Query regarding Inclusive Cache in the abstract configuration

[Yashwant Kumar Balivada]

Hello,
I am currently working on integrating a prefetcher into the BOOM core. In the abstract configuration, I noticed that an Inclusive Cache is instantiated using:

new freechips.rocketchip.subsystem.WithInclusiveCache ++

My goal is to attach a prefetcher to the LLC. For improving the prefetcher’s accuracy, I need to observe which cache lines are being evicted from the LLC.

While exploring the code, I found that in InclusiveCache.scala, the signal:

out.c.bits.address

appears to correspond to the address of the block being evicted from the cache (sent through the TileLink C channel).

What I am trying to figure out is how to snoop or tap into this signal from TLPrefetcher.scala so that my prefetcher can observe eviction events.

Could you suggest an appropriate way to:

• Expose or tap this eviction address signal, and

• Connect or monitor it from the prefetcher module (TLPrefetcher.scala)?

Any guidance on the best way to hook into this TileLink path for eviction monitoring would be very helpful.

Current Configuration:

class BoomPrefetchConfig extends Config(

  new barf.WithTLDCachePrefetcher(barf.NewPrefetcher()) ++

  new chipyard.config.WithTilePrefetchers ++  

  new boom.v3.common.WithNLargeBooms(1) ++

  new chipyard.config.AbstractConfig)