timer_cpulocal.cc revision 10905:a6ca6831e775 
1/*
2 * Copyright (c) 2010-2013 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 "base/intmath.hh"
42#include "base/trace.hh"
43#include "debug/Checkpoint.hh"
44#include "debug/Timer.hh"
45#include "dev/arm/base_gic.hh"
46#include "dev/arm/timer_cpulocal.hh"
47#include "mem/packet.hh"
48#include "mem/packet_access.hh"
49
50CpuLocalTimer::CpuLocalTimer(Params *p)
51    : BasicPioDevice(p, 0x38), gic(p->gic)
52{
53   // Initialize the timer registers for each per cpu timer
54   for (int i = 0; i < CPU_MAX; i++) {
55        std::stringstream oss;
56        oss << name() << ".timer" << i;
57        localTimer[i]._name = oss.str();
58        localTimer[i].parent = this;
59        localTimer[i].intNumTimer = p->int_num_timer;
60        localTimer[i].intNumWatchdog = p->int_num_watchdog;
61        localTimer[i].cpuNum = i;
62    }
63}
64
65CpuLocalTimer::Timer::Timer()
66    : timerControl(0x0), watchdogControl(0x0), rawIntTimer(false), rawIntWatchdog(false),
67      rawResetWatchdog(false), watchdogDisableReg(0x0), pendingIntTimer(false), pendingIntWatchdog(false),
68      timerLoadValue(0x0), watchdogLoadValue(0x0), timerZeroEvent(this), watchdogZeroEvent(this)
69{
70}
71
72Tick
73CpuLocalTimer::read(PacketPtr pkt)
74{
75    assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
76    assert(pkt->getSize() == 4);
77    Addr daddr = pkt->getAddr() - pioAddr;
78    int cpu_id = pkt->req->contextId();
79    DPRINTF(Timer, "Reading from CpuLocalTimer at offset: %#x\n", daddr);
80    assert(cpu_id >= 0);
81    assert(cpu_id < CPU_MAX);
82
83    if (daddr < Timer::Size)
84        localTimer[cpu_id].read(pkt, daddr);
85    else
86        panic("Tried to read CpuLocalTimer at offset %#x that doesn't exist\n", daddr);
87    pkt->makeAtomicResponse();
88    return pioDelay;
89}
90
91
92void
93CpuLocalTimer::Timer::read(PacketPtr pkt, Addr daddr)
94{
95    DPRINTF(Timer, "Reading from CpuLocalTimer at offset: %#x\n", daddr);
96    Tick time;
97
98    switch(daddr) {
99      case TimerLoadReg:
100        pkt->set<uint32_t>(timerLoadValue);
101        break;
102      case TimerCounterReg:
103        DPRINTF(Timer, "Event schedule for timer %d, clock=%d, prescale=%d\n",
104                timerZeroEvent.when(), parent->clockPeriod(),
105                timerControl.prescalar);
106        time = timerZeroEvent.when() - curTick();
107        time = time / parent->clockPeriod() /
108            power(16, timerControl.prescalar);
109        DPRINTF(Timer, "-- returning counter at %d\n", time);
110        pkt->set<uint32_t>(time);
111        break;
112      case TimerControlReg:
113        pkt->set<uint32_t>(timerControl);
114        break;
115      case TimerIntStatusReg:
116        pkt->set<uint32_t>(rawIntTimer);
117        break;
118      case WatchdogLoadReg:
119        pkt->set<uint32_t>(watchdogLoadValue);
120        break;
121      case WatchdogCounterReg:
122        DPRINTF(Timer,
123                "Event schedule for watchdog %d, clock=%d, prescale=%d\n",
124                watchdogZeroEvent.when(), parent->clockPeriod(),
125                watchdogControl.prescalar);
126        time = watchdogZeroEvent.when() - curTick();
127        time = time / parent->clockPeriod() /
128            power(16, watchdogControl.prescalar);
129        DPRINTF(Timer, "-- returning counter at %d\n", time);
130        pkt->set<uint32_t>(time);
