tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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#include <timer-internal.h>
18
19static timer_t event_high_res_timer = 0;
20
21static inline long long timeval_to_ns(const struct timeval *tv)
22{
23 return ((long long) tv->tv_sec * UM_NSEC_PER_SEC) +
24 tv->tv_usec * UM_NSEC_PER_USEC;
25}
26
27static inline long long timespec_to_ns(const struct timespec *ts)
28{
29 return ((long long) ts->tv_sec * UM_NSEC_PER_SEC) + ts->tv_nsec;
30}
31
32long long os_persistent_clock_emulation(void)
33{
34 struct timespec realtime_tp;
35
36 clock_gettime(CLOCK_REALTIME, &realtime_tp);
37 return timespec_to_ns(&realtime_tp);
38}
39
40/**
41 * os_timer_create() - create an new posix (interval) timer
42 */
43int os_timer_create(void)
44{
45 timer_t *t = &event_high_res_timer;
46
47 if (timer_create(CLOCK_MONOTONIC, NULL, t) == -1)
48 return -1;
49
50 return 0;
51}
52
53int os_timer_set_interval(unsigned long long nsecs)
54{
55 struct itimerspec its;
56
57 its.it_value.tv_sec = nsecs / UM_NSEC_PER_SEC;
58 its.it_value.tv_nsec = nsecs % UM_NSEC_PER_SEC;
59
60 its.it_interval.tv_sec = nsecs / UM_NSEC_PER_SEC;
61 its.it_interval.tv_nsec = nsecs % UM_NSEC_PER_SEC;
62
63 if (timer_settime(event_high_res_timer, 0, &its, NULL) == -1)
64 return -errno;
65
66 return 0;
67}
68
69int os_timer_one_shot(unsigned long long nsecs)
70{
71 struct itimerspec its = {
72 .it_value.tv_sec = nsecs / UM_NSEC_PER_SEC,
73 .it_value.tv_nsec = nsecs % UM_NSEC_PER_SEC,
74
75 .it_interval.tv_sec = 0,
76 .it_interval.tv_nsec = 0, // we cheat here
77 };
78
79 timer_settime(event_high_res_timer, 0, &its, NULL);
80 return 0;
81}
82
83/**
84 * os_timer_disable() - disable the posix (interval) timer
85 */
86void os_timer_disable(void)
87{
88 struct itimerspec its;
89
90 memset(&its, 0, sizeof(struct itimerspec));
91 timer_settime(event_high_res_timer, 0, &its, NULL);
92}
93
94long long os_nsecs(void)
95{
96 struct timespec ts;
97
98 clock_gettime(CLOCK_MONOTONIC,&ts);
99 return timespec_to_ns(&ts);
100}
101
102/**
103 * os_idle_sleep() - sleep for a given time of nsecs
104 * @nsecs: nanoseconds to sleep
105 */
106void os_idle_sleep(unsigned long long nsecs)
107{
108 struct timespec ts = {
109 .tv_sec = nsecs / UM_NSEC_PER_SEC,
110 .tv_nsec = nsecs % UM_NSEC_PER_SEC
111 };
112
113 /*
114 * Relay the signal if clock_nanosleep is interrupted.
115 */
116 if (clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL))
117 deliver_alarm();
118}