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 "time_user.h"
  18 #include "kern_constants.h"
  19 #include "os.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 static 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         set_interval(ITIMER_VIRTUAL);
  49 }
  50
  51 void prepare_timer(void * ptr)
  52 {
  53         int usec = 1000000/hz();
  54         *(struct itimerval *)ptr = ((struct itimerval) { { 0, usec },
  55                                                          { 0, usec }});
  56 }
  57
  58 void disable_timer(void)
  59 {
  60         struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
  61         if((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
  62            (setitimer(ITIMER_REAL, &disable, NULL) < 0))
  63                 printk("disnable_timer - setitimer failed, errno = %d\n",
  64                        errno);
  65         /* If there are signals already queued, after unblocking ignore them */
  66         set_handler(SIGALRM, SIG_IGN, 0, -1);
  67         set_handler(SIGVTALRM, SIG_IGN, 0, -1);
  68 }
  69
  70 void switch_timers(int to_real)
  71 {
  72         struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
  73         struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
  74                                                         { 0, 1000000/hz() }});
  75         int old, new;
  76
  77         if(to_real){
  78                 old = ITIMER_VIRTUAL;
  79                 new = ITIMER_REAL;
  80         }
  81         else {
  82                 old = ITIMER_REAL;
  83                 new = ITIMER_VIRTUAL;
  84         }
  85
  86         if((setitimer(old, &disable, NULL) < 0) ||
  87            (setitimer(new, &enable, NULL)))
  88                 printk("switch_timers - setitimer failed, errno = %d\n",
  89                        errno);
  90 }
  91
  92 void uml_idle_timer(void)
  93 {
  94         if(signal(SIGVTALRM, SIG_IGN) == SIG_ERR)
  95                 panic("Couldn't unset SIGVTALRM handler");
  96
  97         set_handler(SIGALRM, (__sighandler_t) alarm_handler,
  98                     SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
  99         set_interval(ITIMER_REAL);
 100 }
 101
 102 extern void ktime_get_ts(struct timespec *ts);
 103 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 104
 105 void time_init(void)
 106 {
 107         struct timespec now;
 108
 109         if(signal(SIGVTALRM, boot_timer_handler) == SIG_ERR)
 110                 panic("Couldn't set SIGVTALRM handler");
 111         set_interval(ITIMER_VIRTUAL);
 112
 113         do_posix_clock_monotonic_gettime(&now);
 114         wall_to_monotonic.tv_sec = -now.tv_sec;
 115         wall_to_monotonic.tv_nsec = -now.tv_nsec;
 116 }
 117
 118 /* Defined in linux/ktimer.h, which can't be included here */
 119 #define clock_was_set()         do { } while (0)
 120
 121 void do_gettimeofday(struct timeval *tv)
 122 {
 123         unsigned long flags;
 124
 125         flags = time_lock();
 126         gettimeofday(tv, NULL);
 127         timeradd(tv, &local_offset, tv);
 128         time_unlock(flags);
 129         clock_was_set();
 130 }
 131
 132 int do_settimeofday(struct timespec *tv)
 133 {
 134         struct timeval now;
 135         unsigned long flags;
 136         struct timeval tv_in;
 137
 138         if ((unsigned long) tv->tv_nsec >= UM_NSEC_PER_SEC)
 139                 return -EINVAL;
 140
 141         tv_in.tv_sec = tv->tv_sec;
 142         tv_in.tv_usec = tv->tv_nsec / 1000;
 143
 144         flags = time_lock();
 145         gettimeofday(&now, NULL);
 146         timersub(&tv_in, &now, &local_offset);
 147         time_unlock(flags);
 148
 149         return(0);
 150 }
 151
 152 void idle_sleep(int secs)
 153 {
 154         struct timespec ts;
 155
 156         ts.tv_sec = secs;
 157         ts.tv_nsec = 0;
 158         nanosleep(&ts, NULL);
 159 }
 160
 161 /* XXX This partly duplicates init_irq_signals */
 162
 163 void user_time_init(void)
 164 {
 165         set_handler(SIGVTALRM, (__sighandler_t) alarm_handler,
 166                     SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
 167                     SIGALRM, SIGUSR2, -1);
 168         set_handler(SIGALRM, (__sighandler_t) alarm_handler,
 169                     SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
 170                     SIGVTALRM, SIGUSR2, -1);
 171         set_interval(ITIMER_VIRTUAL);
 172 }