efi: split efisubsystem from efivars

This registers /sys/firmware/efi/{,systab,efivars/} whenever EFI is enabled
and the system is booted with EFI.

This allows
 *) userspace to check for the existence of /sys/firmware/efi as a way
    to determine whether or it is running on an EFI system.
 *) 'mount -t efivarfs none /sys/firmware/efi/efivars' without manually
    loading any modules.

[ Also, move the efivar API into vars.c and unconditionally compile it.
  This allows us to move efivars.c, which now only contains the sysfs
  variable code, into the firmware/efi directory. Note that the efivars.c
  filename is kept to maintain backwards compatability with the old
  efivars.ko module. With this patch it is now possible for efivarfs
  to be built without CONFIG_EFI_VARS - Matt ]

Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Mike Waychison <mikew@google.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Chun-Yi Lee <jlee@suse.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Tobias Powalowski <tpowa@archlinux.org>
Signed-off-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

4 files changed, 1802 insertions, 0 deletions

diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index e03cd51525c..99245ab5a79 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -1,4 +1,6 @@
 #
 # Makefile for linux kernel
 #
+obj-y					+= efi.o vars.o
+obj-$(CONFIG_EFI_VARS)			+= efivars.o
 obj-$(CONFIG_EFI_VARS_PSTORE)		+= efi-pstore.o
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
new file mode 100644
index 00000000000..32bdf4f8e43
--- /dev/null
+++ b/drivers/firmware/efi/efi.c
@@ -0,0 +1,134 @@
+/*
+ * efi.c - EFI subsystem
+ *
+ * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
+ * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
+ * Copyright (C) 2013 Tom Gundersen <teg@jklm.no>
+ *
+ * This code registers /sys/firmware/efi{,/efivars} when EFI is supported,
+ * allowing the efivarfs to be mounted or the efivars module to be loaded.
+ * The existance of /sys/firmware/efi may also be used by userspace to
+ * determine that the system supports EFI.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/kobject.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/efi.h>
+
+static struct kobject *efi_kobj;
+static struct kobject *efivars_kobj;
+
+/*
+ * Let's not leave out systab information that snuck into
+ * the efivars driver
+ */
+static ssize_t systab_show(struct kobject *kobj,
+			   struct kobj_attribute *attr, char *buf)
+{
+	char *str = buf;
+
+	if (!kobj || !buf)
+		return -EINVAL;
+
+	if (efi.mps != EFI_INVALID_TABLE_ADDR)
+		str += sprintf(str, "MPS=0x%lx\n", efi.mps);
+	if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
+		str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
+	if (efi.acpi != EFI_INVALID_TABLE_ADDR)
+		str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
+	if (efi.smbios != EFI_INVALID_TABLE_ADDR)
+		str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
+	if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
+		str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
+	if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
+		str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
+	if (efi.uga != EFI_INVALID_TABLE_ADDR)
+		str += sprintf(str, "UGA=0x%lx\n", efi.uga);
+
+	return str - buf;
+}
+
+static struct kobj_attribute efi_attr_systab =
+			__ATTR(systab, 0400, systab_show, NULL);
+
+static struct attribute *efi_subsys_attrs[] = {
+	&efi_attr_systab.attr,
+	NULL,	/* maybe more in the future? */
+};
+
+static struct attribute_group efi_subsys_attr_group = {
+	.attrs = efi_subsys_attrs,
+};
+
+static struct efivars generic_efivars;
+static struct efivar_operations generic_ops;
+
+static int generic_ops_register(void)
+{
+	generic_ops.get_variable = efi.get_variable;
+	generic_ops.set_variable = efi.set_variable;
+	generic_ops.get_next_variable = efi.get_next_variable;
+	generic_ops.query_variable_info = efi.query_variable_info;
+
+	return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
+}
+
+static void generic_ops_unregister(void)
+{
+	efivars_unregister(&generic_efivars);
+}
+
+/*
+ * We register the efi subsystem with the firmware subsystem and the
+ * efivars subsystem with the efi subsystem, if the system was booted with
+ * EFI.
