blob: 82183c28a12a529b740d0393766c1d79981aaada [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 = { \
Tejun Heo7b595752007-06-14 03:45:17 +0900134 .attr = {.name = __stringify(_name), .mode = _mode}, \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 .show = _show, \
136 .store = _store, \
137};
138
139#define EFIVAR_ATTR(_name, _mode, _show, _store) \
140struct efivar_attribute efivar_attr_##_name = { \
Tejun Heo7b595752007-06-14 03:45:17 +0900141 .attr = {.name = __stringify(_name), .mode = _mode}, \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 .show = _show, \
143 .store = _store, \
144};
145
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146#define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
147#define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
148
149/*
150 * Prototype for sysfs creation function
151 */
152static int
153efivar_create_sysfs_entry(unsigned long variable_name_size,
154 efi_char16_t *variable_name,
155 efi_guid_t *vendor_guid);
156
157/* Return the number of unicode characters in data */
158static unsigned long
159utf8_strlen(efi_char16_t *data, unsigned long maxlength)
160{
161 unsigned long length = 0;
162
163 while (*data++ != 0 && length < maxlength)
164 length++;
165 return length;
166}
167
168/*
169 * Return the number of bytes is the length of this string
170 * Note: this is NOT the same as the number of unicode characters
171 */
172static inline unsigned long
173utf8_strsize(efi_char16_t *data, unsigned long maxlength)
174{
175 return utf8_strlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
176}
177
178static efi_status_t
179get_var_data(struct efi_variable *var)
180{
181 efi_status_t status;
182
183 spin_lock(&efivars_lock);
184 var->DataSize = 1024;
185 status = efi.get_variable(var->VariableName,
186 &var->VendorGuid,
187 &var->Attributes,
188 &var->DataSize,
189 var->Data);
190 spin_unlock(&efivars_lock);
191 if (status != EFI_SUCCESS) {
192 printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
193 status);
194 }
195 return status;
196}
197
198static ssize_t
199efivar_guid_read(struct efivar_entry *entry, char *buf)
200{
201 struct efi_variable *var = &entry->var;
202 char *str = buf;
203
204 if (!entry || !buf)
205 return 0;
206
207 efi_guid_unparse(&var->VendorGuid, str);
208 str += strlen(str);
209 str += sprintf(str, "\n");
210
211 return str - buf;
212}
213
214static ssize_t
215efivar_attr_read(struct efivar_entry *entry, char *buf)
216{
217 struct efi_variable *var = &entry->var;
218 char *str = buf;
219 efi_status_t status;
220
221 if (!entry || !buf)
222 return -EINVAL;
223
224 status = get_var_data(var);
225 if (status != EFI_SUCCESS)
226 return -EIO;
227
228 if (var->Attributes & 0x1)
229 str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
230 if (var->Attributes & 0x2)
231 str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
232 if (var->Attributes & 0x4)
233 str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
234 return str - buf;
235}
236
237static ssize_t
238efivar_size_read(struct efivar_entry *entry, char *buf)
239{
240 struct efi_variable *var = &entry->var;
241 char *str = buf;
242 efi_status_t status;
243
244 if (!entry || !buf)
245 return -EINVAL;
246
247 status = get_var_data(var);
248 if (status != EFI_SUCCESS)
249 return -EIO;
250
251 str += sprintf(str, "0x%lx\n", var->DataSize);
252 return str - buf;
253}
254
255static ssize_t
256efivar_data_read(struct efivar_entry *entry, char *buf)
257{
258 struct efi_variable *var = &entry->var;
259 efi_status_t status;
260
261 if (!entry || !buf)
262 return -EINVAL;
263
264 status = get_var_data(var);
265 if (status != EFI_SUCCESS)
266 return -EIO;
267
268 memcpy(buf, var->Data, var->DataSize);
269 return var->DataSize;
270}
271/*
272 * We allow each variable to be edited via rewriting the
273 * entire efi variable structure.
