Metadata docs and api cleanup

uncore/src/main/scala/cache.scala

@@ -338,10 +338,6 @@ class L2DataArray(delay: Int) extends L2HellaCacheModule {
   io.write.ready := Bool(true)
 }
 
-class L2SecondaryMissInfo extends TLBundle
-    with HasTileLinkBeatId
-    with HasClientTransactionId
-
 class L2HellaCacheBank extends HierarchicalCoherenceAgent
     with L2HellaCacheParameters {
   require(isPow2(nSets))
@@ -617,10 +613,7 @@ class L2AcquireTracker(trackerId: Int) extends L2XactTracker {
   val pending_coh = Reg{ xact_old_meta.coh.clone }
 
   // Secondary miss queue
-  val ignt_q = Module(new Queue(new L2SecondaryMissInfo, nSecondaryMisses))(innerTLParams)
+  val ignt_q = Module(new Queue(new SecondaryMissInfo, nSecondaryMisses))(innerTLParams)
-  ignt_q.io.enq.bits.client_xact_id := io.iacq().client_xact_id
-  ignt_q.io.enq.bits.addr_beat := io.iacq().addr_beat
-  // TODO add ignt.dst <- iacq.src
 
   // State holding progress made on processing this transaction
   val iacq_data_done = connectIncomingDataBeatCounter(io.inner.acquire)
@@ -741,6 +734,12 @@ class L2AcquireTracker(trackerId: Int) extends L2XactTracker {
                               can_merge_iacq_put ||
                               can_merge_iacq_get
 
+  // Enqueue secondary miss information
+  ignt_q.io.enq.valid := iacq_data_done
+  ignt_q.io.enq.bits.client_xact_id := io.iacq().client_xact_id
+  ignt_q.io.enq.bits.addr_beat := io.iacq().addr_beat
+  // TODO add ignt.dst <- iacq.src
+
   // Track whether any beats are missing from a PutBlock
   pending_puts := (pending_puts & dropPendingBitWhenBeatHasData(io.inner.acquire))
 
@@ -792,22 +791,20 @@ class L2AcquireTracker(trackerId: Int) extends L2XactTracker {
                        addPendingBitWhenBeatHasData(io.inner.release) |
                        addPendingBitWhenBeatHasData(io.outer.grant) |
                        addPendingBitInternal(io.data.resp)
-  ignt_q.io.enq.valid := iacq_data_done
   ignt_q.io.deq.ready := ignt_data_done
-  // Make the Grant message using the data stored in the secondary miss queue
   io.inner.grant.valid := state === s_busy &&
                           ignt_q.io.deq.valid &&
                           (!io.ignt().hasData() ||
                             pending_ignt_data(ignt_data_idx))
+  // Make the Grant message using the data stored in the secondary miss queue
   io.inner.grant.bits := pending_coh.inner.makeGrant(
-                           dst = xact.client_id, // TODO: ignt_q.io.deq.bits.src 
+                           pri = xact,
-                           acq = xact,
+                           sec = ignt_q.io.deq.bits,
-                           client_xact_id = ignt_q.io.deq.bits.client_xact_id,
                            manager_xact_id = UInt(trackerId), 
-                           addr_beat = ignt_data_idx,
                            data = Mux(xact.is(Acquire.putAtomicType),
                                     amo_result,
                                     data_buffer(ignt_data_idx)))
+  io.inner.grant.bits.addr_beat := ignt_data_idx // override based on outgoing counter
 
   val pending_coh_on_ignt = HierarchicalMetadata(
                               pending_coh.inner.onGrant(io.ignt()),

uncore/src/main/scala/metadata.scala

@@ -3,7 +3,7 @@
 package uncore
 import Chisel._
 
-// Classes to represent coherence information in clients and managers
+/** Base class to represent coherence information in clients and managers */
 abstract class CoherenceMetadata extends Bundle {
   val co = params(TLCoherencePolicy)
   val id = params(TLId)
@@ -15,21 +15,35 @@ abstract class CoherenceMetadata extends Bundle {
   * memory operations or [[uncore.Probe]] messages.
   */
 class ClientMetadata extends CoherenceMetadata {
+  /** Actual state information stored in this bundle */
   val state = UInt(width = co.clientStateWidth)
 
+  /** Metadata equality */
   def ===(rhs: ClientMetadata): Bool = this.state === rhs.state
   def !=(rhs: ClientMetadata): Bool = !this.===(rhs)
 
