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-rw-r--r--drivers/staging/dst/thread_pool.c348
1 files changed, 0 insertions, 348 deletions
diff --git a/drivers/staging/dst/thread_pool.c b/drivers/staging/dst/thread_pool.c
deleted file mode 100644
index 29a82b2602f3..000000000000
--- a/drivers/staging/dst/thread_pool.c
+++ /dev/null
@@ -1,348 +0,0 @@
-/*
- * 2007+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
- * All rights reserved.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
-
-#include <linux/kernel.h>
-#include <linux/dst.h>
-#include <linux/kthread.h>
-#include <linux/slab.h>
-
-/*
- * Thread pool abstraction allows to schedule a work to be performed
- * on behalf of kernel thread. One does not operate with threads itself,
- * instead user provides setup and cleanup callbacks for thread pool itself,
- * and action and cleanup callbacks for each submitted work.
- *
- * Each worker has private data initialized at creation time and data,
- * provided by user at scheduling time.
- *
- * When action is being performed, thread can not be used by other users,
- * instead they will sleep until there is free thread to pick their work.
- */
-struct thread_pool_worker {
- struct list_head worker_entry;
-
- struct task_struct *thread;
-
- struct thread_pool *pool;
-
- int error;
- int has_data;
- int need_exit;
- unsigned int id;
-
- wait_queue_head_t wait;
-
- void *private;
- void *schedule_data;
-
- int (*action)(void *private, void *schedule_data);
- void (*cleanup)(void *private);
-};
-
-static void thread_pool_exit_worker(struct thread_pool_worker *w)
-{
- kthread_stop(w->thread);
-
- w->cleanup(w->private);
- kfree(w);
-}
-
-/*
- * Called to mark thread as ready and allow users to schedule new work.
- */
-static void thread_pool_worker_make_ready(struct thread_pool_worker *w)
-{
- struct thread_pool *p = w->pool;
-
- mutex_lock(&p->thread_lock);
-
- if (!w->need_exit) {
- list_move_tail(&w->worker_entry, &p->ready_list);
- w->has_data = 0;
- mutex_unlock(&p->thread_lock);
-
- wake_up(&p->wait);
- } else {
- p->thread_num--;
- list_del(&w->worker_entry);
- mutex_unlock(&p->thread_lock);
-
- thread_pool_exit_worker(w);
- }
-}
-
-/*
- * Thread action loop: waits until there is new work.
- */
-static int thread_pool_worker_func(void *data)
-{
- struct thread_pool_worker *w = data;
-
- while (!kthread_should_stop()) {
- wait_event_interruptible(w->wait,
- kthread_should_stop() || w->has_data);
-
- if (kthread_should_stop())
- break;
-
- if (!w->has_data)
- continue;
-
- w->action(w->private, w->schedule_data);
- thread_pool_worker_make_ready(w);
- }
-
- return 0;
-}
-
-/*
- * Remove single worker without specifying which one.
- */
-void thread_pool_del_worker(struct thread_pool *p)
-{
- struct thread_pool_worker *w = NULL;
-
- while (!w && p->thread_num) {
- wait_event(p->wait, !list_empty(&p->ready_list) ||
- !p->thread_num);
-
- dprintk("%s: locking list_empty: %d, thread_num: %d.\n",
- __func__, list_empty(&p->ready_list),
- p->thread_num);
-
- mutex_lock(&p->thread_lock);
- if (!list_empty(&p->ready_list)) {
- w = list_first_entry(&p->ready_list,
- struct thread_pool_worker,
- worker_entry);
-
- dprintk("%s: deleting w: %p, thread_num: %d, "
- "list: %p [%p.%p].\n", __func__,
- w, p->thread_num, &p->ready_list,
- p->ready_list.prev, p->ready_list.next);
-
- p->thread_num--;
- list_del(&w->worker_entry);
- }
- mutex_unlock(&p->thread_lock);
- }
-
- if (w)
- thread_pool_exit_worker(w);
- dprintk("%s: deleted w: %p, thread_num: %d.\n",
- __func__, w, p->thread_num);
-}
-
-/*
- * Remove a worker with given ID.
- */
-void thread_pool_del_worker_id(struct thread_pool *p, unsigned int id)
-{
- struct thread_pool_worker *w;
- int found = 0;
-
- mutex_lock(&p->thread_lock);
- list_for_each_entry(w, &p->ready_list, worker_entry) {
- if (w->id == id) {
- found = 1;
- p->thread_num--;
- list_del(&w->worker_entry);
- break;
- }
- }
-
- if (!found) {
- list_for_each_entry(w, &p->active_list, worker_entry) {
- if (w->id == id) {
- w->need_exit = 1;
- break;
- }
- }
- }
- mutex_unlock(&p->thread_lock);
-
- if (found)
- thread_pool_exit_worker(w);
-}
-
-/*
- * Add new worker thread with given parameters.
