/**
* complete_all: - signals all threads waiting on this completion
* @x: holds the state of this particular completion
*
* This will wake up all threads waiting on this particular completion event.
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
*/
void complete_all(struct completion *x)
{
unsigned long flags;
spin_lock_irqsave(&x->wait.lock, flags);
x->done += UINT_MAX/2;
__wake_up_locked(&x->wait, TASK_NORMAL, 0);
spin_unlock_irqrestore(&x->wait.lock, flags);
}
/**
* complete: - signals a single thread waiting on this completion
* @x: holds the state of this particular completion
*
* This will wake up a single thread waiting on this completion. Threads will be
* awakened in the same order in which they were queued.
*
* See also complete_all(), wait_for_completion() and related routines.
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
*/
void complete(struct completion *x)
{
unsigned long flags;
spin_lock_irqsave(&x->wait.lock, flags);
if (x->done != UINT_MAX)
x->done++;
__wake_up_locked(&x->wait, TASK_NORMAL, 1);
spin_unlock_irqrestore(&x->wait.lock, flags);
}
// ARM10C 20170701
// &kthreadd_done
void complete(struct completion *x)
{
unsigned long flags;
// &x->wait.lock: &(&kthreadd_done)->wait.lock
spin_lock_irqsave(&x->wait.lock, flags);
// spin_lock_irqsave 에서 한일:
// &(&kthreadd_done)->wait.lock 을 이용하여 spin lock 을 수행하고 cpsr을 flags에 저장
// x->done: (&kthreadd_done)->done: 0
x->done++;
// x->done: (&kthreadd_done)->done: 1
// &x->wait: &(&kthreadd_done)->wait, TASK_NORMAL: 3
__wake_up_locked(&x->wait, TASK_NORMAL, 1);
spin_unlock_irqrestore(&x->wait.lock, flags);
// spin_unlock_irqrestore 에서 한일
// &(&kthreadd_done)->wait.lock 을 이용하여 spin unlock 을 수행하고 flags에 저장된 cpsr을 복원
}
