blob: 5ab5e393b882810556d80c6c7fa5071e444362b3 [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/types.h>
70#include <linux/errno.h>
71#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070072#include <linux/mm.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
81#include <asm/uaccess.h>
82
83#define EFIVARS_VERSION "0.08"
84#define EFIVARS_DATE "2004-May-17"
85
86MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
87MODULE_DESCRIPTION("sysfs interface to EFI Variables");
88MODULE_LICENSE("GPL");
89MODULE_VERSION(EFIVARS_VERSION);
90
91/*
92 * efivars_lock protects two things:
93 * 1) efivar_list - adds, removals, reads, writes
94 * 2) efi.[gs]et_variable() calls.
95 * It must not be held when creating sysfs entries or calling kmalloc.
96 * efi.get_next_variable() is only called from efivars_init(),
97 * which is protected by the BKL, so that path is safe.
98 */
99static DEFINE_SPINLOCK(efivars_lock);
100static LIST_HEAD(efivar_list);
101
102/*
103 * The maximum size of VariableName + Data = 1024
104 * Therefore, it's reasonable to save that much
105 * space in each part of the structure,
106 * and we use a page for reading/writing.
107 */
108
109struct efi_variable {
110 efi_char16_t VariableName[1024/sizeof(efi_char16_t)];
111 efi_guid_t VendorGuid;
112 unsigned long DataSize;
113 __u8 Data[1024];
114 efi_status_t Status;
115 __u32 Attributes;
116} __attribute__((packed));
117
118
119struct efivar_entry {
120 struct efi_variable var;
121 struct list_head list;
122 struct kobject kobj;
123};
124
125#define get_efivar_entry(n) list_entry(n, struct efivar_entry, list)
126
127struct efivar_attribute {
128 struct attribute attr;
129 ssize_t (*show) (struct efivar_entry *entry, char *buf);
130 ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
131};
132
133
134#define EFI_ATTR(_name, _mode, _show, _store) \
135struct subsys_attribute efi_attr_##_name = { \
136 .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \
137 .show = _show, \
138 .store = _store, \
139};
140
141#define EFIVAR_ATTR(_name, _mode, _show, _store) \
142struct efivar_attribute efivar_attr_##_name = { \
143 .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \
144 .show = _show, \
145 .store = _store, \
146};
147
148#define VAR_SUBSYS_ATTR(_name, _mode, _show, _store) \
149struct subsys_attribute var_subsys_attr_##_name = { \
150 .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \
151 .show = _show, \
152 .store = _store, \
153};
154
155#define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
156#define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
157
158/*
159 * Prototype for sysfs creation function
160 */
161static int
162efivar_create_sysfs_entry(unsigned long variable_name_size,
163 efi_char16_t *variable_name,
164 efi_guid_t *vendor_guid);
165
166/* Return the number of unicode characters in data */
167static unsigned long
168utf8_strlen(efi_char16_t *data, unsigned long maxlength)
169{
170 unsigned long length = 0;
171
172 while (*data++ != 0 && length < maxlength)
173 length++;
174 return length;
175}
176
177/*
178 * Return the number of bytes is the length of this string
179 * Note: this is NOT the same as the number of unicode characters
180 */
181static inline unsigned long
182utf8_strsize(efi_char16_t *data, unsigned long maxlength)
183{
184 return utf8_strlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
185}
186
187static efi_status_t
188get_var_data(struct efi_variable *var)
189{
190 efi_status_t status;
191
192 spin_lock(&efivars_lock);
193 var->DataSize = 1024;
194 status = efi.get_variable(var->VariableName,
195 &var->VendorGuid,
196 &var->Attributes,
