diff options
| -rw-r--r-- | include/linux/hrtimer.h | 2 | ||||
| -rw-r--r-- | kernel/hrtimer.c | 65 |
2 files changed, 67 insertions, 0 deletions
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 6d93dce61cbb..becd17db1a1a 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -346,6 +346,8 @@ extern long hrtimer_nanosleep_restart(struct restart_block *restart_block); extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *tsk); +extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode); + /* Soft interrupt function to run the hrtimer queues: */ extern void hrtimer_run_queues(void); extern void hrtimer_run_pending(void); diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index b8e4dce80a74..782137dc755f 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1678,3 +1678,68 @@ void __init hrtimers_init(void) #endif } +/** + * schedule_hrtimeout - sleep until timeout + * @expires: timeout value (ktime_t) + * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL + * + * Make the current task sleep until the given expiry time has + * elapsed. The routine will return immediately unless + * the current task state has been set (see set_current_state()). + * + * You can set the task state as follows - + * + * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to + * pass before the routine returns. + * + * %TASK_INTERRUPTIBLE - the routine may return early if a signal is + * delivered to the current task. + * + * The current task state is guaranteed to be TASK_RUNNING when this + * routine returns. + * + * Returns 0 when the timer has expired otherwise -EINTR + */ +int __sched schedule_hrtimeout(ktime_t *expires, + const enum hrtimer_mode mode) +{ + struct hrtimer_sleeper t; + + /* + * Optimize when a zero timeout value is given. It does not + * matter whether this is an absolute or a relative time. + */ + if (expires && !expires->tv64) { + __set_current_state(TASK_RUNNING); + return 0; + } + + /* + * A NULL parameter means "inifinte" + */ + if (!expires) { + schedule(); + __set_current_state(TASK_RUNNING); + return -EINTR; + } + + hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, mode); + t.timer.expires = *expires; + + hrtimer_init_sleeper(&t, current); + + hrtimer_start(&t.timer, t.timer.expires, mode); + if (!hrtimer_active(&t.timer)) + t.task = NULL; + + if (likely(t.task)) + schedule(); + + hrtimer_cancel(&t.timer); + destroy_hrtimer_on_stack(&t.timer); + + __set_current_state(TASK_RUNNING); + + return !t.task ? 0 : -EINTR; +} +EXPORT_SYMBOL_GPL(schedule_hrtimeout); |