blob: 9b7e4d52ffd474ef9f745b9d36c5db13ad172e2e [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * EFI Variables - efivars.c
3 *
4 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
5 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
6 *
7 * This code takes all variables accessible from EFI runtime and
8 * exports them via sysfs
9 *
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.
14 *
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.
19 *
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
23 *
24 * Changelog:
25 *
26 * 17 May 2004 - Matt Domsch <Matt_Domsch@dell.com>
27 * remove check for efi_enabled in exit
28 * add MODULE_VERSION
29 *
30 * 26 Apr 2004 - Matt Domsch <Matt_Domsch@dell.com>
31 * minor bug fixes
32 *
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
37 *
38 * 10 Dec 2002 - Matt Domsch <Matt_Domsch@dell.com>
39 * fix locking per Peter Chubb's findings
40 *
41 * 25 Mar 2002 - Matt Domsch <Matt_Domsch@dell.com>
42 * move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_unparse()
43 *
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
48 *
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
53 *
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.
57 *
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
63 *
64 * 26 February 2001 - Matt Domsch <Matt_Domsch@dell.com>
65 * v0.01 release to linux-ia64@linuxia64.org
66 */
67
Randy.Dunlapc59ede72006-01-11 12:17:46 -080068#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070069#include <linux/config.h>
70#include <linux/types.h>
71#include <linux/errno.h>
72#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070073#include <linux/mm.h>
74#include <linux/module.h>
75#include <linux/string.h>
76#include <linux/smp.h>
77#include <linux/efi.h>
78#include <linux/sysfs.h>
79#include <linux/kobject.h>
80#include <linux/device.h>
81
82#include <asm/uaccess.h>
83
84#define EFIVARS_VERSION "0.08"
85#define EFIVARS_DATE "2004-May-17"
86
87MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
88MODULE_DESCRIPTION("sysfs interface to EFI Variables");
89MODULE_LICENSE("GPL");
90MODULE_VERSION(EFIVARS_VERSION);
91
92/*
93 * efivars_lock protects two things:
94 * 1) efivar_list - adds, removals, reads, writes
95 * 2) efi.[gs]et_variable() calls.
96 * It must not be held when creating sysfs entries or calling kmalloc.
97 * efi.get_next_variable() is only called from efivars_init(),
98 * which is protected by the BKL, so that path is safe.
99 */
100static DEFINE_SPINLOCK(efivars_lock);
101static LIST_HEAD(efivar_list);
102
103/*
104 * The maximum size of VariableName + Data = 1024
105 * Therefore, it's reasonable to save that much
106 * space in each part of the structure,
107 * and we use a page for reading/writing.
108 */
109
110struct efi_variable {
111 efi_char16_t VariableName[1024/sizeof(efi_char16_t)];
112 efi_guid_t VendorGuid;
113 unsigned long DataSize;
114 __u8 Data[1024];
115 efi_status_t Status;
116 __u32 Attributes;
117} __attribute__((packed));
118
119
120struct efivar_entry {
121 struct efi_variable var;
122 struct list_head list;
123 struct kobject kobj;
124};
125
126#define get_efivar_entry(n) list_entry(n, struct efivar_entry, list)
127
128struct efivar_attribute {
129 struct attribute attr;
130 ssize_t (*show) (struct efivar_entry *entry, char *buf);
131 ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
132};
133
134
135#define EFI_ATTR(_name, _mode, _show, _store) \
136struct subsys_attribute efi_attr_##_name = { \
137 .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \
138 .show = _show, \
139 .store = _store, \
140};
141
142#define EFIVAR_ATTR(_name, _mode, _show, _store) \
143struct efivar_attribute efivar_attr_##_name = { \
144 .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \
145 .show = _show, \
146 .store = _store, \
147};
148
149#define VAR_SUBSYS_ATTR(_name, _mode, _show, _store) \
150struct subsys_attribute var_subsys_attr_##_name = { \
151 .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \
152 .show = _show, \
153 .store = _store, \
154};
155
156#define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
157#define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
158
159/*
160 * Prototype for sysfs creation function
161 */
162static int
163efivar_create_sysfs_entry(unsigned long variable_name_size,
164 efi_char16_t *variable_name,
165 efi_guid_t *vendor_guid);
166
167/* Return the number of unicode characters in data */
