efi: split efisubsystem from efivars
Tom Gundersen [Fri, 8 Feb 2013 15:37:06 +0000 (15:37 +0000)]
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>

MAINTAINERS
drivers/firmware/Makefile
drivers/firmware/efi/Makefile
drivers/firmware/efi/efi.c [new file with mode: 0644]
drivers/firmware/efi/efivars.c [new file with mode: 0644]
drivers/firmware/efi/vars.c [new file with mode: 0644]
drivers/firmware/efivars.c [deleted file]
fs/efivarfs/Kconfig
include/linux/efi.h

index 0855f44..e0cd7e5 100644 (file)
@@ -2987,7 +2987,7 @@ F:        arch/ia64/kernel/efi.c
 F:     arch/x86/boot/compressed/eboot.[ch]
 F:     arch/x86/include/asm/efi.h
 F:     arch/x86/platform/efi/*
-F:     drivers/firmware/efivars.c
+F:     drivers/firmware/efi/*
 F:     include/linux/efi*.h
 
 EFI VARIABLE FILESYSTEM
index 31bf68c..299fad6 100644 (file)
@@ -4,7 +4,6 @@
 obj-$(CONFIG_DMI)              += dmi_scan.o
 obj-$(CONFIG_DMI_SYSFS)                += dmi-sysfs.o
 obj-$(CONFIG_EDD)              += edd.o
-obj-$(CONFIG_EFI_VARS)         += efivars.o
 obj-$(CONFIG_EFI_PCDP)         += pcdp.o
 obj-$(CONFIG_DELL_RBU)          += dell_rbu.o
 obj-$(CONFIG_DCDBAS)           += dcdbas.o
index e03cd51..99245ab 100644 (file)
@@ -1,4 +1,6 @@
 #
 # Makefile for linux kernel
 #
+obj-y                                  += efi.o vars.o
+obj-$(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 (file)
index 0000000..32bdf4f
--- /dev/null
@@ -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 (file)
index 0000000..70635b3
--- /dev/null
@@ -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 (file)
index 0000000..dd1c20a
--- /dev/null
@@ -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);
+}
+
+/**
+ * efivar_init - build the initial list of EFI variables
+ * @func: callback function to invoke for every variable
+ * @data: function-specific data to pass to @func
+ * @atomic: do we need to execute the @func-loop atomically?
+ * @duplicates: error if we encounter duplicates on @head?
+ * @head: initialised head of variable list
+ *
+ * Get every EFI variable from the firmware and invoke @func. @func
+ * should call efivar_entry_add() to build the list of variables.
+ *
+ * Returns 0 on success, or a kernel error code on failure.
+ */
+int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
+               void *data, bool atomic, bool duplicates,
+               struct list_head *head)
+{
+       const struct efivar_operations *ops = __efivars->ops;
+       unsigned long variable_name_size = 1024;
+       efi_char16_t *variable_name;
+       efi_status_t status;
+       efi_guid_t vendor_guid;
+       int err = 0;
+
+       variable_name = kzalloc(variable_name_size, GFP_KERNEL);
+       if (!variable_name) {
+               printk(KERN_ERR "efivars: Memory allocation failed.\n");
+               return -ENOMEM;
+       }
+
+       spin_lock_irq(&__efivars->lock);
+
+       /*
+        * Per EFI spec, the maximum storage allocated for both
+        * the variable name and variable data is 1024 bytes.
+        */
+
+       do {
+               variable_name_size = 1024;
+
+               status = ops->get_next_variable(&variable_name_size,
+                                               variable_name,
+                                               &vendor_guid);
+               switch (status) {
+               case EFI_SUCCESS:
+                       if (!atomic)
+                               spin_unlock_irq(&__efivars->lock);
+
+                       variable_name_size = var_name_strnsize(variable_name,
+                                                              variable_name_size);
+
+                       /*
+                        * Some firmware implementations return the
+                        * same variable name on multiple calls to
+                        * get_next_variable(). Terminate the loop
+                        * immediately as there is no guarantee that
+                        * we'll ever see a different variable name,
+                        * and may end up looping here forever.
+                        */
+                       if (duplicates &&
+                           variable_is_present(variable_name, &vendor_guid, head)) {
+                               dup_variable_bug(variable_name, &vendor_guid,
+                                                variable_name_size);
+                               if (!atomic)
+                                       spin_lock_irq(&__efivars->lock);
+
+                               status = EFI_NOT_FOUND;
+                               break;
+                       }
+
+                       err = func(variable_name, vendor_guid, variable_name_size, data);
+                       if (err)
+                               status = EFI_NOT_FOUND;
+
+                       if (!atomic)
+                               spin_lock_irq(&__efivars->lock);
+
+                       break;
+               case EFI_NOT_FOUND:
+                       break;
+               default:
+                       printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
+                               status);
+                       status = EFI_NOT_FOUND;
+                       break;
+               }
+
+       } while (status != EFI_NOT_FOUND);
+
+       spin_unlock_irq(&__efivars->lock);
+
+       kfree(variable_name);
+
+       return err;
+}
+EXPORT_SYMBOL_GPL(efivar_init);
+
+/**
+ * efivar_entry_add - add entry to variable list
+ * @entry: entry to add to list
+ * @head: list head
+ */
+void efivar_entry_add(struct efivar_entry *entry, struct list_head *head)
+{
+       spin_lock_irq(&__efivars->lock);
+       list_add(&entry->list, head);
+       spin_unlock_irq(&__efivars->lock);
+}
+EXPORT_SYMBOL_GPL(efivar_entry_add);
+
+/**
+ * efivar_entry_remove - remove entry from variable list
+ * @entry: entry to remove from list
+ */
+void efivar_entry_remove(struct efivar_entry *entry)
+{
+       spin_lock_irq(&__efivars->lock);
+       list_del(&entry->list);
+       spin_unlock_irq(&__efivars->lock);
+}
+EXPORT_SYMBOL_GPL(efivar_entry_remove);
+
+/*
+ * efivar_entry_list_del_unlock - remove entry from variable list
+ * @entry: entry to remove
+ *
+ * Remove @entry from the variable list and release the list lock.
+ *
+ * NOTE: slightly weird locking semantics here - we expect to be
+ * called with the efivars lock already held, and we release it before
+ * returning. This is because this function is usually called after
+ * set_variable() while the lock is still held.
