There is a design which has been put forward which eliminates the idea
of a zero register entirely, but in the mean time, to get rid of one
more ISA specific constant, this change moves the ZeroReg constant into
the RegClassInfo class, specifically the IntRegClass instance which is
published by each ISA.
When the idea of zero registers has been eliminated entirely from
non ISA specific code, this and the existing machinery can be
eliminated.
Change-Id: I4302a53220dd5ff6b9b47ecc765bddc6698310ca
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/42685
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The nullStaticInstPtr was low overhead, but the nopStaticInstPtr needed
an actual StaticInst implementation it could point to, and that brought
with it some (minor) additional dependencies. Specifically, the
implementation of advancePC needs the definition of TheISA::PCState,
while all other signatures/impementations in StaticInst are already
passing around that type by reference or could be made to, reducing
dependencies further.
Change-Id: I9ac6a6e5a3106858ea1fc727648f61dc39738a59
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/42968
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
In most ISAs except MIPS and Power, this was implemented as
inst->advancePC(). It works just fine to call this function all the
time, but the idea had originally been that for ISAs which could simply
advance the PC using the PC itself, they could save the virtual function
call. Since the only ISAs which could skip the call were MIPS and Power,
and neither is at the point where that level of performance tuning
matters, this function can be collapsed with little downside.
If this turns out to be a performance bottleneck in the future, the way
the PC is managed could be revisited to see if we can factor out this
trip to the instruction object in the first place.
Change-Id: I533d1ad316e5c936466c529b7f1238a9ab87bd1c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/39335
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Alex Dutu <alexandru.dutu@amd.com>
This DPRINTF accesses the ExtMachInst typed machInst member of the
StaticInst class, and so is ISA dependent. Move the DPRINTF to where the
instructions are actually decoded where that type doesn't have to be
disambiguated.
Also, this change makes this DPRINTF more accurate, since microops are
not really "decoded" when they are extracted from a macroop. The process
of unpacking them to feed into the rest of the CPU should be fairly
trivial, so really they're just being retrieved. With the DPRINTF in
this new position, it will only trigger when an instruction is actually
decoded from memory.
Change-Id: I14145165b93bb004057a729fa7909cd2d3d34d29
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40099
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 mostly not used to begin with, but also when it was used, it
would obscure places where there were types, functions, etc, which were
switched between ISAs at compile time, and which would need to be
cleaned up to allow more than one ISA at a time.
Change-Id: Ieb372feff91b7e946b477fb78e54bcd0c2138966
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/39655
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
The create() method on Params structs usually instantiate SimObjects
using a constructor which takes the Params struct as a parameter
somehow. There has been a lot of needless variation in how that was
done, making it annoying to pass Params down to base classes. Some of
the different forms were:
const Params &
Params &
Params *
const Params *
Params const*
This change goes through and fixes up every constructor and every
create() method to use the const Params & form. We use a reference
because the Params struct should never be null. We use const because
neither the create method nor the consuming object should modify the
record of the parameters as they came in from the config. That would
make consuming them not idempotent, and make it impossible to tell what
the actual simulation configuration was since it would change from any
user visible form (config script, config.ini, dot pdf output).
Change-Id: I77453cba52fdcfd5f4eec92dfb0bddb5a9945f31
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35938
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
In most cases, the microcode ROM doesn't actually do anything. The
structural existence of a microcode ROM doesn't make sense in the
general case, and in architectures that know they have one and need to
interact with it, they can cast their decoder into an arch specific type
and access the ROM that way.
Change-Id: I25b67bfe65df1fdb84eb5bc894cfcb83da1ce64b
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/32898
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This code was at least a little Alpha specific, and now that Alpha is
gone it can no longer be compiled. We could either fix it up to work
with other/all ISAs or delete it, and the consensus was to delete it. It
could potentially be revived in the future by retrieving it from version
control.
Change-Id: Ied073f2b9b166951ecba3442cd762eb19bc690b3
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/32954
Reviewed-by: Steve Reinhardt <stever@gmail.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This parameter is associated with a periodic event which would take a
sample for a kernel profile in FS mode. Unfortunately the only ISA which
had working versions of the necessary classes was alpha, and that has
been deleted. That means that without additional work for any given ISA,
the profile parameter has no chance of working.
Ideally, this parameter should be moved to the Workload classes. There
it can intrinsically be tied to a particular kernel, rather than having
to assume a particular kernel and gate everything on whether you're in
FS mode.
Because this isn't (IMHO) where this parameter should live in the long
term, and because it's currently unusable without additional development
for each of the ISAs, I think it makes the most sense to remove the
front end for this mechanism from the CPU.
Since the sampling/profiling mechanism itself could be useful and could
be re-plumbed somewhere else, the back end and its classes are left alone.
