voltage_domain.cc revision 10249:6bbb7ae309ac 
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 <algorithm>
42
43#include "base/statistics.hh"
44#include "debug/VoltageDomain.hh"
45#include "params/VoltageDomain.hh"
46#include "sim/sim_object.hh"
47#include "sim/voltage_domain.hh"
48
49VoltageDomain::VoltageDomain(const Params *p)
50    : SimObject(p), voltageOpPoints(p->voltage), _perfLevel(0)
51{
52    fatal_if(voltageOpPoints.empty(), "DVFS: Empty set of voltages for "\
53             "voltage domain %s\n", name());
54
55    // Voltages must be sorted in descending order.
56    fatal_if(!std::is_sorted(voltageOpPoints.begin(), voltageOpPoints.end(),
57             std::greater_equal<Voltages::value_type>()), "DVFS: Voltage "\
58             "operation points not in descending order for voltage domain "\
59             "%s\n", name());
60}
61
62void
63VoltageDomain::perfLevel(PerfLevel perf_level)
64{
65    chatty_assert(perf_level < voltageOpPoints.size(),
66                  "DVFS: Requested voltage ID %d is outside the known "\
67                  "range for domain %s.\n", perf_level, name());
68
69    _perfLevel = perf_level;
70
71    DPRINTF(VoltageDomain, "Setting voltage to %.3fV idx: %d for domain %s\n",
72            voltage(), perf_level, name());
73}
74
75bool
76VoltageDomain::sanitiseVoltages()
77{
78    if (numVoltages() == 1)
79        return false;
80
81    // Find the highest requested performance level and update the voltage
82    // domain with it
83    PerfLevel perf_max = (PerfLevel)-1;
84    for (auto dit = srcClockChildren.begin(); dit != srcClockChildren.end(); ++dit) {
85        SrcClockDomain* d = *dit;
86        chatty_assert(d->voltageDomain() == this, "DVFS: Clock domain %s "\
87                      "(id: %d) should not be registered with voltage domain "\
88                      "%s\n", d->name(), d->domainID(), name());
89
90        PerfLevel perf = d->perfLevel();
91
92        DPRINTF(VoltageDomain, "DVFS: Clock domain %s (id: %d) requests perf "\
93                "level %d\n", d->name(), d->domainID(), perf);
94
95        // NOTE: Descending sort of performance levels: 0 - fast, 5 - slow
96        if (perf < perf_max) {
97            DPRINTF(VoltageDomain, "DVFS: Updating max perf level %d -> %d\n",
98                    perf_max, perf);
99            perf_max = perf;
100        }
101    }
102    DPRINTF(VoltageDomain, "DVFS: Setting perf level of voltage domain %s "\
103            "from %d to %d.\n", name(), perfLevel(), perf_max);
104
105    // Set the performance level
106    if (perf_max != perfLevel()) {
107        perfLevel(perf_max);
108        return true;
109    } else {
110        return false;
111    }
112}
113
114void
115VoltageDomain::startup() {
116    bool changed = sanitiseVoltages();
117    if (changed) {
118        warn("DVFS: Perf level for voltage domain %s adapted to "\
119             "requested perf levels from source clock domains.\n", name());
120    }
121}
122
123void
124VoltageDomain::regStats()
125{
126    currentVoltage
127        .method(this, &VoltageDomain::voltage)
128        .name(params()->name + ".voltage")
129        .desc("Voltage in Volts")
130        ;
131}
132
133VoltageDomain *
134VoltageDomainParams::create()
135{
136    return new VoltageDomain(this);
137}
138
139void
140VoltageDomain::serialize(std::ostream &os) {
141    SERIALIZE_SCALAR(_perfLevel);
142}
143
144void
145VoltageDomain::unserialize(Checkpoint *cp, const std::string &section) {
146    UNSERIALIZE_SCALAR(_perfLevel);
147    perfLevel(_perfLevel);
148}
149