+ */
+static int __init efisubsys_init(void)
+{
+	int error;
+
+	if (!efi_enabled(EFI_BOOT))
+		return 0;
+
+	/* We register the efi directory at /sys/firmware/efi */
+	efi_kobj = kobject_create_and_add("efi", firmware_kobj);
+	if (!efi_kobj) {
+		pr_err("efi: Firmware registration failed.\n");
+		return -ENOMEM;
+	}
+
+	error = generic_ops_register();
+	if (error)
+		goto err_put;
+
+	error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
+	if (error) {
+		pr_err("efi: Sysfs attribute export failed with error %d.\n",
+		       error);
+		goto err_unregister;
+	}
+
+	/* and the standard mountpoint for efivarfs */
+	efivars_kobj = kobject_create_and_add("efivars", efi_kobj);
+	if (!efivars_kobj) {
+		pr_err("efivars: Subsystem registration failed.\n");
+		error = -ENOMEM;
+		goto err_remove_group;
+	}
+
+	return 0;
+
+err_remove_group:
+	sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
+err_unregister:
+	generic_ops_unregister();
+err_put:
+	kobject_put(efi_kobj);
+	return error;
+}
+
+subsys_initcall(efisubsys_init);
diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c
new file mode 100644
index 00000000000..70635b3b59d
--- /dev/null
+++ b/drivers/firmware/efi/efivars.c
@@ -0,0 +1,617 @@
+/*
+ * Originally from efivars.c,
+ *
+ * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
+ * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
+ *
+ * This code takes all variables accessible from EFI runtime and
+ *  exports them via sysfs
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Changelog:
+ *
+ *  17 May 2004 - Matt Domsch <Matt_Domsch@dell.com>
+ *   remove check for efi_enabled in exit
+ *   add MODULE_VERSION
+ *
+ *  26 Apr 2004 - Matt Domsch <Matt_Domsch@dell.com>
+ *   minor bug fixes
+ *
+ *  21 Apr 2004 - Matt Tolentino <matthew.e.tolentino@intel.com)
+ *   converted driver to export variable information via sysfs
+ *   and moved to drivers/firmware directory
+ *   bumped revision number to v0.07 to reflect conversion & move
+ *
+ *  10 Dec 2002 - Matt Domsch <Matt_Domsch@dell.com>
+ *   fix locking per Peter Chubb's findings
+ *
+ *  25 Mar 2002 - Matt Domsch <Matt_Domsch@dell.com>
+ *   move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_unparse()
+ *
+ *  12 Feb 2002 - Matt Domsch <Matt_Domsch@dell.com>
+ *   use list_for_each_safe when deleting vars.
+ *   remove ifdef CONFIG_SMP around include <linux/smp.h>
+ *   v0.04 release to linux-ia64@linuxia64.org
+ *
+ *  20 April 2001 - Matt Domsch <Matt_Domsch@dell.com>
+ *   Moved vars from /proc/efi to /proc/efi/vars, and made
+ *   efi.c own the /proc/efi directory.
+ *   v0.03 release to linux-ia64@linuxia64.org
+ *
+ *  26 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
+ *   At the request of Stephane, moved ownership of /proc/efi
+ *   to efi.c, and now efivars lives under /proc/efi/vars.
+ *
+ *  12 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
+ *   Feedback received from Stephane Eranian incorporated.
+ *   efivar_write() checks copy_from_user() return value.
+ *   efivar_read/write() returns proper errno.
