dvfs_handler.hh

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/*
 * Copyright (c) 2013-2014 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.
 *
 * 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
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 * 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,
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 *
 * Authors: Vasileios Spiliopoulos
 *          Akash Bagdia
 *          Stephan Diestelhorst
 */

#ifndef __SIM_DVFS_HANDLER_HH__
#define __SIM_DVFS_HANDLER_HH__

#include <vector>

#include "debug/DVFS.hh"
#include "params/DVFSHandler.hh"
#include "sim/clock_domain.hh"
#include "sim/eventq.hh"
#include "sim/sim_object.hh"

class DVFSHandler : public SimObject
{
  public:
    typedef DVFSHandlerParams Params;
    DVFSHandler(const Params *p);

    typedef SrcClockDomain::DomainID DomainID;
    typedef SrcClockDomain::PerfLevel PerfLevel;

    uint32_t numDomains() const { return domainIDList.size(); }

    DomainID domainID(uint32_t index) const;

    bool validDomainID(DomainID domain_id) const;

    Tick transLatency() const { return _transLatency; }

    bool perfLevel(DomainID domain_id, PerfLevel perf_level);

    PerfLevel perfLevel(DomainID domain_id) const {
         assert(isEnabled());
         return findDomain(domain_id)->perfLevel();
    }

    Tick clkPeriodAtPerfLevel(DomainID domain_id, PerfLevel perf_level) const
    {
        SrcClockDomain *d = findDomain(domain_id);
        assert(d);
        PerfLevel n = d->numPerfLevels();
        if (perf_level < n)
            return d->clkPeriodAtPerfLevel(perf_level);

        warn("DVFSHandler %s reads illegal frequency level %u from "\
             "SrcClockDomain %s. Returning 0\n", name(), perf_level, d->name());
        return Tick(0);
    }

    double voltageAtPerfLevel(DomainID domain_id, PerfLevel perf_level) const;

    PerfLevel numPerfLevels(PerfLevel domain_id) const
    {
        return findDomain(domain_id)->numPerfLevels();
    }

    bool isEnabled() const { return enableHandler; }

    void serialize(CheckpointOut &cp) const override;
    void unserialize(CheckpointIn &cp) override;

  private:
    typedef std::map<DomainID, SrcClockDomain*> Domains;
    Domains domains;

    std::vector<DomainID> domainIDList;

    SrcClockDomain* sysClkDomain;

    SrcClockDomain *findDomain(DomainID domain_id) const {
        auto it = domains.find(domain_id);
        panic_if(it == domains.end(),
                 "DVFS: Could not find a domain for ID %d.\n",domain_id );
        return domains.find(domain_id)->second;
    }

    bool enableHandler;


    const Tick _transLatency;



    struct UpdateEvent : public Event {
        UpdateEvent() : Event(DVFS_Update_Pri), domainIDToSet(0),
                        perfLevelToSet(0) {}

        static DVFSHandler *dvfsHandler;

        DomainID domainIDToSet;

        PerfLevel perfLevelToSet;

        void updatePerfLevel();

        void process() { updatePerfLevel(); }
    };

    typedef std::map<DomainID, UpdateEvent> UpdatePerfLevelEvents;
    UpdatePerfLevelEvents updatePerfLevelEvents;
};

#endif // __SIM_DVFS_HANDLER_HH__