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/*
* Copyright (c) 2013-2014 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,
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "sim/dvfs_handler.hh"
#include <set>
#include <utility>
#include "base/trace.hh"
#include "debug/DVFS.hh"
#include "params/DVFSHandler.hh"
#include "sim/serialize.hh"
#include "sim/stat_control.hh"
#include "sim/voltage_domain.hh"
//
//
// DVFSHandler methods implementation
//
DVFSHandler::DVFSHandler(const Params &p)
: SimObject(p),
sysClkDomain(p.sys_clk_domain),
enableHandler(p.enable),
_transLatency(p.transition_latency)
{
// Check supplied list of domains for sanity and add them to the
// domain ID -> domain* hash
for (auto dit = p.domains.begin(); dit != p.domains.end(); ++dit) {
SrcClockDomain *d = *dit;
DomainID domain_id = d->domainID();
fatal_if(sysClkDomain == d, "DVFS: Domain config list has a "\
"system clk domain entry");
fatal_if(domain_id == SrcClockDomain::emptyDomainID,
"DVFS: Controlled domain %s needs to have a properly "\
" assigned ID.\n", d->name());
auto entry = std::make_pair(domain_id, d);
bool new_elem = domains.insert(entry).second;
fatal_if(!new_elem, "DVFS: Domain %s with ID %d does not have a "\
"unique ID.\n", d->name(), domain_id);
// Create a dedicated event slot per known domain ID
UpdateEvent *event = &updatePerfLevelEvents[domain_id];
event->domainIDToSet = d->domainID();
// Add domain ID to the list of domains
domainIDList.push_back(d->domainID());
}
UpdateEvent::dvfsHandler = this;
}
DVFSHandler *DVFSHandler::UpdateEvent::dvfsHandler;
DVFSHandler::DomainID
DVFSHandler::domainID(uint32_t index) const
{
fatal_if(index >= numDomains(), "DVFS: Requested index out of "\
"bound, max value %d\n", (domainIDList.size() - 1));
assert(domains.find(domainIDList[index]) != domains.end());
return domainIDList[index];
}
bool
DVFSHandler::validDomainID(DomainID domain_id) const
{
assert(isEnabled());
// This is ensure that the domain id as requested by the software is
// availabe in the handler.
if (domains.find(domain_id) != domains.end())
return true;
warn("DVFS: invalid domain ID %d, the DVFS handler does not handle this "\
"domain\n", domain_id);
return false;
}
bool
DVFSHandler::perfLevel(DomainID domain_id, PerfLevel perf_level)
{
assert(isEnabled());
DPRINTF(DVFS, "DVFS: setPerfLevel domain %d -> %d\n", domain_id, perf_level);
auto d = findDomain(domain_id);
if (!d->validPerfLevel(perf_level)) {
warn("DVFS: invalid performance level %d for domain ID %d, request "\
"ignored\n", perf_level, domain_id);
return false;
}
UpdateEvent *update_event = &updatePerfLevelEvents[domain_id];
// Drop an old DVFS change request once we have established that this is a
// reasonable request
if (update_event->scheduled()) {
DPRINTF(DVFS, "DVFS: Overwriting the previous DVFS event.\n");
deschedule(update_event);
}
update_event->perfLevelToSet = perf_level;
// State changes that restore to the current state (and / or overwrite a not
// yet completed in-flight request) will be squashed
if (d->perfLevel() == perf_level) {
DPRINTF(DVFS, "DVFS: Ignoring ineffective performance level change "\
"%d -> %d\n", d->perfLevel(), perf_level);
return false;
}
// At this point, a new transition will certainly take place -> schedule
Tick when = curTick() + _transLatency;
DPRINTF(DVFS, "DVFS: Update for perf event scheduled for %ld\n", when);
schedule(update_event, when);
return true;
}
void
DVFSHandler::UpdateEvent::updatePerfLevel()
{
// Perform explicit stats dump for power estimation before performance
// level migration
Stats::dump();
Stats::reset();
// Update the performance level in the clock domain
auto d = dvfsHandler->findDomain(domainIDToSet);
assert(d->perfLevel() != perfLevelToSet);
d->perfLevel(perfLevelToSet);
}
double
DVFSHandler::voltageAtPerfLevel(DomainID domain_id, PerfLevel perf_level) const
{
VoltageDomain *d = findDomain(domain_id)->voltageDomain();
assert(d);
PerfLevel n = d->numVoltages();
if (perf_level < n)
return d->voltage(perf_level);
// Request outside of the range of the voltage domain
if (n == 1) {
DPRINTF(DVFS, "DVFS: Request for perf-level %i for single-point "\
"voltage domain %s. Returning voltage at level 0: %.2f "\
"V\n", perf_level, d->name(), d->voltage(0));
// Special case for single point voltage domain -> same voltage for
// all points
return d->voltage(0);
}
warn("DVFSHandler %s reads illegal voltage level %u from "\
"VoltageDomain %s. Returning 0 V\n", name(), perf_level, d->name());
return 0.;
}
void
DVFSHandler::serialize(CheckpointOut &cp) const
{
//This is to ensure that the handler status is maintained during the
//entire simulation run and not changed from command line during checkpoint
//and restore
SERIALIZE_SCALAR(enableHandler);
// Pull out the hashed data structure into easy-to-serialise arrays;
// ensuring that the data associated with any pending update event is saved
std::vector<DomainID> domain_ids;
std::vector<PerfLevel> perf_levels;
std::vector<Tick> whens;
for (const auto &ev_pair : updatePerfLevelEvents) {
DomainID id = ev_pair.first;
const UpdateEvent *event = &ev_pair.second;
assert(id == event->domainIDToSet);
domain_ids.push_back(id);
perf_levels.push_back(event->perfLevelToSet);
whens.push_back(event->scheduled() ? event->when() : 0);
}
SERIALIZE_CONTAINER(domain_ids);
SERIALIZE_CONTAINER(perf_levels);
SERIALIZE_CONTAINER(whens);
}
void
DVFSHandler::unserialize(CheckpointIn &cp)
{
bool temp = enableHandler;
UNSERIALIZE_SCALAR(enableHandler);
if (temp != enableHandler) {
warn("DVFS: Forcing enable handler status to unserialized value of %d",
enableHandler);
}
// Reconstruct the map of domain IDs and their scheduled events
std::vector<DomainID> domain_ids;
std::vector<PerfLevel> perf_levels;
std::vector<Tick> whens;
UNSERIALIZE_CONTAINER(domain_ids);
UNSERIALIZE_CONTAINER(perf_levels);
UNSERIALIZE_CONTAINER(whens);
for (size_t i = 0; i < domain_ids.size(); ++i) {;
UpdateEvent *event = &updatePerfLevelEvents[domain_ids[i]];
event->domainIDToSet = domain_ids[i];
event->perfLevelToSet = perf_levels[i];
// Schedule all previously scheduled events
if (whens[i])
schedule(event, whens[i]);
}
UpdateEvent::dvfsHandler = this;
}