Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/kernel/intermodule.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
File MIME type: text/plain
File size: 5261 byte(s)
Tag kernel26-2.6.12-alx-r9
1 | /* Deprecated, do not use. Moved from module.c to here. --RR */ |
2 | |
3 | /* Written by Keith Owens <kaos@ocs.com.au> Oct 2000 */ |
4 | #include <linux/module.h> |
5 | #include <linux/kmod.h> |
6 | #include <linux/spinlock.h> |
7 | #include <linux/list.h> |
8 | #include <linux/slab.h> |
9 | |
10 | /* inter_module functions are always available, even when the kernel is |
11 | * compiled without modules. Consumers of inter_module_xxx routines |
12 | * will always work, even when both are built into the kernel, this |
13 | * approach removes lots of #ifdefs in mainline code. |
14 | */ |
15 | |
16 | static struct list_head ime_list = LIST_HEAD_INIT(ime_list); |
17 | static DEFINE_SPINLOCK(ime_lock); |
18 | static int kmalloc_failed; |
19 | |
20 | struct inter_module_entry { |
21 | struct list_head list; |
22 | const char *im_name; |
23 | struct module *owner; |
24 | const void *userdata; |
25 | }; |
26 | |
27 | /** |
28 | * inter_module_register - register a new set of inter module data. |
29 | * @im_name: an arbitrary string to identify the data, must be unique |
30 | * @owner: module that is registering the data, always use THIS_MODULE |
31 | * @userdata: pointer to arbitrary userdata to be registered |
32 | * |
33 | * Description: Check that the im_name has not already been registered, |
34 | * complain if it has. For new data, add it to the inter_module_entry |
35 | * list. |
36 | */ |
37 | void inter_module_register(const char *im_name, struct module *owner, const void *userdata) |
38 | { |
39 | struct list_head *tmp; |
40 | struct inter_module_entry *ime, *ime_new; |
41 | |
42 | if (!(ime_new = kmalloc(sizeof(*ime), GFP_KERNEL))) { |
43 | /* Overloaded kernel, not fatal */ |
44 | printk(KERN_ERR |
45 | "Aiee, inter_module_register: cannot kmalloc entry for '%s'\n", |
46 | im_name); |
47 | kmalloc_failed = 1; |
48 | return; |
49 | } |
50 | memset(ime_new, 0, sizeof(*ime_new)); |
51 | ime_new->im_name = im_name; |
52 | ime_new->owner = owner; |
53 | ime_new->userdata = userdata; |
54 | |
55 | spin_lock(&ime_lock); |
56 | list_for_each(tmp, &ime_list) { |
57 | ime = list_entry(tmp, struct inter_module_entry, list); |
58 | if (strcmp(ime->im_name, im_name) == 0) { |
59 | spin_unlock(&ime_lock); |
60 | kfree(ime_new); |
61 | /* Program logic error, fatal */ |
62 | printk(KERN_ERR "inter_module_register: duplicate im_name '%s'", im_name); |
63 | BUG(); |
64 | } |
65 | } |
66 | list_add(&(ime_new->list), &ime_list); |
67 | spin_unlock(&ime_lock); |
68 | } |
69 | |
70 | /** |
71 | * inter_module_unregister - unregister a set of inter module data. |
72 | * @im_name: an arbitrary string to identify the data, must be unique |
73 | * |
74 | * Description: Check that the im_name has been registered, complain if |
75 | * it has not. For existing data, remove it from the |
76 | * inter_module_entry list. |
77 | */ |
78 | void inter_module_unregister(const char *im_name) |
79 | { |
80 | struct list_head *tmp; |
81 | struct inter_module_entry *ime; |
82 | |
83 | spin_lock(&ime_lock); |
84 | list_for_each(tmp, &ime_list) { |
85 | ime = list_entry(tmp, struct inter_module_entry, list); |
86 | if (strcmp(ime->im_name, im_name) == 0) { |
87 | list_del(&(ime->list)); |
88 | spin_unlock(&ime_lock); |
89 | kfree(ime); |
90 | return; |
91 | } |
92 | } |
93 | spin_unlock(&ime_lock); |
94 | if (kmalloc_failed) { |
95 | printk(KERN_ERR |
96 | "inter_module_unregister: no entry for '%s', " |
97 | "probably caused by previous kmalloc failure\n", |
98 | im_name); |
99 | return; |
100 | } |
101 | else { |
102 | /* Program logic error, fatal */ |
103 | printk(KERN_ERR "inter_module_unregister: no entry for '%s'", im_name); |
104 | BUG(); |
105 | } |
106 | } |
107 | |
108 | /** |
109 | * inter_module_get - return arbitrary userdata from another module. |
110 | * @im_name: an arbitrary string to identify the data, must be unique |
111 | * |
112 | * Description: If the im_name has not been registered, return NULL. |
113 | * Try to increment the use count on the owning module, if that fails |
114 | * then return NULL. Otherwise return the userdata. |
115 | */ |
116 | static const void *inter_module_get(const char *im_name) |
117 | { |
118 | struct list_head *tmp; |
119 | struct inter_module_entry *ime; |
120 | const void *result = NULL; |
121 | |
122 | spin_lock(&ime_lock); |
123 | list_for_each(tmp, &ime_list) { |
124 | ime = list_entry(tmp, struct inter_module_entry, list); |
125 | if (strcmp(ime->im_name, im_name) == 0) { |
126 | if (try_module_get(ime->owner)) |
127 | result = ime->userdata; |
128 | break; |
129 | } |
130 | } |
131 | spin_unlock(&ime_lock); |
132 | return(result); |
133 | } |
134 | |
135 | /** |
136 | * inter_module_get_request - im get with automatic request_module. |
137 | * @im_name: an arbitrary string to identify the data, must be unique |
138 | * @modname: module that is expected to register im_name |
139 | * |
140 | * Description: If inter_module_get fails, do request_module then retry. |
141 | */ |
142 | const void *inter_module_get_request(const char *im_name, const char *modname) |
143 | { |
144 | const void *result = inter_module_get(im_name); |
145 | if (!result) { |
146 | request_module("%s", modname); |
147 | result = inter_module_get(im_name); |
148 | } |
149 | return(result); |
150 | } |
151 | |
152 | /** |
153 | * inter_module_put - release use of data from another module. |
154 | * @im_name: an arbitrary string to identify the data, must be unique |
155 | * |
156 | * Description: If the im_name has not been registered, complain, |
157 | * otherwise decrement the use count on the owning module. |
158 | */ |
159 | void inter_module_put(const char *im_name) |
160 | { |
161 | struct list_head *tmp; |
162 | struct inter_module_entry *ime; |
163 | |
164 | spin_lock(&ime_lock); |
165 | list_for_each(tmp, &ime_list) { |
166 | ime = list_entry(tmp, struct inter_module_entry, list); |
167 | if (strcmp(ime->im_name, im_name) == 0) { |
168 | if (ime->owner) |
169 | module_put(ime->owner); |
170 | spin_unlock(&ime_lock); |
171 | return; |
172 | } |
173 | } |
174 | spin_unlock(&ime_lock); |
175 | printk(KERN_ERR "inter_module_put: no entry for '%s'", im_name); |
176 | BUG(); |
177 | } |
178 | |
179 | EXPORT_SYMBOL(inter_module_register); |
180 | EXPORT_SYMBOL(inter_module_unregister); |
181 | EXPORT_SYMBOL(inter_module_get_request); |
182 | EXPORT_SYMBOL(inter_module_put); |