sim,dev: Get rid of the global retryTime constant.

This constant isn't in normalized units, ie doesn't scale when the time
value of a Tick changes, is global, has an extremely generic name even
though it's only used by a few ethernet devices, and has an arbitrary
value.

Get rid of it, and replace it with 1ns, what it would typically be
equivalent to when using the default 1ps time scale.

Change-Id: I31d9dad438f854b4152cd53c9a7042a25d13e0a6
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29398
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

cpu: Remove the ancient do_quiesce config option.

This option has existed for a very long time, defaults to True, and is
not used in any of the checked in configs. It enables the "quiesce"
mechanism, originally just pseudo instructions, and it's not clear
why you'd ever want to turn it off.

Change-Id: I92c7e5af22157e8435c7326634857d30bb5d7254
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25143
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-garnet: Remove extraneous loop in Router resetStats.

This outer loop makes no sense.

Change-Id: Ibe4b8b50c5843fba2119906f59ea1cb6c1d8c762
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29254
Reviewed-by: Srikant Bharadwaj <srikant.bharadwaj@amd.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-garnet,mem-ruby: Properly reset garnet2.0 statistics.

Statistics for crossbar activity, and link related statistics were not getting reset when using m5_reset_stats.

Change-Id: Ib84c55200e4a86c6f9190de28498112bd43dde9d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29253
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Srikant Bharadwaj <srikant.bharadwaj@amd.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

util: Add dockerfile for GCN3 w/machine learning

This dockerfile creates an image that installs the software stack needed
to run both machine learning and non-machine learning applications using
the GCN3 gpu model, while also applying patches to the software stack to
optimize machine learning applications, as well as APUs, which is the
current type of GPU in the GCN3 GPU model.

Change-Id: If36c2df1c00c895e27e9d741027fd10c17bf224e
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29192
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>

tests: add ruby_mem_test.py to the tests

This catches ruby functional memory errors we have observed, and ensures
that ruby_mem_test.py itself won't be broken.

The test duration is about 10 seconds, and it can be run as:

./main.py run --uid SuiteUID:tests/gem5/test_ruby_mem_test.py:test-ruby\
_mem_test-NULL-x86_64-opt

Change-Id: I39bc559aaea3ebb41217a96cd4e8dae46271ea1f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26805
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

python: Make DOT config generation optional

By default, DOT configs are always generated when pydot is present.
This change allows a user to pass an empty --dot-config='' to disable
generating the DOT configuration. This can be useful to save space, or
to reduce Gem5 startup time when running many small regression tests.

This brings the behavior in-line with providing an empty
--dump_config='' and/or --json_config='' which similarly disables
generation of those output files.

Change-Id: I5bf39fda0409b948a8d14f3afa95db8fc78de6ee
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29232
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

sim-se: ignore all scheduler related syscalls for arm

With the simplistic syscall emulation fork algorithm that we currently have
of running one thread per call, those calls simply cannot be reasonably
implemented.

However, content can often still work without them.

Change-Id: Iac88dfd055564c47b7a7b6898b7582cf4087f708
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28591
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>

sim-se: implement the getcpu syscall

Change-Id: I63a1384646829b8cf68453c42aed6a7d12172787
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28590
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

sim: Add some methods to create derived symbol tables.

These tables are based on passing the symbols in the current table
through some sort of operator function which can chose to add those
symbols, modified versions of those symbols, or nothing at all into a
new symbol table.

The new table is returned as a shared_ptr so its memory will be
managed automatically.

Change-Id: I8809336e2fc2fda63b16a0400536116ca852ca13
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24786
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

arch,base,cpu,sim: Statically allocate debugSymbolTable.

This singleton object is used thruoughout the simulator. There is
really no reason not to have it statically allocated, except that
whether it was allocated seems to sometimes be used as a signal that
something already put symbols in it, specifically in SE mode.

To keep that functionality for the moment, this change adds an "empty"
method to the SymbolTable class to make it easy to check if the symbol
table is empty, or if someone already populated it.

Change-Id: Ia93510082d3f9809fc504bc5803254d8c308d572
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24785
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

arch,base,cpu,kern,sim: Encapsulate symbols in a class.

The SymbolTable class had been tracking symbols as two independent
pieces, a name and an address, and acted as a way to translate between
them. Symbols can be more complex than that, and so this change
encapsulates the information associated with a symbol in a new class.

As a step towards simplifying the API for reading symbols from a
binary, this change also adds a "binding" field to that class so that
global, local and weak symbols can all go in the same table and be
differentiated later as needed. That should unify the current API
which has a method for each symbol type.

While the innards of SymbolTable were being reworked, this change
also makes that class more STL like by adding iterators, and begin
and end methods. These iterate over a new vector which holds all the
symbols. The address and name keyed maps now hold indexes into that
vector instead of the other half of the symbol.

Change-Id: I8084f86fd737f697ec041bac86a635a315fd1194
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24784
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

cpu: fixed unused variable on fast binary

When gem5.fast is compiled, an error on a variable
used only for debug purposes is raised:

build/X86/cpu/o3/mem_dep_unit_impl.hh:262:19: error: unused variable 'producing_store' [-Werror=unused-variable]
         for (auto producing_store : producing_stores)

This patch remove the variable when *.fast is used.