168static unsigned long
169utf8_strlen(efi_char16_t *data, unsigned long maxlength)
170{
171 unsigned long length = 0;
172
173 while (*data++ != 0 && length < maxlength)
174 length++;
175 return length;
176}
177
178/*
179 * Return the number of bytes is the length of this string
180 * Note: this is NOT the same as the number of unicode characters
181 */
182static inline unsigned long
183utf8_strsize(efi_char16_t *data, unsigned long maxlength)
184{
185 return utf8_strlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
186}
187
188static efi_status_t
189get_var_data(struct efi_variable *var)
190{
191 efi_status_t status;
192
193 spin_lock(&efivars_lock);
194 var->DataSize = 1024;
195 status = efi.get_variable(var->VariableName,
196 &var->VendorGuid,
197 &var->Attributes,
198 &var->DataSize,
199 var->Data);
200 spin_unlock(&efivars_lock);
201 if (status != EFI_SUCCESS) {
202 printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
203 status);
204 }
205 return status;
206}
207
208static ssize_t
209efivar_guid_read(struct efivar_entry *entry, char *buf)
210{
211 struct efi_variable *var = &entry->var;
212 char *str = buf;
213
214 if (!entry || !buf)
215 return 0;
216
217 efi_guid_unparse(&var->VendorGuid, str);
218 str += strlen(str);
219 str += sprintf(str, "\n");
220
221 return str - buf;
222}
223
224static ssize_t
225efivar_attr_read(struct efivar_entry *entry, char *buf)
226{
227 struct efi_variable *var = &entry->var;
228 char *str = buf;
229 efi_status_t status;
230
231 if (!entry || !buf)
232 return -EINVAL;
233
234 status = get_var_data(var);
235 if (status != EFI_SUCCESS)
236 return -EIO;
237
238 if (var->Attributes & 0x1)
239 str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
240 if (var->Attributes & 0x2)
241 str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
242 if (var->Attributes & 0x4)
243 str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
244 return str - buf;
245}
246
247static ssize_t
248efivar_size_read(struct efivar_entry *entry, char *buf)
249{
250 struct efi_variable *var = &entry->var;
251 char *str = buf;
252 efi_status_t status;
253
254 if (!entry || !buf)
255 return -EINVAL;
256
257 status = get_var_data(var);
258 if (status != EFI_SUCCESS)
259 return -EIO;
260
261 str += sprintf(str, "0x%lx\n", var->DataSize);
262 return str - buf;
263}
264
265static ssize_t
266efivar_data_read(struct efivar_entry *entry, char *buf)
267{
268 struct efi_variable *var = &entry->var;
269 efi_status_t status;
270
271 if (!entry || !buf)
272 return -EINVAL;
273
274 status = get_var_data(var);
275 if (status != EFI_SUCCESS)
276 return -EIO;
277
278 memcpy(buf, var->Data, var->DataSize);
279 return var->DataSize;
280}
281/*
282 * We allow each variable to be edited via rewriting the
283 * entire efi variable structure.
284 */
285static ssize_t
286efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
287{
288 struct efi_variable *new_var, *var = &entry->var;
289 efi_status_t status = EFI_NOT_FOUND;
290
291 if (count != sizeof(struct efi_variable))
292 return -EINVAL;
293
294 new_var = (struct efi_variable *)buf;
295 /*
296 * If only updating the variable data, then the name
297 * and guid should remain the same
298 */
299 if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
300 efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
301 printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
302 return -EINVAL;
303 }
304
305 if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
306 printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
307 return -EINVAL;
308 }
309
310 spin_lock(&efivars_lock);
311 status = efi.set_variable(new_var->VariableName,
312 &new_var->VendorGuid,
313 new_var->Attributes,
314 new_var->DataSize,
315 new_var->Data);
316
317 spin_unlock(&efivars_lock);
318
319 if (status != EFI_SUCCESS) {
320 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
321 status);
322 return -EIO;
323 }
324
325 memcpy(&entry->var, new_var, count);
326 return count;
327}
328
329static ssize_t
330efivar_show_raw(struct efivar_entry *entry, char *buf)
331{
332 struct efi_variable *var = &entry->var;
333 efi_status_t status;
334
335 if (!entry || !buf)
336 return 0;
337
338 status = get_var_data(var);
339 if (status != EFI_SUCCESS)
340 return -EIO;
341
342 memcpy(buf, var, sizeof(*var));
343 return sizeof(*var);
344}
345
346/*
347 * Generic read/write functions that call the specific functions of
348 * the atttributes...
