timer_cpulocal.cc revision 8993 
1/*
2 * Copyright (c) 2010-2011 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/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), 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].clock = p->clock;
62        localTimer[i].cpuNum = i;
63    }
64    pioSize = 0x38;
65}
66
67CpuLocalTimer::Timer::Timer()
68    : timerControl(0x0), watchdogControl(0x0), rawIntTimer(false), rawIntWatchdog(false),
69      rawResetWatchdog(false), watchdogDisableReg(0x0), pendingIntTimer(false), pendingIntWatchdog(false),
70      timerLoadValue(0x0), watchdogLoadValue(0x0), timerZeroEvent(this), watchdogZeroEvent(this)
71{
72}
73
74Tick
75CpuLocalTimer::read(PacketPtr pkt)
76{
77    assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
78    assert(pkt->getSize() == 4);
79    Addr daddr = pkt->getAddr() - pioAddr;
80    pkt->allocate();
81    int cpu_id = pkt->req->contextId();
82    DPRINTF(Timer, "Reading from CpuLocalTimer at offset: %#x\n", daddr);
83    assert(cpu_id >= 0);
84    assert(cpu_id < CPU_MAX);
85
86    if (daddr < Timer::Size)
87        localTimer[cpu_id].read(pkt, daddr);
88    else
89        panic("Tried to read CpuLocalTimer at offset %#x that doesn't exist\n", daddr);
90    pkt->makeAtomicResponse();
91    return pioDelay;
92}
93
94
95void
96CpuLocalTimer::Timer::read(PacketPtr pkt, Addr daddr)
97{
98    DPRINTF(Timer, "Reading from CpuLocalTimer at offset: %#x\n", daddr);
99    Tick time;
100
101    switch(daddr) {
102      case TimerLoadReg:
103        pkt->set<uint32_t>(timerLoadValue);
104        break;
105      case TimerCounterReg:
106        DPRINTF(Timer, "Event schedule for timer %d, clock=%d, prescale=%d\n",
107                timerZeroEvent.when(), clock, timerControl.prescalar);
108        time = timerZeroEvent.when() - curTick();
109        time = time / clock / 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, "Event schedule for watchdog %d, clock=%d, prescale=%d\n",
124                watchdogZeroEvent.when(), clock, watchdogControl.prescalar);
125        time = watchdogZeroEvent.when() - curTick();
126        time = time / clock / power(16, watchdogControl.prescalar);
127        DPRINTF(Timer, "-- returning counter at %d\n", time);
128        pkt->set<uint32_t>(time);
129        break;
130      case WatchdogControlReg:
131        pkt->set<uint32_t>(watchdogControl);
132        break;
133      case WatchdogIntStatusReg:
134        pkt->set<uint32_t>(rawIntWatchdog);
135        break;
136      case WatchdogResetStatusReg:
137        pkt->set<uint32_t>(rawResetWatchdog);
138        break;
139      case WatchdogDisableReg:
140        panic("Tried to read from WatchdogDisableRegister\n");
141        break;
142      default:
143        panic("Tried to read CpuLocalTimer at offset %#x\n", daddr);
144        break;
145    }
146}
147
148Tick
149CpuLocalTimer::write(PacketPtr pkt)
150{
151    assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
152    assert(pkt->getSize() == 4);
153    Addr daddr = pkt->getAddr() - pioAddr;
154    pkt->allocate();
155    int cpu_id = pkt->req->contextId();
156    DPRINTF(Timer, "Writing to CpuLocalTimer at offset: %#x\n", daddr);
157    assert(cpu_id >= 0);
158    assert(cpu_id < CPU_MAX);
159
160    if (daddr < Timer::Size)
161        localTimer[cpu_id].write(pkt, daddr);
162    else
163        panic("Tried to write CpuLocalTimer at offset %#x that doesn't exist\n", daddr);
164    pkt->makeAtomicResponse();
165    return pioDelay;
166}
167
168void
169CpuLocalTimer::Timer::write(PacketPtr pkt, Addr daddr)
170{
171    DPRINTF(Timer, "Writing to CpuLocalTimer at offset: %#x\n", daddr);
172    bool old_enable;
173    bool old_wd_mode;
174    uint32_t old_val;
175
176    switch (daddr) {
177      case TimerLoadReg:
178        // Writing to this register also resets the counter register and
179        // starts decrementing if the counter is enabled.
