2 * Originally from efivars.c
4 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
5 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 #include <linux/capability.h>
23 #include <linux/types.h>
24 #include <linux/errno.h>
25 #include <linux/init.h>
27 #include <linux/module.h>
28 #include <linux/string.h>
29 #include <linux/smp.h>
30 #include <linux/efi.h>
31 #include <linux/sysfs.h>
32 #include <linux/device.h>
33 #include <linux/slab.h>
34 #include <linux/ctype.h>
35 #include <linux/ucs2_string.h>
37 /* Private pointer to registered efivars */
38 static struct efivars *__efivars;
40 static bool efivar_wq_enabled = true;
41 DECLARE_WORK(efivar_work, NULL);
42 EXPORT_SYMBOL_GPL(efivar_work);
45 validate_device_path(struct efi_variable *var, int match, u8 *buffer,
48 struct efi_generic_dev_path *node;
51 node = (struct efi_generic_dev_path *)buffer;
53 if (len < sizeof(*node))
56 while (offset <= len - sizeof(*node) &&
57 node->length >= sizeof(*node) &&
58 node->length <= len - offset) {
59 offset += node->length;
61 if ((node->type == EFI_DEV_END_PATH ||
62 node->type == EFI_DEV_END_PATH2) &&
63 node->sub_type == EFI_DEV_END_ENTIRE)
66 node = (struct efi_generic_dev_path *)(buffer + offset);
70 * If we're here then either node->length pointed past the end
71 * of the buffer or we reached the end of the buffer without
72 * finding a device path end node.
78 validate_boot_order(struct efi_variable *var, int match, u8 *buffer,
81 /* An array of 16-bit integers */
89 validate_load_option(struct efi_variable *var, int match, u8 *buffer,
93 int i, desclength = 0, namelen;
95 namelen = ucs2_strnlen(var->VariableName, sizeof(var->VariableName));
97 /* Either "Boot" or "Driver" followed by four digits of hex */
98 for (i = match; i < match+4; i++) {
99 if (var->VariableName[i] > 127 ||
100 hex_to_bin(var->VariableName[i] & 0xff) < 0)
104 /* Reject it if there's 4 digits of hex and then further content */
105 if (namelen > match + 4)
108 /* A valid entry must be at least 8 bytes */
112 filepathlength = buffer[4] | buffer[5] << 8;
115 * There's no stored length for the description, so it has to be
118 desclength = ucs2_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
120 /* Each boot entry must have a descriptor */
125 * If the sum of the length of the description, the claimed filepath
126 * length and the original header are greater than the length of the
127 * variable, it's malformed
129 if ((desclength + filepathlength + 6) > len)
133 * And, finally, check the filepath
135 return validate_device_path(var, match, buffer + desclength + 6,
140 validate_uint16(struct efi_variable *var, int match, u8 *buffer,
143 /* A single 16-bit integer */
151 validate_ascii_string(struct efi_variable *var, int match, u8 *buffer,
156 for (i = 0; i < len; i++) {
167 struct variable_validate {
169 bool (*validate)(struct efi_variable *var, int match, u8 *data,
173 static const struct variable_validate variable_validate[] = {
174 { "BootNext", validate_uint16 },
175 { "BootOrder", validate_boot_order },
176 { "DriverOrder", validate_boot_order },
177 { "Boot*", validate_load_option },
178 { "Driver*", validate_load_option },
179 { "ConIn", validate_device_path },
180 { "ConInDev", validate_device_path },
181 { "ConOut", validate_device_path },
182 { "ConOutDev", validate_device_path },
183 { "ErrOut", validate_device_path },
184 { "ErrOutDev", validate_device_path },
185 { "Timeout", validate_uint16 },
186 { "Lang", validate_ascii_string },
187 { "PlatformLang", validate_ascii_string },
192 efivar_validate(struct efi_variable *var, u8 *data, unsigned long len)
195 u16 *unicode_name = var->VariableName;
197 for (i = 0; variable_validate[i].validate != NULL; i++) {
198 const char *name = variable_validate[i].name;
201 for (match = 0; ; match++) {
202 char c = name[match];
203 u16 u = unicode_name[match];
205 /* All special variables are plain ascii */
209 /* Wildcard in the matching name means we've matched */
