xref: /openbmc/linux/drivers/isdn/mISDN/core.c (revision 9ac8d3fb)
1 /*
2  * Copyright 2008  by Karsten Keil <kkeil@novell.com>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  */
14 
15 #include <linux/types.h>
16 #include <linux/stddef.h>
17 #include <linux/module.h>
18 #include <linux/spinlock.h>
19 #include <linux/mISDNif.h>
20 #include "core.h"
21 
22 static u_int debug;
23 
24 MODULE_AUTHOR("Karsten Keil");
25 MODULE_LICENSE("GPL");
26 module_param(debug, uint, S_IRUGO | S_IWUSR);
27 
28 static LIST_HEAD(devices);
29 DEFINE_RWLOCK(device_lock);
30 static u64		device_ids;
31 #define MAX_DEVICE_ID	63
32 
33 static LIST_HEAD(Bprotocols);
34 DEFINE_RWLOCK(bp_lock);
35 
36 struct mISDNdevice
37 *get_mdevice(u_int id)
38 {
39 	struct mISDNdevice	*dev;
40 
41 	read_lock(&device_lock);
42 	list_for_each_entry(dev, &devices, D.list)
43 		if (dev->id == id) {
44 			read_unlock(&device_lock);
45 			return dev;
46 		}
47 	read_unlock(&device_lock);
48 	return NULL;
49 }
50 
51 int
52 get_mdevice_count(void)
53 {
54 	struct mISDNdevice	*dev;
55 	int			cnt = 0;
56 
57 	read_lock(&device_lock);
58 	list_for_each_entry(dev, &devices, D.list)
59 		cnt++;
60 	read_unlock(&device_lock);
61 	return cnt;
62 }
63 
64 static int
65 get_free_devid(void)
66 {
67 	u_int	i;
68 
69 	for (i = 0; i <= MAX_DEVICE_ID; i++)
70 		if (!test_and_set_bit(i, (u_long *)&device_ids))
71 			return i;
72 	return -1;
73 }
74 
75 int
76 mISDN_register_device(struct mISDNdevice *dev, char *name)
77 {
78 	u_long	flags;
79 	int	err;
80 
81 	dev->id = get_free_devid();
82 	if (dev->id < 0)
83 		return -EBUSY;
84 	if (name && name[0])
85 		strcpy(dev->name, name);
86 	else
87 		sprintf(dev->name, "mISDN%d", dev->id);
88 	if (debug & DEBUG_CORE)
89 		printk(KERN_DEBUG "mISDN_register %s %d\n",
90 			dev->name, dev->id);
91 	err = create_stack(dev);
92 	if (err)
93 		return err;
94 	write_lock_irqsave(&device_lock, flags);
95 	list_add_tail(&dev->D.list, &devices);
96 	write_unlock_irqrestore(&device_lock, flags);
97 	return 0;
98 }
99 EXPORT_SYMBOL(mISDN_register_device);
100 
101 void
102 mISDN_unregister_device(struct mISDNdevice *dev) {
103 	u_long	flags;
104 
105 	if (debug & DEBUG_CORE)
106 		printk(KERN_DEBUG "mISDN_unregister %s %d\n",
107 			dev->name, dev->id);
108 	write_lock_irqsave(&device_lock, flags);
109 	list_del(&dev->D.list);
110 	write_unlock_irqrestore(&device_lock, flags);
111 	test_and_clear_bit(dev->id, (u_long *)&device_ids);
112 	delete_stack(dev);
113 }
114 EXPORT_SYMBOL(mISDN_unregister_device);
115 
116 u_int
117 get_all_Bprotocols(void)
118 {
119 	struct Bprotocol	*bp;
120 	u_int	m = 0;
121 
122 	read_lock(&bp_lock);
123 	list_for_each_entry(bp, &Bprotocols, list)
124 		m |= bp->Bprotocols;
125 	read_unlock(&bp_lock);
126 	return m;
127 }
128 
129 struct Bprotocol *
