Debug: Add mcontext/scontext registers for breakpoint qualification

src/main/scala/diplomaticobjectmodel/logicaltree/RocketLogicalTreeNode.scala

@@ -95,6 +95,8 @@ class RocketLogicalTreeNode(
       interruptLatency = 4,
       nLocalInterrupts = coreParams.nLocalInterrupts,
       nBreakpoints = coreParams.nBreakpoints,
+      mcontextWidth = coreParams.mcontextWidth,
+      scontextWidth = coreParams.scontextWidth,
       branchPredictor = rocketParams.btb.map(OMBTB.makeOMI),
       dcache = Some(omDCache),
       icache = Some(omICache),

src/main/scala/diplomaticobjectmodel/model/OMRocketCore.scala

@@ -23,6 +23,8 @@ case class OMRocketCore(
   interruptLatency: Int,
   nLocalInterrupts: Int,
   nBreakpoints: Int,
+  mcontextWidth: Int,
+  scontextWidth: Int,
   branchPredictor: Option[OMRocketBranchPredictor],
   dcache: Option[OMDCache],
   icache: Option[OMICache],

src/main/scala/rocket/Breakpoint.scala

@@ -31,9 +31,30 @@ class BPControl(implicit p: Parameters) extends CoreBundle()(p) {
   def enabled(mstatus: MStatus) = !mstatus.debug && Cat(m, h, s, u)(mstatus.prv)
 }
 
+class TExtra(implicit p: Parameters) extends CoreBundle()(p) {
+  def mvalueBits: Int = if (xLen == 32) coreParams.mcontextWidth min  6 else coreParams.mcontextWidth min 13
+  def svalueBits: Int = if (xLen == 32) coreParams.scontextWidth min 16 else coreParams.scontextWidth min 34
+  def mselectPos: Int = if (xLen == 32) 25 else 50
+  def mvaluePos : Int = mselectPos + 1
+  def sselectPos: Int = 0
+  def svaluePos : Int = 2
+
+  val mvalue  = UInt(mvalueBits.W)
+  val mselect = Bool()
+  val pad2    = UInt((mselectPos - svalueBits - 2).W)
+  val svalue  = UInt(svalueBits.W)
+  val pad1    = UInt(1.W)
+  val sselect = Bool()
+}
+
 class BP(implicit p: Parameters) extends CoreBundle()(p) {
   val control = new BPControl
   val address = UInt(vaddrBits.W)
+  val textra  = new TExtra
+
+  def contextMatch(mcontext: UInt, scontext: UInt) =
+    (if (coreParams.mcontextWidth > 0) (!textra.mselect || (mcontext(textra.mvalueBits-1,0) === textra.mvalue)) else true.B) &&
+    (if (coreParams.scontextWidth > 0) (!textra.sselect || (scontext(textra.svalueBits-1,0) === textra.svalue)) else true.B)
 
   def mask(dummy: Int = 0) =
     (0 until control.maskMax-1).scanLeft(control.tmatch(0))((m, i) => m && address(i)).asUInt
@@ -62,6 +83,8 @@ class BreakpointUnit(n: Int)(implicit val p: Parameters) extends Module with Has
     val bp = Input(Vec(n, new BP))
     val pc = Input(UInt(vaddrBits.W))
     val ea = Input(UInt(vaddrBits.W))
+    val mcontext = Input(UInt(coreParams.mcontextWidth.W))
+    val scontext = Input(UInt(coreParams.scontextWidth.W))
     val xcpt_if  = Output(Bool())
     val xcpt_ld  = Output(Bool())
     val xcpt_st  = Output(Bool())
@@ -80,9 +103,10 @@ class BreakpointUnit(n: Int)(implicit val p: Parameters) extends Module with Has
 
