetworkBundle {