util: Move the existing systemc example into a subdirectory.

This example is for how to embed gem5 within systemc and make it use
the systemc event queue. This used to be the only method of using
gem5 and systemc together, but now that there are other options, it's
ambiguous to have it as the only thing in the util/systemc directory.

This change moves it into a gem5_within_systemc subdirectory which
clearly shows what type of integration that example corresponds with.

Change-Id: I426d68ccb618397d820bef492cbb1ff8ef4a979b
Reviewed-on: https://gem5-review.googlesource.com/c/13375
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

1 files changed, 0 insertions, 300 deletions

diff --git a/util/systemc/sc_module.cc b/util/systemc/sc_module.cc
deleted file mode 100644
index dafa80ee9..000000000
--- a/util/systemc/sc_module.cc
+++ /dev/null
@@ -1,300 +0,0 @@
-/*
- * Copyright (c) 2014 ARM Limited
- * All rights reserved
- *
- * The license below extends only to copyright in the software and shall
- * not be construed as granting a license to any other intellectual
- * property including but not limited to intellectual property relating
- * to a hardware implementation of the functionality of the software
- * licensed hereunder.  You may use the software subject to the license
- * terms below provided that you ensure that this notice is replicated
- * unmodified and in its entirety in all distributions of the software,
- * modified or unmodified, in source code or in binary form.
- *
- * Copyright (c) 2006 The Regents of The University of Michigan
- * Copyright (c) 2013 Advanced Micro Devices, Inc.
- * Copyright (c) 2013 Mark D. Hill and David A. Wood
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met: redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer;
- * redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution;
- * neither the name of the copyright holders nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * Authors: Nathan Binkert
- *          Steve Reinhardt
- *          Andrew Bardsley
- *          Matthias Jung
- *          Christian Menard
- */
-
-/**
- * @file
- *
- * Defines an sc_module type to wrap a gem5 simulation.  The 'evaluate'
- * thread on that module implements the gem5 event loop.
- *
- * This currently only supports a single event queue and strictly
- * cooperatively threaded SystemC threads and so there should be at
- * most one Gem5Module instantiated in any simulation.
- */
-
-#include "base/logging.hh"
-#include "base/pollevent.hh"
-#include "base/trace.hh"
-#include "debug/Event.hh"
-#include "sc_module.hh"
-#include "sim/async.hh"
-#include "sim/core.hh"
-#include "sim/eventq.hh"
-#include "sim/sim_exit.hh"
-#include "sim/stat_control.hh"
-
-namespace Gem5SystemC
-{
-
-/** There are assumptions throughout Gem5SystemC file that a tick is 1ps.
- *  Make this the case */
-void
-setTickFrequency()
-{
-    ::setClockFrequency(1000000000000);
-}
-
-Module::Module(sc_core::sc_module_name name) : sc_core::sc_channel(name),
-    in_simulate(false)
-{
-    SC_METHOD(eventLoop);
-    sensitive << eventLoopEnterEvent;
-    dont_initialize();
-
-    SC_METHOD(serviceExternalEvent);
-    sensitive << externalSchedulingEvent;
-    dont_initialize();
-}
-
-void
-Module::SCEventQueue::wakeup(Tick when)
-{
-    DPRINTF(Event, "waking up SCEventQueue\n");
-    /* Don't bother to use 'when' for now */
-    module.notify();
-}
-
-void
-Module::setupEventQueues(Module &module)
-{
-    fatal_if(mainEventQueue.size() != 0,
-        "Gem5SystemC::Module::setupEventQueues must be called"
-        " before any gem5 event queues are set up");
-
-    numMainEventQueues = 1;
-    mainEventQueue.push_back(new SCEventQueue("events", module));
-    curEventQueue(getEventQueue(0));
-}
-
-void
-Module::catchup()
-{
-    EventQueue *eventq = getEventQueue(0);
-    Tick systemc_time = sc_core::sc_time_stamp().value();
-    Tick gem5_time = curTick();
-
-    /* gem5 time *must* lag SystemC as SystemC is the master */
-    fatal_if(gem5_time > systemc_time, "gem5 time must lag SystemC time"
-        " gem5: %d SystemC: %d", gem5_time, systemc_time);
-
-    eventq->setCurTick(systemc_time);
-
-    if (!eventq->empty()) {
-        Tick next_event_time M5_VAR_USED = eventq->nextTick();
-
-        fatal_if(gem5_time > next_event_time,
-            "Missed an event at time %d gem5: %d, SystemC: %d",
-            next_event_time, gem5_time, systemc_time);
-    }
-}
-
-void
-Module::notify(sc_core::sc_time time_from_now)
-{
-    externalSchedulingEvent.notify(time_from_now);
-}
-
-void
-Module::serviceAsyncEvent()
