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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_util.h"
12#include "os.h"
13#include "internal.h"
14
15int set_interval(void)
16{
17 int usec = UM_USEC_PER_SEC / UM_HZ;
18 struct itimerval interval = ((struct itimerval) { { 0, usec },
19 { 0, usec } });
20
21 if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1)
22 return -errno;
23
24 return 0;
25}
26
27int timer_one_shot(int ticks)
28{
29 unsigned long usec = ticks * UM_USEC_PER_SEC / UM_HZ;
30 unsigned long sec = usec / UM_USEC_PER_SEC;
31 struct itimerval interval;
32
33 usec %= UM_USEC_PER_SEC;
34 interval = ((struct itimerval) { { 0, 0 }, { sec, usec } });
35
36 if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1)
37 return -errno;
38
39 return 0;
40}
41
42/**
43 * timeval_to_ns - Convert timeval to nanoseconds
44 * @ts: pointer to the timeval variable to be converted
45 *
46 * Returns the scalar nanosecond representation of the timeval
47 * parameter.
48 *
49 * Ripped from linux/time.h because it's a kernel header, and thus
50 * unusable from here.
51 */
52static inline long long timeval_to_ns(const struct timeval *tv)
53{
54 return ((long long) tv->tv_sec * UM_NSEC_PER_SEC) +
55 tv->tv_usec * UM_NSEC_PER_USEC;
56}
57
58long long disable_timer(void)
59{
60 struct itimerval time = ((struct itimerval) { { 0, 0 }, { 0, 0 } });
61 long long remain, max = UM_NSEC_PER_SEC / UM_HZ;
62
63 if (setitimer(ITIMER_VIRTUAL, &time, &time) < 0)
64 printk(UM_KERN_ERR "disable_timer - setitimer failed, "
65 "errno = %d\n", errno);
66
67 remain = timeval_to_ns(&time.it_value);
68 if (remain > max)
69 remain = max;
70
71 return remain;
72}
73
74long long os_nsecs(void)
75{
76 struct timeval tv;
77
78 gettimeofday(&tv, NULL);
79 return timeval_to_ns(&tv);
80}
81
82#ifdef UML_CONFIG_NO_HZ
83static int after_sleep_interval(struct timespec *ts)
84{
85 return 0;
86}
87
88static void deliver_alarm(void)
89{
90 alarm_handler(SIGVTALRM, NULL);
91}
92
93static unsigned long long sleep_time(unsigned long long nsecs)
94{
95 return nsecs;
96}
97
98#else
99unsigned long long last_tick;
100unsigned long long skew;
101
102static void deliver_alarm(void)
103{
104 unsigned long long this_tick = os_nsecs();
105 int one_tick = UM_NSEC_PER_SEC / UM_HZ;
106
107 /* Protection against the host's time going backwards */
108 if ((last_tick != 0) && (this_tick < last_tick))
109 this_tick = last_tick;
110
111 if (last_tick == 0)
112 last_tick = this_tick - one_tick;
113
114 skew += this_tick - last_tick;
115
116 while (skew >= one_tick) {
117 alarm_handler(SIGVTALRM, NULL);
118 skew -= one_tick;
119 }
120
121 last_tick = this_tick;
122}
123
124static unsigned long long sleep_time(unsigned long long nsecs)
125{
126 return nsecs > skew ? nsecs - skew : 0;
127}
128
129static inline long long timespec_to_us(const struct timespec *ts)
130{
131 return ((long long) ts->tv_sec * UM_USEC_PER_SEC) +
132 ts->tv_nsec / UM_NSEC_PER_USEC;
133}
134
135static int after_sleep_interval(struct timespec *ts)
136{
137 int usec = UM_USEC_PER_SEC / UM_HZ;
138 long long start_usecs = timespec_to_us(ts);
139 struct timeval tv;
140 struct itimerval interval;
141
142 /*
143 * It seems that rounding can increase the value returned from
144 * setitimer to larger than the one passed in. Over time,
145 * this will cause the remaining time to be greater than the
146 * tick interval. If this happens, then just reduce the first
147 * tick to the interval value.
148 */
149 if (start_usecs > usec)
150 start_usecs = usec;
151
152 start_usecs -= skew / UM_NSEC_PER_USEC;
153 if (start_usecs < 0)
154 start_usecs = 0;
155
156 tv = ((struct timeval) { .tv_sec = start_usecs / UM_USEC_PER_SEC,
157 .tv_usec = start_usecs % UM_USEC_PER_SEC });
158 interval = ((struct itimerval) { { 0, usec }, tv });
159
160 if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1)
161 return -errno;
162
163 return 0;
164}
165#endif
166
167void idle_sleep(unsigned long long nsecs)
168{
169 struct timespec ts;
170
171 /*
172 * nsecs can come in as zero, in which case, this starts a
173 * busy loop. To prevent this, reset nsecs to the tick
174 * interval if it is zero.
