mem: Move ruby protocols into a directory called ruby_protocol.

Now that the gem5 protocols are split out, it would be nice to put them
in their own protocol directory. It's also confusing to have files
called *_protocol which are not in the protocol directory.

Change-Id: I7475ee111630050a2421816dfd290921baab9f71
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20230
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

ruby: Allow multiple outstanding DMA requests
DMA sequencers and protocols can currently only issue one DMA access at
a time. This patch implements the necessary functionality to support
multiple outstanding DMA requests in Ruby.

scons: Add missing override to appease clang

Make clang happy...again.

ruby: make DMASequencer inherit from RubyPort

This patch essentially rolls back 10518:30e3715c9405 to make RubyPort the
parent class of DMASequencer. It removes redundant code and restores some
features which were lost when directly inheriting from MemObject. For
example,
DMASequencer can now communicate to other devices using PIO, which is useful
for memmory-mapped communication between multiple DMADevices.

misc: Add explicit overrides and fix other clang >= 3.5 issues

This patch adds explicit overrides as this is now required when using
"-Wall" with clang >= 3.5, the latter now part of the most recent
XCode. The patch consequently removes "virtual" for those methods
where "override" is added. The latter should be enough of an
indication.

As part of this patch, a few minor issues that clang >= 3.5 complains
about are also resolved (unused methods and variables).

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.

ruby: rename System.{hh,cc} to RubySystem.{hh,cc}

The eventual aim of this change is to pass RubySystem pointers through to
objects generated from the SLICC protocol code.

Because some of these objects need to dereference their RubySystem pointers,
they need access to the System.hh header file.

In src/mem/ruby/SConscript, the MakeInclude function creates single-line header
files in the build directory that do nothing except include the corresponding
header file from the source tree.

However, SLICC also generates a list of header files from its symbol table, and
writes it to mem/protocol/Types.hh in the build directory. This code assumes
that the header file name is the same as the class name.

The end result of this is the many of the generated slicc files try to include
RubySystem.hh, when the file they really need is System.hh. The path of least
resistence is just to rename System.hh to RubySystem.hh.

ruby: replace Address by Addr
This patch eliminates the type Address defined by the ruby memory system.
This memory system would now use the type Addr that is in use by the
rest of the system.

ruby: replace global g_system_ptr with per-object pointers

This is another step in the process of removing global variables
from Ruby to enable multiple RubySystem instances in a single simulation.

With possibly multiple RubySystem objects, we can no longer use a global
variable to find "the" RubySystem object. Instead, each Ruby component
has to carry a pointer to the RubySystem object to which it belongs.

sim: Refactor and simplify the drain API

The drain() call currently passes around a DrainManager pointer, which
is now completely pointless since there is only ever one global
DrainManager in the system. It also contains vestiges from the time
when SimObjects had to keep track of their child objects that needed
draining.

This changeset moves all of the DrainState handling to the Drainable
base class and changes the drain() and drainResume() calls to reflect
this. Particularly, the drain() call has been updated to take no
parameters (the DrainManager argument isn't needed) and return a
DrainState instead of an unsigned integer (there is no point returning
anything other than 0 or 1 any more). Drainable objects should return
either DrainState::Draining (equivalent to returning 1 in the old
system) if they need more time to drain or DrainState::Drained
(equivalent to returning 0 in the old system) if they are already in a
consistent state. Returning DrainState::Running is considered an
error.

Drain done signalling is now done through the signalDrainDone() method
in the Drainable class instead of using the DrainManager directly. The
new call checks if the state of the object is DrainState::Draining
before notifying the drain manager. This means that it is safe to call
signalDrainDone() without first checking if the simulator has
requested draining. The intention here is to reduce the code needed to
implement draining in simple objects.

mem: Split port retry for all different packet classes

This patch fixes a long-standing isue with the port flow
control. Before this patch the retry mechanism was shared between all
different packet classes. As a result, a snoop response could get
stuck behind a request waiting for a retry, even if the send/recv
functions were split. This caused message-dependent deadlocks in
stress-test scenarios.

