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
,
198 struct efi_generic_dev_path
*node
;
201 node
= (struct efi_generic_dev_path
*)buffer
;
203 if (len
< sizeof(*node
))
206 while (offset
<= len
- sizeof(*node
) &&
207 node
->length
>= sizeof(*node
) &&
208 node
->length
<= len
- offset
) {
209 offset
+= node
->length
;
211 if ((node
->type
== EFI_DEV_END_PATH
||
212 node
->type
== EFI_DEV_END_PATH2
) &&
213 node
->sub_type
== EFI_DEV_END_ENTIRE
)
216 node
= (struct efi_generic_dev_path
*)(buffer
+ offset
);
220 * If we're here then either node->length pointed past the end
221 * of the buffer or we reached the end of the buffer without
222 * finding a device path end node.
228 validate_boot_order(struct efi_variable
*var
, int match
, u8
*buffer
,
231 /* An array of 16-bit integers */
239 validate_load_option(struct efi_variable
*var
, int match
, u8
*buffer
,
243 int i
, desclength
= 0, namelen
;
245 namelen
= utf16_strnlen(var
->VariableName
, sizeof(var
->VariableName
));
247 /* Either "Boot" or "Driver" followed by four digits of hex */
248 for (i
= match
; i
< match
+4; i
++) {
249 if (var
->VariableName
[i
] > 127 ||
250 hex_to_bin(var
->VariableName
[i
] & 0xff) < 0)
254 /* Reject it if there's 4 digits of hex and then further content */
255 if (namelen
> match
+ 4)
258 /* A valid entry must be at least 8 bytes */
262 filepathlength
= buffer
[4] | buffer
[5] << 8;
265 * There's no stored length for the description, so it has to be
268 desclength
= utf16_strsize((efi_char16_t
*)(buffer
+ 6), len
- 6) + 2;
270 /* Each boot entry must have a descriptor */
275 * If the sum of the length of the description, the claimed filepath
276 * length and the original header are greater than the length of the
277 * variable, it's malformed
279 if ((desclength
+ filepathlength
+ 6) > len
)
283 * And, finally, check the filepath
285 return validate_device_path(var
, match
, buffer
+ desclength
+ 6,
290 validate_uint16(struct efi_variable
*var
, int match
, u8
*buffer
,
293 /* A single 16-bit integer */
301 validate_ascii_string(struct efi_variable
*var
, int match
, u8
*buffer
,
306 for (i
= 0; i
< len
; i
++) {
317 struct variable_validate
{
319 bool (*validate
)(struct efi_variable
*var
, int match
, u8
*data
,
323 static const struct variable_validate variable_validate
[] = {
324 { "BootNext", validate_uint16
},
325 { "BootOrder", validate_boot_order
},
326 { "DriverOrder", validate_boot_order
},
327 { "Boot*", validate_load_option
},
328 { "Driver*", validate_load_option
},
329 { "ConIn", validate_device_path
},
330 { "ConInDev", validate_device_path
},
331 { "ConOut", validate_device_path
},
332 { "ConOutDev", validate_device_path
},
333 { "ErrOut", validate_device_path
},
334 { "ErrOutDev", validate_device_path
},
335 { "Timeout", validate_uint16
},
336 { "Lang", validate_ascii_string
},
337 { "PlatformLang", validate_ascii_string
},
342 validate_var(struct efi_variable
*var
, u8
*data
