blob: 2a62ec6390e0bc2b8ebfa8af5dfba77b84294e1d [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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090080#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126struct efivar_attribute {
127 struct attribute attr;
128 ssize_t (*show) (struct efivar_entry *entry, char *buf);
129 ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
130};
131
132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133#define EFIVAR_ATTR(_name, _mode, _show, _store) \
134struct efivar_attribute efivar_attr_##_name = { \
Tejun Heo7b595752007-06-14 03:45:17 +0900135 .attr = {.name = __stringify(_name), .mode = _mode}, \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 .show = _show, \
137 .store = _store, \
138};
139
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140#define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
141#define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
142
143/*
144 * Prototype for sysfs creation function
145 */
146static int
147efivar_create_sysfs_entry(unsigned long variable_name_size,
148 efi_char16_t *variable_name,
149 efi_guid_t *vendor_guid);
150
151/* Return the number of unicode characters in data */
152static unsigned long
153utf8_strlen(efi_char16_t *data, unsigned long maxlength)
154{
155 unsigned long length = 0;
156
157 while (*data++ != 0 && length < maxlength)
158 length++;
159 return length;
160}
161
162/*
163 * Return the number of bytes is the length of this string
164 * Note: this is NOT the same as the number of unicode characters
165 */
166static inline unsigned long
167utf8_strsize(efi_char16_t *data, unsigned long maxlength)
168{
169 return utf8_strlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
170}
171
172static efi_status_t
173get_var_data(struct efi_variable *var)
174{
175 efi_status_t status;
176
177 spin_lock(&efivars_lock);
178 var->DataSize = 1024;
179 status = efi.get_variable(var->VariableName,
180 &var->VendorGuid,
181 &var->Attributes,
182 &var->DataSize,
183 var->Data);
184 spin_unlock(&efivars_lock);
185 if (status != EFI_SUCCESS) {
186 printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
187 status);
188 }
189 return status;
190}
191
192static ssize_t
193efivar_guid_read(struct efivar_entry *entry, char *buf)
194{
195 struct efi_variable *var = &entry->var;
196 char *str = buf;
197
198 if (!entry || !buf)
199 return 0;
200
201 efi_guid_unparse(&var->VendorGuid, str);
202 str += strlen(str);
203 str += sprintf(str, "\n");
204
205 return str - buf;
206}
207
208static ssize_t
209efivar_attr_read(struct efivar_entry *entry, char *buf)
210{
211 struct efi_variable *var = &entry->var;
212 char *str = buf;
213 efi_status_t status;
214
215 if (!entry || !buf)
216 return -EINVAL;
217
218 status = get_var_data(var);
219 if (status != EFI_SUCCESS)
220 return -EIO;
221
222 if (var->Attributes & 0x1)
223 str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
224 if (var->Attributes & 0x2)
225 str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
226 if (var->Attributes & 0x4)
227 str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
228 return str - buf;
229}
230
231static ssize_t
232efivar_size_read(struct efivar_entry *entry, char *buf)
233{
234 struct efi_variable *var = &entry->var;
235 char *str = buf;
236 efi_status_t status;
237
238 if (!entry || !buf)
239 return -EINVAL;
240
241 status = get_var_data(var);
242 if (status != EFI_SUCCESS)
243 return -EIO;
244
245 str += sprintf(str, "0x%lx\n", var->DataSize);
246 return str - buf;
247}
248
249static ssize_t
250efivar_data_read(struct efivar_entry *entry, char *buf)
251{
252 struct efi_variable *var = &entry->var;
253 efi_status_t status;
254
255 if (!entry || !buf)
256 return -EINVAL;
257
258 status = get_var_data(var);
259 if (status != EFI_SUCCESS)
260 return -EIO;
261
262 memcpy(buf, var->Data, var->DataSize);
263 return var->DataSize;
264}
265/*
266 * We allow each variable to be edited via rewriting the
267 * entire efi variable structure.
