arch/um/kernel/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 "signal_user.h"
  18 #include "time_user.h"
  19 #include "kern_constants.h"
  20
  21 /* XXX This really needs to be declared and initialized in a kernel file since
  22  * it's in <linux/time.h>
  23  */
  24 extern struct timespec wall_to_monotonic;
  25
  26 extern struct timeval xtime;
  27
  28 struct timeval local_offset = { 0, 0 };
  29
  30 void timer(void)
  31 {
  32         gettimeofday(&xtime, NULL);
  33         timeradd(&xtime, &local_offset, &xtime);
  34 }
  35
  36 void set_interval(int timer_type)
  37 {
  38         int usec = 1000000/hz();
  39         struct itimerval interval = ((struct itimerval) { { 0, usec },
  40                                                           { 0, usec } });
  41
  42         if(setitimer(timer_type, &interval, NULL) == -1)
  43                 panic("setitimer failed - errno = %d\n", errno);
  44 }
  45
  46 void enable_timer(void)
  47 {
  48         int usec = 1000000/hz();
  49         struct itimerval enable = ((struct itimerval) { { 0, usec },
  50                                                         { 0, usec }});
  51         if(setitimer(ITIMER_VIRTUAL, &enable, NULL))
  52                 printk("enable_timer - setitimer failed, errno = %d\n",
  53                        errno);
  54 }
  55
  56 void disable_timer(void)
  57 {
  58         struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
  59         if((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
  60            (setitimer(ITIMER_REAL, &disable, NULL) < 0))
  61                 printk("disnable_timer - setitimer failed, errno = %d\n",
  62                        errno);
  63 }
  64
  65 void switch_timers(int to_real)
  66 {
  67         struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
  68         struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
  69                                                         { 0, 1000000/hz() }});
  70         int old, new;
  71
  72         if(to_real){
  73                 old = ITIMER_VIRTUAL;
  74                 new = ITIMER_REAL;
  75         }
  76         else {
  77                 old = ITIMER_REAL;
  78                 new = ITIMER_VIRTUAL;
  79         }
  80
  81         if((setitimer(old, &disable, NULL) < 0) ||
  82            (setitimer(new, &enable, NULL)))
  83                 printk("switch_timers - setitimer failed, errno = %d\n",
  84                        errno);
  85 }
  86
  87 void uml_idle_timer(void)
  88 {
  89         if(signal(SIGVTALRM, SIG_IGN) == SIG_ERR)
  90                 panic("Couldn't unset SIGVTALRM handler");
  91
  92         set_handler(SIGALRM, (__sighandler_t) alarm_handler,
  93                     SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
  94         set_interval(ITIMER_REAL);
  95 }
  96
  97 extern int do_posix_clock_monotonic_gettime(struct timespec *tp);
  98
  99 void time_init(void)
 100 {
 101         struct timespec now;
 102
 103         if(signal(SIGVTALRM, boot_timer_handler) == SIG_ERR)
 104                 panic("Couldn't set SIGVTALRM handler");
 105         set_interval(ITIMER_VIRTUAL);
 106
 107         do_posix_clock_monotonic_gettime(&now);
 108         wall_to_monotonic.tv_sec = -now.tv_sec;
 109         wall_to_monotonic.tv_nsec = -now.tv_nsec;
 110 }
 111
 112 /* Declared in linux/time.h, which can't be included here */
 113 extern void clock_was_set(void);
 114
 115 void do_gettimeofday(struct timeval *tv)
 116 {
 117         unsigned long flags;
 118
 119         flags = time_lock();
 120         gettimeofday(tv, NULL);
 121         timeradd(tv, &local_offset, tv);
 122         time_unlock(flags);
 123         clock_was_set();
 124 }
 125
 126 int do_settimeofday(struct timespec *tv)
 127 {
 128         struct timeval now;
 129         unsigned long flags;
 130         struct timeval tv_in;
 131
 132         if ((unsigned long) tv->tv_nsec >= UM_NSEC_PER_SEC)
 133                 return -EINVAL;
 134
 135         tv_in.tv_sec = tv->tv_sec;
 136         tv_in.tv_usec = tv->tv_nsec / 1000;
 137
 138         flags = time_lock();
 139         gettimeofday(&now, NULL);
 140         timersub(&tv_in, &now, &local_offset);
 141         time_unlock(flags);
 142
 143         return(0);
 144 }
 145
 146 void idle_sleep(int secs)
 147 {
 148         struct timespec ts;
 149
 150         ts.tv_sec = secs;
 151         ts.tv_nsec = 0;
 152         nanosleep(&ts, NULL);
 153 }
 154
 155 /*
 156  * Overrides for Emacs so that we follow Linus's tabbing style.
 157  * Emacs will notice this stuff at the end of the file and automatically
 158  * adjust the settings for this buffer only.  This must remain at the end
 159  * of the file.
 160  * ---------------------------------------------------------------------------
 161  * Local variables:
 162  * c-file-style: "linux"
 163  * End:
 164  */