timer_cpulocal.cc revision 9808:13ffc0066b76 
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    pkt->allocate();
79    int cpu_id = pkt->req->contextId();
80    DPRINTF(Timer, "Reading from CpuLocalTimer at offset: %#x\n", daddr);
81    assert(cpu_id >= 0);
82    assert(cpu_id < CPU_MAX);
83
84    if (daddr < Timer::Size)
85        localTimer[cpu_id].read(pkt, daddr);
86    else
87        panic("Tried to read CpuLocalTimer at offset %#x that doesn't exist\n", daddr);
88    pkt->makeAtomicResponse();
89    return pioDelay;
90}
91
92
93void
94CpuLocalTimer::Timer::read(PacketPtr pkt, Addr daddr)
95{
96    DPRINTF(Timer, "Reading from CpuLocalTimer at offset: %#x\n", daddr);
97    Tick time;
98
99    switch(daddr) {
100      case TimerLoadReg:
101        pkt->set<uint32_t>(timerLoadValue);
102        break;
103      case TimerCounterReg:
104        DPRINTF(Timer, "Event schedule for timer %d, clock=%d, prescale=%d\n",
105                timerZeroEvent.when(), parent->clockPeriod(),
106                timerControl.prescalar);
107        time = timerZeroEvent.when() - curTick();
108        time = time / parent->clockPeriod() /
109            power(16, timerControl.prescalar);
110        DPRINTF(Timer, "-- returning counter at %d\n", time);
111        pkt->set<uint32_t>(time);
112        break;
113      case TimerControlReg:
114        pkt->set<uint32_t>(timerControl);
115        break;
116      case TimerIntStatusReg:
117        pkt->set<uint32_t>(rawIntTimer);
118        break;
119      case WatchdogLoadReg:
120        pkt->set<uint32_t>(watchdogLoadValue);
121        break;
122      case WatchdogCounterReg:
123        DPRINTF(Timer,
124                "Event schedule for watchdog %d, clock=%d, prescale=%d\n",
125                watchdogZeroEvent.when(), parent->clockPeriod(),
126                watchdogControl.prescalar);
127        time = watchdogZeroEvent.when() - curTick();
128        time = time / parent->clockPeriod() /
129            power(16, watchdogControl.prescalar);
130        DPRINTF(Timer, "-- returning counter at %d\n", time);
131        pkt->set<uint32_t>(time);
132        break;
133      case WatchdogControlReg:
134        pkt->set<uint32_t>(watchdogControl);
135        break;
136      case WatchdogIntStatusReg:
137        pkt->set<uint32_t>(rawIntWatchdog);
138        break;
139      case WatchdogResetStatusReg:
140        pkt->set<uint32_t>(rawResetWatchdog);
141        break;
142      case WatchdogDisableReg:
143        panic("Tried to read from WatchdogDisableRegister\n");
144        break;
145      default:
146        panic("Tried to read CpuLocalTimer at offset %#x\n", daddr);
147        break;
148    }
149}
150
151Tick
152CpuLocalTimer::write(PacketPtr pkt)
153{
154    assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
155    assert(pkt->getSize() == 4);
156    Addr daddr = pkt->getAddr() - pioAddr;
157    pkt->allocate();
158    int cpu_id = pkt->req->contextId();
159    DPRINTF(Timer, "Writing to CpuLocalTimer at offset: %#x\n", daddr);
160    assert(cpu_id >= 0);
161    assert(cpu_id < CPU_MAX);
162
163    if (daddr < Timer::Size)
164        localTimer[cpu_id].write(pkt, daddr);
165    else
166        panic("Tried to write CpuLocalTimer at offset %#x that doesn't exist\n", daddr);
167    pkt->makeAtomicResponse();
168    return pioDelay;
169}
170
171void
172CpuLocalTimer::Timer::write(PacketPtr pkt, Addr daddr)
173{
174    DPRINTF(Timer, "Writing to CpuLocalTimer at offset: %#x\n", daddr);
175    bool old_enable;
176    bool old_wd_mode;
177    uint32_t old_val;
178
179    switch (daddr) {
180      case TimerLoadReg:
181        // Writing to this register also resets the counter register and
182        // starts decrementing if the counter is enabled.