211 return variable_validate[i].validate(var,
214 /* Case sensitive match */
218 /* Reached the end of the string while matching */
220 return variable_validate[i].validate(var,
227 EXPORT_SYMBOL_GPL(efivar_validate);
230 check_var_size(u32 attributes, unsigned long size)
232 const struct efivar_operations *fops = __efivars->ops;
234 if (!fops->query_variable_store)
235 return EFI_UNSUPPORTED;
237 return fops->query_variable_store(attributes, size);
240 static int efi_status_to_err(efi_status_t status)
248 case EFI_INVALID_PARAMETER:
251 case EFI_OUT_OF_RESOURCES:
254 case EFI_DEVICE_ERROR:
257 case EFI_WRITE_PROTECTED:
260 case EFI_SECURITY_VIOLATION:
273 static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor,
274 struct list_head *head)
276 struct efivar_entry *entry, *n;
277 unsigned long strsize1, strsize2;
280 strsize1 = ucs2_strsize(variable_name, 1024);
281 list_for_each_entry_safe(entry, n, head, list) {
282 strsize2 = ucs2_strsize(entry->var.VariableName, 1024);
283 if (strsize1 == strsize2 &&
284 !memcmp(variable_name, &(entry->var.VariableName),
286 !efi_guidcmp(entry->var.VendorGuid,
296 * Returns the size of variable_name, in bytes, including the
297 * terminating NULL character, or variable_name_size if no NULL
298 * character is found among the first variable_name_size bytes.
300 static unsigned long var_name_strnsize(efi_char16_t *variable_name,
301 unsigned long variable_name_size)
307 * The variable name is, by definition, a NULL-terminated
308 * string, so make absolutely sure that variable_name_size is
309 * the value we expect it to be. If not, return the real size.
311 for (len = 2; len <= variable_name_size; len += sizeof(c)) {
312 c = variable_name[(len / sizeof(c)) - 1];
317 return min(len, variable_name_size);
321 * Print a warning when duplicate EFI variables are encountered and
322 * disable the sysfs workqueue since the firmware is buggy.
324 static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid,
327 size_t i, len8 = len16 / sizeof(efi_char16_t);
331 * Disable the workqueue since the algorithm it uses for
332 * detecting new variables won't work with this buggy
333 * implementation of GetNextVariableName().
335 efivar_wq_enabled = false;
337 s8 = kzalloc(len8, GFP_KERNEL);
341 for (i = 0; i < len8; i++)
344 printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n",
350 * efivar_init - build the initial list of EFI variables
351 * @func: callback function to invoke for every variable
352 * @data: function-specific data to pass to @func
353 * @atomic: do we need to execute the @func-loop atomically?
354 * @duplicates: error if we encounter duplicates on @head?
355 * @head: initialised head of variable list
357 * Get every EFI variable from the firmware and invoke @func. @func
358 * should call efivar_entry_add() to build the list of variables.
360 * Returns 0 on success, or a kernel error code on failure.
362 int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
363 void *data, bool atomic, bool duplicates,
364 struct list_head *head)
366 const struct efivar_operations *ops = __efivars->ops;
367 unsigned long variable_name_size = 1024;
368 efi_char16_t *variable_name;
370 efi_guid_t vendor_guid;
373 variable_name = kzalloc(variable_name_size, GFP_KERNEL);
374 if (!variable_name) {
375 printk(KERN_ERR "efivars: Memory allocation failed.\n");
379 spin_lock_irq(&__efivars->lock);
382 * Per EFI spec, the maximum storage allocated for both
383 * the variable name and variable data is 1024 bytes.
387 variable_name_size = 1024;
389 status = ops->get_next_variable(&variable_name_size,
395 spin_unlock_irq(&__efivars->lock);
397 variable_name_size = var_name_strnsize(variable_name,
401 * Some firmware implementations return the
402 * same variable name on multiple calls to
403 * get_next_variable(). Terminate the loop
404 * immediately as there is no guarantee that
405 * we'll ever see a different variable name,
406 * and may end up looping here forever.
