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/*
* 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.
*/
#ifndef __SIM_SC_MODULE_HH__
#define __SIM_SC_MODULE_HH__
#include <systemc>
#include "sim/eventq.hh"
#include "sim/sim_events.hh"
namespace Gem5SystemC
{
/** A SystemC module implementing the gem5 event queue. This object
* doesn't actually own any of the simulation SimObjects (those need
* to be administered separately) but it does control the event
* queue.
*
* The event loop here services gem5 events in order at the current time
* and then yielding to another SystemC thread. gem5 events are not
* individually scheduled in SystemC. For this reason, asynchronous events
* and function interaction (for example TLM) with gem5 from SystemC must
* notify the module so that the yielding 'wait' can be interrupted.
* From the point of view of another SystemC module calling into gem5,
* curTick can lag SystemC time, be exactly the same time but *never*
* lead SystemC time.
*
* This functionality is wrapped in an sc_module as its intended that
* the a class representing top level simulation control should be derived
* from this class. */
class Module : public sc_core::sc_channel
{
protected:
/** Event to trigger (via. ::notify) for event scheduling from
* outside gem5 */
sc_core::sc_event externalSchedulingEvent;
/** Event to trigger on exit of eventLoop */
sc_core::sc_event eventLoopExitEvent;
/** Event to trigger to enter eventLoop */
sc_core::sc_event eventLoopEnterEvent;
/** Expected exit time of last eventLoop sleep */
Tick wait_exit_time;
/** Are we in Module::simulate? Used to mask events when not inside
* the simulate loop */
bool in_simulate;
/** Placeholder base class for a variant event queue if this becomes
* useful */
class SCEventQueue : public EventQueue
{
protected:
Module &module;
public:
SCEventQueue(const std::string &name,
Module &module_) : EventQueue(name), module(module_)
{ }
/** Signal module to wakeup */
void wakeup(Tick when);
};
/** Service any async event marked up in the globals event_... */
void serviceAsyncEvent();
public:
/** Simulate is a process */
SC_HAS_PROCESS(Module);
Module(sc_core::sc_module_name name);
/** Last exitEvent from eventLoop */
Event *exitEvent;
/** Setup global event queues. Call this before any other event queues
* are created */
static void setupEventQueues(Module &module);
/** Catch gem5 time up with SystemC */
void catchup();
/** Notify an externalSchedulingEvent at the given time from the
* current SystemC time */
void notify(sc_core::sc_time time_from_now = sc_core::SC_ZERO_TIME);
/** Process an event triggered by externalSchedulingEvent and also
* call eventLoop (to try and mop up any events at this time) if there
* are any scheduled events */
void serviceExternalEvent();
/** Process gem5 events up until an exit event or there are no events
* left. */
void eventLoop();
/** Run eventLoop up to num_cycles and return the final event */
GlobalSimLoopExitEvent *simulate(Tick num_cycles = MaxTick);
};
/** There are assumptions throughout Gem5SystemC file that a tick is 1ps.
* Make this the case */
void setTickFrequency();
}
#endif // __SIM_SC_MODULE_HH__