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 validate_device_path(struct efi_variable
*var
, int match
, u8
*buffer
, int len
)
197 struct efi_generic_dev_path
*node
;
200 node
= (struct efi_generic_dev_path
*)buffer
;
202 while (offset
< len
) {
203 offset
+= node
->length
;
208 if ((node
->type
== EFI_DEV_END_PATH
||
209 node
->type
== EFI_DEV_END_PATH2
) &&
210 node
->sub_type
== EFI_DEV_END_ENTIRE
)
213 node
= (struct efi_generic_dev_path
*)(buffer
+ offset
);
217 * If we're here then either node->length pointed past the end
218 * of the buffer or we reached the end of the buffer without
219 * finding a device path end node.
225 validate_boot_order(struct efi_variable
*var
, int match
, u8
*buffer
, int len
)
227 /* An array of 16-bit integers */
235 validate_load_option(struct efi_variable
*var
, int match
, u8
*buffer
, int len
)
238 int i
, desclength
= 0;
240 /* Either "Boot" or "Driver" followed by four digits of hex */
241 for (i
= match
; i
< match
+4; i
++) {
242 if (hex_to_bin(var
->VariableName
[i
] & 0xff) < 0)
246 /* A valid entry must be at least 6 bytes */
250 filepathlength
= buffer
[4] | buffer
[5] << 8;
253 * There's no stored length for the description, so it has to be
256 desclength
= utf16_strsize((efi_char16_t
*)(buffer
+ 6), len
) + 2;
258 /* Each boot entry must have a descriptor */
263 * If the sum of the length of the description, the claimed filepath
264 * length and the original header are greater than the length of the
265 * variable, it's malformed
267 if ((desclength
+ filepathlength
+ 6) > len
)
271 * And, finally, check the filepath
273 return validate_device_path(var
, match
, buffer
+ desclength
+ 6,
278 validate_uint16(struct efi_variable
*var
, int match
, u8
*buffer
, int len
)
280 /* A single 16-bit integer */
288 validate_ascii_string(struct efi_variable
*var
, int match
, u8
*buffer
, int len
)
292 for (i
= 0; i
< len
; i
++) {
303 struct variable_validate
{
305 bool (*validate
)(struct efi_variable
*var
, int match
, u8
*data
,
309 static const struct variable_validate variable_validate
[] = {
310 { "BootNext", validate_uint16
},
311 { "BootOrder", validate_boot_order
},
312 { "DriverOrder", validate_boot_order
},
313 { "Boot*", validate_load_option
},
314 { "Driver*", validate_load_option
},
315 { "ConIn", validate_device_path
},
316 { "ConInDev", validate_device_path
},
317 { "ConOut", validate_device_path
},
318 { "ConOutDev", validate_device_path
},
319 { "ErrOut", validate_device_path
},
320 { "ErrOutDev", validate_device_path
},
321 { "Timeout", validate_uint16
},
322 { "Lang", validate_ascii_string
},
323 { "PlatformLang", validate_ascii_string
},
328 validate_var(struct efi_variable
*var
, u8
*data
, int len
)
331 u16
*unicode_name
= var
->VariableName
;
333 for (i
= 0; variable_validate
[i
].validate
!= NULL
; i
++) {
334 const char *name
= variable_validate
[i
].name
;
337 for (match
= 0; ; match
++) {
338 char c
= name
[match
];
339 u16 u
= unicode_name
[match
];
341 /* All special variables are plain ascii */
345 /* Wildcard in the matching name means we've matched */
347 return variable_validate
[i
].validate(var
,
350 /* Case sensitive match */
354 /* Reached the end of the string while matching */