+ */
+static void efivar_entry_list_del_unlock(struct efivar_entry *entry)
+{
+       WARN_ON(!spin_is_locked(&__efivars->lock));
+
+       list_del(&entry->list);
+       spin_unlock_irq(&__efivars->lock);
+}
+
+/**
+ * __efivar_entry_delete - delete an EFI variable
+ * @entry: entry containing EFI variable to delete
+ *
+ * Delete the variable from the firmware but leave @entry on the
+ * variable list.
+ *
+ * This function differs from efivar_entry_delete() because it does
+ * not remove @entry from the variable list. Also, it is safe to be
+ * called from within a efivar_entry_iter_begin() and
+ * efivar_entry_iter_end() region, unlike efivar_entry_delete().
+ *
+ * Returns 0 on success, or a converted EFI status code if
+ * set_variable() fails.
+ */
+int __efivar_entry_delete(struct efivar_entry *entry)
+{
+       const struct efivar_operations *ops = __efivars->ops;
+       efi_status_t status;
+
+       WARN_ON(!spin_is_locked(&__efivars->lock));
+
+       status = ops->set_variable(entry->var.VariableName,
+                                  &entry->var.VendorGuid,
+                                  0, 0, NULL);
+
+       return efi_status_to_err(status);
+}
+EXPORT_SYMBOL_GPL(__efivar_entry_delete);
+
+/**
+ * efivar_entry_delete - delete variable and remove entry from list
+ * @entry: entry containing variable to delete
+ *
+ * Delete the variable from the firmware and remove @entry from the
+ * variable list. It is the caller's responsibility to free @entry
+ * once we return.
+ *
+ * Returns 0 on success, or a converted EFI status code if
+ * set_variable() fails.
+ */
+int efivar_entry_delete(struct efivar_entry *entry)
+{
+       const struct efivar_operations *ops = __efivars->ops;
+       efi_status_t status;
+
+       spin_lock_irq(&__efivars->lock);
+       status = ops->set_variable(entry->var.VariableName,
+                                  &entry->var.VendorGuid,
+                                  0, 0, NULL);
+       if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) {
+               spin_unlock_irq(&__efivars->lock);
+               return efi_status_to_err(status);
+       }
+
+       efivar_entry_list_del_unlock(entry);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(efivar_entry_delete);
+
+/**
+ * efivar_entry_set - call set_variable()
+ * @entry: entry containing the EFI variable to write
+ * @attributes: variable attributes
+ * @size: size of @data buffer
+ * @data: buffer containing variable data
+ * @head: head of variable list
+ *
+ * Calls set_variable() for an EFI variable. If creating a new EFI
+ * variable, this function is usually followed by efivar_entry_add().
+ *
+ * Before writing the variable, the remaining EFI variable storage
+ * space is checked to ensure there is enough room available.
+ *
+ * If @head is not NULL a lookup is performed to determine whether
+ * the entry is already on the list.
+ *
+ * Returns 0 on success, -EEXIST if a lookup is performed and the entry
+ * already exists on the list, or a converted EFI status code if
+ * set_variable() fails.
+ */
+int efivar_entry_set(struct efivar_entry *entry, u32 attributes,
+                    unsigned long size, void *data, struct list_head *head)
+{
+       const struct efivar_operations *ops = __efivars->ops;
+       efi_status_t status;
+       efi_char16_t *name = entry->var.VariableName;
+       efi_guid_t vendor = entry->var.VendorGuid;
+
+       spin_lock_irq(&__efivars->lock);
+
+       if (head && efivar_entry_find(name, vendor, head, false)) {
+               spin_unlock_irq(&__efivars->lock);
+               return -EEXIST;
+       }
+
+       status = check_var_size(attributes, size + utf16_strsize(name, 1024));
+       if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED)
+               status = ops->set_variable(name, &vendor,
+                                          attributes, size, data);
+
+       spin_unlock_irq(&__efivars->lock);
+
+       return efi_status_to_err(status);
+
+}
+EXPORT_SYMBOL_GPL(efivar_entry_set);
+
+/**
+ * efivar_entry_set_safe - call set_variable() if enough space in firmware
+ * @name: buffer containing the variable name
+ * @vendor: variable vendor guid
+ * @attributes: variable attributes
+ * @block: can we block in this context?
+ * @size: size of @data buffer
+ * @data: buffer containing variable data
+ *
+ * Ensures there is enough free storage in the firmware for this variable, and
+ * if so, calls set_variable(). If creating a new EFI variable, this function
+ * is usually followed by efivar_entry_add().
+ *
+ * Returns 0 on success, -ENOSPC if the firmware does not have enough
+ * space for set_variable() to succeed, or a converted EFI status code
+ * if set_variable() fails.
+ */
+int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes,
+                         bool block, unsigned long size, void *data)
+{
+       const struct efivar_operations *ops = __efivars->ops;
+       unsigned long flags;
+       efi_status_t status;
+
+       if (!ops->query_variable_info)
+               return -ENOSYS;
+
+       if (!block && spin_trylock_irqsave(&__efivars->lock, flags))
+               return -EBUSY;
+       else
+               spin_lock_irqsave(&__efivars->lock, flags);
+
+       status = check_var_size(attributes, size + utf16_strsize(name, 1024));
+       if (status != EFI_SUCCESS) {
+               spin_unlock_irqrestore(&__efivars->lock, flags);
+               return -ENOSPC;
+       }
+
+       status = ops->set_variable(name, &vendor, attributes, size, data);
+
+       spin_unlock_irqrestore(&__efivars->lock, flags);
+
+       return efi_status_to_err(status);
+}
+EXPORT_SYMBOL_GPL(efivar_entry_set_safe);
+
+/**
+ * efivar_entry_find - search for an entry
+ * @name: the EFI variable name
+ * @guid: the EFI variable vendor's guid
+ * @head: head of the variable list
+ * @remove: should we remove the entry from the list?
+ *
+ * Search for an entry on the variable list that has the EFI variable
+ * name @name and vendor guid @guid. If an entry is found on the list
+ * and @remove is true, the entry is removed from the list.
+ *
+ * The caller MUST call efivar_entry_iter_begin() and
+ * efivar_entry_iter_end() before and after the invocation of this
+ * function, respectively.
