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/** 43 * @file 44 * DVFSHandler and DomainConfig class declaration used for managing voltage 45 * and frequency scaling of the various DVFS domains in the system (with each 46 * domain having their independent domain configuration information) 47 */ 48 49 50#ifndef __SIM_DVFS_HANDLER_HH__ 51#define __SIM_DVFS_HANDLER_HH__ 52 53#include <vector> 54
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55#include "debug/DVFS.hh" |
56#include "params/ClockDomain.hh" 57#include "params/DVFSHandler.hh" 58#include "params/VoltageDomain.hh" 59#include "sim/clock_domain.hh" 60#include "sim/eventq.hh" 61#include "sim/sim_object.hh"
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62#include "sim/voltage_domain.hh" |
63
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62
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64/** 65 * DVFS Handler class, maintains a list of all the domains it can handle. 66 * Each entry of that list is an object of the DomainConfig class, and the 67 * handler uses the methods provided by that class to get access to the 68 * configuration of each domain. The handler is responsible for setting/getting 69 * clock periods and voltages from clock/voltage domains. 70 * The handler acts the bridge between software configurable information 71 * for each domain as provided to the controller and the hardware 72 * implementation details for those domains. 73 */ 74class DVFSHandler : public SimObject 75{ 76 public: 77 typedef DVFSHandlerParams Params; 78 DVFSHandler(const Params *p); 79 80 typedef SrcClockDomain::DomainID DomainID; 81 typedef SrcClockDomain::PerfLevel PerfLevel; 82 83 /**
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84 * Get the number of domains assigned to this DVFS handler. 85 * @return Number of domains 86 */ 87 uint32_t numDomains() const { return domainIDList.size(); } 88 89 /** 90 * Get the n-th domain ID, from the domains managed by this handler. 91 * @return Domain ID 92 */ 93 DomainID domainID(uint32_t index) const; 94 95 /** |
96 * Check whether a domain ID is known to the handler or not. 97 * @param domain_id Domain ID to check 98 * @return Domain ID known to handler? 99 */ 100 bool validDomainID(DomainID domain_id) const; 101 102 /** 103 * Get transition latency to switch between performance levels. 104 * @return Transition latency 105 */ 106 Tick transLatency() const { return _transLatency; } 107 108 /** 109 * Set a new performance level for the specified domain. The actual update 110 * will be delayed by transLatency(). 111 * 112 * @param domain_id Software visible ID of the domain to be configured 113 * @param perf_level Requested performance level (0 - fast, >0 slower) 114 * @return status whether the setting was successful 115 */ 116 bool perfLevel(DomainID domain_id, PerfLevel perf_level); 117 118 /** 119 * Get the current performance level of a domain. While a change request is 120 * in-flight, will return the current (i.e. old, unmodified) value. 121 * 122 * @param domain_id Domain ID to query 123 * @return Current performance level of the specified domain 124 */ 125 PerfLevel perfLevel(DomainID domain_id) const { 126 assert(isEnabled()); 127 return findDomain(domain_id)->perfLevel(); 128 } 129 130 /** 131 * Read the clock period of the specified domain at the specified 132 * performance level. 133 * @param domain_id Domain ID to query 134 * @param perf_level Performance level of interest 135 * @return Clock period in ticks for the requested performance level of 136 * the respective domain 137 */ 138 Tick clkPeriodAtPerfLevel(DomainID domain_id, PerfLevel perf_level) const 139 { 140 return findDomain(domain_id)->clkPeriodAtPerfLevel(perf_level); 141 } 142 143 /**
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144 * Read the voltage of the specified domain at the specified 145 * performance level. 146 * @param domain_id Domain ID to query 147 * @param perf_level Performance level of interest 148 * @return Voltage for the requested performance level of the respective 149 * domain 150 */ 151 double voltageAtPerfLevel(DomainID domain_id, PerfLevel perf_level) const 152 { 153 return findDomain(domain_id)->voltageDomain()->voltage(perf_level); 154 } 155 156 /** |
157 * Get the total number of available performance levels. 158 * 159 * @param domain_id Domain ID to query 160 * @return Number of performance levels that where configured for the 161 * respective domain 162 */ 163 PerfLevel numPerfLevels(PerfLevel domain_id) const 164 { 165 return findDomain(domain_id)->numPerfLevels(); 166 } 167 168 /** 169 * Check enable status of the DVFS handler, when the handler is disabled, no 170 * request should be sent to the handler. 171 * @return True, if the handler is enabled 172 */ 173 bool isEnabled() const { return enableHandler; } 174 175 void serialize(std::ostream &os); 176 void unserialize(Checkpoint *cp, const std::string §ion); 177 178 private: 179 typedef std::map<DomainID, SrcClockDomain*> Domains; 180 Domains domains; 181 182 /**
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183 * List of IDs avaiable in the domain list 184 */ 185 std::vector<DomainID> domainIDList; 186 187 /** |
188 * Clock domain of the system the handler is instantiated. 189 */ 190 SrcClockDomain* sysClkDomain; 191 192 /** 193 * Search for a domain based on the domain ID. 194 * 195 * @param domain_id Domain ID to search for 196 * @return Pointer to the source clock domain with matching ID. 197 */ 198 SrcClockDomain *findDomain(DomainID domain_id) const { 199 auto it = domains.find(domain_id); 200 panic_if(it == domains.end(), 201 "DVFS: Could not find a domain for ID %d.\n",domain_id ); 202 return domains.find(domain_id)->second; 203 } 204 205 /** 206 * Disabling the DVFS handler ensures that all the DVFS migration requests 207 * are ignored. Domains remain at their default frequency and voltage. 208 */ 209 bool enableHandler; 210 211 212 /** 213 * This corresponds to the maximum transition latency associated with the 214 * hardware transitioning from a particular performance level to the other 215 */ 216 const Tick _transLatency; 217 218 219 220 /** 221 * Update performance level event, encapsulates all the required information 222 * for a future call to change a domain's performance level. 223 */ 224 struct UpdateEvent : public Event { 225 UpdateEvent() : Event(DVFS_Update_Pri), domainIDToSet(0), 226 perfLevelToSet(0) {} 227 228 /** 229 * Static pointer to the single DVFS hander for all the update events 230 */ 231 static DVFSHandler *dvfsHandler; 232 233 /** 234 * ID of the domain that will be changed by the in-flight event 235 */ 236 DomainID domainIDToSet; 237 238 /** 239 * Target performance level of the in-flight event 240 */ 241 PerfLevel perfLevelToSet; 242 243 /** 244 * Updates the performance level by modifying the clock and the voltage 245 * of the associated clocked objects. Gets information from 246 * domainIDToSet and perfLevelToSet for easier calling through an 247 * event. 248 */ 249 void updatePerfLevel(); 250 251 void process() { updatePerfLevel(); } 252 }; 253 254 typedef std::map<DomainID, UpdateEvent> UpdatePerfLevelEvents; 255 /** 256 * Map from domain IDs -> perf level update events, records in-flight change 257 * requests per domain ID. 258 */ 259 UpdatePerfLevelEvents updatePerfLevelEvents; 260}; 261 262#endif // __SIM_DVFS_HANDLER_HH__
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