2 * EFI Variables - 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 code takes all variables accessible from EFI runtime and
8 * exports them via sysfs
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26 * 17 May 2004 - Matt Domsch <Matt_Domsch@dell.com>
27 * remove check for efi_enabled in exit
30 * 26 Apr 2004 - Matt Domsch <Matt_Domsch@dell.com>
33 * 21 Apr 2004 - Matt Tolentino <matthew.e.tolentino@intel.com)
34 * converted driver to export variable information via sysfs
35 * and moved to drivers/firmware directory
36 * bumped revision number to v0.07 to reflect conversion & move
38 * 10 Dec 2002 - Matt Domsch <Matt_Domsch@dell.com>
39 * fix locking per Peter Chubb's findings
41 * 25 Mar 2002 - Matt Domsch <Matt_Domsch@dell.com>
42 * move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_unparse()
44 * 12 Feb 2002 - Matt Domsch <Matt_Domsch@dell.com>
45 * use list_for_each_safe when deleting vars.
46 * remove ifdef CONFIG_SMP around include <linux/smp.h>
47 * v0.04 release to linux-ia64@linuxia64.org
49 * 20 April 2001 - Matt Domsch <Matt_Domsch@dell.com>
50 * Moved vars from /proc/efi to /proc/efi/vars, and made
51 * efi.c own the /proc/efi directory.
52 * v0.03 release to linux-ia64@linuxia64.org
54 * 26 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
55 * At the request of Stephane, moved ownership of /proc/efi
56 * to efi.c, and now efivars lives under /proc/efi/vars.
58 * 12 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
59 * Feedback received from Stephane Eranian incorporated.
60 * efivar_write() checks copy_from_user() return value.
61 * efivar_read/write() returns proper errno.
62 * v0.02 release to linux-ia64@linuxia64.org
64 * 26 February 2001 - Matt Domsch <Matt_Domsch@dell.com>
65 * v0.01 release to linux-ia64@linuxia64.org
68 #include <linux/capability.h>
69 #include <linux/types.h>
70 #include <linux/errno.h>
71 #include <linux/init.h>
73 #include <linux/module.h>
74 #include <linux/string.h>
75 #include <linux/smp.h>
76 #include <linux/efi.h>
77 #include <linux/sysfs.h>
78 #include <linux/kobject.h>
79 #include <linux/device.h>
80 #include <linux/slab.h>
81 #include <linux/pstore.h>
83 #include <asm/uaccess.h>
85 #define EFIVARS_VERSION "0.08"
86 #define EFIVARS_DATE "2004-May-17"
88 MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
89 MODULE_DESCRIPTION("sysfs interface to EFI Variables");
90 MODULE_LICENSE("GPL");
91 MODULE_VERSION(EFIVARS_VERSION);
93 #define DUMP_NAME_LEN 52
96 * The maximum size of VariableName + Data = 1024
97 * Therefore, it's reasonable to save that much
98 * space in each part of the structure,
99 * and we use a page for reading/writing.
