summaryrefslogtreecommitdiff
path: root/src/dev/arm/energy_ctrl.cc
blob: 9cfce3a48777fbbc3a63d9c41d4c5c70fe47cad3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
/*
 * Copyright (c) 2012-2014 ARM Limited
 * All rights reserved
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors: Vasileios Spiliopoulos
 *          Akash Bagdia
 *          Stephan Diestelhorst
 */

#include "dev/arm/energy_ctrl.hh"

#include "debug/EnergyCtrl.hh"
#include "mem/packet.hh"
#include "mem/packet_access.hh"
#include "params/EnergyCtrl.hh"
#include "sim/dvfs_handler.hh"

EnergyCtrl::EnergyCtrl(const Params *p)
    : BasicPioDevice(p, PIO_NUM_FIELDS * 4),        // each field is 32 bit
      dvfsHandler(p->dvfs_handler),
      domainID(0),
      domainIDIndexToRead(0),
      perfLevelAck(0),
      perfLevelToRead(0),
      updateAckEvent([this]{ updatePLAck(); }, name())
{
    fatal_if(!p->dvfs_handler, "EnergyCtrl: Needs a DVFSHandler for a "
             "functioning system.\n");
}

Tick
EnergyCtrl::read(PacketPtr pkt)
{
    assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
    assert(pkt->getSize() == 4);

    Addr daddr = pkt->getAddr() - pioAddr;
    assert((daddr & 3) == 0);
    Registers reg = Registers(daddr / 4);

    if (!dvfsHandler->isEnabled()) {
        // NB: Zero is a good response if the handler is disabled
        pkt->set<uint32_t>(0);
        warn_once("EnergyCtrl: Disabled handler, ignoring read from reg %i\n",
                  reg);
        DPRINTF(EnergyCtrl, "dvfs handler disabled, return 0 for read from "\
                "reg %i\n", reg);
        pkt->makeAtomicResponse();
        return pioDelay;
    }

    uint32_t result = 0;
    Tick period;
    double voltage;

    switch(reg) {
      case DVFS_HANDLER_STATUS:
        result = 1;
        DPRINTF(EnergyCtrl, "dvfs handler enabled\n");
        break;
      case DVFS_NUM_DOMAINS:
        result = dvfsHandler->numDomains();
        DPRINTF(EnergyCtrl, "reading number of domains %d\n", result);
        break;
      case DVFS_DOMAINID_AT_INDEX:
        result = dvfsHandler->domainID(domainIDIndexToRead);
        DPRINTF(EnergyCtrl, "reading domain id at index %d as %d\n",
                domainIDIndexToRead, result);
        break;
      case DVFS_HANDLER_TRANS_LATENCY:
        // Return transition latency in nanoseconds
        result = dvfsHandler->transLatency() / SimClock::Int::ns;
        DPRINTF(EnergyCtrl, "reading dvfs handler trans latency %d ns\n",
                result);
        break;
      case DOMAIN_ID:
        result = domainID;
        DPRINTF(EnergyCtrl, "reading domain id:%d\n", result);
        break;
      case PERF_LEVEL:
        result = dvfsHandler->perfLevel(domainID);
        DPRINTF(EnergyCtrl, "reading domain %d perf level: %d\n",
                domainID, result);
        break;
      case PERF_LEVEL_ACK:
        result = perfLevelAck;
        DPRINTF(EnergyCtrl, "reading ack:%d\n", result);
        // Signal is set for a single read only
        if (result == 1)
            perfLevelAck = 0;
        break;
      case NUM_OF_PERF_LEVELS:
        result = dvfsHandler->numPerfLevels(domainID);
        DPRINTF(EnergyCtrl, "reading num of perf level:%d\n", result);
        break;
      case FREQ_AT_PERF_LEVEL:
        period = dvfsHandler->clkPeriodAtPerfLevel(domainID, perfLevelToRead);
        result = ticksTokHz(period);
        DPRINTF(EnergyCtrl, "reading freq %d KHz at perf level: %d\n",
                result, perfLevelToRead);
        break;
      case VOLT_AT_PERF_LEVEL:
        voltage = dvfsHandler->voltageAtPerfLevel(domainID, perfLevelToRead);
        result = toMicroVolt(voltage);
        DPRINTF(EnergyCtrl, "reading voltage %d u-volt at perf level: %d\n",
                result, perfLevelToRead);
        break;
      default:
        panic("Tried to read EnergyCtrl at offset %#x / reg %i\n", daddr,
              reg);
    }
    pkt->set<uint32_t>(result);
    pkt->makeAtomicResponse();
    return pioDelay;
}

