arch/um/os-Linux/time.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
   4  * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
   5  * Copyright (C) 2012-2014 Cisco Systems
   6  * Copyright (C) 2000 - 2007 Jeff Dike (jdike{addtoit,linux.intel}.com)
   7  */
   8
   9 #include <stddef.h>
  10 #include <unistd.h>
  11 #include <errno.h>
  12 #include <signal.h>
  13 #include <time.h>
  14 #include <sys/time.h>
  15 #include <kern_util.h>
  16 #include <os.h>
  17 #include <string.h>
  18
  19 static timer_t event_high_res_timer = 0;
  20
  21 static inline long long timespec_to_ns(const struct timespec *ts)
  22 {
  23         return ((long long) ts->tv_sec * UM_NSEC_PER_SEC) + ts->tv_nsec;
  24 }
  25
  26 long long os_persistent_clock_emulation(void)
  27 {
  28         struct timespec realtime_tp;
  29
  30         clock_gettime(CLOCK_REALTIME, &realtime_tp);
  31         return timespec_to_ns(&realtime_tp);
  32 }
  33
  34 /**
  35  * os_timer_create() - create an new posix (interval) timer
  36  */
  37 int os_timer_create(void)
  38 {
  39         timer_t *t = &event_high_res_timer;
  40
  41         if (timer_create(CLOCK_MONOTONIC, NULL, t) == -1)
  42                 return -1;
  43
  44         return 0;
  45 }
  46
  47 int os_timer_set_interval(unsigned long long nsecs)
  48 {
  49         struct itimerspec its;
  50
  51         its.it_value.tv_sec = nsecs / UM_NSEC_PER_SEC;
  52         its.it_value.tv_nsec = nsecs % UM_NSEC_PER_SEC;
  53
  54         its.it_interval.tv_sec = nsecs / UM_NSEC_PER_SEC;
  55         its.it_interval.tv_nsec = nsecs % UM_NSEC_PER_SEC;
  56
  57         if (timer_settime(event_high_res_timer, 0, &its, NULL) == -1)
  58                 return -errno;
  59
  60         return 0;
  61 }
  62
  63 int os_timer_one_shot(unsigned long long nsecs)
  64 {
  65         struct itimerspec its = {
  66                 .it_value.tv_sec = nsecs / UM_NSEC_PER_SEC,
  67                 .it_value.tv_nsec = nsecs % UM_NSEC_PER_SEC,
  68
  69                 .it_interval.tv_sec = 0,
  70                 .it_interval.tv_nsec = 0, // we cheat here
  71         };
  72
  73         timer_settime(event_high_res_timer, 0, &its, NULL);
  74         return 0;
  75 }
  76
  77 /**
  78  * os_timer_disable() - disable the posix (interval) timer
  79  */
  80 void os_timer_disable(void)
  81 {
  82         struct itimerspec its;
  83
  84         memset(&its, 0, sizeof(struct itimerspec));
  85         timer_settime(event_high_res_timer, 0, &its, NULL);
  86 }
  87
  88 long long os_nsecs(void)
  89 {
  90         struct timespec ts;
  91
  92         clock_gettime(CLOCK_MONOTONIC,&ts);
  93         return timespec_to_ns(&ts);
  94 }
  95
  96 /**
  97  * os_idle_sleep() - sleep until interrupted
  98  */
  99 void os_idle_sleep(void)
 100 {
 101         struct itimerspec its;
 102         sigset_t set, old;
 103
 104         /* block SIGALRM while we analyze the timer state */
 105         sigemptyset(&set);
 106         sigaddset(&set, SIGALRM);
 107         sigprocmask(SIG_BLOCK, &set, &old);
 108
 109         /* check the timer, and if it'll fire then wait for it */
 110         timer_gettime(event_high_res_timer, &its);
 111         if (its.it_value.tv_sec || its.it_value.tv_nsec)
 112                 sigsuspend(&old);
 113         /* either way, restore the signal mask */
 114         sigprocmask(SIG_UNBLOCK, &set, NULL);
 115 }