356 return variable_validate
[i
].validate(var
,
365 get_var_data_locked(struct efivars
*efivars
, struct efi_variable
*var
)
369 var
->DataSize
= 1024;
370 status
= efivars
->ops
->get_variable(var
->VariableName
,
379 get_var_data(struct efivars
*efivars
, struct efi_variable
*var
)
383 spin_lock(&efivars
->lock
);
384 status
= get_var_data_locked(efivars
, var
);
385 spin_unlock(&efivars
->lock
);
387 if (status
!= EFI_SUCCESS
) {
388 printk(KERN_WARNING
"efivars: get_variable() failed 0x%lx!\n",
395 efivar_guid_read(struct efivar_entry
*entry
, char *buf
)
397 struct efi_variable
*var
= &entry
->var
;
403 efi_guid_unparse(&var
->VendorGuid
, str
);
405 str
+= sprintf(str
, "\n");
411 efivar_attr_read(struct efivar_entry
*entry
, char *buf
)
413 struct efi_variable
*var
= &entry
->var
;
420 status
= get_var_data(entry
->efivars
, var
);
421 if (status
!= EFI_SUCCESS
)
424 if (var
->Attributes
& 0x1)
425 str
+= sprintf(str
, "EFI_VARIABLE_NON_VOLATILE\n");
426 if (var
->Attributes
& 0x2)
427 str
+= sprintf(str
, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
428 if (var
->Attributes
& 0x4)
429 str
+= sprintf(str
, "EFI_VARIABLE_RUNTIME_ACCESS\n");
434 efivar_size_read(struct efivar_entry
*entry
, char *buf
)
436 struct efi_variable
*var
= &entry
->var
;
443 status
= get_var_data(entry
->efivars
, var
);
444 if (status
!= EFI_SUCCESS
)
447 str
+= sprintf(str
, "0x%lx\n", var
->DataSize
);
452 efivar_data_read(struct efivar_entry
*entry
, char *buf
)
454 struct efi_variable
*var
= &entry
->var
;
460 status
= get_var_data(entry
->efivars
, var
);
461 if (status
!= EFI_SUCCESS
)
464 memcpy(buf
, var
->Data
, var
->DataSize
);
465 return var
->DataSize
;
468 * We allow each variable to be edited via rewriting the
469 * entire efi variable structure.
472 efivar_store_raw(struct efivar_entry
*entry
, const char *buf
, size_t count
)
474 struct efi_variable
*new_var
, *var
= &entry
->var
;
475 struct efivars
*efivars
= entry
->efivars
;
476 efi_status_t status
= EFI_NOT_FOUND
;
478 if (count
!= sizeof(struct efi_variable
))
481 new_var
= (struct efi_variable
*)buf
;
483 * If only updating the variable data, then the name
484 * and guid should remain the same
486 if (memcmp(new_var
->VariableName
, var
->VariableName
, sizeof(var
->VariableName
)) ||
487 efi_guidcmp(new_var
->VendorGuid
, var
->VendorGuid
)) {
488 printk(KERN_ERR
"efivars: Cannot edit the wrong variable!\n");
492 if ((new_var
->DataSize
<= 0) || (new_var
->Attributes
== 0)){
493 printk(KERN_ERR
"efivars: DataSize & Attributes must be valid!\n");
497 if ((new_var
->Attributes
& ~EFI_VARIABLE_MASK
) != 0 ||
498 validate_var(new_var
, new_var
->Data
, new_var
->DataSize
) == false) {
499 printk(KERN_ERR
"efivars: Malformed variable content\n");
503 spin_lock(&efivars
->lock
);
504 status
= efivars
->ops
->set_variable(new_var
->VariableName
,
505 &new_var
->VendorGuid
,
510 spin_unlock(&efivars
->lock
);
512 if (status
!= EFI_SUCCESS
) {
513 printk(KERN_WARNING
"efivars: set_variable() failed: status=%lx\n",
518 memcpy(&entry
->var
, new_var
, count
);
523 efivar_show_raw(struct efivar_entry
*entry
, char *buf
)
525 struct efi_variable
*var
= &entry
->var
;
531 status
= get_var_data(entry
->efivars
, var
