moved ecc lib to uncore, l2 checks for partial write masks when ecc is enabled

uncore/src/main/scala/cache.scala

@@ -15,6 +15,7 @@ case object NPrimaryMisses extends Field[Int]
 case object NSecondaryMisses extends Field[Int]
 case object CacheBlockBytes extends Field[Int]
 case object CacheBlockOffsetBits extends Field[Int]
+case object ECCCode extends Field[Option[Code]]
 
 abstract trait CacheParameters extends UsesParameters {
   val nSets = params(NSets)
@@ -28,6 +29,7 @@ abstract trait CacheParameters extends UsesParameters {
   val rowBits = params(RowBits)
   val rowBytes = rowBits/8
   val rowOffBits = log2Up(rowBytes)
+  val code = params(ECCCode).getOrElse(new IdentityCode)
 }
 
 abstract class CacheBundle extends Bundle with CacheParameters
@@ -176,6 +178,7 @@ abstract trait L2HellaCacheParameters extends CacheParameters with CoherenceAgen
   require(rowBits == innerDataBits) // TODO: relax this by improving s_data_* states
   val nSecondaryMisses = params(NSecondaryMisses)
   val isLastLevelCache = true
+  val ignoresWriteMask = !params(ECCCode).isEmpty
 }
 
 abstract class L2HellaCacheBundle extends Bundle with L2HellaCacheParameters
@@ -462,6 +465,12 @@ abstract class L2XactTracker extends XactTracker with L2HellaCacheParameters {
 
   def dropPendingBitInternal[T <: HasL2BeatAddr] (in: ValidIO[T]) =
     ~Fill(in.bits.refillCycles, in.valid) | ~UIntToOH(in.bits.addr_beat)
+
+  def addPendingBitWhenBeatHasPartialWritemask(in: DecoupledIO[LogicalNetworkIO[Acquire]]): UInt = {
+    val a = in.bits.payload
+    val isPartial = a.wmask() != Acquire.fullWriteMask
+    addPendingBitWhenBeat(in.fire() && isPartial && Bool(ignoresWriteMask), in.bits.payload)
+  }
 }
 
 class L2VoluntaryReleaseTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
@@ -805,7 +814,8 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
                        dropPendingBit(io.data.read) &
                        dropPendingBitWhenBeatHasData(io.inner.release) &
                        dropPendingBitWhenBeatHasData(io.outer.grant)) |
-                     addPendingBitWhenBeatIsGetOrAtomic(io.inner.acquire)
+                     addPendingBitWhenBeatIsGetOrAtomic(io.inner.acquire) |
+                     addPendingBitWhenBeatHasPartialWritemask(io.inner.acquire)
   val curr_read_beat = PriorityEncoder(pending_reads)
   io.data.read.valid := state === s_busy &&
                           pending_reads.orR &&
@@ -880,7 +890,8 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
     pending_reads := Mux(
       io.iacq().isBuiltInType(Acquire.getBlockType) || !io.iacq().isBuiltInType(),
       SInt(-1, width = innerDataBeats),
-      addPendingBitWhenBeatIsGetOrAtomic(io.inner.acquire)).toUInt
+      (addPendingBitWhenBeatIsGetOrAtomic(io.inner.acquire) | 
+        addPendingBitWhenBeatHasPartialWritemask(io.inner.acquire)).toUInt)
     pending_writes := addPendingBitWhenBeatHasData(io.inner.acquire)
     pending_resps := UInt(0)
     pending_ignt_data := UInt(0)

