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1da177e4 LT |
1 | /* |
2 | * w1_int.c | |
3 | * | |
4 | * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru> | |
5 | * | |
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 | #include <linux/kernel.h> | |
23 | #include <linux/list.h> | |
24 | #include <linux/delay.h> | |
25 | ||
26 | #include "w1.h" | |
27 | #include "w1_log.h" | |
28 | #include "w1_netlink.h" | |
29 | ||
30 | static u32 w1_ids = 1; | |
31 | ||
32 | extern struct device_driver w1_driver; | |
33 | extern struct bus_type w1_bus_type; | |
34 | extern struct device w1_device; | |
35 | extern int w1_max_slave_count; | |
36 | extern int w1_max_slave_ttl; | |
37 | extern struct list_head w1_masters; | |
38 | extern spinlock_t w1_mlock; | |
39 | ||
40 | extern int w1_process(void *); | |
41 | ||
42 | struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl, | |
43 | struct device_driver *driver, struct device *device) | |
44 | { | |
45 | struct w1_master *dev; | |
46 | int err; | |
47 | ||
48 | /* | |
49 | * We are in process context(kernel thread), so can sleep. | |
50 | */ | |
51 | dev = kmalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL); | |
52 | if (!dev) { | |
53 | printk(KERN_ERR | |
54 | "Failed to allocate %zd bytes for new w1 device.\n", | |
55 | sizeof(struct w1_master)); | |
56 | return NULL; | |
57 | } | |
58 | ||
59 | memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master)); | |
60 | ||
61 | dev->bus_master = (struct w1_bus_master *)(dev + 1); | |
62 | ||
63 | dev->owner = THIS_MODULE; | |
64 | dev->max_slave_count = slave_count; | |
65 | dev->slave_count = 0; | |
66 | dev->attempts = 0; | |
67 | dev->kpid = -1; | |
68 | dev->initialized = 0; | |
69 | dev->id = id; | |
70 | dev->slave_ttl = slave_ttl; | |
71 | ||
72 | atomic_set(&dev->refcnt, 2); | |
73 | ||
74 | INIT_LIST_HEAD(&dev->slist); | |
75 | init_MUTEX(&dev->mutex); | |
76 | ||
77 | init_completion(&dev->dev_released); | |
78 | init_completion(&dev->dev_exited); | |
79 | ||
80 | memcpy(&dev->dev, device, sizeof(struct device)); | |
81 | snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id), | |
82 | "w1_bus_master%u", dev->id); | |
83 | snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id); | |
84 | ||
85 | dev->driver = driver; | |
86 | ||
87 | dev->groups = 23; | |
88 | dev->seq = 1; | |
89 | dev->nls = netlink_kernel_create(NETLINK_NFLOG, NULL); | |
90 | if (!dev->nls) { | |
91 | printk(KERN_ERR "Failed to create new netlink socket(%u) for w1 master %s.\n", | |
92 | NETLINK_NFLOG, dev->dev.bus_id); | |
93 | } | |
94 | ||
95 | err = device_register(&dev->dev); | |
96 | if (err) { | |
97 | printk(KERN_ERR "Failed to register master device. err=%d\n", err); | |
98 | if (dev->nls && dev->nls->sk_socket) | |
99 | sock_release(dev->nls->sk_socket); | |
100 | memset(dev, 0, sizeof(struct w1_master)); | |
101 | kfree(dev); | |
102 | dev = NULL; | |
103 | } | |
104 | ||
105 | return dev; | |
106 | } | |
107 | ||
108 | void w1_free_dev(struct w1_master *dev) | |
109 | { | |
110 | device_unregister(&dev->dev); | |
111 | if (dev->nls && dev->nls->sk_socket) | |
112 | sock_release(dev->nls->sk_socket); | |
