[WIP] Add PTWProber

src/main/scala/Configs.scala

@@ -4,8 +4,9 @@ import chisel3._
 import freechips.rocketchip.system.BaseConfig
 import freechips.rocketchip.config.{Parameters, Config}
 import freechips.rocketchip.tilelink._
+import freechips.rocketchip.tile._
 import freechips.rocketchip.subsystem._
-import freechips.rocketchip.diplomacy.{AsynchronousCrossing, ClockCrossingType}
+import freechips.rocketchip.diplomacy._
 import freechips.rocketchip.unittest.UnitTests
 
 class WithRingSystemBus(
@@ -117,3 +118,10 @@ class WithSerialTLROMFile(file: String) extends Config((site, here, up) => {
 class WithTilesStartInReset(harts: Int*) extends Config((site, here, up) => {
   case TileResetCtrlKey => up(TileResetCtrlKey, site).copy(initResetHarts = up(TileResetCtrlKey, site).initResetHarts ++ harts)
 })
+
+class WithRoCCPTWProber(opcode: OpcodeSet = OpcodeSet.custom0) extends Config((site, here, up) => {
+  case BuildRoCC => up(BuildRoCC) ++ Seq((p: Parameters) => {
+    val ptw_prober = LazyModule(new PTWProber(opcode)(p))
+    ptw_prober
+  })
+})

src/main/scala/PTWProber.scala

@@ -0,0 +1,101 @@
+package testchipip
+
+import chisel3._
+import chisel3.util._
+
+import freechips.rocketchip.tile._
+import freechips.rocketchip.rocket._
+import freechips.rocketchip.tilelink._
+import freechips.rocketchip.diplomacy._
+import freechips.rocketchip.util._
+import freechips.rocketchip.config.{Parameters}
+
+/*
+ * RoCC "accelerator" which translates a virtual address
+ * Useful for giving user programs info about physical addresses
+ */
+class PTWProber(opcodes: OpcodeSet)(implicit p: Parameters) extends LazyRoCC(opcodes, 1) {
+  val nTrackers = 8
+
+  override val atlNode = TLClientNode(Seq(TLMasterPortParameters.v1(
+    Seq(TLMasterParameters.v1("PTWProber", sourceId = IdRange(0,nTrackers)))
+  )))
+
+  override lazy val module = new LazyRoCCModuleImp(this) with HasCoreParameters {
+    val in_q = Queue(io.cmd)
+    val translate_in_flight = RegInit(false.B)
+
+    class RoCCBundle extends Bundle {
+      val cmd = new RoCCCommand
+      val data = UInt(64.W)
+    }
+
+    val resp_q = Module(new Queue(new RoCCBundle, 2))
+
+    val vm_enabled = usingVM.B && io.ptw(0).ptbr.mode(io.ptw(0).ptbr.mode.getWidth-1) && in_q.bits.status.dprv <= PRV.S.U
+
+    io.ptw(0).req.valid := in_q.valid && resp_q.io.enq.ready && !translate_in_flight && vm_enabled
+    io.ptw(0).req.bits.valid := in_q.valid
+    io.ptw(0).req.bits.bits.addr := in_q.bits.rs1(vaddrBits-1, pgIdxBits)
+    io.ptw(0).req.bits.bits.vstage1 := false.B
+    io.ptw(0).req.bits.bits.stage2 := false.B
+    io.ptw(0).req.bits.bits.need_gpa := false.B
+
+    when (io.ptw(0).req.fire()) {
+      translate_in_flight := true.B
+    } .elsewhen (io.ptw(0).resp.valid) {
+      translate_in_flight := false.B
+    }
+    in_q.ready := Mux(translate_in_flight, io.ptw(0).resp.valid, !vm_enabled && resp_q.io.enq.ready)
+
+
+    resp_q.io.enq.valid := Mux(translate_in_flight, io.ptw(0).resp.valid, !vm_enabled && in_q.valid)
+    resp_q.io.enq.bits.cmd := in_q.bits
+    resp_q.io.enq.bits.data := Mux(translate_in_flight,
+      Mux(io.ptw(0).resp.bits.pf, 0.U, Cat(io.ptw(0).resp.bits.pte.ppn, in_q.bits.rs1(pgIdxBits-1,0))),
+      in_q.bits.rs1)
+
+    dontTouch(io.ptw(0).resp)
+
+    val flush_trackers = RegInit(VecInit(0.U(nTrackers.W).asBools))
+    val flush_ready = !flush_trackers.reduce(_&&_)
+    val (tl_out, edge) = atlNode.out(0)
+
+    io.resp.valid := resp_q.io.deq.valid && resp_q.io.deq.bits.cmd.inst.funct === 0.U
+    io.resp.bits.rd := resp_q.io.deq.bits.cmd.inst.rd
+    io.resp.bits.data := resp_q.io.deq.bits.data
+    resp_q.io.deq.ready := Mux(resp_q.io.deq.bits.cmd.inst.funct === 0.U,
+      io.resp.ready,
+      flush_ready && tl_out.a.ready)
+
+    tl_out.a.valid := resp_q.io.deq.valid && resp_q.io.deq.bits.cmd.inst.funct =/= 0.U && flush_ready
+    tl_out.a.bits := edge.Put(
+      fromSource = PriorityEncoder(~(flush_trackers.asUInt)),
+      toAddress = 0x2010200.U,
+      lgSize = log2Ceil(8).U,
+      data = resp_q.io.deq.bits.data,
+      corrupt = false.B
+    )._2
+    when (tl_out.a.fire()) {
+      flush_trackers(tl_out.a.bits.source) := true.B
+    }
+    tl_out.d.ready := true.B
+    when (tl_out.d.fire()) {
+      flush_trackers(tl_out.d.bits.source) := false.B
+    }
+
+    tl_out.b.ready := false.B
+    tl_out.c.valid := false.B
+    tl_out.c.bits := DontCare
+    tl_out.e.valid := false.B
+    tl_out.e.bits := DontCare
+
+    io.mem := DontCare
+    io.mem.req.valid := false.B
+    io.fpu_req.valid := false.B
+    io.fpu_req.bits := DontCare
+    io.fpu_resp.ready := false.B
+    io.busy := in_q.valid || resp_q.io.deq.valid || flush_trackers.reduce(_||_)
+    io.interrupt := false.B
+  }
+}