src/sim/power_state.hh

   1 /*
   2  * Copyright (c) 2015-2017, 2020 ARM Limited
   3  * All rights reserved
   4  *
   5  * The license below extends only to copyright in the software and shall
   6  * not be construed as granting a license to any other intellectual
   7  * property including but not limited to intellectual property relating
   8  * to a hardware implementation of the functionality of the software
   9  * licensed hereunder.  You may use the software subject to the license
  10  * terms below provided that you ensure that this notice is replicated
  11  * unmodified and in its entirety in all distributions of the software,
  12  * modified or unmodified, in source code or in binary form.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions are
  16  * met: redistributions of source code must retain the above copyright
  17  * notice, this list of conditions and the following disclaimer;
  18  * redistributions in binary form must reproduce the above copyright
  19  * notice, this list of conditions and the following disclaimer in the
  20  * documentation and/or other materials provided with the distribution;
  21  * neither the name of the copyright holders nor the names of its
  22  * contributors may be used to endorse or promote products derived from
  23  * this software without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  26  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  27  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  28  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  29  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  30  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  31  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  35  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 /**
  39  * @file
  40  * PowerState declaration and implementation.
  41  */
  42
  43 #ifndef __SIM_POWER_STATE_HH__
  44 #define __SIM_POWER_STATE_HH__
  45
  46 #include <set>
  47 #include <vector>
  48
  49 #include "base/callback.hh"
  50 #include "base/statistics.hh"
  51 #include "enums/PwrState.hh"
  52 #include "params/PowerState.hh"
  53 #include "sim/core.hh"
  54 #include "sim/sim_object.hh"
  55
  56 class PowerDomain;
  57
  58 /**
  59  * Helper class for objects that have power states. This class provides the
  60  * basic functionality to change between power states.
  61  */
  62 class PowerState : public SimObject
  63 {
  64   public:
  65     PowerState(const PowerStateParams &p);
  66
  67     /** Parameters of PowerState object */
  68     typedef PowerStateParams Params;
  69     const Params &
  70     params() const
  71     {
  72         return reinterpret_cast<const Params &>(_params);
  73     }
  74
  75     virtual void addFollower(PowerState* pwr_obj) {};
  76     void setControlledDomain(PowerDomain* pwr_dom);
  77
  78     void serialize(CheckpointOut &cp) const override;
  79     void unserialize(CheckpointIn &cp) override;
  80
  81     /**
  82      * Change the power state of this object to the power state p
  83      */
  84     void set(Enums::PwrState p);
  85
  86
  87     inline Enums::PwrState get() const
  88     {
  89         return _currState;
  90     }
  91
  92     inline std::string getName() const
  93     {
  94         return Enums::PwrStateStrings[_currState];
  95     }
  96
  97     /** Returns the percentage residency for each power state */
  98     std::vector<double> getWeights() const;
  99
 100     /**
 101      * Record stats values like state residency by computing the time
 102      * difference from previous update. Also, updates the previous evaluation
 103      * tick once all stats are recorded.
 104      * Usually called on power state change and stats dump callback.
 105      */
 106     void computeStats();
 107
 108     /**
 109      * Change the power state of this object to a power state equal to OR more
 110      * performant than p. Returns the power state the object actually went to.
 111      */
 112     Enums::PwrState matchPwrState(Enums::PwrState p);
 113
 114     /**
 115      * Return the power states this object can be in
 116      */
 117     std::set<Enums::PwrState> getPossibleStates() const
 118     {
 119         return possibleStates;
 120     }
 121
 122   protected:
 123
 124     /** To keep track of the current power state */
 125     Enums::PwrState _currState;
 126
 127     /** The possible power states this object can be in */
 128     std::set<Enums::PwrState> possibleStates;
 129
 130     /** Last tick the power stats were calculated */
 131     Tick prvEvalTick = 0;
 132
 133     /**
 134      * The power domain that this power state leads, nullptr if it
 135      * doesn't lead any.
 136      */
 137     PowerDomain* controlledDomain = nullptr;
 138
 139     struct PowerStateStats : public Stats::Group
 140     {
 141         PowerStateStats(PowerState &ps);
 142
 143         void regStats() override;
 144         void preDumpStats() override;
 145
 146         PowerState &powerState;
 147
 148         Stats::Scalar numTransitions;
 149         Stats::Scalar numPwrMatchStateTransitions;
 150         Stats::Distribution ticksClkGated;
 151         /** Tracks the time spent in each of the power states */
 152         Stats::Vector pwrStateResidencyTicks;
 153     } stats;
 154 };
 155
 156 #endif //__SIM_POWER_STATE_HH__