274 */
275static ssize_t
276efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
277{
278 struct efi_variable *new_var, *var = &entry->var;
279 efi_status_t status = EFI_NOT_FOUND;
280
281 if (count != sizeof(struct efi_variable))
282 return -EINVAL;
283
284 new_var = (struct efi_variable *)buf;
285 /*
286 * If only updating the variable data, then the name
287 * and guid should remain the same
288 */
289 if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
290 efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
291 printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
292 return -EINVAL;
293 }
294
295 if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
296 printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
297 return -EINVAL;
298 }
299
300 spin_lock(&efivars_lock);
301 status = efi.set_variable(new_var->VariableName,
302 &new_var->VendorGuid,
303 new_var->Attributes,
304 new_var->DataSize,
305 new_var->Data);
306
307 spin_unlock(&efivars_lock);
308
309 if (status != EFI_SUCCESS) {
310 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
311 status);
312 return -EIO;
313 }
314
315 memcpy(&entry->var, new_var, count);
316 return count;
317}
318
319static ssize_t
320efivar_show_raw(struct efivar_entry *entry, char *buf)
321{
322 struct efi_variable *var = &entry->var;
323 efi_status_t status;
324
325 if (!entry || !buf)
326 return 0;
327
328 status = get_var_data(var);
329 if (status != EFI_SUCCESS)
330 return -EIO;
331
332 memcpy(buf, var, sizeof(*var));
333 return sizeof(*var);
334}
335
336/*
337 * Generic read/write functions that call the specific functions of
338 * the atttributes...
339 */
340static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
341 char *buf)
342{
343 struct efivar_entry *var = to_efivar_entry(kobj);
344 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
Dmitry Torokhov70f28172005-04-29 01:27:34 -0500345 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346
347 if (!capable(CAP_SYS_ADMIN))
348 return -EACCES;
349
350 if (efivar_attr->show) {
351 ret = efivar_attr->show(var, buf);
352 }
353 return ret;
354}
355
356static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
357 const char *buf, size_t count)
358{
359 struct efivar_entry *var = to_efivar_entry(kobj);
360 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
Dmitry Torokhov70f28172005-04-29 01:27:34 -0500361 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362
363 if (!capable(CAP_SYS_ADMIN))
364 return -EACCES;
365
366 if (efivar_attr->store)
367 ret = efivar_attr->store(var, buf, count);
368
369 return ret;
370}
371
372static struct sysfs_ops efivar_attr_ops = {
373 .show = efivar_attr_show,
374 .store = efivar_attr_store,
375};
376
377static void efivar_release(struct kobject *kobj)
378{
379 struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 kfree(var);
381}
382
383static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
384static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
385static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
386static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
387static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
388
389static struct attribute *def_attrs[] = {
390 &efivar_attr_guid.attr,
391 &efivar_attr_size.attr,
392 &efivar_attr_attributes.attr,
393 &efivar_attr_data.attr,
394 &efivar_attr_raw_var.attr,
395 NULL,
396};
397
Greg Kroah-Hartmane89a4112007-10-11 10:47:49 -0600398static struct kobj_type efivar_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 .release = efivar_release,
400 .sysfs_ops = &efivar_attr_ops,
401 .default_attrs = def_attrs,
402};
403
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404static inline void
405efivar_unregister(struct efivar_entry *var)
406{
407 kobject_unregister(&var->kobj);
408}
409
410
Greg Kroah-Hartman97fa5bb2007-11-07 13:56:19 -0800411static ssize_t efivar_create(struct kobject *kobj,
412 struct bin_attribute *bin_attr,
413 char *buf, loff_t pos, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414{
415 struct efi_variable *new_var = (struct efi_variable *)buf;
Matt Domsch496a0fc2007-01-26 00:57:18 -0800416 struct efivar_entry *search_efivar, *n;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 unsigned long strsize1, strsize2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 efi_status_t status = EFI_NOT_FOUND;
419 int found = 0;
420
421 if (!capable(CAP_SYS_ADMIN))
422 return -EACCES;
423
424 spin_lock(&efivars_lock);
425
426 /*
427 * Does this variable already exist?