Change-Id: Ib77c26073db39644e3525bc16edcb7d3bc871d76
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29252
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>

cpu-minor: fix store-release issuing

Store with release flag are treated like store conditionals and are not
bufferable. Also they are only sent when the store buffer is empty to
satisfy the release semantics.

Change-Id: I253ec5ecd39901b14d0dc8efbc82cf7e4b07f08f
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27135
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Gem5 Cloud Project GCB service account <345032938727@cloudbuild.gserviceaccount.com>

cpu-o3: fix store-release issuing

Requests from stores with release semantics are only issued when they
are at the head of the store queue.

Change-Id: I19fbceb5ee057d3aa70175cbeec6b9b466334e8c
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27134
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Gem5 Cloud Project GCB service account <345032938727@cloudbuild.gserviceaccount.com>

arch-arm: Using acquire/release memory flags

Appends the acquire/release memory flags for the instructions with those
semantics.

Change-Id: I9d1e12c6ced511f2ff7a1006c27ae9014965e044
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27133
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>

util: Pull argument parsing functions out of m5.c.

Make them available in other files as well.

Change-Id: I3ddaed1a06023f929acc95c90f8f9adda7ff429c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27243
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>

mem: Remove infinite queue between Ruby and memory

AbstractController sends requests using a QueuedMasterPort which has an
implicit buffer which is unbounded. Remove this by changing the port to
a MasterPort and implement a retry mechanism for AbstractController.
Although the request remains in the MessageBuffer if a retry is needed,
the additional retry logic optimizes serviceMemoryQueue slightly and
prevents the DRAMCtrl retry stats from being incorrect due to multiple
calls to sendTimingReq.

Change-Id: I8c592af92a1a499a418f34cfee16dd69d84803ad
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28387
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Bradford Beckmann <brad.beckmann@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>

arm,x86,sim: Use the new return value suppression in GuestABI.

This gets rid of some dummy Return structure definitions. Also augment
the PseudoInst::pseudoInst dispatch function so it can store or not
store results, depending on what's needed at each call sight.

Change-Id: If4a53bc0a27e5214a26ef1a100c99948ca95418d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28289
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

sim: Convert GuestABI example signatures to comments.

In the base Result and Argument templates, there were private static
functions which weren't meant to be used, but which would act as
documentation for what those functions should look like. They were
marked as private to prevent them from being accidentally used and
causing confusing, hard to debug errors.

Unfortunately, that also meant that those functions exist, and
apparently cause inconsistent problems with SFINAE. I assume if the
functions don't exist at all, then SFINAE will work properly. When
they're private, that seems to cause a substitution failure which
actually is an error which makes the build fail.

Change-Id: I326e9e1d05eafe1b00732ae10264354b07426e74
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28308
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

gpu-compute,mem-ruby: Refactor GPU coalescer

Remove the read/write tables and coalescing table and introduce a two
levels of tables for uncoalesced and coalesced packets. Tokens are
granted to GPU instructions to place in uncoalesced table. If tokens
are available, the operation always succeeds such that the 'Aliased'
status is never returned. Coalesced accesses are placed in the
coalesced table while requests are outstanding. Requests to the same
address are added as targets to the table similar to how MSHRs
operate.

Change-Id: I44983610307b638a97472db3576d0a30df2de600
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27429
Reviewed-by: Bradford Beckmann <brad.beckmann@amd.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Bradford Beckmann <brad.beckmann@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>

arch-arm: SVE instruction in EL1s cannot be trapped to EL2

haveVirtualization() is not a valid check on its own:
We need to check if EL2 trapping is currently supported and this
can only happen if we are in NS state or if SecEL2 is implemented

Change-Id: Ie2312caba1ac0f186a2a3305c55a23c7705ba3fd
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Ciro Santilli <ciro.santilli@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28769
Tested-by: kokoro <noreply+kokoro@google.com>

arch-arm: CPTR.FPEN controlling SVE enablement

CheckSveEnabled shouldn't check for .ZEN only.
SVE instructions require Advanced SIMD to be supported as
well (CPTR.FPEN) with the caveat of ZEN check having priority
over the FPEN.

Change-Id: Ia1b5f7df3e25e7ffcad472542cb973635f62637b
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Ciro Santilli <ciro.santilli@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28768
Tested-by: kokoro <noreply+kokoro@google.com>

arch-arm: Remove checkSveTrap method

This is not part of the arm arm pseudocode and prevents a proper
fix of the checkSveEnabled

Change-Id: I075749095316e59e395d5b84a23db4309bdd7a92
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Ciro Santilli <ciro.santilli@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28767
Tested-by: kokoro <noreply+kokoro@google.com>

cpu-o3: MemDepUnit tracks load-acquire/store-release

MemDepUnit tracks loads/stores that are also barriers, which is the case
of load-acquire / store-release instructions. The tracking logic is also
extended to consider multiple outstanding barriers.

Change-Id: I95b0c710d7c7e4a138492177e3eaaf5143e9a0ba
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27132
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

arch-arm: Fix SVE indx inst by sizeof error and dest overwrite

This patch includes two fixes for SVE FMUL; FMLA FMLS AND FCMLA instructions

+ Fixes indexed functions like FMUL, FMLA, FMLS, FCMLA due to its
destination register overwrite with temporary values, wince the imm
can make changes in vector positions that will be read in the future.