Change-Id: I2a3319c1d5ad0ef8c99f5d35953b93c51b2a8a0b
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/32214
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This patch sets the faulting flag in atomic, timing, minor and o3 CPU
models.
It also fixes the minor/timing CPU models which were not respecting the
ExecFaulting flag. This is now checked before calling dump() on the
tracing object, to bring it in line with the other CPU models.
Change-Id: I9c7b64cc5605596eb7fcf25fdecaeac5c4b5e3d7
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/30135
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The ThreadContext can be used to access the cpu if needed, and is a
more representative interface to various pieces of state than the CPU
itself. Also convert some of the methods in Interupts to use the
locally stored ThreadContext pointer instead of taking one as an
argument. This makes calling those methods simpler and less error
prone.
Change-Id: I740bd99f92e54e052a618a4ae2927ea1c4ece193
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/28988
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The version of vtophys which didn't take a ThreadContext had only been
implemented on Alpha which has since been removed, so this version of
the function was completely unimplemented and never used.
This change also gets rid of the dbg_vtophys which was sometimes
implemented but also never used, and takes the opportunity to fix up
some style problems in some of the vtophys arch files.
Change-Id: Ie10f881f8ce08c7188e71805357cf3264be4c81a
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26224
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
TheISA::initCPU is basically an ISA specific implementation of reset
logic on architectural state. As such, it only needs to be called if
we're not going to load a checkpoint, ie in initState.
Also, since the implementation was the same across all CPUs, this
change collapses all the individual implementations down into the base
CPU class.
Change-Id: Id68133fd7f31619c90bf7b3aad35ae20871acaa4
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24189
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
This was useful when transitioning away from the CPU based
comInstEventQueue, but now that objects backing the ThreadContexts have
access to the underlying comInstEventQueue and can manipulate it
directly, they don't need to do so through a generic interface.
Getting rid of this function narrows and simplifies the interface.
Change-Id: I202d466d266551675ef6792d38c658d8a8f1cb8b
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/22113
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This was initially added in 2003 and only supported in the simple CPUs.
It's oddly specific since there are no other similar event queues for,
for instance, stores, branches, system calls, etc.
Given that this seems like a historical oddity which is only partially
supported and would be very hard to support on more diverse CPU types
like KVM or fast model which don't generally have hooks for counts of
specific instruction types.
Change-Id: I29209b7ffcf896cf424b71545c9c7546f439e2b9
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21780
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This queue was set up to allow triggering events based on the total
number of instructions executed at the system level, and was added in
a change which added a number of things to support McPAT. No code
checked into gem5 actually schedules an event on that queue, and no
code in McPAT (which seems to have gone dormant) either downloadable
from github or found in ext modify gem5 in a way that makes it use
the instEventQueue.
Also, the KVM CPU does not interact with the instEventQueue correctly.
While it does check the per-thread instruction event queue when
deciding how long to run, it does not check the instEventQueue. It will
poke it to run events when it stops for other reasons, but it may (and
likely will) have run beyond the point where it was supposed to stop.
Since this queue doesn't seem to actually be used for anything, isn't
being used properly in all cases anyway, and adds overhead to all the
CPU models, this change eliminates it.
Change-Id: I0e126df14788c37a6d58ca9e1bb2686b70e60d88
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21783
Maintainer: Gabe Black <gabeblack@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Tiago Mück <tiago.muck@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This changeset adds support for partial (or masked) loads/stores, i.e.
loads/stores that can disable accesses to individual bytes within the
target address range. In addition, this changeset extends the code to
crack memory accesses across most CPU models (TimingSimpleCPU still
TBD), so that arbitrarily wide memory accesses are supported. These
changes are required for supporting ISAs with wide vectors.
Additional authors:
- Gabor Dozsa <gabor.dozsa@arm.com>
- Tiago Muck <tiago.muck@arm.com>
Change-Id: Ibad33541c258ad72925c0b1d5abc3e5e8bf92d92
Signed-off-by: Giacomo Gabrielli <giacomo.gabrielli@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/13518
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Then cast to the ISA specific type when necessary. This removes
(mostly) an ISA specific aspect to some of the interfaces. The ISA
specific version of the kernel stats still needs to be constructed and
stored in a few places which means that kernel_stats.hh still needs to
be a switching arch header, for instance.
In the future, I'd like to make the kernel its own object like the
Process objects in SE mode, and then it would be able to instantiate
and maintain its own stats.
Change-Id: I8309d49019124f6bea1482aaea5b5b34e8c97433
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18429
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
MemObject doesn't provide anything beyond its base ClockedObject any
more, so this change removes it from most inheritance hierarchies.
Occasionally MemObject is replaced with SimObject when I was fairly
confident that the extra functionality of ClockedObject wasn't needed.
