systemc: Ensure resets and edges are notified when signaling a change.

Boolean sc_buffers (either pure bool or sc_dt::sc_logic) should signal
positive and negative edges and resets even when their value doesn't
change, unlike sc_signals. The spec doesn't actually say that and just
mentions the value changed event, but it may have been implied that the
other types of events also happen, they just made special mention of
the value change event.

This change moves some code around a bit so that when _signalChange()
is called, if the underlying type is a boolean signal, it will
automatically notify the appropriate edge event and signal any reset.
Putting the functionality in _signalChange instead of delegating it to
the sc_buffer lets us have a single template for sc_buffer and makes
the base class template specialization handle whether the edge events
exist, and if so which should be notified.

Change-Id: Ic4ca86afc3fde6a9df5c15a0a7386e24ac89a9e2
Reviewed-on: https://gem5-review.googlesource.com/c/14916
Reviewed-by: Matthias Jung <jungma@eit.uni-kl.de>
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Get rid of an unused private member in sc_clock.

It's not useful, and having it makes clang upset.

Change-Id: I51366fd18a287e186c88f08af5c6ba8692779003
Reviewed-on: https://gem5-review.googlesource.com/c/13876
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Get rid of leftovers from unimplemented warnings past.

These warnings were removed when the functionality they warned about
was implemented, but there were some leftovers like unnecessary
includes and some helper functions which hid gem5 specific headers
from the ext directory.

Change-Id: Ic886ac0f1264687524e3a7b7eaab8836f318a5a2
Reviewed-on: https://gem5-review.googlesource.com/c/13398
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Switch to using predefined messages for channels.

Create and use predefined messages for channels which match the ones
Accellera uses.

Change-Id: I179214838bbd83604e50225926cdc6b5b1b16923
Reviewed-on: https://gem5-review.googlesource.com/c/13330
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Add a range check to the intial value of sc_semaphore.

Change-Id: I4e1ef90b14074e5a2794a4386e411397213b2789
Reviewed-on: https://gem5-review.googlesource.com/c/13304
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Add some error checks to sc_clock.

The Accellera version reports an error if the period, high or low
portions of the clock are zero.

Change-Id: I2cbb7c3a1b6abe4d969ef875ebf8754d2d1c489a
Reviewed-on: https://gem5-review.googlesource.com/c/13303
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Change how signal based resets work.

The previous implementation used the value changed event to track when
signals changed value, but there were a couple problems with this
approach. First, this piggybacked on the sensitivity mechanism in some
ways, but diverged in others. The sensitivity didn't notify a process
when it was satisfied like other sensitivity types would, and it also
ignored whether the process was disabled.

Second, the value_changed_event is notified by a signal instance as a
delta notification, but reset signals are supposed to act immediately.
That means they should happen before all delta notifications, or in
other words all delta notifications should see the reset status of a
given process. That's particularly important in the case of wait(int n)
where setting the reset clears the reset count, and the count is
checked when determining whether or not to wake up a process when its
sensitivity is satisfied, potentially by a delta notification.

Third, by removing the middle man and not trying to repurpose the
sensitivity mechanism, the code gets simpler and easier to understand.

Change-Id: I0d05d11437291d368b060f6a45a207813615f113
Reviewed-on: https://gem5-review.googlesource.com/c/13294
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Fix a typo in one of the error messages.

This typo was added purposefully to match Accellera's output, but then
it was discovered that some test's golden output had the typo, and some
didn't. That must mean that not all tests have up to date output, and
that Accellera couldn't possibly pass all of their own tests.

To resolve this conflict, this change fixes the typo and manually
updates all the golden output.

Change-Id: I3d80f74ff21e844609e7bde5dfcd99fc56c085b0
Reviewed-on: https://gem5-review.googlesource.com/c/13204
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Implement writer policies.

This includes the nonstandard SC_NO_WRITE_CHECK #define which the
Accellera tests use and depend on.

Change-Id: I106c4c16160325725a00d5c337047251817dca32
Reviewed-on: https://gem5-review.googlesource.com/c/13203
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Implement register_port in all the predefined channels.

