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- /*
- * cn_queue.c
- *
- * 2004+ 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.
- *
- * 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 struct cn_callback_entry *
- cn_queue_alloc_callback_entry(struct cn_queue_dev *dev, const char *name,
- struct cb_id *id,
- void (*callback)(struct cn_msg *,
- struct netlink_skb_parms *))
- {
- struct cn_callback_entry *cbq;
- cbq = kzalloc(sizeof(*cbq), GFP_KERNEL);
- if (!cbq) {
- pr_err("Failed to create new callback queue.\n");
- return NULL;
- }
- atomic_set(&cbq->refcnt, 1);
- atomic_inc(&dev->refcnt);
- cbq->pdev = dev;
- snprintf(cbq->id.name, sizeof(cbq->id.name), "%s", name);
- memcpy(&cbq->id.id, id, sizeof(struct cb_id));
- cbq->callback = callback;
- return cbq;
- }
- void cn_queue_release_callback(struct cn_callback_entry *cbq)
- {
- if (!atomic_dec_and_test(&cbq->refcnt))
- return;
- atomic_dec(&cbq->pdev->refcnt);
- 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, const char *name,
- struct cb_id *id,
- void (*callback)(struct cn_msg *,
- struct netlink_skb_parms *))
- {
- struct cn_callback_entry *cbq, *__cbq;
- int found = 0;
- cbq = cn_queue_alloc_callback_entry(dev, name, id, callback);
- if (!cbq)
- return -ENOMEM;
- spin_lock_bh(&dev->queue_lock);
- list_for_each_entry(__cbq, &dev->queue_list, callback_entry) {
- if (cn_cb_equal(&__cbq->id.id, id)) {
- found = 1;
- break;
- }
- }
- if (!found)
- list_add_tail(&cbq->callback_entry, &dev->queue_list);
- spin_unlock_bh(&dev->queue_lock);
- if (found) {
- cn_queue_release_callback(cbq);
- return -EINVAL;
- }
- cbq->seq = 0;
- cbq->group = cbq->id.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->id.id, id)) {
- list_del(&cbq->callback_entry);
- found = 1;
- break;
- }
- }
- spin_unlock_bh(&dev->queue_lock);
- if (found)
- cn_queue_release_callback(cbq);
- }
- struct cn_queue_dev *cn_queue_alloc_dev(const 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;
- return dev;
- }
- void cn_queue_free_dev(struct cn_queue_dev *dev)
- {
- struct cn_callback_entry *cbq, *n;
- 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)) {
- pr_info("Waiting for %s to become free: refcnt=%d.\n",
- dev->name, atomic_read(&dev->refcnt));
- msleep(1000);
- }
- kfree(dev);
- dev = NULL;
- }
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