102 struct efi_variable {
103 efi_char16_t VariableName[1024/sizeof(efi_char16_t)];
104 efi_guid_t VendorGuid;
105 unsigned long DataSize;
109 } __attribute__((packed));
112 struct efivar_entry {
113 struct efivars *efivars;
114 struct efi_variable var;
115 struct list_head list;
119 struct efivar_attribute {
120 struct attribute attr;
121 ssize_t (*show) (struct efivar_entry *entry, char *buf);
122 ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
125 #define PSTORE_EFI_ATTRIBUTES \
126 (EFI_VARIABLE_NON_VOLATILE | \
127 EFI_VARIABLE_BOOTSERVICE_ACCESS | \
128 EFI_VARIABLE_RUNTIME_ACCESS)
130 #define EFIVAR_ATTR(_name, _mode, _show, _store) \
131 struct efivar_attribute efivar_attr_##_name = { \
132 .attr = {.name = __stringify(_name), .mode = _mode}, \
137 #define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
138 #define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
141 * Prototype for sysfs creation function
144 efivar_create_sysfs_entry(struct efivars *efivars,
145 unsigned long variable_name_size,
146 efi_char16_t *variable_name,
147 efi_guid_t *vendor_guid);
149 /* Return the number of unicode characters in data */
151 utf16_strnlen(efi_char16_t *s, size_t maxlength)
153 unsigned long length = 0;
155 while (*s++ != 0 && length < maxlength)
160 static inline unsigned long
161 utf16_strlen(efi_char16_t *s)
163 return utf16_strnlen(s, ~0UL);
167 * Return the number of bytes is the length of this string
168 * Note: this is NOT the same as the number of unicode characters
170 static inline unsigned long
171 utf16_strsize(efi_char16_t *data, unsigned long maxlength)
173 return utf16_strnlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
177 utf16_strncmp(const efi_char16_t *a, const efi_char16_t *b, size_t len)
186 if (*a == 0) /* implies *b == 0 */
195 get_var_data_locked(struct efivars *efivars, struct efi_variable *var)
199 var->DataSize = 1024;
200 status = efivars->ops->get_variable(var->VariableName,
209 get_var_data(struct efivars *efivars, struct efi_variable *var)
213 spin_lock(&efivars->lock);
214 status = get_var_data_locked(efivars, var);
215 spin_unlock(&efivars->lock);
217 if (status != EFI_SUCCESS) {
218 printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
225 efivar_guid_read(struct efivar_entry *entry, char *buf)
227 struct efi_variable *var = &entry->var;
233 efi_guid_unparse(&var->VendorGuid, str);
235 str += sprintf(str, "\n");
241 efivar_attr_read(struct efivar_entry *entry, char *buf)
243 struct efi_variable *var = &entry->var;
250 status = get_var_data(entry->efivars, var);
251 if (status != EFI_SUCCESS)
254 if (var->Attributes & 0x1)
255 str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
256 if (var->Attributes & 0x2)
257 str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
258 if (var->Attributes & 0x4)
259 str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
264 efivar_size_read(struct efivar_entry *entry, char *buf)
266 struct efi_variable *var = &entry->var;
273 status = get_var_data(entry->efivars, var);
274 if (status != EFI_SUCCESS)
277 str += sprintf(str, "0x%lx\n", var->DataSize);
282 efivar_data_read(struct efivar_entry *entry, char *buf)
284 struct efi_variable *var = &entry->var;
290 status = get_var_data(entry->efivars, var);
291 if (status != EFI_SUCCESS)
294 memcpy(buf, var->Data, var->DataSize);
295 return var->DataSize;
298 * We allow each variable to be edited via rewriting the
299 * entire efi variable structure.