+ *
+ * Returns the entry if found on the list, %NULL otherwise.
+ */
+struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
+                                      struct list_head *head, bool remove)
+{
+       struct efivar_entry *entry, *n;
+       int strsize1, strsize2;
+       bool found = false;
+
+       WARN_ON(!spin_is_locked(&__efivars->lock));
+
+       list_for_each_entry_safe(entry, n, head, list) {
+               strsize1 = utf16_strsize(name, 1024);
+               strsize2 = utf16_strsize(entry->var.VariableName, 1024);
+               if (strsize1 == strsize2 &&
+                   !memcmp(name, &(entry->var.VariableName), strsize1) &&
+                   !efi_guidcmp(guid, entry->var.VendorGuid)) {
+                       found = true;
+                       break;
+               }
+       }
+
+       if (!found)
+               return NULL;
+
+       if (remove)
+               list_del(&entry->list);
+
+       return entry;
+}
+EXPORT_SYMBOL_GPL(efivar_entry_find);
+
+/**
+ * __efivar_entry_size - obtain the size of a variable
+ * @entry: entry for this variable
+ * @size: location to store the variable's size
+ *
+ * The caller MUST call efivar_entry_iter_begin() and
+ * efivar_entry_iter_end() before and after the invocation of this
+ * function, respectively.
+ */
+int __efivar_entry_size(struct efivar_entry *entry, unsigned long *size)
+{
+       const struct efivar_operations *ops = __efivars->ops;
+       efi_status_t status;
+
+       WARN_ON(!spin_is_locked(&__efivars->lock));
+
+       *size = 0;
+       status = ops->get_variable(entry->var.VariableName,
+                                  &entry->var.VendorGuid, NULL, size, NULL);
+       if (status != EFI_BUFFER_TOO_SMALL)
+               return efi_status_to_err(status);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(__efivar_entry_size);
+
+/**
+ * efivar_entry_size - obtain the size of a variable
+ * @entry: entry for this variable
+ * @size: location to store the variable's size
+ */
+int efivar_entry_size(struct efivar_entry *entry, unsigned long *size)
+{
+       const struct efivar_operations *ops = __efivars->ops;
+       efi_status_t status;
+
+       *size = 0;
+
+       spin_lock_irq(&__efivars->lock);
+       status = ops->get_variable(entry->var.VariableName,
+                                  &entry->var.VendorGuid, NULL, size, NULL);
+       spin_unlock_irq(&__efivars->lock);
+
+       if (status != EFI_BUFFER_TOO_SMALL)
+               return efi_status_to_err(status);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(efivar_entry_size);
+
+/**
+ * efivar_entry_get - call get_variable()
+ * @entry: read data for this variable
+ * @attributes: variable attributes
+ * @size: size of @data buffer
+ * @data: buffer to store variable data
+ */
+int efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
+                    unsigned long *size, void *data)
+{
+       const struct efivar_operations *ops = __efivars->ops;
+       efi_status_t status;
+
+       spin_lock_irq(&__efivars->lock);
+       status = ops->get_variable(entry->var.VariableName,
+                                  &entry->var.VendorGuid,
+                                  attributes, size, data);
+       spin_unlock_irq(&__efivars->lock);
+
+       return efi_status_to_err(status);
+}
+EXPORT_SYMBOL_GPL(efivar_entry_get);
+
+/**
+ * efivar_entry_set_get_size - call set_variable() and get new size (atomic)
+ * @entry: entry containing variable to set and get
+ * @attributes: attributes of variable to be written
+ * @size: size of data buffer
+ * @data: buffer containing data to write
+ * @set: did the set_variable() call succeed?
+ *
+ * This is a pretty special (complex) function. See efivarfs_file_write().
+ *
+ * Atomically call set_variable() for @entry and if the call is
+ * successful, return the new size of the variable from get_variable()
+ * in @size. The success of set_variable() is indicated by @set.
+ *
+ * Returns 0 on success, -EINVAL if the variable data is invalid,
+ * -ENOSPC if the firmware does not have enough available space, or a
+ * converted EFI status code if either of set_variable() or
+ * get_variable() fail.
+ *
+ * If the EFI variable does not exist when calling set_variable()
+ * (EFI_NOT_FOUND), @entry is removed from the variable list.
+ */
+int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
+                             unsigned long *size, void *data, bool *set)
+{
+       const struct efivar_operations *ops = __efivars->ops;
+       efi_char16_t *name = entry->var.VariableName;
+       efi_guid_t *vendor = &entry->var.VendorGuid;
+       efi_status_t status;
+       int err;
+
+       *set = false;
+
+       if (efivar_validate(&entry->var, data, *size) == false)
+               return -EINVAL;
+
+       /*
+        * The lock here protects the get_variable call, the conditional
+        * set_variable call, and removal of the variable from the efivars
+        * list (in the case of an authenticated delete).
+        */
+       spin_lock_irq(&__efivars->lock);
+
+       /*
+        * Ensure that the available space hasn't shrunk below the safe level
+        */
+       status = check_var_size(attributes, *size + utf16_strsize(name, 1024));
+       if (status != EFI_SUCCESS) {
+               if (status != EFI_UNSUPPORTED) {
+                       err = efi_status_to_err(status);
+                       goto out;
+               }
+
+               if (*size > 65536) {
+                       err = -ENOSPC;
+                       goto out;
+               }
+       }
+
+       status = ops->set_variable(name, vendor, attributes, *size, data);
+       if (status != EFI_SUCCESS) {
+               err = efi_status_to_err(status);
+               goto out;
+       }
+
+       *set = true;
+
+       /*
+        * Writing to the variable may have caused a change in size (which
+        * could either be an append or an overwrite), or the variable to be
+        * deleted. Perform a GetVariable() so we can tell what actually
+        * happened.
+        */
+       *size = 0;
+       status = ops->get_variable(entry->var.VariableName,
+                                  &entry->var.VendorGuid,
+                                  NULL, size, NULL);
+
+       if (status == EFI_NOT_FOUND)
+               efivar_entry_list_del_unlock(entry);
+       else
+               spin_unlock_irq(&__efivars->lock);
+
+       if (status && status != EFI_BUFFER_TOO_SMALL)
+               return efi_status_to_err(status);
+
+       return 0;
+
+out:
+       spin_unlock_irq(&__efivars->lock);
+       return err;
+
+}
+EXPORT_SYMBOL_GPL(efivar_entry_set_get_size);
+
+/**
+ * efivar_entry_iter_begin - begin iterating the variable list
+ *
+ * Lock the variable list to prevent entry insertion and removal until
+ * efivar_entry_iter_end() is called. This function is usually used in
+ * conjunction with __efivar_entry_iter() or efivar_entry_iter().
