diff options
Diffstat (limited to 'kernel/wait-simple.c')
-rw-r--r-- | kernel/wait-simple.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/kernel/wait-simple.c b/kernel/wait-simple.c new file mode 100644 index 000000000000..9e53eaaa4b68 --- /dev/null +++ b/kernel/wait-simple.c @@ -0,0 +1,63 @@ +/* + * Simple waitqueues without fancy flags and callbacks + * + * (C) 2011 Thomas Gleixner <tglx@linutronix.de> + * + * Based on kernel/wait.c + * + * For licencing details see kernel-base/COPYING + */ +#include <linux/init.h> +#include <linux/export.h> +#include <linux/sched.h> +#include <linux/wait-simple.h> + +void __init_swait_head(struct swait_head *head, struct lock_class_key *key) +{ + raw_spin_lock_init(&head->lock); + lockdep_set_class(&head->lock, key); + INIT_LIST_HEAD(&head->list); +} +EXPORT_SYMBOL_GPL(__init_swait_head); + +void swait_prepare(struct swait_head *head, struct swaiter *w, int state) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&head->lock, flags); + w->task = current; + __swait_enqueue(head, w); + set_current_state(state); + raw_spin_unlock_irqrestore(&head->lock, flags); +} +EXPORT_SYMBOL_GPL(swait_prepare); + +void swait_finish(struct swait_head *head, struct swaiter *w) +{ + unsigned long flags; + + __set_current_state(TASK_RUNNING); + if (w->task) { + raw_spin_lock_irqsave(&head->lock, flags); + __swait_dequeue(w); + raw_spin_unlock_irqrestore(&head->lock, flags); + } +} +EXPORT_SYMBOL_GPL(swait_finish); + +void __swait_wake(struct swait_head *head, unsigned int state) +{ + struct swaiter *curr, *next; + unsigned long flags; + + raw_spin_lock_irqsave(&head->lock, flags); + + list_for_each_entry_safe(curr, next, &head->list, node) { + if (wake_up_state(curr->task, state)) { + __swait_dequeue(curr); + curr->task = NULL; + } + } + + raw_spin_unlock_irqrestore(&head->lock, flags); +} |