minix/servers/pm/time.c

   1 /* This file takes care of those system calls that deal with time.
   2  *
   3  * The entry points into this file are
   4  *   do_getres:         perform the CLOCK_GETRES system call
   5  *   do_gettime:        perform the CLOCK_GETTIME system call
   6  *   do_settime:        perform the CLOCK_SETTIME system call
   7  *   do_time:           perform the GETTIMEOFDAY system call
   8  *   do_stime:          perform the STIME system call
   9  */
  10
  11 #include "pm.h"
  12 #include <minix/callnr.h>
  13 #include <minix/com.h>
  14 #include <signal.h>
  15 #include <sys/time.h>
  16 #include "mproc.h"
  17
  18 /*===========================================================================*
  19  *                              do_gettime                                   *
  20  *===========================================================================*/
  21 int do_gettime()
  22 {
  23   clock_t ticks, realtime, clock;
  24   time_t boottime;
  25   int s;
  26
  27   if ( (s=getuptime(&ticks, &realtime, &boottime)) != OK)
  28         panic("do_time couldn't get uptime: %d", s);
  29
  30   switch (m_in.m_lc_pm_time.clk_id) {
  31         case CLOCK_REALTIME:
  32                 clock = realtime;
  33                 break;
  34         case CLOCK_MONOTONIC:
  35                 clock = ticks;
  36                 break;
  37         default:
  38                 return EINVAL; /* invalid/unsupported clock_id */
  39   }
  40
  41   mp->mp_reply.m_pm_lc_time.sec = boottime + (clock / system_hz);
  42   mp->mp_reply.m_pm_lc_time.nsec =
  43         (uint32_t) ((clock % system_hz) * 1000000000ULL / system_hz);
  44
  45   return(OK);
  46 }
  47
  48 /*===========================================================================*
  49  *                              do_getres                                    *
  50  *===========================================================================*/
  51 int do_getres()
  52 {
  53   switch (m_in.m_lc_pm_time.clk_id) {
  54         case CLOCK_REALTIME:
  55         case CLOCK_MONOTONIC:
  56                 /* tv_sec is always 0 since system_hz is an int */
  57                 mp->mp_reply.m_pm_lc_time.sec = 0;
  58                 mp->mp_reply.m_pm_lc_time.nsec = 1000000000 / system_hz;
  59                 return(OK);
  60         default:
  61                 return EINVAL; /* invalid/unsupported clock_id */
  62   }
  63 }
  64
  65 /*===========================================================================*
  66  *                              do_settime                                   *
  67  *===========================================================================*/
  68 int do_settime()
  69 {
  70   int s;
  71
  72   if (mp->mp_effuid != SUPER_USER) {
  73       return(EPERM);
  74   }
  75
  76   switch (m_in.m_lc_pm_time.clk_id) {
  77         case CLOCK_REALTIME:
  78                 s = sys_settime(m_in.m_lc_pm_time.now, m_in.m_lc_pm_time.clk_id,
  79                         m_in.m_lc_pm_time.sec, m_in.m_lc_pm_time.nsec);
  80                 return(s);
  81         case CLOCK_MONOTONIC: /* monotonic cannot be changed */
  82         default:
  83                 return EINVAL; /* invalid/unsupported clock_id */
  84   }
  85 }
  86
  87 /*===========================================================================*
  88  *                              do_time                                      *
  89  *===========================================================================*/
  90 int do_time()
  91 {
  92 /* Perform the time(tp) system call. This returns the time in seconds since
  93  * 1.1.1970.  MINIX is an astrophysically naive system that assumes the earth
  94  * rotates at a constant rate and that such things as leap seconds do not
  95  * exist.
  96  */
  97   clock_t ticks, realtime;
  98   time_t boottime;
  99   int s;
 100
 101   if ( (s=getuptime(&ticks, &realtime, &boottime)) != OK)
 102         panic("do_time couldn't get uptime: %d", s);
 103
 104   mp->mp_reply.m_pm_lc_time.sec = boottime + (realtime / system_hz);
 105   mp->mp_reply.m_pm_lc_time.nsec =
 106         (uint32_t) ((realtime % system_hz) * 1000000000ULL / system_hz);
 107   return(OK);
 108 }
 109
 110 /*===========================================================================*
 111  *                              do_stime                                     *
 112  *===========================================================================*/
 113 int do_stime()
 114 {
 115 /* Perform the stime(tp) system call. Retrieve the system's uptime (ticks
 116  * since boot) and pass the new time in seconds at system boot to the kernel.
 117  */
 118   clock_t uptime, realtime;
 119   time_t boottime;
 120   int s;
 121
 122   if (mp->mp_effuid != SUPER_USER) {
 123       return(EPERM);
 124   }
 125   if ( (s=getuptime(&uptime, &realtime, &boottime)) != OK)
 126       panic("do_stime couldn't get uptime: %d", s);
 127   boottime = m_in.m_lc_pm_time.sec - (realtime/system_hz);
 128
 129   s= sys_stime(boottime);               /* Tell kernel about boottime */
 130   if (s != OK)
 131         panic("pm: sys_stime failed: %d", s);
 132
 133   return(OK);
 134 }