183        timerLoadValue = pkt->get<uint32_t>();
184        restartTimerCounter(timerLoadValue);
185        break;
186      case TimerCounterReg:
187        // Can be written, doesn't start counting unless the timer is enabled
188        restartTimerCounter(pkt->get<uint32_t>());
189        break;
190      case TimerControlReg:
191        old_enable = timerControl.enable;
192        timerControl = pkt->get<uint32_t>();
193        if ((old_enable == 0) && timerControl.enable)
194            restartTimerCounter(timerLoadValue);
195        break;
196      case TimerIntStatusReg:
197        rawIntTimer = false;
198        if (pendingIntTimer) {
199            pendingIntTimer = false;
200            DPRINTF(Timer, "Clearing interrupt\n");
201        }
202        break;
203      case WatchdogLoadReg:
204        watchdogLoadValue = pkt->get<uint32_t>();
205        restartWatchdogCounter(watchdogLoadValue);
206        break;
207      case WatchdogCounterReg:
208        // Can't be written when in watchdog mode, but can in timer mode
209        if (!watchdogControl.watchdogMode) {
210            restartWatchdogCounter(pkt->get<uint32_t>());
211        }
212        break;
213      case WatchdogControlReg:
214        old_enable = watchdogControl.enable;
215        old_wd_mode = watchdogControl.watchdogMode;
216        watchdogControl = pkt->get<uint32_t>();
217        if ((old_enable == 0) && watchdogControl.enable)
218            restartWatchdogCounter(watchdogLoadValue);
219        // cannot disable watchdog using control register
220        if ((old_wd_mode == 1) && watchdogControl.watchdogMode == 0)
221            watchdogControl.watchdogMode = 1;
222        break;
223      case WatchdogIntStatusReg:
224        rawIntWatchdog = false;
225        if (pendingIntWatchdog) {
226            pendingIntWatchdog = false;
227            DPRINTF(Timer, "Clearing watchdog interrupt\n");
228        }
229        break;
230      case WatchdogResetStatusReg:
231        rawResetWatchdog = false;
232        DPRINTF(Timer, "Clearing watchdog reset flag\n");
233        break;
234      case WatchdogDisableReg:
235        old_val = watchdogDisableReg;
236        watchdogDisableReg = pkt->get<uint32_t>();
237        // if this sequence is observed, turn off watchdog mode
238        if (old_val == 0x12345678 && watchdogDisableReg == 0x87654321)
239            watchdogControl.watchdogMode = 0;
240        break;
241      default:
242        panic("Tried to write CpuLocalTimer timer at offset %#x\n", daddr);
243        break;
244    }
245}
246
247//XXX: Two functions are needed because the control registers are different types
248void
249CpuLocalTimer::Timer::restartTimerCounter(uint32_t val)
250{
251    DPRINTF(Timer, "Resetting timer counter with value %#x\n", val);
252    if (!timerControl.enable)
253        return;
254
255    Tick time = parent->clockPeriod() * power(16, timerControl.prescalar);
256    time *= val;
257
258    if (timerZeroEvent.scheduled()) {
259        DPRINTF(Timer, "-- Event was already schedule, de-scheduling\n");
260        parent->deschedule(timerZeroEvent);
261    }
262    parent->schedule(timerZeroEvent, curTick() + time);
263    DPRINTF(Timer, "-- Scheduling new event for: %d\n", curTick() + time);
264}
265
266void
267CpuLocalTimer::Timer::restartWatchdogCounter(uint32_t val)
268{
269    DPRINTF(Timer, "Resetting watchdog counter with value %#x\n", val);
270    if (!watchdogControl.enable)
271        return;
272
273    Tick time = parent->clockPeriod() * power(16, watchdogControl.prescalar);
274    time *= val;
275
276    if (watchdogZeroEvent.scheduled()) {
277        DPRINTF(Timer, "-- Event was already schedule, de-scheduling\n");
278        parent->deschedule(watchdogZeroEvent);
279    }
280    parent->schedule(watchdogZeroEvent, curTick() + time);
281    DPRINTF(Timer, "-- Scheduling new event for: %d\n", curTick() + time);
282}
283//////
284
285void
286CpuLocalTimer::Timer::timerAtZero()
287{
288    if (!timerControl.enable)
289        return;
290
291    DPRINTF(Timer, "Timer Counter reached zero\n");
292
293    rawIntTimer = true;
294    bool old_pending = pendingIntTimer;
295    if (timerControl.intEnable)
296        pendingIntTimer = true;
297    if (pendingIntTimer && !old_pending) {
298        DPRINTF(Timer, "-- Causing interrupt\n");
299        parent->gic->sendPPInt(intNumTimer, cpuNum);
300    }
301
302    if (!timerControl.autoReload)
303        return;
304    else
305        restartTimerCounter(timerLoadValue);
306}
307
308void
309CpuLocalTimer::Timer::watchdogAtZero()
310{
311    if (!watchdogControl.enable)
312        return;
313
314    DPRINTF(Timer, "Watchdog Counter reached zero\n");
315
316    rawIntWatchdog = true;
317    bool old_pending = pendingIntWatchdog;
318    // generates an interrupt only if the watchdog is in timer
319    // mode.
320    if (watchdogControl.intEnable && !watchdogControl.watchdogMode)
321        pendingIntWatchdog = true;
322    else if (watchdogControl.watchdogMode) {
323        rawResetWatchdog = true;
324        fatal("gem5 ARM Model does not support true watchdog operation!\n");
325        //XXX: Should we ever support a true watchdog reset?
