gem5  v20.1.0.0
voltage_domain.cc
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2012-2014, 2019 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 
38 #include "sim/voltage_domain.hh"
39 
40 #include <algorithm>
41 
42 #include "base/statistics.hh"
43 #include "base/trace.hh"
44 #include "debug/VoltageDomain.hh"
45 #include "params/VoltageDomain.hh"
46 #include "sim/sim_object.hh"
47 
49  : SimObject(p), voltageOpPoints(p->voltage), _perfLevel(0), stats(*this)
50 {
51  fatal_if(voltageOpPoints.empty(), "DVFS: Empty set of voltages for "\
52  "voltage domain %s\n", name());
53 
54  // Voltages must be sorted in descending order.
55  fatal_if(!std::is_sorted(voltageOpPoints.begin(), voltageOpPoints.end(),
56  std::greater<Voltages::value_type>()), "DVFS: Voltage operation "\
57  "points not in descending order for voltage domain %s\n",
58  name());
59 }
60 
61 void
63 {
64  chatty_assert(perf_level < voltageOpPoints.size(),
65  "DVFS: Requested voltage ID %d is outside the known "\
66  "range for domain %s.\n", perf_level, name());
67 
68  if (perf_level == _perfLevel) {
69  // Silently ignore identical overwrites
70  return;
71  }
72 
73  _perfLevel = perf_level;
74 
75  DPRINTF(VoltageDomain, "Setting voltage to %.3fV idx: %d for domain %s\n",
76  voltage(), perf_level, name());
77 }
78 
79 bool
81 {
82  if (numVoltages() == 1)
83  return false;
84 
85  // Find the highest requested performance level and update the voltage
86  // domain with it
87  PerfLevel perf_max = (PerfLevel)-1;
88  for (auto dit = srcClockChildren.begin(); dit != srcClockChildren.end(); ++dit) {
89  SrcClockDomain* d = *dit;
90  chatty_assert(d->voltageDomain() == this, "DVFS: Clock domain %s "\
91  "(id: %d) should not be registered with voltage domain "\
92  "%s\n", d->name(), d->domainID(), name());
93 
94  PerfLevel perf = d->perfLevel();
95 
96  DPRINTF(VoltageDomain, "DVFS: Clock domain %s (id: %d) requests perf "\
97  "level %d\n", d->name(), d->domainID(), perf);
98 
99  // NOTE: Descending sort of performance levels: 0 - fast, 5 - slow
100  if (perf < perf_max) {
101  DPRINTF(VoltageDomain, "DVFS: Updating max perf level %d -> %d\n",
102  perf_max, perf);
103  perf_max = perf;
104  }
105  }
106  DPRINTF(VoltageDomain, "DVFS: Setting perf level of voltage domain %s "\
107  "from %d to %d.\n", name(), perfLevel(), perf_max);
108 
109  // Set the performance level
110  if (perf_max != perfLevel()) {
111  perfLevel(perf_max);
112  return true;
113  } else {
114  return false;
115  }
116 }
117 
118 void
120  bool changed = sanitiseVoltages();
121  if (changed) {
122  warn("DVFS: Perf level for voltage domain %s adapted to "\
123  "requested perf levels from source clock domains.\n", name());
124  }
125 }
126 
128 VoltageDomainParams::create()
129 {
130  return new VoltageDomain(this);
131 }
132 
133 void
135 {
137 }
138 
139 void
141 {
144 }
145 
147  : Stats::Group(&vd),
148  ADD_STAT(voltage, "Voltage in Volts")
149 {
151 }
Stats::ValueBase::method
Derived & method(T *obj, V(T::*method)() const)
Extended functor that calls the specified method of the provided object.
Definition: statistics.hh:898
warn
#define warn(...)