409 variable_is_present(variable_name, &vendor_guid, head)) {
410 dup_variable_bug(variable_name, &vendor_guid,
413 spin_lock_irq(&__efivars->lock);
415 status = EFI_NOT_FOUND;
419 err = func(variable_name, vendor_guid, variable_name_size, data);
421 status = EFI_NOT_FOUND;
424 spin_lock_irq(&__efivars->lock);
430 printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
432 status = EFI_NOT_FOUND;
436 } while (status != EFI_NOT_FOUND);
438 spin_unlock_irq(&__efivars->lock);
440 kfree(variable_name);
444 EXPORT_SYMBOL_GPL(efivar_init);
447 * efivar_entry_add - add entry to variable list
448 * @entry: entry to add to list
451 void efivar_entry_add(struct efivar_entry *entry, struct list_head *head)
453 spin_lock_irq(&__efivars->lock);
454 list_add(&entry->list, head);
455 spin_unlock_irq(&__efivars->lock);
457 EXPORT_SYMBOL_GPL(efivar_entry_add);
460 * efivar_entry_remove - remove entry from variable list
461 * @entry: entry to remove from list
463 void efivar_entry_remove(struct efivar_entry *entry)
465 spin_lock_irq(&__efivars->lock);
466 list_del(&entry->list);
467 spin_unlock_irq(&__efivars->lock);
469 EXPORT_SYMBOL_GPL(efivar_entry_remove);
472 * efivar_entry_list_del_unlock - remove entry from variable list
473 * @entry: entry to remove
475 * Remove @entry from the variable list and release the list lock.
477 * NOTE: slightly weird locking semantics here - we expect to be
478 * called with the efivars lock already held, and we release it before
479 * returning. This is because this function is usually called after
480 * set_variable() while the lock is still held.
482 static void efivar_entry_list_del_unlock(struct efivar_entry *entry)
484 WARN_ON(!spin_is_locked(&__efivars->lock));
486 list_del(&entry->list);
487 spin_unlock_irq(&__efivars->lock);
491 * __efivar_entry_delete - delete an EFI variable
492 * @entry: entry containing EFI variable to delete
494 * Delete the variable from the firmware but leave @entry on the
497 * This function differs from efivar_entry_delete() because it does
498 * not remove @entry from the variable list. Also, it is safe to be
499 * called from within a efivar_entry_iter_begin() and
500 * efivar_entry_iter_end() region, unlike efivar_entry_delete().
502 * Returns 0 on success, or a converted EFI status code if
503 * set_variable() fails.
505 int __efivar_entry_delete(struct efivar_entry *entry)
507 const struct efivar_operations *ops = __efivars->ops;
510 WARN_ON(!spin_is_locked(&__efivars->lock));
512 status = ops->set_variable(entry->var.VariableName,
513 &entry->var.VendorGuid,
516 return efi_status_to_err(status);
518 EXPORT_SYMBOL_GPL(__efivar_entry_delete);
521 * efivar_entry_delete - delete variable and remove entry from list
522 * @entry: entry containing variable to delete
524 * Delete the variable from the firmware and remove @entry from the
525 * variable list. It is the caller's responsibility to free @entry
528 * Returns 0 on success, or a converted EFI status code if
529 * set_variable() fails.
531 int efivar_entry_delete(struct efivar_entry *entry)
533 const struct efivar_operations *ops = __efivars->ops;
536 spin_lock_irq(&__efivars->lock);
537 status = ops->set_variable(entry->var.VariableName,
538 &entry->var.VendorGuid,
540 if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) {
541 spin_unlock_irq(&__efivars->lock);
542 return efi_status_to_err(status);
545 efivar_entry_list_del_unlock(entry);
548 EXPORT_SYMBOL_GPL(efivar_entry_delete);
551 * efivar_entry_set - call set_variable()
552 * @entry: entry containing the EFI variable to write
553 * @attributes: variable attributes
554 * @size: size of @data buffer
555 * @data: buffer containing variable data
556 * @head: head of variable list
558 * Calls set_variable() for an EFI variable. If creating a new EFI
559 * variable, this function is usually followed by efivar_entry_add().
561 * Before writing the variable, the remaining EFI variable storage
562 * space is checked to ensure there is enough room available.
564 * If @head is not NULL a lookup is performed to determine whether
565 * the entry is already on the list.