349 */
350static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
351 char *buf)
352{
353 struct efivar_entry *var = to_efivar_entry(kobj);
354 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
Dmitry Torokhov70f28172005-04-29 01:27:34 -0500355 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356
357 if (!capable(CAP_SYS_ADMIN))
358 return -EACCES;
359
360 if (efivar_attr->show) {
361 ret = efivar_attr->show(var, buf);
362 }
363 return ret;
364}
365
366static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
367 const char *buf, size_t count)
368{
369 struct efivar_entry *var = to_efivar_entry(kobj);
370 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
Dmitry Torokhov70f28172005-04-29 01:27:34 -0500371 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372
373 if (!capable(CAP_SYS_ADMIN))
374 return -EACCES;
375
376 if (efivar_attr->store)
377 ret = efivar_attr->store(var, buf, count);
378
379 return ret;
380}
381
382static struct sysfs_ops efivar_attr_ops = {
383 .show = efivar_attr_show,
384 .store = efivar_attr_store,
385};
386
387static void efivar_release(struct kobject *kobj)
388{
389 struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
390 spin_lock(&efivars_lock);
391 list_del(&var->list);
392 spin_unlock(&efivars_lock);
393 kfree(var);
394}
395
396static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
397static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
398static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
399static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
400static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
401
402static struct attribute *def_attrs[] = {
403 &efivar_attr_guid.attr,
404 &efivar_attr_size.attr,
405 &efivar_attr_attributes.attr,
406 &efivar_attr_data.attr,
407 &efivar_attr_raw_var.attr,
408 NULL,
409};
410
411static struct kobj_type ktype_efivar = {
412 .release = efivar_release,
413 .sysfs_ops = &efivar_attr_ops,
414 .default_attrs = def_attrs,
415};
416
417static ssize_t
418dummy(struct subsystem *sub, char *buf)
419{
420 return -ENODEV;
421}
422
423static inline void
424efivar_unregister(struct efivar_entry *var)
425{
426 kobject_unregister(&var->kobj);
427}
428
429
430static ssize_t
431efivar_create(struct subsystem *sub, const char *buf, size_t count)
432{
433 struct efi_variable *new_var = (struct efi_variable *)buf;
434 struct efivar_entry *search_efivar = NULL;
435 unsigned long strsize1, strsize2;
436 struct list_head *pos, *n;
437 efi_status_t status = EFI_NOT_FOUND;
438 int found = 0;
439
440 if (!capable(CAP_SYS_ADMIN))
441 return -EACCES;
442
443 spin_lock(&efivars_lock);
444
445 /*
446 * Does this variable already exist?
447 */
448 list_for_each_safe(pos, n, &efivar_list) {
449 search_efivar = get_efivar_entry(pos);
450 strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
451 strsize2 = utf8_strsize(new_var->VariableName, 1024);
452 if (strsize1 == strsize2 &&
453 !memcmp(&(search_efivar->var.VariableName),
454 new_var->VariableName, strsize1) &&
455 !efi_guidcmp(search_efivar->var.VendorGuid,
456 new_var->VendorGuid)) {
457 found = 1;
458 break;
459 }
460 }
461 if (found) {
462 spin_unlock(&efivars_lock);
463 return -EINVAL;
464 }
465
466 /* now *really* create the variable via EFI */
467 status = efi.set_variable(new_var->VariableName,
468 &new_var->VendorGuid,
469 new_var->Attributes,
470 new_var->DataSize,
471 new_var->Data);
472
473 if (status != EFI_SUCCESS) {
474 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
475 status);
476 spin_unlock(&efivars_lock);
477 return -EIO;
478 }
479 spin_unlock(&efivars_lock);
480
481 /* Create the entry in sysfs. Locking is not required here */
482 status = efivar_create_sysfs_entry(utf8_strsize(new_var->VariableName,
483 1024), new_var->VariableName, &new_var->VendorGuid);
484 if (status) {
485 printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
486 }
487 return count;
488}
489
490static ssize_t
491efivar_delete(struct subsystem *sub, const char *buf, size_t count)
492{
493 struct efi_variable *del_var = (struct efi_variable *)buf;
494 struct efivar_entry *search_efivar = NULL;
495 unsigned long strsize1, strsize2;
496 struct list_head *pos, *n;
497 efi_status_t status = EFI_NOT_FOUND;
498 int found = 0;
499
500 if (!capable(CAP_SYS_ADMIN))
501 return -EACCES;
502
503 spin_lock(&efivars_lock);
504
505 /*
506 * Does this variable already exist?