+ *   v0.02 release to linux-ia64@linuxia64.org
+ *
+ *  26 February 2001 - Matt Domsch <Matt_Domsch@dell.com>
+ *   v0.01 release to linux-ia64@linuxia64.org
+ */
+
+#include <linux/efi.h>
+#include <linux/module.h>
+
+#define EFIVARS_VERSION "0.08"
+#define EFIVARS_DATE "2004-May-17"
+
+MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
+MODULE_DESCRIPTION("sysfs interface to EFI Variables");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(EFIVARS_VERSION);
+
+LIST_HEAD(efivar_sysfs_list);
+EXPORT_SYMBOL_GPL(efivar_sysfs_list);
+
+static struct kset *efivars_kset;
+
+static struct bin_attribute *efivars_new_var;
+static struct bin_attribute *efivars_del_var;
+
+struct efivar_attribute {
+	struct attribute attr;
+	ssize_t (*show) (struct efivar_entry *entry, char *buf);
+	ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
+};
+
+#define EFIVAR_ATTR(_name, _mode, _show, _store) \
+struct efivar_attribute efivar_attr_##_name = { \
+	.attr = {.name = __stringify(_name), .mode = _mode}, \
+	.show = _show, \
+	.store = _store, \
+};
+
+#define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
+#define to_efivar_entry(obj)  container_of(obj, struct efivar_entry, kobj)
+
+/*
+ * Prototype for sysfs creation function
+ */
+static int
+efivar_create_sysfs_entry(struct efivar_entry *new_var);
+
+static ssize_t
+efivar_guid_read(struct efivar_entry *entry, char *buf)
+{
+	struct efi_variable *var = &entry->var;
+	char *str = buf;
+
+	if (!entry || !buf)
+		return 0;
+
+	efi_guid_unparse(&var->VendorGuid, str);
+	str += strlen(str);
+	str += sprintf(str, "\n");
+
+	return str - buf;
+}
+
+static ssize_t
+efivar_attr_read(struct efivar_entry *entry, char *buf)
+{
+	struct efi_variable *var = &entry->var;
+	char *str = buf;
+
+	if (!entry || !buf)
+		return -EINVAL;
+
+	var->DataSize = 1024;
+	if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data))
+		return -EIO;
+
+	if (var->Attributes & EFI_VARIABLE_NON_VOLATILE)
+		str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
+	if (var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS)
+		str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
+	if (var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS)
+		str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
+	if (var->Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD)
+		str += sprintf(str, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n");
+	if (var->Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS)
+		str += sprintf(str,
+			"EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n");
+	if (var->Attributes &
+			EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)
+		str += sprintf(str,
+			"EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n");
+	if (var->Attributes & EFI_VARIABLE_APPEND_WRITE)
+		str += sprintf(str, "EFI_VARIABLE_APPEND_WRITE\n");
+	return str - buf;
+}
+
+static ssize_t
+efivar_size_read(struct efivar_entry *entry, char *buf)
+{
+	struct efi_variable *var = &entry->var;
+	char *str = buf;
+
+	if (!entry || !buf)
+		return -EINVAL;
+
+	var->DataSize = 1024;
+	if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data))
+		return -EIO;
+
+	str += sprintf(str, "0x%lx\n", var->DataSize);
+	return str - buf;
+}
+
+static ssize_t
+efivar_data_read(struct efivar_entry *entry, char *buf)
+{
+	struct efi_variable *var = &entry->var;
+
+	if (!entry || !buf)
+		return -EINVAL;
+
+	var->DataSize = 1024;
+	if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data))
+		return -EIO;
+
+	memcpy(buf, var->Data, var->DataSize);
+	return var->DataSize;
+}
+/*
+ * We allow each variable to be edited via rewriting the
+ * entire efi variable structure.
