Driver core: move the driver specific module code into the driver core

The module driver specific code should belong in the driver core, not in
the kernel/ directory.  So move this code.  This is done in preparation
for some struct device_driver rework that should be confined to the
driver core code only.

This also lets us keep from exporting these functions, as no external
code should ever be calling it.

Thanks to Andrew Morton for the !CONFIG_MODULES fix.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/base/module.c

@@ -0,0 +1,94 @@
+/*
+ * module.c - module sysfs fun for drivers
+ *
+ * This file is released under the GPLv2
+ *
+ */
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include "base.h"
+
+static char *make_driver_name(struct device_driver *drv)
+{
+	char *driver_name;
+
+	driver_name = kmalloc(strlen(drv->name) + strlen(drv->bus->name) + 2,
+			      GFP_KERNEL);
+	if (!driver_name)
+		return NULL;
+
+	sprintf(driver_name, "%s:%s", drv->bus->name, drv->name);
+	return driver_name;
+}
+
+static void module_create_drivers_dir(struct module_kobject *mk)
+{
+	if (!mk || mk->drivers_dir)
+		return;
+
+	mk->drivers_dir = kobject_create_and_add("drivers", &mk->kobj);
+}
+
+void module_add_driver(struct module *mod, struct device_driver *drv)
+{
+	char *driver_name;
+	int no_warn;
+	struct module_kobject *mk = NULL;
+
+	if (!drv)
+		return;
+
+	if (mod)
+		mk = &mod->mkobj;
+	else if (drv->mod_name) {
+		struct kobject *mkobj;
+
+		/* Lookup built-in module entry in /sys/modules */
+		mkobj = kset_find_obj(module_kset, drv->mod_name);
+		if (mkobj) {
+			mk = container_of(mkobj, struct module_kobject, kobj);
+			/* remember our module structure */
+			drv->mkobj = mk;
+			/* kset_find_obj took a reference */
+			kobject_put(mkobj);
+		}
+	}
+
+	if (!mk)
+		return;
+
+	/* Don't check return codes; these calls are idempotent */
+	no_warn = sysfs_create_link(&drv->kobj, &mk->kobj, "module");
+	driver_name = make_driver_name(drv);
+	if (driver_name) {
+		module_create_drivers_dir(mk);
+		no_warn = sysfs_create_link(mk->drivers_dir, &drv->kobj,
+					    driver_name);
+		kfree(driver_name);
+	}
+}
+
+void module_remove_driver(struct device_driver *drv)
+{
+	struct module_kobject *mk = NULL;
+	char *driver_name;
+
+	if (!drv)
+		return;
+
+	sysfs_remove_link(&drv->kobj, "module");
+
+	if (drv->owner)
+		mk = &drv->owner->mkobj;
+	else if (drv->mkobj)
+		mk = drv->mkobj;
+	if (mk && mk->drivers_dir) {
+		driver_name = make_driver_name(drv);
+		if (driver_name) {
+			sysfs_remove_link(mk->drivers_dir, driver_name);
+			kfree(driver_name);
+		}
+	}
+}