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-rw-r--r--kernel/intermodule.c182
1 files changed, 182 insertions, 0 deletions
diff --git a/kernel/intermodule.c b/kernel/intermodule.c
new file mode 100644
index 000000000000..388977f3e9b7
--- /dev/null
+++ b/kernel/intermodule.c
@@ -0,0 +1,182 @@
+/* Deprecated, do not use. Moved from module.c to here. --RR */
+
+/* Written by Keith Owens <kaos@ocs.com.au> Oct 2000 */
+#include <linux/module.h>
+#include <linux/kmod.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+
+/* inter_module functions are always available, even when the kernel is
+ * compiled without modules. Consumers of inter_module_xxx routines
+ * will always work, even when both are built into the kernel, this
+ * approach removes lots of #ifdefs in mainline code.
+ */
+
+static struct list_head ime_list = LIST_HEAD_INIT(ime_list);
+static DEFINE_SPINLOCK(ime_lock);
+static int kmalloc_failed;
+
+struct inter_module_entry {
+ struct list_head list;
+ const char *im_name;
+ struct module *owner;
+ const void *userdata;
+};
+
+/**
+ * inter_module_register - register a new set of inter module data.
+ * @im_name: an arbitrary string to identify the data, must be unique
+ * @owner: module that is registering the data, always use THIS_MODULE
+ * @userdata: pointer to arbitrary userdata to be registered
+ *
+ * Description: Check that the im_name has not already been registered,
+ * complain if it has. For new data, add it to the inter_module_entry
+ * list.
+ */
+void inter_module_register(const char *im_name, struct module *owner, const void *userdata)
+{
+ struct list_head *tmp;
+ struct inter_module_entry *ime, *ime_new;
+
+ if (!(ime_new = kmalloc(sizeof(*ime), GFP_KERNEL))) {
+ /* Overloaded kernel, not fatal */
+ printk(KERN_ERR
+ "Aiee, inter_module_register: cannot kmalloc entry for '%s'\n",
+ im_name);
+ kmalloc_failed = 1;
+ return;
+ }
+ memset(ime_new, 0, sizeof(*ime_new));
+ ime_new->im_name = im_name;
+ ime_new->owner = owner;
+ ime_new->userdata = userdata;
+
+ spin_lock(&ime_lock);
+ list_for_each(tmp, &ime_list) {
+ ime = list_entry(tmp, struct inter_module_entry, list);
+ if (strcmp(ime->im_name, im_name) == 0) {
+ spin_unlock(&ime_lock);
+ kfree(ime_new);
+ /* Program logic error, fatal */
+ printk(KERN_ERR "inter_module_register: duplicate im_name '%s'", im_name);
+ BUG();
+ }
+ }
+ list_add(&(ime_new->list), &ime_list);
+ spin_unlock(&ime_lock);
+}
+
+/**
+ * inter_module_unregister - unregister a set of inter module data.
+ * @im_name: an arbitrary string to identify the data, must be unique
+ *
+ * Description: Check that the im_name has been registered, complain if
+ * it has not. For existing data, remove it from the
+ * inter_module_entry list.
+ */
+void inter_module_unregister(const char *im_name)
+{
+ struct list_head *tmp;
+ struct inter_module_entry *ime;
+
+ spin_lock(&ime_lock);
+ list_for_each(tmp, &ime_list) {
+ ime = list_entry(tmp, struct inter_module_entry, list);
+ if (strcmp(ime->im_name, im_name) == 0) {
+ list_del(&(ime->list));
+ spin_unlock(&ime_lock);
+ kfree(ime);
+ return;
+ }
+ }
+ spin_unlock(&ime_lock);
+ if (kmalloc_failed) {
+ printk(KERN_ERR
+ "inter_module_unregister: no entry for '%s', "
+ "probably caused by previous kmalloc failure\n",
+ im_name);
+ return;
+ }
+ else {
+ /* Program logic error, fatal */
+ printk(KERN_ERR "inter_module_unregister: no entry for '%s'", im_name);
+ BUG();
+ }
+}
+
+/**
+ * inter_module_get - return arbitrary userdata from another module.
+ * @im_name: an arbitrary string to identify the data, must be unique
+ *
+ * Description: If the im_name has not been registered, return NULL.
+ * Try to increment the use count on the owning module, if that fails
+ * then return NULL. Otherwise return the userdata.
+ */
+static const void *inter_module_get(const char *im_name)
+{
+ struct list_head *tmp;
+ struct inter_module_entry *ime;
+ const void *result = NULL;
+
+ spin_lock(&ime_lock);
+ list_for_each(tmp, &ime_list) {
+ ime = list_entry(tmp, struct inter_module_entry, list);
+ if (strcmp(ime->im_name, im_name) == 0) {
+ if (try_module_get(ime->owner))
+ result = ime->userdata;
+ break;
+ }
+ }
+ spin_unlock(&ime_lock);
+ return(result);
+}
+
+/**
+ * inter_module_get_request - im get with automatic request_module.
+ * @im_name: an arbitrary string to identify the data, must be unique
+ * @modname: module that is expected to register im_name
+ *
+ * Description: If inter_module_get fails, do request_module then retry.
+ */
+const void *inter_module_get_request(const char *im_name, const char *modname)
+{
+ const void *result = inter_module_get(im_name);
+ if (!result) {
+ request_module("%s", modname);
+ result = inter_module_get(im_name);
+ }
+ return(result);
+}
+
+/**
+ * inter_module_put - release use of data from another module.
+ * @im_name: an arbitrary string to identify the data, must be unique
+ *
+ * Description: If the im_name has not been registered, complain,
+ * otherwise decrement the use count on the owning module.
+ */
+void inter_module_put(const char *im_name)
+{
+ struct list_head *tmp;
+ struct inter_module_entry *ime;
+
+ spin_lock(&ime_lock);
+ list_for_each(tmp, &ime_list) {
+ ime = list_entry(tmp, struct inter_module_entry, list);
+ if (strcmp(ime->im_name, im_name) == 0) {
+ if (ime->owner)
+ module_put(ime->owner);
+ spin_unlock(&ime_lock);
+ return;
+ }
+ }
+ spin_unlock(&ime_lock);
+ printk(KERN_ERR "inter_module_put: no entry for '%s'", im_name);
+ BUG();
+}
+
+EXPORT_SYMBOL(inter_module_register);
+EXPORT_SYMBOL(inter_module_unregister);
+EXPORT_SYMBOL(inter_module_get_request);
+EXPORT_SYMBOL(inter_module_put);