, unsigned long len
)
345 u16
*unicode_name
= var
->VariableName
;
347 for (i
= 0; variable_validate
[i
].validate
!= NULL
; i
++) {
348 const char *name
= variable_validate
[i
].name
;
351 for (match
= 0; ; match
++) {
352 char c
= name
[match
];
353 u16 u
= unicode_name
[match
];
355 /* All special variables are plain ascii */
359 /* Wildcard in the matching name means we've matched */
361 return variable_validate
[i
].validate(var
,
364 /* Case sensitive match */
368 /* Reached the end of the string while matching */
370 return variable_validate
[i
].validate(var
,
379 get_var_data_locked(struct efivars
*efivars
, struct efi_variable
*var
)
383 var
->DataSize
= 1024;
384 status
= efivars
->ops
->get_variable(var
->VariableName
,
393 get_var_data(struct efivars
*efivars
, struct efi_variable
*var
)
397 spin_lock(&efivars
->lock
);
398 status
= get_var_data_locked(efivars
, var
);
399 spin_unlock(&efivars
->lock
);
401 if (status
!= EFI_SUCCESS
) {
402 printk(KERN_WARNING
"efivars: get_variable() failed 0x%lx!\n",
409 efivar_guid_read(struct efivar_entry
*entry
, char *buf
)
411 struct efi_variable
*var
= &entry
->var
;
417 efi_guid_unparse(&var
->VendorGuid
, str
);
419 str
+= sprintf(str
, "\n");
425 efivar_attr_read(struct efivar_entry
*entry
, char *buf
)
427 struct efi_variable
*var
= &entry
->var
;
434 status
= get_var_data(entry
->efivars
, var
);
435 if (status
!= EFI_SUCCESS
)
438 if (var
->Attributes
& EFI_VARIABLE_NON_VOLATILE
)
439 str
+= sprintf(str
, "EFI_VARIABLE_NON_VOLATILE\n");
440 if (var
->Attributes
& EFI_VARIABLE_BOOTSERVICE_ACCESS
)
441 str
+= sprintf(str
, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
442 if (var
->Attributes
& EFI_VARIABLE_RUNTIME_ACCESS
)
443 str
+= sprintf(str
, "EFI_VARIABLE_RUNTIME_ACCESS\n");
444 if (var
->Attributes
& EFI_VARIABLE_HARDWARE_ERROR_RECORD
)
445 str
+= sprintf(str
, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n");
446 if (var
->Attributes
& EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS
)
448 "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n");
449 if (var
->Attributes
&
450 EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS
)
452 "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n");
453 if (var
->Attributes
& EFI_VARIABLE_APPEND_WRITE
)
454 str
+= sprintf(str
, "EFI_VARIABLE_APPEND_WRITE\n");
459 efivar_size_read(struct efivar_entry
*entry
, char *buf
)
461 struct efi_variable
*var
= &entry
->var
;
468 status
= get_var_data(entry
->efivars
, var
);
469 if (status
!= EFI_SUCCESS
)
472 str
+= sprintf(str
, "0x%lx\n", var
->DataSize
);
477 efivar_data_read(struct efivar_entry
*entry
, char *buf
)
479 struct efi_variable
*var
= &entry
->var
;
485 status
= get_var_data(entry
->efivars
, var
);
486 if (status
!= EFI_SUCCESS
)
489 memcpy(buf
, var
->Data
, var
->DataSize
);
490 return var
->DataSize
;
493 * We allow each variable to be edited via rewriting the
494 * entire efi variable structure.
