Initial import

1 files changed, 131 insertions, 0 deletions

diff --git a/include/linux/kthread.h b/include/linux/kthread.h
new file mode 100644
index 000000000..13d55206c
--- /dev/null
+++ b/include/linux/kthread.h
@@ -0,0 +1,131 @@
+#ifndef _LINUX_KTHREAD_H
+#define _LINUX_KTHREAD_H
+/* Simple interface for creating and stopping kernel threads without mess. */
+#include <linux/err.h>
+#include <linux/sched.h>
+
+__printf(4, 5)
+struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
+					   void *data,
+					   int node,
+					   const char namefmt[], ...);
+
+#define kthread_create(threadfn, data, namefmt, arg...) \
+	kthread_create_on_node(threadfn, data, -1, namefmt, ##arg)
+
+
+struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
+					  void *data,
+					  unsigned int cpu,
+					  const char *namefmt);
+
+/**
+ * kthread_run - create and wake a thread.
+ * @threadfn: the function to run until signal_pending(current).
+ * @data: data ptr for @threadfn.
+ * @namefmt: printf-style name for the thread.
+ *
+ * Description: Convenient wrapper for kthread_create() followed by
+ * wake_up_process().  Returns the kthread or ERR_PTR(-ENOMEM).
+ */
+#define kthread_run(threadfn, data, namefmt, ...)			   \
+({									   \
+	struct task_struct *__k						   \
+		= kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
+	if (!IS_ERR(__k))						   \
+		wake_up_process(__k);					   \
+	__k;								   \
+})
+
+void kthread_bind(struct task_struct *k, unsigned int cpu);
+int kthread_stop(struct task_struct *k);
+bool kthread_should_stop(void);
+bool kthread_should_park(void);
+bool kthread_freezable_should_stop(bool *was_frozen);
+void *kthread_data(struct task_struct *k);
+void *probe_kthread_data(struct task_struct *k);
+int kthread_park(struct task_struct *k);
+void kthread_unpark(struct task_struct *k);
+void kthread_parkme(void);
+
+int kthreadd(void *unused);
+extern struct task_struct *kthreadd_task;
+extern int tsk_fork_get_node(struct task_struct *tsk);
+
+/*
+ * Simple work processor based on kthread.
+ *
+ * This provides easier way to make use of kthreads.  A kthread_work
+ * can be queued and flushed using queue/flush_kthread_work()
+ * respectively.  Queued kthread_works are processed by a kthread
+ * running kthread_worker_fn().
+ */
+struct kthread_work;
+typedef void (*kthread_work_func_t)(struct kthread_work *work);
+
+struct kthread_worker {
+	spinlock_t		lock;
+	struct list_head	work_list;
+	struct task_struct	*task;
+	struct kthread_work	*current_work;
+};
+
+struct kthread_work {
+	struct list_head	node;
+	kthread_work_func_t	func;
+	struct kthread_worker	*worker;
+};
+
+#define KTHREAD_WORKER_INIT(worker)	{				\
+	.lock = __SPIN_LOCK_UNLOCKED((worker).lock),			\
+	.work_list = LIST_HEAD_INIT((worker).work_list),		\
+	}
+
+#define KTHREAD_WORK_INIT(work, fn)	{				\
+	.node = LIST_HEAD_INIT((work).node),				\
+	.func = (fn),							\
+	}
+
+#define DEFINE_KTHREAD_WORKER(worker)					\
+	struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
+
+#define DEFINE_KTHREAD_WORK(work, fn)					\
+	struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
+
+/*
+ * kthread_worker.lock needs its own lockdep class key when defined on
+ * stack with lockdep enabled.  Use the following macros in such cases.
+ */
+#ifdef CONFIG_LOCKDEP
+# define KTHREAD_WORKER_INIT_ONSTACK(worker)				\
+	({ init_kthread_worker(&worker); worker; })
+# define DEFINE_KTHREAD_WORKER_ONSTACK(worker)				\
+	struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)
+#else
+# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
+#endif
+
+extern void __init_kthread_worker(struct kthread_worker *worker,
+			const char *name, struct lock_class_key *key);
+
+#define init_kthread_worker(worker)					\
+	do {								\
+		static struct lock_class_key __key;			\
+		__init_kthread_worker((worker), "("#worker")->lock", &__key); \
+	} while (0)
+
+#define init_kthread_work(work, fn)					\
+	do {								\
+		memset((work), 0, sizeof(struct kthread_work));		\
+		INIT_LIST_HEAD(&(work)->node);				\
+		(work)->func = (fn);					\
+	} while (0)
+
+int kthread_worker_fn(void *worker_ptr);
+
+bool queue_kthread_work(struct kthread_worker *worker,
+			struct kthread_work *work);
+void flush_kthread_work(struct kthread_work *work);
+void flush_kthread_worker(struct kthread_worker *worker);
+
+#endif /* _LINUX_KTHREAD_H */