Revert "ARM: tegra: tegratab: dummy change"
[linux-2.6.git] / drivers / connector / cn_queue.c
1 /*
2  *      cn_queue.c
3  *
4  * 2004+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
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 struct cn_callback_entry *
35 cn_queue_alloc_callback_entry(struct cn_queue_dev *dev, const char *name,
36                               struct cb_id *id,
37                               void (*callback)(struct cn_msg *, struct netlink_skb_parms *))
38 {
39         struct cn_callback_entry *cbq;
40
41         cbq = kzalloc(sizeof(*cbq), GFP_KERNEL);
42         if (!cbq) {
43                 printk(KERN_ERR "Failed to create new callback queue.\n");
44                 return NULL;
45         }
46
47         atomic_set(&cbq->refcnt, 1);
48
49         atomic_inc(&dev->refcnt);
50         cbq->pdev = dev;
51
52         snprintf(cbq->id.name, sizeof(cbq->id.name), "%s", name);
53         memcpy(&cbq->id.id, id, sizeof(struct cb_id));
54         cbq->callback = callback;
55         return cbq;
56 }
57
58 void cn_queue_release_callback(struct cn_callback_entry *cbq)
59 {
60         if (!atomic_dec_and_test(&cbq->refcnt))
61                 return;
62
63         atomic_dec(&cbq->pdev->refcnt);
64         kfree(cbq);
65 }
66
67 int cn_cb_equal(struct cb_id *i1, struct cb_id *i2)
68 {
69         return ((i1->idx == i2->idx) && (i1->val == i2->val));
70 }
71
72 int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name,
73                           struct cb_id *id,
74                           void (*callback)(struct cn_msg *, struct netlink_skb_parms *))
75 {
76         struct cn_callback_entry *cbq, *__cbq;
77         int found = 0;
78
79         cbq = cn_queue_alloc_callback_entry(dev, name, id, callback);
80         if (!cbq)
81                 return -ENOMEM;
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->id.id, 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                 cn_queue_release_callback(cbq);
96                 return -EINVAL;
97         }
98
99         cbq->seq = 0;
100         cbq->group = cbq->id.id.idx;
101
102         return 0;
103 }
104
105 void cn_queue_del_callback(struct cn_queue_dev *dev, struct cb_id *id)
106 {
107         struct cn_callback_entry *cbq, *n;
108         int found = 0;
109
110         spin_lock_bh(&dev->queue_lock);
111         list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) {
112                 if (cn_cb_equal(&cbq->id.id, id)) {
113                         list_del(&cbq->callback_entry);
114                         found = 1;
115                         break;
116                 }
117         }
118         spin_unlock_bh(&dev->queue_lock);
119
120         if (found)
121                 cn_queue_release_callback(cbq);
122 }
123
124 struct cn_queue_dev *cn_queue_alloc_dev(const char *name, struct sock *nls)
125 {
126         struct cn_queue_dev *dev;
127
128         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
129         if (!dev)
130                 return NULL;
131
132         snprintf(dev->name, sizeof(dev->name), "%s", name);
133         atomic_set(&dev->refcnt, 0);
134         INIT_LIST_HEAD(&dev->queue_list);
135         spin_lock_init(&dev->queue_lock);
136
137         dev->nls = nls;
138
139         return dev;
140 }
141
142 void cn_queue_free_dev(struct cn_queue_dev *dev)
143 {
144         struct cn_callback_entry *cbq, *n;
145
146         spin_lock_bh(&dev->queue_lock);
147         list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry)
148                 list_del(&cbq->callback_entry);
149         spin_unlock_bh(&dev->queue_lock);
150
151         while (atomic_read(&dev->refcnt)) {
152                 printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
153                        dev->name, atomic_read(&dev->refcnt));
154                 msleep(1000);
155         }
156
157         kfree(dev);
158         dev = NULL;
159 }