+ */
+static ssize_t
+efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
+{
+	struct efi_variable *new_var, *var = &entry->var;
+	int err;
+
+	if (count != sizeof(struct efi_variable))
+		return -EINVAL;
+
+	new_var = (struct efi_variable *)buf;
+	/*
+	 * If only updating the variable data, then the name
+	 * and guid should remain the same
+	 */
+	if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
+		efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
+		printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
+		return -EINVAL;
+	}
+
+	if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
+		printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
+		return -EINVAL;
+	}
+
+	if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
+	    efivar_validate(new_var, new_var->Data, new_var->DataSize) == false) {
+		printk(KERN_ERR "efivars: Malformed variable content\n");
+		return -EINVAL;
+	}
+
+	memcpy(&entry->var, new_var, count);
+
+	err = efivar_entry_set(entry, new_var->Attributes,
+			       new_var->DataSize, new_var->Data, false);
+	if (err) {
+		printk(KERN_WARNING "efivars: set_variable() failed: status=%d\n", err);
+		return -EIO;
+	}
+
+	return count;
+}
+
+static ssize_t
+efivar_show_raw(struct efivar_entry *entry, char *buf)
+{
+	struct efi_variable *var = &entry->var;
+
+	if (!entry || !buf)
+		return 0;
+
+	var->DataSize = 1024;
+	if (efivar_entry_get(entry, &entry->var.Attributes,
+			     &entry->var.DataSize, entry->var.Data))
+		return -EIO;
+
+	memcpy(buf, var, sizeof(*var));
+
+	return sizeof(*var);
+}
+
+/*
+ * Generic read/write functions that call the specific functions of
+ * the attributes...
+ */
+static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
+				char *buf)
+{
+	struct efivar_entry *var = to_efivar_entry(kobj);
+	struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
+	ssize_t ret = -EIO;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	if (efivar_attr->show) {
+		ret = efivar_attr->show(var, buf);
+	}
+	return ret;
+}
+
+static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
+				const char *buf, size_t count)
+{
+	struct efivar_entry *var = to_efivar_entry(kobj);
+	struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
+	ssize_t ret = -EIO;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	if (efivar_attr->store)
+		ret = efivar_attr->store(var, buf, count);
+
+	return ret;
+}
+
+static const struct sysfs_ops efivar_attr_ops = {
+	.show = efivar_attr_show,
+	.store = efivar_attr_store,
+};
+
+static void efivar_release(struct kobject *kobj)
+{
+	struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
+	kfree(var);
+}
+
+static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
+static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
+static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
+static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
+static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
+
+static struct attribute *def_attrs[] = {
+	&efivar_attr_guid.attr,
+	&efivar_attr_size.attr,
+	&efivar_attr_attributes.attr,
+	&efivar_attr_data.attr,
+	&efivar_attr_raw_var.attr,
+	NULL,
+};
+
+static struct kobj_type efivar_ktype = {
+	.release = efivar_release,
+	.sysfs_ops = &efivar_attr_ops,
+	.default_attrs = def_attrs,
+};
+
+static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
+			     struct bin_attribute *bin_attr,
+			     char *buf, loff_t pos, size_t count)
+{
+	struct efi_variable *new_var = (struct efi_variable *)buf;
+	struct efivar_entry *new_entry;
+	int err;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
+	    efivar_validate(new_var, new_var->Data, new_var->DataSize) == false) {
+		printk(KERN_ERR "efivars: Malformed variable content\n");
+		return -EINVAL;
+	}
+
+	new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL);
+	if (!new_entry)
+		return -ENOMEM;
+
+	memcpy(&new_entry->var, new_var, sizeof(*new_var));
