diff options
Diffstat (limited to 'drivers/connector/cn_queue.c')
| -rw-r--r-- | drivers/connector/cn_queue.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/drivers/connector/cn_queue.c b/drivers/connector/cn_queue.c new file mode 100644 index 00000000000..966632182e2 --- /dev/null +++ b/drivers/connector/cn_queue.c @@ -0,0 +1,173 @@ +/* + * cn_queue.c + * + * 2004-2005 Copyright (c) Evgeniy Polyakov <johnpol@2ka.mipt.ru> + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/list.h> +#include <linux/workqueue.h> +#include <linux/spinlock.h> +#include <linux/slab.h> +#include <linux/skbuff.h> +#include <linux/suspend.h> +#include <linux/connector.h> +#include <linux/delay.h> + +static void cn_queue_wrapper(void *data) +{ + struct cn_callback_entry *cbq = data; + + cbq->cb->callback(cbq->cb->priv); + cbq->destruct_data(cbq->ddata); + cbq->ddata = NULL; +} + +static struct cn_callback_entry *cn_queue_alloc_callback_entry(struct cn_callback *cb) +{ + struct cn_callback_entry *cbq; + + cbq = kzalloc(sizeof(*cbq), GFP_KERNEL); + if (!cbq) { + printk(KERN_ERR "Failed to create new callback queue.\n"); + return NULL; + } + + cbq->cb = cb; + INIT_WORK(&cbq->work, &cn_queue_wrapper, cbq); + return cbq; +} + +static void cn_queue_free_callback(struct cn_callback_entry *cbq) +{ + cancel_delayed_work(&cbq->work); + flush_workqueue(cbq->pdev->cn_queue); + + kfree(cbq); +} + +int cn_cb_equal(struct cb_id *i1, struct cb_id *i2) +{ + return ((i1->idx == i2->idx) && (i1->val == i2->val)); +} + +int cn_queue_add_callback(struct cn_queue_dev *dev, struct cn_callback *cb) +{ + struct cn_callback_entry *cbq, *__cbq; + int found = 0; + + cbq = cn_queue_alloc_callback_entry(cb); + if (!cbq) + return -ENOMEM; + + atomic_inc(&dev->refcnt); + cbq->pdev = dev; + + spin_lock_bh(&dev->queue_lock); + list_for_each_entry(__cbq, &dev->queue_list, callback_entry) { + if (cn_cb_equal(&__cbq->cb->id, &cb->id)) { + found = 1; + break; + } + } + if (!found) + list_add_tail(&cbq->callback_entry, &dev->queue_list); + spin_unlock_bh(&dev->queue_lock); + + if (found) { + atomic_dec(&dev->refcnt); + cn_queue_free_callback(cbq); + return -EINVAL; + } + + cbq->nls = dev->nls; + cbq->seq = 0; + cbq->group = cbq->cb->id.idx; + + return 0; +} + +void cn_queue_del_callback(struct cn_queue_dev *dev, struct cb_id *id) +{ + struct cn_callback_entry *cbq, *n; + int found = 0; + + spin_lock_bh(&dev->queue_lock); + list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) { + if (cn_cb_equal(&cbq->cb->id, id)) { + list_del(&cbq->callback_entry); + found = 1; + break; + } + } + spin_unlock_bh(&dev->queue_lock); + + if (found) { + cn_queue_free_callback(cbq); + atomic_dec_and_test(&dev->refcnt); + } +} + +struct cn_queue_dev *cn_queue_alloc_dev(char *name, struct sock *nls) +{ + struct cn_queue_dev *dev; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return NULL; + + snprintf(dev->name, sizeof(dev->name), "%s", name); + atomic_set(&dev->refcnt, 0); + INIT_LIST_HEAD(&dev->queue_list); + spin_lock_init(&dev->queue_lock); + + dev->nls = nls; + dev->netlink_groups = 0; + + dev->cn_queue = create_workqueue(dev->name); + if (!dev->cn_queue) { + kfree(dev); + return NULL; + } + + return dev; +} + +void cn_queue_free_dev(struct cn_queue_dev *dev) +{ + struct cn_callback_entry *cbq, *n; + + flush_workqueue(dev->cn_queue); + destroy_workqueue(dev->cn_queue); + + spin_lock_bh(&dev->queue_lock); + list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) + list_del(&cbq->callback_entry); + spin_unlock_bh(&dev->queue_lock); + + while (atomic_read(&dev->refcnt)) { + printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n", + dev->name, atomic_read(&dev->refcnt)); + msleep(1000); + } + + kfree(dev); + dev = NULL; +} |