voltage_domain.cc revision 11793
1/* 2 * Copyright (c) 2012-2014 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 */ 40 41#include "sim/voltage_domain.hh" 42 43#include <algorithm> 44 45#include "base/statistics.hh" 46#include "debug/VoltageDomain.hh" 47#include "params/VoltageDomain.hh" 48#include "sim/sim_object.hh" 49 50VoltageDomain::VoltageDomain(const Params *p) 51 : SimObject(p), voltageOpPoints(p->voltage), _perfLevel(0) 52{ 53 fatal_if(voltageOpPoints.empty(), "DVFS: Empty set of voltages for "\ 54 "voltage domain %s\n", name()); 55 56 // Voltages must be sorted in descending order. 57 fatal_if(!std::is_sorted(voltageOpPoints.begin(), voltageOpPoints.end(), 58 std::greater<Voltages::value_type>()), "DVFS: Voltage operation "\ 59 "points not in descending order for voltage domain %s\n", 60 name()); 61} 62 63void 64VoltageDomain::perfLevel(PerfLevel perf_level) 65{ 66 chatty_assert(perf_level < voltageOpPoints.size(), 67 "DVFS: Requested voltage ID %d is outside the known "\ 68 "range for domain %s.\n", perf_level, name()); 69 70 if (perf_level == _perfLevel) { 71 // Silently ignore identical overwrites 72 return; 73 } 74 75 _perfLevel = perf_level; 76 77 DPRINTF(VoltageDomain, "Setting voltage to %.3fV idx: %d for domain %s\n", 78 voltage(), perf_level, name()); 79} 80 81bool 82VoltageDomain::sanitiseVoltages() 83{ 84 if (numVoltages() == 1) 85 return false; 86 87 // Find the highest requested performance level and update the voltage 88 // domain with it 89 PerfLevel perf_max = (PerfLevel)-1; 90 for (auto dit = srcClockChildren.begin(); dit != srcClockChildren.end(); ++dit) { 91 SrcClockDomain* d = *dit; 92 chatty_assert(d->voltageDomain() == this, "DVFS: Clock domain %s "\ 93 "(id: %d) should not be registered with voltage domain "\ 94 "%s\n", d->name(), d->domainID(), name()); 95 96 PerfLevel perf = d->perfLevel(); 97 98 DPRINTF(VoltageDomain, "DVFS: Clock domain %s (id: %d) requests perf "\ 99 "level %d\n", d->name(), d->domainID(), perf); 100 101 // NOTE: Descending sort of performance levels: 0 - fast, 5 - slow 102 if (perf < perf_max) { 103 DPRINTF(VoltageDomain, "DVFS: Updating max perf level %d -> %d\n", 104 perf_max, perf); 105 perf_max = perf; 106 } 107 } 108 DPRINTF(VoltageDomain, "DVFS: Setting perf level of voltage domain %s "\ 109 "from %d to %d.\n", name(), perfLevel(), perf_max); 110 111 // Set the performance level 112 if (perf_max != perfLevel()) { 113 perfLevel(perf_max); 114 return true; 115 } else { 116 return false; 117 } 118} 119 120void 121VoltageDomain::startup() { 122 bool changed = sanitiseVoltages(); 123 if (changed) { 124 warn("DVFS: Perf level for voltage domain %s adapted to "\ 125 "requested perf levels from source clock domains.\n", name()); 126 } 127} 128 129void 130VoltageDomain::regStats() 131{ 132 SimObject::regStats(); 133 134 currentVoltage 135 .method(this, &VoltageDomain::voltage) 136 .name(params()->name + ".voltage") 137 .desc("Voltage in Volts") 138 ; 139} 140 141VoltageDomain * 142VoltageDomainParams::create() 143{ 144 return new VoltageDomain(this); 145} 146 147void 148VoltageDomain::serialize(CheckpointOut &cp) const 149{ 150 SERIALIZE_SCALAR(_perfLevel); 151} 152 153void 154VoltageDomain::unserialize(CheckpointIn &cp) 155{ 156 UNSERIALIZE_SCALAR(_perfLevel); 157 perfLevel(_perfLevel); 158} 159