clock_domain.hh

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/*
 * Copyright (c) 2013-2014, 2019 ARM Limited
 * Copyright (c) 2013 Cornell University
 * 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
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 * modified or unmodified, in source code or in binary form.
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#ifndef __SIM_CLOCK_DOMAIN_HH__
#define __SIM_CLOCK_DOMAIN_HH__
 
#include <algorithm>
 
#include "base/statistics.hh"
#include "params/ClockDomain.hh"
#include "params/DerivedClockDomain.hh"
#include "params/SrcClockDomain.hh"
#include "sim/sim_object.hh"
 
class DerivedClockDomain;
class VoltageDomain;
class Clocked;
 
class ClockDomain : public SimObject
{
  protected:
 
    Tick _clockPeriod;
 
    VoltageDomain *_voltageDomain;
 
    std::vector<DerivedClockDomain*> children;
 
    std::vector<Clocked *> members;
 
  public:
 
    typedef ClockDomainParams Params;
    ClockDomain(const Params *p, VoltageDomain *voltage_domain);
 
    Tick clockPeriod() const { return _clockPeriod; }
 
    void registerWithClockDomain(Clocked *c)
    {
        assert(c != NULL);
        assert(std::find(members.begin(), members.end(), c) == members.end());
        members.push_back(c);
    }
 
    inline VoltageDomain *voltageDomain() const { return _voltageDomain; }
 
 
    double voltage() const;
 
    void addDerivedDomain(DerivedClockDomain *clock_domain)
    { children.push_back(clock_domain); }
 
  private:
    struct ClockDomainStats : public Stats::Group
    {
        ClockDomainStats(ClockDomain &cd);
 
        Stats::Value clock;
    } stats;
};
 
class SrcClockDomain : public ClockDomain
{
 
  public:
 
    typedef SrcClockDomainParams Params;
    SrcClockDomain(const Params *p);
 
    void clockPeriod(Tick clock_period);
 
    // Explicitly import the otherwise hidden clockPeriod
    using ClockDomain::clockPeriod;
 
    typedef int32_t DomainID;
    static const DomainID emptyDomainID = -1;
 
    uint32_t domainID() const { return _domainID; }
 
    typedef uint32_t PerfLevel;
    bool validPerfLevel(PerfLevel perf_level) const {
        return perf_level < numPerfLevels();
    }
 
    void perfLevel(PerfLevel perf_level);
 
    PerfLevel perfLevel() const { return _perfLevel; }
 
    PerfLevel numPerfLevels() const {return freqOpPoints.size();}
 
    Tick clkPeriodAtPerfLevel() const { return freqOpPoints[perfLevel()]; }
 
    Tick clkPeriodAtPerfLevel(PerfLevel perf_level) const
    {
        assert(validPerfLevel(perf_level));
        return freqOpPoints[perf_level];
    }
 
    void startup() override;
 
    void serialize(CheckpointOut &cp) const override;
    void unserialize(CheckpointIn &cp) override;
 
  private:
    void signalPerfLevelUpdate();
 
    const std::vector<Tick> freqOpPoints;
 
    const uint32_t _domainID;
 
    PerfLevel _perfLevel;
};
 
class DerivedClockDomain: public ClockDomain
{
 
  public:
 
    typedef DerivedClockDomainParams Params;
    DerivedClockDomain(const Params *p);
 
    void updateClockPeriod();
 
  private:
 
    ClockDomain &parent;
 
    const uint64_t clockDivider;
};
 
#endif