coreplex: support multiple memory channels via diplomatic trickery

src/main/scala/coreplex/CoreplexNetwork.scala

@@ -70,27 +70,23 @@ trait BankedL2CoherenceManagers extends CoreplexNetwork {
   require (isPow2(l2Config.nBanksPerChannel))
   require (isPow2(l1tol2_lineBytes))
 
-  val mem = Seq.fill(l2Config.nMemoryChannels) {
+  val mem = TLOutputNode()
+  for (i <- 0 until l2Config.nMemoryChannels) {
     val bankBar = LazyModule(new TLXbar)
-    val output = TLOutputNode()
 
-    output := bankBar.node
+    mem := bankBar.node
     val mask = ~BigInt((l2Config.nBanksPerChannel-1) * l1tol2_lineBytes)
     for (i <- 0 until l2Config.nBanksPerChannel) {
       val (in, out) = l2Config.coherenceManager(p)
       in := TLFilter(AddressSet(i * l1tol2_lineBytes, mask))(l1tol2.node)
       bankBar.node := out
     }
-
-    output
   }
 }
 
 trait BankedL2CoherenceManagersBundle extends CoreplexNetworkBundle {
   val outer: BankedL2CoherenceManagers
-
-  require (l2Config.nMemoryChannels <= 1, "Seq in Chisel Bundle needed to support > 1") // !!!
-  val mem = outer.mem.map(_.bundleOut).toList.headOption // .headOption should be removed !!!
+  val mem = outer.mem.bundleOut
 }
 
 trait BankedL2CoherenceManagersModule extends CoreplexNetworkModule {

src/main/scala/groundtest/Configs.scala

@@ -40,7 +40,7 @@ class MemtestStatelessConfig extends Config(
 // Test ALL the things
 class FancyMemtestConfig extends Config(
   new WithNGenerators(1, 2) ++ new WithNCores(2) ++ new WithMemtest ++
-  new WithNMemoryChannels(1) ++ new WithNBanksPerMemChannel(4) ++ // !!! waiting on Chisel3 support for 2 channels
+  new WithNMemoryChannels(2) ++ new WithNBanksPerMemChannel(4) ++
   new WithL2Cache ++ new GroundTestConfig)
 
 class CacheFillTestConfig extends Config(

src/main/scala/groundtest/TestHarness.scala

@@ -16,11 +16,6 @@ class TestHarness(implicit p: Parameters) extends Module {
   val dut = Module(LazyModule(new GroundTestTop).module)
   io.success := dut.io.success
 
-  if (dut.io.mem_axi4.nonEmpty) {
-    val memSize = p(ExtMem).size
-    require(memSize % dut.io.mem_axi4.size == 0)
-    for (axi4 <- dut.io.mem_axi4) {
-      Module(LazyModule(new SimAXIMem(memSize / dut.io.mem_axi4.size)).module).io.axi4 <> axi4
-    }
-  }
+  val channels = p(coreplex.BankedL2Config).nMemoryChannels
+  if (channels > 0) Module(LazyModule(new SimAXIMem(channels)).module).io.axi4 <> dut.io.mem_axi4
 }

src/main/scala/groundtest/Top.scala

@@ -17,7 +17,7 @@ class GroundTestTop(implicit p: Parameters) extends BaseTop
 
   socBus.node := coreplex.mmio
   coreplex.mmioInt := intBus.intnode
-  (mem zip coreplex.mem) foreach { case (m, c) => m := c }
+  mem.foreach { _ := coreplex.mem }
 }
 
 class GroundTestTopBundle[+L <: GroundTestTop](_outer: L) extends BaseTopBundle(_outer)

src/main/scala/rocketchip/Periphery.scala

@@ -87,11 +87,11 @@ trait PeripheryMasterAXI4Mem {
   private val config = p(ExtMem)
   private val channels = p(BankedL2Config).nMemoryChannels
 
-  val mem_axi4 = Seq.tabulate(channels) { i =>
+  val mem_axi4 = AXI4BlindOutputNode(Seq.tabulate(channels) { i =>
     val c_size = config.size/channels
     val c_base = config.base + c_size*i
 
