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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
19static timer_t event_high_res_timer = 0;
20
21static 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
26long 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 */
37int 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
47int 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
63int 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 */
80void 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
88long 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 */
99void 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}
1/*
2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
6#include <stddef.h>
7#include <errno.h>
8#include <signal.h>
9#include <time.h>
10#include <sys/time.h>
11#include "kern_constants.h"
12#include "kern_util.h"
13#include "os.h"
14#include "process.h"
15#include "user.h"
16
17int set_interval(void)
18{
19 int usec = UM_USEC_PER_SEC / UM_HZ;
20 struct itimerval interval = ((struct itimerval) { { 0, usec },
21 { 0, usec } });
22
23 if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1)
24 return -errno;
25
26 return 0;
27}
28
29int timer_one_shot(int ticks)
30{
31 unsigned long usec = ticks * UM_USEC_PER_SEC / UM_HZ;
32 unsigned long sec = usec / UM_USEC_PER_SEC;
33 struct itimerval interval;
34
35 usec %= UM_USEC_PER_SEC;
36 interval = ((struct itimerval) { { 0, 0 }, { sec, usec } });
37
38 if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1)
39 return -errno;
40
41 return 0;
42}
43
44/**
45 * timeval_to_ns - Convert timeval to nanoseconds
46 * @ts: pointer to the timeval variable to be converted
47 *
48 * Returns the scalar nanosecond representation of the timeval
49 * parameter.
50 *
51 * Ripped from linux/time.h because it's a kernel header, and thus
52 * unusable from here.
53 */
54static inline long long timeval_to_ns(const struct timeval *tv)
55{
56 return ((long long) tv->tv_sec * UM_NSEC_PER_SEC) +
57 tv->tv_usec * UM_NSEC_PER_USEC;
58}
59
60long long disable_timer(void)
61{
62 struct itimerval time = ((struct itimerval) { { 0, 0 }, { 0, 0 } });
63 long long remain, max = UM_NSEC_PER_SEC / UM_HZ;
64
65 if (setitimer(ITIMER_VIRTUAL, &time, &time) < 0)
66 printk(UM_KERN_ERR "disable_timer - setitimer failed, "
67 "errno = %d\n", errno);
68
69 remain = timeval_to_ns(&time.it_value);
70 if (remain > max)
71 remain = max;
72
73 return remain;
74}
75
76long long os_nsecs(void)
77{
78 struct timeval tv;
79
80 gettimeofday(&tv, NULL);
81 return timeval_to_ns(&tv);
82}
83
84#ifdef UML_CONFIG_NO_HZ
85static int after_sleep_interval(struct timespec *ts)
86{
87 return 0;
88}
89
90static void deliver_alarm(void)
91{
92 alarm_handler(SIGVTALRM, NULL);
93}
94
95static unsigned long long sleep_time(unsigned long long nsecs)
96{
97 return nsecs;
98}
99
100#else
101unsigned long long last_tick;
102unsigned long long skew;
103
104static void deliver_alarm(void)
105{
106 unsigned long long this_tick = os_nsecs();
107 int one_tick = UM_NSEC_PER_SEC / UM_HZ;
108
109 /* Protection against the host's time going backwards */
110 if ((last_tick != 0) && (this_tick < last_tick))
111 this_tick = last_tick;
112
113 if (last_tick == 0)
114 last_tick = this_tick - one_tick;
115
116 skew += this_tick - last_tick;
117
118 while (skew >= one_tick) {
119 alarm_handler(SIGVTALRM, NULL);
120 skew -= one_tick;
121 }
122
123 last_tick = this_tick;
124}
125
126static unsigned long long sleep_time(unsigned long long nsecs)
127{
128 return nsecs > skew ? nsecs - skew : 0;
129}
130
131static inline long long timespec_to_us(const struct timespec *ts)
132{
133 return ((long long) ts->tv_sec * UM_USEC_PER_SEC) +
134 ts->tv_nsec / UM_NSEC_PER_USEC;
135}
136
137static int after_sleep_interval(struct timespec *ts)
138{
139 int usec = UM_USEC_PER_SEC / UM_HZ;
140 long long start_usecs = timespec_to_us(ts);
141 struct timeval tv;
142 struct itimerval interval;
143
144 /*
145 * It seems that rounding can increase the value returned from
146 * setitimer to larger than the one passed in. Over time,
147 * this will cause the remaining time to be greater than the
148 * tick interval. If this happens, then just reduce the first
149 * tick to the interval value.
150 */
151 if (start_usecs > usec)
152 start_usecs = usec;
153
154 start_usecs -= skew / UM_NSEC_PER_USEC;
155 if (start_usecs < 0)
156 start_usecs = 0;
157
158 tv = ((struct timeval) { .tv_sec = start_usecs / UM_USEC_PER_SEC,
159 .tv_usec = start_usecs % UM_USEC_PER_SEC });
160 interval = ((struct itimerval) { { 0, usec }, tv });
161
162 if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1)
163 return -errno;
164
165 return 0;
166}
167#endif
168
169void idle_sleep(unsigned long long nsecs)
170{
171 struct timespec ts;
172
173 /*
174 * nsecs can come in as zero, in which case, this starts a
175 * busy loop. To prevent this, reset nsecs to the tick
176 * interval if it is zero.
177 */
178 if (nsecs == 0)
179 nsecs = UM_NSEC_PER_SEC / UM_HZ;
180
181 nsecs = sleep_time(nsecs);
182 ts = ((struct timespec) { .tv_sec = nsecs / UM_NSEC_PER_SEC,
183 .tv_nsec = nsecs % UM_NSEC_PER_SEC });
184
185 if (nanosleep(&ts, &ts) == 0)
186 deliver_alarm();
187 after_sleep_interval(&ts);
188}