428 */
Matt Domsch496a0fc2007-01-26 00:57:18 -0800429 list_for_each_entry_safe(search_efivar, n, &efivar_list, list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
431 strsize2 = utf8_strsize(new_var->VariableName, 1024);
432 if (strsize1 == strsize2 &&
433 !memcmp(&(search_efivar->var.VariableName),
434 new_var->VariableName, strsize1) &&
435 !efi_guidcmp(search_efivar->var.VendorGuid,
436 new_var->VendorGuid)) {
437 found = 1;
438 break;
439 }
440 }
441 if (found) {
442 spin_unlock(&efivars_lock);
443 return -EINVAL;
444 }
445
446 /* now *really* create the variable via EFI */
447 status = efi.set_variable(new_var->VariableName,
448 &new_var->VendorGuid,
449 new_var->Attributes,
450 new_var->DataSize,
451 new_var->Data);
452
453 if (status != EFI_SUCCESS) {
454 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
455 status);
456 spin_unlock(&efivars_lock);
457 return -EIO;
458 }
459 spin_unlock(&efivars_lock);
460
461 /* Create the entry in sysfs. Locking is not required here */
462 status = efivar_create_sysfs_entry(utf8_strsize(new_var->VariableName,
463 1024), new_var->VariableName, &new_var->VendorGuid);
464 if (status) {
465 printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
466 }
467 return count;
468}
469
Greg Kroah-Hartman97fa5bb2007-11-07 13:56:19 -0800470static ssize_t efivar_delete(struct kobject *kobj,
471 struct bin_attribute *bin_attr,
472 char *buf, loff_t pos, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473{
474 struct efi_variable *del_var = (struct efi_variable *)buf;
Matt Domsch496a0fc2007-01-26 00:57:18 -0800475 struct efivar_entry *search_efivar, *n;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 unsigned long strsize1, strsize2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477 efi_status_t status = EFI_NOT_FOUND;
478 int found = 0;
479
480 if (!capable(CAP_SYS_ADMIN))
481 return -EACCES;
482
483 spin_lock(&efivars_lock);
484
485 /*
486 * Does this variable already exist?
487 */
Matt Domsch496a0fc2007-01-26 00:57:18 -0800488 list_for_each_entry_safe(search_efivar, n, &efivar_list, list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
490 strsize2 = utf8_strsize(del_var->VariableName, 1024);
491 if (strsize1 == strsize2 &&
492 !memcmp(&(search_efivar->var.VariableName),
493 del_var->VariableName, strsize1) &&
494 !efi_guidcmp(search_efivar->var.VendorGuid,
495 del_var->VendorGuid)) {
496 found = 1;
497 break;
498 }
499 }
500 if (!found) {
501 spin_unlock(&efivars_lock);
502 return -EINVAL;
503 }
504 /* force the Attributes/DataSize to 0 to ensure deletion */
505 del_var->Attributes = 0;
506 del_var->DataSize = 0;
507
508 status = efi.set_variable(del_var->VariableName,
509 &del_var->VendorGuid,
510 del_var->Attributes,
511 del_var->DataSize,
512 del_var->Data);
513
514 if (status != EFI_SUCCESS) {
515 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
516 status);
517 spin_unlock(&efivars_lock);
518 return -EIO;
519 }
Matt Domsch496a0fc2007-01-26 00:57:18 -0800520 list_del(&search_efivar->list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 /* We need to release this lock before unregistering. */
522 spin_unlock(&efivars_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 efivar_unregister(search_efivar);
524
525 /* It's dead Jim.... */
526 return count;
527}
528
Greg Kroah-Hartman97fa5bb2007-11-07 13:56:19 -0800529static struct bin_attribute var_subsys_attr_new_var = {
530 .attr = {.name = "new_var", .mode = 0200},
531 .write = efivar_create,
532};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533
Greg Kroah-Hartman97fa5bb2007-11-07 13:56:19 -0800534static struct bin_attribute var_subsys_attr_del_var = {
535 .attr = {.name = "del_var", .mode = 0200},
536 .write = efivar_delete,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537};
538
539/*
540 * Let's not leave out systab information that snuck into
541 * the efivars driver
542 */
543static ssize_t
Greg Kroah-Hartman823bccf2007-04-13 13:15:19 -0700544systab_read(struct kset *kset, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545{