497 efivar_store_raw(struct efivar_entry
*entry
, const char *buf
, size_t count
)
499 struct efi_variable
*new_var
, *var
= &entry
->var
;
500 struct efivars
*efivars
= entry
->efivars
;
501 efi_status_t status
= EFI_NOT_FOUND
;
503 if (count
!= sizeof(struct efi_variable
))
506 new_var
= (struct efi_variable
*)buf
;
508 * If only updating the variable data, then the name
509 * and guid should remain the same
511 if (memcmp(new_var
->VariableName
, var
->VariableName
, sizeof(var
->VariableName
)) ||
512 efi_guidcmp(new_var
->VendorGuid
, var
->VendorGuid
)) {
513 printk(KERN_ERR
"efivars: Cannot edit the wrong variable!\n");
517 if ((new_var
->DataSize
<= 0) || (new_var
->Attributes
== 0)){
518 printk(KERN_ERR
"efivars: DataSize & Attributes must be valid!\n");
522 if ((new_var
->Attributes
& ~EFI_VARIABLE_MASK
) != 0 ||
523 validate_var(new_var
, new_var
->Data
, new_var
->DataSize
) == false) {
524 printk(KERN_ERR
"efivars: Malformed variable content\n");
528 spin_lock(&efivars
->lock
);
529 status
= efivars
->ops
->set_variable(new_var
->VariableName
,
530 &new_var
->VendorGuid
,
535 spin_unlock(&efivars
->lock
);
537 if (status
!= EFI_SUCCESS
) {
538 printk(KERN_WARNING
"efivars: set_variable() failed: status=%lx\n",
543 memcpy(&entry
->var
, new_var
, count
);
548 efivar_show_raw(struct efivar_entry
*entry
, char *buf
)
550 struct efi_variable
*var
= &entry
->var
;
556 status
= get_var_data(entry
->efivars
, var
);
557 if (status
!= EFI_SUCCESS
)
560 memcpy(buf
, var
, sizeof(*var
));
565 * Generic read/write functions that call the specific functions of
568 static ssize_t
efivar_attr_show(struct kobject
*kobj
, struct attribute
*attr
,
571 struct efivar_entry
*var
= to_efivar_entry(kobj
);
572 struct efivar_attribute
*efivar_attr
= to_efivar_attr(attr
);
575 if (!capable(CAP_SYS_ADMIN
))
578 if (efivar_attr
->show
) {
579 ret
= efivar_attr
->show(var
, buf
);
584 static ssize_t
efivar_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
585 const char *buf
, size_t count
)
587 struct efivar_entry
*var
= to_efivar_entry(kobj
);
588 struct efivar_attribute
*efivar_attr
= to_efivar_attr(attr
);
591 if (!capable(CAP_SYS_ADMIN
))
594 if (efivar_attr
->store
)
595 ret
= efivar_attr
->store(var
, buf
, count
);
600 static const struct sysfs_ops efivar_attr_ops
= {
601 .show
= efivar_attr_show
,
602 .store
= efivar_attr_store
,
605 static void efivar_release(struct kobject
*kobj
)
607 struct efivar_entry
*var
= container_of(kobj
, struct efivar_entry
, kobj
);
611 static EFIVAR_ATTR(guid
, 0400, efivar_guid_read
, NULL
);
612 static EFIVAR_ATTR(attributes
, 0400, efivar_attr_read
, NULL
);
613 static EFIVAR_ATTR(size
, 0400, efivar_size_read
, NULL
);
614 static EFIVAR_ATTR(data
, 0400, efivar_data_read
, NULL
);
615 static EFIVAR_ATTR(raw_var
, 0600, efivar_show_raw
, efivar_store_raw
);
617 static struct attribute
*def_attrs
[] = {
618 &efivar_attr_guid
.attr
,
619 &efivar_attr_size
.attr
,
620 &efivar_attr_attributes
.attr
,
621 &efivar_attr_data
.attr
,
622 &efivar_attr_raw_var
.attr
,
626 static struct kobj_type efivar_ktype
= {
627 .release
= efivar_release
,
628 .sysfs_ops
= &efivar_attr_ops