507 */
508 list_for_each_safe(pos, n, &efivar_list) {
509 search_efivar = get_efivar_entry(pos);
510 strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
511 strsize2 = utf8_strsize(del_var->VariableName, 1024);
512 if (strsize1 == strsize2 &&
513 !memcmp(&(search_efivar->var.VariableName),
514 del_var->VariableName, strsize1) &&
515 !efi_guidcmp(search_efivar->var.VendorGuid,
516 del_var->VendorGuid)) {
517 found = 1;
518 break;
519 }
520 }
521 if (!found) {
522 spin_unlock(&efivars_lock);
523 return -EINVAL;
524 }
525 /* force the Attributes/DataSize to 0 to ensure deletion */
526 del_var->Attributes = 0;
527 del_var->DataSize = 0;
528
529 status = efi.set_variable(del_var->VariableName,
530 &del_var->VendorGuid,
531 del_var->Attributes,
532 del_var->DataSize,
533 del_var->Data);
534
535 if (status != EFI_SUCCESS) {
536 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
537 status);
538 spin_unlock(&efivars_lock);
539 return -EIO;
540 }
541 /* We need to release this lock before unregistering. */
542 spin_unlock(&efivars_lock);
543
544 efivar_unregister(search_efivar);
545
546 /* It's dead Jim.... */
547 return count;
548}
549
550static VAR_SUBSYS_ATTR(new_var, 0200, dummy, efivar_create);
551static VAR_SUBSYS_ATTR(del_var, 0200, dummy, efivar_delete);
552
553static struct subsys_attribute *var_subsys_attrs[] = {
554 &var_subsys_attr_new_var,
555 &var_subsys_attr_del_var,
556 NULL,
557};
558
559/*
560 * Let's not leave out systab information that snuck into
561 * the efivars driver
562 */
563static ssize_t
564systab_read(struct subsystem *entry, char *buf)
565{
566 char *str = buf;
567
568 if (!entry || !buf)
569 return -EINVAL;
570
Bjorn Helgaasb2c99e32006-03-26 01:37:08 -0800571 if (efi.mps != EFI_INVALID_TABLE_ADDR)
572 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
573 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
574 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
575 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
576 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
577 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
578 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
579 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
580 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
581 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
582 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
583 if (efi.uga != EFI_INVALID_TABLE_ADDR)
584 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585
586 return str - buf;
587}
588
589static EFI_ATTR(systab, 0400, systab_read, NULL);
590
591static struct subsys_attribute *efi_subsys_attrs[] = {
592 &efi_attr_systab,
593 NULL, /* maybe more in the future? */
594};
595
596static decl_subsys(vars, &ktype_efivar, NULL);
597static decl_subsys(efi, NULL, NULL);
598
599/*
600 * efivar_create_sysfs_entry()
601 * Requires:
602 * variable_name_size = number of bytes required to hold
603 * variable_name (not counting the NULL
604 * character at the end.
605 * efivars_lock is not held on entry or exit.