+ sizeof return bytes not bits so division of 128 shouild be of 16 instead

Change-Id: I304d1b254a299069c85bbc3319e5a6d4119436d0
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28228
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: fix possible MOESI_CMP deadlock

Freeing the L2 block only after local invalidates are acked in the OLSF
state may lead to a deadlock.

Change-Id: Ia4b60e5bc9e2d3315b874a8c6616478db6eb38c1
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21929
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: Fixed MOESI_CMP_directory resource tracking

Fixes a few resource allocation issues in the directory controller:

- Added TBE resource checks on allocation.
- Now also allocating a TBE when issuing read requests to the controller
  to allow for a better response to backpressure. Without the TBE as a
  limiting factor, the directory can have an unbounded amount of
  outstanding memory requests.
- Also allocating a TBE for forwarded requests.

Change-Id: I17016668bd64a50a4354baad5d181e6d3802ac46
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21928
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>

mem-ruby: fix MOESI_CMP_directory functional reads

This patch properly sets the access permissions in all controllers.
'Busy' was used for all transient states, which is incorrect in lots of
cases when we still hold a valid copy of the line and are able to handle
a functional read.

In the L2 controller these states were split to differentiate the access
permissions:
IFGXX -> IFGXX, IFGXXD
IGMO -> IGMO, IGMOU
IGMIOF -> IGMIOF, IGMIOFD

Same for the dir. controller:
IS -> IS, IS_M
MM -> MM, MM_M

The dir. controllers also has the states WBI/WBS for lines that have
been queued for a writeback. In these states we hold the data in the TBE
for replying to functional reads until the memory acks the write and we
move to I or S.

Other minor changes includes updated debug messages and asserts.

Change-Id: Ie4f6eac3b4d2641ec91ac6b168a0a017f61c0d6f
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21927
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: Fix MOESI_CMP_directory DMA handling

This patch fixes some issues in the directory controller regarding DMA
handling:

1) Junk data messages were being sent immediately in response to DMA reads
for a line in the S state (one or more sharers, clean). Now, data is
fetched from memory directly and forwarded to the device. Some existing
transitions for handling GETS requests are reused, since it's essentially
the same behavior (except we don't update the list of sharers for DMAs)

2) DMA writes for lines in the I or S states would always overwrite the
whole line. We now check if it's only a partial line write, in which case
we fetch the line from memory, update it, and writeback.

3) Fixed incorrect DMA msg size

Some existing functions were renamed for clarity.

Change-Id: I759344ea4136cd11c3a52f9eaab2e8ce678edd04
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21926
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>

mem-ruby: Missing transition in MOESI_CMP_directory

Change-Id: I3aa9cd0230c141128ef5bddc728775b1ea6bbe14
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21925
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: removed unused checkCoherence

Change-Id: I108b95513f2828470fe70bad5f136b0721598582
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21924
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: removed checkCoherence from MOESI_CMP_directory

The implementation is empty and this is not used by other protocols

Change-Id: Iaed7d6d4b7ef1eb4cd47bdc0710dc9dbb7a86a0c
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21923
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: Removed invalid transition from MOESI_CMP dir

When memory data is received we always have a valid directory
entry or are in a transient state.

Change-Id: I0e9120e320c157fd306909458cbc446275a4f738
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27848
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Gem5 Cloud Project GCB service account <345032938727@cloudbuild.gserviceaccount.com>

mem-ruby: Deallocating unused entries in MOESI_CMP dir

Invalid entries are never removed from the directory the Directory
controller. This patch fixes this by deallocating the entries
when they become invalid.

Change-Id: I616686a78c5eddb7748192bf94bb691a4f158cbc
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27847
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>

mem-ruby: Deallocating unused entries in MOESI_CMP L2

Invalid entries are never removed from the directories in the L2
controller. This patch fixes this by deallocating the entries
when they become invalid. The NP (not present) state was removed
since it's now equivalent to Invalid.

Change-Id: Id807b341a2aadb06008491545aca614d5a09b8df
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21922
Reviewed-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: Check on PerfectCacheMemory deallocate

Allowing deallocate to be called for non-existing blocks may hide
potential bugs.

Change-Id: Ida77e2db1da59d7cdb21d58968e1f17e75eaa6e0
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21921
Reviewed-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: Add deallocate to DirectoryMemory

Change-Id: Ib261ec8b302b55e539d8e13064957170412b752c
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21920
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

arch-arm: show names on --debug-flags MiscRegs write:

Before this commit it would show only numbers:

Writing to misc reg 19 (19) : 0x74178

and now it also shows the name:

Writing MiscReg lockaddr (19 19) : 0x74178

MiscReg reads were already showing names and are unchanged, e.g.:

Reading MiscReg sctlr_el1 with clear res1 bits: 0x18100800

Change-Id: If46da88359ce4a549a6a50080a2b13077d41e373
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28467
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

arch-arm: FCVTZS instruction returns sign extension

This patch fix Fcvtzs instruction adding sign extension instead of
zero extension

Change-Id: I28cdca432fa6baa8a524de4c431f492f23f0e9a6
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28229
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-cache: Fixes to PIF prefetcher

The temporal compactor was never initialized.