Change-Id: Ic014ab61e56402e62548e8c831eb16e26523fdce
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18289
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>
This patch enables all 4 CPU models (AtomicSimpleCPU, TimingSimpleCPU,
MinorCPU and DerivO3CPU) to issue atomic memory (AMO) requests to memory
system.
Atomic memory instruction is treated as a special store instruction in
all CPU models.
In simple CPUs, an AMO request with an associated AtomicOpFunctor is
simply sent to L1 dcache.
In MinorCPU, an AMO request bypasses store buffer and waits for any
conflicting store request(s) currently in the store buffer to retire
before the AMO request is sent to the cache. AMO requests are not buffered
in the store buffer, so their effects appear immediately in the cache.
In DerivO3CPU, an AMO request is inserted in the store buffer so that it
is delivered to the cache only after all previous stores are issued to
the cache. Data forwarding between between an outstanding AMO in the
store buffer and a subsequent load is not allowed since the AMO request
does not hold valid data until it's executed in the cache.
This implementation assumes that a target ISA implementation must insert
enough memory fences as micro-ops around an atomic instruction to
enforce a correct order of memory instructions with respect to its
memory consistency model. Without extra memory fences, this implementation
can allow AMOs and other memory instructions that do not conflict
(i.e., not target the same address) to reorder.
This implementation also assumes that atomic instructions execute within
a cache line boundary since the cache for now is not able to execute an
operation on two different cache lines in one single step. Therefore,
ISAs like x86 that require multi-cache-line atomic instructions need to
either use a pair of locking load and unlocking store or change the
cache implementation to guarantee the atomicity of an atomic
instruction.
Change-Id: Ib8a7c81868ac05b98d73afc7d16eb88486f8cf9a
Reviewed-on: https://gem5-review.googlesource.com/c/8188
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
This patch is changing the underlying type for RequestPtr from Request*
to shared_ptr<Request>. Having memory requests being managed by smart
pointers will simplify the code; it will also prevent memory leakage and
dangling pointers.
Change-Id: I7749af38a11ac8eb4d53d8df1252951e0890fde3
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/10996
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
CPUs have historically instantiated the architecture specific version
of the TLBs to avoid a virtual function call, making them a little bit
more dependent on what the current ISA is. Some simple performance
measurement, the x86 twolf regression on the atomic CPU, shows that
there isn't actually any performance benefit, and if anything the
simulator goes slightly faster (although still within margin of error)
when the TLB functions are virtual.
This change switches everything outside of the architectures themselves
to use the generic BaseTLB type, and then inside the ISA for them to
cast that to their architecture specific type to call into architecture
specific interfaces.
The ARM TLB needed the most adjustment since it was using non-standard
translation function signatures. Specifically, they all took an extra
"type" parameter which defaulted to normal, and translateTiming
returned a Fault. translateTiming actually doesn't need to return a
Fault because everywhere that consumed it just stored it into a
structure which it then deleted(?), and the fault is stored in the
Translation object when the translation is done.
A little more work is needed to fully obviate the arch/tlb.hh header,
so the TheISA::TLB type is still visible outside of the ISAs.
Specifically, the TlbEntry type is used in the generic PageTable which
lives in src/mem.
Change-Id: I51b68ee74411f9af778317eff222f9349d2ed575
Reviewed-on: https://gem5-review.googlesource.com/6921
Maintainer: Gabe Black <gabeblack@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Print faulting instruction for unmapped address panic in faults.cc
and print extra info about corresponding fetched PC in base.cc.
Change-Id: Id9e15d3e88df2ad6b809fb3cf9f6ae97e9e97e0f
Reviewed-on: https://gem5-review.googlesource.com/6461
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
These files aren't a collection of miscellaneous stuff, they're the
definition of the Logger interface, and a few utility macros for
calling into that interface (panic, warn, etc.).
Change-Id: I84267ac3f45896a83c0ef027f8f19c5e9a5667d1
Reviewed-on: https://gem5-review.googlesource.com/6226
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>
Move the code responsible for performing the actual probe point notify
into BaseCPU. Use BaseCPU activateContext and suspendContext to keep
track of sleep cycles. Create a probe point (ppActiveCycles) that does
not count cycles where the processor was asleep. Rename ppCycles
to ppAllCycles to reflect its nature.
Change-Id: I1907ddd07d0ff9f2ef22cc9f61f5f46c630c9d66
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5762
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reiley's update :) of the isa parser definitions. My addition of the
vector element operand concept for the ISA parser. Nathanael's modification
creating a hierarchy between vector registers and its constituencies to the
isa parser.
Some fixes/updates on top to consider instructions as vectors instead of
floating when they use the VectorRF. Some counters added to all the
models to keep faithful counts.
Change-Id: Id8f162a525240dfd7ba884c5a4d9fa69f4050101
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2706
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