130 get_Bprotocol4mask(u_int m)
131 {
132 	struct Bprotocol	*bp;
133 
134 	read_lock(&bp_lock);
135 	list_for_each_entry(bp, &Bprotocols, list)
136 		if (bp->Bprotocols & m) {
137 			read_unlock(&bp_lock);
138 			return bp;
139 		}
140 	read_unlock(&bp_lock);
141 	return NULL;
142 }
143 
144 struct Bprotocol *
145 get_Bprotocol4id(u_int id)
146 {
147 	u_int	m;
148 
149 	if (id < ISDN_P_B_START || id > 63) {
150 		printk(KERN_WARNING "%s id not in range  %d\n",
151 		    __func__, id);
152 		return NULL;
153 	}
154 	m = 1 << (id & ISDN_P_B_MASK);
155 	return get_Bprotocol4mask(m);
156 }
157 
158 int
159 mISDN_register_Bprotocol(struct Bprotocol *bp)
160 {
161 	u_long			flags;
162 	struct Bprotocol	*old;
163 
164 	if (debug & DEBUG_CORE)
165 		printk(KERN_DEBUG "%s: %s/%x\n", __func__,
166 		    bp->name, bp->Bprotocols);
167 	old = get_Bprotocol4mask(bp->Bprotocols);
168 	if (old) {
169 		printk(KERN_WARNING
170 		    "register duplicate protocol old %s/%x new %s/%x\n",
171 		    old->name, old->Bprotocols, bp->name, bp->Bprotocols);
172 		return -EBUSY;
173 	}
174 	write_lock_irqsave(&bp_lock, flags);
175 	list_add_tail(&bp->list, &Bprotocols);
176 	write_unlock_irqrestore(&bp_lock, flags);
177 	return 0;
178 }
179 EXPORT_SYMBOL(mISDN_register_Bprotocol);
180 
181 void
182 mISDN_unregister_Bprotocol(struct Bprotocol *bp)
183 {
184 	u_long	flags;
185 
186 	if (debug & DEBUG_CORE)
187 		printk(KERN_DEBUG "%s: %s/%x\n", __func__, bp->name,
188 			bp->Bprotocols);
189 	write_lock_irqsave(&bp_lock, flags);
190 	list_del(&bp->list);
191 	write_unlock_irqrestore(&bp_lock, flags);
192 }
193 EXPORT_SYMBOL(mISDN_unregister_Bprotocol);
194 
195 int
196 mISDNInit(void)
197 {
198 	int	err;
199 
200 	printk(KERN_INFO "Modular ISDN core version %d.%d.%d\n",
201 		MISDN_MAJOR_VERSION, MISDN_MINOR_VERSION, MISDN_RELEASE);
202 	mISDN_initstack(&debug);
203 	err = mISDN_inittimer(&debug);
204 	if (err)
205 		goto error;
206 	err = l1_init(&debug);
207 	if (err) {
208 		mISDN_timer_cleanup();
209 		goto error;
210 	}
211 	err = Isdnl2_Init(&debug);
212 	if (err) {
213 		mISDN_timer_cleanup();
214 		l1_cleanup();
215 		goto error;
216 	}
217 	err = misdn_sock_init(&debug);
218 	if (err) {
219 		mISDN_timer_cleanup();
220 		l1_cleanup();
221 		Isdnl2_cleanup();
222 	}
223 error:
224 	return err;
225 }
226 
227 void mISDN_cleanup(void)
228 {
229 	misdn_sock_cleanup();
230 	mISDN_timer_cleanup();
231 	l1_cleanup();
232 	Isdnl2_cleanup();
233 
234 	if (!list_empty(&devices))
235 		printk(KERN_ERR "%s devices still registered\n", __func__);
236 
237 	if (!list_empty(&Bprotocols))
238 		printk(KERN_ERR "%s Bprotocols still registered\n", __func__);
239 	printk(KERN_DEBUG "mISDNcore unloaded\n");
240 }
241 
242 module_init(mISDNInit);
243 module_exit(mISDN_cleanup);
244 
245