mem: Put gem5 protocols in their own directory.

This reduces clutter in the src/mem directory, and makes it clear that
those protocols are for the classic gem5 memory system, not ruby, TLM,
etc.

Change-Id: I6cf6b21134d82f4f01991e4fe92dbea8c7e82081
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20231
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>

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>

mem-ruby: fix build with PROTOCOL=MOESI_hammer

Was failing with:

Error: Unrecognized variable: l1i_victim_addr

since: I2c43f22aba5af3a57e54b1c435e5d3fbba86d1d5

Change-Id: I7df666acb724ee541804dd7557753a9ba4005516
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20261
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Reviewed-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: Use check_on_cache_probe on MI

This change uses check_on_cache_probe statement to check if the cacheline
subject to eviction is locked in MI.

Change-Id: I276822e987e52f7682ff30f55880f295b6af023d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19888
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Use check_on_cache_probe on MOESI hammer

This change uses check_on_cache_probe statement to check if the cacheline
subject to eviction is locked in MOESI hammer.

Change-Id: I2c43f22aba5af3a57e54b1c435e5d3fbba86d1d5
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19891
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Use check_on_cache_probe on MOESI CMP

This change uses check_on_cache_probe statement to check if the cacheline
subject to eviction is locked in MOESI CMP.

Change-Id: I3a8879e10ebd94ef68194836475e656761fed62c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19908
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Use check_on_cache_probe on MOESI

This change uses check_on_cache_probe statement to check if the cacheline
subject to eviction is locked in MOESI.

Change-Id: Ie650ccdc15bb41b4088e534975b662408aaccf24
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19890
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Use check_on_cache_probe to protect locked lines from eviction

This change uses check_on_cache_probe statement to check if the cacheline
subject to eviction is locked in MESI Three Level.

Change-Id: Ib0de54aa067c7603db1f7321cc4825b123b641ac
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19868
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: Use check_on_cache_probe to protect locked lines from eviction

This change uses check_on_cache_probe statement to check if the cacheline
subject to eviction is locked in MESI Two Level. Other protocols should
be updated accordingly.

Signed-off-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>
Change-Id: Idcdbc8ee528eb5e4e2f8d56a268a3a92eadd95b1
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/16809
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: Bloom filters - Remove in/decrement

Increment and decrement were functions created to supply the
different naming convention used by the counting bloom filter.
They were removed, and the set and unset functions were used
in their place instead, as in the other filters.

Change-Id: I45732bdfa3083add0a975f374a0f3560003e9d09
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18729
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>

mem-ruby: MOESI_CMP_dir cleanup

Removed unused states and actions

Change-Id: I3dc684c78d4b92d219e71522ddb706a13f9874d1
Signed-off-by: Tiago Muck <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18415
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: John Alsop <johnathan.alsop@amd.com>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Cache latencies for MOESI_CMP_dir

Modified both L1 and L2 controllers to take into account the cache
latency parameters. Default values in the configuration script updated
as well.

Change-Id: I72bb8dd29ee0b02da06e1addf13b266fe4d1e979
Signed-off-by: Tiago Muck <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18414
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Unique ranks for MOESI_CMP_dir in ports

Setting different values for the rank parameter for all inputs ports.
If left unset, it defaults to 0. This may cause issues since the rank is
used as an index in the controller's list of stalled buffers.

Change-Id: Ie8ff660b7450df959292311040aebf802657efcf
Signed-off-by: Tiago Muck <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18411
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Change MOESI_CMP_Dir L2 addressing

L1 controller selects the L2 to message based on the assigned address
ranges instead of explicitly interleaving bits in the L1 controller. This
simplifies the L1 controller implementation a bit and allows for more
flexibility when changing the address->controller mapping.

Change-Id: Ie67999bb977566939432a5045f65dbd2da81816a
Signed-off-by: Tiago Muck <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18410
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Fix MOESI_CMP_dir debug msg

Change-Id: I3fd32bd2e81dbf9a8ea49a43727564b8a9d64767
Signed-off-by: Tiago Muck <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18409
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Prevent response stalls on MOESI_CMP_directory

When a message triggers a transition that has actions which allocate
TBEs, the generated code automatically includes a check for the TBETable
size before executing any action. If the table is full, the transition
returns TransitionResult_ResourceStall and no more messages from the
buffer are handled (until the next cycle).

This behavior may lead to deadlocks in the MOESI_CMP_directory protocol
since events triggered by the response queue may allocate TBEs (e.g.
L2 replacements triggered by the response queue). If the table is full,
the queue is stalled preventing other responses from freeing TBEs.

This patch fixes this by handling WRITEBACK_DIRTY_DATA/CLEAN_DATA messages
as requests and WB_ACK/WB_NACK as responses. All controllers are changed
to work with the new types. With this fix, responses are always
handled first in all controllers, and no response triggers TBE
allocations.

Change-Id: I377c0ec4f06d528e9f0541daf3dcc621184f2524
Signed-off-by: Tiago Muck <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18408
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: John Alsop <johnathan.alsop@amd.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Fix MOESI_CMP_directory blocked line handling

Using recycle in the L2 controllers to put messages back into the buffer
may lead to starvation when there are many L1 requests for the same line.
This can easily trigger the deadlock detection mechanism in configurations
with many cores (16+). Replacing recycle by stall_and_wait for L1
requests avoids this issue. wakeUpBuffers calls were added to all
transitions from transient to stable states.

Change-Id: I28b8aeacc48919ccf38e69653cd9205a4153514b
Signed-off-by: Tiago Muck <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17568
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: Fixing MESI Three Level

Adding back some changes done in patch 676ae57827.
Transient state IS_I, STALE_DATA, Data_Stale event are necessary.

Issue: (cacheline A, initial state for P0 and P1 is I)
| P0 | P1 |
|GETX (A)| |
| |GETS (A)|
|Inv_All | |
P1 never sends the ACK - deadlock
It should ACK, later upon data use it as stale data, and got to I.

