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 *          Stephan Diestelhorst
40 */
41
42#include "dev/arm/energy_ctrl.hh"
43
44#include "debug/EnergyCtrl.hh"
45#include "mem/packet.hh"
46#include "mem/packet_access.hh"
47#include "params/EnergyCtrl.hh"
48#include "sim/dvfs_handler.hh"
49
50EnergyCtrl::EnergyCtrl(const Params *p)
51    : BasicPioDevice(p, PIO_NUM_FIELDS * 4),        // each field is 32 bit
52      dvfsHandler(p->dvfs_handler),
53      domainID(0),
54      domainIDIndexToRead(0),
55      perfLevelAck(0),
56      perfLevelToRead(0),
57      updateAckEvent([this]{ updatePLAck(); }, name())
58{
59    fatal_if(!p->dvfs_handler, "EnergyCtrl: Needs a DVFSHandler for a "
60             "functioning system.\n");
61}
62
63Tick
64EnergyCtrl::read(PacketPtr pkt)
65{
66    assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
67    assert(pkt->getSize() == 4);
68
69    Addr daddr = pkt->getAddr() - pioAddr;
70    assert((daddr & 3) == 0);
71    Registers reg = Registers(daddr / 4);
72
73    if (!dvfsHandler->isEnabled()) {
74        // NB: Zero is a good response if the handler is disabled
75        pkt->setLE<uint32_t>(0);
76        warn_once("EnergyCtrl: Disabled handler, ignoring read from reg %i\n",
77                  reg);
78        DPRINTF(EnergyCtrl, "dvfs handler disabled, return 0 for read from "\
79                "reg %i\n", reg);
80        pkt->makeAtomicResponse();
81        return pioDelay;
82    }
83
84    uint32_t result = 0;
85    Tick period;
86    double voltage;
87
88    switch(reg) {
89      case DVFS_HANDLER_STATUS:
90        result = 1;
91        DPRINTF(EnergyCtrl, "dvfs handler enabled\n");
92        break;
93      case DVFS_NUM_DOMAINS:
94        result = dvfsHandler->numDomains();
95        DPRINTF(EnergyCtrl, "reading number of domains %d\n", result);
96        break;
97      case DVFS_DOMAINID_AT_INDEX:
98        result = dvfsHandler->domainID(domainIDIndexToRead);
99        DPRINTF(EnergyCtrl, "reading domain id at index %d as %d\n",
100                domainIDIndexToRead, result);
101        break;
102      case DVFS_HANDLER_TRANS_LATENCY:
103        // Return transition latency in nanoseconds
104        result = dvfsHandler->transLatency() / SimClock::Int::ns;
105        DPRINTF(EnergyCtrl, "reading dvfs handler trans latency %d ns\n",
106                result);
107        break;
108      case DOMAIN_ID:
109        result = domainID;
110        DPRINTF(EnergyCtrl, "reading domain id:%d\n", result);
111        break;
112      case PERF_LEVEL:
113        result = dvfsHandler->perfLevel(domainID);
114        DPRINTF(EnergyCtrl, "reading domain %d perf level: %d\n",
115                domainID, result);
116        break;
117      case PERF_LEVEL_ACK:
118        result = perfLevelAck;
119        DPRINTF(EnergyCtrl, "reading ack:%d\n", result);
120        // Signal is set for a single read only
121        if (result == 1)
122            perfLevelAck = 0;
123        break;
124      case NUM_OF_PERF_LEVELS:
125        result = dvfsHandler->numPerfLevels(domainID);
126        DPRINTF(EnergyCtrl, "reading num of perf level:%d\n", result);
127        break;
128      case FREQ_AT_PERF_LEVEL:
129        period = dvfsHandler->clkPeriodAtPerfLevel(domainID, perfLevelToRead);
130        result = ticksTokHz(period);
131        DPRINTF(EnergyCtrl, "reading freq %d KHz at perf level: %d\n",
132                result, perfLevelToRead);
133        break;
134      case VOLT_AT_PERF_LEVEL:
135        voltage = dvfsHandler->voltageAtPerfLevel(domainID, perfLevelToRead);
136        result = toMicroVolt(voltage);
137        DPRINTF(EnergyCtrl, "reading voltage %d u-volt at perf level: %d\n",
138                result, perfLevelToRead);
139        break;
140      default:
141        panic("Tried to read EnergyCtrl at offset %#x / reg %i\n", daddr,
142              reg);
143    }