+ */
+void efivar_entry_iter_begin(void)
+{
+       spin_lock_irq(&__efivars->lock);
+}
+EXPORT_SYMBOL_GPL(efivar_entry_iter_begin);
+
+/**
+ * efivar_entry_iter_end - finish iterating the variable list
+ *
+ * Unlock the variable list and allow modifications to the list again.
+ */
+void efivar_entry_iter_end(void)
+{
+       spin_unlock_irq(&__efivars->lock);
+}
+EXPORT_SYMBOL_GPL(efivar_entry_iter_end);
+
+/**
+ * __efivar_entry_iter - iterate over variable list
+ * @func: callback function
+ * @head: head of the variable list
+ * @data: function-specific data to pass to callback
+ * @prev: entry to begin iterating from
+ *
+ * Iterate over the list of EFI variables and call @func with every
+ * entry on the list. It is safe for @func to remove entries in the
+ * list via efivar_entry_delete().
+ *
+ * You MUST call efivar_enter_iter_begin() before this function, and
+ * efivar_entry_iter_end() afterwards.
+ *
+ * It is possible to begin iteration from an arbitrary entry within
+ * the list by passing @prev. @prev is updated on return to point to
+ * the last entry passed to @func. To begin iterating from the
+ * beginning of the list @prev must be %NULL.
+ *
+ * The restrictions for @func are the same as documented for
+ * efivar_entry_iter().
+ */
+int __efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
+                       struct list_head *head, void *data,
+                       struct efivar_entry **prev)
+{
+       struct efivar_entry *entry, *n;
+       int err = 0;
+
+       if (!prev || !*prev) {
+               list_for_each_entry_safe(entry, n, head, list) {
+                       err = func(entry, data);
+                       if (err)
+                               break;
+               }
+
+               if (prev)
+                       *prev = entry;
+
+               return err;
+       }
+
+
+       list_for_each_entry_safe_continue((*prev), n, head, list) {
+               err = func(*prev, data);
+               if (err)
+                       break;
+       }
+
+       return err;
+}
+EXPORT_SYMBOL_GPL(__efivar_entry_iter);
+
+/**
+ * efivar_entry_iter - iterate over variable list
+ * @func: callback function
+ * @head: head of variable list
+ * @data: function-specific data to pass to callback
+ *
+ * Iterate over the list of EFI variables and call @func with every
+ * entry on the list. It is safe for @func to remove entries in the
+ * list via efivar_entry_delete() while iterating.
+ *
+ * Some notes for the callback function:
+ *  - a non-zero return value indicates an error and terminates the loop
+ *  - @func is called from atomic context
+ */
+int efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
+                     struct list_head *head, void *data)
+{
+       int err = 0;
+
+       efivar_entry_iter_begin();
+       err = __efivar_entry_iter(func, head, data, NULL);
+       efivar_entry_iter_end();
+
+       return err;
+}
+EXPORT_SYMBOL_GPL(efivar_entry_iter);
+
+/**
+ * efivars_kobject - get the kobject for the registered efivars
+ *
+ * If efivars_register() has not been called we return NULL,
+ * otherwise return the kobject used at registration time.
+ */
+struct kobject *efivars_kobject(void)
+{
+       if (!__efivars)
+               return NULL;
+
+       return __efivars->kobject;
+}
+EXPORT_SYMBOL_GPL(efivars_kobject);
+
+/**
+ * efivar_run_worker - schedule the efivar worker thread
+ */
+void efivar_run_worker(void)
+{
+       if (efivar_wq_enabled)
+               schedule_work(&efivar_work);
+}
+EXPORT_SYMBOL_GPL(efivar_run_worker);
+
+/**
+ * efivars_register - register an efivars
+ * @efivars: efivars to register
+ * @ops: efivars operations
+ * @kobject: @efivars-specific kobject
+ *
+ * Only a single efivars can be registered at any time.
+ */
+int efivars_register(struct efivars *efivars,
+                    const struct efivar_operations *ops,
+                    struct kobject *kobject)
+{
+       spin_lock_init(&efivars->lock);
+       efivars->ops = ops;
+       efivars->kobject = kobject;
+
+       __efivars = efivars;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(efivars_register);
+
+/**
+ * efivars_unregister - unregister an efivars
+ * @efivars: efivars to unregister
+ *
+ * The caller must have already removed every entry from the list,
+ * failure to do so is an error.
+ */
+int efivars_unregister(struct efivars *efivars)
+{
+       int rv;
+
+       if (!__efivars) {
+               printk(KERN_ERR "efivars not registered\n");
+               rv = -EINVAL;
+               goto out;
+       }
+
+       if (__efivars != efivars) {
+               rv = -EINVAL;
+               goto out;
+       }
+
+       __efivars = NULL;
+
+       rv = 0;
+out:
+       return rv;
+}
+EXPORT_SYMBOL_GPL(efivars_unregister);
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
deleted file mode 100644 (file)
index af39675..0000000
+++ /dev/null
@@ -1,1794 +0,0 @@
-/*
- * EFI Variables - 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/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/kobject.h>
-#include <linux/device.h>
-#include <linux/slab.h>
-#include <linux/ctype.h>
-
-#include <linux/fs.h>
-#include <linux/ramfs.h>
-#include <linux/pagemap.h>
-
-#include <asm/uaccess.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);
-
-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);
-};
-
-/* Private pointer to registered efivars */
-static struct efivars *__efivars;
-
-static struct kset *efivars_kset;
-
-static struct bin_attribute *efivars_new_var;
-static struct bin_attribute *efivars_del_var;
-
-#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);
-
-/*
- * Prototype for workqueue functions updating sysfs entry
- */
-
-static void efivar_update_sysfs_entries(struct work_struct *);
-static DECLARE_WORK(efivar_work, efivar_update_sysfs_entries);
-static bool efivar_wq_enabled = true;
-
-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 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 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 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;
-}
-
-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;
-}
-
-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;
-}
-
-/*
- * 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);
-}
-
-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);
-}
-
-/*
- * 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 kobject *efi_kobj;
-
-/**
- * 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 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;
-}
-
-/*
- * 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);
-}
-
-static struct kobject *efivars_kobj;
-
-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);
-       kobject_put(efivars_kobj);
-       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;
-       }
-
-       efivars_kobj = kobject_create_and_add("efivars", parent_kobj);
-       if (!efivars_kobj) {
-               pr_err("efivars: Subsystem registration failed.\n");
-               kset_unregister(efivars_kset);
-               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;
-}
-EXPORT_SYMBOL_GPL(efivars_sysfs_init);
-
-/**
- * efivar_init - build the initial list of EFI variables
- * @func: callback function to invoke for every variable
- * @data: function-specific data to pass to @func
- * @atomic: do we need to execute the @func-loop atomically?
