@@ -346,3 +346,14 @@ config VIRTIO_UML
help
This driver provides support for virtio based paravirtual device
drivers over vhost-user sockets.
+
+config UML_RTC
+ bool "UML RTC driver"
+ depends on RTC_CLASS
+ # there's no use in this if PM_SLEEP isn't enabled ...
+ depends on PM_SLEEP
+ help
+ When PM_SLEEP is configured, it may be desirable to wake up using
+ rtcwake, especially in time-travel mode. This driver enables that
+ by providing a fake RTC clock that causes a wakeup at the right
+ time.
@@ -17,6 +17,7 @@ hostaudio-objs := hostaudio_kern.o
ubd-objs := ubd_kern.o ubd_user.o
port-objs := port_kern.o port_user.o
harddog-objs := harddog_kern.o harddog_user.o
+rtc-objs := rtc_kern.o rtc_user.o
LDFLAGS_pcap.o = $(shell $(CC) $(KBUILD_CFLAGS) -print-file-name=libpcap.a)
@@ -62,6 +63,7 @@ obj-$(CONFIG_UML_WATCHDOG) += harddog.o
obj-$(CONFIG_BLK_DEV_COW_COMMON) += cow_user.o
obj-$(CONFIG_UML_RANDOM) += random.o
obj-$(CONFIG_VIRTIO_UML) += virtio_uml.o
+obj-$(CONFIG_UML_RTC) += rtc.o
# pcap_user.o must be added explicitly.
USER_OBJS := fd.o null.o pty.o tty.o xterm.o slip_common.o pcap_user.o vde_user.o vector_user.o
new file mode 100644
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 Intel Corporation
+ * Author: Johannes Berg <johannes@sipsolutions.net>
+ */
+#ifndef __UM_RTC_H__
+#define __UM_RTC_H__
+
+int uml_rtc_start(bool timetravel);
+int uml_rtc_enable_alarm(unsigned long long delta_seconds);
+void uml_rtc_disable_alarm(void);
+void uml_rtc_stop(bool timetravel);
+void uml_rtc_send_timetravel_alarm(void);
+
+#endif /* __UM_RTC_H__ */
new file mode 100644
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 Intel Corporation
+ * Author: Johannes Berg <johannes@sipsolutions.net>
+ */
+#include <linux/platform_device.h>
+#include <linux/time-internal.h>
+#include <linux/suspend.h>
+#include <linux/err.h>
+#include <linux/rtc.h>
+#include <kern_util.h>
+#include <irq_kern.h>
+#include <os.h>
+#include "rtc.h"
+
+static time64_t uml_rtc_alarm_time;
+static bool uml_rtc_alarm_enabled;
+static struct rtc_device *uml_rtc;
+static int uml_rtc_irq_fd, uml_rtc_irq;
+
+#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
+
+static void uml_rtc_time_travel_alarm(struct time_travel_event *ev)
+{
+ uml_rtc_send_timetravel_alarm();
+}
+
+static struct time_travel_event uml_rtc_alarm_event = {
+ .fn = uml_rtc_time_travel_alarm,
+};
+#endif
+
+static int uml_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct timespec64 ts;
+
+ /* Use this to get correct time in time-travel mode */
+ read_persistent_clock64(&ts);
+ rtc_time64_to_tm(timespec64_to_ktime(ts) / NSEC_PER_SEC, tm);
+
+ return 0;
+}
+
+static int uml_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ rtc_time64_to_tm(uml_rtc_alarm_time, &alrm->time);
+ alrm->enabled = uml_rtc_alarm_enabled;
+
+ return 0;
+}
+
+static int uml_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
+{
+ unsigned long long secs;
+
+ if (!enable && !uml_rtc_alarm_enabled)
+ return 0;
+
+ uml_rtc_alarm_enabled = enable;
+
+ secs = uml_rtc_alarm_time - ktime_get_real_seconds();
+
+ if (time_travel_mode == TT_MODE_OFF) {
+ if (!enable) {
+ uml_rtc_disable_alarm();
+ return 0;
+ }
+
+ /* enable or update */
+ return uml_rtc_enable_alarm(secs);
+ } else {
+ time_travel_del_event(¨_rtc_alarm_event);
+
+ if (enable)
+ time_travel_add_event_rel(¨_rtc_alarm_event,
+ secs * NSEC_PER_SEC);
+ }
+
+ return 0;
+}
+
+static int uml_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ uml_rtc_alarm_irq_enable(dev, 0);
+ uml_rtc_alarm_time = rtc_tm_to_time64(&alrm->time);
+ uml_rtc_alarm_irq_enable(dev, alrm->enabled);
+
+ return 0;
+}
+
+static const struct rtc_class_ops uml_rtc_ops = {
