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-rw-r--r--kernel/Makefile2
-rw-r--r--kernel/wait-simple.c68
2 files changed, 69 insertions, 1 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index 7fc87d5..b3ff0a8 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -10,7 +10,7 @@ obj-y = fork.o exec_domain.o panic.o \
kthread.o wait.o sys_ni.o posix-cpu-timers.o \
hrtimer.o nsproxy.o srcu.o semaphore.o \
notifier.o ksysfs.o cred.o reboot.o \
- async.o range.o groups.o lglock.o smpboot.o
+ async.o range.o groups.o lglock.o smpboot.o wait-simple.o
ifdef CONFIG_FUNCTION_TRACER
# Do not trace debug files and internal ftrace files
diff --git a/kernel/wait-simple.c b/kernel/wait-simple.c
new file mode 100644
index 0000000..040d714
--- /dev/null
+++ b/kernel/wait-simple.c
@@ -0,0 +1,68 @@
+/*
+ * 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(__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;
+ if (list_empty(&w->node))
+ __swait_enqueue(head, w);
+ set_current_state(state);
+ raw_spin_unlock_irqrestore(&head->lock, flags);
+}
+EXPORT_SYMBOL(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(swait_finish);
+
+int __swait_wake(struct swait_head *head, unsigned int state)
+{
+ struct swaiter *curr, *next;
+ unsigned long flags;
+ int woken = 0;
+
+ 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;
+ woken++;
+ }
+ }
+
+ raw_spin_unlock_irqrestore(&head->lock, flags);
+ return woken;
+}
+EXPORT_SYMBOL(__swait_wake);