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Diffstat (limited to 'arch/um/drivers/rtc_user.c')
-rw-r--r--arch/um/drivers/rtc_user.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/um/drivers/rtc_user.c b/arch/um/drivers/rtc_user.c
new file mode 100644
index 0000000000..7c3cec4c68
--- /dev/null
+++ b/arch/um/drivers/rtc_user.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 Intel Corporation
+ * Author: Johannes Berg <johannes@sipsolutions.net>
+ */
+#include <stdbool.h>
+#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]);
+}