timer_cpulocal.cc revision 13106 
1/*
2 * Copyright (c) 2010-2013,2018 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: Ali Saidi
38 *          Geoffrey Blake
39 */
40
41#include "dev/arm/timer_cpulocal.hh"
42
43#include "arch/arm/system.hh"
44#include "base/intmath.hh"
45#include "base/trace.hh"
46#include "debug/Checkpoint.hh"
47#include "debug/Timer.hh"
48#include "dev/arm/base_gic.hh"
49#include "mem/packet.hh"
50#include "mem/packet_access.hh"
51
52CpuLocalTimer::CpuLocalTimer(Params *p)
53    : BasicPioDevice(p, 0x38)
54{
55}
56
57void
58CpuLocalTimer::init()
59{
60   auto p = params();
61   // Initialize the timer registers for each per cpu timer
62   for (int i = 0; i < sys->numContexts(); i++) {
63        ThreadContext* tc = sys->getThreadContext(i);
64        std::stringstream oss;
65        oss << name() << ".timer" << i;
66
67        localTimer.emplace_back(
68            new Timer(oss.str(), this,
69                      p->int_timer->get(tc),
70                      p->int_watchdog->get(tc)));
71    }
72
73    BasicPioDevice::init();
74}
75
76CpuLocalTimer::Timer::Timer(const std::string &timer_name,
77                            CpuLocalTimer* _parent,
78                            ArmInterruptPin* int_timer,
79                            ArmInterruptPin* int_watchdog)
80    : _name(timer_name), parent(_parent), intTimer(int_timer),
81      intWatchdog(int_watchdog), timerControl(0x0), watchdogControl(0x0),
82      rawIntTimer(false), rawIntWatchdog(false),
83      rawResetWatchdog(false), watchdogDisableReg(0x0),
84      pendingIntTimer(false), pendingIntWatchdog(false),
85      timerLoadValue(0x0), watchdogLoadValue(0x0),
86      timerZeroEvent([this]{ timerAtZero(); }, name()),
87      watchdogZeroEvent([this]{ watchdogAtZero(); }, name())
88{
89}
90
91Tick
92CpuLocalTimer::read(PacketPtr pkt)
93{
94    assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
95    assert(pkt->getSize() == 4);
96    Addr daddr = pkt->getAddr() - pioAddr;
97    ContextID cpu_id = pkt->req->contextId();
98    DPRINTF(Timer, "Reading from CpuLocalTimer at offset: %#x\n", daddr);
99    assert(cpu_id >= 0);
100    assert(cpu_id < localTimer.size());
101
102    if (daddr < Timer::Size)
103        localTimer[cpu_id]->read(pkt, daddr);
104    else
105        panic("Tried to read CpuLocalTimer at offset %#x that doesn't exist\n", daddr);
106    pkt->makeAtomicResponse();
107    return pioDelay;
108}
109
110
111void
112CpuLocalTimer::Timer::read(PacketPtr pkt, Addr daddr)
113{
114    DPRINTF(Timer, "Reading from CpuLocalTimer at offset: %#x\n", daddr);
115    Tick time;
116
117    switch(daddr) {
118      case TimerLoadReg:
119        pkt->set<uint32_t>(timerLoadValue);
120        break;
121      case TimerCounterReg:
122        DPRINTF(Timer, "Event schedule for timer %d, clock=%d, prescale=%d\n",
123                timerZeroEvent.when(), parent->clockPeriod(),
124                timerControl.prescalar);
125        time = timerZeroEvent.when() - curTick();
126        time = time / parent->clockPeriod() /
127            power(16, timerControl.prescalar);
128        DPRINTF(Timer, "-- returning counter at %d\n", time);
129        pkt->set<uint32_t>(time);
130        break;
131      case TimerControlReg:
132        pkt->set<uint32_t>(timerControl);
133        break;
134      case TimerIntStatusReg:
135        pkt->set<uint32_t>(rawIntTimer);
136        break;
137      case WatchdogLoadReg:
138        pkt->set<uint32_t>(watchdogLoadValue);
139        break;
140      case WatchdogCounterReg:
141        DPRINTF(Timer,
