dvfs_handler.hh

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/*
 * Copyright (c) 2013-2014 ARM Limited
 * All rights reserved
 *
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 * 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
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 * modified or unmodified, in source code or in binary form.
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#ifndef __SIM_DVFS_HANDLER_HH__
#define __SIM_DVFS_HANDLER_HH__
 
#include <cassert>
#include <map>
#include <vector>
 
#include "base/logging.hh"
#include "base/types.hh"
#include "debug/DVFS.hh"
#include "params/DVFSHandler.hh"
#include "sim/clock_domain.hh"
#include "sim/eventq.hh"
#include "sim/sim_object.hh"
 
namespace gem5
{
 
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;
};
 
} // namespace gem5
 
#endif // __SIM_DVFS_HANDLER_HH__