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>

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>

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>

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>

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: 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>

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 '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.

style: remove trailing whitespace

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

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