arch-arm: Allow ArmPPI usage for PMU

Differently from ArmSPIs, ArmPPI interrupts need to be instantiated by
giving a ThreadContext pointer in the ArmPPIGen::get() method. Since the
PMU is registering the ThreadContext only at ISA startup time, ArmPPI
generation in deferred until the PMU has a non NULL pointer.

Change-Id: I17daa6f0e355363b8778d707b440cab9f75aaea2
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/16204
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arm: Get rid of some register type definitions.

These are IntReg, FloatReg, FloatRegBits, and MiscReg. These have been
supplanted by the global types RegVal and FloatRegVal.

Change-Id: Ief1cd85d0eff7156282ddb1ce168a2a5677f7435
Reviewed-on: https://gem5-review.googlesource.com/c/13625
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>

arch-arm: raise/clear IRQ when writing to PMOVSCLR/SET

Writing a 1 to the Overflow Flag Status register should trigger an
interrupt raise/clear depending on the register we are currently using
(PMOVSCLR for clearing and PMOVSSET for raising).

Change-Id: I2091456685a245712045cf7a4932ac36b7dded1d
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/12531
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arm: Use the interrupt adaptor in the PMU

Rewrite interrupt handling in the PMU model to use the new interrupt
adaptor.

Change-Id: I2cbb99580c46d3e21a1335b897843b7b6e41f10c
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/12400
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>

arch-arm: ArmPMU refactor

Change the definition of PMU events in order to integrate events not
cannot easily be represented by probe points. The software
increment event is now defined as a special type with its separate
implementation in pmu.cc and pmu.hh.

Change-Id: I43874b9641bf38c54f6ba2c26386542b6a73e282
Signed-off-by: Jose Marinho <jose.marinho@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5764
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-arm: Support PMU evens in the 0x4000-0x4040 range

ARMv8.1 added a second architected event range, 0x4000-0x4040. Events
in this range are discovered using the high word of PMCEID{0,1}_EL0

Change-Id: I4cd01264230e5da4c841268a7cf3e6bd307c7180
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/3960

misc: Remove redundant compiler-specific defines

This patch moves away from using M5_ATTR_OVERRIDE and the m5::hashmap
(and similar) abstractions, as these are no longer needed with gcc 4.7
and clang 3.1 as minimum compiler versions.

sim: Refactor the serialization base class

Objects that are can be serialized are supposed to inherit from the
Serializable class. This class is meant to provide a unified API for
such objects. However, so far it has mainly been used by SimObjects
due to some fundamental design limitations. This changeset redesigns
to the serialization interface to make it more generic and hide the
underlying checkpoint storage. Specifically:

* Add a set of APIs to serialize into a subsection of the current
object. Previously, objects that needed this functionality would
use ad-hoc solutions using nameOut() and section name
generation. In the new world, an object that implements the
interface has the methods serializeSection() and
unserializeSection() that serialize into a named /subsection/ of
the current object. Calling serialize() serializes an object into
the current section.

* Move the name() method from Serializable to SimObject as it is no
longer needed for serialization. The fully qualified section name
is generated by the main serialization code on the fly as objects
serialize sub-objects.

* Add a scoped ScopedCheckpointSection helper class. Some objects
need to serialize data structures, that are not deriving from
Serializable, into subsections. Previously, this was done using
nameOut() and manual section name generation. To simplify this,
this changeset introduces a ScopedCheckpointSection() helper
class. When this class is instantiated, it adds a new /subsection/
and subsequent serialization calls during the lifetime of this
helper class happen inside this section (or a subsection in case
of nested sections).

* The serialize() call is now const which prevents accidental state
manipulation during serialization. Objects that rely on modifying
state can use the serializeOld() call instead. The default
implementation simply calls serialize(). Note: The old-style calls
need to be explicitly called using the
serializeOld()/serializeSectionOld() style APIs. These are used by
default when serializing SimObjects.

* Both the input and output checkpoints now use their own named
types. This hides underlying checkpoint implementation from
objects that need checkpointing and makes it easier to change the
underlying checkpoint storage code.

arm: Add support for filtering in the PMU

This patch adds support for filtering events in the PMU. In order to
do so, it updates the ISADevice base class to forward an ISA pointer
to ISA devices. This enables such devices to access the MiscReg file
to determine the current execution level.

arm: Add a model of an ARM PMUv3

This class implements a subset of the ARM PMU v3 specification as
described in the ARMv8 reference manual. It supports most of the
features of the PMU, however the following features are known to be
missing:

* Event filtering (e.g., from different privilege levels).
* Access controls (the PMU currently ignores the execution level).
* The chain counter (event no. 0x1E) is unimplemented.

The PMU itself does not implement any events, it merely provides an
interface for the configuration scripts to hook up probes that drive
events. Configuration scripts should call addEventProbe() to configure
custom events or high-level methods to configure architected
events. The Python implementation of addEventProbe() automatically
delays event type registration until after instantiation.

In order to support CPU switching and some combined counters (e.g.,
memory references synthesized from loads and stores), the PMU allows
multiple probes per event type. When creating a system that switches
between CPU models that share the same PMU, PMU events for all of the
CPU models can be registered with the PMU.

Kudos to Matt Horsnell for the initial gem5 implementation of the PMU.