diff options
| -rw-r--r-- | arch/um/drivers/Kconfig | 11 | ||||
| -rw-r--r-- | arch/um/drivers/Makefile | 2 | ||||
| -rw-r--r-- | arch/um/drivers/rtc.h | 15 | ||||
| -rw-r--r-- | arch/um/drivers/rtc_kern.c | 211 | ||||
| -rw-r--r-- | arch/um/drivers/rtc_user.c | 80 | ||||
| -rw-r--r-- | arch/um/include/linux/time-internal.h | 11 | ||||
| -rw-r--r-- | arch/um/kernel/time.c | 10 |
7 files changed, 339 insertions, 1 deletions
diff --git a/arch/um/drivers/Kconfig b/arch/um/drivers/Kconfig index 58e3ffc17b7d..03ba34b61115 100644 --- a/arch/um/drivers/Kconfig +++ b/arch/um/drivers/Kconfig @@ -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. diff --git a/arch/um/drivers/Makefile b/arch/um/drivers/Makefile index 2a249f619467..dcc64a02f81f 100644 --- a/arch/um/drivers/Makefile +++ b/arch/um/drivers/Makefile @@ -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 diff --git a/arch/um/drivers/rtc.h b/arch/um/drivers/rtc.h new file mode 100644 index 000000000000..95e41c7d35c4 --- /dev/null +++ b/arch/um/drivers/rtc.h @@ -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__ */ diff --git a/arch/um/drivers/rtc_kern.c b/arch/um/drivers/rtc_kern.c new file mode 100644 index 000000000000..97ceb205cfe6 --- /dev/null +++ b/arch/um/drivers/rtc_kern.c @@ -0,0 +1,211 @@ +// 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) +{ + unsigned long long c = 0; + + /* alarm triggered, it's now off */ + uml_rtc_alarm_enabled = false; + + os_read_file(uml_rtc_irq_fd, &c, sizeof(c)); + WARN_ON(c == 0); + + 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 (WARN(err < 0, "err = %d\n", err)) + 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; + + device_init_wakeup(&pdev->dev, 1); + + err = devm_rtc_register_device(uml_rtc); + if (err) + goto cleanup; + + 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); diff --git a/arch/um/drivers/rtc_user.c b/arch/um/drivers/rtc_user.c new file mode 100644 index 000000000000..4016bc1d577e --- /dev/null +++ b/arch/um/drivers/rtc_user.c @@ -0,0 +1,80 @@ +// 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]); +} diff --git a/arch/um/include/linux/time-internal.h b/arch/um/include/linux/time-internal.h index 8688e16e832b..759956ab0108 100644 --- a/arch/um/include/linux/time-internal.h +++ b/arch/um/include/linux/time-internal.h @@ -55,6 +55,9 @@ 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 { }; @@ -80,6 +83,14 @@ static inline void time_travel_add_irq_event(struct time_travel_event *e) { WARN_ON(1); } + +/* + * 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 */ /* diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c index 8144406b6ea3..e0cdb9694fb8 100644 --- a/arch/um/kernel/time.c +++ b/arch/um/kernel/time.c @@ -321,6 +321,12 @@ 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, @@ -384,7 +390,7 @@ 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) { unsigned long flags; @@ -594,6 +600,8 @@ 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 |