,
629 .default_attrs
= def_attrs
,
632 static struct pstore_info efi_pstore_info
;
635 efivar_unregister(struct efivar_entry
*var
)
637 kobject_put(&var
->kobj
);
642 static int efi_pstore_open(struct pstore_info
*psi
)
644 struct efivars
*efivars
= psi
->data
;
646 spin_lock(&efivars
->lock
);
647 efivars
->walk_entry
= list_first_entry(&efivars
->list
,
648 struct efivar_entry
, list
);
652 static int efi_pstore_close(struct pstore_info
*psi
)
654 struct efivars
*efivars
= psi
->data
;
656 spin_unlock(&efivars
->lock
);
660 static ssize_t
efi_pstore_read(u64
*id
, enum pstore_type_id
*type
,
661 struct timespec
*timespec
,
662 char **buf
, struct pstore_info
*psi
)
664 efi_guid_t vendor
= LINUX_EFI_CRASH_GUID
;
665 struct efivars
*efivars
= psi
->data
;
666 char name
[DUMP_NAME_LEN
];
668 unsigned int part
, size
;
671 while (&efivars
->walk_entry
->list
!= &efivars
->list
) {
672 if (!efi_guidcmp(efivars
->walk_entry
->var
.VendorGuid
,
674 for (i
= 0; i
< DUMP_NAME_LEN
; i
++) {
675 name
[i
] = efivars
->walk_entry
->var
.VariableName
[i
];
677 if (sscanf(name
, "dump-type%u-%u-%lu", type
, &part
, &time
) == 3) {
679 timespec
->tv_sec
= time
;
680 timespec
->tv_nsec
= 0;
681 get_var_data_locked(efivars
, &efivars
->walk_entry
->var
);
682 size
= efivars
->walk_entry
->var
.DataSize
;
683 *buf
= kmalloc(size
, GFP_KERNEL
);
686 memcpy(*buf
, efivars
->walk_entry
->var
.Data
,
688 efivars
->walk_entry
= list_entry(efivars
->walk_entry
->list
.next
,
689 struct efivar_entry
, list
);
693 efivars
->walk_entry
= list_entry(efivars
->walk_entry
->list
.next
,
694 struct efivar_entry
, list
);
699 static int efi_pstore_write(enum pstore_type_id type
,
700 enum kmsg_dump_reason reason
, u64
*id
,
701 unsigned int part
, size_t size
, struct pstore_info
*psi
)
703 char name
[DUMP_NAME_LEN
];
704 char stub_name
[DUMP_NAME_LEN
];
705 efi_char16_t efi_name
[DUMP_NAME_LEN
];
706 efi_guid_t vendor
= LINUX_EFI_CRASH_GUID
;
707 struct efivars
*efivars
= psi
->data
;
708 struct efivar_entry
*entry
, *found
= NULL
;
711 sprintf(stub_name
, "dump-type%u-%u-", type
, part
);
712 sprintf(name
, "%s%lu", stub_name
, get_seconds());
714 spin_lock(&efivars
->lock
);
716 for (i
= 0; i
< DUMP_NAME_LEN
; i
++)
717 efi_name
[i
] = stub_name
[i
];
720 * Clean up any entries with the same name
723 list_for_each_entry(entry
, &efivars
->list
, list
) {
724 get_var_data_locked(efivars
, &entry
->var
);
726 if (efi_guidcmp(entry
->var
.VendorGuid
, vendor
))
728 if (utf16_strncmp(entry
->var
.VariableName
, efi_name
,
729 utf16_strlen(efi_name
)))
731 /* Needs to be a prefix */
732 if (entry
->var
.VariableName
[utf16_strlen(efi_name
)] == 0)
737 efivars
->ops
->set_variable(entry
->var
.VariableName
,
738 &entry
->var
.VendorGuid
,
739 PSTORE_EFI_ATTRIBUTES
,
744 list_del(&found
->list
);
746 for (i
= 0; i
< DUMP_NAME_LEN
; i
++)
747 efi_name
[i
] = name
[i
];
749 efivars
->ops
->set_variable(efi_name
, &vendor
, PSTORE_EFI_ATTRIBUTES
,
752 spin_unlock(&efivars
->lock
);
755 efivar_unregister(found
);
758 ret
= efivar_create_sysfs_entry(efivars
,
759 utf16_strsize(efi_name
,
767 static int efi_pstore_erase(enum pstore_type_id type
