parisc: sba_iommu: fix build bug when CONFIG_PARISC_AGP=y
[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 void cn_queue_wrapper(struct work_struct *work)
35 {
36         struct cn_callback_entry *cbq =
37                 container_of(work, struct cn_callback_entry, work);
38         struct cn_callback_data *d = &cbq->data;
39
40         d->callback(d->callback_priv);
41
42         d->destruct_data(d->ddata);
43         d->ddata = NULL;
44
45         kfree(d->free);
46 }
47
48 static struct cn_callback_entry *cn_queue_alloc_callback_entry(char *name, struct cb_id *id, void (*callback)(void *))
49 {
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
58         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         
62         INIT_WORK(&cbq->work, &cn_queue_wrapper);
63         return cbq;
64 }
65
66 static void cn_queue_free_callback(struct cn_callback_entry *cbq)
67 {
68         flush_workqueue(cbq->pdev->cn_queue);
69
70         kfree(cbq);
71 }
72
73 int cn_cb_equal(struct cb_id *i1, struct cb_id *i2)
74 {
75         return ((i1->idx == i2->idx) && (i1->val == i2->val));
76 }
77
78 int cn_queue_add_callback(struct cn_queue_dev *dev, char *name, struct cb_id *id, void (*callback)(void *))
79 {
80         struct cn_callback_entry *cbq, *__cbq;
81         int found = 0;
82
83         cbq = cn_queue_alloc_callback_entry(name, id, callback);
84         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) {
92                 if (cn_cb_equal(&__cbq->id.id, id)) {
93                         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                 cn_queue_free_callback(cbq);
103                 atomic_dec(&dev->refcnt);
104                 return -EINVAL;
105         }
106
107         cbq->seq = 0;
108         cbq->group = cbq->id.id.idx;
109
110         return 0;
111 }
112
113 void cn_queue_del_callback(struct cn_queue_dev *dev, struct cb_id *id)
114 {
115         struct cn_callback_entry *cbq, *n;
116         int found = 0;
117
118         spin_lock_bh(&dev->queue_lock);
119         list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) {
120                 if (cn_cb_equal(&cbq->id.id, id)) {
121                         list_del(&cbq->callback_entry);
122                         found = 1;
123                         break;
124                 }
125         }
126         spin_unlock_bh(&dev->queue_lock);
127
128         if (found) {
129                 cn_queue_free_callback(cbq);
130                 atomic_dec(&dev->refcnt);
131         }
132 }
133
134 struct cn_queue_dev *cn_queue_alloc_dev(char *name, struct sock *nls)
135 {
136         struct cn_queue_dev *dev;
137
138         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
139         if (!dev)
140                 return NULL;
141
142         snprintf(dev->name, sizeof(dev->name), "%s", name);
143         atomic_set(&dev->refcnt, 0);
144         INIT_LIST_HEAD(&dev->queue_list);
145         spin_lock_init(&dev->queue_lock);
146
147         dev->nls = nls;
148
149         dev->cn_queue = create_singlethread_workqueue(dev->name);
150         if (!dev->cn_queue) {
151                 kfree(dev);
152                 return NULL;
153         }
154
155         return dev;
156 }
157
158 void cn_queue_free_dev(struct cn_queue_dev *dev)
159 {
160         struct cn_callback_entry *cbq, *n;
161
162         flush_workqueue(dev->cn_queue);
163         destroy_workqueue(dev->cn_queue);
164
165         spin_lock_bh(&dev->queue_lock);
166         list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry)
167                 list_del(&cbq->callback_entry);
168         spin_unlock_bh(&dev->queue_lock);
169
170         while (atomic_read(&dev->refcnt)) {
171                 printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
172                        dev->name, atomic_read(&dev->refcnt));
173                 msleep(1000);
174         }
175
176         kfree(dev);
177         dev = NULL;
178 }