113 | memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master)); | |
114 | kfree(dev); | |
115 | } | |
116 | ||
117 | int w1_add_master_device(struct w1_bus_master *master) | |
118 | { | |
119 | struct w1_master *dev; | |
120 | int retval = 0; | |
121 | struct w1_netlink_msg msg; | |
122 | ||
123 | dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_driver, &w1_device); | |
124 | if (!dev) | |
125 | return -ENOMEM; | |
126 | ||
127 | dev->kpid = kernel_thread(&w1_process, dev, 0); | |
128 | if (dev->kpid < 0) { | |
129 | dev_err(&dev->dev, | |
130 | "Failed to create new kernel thread. err=%d\n", | |
131 | dev->kpid); | |
132 | retval = dev->kpid; | |
133 | goto err_out_free_dev; | |
134 | } | |
135 | ||
136 | retval = w1_create_master_attributes(dev); | |
137 | if (retval) | |
138 | goto err_out_kill_thread; | |
139 | ||
140 | memcpy(dev->bus_master, master, sizeof(struct w1_bus_master)); | |
141 | ||
142 | dev->initialized = 1; | |
143 | ||
144 | spin_lock(&w1_mlock); | |
145 | list_add(&dev->w1_master_entry, &w1_masters); | |
146 | spin_unlock(&w1_mlock); | |
147 | ||
148 | msg.id.mst.id = dev->id; | |
149 | msg.id.mst.pid = dev->kpid; | |
150 | msg.type = W1_MASTER_ADD; | |
151 | w1_netlink_send(dev, &msg); | |
152 | ||
153 | return 0; | |
154 | ||
155 | err_out_kill_thread: | |
156 | dev->need_exit = 1; | |
157 | if (kill_proc(dev->kpid, SIGTERM, 1)) | |
158 | dev_err(&dev->dev, | |
159 | "Failed to send signal to w1 kernel thread %d.\n", | |
160 | dev->kpid); | |
161 | wait_for_completion(&dev->dev_exited); | |
162 | ||
163 | err_out_free_dev: | |
164 | w1_free_dev(dev); | |
165 | ||
166 | return retval; | |
167 | } | |
168 | ||
169 | void __w1_remove_master_device(struct w1_master *dev) | |
170 | { | |
171 | int err; | |
172 | struct w1_netlink_msg msg; | |
173 | ||
174 | dev->need_exit = 1; | |
175 | err = kill_proc(dev->kpid, SIGTERM, 1); | |
176 | if (err) | |
177 | dev_err(&dev->dev, | |
178 | "%s: Failed to send signal to w1 kernel thread %d.\n", | |
179 | __func__, dev->kpid); | |
180 | ||
181 | while (atomic_read(&dev->refcnt)) { | |
182 | printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n", | |
183 | dev->name, atomic_read(&dev->refcnt)); | |
184 | ||
185 | if (msleep_interruptible(1000)) | |
186 | flush_signals(current); | |
187 | } | |
188 | ||
189 | msg.id.mst.id = dev->id; | |
190 | msg.id.mst.pid = dev->kpid; | |
191 | msg.type = W1_MASTER_REMOVE; | |
192 | w1_netlink_send(dev, &msg); | |
193 | ||
194 | w1_free_dev(dev); | |
195 | } | |
196 | ||
197 | void w1_remove_master_device(struct w1_bus_master *bm) | |
198 | { | |
199 | struct w1_master *dev = NULL; | |
200 | struct list_head *ent, *n; | |
201 | ||
202 | list_for_each_safe(ent, n, &w1_masters) { | |
203 | dev = list_entry(ent, struct w1_master, w1_master_entry); | |
204 | if (!dev->initialized) | |
205 | continue; | |
206 | ||
207 | if (dev->bus_master->data == bm->data) | |
208 | break; | |
209 | } | |
210 | ||
211 | if (!dev) { | |
212 | printk(KERN_ERR "Device doesn't exist.\n"); | |
213 | return; | |
214 | } | |
215 | ||
216 | __w1_remove_master_device(dev); | |
217 | } | |
218 | ||
219 | EXPORT_SYMBOL(w1_add_master_device); | |
220 | EXPORT_SYMBOL(w1_remove_master_device); |