, u64 id
,
768 struct pstore_info
*psi
)
770 efi_pstore_write(type
, 0, &id
, (unsigned int)id
, 0, psi
);
775 static int efi_pstore_open(struct pstore_info
*psi
)
780 static int efi_pstore_close(struct pstore_info
*psi
)
785 static ssize_t
efi_pstore_read(u64
*id
, enum pstore_type_id
*type
,
786 struct timespec
*timespec
,
787 char **buf
, struct pstore_info
*psi
)
792 static int efi_pstore_write(enum pstore_type_id type
,
793 enum kmsg_dump_reason reason
, u64
*id
,
794 unsigned int part
, size_t size
, struct pstore_info
*psi
)
799 static int efi_pstore_erase(enum pstore_type_id type
, u64 id
,
800 struct pstore_info
*psi
)
806 static struct pstore_info efi_pstore_info
= {
807 .owner
= THIS_MODULE
,
809 .open
= efi_pstore_open
,
810 .close
= efi_pstore_close
,
811 .read
= efi_pstore_read
,
812 .write
= efi_pstore_write
,
813 .erase
= efi_pstore_erase
,
816 static ssize_t
efivar_create(struct file
*filp
, struct kobject
*kobj
,
817 struct bin_attribute
*bin_attr
,
818 char *buf
, loff_t pos
, size_t count
)
820 struct efi_variable
*new_var
= (struct efi_variable
*)buf
;
821 struct efivars
*efivars
= bin_attr
->private;
822 struct efivar_entry
*search_efivar
, *n
;
823 unsigned long strsize1
, strsize2
;
824 efi_status_t status
= EFI_NOT_FOUND
;
827 if (!capable(CAP_SYS_ADMIN
))
830 if ((new_var
->Attributes
& ~EFI_VARIABLE_MASK
) != 0 ||
831 validate_var(new_var
, new_var
->Data
, new_var
->DataSize
) == false) {
832 printk(KERN_ERR
"efivars: Malformed variable content\n");
836 spin_lock(&efivars
->lock
);
839 * Does this variable already exist?
841 list_for_each_entry_safe(search_efivar
, n
, &efivars
->list
, list
) {
842 strsize1
= utf16_strsize(search_efivar
->var
.VariableName
, 1024);
843 strsize2
= utf16_strsize(new_var
->VariableName
, 1024);
844 if (strsize1
== strsize2
&&
845 !memcmp(&(search_efivar
->var
.VariableName
),
846 new_var
->VariableName
, strsize1
) &&
847 !efi_guidcmp(search_efivar
->var
.VendorGuid
,
848 new_var
->VendorGuid
)) {
854 spin_unlock(&efivars
->lock
);
858 /* now *really* create the variable via EFI */
859 status
= efivars
->ops
->set_variable(new_var
->VariableName
,
860 &new_var
->VendorGuid
,
865 if (status
!= EFI_SUCCESS
) {
866 printk(KERN_WARNING
"efivars: set_variable() failed: status=%lx\n",
868 spin_unlock(&efivars
->lock
);
871 spin_unlock(&efivars
->lock
);
873 /* Create the entry in sysfs. Locking is not required here */
874 status
= efivar_create_sysfs_entry(efivars
,
875 utf16_strsize(new_var
->VariableName
,
877 new_var
->VariableName
,
878 &new_var
->VendorGuid
);
880 printk(KERN_WARNING
"efivars: variable created, but sysfs entry wasn't.\n");
885 static ssize_t
efivar_delete(struct file
*filp
, struct kobject
*kobj
,
886 struct bin_attribute
*bin_attr
,
887 char *buf
, loff_t pos
, size_t count
)
889 struct efi_variable
*del_var
= (struct efi_variable
*)buf
;
890 struct efivars
*efivars
= bin_attr
->private;
891 struct efivar_entry
*search_efivar
, *n
;
892 unsigned long strsize1
, strsize2
;
893 efi_status_t status
= EFI_NOT_FOUND
;
896 if (!capable(CAP_SYS_ADMIN
))
899 spin_lock(&efivars
->lock
);
902 * Does this variable already exist?