197 &var->DataSize,
198 var->Data);
199 spin_unlock(&efivars_lock);
200 if (status != EFI_SUCCESS) {
201 printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
202 status);
203 }
204 return status;
205}
206
207static ssize_t
208efivar_guid_read(struct efivar_entry *entry, char *buf)
209{
210 struct efi_variable *var = &entry->var;
211 char *str = buf;
212
213 if (!entry || !buf)
214 return 0;
215
216 efi_guid_unparse(&var->VendorGuid, str);
217 str += strlen(str);
218 str += sprintf(str, "\n");
219
220 return str - buf;
221}
222
223static ssize_t
224efivar_attr_read(struct efivar_entry *entry, char *buf)
225{
226 struct efi_variable *var = &entry->var;
227 char *str = buf;
228 efi_status_t status;
229
230 if (!entry || !buf)
231 return -EINVAL;
232
233 status = get_var_data(var);
234 if (status != EFI_SUCCESS)
235 return -EIO;
236
237 if (var->Attributes & 0x1)
238 str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
239 if (var->Attributes & 0x2)
240 str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
241 if (var->Attributes & 0x4)
242 str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
243 return str - buf;
244}
245
246static ssize_t
247efivar_size_read(struct efivar_entry *entry, char *buf)
248{
249 struct efi_variable *var = &entry->var;
250 char *str = buf;
251 efi_status_t status;
252
253 if (!entry || !buf)
254 return -EINVAL;
255
256 status = get_var_data(var);
257 if (status != EFI_SUCCESS)
258 return -EIO;
259
260 str += sprintf(str, "0x%lx\n", var->DataSize);
261 return str - buf;
262}
263
264static ssize_t
265efivar_data_read(struct efivar_entry *entry, char *buf)
266{
267 struct efi_variable *var = &entry->var;
268 efi_status_t status;
269
270 if (!entry || !buf)
271 return -EINVAL;
272
273 status = get_var_data(var);
274 if (status != EFI_SUCCESS)
275 return -EIO;
276
277 memcpy(buf, var->Data, var->DataSize);
278 return var->DataSize;
279}
280/*
281 * We allow each variable to be edited via rewriting the
282 * entire efi variable structure.
283 */
284static ssize_t
285efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
286{
287 struct efi_variable *new_var, *var = &entry->var;
288 efi_status_t status = EFI_NOT_FOUND;
289
290 if (count != sizeof(struct efi_variable))
291 return -EINVAL;
292
293 new_var = (struct efi_variable *)buf;
294 /*
295 * If only updating the variable data, then the name
296 * and guid should remain the same
297 */
298 if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
299 efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
300 printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
301 return -EINVAL;
302 }
303
304 if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
305 printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
306 return -EINVAL;
307 }
308
309 spin_lock(&efivars_lock);
310 status = efi.set_variable(new_var->VariableName,
311 &new_var->VendorGuid,
312 new_var->Attributes,
313 new_var->DataSize,
314 new_var->Data);
315
316 spin_unlock(&efivars_lock);
317
318 if (status != EFI_SUCCESS) {
319 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
320 status);
321 return -EIO;
322 }
323
324 memcpy(&entry->var, new_var, count);
325 return count;
326}
327
328static ssize_t
329efivar_show_raw(struct efivar_entry *entry, char *buf)
330{
331 struct efi_variable *var = &entry->var;
332 efi_status_t status;
333
334 if (!entry || !buf)
335 return 0;
336
337 status = get_var_data(var);
338 if (status != EFI_SUCCESS)
339 return -EIO;
340
341 memcpy(buf, var, sizeof(*var));
342 return sizeof(*var);
343}
344
345/*
346 * Generic read/write functions that call the specific functions of
347 * the atttributes...
