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Allow setting of number of raw devices as a module parameter
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1da177e4
LT
1/*
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
c59ede7b 68#include <linux/capability.h>
1da177e4
LT
69#include <linux/types.h>
70#include <linux/errno.h>
71#include <linux/init.h>
1da177e4
LT
72#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>
5a0e3ad6 80#include <linux/slab.h>
1da177e4
LT
81
82#include <asm/uaccess.h>
83
84#define EFIVARS_VERSION "0.08"
85#define EFIVARS_DATE "2004-May-17"
86
87MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
88MODULE_DESCRIPTION("sysfs interface to EFI Variables");
89MODULE_LICENSE("GPL");
90MODULE_VERSION(EFIVARS_VERSION);
91
1da177e4
LT
92/*
93 * The maximum size of VariableName + Data = 1024
94 * Therefore, it's reasonable to save that much
95 * space in each part of the structure,
96 * and we use a page for reading/writing.
97 */
98
99struct efi_variable {
100 efi_char16_t VariableName[1024/sizeof(efi_char16_t)];
101 efi_guid_t VendorGuid;
102 unsigned long DataSize;
103 __u8 Data[1024];
104 efi_status_t Status;
105 __u32 Attributes;
106} __attribute__((packed));
107
108
109struct efivar_entry {
4142ef14 110 struct efivars *efivars;
1da177e4
LT
111 struct efi_variable var;
112 struct list_head list;
113 struct kobject kobj;
114};
115
1da177e4
LT
116struct efivar_attribute {
117 struct attribute attr;
118 ssize_t (*show) (struct efivar_entry *entry, char *buf);
119 ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
120};
121
122
1da177e4
LT
123#define EFIVAR_ATTR(_name, _mode, _show, _store) \
124struct efivar_attribute efivar_attr_##_name = { \
7b595756 125 .attr = {.name = __stringify(_name), .mode = _mode}, \
1da177e4
LT
126 .show = _show, \
127 .store = _store, \
128};
129
1da177e4
LT
130#define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
131#define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
132
133/*
134 * Prototype for sysfs creation function
135 */
136static int
4142ef14
MW
137efivar_create_sysfs_entry(struct efivars *efivars,
138 unsigned long variable_name_size,
139 efi_char16_t *variable_name,
140 efi_guid_t *vendor_guid);
1da177e4
LT
141
142/* Return the number of unicode characters in data */
143static unsigned long
144utf8_strlen(efi_char16_t *data, unsigned long maxlength)
145{
146 unsigned long length = 0;
147
148 while (*data++ != 0 && length < maxlength)
149 length++;
150 return length;
151}
152
153/*
154 * Return the number of bytes is the length of this string
155 * Note: this is NOT the same as the number of unicode characters
156 */
157static inline unsigned long
158utf8_strsize(efi_char16_t *data, unsigned long maxlength)
159{
160 return utf8_strlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
161}
162
163static efi_status_t
4142ef14 164get_var_data(struct efivars *efivars, struct efi_variable *var)
1da177e4
LT
165{
166 efi_status_t status;
167
29422693 168 spin_lock(&efivars->lock);
1da177e4 169 var->DataSize = 1024;
3295814d
MW
170 status = efivars->ops->get_variable(var->VariableName,
171 &var->VendorGuid,
172 &var->Attributes,
173 &var->DataSize,
174 var->Data);
29422693 175 spin_unlock(&efivars->lock);
1da177e4
LT
176 if (status != EFI_SUCCESS) {
177 printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
178 status);
179 }
180 return status;
181}
182
183static ssize_t
184efivar_guid_read(struct efivar_entry *entry, char *buf)
185{
186 struct efi_variable *var = &entry->var;
187 char *str = buf;
188