180        timerLoadValue = pkt->get<uint32_t>();
181        restartTimerCounter(timerLoadValue);
182        break;
183      case TimerCounterReg:
184        // Can be written, doesn't start counting unless the timer is enabled
185        restartTimerCounter(pkt->get<uint32_t>());
186        break;
187      case TimerControlReg:
188        old_enable = timerControl.enable;
189        timerControl = pkt->get<uint32_t>();
190        if ((old_enable == 0) && timerControl.enable)
191            restartTimerCounter(timerLoadValue);
192        break;
193      case TimerIntStatusReg:
194        rawIntTimer = false;
195        if (pendingIntTimer) {
196            pendingIntTimer = false;
197            DPRINTF(Timer, "Clearing interrupt\n");
198        }
199        break;
200      case WatchdogLoadReg:
201        watchdogLoadValue = pkt->get<uint32_t>();
202        restartWatchdogCounter(watchdogLoadValue);
203        break;
204      case WatchdogCounterReg:
205        // Can't be written when in watchdog mode, but can in timer mode
206        if (!watchdogControl.watchdogMode) {
207            restartWatchdogCounter(pkt->get<uint32_t>());
208        }
209        break;
210      case WatchdogControlReg:
211        old_enable = watchdogControl.enable;
212        old_wd_mode = watchdogControl.watchdogMode;
213        watchdogControl = pkt->get<uint32_t>();
214        if ((old_enable == 0) && watchdogControl.enable)
215            restartWatchdogCounter(watchdogLoadValue);
216        // cannot disable watchdog using control register
217        if ((old_wd_mode == 1) && watchdogControl.watchdogMode == 0)
218            watchdogControl.watchdogMode = 1;
219        break;
220      case WatchdogIntStatusReg:
221        rawIntWatchdog = false;
222        if (pendingIntWatchdog) {
223            pendingIntWatchdog = false;
224            DPRINTF(Timer, "Clearing watchdog interrupt\n");
225        }
226        break;
227      case WatchdogResetStatusReg:
228        rawResetWatchdog = false;
229        DPRINTF(Timer, "Clearing watchdog reset flag\n");
230        break;
231      case WatchdogDisableReg:
232        old_val = watchdogDisableReg;
233        watchdogDisableReg = pkt->get<uint32_t>();
234        // if this sequence is observed, turn off watchdog mode
235        if (old_val == 0x12345678 && watchdogDisableReg == 0x87654321)
236            watchdogControl.watchdogMode = 0;
237        break;
238      default:
239        panic("Tried to write CpuLocalTimer timer at offset %#x\n", daddr);
240        break;
241    }
242}
243
244//XXX: Two functions are needed because the control registers are different types
245void
246CpuLocalTimer::Timer::restartTimerCounter(uint32_t val)
247{
248    DPRINTF(Timer, "Resetting timer counter with value %#x\n", val);
249    if (!timerControl.enable)
250        return;
251
252    Tick time = clock * power(16, timerControl.prescalar);
253    time *= val;
254
255    if (timerZeroEvent.scheduled()) {
256        DPRINTF(Timer, "-- Event was already schedule, de-scheduling\n");
257        parent->deschedule(timerZeroEvent);
258    }
259    parent->schedule(timerZeroEvent, curTick() + time);
260    DPRINTF(Timer, "-- Scheduling new event for: %d\n", curTick() + time);
261}
262
263void
264CpuLocalTimer::Timer::restartWatchdogCounter(uint32_t val)
265{
266    DPRINTF(Timer, "Resetting watchdog counter with value %#x\n", val);
267    if (!watchdogControl.enable)
268        return;
269
270    Tick time = clock * power(16, watchdogControl.prescalar);
271    time *= val;
272
273    if (watchdogZeroEvent.scheduled()) {
274        DPRINTF(Timer, "-- Event was already schedule, de-scheduling\n");
275        parent->deschedule(watchdogZeroEvent);
276    }
277    parent->schedule(watchdogZeroEvent, curTick() + time);
278    DPRINTF(Timer, "-- Scheduling new event for: %d\n", curTick() + time);
279}
280//////
281
282void
283CpuLocalTimer::Timer::timerAtZero()
284{
285    if (!timerControl.enable)
286        return;
287
288    DPRINTF(Timer, "Timer Counter reached zero\n");
289
290    rawIntTimer = true;
291    bool old_pending = pendingIntTimer;
292    if (timerControl.intEnable)
293        pendingIntTimer = true;
294    if (pendingIntTimer && !old_pending) {
295        DPRINTF(Timer, "-- Causing interrupt\n");
296        parent->gic->sendPPInt(intNumTimer, cpuNum);
297    }
298
299    if (!timerControl.autoReload)
300        return;
301    else
302        restartTimerCounter(timerLoadValue);
303}
304
305void
306CpuLocalTimer::Timer::watchdogAtZero()
307{
308    if (!watchdogControl.enable)
309        return;
310
311    DPRINTF(Timer, "Watchdog Counter reached zero\n");
312
313    rawIntWatchdog = true;
314    bool old_pending = pendingIntWatchdog;
315    // generates an interrupt only if the watchdog is in timer
316    // mode.