Solution:
P1(A):
GETS: I->IS
Inv_All: IS->IS_I, Send ACK
Data: IS_I->I, STALE_DATA to L0

Signed-off-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>
Change-Id: I1e7b2c05439d08579c68d8eb444e0f332e75e07f
Reviewed-on: https://gem5-review.googlesource.com/c/15715
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Fix missing TBE allocation and deallocation

The TBE allocation and deallcation are currently missing during
the directory state transition from I to M in protocol MI_example.

Change-Id: If7569c02faf56ea84c34ee1345f1a33d318cdfff
Signed-off-by: Zicong Wang <wangzicong@nudt.edu.cn>
Reviewed-on: https://gem5-review.googlesource.com/c/15535
Reviewed-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Fix MOESI_CMP_directory in ports order

To avoid deadlocks ruby objects typically prioritize the handling of
responses to all other events. The order in which in_port statements
are written determine the order in which they are handled. This patch
fixes the order of in_order statements for the L2 cache in the
MOESI_CMP_directory.

Change-Id: I62248b0480a88ac2cd945425155f0961a1cf6cb1
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/13595
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

ruby,gpu-compute: bugfix for GPU_VIPER* protocols

12db50c895 changed how directory mapping works, but it seems to have
broken the VIPER variants of the GPU protocols. The fix involves
declaring the function in the related '.sm' files.

Change-Id: I116980d42a4aa648369058b529c9f8d9693eb894
Reviewed-on: https://gem5-review.googlesource.com/8521
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>

ruby: bugfix for MESI_Three_Level protocol

Since a3177645, the MESI_Three_Level protocol does not build. This
changeset addresses the problem by adding the L0Cache machine type
to the static machine type declaration in Ruby's export file.

Change-Id: I6327547fcb34595619caeb73932c0032f5f65c9f
Reviewed-on: https://gem5-review.googlesource.com/8383
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: fix more style issues in AMD licenses

Change-Id: I6585c5664d966989991f61303548aed634cf298a
Reviewed-on: https://gem5-review.googlesource.com/9841
Reviewed-by: Michael LeBeane <Michael.Lebeane@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>

configs, mem-ruby: fix issues with style in AMD license

fixes line length and white space issues.

Change-Id: Ia04a91ec68cae2bcdabeb93bb1a0f74e8e5486c3
Reviewed-on: https://gem5-review.googlesource.com/9801
Reviewed-by: Bradford Beckmann <brad.beckmann@amd.com>
Maintainer: Bradford Beckmann <brad.beckmann@amd.com>

mem-ruby: Fix RubyPrefetcher support in MESI_Two_Level

Only a small quantity of prefetches were issued, as the positive
feedback mechanism was not implemented. This commit adds a new
action po_observeHit, which notifies the RubyPrefetcher of
successful prefetches and resets the prefetch flag.

When a cache line was replaced by a prefetch, the wrong queue could
be stalled. This commit adds a new event PF_L1_Replacement, which
stalls the correct queue.

The behavior when receiving a prefetch or instruction fetch while
in PF_IS_I (prefetch caused GETs, but got invalidated before the
response was received) was undefined. This was changed to drop the
prefetch request or change the state to non-prefetch, respectively.
This behavior is analogous to IS_I (non-prefetch caused GETs, but
got invalidated before the response was received) and the data case,
respectively.

In my local branch a major (20+%) performance increase can be
observed in SPEC2006 gobmk and leslie3d when enabling the
prefetcher. Some other benchmarks like bwaves, GemsFDTD, sphinx and
wrf show smaller (~10%) performance increases. Unfortunately, the
performance in most other SPEC benchmarks is still poor, most likely
as the prefetcher does not detect strides fast/often enough. In
order to push the change timely (most benchmarks have runtimes in
the order of days on my machine even with the smallest parameters)
after checkout, I have only run gobmk with the base repository
+ this commit. The results match those of my local branch.

Change-Id: I9903a2fcd02060ea5e619b409f31f7d6fac47ae8
Reviewed-on: https://gem5-review.googlesource.com/8801
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Swapnil Haria <swapnilster@gmail.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Fix wakeup timeouts for the MOESI_CMP_token protocol

This changeset fixes a bug that was affecting the MOESI_CMP_token
protocol where setting the next timeout required an absolute tick in
the future.

Change-Id: Ibfdb59354e13c7e552cb3389e71bda010f333249
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7163
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Remove function that maps responses to a DMA engine

The function map_Address_to_DMA was used to route responses to the
first (and assumed to be the only) DMA engine in the system. This
function is now unused as protocols handle responses and route them to
the right DMA engine.

Change-Id: I2fba913cf2f12321d1a1e38e7ee85bdf26b8a47a
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7162
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Add support for multiple DMA engines in MESI_Two_Level

Previously the MESI_Two_Level protocol supported systems with a single
DMA engine and responses from the directory to DMA requests were
routed back to the only DMA engine. This changeset adds support for
multiple DMA engines in the system by routing the response to the DMA
engine that originally sent the request.

Change-Id: I10ceda682ea29746636862ec8ef2a9c4220ca045
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7161
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

scons: Move Transform and termcap functionality into their own files.

Change-Id: Ica08e93f3873a7eafd02fe7d44c3bdbf0ce7f6b7
Reviewed-on: https://gem5-review.googlesource.com/5565
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

ruby: Add support for address ranges in the directory

Previously the directory covered a flat address range that always
started from address 0. This change adds a vector of address ranges
with interleaving and hashing that each directory keeps track of and
the necessary flexibility to support systems with non continuous
memory ranges.

Change-Id: I6ea1c629bdf4c5137b7d9c89dbaf6c826adfd977
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2903
Reviewed-by: Bradford Beckmann <brad.beckmann@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

ruby: Fix MOESI_CMP_directory for new DMA status changes.

Multiple outstanding DMA requests introduced new DMA states that didn't
be considered into slicc code. This patch implements the missed DMA state
changes on MOESI_CMP_directory protocol.