302 efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
304 struct efi_variable *new_var, *var = &entry->var;
305 struct efivars *efivars = entry->efivars;
306 efi_status_t status = EFI_NOT_FOUND;
308 if (count != sizeof(struct efi_variable))
311 new_var = (struct efi_variable *)buf;
313 * If only updating the variable data, then the name
314 * and guid should remain the same
316 if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
317 efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
318 printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
322 if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
323 printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
327 spin_lock(&efivars->lock);
328 status = efivars->ops->set_variable(new_var->VariableName,
329 &new_var->VendorGuid,
334 spin_unlock(&efivars->lock);
336 if (status != EFI_SUCCESS) {
337 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
342 memcpy(&entry->var, new_var, count);
347 efivar_show_raw(struct efivar_entry *entry, char *buf)
349 struct efi_variable *var = &entry->var;
355 status = get_var_data(entry->efivars, var);
356 if (status != EFI_SUCCESS)
359 memcpy(buf, var, sizeof(*var));
364 * Generic read/write functions that call the specific functions of
367 static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
370 struct efivar_entry *var = to_efivar_entry(kobj);
371 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
374 if (!capable(CAP_SYS_ADMIN))
377 if (efivar_attr->show) {
378 ret = efivar_attr->show(var, buf);
383 static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
384 const char *buf, size_t count)
386 struct efivar_entry *var = to_efivar_entry(kobj);
387 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
390 if (!capable(CAP_SYS_ADMIN))
393 if (efivar_attr->store)
394 ret = efivar_attr->store(var, buf, count);
399 static const struct sysfs_ops efivar_attr_ops = {
400 .show = efivar_attr_show,
401 .store = efivar_attr_store,
404 static void efivar_release(struct kobject *kobj)
406 struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
410 static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
411 static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
412 static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
413 static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
414 static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
416 static struct attribute *def_attrs[] = {
417 &efivar_attr_guid.attr,
418 &efivar_attr_size.attr,
419 &efivar_attr_attributes.attr,
420 &efivar_attr_data.attr,
421 &efivar_attr_raw_var.attr,
425 static struct kobj_type efivar_ktype = {
426 .release = efivar_release,
427 .sysfs_ops = &efivar_attr_ops,
428 .default_attrs = def_attrs,
431 static struct pstore_info efi_pstore_info;
434 efivar_unregister(struct efivar_entry *var)
436 kobject_put(&var->kobj);
441 static int efi_pstore_open(struct pstore_info *psi)
443 struct efivars *efivars = psi->data;
445 spin_lock(&efivars->lock);
446 efivars->walk_entry = list_first_entry(&efivars->list,
447 struct efivar_entry, list);
451 static int efi_pstore_close(struct pstore_info *psi)
453 struct efivars *efivars = psi->data;
455 spin_unlock(&efivars->lock);
459 static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
460 struct timespec *timespec,
461 char **buf, struct pstore_info *psi)
463 efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
464 struct efivars *efivars = psi->data;
465 char name[DUMP_NAME_LEN];
467 unsigned int part, size;
470 while (&efivars->walk_entry->list != &efivars->list) {
471 if (!efi_guidcmp(efivars->walk_entry->var.VendorGuid,
473 for (i = 0; i < DUMP_NAME_LEN; i++) {
474 name[i] = efivars->walk_entry->var.VariableName[i];
476 if (sscanf(name, "dump-type%u-%u-%lu", type, &part, &time) == 3) {
478 timespec->tv_sec = time;
479 timespec->tv_nsec = 0;
480 get_var_data_locked(efivars, &efivars->walk_entry->var);
481 size = efivars->walk_entry->var.DataSize;
482 *buf = kmalloc(size, GFP_KERNEL);
485 memcpy(*buf, efivars->walk_entry->var.Data,
487 efivars->walk_entry = list_entry(efivars->walk_entry->list.next,
488 struct efivar_entry, list);
492 efivars->walk_entry = list_entry(efivars->walk_entry->list.next,
493 struct efivar_entry, list);
