cpu: Limit TrafficGen outstanding reqs

Parameter to limit the number of requests waiting for a response.

Change-Id: I6cf9e8782a06ae978fb66f7c4278f4c9e9980c79
Signed-off-by: Tiago Muck <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18417
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

cpu: TrafficGen as BaseCPU

TrafficGen has additional attributes to behave like a BaseCPU. Python
scripts that expect sim. objects derived from BaseCPU can now be used with
TrafficGen without additional modifications.

Change-Id: Iee848b2ba0ac1851c487b1003da9bd96253d291a
Signed-off-by: Tiago Muck <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18416
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem: Minimize the use of MemObject.

MemObject doesn't provide anything beyond its base ClockedObject any
more, so this change removes it from most inheritance hierarchies.
Occasionally MemObject is replaced with SimObject when I was fairly
confident that the extra functionality of ClockedObject wasn't needed.

Change-Id: Ic014ab61e56402e62548e8c831eb16e26523fdce
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18289
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>

python: Don't assume SimObjects live in the global namespace

The importer in Python 3 doesn't like the way we import SimObjects
from the global namespace. Convert the existing SimObject declarations
to import from m5.objects. As a side-effect, this makes these files
consistent with configuration files.

Change-Id: I11153502b430822130722839e1fa767b82a027aa
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15981
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>

cpu: Stream/SubstreamID support in TrafficGen

This patch is adding support for generating memory requests which set
the StreamID/SubstreamID field, so that is possible to emulate devices
attached to an external IOMMU/SMMU with a Traffic generator.

Change-Id: Iea068de581ae7125a9d49314124a08c045c75b49
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/12188

cpu: Split the traffic generator into two classes

The traffic generator currently assumes that it is always driven from
a configuration file. Split it into a base class (BaseTrafficGen) that
handles basic packet generation and a derived class that implements
the config handling (TrafficGen).

Change-Id: I9407f04c40ad7e40a263c8d1ef29d37ff8e6f1b4
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/11515