317    if (watchdogControl.intEnable && !watchdogControl.watchdogMode)
318        pendingIntWatchdog = true;
319    else if (watchdogControl.watchdogMode) {
320        rawResetWatchdog = true;
321        fatal("gem5 ARM Model does not support true watchdog operation!\n");
322        //XXX: Should we ever support a true watchdog reset?
323    }
324
325    if (pendingIntWatchdog && !old_pending) {
326        DPRINTF(Timer, "-- Causing interrupt\n");
327        parent->gic->sendPPInt(intNumWatchdog, cpuNum);
328    }
329
330    if (watchdogControl.watchdogMode)
331        return;
332    else if (watchdogControl.autoReload)
333        restartWatchdogCounter(watchdogLoadValue);
334}
335
336void
337CpuLocalTimer::Timer::serialize(std::ostream &os)
338{
339    DPRINTF(Checkpoint, "Serializing Arm CpuLocalTimer\n");
340    SERIALIZE_SCALAR(intNumTimer);
341    SERIALIZE_SCALAR(intNumWatchdog);
342    SERIALIZE_SCALAR(clock);
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(Checkpoint *cp, const std::string &section)
377{
378    DPRINTF(Checkpoint, "Unserializing Arm CpuLocalTimer\n");
379
380    UNSERIALIZE_SCALAR(intNumTimer);
381    UNSERIALIZE_SCALAR(intNumWatchdog);
382    UNSERIALIZE_SCALAR(clock);
383
384    uint32_t timer_control_serial;
385    UNSERIALIZE_SCALAR(timer_control_serial);
386    timerControl = timer_control_serial;
387    uint32_t watchdog_control_serial;
388    UNSERIALIZE_SCALAR(watchdog_control_serial);
389    watchdogControl = watchdog_control_serial;
390
391    UNSERIALIZE_SCALAR(rawIntTimer);
392    UNSERIALIZE_SCALAR(rawIntWatchdog);
393    UNSERIALIZE_SCALAR(rawResetWatchdog);
394    UNSERIALIZE_SCALAR(watchdogDisableReg);
395    UNSERIALIZE_SCALAR(pendingIntTimer);
396    UNSERIALIZE_SCALAR(pendingIntWatchdog);
397    UNSERIALIZE_SCALAR(timerLoadValue);
398    UNSERIALIZE_SCALAR(watchdogLoadValue);
399
400    bool timer_is_in_event;
401    UNSERIALIZE_SCALAR(timer_is_in_event);
402    bool watchdog_is_in_event;
403    UNSERIALIZE_SCALAR(watchdog_is_in_event);
404
405    Tick timer_event_time;
406    if (timer_is_in_event){
407        UNSERIALIZE_SCALAR(timer_event_time);
408        parent->schedule(timerZeroEvent, timer_event_time);
409    }
410    Tick watchdog_event_time;
411    if (watchdog_is_in_event) {
412        UNSERIALIZE_SCALAR(watchdog_event_time);
413        parent->schedule(watchdogZeroEvent, watchdog_event_time);
414    }
415}
416
417
418
419void
420CpuLocalTimer::serialize(std::ostream &os)
421{
422    for (int i = 0; i < CPU_MAX; i++) {
423        nameOut(os, csprintf("%s.timer%d", name(), i));
424        localTimer[i].serialize(os);
425    }
426}
427
428void
429CpuLocalTimer::unserialize(Checkpoint *cp, const std::string &section)
430{
431    for (int i = 0; i < CPU_MAX; i++) {
432        localTimer[i].unserialize(cp, csprintf("%s.timer%d", section, i));
433    }
434}
435
436CpuLocalTimer *
437CpuLocalTimerParams::create()
438{
439    return new CpuLocalTimer(this);
440}
441