567 * Returns 0 on success, -EEXIST if a lookup is performed and the entry
568 * already exists on the list, or a converted EFI status code if
569 * set_variable() fails.
571 int efivar_entry_set(struct efivar_entry *entry, u32 attributes,
572 unsigned long size, void *data, struct list_head *head)
574 const struct efivar_operations *ops = __efivars->ops;
576 efi_char16_t *name = entry->var.VariableName;
577 efi_guid_t vendor = entry->var.VendorGuid;
579 spin_lock_irq(&__efivars->lock);
581 if (head && efivar_entry_find(name, vendor, head, false)) {
582 spin_unlock_irq(&__efivars->lock);
586 status = check_var_size(attributes, size + ucs2_strsize(name, 1024));
587 if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED)
588 status = ops->set_variable(name, &vendor,
589 attributes, size, data);
591 spin_unlock_irq(&__efivars->lock);
593 return efi_status_to_err(status);
596 EXPORT_SYMBOL_GPL(efivar_entry_set);
599 * efivar_entry_set_safe - call set_variable() if enough space in firmware
600 * @name: buffer containing the variable name
601 * @vendor: variable vendor guid
602 * @attributes: variable attributes
603 * @block: can we block in this context?
604 * @size: size of @data buffer
605 * @data: buffer containing variable data
607 * Ensures there is enough free storage in the firmware for this variable, and
608 * if so, calls set_variable(). If creating a new EFI variable, this function
609 * is usually followed by efivar_entry_add().
611 * Returns 0 on success, -ENOSPC if the firmware does not have enough
612 * space for set_variable() to succeed, or a converted EFI status code
613 * if set_variable() fails.
615 int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes,
616 bool block, unsigned long size, void *data)
618 const struct efivar_operations *ops = __efivars->ops;
622 if (!ops->query_variable_store)
626 if (!spin_trylock_irqsave(&__efivars->lock, flags))
629 spin_lock_irqsave(&__efivars->lock, flags);
632 status = check_var_size(attributes, size + ucs2_strsize(name, 1024));
633 if (status != EFI_SUCCESS) {
634 spin_unlock_irqrestore(&__efivars->lock, flags);
638 status = ops->set_variable(name, &vendor, attributes, size, data);
640 spin_unlock_irqrestore(&__efivars->lock, flags);
642 return efi_status_to_err(status);
644 EXPORT_SYMBOL_GPL(efivar_entry_set_safe);
647 * efivar_entry_find - search for an entry
648 * @name: the EFI variable name
649 * @guid: the EFI variable vendor's guid
650 * @head: head of the variable list
651 * @remove: should we remove the entry from the list?
653 * Search for an entry on the variable list that has the EFI variable
654 * name @name and vendor guid @guid. If an entry is found on the list
655 * and @remove is true, the entry is removed from the list.
657 * The caller MUST call efivar_entry_iter_begin() and
658 * efivar_entry_iter_end() before and after the invocation of this
659 * function, respectively.
661 * Returns the entry if found on the list, %NULL otherwise.
663 struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
664 struct list_head *head, bool remove)
666 struct efivar_entry *entry, *n;
667 int strsize1, strsize2;
670 WARN_ON(!spin_is_locked(&__efivars->lock));
672 list_for_each_entry_safe(entry, n, head, list) {
673 strsize1 = ucs2_strsize(name, 1024);
674 strsize2 = ucs2_strsize(entry->var.VariableName, 1024);
675 if (strsize1 == strsize2 &&
676 !memcmp(name, &(entry->var.VariableName), strsize1) &&
677 !efi_guidcmp(guid, entry->var.VendorGuid)) {
687 list_del(&entry->list);
691 EXPORT_SYMBOL_GPL(efivar_entry_find);
694 * efivar_entry_size - obtain the size of a variable
695 * @entry: entry for this variable
696 * @size: location to store the variable's size
698 int efivar_entry_size(struct efivar_entry *entry, unsigned long *size)
700 const struct efivar_operations *ops = __efivars->ops;
705 spin_lock_irq(&__efivars->lock);
706 status = ops->get_variable(entry->var.VariableName,
707 &entry->var.VendorGuid, NULL, size, NULL);
708 spin_unlock_irq(&__efivars->lock);
710 if (status != EFI_BUFFER_TOO_SMALL)
711 return efi_status_to_err(status);
715 EXPORT_SYMBOL_GPL(efivar_entry_size);
718 * __efivar_entry_get - call get_variable()
719 * @entry: read data for this variable
720 * @attributes: variable attributes
721 * @size: size of @data buffer
722 * @data: buffer to store variable data
724 * The caller MUST call efivar_entry_iter_begin() and
725 * efivar_entry_iter_end() before and after the invocation of this
726 * function, respectively.