142                "Event schedule for watchdog %d, clock=%d, prescale=%d\n",
143                watchdogZeroEvent.when(), parent->clockPeriod(),
144                watchdogControl.prescalar);
145        time = watchdogZeroEvent.when() - curTick();
146        time = time / parent->clockPeriod() /
147            power(16, watchdogControl.prescalar);
148        DPRINTF(Timer, "-- returning counter at %d\n", time);
149        pkt->set<uint32_t>(time);
150        break;
151      case WatchdogControlReg:
152        pkt->set<uint32_t>(watchdogControl);
153        break;
154      case WatchdogIntStatusReg:
155        pkt->set<uint32_t>(rawIntWatchdog);
156        break;
157      case WatchdogResetStatusReg:
158        pkt->set<uint32_t>(rawResetWatchdog);
159        break;
160      case WatchdogDisableReg:
161        panic("Tried to read from WatchdogDisableRegister\n");
162        break;
163      default:
164        panic("Tried to read CpuLocalTimer at offset %#x\n", daddr);
165        break;
166    }
167}
168
169Tick
170CpuLocalTimer::write(PacketPtr pkt)
171{
172    assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
173    assert(pkt->getSize() == 4);
174    Addr daddr = pkt->getAddr() - pioAddr;
175    ContextID cpu_id = pkt->req->contextId();
176    DPRINTF(Timer, "Writing to CpuLocalTimer at offset: %#x\n", daddr);
177    assert(cpu_id >= 0);
178    assert(cpu_id < localTimer.size());
179
180    if (daddr < Timer::Size)
181        localTimer[cpu_id]->write(pkt, daddr);
182    else
183        panic("Tried to write CpuLocalTimer at offset %#x that doesn't exist\n", daddr);
184    pkt->makeAtomicResponse();
185    return pioDelay;
186}
187
188void
189CpuLocalTimer::Timer::write(PacketPtr pkt, Addr daddr)
190{
191    DPRINTF(Timer, "Writing to CpuLocalTimer at offset: %#x\n", daddr);
192    bool old_enable;
193    bool old_wd_mode;
194    uint32_t old_val;
195
196    switch (daddr) {
197      case TimerLoadReg:
198        // Writing to this register also resets the counter register and
199        // starts decrementing if the counter is enabled.
200        timerLoadValue = pkt->get<uint32_t>();
201        restartTimerCounter(timerLoadValue);
202        break;
203      case TimerCounterReg:
204        // Can be written, doesn't start counting unless the timer is enabled
205        restartTimerCounter(pkt->get<uint32_t>());
206        break;
207      case TimerControlReg:
208        old_enable = timerControl.enable;
209        timerControl = pkt->get<uint32_t>();
210        if ((old_enable == 0) && timerControl.enable)
211            restartTimerCounter(timerLoadValue);
212        break;
213      case TimerIntStatusReg:
214        rawIntTimer = false;
215        if (pendingIntTimer) {
216            pendingIntTimer = false;
217            DPRINTF(Timer, "Clearing interrupt\n");
218        }
219        break;
220      case WatchdogLoadReg:
221        watchdogLoadValue = pkt->get<uint32_t>();
222        restartWatchdogCounter(watchdogLoadValue);
223        break;
224      case WatchdogCounterReg:
225        // Can't be written when in watchdog mode, but can in timer mode
226        if (!watchdogControl.watchdogMode) {
227            restartWatchdogCounter(pkt->get<uint32_t>());
228        }
229        break;
230      case WatchdogControlReg:
231        old_enable = watchdogControl.enable;
232        old_wd_mode = watchdogControl.watchdogMode;
233        watchdogControl = pkt->get<uint32_t>();
234        if ((old_enable == 0) && watchdogControl.enable)
235            restartWatchdogCounter(watchdogLoadValue);
236        // cannot disable watchdog using control register