There were more possible indexes to the prec/succ vectors than
entries, so a block distance of zero would seg fault.

When checking for an address the wrong vector was being used.

From the original paper, "The prediction mechanism searches for
the PC of the accessed instruction in the index table"

Change-Id: I3c3aceac3c0adbbe8aef5c634c88cb35ba7487be
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28487
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

arch-arm: Decode SEVL instruction for A32 and T32 IS

The instruction had been defined but it was not used for AArch32

Change-Id: I2bb106e98647eaa1f4c71fffb541e76ac1688674
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Ciro Santilli <ciro.santilli@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28450
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: MESI_Three_level prefetcher page crossing

This patch allows MESI_Three_level using the Ruby prefetcher to
safely cross page boundaries by determining if an address is bad
and cannot be mapped to a memory controller.

Change-Id: I675a13dfa6deb5b6a9f986ced5a3130436db911d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28048
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: MESI_Three_level prefetcher support

Add support for the Ruby stride prefetcher to MESI_Three_Level.

Change-Id: Id68935e2a7d3ccd0e22a59f43a15f167410632a2
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27715
Reviewed-by: Bradford Beckmann <brad.beckmann@amd.com>
Maintainer: Bradford Beckmann <brad.beckmann@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: MESI_Three_Level LL/SC improvements

This patch fixes the MESI_Three_Level protocols so that it correctly
informers the Ruby sequencer when a line eviction occurs. Furthermore,
the patch allows the protocol to recognize the 'Store_Conditional'
RubyRequestType and shortcuts this operation if the monitored line
has been cleared from the address monitor. This prevents certain
livelock behaviour in which a line could ping-pong between competing
cores.

The patch establishes a new C/C++ preprocessor definition which allows
the Sequencer to send the 'Store_Conditional' RubyRequestType to
MESI_Three_Level instead of 'ST'. This is a temporary measure until
the other protocols explicitely recognize 'Store_Conditional'.

Change-Id: I27ae041ab0e015a4f54f20df666f9c4873c7583d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28328
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: LL/SC fixes

The implementation for load-linked/store-conditional did not work
correctly for multi-core simulations. Since load-links were treated as
stores, it was not possible for a line to have multiple readers which
often resulted in livelock when using these instructions to implemented
mutexes. This improved implementation treats load-linked instructions
similarly to loads but locks the line after a copy has been fetched
locally. Writes to a monitored address ensure the 'linked' property is
blown away and any subsequent store-conditional will fail.

Change-Id: I19bd74459e26732c92c8b594901936e6439fb073
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27103
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>

util: Add support for multiple call types in the m5 utility.

Using mechanisms added in previous CLs, this change modifies the m5
utility so that it can use any of the back ends enabled and implemented
by each variant, defaulting to one particular implementation if not is
selected explicitly.

On x86, the default mechanism is the magic address. All other variants
default to the magic instruction since they don't have a well
established address to use or even in most cases an implementation to
use.

The ability to override the particular magic address the utility wants
to use (necessary on variants such as aarch64) will be added in a future
CL.

Change-Id: I5fc414740e30759e7dde719cddcc8d5d41f8cc74
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27242
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

misc: added news on RISC-V to RELEASE-NOTES.md.

Change-Id: I9b60cd2f533e6d4ce677e8a9b7bb5a5698e51c61
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28448
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

arch-riscv: be prepared for CSR changes during PT walk.

If the address space is changed (by writing to SATP), it can happen that
a page table walk is in progress. Previously, this failed if the ASID
changed, because we then used the wrong ASID for the lookup.

This commit makes sure that we don't access CSRs after the beginning of
the walk by loading SATP, STATUS, and PRV at the beginning.

Change-Id: I8c184c7ae7dd44d78e881bb5ec8d430dd480849c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28447
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: fix MESI_Three_Level erroneous transition

The MESI_Three_Level protocol includes a transition in its L1
definition to invalidate an SM state but this transition does
not notify the L0 cache. The unintended side effect of this
allows stale values to be read by the L0 cache. This can cause
incorrect behaviour when executing LL/SC based mutexes. This
patch ensures that all invalidates to SM states are exposed to
the L0 cache.

Change-Id: I7fefabdaa8027fdfa4c9c362abd7e467493196aa
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28047
Reviewed-by: John Alsop <johnathan.alsop@amd.com>
Reviewed-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>

tests: Update tests to save output on failure

The previous commit which tried to do this, did not work with parallel
execution. In this case, the fixtures that were modified were in the
child process and the parent process's fixtures were never updated.
Instead of modifying the object, use the information passed in from the
testlib.

See 4c28149ffa5d09e6fe14952dcaf8df5d0cd8f328
Previous review:
https://gem5-review.googlesource.com/c/public/gem5/+/17451

Change-Id: Ib4c06c5e3f82994199d6f0c1fa69452e93444d75
Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19529
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

ext: Fix tmpfiles in testlib

Previously, the testlib would generate and not clean up 100s of
temporary files in /tmp. This puts all of the tempfiles in the same
directory to make sure they are cleaned up on a successful test.

Change-Id: If4dcd93ab4b5df556c046753266a71365d1388c1
Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19528
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

scons: Build the marshal binary in a bare minimum environment

This change adds an additional bare minimum environment that includes
python only and changes the marshal binary to compile using it.