+ .read_time = uml_rtc_read_time,
+ .read_alarm = uml_rtc_read_alarm,
+ .alarm_irq_enable = uml_rtc_alarm_irq_enable,
+ .set_alarm = uml_rtc_set_alarm,
+};
+
+static irqreturn_t uml_rtc_interrupt(int irq, void *data)
+{
+ char c = -1;
+
+ /* alarm triggered, it's now off */
+ uml_rtc_alarm_enabled = false;
+
+ os_read_file(uml_rtc_irq_fd, &c, sizeof(c));
+ WARN_ON(c);
+
+ pm_system_wakeup();
+ rtc_update_irq(uml_rtc, 1, RTC_IRQF | RTC_AF);
+
+ return IRQ_HANDLED;
+}
+
+static int uml_rtc_setup(void)
+{
+ int err;
+
+ err = uml_rtc_start(time_travel_mode != TT_MODE_OFF);
+ if (err < 0)
+ return err;
+
+ uml_rtc_irq_fd = err;
+
+ err = um_request_irq(UM_IRQ_ALLOC, uml_rtc_irq_fd, IRQ_READ,
+ uml_rtc_interrupt, 0, "rtc", NULL);
+ if (err < 0) {
+ uml_rtc_stop(time_travel_mode != TT_MODE_OFF);
+ return err;
+ }
+
+ irq_set_irq_wake(err, 1);
+
+ uml_rtc_irq = err;
+ return 0;
+}
+
+static void uml_rtc_cleanup(void)
+{
+ um_free_irq(uml_rtc_irq, NULL);
+ uml_rtc_stop(time_travel_mode != TT_MODE_OFF);
+}
+
+static int uml_rtc_probe(struct platform_device *pdev)
+{
+ int err;
+
+ err = uml_rtc_setup();
+ if (err)
+ return err;
+
+ uml_rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(uml_rtc)) {
+ err = PTR_ERR(uml_rtc);
+ goto cleanup;
+ }
+
+ uml_rtc->ops = ¨_rtc_ops;
+
+ err = rtc_register_device(uml_rtc);
+ if (err)
+ goto cleanup;
+
+ device_init_wakeup(&pdev->dev, 1);
+ return 0;
+cleanup:
+ uml_rtc_cleanup();
+ return err;
+}
+
+static int uml_rtc_remove(struct platform_device *pdev)
+{
+ device_init_wakeup(&pdev->dev, 0);
+ uml_rtc_cleanup();
+ return 0;
+}
+
+static struct platform_driver uml_rtc_driver = {
+ .probe = uml_rtc_probe,
+ .remove = uml_rtc_remove,
+ .driver = {
+ .name = "uml-rtc",
+ },
+};
+
+static int __init uml_rtc_init(void)
+{
+ struct platform_device *pdev;
+ int err;
+
+ err = platform_driver_register(¨_rtc_driver);
+ if (err)
+ return err;
+
+ pdev = platform_device_alloc("uml-rtc", 0);
+ if (!pdev) {
+ err = -ENOMEM;
+ goto unregister;
+ }
+
+ err = platform_device_add(pdev);
+ if (err)
+ goto unregister;
+ return 0;
+
+unregister:
+ platform_device_put(pdev);
+ platform_driver_unregister(¨_rtc_driver);
+ return err;
+}
+device_initcall(uml_rtc_init);
new file mode 100644
@@ -0,0 +1,194 @@
+// 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 "rtc.h"
+
+/*
+ * It seems we should just be able to use a timerfd here,
+ * but apparently they don't send SIGIO. So use our own
+ * helper thread instead.
+ */
+
+static unsigned long uml_rtc_stack;
+static int uml_rtc_comm_fds[2];
+static int uml_rtc_irq_fds[2];
+static int uml_rtc_thread_pid;
+
+struct uml_rtc_message {
+ unsigned long long secs;
+ bool enabled;
+};
+
+static int uml_rtc_signal_wake(int fd)
+{
+ char c = 0;
+ int err;
+
+ CATCH_EINTR(err = write(fd, &c, sizeof(c)));
+ if (err != 1) {
+ printf("rtc helper: failed to write irq (errno=%d)\n",
+ errno);
+ fflush(stdout);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+void uml_rtc_send_timetravel_alarm(void)
+{
+ uml_rtc_signal_wake(uml_rtc_irq_fds[1]);
+}
+
+static int uml_rtc_thread(void *_data)
+{
+ struct timeval timeout = {};
+ bool enabled = false;
+
+ os_fix_helper_signals();
+
+ os_close_file(uml_rtc_irq_fds[0]);
+ os_close_file(uml_rtc_comm_fds[0]);
+
+ while (1) {
+ fd_set fdset;
+ int readable, err;
+
+ FD_ZERO(&fdset);
+ FD_SET(uml_rtc_comm_fds[1], &fdset);
+
+ readable = select(uml_rtc_comm_fds[1] + 1, &fdset, NULL, NULL,
+ enabled ? &timeout : NULL);
+ if (readable == 1) {
+ struct uml_rtc_message msg;
+ char c = 0;
+
+ CATCH_EINTR(err = read(uml_rtc_comm_fds[1], &msg,
+ sizeof(msg)));
+ if (err != sizeof(msg)) {
+ fflush(stdout);
