dvfs_handler.cc revision 10249:6bbb7ae309ac
1/* 2 * Copyright (c) 2013-2014 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 * Authors: Vasileios Spiliopoulos 38 * Akash Bagdia 39 * Stephan Diestelhorst 40 */ 41 42#include <set> 43#include <utility> 44 45#include "base/misc.hh" 46#include "debug/DVFS.hh" 47#include "params/DVFSHandler.hh" 48#include "sim/clock_domain.hh" 49#include "sim/dvfs_handler.hh" 50#include "sim/stat_control.hh" 51#include "sim/voltage_domain.hh" 52 53// 54// 55// DVFSHandler methods implementation 56// 57 58DVFSHandler::DVFSHandler(const Params *p) 59 : SimObject(p), 60 sysClkDomain(p->sys_clk_domain), 61 enableHandler(p->enable), 62 _transLatency(p->transition_latency) 63{ 64 // Check supplied list of domains for sanity and add them to the 65 // domain ID -> domain* hash 66 for(auto dit = p->domains.begin(); dit != p->domains.end(); ++dit) { 67 SrcClockDomain *d = *dit; 68 DomainID domain_id = d->domainID(); 69 70 fatal_if(sysClkDomain == d, "DVFS: Domain config list has a "\ 71 "system clk domain entry"); 72 fatal_if(domain_id == SrcClockDomain::emptyDomainID, 73 "DVFS: Controlled domain %s needs to have a properly "\ 74 " assigned ID.\n", d->name()); 75 76 auto entry = std::make_pair(domain_id, d); 77 bool new_elem = domains.insert(entry).second; 78 fatal_if(!new_elem, "DVFS: Domain %s with ID %d does not have a "\ 79 "unique ID.\n", d->name(), domain_id); 80 81 // Create a dedicated event slot per known domain ID 82 UpdateEvent *event = &updatePerfLevelEvents[domain_id]; 83 event->domainIDToSet = d->domainID(); 84 } 85 UpdateEvent::dvfsHandler = this; 86} 87 88DVFSHandler *DVFSHandler::UpdateEvent::dvfsHandler; 89 90bool 91DVFSHandler::validDomainID(DomainID domain_id) const 92{ 93 assert(isEnabled()); 94 // This is ensure that the domain id as requested by the software is 95 // availabe in the handler. 96 if (domains.find(domain_id) != domains.end()) 97 return true; 98 warn("DVFS: invalid domain ID %d, the DVFS handler does not handle this "\ 99 "domain\n", domain_id); 100 return false; 101} 102 103bool 104DVFSHandler::perfLevel(DomainID domain_id, PerfLevel perf_level) 105{ 106 assert(isEnabled()); 107 108 DPRINTF(DVFS, "DVFS: setPerfLevel domain %d -> %d\n", domain_id, perf_level); 109 110 auto d = findDomain(domain_id); 111 if (!d->validPerfLevel(perf_level)) { 112 warn("DVFS: invalid performance level %d for domain ID %d, request "\ 113 "ignored\n", perf_level, domain_id); 114 return false; 115 } 116 117 UpdateEvent *update_event = &updatePerfLevelEvents[domain_id]; 118 // Drop an old DVFS change request once we have established that this is a 119 // reasonable request 120 if (update_event->scheduled()) { 121 DPRINTF(DVFS, "DVFS: Overwriting the previous DVFS event.\n"); 122 deschedule(update_event); 123 } 124 125 update_event->perfLevelToSet = perf_level; 126 127 // State changes that restore to the current state (and / or overwrite a not 128 // yet completed in-flight request) will be squashed 129 if (d->perfLevel() == perf_level) { 130 DPRINTF(DVFS, "DVFS: Ignoring ineffective performance level change "\ 131 "%d -> %d\n", d->perfLevel(), perf_level); 132 return false; 133 } 134 135 // At this point, a new transition will certainly take place -> schedule 136 Tick when = curTick() + _transLatency; 137 DPRINTF(DVFS, "DVFS: Update for perf event scheduled for %ld\n", when); 138 139 schedule(update_event, when); 140 return true; 141} 142 143void 144DVFSHandler::UpdateEvent::updatePerfLevel() 145{ 146 // Perform explicit stats dump for power estimation before performance 147 // level migration 148 Stats::dump(); 149 Stats::reset(); 150 151 // Update the performance level in the clock domain 152 auto d = dvfsHandler->findDomain(domainIDToSet); 153 assert(d->perfLevel() != perfLevelToSet); 154 155 d->perfLevel(perfLevelToSet); 156} 157 158void 159DVFSHandler::serialize(std::ostream &os) 160{ 161 //This is to ensure that the handler status is maintained during the 162 //entire simulation run and not changed from command line during checkpoint 163 //and restore 164 SERIALIZE_SCALAR(enableHandler); 165 166 // Pull out the hashed data structure into easy-to-serialise arrays; 167 // ensuring that the data associated with any pending update event is saved 168 std::vector<DomainID> domain_ids; 169 std::vector<PerfLevel> perf_levels; 170 std::vector<Tick> whens; 171 for (auto it = updatePerfLevelEvents.begin(); 172 it != updatePerfLevelEvents.end(); ++it) { 173 DomainID id = it->first; 174 UpdateEvent *event = &it->second; 175 176 assert(id == event->domainIDToSet); 177 domain_ids.push_back(id); 178 perf_levels.push_back(event->perfLevelToSet); 179 whens.push_back(event->scheduled() ? event->when() : 0); 180 } 181 arrayParamOut(os, "domain_ids", domain_ids); 182 arrayParamOut(os, "perf_levels", perf_levels); 183 arrayParamOut(os, "whens", whens); 184} 185 186void 187DVFSHandler::unserialize(Checkpoint *cp, const std::string §ion) 188{ 189 UNSERIALIZE_SCALAR(enableHandler); 190 191 // Reconstruct the map of domain IDs and their scheduled events 192 std::vector<DomainID> domain_ids; 193 std::vector<PerfLevel> perf_levels; 194 std::vector<Tick> whens; 195 arrayParamIn(cp, section, "domain_ids", domain_ids); 196 arrayParamIn(cp, section, "perf_levels", perf_levels); 197 arrayParamIn(cp, section, "whens", whens); 198 199 for (size_t i = 0; i < domain_ids.size(); ++i) {; 200 UpdateEvent *event = &updatePerfLevelEvents[domain_ids[i]]; 201 202 event->domainIDToSet = domain_ids[i]; 203 event->perfLevelToSet = perf_levels[i]; 204 205 // Schedule all previously scheduled events 206 if (whens[i]) 207 schedule(event, whens[i]); 208 } 209 UpdateEvent::dvfsHandler = this; 210} 211 212DVFSHandler* 213DVFSHandlerParams::create() 214{ 215 return new DVFSHandler(this); 216} 217