dvfs_handler.cc revision 11793
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 "sim/dvfs_handler.hh" 43 44#include <set> 45#include <utility> 46 47#include "base/misc.hh" 48#include "debug/DVFS.hh" 49#include "params/DVFSHandler.hh" 50#include "sim/clock_domain.hh" 51#include "sim/stat_control.hh" 52#include "sim/voltage_domain.hh" 53 54// 55// 56// DVFSHandler methods implementation 57// 58 59DVFSHandler::DVFSHandler(const Params *p) 60 : SimObject(p), 61 sysClkDomain(p->sys_clk_domain), 62 enableHandler(p->enable), 63 _transLatency(p->transition_latency) 64{ 65 // Check supplied list of domains for sanity and add them to the 66 // domain ID -> domain* hash 67 for (auto dit = p->domains.begin(); dit != p->domains.end(); ++dit) { 68 SrcClockDomain *d = *dit; 69 DomainID domain_id = d->domainID(); 70 71 fatal_if(sysClkDomain == d, "DVFS: Domain config list has a "\ 72 "system clk domain entry"); 73 fatal_if(domain_id == SrcClockDomain::emptyDomainID, 74 "DVFS: Controlled domain %s needs to have a properly "\ 75 " assigned ID.\n", d->name()); 76 77 auto entry = std::make_pair(domain_id, d); 78 bool new_elem = domains.insert(entry).second; 79 fatal_if(!new_elem, "DVFS: Domain %s with ID %d does not have a "\ 80 "unique ID.\n", d->name(), domain_id); 81 82 // Create a dedicated event slot per known domain ID 83 UpdateEvent *event = &updatePerfLevelEvents[domain_id]; 84 event->domainIDToSet = d->domainID(); 85 86 // Add domain ID to the list of domains 87 domainIDList.push_back(d->domainID()); 88 } 89 UpdateEvent::dvfsHandler = this; 90} 91 92DVFSHandler *DVFSHandler::UpdateEvent::dvfsHandler; 93 94DVFSHandler::DomainID 95DVFSHandler::domainID(uint32_t index) const 96{ 97 fatal_if(index >= numDomains(), "DVFS: Requested index out of "\ 98 "bound, max value %d\n", (domainIDList.size() - 1)); 99 100 assert(domains.find(domainIDList[index]) != domains.end()); 101 102 return domainIDList[index]; 103} 104 105bool 106DVFSHandler::validDomainID(DomainID domain_id) const 107{ 108 assert(isEnabled()); 109 // This is ensure that the domain id as requested by the software is 110 // availabe in the handler. 111 if (domains.find(domain_id) != domains.end()) 112 return true; 113 warn("DVFS: invalid domain ID %d, the DVFS handler does not handle this "\ 114 "domain\n", domain_id); 115 return false; 116} 117 118bool 119DVFSHandler::perfLevel(DomainID domain_id, PerfLevel perf_level) 120{ 121 assert(isEnabled()); 122 123 DPRINTF(DVFS, "DVFS: setPerfLevel domain %d -> %d\n", domain_id, perf_level); 124 125 auto d = findDomain(domain_id); 126 if (!d->validPerfLevel(perf_level)) { 127 warn("DVFS: invalid performance level %d for domain ID %d, request "\ 128 "ignored\n", perf_level, domain_id); 129 return false; 130 } 131 132 UpdateEvent *update_event = &updatePerfLevelEvents[domain_id]; 133 // Drop an old DVFS change request once we have established that this is a 134 // reasonable request 135 if (update_event->scheduled()) { 136 DPRINTF(DVFS, "DVFS: Overwriting the previous DVFS event.\n"); 137 deschedule(update_event); 138 } 139 140 update_event->perfLevelToSet = perf_level; 141 142 // State changes that restore to the current state (and / or overwrite a not 143 // yet completed in-flight request) will be squashed 144 if (d->perfLevel() == perf_level) { 145 DPRINTF(DVFS, "DVFS: Ignoring ineffective performance level change "\ 146 "%d -> %d\n", d->perfLevel(), perf_level); 147 return false; 148 } 149 150 // At this point, a new transition will certainly take place -> schedule 151 Tick when = curTick() + _transLatency; 152 DPRINTF(DVFS, "DVFS: Update for perf event scheduled for %ld\n", when); 153 154 schedule(update_event, when); 155 return true; 156} 157 158void 159DVFSHandler::UpdateEvent::updatePerfLevel() 160{ 161 // Perform explicit stats dump for power estimation before performance 162 // level migration 163 Stats::dump(); 164 Stats::reset(); 165 166 // Update the performance level in the clock domain 167 auto d = dvfsHandler->findDomain(domainIDToSet); 168 assert(d->perfLevel() != perfLevelToSet); 169 170 d->perfLevel(perfLevelToSet); 171} 172 173void 174DVFSHandler::serialize(CheckpointOut &cp) const 175{ 176 //This is to ensure that the handler status is maintained during the 177 //entire simulation run and not changed from command line during checkpoint 178 //and restore 179 SERIALIZE_SCALAR(enableHandler); 180 181 // Pull out the hashed data structure into easy-to-serialise arrays; 182 // ensuring that the data associated with any pending update event is saved 183 std::vector<DomainID> domain_ids; 184 std::vector<PerfLevel> perf_levels; 185 std::vector<Tick> whens; 186 for (const auto &ev_pair : updatePerfLevelEvents) { 187 DomainID id = ev_pair.first; 188 const UpdateEvent *event = &ev_pair.second; 189 190 assert(id == event->domainIDToSet); 191 domain_ids.push_back(id); 192 perf_levels.push_back(event->perfLevelToSet); 193 whens.push_back(event->scheduled() ? event->when() : 0); 194 } 195 SERIALIZE_CONTAINER(domain_ids); 196 SERIALIZE_CONTAINER(perf_levels); 197 SERIALIZE_CONTAINER(whens); 198} 199 200void 201DVFSHandler::unserialize(CheckpointIn &cp) 202{ 203 bool temp = enableHandler; 204 205 UNSERIALIZE_SCALAR(enableHandler); 206 207 if (temp != enableHandler) { 208 warn("DVFS: Forcing enable handler status to unserialized value of %d", 209 enableHandler); 210 } 211 212 // Reconstruct the map of domain IDs and their scheduled events 213 std::vector<DomainID> domain_ids; 214 std::vector<PerfLevel> perf_levels; 215 std::vector<Tick> whens; 216 UNSERIALIZE_CONTAINER(domain_ids); 217 UNSERIALIZE_CONTAINER(perf_levels); 218 UNSERIALIZE_CONTAINER(whens); 219 220 for (size_t i = 0; i < domain_ids.size(); ++i) {; 221 UpdateEvent *event = &updatePerfLevelEvents[domain_ids[i]]; 222 223 event->domainIDToSet = domain_ids[i]; 224 event->perfLevelToSet = perf_levels[i]; 225 226 // Schedule all previously scheduled events 227 if (whens[i]) 228 schedule(event, whens[i]); 229 } 230 UpdateEvent::dvfsHandler = this; 231} 232 233DVFSHandler* 234DVFSHandlerParams::create() 235{ 236 return new DVFSHandler(this); 237} 238