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/*
* Copyright (c) 2017, 2019-2020 ARM Limited
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*
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*
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* this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#ifndef __SIM_POWER_DOMAIN_HH__
#define __SIM_POWER_DOMAIN_HH__
#include <string>
#include <vector>
#include "base/statistics.hh"
#include "params/PowerDomain.hh"
#include "sim/clocked_object.hh"
#include "sim/power_state.hh"
/**
* The PowerDomain groups PowerState objects together to regulate their
* power states. As the PowerDomain itself is a PowerState object, you can
* create hierarchies of PowerDomains. All objects in a power domain will be in
* the power state of the domain OR a more performant one.
*/
class PowerDomain : public PowerState
{
public:
PowerDomain(const PowerDomainParams &p);
typedef PowerDomainParams Params;
~PowerDomain() override {};
/**
* During startup, the list of possible power states the
* PowerDomain can be in is populated, the power state of the
* PowerDomain is set and some assertions about the PowerState objects
* in the Domain are checked.
*/
void startup() override;
/**
* Register the change in power state in one of the leader. The power
* domain will change its own power state if required and if there is a
* power state, it will schedule an event to update its followers
*/
void pwrStateChangeCallback(Enums::PwrState new_pwr_state,
PowerState* leader);
/**
* Function called by a follower to register itself as
* a dependant of this power domain
*/
void addFollower(PowerState* pwr_obj) override;
private:
/**
* Calculate the power state of the power domain, based upon the power
* states of the leaders. This will be called if one the leaders
* changes its power states.
* If no inputs are given, only the leaders will be polled on their
* power state. You can also pass a vector containing the power states
* which the followers returned when asked to match a certain power
* state (called from setFollowerPowerStates)
*/
Enums::PwrState calculatePowerDomainState(
const std::vector<Enums::PwrState> &f_states={});
/**
* Check if a given p_state is available across all leaders and
* followers in this domain.
*/
bool isPossiblePwrState(Enums::PwrState p_state);
/**
* Calculate the possible power states of the domain based upon the
* intersection of the power states of the individual objects within
* the domain. Done at startup.
*/
void calculatePossiblePwrStates();
/**
* Update the followers of the newly updated power state. They are
* required to match the power state of the power domain i.e. go to the
* same power state or a more performant one
*/
void setFollowerPowerStates();
private: /* Power domain attributes */
/**
* List of all leaders in the PowerDomain. A leader can
* independently change its power state and does not depend on the
* PowerDomain to change its power state. A leader needs to be a
* PowerState object and can also be another PowerDomain. Each
* PowerDomain needs to have at least one leader.
*/
std::vector<PowerState*> leaders;
/**
* Power state requested by the leader. This is not necessarily the
* power state of the domain as whole (as that one depends on the
* matched power states of the followers
*/
Enums::PwrState leaderTargetState;
/**
* List of all followers in the PowerDomain. The power state of the
* domain will determine the power state of the followers. A follower
* cannot change its power state independently.
*/
std::vector<PowerState*> followers;
/**
* Latency with which power state changes of the leaders will ripple
* through to the followers.
*/
const Tick updateLatency = 1;
/**
* Event to update the power states of the followers
*/
EventWrapper<PowerDomain, &PowerDomain::setFollowerPowerStates>
pwrStateUpdateEvent;
protected:
struct PowerDomainStats : public Stats::Group
{
PowerDomainStats(PowerDomain &pd);
void regStats() override;
Stats::Scalar numLeaderCalls;
Stats::Scalar numLeaderCallsChangingState;
} stats;
};
#endif // __SIM_POWER_DOMAIN_HH__