348 */
349static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
350 char *buf)
351{
352 struct efivar_entry *var = to_efivar_entry(kobj);
353 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
Dmitry Torokhov70f28172005-04-29 01:27:34 -0500354 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355
356 if (!capable(CAP_SYS_ADMIN))
357 return -EACCES;
358
359 if (efivar_attr->show) {
360 ret = efivar_attr->show(var, buf);
361 }
362 return ret;
363}
364
365static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
366 const char *buf, size_t count)
367{
368 struct efivar_entry *var = to_efivar_entry(kobj);
369 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
Dmitry Torokhov70f28172005-04-29 01:27:34 -0500370 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371
372 if (!capable(CAP_SYS_ADMIN))
373 return -EACCES;
374
375 if (efivar_attr->store)
376 ret = efivar_attr->store(var, buf, count);
377
378 return ret;
379}
380
381static struct sysfs_ops efivar_attr_ops = {
382 .show = efivar_attr_show,
383 .store = efivar_attr_store,
384};
385
386static void efivar_release(struct kobject *kobj)
387{
388 struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
389 spin_lock(&efivars_lock);
390 list_del(&var->list);
391 spin_unlock(&efivars_lock);
392 kfree(var);
393}
394
395static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
396static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
397static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
398static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
399static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
400
401static struct attribute *def_attrs[] = {
402 &efivar_attr_guid.attr,
403 &efivar_attr_size.attr,
404 &efivar_attr_attributes.attr,
405 &efivar_attr_data.attr,
406 &efivar_attr_raw_var.attr,
407 NULL,
408};
409
410static struct kobj_type ktype_efivar = {
411 .release = efivar_release,
412 .sysfs_ops = &efivar_attr_ops,
413 .default_attrs = def_attrs,
414};
415
416static ssize_t
417dummy(struct subsystem *sub, char *buf)
418{
419 return -ENODEV;
420}
421
422static inline void
423efivar_unregister(struct efivar_entry *var)
424{
425 kobject_unregister(&var->kobj);
426}
427
428
429static ssize_t
430efivar_create(struct subsystem *sub, const char *buf, size_t count)
431{
432 struct efi_variable *new_var = (struct efi_variable *)buf;
433 struct efivar_entry *search_efivar = NULL;
434 unsigned long strsize1, strsize2;
435 struct list_head *pos, *n;
436 efi_status_t status = EFI_NOT_FOUND;
437 int found = 0;
438
439 if (!capable(CAP_SYS_ADMIN))
440 return -EACCES;
441
442 spin_lock(&efivars_lock);
443
444 /*
445 * Does this variable already exist?
446 */
447 list_for_each_safe(pos, n, &efivar_list) {
448 search_efivar = get_efivar_entry(pos);
449 strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
450 strsize2 = utf8_strsize(new_var->VariableName, 1024);
451 if (strsize1 == strsize2 &&
452 !memcmp(&(search_efivar->var.VariableName),
453 new_var->VariableName, strsize1) &&
454 !efi_guidcmp(search_efivar->var.VendorGuid,
455 new_var->VendorGuid)) {
456 found = 1;
457 break;
458 }
459 }
460 if (found) {
461 spin_unlock(&efivars_lock);
462 return -EINVAL;
463 }
464
465 /* now *really* create the variable via EFI */
466 status = efi.set_variable(new_var->VariableName,
467 &new_var->VendorGuid,
468 new_var->Attributes,
469 new_var->DataSize,
470 new_var->Data);
471
472 if (status != EFI_SUCCESS) {
473 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
474 status);
475 spin_unlock(&efivars_lock);
476 return -EIO;
477 }
478 spin_unlock(&efivars_lock);
479
480 /* Create the entry in sysfs. Locking is not required here */
481 status = efivar_create_sysfs_entry(utf8_strsize(new_var->VariableName,
482 1024), new_var->VariableName, &new_var->VendorGuid);
483 if (status) {
484 printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
485 }
486 return count;
487}
488
489static ssize_t
490efivar_delete(struct subsystem *sub, const char *buf, size_t count)
491{
492 struct efi_variable *del_var = (struct efi_variable *)buf;
493 struct efivar_entry *search_efivar = NULL;
494 unsigned long strsize1, strsize2;
495 struct list_head *pos, *n;
496 efi_status_t status = EFI_NOT_FOUND;
497 int found = 0;
498
499 if (!capable(CAP_SYS_ADMIN))
500 return -EACCES;
501
502 spin_lock(&efivars_lock);
503
504 /*
505 * Does this variable already exist?