+  /** Is the block's data present in this cache */
   def isValid(dummy: Int = 0): Bool = co.isValid(this)
-  def isHit(cmd: UInt): Bool = co.isHit(cmd, this)
+  /** Does this cache have permissions on this block sufficient to perform op */
-  def isMiss(cmd: UInt): Bool = !co.isHit(cmd, this)
+  def isHit(op_code: UInt): Bool = co.isHit(op_code, this)
-  def requiresAcquireOnSecondaryMiss(first_cmd: UInt, second_cmd: UInt): Bool =
+  /** Does this cache lack permissions on this block sufficient to perform op */ 
-    co.requiresAcquireOnSecondaryMiss(first_cmd, second_cmd, this)
+  def isMiss(op_code: UInt): Bool = !co.isHit(op_code, this)
-  def requiresReleaseOnCacheControl(cmd: UInt): Bool =
+  /** Does a secondary miss on the block require another Acquire message */
-    co.requiresReleaseOnCacheControl(cmd: UInt, this)
+  def requiresAcquireOnSecondaryMiss(first_op: UInt, second_op: UInt): Bool =
+    co.requiresAcquireOnSecondaryMiss(first_op, second_op, this)
+  /** Does op require a Release to be made to outer memory */
+  def requiresReleaseOnCacheControl(op_code: UInt): Bool =
+    co.requiresReleaseOnCacheControl(op_code: UInt, this)
+  /** Does an eviction require a Release to be made to outer memory */
   def requiresVoluntaryWriteback(dummy: Int = 0): Bool =
     co.requiresReleaseOnCacheControl(M_FLUSH, this)
 
+  /** Constructs an Acquire message based on this metdata and a memory operation
+    *
+    * @param client_xact_id client's transaction id
+    * @param addr_block address of the cache block
+    * @param op_code a memory operation from [[uncore.MemoryOpConstants]]
+    */
   def makeAcquire(
       client_xact_id: UInt,
       addr_block: UInt,
@@ -43,6 +57,13 @@ class ClientMetadata extends CoherenceMetadata {
       { case TLId => id })
   }
 
+  /** Constructs a Release message based on this metadata on an eviction
+    *
+    * @param client_xact_id client's transaction id
+    * @param addr_block address of the cache block
+    * @param addr_beat sub-block address (which beat)
+    * @param data data being written back
+    */
   def makeVoluntaryWriteback(
       client_xact_id: UInt,
       addr_block: UInt,
@@ -57,6 +78,12 @@ class ClientMetadata extends CoherenceMetadata {
       data = data), { case TLId => id })
   }
 
+  /** Constructs a Release message based on this metadata and a [[uncore.Probe]]
+    *
+    * @param the incoming [[uncore.Probe]]
+    * @param addr_beat sub-block address (which beat)
+    * @param data data being released
+    */
   def makeRelease(
       prb: Probe,
       addr_beat: UInt = UInt(0),
@@ -70,16 +97,37 @@ class ClientMetadata extends CoherenceMetadata {
       data = data), { case TLId => id })
   }
 
+  /** New metadata after receiving a [[uncore.Grant]]
+    *
+    * @param incoming the incoming [[uncore.Grant]]
+    * @param pending the mem op that triggered this transaction
+    */
   def onGrant(incoming: Grant, pending: UInt): ClientMetadata =
     Bundle(co.clientMetadataOnGrant(incoming, pending, this), { case TLId => id })
+
+  /** New metadata after receiving a [[uncore.Probe]]
+    *
+    * @param incoming the incoming [[uncore.Probe]]
+    */
   def onProbe(incoming: Probe): ClientMetadata =
     Bundle(co.clientMetadataOnProbe(incoming, this), { case TLId => id })
-  def onHit(cmd: UInt): ClientMetadata =
+
-    Bundle(co.clientMetadataOnHit(cmd, this), { case TLId => id })
+  /** New metadata after a op_code hits this block
-  def onCacheControl(cmd: UInt): ClientMetadata =
+    *
-    Bundle(co.clientMetadataOnCacheControl(cmd, this), { case TLId => id })
+    * @param op_code a memory operation from [[uncore.MemoryOpConstants]]
+    */
+  def onHit(op_code: UInt): ClientMetadata =
+    Bundle(co.clientMetadataOnHit(op_code, this), { case TLId => id })
+
+  /** New metadata after receiving a [[uncore.Probe]]
+    *
+    * @param op_code a memory operation from [[uncore.MemoryOpConstants]]
+    */
+  def onCacheControl(op_code: UInt): ClientMetadata =
+    Bundle(co.clientMetadataOnCacheControl(op_code, this), { case TLId => id })
 }
 
+/** Factories for ClientMetadata, including on reset */
 object ClientMetadata {
   def apply(state: UInt) = {
     val meta = new ClientMetadata
@@ -89,33 +137,64 @@ object ClientMetadata {
   def onReset = new ClientMetadata().co.clientMetadataOnReset
 }
 