+ return -EIO;
+ }
+
+ enabled = msg.enabled;
+ timeout.tv_usec = 0;
+ timeout.tv_sec = msg.secs;
+
+ CATCH_EINTR(err = write(uml_rtc_comm_fds[1], &c,
+ sizeof(c)));
+ if (err != 1) {
+ fflush(stdout);
+ return -EIO;
+ }
+ } else if (readable == 0) {
+ enabled = false;
+
+ err = uml_rtc_signal_wake(uml_rtc_irq_fds[1]);
+ if (err)
+ return err;
+ }
+ /* else ... should we update the timeout if enabled? */
+ }
+
+ return 0;
+}
+
+int uml_rtc_send(struct uml_rtc_message *msg)
+{
+ char c;
+ int err;
+
+ CATCH_EINTR(err = write(uml_rtc_comm_fds[0], msg, sizeof(*msg)));
+ if (err != sizeof(*msg))
+ return err >= 0 ? -EPIPE : err;
+
+ CATCH_EINTR(err = read(uml_rtc_comm_fds[0], &c, sizeof(c)));
+ if (err != sizeof(c))
+ return err >= 0 ? -EPIPE : err;
+
+ return 0;
+}
+
+int uml_rtc_start(bool timetravel)
+{
+ struct uml_rtc_message msg = {
+ .enabled = false,
+ };
+ int err;
+
+ if (uml_rtc_stack)
+ return -EBUSY;
+
+ err = os_pipe(uml_rtc_irq_fds, 1, 1);
+ if (err)
+ return err;
+
+ if (!timetravel) {
+ err = os_pipe(uml_rtc_comm_fds, 1, 1);
+ if (err)
+ goto fail;
+
+ err = run_helper_thread(uml_rtc_thread, NULL, 0,
+ ¨_rtc_stack);
+ if (err < 0)
+ goto fail;
+ uml_rtc_thread_pid = err;
+
+ err = uml_rtc_send(&msg);
+ if (err)
+ 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 uml_rtc_message msg = {
+ .enabled = true,
+ .secs = delta_seconds,
+ };
+
+ return uml_rtc_send(&msg);
+}
+
+void uml_rtc_disable_alarm(void)
+{
+ struct uml_rtc_message msg = {
+ .enabled = false,
+ };
+
+ uml_rtc_send(&msg);
+}
+
+void uml_rtc_stop(bool timetravel)
+{
+ os_close_file(uml_rtc_irq_fds[1]);
+ os_close_file(uml_rtc_irq_fds[0]);
+
+ if (timetravel)
+ return;
+
+ os_close_file(uml_rtc_comm_fds[1]);
+ os_close_file(uml_rtc_comm_fds[0]);
+
+ if (uml_rtc_thread_pid)
+ os_kill_process(uml_rtc_thread_pid, 1);
+ if (uml_rtc_stack)
+ free_stack(uml_rtc_stack, 0);
+ uml_rtc_thread_pid = 0;
+ uml_rtc_stack = 0;
+}
@@ -54,6 +54,9 @@ static inline void time_travel_wait_readable(int fd)
}
void time_travel_add_irq_event(struct time_travel_event *e);
+void time_travel_add_event_rel(struct time_travel_event *e,
+ unsigned long long delay_ns);
+bool time_travel_del_event(struct time_travel_event *e);
#else
struct time_travel_event {
};
@@ -74,6 +77,14 @@ static inline void time_travel_propagate_time(void)
static inline void time_travel_wait_readable(int fd)
{
}
+
+/*
+ * not inlines so the data structure need not exist,
+ * cause linker failures
+ */
+extern void time_travel_not_configured(void);
+#define time_travel_add_event_rel(...) time_travel_not_configured()
+#define time_travel_del_event(...) time_travel_not_configured()
#endif /* CONFIG_UML_TIME_TRAVEL_SUPPORT */
/*
@@ -302,6 +302,12 @@ static void time_travel_add_event(struct time_travel_event *e,
__time_travel_add_event(e, time);
}
+void time_travel_add_event_rel(struct time_travel_event *e,
+ unsigned long long delay_ns)
+{
+ time_travel_add_event(e, time_travel_time + delay_ns);
+}
+
void time_travel_periodic_timer(struct time_travel_event *e)
{
time_travel_add_event(&time_travel_timer_event,
@@ -328,7 +334,7 @@ static void time_travel_deliver_event(struct time_travel_event *e)
}
}
-static bool time_travel_del_event(struct time_travel_event *e)
+bool time_travel_del_event(struct time_travel_event *e)
{
if (!e->pending)
return false;
@@ -504,6 +510,8 @@ extern u64 time_travel_ext_req(u32 op, u64 time);
/* these are empty macros so the struct/fn need not exist */
#define time_travel_add_event(e, time) do { } while (0)
+/* externally not usable - redefine here so we can */
+#undef time_travel_del_event
#define time_travel_del_event(e) do { } while (0)
#endif