vmxnet3: convert BUG_ON(true) into a simple BUG()
[platform/adaptation/renesas_rcar/renesas_kernel.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 *,
38                                                struct netlink_skb_parms *))
39 {
40         struct cn_callback_entry *cbq;
41
42         cbq = kzalloc(sizeof(*cbq), GFP_KERNEL);
43         if (!cbq) {
44                 pr_err("Failed to create new callback queue.\n");
45                 return NULL;
46         }
47
48         atomic_set(&cbq->refcnt, 1);
49
50         atomic_inc(&dev->refcnt);
51         cbq->pdev = dev;
52
53         snprintf(cbq->id.name, sizeof(cbq->id.name), "%s", name);
54         memcpy(&cbq->id.id, id, sizeof(struct cb_id));
55         cbq->callback = callback;
56         return cbq;
57 }
58
59 void cn_queue_release_callback(struct cn_callback_entry *cbq)
60 {
61         if (!atomic_dec_and_test(&cbq->refcnt))
62                 return;
63
64         atomic_dec(&cbq->pdev->refcnt);
65         kfree(cbq);
66 }
67
68 int cn_cb_equal(struct cb_id *i1, struct cb_id *i2)
69 {
70         return ((i1->idx == i2->idx) && (i1->val == i2->val));
71 }
72
73 int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name,
74                           struct cb_id *id,
75                           void (*callback)(struct cn_msg *,
76                                            struct netlink_skb_parms *))
77 {
78         struct cn_callback_entry *cbq, *__cbq;
79         int found = 0;
80
81         cbq = cn_queue_alloc_callback_entry(dev, name, id, callback);
82         if (!cbq)
83                 return -ENOMEM;
84
85         spin_lock_bh(&dev->queue_lock);
86         list_for_each_entry(__cbq, &dev->queue_list, callback_entry) {
87                 if (cn_cb_equal(&__cbq->id.id, id)) {
88                         found = 1;
89                         break;
90                 }
91         }
92         if (!found)
93                 list_add_tail(&cbq->callback_entry, &dev->queue_list);
94         spin_unlock_bh(&dev->queue_lock);
95
96         if (found) {
97                 cn_queue_release_callback(cbq);
98                 return -EINVAL;
99         }
100
101         cbq->seq = 0;
102         cbq->group = cbq->id.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->id.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_release_callback(cbq);
124 }
125
126 struct cn_queue_dev *cn_queue_alloc_dev(const char *name, struct sock *nls)
127 {
128         struct cn_queue_dev *dev;
129
130         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
131         if (!dev)
132                 return NULL;
133
134         snprintf(dev->name, sizeof(dev->name), "%s", name);
135         atomic_set(&dev->refcnt, 0);
136         INIT_LIST_HEAD(&dev->queue_list);
137         spin_lock_init(&dev->queue_lock);
138
139         dev->nls = nls;
140
141         return dev;
142 }
143
144 void cn_queue_free_dev(struct cn_queue_dev *dev)
145 {
146         struct cn_callback_entry *cbq, *n;
147
148         spin_lock_bh(&dev->queue_lock);
149         list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry)
150                 list_del(&cbq->callback_entry);
151         spin_unlock_bh(&dev->queue_lock);
152
153         while (atomic_read(&dev->refcnt)) {
154                 pr_info("Waiting for %s to become free: refcnt=%d.\n",
155                        dev->name, atomic_read(&dev->refcnt));
156                 msleep(1000);
157         }
158
159         kfree(dev);
160         dev = NULL;
161 }