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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /kernel/intermodule.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
Diffstat (limited to 'kernel/intermodule.c')
-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);