);
532 if (status
!= EFI_SUCCESS
)
535 memcpy(buf
, var
, sizeof(*var
));
540 * Generic read/write functions that call the specific functions of
543 static ssize_t
efivar_attr_show(struct kobject
*kobj
, struct attribute
*attr
,
546 struct efivar_entry
*var
= to_efivar_entry(kobj
);
547 struct efivar_attribute
*efivar_attr
= to_efivar_attr(attr
);
550 if (!capable(CAP_SYS_ADMIN
))
553 if (efivar_attr
->show
) {
554 ret
= efivar_attr
->show(var
, buf
);
559 static ssize_t
efivar_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
560 const char *buf
, size_t count
)
562 struct efivar_entry
*var
= to_efivar_entry(kobj
);
563 struct efivar_attribute
*efivar_attr
= to_efivar_attr(attr
);
566 if (!capable(CAP_SYS_ADMIN
))
569 if (efivar_attr
->store
)
570 ret
= efivar_attr
->store(var
, buf
, count
);
575 static const struct sysfs_ops efivar_attr_ops
= {
576 .show
= efivar_attr_show
,
577 .store
= efivar_attr_store
,
580 static void efivar_release(struct kobject
*kobj
)
582 struct efivar_entry
*var
= container_of(kobj
, struct efivar_entry
, kobj
);
586 static EFIVAR_ATTR(guid
, 0400, efivar_guid_read
, NULL
);
587 static EFIVAR_ATTR(attributes
, 0400, efivar_attr_read
, NULL
);
588 static EFIVAR_ATTR(size
, 0400, efivar_size_read
, NULL
);
589 static EFIVAR_ATTR(data
, 0400, efivar_data_read
, NULL
);
590 static EFIVAR_ATTR(raw_var
, 0600, efivar_show_raw
, efivar_store_raw
);
592 static struct attribute
*def_attrs
[] = {
593 &efivar_attr_guid
.attr
,
594 &efivar_attr_size
.attr
,
595 &efivar_attr_attributes
.attr
,
596 &efivar_attr_data
.attr
,
597 &efivar_attr_raw_var
.attr
,
601 static struct kobj_type efivar_ktype
= {
602 .release
= efivar_release
,
603 .sysfs_ops
= &efivar_attr_ops
,
604 .default_attrs
= def_attrs
,
607 static struct pstore_info efi_pstore_info
;
610 efivar_unregister(struct efivar_entry
*var
)
612 kobject_put(&var
->kobj
);
617 static int efi_pstore_open(struct pstore_info
*psi
)
619 struct efivars
*efivars
= psi
->data
;
621 spin_lock(&efivars
->lock
);
622 efivars
->walk_entry
= list_first_entry(&efivars
->list
,
623 struct efivar_entry
, list
);
627 static int efi_pstore_close(struct pstore_info
*psi
)
629 struct efivars
*efivars
= psi
->data
;
631 spin_unlock(&efivars
->lock
);
635 static ssize_t
efi_pstore_read(u64
*id
, enum pstore_type_id
*type
,
636 struct timespec
*timespec
,
637 char **buf
, struct pstore_info
*psi
)
639 efi_guid_t vendor
= LINUX_EFI_CRASH_GUID
;
640 struct efivars
*efivars
= psi
->data
;
641 char name
[DUMP_NAME_LEN
];
643 unsigned int part
, size
;
646 while (&efivars
->walk_entry
->list
!= &efivars
->list
) {
647 if (!efi_guidcmp(efivars
->walk_entry
->var
.VendorGuid
,
649 for (i
= 0; i
< DUMP_NAME_LEN
; i
++) {
650 name
[i
] = efivars
->walk_entry
->var
.VariableName
[i
];
652 if (sscanf(name
, "dump-type%u-%u-%lu", type
, &part
, &time
) == 3) {
654 timespec
->tv_sec
= time
;
655 timespec
->tv_nsec
= 0;
656 get_var_data_locked(efivars
, &efivars
->walk_entry
->var
);
657 size
= efivars
->walk_entry
->var
.DataSize
;
658 *buf
= kmalloc(size
, GFP_KERNEL
);
661 memcpy(*buf
, efivars
->walk_entry
->var
.Data
,
663 efivars
->walk_entry
= list_entry(efivars
->walk_entry
->list
.next
,
664 struct efivar_entry
, list
);