-    AXI4BlindOutputNode(Seq(AXI4SlavePortParameters(
+    AXI4SlavePortParameters(
       slaves = Seq(AXI4SlaveParameters(
         address       = List(AddressSet(c_base, c_size-1)),
         regionType    = RegionType.UNCACHED,   // cacheable
@@ -99,12 +99,12 @@ trait PeripheryMasterAXI4Mem {
         supportsWrite = TransferSizes(1, 256), // The slave supports 1-256 byte transfers
         supportsRead  = TransferSizes(1, 256),
         interleavedId = Some(0))),             // slave does not interleave read responses
-      beatBytes = config.beatBytes)))
-  }
+      beatBytes = config.beatBytes)
+  })
 
-  val mem = mem_axi4.map { node =>
+  val mem = Seq.fill(channels) {
     val converter = LazyModule(new TLToAXI4(config.idBits))
-    node := AXI4Buffer()(converter.node)
+    mem_axi4 := AXI4Buffer()(converter.node)
     converter.node
   }
 }
@@ -113,7 +113,7 @@ trait PeripheryMasterAXI4MemBundle {
   this: TopNetworkBundle {
     val outer: PeripheryMasterAXI4Mem
   } =>
-  val mem_axi4 = outer.mem_axi4.map(_.bundleOut).toList.headOption // !!! remove headOption when Seq supported
+  val mem_axi4 = outer.mem_axi4.bundleOut
 }
 
 trait PeripheryMasterAXI4MemModule {

src/main/scala/rocketchip/RocketPlexMaster.scala

@@ -19,7 +19,7 @@ trait RocketPlexMaster extends L2Crossbar {
   coreplex.l2in := l2.node
   socBus.node := coreplex.mmio
   coreplex.mmioInt := intBus.intnode
-  (mem zip coreplex.mem) foreach { case (m, c) => m := c }
+  mem.foreach { _ := coreplex.mem }
 }
 
 trait RocketPlexMasterBundle extends L2CrossbarBundle {

src/main/scala/rocketchip/TestHarness.scala

@@ -18,13 +18,8 @@ class TestHarness()(implicit p: Parameters) extends Module {
   for (int <- dut.io.interrupts(0))
     int := Bool(false)
 
-  if (dut.io.mem_axi4.nonEmpty) {
-    val memSize = p(ExtMem).size
-    require(memSize % dut.io.mem_axi4.size == 0)
-    for (axi4 <- dut.io.mem_axi4) {
-      Module(LazyModule(new SimAXIMem(memSize / dut.io.mem_axi4.size)).module).io.axi4 <> axi4
-    }
-  }
+  val channels = p(coreplex.BankedL2Config).nMemoryChannels
+  if (channels > 0) Module(LazyModule(new SimAXIMem(channels)).module).io.axi4 <> dut.io.mem_axi4
 
   if (!p(IncludeJtagDTM)) {
     val dtm = Module(new SimDTM).connect(clock, reset, dut.io.debug.get, io.success)
@@ -32,7 +27,7 @@ class TestHarness()(implicit p: Parameters) extends Module {
      val jtag = Module(new JTAGVPI).connect(dut.io.jtag.get, reset, io.success)		
   }
 
-  val mmio_sim = Module(LazyModule(new SimAXIMem(4096)).module)
+  val mmio_sim = Module(LazyModule(new SimAXIMem(1, 4096)).module)
   mmio_sim.io.axi4 <> dut.io.mmio_axi4
 
   val l2_axi4 = dut.io.l2_axi4(0)
@@ -43,12 +38,19 @@ class TestHarness()(implicit p: Parameters) extends Module {
   l2_axi4.b .ready := Bool(true)
 }
 
-class SimAXIMem(size: BigInt)(implicit p: Parameters) extends LazyModule {
+class SimAXIMem(channels: Int, forceSize: BigInt = 0)(implicit p: Parameters) extends LazyModule {
   val config = p(ExtMem)
+  val totalSize = if (forceSize > 0) forceSize else BigInt(config.size)
+  val size = totalSize / channels
+  require(totalSize % channels == 0)
 
-  val node = AXI4BlindInputNode(Seq(AXI4MasterPortParameters(Seq(AXI4MasterParameters(IdRange(0, 1 << config.idBits))))))
+  val node = AXI4BlindInputNode(Seq.fill(channels) {
+    AXI4MasterPortParameters(Seq(AXI4MasterParameters(IdRange(0, 1 << config.idBits))))})
+
+  for (i <- 0 until channels) {
     val sram = LazyModule(new AXI4RAM(AddressSet(0, size-1), beatBytes = config.beatBytes))
     sram.node := AXI4Buffer()(AXI4Fragmenter(maxInFlight = 4)(node))
+  }
 
   lazy val module = new LazyModuleImp(this) {
     val io = new Bundle {