- * If initialization callback fails, return error.
- */
-int thread_pool_add_worker(struct thread_pool *p,
- char *name,
- unsigned int id,
- void *(*init)(void *private),
- void (*cleanup)(void *private),
- void *private)
-{
- struct thread_pool_worker *w;
- int err = -ENOMEM;
-
- w = kzalloc(sizeof(struct thread_pool_worker), GFP_KERNEL);
- if (!w)
- goto err_out_exit;
-
- w->pool = p;
- init_waitqueue_head(&w->wait);
- w->cleanup = cleanup;
- w->id = id;
-
- w->thread = kthread_run(thread_pool_worker_func, w, "%s", name);
- if (IS_ERR(w->thread)) {
- err = PTR_ERR(w->thread);
- goto err_out_free;
- }
-
- w->private = init(private);
- if (IS_ERR(w->private)) {
- err = PTR_ERR(w->private);
- goto err_out_stop_thread;
- }
-
- mutex_lock(&p->thread_lock);
- list_add_tail(&w->worker_entry, &p->ready_list);
- p->thread_num++;
- mutex_unlock(&p->thread_lock);
-
- return 0;
-
-err_out_stop_thread:
- kthread_stop(w->thread);
-err_out_free:
- kfree(w);
-err_out_exit:
- return err;
-}
-
-/*
- * Destroy the whole pool.
- */
-void thread_pool_destroy(struct thread_pool *p)
-{
- while (p->thread_num) {
- dprintk("%s: num: %d.\n", __func__, p->thread_num);
- thread_pool_del_worker(p);
- }
-
- kfree(p);
-}
-
-/*
- * Create a pool with given number of threads.
- * They will have sequential IDs started from zero.
- */
-struct thread_pool *thread_pool_create(int num, char *name,
- void *(*init)(void *private),
- void (*cleanup)(void *private),
- void *private)
-{
- struct thread_pool_worker *w, *tmp;
- struct thread_pool *p;
- int err = -ENOMEM;
- int i;
-
- p = kzalloc(sizeof(struct thread_pool), GFP_KERNEL);
- if (!p)
- goto err_out_exit;
-
- init_waitqueue_head(&p->wait);
- mutex_init(&p->thread_lock);
- INIT_LIST_HEAD(&p->ready_list);
- INIT_LIST_HEAD(&p->active_list);
- p->thread_num = 0;
-
- for (i = 0; i < num; ++i) {
- err = thread_pool_add_worker(p, name, i, init,
- cleanup, private);
- if (err)
- goto err_out_free_all;
- }
-
- return p;
-
-err_out_free_all:
- list_for_each_entry_safe(w, tmp, &p->ready_list, worker_entry) {
- list_del(&w->worker_entry);
- thread_pool_exit_worker(w);
- }
- kfree(p);
-err_out_exit:
- return ERR_PTR(err);
-}
-
-/*
- * Schedule execution of the action on a given thread,
- * provided ID pointer has to match previously stored
- * private data.
- */
-int thread_pool_schedule_private(struct thread_pool *p,
- int (*setup)(void *private, void *data),
- int (*action)(void *private, void *data),
- void *data, long timeout, void *id)
-{
- struct thread_pool_worker *w, *tmp, *worker = NULL;
- int err = 0;
-
- while (!worker && !err) {
- timeout = wait_event_interruptible_timeout(p->wait,
- !list_empty(&p->ready_list),
- timeout);
-
- if (!timeout) {
- err = -ETIMEDOUT;
- break;
- }
-
- worker = NULL;
- mutex_lock(&p->thread_lock);
- list_for_each_entry_safe(w, tmp, &p->ready_list, worker_entry) {
- if (id && id != w->private)
- continue;
-
- worker = w;
-
- list_move_tail(&w->worker_entry, &p->active_list);
-
- err = setup(w->private, data);
- if (!err) {
- w->schedule_data = data;
- w->action = action;
- w->has_data = 1;
- wake_up(&w->wait);
- } else {
- list_move_tail(&w->worker_entry,
- &p->ready_list);
- }
-
- break;
- }
- mutex_unlock(&p->thread_lock);
- }
-
- return err;
-}
-
-/*
- * Schedule execution on arbitrary thread from the pool.
- */
-int thread_pool_schedule(struct thread_pool *p,
- int (*setup)(void *private, void *data),
- int (*action)(void *private, void *data),
- void *data, long timeout)
-{
- return thread_pool_schedule_private(p, setup,
- action, data, timeout, NULL);
-}