The BaseCPU type had been specializing itself based on the value of
TARGET_ISA, which is not compatible with building more than one ISA at a
time.
This change refactors the CPU models so that the BaseCPU is more
general, and the ISA specific components are added to the CPU when the
CPU types are fully specialized. For instance, The AtomicSimpleCPU has a
version called X86AtomicSimpleCPU which installs the X86 specific
aspects of the CPU.
This specialization is done in three ways.
1. The mmu parameter is assigned an instance of the architecture
specific MMU type. This provides a reasonable default, but also avoids
having having to use the ISA specific type when the parameter is
created.
2. The ISA specific types are made available as class attributes, and
the utility functions (including __init__!) in the BaseCPU class can
refer to them to get the types they need to set up the CPU at run time.
Because SimObjects have strange, unhelpful semantics as far as assigning
to their attributes, these types need to be set up in a non-SimObject
class, which is then brought in as a base of the actual SimObject type.
Because the metaclass of this other type is just "type", things work
like you would expect. The SimObject doesn't do any special processing
of base classes if they aren't also SimObjects, so these attributes
survive and are accessible using normal lookup in the BaseCPU class.
3. There are some methods like addCheckerCPU and properties like
needsTSO which have ISA specific values or behaviors. These are set in
the ISA specific subclass, where they are inherently specific to an ISA
and don't need to check TARGET_ISA.
Also, the DummyChecker which was set up for the BaseSimpleCPU which
doesn't actually do anything in either C++ or python was not carried
forward. The CPU type still exists, but it isn't installed in the
simple CPUs.
To provide backward compatibility, each ISA implements a .py file which
matches the original .py for a CPU, and the original is renamed with a
Base prefix. The ISA specific version creates an alias with the old CPU
name which maps to the ISA specific type. This way, old scripts which
refer to, for example, AtomicSimpleCPU, will get the X86AtomicSimpleCPU
if the x86 version was compiled in, the ArmAtomicSimpleCPU on arm, etc.
Unfortunately, because of how tags on PySource and by extension SimObjects
are implemented right now, if you set the tags on two SimObjects or
PySources which have the same module path, the later will overwrite the
former whether or not they both would be included. There are some
changes in review which would revamp this and make it work like you
would expect, without this central bookkeeping which has the conflict.
Since I can't use that here, I fell back to checking TARGET_ISA to
decide whether to tell SCons about those files at all.
In the long term, this mechanism should be revamped so that these
compatibility types are only available if there is exactly one ISA
compiled into gem5. After the configs have been updated and no longer
assume they can use AtomicSimpleCPU in all cases, then these types can
be deleted.
Also, because ISAs can now either provide subclasses for a CPU or not,
the CPU_MODELS variable has been removed, meaning the non-ISA
specialized versions of those CPU models will always be included in
gem5, except when building the NULL ISA.
In the future, a more granular config mechanism will hopefully be
implemented for *all* of gem5 and not just the CPUs, and these can be
conditional again in case you only need certain models, and want to
reduce build time or binary size by excluding the others.
Change-Id: I02fc3f645c551678ede46268bbea9f66c3f6c74b
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/52490
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This patch augments the MESI_Three_Level Ruby protocol with hardware
transactional memory support.
The HTM implementation relies on buffering of speculative memory updates.
The core notifies the L0 cache controller that a new transaction has
started and the controller in turn places itself in transactional state
(htmTransactionalState := true).
When operating in transactional state, the usual MESI protocol changes
slightly. Lines loaded or stored are marked as part of a transaction's
read and write set respectively. If there is an invalidation request to
cache line in the read/write set, the transaction is marked as failed.
Similarly, if there is a read request by another core to a speculatively
written cache line, i.e. in the write set, the transaction is marked as
failed. If failed, all subsequent loads and stores from the core are
made benign, i.e. made into NOPS at the cache controller, and responses
are marked to indicate that the transactional state has failed. When the
core receives these marked responses, it generates a HtmFailureFault
with the reason for the transaction failure. Servicing this fault does
two things--
(a) Restores the architectural checkpoint
(b) Sends an HTM abort signal to the cache controller
The restoration includes all registers in the checkpoint as well as the
program counter of the instruction before the transaction started.
The abort signal is sent to the L0 cache controller and resets the
failed transactional state. It resets the transactional read and write
sets and invalidates any speculatively written cache lines. It also
exits the transactional state so that the MESI protocol operates as
usual.
Alternatively, if the instructions within a transaction complete without
triggering a HtmFailureFault, the transaction can be committed. The core
is responsible for notifying the cache controller that the transaction
is complete and the cache controller makes all speculative writes
visible to the rest of the system and exits the transactional state.
Notifting the cache controller is done through HtmCmd Requests which are
a subtype of Load Requests.