904 list_for_each_entry_safe(search_efivar
, n
, &efivars
->list
, list
) {
905 strsize1
= utf16_strsize(search_efivar
->var
.VariableName
, 1024);
906 strsize2
= utf16_strsize(del_var
->VariableName
, 1024);
907 if (strsize1
== strsize2
&&
908 !memcmp(&(search_efivar
->var
.VariableName
),
909 del_var
->VariableName
, strsize1
) &&
910 !efi_guidcmp(search_efivar
->var
.VendorGuid
,
911 del_var
->VendorGuid
)) {
917 spin_unlock(&efivars
->lock
);
920 /* force the Attributes/DataSize to 0 to ensure deletion */
921 del_var
->Attributes
= 0;
922 del_var
->DataSize
= 0;
924 status
= efivars
->ops
->set_variable(del_var
->VariableName
,
925 &del_var
->VendorGuid
,
930 if (status
!= EFI_SUCCESS
) {
931 printk(KERN_WARNING
"efivars: set_variable() failed: status=%lx\n",
933 spin_unlock(&efivars
->lock
);
936 list_del(&search_efivar
->list
);
937 /* We need to release this lock before unregistering. */
938 spin_unlock(&efivars
->lock
);
939 efivar_unregister(search_efivar
);
941 /* It's dead Jim.... */
946 * Let's not leave out systab information that snuck into
949 static ssize_t
systab_show(struct kobject
*kobj
,
950 struct kobj_attribute
*attr
, char *buf
)
957 if (efi
.mps
!= EFI_INVALID_TABLE_ADDR
)
958 str
+= sprintf(str
, "MPS=0x%lx\n", efi
.mps
);
959 if (efi
.acpi20
!= EFI_INVALID_TABLE_ADDR
)
960 str
+= sprintf(str
, "ACPI20=0x%lx\n", efi
.acpi20
);
961 if (efi
.acpi
!= EFI_INVALID_TABLE_ADDR
)
962 str
+= sprintf(str
, "ACPI=0x%lx\n", efi
.acpi
);
963 if (efi
.smbios
!= EFI_INVALID_TABLE_ADDR
)
964 str
+= sprintf(str
, "SMBIOS=0x%lx\n", efi
.smbios
);
965 if (efi
.hcdp
!= EFI_INVALID_TABLE_ADDR
)
966 str
+= sprintf(str
, "HCDP=0x%lx\n", efi
.hcdp
);
967 if (efi
.boot_info
!= EFI_INVALID_TABLE_ADDR
)
968 str
+= sprintf(str
, "BOOTINFO=0x%lx\n", efi
.boot_info
);
969 if (efi
.uga
!= EFI_INVALID_TABLE_ADDR
)
970 str
+= sprintf(str
, "UGA=0x%lx\n", efi
.uga
);
975 static struct kobj_attribute efi_attr_systab
=
976 __ATTR(systab
, 0400, systab_show
, NULL
);
978 static struct attribute
*efi_subsys_attrs
[] = {
979 &efi_attr_systab
.attr
,
980 NULL
, /* maybe more in the future? */
983 static struct attribute_group efi_subsys_attr_group
= {
984 .attrs
= efi_subsys_attrs
,
987 static struct kobject
*efi_kobj
;
990 * efivar_create_sysfs_entry()
992 * variable_name_size = number of bytes required to hold
993 * variable_name (not counting the NULL
994 * character at the end.
995 * efivars->lock is not held on entry or exit.
