um/os-Linux/time.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
0004  * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
0005  * Copyright (C) 2012-2014 Cisco Systems
0006  * Copyright (C) 2000 - 2007 Jeff Dike (jdike{addtoit,linux.intel}.com)
0007  */
0008
0009 #include <stddef.h>
0010 #include <unistd.h>
0011 #include <errno.h>
0012 #include <signal.h>
0013 #include <time.h>
0014 #include <sys/time.h>
0015 #include <kern_util.h>
0016 #include <os.h>
0017 #include <string.h>
0018
0019 static timer_t event_high_res_timer = 0;
0020
0021 static inline long long timespec_to_ns(const struct timespec *ts)
0022 {
0023     return ((long long) ts->tv_sec * UM_NSEC_PER_SEC) + ts->tv_nsec;
0024 }
0025
0026 long long os_persistent_clock_emulation(void)
0027 {
0028     struct timespec realtime_tp;
0029
0030     clock_gettime(CLOCK_REALTIME, &realtime_tp);
0031     return timespec_to_ns(&realtime_tp);
0032 }
0033
0034 /**
0035  * os_timer_create() - create an new posix (interval) timer
0036  */
0037 int os_timer_create(void)
0038 {
0039     timer_t *t = &event_high_res_timer;
0040
0041     if (timer_create(CLOCK_MONOTONIC, NULL, t) == -1)
0042         return -1;
0043
0044     return 0;
0045 }
0046
0047 int os_timer_set_interval(unsigned long long nsecs)
0048 {
0049     struct itimerspec its;
0050
0051     its.it_value.tv_sec = nsecs / UM_NSEC_PER_SEC;
0052     its.it_value.tv_nsec = nsecs % UM_NSEC_PER_SEC;
0053
0054     its.it_interval.tv_sec = nsecs / UM_NSEC_PER_SEC;
0055     its.it_interval.tv_nsec = nsecs % UM_NSEC_PER_SEC;
0056
0057     if (timer_settime(event_high_res_timer, 0, &its, NULL) == -1)
0058         return -errno;
0059
0060     return 0;
0061 }
0062
0063 int os_timer_one_shot(unsigned long long nsecs)
0064 {
0065     struct itimerspec its = {
0066         .it_value.tv_sec = nsecs / UM_NSEC_PER_SEC,
0067         .it_value.tv_nsec = nsecs % UM_NSEC_PER_SEC,
0068
0069         .it_interval.tv_sec = 0,
0070         .it_interval.tv_nsec = 0, // we cheat here
0071     };
0072
0073     timer_settime(event_high_res_timer, 0, &its, NULL);
0074     return 0;
0075 }
0076
0077 /**
0078  * os_timer_disable() - disable the posix (interval) timer
0079  */
0080 void os_timer_disable(void)
0081 {
0082     struct itimerspec its;
0083
0084     memset(&its, 0, sizeof(struct itimerspec));
0085     timer_settime(event_high_res_timer, 0, &its, NULL);
0086 }
0087
0088 long long os_nsecs(void)
0089 {
0090     struct timespec ts;
0091
0092     clock_gettime(CLOCK_MONOTONIC,&ts);
0093     return timespec_to_ns(&ts);
0094 }
0095
0096 /**
0097  * os_idle_sleep() - sleep until interrupted
0098  */
0099 void os_idle_sleep(void)
0100 {
0101     struct itimerspec its;
0102     sigset_t set, old;
0103
0104     /* block SIGALRM while we analyze the timer state */
0105     sigemptyset(&set);
0106     sigaddset(&set, SIGALRM);
0107     sigprocmask(SIG_BLOCK, &set, &old);
0108
0109     /* check the timer, and if it'll fire then wait for it */
0110     timer_gettime(event_high_res_timer, &its);
0111     if (its.it_value.tv_sec || its.it_value.tv_nsec)
0112         sigsuspend(&old);
0113     /* either way, restore the signal mask */
0114     sigprocmask(SIG_UNBLOCK, &set, NULL);
0115 }