linux/arch/um/drivers/rtc_user.c

81 lines
1.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020 Intel Corporation
* Author: Johannes Berg <johannes@sipsolutions.net>
*/
#include <os.h>
#include <errno.h>
#include <sched.h>
#include <unistd.h>
#include <kern_util.h>
#include <sys/select.h>
#include <stdio.h>
#include <sys/timerfd.h>
#include "rtc.h"
static int uml_rtc_irq_fds[2];
void uml_rtc_send_timetravel_alarm(void)
{
unsigned long long c = 1;
CATCH_EINTR(write(uml_rtc_irq_fds[1], &c, sizeof(c)));
}
int uml_rtc_start(bool timetravel)
{
int err;
if (timetravel) {
int err = os_pipe(uml_rtc_irq_fds, 1, 1);
if (err)
goto fail;
} else {
uml_rtc_irq_fds[0] = timerfd_create(CLOCK_REALTIME, TFD_CLOEXEC);
if (uml_rtc_irq_fds[0] < 0) {
err = -errno;
goto fail;
}
/* apparently timerfd won't send SIGIO, use workaround */
sigio_broken(uml_rtc_irq_fds[0]);
err = add_sigio_fd(uml_rtc_irq_fds[0]);
if (err < 0) {
close(uml_rtc_irq_fds[0]);
goto fail;
}
}
return uml_rtc_irq_fds[0];
fail:
uml_rtc_stop(timetravel);
return err;
}
int uml_rtc_enable_alarm(unsigned long long delta_seconds)
{
struct itimerspec it = {
.it_value = {
.tv_sec = delta_seconds,
},
};
if (timerfd_settime(uml_rtc_irq_fds[0], 0, &it, NULL))
return -errno;
return 0;
}
void uml_rtc_disable_alarm(void)
{
uml_rtc_enable_alarm(0);
}
void uml_rtc_stop(bool timetravel)
{
if (timetravel)
os_close_file(uml_rtc_irq_fds[1]);
else
ignore_sigio_fd(uml_rtc_irq_fds[0]);
os_close_file(uml_rtc_irq_fds[0]);
}