Definition: logging.hh:239
SimObject::Params
SimObjectParams Params
Definition: sim_object.hh:113
voltage_domain.hh
VoltageDomain::srcClockChildren
SrcClockChildren srcClockChildren
Definition: voltage_domain.hh:156
UNSERIALIZE_SCALAR
#define UNSERIALIZE_SCALAR(scalar)
Definition: serialize.hh:797
VoltageDomain::voltage
double voltage() const
Get the current voltage.
Definition: voltage_domain.hh:67
VoltageDomain::numVoltages
uint32_t numVoltages() const
Definition: voltage_domain.hh:84
SrcClockDomain
The source clock domains provides the notion of a clock domain that is connected to a tunable clock s...
Definition: clock_domain.hh:163
VoltageDomain::startup
void startup() override
Startup has all SrcClockDomains registered with this voltage domain, so try to make sure that all per...
Definition: voltage_domain.cc:119
ArmISA::dit
Bitfield< 51, 48 > dit
Definition: miscregs_types.hh:165
cp
Definition: cprintf.cc:40
sim_object.hh
DPRINTF
#define DPRINTF(x,...)
Definition: trace.hh:234
ADD_STAT
#define ADD_STAT(n,...)
Convenience macro to add a stat to a statistics group.
Definition: group.hh:67
VoltageDomain::sanitiseVoltages
bool sanitiseVoltages()
Recomputes the highest (fastest, i.e., numerically lowest) requested performance level of all associa...
Definition: voltage_domain.cc:80
ArmISA::d
Bitfield< 9 > d
Definition: miscregs_types.hh:60
statistics.hh
VoltageDomain
A VoltageDomain is used to group clock domains that operate under the same voltage.
Definition: voltage_domain.hh:53
VoltageDomain::_perfLevel
PerfLevel _perfLevel
Definition: voltage_domain.hh:139
chatty_assert
#define chatty_assert(cond,...)
The chatty assert macro will function like a normal assert, but will allow the specification of addit...
Definition: logging.hh:292
VoltageDomain::VoltageDomainStats::VoltageDomainStats
VoltageDomainStats(VoltageDomain &vd)
Definition: voltage_domain.cc:146
VoltageDomain::perfLevel
PerfLevel perfLevel() const
Get the voltage point of the domain.
Definition: voltage_domain.hh:96
VoltageDomain::VoltageDomain
VoltageDomain(const Params *p)
Definition: voltage_domain.cc:48
SERIALIZE_SCALAR
#define SERIALIZE_SCALAR(scalar)
Definition: serialize.hh:790
SimObject::name
virtual const std::string name() const
Definition: sim_object.hh:133
VoltageDomain::voltageOpPoints
const Voltages voltageOpPoints
List of possible minimum voltage at each of the frequency operational points, should be in descending...
Definition: voltage_domain.hh:138
VoltageDomain::unserialize
void unserialize(CheckpointIn &cp) override
Unserialize an object.
Definition: voltage_domain.cc:140
CheckpointOut
std::ostream CheckpointOut
Definition: serialize.hh:63
Stats
Definition: statistics.cc:61
trace.hh
VoltageDomain::serialize
void serialize(CheckpointOut &cp) const override
Serialize an object.
Definition: voltage_domain.cc:134
MipsISA::p
Bitfield< 0 > p
Definition: pra_constants.hh:323
fatal_if
#define fatal_if(cond,...)
Conditional fatal macro that checks the supplied condition and only causes a fatal error if the condi...
Definition: logging.hh:219
CheckpointIn
Definition: serialize.hh:67
VoltageDomain::VoltageDomainStats::voltage
Stats::Value voltage
Stat for reporting voltage of the domain.
Definition: voltage_domain.hh:148
VoltageDomain::PerfLevel
SrcClockDomain::PerfLevel PerfLevel
Definition: voltage_domain.hh:60
SimObject
Abstract superclass for simulation objects.
Definition: sim_object.hh:92

Generated on Wed Sep 30 2020 14:02:14 for gem5 by doxygen 1.8.17