+
+	err = efivar_entry_set(new_entry, new_var->Attributes, new_var->DataSize,
+			       new_var->Data, &efivar_sysfs_list);
+	if (err) {
+		if (err == -EEXIST)
+			err = -EINVAL;
+		goto out;
+	}
+
+	if (efivar_create_sysfs_entry(new_entry)) {
+		printk(KERN_WARNING "efivars: failed to create sysfs entry.\n");
+		kfree(new_entry);
+	}
+	return count;
+
+out:
+	kfree(new_entry);
+	return err;
+}
+
+static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
+			     struct bin_attribute *bin_attr,
+			     char *buf, loff_t pos, size_t count)
+{
+	struct efi_variable *del_var = (struct efi_variable *)buf;
+	struct efivar_entry *entry;
+	int err = 0;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	efivar_entry_iter_begin();
+	entry = efivar_entry_find(del_var->VariableName, del_var->VendorGuid,
+				  &efivar_sysfs_list, true);
+	if (!entry)
+		err = -EINVAL;
+	else if (__efivar_entry_delete(entry))
+		err = -EIO;
+
+	efivar_entry_iter_end();
+
+	if (err)
+		return err;
+
+	efivar_unregister(entry);
+
+	/* It's dead Jim.... */
+	return count;
+}
+
+/**
+ * efivar_create_sysfs_entry - create a new entry in sysfs
+ * @new_var: efivar entry to create
+ *
+ * Returns 1 on failure, 0 on success
+ */
+static int
+efivar_create_sysfs_entry(struct efivar_entry *new_var)
+{
+	int i, short_name_size;
+	char *short_name;
+	unsigned long variable_name_size;
+	efi_char16_t *variable_name;
+
+	variable_name = new_var->var.VariableName;
+	variable_name_size = utf16_strlen(variable_name) * sizeof(efi_char16_t);
+
+	/*
+	 * Length of the variable bytes in ASCII, plus the '-' separator,
+	 * plus the GUID, plus trailing NUL
+	 */
+	short_name_size = variable_name_size / sizeof(efi_char16_t)
+				+ 1 + EFI_VARIABLE_GUID_LEN + 1;
+
+	short_name = kzalloc(short_name_size, GFP_KERNEL);
+
+	if (!short_name) {
+		kfree(short_name);
+		return 1;
+	}
+
+	/* Convert Unicode to normal chars (assume top bits are 0),
+	   ala UTF-8 */
+	for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
+		short_name[i] = variable_name[i] & 0xFF;
+	}
+	/* This is ugly, but necessary to separate one vendor's
+	   private variables from another's.         */
+
+	*(short_name + strlen(short_name)) = '-';
+	efi_guid_unparse(&new_var->var.VendorGuid,
+			 short_name + strlen(short_name));
+
+	new_var->kobj.kset = efivars_kset;
+
+	i = kobject_init_and_add(&new_var->kobj, &efivar_ktype,
+				   NULL, "%s", short_name);
+	kfree(short_name);
+	if (i)
+		return 1;
+
+	kobject_uevent(&new_var->kobj, KOBJ_ADD);
+	efivar_entry_add(new_var, &efivar_sysfs_list);
+
+	return 0;
+}
+
+static int
+create_efivars_bin_attributes(void)
+{
+	struct bin_attribute *attr;
+	int error;
+
+	/* new_var */
+	attr = kzalloc(sizeof(*attr), GFP_KERNEL);
+	if (!attr)
+		return -ENOMEM;
+
+	attr->attr.name = "new_var";
+	attr->attr.mode = 0200;
+	attr->write = efivar_create;
+	efivars_new_var = attr;
+
+	/* del_var */
+	attr = kzalloc(sizeof(*attr), GFP_KERNEL);
+	if (!attr) {
+		error = -ENOMEM;
+		goto out_free;
+	}
+	attr->attr.name = "del_var";
+	attr->attr.mode = 0200;
+	attr->write = efivar_delete;
+	efivars_del_var = attr;
+
+	sysfs_bin_attr_init(efivars_new_var);
+	sysfs_bin_attr_init(efivars_del_var);
+
+	/* Register */
+	error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_new_var);
+	if (error) {
+		printk(KERN_ERR "efivars: unable to create new_var sysfs file"
+			" due to error %d\n", error);
+		goto out_free;
+	}
+
+	error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_del_var);
+	if (error) {
+		printk(KERN_ERR "efivars: unable to create del_var sysfs file"
+			" due to error %d\n", error);
+		sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var);
+		goto out_free;
+	}
+
+	return 0;
+out_free:
+	kfree(efivars_del_var);
+	efivars_del_var = NULL;
+	kfree(efivars_new_var);
+	efivars_new_var = NULL;
+	return error;
+}
+