606 * Returns 1 on failure, 0 on success
607 */
608static int
609efivar_create_sysfs_entry(unsigned long variable_name_size,
610 efi_char16_t *variable_name,
611 efi_guid_t *vendor_guid)
612{
613 int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38;
614 char *short_name;
615 struct efivar_entry *new_efivar;
616
Deepak Saxena9c215382005-11-07 01:01:24 -0800617 short_name = kzalloc(short_name_size + 1, GFP_KERNEL);
618 new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619
620 if (!short_name || !new_efivar) {
Jesper Juhl0933ad92005-06-25 14:59:15 -0700621 kfree(short_name);
622 kfree(new_efivar);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 return 1;
624 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625
626 memcpy(new_efivar->var.VariableName, variable_name,
627 variable_name_size);
628 memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));
629
630 /* Convert Unicode to normal chars (assume top bits are 0),
631 ala UTF-8 */
632 for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
633 short_name[i] = variable_name[i] & 0xFF;
634 }
635 /* This is ugly, but necessary to separate one vendor's
636 private variables from another's. */
637
638 *(short_name + strlen(short_name)) = '-';
639 efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
640
641 kobject_set_name(&new_efivar->kobj, "%s", short_name);
642 kobj_set_kset_s(new_efivar, vars_subsys);
643 kobject_register(&new_efivar->kobj);
644
Jesper Juhl0933ad92005-06-25 14:59:15 -0700645 kfree(short_name);
646 short_name = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647
648 spin_lock(&efivars_lock);
649 list_add(&new_efivar->list, &efivar_list);
650 spin_unlock(&efivars_lock);
651
652 return 0;
653}
654/*
655 * For now we register the efi subsystem with the firmware subsystem
656 * and the vars subsystem with the efi subsystem. In the future, it
657 * might make sense to split off the efi subsystem into its own
658 * driver, but for now only efivars will register with it, so just
659 * include it here.
660 */
661
662static int __init
663efivars_init(void)
664{
665 efi_status_t status = EFI_NOT_FOUND;
666 efi_guid_t vendor_guid;
667 efi_char16_t *variable_name;
668 struct subsys_attribute *attr;
669 unsigned long variable_name_size = 1024;
670 int i, error = 0;
671
672 if (!efi_enabled)
673 return -ENODEV;
674
Deepak Saxena9c215382005-11-07 01:01:24 -0800675 variable_name = kzalloc(variable_name_size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 if (!variable_name) {
677 printk(KERN_ERR "efivars: Memory allocation failed.\n");
678 return -ENOMEM;
679 }
680
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
682 EFIVARS_DATE);
683
684 /*
685 * For now we'll register the efi subsys within this driver
686 */
687
688 error = firmware_register(&efi_subsys);
689
690 if (error) {
691 printk(KERN_ERR "efivars: Firmware registration failed with error %d.\n", error);
692 goto out_free;
693 }
694
695 kset_set_kset_s(&vars_subsys, efi_subsys);
696
697 error = subsystem_register(&vars_subsys);
698
699 if (error) {
700 printk(KERN_ERR "efivars: Subsystem registration failed with error %d.\n", error);
701 goto out_firmware_unregister;
702 }
703
704 /*
705 * Per EFI spec, the maximum storage allocated for both
706 * the variable name and variable data is 1024 bytes.
707 */
708
709 do {
710 variable_name_size = 1024;
711
712 status = efi.get_next_variable(&variable_name_size,
713 variable_name,
714 &vendor_guid);
715 switch (status) {
716 case EFI_SUCCESS:
717 efivar_create_sysfs_entry(variable_name_size,
718 variable_name,
719 &vendor_guid);
720 break;
721 case EFI_NOT_FOUND:
722 break;
723 default:
724 printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
725 status);
726 status = EFI_NOT_FOUND;
727 break;
728 }
729 } while (status != EFI_NOT_FOUND);
730
731 /*
732 * Now add attributes to allow creation of new vars
733 * and deletion of existing ones...
734 */
735
736 for (i = 0; (attr = var_subsys_attrs[i]) && !error; i++) {
737 if (attr->show && attr->store)
738 error = subsys_create_file(&vars_subsys, attr);
739 }
740
741 /* Don't forget the systab entry */
742
743 for (i = 0; (attr = efi_subsys_attrs[i]) && !error; i++) {
744 if (attr->show)
745 error = subsys_create_file(&efi_subsys, attr);
746 }
747
748 if (error)
749 printk(KERN_ERR "efivars: Sysfs attribute export failed with error %d.\n", error);
750 else
751 goto out_free;
752
753 subsystem_unregister(&vars_subsys);
754
755out_firmware_unregister:
756 firmware_unregister(&efi_subsys);
757
758out_free:
759 kfree(variable_name);
760
761 return error;
762}
763
764static void __exit
765efivars_exit(void)
766{
767 struct list_head *pos, *n;
768
769 list_for_each_safe(pos, n, &efivar_list)
770 efivar_unregister(get_efivar_entry(pos));
771
772 subsystem_unregister(&vars_subsys);
773 firmware_unregister(&efi_subsys);
774}
775
776module_init(efivars_init);
777module_exit(efivars_exit);
778