Change-Id: I700d441d76556b7e77e0d507904af6ec6ba59cc2
Signed-off-by: Michael LeBeane <michael.lebeane@amd.com>
Reviewed-on: https://gem5-review.googlesource.com/2380
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Michael LeBeane <Michael.Lebeane@amd.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

ruby: init MessageSizeType of SequencerMsg to Request_Control

SequencerMsg is autogenerated by slicc scripts and the MessageSizeType is
initialized to the max enume value by default. The DMASequencer pushes this
message to the mandatory queue and since the MessageSizeType is unitialized,
string_to_MessageSizeType() function used by traces to print the message fails
with a panic. This patch avoids this problem by initializing MessageSizeType
of SequencerMsg to Request_Control.

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.

ruby: rename ALPHA_Network_test protocol to Garnet_standalone.
Over the past 6 years, we realized that the protocol is essentially used
to run the garnet network in a standalone manner, and feed standard synthetic
traffic patterns through it.

ruby: Rename pkt to m_pkt so it may be accessed via SLICC

Allow usage of packet class in ruby for convenience purposes. This may be
used to access members of the packet/request class (e.g., via helper
functions) and/or push protocol specific information to the packets
SenderState without needing to modify SLICC types and protocols in multiple
locations.

ruby: removed Write_Only AccessPermission

gpu-compute: AMD's baseline GPU model

mem: write combining for ruby protocols

This patch adds support for write-combining in ruby.

* * *
mem: support for gpu-style RMWs in ruby

This patch adds support for GPU-style read-modify-write (RMW) operations in
ruby. Such atomic operations are traditionally executed at the memory controller
(instead of through an L1 cache using cache-line locking).

Currently, this patch works by propogating operation functors through the memory
system.

mem: misc flags for AMD gpu model

This patch add support to mark memory requests/packets with attributes defined
in HSA, such as memory order and scope.

ruby: slicc: have a static MachineType

This patch is imported from reviewboard patch 2551 by Nilay.
This patch moves from a dynamically defined MachineType to a statically
defined one. The need for this patch was felt since a dynamically defined
type prevents us from having types for which no machine definition may
exist.

The following changes have been made:
i. each machine definition now uses a type from the MachineType enumeration
instead of any random identifier. This required changing the grammar and the
*.sm files.
ii. MachineType enumeration defined statically in RubySlicc_Exports.sm.
* * *
normal protocol fixes for nilay's parser machine type fix

ruby: slicc: remove support for single machine, multiple types

This patch is imported from reviewboard patch 2550 by Nilay.
It was possible to specify multiple machine types with a single state machine.
This seems unnecessary and is being removed.

slicc: fixes for the Address to Addr changeset (11025)

misc changes now that Address has become Addr including int to address util
function

ruby: add BoolVec

The BoolVec typedef and insertion operator overload function simplify usage of
vectors of type bool

ruby: bloom filters: refactor code

ruby: print addresses in hex
Changeset 4872dbdea907 replaced Address by Addr, but did not make changes to
print statements. So the addresses which were being printed in hex earlier
along with their line address, were now being printed in decimals. This patch
adds a function printAddress(Addr) that can be used to print the address in hex
along with the lines address. This function has been put to use in some of the
places. At other places, change has been made to print just the address in
hex.

ruby: Add missing block deallocations in MOESI_hammer

Some blocks in MOESI hammer were not getting deallocated when they were set to
an idle state (e.g. by invalidate or other_getx/s messages). While
functionally correct, this caused some bad effects on performance, such as
blocks in I in the L1s getting sent to the L2 upon eviction, in turn evicting
valid blocks. Also, if a valid block was in LRU, that block could be evicted
rather than a block in I. This patch adds in the missing deallocations.

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

ruby: message buffer, timer table: significant changes

This patch changes MessageBuffer and TimerTable, two structures used for
buffering messages by components in ruby. These structures would no longer
maintain pointers to clock objects. Functions in these structures have been
changed to take as input current time in Tick. Similarly, these structures
will not operate on Cycle valued latencies for different operations. The
corresponding functions would need to be provided with these latencies by
components invoking the relevant functions. These latencies should also be
in Ticks.

I felt the need for these changes while trying to speed up ruby. The ultimate
aim is to eliminate Consumer class and replace it with an EventManager object in
the MessageBuffer and TimerTable classes. This object would be used for
scheduling events. The event itself would contain information on the object and
function to be invoked.

In hindsight, it seems I should have done this while I was moving away from use
of a single global clock in the memory system. That change led to introduction
of clock objects that replaced the global clock object. It never crossed my
mind that having clock object pointers is not a good design. And now I really
don't like the fact that we have separate consumer, receiver and sender
pointers in message buffers.

slicc: export uint64_t instead of uint64

ruby: call setMRU from L1 controllers, not from sequencer
Currently the sequencer calls the function setMRU that updates the replacement
policy structures with the first level caches. While functionally this is
correct, the problem is that this requires calling findTagInSet() which is an
expensive function. This patch removes the calls to setMRU from the sequencer.
All controllers should now update the replacement policy on their own.

The set and the way index for a given cache entry can be found within the
AbstractCacheEntry structure. Use these indicies to update the replacement
policy structures.

ruby: declare all protocol message buffers as parameters

MessageBuffer is a SimObject now. There were protocols that still declared
some of the message buffers are variables of the controller, but not as input
parameters. Special handling was required for these variables in the SLICC
compiler. This patch changes this. Now all message buffers are declared as
input parameters.

ruby: reverts to changeset: bf82f1f7b040

ruby: add accessor functions to SLICC def of MachineID

ruby: call setMRU from L1 controllers, not from sequencer
Currently the sequencer calls the function setMRU that updates the replacement
policy structures with the first level caches. While functionally this is
correct, the problem is that this requires calling findTagInSet() which is an
expensive function. This patch removes the calls to setMRU from the sequencer.
All controllers should now update the replacement policy on their own.

The set and the way index for a given cache entry can be found within the
AbstractCacheEntry structure. Use these indicies to update the replacement
policy structures.

ruby: drop the [] notation for lookup function.

