1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2020 Intel Corporation
4 * Author: Johannes Berg <johannes@sipsolutions.net>
5 */
6 #include <os.h>
7 #include <errno.h>
8 #include <sched.h>
9 #include <unistd.h>
10 #include <kern_util.h>
11 #include <sys/select.h>
12 #include <stdio.h>
13 #include <sys/timerfd.h>
14 #include "rtc.h"
15
16 static int uml_rtc_irq_fds[2];
17
uml_rtc_send_timetravel_alarm(void)18 void uml_rtc_send_timetravel_alarm(void)
19 {
20 unsigned long long c = 1;
21
22 CATCH_EINTR(write(uml_rtc_irq_fds[1], &c, sizeof(c)));
23 }
24
uml_rtc_start(bool timetravel)25 int uml_rtc_start(bool timetravel)
26 {
27 int err;
28
29 if (timetravel) {
30 int err = os_pipe(uml_rtc_irq_fds, 1, 1);
31 if (err)
32 goto fail;
33 } else {
34 uml_rtc_irq_fds[0] = timerfd_create(CLOCK_REALTIME, TFD_CLOEXEC);
35 if (uml_rtc_irq_fds[0] < 0) {
36 err = -errno;
37 goto fail;
38 }
39
40 /* apparently timerfd won't send SIGIO, use workaround */
41 sigio_broken(uml_rtc_irq_fds[0]);
42 err = add_sigio_fd(uml_rtc_irq_fds[0]);
43 if (err < 0) {
44 close(uml_rtc_irq_fds[0]);
45 goto fail;
46 }
47 }
48
49 return uml_rtc_irq_fds[0];
50 fail:
51 uml_rtc_stop(timetravel);
52 return err;
53 }
54
uml_rtc_enable_alarm(unsigned long long delta_seconds)55 int uml_rtc_enable_alarm(unsigned long long delta_seconds)
56 {
57 struct itimerspec it = {
58 .it_value = {
59 .tv_sec = delta_seconds,
60 },
61 };
62
63 if (timerfd_settime(uml_rtc_irq_fds[0], 0, &it, NULL))
64 return -errno;
65 return 0;
66 }
67
uml_rtc_disable_alarm(void)68 void uml_rtc_disable_alarm(void)
69 {
70 uml_rtc_enable_alarm(0);
71 }
72
uml_rtc_stop(bool timetravel)73 void uml_rtc_stop(bool timetravel)
74 {
75 if (timetravel)
76 os_close_file(uml_rtc_irq_fds[1]);
77 else
78 ignore_sigio_fd(uml_rtc_irq_fds[0]);
79 os_close_file(uml_rtc_irq_fds[0]);
80 }
81