131        break;
132      case WatchdogControlReg:
133        pkt->set<uint32_t>(watchdogControl);
134        break;
135      case WatchdogIntStatusReg:
136        pkt->set<uint32_t>(rawIntWatchdog);
137        break;
138      case WatchdogResetStatusReg:
139        pkt->set<uint32_t>(rawResetWatchdog);
140        break;
141      case WatchdogDisableReg:
142        panic("Tried to read from WatchdogDisableRegister\n");
143        break;
144      default:
145        panic("Tried to read CpuLocalTimer at offset %#x\n", daddr);
146        break;
147    }
148}
149
150Tick
151CpuLocalTimer::write(PacketPtr pkt)
152{
153    assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
154    assert(pkt->getSize() == 4);
155    Addr daddr = pkt->getAddr() - pioAddr;
156    int cpu_id = pkt->req->contextId();
157    DPRINTF(Timer, "Writing to CpuLocalTimer at offset: %#x\n", daddr);
158    assert(cpu_id >= 0);
159    assert(cpu_id < CPU_MAX);
160
161    if (daddr < Timer::Size)
162        localTimer[cpu_id].write(pkt, daddr);
163    else
164        panic("Tried to write CpuLocalTimer at offset %#x that doesn't exist\n", daddr);
165    pkt->makeAtomicResponse();
166    return pioDelay;
167}
168
169void
170CpuLocalTimer::Timer::write(PacketPtr pkt, Addr daddr)
171{
172    DPRINTF(Timer, "Writing to CpuLocalTimer at offset: %#x\n", daddr);
173    bool old_enable;
174    bool old_wd_mode;
175    uint32_t old_val;
176
177    switch (daddr) {
178      case TimerLoadReg:
179        // Writing to this register also resets the counter register and
180        // starts decrementing if the counter is enabled.
181        timerLoadValue = pkt->get<uint32_t>();
182        restartTimerCounter(timerLoadValue);
183        break;
184      case TimerCounterReg:
185        // Can be written, doesn't start counting unless the timer is enabled
186        restartTimerCounter(pkt->get<uint32_t>());
187        break;
188      case TimerControlReg:
189        old_enable = timerControl.enable;
190        timerControl = pkt->get<uint32_t>();
191        if ((old_enable == 0) && timerControl.enable)
192            restartTimerCounter(timerLoadValue);
193        break;
194      case TimerIntStatusReg:
195        rawIntTimer = false;
196        if (pendingIntTimer) {
197            pendingIntTimer = false;
198            DPRINTF(Timer, "Clearing interrupt\n");
199        }
200        break;
201      case WatchdogLoadReg:
202        watchdogLoadValue = pkt->get<uint32_t>();
203        restartWatchdogCounter(watchdogLoadValue);
204        break;
205      case WatchdogCounterReg:
206        // Can't be written when in watchdog mode, but can in timer mode
207        if (!watchdogControl.watchdogMode) {
208            restartWatchdogCounter(pkt->get<uint32_t>());
209        }
210        break;
211      case WatchdogControlReg:
212        old_enable = watchdogControl.enable;
213        old_wd_mode = watchdogControl.watchdogMode;
214        watchdogControl = pkt->get<uint32_t>();
215        if ((old_enable == 0) && watchdogControl.enable)
216            restartWatchdogCounter(watchdogLoadValue);
217        // cannot disable watchdog using control register
218        if ((old_wd_mode == 1) && watchdogControl.watchdogMode == 0)
219            watchdogControl.watchdogMode = 1;
220        break;
221      case WatchdogIntStatusReg:
222        rawIntWatchdog = false;
223        if (pendingIntWatchdog) {