-{
-    EventQueue *eventq = getEventQueue(0);
-    std::lock_guard<EventQueue> lock(*eventq);
-
-    assert(async_event);
-
-    /* Catch up gem5 time with SystemC time so that any event here won't
-     * be in the past relative to the current time */
-    Tick systemc_time = sc_core::sc_time_stamp().value();
-
-    /* Move time on to match SystemC */
-    catchup();
-
-    async_event = false;
-    if (async_statdump || async_statreset) {
-        Stats::schedStatEvent(async_statdump, async_statreset);
-        async_statdump = false;
-        async_statreset = false;
-    }
-
-    if (async_exit) {
-        async_exit = false;
-        exitSimLoop("user interrupt received");
-    }
-
-    if (async_io) {
-        async_io = false;
-        pollQueue.service();
-    }
-
-    if (async_exception)
-        fatal("received async_exception, shouldn't be possible");
-}
-
-void
-Module::serviceExternalEvent()
-{
-    EventQueue *eventq = getEventQueue(0);
-
-    if (!in_simulate && !async_event)
-        warn("Gem5SystemC external event received while not in simulate");
-
-    if (async_event)
-        serviceAsyncEvent();
-
-    if (in_simulate && !eventq->empty())
-        eventLoop();
-}
-
-void
-Module::eventLoop()
-{
-    EventQueue *eventq = getEventQueue(0);
-
-    fatal_if(!in_simulate, "Gem5SystemC event loop entered while"
-        " outside Gem5SystemC::Module::simulate");
-
-    if (async_event)
-        serviceAsyncEvent();
-
-    while (!eventq->empty()) {
-        Tick next_event_time = eventq->nextTick();
-
-        /* Move time on to match SystemC */
-        catchup();
-
-        Tick gem5_time = curTick();
-
-        /* Woken up early */
-        if (wait_exit_time > sc_core::sc_time_stamp().value()) {
-            DPRINTF(Event, "Woken up early\n");
-            wait_exit_time = sc_core::sc_time_stamp().value();
-        }
-
-        if (gem5_time < next_event_time) {
-            Tick wait_period = next_event_time - gem5_time;
-            wait_exit_time = gem5_time + wait_period;
-
-            DPRINTF(Event, "Waiting for %d ticks for next gem5 event\n",
-                wait_period);
-
-            /* The next event is scheduled in the future, wait until
-             *  then or until externalSchedulingEvent */
-            eventLoopEnterEvent.notify(sc_core::sc_time::from_value(
-                sc_dt::uint64(wait_period)));
-
-            return;
-        } else if (gem5_time > next_event_time) {
-            Tick systemc_time = sc_core::sc_time_stamp().value();
-
-            /* Missed event, for some reason the above test didn't work
-             *  or an event was scheduled in the past */
-            fatal("Missed an event at time %d gem5: %d, SystemC: %d",
-                next_event_time, gem5_time, systemc_time);
-        } else {
-            /* Service an event */
-            exitEvent = eventq->serviceOne();
-
-            if (exitEvent) {
-                eventLoopExitEvent.notify(sc_core::SC_ZERO_TIME);
-                return;
-            }
-        }
-    }
-
-    fatal("Ran out of events without seeing exit event");
-}
-
-GlobalSimLoopExitEvent *
-Module::simulate(Tick num_cycles)
-{
-    inform("Entering event queue @ %d.  Starting simulation...", curTick());
-
-    if (num_cycles < MaxTick - curTick())
-        num_cycles = curTick() + num_cycles;
-    else /* counter would roll over or be set to MaxTick anyhow */
-        num_cycles = MaxTick;
-
-    GlobalEvent *limit_event = new GlobalSimLoopExitEvent(num_cycles,
-        "simulate() limit reached", 0, 0);
-
-    exitEvent = NULL;
-
-    /* Cancel any outstanding events */
-    eventLoopExitEvent.cancel();
-    externalSchedulingEvent.cancel();
-
-    in_simulate = true;
-    eventLoopEnterEvent.notify(sc_core::SC_ZERO_TIME);
-
-    /* Wait for event queue to exit, guarded by exitEvent just incase
-     *  it already has exited and we don't want to completely rely
-     *  on notify semantics */
-    if (!exitEvent)
-        wait(eventLoopExitEvent);
-
-    /* Cancel any outstanding event loop entries */
-    eventLoopEnterEvent.cancel();
-    in_simulate = false;
-
-    /* Locate the global exit event */
-    BaseGlobalEvent *global_event = exitEvent->globalEvent();
-    assert(global_event != NULL);
-
-    GlobalSimLoopExitEvent *global_exit_event =
-        dynamic_cast<GlobalSimLoopExitEvent *>(global_event);
-    assert(global_exit_event != NULL);
-
-    if (global_exit_event != limit_event) {
-        limit_event->deschedule();
-        delete limit_event;
-    }
-
-    return global_exit_event;
-}
-
-}