Change-Id: Id5d1ee6899796d746d8dc1a004cfe4795f040c55
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28428
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

tests: update linux boot tests

This change updates the config scripts used by linux boot
tests to make them compatible with change that deprecated
LinuxX86System

JIRA: https://gem5.atlassian.net/browse/GEM5-440

Change-Id: I04beff2915c03a2c3a774351edbba60d7ff26867
Signed-off-by: Ayaz Akram <yazakram@ucdavis.edu>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28427
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-cache: Use AssociativeSet in Stride prefetcher

Avoid replicating associative set functionality in Stride prefetcher's
pc tables.

The indexing policy used previously had some peculiarities, so both
the extractTag and extractSet have been made virtual so that previous
behavior could be kept.

Change-Id: I19a86cb3c4b40031fef427d5f7eed9d5c5673a44
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24603
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-cache: Use SatCounter in Stride prefetcher

There is no need to reimplement saturating counter functionality.

Change-Id: Ie7753089873f41a378ab88fd5f095302c3428797
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24542
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-cache: Cleanup of SBOOE prefetcher

Made the latencyBuffer a CircularQueue.

Improved encapsulation of the Sandbox struct.

Fixed score() to follow function declaration guidelines.

Removed redundant fatal error checking for score threshold.

Change-Id: I1904884e96f103c67930abafc28b75796aadc406
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24541
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-cache: Use CircularQueue in PIF prefetcher

Use CircularQueue for PIF's history buffer, and change the indexing
storage to a CQ iterator.

Change-Id: I75bbb75a6be41bd063f662baedbd4c9de33644de
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24540
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-cache: Use CircularQueue for the STeMS's RMOB

Replace rmobHead functionality with a CircularQueue. As a side
effect, RMOB entry's valid bit was removed.

Change-Id: If0b39cfe15de1e47dde0689a0ebc46b623ec1e55
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24539
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Javier Bueno Hedo <javier.bueno@metempsy.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-cache: Fix DCPT with CircularQueue

This patch fixes the following bugs:

- Previously when deltaPointer was 0 or 1, getting the last or penultimate deltas
  would be wrong for non-pow2 deltas.size(). For example, if the last added delta
  was to position 0, the previous should be in position 19, if deltas.size() = 20.
  However, 0-1=4294967295, and 4294967295%20=15.

- When searching for the previous late and penultimate, the oldest entry was being
  skipped.

Change-Id: Id800b60b77531ac4c2920bb90c15cc8cebb137a9
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24538
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Javier Bueno Hedo <javier.bueno@metempsy.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

cpu: Don't assert on branch target addresses

We should assume a branch target can be any address.

JIRA: https://gem5.atlassian.net/browse/GEM5-483

Change-Id: I6f6da1f9260d6e8978536967dc7fcf1808965db2
Signed-off-by: Hsuan Hsu <hsuan.hsu@mediatek.com>
Signed-off-by: Howard Wang <Howard.Wang@mediatek.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28347
Reviewed-by: Trivikram Reddy <tvreddy@ucdavis.edu>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

misc: Added RELEASE-NOTES.md

These release notes will enable users to keep track of the main changes
between gem5 versions. The RELEASE-NOTES.md should also notify the user
of any API changes they should be aware of when using this release of
gem5.

Notes on major changes should be apended to the end of the list as
they are added to the repo.

Change-Id: If75748306a8086b2abbe2f912dbb2ec9f1a6895f
Issue-on: https://gem5.atlassian.net/browse/GEM5-439
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27807
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

python: Fix compareVersions for python 3.

When the internal utility function make_version_list sees a string, it
tries to convert it into a list using the map() function. In python 3,
that returns an iterator. The following call to zip() will consume those
iterators, and then the following calls to len() will die because they
don't work on map iterators.

This is only a problem if all the common components of the version lists
are equal, and the comparison needs to then check if one of the lists
was equal to the other but with more components. When versions are
equal, for instance when compiling with the oldest supported version of
gcc (4.8.0) this error surfaces and breaks our scons build.

A simple fix is to just wrap the call to map() with list() to convert
the iterator to a flat list, making the other logic work as before.

Change-Id: If9dc5cd7fff70c21229ac3dd9a017edeccd26148
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28309
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-cache: Fix priority of multi compressor

The priority queue comparator orders such that false gives the
entry a higher priority. Therefore, if it is desired to make
the entry with lowest decompression latency have higher priority,
the comparison must be inverted.

Can be tested with:
  MultiCompressor(compressors=[
    PerfectCompressor(decompression_latency=1),
    PerfectCompressor(decompression_latency=2)])

Where it is expected that compressor0 (the one with decomp lat
of 1) is always chosen.

Change-Id: I44acbf5f51c6e47efdd2a16fba9596935cf2eb69
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28367
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem: Token port implementation

Adds a TokenPort which uses tokens for flow control rather than the
standard retry mechanism in gem5. The port is intended to be used
for flow control where speculatively sending packets is not possible.
For example, GPU instructions require this to send memory requests
to the cache coalescer.

