arch, base, cpu, dev, mem, sim: Remove #if 0-ed out code.

This code will be preserved through version control, but otherwise
creates clutter and will rot in place since it's never compiled.

Change-Id: Id265f6deac445116843956ea5cf1210d8127274e
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18608
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

dev: Use the new Port role mechanism to make an EtherInt Port type.

This type always uses the same "ETHERNET" role, and all connections are
symmetric and self compatible.

Change-Id: I1d060f8c098d52ae9f65c052f816bc813590ff9c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18171
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch, cpu, dev, gpu, mem, sim, python: start using getPort.

Replace the getMasterPort, getSlavePort, and getEthPort functions
with getPort, and remove extraneous mechanisms that are no longer
necessary.

Change-Id: Iab7e3c02d2f3a0cf33e7e824e18c28646b5bc318
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17040
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

mem: Move bind() and unbind() into the Port class.

These are now pure virtual methods which more specialized port
subclasses will need to implement. The SlavePort class implements them
by ignoring them and then providing parallel functions for the
MasterPort to call. The MasterPort's methods do basically what they
did before, except now bind() uses dynamic cast to check if its peer
is of the appropriate type and also to convert it into that type before
connecting to it.

Change-Id: I0948799bc954acaebf371e6b6612cee1d3023bc4
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17038
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

dev: Make EtherInt inherit from Port.

This way a common function can return EtherInt (and master and slave
ports).

Change-Id: I1215baaad918ef0352b228877241b2b6dd2503fc
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17035
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>

dev: Make the EtherDevice class inherit EtherObject.

This avoids having to define two parallel versions of the getEthPort
function, and the complex dynamic_cast macrame in connectPorts().

Change-Id: I24c09864005ff39a049e50d7245ff17e9480edea
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17029
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

dev: Turn EtherObject into an interface class.

This class used to drive from SimObject so that it could be derived
from to get both the interface and SimObject while still using single
inheritance.

With this change, EtherObject is now just an interface class with only
one pure virtual function which can be inherited alongside SimObject.
This makes it more flexible so that it can be used in places where you
might want a different inheritance hierarchy, for instance to inherit
from MemObject.

Change-Id: I0f07664d104eed012cf4ce6e30c416ada19505a7
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17028
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

python: Don't assume SimObjects live in the global namespace

The importer in Python 3 doesn't like the way we import SimObjects
from the global namespace. Convert the existing SimObject declarations
to import from m5.objects. As a side-effect, this makes these files
consistent with configuration files.

Change-Id: I11153502b430822130722839e1fa767b82a027aa
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15981
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>

dev: Explicitly specify the endianness for packet accessors.

Generally speaking, the endianness of the data devices provide or
accept is dependent on the device and not the ISA the system
executes. This change makes the devices in dev pick an endianness
rather than using the guest's.

For the ISA bus and the UART, accesses are byte sized and so endianness
doesn't matter. The ISA and PCI busses and the devices which use them
are defined to be little endian.

Change-Id: Ib0aa70f192e1d6f3b886d9f3ad41ae03bddb583f
Reviewed-on: https://gem5-review.googlesource.com/c/13462
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

dev: Build most of the networking devices in the NULL_ISA build.

The only part of these devices which are incompatible with other ISAs,
with the possible exception of endianness transformation, is that
the dist_iface implementation refers to ThreadContext methods and
that class is heavily tied to the guest ISA. Only those few lines are
excluded in a NULL_ISA build.

Change-Id: Ic6d643fdbb792d0a996a37d75e027c5ce0ecd460
Reviewed-on: https://gem5-review.googlesource.com/c/13469
Reviewed-by: Gabor Dozsa <gabor.dozsa@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

net: Fix a bug when receiving fragamented packets

In the previous implementation, the function EtherTap::recvReal will only
read one packet when received some ``interrupt'' (explicitly, when async_IO
set to true). When someone tries to send a large message to the simulated
device, the message will be divided to several packets due to packet
fragmentation. In this situation recvReal will only read one packet and
left the other packets in the buffer. This significantly increases the
networking latency. So before reading from socket, I change the socket into
non-blocking mode and keep reading from it until there's no packet left.

Change-Id: Ieb94a8532cd3994862b6f3eb9474caf7ccf617da
Reviewed-on: https://gem5-review.googlesource.com/12338
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

net: Fix a bug when handling IPv6 packets

When gem5 runs with the networking support, it will run into an assertion
fail and aborted. This is because it tries to calculate checksum for IPv6
packet and this makes the IpPtr pointer ``ip'' become NULL. For that there
is functions and classes for IPv6 in base/inet.cc, I added IPv6 support for
i8254xGBe.cc. Because IPv6 header does not have identification number, I
ignored some of the debug messages using ip->id().