498 static int efi_pstore_write(enum pstore_type_id type,
499 enum kmsg_dump_reason reason, u64 *id,
500 unsigned int part, size_t size, struct pstore_info *psi)
502 char name[DUMP_NAME_LEN];
503 char stub_name[DUMP_NAME_LEN];
504 efi_char16_t efi_name[DUMP_NAME_LEN];
505 efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
506 struct efivars *efivars = psi->data;
507 struct efivar_entry *entry, *found = NULL;
510 sprintf(stub_name, "dump-type%u-%u-", type, part);
511 sprintf(name, "%s%lu", stub_name, get_seconds());
513 spin_lock(&efivars->lock);
515 for (i = 0; i < DUMP_NAME_LEN; i++)
516 efi_name[i] = stub_name[i];
519 * Clean up any entries with the same name
522 list_for_each_entry(entry, &efivars->list, list) {
523 get_var_data_locked(efivars, &entry->var);
525 if (efi_guidcmp(entry->var.VendorGuid, vendor))
527 if (utf16_strncmp(entry->var.VariableName, efi_name,
528 utf16_strlen(efi_name)))
530 /* Needs to be a prefix */
531 if (entry->var.VariableName[utf16_strlen(efi_name)] == 0)
536 efivars->ops->set_variable(entry->var.VariableName,
537 &entry->var.VendorGuid,
538 PSTORE_EFI_ATTRIBUTES,
543 list_del(&found->list);
545 for (i = 0; i < DUMP_NAME_LEN; i++)
546 efi_name[i] = name[i];
548 efivars->ops->set_variable(efi_name, &vendor, PSTORE_EFI_ATTRIBUTES,
551 spin_unlock(&efivars->lock);
554 efivar_unregister(found);
557 ret = efivar_create_sysfs_entry(efivars,
558 utf16_strsize(efi_name,
566 static int efi_pstore_erase(enum pstore_type_id type, u64 id,
567 struct pstore_info *psi)
569 efi_pstore_write(type, 0, &id, (unsigned int)id, 0, psi);
574 static int efi_pstore_open(struct pstore_info *psi)
579 static int efi_pstore_close(struct pstore_info *psi)
584 static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
585 struct timespec *time, struct pstore_info *psi)
590 static int efi_pstore_write(enum pstore_type_id type,
591 enum kmsg_dump_reason reason, u64 *id,
592 unsigned int part, size_t size, struct pstore_info *psi)
597 static int efi_pstore_erase(enum pstore_type_id type, u64 id,
598 struct pstore_info *psi)
604 static struct pstore_info efi_pstore_info = {
605 .owner = THIS_MODULE,
607 .open = efi_pstore_open,
608 .close = efi_pstore_close,
609 .read = efi_pstore_read,
610 .write = efi_pstore_write,
611 .erase = efi_pstore_erase,
614 static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
615 struct bin_attribute *bin_attr,
616 char *buf, loff_t pos, size_t count)
618 struct efi_variable *new_var = (struct efi_variable *)buf;
619 struct efivars *efivars = bin_attr->private;
620 struct efivar_entry *search_efivar, *n;
621 unsigned long strsize1, strsize2;
622 efi_status_t status = EFI_NOT_FOUND;
625 if (!capable(CAP_SYS_ADMIN))
628 spin_lock(&efivars->lock);
631 * Does this variable already exist?
633 list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
634 strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
635 strsize2 = utf16_strsize(new_var->VariableName, 1024);
636 if (strsize1 == strsize2 &&
637 !memcmp(&(search_efivar->var.VariableName),
638 new_var->VariableName, strsize1) &&
639 !efi_guidcmp(search_efivar->var.VendorGuid,
640 new_var->VendorGuid)) {
646 spin_unlock(&efivars->lock);
650 /* now *really* create the variable via EFI */
651 status = efivars->ops->set_variable(new_var->VariableName,
652 &new_var->VendorGuid,
657 if (status != EFI_SUCCESS) {
658 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
660 spin_unlock(&efivars->lock);
663 spin_unlock(&efivars->lock);
665 /* Create the entry in sysfs. Locking is not required here */
666 status = efivar_create_sysfs_entry(efivars,
667 utf16_strsize(new_var->VariableName,
669 new_var->VariableName,
670 &new_var->VendorGuid);
672 printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
677 static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
678 struct bin_attribute *bin_attr,
679 char *buf, loff_t pos, size_t count)
681 struct efi_variable *del_var = (struct efi_variable *)buf;
682 struct efivars *efivars = bin_attr->private;
683 struct efivar_entry *search_efivar, *n;
684 unsigned long strsize1, strsize2;
685 efi_status_t status = EFI_NOT_FOUND;
688 if (!capable(CAP_SYS_ADMIN))
691 spin_lock(&efivars->lock);
694 * Does this variable already exist?
