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7672d0b5 EP |
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 | } |