268 */
269static ssize_t
270efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
271{
272 struct efi_variable *new_var, *var = &entry->var;
273 efi_status_t status = EFI_NOT_FOUND;
274
275 if (count != sizeof(struct efi_variable))
276 return -EINVAL;
277
278 new_var = (struct efi_variable *)buf;
279 /*
280 * If only updating the variable data, then the name
281 * and guid should remain the same
282 */
283 if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
284 efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
285 printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
286 return -EINVAL;
287 }
288
289 if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
290 printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
291 return -EINVAL;
292 }
293
294 spin_lock(&efivars_lock);
295 status = efi.set_variable(new_var->VariableName,
296 &new_var->VendorGuid,
297 new_var->Attributes,
298 new_var->DataSize,
299 new_var->Data);
300
301 spin_unlock(&efivars_lock);
302
303 if (status != EFI_SUCCESS) {
304 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
305 status);
306 return -EIO;
307 }
308
309 memcpy(&entry->var, new_var, count);
310 return count;
311}
312
313static ssize_t
314efivar_show_raw(struct efivar_entry *entry, char *buf)
315{
316 struct efi_variable *var = &entry->var;
317 efi_status_t status;
318
319 if (!entry || !buf)
320 return 0;
321
322 status = get_var_data(var);
323 if (status != EFI_SUCCESS)
324 return -EIO;
325
326 memcpy(buf, var, sizeof(*var));
327 return sizeof(*var);
328}
329
330/*
331 * Generic read/write functions that call the specific functions of
332 * the atttributes...
333 */
334static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
335 char *buf)
336{
337 struct efivar_entry *var = to_efivar_entry(kobj);
338 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
Dmitry Torokhov70f28172005-04-29 01:27:34 -0500339 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340
341 if (!capable(CAP_SYS_ADMIN))
342 return -EACCES;
343
344 if (efivar_attr->show) {
345 ret = efivar_attr->show(var, buf);
346 }
347 return ret;
348}
349
350static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
351 const char *buf, size_t count)
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->store)
361 ret = efivar_attr->store(var, buf, count);
362
363 return ret;
364}
365
Emese Revfy52cf25d2010-01-19 02:58:23 +0100366static const struct sysfs_ops efivar_attr_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 .show = efivar_attr_show,
368 .store = efivar_attr_store,
369};
370
371static void efivar_release(struct kobject *kobj)
372{
373 struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 kfree(var);
375}
376
377static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
378static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
379static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
380static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
381static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
382
383static struct attribute *def_attrs[] = {
384 &efivar_attr_guid.attr,
385 &efivar_attr_size.attr,
386 &efivar_attr_attributes.attr,
387 &efivar_attr_data.attr,
388 &efivar_attr_raw_var.attr,
389 NULL,
390};
391
Greg Kroah-Hartmane89a4112007-10-11 10:47:49 -0600392static struct kobj_type efivar_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 .release = efivar_release,
394 .sysfs_ops = &efivar_attr_ops,
395 .default_attrs = def_attrs,
396};
397
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398static inline void
399efivar_unregister(struct efivar_entry *var)
400{
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800401 kobject_put(&var->kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402}
403
404
Chris Wright2c3c8be2010-05-12 18:28:57 -0700405static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
Greg Kroah-Hartman97fa5bb2007-11-07 13:56:19 -0800406 struct bin_attribute *bin_attr,
407 char *buf, loff_t pos, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408{
409 struct efi_variable *new_var = (struct efi_variable *)buf;
Matt Domsch496a0fc2007-01-26 00:57:18 -0800410 struct efivar_entry *search_efivar, *n;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 unsigned long strsize1, strsize2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 efi_status_t status = EFI_NOT_FOUND;
413 int found = 0;
414
415 if (!capable(CAP_SYS_ADMIN))
416 return -EACCES;
417
418 spin_lock(&efivars_lock);
419
420 /*
421 * Does this variable already exist?
422 */
Matt Domsch496a0fc2007-01-26 00:57:18 -0800423 list_for_each_entry_safe(search_efivar, n, &efivar_list, list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424 strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
425 strsize2 = utf8_strsize(new_var->VariableName, 1024);
426 if (strsize1 == strsize2 &&
427 !memcmp(&(search_efivar->var.VariableName),
428 new_var->VariableName, strsize1) &&
429 !efi_guidcmp(search_efivar->var.VendorGuid,
430 new_var->VendorGuid)) {
431 found = 1;
432 break;
433 }
434 }
435 if (found) {
436 spin_unlock(&efivars_lock);
437 return -EINVAL;
438 }
439
440 /* now *really* create the variable via EFI */
441 status = efi.set_variable(new_var->VariableName,
442 &new_var->VendorGuid,
443 new_var->Attributes,
444 new_var->DataSize,
445 new_var->Data);
446
447 if (status != EFI_SUCCESS) {
448 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
449 status);
450 spin_unlock(&efivars_lock);
451 return -EIO;
452 }
453 spin_unlock(&efivars_lock);
454
455 /* Create the entry in sysfs. Locking is not required here */
456 status = efivar_create_sysfs_entry(utf8_strsize(new_var->VariableName,
457 1024), new_var->VariableName, &new_var->VendorGuid);
458 if (status) {
459 printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
460 }
461 return count;
462}
463
Chris Wright2c3c8be2010-05-12 18:28:57 -0700464static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
Greg Kroah-Hartman97fa5bb2007-11-07 13:56:19 -0800465 struct bin_attribute *bin_attr,
466 char *buf, loff_t pos, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467{
468 struct efi_variable *del_var = (struct efi_variable *)buf;
Matt Domsch496a0fc2007-01-26 00:57:18 -0800469 struct efivar_entry *search_efivar, *n;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 unsigned long strsize1, strsize2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 efi_status_t status = EFI_NOT_FOUND;
472 int found = 0;
473
474 if (!capable(CAP_SYS_ADMIN))
475 return -EACCES;
476
477 spin_lock(&efivars_lock);
478
479 /*
480 * Does this variable already exist?
