blob: c6281ccd4fe7d3c09bf71a8eb8cc2467fc19cc32 [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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125struct efivar_attribute {
126 struct attribute attr;
127 ssize_t (*show) (struct efivar_entry *entry, char *buf);
128 ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
129};
130
131
132#define EFI_ATTR(_name, _mode, _show, _store) \
133struct subsys_attribute efi_attr_##_name = { \
134 .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \
135 .show = _show, \
136 .store = _store, \
137};
138
139#define EFIVAR_ATTR(_name, _mode, _show, _store) \
140struct efivar_attribute efivar_attr_##_name = { \
141 .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \
142 .show = _show, \
143 .store = _store, \
144};
145
146#define VAR_SUBSYS_ATTR(_name, _mode, _show, _store) \
147struct subsys_attribute var_subsys_attr_##_name = { \
148 .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \
149 .show = _show, \
150 .store = _store, \
151};
152
153#define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
154#define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
155
156/*
157 * Prototype for sysfs creation function
158 */
159static int
160efivar_create_sysfs_entry(unsigned long variable_name_size,
161 efi_char16_t *variable_name,
162 efi_guid_t *vendor_guid);
163
164/* Return the number of unicode characters in data */
165static unsigned long
166utf8_strlen(efi_char16_t *data, unsigned long maxlength)
167{
168 unsigned long length = 0;
169
170 while (*data++ != 0 && length < maxlength)
171 length++;
172 return length;
173}
174
175/*
176 * Return the number of bytes is the length of this string
177 * Note: this is NOT the same as the number of unicode characters
178 */
179static inline unsigned long
180utf8_strsize(efi_char16_t *data, unsigned long maxlength)
181{
182 return utf8_strlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
183}
184
185static efi_status_t
186get_var_data(struct efi_variable *var)
187{
188 efi_status_t status;
189
190 spin_lock(&efivars_lock);
191 var->DataSize = 1024;
192 status = efi.get_variable(var->VariableName,
193 &var->VendorGuid,
194 &var->Attributes,
195 &var->DataSize,
196 var->Data);
197 spin_unlock(&efivars_lock);
198 if (status != EFI_SUCCESS) {
199 printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
200 status);
201 }
202 return status;
203}
204
205static ssize_t
206efivar_guid_read(struct efivar_entry *entry, char *buf)
207{
208 struct efi_variable *var = &entry->var;
209 char *str = buf;
210
211 if (!entry || !buf)
212 return 0;
213
214 efi_guid_unparse(&var->VendorGuid, str);
215 str += strlen(str);
216 str += sprintf(str, "\n");
217
218 return str - buf;
219}
220
221static ssize_t
222efivar_attr_read(struct efivar_entry *entry, char *buf)
223{
224 struct efi_variable *var = &entry->var;
225 char *str = buf;
226 efi_status_t status;
227
228 if (!entry || !buf)
229 return -EINVAL;
230
231 status = get_var_data(var);
232 if (status != EFI_SUCCESS)
233 return -EIO;
234
235 if (var->Attributes & 0x1)
236 str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
237 if (var->Attributes & 0x2)
238 str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
239 if (var->Attributes & 0x4)
240 str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
241 return str - buf;
242}
243
244static ssize_t
245efivar_size_read(struct efivar_entry *entry, char *buf)
246{
247 struct efi_variable *var = &entry->var;
248 char *str = buf;
249 efi_status_t status;
250
251 if (!entry || !buf)
252 return -EINVAL;
253
254 status = get_var_data(var);
255 if (status != EFI_SUCCESS)
256 return -EIO;
257
258 str += sprintf(str, "0x%lx\n", var->DataSize);
259 return str - buf;
260}
261
262static ssize_t
263efivar_data_read(struct efivar_entry *entry, char *buf)
264{
265 struct efi_variable *var = &entry->var;
266 efi_status_t status;
267
268 if (!entry || !buf)
269 return -EINVAL;
270
271 status = get_var_data(var);
272 if (status != EFI_SUCCESS)
273 return -EIO;
274
275 memcpy(buf, var->Data, var->DataSize);
276 return var->DataSize;
277}
278/*
279 * We allow each variable to be edited via rewriting the
280 * entire efi variable structure.