224            pendingIntWatchdog = false;
225            DPRINTF(Timer, "Clearing watchdog interrupt\n");
226        }
227        break;
228      case WatchdogResetStatusReg:
229        rawResetWatchdog = false;
230        DPRINTF(Timer, "Clearing watchdog reset flag\n");
231        break;
232      case WatchdogDisableReg:
233        old_val = watchdogDisableReg;
234        watchdogDisableReg = pkt->get<uint32_t>();
235        // if this sequence is observed, turn off watchdog mode
236        if (old_val == 0x12345678 && watchdogDisableReg == 0x87654321)
237            watchdogControl.watchdogMode = 0;
238        break;
239      default:
240        panic("Tried to write CpuLocalTimer timer at offset %#x\n", daddr);
241        break;
242    }
243}
244
245//XXX: Two functions are needed because the control registers are different types
246void
247CpuLocalTimer::Timer::restartTimerCounter(uint32_t val)
248{
249    DPRINTF(Timer, "Resetting timer counter with value %#x\n", val);
250    if (!timerControl.enable)
251        return;
252
253    Tick time = parent->clockPeriod() * power(16, timerControl.prescalar);
254    time *= val;
255
256    if (timerZeroEvent.scheduled()) {
257        DPRINTF(Timer, "-- Event was already schedule, de-scheduling\n");
258        parent->deschedule(timerZeroEvent);
259    }
260    parent->schedule(timerZeroEvent, curTick() + time);
261    DPRINTF(Timer, "-- Scheduling new event for: %d\n", curTick() + time);
262}
263
264void
265CpuLocalTimer::Timer::restartWatchdogCounter(uint32_t val)
266{
267    DPRINTF(Timer, "Resetting watchdog counter with value %#x\n", val);
268    if (!watchdogControl.enable)
269        return;
270
271    Tick time = parent->clockPeriod() * power(16, watchdogControl.prescalar);
272    time *= val;
273
274    if (watchdogZeroEvent.scheduled()) {
275        DPRINTF(Timer, "-- Event was already schedule, de-scheduling\n");
276        parent->deschedule(watchdogZeroEvent);
277    }
278    parent->schedule(watchdogZeroEvent, curTick() + time);
279    DPRINTF(Timer, "-- Scheduling new event for: %d\n", curTick() + time);
280}
281//////
282
283void
284CpuLocalTimer::Timer::timerAtZero()
285{
286    if (!timerControl.enable)
287        return;
288
289    DPRINTF(Timer, "Timer Counter reached zero\n");
290
291    rawIntTimer = true;
292    bool old_pending = pendingIntTimer;
293    if (timerControl.intEnable)
294        pendingIntTimer = true;
295    if (pendingIntTimer && !old_pending) {
296        DPRINTF(Timer, "-- Causing interrupt\n");
297        parent->gic->sendPPInt(intNumTimer, cpuNum);
298    }
299
300    if (!timerControl.autoReload)
301        return;
302    else
303        restartTimerCounter(timerLoadValue);
304}
305
306void
307CpuLocalTimer::Timer::watchdogAtZero()
308{
309    if (!watchdogControl.enable)
310        return;
311
312    DPRINTF(Timer, "Watchdog Counter reached zero\n");
313
314    rawIntWatchdog = true;
315    bool old_pending = pendingIntWatchdog;
316    // generates an interrupt only if the watchdog is in timer
317    // mode.
318    if (watchdogControl.intEnable && !watchdogControl.watchdogMode)
319        pendingIntWatchdog = true;
320    else if (watchdogControl.watchdogMode) {
321        rawResetWatchdog = true;
322        fatal("gem5 ARM Model does not support true watchdog operation!\n");
323        //XXX: Should we ever support a true watchdog reset?