+static int efivar_update_sysfs_entry(efi_char16_t *name, efi_guid_t vendor,
+				     unsigned long name_size, void *data)
+{
+	struct efivar_entry *entry = data;
+
+	if (efivar_entry_find(name, vendor, &efivar_sysfs_list, false))
+		return 0;
+
+	memcpy(entry->var.VariableName, name, name_size);
+	memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
+
+	return 1;
+}
+
+static void efivar_update_sysfs_entries(struct work_struct *work)
+{
+	struct efivar_entry *entry;
+	int err;
+
+	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry)
+		return;
+
+	/* Add new sysfs entries */
+	while (1) {
+		memset(entry, 0, sizeof(*entry));
+
+		err = efivar_init(efivar_update_sysfs_entry, entry,
+				  true, false, &efivar_sysfs_list);
+		if (!err)
+			break;
+
+		efivar_create_sysfs_entry(entry);
+	}
+
+	kfree(entry);
+}
+
+static int efivars_sysfs_callback(efi_char16_t *name, efi_guid_t vendor,
+				  unsigned long name_size, void *data)
+{
+	struct efivar_entry *entry;
+
+	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry)
+		return -ENOMEM;
+
+	memcpy(entry->var.VariableName, name, name_size);
+	memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
+
+	efivar_create_sysfs_entry(entry);
+
+	return 0;
+}
+
+static int efivar_sysfs_destroy(struct efivar_entry *entry, void *data)
+{
+	efivar_entry_remove(entry);
+	efivar_unregister(entry);
+	return 0;
+}
+
+void efivars_sysfs_exit(void)
+{
+	/* Remove all entries and destroy */
+	__efivar_entry_iter(efivar_sysfs_destroy, &efivar_sysfs_list, NULL, NULL);
+
+	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);
+}
+
+int efivars_sysfs_init(void)
+{
+	struct kobject *parent_kobj = efivars_kobject();
+	int error = 0;
+
+	/* No efivars has been registered yet */
+	if (!parent_kobj)
+		return 0;
+
+	printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
+	       EFIVARS_DATE);
+
+	efivars_kset = kset_create_and_add("vars", NULL, parent_kobj);
+	if (!efivars_kset) {
+		printk(KERN_ERR "efivars: Subsystem registration failed.\n");
+		return -ENOMEM;
+	}
+
+	efivar_init(efivars_sysfs_callback, NULL, false,
+		    true, &efivar_sysfs_list);
+
+	error = create_efivars_bin_attributes();
+	if (error) {
+		efivars_sysfs_exit();
+		return error;
+	}
+
+	INIT_WORK(&efivar_work, efivar_update_sysfs_entries);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(efivars_sysfs_init);
+
+module_init(efivars_sysfs_init);
+module_exit(efivars_sysfs_exit);
diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
new file mode 100644
index 00000000000..dd1c20a426f
--- /dev/null
+++ b/drivers/firmware/efi/vars.c
@@ -0,0 +1,1049 @@
+/*
+ * Originally from efivars.c
+ *
+ * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
+ * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/capability.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/smp.h>
+#include <linux/efi.h>
+#include <linux/sysfs.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/ctype.h>
+
+/* Private pointer to registered efivars */
+static struct efivars *__efivars;
+
+static bool efivar_wq_enabled = true;
+DECLARE_WORK(efivar_work, NULL);
+EXPORT_SYMBOL_GPL(efivar_work);
+
+static bool
+validate_device_path(struct efi_variable *var, int match, u8 *buffer,
+		     unsigned long len)
+{
+	struct efi_generic_dev_path *node;
+	int offset = 0;
+
+	node = (struct efi_generic_dev_path *)buffer;
+
+	if (len < sizeof(*node))
+		return false;
+
+	while (offset <= len - sizeof(*node) &&
+	       node->length >= sizeof(*node) &&
+		node->length <= len - offset) {
+		offset += node->length;
+
+		if ((node->type == EFI_DEV_END_PATH ||
+		     node->type == EFI_DEV_END_PATH2) &&
+		    node->sub_type == EFI_DEV_END_ENTIRE)
+			return true;
+
+		node = (struct efi_generic_dev_path *)(buffer + offset);
+	}
+
+	/*
+	 * If we're here then either node->length pointed past the end
+	 * of the buffer or we reached the end of the buffer without
+	 * finding a device path end node.