Change-Id: Ida5e36aefd2c5c26053f8152a0aac24191e7757c
Reviewed-on: https://gem5-review.googlesource.com/12339
Reviewed-by: Earl Ou <shunhsingou@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

dev: Make sure the EtherTap device uses the right event queue.

The EtherTap device may be called into from an event on the PollQueue when
some event queue other than its own is active. This change ensures that it
switches event queues if necessary before doing anything that may cause more
events to be scheduled.

Change-Id: If8666542d7664780c0b371230e1e5fba93fbc1c0
Reviewed-on: https://gem5-review.googlesource.com/9521
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

dev: Don't fall through into BRAR after RFDR case

If the switch block inside the RFDR case selects the non-default case
and breaks out, it will fall through into the BRAR case, which seems
incorrect. Put in a break to ensure that it breaks out of the parent
switch block as well.

Change-Id: Ie4cedf66954b7e8f4b884ad9e3a653968bbfaef7
Signed-off-by: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com>
Reviewed-on: https://gem5-review.googlesource.com/8563
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

dev: Leave last byte in strncpy for NULL

The length of the strncpy should be one less than the destination to
ensure that there is space for the last NULL byte in case the source
is longer than the destination.

Change-Id: Iea65fa6327c8242bd8ddf4bf9a5a2b5164996495
Signed-off-by: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com>
Reviewed-on: https://gem5-review.googlesource.com/8561
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

misc: Updates for gcc7.2 for x86

GCC 7.2 is much stricter than previous GCC versions. The following changes
are needed:

* There is now a warning if there is an implicit fallthrough between two
case statments. C++17 adds the [[fallthrough]]; declaration. However,
to support non C++17 standards (i.e., C++11), we use M5_FALLTHROUGH.
M5_FALLTHROUGH checks for [[fallthrough]] compliant C++17 compiler and
if that doesn't exist, it defaults to nothing (no older compilers
generate warnings).
* The above resulted in a couple of bugs that were found. This is noted
in the review request on gerrit.
* throw() for dynamic exception specification is deprecated
* There were a couple of new uninitialized variable warnings
* Can no longer perform bitwise operations on a bool.
* Must now include <functional> for std::function
* Compiler bug for void* lambda. Changed to auto as work around. See
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82878

Change-Id: I5d4c782a4e133fa4cdb119e35d9aff68c6e2958e
Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-on: https://gem5-review.googlesource.com/5802
Reviewed-by: Gabe Black <gabeblack@google.com>

misc: Rename misc.(hh|cc) to logging.(hh|cc)

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>

net: Refactor some Event subclasses to lambdas

Change-Id: I0e23f1529b26c36d749bf5211ee8623744d0b10f
Signed-off-by: Sean Wilson <spwilson2@wisc.edu>
Reviewed-on: https://gem5-review.googlesource.com/3927
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>

dev: Replace EventWrapper use with EventFunctionWrapper

Change-Id: I6b03cc6f67e76dffb79940431711ae6171901c6a
Signed-off-by: Sean Wilson <spwilson2@wisc.edu>
Reviewed-on: https://gem5-review.googlesource.com/3748
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

dev: Avoid arbitrarily deep stack depth in the i8254xGBe model.

When it comes time to send a packet with the i8254xGBe model hooked up to
EtherTap and while running in KVM mode, the packet will first go to the
EtherTap over the network style port between them. EtherTap, because it's
not actually a model of anything in the simulation, will immediately pass
the packet off to the real network and report that the transmission was
successful to the i8254xGBe. The i8254xGBe will notice that it still has
stuff it can send (the KVM mode CPU has no trouble keeping it full) and
will, without returning and collapsing the stack, immediately call back
into EtherTap with the next packet. This loop repeats, continually
deepening the stack, until gem5 crashes with a segfault.

To break this loop, a few small changes have been made. First, txFifoTick
has been repurposed slightly so that it continuously keeps track of
whether there's still work to do to flush out the fifo during the current
tick. The code in txWire has been adjusted slightly so that it clears that
variable at the start (also removing some redundancy), so that other code
can set it again if more work needs to be done. Specifically, the
ethTxDone function will set that flag.

If there's more work to be done flushing the Fifo while in tick(), it
will loop until txFifoTick stays cleared, meaning either the Fifo is
empty, or the object on the other end hasn't said it's done yet.

Finally, a new bool member called inTick has been added which keeps track
of whether the tick() function is still active somewhere in the callstack.
If it is, then the tick event shouldn't be rescheduled in ethTxDone, since
tick will take care of that before it returns. It won't check to see if it
needs to, and so without this check there's a panic from scheduling the
same event twice.

It's not completely clear that the Fifo should send packets over and over
as fast as the other side accepts them within the same tick, although it's
not clear that it shouldn't either. If not, then probably all that would
need to change would be to remove the "while" loop so that the tick event
would be rescheduled, and the Fifo would be further emptied the next time
around.