- * @duplicates: error if we encounter duplicates on @head?
- * @head: initialised head of variable list
- *
- * Get every EFI variable from the firmware and invoke @func. @func
- * should call efivar_entry_add() to build the list of variables.
- *
- * Returns 0 on success, or a kernel error code on failure.
- */
-int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
-               void *data, bool atomic, bool duplicates,
-               struct list_head *head)
-{
-       const struct efivar_operations *ops = __efivars->ops;
-       unsigned long variable_name_size = 1024;
-       efi_char16_t *variable_name;
-       efi_status_t status;
-       efi_guid_t vendor_guid;
-       int err = 0;
-
-       variable_name = kzalloc(variable_name_size, GFP_KERNEL);
-       if (!variable_name) {
-               printk(KERN_ERR "efivars: Memory allocation failed.\n");
-               return -ENOMEM;
-       }
-
-       spin_lock_irq(&__efivars->lock);
-
-       /*
-        * Per EFI spec, the maximum storage allocated for both
-        * the variable name and variable data is 1024 bytes.
-        */
-
-       do {
-               variable_name_size = 1024;
-
-               status = ops->get_next_variable(&variable_name_size,
-                                               variable_name,
-                                               &vendor_guid);
-               switch (status) {
-               case EFI_SUCCESS:
-                       if (!atomic)
-                               spin_unlock_irq(&__efivars->lock);
-
-                       variable_name_size = var_name_strnsize(variable_name,
-                                                              variable_name_size);
-
-                       /*
-                        * Some firmware implementations return the
-                        * same variable name on multiple calls to
-                        * get_next_variable(). Terminate the loop
-                        * immediately as there is no guarantee that
-                        * we'll ever see a different variable name,
-                        * and may end up looping here forever.
-                        */
-                       if (duplicates &&
-                           variable_is_present(variable_name, &vendor_guid, head)) {
-                               dup_variable_bug(variable_name, &vendor_guid,
-                                                variable_name_size);
-                               if (!atomic)
-                                       spin_lock_irq(&__efivars->lock);
-
-                               status = EFI_NOT_FOUND;
-                               break;
-                       }
-
-                       err = func(variable_name, vendor_guid, variable_name_size, data);
-                       if (err)
-                               status = EFI_NOT_FOUND;
-
-                       if (!atomic)
-                               spin_lock_irq(&__efivars->lock);
-
-                       break;
-               case EFI_NOT_FOUND:
-                       break;
-               default:
-                       printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
-                               status);
-                       status = EFI_NOT_FOUND;
-                       break;
-               }
-
-       } while (status != EFI_NOT_FOUND);
-
-       spin_unlock_irq(&__efivars->lock);
-
-       kfree(variable_name);
-
-       return err;
-}
-EXPORT_SYMBOL_GPL(efivar_init);
-
-/**
- * efivar_entry_add - add entry to variable list
- * @entry: entry to add to list
- * @head: list head
- */
-void efivar_entry_add(struct efivar_entry *entry, struct list_head *head)
-{
-       spin_lock_irq(&__efivars->lock);
-       list_add(&entry->list, head);
-       spin_unlock_irq(&__efivars->lock);
-}
-EXPORT_SYMBOL_GPL(efivar_entry_add);
-
-/**
- * efivar_entry_remove - remove entry from variable list
- * @entry: entry to remove from list
- */
-void efivar_entry_remove(struct efivar_entry *entry)
-{
-       spin_lock_irq(&__efivars->lock);
-       list_del(&entry->list);
-       spin_unlock_irq(&__efivars->lock);
-}
-EXPORT_SYMBOL_GPL(efivar_entry_remove);
-
-/*
- * efivar_entry_list_del_unlock - remove entry from variable list
- * @entry: entry to remove
- *
- * Remove @entry from the variable list and release the list lock.
- *
- * NOTE: slightly weird locking semantics here - we expect to be
- * called with the efivars lock already held, and we release it before
- * returning. This is because this function is usually called after
- * set_variable() while the lock is still held.
- */
-static void efivar_entry_list_del_unlock(struct efivar_entry *entry)
-{
-       WARN_ON(!spin_is_locked(&__efivars->lock));
-
-       list_del(&entry->list);
-       spin_unlock_irq(&__efivars->lock);
-}
-
-/**
- * __efivar_entry_delete - delete an EFI variable
- * @entry: entry containing EFI variable to delete
- *
- * Delete the variable from the firmware and remove @entry from the
- * variable list. It is the caller's responsibility to free @entry
- * once we return.
- *
- * This function differs from efivar_entry_delete() because it is
- * safe to be called from within a efivar_entry_iter_begin() and
- * efivar_entry_iter_end() region, unlike efivar_entry_delete().
- *
- * Returns 0 on success, or a converted EFI status code if
- * set_variable() fails. If set_variable() fails the entry remains
- * on the list.
- */
-int __efivar_entry_delete(struct efivar_entry *entry)
-{
-       const struct efivar_operations *ops = __efivars->ops;
-       efi_status_t status;
-
-       WARN_ON(!spin_is_locked(&__efivars->lock));
-
-       status = ops->set_variable(entry->var.VariableName,
-                                  &entry->var.VendorGuid,
-                                  0, 0, NULL);
-       if (status)
-               return efi_status_to_err(status);
-
-       list_del(&entry->list);
-
-       return 0;
-}
-EXPORT_SYMBOL_GPL(__efivar_entry_delete);
-
-/**
- * efivar_entry_delete - delete variable and remove entry from list
- * @entry: entry containing variable to delete
- *
- * Delete the variable from the firmware and remove @entry from the
- * variable list. It is the caller's responsibility to free @entry
- * once we return.
