1 files changed, 171 insertions, 38 deletions

diff --git a/include/linux/kthread.h b/include/linux/kthread.h
index 7dcef3317689..8d27403888ce 100644
--- a/include/linux/kthread.h
+++ b/include/linux/kthread.h
@@ -1,17 +1,31 @@
+/* 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, -1, namefmt, ##arg)
+	kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)
 
 
 struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
@@ -19,6 +33,12 @@ struct task_struct *kthread_create_on_cpu(int (*threadfn)(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).
@@ -37,16 +57,49 @@ struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
 	__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_affine_preferred(struct task_struct *p, const struct cpumask *mask);
 int kthread_stop(struct task_struct *k);
+int kthread_stop_put(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 *probe_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;
@@ -56,16 +109,23 @@ 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()
+ * 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 {
-	spinlock_t		lock;
+	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;
 };
@@ -73,68 +133,141 @@ struct kthread_worker {
 struct kthread_work {
 	struct list_head	node;
 	kthread_work_func_t	func;
-	wait_queue_head_t	done;
 	struct kthread_worker	*worker;
+	/* Number of canceling calls that are running at the moment. */
+	int			canceling;
 };
 
-#define KTHREAD_WORKER_INIT(worker)	{				\
-	.lock = __SPIN_LOCK_UNLOCKED((worker).lock),			\
-	.work_list = LIST_HEAD_INIT((worker).work_list),		\
-	}
+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),							\
-	.done = __WAIT_QUEUE_HEAD_INITIALIZER((work).done),		\
 	}
 
-#define DEFINE_KTHREAD_WORKER(worker)					\
-	struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
+#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)
 
-/*
- * kthread_worker.lock and kthread_work.done need their own lockdep class
- * keys if they are defined on stack with lockdep enabled.  Use the
- * following macros when defining them on stack.
- */
-#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)
-# define KTHREAD_WORK_INIT_ONSTACK(work, fn)				\
-	({ init_kthread_work((&work), fn); work; })
-# define DEFINE_KTHREAD_WORK_ONSTACK(work, fn)				\
-	struct kthread_work work = KTHREAD_WORK_INIT_ONSTACK(work, fn)
-#else
-# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
-# define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) DEFINE_KTHREAD_WORK(work, fn)
-#endif
+#define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn)				\
+	struct kthread_delayed_work dwork =				\
+		KTHREAD_DELAYED_WORK_INIT(dwork, fn)
 
-extern void __init_kthread_worker(struct kthread_worker *worker,
+extern void __kthread_init_worker(struct kthread_worker *worker,
 			const char *name, struct lock_class_key *key);
 
-#define init_kthread_worker(worker)					\
+#define kthread_init_worker(worker)					\
 	do {								\
 		static struct lock_class_key __key;			\
-		__init_kthread_worker((worker), "("#worker")->lock", &__key); \
+		__kthread_init_worker((worker), "("#worker")->lock", &__key); \
 	} while (0)
 
-#define init_kthread_work(work, fn)					\
+#define kthread_init_work(work, fn)					\
 	do {								\
 		memset((work), 0, sizeof(struct kthread_work));		\
 		INIT_LIST_HEAD(&(work)->node);				\
 		(work)->func = (fn);					\
-		init_waitqueue_head(&(work)->done);			\
+	} 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);
 
-bool queue_kthread_work(struct kthread_worker *worker,
+__printf(3, 4)
+struct kthread_worker *kthread_create_worker_on_node(unsigned int flags,
+						     int node,
+						     const char namefmt[], ...);
+
+#define kthread_create_worker(flags, namefmt, ...) \
+	kthread_create_worker_on_node(flags, NUMA_NO_NODE, namefmt, ## __VA_ARGS__);
+
+/**
+ * kthread_run_worker - create and wake a kthread worker.
+ * @flags: flags modifying the default behavior of the worker
+ * @namefmt: printf-style name for the thread.
+ *
+ * Description: Convenient wrapper for kthread_create_worker() followed by
+ * wake_up_process().  Returns the kthread_worker or ERR_PTR(-ENOMEM).
+ */
+#define kthread_run_worker(flags, namefmt, ...)					\
+({										\
+	struct kthread_worker *__kw						\
+		= kthread_create_worker(flags, namefmt, ## __VA_ARGS__);	\
+	if (!IS_ERR(__kw))							\
+		wake_up_process(__kw->task);					\
+	__kw;									\
+})
+
+struct kthread_worker *
+kthread_create_worker_on_cpu(int cpu, unsigned int flags,
+			     const char namefmt[]);
+
+/**
+ * kthread_run_worker_on_cpu - create and wake a cpu bound kthread worker.
+ * @cpu: CPU number
+ * @flags: flags modifying the default behavior of the worker
+ * @namefmt: printf-style name for the thread. Format is restricted
+ *	     to "name.*%u". Code fills in cpu number.
+ *
+ * Description: Convenient wrapper for kthread_create_worker_on_cpu()
+ * followed by wake_up_process().  Returns the kthread_worker or
+ * ERR_PTR(-ENOMEM).
+ */
+static inline struct kthread_worker *
+kthread_run_worker_on_cpu(int cpu, unsigned int flags,
+			  const char namefmt[])
+{
+	struct kthread_worker *kw;
+
+	kw = kthread_create_worker_on_cpu(cpu, flags, namefmt);
+	if (!IS_ERR(kw))
+		wake_up_process(kw->task);
+
+	return kw;
+}
+
+bool kthread_queue_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);
 
+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 */