This is in preparation for adding a second arugment to the lookup
function for the CacheMemory class. The change to *.sm files was made using
the following sed command:

sed -i 's/\[\([0-9A-Za-z._()]*\)\]/.lookup(\1)/' src/mem/protocol/*.sm

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: rename variables Addr to addr

Avoid clash between type Addr and variable name Addr.

ruby: Protocol changes for SimObject MessageBuffers

ruby: Expose MessageBuffers as SimObjects

Expose MessageBuffers from SLICC controllers as SimObjects that can be
manipulated in Python. This patch has numerous benefits:
1) First and foremost, it exposes MessageBuffers as SimObjects that can be
manipulated in Python code. This allows parameters to be set and checked in
Python code to avoid obfuscating parameters within protocol files. Further, now
as SimObjects, MessageBuffer parameters are printed to config output files as a
way to track parameters across simulations (e.g. buffer sizes)

2) Cleans up special-case code for responseFromMemory buffers, and aligns their
instantiation and use with mandatoryQueue buffers. These two special buffers
are the only MessageBuffers that are exposed to components outside of SLICC
controllers, and they're both slave ends of these buffers. They should be
exposed outside of SLICC in the same way, and this patch does it.

3) Distinguishes buffer-specific parameters from buffer-to-network parameters.
Specifically, buffer size, randomization, ordering, recycle latency, and ports
are all specific to a MessageBuffer, while the virtual network ID and type are
intrinsics of how the buffer is connected to network ports. The former are
specified in the Python object, while the latter are specified in the
controller *.sm files. Unlike buffer-specific parameters, which may need to
change depending on the simulated system structure, buffer-to-network
parameters can be specified statically for most or all different simulated
systems.

ruby: Change PerfectCacheMemory::lookup to return pointer

CacheMemory and DirectoryMemory lookup functions return pointers to entries
stored in the memory. Bring PerfectCacheMemory in line with this convention,
and clean up SLICC code generation that was in place solely to handle
references like that which was returned by PerfectCacheMemory::lookup.

ruby: mesi three level: multiple corrections to the protocol

1. Eliminate state NP in L0 and L1 Caches: The two states 'NP' and 'I' both
mean that the cache block is not present in the cache. 'I' also means that the
cache entry has been allocated. This causes problems when we do not correctly
initialize the cache entry when it is re-used. Hence, this patch eliminates
the state NP altogether. Everytime a new block comes into the cache, a cache
entry is allocated. Everytime a block leaves, the corresponding entry is
deallocated.

2. Separate transient state for instruction fetches: purely for accouting
purposes.

3. Drop state IS_I in L1 Cache and the message type STALE_DATA: when
invalidation is received for a block in IS, the block used to be moved to IS_I.
This meant that the data that would arrive in future would be used but not
stored since the controller lost the permissions after gaining them. This
state is being dropped and now invalidation messages would not processed till
the data has arrived. This also means that STALE_DATA type is not longer
required.

ruby: mesi two,three level: copy data only when dirty

The level 2 controller has a bug. In one particular action, the data block was
copied from a message irrespective whether the block is dirty or not. In cases
when L1 sends no data, the data value copied was incorrect.

slicc: enable overloading in functions not in classes

For many years the slicc symbol table has supported overloaded functions in
external classes. This patch extends that support to functions that are not
part of classes (a.k.a. no parent). For example, this support allows slicc
to understand that mapAddressToRange is overloaded and the NodeID is an
optional parameter.

ruby: adds size and empty apis to the msg buffer stallmap

ruby: fix deadlock bug in banked array resource checks

The Ruby banked array resource checks (initiated from SLICC) did a check and
allocate at the same time. If a transition needs more than one resource, then
it might check/allocate resource #1, then fail to get resource #2. Another
transition might then try to get the same resources, but in reverse order.
Deadlock.

This patch separates resource checking and resource reservation into two
steps to avoid deadlock.

mem: add request types for acquire and release

Add support for acquire and release requests. These synchronization operations
are commonly supported by several modern instruction sets.

ruby: allocate a block in CacheMemory without updating LRU state

ruby: speed up function used for cache walks

This patch adds a few helpful functions that allow .sm files to directly
invalidate all cache blocks using a trigger queue rather than rely on each
individual cache block to be invalidated via requests from the mandatory
queue.

ruby: give access to cache tag/data latencies from SLICC

This patch exposes the tag and data array latencies to the SLICC state machines
so that it can be used to determine the correct enqueue latency for response
messages.

slicc: support for multiple message types on the same buffer

This patch allows SLICC protocols to use more than one message type with a
message buffer. For example, you can declare two in ports as such:

in_port(ResponseQueue_in, ResponseMsg, responseFromDir, rank=3) { ... }
in_port(tgtResponseQueue_in, TgtResponseMsg, responseFromDir, rank=2) { ... }

ruby: re-added the addressToInt slicc interface function

This helper function is very useful converting address offsets to integers
that can be used for protocol specific destination mapping.

ruby: drop NetworkMessage class

This patch drops the NetworkMessage class. The relevant data members and functions
have been moved to the Message class, which was the parent of NetworkMessage.

ruby: mesi three level: name change to avoid clash
The accessor function getDestination() for Destination variable in the
coherence message clashes with the getDestination() that is part of the Message
class. Hence the name change.

ruby: Fix MESI consistency bug

Fixes missed forward eviction to CPU. With the O3CPU this can lead to load-load
reordering, as the LQ is never notified of the invalidate.

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

ruby: interface with classic memory controller
This patch is the final in the series. The whole series and this patch in
particular were written with the aim of interfacing ruby's directory controller
with the memory controller in the classic memory system. This is being done
since ruby's memory controller has not being kept up to date with the changes
going on in DRAMs. Classic's memory controller is more up to date and
supports multiple different types of DRAM. This also brings classic and
ruby ever more close. The patch also changes ruby's memory controller to
expose the same interface.

ruby: coherence protocols: remove data block from dirctory entry
This patch removes the data block present in the directory entry structure
of each protocol in gem5's mainline. Firstly, this is required for moving
towards common set of memory controllers for classic and ruby memory systems.
Secondly, the data block was being misused in several places. It was being
used for having free access to the physical memory instead of calling on the
memory controller.

From now on, the directory controller will not have a direct visibility into
the physical memory. The Memory Vector object now resides in the
Memory Controller class. This also means that some significant changes are
being made to the functional accesses in ruby.