481 */
Matt Domsch496a0fc2007-01-26 00:57:18 -0800482 list_for_each_entry_safe(search_efivar, n, &efivar_list, list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
484 strsize2 = utf8_strsize(del_var->VariableName, 1024);
485 if (strsize1 == strsize2 &&
486 !memcmp(&(search_efivar->var.VariableName),
487 del_var->VariableName, strsize1) &&
488 !efi_guidcmp(search_efivar->var.VendorGuid,
489 del_var->VendorGuid)) {
490 found = 1;
491 break;
492 }
493 }
494 if (!found) {
495 spin_unlock(&efivars_lock);
496 return -EINVAL;
497 }
498 /* force the Attributes/DataSize to 0 to ensure deletion */
499 del_var->Attributes = 0;
500 del_var->DataSize = 0;
501
502 status = efi.set_variable(del_var->VariableName,
503 &del_var->VendorGuid,
504 del_var->Attributes,
505 del_var->DataSize,
506 del_var->Data);
507
508 if (status != EFI_SUCCESS) {
509 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
510 status);
511 spin_unlock(&efivars_lock);
512 return -EIO;
513 }
Matt Domsch496a0fc2007-01-26 00:57:18 -0800514 list_del(&search_efivar->list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 /* We need to release this lock before unregistering. */
516 spin_unlock(&efivars_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 efivar_unregister(search_efivar);
518
519 /* It's dead Jim.... */
520 return count;
521}
522
Greg Kroah-Hartman97fa5bb2007-11-07 13:56:19 -0800523static struct bin_attribute var_subsys_attr_new_var = {
524 .attr = {.name = "new_var", .mode = 0200},
525 .write = efivar_create,
526};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527
Greg Kroah-Hartman97fa5bb2007-11-07 13:56:19 -0800528static struct bin_attribute var_subsys_attr_del_var = {
529 .attr = {.name = "del_var", .mode = 0200},
530 .write = efivar_delete,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531};
532
533/*
534 * Let's not leave out systab information that snuck into
535 * the efivars driver
536 */
Greg Kroah-Hartman334c6302007-11-02 13:20:40 -0700537static ssize_t systab_show(struct kobject *kobj,
538 struct kobj_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539{
540 char *str = buf;
541
Greg Kroah-Hartman334c6302007-11-02 13:20:40 -0700542 if (!kobj || !buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 return -EINVAL;
544
Bjorn Helgaasb2c99e32006-03-26 01:37:08 -0800545 if (efi.mps != EFI_INVALID_TABLE_ADDR)
546 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
547 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
548 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
549 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
550 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
551 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
552 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
553 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
554 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
555 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
556 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
557 if (efi.uga != EFI_INVALID_TABLE_ADDR)
558 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559
560 return str - buf;
561}
562
Greg Kroah-Hartman334c6302007-11-02 13:20:40 -0700563static struct kobj_attribute efi_attr_systab =
564 __ATTR(systab, 0400, systab_show, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565
Greg Kroah-Hartman334c6302007-11-02 13:20:40 -0700566static struct attribute *efi_subsys_attrs[] = {
567 &efi_attr_systab.attr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 NULL, /* maybe more in the future? */
569};
570
Greg Kroah-Hartman334c6302007-11-02 13:20:40 -0700571static struct attribute_group efi_subsys_attr_group = {
572 .attrs = efi_subsys_attrs,
573};
574
575
Greg Kroah-Hartman66ac8312007-11-02 13:20:40 -0700576static struct kset *vars_kset;
Greg Kroah-Hartmanbc87d2f2007-11-07 13:56:19 -0800577static struct kobject *efi_kobj;
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
Greg Kroah-Hartman66ac8312007-11-02 13:20:40 -0700621 new_efivar->kobj.kset = vars_kset;
Greg Kroah-Hartmand6d292c2007-12-17 15:54:39 -0400622 i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL,
623 "%s", short_name);
Jeff Garzik69b21862006-10-11 01:22:23 -0700624 if (i) {
625 kfree(short_name);
626 kfree(new_efivar);
627 return 1;
628 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629