668 efivars
->walk_entry
= list_entry(efivars
->walk_entry
->list
.next
,
669 struct efivar_entry
, list
);
674 static int efi_pstore_write(enum pstore_type_id type
,
675 enum kmsg_dump_reason reason
, u64
*id
,
676 unsigned int part
, size_t size
, struct pstore_info
*psi
)
678 char name
[DUMP_NAME_LEN
];
679 char stub_name
[DUMP_NAME_LEN
];
680 efi_char16_t efi_name
[DUMP_NAME_LEN
];
681 efi_guid_t vendor
= LINUX_EFI_CRASH_GUID
;
682 struct efivars
*efivars
= psi
->data
;
683 struct efivar_entry
*entry
, *found
= NULL
;
686 sprintf(stub_name
, "dump-type%u-%u-", type
, part
);
687 sprintf(name
, "%s%lu", stub_name
, get_seconds());
689 spin_lock(&efivars
->lock
);
691 for (i
= 0; i
< DUMP_NAME_LEN
; i
++)
692 efi_name
[i
] = stub_name
[i
];
695 * Clean up any entries with the same name
698 list_for_each_entry(entry
, &efivars
->list
, list
) {
699 get_var_data_locked(efivars
, &entry
->var
);
701 if (efi_guidcmp(entry
->var
.VendorGuid
, vendor
))
703 if (utf16_strncmp(entry
->var
.VariableName
, efi_name
,
704 utf16_strlen(efi_name
)))
706 /* Needs to be a prefix */
707 if (entry
->var
.VariableName
[utf16_strlen(efi_name
)] == 0)
712 efivars
->ops
->set_variable(entry
->var
.VariableName
,
713 &entry
->var
.VendorGuid
,
714 PSTORE_EFI_ATTRIBUTES
,
719 list_del(&found
->list
);
721 for (i
= 0; i
< DUMP_NAME_LEN
; i
++)
722 efi_name
[i
] = name
[i
];
724 efivars
->ops
->set_variable(efi_name
, &vendor
, PSTORE_EFI_ATTRIBUTES
,
727 spin_unlock(&efivars
->lock
);
730 efivar_unregister(found
);
733 ret
= efivar_create_sysfs_entry(efivars
,
734 utf16_strsize(efi_name
,
742 static int efi_pstore_erase(enum pstore_type_id type
, u64 id
,
743 struct pstore_info
*psi
)
745 efi_pstore_write(type
, 0, &id
, (unsigned int)id
, 0, psi
);
750 static int efi_pstore_open(struct pstore_info
*psi
)
755 static int efi_pstore_close(struct pstore_info
*psi
)
760 static ssize_t
efi_pstore_read(u64
*id
, enum pstore_type_id
*type
,
761 struct timespec
*timespec
,
762 char **buf
, struct pstore_info
*psi
)
767 static int efi_pstore_write(enum pstore_type_id type
,
768 enum kmsg_dump_reason reason
, u64
*id
,
769 unsigned int part
, size_t size
, struct pstore_info
*psi
)
774 static int efi_pstore_erase(enum pstore_type_id type
, u64 id
,
775 struct pstore_info
*psi
)
781 static struct pstore_info efi_pstore_info
= {
782 .owner
= THIS_MODULE
,
784 .open
= efi_pstore_open
,
785 .close
= efi_pstore_close
,
786 .read
= efi_pstore_read
,
787 .write
= efi_pstore_write
,
788 .erase
= efi_pstore_erase
,
791 static ssize_t
efivar_create(struct file
*filp
, struct kobject
*kobj
,
792 struct bin_attribute
*bin_attr
,
793 char *buf
, loff_t pos
, size_t count
)
795 struct efi_variable
*new_var
= (struct efi_variable
*)buf
;
796 struct efivars
*efivars
= bin_attr
->private;
797 struct efivar_entry
*search_efivar
, *n
;
798 unsigned long strsize1
, strsize2
;
799 efi_status_t status
= EFI_NOT_FOUND
;
802 if (!capable(CAP_SYS_ADMIN
))
805 if ((new_var
->Attributes
& ~EFI_VARIABLE_MASK
) != 0 ||
806 validate_var(new_var
, new_var
->Data
, new_var
->DataSize
) == false) {
807 printk(KERN_ERR
"efivars: Malformed variable content\n");
811 spin_lock(&efivars
->lock
);
814 * Does this variable already exist?