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: mesi: slight renaming

ruby: message buffers: significant changes

This patch is the final patch in a series of patches. The aim of the series
is to make ruby more configurable than it was. More specifically, the
connections between controllers are not at all possible (unless one is ready
to make significant changes to the coherence protocol). Moreover the buffers
themselves are magically connected to the network inside the slicc code.
These connections are not part of the configuration file.

This patch makes changes so that these connections will now be made in the
python configuration files associated with the protocols. This requires
each state machine to expose the message buffers it uses for input and output.
So, the patch makes these buffers configurable members of the machines.

The patch drops the slicc code that usd to connect these buffers to the
network. Now these buffers are exposed to the python configuration system
as Master and Slave ports. In the configuration files, any master port
can be connected any slave port. The file pyobject.cc has been modified to
take care of allocating the actual message buffer. This is inline with how
other port connections work.

ruby: slicc: change the way configurable members are specified
There are two changes this patch makes to the way configurable members of a
state machine are specified in SLICC. The first change is that the data
member declarations will need to be separated by a semi-colon instead of a
comma. Secondly, the default value to be assigned would now use SLICC's
assignment operator i.e. ':='.

ruby: mesi three level: slight naming changes.

ruby: slicc: donot prefix machine name to variables
This changeset does away with prefixing of member variables of state machines
with the identity of the machine itself.

style: eliminate equality tests with true and false

Using '== true' in a boolean expression is totally redundant,
and using '== false' is pretty verbose (and arguably less
readable in most cases) compared to '!'.

It's somewhat of a pet peeve, perhaps, but I had some time
waiting for some tests to run and decided to clean these up.

Unfortunately, SLICC appears not to have the '!' operator,
so I had to leave the '== false' tests in the SLICC code.

ruby: remove old protocol documentation

ruby: message buffer: drop dequeue_getDelayCycles()
The functionality of updating and returning the delay cycles would now be
performed by the dequeue() function itself.

ruby: slicc: change enqueue statement
As of now, the enqueue statement can take in any number of 'pairs' as
argument. But we only use the pair in which latency is the key. This
latency is allowed to be either a fixed integer or a member variable of
controller in which the expression appears. This patch drops the use of pairs
in an enqueue statement. Instead, an expression is allowed which will be
interpreted to be the latency of the enqueue. This expression can anything
allowed by slicc including a constant integer or a member variable.

ruby: coherence protocols: drop the phrase IntraChip
The phrase is no longer valid since we do not distinguish between
inter and intra chip communication.

ruby: protocols: remove unused action z_stall

ruby: mesi three level: rename incorrectly named files
Two files had been incorrectly named with a .cache suffix.

ruby: remove unused label no_vector

ruby: add a three level MESI protocol.

The first two levels (L0, L1) are private to the core, the third level (L2)is
possibly shared. The protocol supports clustered designs. For example, one
can have two sets of two cores. Each core has an L0 and L1 cache. There are
two L2 controllers where each set accesses only one of the L2 controllers.

ruby: rename MESI_CMP_directory to MESI_Two_Level

This is because the next patch introduces a three level hierarchy.

ruby: add support for clusters

A cluster over here means a set of controllers that can be accessed only by a
certain set of cores. For example, consider a two level hierarchy. Assume
there are 4 L1 controllers (private) and 2 L2 controllers. We can have two
different hierarchies here:

a. the address space is partitioned between the two L2 controllers. Each L1
controller accesses both the L2 controllers. In this case, each L1 controller
is a cluster initself.

b. both the L2 controllers can cache any address. An L1 controller has access
to only one of the L2 controllers. In this case, each L2 controller
along with the L1 controllers that access it, form a cluster.

This patch allows for each controller to have a cluster ID, which is 0 by
default. By setting the cluster ID properly, one can instantiate hierarchies
with clusters. Note that the coherence protocol might have to be changed as
well.

ruby: fix bugs in mesi cmp directory protocol
This patch fixes couple of bugs in the L2 controller of the mesi cmp
directory protocol.

1. The state MT_I was transitioning to NP on receiving a clean writeback
from the L1 controller. This patch makes it inform the directory controller
about the writeback.

2. The L2 controller was sending the dirty bit to the L1 controller and the
L2 controller used writeback from the L1 controller to update the dirty bit
unconditionally. Now, the L1 controller always assumes that the incoming
data is clean. The L2 controller updates the dirty bit only when the L1
controller writes to the block.

3. Certain unused functions and events are being removed.

ruby: mesi: remove owner and sharer fields from directory tags

The directory controller should not have the sharer field since there is
only one level 2 cache. Anyway the field was not in use. The owner field
was being used to track the l2 cache version (in case of distributed l2) that
has the cache block under consideration. The information is not required
since the version of the level 2 cache can be obtained from a subset of the
address bits.

ruby: set SenderMachine in messages of MOESI_CMP_directory
This patch adds missing initializations of the SenderMachine field of
out_msg's when thery are created in the L2 cache controller of the
MOESI_CMP_directory coherence protocol. When an out_msg is created and this
field is left uninitialized, it is set to the default value MachineType_NUM.
This causes a panic in the MachineType_to_string function when gem5 is
executed with the Ruby debug flag on and it tries to print the message.

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

ruby: remove undefined message size type
This message size type does not work well with one of the statistical
variables. It also seems unnecessary.

ruby: moesi cmp directory: separate actions for external hits
This patch adds separate actions for requests that missed in the local cache
and messages were sent out to get the requested line. These separate actions
are required for differentiating between the hit and miss latencies in the
statistics collected.

ruby: mesi cmp directory: separate actions for external hits
This patch adds separate actions for requests that missed in the local cache
and messages were sent out to get the requested line. These separate actions
are required for differentiating between the hit and miss latencies in the
statistics collected.

ruby: profiler: lots of inter-related changes
The patch started of with removing the global variables from the profiler for
profiling the miss latency of requests made to the cache. The corrresponding
histograms have been moved to the Sequencer. These are combined together when
the histograms are printed. Separate histograms are now maintained for
tracking latency of all requests together, of hits only and of misses only.

