1 // SPDX-License-Identifier: GPL-2.0
3  *  Kernel internal schedule timeout and sleeping functions
12 #include "tick-internal.h"
25 	struct process_timer *timeout = from_timer(timeout, t, timer);  in process_timeout()  local
27 	wake_up_process(timeout->task);  in process_timeout()
31  * schedule_timeout - sleep until timeout
32  * @timeout: timeout value in jiffies
34  * Make the current task sleep until @timeout jiffies have elapsed.
38  * %TASK_RUNNING - the scheduler is called, but the task does not sleep
42  * %TASK_UNINTERRUPTIBLE - at least @timeout jiffies are guaranteed to
46  * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
53  * Specifying a @timeout value of %MAX_SCHEDULE_TIMEOUT will schedule
54  * the CPU away without a bound on the timeout. In this case the return
59  * to be non-negative.
61 signed long __sched schedule_timeout(signed long timeout)  in schedule_timeout()  argument
66 	switch (timeout) {  in schedule_timeout()
85 		if (timeout < 0) {  in schedule_timeout()
86 			pr_err("%s: wrong timeout value %lx\n", __func__, timeout);  in schedule_timeout()
93 	expire = timeout + jiffies;  in schedule_timeout()
105 	timeout = expire - jiffies;  in schedule_timeout()
108 	return timeout < 0 ? 0 : timeout;  in schedule_timeout()
118  * schedule_timeout_interruptible - sleep until timeout (interruptible)
119  * @timeout: timeout value in jiffies
123  * Task state is set to TASK_INTERRUPTIBLE before starting the timeout.
125 signed long __sched schedule_timeout_interruptible(signed long timeout)  in schedule_timeout_interruptible()  argument
128 	return schedule_timeout(timeout);  in schedule_timeout_interruptible()
133  * schedule_timeout_killable - sleep until timeout (killable)
134  * @timeout: timeout value in jiffies
138  * Task state is set to TASK_KILLABLE before starting the timeout.
140 signed long __sched schedule_timeout_killable(signed long timeout)  in schedule_timeout_killable()  argument
143 	return schedule_timeout(timeout);  in schedule_timeout_killable()
148  * schedule_timeout_uninterruptible - sleep until timeout (uninterruptible)
149  * @timeout: timeout value in jiffies
153  * Task state is set to TASK_UNINTERRUPTIBLE before starting the timeout.
155 signed long __sched schedule_timeout_uninterruptible(signed long timeout)  in schedule_timeout_uninterruptible()  argument
158 	return schedule_timeout(timeout);  in schedule_timeout_uninterruptible()
163  * schedule_timeout_idle - sleep until timeout (idle)
164  * @timeout: timeout value in jiffies
168  * Task state is set to TASK_IDLE before starting the timeout. It is similar to
172 signed long __sched schedule_timeout_idle(signed long timeout)  in schedule_timeout_idle()  argument
175 	return schedule_timeout(timeout);  in schedule_timeout_idle()
180  * schedule_hrtimeout_range_clock - sleep until timeout
181  * @expires:	timeout value (ktime_t)
182  * @delta:	slack in expires timeout (ktime_t)
195 	 * Optimize when a zero timeout value is given. It does not  in schedule_hrtimeout_range_clock()
208 		return -EINTR;  in schedule_hrtimeout_range_clock()
223 	return !t.task ? 0 : -EINTR;  in schedule_hrtimeout_range_clock()
228  * schedule_hrtimeout_range - sleep until timeout
229  * @expires:	timeout value (ktime_t)
230  * @delta:	slack in expires timeout (ktime_t)
243  * You can set the task state as follows -
245  * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
249  * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
258  * by an explicit wakeup, it returns -EINTR.
269  * schedule_hrtimeout - sleep until timeout
270  * @expires:	timeout value (ktime_t)
283  * msleep - sleep safely even with waitqueue interruptions
303  *   all sleep durations greater or equal 4ms will meet the constraints.
305  *   all sleep durations greater or equal 8ms will meet the constraints.
307  *   all sleep durations greater or equal 16ms will meet the constraints.
309  *   all sleep durations greater or equal 32ms will meet the constraints.
315 	unsigned long timeout = msecs_to_jiffies(msecs);  in msleep()  local
317 	while (timeout)  in msleep()
318 		timeout = schedule_timeout_uninterruptible(timeout);  in msleep()
323  * msleep_interruptible - sleep waiting for signals
336 	unsigned long timeout = msecs_to_jiffies(msecs);  in msleep_interruptible()  local
338 	while (timeout && !signal_pending(current))  in msleep_interruptible()
339 		timeout = schedule_timeout_interruptible(timeout);  in msleep_interruptible()
340 	return jiffies_to_msecs(timeout);  in msleep_interruptible()
345  * usleep_range_state - Sleep for an approximate time in a given state
358  * In non-atomic context where the exact wakeup time is flexible, use
360  * responsiveness by avoiding the CPU-hogging busy-wait of udelay().
365 	u64 delta = (u64)(max - min) * NSEC_PER_USEC;  in usleep_range_state()