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Evgeniy Polyakov7672d0b2005-09-11 19:15:07 -07001/*
2 * cn_queue.c
3 *
4 * 2004-2005 Copyright (c) Evgeniy Polyakov <johnpol@2ka.mipt.ru>
5 * All rights reserved.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 *
21 */
22
23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/list.h>
26#include <linux/workqueue.h>
27#include <linux/spinlock.h>
28#include <linux/slab.h>
29#include <linux/skbuff.h>
30#include <linux/suspend.h>
31#include <linux/connector.h>
32#include <linux/delay.h>
33
David Howellsc4028952006-11-22 14:57:56 +000034void cn_queue_wrapper(struct work_struct *work)
Evgeniy Polyakov7672d0b2005-09-11 19:15:07 -070035{
David Howellsc4028952006-11-22 14:57:56 +000036 struct cn_callback_entry *cbq =
Evgeniy Polyakova240d9f2006-12-18 01:53:58 -080037 container_of(work, struct cn_callback_entry, work);
David Howellsc4028952006-11-22 14:57:56 +000038 struct cn_callback_data *d = &cbq->data;
Evgeniy Polyakov7672d0b2005-09-11 19:15:07 -070039
Evgeniy Polyakovacd042b2005-09-26 15:06:50 -070040 d->callback(d->callback_priv);
41
42 d->destruct_data(d->ddata);
43 d->ddata = NULL;
44
45 kfree(d->free);
Evgeniy Polyakov7672d0b2005-09-11 19:15:07 -070046}
47
Evgeniy Polyakovacd042b2005-09-26 15:06:50 -070048static struct cn_callback_entry *cn_queue_alloc_callback_entry(char *name, struct cb_id *id, void (*callback)(void *))
Evgeniy Polyakov7672d0b2005-09-11 19:15:07 -070049{
50 struct cn_callback_entry *cbq;
51
52 cbq = kzalloc(sizeof(*cbq), GFP_KERNEL);
53 if (!cbq) {
54 printk(KERN_ERR "Failed to create new callback queue.\n");
55 return NULL;
56 }
57
Evgeniy Polyakovacd042b2005-09-26 15:06:50 -070058 snprintf(cbq->id.name, sizeof(cbq->id.name), "%s", name);
59 memcpy(&cbq->id.id, id, sizeof(struct cb_id));
60 cbq->data.callback = callback;
61
Evgeniy Polyakova240d9f2006-12-18 01:53:58 -080062 INIT_WORK(&cbq->work, &cn_queue_wrapper);
Evgeniy Polyakov7672d0b2005-09-11 19:15:07 -070063 return cbq;
64}
65
66static void cn_queue_free_callback(struct cn_callback_entry *cbq)
67{
Evgeniy Polyakov7672d0b2005-09-11 19:15:07 -070068 flush_workqueue(cbq->pdev->cn_queue);
69
70 kfree(cbq);
71}
72
73int cn_cb_equal(struct cb_id *i1, struct cb_id *i2)
74{
75 return ((i1->idx == i2->idx) && (i1->val == i2->val));
76}
77
Evgeniy Polyakovacd042b2005-09-26 15:06:50 -070078int cn_queue_add_callback(struct cn_queue_dev *dev, char *name, struct cb_id *id, void (*callback)(void *))
Evgeniy Polyakov7672d0b2005-09-11 19:15:07 -070079{
80 struct cn_callback_entry *cbq, *__cbq;
81 int found = 0;
82
Evgeniy Polyakovacd042b2005-09-26 15:06:50 -070083 cbq = cn_queue_alloc_callback_entry(name, id, callback);
Evgeniy Polyakov7672d0b2005-09-11 19:15:07 -070084 if (!cbq)
85 return -ENOMEM;
86
87 atomic_inc(&dev->refcnt);
88 cbq->pdev = dev;
89
90 spin_lock_bh(&dev->queue_lock);
91 list_for_each_entry(__cbq, &dev->queue_list, callback_entry) {
Evgeniy Polyakovacd042b2005-09-26 15:06:50 -070092 if (cn_cb_equal(&__cbq->id.id, id)) {
Evgeniy Polyakov7672d0b2005-09-11 19:15:07 -070093 found = 1;
94 break;
95 }
96 }
97 if (!found)
98 list_add_tail(&cbq->callback_entry, &dev->queue_list);
99 spin_unlock_bh(&dev->queue_lock);
100
101 if (found) {
102 atomic_dec(&dev->refcnt);
103 cn_queue_free_callback(cbq);
104 return -EINVAL;
105 }
106
107 cbq->nls = dev->nls;
108 cbq->seq = 0;
Evgeniy Polyakovacd042b2005-09-26 15:06:50 -0700109 cbq->group = cbq->id.id.idx;
Evgeniy Polyakov7672d0b2005-09-11 19:15:07 -0700110
111 return 0;
112}
113
114void cn_queue_del_callback(struct cn_queue_dev *dev, struct cb_id *id)
115{
116 struct cn_callback_entry *cbq, *n;
117 int found = 0;
118
119 spin_lock_bh(&dev->queue_lock);
120 list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) {
Evgeniy Polyakovacd042b2005-09-26 15:06:50 -0700121 if (cn_cb_equal(&cbq->id.id, id)) {
Evgeniy Polyakov7672d0b2005-09-11 19:15:07 -0700122 list_del(&cbq->callback_entry);
123 found = 1;
124 break;
125 }
126 }
127 spin_unlock_bh(&dev->queue_lock);
128
129 if (found) {
130 cn_queue_free_callback(cbq);
Andreas Schwabcec6f7f2006-06-05 21:21:57 -0700131 atomic_dec(&dev->refcnt);
Evgeniy Polyakov7672d0b2005-09-11 19:15:07 -0700132 }
133}
134
135struct cn_queue_dev *cn_queue_alloc_dev(char *name, struct sock *nls)
136{
137 struct cn_queue_dev *dev;
138
139 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
140 if (!dev)
141 return NULL;
142
143 snprintf(dev->name, sizeof(dev->name), "%s", name);
144 atomic_set(&dev->refcnt, 0);
145 INIT_LIST_HEAD(&dev->queue_list);
146 spin_lock_init(&dev->queue_lock);
147
148 dev->nls = nls;
149 dev->netlink_groups = 0;
150
151 dev->cn_queue = create_workqueue(dev->name);
152 if (!dev->cn_queue) {
153 kfree(dev);
154 return NULL;
155 }
156
157 return dev;
158}
159
160void cn_queue_free_dev(struct cn_queue_dev *dev)
161{
162 struct cn_callback_entry *cbq, *n;
163
164 flush_workqueue(dev->cn_queue);
165 destroy_workqueue(dev->cn_queue);
166
167 spin_lock_bh(&dev->queue_lock);
168 list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry)
169 list_del(&cbq->callback_entry);
170 spin_unlock_bh(&dev->queue_lock);
171
172 while (atomic_read(&dev->refcnt)) {
173 printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
174 dev->name, atomic_read(&dev->refcnt));
175 msleep(1000);
176 }
177
178 kfree(dev);
179 dev = NULL;
180}