/* * 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> void cn_queue_wrapper(void *data) { struct cn_callback_data *d = data; d->callback(d->callback_priv); d->destruct_data(d->ddata); d->ddata = NULL; kfree(d->free); } static struct cn_callback_entry *cn_queue_alloc_callback_entry(char *name, struct cb_id *id, void (*callback)(void *)) { 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; } snprintf(cbq->id.name, sizeof(cbq->id.name), "%s", name); memcpy(&cbq->id.id, id, sizeof(struct cb_id)); cbq->data.callback = callback; INIT_WORK(&cbq->work, &cn_queue_wrapper, &cbq->data); 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, char *name, struct cb_id *id, void (*callback)(void *)) { struct cn_callback_entry *cbq, *__cbq; int found = 0; cbq = cn_queue_alloc_callback_entry(name, id, callback); 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->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) { atomic_dec(&dev->refcnt); cn_queue_free_callback(cbq); return -EINVAL; } cbq->nls = dev->nls; 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_free_callback(cbq); atomic_dec(&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; }