281 */
282static ssize_t
283efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
284{
285 struct efi_variable *new_var, *var = &entry->var;
286 efi_status_t status = EFI_NOT_FOUND;
287
288 if (count != sizeof(struct efi_variable))
289 return -EINVAL;
290
291 new_var = (struct efi_variable *)buf;
292 /*
293 * If only updating the variable data, then the name
294 * and guid should remain the same
295 */
296 if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
297 efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
298 printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
299 return -EINVAL;
300 }
301
302 if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
303 printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
304 return -EINVAL;
305 }
306
307 spin_lock(&efivars_lock);
308 status = efi.set_variable(new_var->VariableName,
309 &new_var->VendorGuid,
310 new_var->Attributes,
311 new_var->DataSize,
312 new_var->Data);
313
314 spin_unlock(&efivars_lock);
315
316 if (status != EFI_SUCCESS) {
317 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
318 status);
319 return -EIO;
320 }
321
322 memcpy(&entry->var, new_var, count);
323 return count;
324}
325
326static ssize_t
327efivar_show_raw(struct efivar_entry *entry, char *buf)
328{
329 struct efi_variable *var = &entry->var;
330 efi_status_t status;
331
332 if (!entry || !buf)
333 return 0;
334
335 status = get_var_data(var);
336 if (status != EFI_SUCCESS)
337 return -EIO;
338
339 memcpy(buf, var, sizeof(*var));
340 return sizeof(*var);
341}
342
343/*
344 * Generic read/write functions that call the specific functions of
345 * the atttributes...
346 */
347static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
348 char *buf)
349{
350 struct efivar_entry *var = to_efivar_entry(kobj);
351 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
Dmitry Torokhov70f28172005-04-29 01:27:34 -0500352 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353
354 if (!capable(CAP_SYS_ADMIN))
355 return -EACCES;
356
357 if (efivar_attr->show) {
358 ret = efivar_attr->show(var, buf);
359 }
360 return ret;
361}
362
363static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
364 const char *buf, size_t count)
365{
366 struct efivar_entry *var = to_efivar_entry(kobj);
367 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
Dmitry Torokhov70f28172005-04-29 01:27:34 -0500368 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369
370 if (!capable(CAP_SYS_ADMIN))
371 return -EACCES;
372
373 if (efivar_attr->store)
374 ret = efivar_attr->store(var, buf, count);
375
376 return ret;
377}
378
379static struct sysfs_ops efivar_attr_ops = {
380 .show = efivar_attr_show,
381 .store = efivar_attr_store,
382};
383
384static void efivar_release(struct kobject *kobj)
385{
386 struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 kfree(var);
388}
389
390static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
391static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
392static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
393static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
394static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
395
396static struct attribute *def_attrs[] = {
397 &efivar_attr_guid.attr,
398 &efivar_attr_size.attr,
399 &efivar_attr_attributes.attr,
400 &efivar_attr_data.attr,
401 &efivar_attr_raw_var.attr,
402 NULL,
403};
404
405static struct kobj_type ktype_efivar = {
406 .release = efivar_release,
407 .sysfs_ops = &efivar_attr_ops,
408 .default_attrs = def_attrs,
409};
410
411static ssize_t
412dummy(struct subsystem *sub, char *buf)
413{
414 return -ENODEV;
415}
416
417static inline void
418efivar_unregister(struct efivar_entry *var)
419{
420 kobject_unregister(&var->kobj);
421}
422
423
424static ssize_t
425efivar_create(struct subsystem *sub, const char *buf, size_t count)
426{
427 struct efi_variable *new_var = (struct efi_variable *)buf;
Matt Domsch496a0fc2007-01-26 00:57:18 -0800428 struct efivar_entry *search_efivar, *n;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 unsigned long strsize1, strsize2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 efi_status_t status = EFI_NOT_FOUND;
431 int found = 0;
432
433 if (!capable(CAP_SYS_ADMIN))
434 return -EACCES;
435
436 spin_lock(&efivars_lock);
437
438 /*
439 * Does this variable already exist?
440 */
Matt Domsch496a0fc2007-01-26 00:57:18 -0800441 list_for_each_entry_safe(search_efivar, n, &efivar_list, list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
443 strsize2 = utf8_strsize(new_var->VariableName, 1024);
444 if (strsize1 == strsize2 &&
445 !memcmp(&(search_efivar->var.VariableName),
446 new_var->VariableName, strsize1) &&
447 !efi_guidcmp(search_efivar->var.VendorGuid,
448 new_var->VendorGuid)) {
449 found = 1;
450 break;
451 }
452 }
453 if (found) {
454 spin_unlock(&efivars_lock);
455 return -EINVAL;
456 }
457
458 /* now *really* create the variable via EFI */
459 status = efi.set_variable(new_var->VariableName,
460 &new_var->VendorGuid,
461 new_var->Attributes,
462 new_var->DataSize,
463 new_var->Data);
464
465 if (status != EFI_SUCCESS) {
466 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
467 status);
468 spin_unlock(&efivars_lock);
469 return -EIO;
470 }
471 spin_unlock(&efivars_lock);
472
473 /* Create the entry in sysfs. Locking is not required here */
474 status = efivar_create_sysfs_entry(utf8_strsize(new_var->VariableName,
475 1024), new_var->VariableName, &new_var->VendorGuid);
476 if (status) {
477 printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
478 }
479 return count;
480}
481
482static ssize_t
483efivar_delete(struct subsystem *sub, const char *buf, size_t count)
484{
485 struct efi_variable *del_var = (struct efi_variable *)buf;
Matt Domsch496a0fc2007-01-26 00:57:18 -0800486 struct efivar_entry *search_efivar, *n;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 unsigned long strsize1, strsize2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 efi_status_t status = EFI_NOT_FOUND;
489 int found = 0;
490
491 if (!capable(CAP_SYS_ADMIN))
492 return -EACCES;
493
494 spin_lock(&efivars_lock);
495
496 /*
497 * Does this variable already exist?
