Changes to the Cluster API used by the GPU Project #3714
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Largely follows TileParams / CanAttachTile.
NullIntSource acts as an additional cease source node that always produces 0, and this breaks AND'ing all cease sources to produce cluster-wide cease (which is used at the ChipyardSubsystem to terminate simulation.)
…to ucb-bar-master
…into upstream-master
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Can you summarize the changes in the PR comment? |
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@hansungk can summarize :) |
| (CCBUS(clusterId), ccbus)) ++ (if (coherence.nBanks == 0) Nil else List( | ||
| (CMBUS(clusterId), csbus), | ||
| (CCOH (clusterId), CoherenceManagerWrapperParams(csbus.blockBytes, csbus.beatBytes, coherence.nBanks, CCOH(clusterId).name)(coherence.coherenceManager)))), | ||
| connections = if (coherence.nBanks == 0) Nil else List( | ||
| (CSBUS(clusterId), CCOH (clusterId), TLBusWrapperConnection(driveClockFromMaster = Some(true), nodeBinding = BIND_STAR)()), | ||
| // NOTE(hansung): not sure this is necessary | ||
| (CLBUS(clusterId), CCOH (clusterId), TLBusWrapperConnection(driveClockFromMaster = Some(true), nodeBinding = BIND_STAR)()), |
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What is the difference between the CLBUS and the CSBUS?
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If you want the CLBUS to be totally private, you probably don't want it to the CCOH (ClusterCoherence) device, since that exposes cluster-external memory
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Ah, thanks for the heads up
| case class ClusterParams( | ||
| val clusterId: Int, | ||
| val clockSinkParams: ClockSinkParameters = ClockSinkParameters() | ||
| ) extends HierarchicalElementParams { | ||
| ) extends InstantiableClusterParams[Cluster] { |
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Are many of these changes intended to let you extend Cluster?
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Yep, mostly to have Cluster extensible to other concrete impls. CLBUS is intended for cluster-local interconnect that's isolated from the outside system bus, which I think CSBUS connects to. Used for the SIMT core <-> scratchpad traffic that should not escape the cluster scope. |
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Ah, can you leave CLBUS outside the scope of this PR then, and leave it in your extension to Cluster? I think you can pass a custom ClusterBusTopologyParams |
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Yeah can do that, was unsure this would be a common use case, actually |
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CLBUS changes should be moved here ucb-bar@d20e98d |
Related issue:
Type of change: other enhancement
Impact: API modification
Development Phase: implementation
Release Notes
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