Change-Id: I653379b43389d0539ecfadb3fc6c40e38a8864c2
Reviewed-on: https://gem5-review.googlesource.com/3642
Reviewed-by: Andreas Hansson <andreas.hansson@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>

dev: Add a version of EtherTap which uses the tap driver.

The object is called EtherTap (as opposed to EtherTapStub, what the former
EtherTap was renamed to), and its existance is gated on the linux/if_tun.h
header file existing. That's probably overly strict, but it will hopefully
be minimally likely to break the build for other systems.

Change-Id: Ie03507fadf0d843a4d4d52f283c44a416c6f2a74
Reviewed-on: https://gem5-review.googlesource.com/3646
Reviewed-by: Nathan Binkert <nate@binkert.org>
Maintainer: Nathan Binkert <nate@binkert.org>

dev: Refactor the EtherTapStub to make room for using tap.

A lot of the implementation of EtherTapStub can be shared with a version
which uses a tap device directly. This change factors out those parts to
accommodate that.

Change-Id: I9c2e31f1be139ca73859a83f05457cef90101006
Reviewed-on: https://gem5-review.googlesource.com/3645
Reviewed-by: Nathan Binkert <nate@binkert.org>
Maintainer: Nathan Binkert <nate@binkert.org>

dev: Rename EtherTap to be EtherTapStub.

The EtherTap object is going to be reworked so that it connects to a tap
device directly, but it's worthwhile to still be able to use the m5tap
utility (util/tap) to send/receive packets on systems which don't support
tap but do support the pcap API. It can also be used to replay ethernet
frames, to capture the ethernet frames coming from gem5 for analysis, to
programmatically consume and/or generate the frames, or even to forward
them to/from a remote system.

Change-Id: Ic7bd763d86cd913ac373dd10a8d6d1fc6b35f95a
Reviewed-on: https://gem5-review.googlesource.com/3644
Reviewed-by: Nathan Binkert <nate@binkert.org>
Maintainer: Nathan Binkert <nate@binkert.org>

dev: Add a missing parameter to the EtherTap device.

There needs to be a SlavePort called "tap" for the ethertap device to be
able to connect to the gem5 network successfully.

Change-Id: I1ad81219f612fd1ec278c6148af728d20bc916da
Reviewed-on: https://gem5-review.googlesource.com/3580
Reviewed-by: Nathan Binkert <nate@binkert.org>
Maintainer: Nathan Binkert <nate@binkert.org>

base, sim, dev: Remove SWIG

Remove SWIG guards and SWIG-specific C++ code.

Change-Id: Icaad6720513b6f48153727ef3f70e0dba0df4bee
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Andreas Hansson <andreas.hansson@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2921
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Tony Gutierrez <anthony.gutierrez@amd.com>

dev: net/i8254xGBe add two more wakeup registers to ignore

There are drivers writing to WUFC uncondtionally of anything. In order to
not panic gem5 in these cases, ignore writes to WUFC and WUS as we do for
WUC. Similarly return 0 (default reset value) on reads.

Testing Done: Booted in FS with such a driver revision which would
previously panic and now boots fine.

Reviewed at http://reviews.gem5.org/r/3791/

Signed-off-by: Jason Lowe-Power <jason@lowepower.com>

style: [patch 3/22] reduce include dependencies in some headers

Used cppclean to help identify useless includes and removed them. This
involved erroneously included headers, but also cases where forward
declarations could have been used rather than a full include.

dev: Fix race conditions at terminating dist-gem5 simulations

Two problems may arise when a distributed gem5 simulation terminates:
(i) simulation thread(s) may get stuck in an incomplete synchronisation
event which prohibits processing the simulation exit event; and (ii) a
stale receiver thread may try to access objects that have already been
deleted while exiting gem5. This patch terminates receive threads properly
and aborts the processing of any incomplete synchronisation event.

Change-Id: I72337aa12c7926cece00309640d478b61e55a429
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>

dev: Fix buffer length when unserializing an eth pkt

Changeset 11701 only serialized the useful portion of of an ethernet packets'
payload. However, the device models expect each ethernet packet to contain
a 16KB buffer, even if there is no data in it. This patch adds a 'bufLength'
field to EthPacketData so the original size of the packet buffer can always
be unserialized.