189 if (!entry || !buf)
190 return 0;
191
192 efi_guid_unparse(&var->VendorGuid, str);
193 str += strlen(str);
194 str += sprintf(str, "\n");
195
196 return str - buf;
197}
198
199static ssize_t
200efivar_attr_read(struct efivar_entry *entry, char *buf)
201{
202 struct efi_variable *var = &entry->var;
203 char *str = buf;
204 efi_status_t status;
205
206 if (!entry || !buf)
207 return -EINVAL;
208
4142ef14 209 status = get_var_data(entry->efivars, var);
1da177e4
LT
210 if (status != EFI_SUCCESS)
211 return -EIO;
212
213 if (var->Attributes & 0x1)
214 str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
215 if (var->Attributes & 0x2)
216 str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
217 if (var->Attributes & 0x4)
218 str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
219 return str - buf;
220}
221
222static ssize_t
223efivar_size_read(struct efivar_entry *entry, char *buf)
224{
225 struct efi_variable *var = &entry->var;
226 char *str = buf;
227 efi_status_t status;
228
229 if (!entry || !buf)
230 return -EINVAL;
231
4142ef14 232 status = get_var_data(entry->efivars, var);
1da177e4
LT
233 if (status != EFI_SUCCESS)
234 return -EIO;
235
236 str += sprintf(str, "0x%lx\n", var->DataSize);
237 return str - buf;
238}
239
240static ssize_t
241efivar_data_read(struct efivar_entry *entry, char *buf)
242{
243 struct efi_variable *var = &entry->var;
244 efi_status_t status;
245
246 if (!entry || !buf)
247 return -EINVAL;
248
4142ef14 249 status = get_var_data(entry->efivars, var);
1da177e4
LT
250 if (status != EFI_SUCCESS)
251 return -EIO;
252
253 memcpy(buf, var->Data, var->DataSize);
254 return var->DataSize;
255}
256/*
257 * We allow each variable to be edited via rewriting the
258 * entire efi variable structure.
259 */
260static ssize_t
261efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
262{
263 struct efi_variable *new_var, *var = &entry->var;
4142ef14 264 struct efivars *efivars = entry->efivars;
1da177e4
LT
265 efi_status_t status = EFI_NOT_FOUND;
266
267 if (count != sizeof(struct efi_variable))
268 return -EINVAL;
269
270 new_var = (struct efi_variable *)buf;
271 /*
272 * If only updating the variable data, then the name
273 * and guid should remain the same
274 */
275 if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
276 efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
277 printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
278 return -EINVAL;
279 }
280
281 if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
282 printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
283 return -EINVAL;
284 }
285
29422693 286 spin_lock(&efivars->lock);
3295814d
MW
287 status = efivars->ops->set_variable(new_var->VariableName,
288 &new_var->VendorGuid,
289 new_var->Attributes,
290 new_var->DataSize,
291 new_var->Data);
1da177e4 292
29422693 293 spin_unlock(&efivars->lock);
1da177e4
LT
294
295 if (status != EFI_SUCCESS) {
296 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
297 status);
298 return -EIO;
299 }
300
301 memcpy(&entry->var, new_var, count);
302 return count;
303}
304
305static ssize_t
306efivar_show_raw(struct efivar_entry *entry, char *buf)
307{
308 struct efi_variable *var = &entry->var;
309 efi_status_t status;
310
311 if (!entry || !buf)
312 return 0;
313
4142ef14 314 status = get_var_data(entry->efivars, var);
1da177e4
LT
315 if (status != EFI_SUCCESS)
316 return -EIO;
317
318 memcpy(buf, var, sizeof(*var));
319 return sizeof(*var);
320}
321
322/*
323 * Generic read/write functions that call the specific functions of
324 * the atttributes...