The patch splits the retry into one per packet (message) class. Thus,
sendTimingReq has a corresponding recvReqRetry, sendTimingResp has
recvRespRetry etc. Most of the changes to the code involve simply
clarifying what type of request a specific object was accepting.

The biggest change in functionality is in the cache downstream packet
queue, facing the memory. This queue was shared by requests and snoop
responses, and it is now split into two queues, each with their own
flow control, but the same physical MasterPort. These changes fixes
the previously seen deadlocks.

Ruby: Update backing store option to propagate through to all RubyPorts

Previously, the user would have to manually set access_backing_store=True
on all RubyPorts (Sequencers) in the config files.
Now, instead there is one global option that each RubyPort checks on
initialization.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>

ruby: single physical memory in fs mode
Both ruby and the system used to maintain memory copies. With the changes
carried for programmed io accesses, only one single memory is required for
fs simulations. This patch sets the copy of memory that used to reside
with the system to null, so that no space is allocated, but address checks
can still be carried out. All the memory accesses now source and sink values
to the memory maintained by ruby.

ruby: dma sequencer: remove RubyPort as parent class
As of now DMASequencer inherits from the RubyPort class. But the code in
RubyPort class is heavily tailored for the CPU Sequencer. There are parts of
the code that are not required at all for the DMA sequencer. Moreover, the
next patch uses the dma sequencer for carrying out memory accesses for all the
io devices. Hence, it is better to have a leaner dma sequencer.

mem: Use shared_ptr for Ruby Message classes

This patch transitions the Ruby Message and its derived classes from
the ad-hoc RefCountingPtr to the c++11 shared_ptr. There are no
changes in behaviour, and the code modifications are mainly replacing
"new" with "make_shared".

The cloning of derived messages is slightly changed as they previously
relied on overriding the base-class through covariant return types.

scons: Fix warnings issued by clang 3.2svn (XCode 4.6)

This patch fixes the warnings that clang3.2svn emit due to the "-Wall"
flag. There is one case of an uninitialised value in the ARM neon ISA
description, and then a whole range of unused private fields that are
pruned.

Ruby: Use uint8_t instead of uint8 everywhere

Ruby: remove config information from ruby.stats
This patch removes printConfig() functions from all structures in Ruby.
Most of the information is already part of config.ini, and where ever it
is not, it would become in due course.

ruby: tag and data cache access support

Updates to Ruby to support statistics counting of cache accesses. This feature
serves multiple purposes beyond simple stats collection. It provides the
foundation for ruby to model the cache tag and data arrays as physical
resources, as well as provide the necessary input data for McPAT power
modeling.

Ruby: Resurrect Cache Warmup Capability
This patch resurrects ruby's cache warmup capability. It essentially
makes use of all the infrastructure that was added to the controllers,
memories and the cache recorder.

Ruby: Process packet instead of RubyRequest in Sequencer
This patch changes the implementation of Ruby's recvTiming() function so
that it pushes a packet in to the Sequencer instead of a RubyRequest. This
requires changes in the Sequencer's makeRequest() and issueRequest()
functions, as they also need to operate on a Packet instead of RubyRequest.

ruby: style pass

ruby: Fix copyrights on files
Mostly files missed during import or screwed up during import

ruby: Removed static members in RubyPort including hitcallback
Removed static members in RubyPort and removed the ruby request unique id.

ruby: Convert most Ruby objects to M5 SimObjects.
The necessary companion conversion of Ruby objects generated by SLICC
are converted to M5 SimObjects in the following patch, so this patch
alone does not compile.
Conversion of Garnet network models is also handled in a separate
patch; that code is temporarily disabled from compiling to allow
testing of interim code.

[mq]: first_patch

ruby: fixed dma sequencer bug

The DMASequencer was still using a parameter from the old RubyConfig,
causing an offset error when the requested data wasn't block aligned.
This changeset also includes a fix to MI_example for a similar bug.

ruby: Import the latest ruby changes from gems.
This was done with an automated process, so there could be things that were
done in this tree in the past that didn't make it. One known regression
is that atomic memory operations do not seem to work properly anymore.