1 files changed, 226 insertions, 0 deletions
diff --git a/include/linux/kthread.h b/include/linux/kthread.h
new file mode 100644
index 000000000..2c30ade43
--- /dev/null
+++ b/include/linux/kthread.h
@@ -0,0 +1,226 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#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>
+
+struct mm_struct;
+
+__printf(4, 5)
+struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
+					   void *data,
+					   int node,
+					   const char namefmt[], ...);
+
+/**
+ * kthread_create - create a kthread on the current node
+ * @threadfn: the function to run in the thread
+ * @data: data pointer for @threadfn()
+ * @namefmt: printf-style format string for the thread name
+ * @arg: arguments for @namefmt.
+ *
+ * This macro will create a kthread on the current node, leaving it in
+ * the stopped state.  This is just a helper for kthread_create_on_node();
+ * see the documentation there for more details.
+ */
+#define kthread_create(threadfn, data, namefmt, arg...) \
+	kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)
+
+
+struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
+					  void *data,
+					  unsigned int cpu,
+					  const char *namefmt);
+
+void get_kthread_comm(char *buf, size_t buf_size, struct task_struct *tsk);
+bool set_kthread_struct(struct task_struct *p);
+
+void kthread_set_per_cpu(struct task_struct *k, int cpu);
+bool kthread_is_per_cpu(struct task_struct *k);
+
+/**
+ * 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;								   \
+})
+
+/**
+ * kthread_run_on_cpu - create and wake a cpu bound thread.
+ * @threadfn: the function to run until signal_pending(current).
+ * @data: data ptr for @threadfn.
+ * @cpu: The cpu on which the thread should be bound,
+ * @namefmt: printf-style name for the thread. Format is restricted
+ *	     to "name.*%u". Code fills in cpu number.
+ *
+ * Description: Convenient wrapper for kthread_create_on_cpu()
+ * followed by wake_up_process().  Returns the kthread or
+ * ERR_PTR(-ENOMEM).
+ */
+static inline struct task_struct *
+kthread_run_on_cpu(int (*threadfn)(void *data), void *data,
+			unsigned int cpu, const char *namefmt)
+{
+	struct task_struct *p;
+
+	p = kthread_create_on_cpu(threadfn, data, cpu, namefmt);
+	if (!IS_ERR(p))
+		wake_up_process(p);
+
+	return p;
+}
+
+void free_kthread_struct(struct task_struct *k);
+void kthread_bind(struct task_struct *k, unsigned int cpu);
+void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask);
+int kthread_stop(struct task_struct *k);
+bool kthread_should_stop(void);
+bool kthread_should_park(void);
+bool kthread_should_stop_or_park(void);
+bool kthread_freezable_should_stop(bool *was_frozen);
+void *kthread_func(struct task_struct *k);
+void *kthread_data(struct task_struct *k);
+void *kthread_probe_data(struct task_struct *k);
+int kthread_park(struct task_struct *k);
+void kthread_unpark(struct task_struct *k);
+void kthread_parkme(void);
+void kthread_exit(long result) __noreturn;
+void kthread_complete_and_exit(struct completion *, long) __noreturn;
+
+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/kthread_flush_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);
+void kthread_delayed_work_timer_fn(struct timer_list *t);
+
+enum {
+	KTW_FREEZABLE		= 1 << 0,	/* freeze during suspend */
+};
+
+struct kthread_worker {
+	unsigned int		flags;
+	raw_spinlock_t		lock;
+	struct list_head	work_list;
+	struct list_head	delayed_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;
+	/* Number of canceling calls that are running at the moment. */
+	int			canceling;
+};
+
+struct kthread_delayed_work {
+	struct kthread_work work;
+	struct timer_list timer;
+};
+
+#define KTHREAD_WORK_INIT(work, fn)	{				\
+	.node = LIST_HEAD_INIT((work).node),				\
+	.func = (fn),							\
+	}
+
+#define KTHREAD_DELAYED_WORK_INIT(dwork, fn) {				\
+	.work = KTHREAD_WORK_INIT((dwork).work, (fn)),			\
+	.timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\
+				     TIMER_IRQSAFE),			\
+	}
+
+#define DEFINE_KTHREAD_WORK(work, fn)					\
+	struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
+
+#define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn)				\
+	struct kthread_delayed_work dwork =				\
+		KTHREAD_DELAYED_WORK_INIT(dwork, fn)
+
+extern void __kthread_init_worker(struct kthread_worker *worker,
+			const char *name, struct lock_class_key *key);
+
+#define kthread_init_worker(worker)					\
+	do {								\
+		static struct lock_class_key __key;			\
+		__kthread_init_worker((worker), "("#worker")->lock", &__key); \
+	} while (0)
+
+#define kthread_init_work(work, fn)					\
+	do {								\
+		memset((work), 0, sizeof(struct kthread_work));		\
+		INIT_LIST_HEAD(&(work)->node);				\
+		(work)->func = (fn);					\
+	} while (0)
+
+#define kthread_init_delayed_work(dwork, fn)				\
+	do {								\
+		kthread_init_work(&(dwork)->work, (fn));		\
+		timer_setup(&(dwork)->timer,				\
+			     kthread_delayed_work_timer_fn,		\
+			     TIMER_IRQSAFE);				\
+	} while (0)
+
+int kthread_worker_fn(void *worker_ptr);
+
+__printf(2, 3)
+struct kthread_worker *
+kthread_create_worker(unsigned int flags, const char namefmt[], ...);
+
+__printf(3, 4) struct kthread_worker *
+kthread_create_worker_on_cpu(int cpu, unsigned int flags,
+			     const char namefmt[], ...);
+
+bool kthread_queue_work(struct kthread_worker *worker,
+			struct kthread_work *work);
+
+bool kthread_queue_delayed_work(struct kthread_worker *worker,
+				struct kthread_delayed_work *dwork,
+				unsigned long delay);
+
+bool kthread_mod_delayed_work(struct kthread_worker *worker,
+			      struct kthread_delayed_work *dwork,
+			      unsigned long delay);
+
+void kthread_flush_work(struct kthread_work *work);
+void kthread_flush_worker(struct kthread_worker *worker);
+
+bool kthread_cancel_work_sync(struct kthread_work *work);
+bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);
+
+void kthread_destroy_worker(struct kthread_worker *worker);
+
+void kthread_use_mm(struct mm_struct *mm);
+void kthread_unuse_mm(struct mm_struct *mm);
+
+struct cgroup_subsys_state;
+
+#ifdef CONFIG_BLK_CGROUP
+void kthread_associate_blkcg(struct cgroup_subsys_state *css);
+struct cgroup_subsys_state *kthread_blkcg(void);
+#else
+static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { }
+#endif
+#endif /* _LINUX_KTHREAD_H */