325 */
326static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
327 char *buf)
328{
329 struct efivar_entry *var = to_efivar_entry(kobj);
330 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
70f2817a 331 ssize_t ret = -EIO;
1da177e4
LT
332
333 if (!capable(CAP_SYS_ADMIN))
334 return -EACCES;
335
336 if (efivar_attr->show) {
337 ret = efivar_attr->show(var, buf);
338 }
339 return ret;
340}
341
342static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
343 const char *buf, size_t count)
344{
345 struct efivar_entry *var = to_efivar_entry(kobj);
346 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
70f2817a 347 ssize_t ret = -EIO;
1da177e4
LT
348
349 if (!capable(CAP_SYS_ADMIN))
350 return -EACCES;
351
352 if (efivar_attr->store)
353 ret = efivar_attr->store(var, buf, count);
354
355 return ret;
356}
357
52cf25d0 358static const struct sysfs_ops efivar_attr_ops = {
1da177e4
LT
359 .show = efivar_attr_show,
360 .store = efivar_attr_store,
361};
362
363static void efivar_release(struct kobject *kobj)
364{
365 struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
1da177e4
LT
366 kfree(var);
367}
368
369static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
370static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
371static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
372static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
373static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
374
375static struct attribute *def_attrs[] = {
376 &efivar_attr_guid.attr,
377 &efivar_attr_size.attr,
378 &efivar_attr_attributes.attr,
379 &efivar_attr_data.attr,
380 &efivar_attr_raw_var.attr,
381 NULL,
382};
383
e89a4116 384static struct kobj_type efivar_ktype = {
1da177e4
LT
385 .release = efivar_release,
386 .sysfs_ops = &efivar_attr_ops,
387 .default_attrs = def_attrs,
388};
389
1da177e4
LT
390static inline void
391efivar_unregister(struct efivar_entry *var)
392{
c10997f6 393 kobject_put(&var->kobj);
1da177e4
LT
394}
395
396
2c3c8bea 397static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
97fa5bb7
GKH
398 struct bin_attribute *bin_attr,
399 char *buf, loff_t pos, size_t count)
1da177e4
LT
400{
401 struct efi_variable *new_var = (struct efi_variable *)buf;
4142ef14 402 struct efivars *efivars = bin_attr->private;
496a0fc8 403 struct efivar_entry *search_efivar, *n;
1da177e4 404 unsigned long strsize1, strsize2;
1da177e4
LT
405 efi_status_t status = EFI_NOT_FOUND;
406 int found = 0;
407
408 if (!capable(CAP_SYS_ADMIN))
409 return -EACCES;
410
29422693 411 spin_lock(&efivars->lock);
1da177e4
LT
412
413 /*
414 * Does this variable already exist?
415 */
29422693 416 list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
1da177e4
LT
417 strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
418 strsize2 = utf8_strsize(new_var->VariableName, 1024);
419 if (strsize1 == strsize2 &&
420 !memcmp(&(search_efivar->var.VariableName),
421 new_var->VariableName, strsize1) &&
422 !efi_guidcmp(search_efivar->var.VendorGuid,
423 new_var->VendorGuid)) {
424 found = 1;
425 break;
426 }
427 }
428 if (found) {
29422693 429 spin_unlock(&efivars->lock);
1da177e4
LT
430 return -EINVAL;
431 }
432
433 /* now *really* create the variable via EFI */
3295814d
MW
434 status = efivars->ops->set_variable(new_var->VariableName,
435 &new_var->VendorGuid,
436 new_var->Attributes,
437 new_var->DataSize,
438 new_var->Data);
1da177e4
LT
439
440 if (status != EFI_SUCCESS) {
441 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
442 status);
29422693 443 spin_unlock(&efivars->lock);
1da177e4
LT
444 return -EIO;
445 }
29422693 446 spin_unlock(&efivars->lock);
1da177e4
LT
447
448 /* Create the entry in sysfs. Locking is not required here */
4142ef14
MW
449 status = efivar_create_sysfs_entry(efivars,
450 utf8_strsize(new_var->VariableName,
451 1024),
452 new_var->VariableName,
453 &new_var->VendorGuid);
1da177e4
LT
454 if (status) {
455 printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
456 }
457 return count;
458}
459
2c3c8bea 460static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
97fa5bb7
GKH
461 struct bin_attribute *bin_attr,
462 char *buf, loff_t pos, size_t count)
1da177e4
LT
463{
464 struct efi_variable *del_var = (struct efi_variable *)buf;
4142ef14 465 struct efivars *efivars = bin_attr->private;
496a0fc8 466 struct efivar_entry *search_efivar, *n;
1da177e4 467 unsigned long strsize1, strsize2;
1da177e4
LT
468 efi_status_t status = EFI_NOT_FOUND;
469 int found = 0;
470
471 if (!capable(CAP_SYS_ADMIN))
472 return -EACCES;
473
29422693 474 spin_lock(&efivars->lock);
1da177e4
LT
475
476 /*
477 * Does this variable already exist?
