arch/um/os-Linux/time.c

   1 /*
   2  * Copyright (C) 2000 - 2007 Jeff Dike (jdike{addtoit,linux.intel}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <stddef.h>
   7 #include <errno.h>
   8 #include <signal.h>
   9 #include <time.h>
  10 #include <sys/time.h>
  11 #include "kern_constants.h"
  12 #include "os.h"
  13 #include "user.h"
  14
  15 int set_interval(void)
  16 {
  17         int usec = 1000000/UM_HZ;
  18         struct itimerval interval = ((struct itimerval) { { 0, usec },
  19                                                           { 0, usec } });
  20
  21         if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1)
  22                 return -errno;
  23
  24         return 0;
  25 }
  26
  27 int timer_one_shot(int ticks)
  28 {
  29         unsigned long usec = ticks * 1000000 / UM_HZ;
  30         unsigned long sec = usec / 1000000;
  31         struct itimerval interval;
  32
  33         usec %= 1000000;
  34         interval = ((struct itimerval) { { 0, 0 }, { sec, usec } });
  35
  36         if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1)
  37                 return -errno;
  38
  39         return 0;
  40 }
  41
  42 /**
  43  * timeval_to_ns - Convert timeval to nanoseconds
  44  * @ts:         pointer to the timeval variable to be converted
  45  *
  46  * Returns the scalar nanosecond representation of the timeval
  47  * parameter.
  48  *
  49  * Ripped from linux/time.h because it's a kernel header, and thus
  50  * unusable from here.
  51  */
  52 static inline long long timeval_to_ns(const struct timeval *tv)
  53 {
  54         return ((long long) tv->tv_sec * UM_NSEC_PER_SEC) +
  55                 tv->tv_usec * UM_NSEC_PER_USEC;
  56 }
  57
  58 long long disable_timer(void)
  59 {
  60         struct itimerval time = ((struct itimerval) { { 0, 0 }, { 0, 0 } });
  61
  62         if(setitimer(ITIMER_VIRTUAL, &time, &time) < 0)
  63                 printk(UM_KERN_ERR "disable_timer - setitimer failed, "
  64                        "errno = %d\n", errno);
  65
  66         return timeval_to_ns(&time.it_value);
  67 }
  68
  69 long long os_nsecs(void)
  70 {
  71         struct timeval tv;
  72
  73         gettimeofday(&tv, NULL);
  74         return timeval_to_ns(&tv);
  75 }
  76
  77 extern void alarm_handler(int sig, struct sigcontext *sc);
  78
  79 void idle_sleep(unsigned long long nsecs)
  80 {
  81         struct timespec ts = { .tv_sec  = nsecs / BILLION,
  82                                .tv_nsec = nsecs % BILLION };
  83
  84         if (nanosleep(&ts, &ts) == 0)
  85                 alarm_handler(SIGVTALRM, NULL);
  86 }