Something the Accellera implementation does which would be good to do
in the gem5 implementation is to create a base class for sc_signal
which isn't templated, and which holds the common/non-type specific
versions of the various sc_signal methods. This will reduce code
redundancy and binary size, and also let us hide more code in .cc
files so that it's less likely we'd need to recompile model code to
fix a bug.

Also, since this all uses of sc_channel_warn_unimple have now been
eliminated, remove that function.

Change-Id: Ia574647c034e7136093c2047b69de725ac34f52f
Reviewed-on: https://gem5-review.googlesource.com/c/13200
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Implement sc_event_queue.

Change-Id: I58fd72b8c64ee82eb478d810f7114bab7a31cbfa
Reviewed-on: https://gem5-review.googlesource.com/c/13184
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Change an error message to match the reference outputs.

This is different from the message the Accellera implementation would
print, so it looks like it wouldn't pass this test as is.

Change-Id: I0286fd3e3df7bc3e87f38c35086a32d8dec0bcc9
Reviewed-on: https://gem5-review.googlesource.com/c/12814
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Implement the sc_*_resolved classes.

Change-Id: Ib595da10e0f900ee4cc1847d41d29251dacb55d7
Reviewed-on: https://gem5-review.googlesource.com/c/12620
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Implement the sc_clock::time_stamp function.

This is just a non-standard static alias for the sc_time_stamp
function.

Change-Id: Ibcd0559e7dab8232528628259abb8d1bfaee16e0
Reviewed-on: https://gem5-review.googlesource.com/c/12619
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Implement sc_mutex.

Change-Id: I8a5bd03b46d44aeca3bba15a01a5f2180b4ed5c7
Reviewed-on: https://gem5-review.googlesource.com/c/12618
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Implement sc_semaphore.

Change-Id: I778d41bd81880e76caa71dc92359a00127d8f987
Reviewed-on: https://gem5-review.googlesource.com/c/12617
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Keep all pre-init processes on a single list.

We were keeping track of processes which should be initialized and
those which shouldn't on two different lists, and then processing
each list one after the other. This could reorder processes from the
order they were created, and so cause spurious differences which cause
the Accellera tests to fail.

This does make the scheduler slightly simpler, so it's not all bad.

Change-Id: I63306a41ce7bea91fa9ff2f6774ce9150134ce48
Reviewed-on: https://gem5-review.googlesource.com/c/12613
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Change how sc_clock creates processes to match the tests.

Accellera sets up the mechanism which toggles sc_clock differently
than it's set up in gem5. This change moves things around a little to
more closely match the order things are done by Accellera so that the
test output matches.

Change-Id: Ia6d327f4cd5d689f6969398f02a66278a3dc010c
Reviewed-on: https://gem5-review.googlesource.com/c/12609
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Warn if a process is dont_initialize with no static sensitivieis.

Change-Id: I4db64f42872a6fb459faa401abdad3f168297347
Reviewed-on: https://gem5-review.googlesource.com/c/12599
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Raise an error when SC_METHOD, etc. is used after starting.

Those mechanisms for creating processes are only allowed before the
end of elaboration, or in other words before sc_start is called.
Technically the check in Accellera's implementation won't trigger if
the simulation is stopped, and we immitate that behavior.

Change-Id: I9b8b5bd32f876781b6e0d5c0ee0e09de19bdabc1
Reviewed-on: https://gem5-review.googlesource.com/c/12447
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Implement a significant portion of sc_clock.

Change-Id: Ic195f46ac13b46a02c86a5fc8d90ba66a415a9c8
Reviewed-on: https://gem5-review.googlesource.com/12215
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Add the nonstandard time_stamp function.

Change-Id: I608c390b125611e5b62483c7e8567bb5479df553
Reviewed-on: https://gem5-review.googlesource.com/11281
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Add some deprecated features to sc_clock.*.

Add in two deprecated typedefs, and a deprecated constructor. These
are necessary to get the regressions to build.

Change-Id: Id8320a67c680acbca0abaee9898158ffd2678d67
Reviewed-on: https://gem5-review.googlesource.com/11183
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Stub out the predefined channels.

Change-Id: Ie030aad26875bd49e54981ec1e9076b7b5af6630
Reviewed-on: https://gem5-review.googlesource.com/10839
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>