Change-Id: Id0d55ab65b7c773e97752b8514a780cdf7d88707
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27428
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>

misc: Add build opts for GCN3 GPU ISA

Change-Id: I5f2662fe72d876b7bf816b0353aaefb85fc6c1c9
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28130
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>

configs: add option to set the timeouts for the TCPs and SQCs

Change-Id: Icff2bd0237ddcc0d21db17208df8e53ff6f43e86
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28129
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

dev-hsa: Add HSA device and HSA packet processor

This change adds support for HSA devices, which are
DMA devices that have an HSA packet processor (HSAPP).

An HSA packet processor model is also included. The
HSAPP is a DMA device that matains AQL packet queues
and handles extraction of AQL packets, scheduling
of AQL queues, and initiates kernel launch for HSA
devices.

Because these devices directly interact with low-level
software and aid in the implementation of the HSA ABI
we also include some headers from the ROCm runtime:
the hsa.h and kfd_ioctl.h headers. These aid with
support ROCm for the HSA devices and drivers.

Change-Id: I24305e0337edc6fa555d436697b4e607a1e097d5
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28128
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

arch-gcn3: Add files for arch gcn3 (GPU machine ISA)

Decoder: gpu_decoder.hh and decoder.cc:
    The decoder is defined in these files. The decoder
    is implemented as a lookup table of function pointers
    where each decode function will decode to a unique
    ISA instruction, or do some sub-decoding to infer
    the next decode function to call.

    The format for each OP encoding is defined in the
    header file.

Registers:
    registers.[hh|cc] define the special registers and
    operand selector values, which are used to map
    operands to registers/special values. many
    convenience functions are also provides to determine
    the source/type of an operand, for example vector
    vs. scalar, register operand vs. constant, etc.

GPU ISA:
    Some special GPU ISA state is maintained in gpu_isa.hh
    and isa.cc. This class is used to hold some special
    registers and values that can be used as operands
    by ISA instructions. Eventually more ISA-specific
    state should be moved here, and out of the WF class.

Vector Operands:
    The operands for GCN3 instructions are defined in
    operand.hh. This file defines both scalar and
    vector operands wth GCN3 specific semantics. The
    vector operand class is desgned around the generic
    vec_reg.hh that is already present in gem5.

Instructions:
    The GCN3 instructions are defined and implemented
    throughout gpu_static_inst.[hh|cc], instructions.[hh|cc],
    op_encodings.[hh|cc], and inst_util.hh. GCN3 instructions
    all fall under one of the OP encoding types; for example
    scalar memory operands are of the type SMEM, vector
    ALU instructions can be VOP3, VOP2, etc. The base code
    common to all instructions of a certain OP encoding type
    is implemented in the OP encodings files, which includes
    operand information, disassembly methods, encoding type,
    etc.

    Each individual ISA isntruction is implemented as
    a class object in instructions.[hh|cc] and are derived
    from one of the OP encoding types. The instructions.cc
    file is primarily for the execute() methods of each
    individual instruction, and the header file provides
    the class definition and a few instruction specific
    API calls.

    Note that these instruction classes were auto-generated
    but not using the gem5 ISA description language. A
    custom ISA description was used and that cannot be released
    publicly, therefore we are providing them already in C++.

Change-Id: I14d2a02d6b87109f41341c8f50a69a2cca9f3d14
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28127
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>

sim: Inheritance fixes in varargs

Change-Id: I3c6027223893363df098d1990a4ad3d07c2ff5ff
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28250
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: Avoid const from member due to &Message::operator=(...)

Change-Id: I172f48ce8ee4a3870165309342dadc2ac39ded9a
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28249
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>

arch-arm: Fix access modifier in Arm*ProcessBits class

Change-Id: Ie983abc94dd9e62bbec3f584b70b0d04d6e8305d
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28248
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

scons: Disable unsupported -Wl,--as-needed in MacOS

Change-Id: Id6f8199b818217c4fcf4b80efdb7cc9e1d14e32b
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28173
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

arch-arm: Fix inconsistency in variable name

Change-Id: I091a2d0cc8bfa7b8d98c4f508d175868d0fd7249
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28172
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-ruby: Removed the unused parameter m_id from VirtualChannel

Change-Id: Ie6f8db9b1cb0d0e0ca694c631c6662413fd833c1
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28171
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Srikant Bharadwaj <srikant.bharadwaj@amd.com>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>

arch-arm: Fix function signature inconsistencies in semihosting

Change-Id: Icb1aa30cb67b676d49681f68e1d62b3af409e26b
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28170
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

sim: Fix mismatch between #ifndef and #define in varargs.hh

Change-Id: I558b6c3c69a5003a77cc95b414e620715c3dbbae
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28169
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

arch-arm, mem-ruby, sim: Add missing overrides

Change-Id: I5ab18960bd61953e68777746426adb657818f825
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28168
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

arch-arm: Downgrade constexpr causing build errors to const

Change-Id: Idf5ae62603b6181d44aaaef91b774fa7b26eb718
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28167
Tested-by: kokoro <noreply+kokoro@google.com>

sim: Add an option to suppress the return value in invokeSimcall.

Sometimes when using the GuestABI mechanism, gem5 wants to know that a
function was called and with what arguments to do its own processing,
but doesn't want to return its own value since it will still let the
simulated system execute its own function. There are also situations
where gem5 wants to return a value, but not through the normal
mechanism. That happens when, for instance, a gem5 op is triggered by a
memory access, and that access is what should return the value, not a
particular fixed register.