-/* The ManagerMetadata stores manager-side information about the status 
+/** Stores manager-side information about the status 
-    of a cache block, including whether it has any known sharers. Its
+  * of a cache block, including whether it has any known sharers.
-    API can be used to create Probe and Grant TileLink messages.
+  *
-*/
+  * Its API can be used to create [[uncore.Probe]] and [[uncore.Grant]] messages.
+  */
 class ManagerMetadata extends CoherenceMetadata {
+  // Currently no coherence policies assume manager-side state information
   // val state = UInt(width = co.masterStateWidth) TODO: Fix 0-width wires in Chisel
+
+  /** The directory information for this block */
   val sharers = UInt(width = co.dir.width)
 
+  /** Metadata equality */
   def ===(rhs: ManagerMetadata): Bool = //this.state === rhs.state && TODO: Fix 0-width wires in Chisel
                                          this.sharers === rhs.sharers
   def !=(rhs: ManagerMetadata): Bool = !this.===(rhs)
-  def full(dummy: Int = 0) = co.dir.full(this.sharers)
 
+  /** Converts the directory info into an N-hot sharer bitvector (i.e. full representation) */
+  def full(dummy: Int = 0): UInt = co.dir.full(this.sharers)
+
+  /** Does this [[uncore.Acquire]] require [[uncore.Probes]] to be sent */
   def requiresProbes(acq: Acquire): Bool = co.requiresProbes(acq, this)
-  def requiresProbes(cmd: UInt): Bool = co.requiresProbes(cmd, this)
+  /** Does this memory op require [[uncore.Probes]] to be sent */
+  def requiresProbes(op_code: UInt): Bool = co.requiresProbes(op_code, this)
+  /** Does an eviction require [[uncore.Probes]] to be sent */
   def requiresProbesOnVoluntaryWriteback(dummy: Int = 0): Bool =
     co.requiresProbes(M_FLUSH, this)
 
-  def makeProbe(dst: UInt, cmd: UInt, addr_block: UInt): ProbeToDst =
+  /** Construct an appropriate [[uncore.ProbeToDst]] for a given [[uncore.Acquire]]
-    Bundle(Probe(dst, co.getProbeType(cmd, this), addr_block), { case TLId => id })
+    *
-
+    * @param dst Destination client id for this Probe
+    * @param acq Acquire message triggering this Probe
+    */
   def makeProbe(dst: UInt, acq: Acquire): ProbeToDst = 
     Bundle(Probe(dst, co.getProbeType(acq, this), acq.addr_block), { case TLId => id })
 
+  /** Construct an appropriate [[uncore.ProbeToDst]] for a given mem op
+    *
+    * @param dst Destination client id for this Probe
+    * @param op_code memory operation triggering this Probe
+    * @param addr_block address of the cache block being probed
+    */
+  def makeProbe(dst: UInt, op_code: UInt, addr_block: UInt): ProbeToDst =
+    Bundle(Probe(dst, co.getProbeType(op_code, this), addr_block), { case TLId => id })
+
+  /** Construct an appropriate [[uncore.ProbeToDst]] for an eviction
+    *
+    * @param dst Destination client id for this Probe
+    * @param addr_block address of the cache block being probed prior to eviction
+    */
   def makeProbeForVoluntaryWriteback(dst: UInt, addr_block: UInt): ProbeToDst =
     makeProbe(dst, M_FLUSH, addr_block)
 
+  /** Construct an appropriate [[uncore.GrantToDst]] to acknowledge an [[uncore.Release]]
+    *
+    * @param rel Release message being acknowledged by this Grant
+    * @param manager_xact_id manager's transaction id
+    */
   def makeGrant(rel: ReleaseFromSrc, manager_xact_id: UInt): GrantToDst = {
     Bundle(Grant(
       dst = rel.client_id,
@@ -125,6 +204,15 @@ class ManagerMetadata extends CoherenceMetadata {
       manager_xact_id = manager_xact_id), { case TLId => id })
   }
 
+  /** Construct an appropriate [[uncore.GrantToDst]] to respond to an [[uncore.Acquire]]
+    *
+    * May contain single or multiple beats of data, or just be a permissions upgrade.
+    *
+    * @param acq Acquire message being responded to by this Grant
+    * @param manager_xact_id manager's transaction id
+    * @param addr_beat beat id of the data
+    * @param data data being refilled to the original requestor
+    */
   def makeGrant(
       acq: AcquireFromSrc,
       manager_xact_id: UInt, 
@@ -142,26 +230,42 @@ class ManagerMetadata extends CoherenceMetadata {
       data = data), { case TLId => id })
   }
 
