tree aa3187280ff7c899a12b5262778192c7419c81ea
parent bc1438414a1e48395797ffbe2e6b5f54d53249a5
author Giacomo Travaglini <giacomo.travaglini@arm.com> 1631524999 +0100
committer Giacomo Travaglini <giacomo.travaglini@arm.com> 1634114725 +0000

mem: Make ruby AbstractController compatible with XBar

At the moment the ruby AbstractController is trying to re-send the same
memory request every clock cycle until it finally succeeds [1]
(in other words it is not waiting for a recvReqRetry from the peer
port)

This polling behaviour is not compatible with the gem5 XBar, which is
panicking if it receives two consecutive requests to the same BUSY
layer [2]

This patch is fixing the incompatibility by inhibiting the
AbstractController retry until it gets a notification from the peer
response port

[1]: https://github.com/gem5/gem5/blob/v21.1.0.1/\
    src/mem/ruby/slicc_interface/AbstractController.cc#L303
[2]: https://github.com/gem5/gem5/blob/v21.1.0.1/src/mem/xbar.cc#L196

Change-Id: I0ac38ce286051fb714844de569c2ebf85e71a523
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/50367
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>