util/systemc/gem5_within_systemc/sc_module.cc - public/gem5 - Git at Google

 /*
  * 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.
  */

 /**
  * @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 <cassert>

 #include "base/compiler.hh"
 #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/cur_tick.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()
 {
     ::gem5::setClockFrequency(1000000000000);
     ::gem5::fixClockFrequency();
 }

 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(gem5::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");

     gem5::numMainEventQueues = 1;
     gem5::mainEventQueue.push_back(new SCEventQueue("events", module));
     gem5::curEventQueue(getEventQueue(0));
 }

 void
 Module::catchup()
 {
     gem5::EventQueue *eventq = getEventQueue(0);
     gem5::Tick systemc_time = sc_core::sc_time_stamp().value();
     gem5::Tick gem5_time = gem5::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()) {
         gem5::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()
 {
     gem5::EventQueue *eventq = gem5::getEventQueue(0);
     std::lock_guard<gem5::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 */
     gem5::Tick systemc_time = sc_core::sc_time_stamp().value();

     /* Move time on to match SystemC */
     catchup();

     async_event = false;
     if (async_statdump || async_statreset) {
         statistics::schedStatEvent(async_statdump, async_statreset);
         async_statdump = false;
         async_statreset = false;
     }

     if (async_exit) {
         async_exit = false;
         gem5::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()
 {
     gem5::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()
 {
     gem5::EventQueue *eventq = getEventQueue(0);

     fatal_if(!in_simulate, "Gem5SystemC event loop entered while"
         " outside Gem5SystemC::Module::simulate");

     if (async_event)
         serviceAsyncEvent();

     while (!eventq->empty()) {
         gem5::Tick next_event_time = eventq->nextTick();

         /* Move time on to match SystemC */
         catchup();

         gem5::Tick gem5_time = gem5::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) {
             gem5::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) {
             gem5::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...",
         gem5::curTick());

     if (num_cycles < gem5::MaxTick - gem5::curTick())
         num_cycles = gem5::curTick() + num_cycles;
     else /* counter would roll over or be set to MaxTick anyhow */
         num_cycles = gem5::MaxTick;

     gem5::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 */
     gem5::BaseGlobalEvent *global_event = exitEvent->globalEvent();
     assert(global_event != NULL);

     gem5::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;
 }

 } // namespace Gem5SystemC
	/*
	* 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.
	*/

	/**
	* @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 <cassert>

	#include "base/compiler.hh"
	#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/cur_tick.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()
	{
	::gem5::setClockFrequency(1000000000000);
	::gem5::fixClockFrequency();
	}

	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(gem5::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");

	gem5::numMainEventQueues = 1;
	gem5::mainEventQueue.push_back(new SCEventQueue("events", module));
	gem5::curEventQueue(getEventQueue(0));
	}

	void
	Module::catchup()
	{
	gem5::EventQueue *eventq = getEventQueue(0);
	gem5::Tick systemc_time = sc_core::sc_time_stamp().value();
	gem5::Tick gem5_time = gem5::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()) {
	gem5::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()
	{
	gem5::EventQueue *eventq = gem5::getEventQueue(0);
	std::lock_guard<gem5::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 */
	gem5::Tick systemc_time = sc_core::sc_time_stamp().value();

	/* Move time on to match SystemC */
	catchup();

	async_event = false;
	if (async_statdump \|\| async_statreset) {
	statistics::schedStatEvent(async_statdump, async_statreset);
	async_statdump = false;
	async_statreset = false;
	}

	if (async_exit) {
	async_exit = false;
	gem5::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()
	{
	gem5::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()
	{
	gem5::EventQueue *eventq = getEventQueue(0);

	fatal_if(!in_simulate, "Gem5SystemC event loop entered while"
	" outside Gem5SystemC::Module::simulate");

	if (async_event)
	serviceAsyncEvent();

	while (!eventq->empty()) {
	gem5::Tick next_event_time = eventq->nextTick();

	/* Move time on to match SystemC */
	catchup();

	gem5::Tick gem5_time = gem5::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) {
	gem5::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) {
	gem5::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...",
	gem5::curTick());

	if (num_cycles < gem5::MaxTick - gem5::curTick())
	num_cycles = gem5::curTick() + num_cycles;
	else /* counter would roll over or be set to MaxTick anyhow */
	num_cycles = gem5::MaxTick;

	gem5::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 */
	gem5::BaseGlobalEvent *global_event = exitEvent->globalEvent();
	assert(global_event != NULL);

	gem5::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;
	}

	} // namespace Gem5SystemC