144    pkt->setLE<uint32_t>(result);
145    pkt->makeAtomicResponse();
146    return pioDelay;
147}
148
149Tick
150EnergyCtrl::write(PacketPtr pkt)
151{
152    assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
153    assert(pkt->getSize() == 4);
154
155    uint32_t data;
156    data = pkt->getLE<uint32_t>();
157
158    Addr daddr = pkt->getAddr() - pioAddr;
159    assert((daddr & 3) == 0);
160    Registers reg = Registers(daddr / 4);
161
162    if (!dvfsHandler->isEnabled()) {
163        // Ignore writes to a disabled controller
164        warn_once("EnergyCtrl: Disabled handler, ignoring write %u to "\
165                  "reg %i\n", data, reg);
166        DPRINTF(EnergyCtrl, "dvfs handler disabled, ignoring write %u to "\
167                "reg %i\n", data, reg);
168        pkt->makeAtomicResponse();
169        return pioDelay;
170    }
171
172    switch(reg) {
173      case DVFS_DOMAINID_AT_INDEX:
174        domainIDIndexToRead = data;
175        DPRINTF(EnergyCtrl, "writing domain id index:%d\n",
176                domainIDIndexToRead);
177        break;
178      case DOMAIN_ID:
179        // Extra check to ensure that a valid domain ID is being queried
180        if (dvfsHandler->validDomainID(data)) {
181            domainID = data;
182            DPRINTF(EnergyCtrl, "writing domain id:%d\n", domainID);
183        } else {
184           DPRINTF(EnergyCtrl, "invalid domain id:%d\n", domainID);
185        }
186        break;
187      case PERF_LEVEL:
188        if (dvfsHandler->perfLevel(domainID, data)) {
189            if (updateAckEvent.scheduled()) {
190                // The OS driver is trying to change the perf level while
191                // another change is in flight.  This is fine, but only a
192                // single acknowledgment will be sent.
193                DPRINTF(EnergyCtrl, "descheduling previous pending ack "\
194                        "event\n");
195                deschedule(updateAckEvent);
196            }
197            schedule(updateAckEvent, curTick() + dvfsHandler->transLatency());
198            DPRINTF(EnergyCtrl, "writing domain %d perf level: %d\n",
199                    domainID, data);
200        } else {
201            DPRINTF(EnergyCtrl, "invalid / ineffective perf level:%d for "\
202                    "domain:%d\n", data, domainID);
203        }
204        break;
205      case PERF_LEVEL_TO_READ:
206        perfLevelToRead = data;
207        DPRINTF(EnergyCtrl, "writing perf level to read opp at: %d\n",
208                data);
209        break;
210      default:
211        panic("Tried to write EnergyCtrl at offset %#x\n", daddr);
212        break;
213    }
214
215    pkt->makeAtomicResponse();
216    return pioDelay;
217}
218
219void
220EnergyCtrl::serialize(CheckpointOut &cp) const
221{
222    SERIALIZE_SCALAR(domainID);
223    SERIALIZE_SCALAR(domainIDIndexToRead);
224    SERIALIZE_SCALAR(perfLevelToRead);
225    SERIALIZE_SCALAR(perfLevelAck);
226
227    Tick next_event = updateAckEvent.scheduled() ? updateAckEvent.when() : 0;
228    SERIALIZE_SCALAR(next_event);
229}
230
231void
232EnergyCtrl::unserialize(CheckpointIn &cp)
233{
234    UNSERIALIZE_SCALAR(domainID);
235    UNSERIALIZE_SCALAR(domainIDIndexToRead);
236    UNSERIALIZE_SCALAR(perfLevelToRead);
237    UNSERIALIZE_SCALAR(perfLevelAck);
238    Tick next_event = 0;
239    UNSERIALIZE_SCALAR(next_event);
240
241    // restore scheduled events
242    if (next_event != 0) {
243        schedule(updateAckEvent, next_event);
244    }
245}
246
247EnergyCtrl * EnergyCtrlParams::create()
248{
249    return new EnergyCtrl(this);
250}
251
252void
253EnergyCtrl::startup()
254{
255    if (!dvfsHandler->isEnabled()) {
256        warn("Existing EnergyCtrl, but no enabled DVFSHandler found.\n");
257    }
258}
259
260void
261EnergyCtrl::init()
262{
263    BasicPioDevice::init();
264}
265