Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Pekka J Enberg | dd39271 | 2005-09-06 15:18:31 -0700 | [diff] [blame] | 42 | if (!(ime_new = kzalloc(sizeof(*ime), GFP_KERNEL))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | ime_new->im_name = im_name; |
| 51 | ime_new->owner = owner; |
| 52 | ime_new->userdata = userdata; |
| 53 | |
| 54 | spin_lock(&ime_lock); |
| 55 | list_for_each(tmp, &ime_list) { |
| 56 | ime = list_entry(tmp, struct inter_module_entry, list); |
| 57 | if (strcmp(ime->im_name, im_name) == 0) { |
| 58 | spin_unlock(&ime_lock); |
| 59 | kfree(ime_new); |
| 60 | /* Program logic error, fatal */ |
| 61 | printk(KERN_ERR "inter_module_register: duplicate im_name '%s'", im_name); |
| 62 | BUG(); |
| 63 | } |
| 64 | } |
| 65 | list_add(&(ime_new->list), &ime_list); |
| 66 | spin_unlock(&ime_lock); |
| 67 | } |
| 68 | |
| 69 | /** |
| 70 | * inter_module_unregister - unregister a set of inter module data. |
| 71 | * @im_name: an arbitrary string to identify the data, must be unique |
| 72 | * |
| 73 | * Description: Check that the im_name has been registered, complain if |
| 74 | * it has not. For existing data, remove it from the |
| 75 | * inter_module_entry list. |
| 76 | */ |
| 77 | void inter_module_unregister(const char *im_name) |
| 78 | { |
| 79 | struct list_head *tmp; |
| 80 | struct inter_module_entry *ime; |
| 81 | |
| 82 | spin_lock(&ime_lock); |
| 83 | list_for_each(tmp, &ime_list) { |
| 84 | ime = list_entry(tmp, struct inter_module_entry, list); |
| 85 | if (strcmp(ime->im_name, im_name) == 0) { |
| 86 | list_del(&(ime->list)); |
| 87 | spin_unlock(&ime_lock); |
| 88 | kfree(ime); |
| 89 | return; |
| 90 | } |
| 91 | } |
| 92 | spin_unlock(&ime_lock); |
| 93 | if (kmalloc_failed) { |
| 94 | printk(KERN_ERR |
| 95 | "inter_module_unregister: no entry for '%s', " |
| 96 | "probably caused by previous kmalloc failure\n", |
| 97 | im_name); |
| 98 | return; |
| 99 | } |
| 100 | else { |
| 101 | /* Program logic error, fatal */ |
| 102 | printk(KERN_ERR "inter_module_unregister: no entry for '%s'", im_name); |
| 103 | BUG(); |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | /** |
| 108 | * inter_module_get - return arbitrary userdata from another module. |
| 109 | * @im_name: an arbitrary string to identify the data, must be unique |
| 110 | * |
| 111 | * Description: If the im_name has not been registered, return NULL. |
| 112 | * Try to increment the use count on the owning module, if that fails |
| 113 | * then return NULL. Otherwise return the userdata. |
| 114 | */ |
| 115 | static const void *inter_module_get(const char *im_name) |
| 116 | { |
| 117 | struct list_head *tmp; |
| 118 | struct inter_module_entry *ime; |
| 119 | const void *result = NULL; |
| 120 | |
| 121 | spin_lock(&ime_lock); |
| 122 | list_for_each(tmp, &ime_list) { |
| 123 | ime = list_entry(tmp, struct inter_module_entry, list); |
| 124 | if (strcmp(ime->im_name, im_name) == 0) { |
| 125 | if (try_module_get(ime->owner)) |
| 126 | result = ime->userdata; |
| 127 | break; |
| 128 | } |
| 129 | } |
| 130 | spin_unlock(&ime_lock); |
| 131 | return(result); |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * inter_module_get_request - im get with automatic request_module. |
| 136 | * @im_name: an arbitrary string to identify the data, must be unique |
| 137 | * @modname: module that is expected to register im_name |
| 138 | * |
| 139 | * Description: If inter_module_get fails, do request_module then retry. |
| 140 | */ |
| 141 | const void *inter_module_get_request(const char *im_name, const char *modname) |
| 142 | { |
| 143 | const void *result = inter_module_get(im_name); |
| 144 | if (!result) { |
| 145 | request_module("%s", modname); |
| 146 | result = inter_module_get(im_name); |
| 147 | } |
| 148 | return(result); |
| 149 | } |
| 150 | |
| 151 | /** |
| 152 | * inter_module_put - release use of data from another module. |
| 153 | * @im_name: an arbitrary string to identify the data, must be unique |
| 154 | * |
| 155 | * Description: If the im_name has not been registered, complain, |
| 156 | * otherwise decrement the use count on the owning module. |
| 157 | */ |
| 158 | void inter_module_put(const char *im_name) |
| 159 | { |
| 160 | struct list_head *tmp; |
| 161 | struct inter_module_entry *ime; |
| 162 | |
| 163 | spin_lock(&ime_lock); |
| 164 | list_for_each(tmp, &ime_list) { |
| 165 | ime = list_entry(tmp, struct inter_module_entry, list); |
| 166 | if (strcmp(ime->im_name, im_name) == 0) { |
| 167 | if (ime->owner) |
| 168 | module_put(ime->owner); |
| 169 | spin_unlock(&ime_lock); |
| 170 | return; |
| 171 | } |
| 172 | } |
| 173 | spin_unlock(&ime_lock); |
| 174 | printk(KERN_ERR "inter_module_put: no entry for '%s'", im_name); |
| 175 | BUG(); |
| 176 | } |
| 177 | |
| 178 | EXPORT_SYMBOL(inter_module_register); |
| 179 | EXPORT_SYMBOL(inter_module_unregister); |
| 180 | EXPORT_SYMBOL(inter_module_get_request); |
| 181 | EXPORT_SYMBOL(inter_module_put); |