+	 */
+	return false;
+}
+
+static bool
+validate_boot_order(struct efi_variable *var, int match, u8 *buffer,
+		    unsigned long len)
+{
+	/* An array of 16-bit integers */
+	if ((len % 2) != 0)
+		return false;
+
+	return true;
+}
+
+static bool
+validate_load_option(struct efi_variable *var, int match, u8 *buffer,
+		     unsigned long len)
+{
+	u16 filepathlength;
+	int i, desclength = 0, namelen;
+
+	namelen = utf16_strnlen(var->VariableName, sizeof(var->VariableName));
+
+	/* Either "Boot" or "Driver" followed by four digits of hex */
+	for (i = match; i < match+4; i++) {
+		if (var->VariableName[i] > 127 ||
+		    hex_to_bin(var->VariableName[i] & 0xff) < 0)
+			return true;
+	}
+
+	/* Reject it if there's 4 digits of hex and then further content */
+	if (namelen > match + 4)
+		return false;
+
+	/* A valid entry must be at least 8 bytes */
+	if (len < 8)
+		return false;
+
+	filepathlength = buffer[4] | buffer[5] << 8;
+
+	/*
+	 * There's no stored length for the description, so it has to be
+	 * found by hand
+	 */
+	desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
+
+	/* Each boot entry must have a descriptor */
+	if (!desclength)
+		return false;
+
+	/*
+	 * If the sum of the length of the description, the claimed filepath
+	 * length and the original header are greater than the length of the
+	 * variable, it's malformed
+	 */
+	if ((desclength + filepathlength + 6) > len)
+		return false;
+
+	/*
+	 * And, finally, check the filepath
+	 */
+	return validate_device_path(var, match, buffer + desclength + 6,
+				    filepathlength);
+}
+
+static bool
+validate_uint16(struct efi_variable *var, int match, u8 *buffer,
+		unsigned long len)
+{
+	/* A single 16-bit integer */
+	if (len != 2)
+		return false;
+
+	return true;
+}
+
+static bool
+validate_ascii_string(struct efi_variable *var, int match, u8 *buffer,
+		      unsigned long len)
+{
+	int i;
+
+	for (i = 0; i < len; i++) {
+		if (buffer[i] > 127)
+			return false;
+
+		if (buffer[i] == 0)
+			return true;
+	}
+
+	return false;
+}
+
+struct variable_validate {
+	char *name;
+	bool (*validate)(struct efi_variable *var, int match, u8 *data,
+			 unsigned long len);
+};
+
+static const struct variable_validate variable_validate[] = {
+	{ "BootNext", validate_uint16 },
+	{ "BootOrder", validate_boot_order },
+	{ "DriverOrder", validate_boot_order },
+	{ "Boot*", validate_load_option },
+	{ "Driver*", validate_load_option },
+	{ "ConIn", validate_device_path },
+	{ "ConInDev", validate_device_path },
+	{ "ConOut", validate_device_path },
+	{ "ConOutDev", validate_device_path },
+	{ "ErrOut", validate_device_path },
+	{ "ErrOutDev", validate_device_path },
+	{ "Timeout", validate_uint16 },
+	{ "Lang", validate_ascii_string },
+	{ "PlatformLang", validate_ascii_string },
+	{ "", NULL },
+};
+
+bool
+efivar_validate(struct efi_variable *var, u8 *data, unsigned long len)
+{
+	int i;
+	u16 *unicode_name = var->VariableName;
+
+	for (i = 0; variable_validate[i].validate != NULL; i++) {
+		const char *name = variable_validate[i].name;
+		int match;
+
+		for (match = 0; ; match++) {
+			char c = name[match];
+			u16 u = unicode_name[match];
+
+			/* All special variables are plain ascii */
+			if (u > 127)
+				return true;
+
+			/* Wildcard in the matching name means we've matched */
+			if (c == '*')
+				return variable_validate[i].validate(var,
+							     match, data, len);
+
