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         /* If there are signals already queued, after unblocking ignore them */
  64         set_handler(SIGALRM, SIG_IGN, 0, -1);
  65         set_handler(SIGVTALRM, SIG_IGN, 0, -1);
  66 }
  67
  68 void switch_timers(int to_real)
  69 {
  70         struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
  71         struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
  72                                                         { 0, 1000000/hz() }});
  73         int old, new;
  74
  75         if(to_real){
  76                 old = ITIMER_VIRTUAL;
  77                 new = ITIMER_REAL;
  78         }
  79         else {
  80                 old = ITIMER_REAL;
  81                 new = ITIMER_VIRTUAL;
  82         }
  83
  84         if((setitimer(old, &disable, NULL) < 0) ||
  85            (setitimer(new, &enable, NULL)))
  86                 printk("switch_timers - setitimer failed, errno = %d\n",
  87                        errno);
  88 }
  89
  90 void uml_idle_timer(void)
  91 {
  92         if(signal(SIGVTALRM, SIG_IGN) == SIG_ERR)
  93                 panic("Couldn't unset SIGVTALRM handler");
  94
  95         set_handler(SIGALRM, (__sighandler_t) alarm_handler,
  96                     SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
  97         set_interval(ITIMER_REAL);
  98 }
  99
 100 extern int do_posix_clock_monotonic_gettime(struct timespec *tp);
 101
 102 void time_init(void)
 103 {
 104         struct timespec now;
 105
 106         if(signal(SIGVTALRM, boot_timer_handler) == SIG_ERR)
 107                 panic("Couldn't set SIGVTALRM handler");
 108         set_interval(ITIMER_VIRTUAL);
 109
 110         do_posix_clock_monotonic_gettime(&now);
 111         wall_to_monotonic.tv_sec = -now.tv_sec;
 112         wall_to_monotonic.tv_nsec = -now.tv_nsec;
 113 }
 114
 115 /* Declared in linux/time.h, which can't be included here */
 116 extern void clock_was_set(void);
 117
 118 void do_gettimeofday(struct timeval *tv)
 119 {
 120         unsigned long flags;
 121
 122         flags = time_lock();
 123         gettimeofday(tv, NULL);
 124         timeradd(tv, &local_offset, tv);
 125         time_unlock(flags);
 126         clock_was_set();
 127 }
 128
 129 int do_settimeofday(struct timespec *tv)
 130 {
 131         struct timeval now;
 132         unsigned long flags;
 133         struct timeval tv_in;
 134
 135         if ((unsigned long) tv->tv_nsec >= UM_NSEC_PER_SEC)
 136                 return -EINVAL;
 137
 138         tv_in.tv_sec = tv->tv_sec;
 139         tv_in.tv_usec = tv->tv_nsec / 1000;
 140
 141         flags = time_lock();
 142         gettimeofday(&now, NULL);
 143         timersub(&tv_in, &now, &local_offset);
 144         time_unlock(flags);
 145
 146         return(0);
 147 }
 148
 149 void idle_sleep(int secs)
 150 {
 151         struct timespec ts;
 152
 153         ts.tv_sec = secs;
 154         ts.tv_nsec = 0;
 155         nanosleep(&ts, NULL);
 156 }
 157
 158 /*
 159  * Overrides for Emacs so that we follow Linus's tabbing style.
 160  * Emacs will notice this stuff at the end of the file and automatically
 161  * adjust the settings for this buffer only.  This must remain at the end
 162  * of the file.
 163  * ---------------------------------------------------------------------------
 164  * Local variables:
 165  * c-file-style: "linux"
 166  * End:
 167  */