Tick
EnergyCtrl::write(PacketPtr pkt)
{
    assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
    assert(pkt->getSize() == 4);

    uint32_t data;
    data = pkt->get<uint32_t>();

    Addr daddr = pkt->getAddr() - pioAddr;
    assert((daddr & 3) == 0);
    Registers reg = Registers(daddr / 4);

    if (!dvfsHandler->isEnabled()) {
        // Ignore writes to a disabled controller
        warn_once("EnergyCtrl: Disabled handler, ignoring write %u to "\
                  "reg %i\n", data, reg);
        DPRINTF(EnergyCtrl, "dvfs handler disabled, ignoring write %u to "\
                "reg %i\n", data, reg);
        pkt->makeAtomicResponse();
        return pioDelay;
    }

    switch(reg) {
      case DVFS_DOMAINID_AT_INDEX:
        domainIDIndexToRead = data;
        DPRINTF(EnergyCtrl, "writing domain id index:%d\n",
                domainIDIndexToRead);
        break;
      case DOMAIN_ID:
        // Extra check to ensure that a valid domain ID is being queried
        if (dvfsHandler->validDomainID(data)) {
            domainID = data;
            DPRINTF(EnergyCtrl, "writing domain id:%d\n", domainID);
        } else {
           DPRINTF(EnergyCtrl, "invalid domain id:%d\n", domainID);
        }
        break;
      case PERF_LEVEL:
        if (dvfsHandler->perfLevel(domainID, data)) {
            if (updateAckEvent.scheduled()) {
                // The OS driver is trying to change the perf level while
                // another change is in flight.  This is fine, but only a
                // single acknowledgment will be sent.
                DPRINTF(EnergyCtrl, "descheduling previous pending ack "\
                        "event\n");
                deschedule(updateAckEvent);
            }
            schedule(updateAckEvent, curTick() + dvfsHandler->transLatency());
            DPRINTF(EnergyCtrl, "writing domain %d perf level: %d\n",
                    domainID, data);
        } else {
            DPRINTF(EnergyCtrl, "invalid / ineffective perf level:%d for "\
                    "domain:%d\n", data, domainID);
        }
        break;
      case PERF_LEVEL_TO_READ:
        perfLevelToRead = data;
        DPRINTF(EnergyCtrl, "writing perf level to read opp at: %d\n",
                data);
        break;
      default:
        panic("Tried to write EnergyCtrl at offset %#x\n", daddr);
        break;
    }

    pkt->makeAtomicResponse();
    return pioDelay;
}

void
EnergyCtrl::serialize(CheckpointOut &cp) const
{
    SERIALIZE_SCALAR(domainID);
    SERIALIZE_SCALAR(domainIDIndexToRead);
    SERIALIZE_SCALAR(perfLevelToRead);
    SERIALIZE_SCALAR(perfLevelAck);

    Tick next_event = updateAckEvent.scheduled() ? updateAckEvent.when() : 0;
    SERIALIZE_SCALAR(next_event);
}

void
EnergyCtrl::unserialize(CheckpointIn &cp)
{
    UNSERIALIZE_SCALAR(domainID);
    UNSERIALIZE_SCALAR(domainIDIndexToRead);
    UNSERIALIZE_SCALAR(perfLevelToRead);
    UNSERIALIZE_SCALAR(perfLevelAck);
    Tick next_event = 0;
    UNSERIALIZE_SCALAR(next_event);

    // restore scheduled events
    if (next_event != 0) {
        schedule(updateAckEvent, next_event);
    }
}

EnergyCtrl * EnergyCtrlParams::create()
{
    return new EnergyCtrl(this);
}

void
EnergyCtrl::startup()
{
    if (!dvfsHandler->isEnabled()) {
        warn("Existing EnergyCtrl, but no enabled DVFSHandler found.\n");
    }
}

void
EnergyCtrl::init()
{
    BasicPioDevice::init();
}