arch/um/os-Linux/time.c

   1 /*
   2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <unistd.h>
   9 #include <time.h>
  10 #include <sys/time.h>
  11 #include <signal.h>
  12 #include <errno.h>
  13 #include "user_util.h"
  14 #include "kern_util.h"
  15 #include "user.h"
  16 #include "process.h"
  17 #include "kern_constants.h"
  18 #include "os.h"
  19
  20 /* XXX This really needs to be declared and initialized in a kernel file since
  21  * it's in <linux/time.h>
  22  */
  23 extern struct timespec wall_to_monotonic;
  24
  25 static void set_interval(int timer_type)
  26 {
  27         int usec = 1000000/hz();
  28         struct itimerval interval = ((struct itimerval) { { 0, usec },
  29                                                           { 0, usec } });
  30
  31         if(setitimer(timer_type, &interval, NULL) == -1)
  32                 panic("setitimer failed - errno = %d\n", errno);
  33 }
  34
  35 void enable_timer(void)
  36 {
  37         set_interval(ITIMER_VIRTUAL);
  38 }
  39
  40 void disable_timer(void)
  41 {
  42         struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
  43         if((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
  44            (setitimer(ITIMER_REAL, &disable, NULL) < 0))
  45                 printk("disnable_timer - setitimer failed, errno = %d\n",
  46                        errno);
  47         /* If there are signals already queued, after unblocking ignore them */
  48         set_handler(SIGALRM, SIG_IGN, 0, -1);
  49         set_handler(SIGVTALRM, SIG_IGN, 0, -1);
  50 }
  51
  52 void switch_timers(int to_real)
  53 {
  54         struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
  55         struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
  56                                                         { 0, 1000000/hz() }});
  57         int old, new;
  58
  59         if(to_real){
  60                 old = ITIMER_VIRTUAL;
  61                 new = ITIMER_REAL;
  62         }
  63         else {
  64                 old = ITIMER_REAL;
  65                 new = ITIMER_VIRTUAL;
  66         }
  67
  68         if((setitimer(old, &disable, NULL) < 0) ||
  69            (setitimer(new, &enable, NULL)))
  70                 printk("switch_timers - setitimer failed, errno = %d\n",
  71                        errno);
  72 }
  73
  74 void uml_idle_timer(void)
  75 {
  76         if(signal(SIGVTALRM, SIG_IGN) == SIG_ERR)
  77                 panic("Couldn't unset SIGVTALRM handler");
  78
  79         set_handler(SIGALRM, (__sighandler_t) alarm_handler,
  80                     SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
  81         set_interval(ITIMER_REAL);
  82 }
  83
  84 void time_init(void)
  85 {
  86         if(signal(SIGVTALRM, boot_timer_handler) == SIG_ERR)
  87                 panic("Couldn't set SIGVTALRM handler");
  88         set_interval(ITIMER_VIRTUAL);
  89         time_init_kern();
  90 }
  91
  92 unsigned long long os_nsecs(void)
  93 {
  94         struct timeval tv;
  95
  96         gettimeofday(&tv, NULL);
  97         return((unsigned long long) tv.tv_sec * BILLION + tv.tv_usec * 1000);
  98 }
  99
 100 void idle_sleep(int secs)
 101 {
 102         struct timespec ts;
 103
 104         ts.tv_sec = secs;
 105         ts.tv_nsec = 0;
 106         nanosleep(&ts, NULL);
 107 }
 108
 109 /* XXX This partly duplicates init_irq_signals */
 110
 111 void user_time_init(void)
 112 {
 113         set_handler(SIGVTALRM, (__sighandler_t) alarm_handler,
 114                     SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
 115                     SIGALRM, SIGUSR2, -1);
 116         set_handler(SIGALRM, (__sighandler_t) alarm_handler,
 117                     SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
 118                     SIGVTALRM, SIGUSR2, -1);
 119         set_interval(ITIMER_VIRTUAL);
 120 }