This option is a template parameter rather than a function argument so
that if it's not going to be used, no "Return" type needs to be defined
since it's not present at all in the chain of functions invokeSimcall
expands to.

This will also make it easier to reuse generic ABIs in those situations
without having to make custom wrappers.

Change-Id: I969e78495c8f4e73f4de1a3dfb4d74c9b30f5af5
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28288
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

misc: Use the protobuf version to choose between ByteSize(Long).

Older versions of protobuf are apparently still what's provided with
some current versions of some distributions. To avoid breaking the build
on those distributions and to avoid an annoying deprecation warning on
newer systems, check GOOGLE_PROTOBUF_VERSION to choose which to use.

According to the CHANGES.txt file here:

https://github.com/protocolbuffers/protobuf/blob/master/CHANGES.txt

The new ByteSizeLong function was introduced in version 3.1.0 in 2016.

Change-Id: I7f8eeda144bf9556d17d7a0a741996f3137b48b4
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28287
Reviewed-by: Tommaso Marinelli <tommarin@ucm.es>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

sim-power: Addition of PowerDomains

PowerDomains group multiple objects together to regulate their power
state. There are 2 types of objects in a PowerDomain: leaders and
followers. The power state of a PowerDomain is the most performant
power state of any of the leaders. The power state of the followers is
determined by the power state of the PowerDomain they belong to: they
need to be in a power state which is more or equally performant to the
power state of the PowerDomain.

Leaders can be ClockedObjects or other PowerDomains. Followers can
only be ClockedObjects. PowerDomains can be be nested but a
PowerDomain can only be a leader of another PowerDomain, NOT a
follower. PowerDomains are not present in the hierarchy by default,
the user needs to create and configure them in the configuration file.

The user can add an hierachy by setting the led_by parameter. gem5
will then create leaders and followers for each domain and calculate
the allowed power states for the domain.

Objects in a PowerDomain need to have at least the ON state in the
possible_states.

An example of a powerDomain config is:

pd = PowerDomain()
cpu0 = BaseCPU()
cpu1 = BaseCPU()
shared_cache = BaseCache()
cache.power_state.led_by = pd
pd.led_by = [cpu0, cpu1]

This will create a PowerDomain, where the CPUs determine their own
power states and the shared cache (via the PowerDomain) follows those
power states (when possible).

Change-Id: I4c4cd01f06d45476c6e0fb2afeb778613733e2ff
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28051
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

sim-power: Specify the states a PowerState object can be in

This commit adds the concept of possible power states to the
PowerState SimObject. This is a list of the power states a specific
object can be in. Before transitioning to a power state, a PowerState
object will first check if the requested power states is actually an
allowed state. The user can restricted the power states a
ClockedObject can go to during configuration. In addition, this change
sets the power states, a CPU can be in.

Change-Id: Ida414a87554a14f09767a272b54b5d19bfc8e911
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28050
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

sim-power: Creation of PowerState class

This commit does not make any functional changes but just rearranges
the existing code with regard to the power states. Previously, all
code regarding power states was in the ClockedObjects. However, it
seems more logical and cleaner to move this code into a separate
class, called PowerState. The PowerState is a now SimObject. Every
ClockedObject has a PowerState but this patch also allows for objects
with PowerState which are not ClockedObjects.

Change-Id: Id2db86dc14f140dc9d0912a8a7de237b9df9120d
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28049
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

configs: Change fs_power.py to use absolute paths for stats

fs_power.py is an example script that demonstrates how power models
can be used with gem5. Previously, the formulas used to calculate the
dynamic and static power of the cores and the L2 cache were using
stats in equations as determined by their path relative to the
SimObject where the power model is attached to or full paths. This CL
changes these formulas to refer to the stats only by their full paths.

Change-Id: I91ea16c88c6a884fce90fd4cd2dfabcba4a1326c
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27893
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

sim-power: Fix the way the power model accesses stats

With the introduction of StatGroups the organization of stats has
changed and the power modeling framework has been broken. This CL uses
the new function Stats::resolve to retrieve pointers to the necesary
stats and use them in the power estimation formulas.

Change-Id: Iedaa97eeddf51f7a0a1f222918715da309943be3
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27892
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>

base, python, sim: Add support for resoving a stat using its name

This CL adds resolve, a function in the Stats namespace that allows
access to a stat as specified by its name.

Change-Id: I4fa8bed394b4cb35d9c6cf5d8db062b8d6bb9ca5
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27891
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

base: Add support for resolving stats within groups by name

This change adds a member function to the Group class that returns a
stat given its name. The function will go through all stats in the
group and its subgroups and will return the stat that matches the
name. For example, if g is the Group system.bigCluster.cpus then a
call to

p = g.resolveStat("ipc")

will return a pointer to the stat system.bigCluster.cpus.ipc.

Change-Id: I5af8401b38b41aee611728f6d1a595f99d22d9de
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27890
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

sim: Add function that returns all variables in a MathExpr

This changes adds support for retrieving all variables in a math
expression. The added function can be called in all valid expressions
and will return the variables in a vector of strings.

Change-Id: I086ba04aa1f798400c97a0b6bf982018a2457c64
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27889
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

tests: create tests for various traffic generators on NULL

New tests were added for:

- garnet_synth_traffic.py
- ruby_random_test.py
- ruby_direct_test.py

These tests are factored out with the tests for:

- memcheck.py
- ruby_mem_test.py

Each new test was calibrated to last about 5 seconds on a Lenovo ThinkPad
P51.