A particular set of histograms used to use the type GenericMachineType defined
in one of the protocol files. This patch removes this type. Now, everything
that relied on this type would use MachineType instead. To do this, SLICC has
been changed so that multiple machine types can be declared by a controller
in its preamble.

ruby: remove the three files related to profiling
This patch removes the following three files: RubySlicc_Profiler.sm,
RubySlicc_Profiler_interface.cc and RubySlicc_Profiler_interface.hh.
Only one function prototyped in the file RubySlicc_Profiler.sm. Rest of the
code appearing in any of these files is not in use. Therefore, these files
are being removed.

That one single function, profileMsgDelay(), is being moved to the protocol
files where it is in use. If we need any of these deleted functions, I think
the right way to make them visible is to have the AbstractController class in
a .sm and let the controller state machine inherit from this class. The
AbstractController class can then have the prototypes of these profiling
functions in its definition.

ruby: fix typo in MOESI_CMP_token protocol

ruby: Fix prefetching for MESI_CMP_Directory

Transitions from present on PF_Ifetch were missing, causing a crash when
prefetching is enabled.

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

ruby: restrict Address to being a type and not a variable name
Change all occurrances of Address as a variable name to instead use Addr.
Address is an allowed name in slicc even when Address is also being used as a
type, leading to declarations of "Address Address". While this works, it
prevents adding another field of type Address because the compiler then thinks
Address is a variable name, not type.

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

ruby: moesi hammer: cosmetic changes
Updates copyright years, removes space at the end of lines, shortens
variable names.

ruby: mesi cmp directory: cosmetic changes
Updates copyright years, removes space at the end of lines, shortens
variable names.

ruby: moesi cmp token: cosmetic changes
Updates copyright years, removes space at the end of lines, shortens
variable names.

ruby: moesi cmp directory: cosmetic changes
Updates copyright years, removes space at the end of lines, shortens
variable names.

ruby: add stats to .sm files, remove cache profiler
This patch changes the way cache statistics are collected in ruby.

As of now, there is separate entity called CacheProfiler which holds
statistical variables for caches. The CacheMemory class defines different
functions for accessing the CacheProfiler. These functions are then invoked
in the .sm files. I find this approach opaque and prone to error. Secondly,
we probably should not be paying the cost of a function call for recording
statistics.

Instead, this patch allows for accessing statistical variables in the
.sm files. The collection would become transparent. Secondly, it would happen
in place, so no function calls. The patch also removes the CacheProfiler class.

ruby: mesi coherence protocol: remove unused state M_MB

ruby: moesi cmp directory: add copyright notice

ruby: remove unsued profile functions

ruby: mesi coherence protocol: invalidate lock
The MESI CMP directory coherence protocol, while transitioning from SM to IM,
did not invalidate the lock that it might have taken on a cache line. This
patch adds an action for doing so.

The problem was found by Dibakar, but I was not happy with his proposed
solution. So I implemented a different solution.

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

ruby: MI protocol: add a missing transition
The transition for state MII and event Store was found missing during testing.
The transition is being added. The controller will not stall the Store request
in state MII

ruby: replace Time with Cycles (final patch in the series)
This patch is as of now the final patch in the series of patches that replace
Time with Cycles.This patch further replaces Time with Cycles in Sequencer,
Profiler, different protocols and related entities.

Though Time has not been completely removed, the places where it is in use
seem benign as of now.

ruby: replaces Time with Cycles in many places
The patch started of with replacing Time with Cycles in the Consumer class.
But to get ruby to compile, the rest of the changes had to be carried out.
Subsequent patches will further this process, till we completely replace
Time with Cycles.

ruby: record fully busy cycle with in the controller
This patch does several things. First, the counter for fully busy cycles for a
controller is now kept with in the controller, instead of being part of the profiler.
Second, the topology class no longer keeps an array of controllers which was only
used for printing stats. Instead, ruby system will now ask each controller to print
the stats. Thirdly, the statistical variable for recording how many different types
were created is being moved in to the controller from the profiler. Note that for
printing, the profiler will collate results from different controllers.

ruby: remove get_time()
This patch replaces get_time() in *.sm files with curCycle() which
is now possible since controllers are clocked objects.

Ruby: use ClockedObject in Consumer class
Many Ruby structures inherit from the Consumer, which is used for scheduling
events. The Consumer used to relay on an Event Manager for scheduling events
and on g_system_ptr for time. With this patch, the Consumer will now use a
ClockedObject to schedule events and to query for current time. This resulted
in several structures being converted from SimObjects to ClockedObjects. Also,
the MessageBuffer class now requires a pointer to a ClockedObject so as to
query for time.

ruby: add support for prefetching to MESI protocol

ruby: change slicc to allow for constructor args
The patch adds support to slicc for recognizing arguments that should be
passed to the constructor of a class. I did not like the fact that an explicit
check was being carried on the type 'TBETable' to figure out the arguments to
be passed to the constructor.
The patch also moves some of the member variables that are declared for all
the controllers to the base class AbstractController.

ruby: functional access updates to network test protocol
I had forgotten to change the network test protocol while making changes to
ruby for supporting functional accesses. This patch updates the protocol so
that it can compile correctly.

ruby: improved support for functional accesses
This patch adds support to different entities in the ruby memory system
for more reliable functional read/write accesses. Only the simple network
has been augmented as of now. Later on Garnet will also support functional
accesses.
The patch adds functional access code to all the different types of messages
that protocols can send around. These messages are functionally accessed
by going through the buffers maintained by the network entities.
The patch also rectifies some of the bugs found in coherence protocols while
testing the patch.

With this patch applied, functional writes always succeed. But functional
reads can still fail.

ruby: allow function definition in slicc structs
This patch adds support for function definitions to appear in slicc structs.
This is required for supporting functional accesses for different types of
messages. Subsequent patches will use this to development.

ruby: rename template_hack to template
I don't like using the word hack. Hence, the patch.

ruby: remove unused code in protocols

MI coherence protocol: add copyright notice

Ruby: Modify Scons so that we can put .sm files in extras
Also allows for header files which are required in slicc generated
code to be in a directory other than src/mem/ruby/slicc_interface.