816 list_for_each_entry_safe(search_efivar
, n
, &efivars
->list
, list
) {
817 strsize1
= utf16_strsize(search_efivar
->var
.VariableName
, 1024);
818 strsize2
= utf16_strsize(new_var
->VariableName
, 1024);
819 if (strsize1
== strsize2
&&
820 !memcmp(&(search_efivar
->var
.VariableName
),
821 new_var
->VariableName
, strsize1
) &&
822 !efi_guidcmp(search_efivar
->var
.VendorGuid
,
823 new_var
->VendorGuid
)) {
829 spin_unlock(&efivars
->lock
);
833 /* now *really* create the variable via EFI */
834 status
= efivars
->ops
->set_variable(new_var
->VariableName
,
835 &new_var
->VendorGuid
,
840 if (status
!= EFI_SUCCESS
) {
841 printk(KERN_WARNING
"efivars: set_variable() failed: status=%lx\n",
843 spin_unlock(&efivars
->lock
);
846 spin_unlock(&efivars
->lock
);
848 /* Create the entry in sysfs. Locking is not required here */
849 status
= efivar_create_sysfs_entry(efivars
,
850 utf16_strsize(new_var
->VariableName
,
852 new_var
->VariableName
,
853 &new_var
->VendorGuid
);
855 printk(KERN_WARNING
"efivars: variable created, but sysfs entry wasn't.\n");
860 static ssize_t
efivar_delete(struct file
*filp
, struct kobject
*kobj
,
861 struct bin_attribute
*bin_attr
,
862 char *buf
, loff_t pos
, size_t count
)
864 struct efi_variable
*del_var
= (struct efi_variable
*)buf
;
865 struct efivars
*efivars
= bin_attr
->private;
866 struct efivar_entry
*search_efivar
, *n
;
867 unsigned long strsize1
, strsize2
;
868 efi_status_t status
= EFI_NOT_FOUND
;
871 if (!capable(CAP_SYS_ADMIN
))
874 spin_lock(&efivars
->lock
);
877 * Does this variable already exist?
879 list_for_each_entry_safe(search_efivar
, n
, &efivars
->list
, list
) {
880 strsize1
= utf16_strsize(search_efivar
->var
.VariableName
, 1024);
881 strsize2
= utf16_strsize(del_var
->VariableName
, 1024);
882 if (strsize1
== strsize2
&&
883 !memcmp(&(search_efivar
->var
.VariableName
),
884 del_var
->VariableName
, strsize1
) &&
885 !efi_guidcmp(search_efivar
->var
.VendorGuid
,
886 del_var
->VendorGuid
)) {
892 spin_unlock(&efivars
->lock
);
895 /* force the Attributes/DataSize to 0 to ensure deletion */
896 del_var
->Attributes
= 0;
897 del_var
->DataSize
= 0;
899 status
= efivars
->ops
->set_variable(del_var
->VariableName
,
900 &del_var
->VendorGuid
,
905 if (status
!= EFI_SUCCESS
) {
906 printk(KERN_WARNING
"efivars: set_variable() failed: status=%lx\n",
908 spin_unlock(&efivars
->lock
);
911 list_del(&search_efivar
->list
);
912 /* We need to release this lock before unregistering. */
913 spin_unlock(&efivars
->lock
);
914 efivar_unregister(search_efivar
);
916 /* It's dead Jim.... */
921 * Let's not leave out systab information that snuck into
924 static ssize_t
systab_show(struct kobject
*kobj
,
925 struct kobj_attribute
*attr
, char *buf
)
932 if (efi
.mps
!= EFI_INVALID_TABLE_ADDR
)
933 str
+= sprintf(str
, "MPS=0x%lx\n", efi
.mps
);
934 if (efi
.acpi20
!= EFI_INVALID_TABLE_ADDR
)
935 str
+= sprintf(str
, "ACPI20=0x%lx\n", efi
.acpi20
);
936 if (efi
.acpi
!= EFI_INVALID_TABLE_ADDR
)
937 str
+= sprintf(str
, "ACPI=0x%lx\n", efi
.acpi
);
938 if (efi
.smbios
!= EFI_INVALID_TABLE_ADDR
)
939 str
+= sprintf(str
, "SMBIOS=0x%lx\n", efi
.smbios
);
940 if (efi
.hcdp
!= EFI_INVALID_TABLE_ADDR
)
941 str
+= sprintf(str
, "HCDP=0x%lx\n", efi
.hcdp
);
942 if (efi
.boot_info
!= EFI_INVALID_TABLE_ADDR
)
943 str
+= sprintf(str
, "BOOTINFO=0x%lx\n", efi
.boot_info
);
944 if (efi
.uga
!= EFI_INVALID_TABLE_ADDR
)
945 str
+= sprintf(str
, "UGA=0x%lx\n", efi
.uga
);
950 static struct kobj_attribute efi_attr_systab
=
951 __ATTR(systab
, 0400, systab_show
, NULL
);
953 static struct attribute
*efi_subsys_attrs
[] = {
954 &efi_attr_systab
.attr
,
955 NULL
, /* maybe more in the future? */
958 static struct attribute_group efi_subsys_attr_group
= {
959 .attrs
= efi_subsys_attrs
,
962 static struct kobject
*efi_kobj
;
965 * efivar_create_sysfs_entry()
967 * variable_name_size = number of bytes required to hold
968 * variable_name (not counting the NULL
969 * character at the end.