506 */
507 list_for_each_safe(pos, n, &efivar_list) {
508 search_efivar = get_efivar_entry(pos);
509 strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
510 strsize2 = utf8_strsize(del_var->VariableName, 1024);
511 if (strsize1 == strsize2 &&
512 !memcmp(&(search_efivar->var.VariableName),
513 del_var->VariableName, strsize1) &&
514 !efi_guidcmp(search_efivar->var.VendorGuid,
515 del_var->VendorGuid)) {
516 found = 1;
517 break;
518 }
519 }
520 if (!found) {
521 spin_unlock(&efivars_lock);
522 return -EINVAL;
523 }
524 /* force the Attributes/DataSize to 0 to ensure deletion */
525 del_var->Attributes = 0;
526 del_var->DataSize = 0;
527
528 status = efi.set_variable(del_var->VariableName,
529 &del_var->VendorGuid,
530 del_var->Attributes,
531 del_var->DataSize,
532 del_var->Data);
533
534 if (status != EFI_SUCCESS) {
535 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
536 status);
537 spin_unlock(&efivars_lock);
538 return -EIO;
539 }
540 /* We need to release this lock before unregistering. */
541 spin_unlock(&efivars_lock);
542
543 efivar_unregister(search_efivar);
544
545 /* It's dead Jim.... */
546 return count;
547}
548
549static VAR_SUBSYS_ATTR(new_var, 0200, dummy, efivar_create);
550static VAR_SUBSYS_ATTR(del_var, 0200, dummy, efivar_delete);
551
552static struct subsys_attribute *var_subsys_attrs[] = {
553 &var_subsys_attr_new_var,
554 &var_subsys_attr_del_var,
555 NULL,
556};
557
558/*
559 * Let's not leave out systab information that snuck into
560 * the efivars driver
561 */
562static ssize_t
563systab_read(struct subsystem *entry, char *buf)
564{
565 char *str = buf;
566
567 if (!entry || !buf)
568 return -EINVAL;
569
Bjorn Helgaasb2c99e32006-03-26 01:37:08 -0800570 if (efi.mps != EFI_INVALID_TABLE_ADDR)
571 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
572 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
573 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
574 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
575 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
576 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
577 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
578 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
579 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
580 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
581 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
582 if (efi.uga != EFI_INVALID_TABLE_ADDR)
583 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584
585 return str - buf;
586}
587
588static EFI_ATTR(systab, 0400, systab_read, NULL);
589
590static struct subsys_attribute *efi_subsys_attrs[] = {
591 &efi_attr_systab,
592 NULL, /* maybe more in the future? */
593};
594
595static decl_subsys(vars, &ktype_efivar, NULL);
596static decl_subsys(efi, NULL, NULL);
597
598/*
599 * efivar_create_sysfs_entry()
600 * Requires:
601 * variable_name_size = number of bytes required to hold
602 * variable_name (not counting the NULL
603 * character at the end.
604 * efivars_lock is not held on entry or exit.
605 * Returns 1 on failure, 0 on success
606 */
607static int
608efivar_create_sysfs_entry(unsigned long variable_name_size,
609 efi_char16_t *variable_name,
610 efi_guid_t *vendor_guid)
611{
612 int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38;
613 char *short_name;
614 struct efivar_entry *new_efivar;
615
Deepak Saxena9c215382005-11-07 01:01:24 -0800616 short_name = kzalloc(short_name_size + 1, GFP_KERNEL);
617 new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618
619 if (!short_name || !new_efivar) {
Jesper Juhl0933ad92005-06-25 14:59:15 -0700620 kfree(short_name);
621 kfree(new_efivar);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 return 1;
623 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624
625 memcpy(new_efivar->var.VariableName, variable_name,
626 variable_name_size);
627 memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));
628
629 /* Convert Unicode to normal chars (assume top bits are 0),
630 ala UTF-8 */
631 for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
632 short_name[i] = variable_name[i] & 0xFF;
633 }
634 /* This is ugly, but necessary to separate one vendor's
635 private variables from another's. */
636
637 *(short_name + strlen(short_name)) = '-';
638 efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
639
640 kobject_set_name(&new_efivar->kobj, "%s", short_name);
641 kobj_set_kset_s(new_efivar, vars_subsys);
Jeff Garzik69b21862006-10-11 01:22:23 -0700642 i = kobject_register(&new_efivar->kobj);
643 if (i) {
644 kfree(short_name);
645 kfree(new_efivar);
646 return 1;
647 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648
Jesper Juhl0933ad92005-06-25 14:59:15 -0700649 kfree(short_name);
650 short_name = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651
652 spin_lock(&efivars_lock);
653 list_add(&new_efivar->list, &efivar_list);
654 spin_unlock(&efivars_lock);
655
656 return 0;
657}
658/*
659 * For now we register the efi subsystem with the firmware subsystem
660 * and the vars subsystem with the efi subsystem. In the future, it
661 * might make sense to split off the efi subsystem into its own
662 * driver, but for now only efivars will register with it, so just
663 * include it here.