MESI Protocol: Correct the virtual network in profile functions
The virtual network in a couple of places was incorrectly mentioned
as 3 in place of 1. This is being corrected.

MESI Coherence Protocol: Add copyright notice

Ruby: remove some unused stuff from SLICC files

ruby: banked cache array resource model

This patch models a cache as separate tag and data arrays. The patch exposes
the banked array as another resource that is checked by SLICC before a
transition is allowed to execute. This is similar to how TBE entries and slots
in output ports are modeled.

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.

MOESI_hammer: tbe allocation and dependent wakeup fixes

MOESI_hammer: fixed bug with single cpu + flushes, then modified the regression tester to check this functionality

build scripts: Made minor modifications to reduce build overhead time.

1. --implicit-cache behavior is default.
2. makeEnv in src/SConscript is conditionally called.
3. decider set to MD5-timestamp
4. NO_HTML build option changed to SLICC_HTML (defaults to False)

MESI: Add queues for stalled requests
This patch adds support for stalling the requests queued up at different
controllers for the MESI CMP directory protocol. Earlier the controllers
would recycle the requests using some fixed latency. This results in
younger requests getting serviced first at times, and can result in
starvation. Instead all the requests that need a particular block to be
in a stable state are moved to a separate queue, where they wait till
that block returns to a stable state and then they are processed.

Merge with main repository.

O3, Ruby: Forward invalidations from Ruby to O3 CPU
This patch implements the functionality for forwarding invalidations and
replacements from the L1 cache of the Ruby memory system to the O3 CPU. The
implementation adds a list of ports to RubyPort. Whenever a replacement or an
invalidation is performed, the L1 cache forwards this to all the ports, which
is the LSQ in case of the O3 CPU.

Ruby: Change the access permissions for MOESI hammer

This patch changes the access permission for the WB_E_W state from
Busy to Read_Write to avoid having issues in follow-on patches with
functional accesses going through Ruby. This change was made after
consultation with all involved parties and is more of a work-around
than a fix.

MOESI Hammer: Remove a couple of bugs
A couple of bugs were observed while building checkpointing support in Ruby.
This patch changes transitions to remove those errors.

MESI Coherence Protocol: Fix L2 miss statistics
This patch removes calls to uu_ProfileMiss from transitions where the request
is satisfied by the L2 cache controller.

SLICC: Use pointers for directory entries
SLICC uses pointers for cache and TBE entries but not for directory entries.
This patch changes the protocols, SLICC and Ruby memory system so that even
directory entries are referenced using pointers.

MOESI_hammer: fixed L2 to L1 infinite stalls and deadlock

Remove standard_1level_CMP-protocol.sm include statement from Network

MESI Protocol: Add functions for profiling misses

Protocol: Remove standard one and two level files

Ruby: Remove some unused typedefs
This patch removes some of the unused typedefs. It also moves
some of the typedefs from Global.hh to TypeDefines.hh. The patch
also eliminates the file NodeID.hh.

Ruby: Reorganize mapping of components
In RubySlicc_ComponentMapping.hh, certain '#define's have been used for
mapping MachineType to GenericMachineType. These '#define's are being
eliminated and the code will now be generated by SLICC instead. Also
are being eliminated some of the unused functions from
RubySlicc_ComponentMapping.sm.

Functional Accesses: Update states to support Broadcast/Snooping protocols.

In the current implementation of Functional Accesses, it's very hard to
implement broadcast or snooping protocols where the memory has no idea if it
has exclusive access to a cache block or not. Without this knowledge, making
sure the RW vs. RO permissions are right are next to impossible. So we add a
new state called Backing_Store to enable the conveyance that this is the backup
storage for a block, so that it can be written if it is the only possibly RW
block in the system, or written even if there is another RW block in the
system, without causing problems.

Also, a small change to actually set the m_name field for each Controller so
that debugging can be easier. Now you can access a controller's name just by
controller->getName().

BuildEnv: Eliminate RUBY as build environment variable
This patch replaces RUBY with PROTOCOL in all the SConscript files as
the environment variable that decides whether or not certain components
of the simulator are compiled.

Ruby: Remove files and includes not in use

Scons: Drop RUBY as compile time option.
This patch drops RUBY as a compile time option. Instead the PROTOCOL option
is used to figure out whether or not to build Ruby. If the specified protocol
is 'None', then Ruby is not compiled.

ruby: added generic dma machine

MOESI_hammer: Fixed uniprocessor DMA bug

slicc: add a protocol statement and an include statement
All protocols must specify their name
The include statement allows any file to include another file.

slicc: cleanup slicc code and make it less verbose

Network_test: Conform it with functional access changes in Ruby
Addition of functional access support to Ruby necessitated some changes to
the way coherence protocols are written. I had forgotten to update the
Network_test protocol. This patch makes those updates.

Ruby: Add support for functional accesses
This patch rpovides functional access support in Ruby. Currently only
the M5Port of RubyPort supports functional accesses. The support for
functional through the PioPort will be added as a separate patch.

Ruby: Correctly set access permissions for directory entries
The access permissions for the directory entries are not being set correctly.
This is because pointers are not used for handling directory entries.
function. get and set functions for access permissions have been added to the
Controller state machine. The changePermission() function provided by the
AbstractEntry and AbstractCacheEntry classes has been exposed to SLICC
code once again. The set_permission() functionality has been removed.

NOTE: Each protocol will have to define these get and set functions in order
to compile successfully.

slicc: added vnet_type to MI_example

Forgot to add this to MI_example in my previous patch.

slicc: added vnet_type field to identify response vnets from others

Identifying response vnets versus other vnets will allow garnet to
determine which vnets will carry data packets, and which will carry
ctrl packets, and use appropriate buffer sizes (since data packets are larger
than ctrl packets). This in turn allows the orion power model to accurately
estimate buffer power.

network: convert links & switches to first class C++ SimObjects

This patch converts links and switches from second class simobjects that were
virtually ignored by the networks (both simple and Garnet) to first class
simobjects that directly correspond to c++ ojbects manipulated by the
topology and network classes. This is especially true for Garnet, where the
links and switches directly correspond to specific C++ objects.