970 * efivars->lock is not held on entry or exit.
971 * Returns 1 on failure, 0 on success
974 efivar_create_sysfs_entry(struct efivars
*efivars
,
975 unsigned long variable_name_size
,
976 efi_char16_t
*variable_name
,
977 efi_guid_t
*vendor_guid
)
979 int i
, short_name_size
= variable_name_size
/ sizeof(efi_char16_t
) + 38;
981 struct efivar_entry
*new_efivar
;
983 short_name
= kzalloc(short_name_size
+ 1, GFP_KERNEL
);
984 new_efivar
= kzalloc(sizeof(struct efivar_entry
), GFP_KERNEL
);
986 if (!short_name
|| !new_efivar
) {
992 new_efivar
->efivars
= efivars
;
993 memcpy(new_efivar
->var
.VariableName
, variable_name
,
995 memcpy(&(new_efivar
->var
.VendorGuid
), vendor_guid
, sizeof(efi_guid_t
));
997 /* Convert Unicode to normal chars (assume top bits are 0),
999 for (i
=0; i
< (int)(variable_name_size
/ sizeof(efi_char16_t
)); i
++) {
1000 short_name
[i
] = variable_name
[i
] & 0xFF;
1002 /* This is ugly, but necessary to separate one vendor's
1003 private variables from another's. */
1005 *(short_name
+ strlen(short_name
)) = '-';
1006 efi_guid_unparse(vendor_guid
, short_name
+ strlen(short_name
));
1008 new_efivar
->kobj
.kset
= efivars
->kset
;
1009 i
= kobject_init_and_add(&new_efivar
->kobj
, &efivar_ktype
, NULL
,
1017 kobject_uevent(&new_efivar
->kobj
, KOBJ_ADD
);
1021 spin_lock(&efivars
->lock
);
1022 list_add(&new_efivar
->list
, &efivars
->list
);
1023 spin_unlock(&efivars
->lock
);
1029 create_efivars_bin_attributes(struct efivars
*efivars
)
1031 struct bin_attribute
*attr
;
1035 attr
= kzalloc(sizeof(*attr
), GFP_KERNEL
);
1039 attr
->attr
.name
= "new_var";
1040 attr
->attr
.mode
= 0200;
1041 attr
->write
= efivar_create
;
1042 attr
->private = efivars
;
1043 efivars
->new_var
= attr
;
1046 attr
= kzalloc(sizeof(*attr
), GFP_KERNEL
);
1051 attr
->attr
.name
= "del_var";
1052 attr
->attr
.mode
= 0200;
1053 attr
->write
= efivar_delete
;
1054 attr
->private = efivars
;
1055 efivars
->del_var
= attr
;
1057 sysfs_bin_attr_init(efivars
->new_var
);
1058 sysfs_bin_attr_init(efivars
->del_var
);
1061 error
= sysfs_create_bin_file(&efivars
->kset
->kobj
,
1064 printk(KERN_ERR
"efivars: unable to create new_var sysfs file"
1065 " due to error %d\n", error
);
1068 error
= sysfs_create_bin_file(&efivars
->kset
->kobj
,
1071 printk(KERN_ERR
"efivars: unable to create del_var sysfs file"
1072 " due to error %d\n", error
);
1073 sysfs_remove_bin_file(&efivars
->kset
->kobj
,
1080 kfree(efivars
->del_var
);
1081 efivars
->del_var
= NULL
;
1082 kfree(efivars
->new_var
);
1083 efivars
->new_var
= NULL
;
1087 void unregister_efivars(struct efivars
*efivars
)
1089 struct efivar_entry
*entry
, *n
;
1091 list_for_each_entry_safe(entry
, n
, &efivars
->list
, list
) {
1092 spin_lock(&efivars
->lock
);
1093 list_del(&entry
->list
);
1094 spin_unlock(&efivars
->lock
);
1095 efivar_unregister(entry
);
1097 if (efivars
->new_var
)
1098 sysfs_remove_bin_file(&efivars
->kset
->kobj
, efivars
->new_var
);
1099 if (efivars
->del_var
)
1100 sysfs_remove_bin_file(&efivars
->kset