+			/* Case sensitive match */
+			if (c != u)
+				break;
+
+			/* Reached the end of the string while matching */
+			if (!c)
+				return variable_validate[i].validate(var,
+							     match, data, len);
+		}
+	}
+
+	return true;
+}
+EXPORT_SYMBOL_GPL(efivar_validate);
+
+static efi_status_t
+check_var_size(u32 attributes, unsigned long size)
+{
+	u64 storage_size, remaining_size, max_size;
+	efi_status_t status;
+	const struct efivar_operations *fops = __efivars->ops;
+
+	if (!fops->query_variable_info)
+		return EFI_UNSUPPORTED;
+
+	status = fops->query_variable_info(attributes, &storage_size,
+					   &remaining_size, &max_size);
+
+	if (status != EFI_SUCCESS)
+		return status;
+
+	if (!storage_size || size > remaining_size || size > max_size ||
+	    (remaining_size - size) < (storage_size / 2))
+		return EFI_OUT_OF_RESOURCES;
+
+	return status;
+}
+
+static int efi_status_to_err(efi_status_t status)
+{
+	int err;
+
+	switch (status) {
+	case EFI_SUCCESS:
+		err = 0;
+		break;
+	case EFI_INVALID_PARAMETER:
+		err = -EINVAL;
+		break;
+	case EFI_OUT_OF_RESOURCES:
+		err = -ENOSPC;
+		break;
+	case EFI_DEVICE_ERROR:
+		err = -EIO;
+		break;
+	case EFI_WRITE_PROTECTED:
+		err = -EROFS;
+		break;
+	case EFI_SECURITY_VIOLATION:
+		err = -EACCES;
+		break;
+	case EFI_NOT_FOUND:
+		err = -ENOENT;
+		break;
+	default:
+		err = -EINVAL;
+	}
+
+	return err;
+}
+
+static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor,
+				struct list_head *head)
+{
+	struct efivar_entry *entry, *n;
+	unsigned long strsize1, strsize2;
+	bool found = false;
+
+	strsize1 = utf16_strsize(variable_name, 1024);
+	list_for_each_entry_safe(entry, n, head, list) {
+		strsize2 = utf16_strsize(entry->var.VariableName, 1024);
+		if (strsize1 == strsize2 &&
+			!memcmp(variable_name, &(entry->var.VariableName),
+				strsize2) &&
+			!efi_guidcmp(entry->var.VendorGuid,
+				*vendor)) {
+			found = true;
+			break;
+		}
+	}
+	return found;
+}
+
+/*
+ * Returns the size of variable_name, in bytes, including the
+ * terminating NULL character, or variable_name_size if no NULL
+ * character is found among the first variable_name_size bytes.
+ */
+static unsigned long var_name_strnsize(efi_char16_t *variable_name,
+				       unsigned long variable_name_size)
+{
+	unsigned long len;
+	efi_char16_t c;
+
+	/*
+	 * The variable name is, by definition, a NULL-terminated
+	 * string, so make absolutely sure that variable_name_size is
+	 * the value we expect it to be. If not, return the real size.
+	 */
+	for (len = 2; len <= variable_name_size; len += sizeof(c)) {
+		c = variable_name[(len / sizeof(c)) - 1];
+		if (!c)
+			break;
+	}
+
+	return min(len, variable_name_size);
+}
+
+/*
+ * Print a warning when duplicate EFI variables are encountered and
+ * disable the sysfs workqueue since the firmware is buggy.
+ */
+static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid,
+			     unsigned long len16)
+{
+	size_t i, len8 = len16 / sizeof(efi_char16_t);
+	char *s8;
+
+	/*
+	 * Disable the workqueue since the algorithm it uses for
+	 * detecting new variables won't work with this buggy
+	 * implementation of GetNextVariableName().
+	 */
+	efivar_wq_enabled = false;
+
+	s8 = kzalloc(len8, GFP_KERNEL);
+	if (!s8)
+		return;
+
+	for (i = 0; i < len8; i++)
+		s8[i] = s16[i];
+
+	printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n",
+	       s8, vendor_guid);
+	kfree(s8);
+}
+
+