efivars: Split out variable registration

In anticipation of re-using the variable facilities in efivars from
elsewhere, split out the registration and unregistration of struct
efivars from the rest of the EFI specific sysfs code.

Signed-off-by: Mike Waychison <mikew@google.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>,
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 67 insertions, 55 deletions

diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index 5633018c34af..f22bfcf2b968 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -95,7 +95,7 @@ struct efivars {
          * 1) ->list - adds, removals, reads, writes
          * 2) efi.[gs]et_variable() calls.
          * It must not be held when creating sysfs entries or calling kmalloc.
-         * efi.get_next_variable() is only called from efivars_init(),
+         * efi.get_next_variable() is only called from register_efivars(),
          * which is protected by the BKL, so that path is safe.
          */
         spinlock_t lock;
@@ -699,54 +699,48 @@ out_free:
         return error;
 }
 
-static struct efivars __efivars;
+static void unregister_efivars(struct efivars *efivars)
+{
+        struct efivar_entry *entry, *n;
 
-/*
- * For now we register the efi subsystem with the firmware subsystem
- * and the vars subsystem with the efi subsystem.  In the future, it
- * might make sense to split off the efi subsystem into its own
- * driver, but for now only efivars will register with it, so just
- * include it here.
- */
+        list_for_each_entry_safe(entry, n, &efivars->list, list) {
+                spin_lock(&efivars->lock);
+                list_del(&entry->list);
+                spin_unlock(&efivars->lock);
+                efivar_unregister(entry);
+        }
+        if (efivars->new_var)
+                sysfs_remove_bin_file(&efivars->kset->kobj, efivars->new_var);
+        if (efivars->del_var)
+                sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var);
+        kfree(efivars->new_var);
+        kfree(efivars->del_var);
+        kset_unregister(efivars->kset);
+}
 
-static int __init
-efivars_init(void)
+static int register_efivars(struct efivars *efivars,
+                            struct kobject *parent_kobj)
 {
         efi_status_t status = EFI_NOT_FOUND;
         efi_guid_t vendor_guid;
         efi_char16_t *variable_name;
         unsigned long variable_name_size = 1024;
-        struct efivars *efivars = &__efivars;
         int error = 0;
 
-        if (!efi_enabled)
-                return -ENODEV;
-
         variable_name = kzalloc(variable_name_size, GFP_KERNEL);
         if (!variable_name) {
                 printk(KERN_ERR "efivars: Memory allocation failed.\n");
                 return -ENOMEM;
         }
 
-        printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
-               EFIVARS_DATE);
-
-        /* For now we'll register the efi directory at /sys/firmware/efi */
-        efi_kobj = kobject_create_and_add("efi", firmware_kobj);
-        if (!efi_kobj) {
-                printk(KERN_ERR "efivars: Firmware registration failed.\n");
-                error = -ENOMEM;
-                goto out_free;
-        }
-
         spin_lock_init(&efivars->lock);
         INIT_LIST_HEAD(&efivars->list);
 
-        efivars->kset = kset_create_and_add("vars", NULL, efi_kobj);
+        efivars->kset = kset_create_and_add("vars", NULL, parent_kobj);
         if (!efivars->kset) {
                 printk(KERN_ERR "efivars: Subsystem registration failed.\n");
                 error = -ENOMEM;
-                goto out_firmware_unregister;
+                goto out;
         }
 
         /*
@@ -778,21 +772,54 @@ efivars_init(void)
         } while (status != EFI_NOT_FOUND);
 
         error = create_efivars_bin_attributes(efivars);
-
-        /* Don't forget the systab entry */
-        error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
         if (error)
-                printk(KERN_ERR "efivars: Sysfs attribute export failed with error %d.\n", error);
-        else
-                goto out_free;
+                unregister_efivars(efivars);
 
-        kset_unregister(efivars->kset);
+out:
+        kfree(variable_name);
 
-out_firmware_unregister:
-        kobject_put(efi_kobj);
+        return error;
+}
 
-out_free:
-        kfree(variable_name);
+static struct efivars __efivars;
+
+/*
+ * For now we register the efi subsystem with the firmware subsystem
+ * and the vars subsystem with the efi subsystem.  In the future, it
+ * might make sense to split off the efi subsystem into its own
+ * driver, but for now only efivars will register with it, so just
+ * include it here.
+ */
+
+static int __init
+efivars_init(void)
+{
+        int error = 0;
+
+        printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
+               EFIVARS_DATE);
+
+        if (!efi_enabled)
+                return -ENODEV;
+
+        /* For now we'll register the efi directory at /sys/firmware/efi */
+        efi_kobj = kobject_create_and_add("efi", firmware_kobj);
+        if (!efi_kobj) {
+                printk(KERN_ERR "efivars: Firmware registration failed.\n");
+                return -ENOMEM;
+        }
+
+        error = register_efivars(&__efivars, efi_kobj);
+
+        /* Don't forget the systab entry */
+        error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
+        if (error) {
+                printk(KERN_ERR
+                       "efivars: Sysfs attribute export failed with error %d.\n",
+                       error);
+                unregister_efivars(&__efivars);
+                kobject_put(efi_kobj);
+        }
 
         return error;
 }
@@ -800,22 +827,7 @@ out_free:
 static void __exit
 efivars_exit(void)
 {
-        struct efivars *efivars = &__efivars;
-        struct efivar_entry *entry, *n;
-
-        list_for_each_entry_safe(entry, n, &efivars->list, list) {
-                spin_lock(&efivars->lock);
-                list_del(&entry->list);
-                spin_unlock(&efivars->lock);
-                efivar_unregister(entry);
-        }
-        if (efivars->new_var)
-                sysfs_remove_bin_file(&efivars->kset->kobj, efivars->new_var);
-        if (efivars->del_var)
-                sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var);
-        kfree(efivars->new_var);
-        kfree(efivars->del_var);
-        kset_unregister(efivars->kset);
+        unregister_efivars(&__efivars);
         kobject_put(efi_kobj);
 }