+  /** Construct an [[uncore.GrantToDst]] to respond to an [[uncore.Acquire]] with some overrides
+    *
+    * Used to respond to secondary misses merged into this transaction.
+    * May contain single or multiple beats of data.
+    *
+    * @param pri Primary miss's Acquire message, used to get g_type and dst
+    * @param sec Secondary miss info, used to get beat and client_xact_id
+    * @param manager_xact_id manager's transaction id
+    * @param data data being refilled to the original requestor
+    */
   def makeGrant(
-      dst: UInt,
+      pri: AcquireFromSrc,
-      acq: AcquireFromSrc,
+      sec: SecondaryMissInfo,
-      client_xact_id: UInt,
       manager_xact_id: UInt, 
-      addr_beat: UInt,
       data: UInt): GrantToDst = {
-    val g = makeGrant(acq, manager_xact_id, addr_beat, data)
+    val g = makeGrant(pri, manager_xact_id, sec.addr_beat, data)
-    g.client_id := dst
+    g.client_xact_id := sec.client_xact_id
-    g.client_xact_id := client_xact_id
     g
   }
     
+  /** New metadata after receiving a [[uncore.ReleaseFromSrc]]
+    *
+    * @param incoming the incoming [[uncore.ReleaseFromSrc]]
+    */
   def onRelease(incoming: ReleaseFromSrc): ManagerMetadata =
     Bundle(co.managerMetadataOnRelease(incoming, incoming.client_id, this), { case TLId => id })
 
+  /** New metadata after sending a [[uncore.GrantToDst]]
+    *
+    * @param outgoing the outgoing [[uncore.GrantToDst]]
+    */
   def onGrant(outgoing: GrantToDst): ManagerMetadata =
     Bundle(co.managerMetadataOnGrant(outgoing, outgoing.client_id, this), { case TLId => id })
 }
 
+/** Factories for ManagerMetadata, including on reset */
 object ManagerMetadata {
   def apply(sharers: UInt, state: UInt = UInt(width = 0)) = {
     val meta = new ManagerMetadata
@@ -178,10 +282,14 @@ object ManagerMetadata {
   def onReset = new ManagerMetadata().co.managerMetadataOnReset
 }
 
-/* HierarchicalMetadata is used in a cache in a multi-level memory hierarchy
+/** HierarchicalMetadata is used in a cache in a multi-level memory hierarchy
-    that is a Manager with respect to some inner caches and a Client with
+  * that is a manager with respect to some inner caches and a client with
-    respect to some outer cache.
+  * respect to some outer cache.
-*/ 
+  *
+  * This class makes use of two different sets of TileLink parameters, which are
+  * applied by contextually mapping [[uncore.TLId]] to one of 
+  * [[uncore.InnerTLId]] or [[uncore.OuterTLId]].
+  */ 
 class HierarchicalMetadata extends CoherenceMetadata {
   val inner: ManagerMetadata = Bundle(new ManagerMetadata, {case TLId => params(InnerTLId)})
   val outer: ClientMetadata = Bundle(new ClientMetadata, {case TLId => params(OuterTLId)})
@@ -190,6 +298,7 @@ class HierarchicalMetadata extends CoherenceMetadata {
   def !=(rhs: HierarchicalMetadata): Bool = !this.===(rhs)
 }
 
+/** Factories for HierarchicalMetadata, including on reset */
 object HierarchicalMetadata {
   def apply(inner: ManagerMetadata, outer: ClientMetadata): HierarchicalMetadata = {
     val m = new HierarchicalMetadata
@@ -200,5 +309,7 @@ object HierarchicalMetadata {
   def onReset: HierarchicalMetadata = apply(ManagerMetadata.onReset, ClientMetadata.onReset)
 }
 
+/** Identifies the TLId of the inner network in a hierarchical cache controller */ 
 case object InnerTLId extends Field[String]
+/** Identifies the TLId of the outer network in a hierarchical cache controller */ 
 case object OuterTLId extends Field[String]

uncore/src/main/scala/tilelink.scala

@@ -785,6 +785,13 @@ class ClientTileLinkIOWrapper extends TLModule {
   io.out.release.valid := Bool(false)
 }
 
+/** Used to track metadata for transactions where multiple secondary misses have been merged
+  * and handled by a single transaction tracker.
+  */
+class SecondaryMissInfo extends TLBundle // TODO: add a_type to merge e.g. Get+GetBlocks, and/or HasClientId
+    with HasTileLinkBeatId
+    with HasClientTransactionId
+
 /** A helper module that automatically issues [[uncore.Finish]] messages in repsonse
   * to [[uncore.Grant]] that it receives from a manager and forwards to a client
   */