696 list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
697 strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
698 strsize2 = utf16_strsize(del_var->VariableName, 1024);
699 if (strsize1 == strsize2 &&
700 !memcmp(&(search_efivar->var.VariableName),
701 del_var->VariableName, strsize1) &&
702 !efi_guidcmp(search_efivar->var.VendorGuid,
703 del_var->VendorGuid)) {
709 spin_unlock(&efivars->lock);
712 /* force the Attributes/DataSize to 0 to ensure deletion */
713 del_var->Attributes = 0;
714 del_var->DataSize = 0;
716 status = efivars->ops->set_variable(del_var->VariableName,
717 &del_var->VendorGuid,
722 if (status != EFI_SUCCESS) {
723 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
725 spin_unlock(&efivars->lock);
728 list_del(&search_efivar->list);
729 /* We need to release this lock before unregistering. */
730 spin_unlock(&efivars->lock);
731 efivar_unregister(search_efivar);
733 /* It's dead Jim.... */
738 * Let's not leave out systab information that snuck into
741 static ssize_t systab_show(struct kobject *kobj,
742 struct kobj_attribute *attr, char *buf)
749 if (efi.mps != EFI_INVALID_TABLE_ADDR)
750 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
751 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
752 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
753 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
754 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
755 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
756 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
757 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
758 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
759 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
760 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
761 if (efi.uga != EFI_INVALID_TABLE_ADDR)
762 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
767 static struct kobj_attribute efi_attr_systab =
768 __ATTR(systab, 0400, systab_show, NULL);
770 static struct attribute *efi_subsys_attrs[] = {
771 &efi_attr_systab.attr,
772 NULL, /* maybe more in the future? */
775 static struct attribute_group efi_subsys_attr_group = {
776 .attrs = efi_subsys_attrs,
779 static struct kobject *efi_kobj;
782 * efivar_create_sysfs_entry()
784 * variable_name_size = number of bytes required to hold
785 * variable_name (not counting the NULL
786 * character at the end.
787 * efivars->lock is not held on entry or exit.
788 * Returns 1 on failure, 0 on success
791 efivar_create_sysfs_entry(struct efivars *efivars,
792 unsigned long variable_name_size,
793 efi_char16_t *variable_name,
794 efi_guid_t *vendor_guid)
796 int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38;
798 struct efivar_entry *new_efivar;
800 short_name = kzalloc(short_name_size + 1, GFP_KERNEL);
801 new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
803 if (!short_name || !new_efivar) {
809 new_efivar->efivars = efivars;
810 memcpy(new_efivar->var.VariableName, variable_name,
812 memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));
814 /* Convert Unicode to normal chars (assume top bits are 0),
816 for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
817 short_name[i] = variable_name[i] & 0xFF;
819 /* This is ugly, but necessary to separate one vendor's
820 private variables from another's. */
822 *(short_name + strlen(short_name)) = '-';
823 efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
825 new_efivar->kobj.kset = efivars->kset;
826 i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL,
834 kobject_uevent(&new_efivar->kobj, KOBJ_ADD);
838 spin_lock(&efivars->lock);
839 list_add(&new_efivar->list, &efivars->list);
840 spin_unlock(&efivars->lock);
846 create_efivars_bin_attributes(struct efivars *efivars)
848 struct bin_attribute *attr;
852 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
856 attr->attr.name = "new_var";
857 attr->attr.mode = 0200;
858 attr->write = efivar_create;
859 attr->private = efivars;
860 efivars->new_var = attr;
863 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