664 */
665
666static int __init
667efivars_init(void)
668{
669 efi_status_t status = EFI_NOT_FOUND;
670 efi_guid_t vendor_guid;
671 efi_char16_t *variable_name;
672 struct subsys_attribute *attr;
673 unsigned long variable_name_size = 1024;
674 int i, error = 0;
675
676 if (!efi_enabled)
677 return -ENODEV;
678
Deepak Saxena9c215382005-11-07 01:01:24 -0800679 variable_name = kzalloc(variable_name_size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 if (!variable_name) {
681 printk(KERN_ERR "efivars: Memory allocation failed.\n");
682 return -ENOMEM;
683 }
684
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
686 EFIVARS_DATE);
687
688 /*
689 * For now we'll register the efi subsys within this driver
690 */
691
692 error = firmware_register(&efi_subsys);
693
694 if (error) {
695 printk(KERN_ERR "efivars: Firmware registration failed with error %d.\n", error);
696 goto out_free;
697 }
698
699 kset_set_kset_s(&vars_subsys, efi_subsys);
700
701 error = subsystem_register(&vars_subsys);
702
703 if (error) {
704 printk(KERN_ERR "efivars: Subsystem registration failed with error %d.\n", error);
705 goto out_firmware_unregister;
706 }
707
708 /*
709 * Per EFI spec, the maximum storage allocated for both
710 * the variable name and variable data is 1024 bytes.
711 */
712
713 do {
714 variable_name_size = 1024;
715
716 status = efi.get_next_variable(&variable_name_size,
717 variable_name,
718 &vendor_guid);
719 switch (status) {
720 case EFI_SUCCESS:
721 efivar_create_sysfs_entry(variable_name_size,
722 variable_name,
723 &vendor_guid);
724 break;
725 case EFI_NOT_FOUND:
726 break;
727 default:
728 printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
729 status);
730 status = EFI_NOT_FOUND;
731 break;
732 }
733 } while (status != EFI_NOT_FOUND);
734
735 /*
736 * Now add attributes to allow creation of new vars
737 * and deletion of existing ones...
738 */
739
740 for (i = 0; (attr = var_subsys_attrs[i]) && !error; i++) {
741 if (attr->show && attr->store)
742 error = subsys_create_file(&vars_subsys, attr);
743 }
744
745 /* Don't forget the systab entry */
746
747 for (i = 0; (attr = efi_subsys_attrs[i]) && !error; i++) {
748 if (attr->show)
749 error = subsys_create_file(&efi_subsys, attr);
750 }
751
752 if (error)
753 printk(KERN_ERR "efivars: Sysfs attribute export failed with error %d.\n", error);
754 else
755 goto out_free;
756
757 subsystem_unregister(&vars_subsys);
758
759out_firmware_unregister:
760 firmware_unregister(&efi_subsys);
761
762out_free:
763 kfree(variable_name);
764
765 return error;
766}
767
768static void __exit
769efivars_exit(void)
770{
771 struct list_head *pos, *n;
772
773 list_for_each_safe(pos, n, &efivar_list)
774 efivar_unregister(get_efivar_entry(pos));
775
776 subsystem_unregister(&vars_subsys);
777 firmware_unregister(&efi_subsys);
778}
779
780module_init(efivars_init);
781module_exit(efivars_exit);
782