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 static int is_real_timer = 0;
  16
  17 int set_interval(int is_virtual)
  18 {
  19         int usec = 1000000/UM_HZ;
  20         int timer_type = is_virtual ? ITIMER_VIRTUAL : ITIMER_REAL;
  21         struct itimerval interval = ((struct itimerval) { { 0, usec },
  22                                                           { 0, usec } });
  23
  24         if (setitimer(timer_type, &interval, NULL) == -1)
  25                 return -errno;
  26
  27         return 0;
  28 }
  29
  30 void disable_timer(void)
  31 {
  32         struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
  33
  34         if ((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
  35             (setitimer(ITIMER_REAL, &disable, NULL) < 0))
  36                 printk(UM_KERN_ERR "disable_timer - setitimer failed, "
  37                        "errno = %d\n", errno);
  38
  39         /* If there are signals already queued, after unblocking ignore them */
  40         signal(SIGALRM, SIG_IGN);
  41         signal(SIGVTALRM, SIG_IGN);
  42 }
  43
  44 int switch_timers(int to_real)
  45 {
  46         struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
  47         struct itimerval enable;
  48         int old, new, old_type = is_real_timer;
  49
  50         if(to_real == old_type)
  51                 return to_real;
  52
  53         if (to_real) {
  54                 old = ITIMER_VIRTUAL;
  55                 new = ITIMER_REAL;
  56         }
  57         else {
  58                 old = ITIMER_REAL;
  59                 new = ITIMER_VIRTUAL;
  60         }
  61
  62         if (setitimer(old, &disable, &enable) < 0)
  63                 printk(UM_KERN_ERR "switch_timers - setitimer disable failed, "
  64                        "errno = %d\n", errno);
  65
  66         if((enable.it_value.tv_sec == 0) && (enable.it_value.tv_usec == 0))
  67                 enable.it_value = enable.it_interval;
  68
  69         if (setitimer(new, &enable, NULL))
  70                 printk(UM_KERN_ERR "switch_timers - setitimer enable failed, "
  71                        "errno = %d\n", errno);
  72
  73         is_real_timer = to_real;
  74         return old_type;
  75 }
  76
  77 unsigned long long os_nsecs(void)
  78 {
  79         struct timeval tv;
  80
  81         gettimeofday(&tv, NULL);
  82         return (unsigned long long) tv.tv_sec * BILLION + tv.tv_usec * 1000;
  83 }
  84
  85 void idle_sleep(int secs)
  86 {
  87         struct timespec ts;
  88
  89         ts.tv_sec = secs;
  90         ts.tv_nsec = 0;
  91         nanosleep(&ts, NULL);
  92 }