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/*
* Copyright (c) 2015-2016 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
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* 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,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Akash Bagdia
* David Guillen Fandos
*/
#include "sim/clocked_object.hh"
#include "base/logging.hh"
#include "sim/power/power_model.hh"
ClockedObject::ClockedObject(const ClockedObjectParams *p) :
SimObject(p), Clocked(*p->clk_domain),
_currPwrState(p->default_p_state),
prvEvalTick(0),
stats(*this)
{
// Register the power_model with the object
for (auto & power_model: p->power_model)
power_model->setClockedObject(this);
}
void
ClockedObject::serialize(CheckpointOut &cp) const
{
unsigned int currPwrState = (unsigned int)_currPwrState;
SERIALIZE_SCALAR(currPwrState);
SERIALIZE_SCALAR(prvEvalTick);
}
void
ClockedObject::unserialize(CheckpointIn &cp)
{
unsigned int currPwrState;
UNSERIALIZE_SCALAR(currPwrState);
UNSERIALIZE_SCALAR(prvEvalTick);
_currPwrState = Enums::PwrState(currPwrState);
}
void
ClockedObject::pwrState(Enums::PwrState p)
{
// Function should ideally be called only when there is a state change
if (_currPwrState == p) {
warn_once("ClockedObject: Already in the requested power state, " \
"request ignored");
return;
}
// No need to compute stats if in the same tick, update state though. This
// can happen in cases like a) during start of the simulation multiple
// state changes happens in init/startup phase, b) one takes a decision to
// migrate state but decides to reverts back to the original state in the
// same tick if other conditions are not met elsewhere.
// Any state change related stats would have been recorded on previous call
// to the pwrState() function.
if (prvEvalTick == curTick() && curTick() != 0) {
warn("ClockedObject %s: More than one power state change request "\
"encountered within the same simulation tick %d",
name(), prvEvalTick);
_currPwrState = p;
return;
}
// Record stats for previous state.
computeStats();
_currPwrState = p;
stats.numPwrStateTransitions++;
}
void
ClockedObject::computeStats()
{
// Calculate time elapsed from last (valid) state change
Tick elapsed_time = curTick() - prvEvalTick;
stats.pwrStateResidencyTicks[_currPwrState] += elapsed_time;
// Time spent in CLK_GATED state, this might change depending on
// transition to other low power states in respective simulation
// objects.
if (_currPwrState == Enums::PwrState::CLK_GATED) {
stats.pwrStateClkGateDist.sample(elapsed_time);
}
prvEvalTick = curTick();
}
std::vector<double>
ClockedObject::pwrStateWeights() const
{
// Get residency stats
std::vector<double> ret;
Stats::VCounter residencies;
stats.pwrStateResidencyTicks.value(residencies);
// Account for current state too!
Tick elapsed_time = curTick() - prvEvalTick;
residencies[_currPwrState] += elapsed_time;
ret.resize(Enums::PwrState::Num_PwrState);
for (unsigned i = 0; i < Enums::PwrState::Num_PwrState; i++)
ret[i] = residencies[i] / \
(stats.pwrStateResidencyTicks.total() + elapsed_time);
return ret;
}
ClockedObject::ClockedObjectStats::ClockedObjectStats(ClockedObject &co)
: Stats::Group(&co),
clockedObject(co),
ADD_STAT(numPwrStateTransitions,
"Number of power state transitions"),
ADD_STAT(pwrStateClkGateDist,
"Distribution of time spent in the clock gated state"),
ADD_STAT(pwrStateResidencyTicks,
"Cumulative time (in ticks) in various power states")
{
}
void
ClockedObject::ClockedObjectStats::regStats()
{
Stats::Group::regStats();
using namespace Stats;
const ClockedObjectParams *p = clockedObject.params();
numPwrStateTransitions.flags(nozero);
// Each sample is time in ticks
unsigned num_bins = std::max(p->p_state_clk_gate_bins, 10U);
pwrStateClkGateDist
.init(p->p_state_clk_gate_min, p->p_state_clk_gate_max,
(p->p_state_clk_gate_max / num_bins))
.flags(pdf | nozero | nonan)
;
pwrStateResidencyTicks
.init(Enums::PwrState::Num_PwrState)
.flags(nozero)
;
for (int i = 0; i < Enums::PwrState::Num_PwrState; i++) {
pwrStateResidencyTicks.subname(i, Enums::PwrStateStrings[i]);
}
numPwrStateTransitions = 0;
}
void
ClockedObject::ClockedObjectStats::preDumpStats()
{
Stats::Group::preDumpStats();
/**
* For every stats dump, the power state residency and other distribution
* stats should be computed just before the dump to ensure correct stats
* value being reported for current dump window. It avoids things like
* having any unreported time spent in a power state to be forwarded to the
* next dump window which might have rather unpleasant effects (like
* perturbing the distribution stats).
*/
clockedObject.computeStats();
}