728 int __efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
729 unsigned long *size, void *data)
731 const struct efivar_operations *ops = __efivars->ops;
734 WARN_ON(!spin_is_locked(&__efivars->lock));
736 status = ops->get_variable(entry->var.VariableName,
737 &entry->var.VendorGuid,
738 attributes, size, data);
740 return efi_status_to_err(status);
742 EXPORT_SYMBOL_GPL(__efivar_entry_get);
745 * efivar_entry_get - call get_variable()
746 * @entry: read data for this variable
747 * @attributes: variable attributes
748 * @size: size of @data buffer
749 * @data: buffer to store variable data
751 int efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
752 unsigned long *size, void *data)
754 const struct efivar_operations *ops = __efivars->ops;
757 spin_lock_irq(&__efivars->lock);
758 status = ops->get_variable(entry->var.VariableName,
759 &entry->var.VendorGuid,
760 attributes, size, data);
761 spin_unlock_irq(&__efivars->lock);
763 return efi_status_to_err(status);
765 EXPORT_SYMBOL_GPL(efivar_entry_get);
768 * efivar_entry_set_get_size - call set_variable() and get new size (atomic)
769 * @entry: entry containing variable to set and get
770 * @attributes: attributes of variable to be written
771 * @size: size of data buffer
772 * @data: buffer containing data to write
773 * @set: did the set_variable() call succeed?
775 * This is a pretty special (complex) function. See efivarfs_file_write().
777 * Atomically call set_variable() for @entry and if the call is
778 * successful, return the new size of the variable from get_variable()
779 * in @size. The success of set_variable() is indicated by @set.
781 * Returns 0 on success, -EINVAL if the variable data is invalid,
782 * -ENOSPC if the firmware does not have enough available space, or a
783 * converted EFI status code if either of set_variable() or
784 * get_variable() fail.
786 * If the EFI variable does not exist when calling set_variable()
787 * (EFI_NOT_FOUND), @entry is removed from the variable list.
789 int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
790 unsigned long *size, void *data, bool *set)
792 const struct efivar_operations *ops = __efivars->ops;
793 efi_char16_t *name = entry->var.VariableName;
794 efi_guid_t *vendor = &entry->var.VendorGuid;
800 if (efivar_validate(&entry->var, data, *size) == false)
804 * The lock here protects the get_variable call, the conditional
805 * set_variable call, and removal of the variable from the efivars
806 * list (in the case of an authenticated delete).
808 spin_lock_irq(&__efivars->lock);
811 * Ensure that the available space hasn't shrunk below the safe level
813 status = check_var_size(attributes, *size + ucs2_strsize(name, 1024));
814 if (status != EFI_SUCCESS) {
815 if (status != EFI_UNSUPPORTED) {
816 err = efi_status_to_err(status);
826 status = ops->set_variable(name, vendor, attributes, *size, data);
827 if (status != EFI_SUCCESS) {
828 err = efi_status_to_err(status);
835 * Writing to the variable may have caused a change in size (which
836 * could either be an append or an overwrite), or the variable to be
837 * deleted. Perform a GetVariable() so we can tell what actually
841 status = ops->get_variable(entry->var.VariableName,
842 &entry->var.VendorGuid,
845 if (status == EFI_NOT_FOUND)
846 efivar_entry_list_del_unlock(entry);
848 spin_unlock_irq(&__efivars->lock);
850 if (status && status != EFI_BUFFER_TOO_SMALL)
851 return efi_status_to_err(status);
856 spin_unlock_irq(&__efivars->lock);
860 EXPORT_SYMBOL_GPL(efivar_entry_set_get_size);
863 * efivar_entry_iter_begin - begin iterating the variable list
865 * Lock the variable list to prevent entry insertion and removal until
866 * efivar_entry_iter_end() is called. This function is usually used in
867 * conjunction with __efivar_entry_iter() or efivar_entry_iter().