546 char *str = buf;
547
Greg Kroah-Hartman823bccf2007-04-13 13:15:19 -0700548 if (!kset || !buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 return -EINVAL;
550
Bjorn Helgaasb2c99e32006-03-26 01:37:08 -0800551 if (efi.mps != EFI_INVALID_TABLE_ADDR)
552 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
553 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
554 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
555 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
556 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
557 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
558 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
559 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
560 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
561 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
562 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
563 if (efi.uga != EFI_INVALID_TABLE_ADDR)
564 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565
566 return str - buf;
567}
568
569static EFI_ATTR(systab, 0400, systab_read, NULL);
570
571static struct subsys_attribute *efi_subsys_attrs[] = {
572 &efi_attr_systab,
573 NULL, /* maybe more in the future? */
574};
575
Greg Kroah-Hartman3514fac2007-10-16 10:11:44 -0600576static decl_subsys(vars, NULL);
577static decl_subsys(efi, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578
579/*
580 * efivar_create_sysfs_entry()
581 * Requires:
582 * variable_name_size = number of bytes required to hold
583 * variable_name (not counting the NULL
584 * character at the end.
585 * efivars_lock is not held on entry or exit.
586 * Returns 1 on failure, 0 on success
587 */
588static int
589efivar_create_sysfs_entry(unsigned long variable_name_size,
590 efi_char16_t *variable_name,
591 efi_guid_t *vendor_guid)
592{
593 int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38;
594 char *short_name;
595 struct efivar_entry *new_efivar;
596
Deepak Saxena9c215382005-11-07 01:01:24 -0800597 short_name = kzalloc(short_name_size + 1, GFP_KERNEL);
598 new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599
600 if (!short_name || !new_efivar) {
Jesper Juhl0933ad92005-06-25 14:59:15 -0700601 kfree(short_name);
602 kfree(new_efivar);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 return 1;
604 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605
606 memcpy(new_efivar->var.VariableName, variable_name,
607 variable_name_size);
608 memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));
609
610 /* Convert Unicode to normal chars (assume top bits are 0),
611 ala UTF-8 */
612 for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
613 short_name[i] = variable_name[i] & 0xFF;
614 }
615 /* This is ugly, but necessary to separate one vendor's
616 private variables from another's. */
617
618 *(short_name + strlen(short_name)) = '-';
619 efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
620
621 kobject_set_name(&new_efivar->kobj, "%s", short_name);
Greg Kroah-Hartman3514fac2007-10-16 10:11:44 -0600622 new_efivar->kobj.kset = &vars_subsys;
623 new_efivar->kobj.ktype = &efivar_ktype;
Jeff Garzik69b21862006-10-11 01:22:23 -0700624 i = kobject_register(&new_efivar->kobj);
625 if (i) {
626 kfree(short_name);
627 kfree(new_efivar);
628 return 1;
629 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630
Jesper Juhl0933ad92005-06-25 14:59:15 -0700631 kfree(short_name);
632 short_name = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633
634 spin_lock(&efivars_lock);
635 list_add(&new_efivar->list, &efivar_list);
636 spin_unlock(&efivars_lock);
637
638 return 0;
639}
640/*
641 * For now we register the efi subsystem with the firmware subsystem
642 * and the vars subsystem with the efi subsystem. In the future, it
643 * might make sense to split off the efi subsystem into its own
644 * driver, but for now only efivars will register with it, so just
645 * include it here.