478 */
29422693 479 list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
1da177e4
LT
480 strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
481 strsize2 = utf8_strsize(del_var->VariableName, 1024);
482 if (strsize1 == strsize2 &&
483 !memcmp(&(search_efivar->var.VariableName),
484 del_var->VariableName, strsize1) &&
485 !efi_guidcmp(search_efivar->var.VendorGuid,
486 del_var->VendorGuid)) {
487 found = 1;
488 break;
489 }
490 }
491 if (!found) {
29422693 492 spin_unlock(&efivars->lock);
1da177e4
LT
493 return -EINVAL;
494 }
495 /* force the Attributes/DataSize to 0 to ensure deletion */
496 del_var->Attributes = 0;
497 del_var->DataSize = 0;
498
3295814d
MW
499 status = efivars->ops->set_variable(del_var->VariableName,
500 &del_var->VendorGuid,
501 del_var->Attributes,
502 del_var->DataSize,
503 del_var->Data);
1da177e4
LT
504
505 if (status != EFI_SUCCESS) {
506 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
507 status);
29422693 508 spin_unlock(&efivars->lock);
1da177e4
LT
509 return -EIO;
510 }
496a0fc8 511 list_del(&search_efivar->list);
1da177e4 512 /* We need to release this lock before unregistering. */
29422693 513 spin_unlock(&efivars->lock);
1da177e4
LT
514 efivar_unregister(search_efivar);
515
516 /* It's dead Jim.... */
517 return count;
518}
519
1da177e4
LT
520/*
521 * Let's not leave out systab information that snuck into
522 * the efivars driver
523 */
334c6307
GKH
524static ssize_t systab_show(struct kobject *kobj,
525 struct kobj_attribute *attr, char *buf)
1da177e4
LT
526{
527 char *str = buf;
528
334c6307 529 if (!kobj || !buf)
1da177e4
LT
530 return -EINVAL;
531
b2c99e3c
BH
532 if (efi.mps != EFI_INVALID_TABLE_ADDR)
533 str += sprintf(str, "MPS=0x%lx\n", efi.mps);
534 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
535 str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
536 if (efi.acpi != EFI_INVALID_TABLE_ADDR)
537 str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
538 if (efi.smbios != EFI_INVALID_TABLE_ADDR)
539 str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
540 if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
541 str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
542 if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
543 str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
544 if (efi.uga != EFI_INVALID_TABLE_ADDR)
545 str += sprintf(str, "UGA=0x%lx\n", efi.uga);
1da177e4
LT
546
547 return str - buf;
548}
549
334c6307
GKH
550static struct kobj_attribute efi_attr_systab =
551 __ATTR(systab, 0400, systab_show, NULL);
1da177e4 552
334c6307
GKH
553static struct attribute *efi_subsys_attrs[] = {
554 &efi_attr_systab.attr,
1da177e4
LT
555 NULL, /* maybe more in the future? */
556};
557
334c6307
GKH
558static struct attribute_group efi_subsys_attr_group = {
559 .attrs = efi_subsys_attrs,
560};
561
bc87d2fe 562static struct kobject *efi_kobj;
1da177e4
LT
563
564/*
565 * efivar_create_sysfs_entry()
566 * Requires:
567 * variable_name_size = number of bytes required to hold
568 * variable_name (not counting the NULL
569 * character at the end.
29422693 570 * efivars->lock is not held on entry or exit.