KUDOS:
The code is based on a previous pull request by Pradip Vallathol who
developed HTM and TSX support in Gem5 as part of his master’s thesis:
http://reviews.gem5.org/r/2308/index.html
JIRA: https://gem5.atlassian.net/browse/GEM5-587
Change-Id: Icc328df93363486e923b8bd54f4d77741d8f5650
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/30319
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This was primarily in Alpha where disassmbly output could be compatible
(default off, probably not usd in a long time), and floating point
could be compatible (default on). A small bit had crept into x86 from
long ago which is also removed.
Change-Id: Ibb68b63787f370259bd1613b393e0b057c007704
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25012
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Add NUMBER_BITS_PER_SET environment variable to control
the size of the bitmask in Set.hh (default=64).
Necessary for configs which require >64 instances of a given
machine type. This can be set in the build_opts file, e.g.
by adding the following line:
NUMBER_BITS_PER_SET = <number>
Change-Id: I314a3cadca8ce975fcf4a60d9022494751688e88
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18968
Reviewed-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Previously ARM binaries were by default compiled with the MI_example
protocol. The MI_example protocol cannot properly support load/store
exclusive instructions and therefore it cannot be used to simulate
multicore ARM systems. This change changes to MOESI_CMP_directory as
the default ruby protocol for ARM systems.
Change-Id: I942d950ba466aea9a75f3d8764f9f3eddd0c3baa
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2906
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Last of five patches adding RISC-V to GEM5. This patch adds support for
timing, minor, and detailed CPU models that was missing in the last four,
which basically consists of handling timing-mode memory accesses and
telling the minor and detailed models what a no-op instruction should
be (addi zero, zero, 0).
Patches 1-4 introduced RISC-V and implemented the base instruction set,
RV64I, and added the multiply, floating point, and atomic memory
extensions, RV64MAFD.
[Fixed compatibility with edit from patch 1.]
[Fixed compatibility with hg copy edit from patch 1.]
[Fixed some style errors in locked_mem.hh.]
Signed-off by: Alec Roelke
Signed-off by: Jason Lowe-Power <jason@lowepower.com>
First of five patches adding RISC-V to GEM5. This patch introduces the
base 64-bit ISA (RV64I) in src/arch/riscv for use with syscall emulation.
The multiply, floating point, and atomic memory instructions will be added
in additional patches, as well as support for more detailed CPU models.
The loader is also modified to be able to parse RISC-V ELF files, and a
"Hello world\!" example for RISC-V is added to test-progs.
Patch 2 will implement the multiply extension, RV64M; patch 3 will implement
the floating point (single- and double-precision) extensions, RV64FD;
patch 4 will implement the atomic memory instructions, RV64A, and patch 5
will add support for timing, minor, and detailed CPU models that is missing
from the first four patches (such as handling locked memory).
[Removed several unused parameters and imports from RiscvInterrupts.py,
RiscvISA.py, and RiscvSystem.py.]
[Fixed copyright information in RISC-V files copied from elsewhere that had
ARM licenses attached.]
[Reorganized instruction definitions in decoder.isa so that they are sorted
by opcode in preparation for the addition of ISA extensions M, A, F, D.]
[Fixed formatting of several files, removed some variables and
instructions that were missed when moving them to other patches, fixed
RISC-V Foundation copyright attribution, and fixed history of files
copied from other architectures using hg copy.]
[Fixed indentation of switch cases in isa.cc.]
[Reorganized syscall descriptions in linux/process.cc to remove large
number of repeated unimplemented system calls and added implmementations
to functions that have received them since it process.cc was first
created.]
[Fixed spacing for some copyright attributions.]
[Replaced the rest of the file copies using hg copy.]
[Fixed style check errors and corrected unaligned memory accesses.]
[Fix some minor formatting mistakes.]
Signed-off by: Alec Roelke
Signed-off by: Jason Lowe-Power <jason@lowepower.com>
This patch avoids compiling ALPHA six times as part of running
'util/regress', and instead relis on NULL with different protocols to
run the rubytest. All we need is the memory system, so there is really
no need to compile the ISA over and over again.
The one downside is the removal of running 'hello' for the variuos
ALPHA and protocol combinations, but if this is a concern we should
rather beef up the synthetic tests for the variuos protocols.