   (io.bpwatch zip io.bp).foldLeft((true.B, true.B, true.B)) { case ((ri, wi, xi), (bpw, bp)) =>
     val en = bp.control.enabled(io.status)
-    val r = en && bp.control.r && bp.addressMatch(io.ea)
-    val w = en && bp.control.w && bp.addressMatch(io.ea)
-    val x = en && bp.control.x && bp.addressMatch(io.pc)
+    val cx = bp.contextMatch(io.mcontext, io.scontext)
+    val r = en && bp.control.r && bp.addressMatch(io.ea) && cx
+    val w = en && bp.control.w && bp.addressMatch(io.ea) && cx
+    val x = en && bp.control.x && bp.addressMatch(io.pc) && cx
     val end = !bp.control.chain
     val action = bp.control.action
 

src/main/scala/rocket/CSR.scala

@@ -228,6 +228,8 @@ class CSRFileIO(implicit p: Parameters) extends CoreBundle
   val csrw_counter = UInt(OUTPUT, CSR.nCtr)
   val inst = Vec(retireWidth, UInt(width = iLen)).asInput
   val trace = Vec(retireWidth, new TracedInstruction).asOutput
+  val mcontext = Output(UInt(coreParams.mcontextWidth.W))
+  val scontext = Output(UInt(coreParams.scontextWidth.W))
 
   val vector = usingVector.option(new Bundle {
     val vconfig = new VConfig().asOutput
@@ -363,6 +365,9 @@ class CSRFile(
   val reg_dscratch = Reg(UInt(width = xLen))
   val reg_singleStepped = Reg(Bool())
 
+  val reg_mcontext = (coreParams.mcontextWidth > 0).option(RegInit(0.U(coreParams.mcontextWidth.W)))
+  val reg_scontext = (coreParams.scontextWidth > 0).option(RegInit(0.U(coreParams.scontextWidth.W)))
+
   val reg_tselect = Reg(UInt(width = log2Up(nBreakpoints)))
   val reg_bp = Reg(Vec(1 << log2Up(nBreakpoints), new BP))
   val reg_pmp = Reg(Vec(nPMPs, new PMPReg))
@@ -439,6 +444,8 @@ class CSRFile(
   io.interrupt := (anyInterrupt && !io.singleStep || reg_singleStepped) && !(reg_debug || io.status.cease)
   io.interrupt_cause := interruptCause
   io.bp := reg_bp take nBreakpoints
+  io.mcontext := reg_mcontext.getOrElse(0.U)
+  io.scontext := reg_scontext.getOrElse(0.U)
   io.pmp := reg_pmp.map(PMP(_))
 
   val isaMaskString =
@@ -463,6 +470,7 @@ class CSRFile(
     CSRs.tselect -> reg_tselect,
     CSRs.tdata1 -> reg_bp(reg_tselect).control.asUInt,
     CSRs.tdata2 -> reg_bp(reg_tselect).address.sextTo(xLen),
+    CSRs.tdata3 -> reg_bp(reg_tselect).textra.asUInt,
     CSRs.misa -> reg_misa,
     CSRs.mstatus -> read_mstatus,
     CSRs.mtvec -> read_mtvec,
@@ -479,6 +487,10 @@ class CSRFile(
     CSRs.dpc -> readEPC(reg_dpc).sextTo(xLen),
     CSRs.dscratch -> reg_dscratch.asUInt)
 
+  val context_csrs = LinkedHashMap[Int,Bits]() ++
+    reg_mcontext.map(r => CSRs.mcontext -> r) ++
+    reg_scontext.map(r => CSRs.scontext -> r)
+
   val read_fcsr = Cat(reg_frm, reg_fflags)
   val fp_csrs = LinkedHashMap[Int,Bits]() ++
     usingFPU.option(CSRs.fflags -> reg_fflags) ++
@@ -496,6 +508,7 @@ class CSRFile(
     CSRs.vlenb -> (vLen / 8).U)
 
   read_mapping ++= debug_csrs
+  read_mapping ++= context_csrs
   read_mapping ++= fp_csrs
   read_mapping ++= vector_csrs
 