- *
- * Returns 0 on success, or a converted EFI status code if
- * set_variable() fails.
- */
-int efivar_entry_delete(struct efivar_entry *entry)
-{
-       const struct efivar_operations *ops = __efivars->ops;
-       efi_status_t status;
-
-       spin_lock_irq(&__efivars->lock);
-       status = ops->set_variable(entry->var.VariableName,
-                                  &entry->var.VendorGuid,
-                                  0, 0, NULL);
-       if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) {
-               spin_unlock_irq(&__efivars->lock);
-               return efi_status_to_err(status);
-       }
-
-       efivar_entry_list_del_unlock(entry);
-       return 0;
-}
-EXPORT_SYMBOL_GPL(efivar_entry_delete);
-
-/**
- * efivar_entry_set - call set_variable()
- * @entry: entry containing the EFI variable to write
- * @attributes: variable attributes
- * @size: size of @data buffer
- * @data: buffer containing variable data
- * @head: head of variable list
- *
- * Calls set_variable() for an EFI variable. If creating a new EFI
- * variable, this function is usually followed by efivar_entry_add().
- *
- * Before writing the variable, the remaining EFI variable storage
- * space is checked to ensure there is enough room available.
- *
- * If @head is not NULL a lookup is performed to determine whether
- * the entry is already on the list.
- *
- * Returns 0 on success, -EEXIST if a lookup is performed and the entry
- * already exists on the list, or a converted EFI status code if
- * set_variable() fails.
- */
-int efivar_entry_set(struct efivar_entry *entry, u32 attributes,
-                    unsigned long size, void *data, struct list_head *head)
-{
-       const struct efivar_operations *ops = __efivars->ops;
-       efi_status_t status;
-       efi_char16_t *name = entry->var.VariableName;
-       efi_guid_t vendor = entry->var.VendorGuid;
-
-       spin_lock_irq(&__efivars->lock);
-
-       if (head && efivar_entry_find(name, vendor, head, false)) {
-               spin_unlock_irq(&__efivars->lock);
-               return -EEXIST;
-       }
-
-       status = check_var_size(attributes, size + utf16_strsize(name, 1024));
-       if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED)
-               status = ops->set_variable(name, &vendor,
-                                          attributes, size, data);
-
-       spin_unlock_irq(&__efivars->lock);
-
-       return efi_status_to_err(status);
-}
-EXPORT_SYMBOL_GPL(efivar_entry_set);
-
-/**
- * efivar_entry_set_safe - call set_variable() if enough space in firmware
- * @name: buffer containing the variable name
- * @vendor: variable vendor guid
- * @attributes: variable attributes
- * @block: can we block in this context?
- * @size: size of @data buffer
- * @data: buffer containing variable data
- *
- * Ensures there is enough free storage in the firmware for this variable, and
- * if so, calls set_variable(). If creating a new EFI variable, this function
- * is usually followed by efivar_entry_add().
- *
- * Returns 0 on success, -ENOSPC if the firmware does not have enough
- * space for set_variable() to succeed, or a converted EFI status code
- * if set_variable() fails.
- */
-int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes,
-                         bool block, unsigned long size, void *data)
-{
-       const struct efivar_operations *ops = __efivars->ops;
-       unsigned long flags;
-       efi_status_t status;
-
-       if (!ops->query_variable_info)
-               return -ENOSYS;
-
-       if (!block && !spin_trylock_irqsave(&__efivars->lock, flags))
-               return -EBUSY;
-       else
-               spin_lock_irqsave(&__efivars->lock, flags);
-
-       status = check_var_size(attributes, size + utf16_strsize(name, 1024));
-       if (status != EFI_SUCCESS) {
-               spin_unlock_irqrestore(&__efivars->lock, flags);
-               return -ENOSPC;
-       }
-
-       status = ops->set_variable(name, &vendor, attributes, size, data);
-
-       spin_unlock_irqrestore(&__efivars->lock, flags);
-
-       return efi_status_to_err(status);
-}
-EXPORT_SYMBOL_GPL(efivar_entry_set_safe);
-
-/**
- * efivar_entry_find - search for an entry
- * @name: the EFI variable name
- * @guid: the EFI variable vendor's guid
- * @head: head of the variable list
- * @remove: should we remove the entry from the list?
- *
- * Search for an entry on the variable list that has the EFI variable
- * name @name and vendor guid @guid. If an entry is found on the list
- * and @remove is true, the entry is removed from the list.
- *
- * The caller MUST call efivar_entry_iter_begin() and
- * efivar_entry_iter_end() before and after the invocation of this
- * function, respectively.
- *
- * Returns the entry if found on the list, %NULL otherwise.
- */
-struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
-                                      struct list_head *head, bool remove)
-{
-       struct efivar_entry *entry, *n;
-       int strsize1, strsize2;
-       bool found = false;
-
-       WARN_ON(!spin_is_locked(&__efivars->lock));
-
-       list_for_each_entry_safe(entry, n, head, list) {
-               strsize1 = utf16_strsize(name, 1024);
-               strsize2 = utf16_strsize(entry->var.VariableName, 1024);
-               if (strsize1 == strsize2 &&
-                   !memcmp(name, &(entry->var.VariableName), strsize1) &&
-                   !efi_guidcmp(guid, entry->var.VendorGuid)) {
-                       found = true;
-                       break;
-               }
-       }
-
-       if (!found)
-               return NULL;
-
-       if (remove)
-               list_del(&entry->list);
-
-       return entry;
-}
-EXPORT_SYMBOL_GPL(efivar_entry_find);
-
-/**
- * __efivar_entry_size - obtain the size of a variable
- * @entry: entry for this variable
- * @size: location to store the variable's size
- *
- * The caller MUST call efivar_entry_iter_begin() and
- * efivar_entry_iter_end() before and after the invocation of this
- * function, respectively.