326    }
327
328    if (pendingIntWatchdog && !old_pending) {
329        DPRINTF(Timer, "-- Causing interrupt\n");
330        parent->gic->sendPPInt(intNumWatchdog, cpuNum);
331    }
332
333    if (watchdogControl.watchdogMode)
334        return;
335    else if (watchdogControl.autoReload)
336        restartWatchdogCounter(watchdogLoadValue);
337}
338
339void
340CpuLocalTimer::Timer::serialize(std::ostream &os)
341{
342    DPRINTF(Checkpoint, "Serializing Arm CpuLocalTimer\n");
343    SERIALIZE_SCALAR(intNumTimer);
344    SERIALIZE_SCALAR(intNumWatchdog);
345
346    uint32_t timer_control_serial = timerControl;
347    uint32_t watchdog_control_serial = watchdogControl;
348    SERIALIZE_SCALAR(timer_control_serial);
349    SERIALIZE_SCALAR(watchdog_control_serial);
350
351    SERIALIZE_SCALAR(rawIntTimer);
352    SERIALIZE_SCALAR(rawIntWatchdog);
353    SERIALIZE_SCALAR(rawResetWatchdog);
354    SERIALIZE_SCALAR(watchdogDisableReg);
355    SERIALIZE_SCALAR(pendingIntTimer);
356    SERIALIZE_SCALAR(pendingIntWatchdog);
357    SERIALIZE_SCALAR(timerLoadValue);
358    SERIALIZE_SCALAR(watchdogLoadValue);
359
360    bool timer_is_in_event = timerZeroEvent.scheduled();
361    SERIALIZE_SCALAR(timer_is_in_event);
362    bool watchdog_is_in_event = watchdogZeroEvent.scheduled();
363    SERIALIZE_SCALAR(watchdog_is_in_event);
364
365    Tick timer_event_time;
366    if (timer_is_in_event){
367        timer_event_time = timerZeroEvent.when();
368        SERIALIZE_SCALAR(timer_event_time);
369    }
370    Tick watchdog_event_time;
371    if (watchdog_is_in_event){
372        watchdog_event_time = watchdogZeroEvent.when();
373        SERIALIZE_SCALAR(watchdog_event_time);
374    }
375}
376
377void
378CpuLocalTimer::Timer::unserialize(Checkpoint *cp, const std::string &section)
379{
380    DPRINTF(Checkpoint, "Unserializing Arm CpuLocalTimer\n");
381
382    UNSERIALIZE_SCALAR(intNumTimer);
383    UNSERIALIZE_SCALAR(intNumWatchdog);
384
385    uint32_t timer_control_serial;
386    UNSERIALIZE_SCALAR(timer_control_serial);
387    timerControl = timer_control_serial;
388    uint32_t watchdog_control_serial;
389    UNSERIALIZE_SCALAR(watchdog_control_serial);
390    watchdogControl = watchdog_control_serial;
391
392    UNSERIALIZE_SCALAR(rawIntTimer);
393    UNSERIALIZE_SCALAR(rawIntWatchdog);
394    UNSERIALIZE_SCALAR(rawResetWatchdog);
395    UNSERIALIZE_SCALAR(watchdogDisableReg);
396    UNSERIALIZE_SCALAR(pendingIntTimer);
397    UNSERIALIZE_SCALAR(pendingIntWatchdog);
398    UNSERIALIZE_SCALAR(timerLoadValue);
399    UNSERIALIZE_SCALAR(watchdogLoadValue);
400
401    bool timer_is_in_event;
402    UNSERIALIZE_SCALAR(timer_is_in_event);
403    bool watchdog_is_in_event;
404    UNSERIALIZE_SCALAR(watchdog_is_in_event);
405
406    Tick timer_event_time;
407    if (timer_is_in_event){
408        UNSERIALIZE_SCALAR(timer_event_time);
409        parent->schedule(timerZeroEvent, timer_event_time);
410    }
411    Tick watchdog_event_time;
412    if (watchdog_is_in_event) {
413        UNSERIALIZE_SCALAR(watchdog_event_time);
414        parent->schedule(watchdogZeroEvent, watchdog_event_time);
415    }
416}
417
418
419
420void
421CpuLocalTimer::serialize(std::ostream &os)
422{
423    for (int i = 0; i < CPU_MAX; i++) {
424        nameOut(os, csprintf("%s.timer%d", name(), i));
425        localTimer[i].serialize(os);
426    }
427}
428
429void
430CpuLocalTimer::unserialize(Checkpoint *cp, const std::string &section)
431{
432    for (int i = 0; i < CPU_MAX; i++) {
433        localTimer[i].unserialize(cp, csprintf("%s.timer%d", section, i));
434    }
435}
436
437CpuLocalTimer *
438CpuLocalTimerParams::create()
439{
440    return new CpuLocalTimer(this);
441}
442