324    }
325
326    if (pendingIntWatchdog && !old_pending) {
327        DPRINTF(Timer, "-- Causing interrupt\n");
328        parent->gic->sendPPInt(intNumWatchdog, cpuNum);
329    }
330
331    if (watchdogControl.watchdogMode)
332        return;
333    else if (watchdogControl.autoReload)
334        restartWatchdogCounter(watchdogLoadValue);
335}
336
337void
338CpuLocalTimer::Timer::serialize(CheckpointOut &cp) const
339{
340    DPRINTF(Checkpoint, "Serializing Arm CpuLocalTimer\n");
341    SERIALIZE_SCALAR(intNumTimer);
342    SERIALIZE_SCALAR(intNumWatchdog);
343
344    uint32_t timer_control_serial = timerControl;
345    uint32_t watchdog_control_serial = watchdogControl;
346    SERIALIZE_SCALAR(timer_control_serial);
347    SERIALIZE_SCALAR(watchdog_control_serial);
348
349    SERIALIZE_SCALAR(rawIntTimer);
350    SERIALIZE_SCALAR(rawIntWatchdog);
351    SERIALIZE_SCALAR(rawResetWatchdog);
352    SERIALIZE_SCALAR(watchdogDisableReg);
353    SERIALIZE_SCALAR(pendingIntTimer);
354    SERIALIZE_SCALAR(pendingIntWatchdog);
355    SERIALIZE_SCALAR(timerLoadValue);
356    SERIALIZE_SCALAR(watchdogLoadValue);
357
358    bool timer_is_in_event = timerZeroEvent.scheduled();
359    SERIALIZE_SCALAR(timer_is_in_event);
360    bool watchdog_is_in_event = watchdogZeroEvent.scheduled();
361    SERIALIZE_SCALAR(watchdog_is_in_event);
362
363    Tick timer_event_time;
364    if (timer_is_in_event){
365        timer_event_time = timerZeroEvent.when();
366        SERIALIZE_SCALAR(timer_event_time);
367    }
368    Tick watchdog_event_time;
369    if (watchdog_is_in_event){
370        watchdog_event_time = watchdogZeroEvent.when();
371        SERIALIZE_SCALAR(watchdog_event_time);
372    }
373}
374
375void
376CpuLocalTimer::Timer::unserialize(CheckpointIn &cp)
377{
378    DPRINTF(Checkpoint, "Unserializing Arm CpuLocalTimer\n");
379
380    UNSERIALIZE_SCALAR(intNumTimer);
381    UNSERIALIZE_SCALAR(intNumWatchdog);
382
383    uint32_t timer_control_serial;
384    UNSERIALIZE_SCALAR(timer_control_serial);
385    timerControl = timer_control_serial;
386    uint32_t watchdog_control_serial;
387    UNSERIALIZE_SCALAR(watchdog_control_serial);
388    watchdogControl = watchdog_control_serial;
389
390    UNSERIALIZE_SCALAR(rawIntTimer);
391    UNSERIALIZE_SCALAR(rawIntWatchdog);
392    UNSERIALIZE_SCALAR(rawResetWatchdog);
393    UNSERIALIZE_SCALAR(watchdogDisableReg);
394    UNSERIALIZE_SCALAR(pendingIntTimer);
395    UNSERIALIZE_SCALAR(pendingIntWatchdog);
396    UNSERIALIZE_SCALAR(timerLoadValue);
397    UNSERIALIZE_SCALAR(watchdogLoadValue);
398
399    bool timer_is_in_event;
400    UNSERIALIZE_SCALAR(timer_is_in_event);
401    bool watchdog_is_in_event;
402    UNSERIALIZE_SCALAR(watchdog_is_in_event);
403
404    Tick timer_event_time;
405    if (timer_is_in_event){
406        UNSERIALIZE_SCALAR(timer_event_time);
407        parent->schedule(timerZeroEvent, timer_event_time);
408    }
409    Tick watchdog_event_time;
410    if (watchdog_is_in_event) {
411        UNSERIALIZE_SCALAR(watchdog_event_time);
412        parent->schedule(watchdogZeroEvent, watchdog_event_time);
413    }
414}
415
416
417
418void
419CpuLocalTimer::serialize(CheckpointOut &cp) const
420{
421    for (int i = 0; i < CPU_MAX; i++)
422        localTimer[i].serializeSection(cp, csprintf("timer%d", i));
423}
424
425void
426CpuLocalTimer::unserialize(CheckpointIn &cp)
427{
428    for (int i = 0; i < CPU_MAX; i++)
429        localTimer[i].unserializeSection(cp, csprintf("timer%d", i));
430}
431
432CpuLocalTimer *
433CpuLocalTimerParams::create()
434{
435    return new CpuLocalTimer(this);
436}
437