237        if ((old_wd_mode == 1) && watchdogControl.watchdogMode == 0)
238            watchdogControl.watchdogMode = 1;
239        break;
240      case WatchdogIntStatusReg:
241        rawIntWatchdog = false;
242        if (pendingIntWatchdog) {
243            pendingIntWatchdog = false;
244            DPRINTF(Timer, "Clearing watchdog interrupt\n");
245        }
246        break;
247      case WatchdogResetStatusReg:
248        rawResetWatchdog = false;
249        DPRINTF(Timer, "Clearing watchdog reset flag\n");
250        break;
251      case WatchdogDisableReg:
252        old_val = watchdogDisableReg;
253        watchdogDisableReg = pkt->get<uint32_t>();
254        // if this sequence is observed, turn off watchdog mode
255        if (old_val == 0x12345678 && watchdogDisableReg == 0x87654321)
256            watchdogControl.watchdogMode = 0;
257        break;
258      default:
259        panic("Tried to write CpuLocalTimer timer at offset %#x\n", daddr);
260        break;
261    }
262}
263
264//XXX: Two functions are needed because the control registers are different types
265void
266CpuLocalTimer::Timer::restartTimerCounter(uint32_t val)
267{
268    DPRINTF(Timer, "Resetting timer counter with value %#x\n", val);
269    if (!timerControl.enable)
270        return;
271
272    Tick time = parent->clockPeriod() * power(16, timerControl.prescalar);
273    time *= val;
274
275    if (timerZeroEvent.scheduled()) {
276        DPRINTF(Timer, "-- Event was already schedule, de-scheduling\n");
277        parent->deschedule(timerZeroEvent);
278    }
279    parent->schedule(timerZeroEvent, curTick() + time);
280    DPRINTF(Timer, "-- Scheduling new event for: %d\n", curTick() + time);
281}
282
283void
284CpuLocalTimer::Timer::restartWatchdogCounter(uint32_t val)
285{
286    DPRINTF(Timer, "Resetting watchdog counter with value %#x\n", val);
287    if (!watchdogControl.enable)
288        return;
289
290    Tick time = parent->clockPeriod() * power(16, watchdogControl.prescalar);
291    time *= val;
292
293    if (watchdogZeroEvent.scheduled()) {
294        DPRINTF(Timer, "-- Event was already schedule, de-scheduling\n");
295        parent->deschedule(watchdogZeroEvent);
296    }
297    parent->schedule(watchdogZeroEvent, curTick() + time);
298    DPRINTF(Timer, "-- Scheduling new event for: %d\n", curTick() + time);
299}
300//////
301
302void
303CpuLocalTimer::Timer::timerAtZero()
304{
305    if (!timerControl.enable)
306        return;
307
308    DPRINTF(Timer, "Timer Counter reached zero\n");
309
310    rawIntTimer = true;
311    bool old_pending = pendingIntTimer;
312    if (timerControl.intEnable)
313        pendingIntTimer = true;
314    if (pendingIntTimer && !old_pending) {
315        DPRINTF(Timer, "-- Causing interrupt\n");
316        intTimer->raise();
317    }
318
319    if (!timerControl.autoReload)
320        return;
321    else
322        restartTimerCounter(timerLoadValue);
323}
324
325void
326CpuLocalTimer::Timer::watchdogAtZero()
327{
328    if (!watchdogControl.enable)
329        return;
330
331    DPRINTF(Timer, "Watchdog Counter reached zero\n");
332
333    rawIntWatchdog = true;
334    bool old_pending = pendingIntWatchdog;
335    // generates an interrupt only if the watchdog is in timer
336    // mode.
337    if (watchdogControl.intEnable && !watchdogControl.watchdogMode)
338        pendingIntWatchdog = true;
339    else if (watchdogControl.watchdogMode) {
340        rawResetWatchdog = true;
341        fatal("gem5 ARM Model does not support true watchdog operation!\n");
342        //XXX: Should we ever support a true watchdog reset?