869 void efivar_entry_iter_begin(void)
871 spin_lock_irq(&__efivars->lock);
873 EXPORT_SYMBOL_GPL(efivar_entry_iter_begin);
876 * efivar_entry_iter_end - finish iterating the variable list
878 * Unlock the variable list and allow modifications to the list again.
880 void efivar_entry_iter_end(void)
882 spin_unlock_irq(&__efivars->lock);
884 EXPORT_SYMBOL_GPL(efivar_entry_iter_end);
887 * __efivar_entry_iter - iterate over variable list
888 * @func: callback function
889 * @head: head of the variable list
890 * @data: function-specific data to pass to callback
891 * @prev: entry to begin iterating from
893 * Iterate over the list of EFI variables and call @func with every
894 * entry on the list. It is safe for @func to remove entries in the
895 * list via efivar_entry_delete().
897 * You MUST call efivar_enter_iter_begin() before this function, and
898 * efivar_entry_iter_end() afterwards.
900 * It is possible to begin iteration from an arbitrary entry within
901 * the list by passing @prev. @prev is updated on return to point to
902 * the last entry passed to @func. To begin iterating from the
903 * beginning of the list @prev must be %NULL.
905 * The restrictions for @func are the same as documented for
906 * efivar_entry_iter().
908 int __efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
909 struct list_head *head, void *data,
910 struct efivar_entry **prev)
912 struct efivar_entry *entry, *n;
915 if (!prev || !*prev) {
916 list_for_each_entry_safe(entry, n, head, list) {
917 err = func(entry, data);
929 list_for_each_entry_safe_continue((*prev), n, head, list) {
930 err = func(*prev, data);
937 EXPORT_SYMBOL_GPL(__efivar_entry_iter);
940 * efivar_entry_iter - iterate over variable list
941 * @func: callback function
942 * @head: head of variable list
943 * @data: function-specific data to pass to callback
945 * Iterate over the list of EFI variables and call @func with every
946 * entry on the list. It is safe for @func to remove entries in the
947 * list via efivar_entry_delete() while iterating.
949 * Some notes for the callback function:
950 * - a non-zero return value indicates an error and terminates the loop
951 * - @func is called from atomic context
953 int efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
954 struct list_head *head, void *data)
958 efivar_entry_iter_begin();
959 err = __efivar_entry_iter(func, head, data, NULL);
960 efivar_entry_iter_end();
964 EXPORT_SYMBOL_GPL(efivar_entry_iter);
967 * efivars_kobject - get the kobject for the registered efivars
969 * If efivars_register() has not been called we return NULL,
970 * otherwise return the kobject used at registration time.
972 struct kobject *efivars_kobject(void)
977 return __efivars->kobject;
979 EXPORT_SYMBOL_GPL(efivars_kobject);
982 * efivar_run_worker - schedule the efivar worker thread
984 void efivar_run_worker(void)
986 if (efivar_wq_enabled)
987 schedule_work(&efivar_work);
989 EXPORT_SYMBOL_GPL(efivar_run_worker);
992 * efivars_register - register an efivars
993 * @efivars: efivars to register
994 * @ops: efivars operations
995 * @kobject: @efivars-specific kobject
997 * Only a single efivars can be registered at any time.
999 int efivars_register(struct efivars *efivars,
1000 const struct efivar_operations *ops,
1001 struct kobject *kobject)
1003 spin_lock_init(&efivars->lock);
1005 efivars->kobject = kobject;
1007 __efivars = efivars;
1011 EXPORT_SYMBOL_GPL(efivars_register);
1014 * efivars_unregister - unregister an efivars
1015 * @efivars: efivars to unregister
1017 * The caller must have already removed every entry from the list,
1018 * failure to do so is an error.
1020 int efivars_unregister(struct efivars *efivars)
1025 printk(KERN_ERR "efivars not registered\n");
1030 if (__efivars != efivars) {
1041 EXPORT_SYMBOL_GPL(efivars_unregister);