996 * Returns 1 on failure, 0 on success
999 efivar_create_sysfs_entry(struct efivars
*efivars
,
1000 unsigned long variable_name_size
,
1001 efi_char16_t
*variable_name
,
1002 efi_guid_t
*vendor_guid
)
1004 int i
, short_name_size
= variable_name_size
/ sizeof(efi_char16_t
) + 38;
1006 struct efivar_entry
*new_efivar
;
1008 short_name
= kzalloc(short_name_size
+ 1, GFP_KERNEL
);
1009 new_efivar
= kzalloc(sizeof(struct efivar_entry
), GFP_KERNEL
);
1011 if (!short_name
|| !new_efivar
) {
1017 new_efivar
->efivars
= efivars
;
1018 memcpy(new_efivar
->var
.VariableName
, variable_name
,
1019 variable_name_size
);
1020 memcpy(&(new_efivar
->var
.VendorGuid
), vendor_guid
, sizeof(efi_guid_t
));
1022 /* Convert Unicode to normal chars (assume top bits are 0),
1024 for (i
=0; i
< (int)(variable_name_size
/ sizeof(efi_char16_t
)); i
++) {
1025 short_name
[i
] = variable_name
[i
] & 0xFF;
1027 /* This is ugly, but necessary to separate one vendor's
1028 private variables from another's. */
1030 *(short_name
+ strlen(short_name
)) = '-';
1031 efi_guid_unparse(vendor_guid
, short_name
+ strlen(short_name
));
1033 new_efivar
->kobj
.kset
= efivars
->kset
;
1034 i
= kobject_init_and_add(&new_efivar
->kobj
, &efivar_ktype
, NULL
,
1042 kobject_uevent(&new_efivar
->kobj
, KOBJ_ADD
);
1046 spin_lock(&efivars
->lock
);
1047 list_add(&new_efivar
->list
, &efivars
->list
);
1048 spin_unlock(&efivars
->lock
);
1054 create_efivars_bin_attributes(struct efivars
*efivars
)
1056 struct bin_attribute
*attr
;
1060 attr
= kzalloc(sizeof(*attr
), GFP_KERNEL
);
1064 attr
->attr
.name
= "new_var";
1065 attr
->attr
.mode
= 0200;
1066 attr
->write
= efivar_create
;
1067 attr
->private = efivars
;
1068 efivars
->new_var
= attr
;
1071 attr
= kzalloc(sizeof(*attr
), GFP_KERNEL
);
1076 attr
->attr
.name
= "del_var";
1077 attr
->attr
.mode
= 0200;
1078 attr
->write
= efivar_delete
;
1079 attr
->private = efivars
;
1080 efivars
->del_var
= attr
;
1082 sysfs_bin_attr_init(efivars
->new_var
);
1083 sysfs_bin_attr_init(efivars
->del_var
);
1086 error
= sysfs_create_bin_file(&efivars
->kset
->kobj
,
1089 printk(KERN_ERR
"efivars: unable to create new_var sysfs file"
1090 " due to error %d\n", error
);
1093 error
= sysfs_create_bin_file(&efivars
->kset
->kobj
,
1096 printk(KERN_ERR
"efivars: unable to create del_var sysfs file"
1097 " due to error %d\n", error
);
1098 sysfs_remove_bin_file(&efivars
->kset
->kobj
,
1105 kfree(efivars
->del_var
);
1106 efivars
->del_var
= NULL
;
1107 kfree(efivars
->new_var
);
1108 efivars
->new_var
= NULL
;
1112 void unregister_efivars(struct efivars
*efivars
)
1114 struct efivar_entry
*entry
, *n
;
1116 list_for_each_entry_safe(entry
, n
, &efivars
->list
, list
) {
1117 spin_lock(&efivars
->lock
);
1118 list_del(&entry
->list
);
1119 spin_unlock(&efivars
->lock
);
1120 efivar_unregister(entry
);
1122 if (efivars
->new_var
)
1123 sysfs_remove_bin_file(&efivars
->kset
->kobj
, efivars
->new_var
);
1124 if (efivars
->del_var
)
1125 sysfs_remove_bin_file(&efivars
->kset
->kobj
