[PATCH 3/4] efi: add efivars kobject to efi sysfs folder

[Andy Whitcroft]

From: "Lee, Chun-Yi" <joeyli.kernel at gmail.com>

UEFI variable filesystem need a new mount point, so this patch add
efivars kobject to efi_kobj for create a /sys/firmware/efi/efivars
folder.

Cc: Matthew Garrett <mjg at redhat.com>
Cc: H. Peter Anvin <hpa at zytor.com>
Signed-off-by: Lee, Chun-Yi <jlee at suse.com>
Signed-off-by: Jeremy Kerr <jeremy.kerr at canonical.com>
Signed-off-by: Matt Fleming <matt.fleming at intel.com>

(cherry-picked from commit 7b218e8e5d433fc8b531ce911926e06de3e6f1f6 efi.git)
BugLink: http://bugs.launchpad.net/bugs/1063061
Signed-off-by: Andy Whitcroft <apw at canonical.com>
---
 drivers/firmware/efivars.c |   11 +++++++++++
 include/linux/efi.h        |    1 +
 2 files changed, 12 insertions(+)

diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index 6d43bbd..4b12a8fd 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -1527,6 +1527,7 @@ void unregister_efivars(struct efivars *efivars)
 		sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var);
 	kfree(efivars->new_var);
 	kfree(efivars->del_var);
+	kobject_put(efivars->kobject);
 	kset_unregister(efivars->kset);
 }
 EXPORT_SYMBOL_GPL(unregister_efivars);
@@ -1558,6 +1559,13 @@ int register_efivars(struct efivars *efivars,
 		goto out;
 	}
 
+	efivars->kobject = kobject_create_and_add("efivars", parent_kobj);
+	if (!efivars->kobject) {
+		pr_err("efivars: Subsystem registration failed.\n");
+		error = -ENOMEM;
+		goto err_unreg_vars;
+	}
+
 	/*
 	 * Per EFI spec, the maximum storage allocated for both
 	 * the variable name and variable data is 1024 bytes.
@@ -1602,6 +1610,9 @@ int register_efivars(struct efivars *efivars,
 
 	register_filesystem(&efivarfs_type);
 
+err_unreg_vars:
+	kset_unregister(efivars->kset);
+
 out:
 	kfree(variable_name);
 
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 1829a97..c993f54 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -654,6 +654,7 @@ struct efivars {
 	spinlock_t lock;
 	struct list_head list;
 	struct kset *kset;
+	struct kobject *kobject;
 	struct bin_attribute *new_var, *del_var;
 	const struct efivar_operations *ops;
 	struct efivar_entry *walk_entry;
-- 
1.7.9.5