175 */
176 if (nsecs == 0)
177 nsecs = UM_NSEC_PER_SEC / UM_HZ;
178
179 nsecs = sleep_time(nsecs);
180 ts = ((struct timespec) { .tv_sec = nsecs / UM_NSEC_PER_SEC,
181 .tv_nsec = nsecs % UM_NSEC_PER_SEC });
182
183 if (nanosleep(&ts, &ts) == 0)
184 deliver_alarm();
185 after_sleep_interval(&ts);
186}
1/*
2 * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
3 * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
4 * Copyright (C) 2012-2014 Cisco Systems
5 * Copyright (C) 2000 - 2007 Jeff Dike (jdike{addtoit,linux.intel}.com)
6 * Licensed under the GPL
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) +
30 ts->tv_nsec;
31}
32
33long long os_persistent_clock_emulation (void) {
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* timer) {
44
45 timer_t* t = timer;
46
47 if(t == NULL) {
48 t = &event_high_res_timer;
49 }
50
51 if (timer_create(
52 CLOCK_MONOTONIC,
53 NULL,
54 t) == -1) {
55 return -1;
56 }
57 return 0;
58}
59
60int os_timer_set_interval(void* timer, void* i)
61{
62 struct itimerspec its;
63 unsigned long long nsec;
64 timer_t* t = timer;
65 struct itimerspec* its_in = i;
66
67 if(t == NULL) {
68 t = &event_high_res_timer;
69 }
70
71 nsec = UM_NSEC_PER_SEC / UM_HZ;
72
73 if(its_in != NULL) {
74 its.it_value.tv_sec = its_in->it_value.tv_sec;
75 its.it_value.tv_nsec = its_in->it_value.tv_nsec;
76 } else {
77 its.it_value.tv_sec = 0;
78 its.it_value.tv_nsec = nsec;
79 }
80
81 its.it_interval.tv_sec = 0;
82 its.it_interval.tv_nsec = nsec;
83
84 if(timer_settime(*t, 0, &its, NULL) == -1) {
85 return -errno;
86 }
87
88 return 0;
89}
90
91/**
92 * os_timer_remain() - returns the remaining nano seconds of the given interval
93 * timer
94 * Because this is the remaining time of an interval timer, which correspondends
95 * to HZ, this value can never be bigger than one second. Just
96 * the nanosecond part of the timer is returned.
97 * The returned time is relative to the start time of the interval timer.
98 * Return an negative value in an error case.
99 */
100long os_timer_remain(void* timer)
101{
102 struct itimerspec its;
103 timer_t* t = timer;
104
105 if(t == NULL) {
106 t = &event_high_res_timer;
107 }
108
109 if(timer_gettime(t, &its) == -1) {
110 return -errno;
111 }
112
113 return its.it_value.tv_nsec;
114}
115
116int os_timer_one_shot(int ticks)
117{
118 struct itimerspec its;
119 unsigned long long nsec;
120 unsigned long sec;
121
122 nsec = (ticks + 1);
123 sec = nsec / UM_NSEC_PER_SEC;
124 nsec = nsec % UM_NSEC_PER_SEC;
125
126 its.it_value.tv_sec = nsec / UM_NSEC_PER_SEC;
127 its.it_value.tv_nsec = nsec;
128
129 its.it_interval.tv_sec = 0;
130 its.it_interval.tv_nsec = 0; // we cheat here
131
132 timer_settime(event_high_res_timer, 0, &its, NULL);
133 return 0;
134}
135
136/**
137 * os_timer_disable() - disable the posix (interval) timer
138 * Returns the remaining interval timer time in nanoseconds
139 */
140long long os_timer_disable(void)
141{
142 struct itimerspec its;
143
144 memset(&its, 0, sizeof(struct itimerspec));
145 timer_settime(event_high_res_timer, 0, &its, &its);
146
147 return its.it_value.tv_sec * UM_NSEC_PER_SEC + its.it_value.tv_nsec;
148}
149
150long long os_vnsecs(void)
151{
152 struct timespec ts;
153
154 clock_gettime(CLOCK_PROCESS_CPUTIME_ID,&ts);
155 return timespec_to_ns(&ts);
156}
157
158long long os_nsecs(void)
159{
160 struct timespec ts;
161
162 clock_gettime(CLOCK_MONOTONIC,&ts);
163 return timespec_to_ns(&ts);
164}
165
166/**
167 * os_idle_sleep() - sleep for a given time of nsecs
168 * @nsecs: nanoseconds to sleep
169 */
170void os_idle_sleep(unsigned long long nsecs)
171{
172 struct timespec ts;
173
174 if (nsecs <= 0) {
175 return;
176 }
177
178 ts = ((struct timespec) {
179 .tv_sec = nsecs / UM_NSEC_PER_SEC,
180 .tv_nsec = nsecs % UM_NSEC_PER_SEC
181 });
182
183 /*
184 * Relay the signal if clock_nanosleep is interrupted.
185 */
186 if (clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL)) {
187 deliver_alarm();
188 }
189}