@@ -940,6 +953,16 @@ class CSRFile(
       for ((bp, i) <- reg_bp.zipWithIndex) {
         when (i === reg_tselect && (!bp.control.dmode || reg_debug)) {
           when (decoded_addr(CSRs.tdata2)) { bp.address := wdata }
+          when (decoded_addr(CSRs.tdata3)) {
+            if (coreParams.mcontextWidth > 0) {
+              bp.textra.mselect := wdata(bp.textra.mselectPos)
+              bp.textra.mvalue  := wdata >> bp.textra.mvaluePos
+            }
+            if (coreParams.scontextWidth > 0) {
+              bp.textra.sselect := wdata(bp.textra.sselectPos)
+              bp.textra.svalue  := wdata >> bp.textra.svaluePos
+            }
+          }
           when (decoded_addr(CSRs.tdata1)) {
             bp.control := wdata.asTypeOf(bp.control)
 
@@ -956,6 +979,8 @@ class CSRFile(
         }
       }
     }
+    reg_mcontext.foreach { r => when (decoded_addr(CSRs.mcontext)) { r := wdata }}
+    reg_scontext.foreach { r => when (decoded_addr(CSRs.scontext)) { r := wdata }}
     if (reg_pmp.nonEmpty) for (((pmp, next), i) <- (reg_pmp zip (reg_pmp.tail :+ reg_pmp.last)) zipWithIndex) {
       require(xLen % pmp.cfg.getWidth == 0)
       when (decoded_addr(CSRs.pmpcfg0 + pmpCfgIndex(i)) && !pmp.cfgLocked) {
@@ -1036,6 +1061,10 @@ class CSRFile(
       bpc.x := false
     }
   }
+  for (bpx <- reg_bp map {_.textra}) {
+    if (coreParams.mcontextWidth == 0) bpx.mselect := false.B
+    if (coreParams.scontextWidth == 0) bpx.sselect := false.B
+  }
   for (bp <- reg_bp drop nBreakpoints)
     bp := new BP().fromBits(0)
   for (pmp <- reg_pmp) {

src/main/scala/rocket/Instructions.scala

@@ -911,6 +911,9 @@ object CSRs {
   val tdata1 = 0x7a1
   val tdata2 = 0x7a2
   val tdata3 = 0x7a3
+  val scontext = 0x5a8
+  val hcontext = 0x6a8
+  val mcontext = 0x7a8
   val dcsr = 0x7b0
   val dpc = 0x7b1
   val dscratch = 0x7b2
@@ -1167,6 +1170,9 @@ object CSRs {
     res += tdata1
     res += tdata2
     res += tdata3
+    res += scontext
+    res += hcontext
+    res += mcontext
     res += dcsr
     res += dpc
     res += dscratch

src/main/scala/rocket/RocketCore.scala

@@ -29,6 +29,8 @@ case class RocketCoreParams(
   nLocalInterrupts: Int = 0,
   nBreakpoints: Int = 1,
   useBPWatch: Boolean = false,
+  mcontextWidth: Int = 0,
+  scontextWidth: Int = 0,
   nPMPs: Int = 8,
   nPerfCounters: Int = 0,
   haveBasicCounters: Boolean = true,
@@ -319,6 +321,8 @@ class Rocket(tile: RocketTile)(implicit p: Parameters) extends CoreModule()(p)
   bpu.io.bp := csr.io.bp
   bpu.io.pc := ibuf.io.pc
   bpu.io.ea := mem_reg_wdata
+  bpu.io.mcontext := csr.io.mcontext
+  bpu.io.scontext := csr.io.scontext
 
   val id_xcpt0 = ibuf.io.inst(0).bits.xcpt0
   val id_xcpt1 = ibuf.io.inst(0).bits.xcpt1

src/main/scala/tile/Core.scala

@@ -35,6 +35,8 @@ trait CoreParams {
   val pmpGranularity: Int
   val nBreakpoints: Int
   val useBPWatch: Boolean
+  val mcontextWidth: Int
+  val scontextWidth: Int
   val nPerfCounters: Int
   val haveBasicCounters: Boolean
   val haveFSDirty: Boolean