Reported-by: Gabor Dozsa <Gabor.Dozsa@arm.com>

dev: Add m5 op to toggle synchronization for dist-gem5.
This patch adds the ability for an application to request dist-gem5 to begin/
end synchronization using an m5 op. When toggling on sync, all nodes agree
on the next sync point based on the maximum of all nodes' ticks. CPUs are
suspended until the sync point to avoid sending network messages until sync has
been enabled. Toggling off sync acts like a global execution barrier, where
all CPUs are disabled until every node reaches the toggle off point. This
avoids tricky situations such as one node hitting a toggle off followed by a
toggle on before the other nodes hit the first toggle off.

dev: Add 'simLength' parameter in EthPacketData
Currently, all the network devices create a 16K buffer for the 'data' field
in EthPacketData, and use 'length' to keep track of the size of the packet
in the buffer. This patch introduces the 'simLength' parameter to
EthPacketData, which is used to hold the effective length of the packet used
for all timing calulations in the simulator. Serialization is performed using
only the useful data in the packet ('length') and not necessarily the entire
original buffer.

dev: Exit correctly in dist-gem5
The receiver thread in dist_iface is allowed to directly exit the simulation.
This can cause exit to be called twice if the main thread simultaneously wants
to exit the simulation. Therefore, have the receiver thread enqueue a request
to exit on the primary event queue for the main simulation thread to handle.

dev, dist: Fixed a scheduling bug in the etherswitch

This patch fixes a bug in etherswitch. When a packet gets inserted
in the output fifo, the txEvent has to always be reschedule,
not only when an event is already scheduled. This can raise
the assertion in the reschedule function.

dist, dev: Fixed the packet ordering in etherswitch

This patch fixes the order that packets gets pushed into the output fifo
of etherswitch. If two packets arrive at the same tick to the etherswitch,
we sort and push them based on their source port id.
In dist-gem5 simulations, if there is no ordering inforced while two
packets arrive at the same tick, it can lead to non-deterministic simulations

Committed by Jason Lowe-Power <power.jg@gmail.com>

sim: Call regStats of base-class as well

We want to extend the stats of objects hierarchically and thus it is necessary
to register the statistics of the base-class(es), as well. For now, these are
empty, but generic stats will be added there.

Patch originally provided by Akash Bagdia at ARM Ltd.

base: Add support for changing output directories

This changeset adds support for changing the simulator output
directory. This can be useful when the simulation goes through several
stages (e.g., a warming phase, a simulation phase, and a verification
phase) since it allows the output from each stage to be located in a
different directory. Relocation is done by calling core.setOutputDir()
from Python or simout.setOutputDirectory() from C++.

This change affects several parts of the design of the gem5's output
subsystem. First, files returned by an OutputDirectory instance (e.g.,
simout) are of the type OutputStream instead of a std::ostream. This
allows us to do some more book keeping and control re-opening of files
when the output directory is changed. Second, new subdirectories are
OutputDirectory instances, which should be used to create files in
that sub-directory.

Signed-off-by: Andreas Sandberg <andreas@sandberg.pp.se>
[sascha.bischoff@arm.com: Rebased patches onto a newer gem5 version]
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>

misc: Add missing overrides to appease clang

Since the last round of fixes a few new issues have snuck in. We
should consider switching the regression runs to clang.

style: eliminate explicit boolean comparisons

Result of running 'hg m5style --skip-all --fix-control -a' to get
rid of '== true' comparisons, plus trivial manual edits to get
rid of '== false'/'== False' comparisons.

Left a couple of explicit comparisons in where they didn't seem
unreasonable:
invalid boolean comparison in src/arch/mips/interrupts.cc:155
>> DPRINTF(Interrupt, "Interrupts OnCpuTimerINterrupt(tc) == true\n");<<
invalid boolean comparison in src/unittest/unittest.hh:110
>> "EXPECT_FALSE(" #expr ")", (expr) == false)<<

style: remove trailing whitespace

Result of running 'hg m5style --skip-all --fix-white -a'.

dist, dev: add an ethernet switch model

sim: don't ignore SIG_TRAP

By ignoring SIG_TRAP, using --debug-break <N> when not connected to
a debugger becomes a no-op. Apparently this was intended to be a
feature, though the rationale is not clear.

If we don't ignore SIG_TRAP, then using --debug-break <N> when not
connected to a debugger causes the simulation process to terminate
at tick N. This is occasionally useful, e.g., if you just want to
collect a trace for a specific window of execution then you can combine
this with --debug-start to do exactly that.

In addition to not ignoring the signal, this patch also updates
the --debug-break help message and deletes a handful of unprotected
calls to Debug::breakpoint() that relied on the prior behavior.

scons: Enable -Wextra by default

Make best use of the compiler, and enable -Wextra as well as
-Wall. There are a few issues that had to be resolved, but they are
all trivial.

dev: Distributed Ethernet link for distributed gem5 simulations

Distributed gem5 (abbreviated dist-gem5) is the result of the
convergence effort between multi-gem5 and pd-gem5 (from Univ. of
Wisconsin). It relies on the base multi-gem5 infrastructure for packet
forwarding, synchronisation and checkpointing but combines those with
the elaborated network switch model from pd-gem5.

dev: Move network devices to src/dev/net/