--HG--
rename : build_opts/NULL => build_opts/NULL_MESI_Two_Level
rename : build_opts/NULL => build_opts/NULL_MOESI_CMP_directory
rename : build_opts/NULL => build_opts/NULL_MOESI_CMP_token
rename : build_opts/NULL => build_opts/NULL_MOESI_hammer
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MESI_Two_Level/config.ini => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MESI_Two_Level/config.ini
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MESI_Two_Level/simerr => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MESI_Two_Level/simerr
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MESI_Two_Level/simout => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MESI_Two_Level/simout
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MESI_Two_Level/stats.txt => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MESI_Two_Level/stats.txt
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MOESI_CMP_directory/config.ini => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MOESI_CMP_directory/config.ini
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MOESI_CMP_directory/simerr => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MOESI_CMP_directory/simerr
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MOESI_CMP_directory/simout => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MOESI_CMP_directory/simout
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MOESI_CMP_directory/stats.txt => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MOESI_CMP_directory/stats.txt
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MOESI_CMP_token/config.ini => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MOESI_CMP_token/config.ini
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MOESI_CMP_token/simerr => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MOESI_CMP_token/simerr
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MOESI_CMP_token/simout => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MOESI_CMP_token/simout
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MOESI_CMP_token/stats.txt => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MOESI_CMP_token/stats.txt
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MOESI_hammer/config.ini => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MOESI_hammer/config.ini
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MOESI_hammer/simerr => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MOESI_hammer/simerr
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MOESI_hammer/simout => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MOESI_hammer/simout
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby-MOESI_hammer/stats.txt => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby-MOESI_hammer/stats.txt
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby/config.ini => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby/config.ini
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby/simerr => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby/simerr
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby/simout => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby/simout
rename : tests/quick/se/60.rubytest/ref/alpha/linux/rubytest-ruby/stats.txt => tests/quick/se/60.rubytest/ref/null/none/rubytest-ruby/stats.txt
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.
This patch avoids building the 'inorder' CPU model for any permutation
of ALPHA, and also removes the ALPHA regressions using the 'inorder'
CPU. The 'minor' CPU is already providing a broader test coverage.
A later changeset changes the file src/python/swig/pyobject.cc to include
a header file that includes a header file generated at build time depending
on the PROTOCOL in use. Since NULL ISA was not specifying any protocol,
this resulted in compilation problems. Hence, the changeset.
This patch contains a new CPU model named `Minor'. Minor models a four
stage in-order execution pipeline (fetch lines, decompose into
macroops, decompose macroops into microops, execute).
The model was developed to support the ARM ISA but should be fixable
to support all the remaining gem5 ISAs. It currently also works for
Alpha, and regressions are included for ARM and Alpha (including Linux
boot).
Documentation for the model can be found in src/doc/inside-minor.doxygen and
its internal operations can be visualised using the Minorview tool
utils/minorview.py.
Minor was designed to be fairly simple and not to engage in a lot of
instruction annotation. As such, it currently has very few gathered
stats and may lack other gem5 features.
Minor is faster than the o3 model. Sample results:
Benchmark | Stat host_seconds (s)
---------------+--------v--------v--------
(on ARM, opt) | simple | o3 | minor
| timing | timing | timing
---------------+--------+--------+--------
10.linux-boot | 169 | 1883 | 1075
10.mcf | 117 | 967 | 491
20.parser | 668 | 6315 | 3146
30.eon | 542 | 3413 | 2414
40.perlbmk | 2339 | 20905 | 11532
50.vortex | 122 | 1094 | 588
60.bzip2 | 2045 | 18061 | 9662
70.twolf | 207 | 2736 | 1036
This patch makes it possible to once again build gem5 without any
ISA. The main purpose is to enable work around the interconnect and
memory system without having to build any CPU models or device models.
The regress script is updated to include the NULL ISA target. Currently
no regressions make use of it, but all the testers could (and perhaps
should) transition to it.
--HG--
rename : build_opts/NOISA => build_opts/NULL
rename : src/arch/noisa/SConsopts => src/arch/null/SConsopts
rename : src/arch/noisa/cpu_dummy.hh => src/arch/null/cpu_dummy.hh
rename : src/cpu/intr_control.cc => src/cpu/intr_control_noisa.cc
There is some problem with the way listing cpu options right now.
Since Ruby uses the options variable, this variable has to be created in the
config file that runs the fs test for x86 and mesi cmp directory combination.
While creating the variable, some error is occurs due to the way list of cpu
types is now created. Hence, we need to compile all the cpu models.
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.
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.
MIPS_FS doesn't build and presumably doesn't work right now. Users might see
the MIP_FS file in build_opts and expect it to work. To avoid confusion, this
change deletes that file.
This patch includes the necessary regression updates to test the new ruby
configuration system. The patch includes support for multiple ruby protocols
and adds the ruby random tester. The patch removes atomic mode test for
ruby since ruby does not support atomic mode acceses. These tests can be
added back in when ruby supports atomic mode for real.
--HG--
rename : tests/quick/50.memtest/test.py => tests/quick/60.rubytest/test.py
This adds support for the 32-bit, big endian Power ISA. This supports both
integer and floating point instructions based on the Power ISA Book I v2.06.