498 */
Matt Domsch496a0fc2007-01-26 00:57:18 -0800499 list_for_each_entry_safe(search_efivar, n, &efivar_list, list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
501 strsize2 = utf8_strsize(del_var->VariableName, 1024);
502 if (strsize1 == strsize2 &&
503 !memcmp(&(search_efivar->var.VariableName),
504 del_var->VariableName, strsize1) &&
505 !efi_guidcmp(search_efivar->var.VendorGuid,
506 del_var->VendorGuid)) {
507 found = 1;
508 break;
509 }
510 }
511 if (!found) {
512 spin_unlock(&efivars_lock);
513 return -EINVAL;
514 }
515 /* force the Attributes/DataSize to 0 to ensure deletion */
516 del_var->Attributes = 0;
517 del_var->DataSize = 0;
518
519 status = efi.set_variable(del_var->VariableName,
520 &del_var->VendorGuid,
521 del_var->Attributes,
522 del_var->DataSize,
523 del_var->Data);
524
525 if (status != EFI_SUCCESS) {
526 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
527 status);
528 spin_unlock(&efivars_lock);
529 return -EIO;
530 }
Matt Domsch496a0fc2007-01-26 00:57:18 -0800531 list_del(&search_efivar->list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 /* We need to release this lock before unregistering. */
533 spin_unlock(&efivars_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534 efivar_unregister(search_efivar);
535
536 /* It's dead Jim.... */
537 return count;
538}
539
540static VAR_SUBSYS_ATTR(new_var, 0200, dummy, efivar_create);
541static VAR_SUBSYS_ATTR(del_var, 0200, dummy, efivar_delete);
542
543static struct subsys_attribute *var_subsys_attrs[] = {
544 &var_subsys_attr_new_var,
545 &var_subsys_attr_del_var,
546 NULL,
547};
548
549/*
550 * Let's not leave out systab information that snuck into
551 * the efivars driver
552 */
553static ssize_t
554systab_read(struct subsystem *entry, char *buf)
555{
556 char *str = buf;
557
558 if (!entry || !buf)
559 return -EINVAL;
560
Bjorn Helgaasb2c99e32006-03-26 01:37:08 -0800561 if (efi.mps != EFI_INVALID_TABLE_ADDR)
562 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
563 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
564 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
565 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
566 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
567 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
568 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
569 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
570 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
571 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
572 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
573 if (efi.uga != EFI_INVALID_TABLE_ADDR)
574 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575
576 return str - buf;
577}
578
579static EFI_ATTR(systab, 0400, systab_read, NULL);
580
581static struct subsys_attribute *efi_subsys_attrs[] = {
582 &efi_attr_systab,
583 NULL, /* maybe more in the future? */
584};
585
586static decl_subsys(vars, &ktype_efivar, NULL);
587static decl_subsys(efi, NULL, NULL);
588
589/*
590 * efivar_create_sysfs_entry()
591 * Requires:
592 * variable_name_size = number of bytes required to hold
593 * variable_name (not counting the NULL
594 * character at the end.
595 * efivars_lock is not held on entry or exit.
