[NET]: Add netlink connector.
[linux-2.6.git] / drivers / connector / cn_queue.c
1 /*
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
34 static void cn_queue_wrapper(void *data)
35 {
36         struct cn_callback_entry *cbq = data;
37
38         cbq->cb->callback(cbq->cb->priv);
39         cbq->destruct_data(cbq->ddata);
40         cbq->ddata = NULL;
41 }
42
43 static struct cn_callback_entry *cn_queue_alloc_callback_entry(struct cn_callback *cb)
44 {
45         struct cn_callback_entry *cbq;
46
47         cbq = kzalloc(sizeof(*cbq), GFP_KERNEL);
48         if (!cbq) {
49                 printk(KERN_ERR "Failed to create new callback queue.\n");
50                 return NULL;
51         }
52
53         cbq->cb = cb;
54         INIT_WORK(&cbq->work, &cn_queue_wrapper, cbq);
55         return cbq;
56 }
57
58 static void cn_queue_free_callback(struct cn_callback_entry *cbq)
59 {
60         cancel_delayed_work(&cbq->work);
61         flush_workqueue(cbq->pdev->cn_queue);
62
63         kfree(cbq);
64 }
65
66 int cn_cb_equal(struct cb_id *i1, struct cb_id *i2)
67 {
68         return ((i1->idx == i2->idx) && (i1->val == i2->val));
69 }
70
71 int cn_queue_add_callback(struct cn_queue_dev *dev, struct cn_callback *cb)
72 {
73         struct cn_callback_entry *cbq, *__cbq;
74         int found = 0;
75
76         cbq = cn_queue_alloc_callback_entry(cb);
77         if (!cbq)
78                 return -ENOMEM;
79
80         atomic_inc(&dev->refcnt);
81         cbq->pdev = dev;
82
83         spin_lock_bh(&dev->queue_lock);
84         list_for_each_entry(__cbq, &dev->queue_list, callback_entry) {
85                 if (cn_cb_equal(&__cbq->cb->id, &cb->id)) {
86                         found = 1;
87                         break;
88                 }
89         }
90         if (!found)
91                 list_add_tail(&cbq->callback_entry, &dev->queue_list);
92         spin_unlock_bh(&dev->queue_lock);
93
94         if (found) {
95                 atomic_dec(&dev->refcnt);
96                 cn_queue_free_callback(cbq);
97                 return -EINVAL;
98         }
99
100         cbq->nls = dev->nls;
101         cbq->seq = 0;
102         cbq->group = cbq->cb->id.idx;
103
104         return 0;
105 }
106
107 void cn_queue_del_callback(struct cn_queue_dev *dev, struct cb_id *id)
108 {
109         struct cn_callback_entry *cbq, *n;
110         int found = 0;
111
112         spin_lock_bh(&dev->queue_lock);
113         list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) {
114                 if (cn_cb_equal(&cbq->cb->id, id)) {
115                         list_del(&cbq->callback_entry);
116                         found = 1;
117                         break;
118                 }
119         }
120         spin_unlock_bh(&dev->queue_lock);
121
122         if (found) {
123                 cn_queue_free_callback(cbq);
124                 atomic_dec_and_test(&dev->refcnt);
125         }
126 }
127
128 struct cn_queue_dev *cn_queue_alloc_dev(char *name, struct sock *nls)
129 {
130         struct cn_queue_dev *dev;
131
132         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
133         if (!dev)
134                 return NULL;
135
136         snprintf(dev->name, sizeof(dev->name), "%s", name);
137         atomic_set(&dev->refcnt, 0);
138         INIT_LIST_HEAD(&dev->queue_list);
139         spin_lock_init(&dev->queue_lock);
140
141         dev->nls = nls;
142         dev->netlink_groups = 0;
143
144         dev->cn_queue = create_workqueue(dev->name);
145         if (!dev->cn_queue) {
146                 kfree(dev);
147                 return NULL;
148         }
149
150         return dev;
151 }
152
153 void cn_queue_free_dev(struct cn_queue_dev *dev)
154 {
155         struct cn_callback_entry *cbq, *n;
156
157         flush_workqueue(dev->cn_queue);
158         destroy_workqueue(dev->cn_queue);
159
160         spin_lock_bh(&dev->queue_lock);
161         list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry)
162                 list_del(&cbq->callback_entry);
163         spin_unlock_bh(&dev->queue_lock);
164
165         while (atomic_read(&dev->refcnt)) {
166                 printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
167                        dev->name, atomic_read(&dev->refcnt));
168                 msleep(1000);
169         }
170
171         kfree(dev);
172         dev = NULL;
173 }