1da177e4
LT
571 * Returns 1 on failure, 0 on success
572 */
573static int
4142ef14
MW
574efivar_create_sysfs_entry(struct efivars *efivars,
575 unsigned long variable_name_size,
576 efi_char16_t *variable_name,
577 efi_guid_t *vendor_guid)
1da177e4
LT
578{
579 int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38;
580 char *short_name;
581 struct efivar_entry *new_efivar;
582
9c215384
DS
583 short_name = kzalloc(short_name_size + 1, GFP_KERNEL);
584 new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
1da177e4
LT
585
586 if (!short_name || !new_efivar) {
0933ad9c
JJ
587 kfree(short_name);
588 kfree(new_efivar);
1da177e4
LT
589 return 1;
590 }
1da177e4 591
4142ef14 592 new_efivar->efivars = efivars;
1da177e4
LT
593 memcpy(new_efivar->var.VariableName, variable_name,
594 variable_name_size);
595 memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));
596
597 /* Convert Unicode to normal chars (assume top bits are 0),
598 ala UTF-8 */
599 for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
600 short_name[i] = variable_name[i] & 0xFF;
601 }
602 /* This is ugly, but necessary to separate one vendor's
603 private variables from another's. */
604
605 *(short_name + strlen(short_name)) = '-';
606 efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
607
29422693 608 new_efivar->kobj.kset = efivars->kset;
d6d292c4
GKH
609 i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL,
610 "%s", short_name);
69b2186c
JG
611 if (i) {
612 kfree(short_name);
613 kfree(new_efivar);
614 return 1;
615 }
1da177e4 616
d6d292c4 617 kobject_uevent(&new_efivar->kobj, KOBJ_ADD);
0933ad9c
JJ
618 kfree(short_name);
619 short_name = NULL;
1da177e4 620
29422693
MW
621 spin_lock(&efivars->lock);
622 list_add(&new_efivar->list, &efivars->list);
623 spin_unlock(&efivars->lock);
1da177e4
LT
624
625 return 0;
626}
d502fbb0
MW
627
628static int
629create_efivars_bin_attributes(struct efivars *efivars)
630{
631 struct bin_attribute *attr;
632 int error;
633
634 /* new_var */
635 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
636 if (!attr)
637 return -ENOMEM;
638
639 attr->attr.name = "new_var";
640 attr->attr.mode = 0200;
641 attr->write = efivar_create;
642 attr->private = efivars;
643 efivars->new_var = attr;
644
645 /* del_var */
646 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
647 if (!attr) {
648 error = -ENOMEM;
649 goto out_free;
650 }
651 attr->attr.name = "del_var";
652 attr->attr.mode = 0200;
653 attr->write = efivar_delete;
654 attr->private = efivars;
655 efivars->del_var = attr;
656
657 sysfs_bin_attr_init(efivars->new_var);
658 sysfs_bin_attr_init(efivars->del_var);
659
660 /* Register */
661 error = sysfs_create_bin_file(&efivars->kset->kobj,
662 efivars->new_var);
663 if (error) {
664 printk(KERN_ERR "efivars: unable to create new_var sysfs file"
665 " due to error %d\n", error);
666 goto out_free;
667 }
668 error = sysfs_create_bin_file(&efivars->kset->kobj,
669 efivars->del_var);
670 if (error) {
671 printk(KERN_ERR "efivars: unable to create del_var sysfs file"
672 " due to error %d\n", error);
673 sysfs_remove_bin_file(&efivars->kset->kobj,
674 efivars->new_var);
675 goto out_free;
676 }
677
678 return 0;
679out_free:
051d51bc
DC
680 kfree(efivars->del_var);
681 efivars->del_var = NULL;
d502fbb0
MW
682 kfree(efivars->new_var);
683 efivars->new_var = NULL;
684 return error;
685}
686
4fc756bd 687void unregister_efivars(struct efivars *efivars)
76b53f7c
MW
688{
689 struct efivar_entry *entry, *n;
4142ef14 690
76b53f7c
MW
691 list_for_each_entry_safe(entry, n, &efivars->list, list) {
692 spin_lock(&efivars->lock);
693 list_del(&entry->list);
694 spin_unlock(&efivars->lock);
695 efivar_unregister(entry);
696 }
697 if (efivars->new_var)
698 sysfs_remove_bin_file(&efivars->kset->kobj, efivars->new_var);
699 if (efivars->del_var)
700 sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var);
701 kfree(efivars->new_var);
702 kfree(efivars->del_var);
703 kset_unregister(efivars->kset);
704}
4fc756bd 705EXPORT_SYMBOL_GPL(unregister_efivars);
1da177e4 706
4fc756bd
MW
707int register_efivars(struct efivars *efivars,
708 const struct efivar_operations *ops,
709 struct kobject *parent_kobj)
1da177e4
LT
710{
711 efi_status_t status = EFI_NOT_FOUND;
712 efi_guid_t vendor_guid;
713 efi_char16_t *variable_name;
1da177e4 714 unsigned long variable_name_size = 1024;
334c6307 715 int error = 0;
1da177e4 716
9c215384 717 variable_name = kzalloc(variable_name_size, GFP_KERNEL);
1da177e4
LT
718 if (!variable_name) {
719 printk(KERN_ERR "efivars: Memory allocation failed.\n");
720 return -ENOMEM;
721 }
722
29422693
MW
723 spin_lock_init(&efivars->lock);
724 INIT_LIST_HEAD(&efivars->list);
3295814d 725 efivars->ops = ops;
29422693 726
76b53f7c 727 efivars->kset = kset_create_and_add("vars", NULL, parent_kobj);
29422693 728 if (!efivars->kset) {
66ac831e
GKH
729 printk(KERN_ERR "efivars: Subsystem registration failed.\n");
730 error = -ENOMEM;
76b53f7c 731 goto out;
1da177e4
LT
732 }
733
734 /*
735 * Per EFI spec, the maximum storage allocated for both
736 * the variable name and variable data is 1024 bytes.