596 * Returns 1 on failure, 0 on success
597 */
598static int
599efivar_create_sysfs_entry(unsigned long variable_name_size,
600 efi_char16_t *variable_name,
601 efi_guid_t *vendor_guid)
602{
603 int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38;
604 char *short_name;
605 struct efivar_entry *new_efivar;
606
Deepak Saxena9c215382005-11-07 01:01:24 -0800607 short_name = kzalloc(short_name_size + 1, GFP_KERNEL);
608 new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609
610 if (!short_name || !new_efivar) {
Jesper Juhl0933ad92005-06-25 14:59:15 -0700611 kfree(short_name);
612 kfree(new_efivar);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 return 1;
614 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615
616 memcpy(new_efivar->var.VariableName, variable_name,
617 variable_name_size);
618 memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));
619
620 /* Convert Unicode to normal chars (assume top bits are 0),
621 ala UTF-8 */
622 for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
623 short_name[i] = variable_name[i] & 0xFF;
624 }
625 /* This is ugly, but necessary to separate one vendor's
626 private variables from another's. */
627
628 *(short_name + strlen(short_name)) = '-';
629 efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
630
631 kobject_set_name(&new_efivar->kobj, "%s", short_name);
632 kobj_set_kset_s(new_efivar, vars_subsys);
Jeff Garzik69b21862006-10-11 01:22:23 -0700633 i = kobject_register(&new_efivar->kobj);
634 if (i) {
635 kfree(short_name);
636 kfree(new_efivar);
637 return 1;
638 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639
Jesper Juhl0933ad92005-06-25 14:59:15 -0700640 kfree(short_name);
641 short_name = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642
643 spin_lock(&efivars_lock);
644 list_add(&new_efivar->list, &efivar_list);
645 spin_unlock(&efivars_lock);
646
647 return 0;
648}
649/*
650 * For now we register the efi subsystem with the firmware subsystem
651 * and the vars subsystem with the efi subsystem. In the future, it
652 * might make sense to split off the efi subsystem into its own
653 * driver, but for now only efivars will register with it, so just
654 * include it here.
655 */
656
657static int __init
658efivars_init(void)
659{
660 efi_status_t status = EFI_NOT_FOUND;
661 efi_guid_t vendor_guid;
662 efi_char16_t *variable_name;
663 struct subsys_attribute *attr;
664 unsigned long variable_name_size = 1024;
665 int i, error = 0;
666
667 if (!efi_enabled)
668 return -ENODEV;
669
Deepak Saxena9c215382005-11-07 01:01:24 -0800670 variable_name = kzalloc(variable_name_size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 if (!variable_name) {
672 printk(KERN_ERR "efivars: Memory allocation failed.\n");
673 return -ENOMEM;
674 }
675
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
677 EFIVARS_DATE);
678
679 /*
680 * For now we'll register the efi subsys within this driver
681 */
682
683 error = firmware_register(&efi_subsys);
684
685 if (error) {
686 printk(KERN_ERR "efivars: Firmware registration failed with error %d.\n", error);
687 goto out_free;
688 }
689
690 kset_set_kset_s(&vars_subsys, efi_subsys);
691
692 error = subsystem_register(&vars_subsys);
693
694 if (error) {
695 printk(KERN_ERR "efivars: Subsystem registration failed with error %d.\n", error);
696 goto out_firmware_unregister;
697 }
698
699 /*
700 * Per EFI spec, the maximum storage allocated for both
701 * the variable name and variable data is 1024 bytes.
702 */
703
704 do {
705 variable_name_size = 1024;
706
707 status = efi.get_next_variable(&variable_name_size,
708 variable_name,
709 &vendor_guid);
710 switch (status) {
711 case EFI_SUCCESS:
712 efivar_create_sysfs_entry(variable_name_size,
713 variable_name,
714 &vendor_guid);
715 break;
716 case EFI_NOT_FOUND:
717 break;
718 default:
719 printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
720 status);
721 status = EFI_NOT_FOUND;
722 break;
723 }
724 } while (status != EFI_NOT_FOUND);
725
726 /*
727 * Now add attributes to allow creation of new vars
728 * and deletion of existing ones...
729 */
730
731 for (i = 0; (attr = var_subsys_attrs[i]) && !error; i++) {
732 if (attr->show && attr->store)
733 error = subsys_create_file(&vars_subsys, attr);
734 }
735
736 /* Don't forget the systab entry */
737
738 for (i = 0; (attr = efi_subsys_attrs[i]) && !error; i++) {
739 if (attr->show)
740 error = subsys_create_file(&efi_subsys, attr);
741 }
742
743 if (error)
744 printk(KERN_ERR "efivars: Sysfs attribute export failed with error %d.\n", error);
745 else
746 goto out_free;
747
748 subsystem_unregister(&vars_subsys);
749
750out_firmware_unregister:
751 firmware_unregister(&efi_subsys);
752
753out_free:
754 kfree(variable_name);
755
756 return error;
757}
758
759static void __exit
760efivars_exit(void)
761{
Matt Domsch496a0fc2007-01-26 00:57:18 -0800762 struct efivar_entry *entry, *n;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763
Matt Domsch496a0fc2007-01-26 00:57:18 -0800764 list_for_each_entry_safe(entry, n, &efivar_list, list) {
765 spin_lock(&efivars_lock);
766 list_del(&entry->list);
767 spin_unlock(&efivars_lock);
768 efivar_unregister(entry);
769 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770
771 subsystem_unregister(&vars_subsys);
772 firmware_unregister(&efi_subsys);
773}
774
775module_init(efivars_init);
776module_exit(efivars_exit);
777