uncore/src/main/scala/ecc.scala

@@ -0,0 +1,146 @@
+// See LICENSE for license details.
+
+package uncore
+
+import Chisel._
+
+abstract class Decoding
+{
+  def uncorrected: Bits
+  def corrected: Bits
+  def correctable: Bool
+  def uncorrectable: Bool
+  def error = correctable || uncorrectable
+}
+
+abstract class Code
+{
+  def width(w0: Int): Int
+  def encode(x: Bits): Bits
+  def decode(x: Bits): Decoding
+}
+
+class IdentityCode extends Code
+{
+  def width(w0: Int) = w0
+  def encode(x: Bits) = x
+  def decode(y: Bits) = new Decoding {
+    def uncorrected = y
+    def corrected = y
+    def correctable = Bool(false)
+    def uncorrectable = Bool(false)
+  }
+}
+
+class ParityCode extends Code
+{
+  def width(w0: Int) = w0+1
+  def encode(x: Bits) = Cat(x.xorR, x)
+  def decode(y: Bits) = new Decoding {
+    def uncorrected = y(y.getWidth-2,0)
+    def corrected = uncorrected
+    def correctable = Bool(false)
+    def uncorrectable = y.xorR
+  }
+}
+
+class SECCode extends Code
+{
+  def width(k: Int) = {
+    val m = new Unsigned(k).log2 + 1
+    k + m + (if((1 << m) < m+k+1) 1 else 0)
+  }
+  def encode(x: Bits) = {
+    val k = x.getWidth
+    require(k > 0)
+    val n = width(k)
+
+    val y = for (i <- 1 to n) yield {
+      if (isPow2(i)) {
+        val r = for (j <- 1 to n; if j != i && (j & i) != 0)
+          yield x(mapping(j))
+        r reduce (_^_)
+      } else
+        x(mapping(i))
+    }
+    Vec(y).toBits
+  }
+  def decode(y: Bits) = new Decoding {
+    val n = y.getWidth
+    require(n > 0 && !isPow2(n))
+
+    val p2 = for (i <- 0 until log2Up(n)) yield 1 << i
+    val syndrome = p2 map { i =>
+      val r = for (j <- 1 to n; if (j & i) != 0)
+        yield y(j-1)
+      r reduce (_^_)
+    }
+    val s = Vec(syndrome).toBits
+
+    private def swizzle(z: Bits) = Vec((1 to n).filter(i => !isPow2(i)).map(i => z(i-1))).toBits
+    def uncorrected = swizzle(y)
+    def corrected = swizzle(((y.toUInt << UInt(1)) ^ UIntToOH(s)) >> UInt(1))
+    def correctable = s.orR
+    def uncorrectable = Bool(false)
+  }
+  private def mapping(i: Int) = i-1-log2Up(i)
+}
+
+class SECDEDCode extends Code
+{
+  private val sec = new SECCode
+  private val par = new ParityCode
+
+  def width(k: Int) = sec.width(k)+1
+  def encode(x: Bits) = par.encode(sec.encode(x))
+  def decode(x: Bits) = new Decoding {
+    val secdec = sec.decode(x(x.getWidth-2,0))
+    val pardec = par.decode(x)
+
+    def uncorrected = secdec.uncorrected
+    def corrected = secdec.corrected
+    def correctable = pardec.uncorrectable
+    def uncorrectable = !pardec.uncorrectable && secdec.correctable
+  }
+}
+
+object ErrGen
+{
+  // generate a 1-bit error with approximate probability 2^-f
+  def apply(width: Int, f: Int): Bits = {
+    require(width > 0 && f >= 0 && log2Up(width) + f <= 16)
+    UIntToOH(LFSR16()(log2Up(width)+f-1,0))(width-1,0)
+  }
+  def apply(x: Bits, f: Int): Bits = x ^ apply(x.getWidth, f)
+}
+
+class SECDEDTest extends Module
+{
+  val code = new SECDEDCode
+  val k = 4
+  val n = code.width(k)
+
+  val io = new Bundle {
+    val original = Bits(OUTPUT, k)
+    val encoded = Bits(OUTPUT, n)
+    val injected = Bits(OUTPUT, n)
+    val uncorrected = Bits(OUTPUT, k)
+    val corrected = Bits(OUTPUT, k)
+    val correctable = Bool(OUTPUT)
+    val uncorrectable = Bool(OUTPUT)
+  }
+
+  val c = Counter(Bool(true), 1 << k)
+  val numErrors = Counter(c._2, 3)._1
+  val e = code.encode(c._1)
+  val i = e ^ Mux(numErrors < UInt(1), UInt(0), ErrGen(n, 1)) ^ Mux(numErrors < UInt(2), UInt(0), ErrGen(n, 1))
+  val d = code.decode(i)
+
+  io.original := c._1
+  io.encoded := e
+  io.injected := i
+  io.uncorrected := d.uncorrected
+  io.corrected := d.corrected
+  io.correctable := d.correctable
+  io.uncorrectable := d.uncorrectable
+}

uncore/src/main/scala/uncore.scala

@@ -132,8 +132,10 @@ class HierarchicalXactTrackerIO extends HierarchicalTLIO with HasTrackerConflict
 
 abstract class XactTracker extends CoherenceAgentModule
     with HasDataBeatCounters {
-  def addPendingBitWhenBeat[T <: HasBeat](inc: Bool, in: T): UInt  =  Fill(in.tlDataBeats, inc) &  UIntToOH(in.addr_beat)
-  def dropPendingBitWhenBeat[T <: HasBeat](dec: Bool, in: T): UInt = ~Fill(in.tlDataBeats, dec) | ~UIntToOH(in.addr_beat)
+  def addPendingBitWhenBeat[T <: HasBeat](inc: Bool, in: T): UInt =
+    Fill(in.tlDataBeats, inc) &  UIntToOH(in.addr_beat)
+  def dropPendingBitWhenBeat[T <: HasBeat](dec: Bool, in: T): UInt =
+    ~Fill(in.tlDataBeats, dec) | ~UIntToOH(in.addr_beat)
 
   def addPendingBitWhenBeatHasData[T <: Data : TypeTag](in: DecoupledIO[T]): UInt = {
     in.bits match {

uncore/src/main/scala/util.scala

@@ -5,6 +5,14 @@ package uncore
 import Chisel._
 import scala.math._
 
+class Unsigned(x: Int) {
+  require(x >= 0)
+  def clog2: Int = { require(x > 0); ceil(log(x)/log(2)).toInt }
+  def log2: Int = { require(x > 0); floor(log(x)/log(2)).toInt }
+  def isPow2: Boolean = x > 0 && (x & (x-1)) == 0
+  def nextPow2: Int = if (x == 0) 1 else 1 << clog2
+}
+
 object MuxBundle {
   def apply[T <: Data] (default: T, mapping: Seq[(Bool, T)]): T = {
     mapping.reverse.foldLeft(default)((b, a) => Mux(a._1, a._2, b))