Greg Kroah-Hartmand6d292c2007-12-17 15:54:39 -0400630 kobject_uevent(&new_efivar->kobj, KOBJ_ADD);
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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 unsigned long variable_name_size = 1024;
Greg Kroah-Hartman334c6302007-11-02 13:20:40 -0700655 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656
657 if (!efi_enabled)
658 return -ENODEV;
659
Deepak Saxena9c215382005-11-07 01:01:24 -0800660 variable_name = kzalloc(variable_name_size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 if (!variable_name) {
662 printk(KERN_ERR "efivars: Memory allocation failed.\n");
663 return -ENOMEM;
664 }
665
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666 printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
667 EFIVARS_DATE);
668
Greg Kroah-Hartmanbc87d2f2007-11-07 13:56:19 -0800669 /* For now we'll register the efi directory at /sys/firmware/efi */
670 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
671 if (!efi_kobj) {
Greg Kroah-Hartman89a07e32007-11-02 13:20:40 -0700672 printk(KERN_ERR "efivars: Firmware registration failed.\n");
673 error = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 goto out_free;
675 }
676
Greg Kroah-Hartmanbc87d2f2007-11-07 13:56:19 -0800677 vars_kset = kset_create_and_add("vars", NULL, efi_kobj);
Greg Kroah-Hartman66ac8312007-11-02 13:20:40 -0700678 if (!vars_kset) {
679 printk(KERN_ERR "efivars: Subsystem registration failed.\n");
680 error = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 goto out_firmware_unregister;
682 }
683
684 /*
685 * Per EFI spec, the maximum storage allocated for both
686 * the variable name and variable data is 1024 bytes.
687 */
688
689 do {
690 variable_name_size = 1024;
691
692 status = efi.get_next_variable(&variable_name_size,
693 variable_name,
694 &vendor_guid);
695 switch (status) {
696 case EFI_SUCCESS:
697 efivar_create_sysfs_entry(variable_name_size,
698 variable_name,
699 &vendor_guid);
700 break;
701 case EFI_NOT_FOUND:
702 break;
703 default:
704 printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
705 status);
706 status = EFI_NOT_FOUND;
707 break;
708 }
709 } while (status != EFI_NOT_FOUND);
710
711 /*
712 * Now add attributes to allow creation of new vars
713 * and deletion of existing ones...
714 */
Greg Kroah-Hartman66ac8312007-11-02 13:20:40 -0700715 error = sysfs_create_bin_file(&vars_kset->kobj,
Greg Kroah-Hartman97fa5bb2007-11-07 13:56:19 -0800716 &var_subsys_attr_new_var);
717 if (error)
718 printk(KERN_ERR "efivars: unable to create new_var sysfs file"
719 " due to error %d\n", error);
Greg Kroah-Hartman66ac8312007-11-02 13:20:40 -0700720 error = sysfs_create_bin_file(&vars_kset->kobj,
Greg Kroah-Hartman97fa5bb2007-11-07 13:56:19 -0800721 &var_subsys_attr_del_var);
722 if (error)
723 printk(KERN_ERR "efivars: unable to create del_var sysfs file"
724 " due to error %d\n", error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725
726 /* Don't forget the systab entry */
Greg Kroah-Hartmanbc87d2f2007-11-07 13:56:19 -0800727 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 if (error)
729 printk(KERN_ERR "efivars: Sysfs attribute export failed with error %d.\n", error);
730 else
731 goto out_free;
732
Greg Kroah-Hartman66ac8312007-11-02 13:20:40 -0700733 kset_unregister(vars_kset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734
735out_firmware_unregister:
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800736 kobject_put(efi_kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737
738out_free:
739 kfree(variable_name);
740
741 return error;
742}
743
744static void __exit
745efivars_exit(void)
746{
Matt Domsch496a0fc2007-01-26 00:57:18 -0800747 struct efivar_entry *entry, *n;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748
Matt Domsch496a0fc2007-01-26 00:57:18 -0800749 list_for_each_entry_safe(entry, n, &efivar_list, list) {
750 spin_lock(&efivars_lock);
751 list_del(&entry->list);
752 spin_unlock(&efivars_lock);
753 efivar_unregister(entry);
754 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755
Greg Kroah-Hartman66ac8312007-11-02 13:20:40 -0700756 kset_unregister(vars_kset);
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800757 kobject_put(efi_kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758}
759
760module_init(efivars_init);
761module_exit(efivars_exit);
762