->kobj
, efivars
->del_var
);
1101 kfree(efivars
->new_var
);
1102 kfree(efivars
->del_var
);
1103 kset_unregister(efivars
->kset
);
1105 EXPORT_SYMBOL_GPL(unregister_efivars
);
1107 int register_efivars(struct efivars
*efivars
,
1108 const struct efivar_operations
*ops
,
1109 struct kobject
*parent_kobj
)
1111 efi_status_t status
= EFI_NOT_FOUND
;
1112 efi_guid_t vendor_guid
;
1113 efi_char16_t
*variable_name
;
1114 unsigned long variable_name_size
= 1024;
1117 variable_name
= kzalloc(variable_name_size
, GFP_KERNEL
);
1118 if (!variable_name
) {
1119 printk(KERN_ERR
"efivars: Memory allocation failed.\n");
1123 spin_lock_init(&efivars
->lock
);
1124 INIT_LIST_HEAD(&efivars
->list
);
1127 efivars
->kset
= kset_create_and_add("vars", NULL
, parent_kobj
);
1128 if (!efivars
->kset
) {
1129 printk(KERN_ERR
"efivars: Subsystem registration failed.\n");
1135 * Per EFI spec, the maximum storage allocated for both
1136 * the variable name and variable data is 1024 bytes.
1140 variable_name_size
= 1024;
1142 status
= ops
->get_next_variable(&variable_name_size
,
1147 efivar_create_sysfs_entry(efivars
,
1155 printk(KERN_WARNING
"efivars: get_next_variable: status=%lx\n",
1157 status
= EFI_NOT_FOUND
;
1160 } while (status
!= EFI_NOT_FOUND
);
1162 error
= create_efivars_bin_attributes(efivars
);
1164 unregister_efivars(efivars
);
1166 efivars
->efi_pstore_info
= efi_pstore_info
;
1168 efivars
->efi_pstore_info
.buf
= kmalloc(4096, GFP_KERNEL
);
1169 if (efivars
->efi_pstore_info
.buf
) {
1170 efivars
->efi_pstore_info
.bufsize
= 1024;
1171 efivars
->efi_pstore_info
.data
= efivars
;
1172 spin_lock_init(&efivars
->efi_pstore_info
.buf_lock
);
1173 pstore_register(&efivars
->efi_pstore_info
);
1177 kfree(variable_name
);
1181 EXPORT_SYMBOL_GPL(register_efivars
);
1183 static struct efivars __efivars
;
1184 static struct efivar_operations ops
;
1187 * For now we register the efi subsystem with the firmware subsystem
1188 * and the vars subsystem with the efi subsystem. In the future, it
1189 * might make sense to split off the efi subsystem into its own
1190 * driver, but for now only efivars will register with it, so just
1199 printk(KERN_INFO
"EFI Variables Facility v%s %s\n", EFIVARS_VERSION
,
1205 /* For now we'll register the efi directory at /sys/firmware/efi */
1206 efi_kobj
= kobject_create_and_add("efi", firmware_kobj
);
1208 printk(KERN_ERR
"efivars: Firmware registration failed.\n");
1212 ops
.get_variable
= efi
.get_variable
;
1213 ops
.set_variable
= efi
.set_variable
;
1214 ops
.get_next_variable
= efi
.get_next_variable
;
1215 error
= register_efivars(&__efivars
, &ops
, efi_kobj
);
1219 /* Don't forget the systab entry */
1220 error
= sysfs_create_group(efi_kobj
, &efi_subsys_attr_group
);
1223 "efivars: Sysfs attribute export failed with error %d.\n",
1225 goto err_unregister
;
1231 unregister_efivars(&__efivars
);
1233 kobject_put(efi_kobj
);
1241 unregister_efivars(&__efivars
);
1242 kobject_put(efi_kobj
);
1246 module_init(efivars_init
);
1247 module_exit(efivars_exit
);