343    }
344
345    if (pendingIntWatchdog && !old_pending) {
346        DPRINTF(Timer, "-- Causing interrupt\n");
347        intWatchdog->raise();
348    }
349
350    if (watchdogControl.watchdogMode)
351        return;
352    else if (watchdogControl.autoReload)
353        restartWatchdogCounter(watchdogLoadValue);
354}
355
356void
357CpuLocalTimer::Timer::serialize(CheckpointOut &cp) const
358{
359    DPRINTF(Checkpoint, "Serializing Arm CpuLocalTimer\n");
360
361    uint32_t timer_control_serial = timerControl;
362    uint32_t watchdog_control_serial = watchdogControl;
363    SERIALIZE_SCALAR(timer_control_serial);
364    SERIALIZE_SCALAR(watchdog_control_serial);
365
366    SERIALIZE_SCALAR(rawIntTimer);
367    SERIALIZE_SCALAR(rawIntWatchdog);
368    SERIALIZE_SCALAR(rawResetWatchdog);
369    SERIALIZE_SCALAR(watchdogDisableReg);
370    SERIALIZE_SCALAR(pendingIntTimer);
371    SERIALIZE_SCALAR(pendingIntWatchdog);
372    SERIALIZE_SCALAR(timerLoadValue);
373    SERIALIZE_SCALAR(watchdogLoadValue);
374
375    bool timer_is_in_event = timerZeroEvent.scheduled();
376    SERIALIZE_SCALAR(timer_is_in_event);
377    bool watchdog_is_in_event = watchdogZeroEvent.scheduled();
378    SERIALIZE_SCALAR(watchdog_is_in_event);
379
380    Tick timer_event_time;
381    if (timer_is_in_event){
382        timer_event_time = timerZeroEvent.when();
383        SERIALIZE_SCALAR(timer_event_time);
384    }
385    Tick watchdog_event_time;
386    if (watchdog_is_in_event){
387        watchdog_event_time = watchdogZeroEvent.when();
388        SERIALIZE_SCALAR(watchdog_event_time);
389    }
390}
391
392void
393CpuLocalTimer::Timer::unserialize(CheckpointIn &cp)
394{
395    DPRINTF(Checkpoint, "Unserializing Arm CpuLocalTimer\n");
396
397    uint32_t timer_control_serial;
398    UNSERIALIZE_SCALAR(timer_control_serial);
399    timerControl = timer_control_serial;
400    uint32_t watchdog_control_serial;
401    UNSERIALIZE_SCALAR(watchdog_control_serial);
402    watchdogControl = watchdog_control_serial;
403
404    UNSERIALIZE_SCALAR(rawIntTimer);
405    UNSERIALIZE_SCALAR(rawIntWatchdog);
406    UNSERIALIZE_SCALAR(rawResetWatchdog);
407    UNSERIALIZE_SCALAR(watchdogDisableReg);
408    UNSERIALIZE_SCALAR(pendingIntTimer);
409    UNSERIALIZE_SCALAR(pendingIntWatchdog);
410    UNSERIALIZE_SCALAR(timerLoadValue);
411    UNSERIALIZE_SCALAR(watchdogLoadValue);
412
413    bool timer_is_in_event;
414    UNSERIALIZE_SCALAR(timer_is_in_event);
415    bool watchdog_is_in_event;
416    UNSERIALIZE_SCALAR(watchdog_is_in_event);
417
418    Tick timer_event_time;
419    if (timer_is_in_event){
420        UNSERIALIZE_SCALAR(timer_event_time);
421        parent->schedule(timerZeroEvent, timer_event_time);
422    }
423    Tick watchdog_event_time;
424    if (watchdog_is_in_event) {
425        UNSERIALIZE_SCALAR(watchdog_event_time);
426        parent->schedule(watchdogZeroEvent, watchdog_event_time);
427    }
428}
429
430
431
432void
433CpuLocalTimer::serialize(CheckpointOut &cp) const
434{
435    for (int i = 0; i < sys->numContexts(); i++)
436        localTimer[i]->serializeSection(cp, csprintf("timer%d", i));
437}
438
439void
440CpuLocalTimer::unserialize(CheckpointIn &cp)
441{
442    for (int i = 0; i < sys->numContexts(); i++)
443        localTimer[i]->unserializeSection(cp, csprintf("timer%d", i));
444}
445
446CpuLocalTimer *
447CpuLocalTimerParams::create()
448{
449    return new CpuLocalTimer(this);
450}
451