By making this change, many aspects of the Topology class were simplified.

hammer: fixed dma uniproc error

Fixed an error reguarding DMA for uninprocessor systems. Basically removed an
overly agressive optimization that lead to inconsistent state between the
cache and the directory.

CacheMemory: add allocateVoid() that is == allocate() but no return value.
This function duplicates the functionality of allocate() exactly, except that it does not return
a return value. In protocols where you just want to allocate a block
but do not want that block to be your implicitly passed cache_entry, use this function.
Otherwise, SLICC will complain if you do not consume the pointer returned by allocate(),
and if you do a dummy assignment Entry foo := cache.allocate(address), the C++
compiler will complain of an unused variable. This is kind of a hack to get around
those issues, but suggestions welcome.

Ruby: Add new object called WireBuffer to mimic a Wire.
This is a substitute for MessageBuffers between controllers where you don't
want messages to actually go through the Network, because requests/responses can
always get reordered wrt to one another (even if you turn off Randomization and turn on Ordered)
because you are, after all, going through a network with contention. For systems where you model
multiple controllers that are very tightly coupled and do not actually go through a network,
it is a pain to have to write a coherence protocol to account for mixed up request/response orderings
despite the fact that it's completely unrealistic. This is *not* meant as a substitute for real
MessageBuffers when messages do in fact go over a network.

Ruby: pass Packet->Req->contextId() to Ruby.
It is useful for Ruby to understand from whence request packets came.
This has all request packets going into Ruby pass the contextId value, if
it exists. This supplants the old libruby proc_id value passed around in
all the Messages, so I've also removed the unused unsigned proc_id; member
generated by SLICC for all Message types.

This patch supports cache flushing in MOESI_hammer

Ruby: Remove CacheMsg class from SLICC
The goal of the patch is to do away with the CacheMsg class currently in use
in coherence protocols. In place of CacheMsg, the RubyRequest class will used.
This class is already present in slicc_interface/RubyRequest.hh. In fact,
objects of class CacheMsg are generated by copying values from a RubyRequest
object.

This patch adds the network tester for simple and garnet networks.
The tester code is in testers/networktest.
The tester can be invoked by configs/example/ruby_network_test.py.
A dummy coherence protocol called Network_test is also addded for network-only simulations and testing. The protocol takes in messages from the tester and just pushes them into the network in the appropriate vnet, without storing any state.

Ruby: Convert CacheRequestType to RubyRequestType
This patch converts CacheRequestType to RubyRequestType so that both the
protocol dependent and independent code makes use of the same request type.

Ruby: Convert AccessModeType to RubyAccessMode
This patch converts AccessModeType to RubyAccessMode so that both the
protocol dependent and independent code uses the same access mode.

MOESI_hammer: minor fixes to full-bit dir

MOESI_hammer: fixed dma bug with shared data

MOESI_CMP_directory: significant dma bug fixes

SLICC: Remove external_type for structures
In SLICC, in order to define a type a data type for which it should not
generate any code, the keyword external_type is used. For those data types for
which code should be generated, the keyword structure is used. This patch
eliminates the use of keyword external_type for defining structures. structure
key word can now have an optional attribute external, which would be used for
figuring out whether or not to generate the code for this structure. Also, now
structures can have functions as well data members in them.

SLICC: Remove the keyword wake_up_dependents
In order to add stall and wait facility for protocols, a keyword
wake_up_dependents was introduced. This patch removes the keyword,
instead this functionality is now implemented as function call.

SLICC: Remove the keyword wake_up_all_dependents
In order to add stall and wait facility for protocols, a keyword
wake_up_all_dependents was introduced. This patch removes the keyword,
instead this functionality is now implemented as function call.

Ruby: expose a simple mod function in slicc interface.

SCons: Clean up some inconsistent capitalization in scons options.

ruby: automate permission setting

This patch integrates permissions with cache and memory states, and then
automates the setting of permissions within the generated code. No longer
does one need to manually set the permissions within the setState funciton.
This patch will faciliate easier functional access support by always correctly
setting permissions for both cache and memory states.

MOESI_hammer: cache probe address clean up

ruby: cleaned up access permission enum

ruby: removed unsupported protocol files

m5: merged in hammer fix

MOESI_hammer: fixed wakeup for SS->S transistion

Ruby: Machine Type missing in MOESI CMP directory protocol
In certain actions of the L1 cache controller, while creating an outgoing
message, the machine type was not being set. This results in a
segmentation fault when trace is collected. Joseph Pusudesris provided
his patch for fixing this issue.

Ruby: clean MOESI CMP directory protocol
The L1 cache controller file contains references to foo and goo queues, which
are not in use at all. These have been removed.

Ruby: Reorder Cache Lookup in Protocol Files
The patch changes the order in which L1 dcache and icache are looked up when
a request comes in. Earlier, if a request came in for instruction fetch, the
dcache was looked up before the icache, to correctly handle self-modifying
code. But, in the common case, dcache is going to report a miss and the
subsequent icache lookup is going to report a hit. Given the invariant -
caches under the same controller keep track of disjoint sets of cache blocks,
we can move the icache lookup before the dcache lookup. In case of a hit in
the icache, using our invariant, we know that the dcache would have reported
a miss. In case of a miss in the icache, we know that icache would have
missed even if the dcache was looked up before looking up the icache.
Effectively, we are doing the same thing as before, though in the common case,
we expect reduction in the number of lookups. This was empirically confirmed
for MOESI hammer. The ratio lookups to access requests is now about 1.1 to 1.

MESI CMP: Unset TBE pointer in L2 cache controller
The TBE pointer in the MESI CMP implementation was not being set to NULL
when the TBE is deallocated. This resulted in segmentation fault on testing
the protocol when the ProtocolTrace was switched on.

ruby: support to stallAndWait the mandatory queue

By stalling and waiting the mandatory queue instead of recycling it, one can
ensure that no incoming messages are starved when the mandatory queue puts
signficant of pressure on the L1 cache controller (i.e. the ruby memtester).

MOESI_hammer: fixed dir bug counting received acks