- */
-int __efivar_entry_size(struct efivar_entry *entry, unsigned long *size)
-{
-       const struct efivar_operations *ops = __efivars->ops;
-       efi_status_t status;
-
-       WARN_ON(!spin_is_locked(&__efivars->lock));
-
-       *size = 0;
-       status = ops->get_variable(entry->var.VariableName,
-                                  &entry->var.VendorGuid, NULL, size, NULL);
-       if (status != EFI_BUFFER_TOO_SMALL)
-               return efi_status_to_err(status);
-
-       return 0;
-}
-EXPORT_SYMBOL_GPL(__efivar_entry_size);
-
-/**
- * efivar_entry_size - obtain the size of a variable
- * @entry: entry for this variable
- * @size: location to store the variable's size
- */
-int efivar_entry_size(struct efivar_entry *entry, unsigned long *size)
-{
-       const struct efivar_operations *ops = __efivars->ops;
-       efi_status_t status;
-
-       *size = 0;
-
-       spin_lock_irq(&__efivars->lock);
-       status = ops->get_variable(entry->var.VariableName,
-                                  &entry->var.VendorGuid, NULL, size, NULL);
-       spin_unlock_irq(&__efivars->lock);
-
-       if (status != EFI_BUFFER_TOO_SMALL)
-               return efi_status_to_err(status);
-
-       return 0;
-}
-EXPORT_SYMBOL_GPL(efivar_entry_size);
-
-/**
- * efivar_entry_get - call get_variable()
- * @entry: read data for this variable
- * @attributes: variable attributes
- * @size: size of @data buffer
- * @data: buffer to store variable data
- */
-int efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
-                    unsigned long *size, void *data)
-{
-       const struct efivar_operations *ops = __efivars->ops;
-       efi_status_t status;
-
-       spin_lock_irq(&__efivars->lock);
-       status = ops->get_variable(entry->var.VariableName,
-                                  &entry->var.VendorGuid,
-                                  attributes, size, data);
-       spin_unlock_irq(&__efivars->lock);
-
-       return efi_status_to_err(status);
-}
-EXPORT_SYMBOL_GPL(efivar_entry_get);
-
-/**
- * efivar_entry_set_get_size - call set_variable() and get new size (atomic)
- * @entry: entry containing variable to set and get
- * @attributes: attributes of variable to be written
- * @size: size of data buffer
- * @data: buffer containing data to write
- * @set: did the set_variable() call succeed?
- *
- * This is a pretty special (complex) function. See efivarfs_file_write().
- *
- * Atomically call set_variable() for @entry and if the call is
- * successful, return the new size of the variable from get_variable()
- * in @size. The success of set_variable() is indicated by @set.
- *
- * Returns 0 on success, -EINVAL if the variable data is invalid,
- * -ENOSPC if the firmware does not have enough available space, or a
- * converted EFI status code if either of set_variable() or
- * get_variable() fail.
- *
- * If the EFI variable does not exist when calling set_variable()
- * (EFI_NOT_FOUND), @entry is removed from the variable list.
- */
-int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
-                             unsigned long *size, void *data, bool *set)
-{
-       const struct efivar_operations *ops = __efivars->ops;
-       efi_char16_t *name = entry->var.VariableName;
-       efi_guid_t *vendor = &entry->var.VendorGuid;
-       efi_status_t status;
-       int err;
-
-       *set = false;
-
-       if (efivar_validate(&entry->var, data, *size) == false)
-               return -EINVAL;
-
-       /*
-        * The lock here protects the get_variable call, the conditional
-        * set_variable call, and removal of the variable from the efivars
-        * list (in the case of an authenticated delete).
-        */
-       spin_lock_irq(&__efivars->lock);
-
-       /*
-        * Ensure that the available space hasn't shrunk below the safe level
-        */
-       status = check_var_size(attributes, *size + utf16_strsize(name, 1024));
-       if (status != EFI_SUCCESS) {
-               if (status != EFI_UNSUPPORTED) {
-                       err = efi_status_to_err(status);
-                       goto out;
-               }
-
-               if (*size > 65536) {
-                       err = -ENOSPC;
-                       goto out;
-               }
-       }
-
-       status = ops->set_variable(name, vendor, attributes, *size, data);
-       if (status != EFI_SUCCESS) {
-               err = efi_status_to_err(status);
-               goto out;
-       }
-
-       *set = true;
-
-       /*
-        * Writing to the variable may have caused a change in size (which
-        * could either be an append or an overwrite), or the variable to be
-        * deleted. Perform a GetVariable() so we can tell what actually
-        * happened.
-        */
-       *size = 0;
-       status = ops->get_variable(entry->var.VariableName,
-                                  &entry->var.VendorGuid,
-                                  NULL, size, NULL);
-
-       if (status == EFI_NOT_FOUND)
-               efivar_entry_list_del_unlock(entry);
-       else
-               spin_unlock_irq(&__efivars->lock);
-
-       if (status && status != EFI_BUFFER_TOO_SMALL)
-               return efi_status_to_err(status);
-
-       return 0;
-
-out:
-       spin_unlock_irq(&__efivars->lock);
-       return err;
-
-}
-EXPORT_SYMBOL_GPL(efivar_entry_set_get_size);
-
-/**
- * efivar_entry_iter_begin - begin iterating the variable list
- *
- * Lock the variable list to prevent entry insertion and removal until
- * efivar_entry_iter_end() is called. This function is usually used in
- * conjunction with __efivar_entry_iter() or efivar_entry_iter().
- */
-void efivar_entry_iter_begin(void)
-{
-       spin_lock_irq(&__efivars->lock);
-}
-EXPORT_SYMBOL_GPL(efivar_entry_iter_begin);
-
-/**
- * efivar_entry_iter_end - finish iterating the variable list
- *
- * Unlock the variable list and allow modifications to the list again.
- */
-void efivar_entry_iter_end(void)
-{
-       spin_unlock_irq(&__efivars->lock);
-}
-EXPORT_SYMBOL_GPL(efivar_entry_iter_end);
-
-/**
- * __efivar_entry_iter - iterate over variable list
- * @func: callback function
- * @head: head of the variable list
- * @data: function-specific data to pass to callback
- * @prev: entry to begin iterating from
- *
- * Iterate over the list of EFI variables and call @func with every
- * entry on the list. It is safe for @func to remove entries in the
- * list via efivar_entry_delete().
- *
- * You MUST call efivar_enter_iter_begin() before this function, and
- * efivar_entry_iter_end() afterwards.