737 */
738
739 do {
740 variable_name_size = 1024;
741
3295814d 742 status = ops->get_next_variable(&variable_name_size,
1da177e4
LT
743 variable_name,
744 &vendor_guid);
745 switch (status) {
746 case EFI_SUCCESS:
4142ef14
MW
747 efivar_create_sysfs_entry(efivars,
748 variable_name_size,
749 variable_name,
750 &vendor_guid);
1da177e4
LT
751 break;
752 case EFI_NOT_FOUND:
753 break;
754 default:
755 printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
756 status);
757 status = EFI_NOT_FOUND;
758 break;
759 }
760 } while (status != EFI_NOT_FOUND);
761
d502fbb0 762 error = create_efivars_bin_attributes(efivars);
1da177e4 763 if (error)
76b53f7c 764 unregister_efivars(efivars);
1da177e4 765
76b53f7c
MW
766out:
767 kfree(variable_name);
1da177e4 768
76b53f7c
MW
769 return error;
770}
4fc756bd 771EXPORT_SYMBOL_GPL(register_efivars);
1da177e4 772
76b53f7c 773static struct efivars __efivars;
3295814d 774static struct efivar_operations ops;
76b53f7c
MW
775
776/*
777 * For now we register the efi subsystem with the firmware subsystem
778 * and the vars subsystem with the efi subsystem. In the future, it
779 * might make sense to split off the efi subsystem into its own
780 * driver, but for now only efivars will register with it, so just
781 * include it here.
782 */
783
784static int __init
785efivars_init(void)
786{
787 int error = 0;
788
789 printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
790 EFIVARS_DATE);
791
792 if (!efi_enabled)
4fc756bd 793 return 0;
76b53f7c
MW
794
795 /* For now we'll register the efi directory at /sys/firmware/efi */
796 efi_kobj = kobject_create_and_add("efi", firmware_kobj);
797 if (!efi_kobj) {
798 printk(KERN_ERR "efivars: Firmware registration failed.\n");
799 return -ENOMEM;
800 }
801
3295814d
MW
802 ops.get_variable = efi.get_variable;
803 ops.set_variable = efi.set_variable;
804 ops.get_next_variable = efi.get_next_variable;
805 error = register_efivars(&__efivars, &ops, efi_kobj);
3116aabc
DC
806 if (error)
807 goto err_put;
76b53f7c
MW
808
809 /* Don't forget the systab entry */
810 error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
811 if (error) {
812 printk(KERN_ERR
813 "efivars: Sysfs attribute export failed with error %d.\n",
814 error);
3116aabc 815 goto err_unregister;
76b53f7c 816 }
1da177e4 817
3116aabc
DC
818 return 0;
819
820err_unregister:
821 unregister_efivars(&__efivars);
822err_put:
823 kobject_put(efi_kobj);
1da177e4
LT
824 return error;
825}
826
827static void __exit
828efivars_exit(void)
829{
76b53f7c 830 unregister_efivars(&__efivars);
c10997f6 831 kobject_put(efi_kobj);
1da177e4
LT
832}
833
834module_init(efivars_init);
835module_exit(efivars_exit);
836