646 */
647
648static int __init
649efivars_init(void)
650{
651 efi_status_t status = EFI_NOT_FOUND;
652 efi_guid_t vendor_guid;
653 efi_char16_t *variable_name;
654 struct subsys_attribute *attr;
655 unsigned long variable_name_size = 1024;
656 int i, error = 0;
657
658 if (!efi_enabled)
659 return -ENODEV;
660
Deepak Saxena9c215382005-11-07 01:01:24 -0800661 variable_name = kzalloc(variable_name_size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 if (!variable_name) {
663 printk(KERN_ERR "efivars: Memory allocation failed.\n");
664 return -ENOMEM;
665 }
666
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
668 EFIVARS_DATE);
669
670 /*
671 * For now we'll register the efi subsys within this driver
672 */
673
674 error = firmware_register(&efi_subsys);
675
676 if (error) {
677 printk(KERN_ERR "efivars: Firmware registration failed with error %d.\n", error);
678 goto out_free;
679 }
680
Greg Kroah-Hartman3514fac2007-10-16 10:11:44 -0600681 vars_subsys.kobj.kset = &efi_subsys;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682
683 error = subsystem_register(&vars_subsys);
684
685 if (error) {
686 printk(KERN_ERR "efivars: Subsystem registration failed with error %d.\n", error);
687 goto out_firmware_unregister;
688 }
689
690 /*
691 * Per EFI spec, the maximum storage allocated for both
692 * the variable name and variable data is 1024 bytes.
693 */
694
695 do {
696 variable_name_size = 1024;
697
698 status = efi.get_next_variable(&variable_name_size,
699 variable_name,
700 &vendor_guid);
701 switch (status) {
702 case EFI_SUCCESS:
703 efivar_create_sysfs_entry(variable_name_size,
704 variable_name,
705 &vendor_guid);
706 break;
707 case EFI_NOT_FOUND:
708 break;
709 default:
710 printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
711 status);
712 status = EFI_NOT_FOUND;
713 break;
714 }
715 } while (status != EFI_NOT_FOUND);
716
717 /*
718 * Now add attributes to allow creation of new vars
719 * and deletion of existing ones...
720 */
Greg Kroah-Hartman97fa5bb2007-11-07 13:56:19 -0800721 error = sysfs_create_bin_file(&vars_subsys.kobj,
722 &var_subsys_attr_new_var);
723 if (error)
724 printk(KERN_ERR "efivars: unable to create new_var sysfs file"
725 " due to error %d\n", error);
726 error = sysfs_create_bin_file(&vars_subsys.kobj,
727 &var_subsys_attr_del_var);
728 if (error)
729 printk(KERN_ERR "efivars: unable to create del_var sysfs file"
730 " due to error %d\n", error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731
732 /* Don't forget the systab entry */
733
734 for (i = 0; (attr = efi_subsys_attrs[i]) && !error; i++) {
735 if (attr->show)
736 error = subsys_create_file(&efi_subsys, attr);
737 }
738
739 if (error)
740 printk(KERN_ERR "efivars: Sysfs attribute export failed with error %d.\n", error);
741 else
742 goto out_free;
743
744 subsystem_unregister(&vars_subsys);
745
746out_firmware_unregister:
747 firmware_unregister(&efi_subsys);
748
749out_free:
750 kfree(variable_name);
751
752 return error;
753}
754
755static void __exit
756efivars_exit(void)
757{
Matt Domsch496a0fc2007-01-26 00:57:18 -0800758 struct efivar_entry *entry, *n;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759
Matt Domsch496a0fc2007-01-26 00:57:18 -0800760 list_for_each_entry_safe(entry, n, &efivar_list, list) {
761 spin_lock(&efivars_lock);
762 list_del(&entry->list);
763 spin_unlock(&efivars_lock);
764 efivar_unregister(entry);
765 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766
767 subsystem_unregister(&vars_subsys);
768 firmware_unregister(&efi_subsys);
769}
770
771module_init(efivars_init);
772module_exit(efivars_exit);
773