- *
- * It is possible to begin iteration from an arbitrary entry within
- * the list by passing @prev. @prev is updated on return to point to
- * the last entry passed to @func. To begin iterating from the
- * beginning of the list @prev must be %NULL.
- *
- * The restrictions for @func are the same as documented for
- * efivar_entry_iter().
- */
-int __efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
-                       struct list_head *head, void *data,
-                       struct efivar_entry **prev)
-{
-       struct efivar_entry *entry, *n;
-       int err = 0;
-
-       if (!prev || !*prev) {
-               list_for_each_entry_safe(entry, n, head, list) {
-                       err = func(entry, data);
-                       if (err)
-                               break;
-               }
-
-               if (prev)
-                       *prev = entry;
-
-               return err;
-       }
-
-
-       list_for_each_entry_safe_continue((*prev), n, head, list) {
-               err = func(*prev, data);
-               if (err)
-                       break;
-       }
-
-       return err;
-}
-EXPORT_SYMBOL_GPL(__efivar_entry_iter);
-
-/**
- * efivar_entry_iter - iterate over variable list
- * @func: callback function
- * @head: head of variable list
- * @data: function-specific data to pass to callback
- *
- * Iterate over the list of EFI variables and call @func with every
- * entry on the list. It is safe for @func to remove entries in the
- * list via efivar_entry_delete() while iterating.
- *
- * Some notes for the callback function:
- *  - a non-zero return value indicates an error and terminates the loop
- *  - @func is called from atomic context
- */
-int efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
-                     struct list_head *head, void *data)
-{
-       int err = 0;
-
-       efivar_entry_iter_begin();
-       err = __efivar_entry_iter(func, head, data, NULL);
-       efivar_entry_iter_end();
-
-       return err;
-}
-EXPORT_SYMBOL_GPL(efivar_entry_iter);
-
-/**
- * efivars_kobject - get the kobject for the registered efivars
- *
- * If efivars_register() has not been called we return NULL,
- * otherwise return the kobject used at registration time.
- */
-struct kobject *efivars_kobject(void)
-{
-       if (!__efivars)
-               return NULL;
-
-       return __efivars->kobject;
-}
-EXPORT_SYMBOL_GPL(efivars_kobject);
-
-/**
- * efivar_run_worker - schedule the efivar worker thread
- */
-void efivar_run_worker(void)
-{
-       if (efivar_wq_enabled)
-               schedule_work(&efivar_work);
-}
-EXPORT_SYMBOL_GPL(efivar_run_worker);
-
-/**
- * efivars_register - register an efivars
- * @efivars: efivars to register
- * @ops: efivars operations
- * @kobject: @efivars-specific kobject
- *
- * Only a single efivars can be registered at any time.
- */
-int efivars_register(struct efivars *efivars,
-                    const struct efivar_operations *ops,
-                    struct kobject *kobject)
-{
-       spin_lock_init(&efivars->lock);
-       efivars->ops = ops;
-       efivars->kobject = kobject;
-
-       __efivars = efivars;
-
-       return 0;
-}
-EXPORT_SYMBOL_GPL(efivars_register);
-
-/**
- * efivars_unregister - unregister an efivars
- * @efivars: efivars to unregister
- *
- * The caller must have already removed every entry from the list,
- * failure to do so is an error.
- */
-int efivars_unregister(struct efivars *efivars)
-{
-       int rv;
-
-       if (!__efivars) {
-               printk(KERN_ERR "efivars not registered\n");
-               rv = -EINVAL;
-               goto out;
-       }
-
-       if (__efivars != efivars) {
-               rv = -EINVAL;
-               goto out;
-       }
-
-       __efivars = NULL;
-
-       rv = 0;
-out:
-       return rv;
-}
-EXPORT_SYMBOL_GPL(efivars_unregister);
-
-static struct efivars generic_efivars;
-static struct efivar_operations generic_ops;
-
-static int generic_ops_register(void)
-{
-       int error;
-
-       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;
-
-       error = efivars_register(&generic_efivars, &generic_ops, efi_kobj);
-       if (error)
-               return error;
-
-       error = efivars_sysfs_init();
-       if (error)
-               efivars_unregister(&generic_efivars);
-
-       return error;
-}
-
-static void generic_ops_unregister(void)
-{
-       efivars_sysfs_exit();
-       efivars_unregister(&generic_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;
-
-       if (!efi_enabled(EFI_RUNTIME_SERVICES))
-               return 0;
-
-       /* 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 = generic_ops_register();
-       if (error)
-               goto err_put;
-
-       /* 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);
-               goto err_unregister;
-       }
-
-       return 0;
-
-err_unregister:
-       generic_ops_unregister();
-err_put:
-       kobject_put(efi_kobj);
-       return error;
-}
-
-static void __exit
-efivars_exit(void)
-{
-       cancel_work_sync(&efivar_work);
-
-       if (efi_enabled(EFI_RUNTIME_SERVICES)) {
-               generic_ops_unregister();
-               kobject_put(efi_kobj);
-       }
-}
-
-module_init(efivars_init);
-module_exit(efivars_exit);
-
index 1fb2b7f..367bbb1 100644 (file)
@@ -1,6 +1,6 @@
 config EFIVAR_FS
        tristate "EFI Variable filesystem"
-       depends on EFI_VARS
+       depends on EFI
        help
          efivarfs is a replacement filesystem for the old EFI
          variable support via sysfs, as it doesn't suffer from the
index 8ff6ec1..2fc8166 100644 (file)
@@ -742,7 +742,6 @@ utf16_strlen(efi_char16_t *s)
        return utf16_strnlen(s, ~0UL);
 }
 
-#if defined(CONFIG_EFI_VARS) || defined(CONFIG_EFI_VARS_MODULE)
 /*
  * Return the number of bytes is the length of this string
  * Note: this is NOT the same as the number of unicode characters
@@ -872,8 +871,10 @@ struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
 
 bool efivar_validate(struct efi_variable *var, u8 *data, unsigned long len);
 
+extern struct work_struct efivar_work;
 void efivar_run_worker(void);
 
+#if defined(CONFIG_EFI_VARS) || defined(CONFIG_EFI_VARS_MODULE)
 int efivars_sysfs_init(void);
 
 #endif /* CONFIG_EFI_VARS */