This makes what are configuration and what are internal SCons variables
explicit and separate, and makes it unnecessary to call out what
variables to export to C++.
These variables will also be plumbed into and out of kconfiglib in later
changes.
Change-Id: Iaf5e098d7404af06285c421dbdf8ef4171b3f001
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/56892
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
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>
Rather than make each ISA include boilerplate to ignore a
SyscallReturn's value when it's marked as suppressed or needing a retry,
put that code into the SyscallDesc::doSyscall method instead.
That has two benefits. First, it removes a decent amount of code
duplication which is nice from a maintenance perspective. Second, it
puts the SyscallDesc in charge of figuring out what to do once a system
call implementation finishes. That will let it schedule a retry of the
system call for instance, without worrying about what the ISA is doing
with the SyscallReturn behind its back.
Jira Issue: https://gem5.atlassian.net/browse/GEM5-1123
Change-Id: I3732a98c8e0d0b2b94d61313960aa0782c0b971f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/54023
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Move the instDone flag, and the instReady function which was
consistently implemented just to return it, to the base InstDecoder
class. This flag can still be accessed easily from the subclasses, but
now it can be retrieved with just an InstDecoder pointer without a
virtual function call.
Change-Id: I8c662aa01da8fe33ffe679071c701e0aadc1a795
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/52072
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
By using a PCStateBase pointer or reference, we can (mostly) avoid
having to know what the ISA specific PState class is, letting the ISA
specific instruction classes cast to the type they need internally.
There are a couple minor places where we need to do those casts outside
of ISA specific types, one in the generic NopStaticInstPtr class, and a
few in generic faults.
Right now, we'll just use the TheISA::PCState type in those isolated
spots (sometimes hidden by auto), and deal with it later, possibly
with a virtual "advance" method of some sort.
Change-Id: I774c67dc648a85556230f601e087211b3d5630a9
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/52043
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Most of the time, the type pointed to by a PCState pointer or reference
will be the same as all the others, if not nullptr.
This change adds a set of "set" functions which assume that the
underlying type of each pointer or reference are the same, and handles
casting, copying things over, creating a new copy, etc, for you. It uses
a new "update" virtual method on PCState subclasses which casts the
source to the same type as the destination and copies values over.
Note that the "set" function doesn't actually verify that the two types
are the same, just like the overloaded ==, != and << operators. In the
future, those checks can be added for debugging purposes, probably
guarded by a configuration variable which can be toggled on or off to
get better performance or more thorough error checking.
The main advantage of these wrappers are that they allows consistent
semantics whether your moving a value from a pointer, or from a yet
unconverted PCState subclass, or vice versa, which will be particularly
helpful while transitioning between using raw PCState instances and
using primarily pointers and references.
This change also adds wrappers which handle std::unique_ptr, which makes
it easier to use them as arguments to these functions. Otherwise, if the
std::unique_ptr is a temporary value, using the return value of .get()
will let the std::unique_ptr go out of scope, making it delete the data
pointed to by the returned pointed. By keeping the std::unique_ptr
around on the stack, that prevents it from going out of scope.
Change-Id: I2c737b08e0590a2c46e212a7b9efa543bdb81ad3
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/52041
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
This method is the seed which creates a new PCState object of the
appropriate type. It can be used to initialize PCStateBase *s so that they
always point to something valid and can be manipulated without having to
first check if there's something there, as opposed to the alternative
where a pointer might be null until it's first pointed at something.
Change-Id: If06ee633846603acbfd2432f3d8bac6746a8b729
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/52040
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The workload would have a better idea of what it's endianness is than
the system object that holds it. This is the first step towards getting
rid of the getByteOrder method on the system object, which currently
checks TARGET_ISA to determine what the default endianness should be.
If it makes sense for a Workload, it could determine the endianness
dynamically by, for instance, reading it out of a binary image before
putting it into memory.
This does assume that the workload has a consistent endianness
throughout which may not be true, but this is not a new assumption.
Also, mark the SEWorkload SimObject class as "abstract", since it isn't
useful until they get subclassed by some arch specific version.
Change-Id: I8d4ba8382f22236a81f9738cc3506cdb97bdbfb2
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/52104
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This will let callers create a separate copy of a PCState class
instance. This makes it more explicit when creating copies of a PCState
to make sure the programmer is more aware, and avoids having to know
what the actual type is to make a copy.
Change-Id: I728a278afdb55b800c753a5b7f65f62f4a80c043
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/52035
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
