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 <errno.h>
  11 #include <signal.h>
  12 #include <time.h>
  13 #include <sys/time.h>
  14 #include <kern_util.h>
  15 #include <os.h>
  16 #include <string.h>
  17
  18 static timer_t event_high_res_timer = 0;
  19
  20 static inline long long timeval_to_ns(const struct timeval *tv)
  21 {
  22         return ((long long) tv->tv_sec * UM_NSEC_PER_SEC) +
  23                 tv->tv_usec * UM_NSEC_PER_USEC;
  24 }
  25
  26 static inline long long timespec_to_ns(const struct timespec *ts)
  27 {
  28         return ((long long) ts->tv_sec * UM_NSEC_PER_SEC) + ts->tv_nsec;
  29 }
  30
  31 long long os_persistent_clock_emulation(void)
  32 {
  33         struct timespec realtime_tp;
  34
  35         clock_gettime(CLOCK_REALTIME, &realtime_tp);
  36         return timespec_to_ns(&realtime_tp);
  37 }
  38
  39 /**
  40  * os_timer_create() - create an new posix (interval) timer
  41  */
  42 int os_timer_create(void)
  43 {
  44         timer_t *t = &event_high_res_timer;
  45
  46         if (timer_create(CLOCK_MONOTONIC, NULL, t) == -1)
  47                 return -1;
  48
  49         return 0;
  50 }
  51
  52 int os_timer_set_interval(unsigned long long nsecs)
  53 {
  54         struct itimerspec its;
  55
  56         its.it_value.tv_sec = nsecs / UM_NSEC_PER_SEC;
  57         its.it_value.tv_nsec = nsecs % UM_NSEC_PER_SEC;
  58
  59         its.it_interval.tv_sec = nsecs / UM_NSEC_PER_SEC;
  60         its.it_interval.tv_nsec = nsecs % UM_NSEC_PER_SEC;
  61
  62         if (timer_settime(event_high_res_timer, 0, &its, NULL) == -1)
  63                 return -errno;
  64
  65         return 0;
  66 }
  67
  68 int os_timer_one_shot(unsigned long long nsecs)
  69 {
  70         struct itimerspec its = {
  71                 .it_value.tv_sec = nsecs / UM_NSEC_PER_SEC,
  72                 .it_value.tv_nsec = nsecs % UM_NSEC_PER_SEC,
  73
  74                 .it_interval.tv_sec = 0,
  75                 .it_interval.tv_nsec = 0, // we cheat here
  76         };
  77
  78         timer_settime(event_high_res_timer, 0, &its, NULL);
  79         return 0;
  80 }
  81
  82 /**
  83  * os_timer_disable() - disable the posix (interval) timer
  84  */
  85 void os_timer_disable(void)
  86 {
  87         struct itimerspec its;
  88
  89         memset(&its, 0, sizeof(struct itimerspec));
  90         timer_settime(event_high_res_timer, 0, &its, NULL);
  91 }
  92
  93 long long os_nsecs(void)
  94 {
  95         struct timespec ts;
  96
  97         clock_gettime(CLOCK_MONOTONIC,&ts);
  98         return timespec_to_ns(&ts);
  99 }
 100
 101 /**
 102  * os_idle_sleep() - sleep for a given time of nsecs
 103  * @nsecs: nanoseconds to sleep
 104  */
 105 void os_idle_sleep(unsigned long long nsecs)
 106 {
 107         struct timespec ts = {
 108                 .tv_sec  = nsecs / UM_NSEC_PER_SEC,
 109                 .tv_nsec = nsecs % UM_NSEC_PER_SEC
 110         };
 111
 112         /*
 113          * Relay the signal if clock_nanosleep is interrupted.
 114          */
 115         if (clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL))
 116                 deliver_alarm();
 117 }