+++ /dev/null
-/* Kernel thread helper functions.
- * Copyright (C) 2004 IBM Corporation, Rusty Russell.
- *
- * Creation is done via kthreadd, so that we get a clean environment
- * even if we're invoked from userspace (think modprobe, hotplug cpu,
- * etc.).
- */
-#include <linux/sched.h>
-#include <linux/kthread.h>
-#include <linux/completion.h>
-#include <linux/err.h>
-#include <linux/cpuset.h>
-#include <linux/unistd.h>
-#include <linux/file.h>
-#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/slab.h>
-#include <linux/freezer.h>
-#include <trace/events/sched.h>
-
-void __init_kthread_worker(struct kthread_worker *worker,
- const char *name,
- struct lock_class_key *key)
-{
- spin_lock_init(&worker->lock);
- lockdep_set_class_and_name(&worker->lock, key, name);
- INIT_LIST_HEAD(&worker->work_list);
- worker->task = NULL;
-}
-EXPORT_SYMBOL_GPL(__init_kthread_worker);
-
-/**
- * kthread_worker_fn - kthread function to process kthread_worker
- * @worker_ptr: pointer to initialized kthread_worker
- *
- * This function can be used as @threadfn to kthread_create() or
- * kthread_run() with @worker_ptr argument pointing to an initialized
- * kthread_worker. The started kthread will process work_list until
- * the it is stopped with kthread_stop(). A kthread can also call
- * this function directly after extra initialization.
- *
- * Different kthreads can be used for the same kthread_worker as long
- * as there's only one kthread attached to it at any given time. A
- * kthread_worker without an attached kthread simply collects queued
- * kthread_works.
- */
-int kthread_worker_fn(void *worker_ptr)
-{
- struct kthread_worker *worker = worker_ptr;
- struct kthread_work *work;
-
- WARN_ON(worker->task);
- worker->task = current;
-repeat:
- set_current_state(TASK_INTERRUPTIBLE); /* mb paired w/ kthread_stop */
-
- if (kthread_should_stop()) {
- __set_current_state(TASK_RUNNING);
- spin_lock_irq(&worker->lock);
- worker->task = NULL;
- spin_unlock_irq(&worker->lock);
- return 0;
- }
-
- work = NULL;
- spin_lock_irq(&worker->lock);
- if (!list_empty(&worker->work_list)) {
- work = list_first_entry(&worker->work_list,
- struct kthread_work, node);
- list_del_init(&work->node);
- }
- spin_unlock_irq(&worker->lock);
-
- if (work) {
- __set_current_state(TASK_RUNNING);
- work->func(work);
- smp_wmb(); /* wmb worker-b0 paired with flush-b1 */
- work->done_seq = work->queue_seq;
- smp_mb(); /* mb worker-b1 paired with flush-b0 */
- if (atomic_read(&work->flushing))
- wake_up_all(&work->done);
- } else if (!freezing(current))
- schedule();
-
- try_to_freeze();
- goto repeat;
-}
-EXPORT_SYMBOL_GPL(kthread_worker_fn);
-
-/**
- * queue_kthread_work - queue a kthread_work
- * @worker: target kthread_worker
- * @work: kthread_work to queue
- *
- * Queue @work to work processor @task for async execution. @task
- * must have been created with kthread_worker_create(). Returns %true
- * if @work was successfully queued, %false if it was already pending.
- */
-bool queue_kthread_work(struct kthread_worker *worker,
- struct kthread_work *work)
-{
- bool ret = false;
- unsigned long flags;
-
- spin_lock_irqsave(&worker->lock, flags);
- if (list_empty(&work->node)) {
- list_add_tail(&work->node, &worker->work_list);
- work->queue_seq++;
- if (likely(worker->task))
- wake_up_process(worker->task);
- ret = true;
- }
- spin_unlock_irqrestore(&worker->lock, flags);
- return ret;
-}
-EXPORT_SYMBOL_GPL(queue_kthread_work);
-
-/**
- * flush_kthread_work - flush a kthread_work
- * @work: work to flush
- *
- * If @work is queued or executing, wait for it to finish execution.
- */
-void flush_kthread_work(struct kthread_work *work)
-{
- int seq = work->queue_seq;
-
- atomic_inc(&work->flushing);
-
- /*
- * mb flush-b0 paired with worker-b1, to make sure either
- * worker sees the above increment or we see done_seq update.
- */
- smp_mb__after_atomic_inc();
-
- /* A - B <= 0 tests whether B is in front of A regardless of overflow */
- wait_event(work->done, seq - work->done_seq <= 0);
- atomic_dec(&work->flushing);
-
- /*
- * rmb flush-b1 paired with worker-b0, to make sure our caller
- * sees every change made by work->func().
- */
- smp_mb__after_atomic_dec();
-}
-EXPORT_SYMBOL_GPL(flush_kthread_work);
-
-struct kthread_flush_work {
- struct kthread_work work;
- struct completion done;
-};
-
-static void kthread_flush_work_fn(struct kthread_work *work)
-{
- struct kthread_flush_work *fwork =
- container_of(work, struct kthread_flush_work, work);
- complete(&fwork->done);
-}
-
-/**
- * flush_kthread_worker - flush all current works on a kthread_worker
- * @worker: worker to flush
- *
- * Wait until all currently executing or pending works on @worker are
- * finished.
- */
-void flush_kthread_worker(struct kthread_worker *worker)
-{
- struct kthread_flush_work fwork = {
- KTHREAD_WORK_INIT(fwork.work, kthread_flush_work_fn),
- COMPLETION_INITIALIZER_ONSTACK(fwork.done),
- };
-
- queue_kthread_work(worker, &fwork.work);
- wait_for_completion(&fwork.done);
-}
-EXPORT_SYMBOL_GPL(flush_kthread_worker);
+++ /dev/null
-/*
- * 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().
- *
- * A kthread_work can't be freed while it is executing.
- */
-#ifndef BACKPORT_LINUX_KTHREAD_H
-#define BACKPORT_LINUX_KTHREAD_H
-
-#include <linux/version.h>
-
-#include_next <linux/kthread.h>
-
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,35))
-
-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 {
- struct list_head node;
- kthread_work_func_t func;
- wait_queue_head_t done;
- atomic_t flushing;
- int queue_seq;
- int done_seq;
-};
-
-#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), \
- .done = __WAIT_QUEUE_HEAD_INITIALIZER((work).done), \
- .flushing = ATOMIC_INIT(0), \
- }
-
-#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 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
-
-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); \
- init_waitqueue_head(&(work)->done); \
- } 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_VERSION_CODE < 2.6.35 */
-
-#if (LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,38))
-/*
- * Kernels between 2.6.36 and 2.6.38 have the above functions but still lack the
- * following.
- */
-#define kthread_create_on_node(threadfn, data, node, namefmt, arg...) \
- kthread_create(threadfn, data, namefmt, ##arg)
-
-#endif /* LINUX_VERSION_CODE < 2.6.38 */
-
-#endif /* _LINUX_KTHREAD_H */
-