Change-Id: Ie13d3963e1163cffae5dce329b623fbebbf2b983
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26808
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

tests: fix the memcheck test

The file was raising due to the undefined constant `verifiers`, leading
the test to be ignored.

./main.py list -v

would show this as:

```
Traceback (most recent call last):
  File "/gem5/tests/../ext/testlib/loader.py", line 239, in load_file
    execfile(path, newdict, newdict)
  File "/gem5/tests/gem5/memcheck/test_memcheck.py", line 32, in <module>
    verifiers=verifiers,
NameError: name 'verifiers' is not defined

Exception thrown while loading "/gem5/tests/gem5/memcheck/test_memcheck.py"
Ignoring all tests in this file.
```

The test has been modified to have an empty verifiers list, which should
still catch bugs since src/mem/mem_checker.cc has several asserts already
which would be caught by the test system due to the exit status.

Also make the following changes to the test:

-   move it to tests/gem5/memory/test.py with other memory tests.

    This makes it easier to see all the tests in the source in one go, and
    might make it easier to factor certain memory things out later on.

-   reduce --maxtick to a value that finishes in 7 seconds on a Lenovo
    ThinkPad P51.

    The previous value would take 50x longer, which feels too long for a
    single test.

-   enable --prefetchers to also stress a prefetcher in the test

Change-Id: I58bd598b1142f349d25fa4fa4a8e41529e61a9ee
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26807
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem: make MemTest panic on a packet error

Before this change, running:

./build/NULL/gem5.opt configs/example/ruby_mem_test.py -m 20000000 \
  --functional 10

would only print warning for memory errors such as:

warn: Read access failed at 0x107a00

and there was no way to make the simulation fail.

This commit makes those warnings into errors such as:

panic: Read access failed at 0x107a00

unless --suppress-func-errors is given.

This will be used to automate MemTest testing in later commits.

Change-Id: I1840c1ed1853f1a71ec73bd50cadaac095794f91
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26804
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

configs: remove exec of Options.py from ruby_mem_test.py

The removed exec statement does not appear to be needed however,
since Options is already imported above with:

from common import Options

Change-Id: I934a65d21fa5099a786224a5476d609e4d707205
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26803
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

arch-riscv: report that we don't have debugging support.

According to the debugging spec (page 47), a debugger can test which
triggers are enabled by writing 0 to TSELECT and reading it back. If a
different value is read, the trigger is not supported.

Therefore, we currently always set a different value to indicate that
we do not support any triggers.

Change-Id: If222e913c4517adb2da4f6f0ffeedb4e4808a586
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25659
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Gem5 Cloud Project GCB service account <345032938727@cloudbuild.gserviceaccount.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>

arch-riscv: respect IALIGN, influenced by toggling 'c' extension.

According to the privileged ISA spec, SEPC[0]/MEPC[0] reads always 0
and SEPC[1]/MEPC[1] reads 0 if the compressed extension is disabled.

Additionally, the compressed extension can only be disabled if the next
instruction is 4-byte aligned.

Change-Id: I590c05e4000b59a5ba283f47933f7a92959d8e38
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25658
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>

arch-riscv: let FPU instructions fault if status.FS = off.

These checks are required for some tests in the RISC-V test suite.
However, actually we also need to set the INITIAL/CLEAN/DIRTY flags
accordingly, which is not done yet.

Change-Id: If5d6ac22069b51a57b6353cd6d45b77ee51a4d55
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25657
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Gem5 Cloud Project GCB service account <345032938727@cloudbuild.gserviceaccount.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>

arch-riscv: make uret,sret,mret SerializeAfter,NonSpeculative.

These instructions potentially change the privilege level, upon which
the execution of other instructions depends. For that reason, we need to
make *ret SerializeAfter and we also don't want to execute them
speculatively.

Change-Id: If3b5ba6ec3b4102d53c51cf723eba5d5da3eaa2f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25656
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Gem5 Cloud Project GCB service account <345032938727@cloudbuild.gserviceaccount.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>

arch-riscv: make accesses to CSRs SerializeAfter.

According to page 57 in the RISC-V manual, CSR accesses "need to be
performed in program order with respect to those instructions whose
execution behavior is affected by the state of the accessed CSR".

Thus, we need to make them SerializeAfter to ensure that the following
instructions are executed with the potential changes to the CSR. In
theory, we could be smarter here by only considering write accesses to
CSRs and considering the following instructions, but for now we simply
serialize for every CSR access.

Change-Id: I69391fccaec31c34d944c55bac2f04d37947ebfe
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25655
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Gem5 Cloud Project GCB service account <345032938727@cloudbuild.gserviceaccount.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>

arch-riscv: fault according to status.{TVM,TSK,TW}.

Change-Id: I38dddadb3373d2156b8fc57eabff861a062021cf
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25654
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>

arch-riscv: added dummy implementation of wfi instruction.

Change-Id: I7ca86f57c7d794bf544e34e747875049a3f29d6a
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25653
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Gem5 Cloud Project GCB service account <345032938727@cloudbuild.gserviceaccount.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>