, efivars
->del_var
);
1126 kfree(efivars
->new_var
);
1127 kfree(efivars
->del_var
);
1128 kset_unregister(efivars
->kset
);
1130 EXPORT_SYMBOL_GPL(unregister_efivars
);
1132 int register_efivars(struct efivars
*efivars
,
1133 const struct efivar_operations
*ops
,
1134 struct kobject
*parent_kobj
)
1136 efi_status_t status
= EFI_NOT_FOUND
;
1137 efi_guid_t vendor_guid
;
1138 efi_char16_t
*variable_name
;
1139 unsigned long variable_name_size
= 1024;
1142 variable_name
= kzalloc(variable_name_size
, GFP_KERNEL
);
1143 if (!variable_name
) {
1144 printk(KERN_ERR
"efivars: Memory allocation failed.\n");
1148 spin_lock_init(&efivars
->lock
);
1149 INIT_LIST_HEAD(&efivars
->list
);
1152 efivars
->kset
= kset_create_and_add("vars", NULL
, parent_kobj
);
1153 if (!efivars
->kset
) {
1154 printk(KERN_ERR
"efivars: Subsystem registration failed.\n");
1160 * Per EFI spec, the maximum storage allocated for both
1161 * the variable name and variable data is 1024 bytes.
1165 variable_name_size
= 1024;
1167 status
= ops
->get_next_variable(&variable_name_size
,
1172 efivar_create_sysfs_entry(efivars
,
1180 printk(KERN_WARNING
"efivars: get_next_variable: status=%lx\n",
1182 status
= EFI_NOT_FOUND
;
1185 } while (status
!= EFI_NOT_FOUND
);
1187 error
= create_efivars_bin_attributes(efivars
);
1189 unregister_efivars(efivars
);
1191 efivars
->efi_pstore_info
= efi_pstore_info
;
1193 efivars
->efi_pstore_info
.buf
= kmalloc(4096, GFP_KERNEL
);
1194 if (efivars
->efi_pstore_info
.buf
) {
1195 efivars
->efi_pstore_info
.bufsize
= 1024;
1196 efivars
->efi_pstore_info
.data
= efivars
;
1197 spin_lock_init(&efivars
->efi_pstore_info
.buf_lock
);
1198 pstore_register(&efivars
->efi_pstore_info
);
1202 kfree(variable_name
);
1206 EXPORT_SYMBOL_GPL(register_efivars
);
1208 static struct efivars __efivars
;
1209 static struct efivar_operations ops
;
1212 * For now we register the efi subsystem with the firmware subsystem
1213 * and the vars subsystem with the efi subsystem. In the future, it
1214 * might make sense to split off the efi subsystem into its own
1215 * driver, but for now only efivars will register with it, so just
1224 printk(KERN_INFO
"EFI Variables Facility v%s %s\n", EFIVARS_VERSION
,
1230 /* For now we'll register the efi directory at /sys/firmware/efi */
1231 efi_kobj
= kobject_create_and_add("efi", firmware_kobj
);
1233 printk(KERN_ERR
"efivars: Firmware registration failed.\n");
1237 ops
.get_variable
= efi
.get_variable
;
1238 ops
.set_variable
= efi
.set_variable
;
1239 ops
.get_next_variable
= efi
.get_next_variable
;
1240 error
= register_efivars(&__efivars
, &ops
, efi_kobj
);
1244 /* Don't forget the systab entry */
1245 error
= sysfs_create_group(efi_kobj
, &efi_subsys_attr_group
);
1248 "efivars: Sysfs attribute export failed with error %d.\n",
1250 goto err_unregister
;
1256 unregister_efivars(&__efivars
);
1258 kobject_put(efi_kobj
);
1266 unregister_efivars(&__efivars
);
1267 kobject_put(efi_kobj
);
1271 module_init(efivars_init
);
1272 module_exit(efivars_exit
);