linux/tools/testing/selftests/timers/alarmtimer-suspend.c
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   1/* alarmtimer suspend test
   2 *              John Stultz (john.stultz@linaro.org)
   3 *              (C) Copyright Linaro 2013
   4 *              Licensed under the GPLv2
   5 *
   6 *   This test makes sure the alarmtimer & RTC wakeup code is
   7 *   functioning.
   8 *
   9 *  To build:
  10 *      $ gcc alarmtimer-suspend.c -o alarmtimer-suspend -lrt
  11 *
  12 *   This program is free software: you can redistribute it and/or modify
  13 *   it under the terms of the GNU General Public License as published by
  14 *   the Free Software Foundation, either version 2 of the License, or
  15 *   (at your option) any later version.
  16 *
  17 *   This program is distributed in the hope that it will be useful,
  18 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 *   GNU General Public License for more details.
  21 */
  22
  23
  24#include <stdio.h>
  25#include <unistd.h>
  26#include <time.h>
  27#include <string.h>
  28#include <signal.h>
  29#include <stdlib.h>
  30#include <pthread.h>
  31#include "../kselftest.h"
  32
  33#define CLOCK_REALTIME                  0
  34#define CLOCK_MONOTONIC                 1
  35#define CLOCK_PROCESS_CPUTIME_ID        2
  36#define CLOCK_THREAD_CPUTIME_ID         3
  37#define CLOCK_MONOTONIC_RAW             4
  38#define CLOCK_REALTIME_COARSE           5
  39#define CLOCK_MONOTONIC_COARSE          6
  40#define CLOCK_BOOTTIME                  7
  41#define CLOCK_REALTIME_ALARM            8
  42#define CLOCK_BOOTTIME_ALARM            9
  43#define CLOCK_HWSPECIFIC                10
  44#define CLOCK_TAI                       11
  45#define NR_CLOCKIDS                     12
  46
  47
  48#define NSEC_PER_SEC 1000000000ULL
  49#define UNREASONABLE_LAT (NSEC_PER_SEC * 5) /* hopefully we resume in 5 secs */
  50
  51#define SUSPEND_SECS 15
  52int alarmcount;
  53int alarm_clock_id;
  54struct timespec start_time;
  55
  56
  57char *clockstring(int clockid)
  58{
  59        switch (clockid) {
  60        case CLOCK_REALTIME:
  61                return "CLOCK_REALTIME";
  62        case CLOCK_MONOTONIC:
  63                return "CLOCK_MONOTONIC";
  64        case CLOCK_PROCESS_CPUTIME_ID:
  65                return "CLOCK_PROCESS_CPUTIME_ID";
  66        case CLOCK_THREAD_CPUTIME_ID:
  67                return "CLOCK_THREAD_CPUTIME_ID";
  68        case CLOCK_MONOTONIC_RAW:
  69                return "CLOCK_MONOTONIC_RAW";
  70        case CLOCK_REALTIME_COARSE:
  71                return "CLOCK_REALTIME_COARSE";
  72        case CLOCK_MONOTONIC_COARSE:
  73                return "CLOCK_MONOTONIC_COARSE";
  74        case CLOCK_BOOTTIME:
  75                return "CLOCK_BOOTTIME";
  76        case CLOCK_REALTIME_ALARM:
  77                return "CLOCK_REALTIME_ALARM";
  78        case CLOCK_BOOTTIME_ALARM:
  79                return "CLOCK_BOOTTIME_ALARM";
  80        case CLOCK_TAI:
  81                return "CLOCK_TAI";
  82        };
  83        return "UNKNOWN_CLOCKID";
  84}
  85
  86
  87long long timespec_sub(struct timespec a, struct timespec b)
  88{
  89        long long ret = NSEC_PER_SEC * b.tv_sec + b.tv_nsec;
  90
  91        ret -= NSEC_PER_SEC * a.tv_sec + a.tv_nsec;
  92        return ret;
  93}
  94
  95int final_ret = 0;
  96
  97void sigalarm(int signo)
  98{
  99        long long delta_ns;
 100        struct timespec ts;
 101
 102        clock_gettime(alarm_clock_id, &ts);
 103        alarmcount++;
 104
 105        delta_ns = timespec_sub(start_time, ts);
 106        delta_ns -= NSEC_PER_SEC * SUSPEND_SECS * alarmcount;
 107
 108        printf("ALARM(%i): %ld:%ld latency: %lld ns ", alarmcount, ts.tv_sec,
 109                                                        ts.tv_nsec, delta_ns);
 110
 111        if (delta_ns > UNREASONABLE_LAT) {
 112                printf("[FAIL]\n");
 113                final_ret = -1;
 114        } else
 115                printf("[OK]\n");
 116
 117}
 118
 119int main(void)
 120{
 121        timer_t tm1;
 122        struct itimerspec its1, its2;
 123        struct sigevent se;
 124        struct sigaction act;
 125        int signum = SIGRTMAX;
 126
 127        /* Set up signal handler: */
 128        sigfillset(&act.sa_mask);
 129        act.sa_flags = 0;
 130        act.sa_handler = sigalarm;
 131        sigaction(signum, &act, NULL);
 132
 133        /* Set up timer: */
 134        memset(&se, 0, sizeof(se));
 135        se.sigev_notify = SIGEV_SIGNAL;
 136        se.sigev_signo = signum;
 137        se.sigev_value.sival_int = 0;
 138
 139        for (alarm_clock_id = CLOCK_REALTIME_ALARM;
 140                        alarm_clock_id <= CLOCK_BOOTTIME_ALARM;
 141                        alarm_clock_id++) {
 142
 143                alarmcount = 0;
 144                if (timer_create(alarm_clock_id, &se, &tm1) == -1) {
 145                        printf("timer_create failed, %s unsupported?\n",
 146                                        clockstring(alarm_clock_id));
 147                        break;
 148                }
 149
 150                clock_gettime(alarm_clock_id, &start_time);
 151                printf("Start time (%s): %ld:%ld\n", clockstring(alarm_clock_id),
 152                                start_time.tv_sec, start_time.tv_nsec);
 153                printf("Setting alarm for every %i seconds\n", SUSPEND_SECS);
 154                its1.it_value = start_time;
 155                its1.it_value.tv_sec += SUSPEND_SECS;
 156                its1.it_interval.tv_sec = SUSPEND_SECS;
 157                its1.it_interval.tv_nsec = 0;
 158
 159                timer_settime(tm1, TIMER_ABSTIME, &its1, &its2);
 160
 161                while (alarmcount < 5)
 162                        sleep(1); /* First 5 alarms, do nothing */
 163
 164                printf("Starting suspend loops\n");
 165                while (alarmcount < 10) {
 166                        int ret;
 167
 168                        sleep(3);
 169                        ret = system("echo mem > /sys/power/state");
 170                        if (ret)
 171                                break;
 172                }
 173                timer_delete(tm1);
 174        }
 175        if (final_ret)
 176                return ksft_exit_fail();
 177        return ksft_exit_pass();
 178}
 179