868 attr->attr.name = "del_var";
869 attr->attr.mode = 0200;
870 attr->write = efivar_delete;
871 attr->private = efivars;
872 efivars->del_var = attr;
874 sysfs_bin_attr_init(efivars->new_var);
875 sysfs_bin_attr_init(efivars->del_var);
878 error = sysfs_create_bin_file(&efivars->kset->kobj,
881 printk(KERN_ERR "efivars: unable to create new_var sysfs file"
882 " due to error %d\n", error);
885 error = sysfs_create_bin_file(&efivars->kset->kobj,
888 printk(KERN_ERR "efivars: unable to create del_var sysfs file"
889 " due to error %d\n", error);
890 sysfs_remove_bin_file(&efivars->kset->kobj,
897 kfree(efivars->del_var);
898 efivars->del_var = NULL;
899 kfree(efivars->new_var);
900 efivars->new_var = NULL;
904 void unregister_efivars(struct efivars *efivars)
906 struct efivar_entry *entry, *n;
908 list_for_each_entry_safe(entry, n, &efivars->list, list) {
909 spin_lock(&efivars->lock);
910 list_del(&entry->list);
911 spin_unlock(&efivars->lock);
912 efivar_unregister(entry);
914 if (efivars->new_var)
915 sysfs_remove_bin_file(&efivars->kset->kobj, efivars->new_var);
916 if (efivars->del_var)
917 sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var);
918 kfree(efivars->new_var);
919 kfree(efivars->del_var);
920 kset_unregister(efivars->kset);
922 EXPORT_SYMBOL_GPL(unregister_efivars);
924 int register_efivars(struct efivars *efivars,
925 const struct efivar_operations *ops,
926 struct kobject *parent_kobj)
928 efi_status_t status = EFI_NOT_FOUND;
929 efi_guid_t vendor_guid;
930 efi_char16_t *variable_name;
931 unsigned long variable_name_size = 1024;
934 variable_name = kzalloc(variable_name_size, GFP_KERNEL);
935 if (!variable_name) {
936 printk(KERN_ERR "efivars: Memory allocation failed.\n");
940 spin_lock_init(&efivars->lock);
941 INIT_LIST_HEAD(&efivars->list);
944 efivars->kset = kset_create_and_add("vars", NULL, parent_kobj);
945 if (!efivars->kset) {
946 printk(KERN_ERR "efivars: Subsystem registration failed.\n");
952 * Per EFI spec, the maximum storage allocated for both
953 * the variable name and variable data is 1024 bytes.
957 variable_name_size = 1024;
959 status = ops->get_next_variable(&variable_name_size,
964 efivar_create_sysfs_entry(efivars,
972 printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
974 status = EFI_NOT_FOUND;
977 } while (status != EFI_NOT_FOUND);
979 error = create_efivars_bin_attributes(efivars);
981 unregister_efivars(efivars);
983 efivars->efi_pstore_info = efi_pstore_info;
985 efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
986 if (efivars->efi_pstore_info.buf) {
987 efivars->efi_pstore_info.bufsize = 1024;
988 efivars->efi_pstore_info.data = efivars;
989 spin_lock_init(&efivars->efi_pstore_info.buf_lock);
990 pstore_register(&efivars->efi_pstore_info);
994 kfree(variable_name);
998 EXPORT_SYMBOL_GPL(register_efivars);
1000 static struct efivars __efivars;
1001 static struct efivar_operations ops;
1004 * For now we register the efi subsystem with the firmware subsystem
1005 * and the vars subsystem with the efi subsystem. In the future, it
1006 * might make sense to split off the efi subsystem into its own
1007 * driver, but for now only efivars will register with it, so just
1016 printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
1022 /* For now we'll register the efi directory at /sys/firmware/efi */
1023 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
1025 printk(KERN_ERR "efivars: Firmware registration failed.\n");
1029 ops.get_variable = efi.get_variable;
1030 ops.set_variable = efi.set_variable;
1031 ops.get_next_variable = efi.get_next_variable;
1032 error = register_efivars(&__efivars, &ops, efi_kobj);
1036 /* Don't forget the systab entry */
1037 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
1040 "efivars: Sysfs attribute export failed with error %d.\n",
1042 goto err_unregister;
1048 unregister_efivars(&__efivars);
1050 kobject_put(efi_kobj);
1058 unregister_efivars(&__efivars);
1059 kobject_put(efi_kobj);
1063 module_init(efivars_init);
1064 module_exit(efivars_exit);