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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 | |
68 | #include <linux/capability.h> |
69 | #include <linux/types.h> |
70 | #include <linux/errno.h> |
71 | #include <linux/init.h> |
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> |
80 | #include <linux/slab.h> |
81 | |
82 | #include <asm/uaccess.h> |
83 | |
84 | #define EFIVARS_VERSION "0.08" |
85 | #define EFIVARS_DATE "2004-May-17" |
86 | |
87 | MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>"); |
88 | MODULE_DESCRIPTION("sysfs interface to EFI Variables"); |
89 | MODULE_LICENSE("GPL"); |
90 | MODULE_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 | */ |
100 | static DEFINE_SPINLOCK(efivars_lock); |
101 | static 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 | |
110 | struct 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 | |
120 | struct efivar_entry { |
121 | struct efi_variable var; |
122 | struct list_head list; |
123 | struct kobject kobj; |
124 | }; |
125 | |
126 | struct 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 | |
133 | #define EFIVAR_ATTR(_name, _mode, _show, _store) \ |
134 | struct efivar_attribute efivar_attr_##_name = { \ |
135 | .attr = {.name = __stringify(_name), .mode = _mode}, \ |
136 | .show = _show, \ |
137 | .store = _store, \ |
138 | }; |
139 | |
140 | #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 | */ |
146 | static int |
147 | efivar_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 */ |
152 | static unsigned long |
153 | utf8_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 | */ |
166 | static inline unsigned long |
167 | utf8_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 | |
172 | static efi_status_t |
173 | get_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 | |
192 | static ssize_t |
193 | efivar_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 | |
208 | static ssize_t |
209 | efivar_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 | |
231 | static ssize_t |
232 | efivar_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 | |
249 | static ssize_t |
250 | efivar_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 | */ |
269 | static ssize_t |
270 | efivar_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 | |
313 | static ssize_t |
314 | efivar_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 | */ |
334 | static 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); |
339 | ssize_t ret = -EIO; |
340 | |
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 | |
350 | static 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); |
355 | ssize_t ret = -EIO; |
356 | |
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 | |
366 | static const struct sysfs_ops efivar_attr_ops = { |
367 | .show = efivar_attr_show, |
368 | .store = efivar_attr_store, |
369 | }; |
370 | |
371 | static void efivar_release(struct kobject *kobj) |
372 | { |
373 | struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj); |
374 | kfree(var); |
375 | } |
376 | |
377 | static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL); |
378 | static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL); |
379 | static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL); |
380 | static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL); |
381 | static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw); |
382 | |
383 | static 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 | |
392 | static struct kobj_type efivar_ktype = { |
393 | .release = efivar_release, |
394 | .sysfs_ops = &efivar_attr_ops, |
395 | .default_attrs = def_attrs, |
396 | }; |
397 | |
398 | static inline void |
399 | efivar_unregister(struct efivar_entry *var) |
400 | { |
401 | kobject_put(&var->kobj); |
402 | } |
403 | |
404 | |
405 | static ssize_t efivar_create(struct file *filp, struct kobject *kobj, |
406 | struct bin_attribute *bin_attr, |
407 | char *buf, loff_t pos, size_t count) |
408 | { |
409 | struct efi_variable *new_var = (struct efi_variable *)buf; |
410 | struct efivar_entry *search_efivar, *n; |
411 | unsigned long strsize1, strsize2; |
412 | 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 | */ |
423 | list_for_each_entry_safe(search_efivar, n, &efivar_list, list) { |
424 | 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 | |
464 | static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, |
465 | struct bin_attribute *bin_attr, |
466 | char *buf, loff_t pos, size_t count) |
467 | { |
468 | struct efi_variable *del_var = (struct efi_variable *)buf; |
469 | struct efivar_entry *search_efivar, *n; |
470 | unsigned long strsize1, strsize2; |
471 | 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 | */ |
482 | list_for_each_entry_safe(search_efivar, n, &efivar_list, list) { |
483 | 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 | } |
514 | list_del(&search_efivar->list); |
515 | /* We need to release this lock before unregistering. */ |
516 | spin_unlock(&efivars_lock); |
517 | efivar_unregister(search_efivar); |
518 | |
519 | /* It's dead Jim.... */ |
520 | return count; |
521 | } |
522 | |
523 | static struct bin_attribute var_subsys_attr_new_var = { |
524 | .attr = {.name = "new_var", .mode = 0200}, |
525 | .write = efivar_create, |
526 | }; |
527 | |
528 | static struct bin_attribute var_subsys_attr_del_var = { |
529 | .attr = {.name = "del_var", .mode = 0200}, |
530 | .write = efivar_delete, |
531 | }; |
532 | |
533 | /* |
534 | * Let's not leave out systab information that snuck into |
535 | * the efivars driver |
536 | */ |
537 | static ssize_t systab_show(struct kobject *kobj, |
538 | struct kobj_attribute *attr, char *buf) |
539 | { |
540 | char *str = buf; |
541 | |
542 | if (!kobj || !buf) |
543 | return -EINVAL; |
544 | |
545 | 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); |
559 | |
560 | return str - buf; |
561 | } |
562 | |
563 | static struct kobj_attribute efi_attr_systab = |
564 | __ATTR(systab, 0400, systab_show, NULL); |
565 | |
566 | static struct attribute *efi_subsys_attrs[] = { |
567 | &efi_attr_systab.attr, |
568 | NULL, /* maybe more in the future? */ |
569 | }; |
570 | |
571 | static struct attribute_group efi_subsys_attr_group = { |
572 | .attrs = efi_subsys_attrs, |
573 | }; |
574 | |
575 | |
576 | static struct kset *vars_kset; |
577 | static struct kobject *efi_kobj; |
578 | |
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 | */ |
588 | static int |
589 | efivar_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 | |
597 | short_name = kzalloc(short_name_size + 1, GFP_KERNEL); |
598 | new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL); |
599 | |
600 | if (!short_name || !new_efivar) { |
601 | kfree(short_name); |
602 | kfree(new_efivar); |
603 | return 1; |
604 | } |
605 | |
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 | new_efivar->kobj.kset = vars_kset; |
622 | i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL, |
623 | "%s", short_name); |
624 | if (i) { |
625 | kfree(short_name); |
626 | kfree(new_efivar); |
627 | return 1; |
628 | } |
629 | |
630 | kobject_uevent(&new_efivar->kobj, KOBJ_ADD); |
631 | kfree(short_name); |
632 | short_name = NULL; |
633 | |
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 | |
648 | static int __init |
649 | efivars_init(void) |
650 | { |
651 | efi_status_t status = EFI_NOT_FOUND; |
652 | efi_guid_t vendor_guid; |
653 | efi_char16_t *variable_name; |
654 | unsigned long variable_name_size = 1024; |
655 | int error = 0; |
656 | |
657 | if (!efi_enabled) |
658 | return -ENODEV; |
659 | |
660 | variable_name = kzalloc(variable_name_size, GFP_KERNEL); |
661 | if (!variable_name) { |
662 | printk(KERN_ERR "efivars: Memory allocation failed.\n"); |
663 | return -ENOMEM; |
664 | } |
665 | |
666 | printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION, |
667 | EFIVARS_DATE); |
668 | |
669 | /* 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) { |
672 | printk(KERN_ERR "efivars: Firmware registration failed.\n"); |
673 | error = -ENOMEM; |
674 | goto out_free; |
675 | } |
676 | |
677 | vars_kset = kset_create_and_add("vars", NULL, efi_kobj); |
678 | if (!vars_kset) { |
679 | printk(KERN_ERR "efivars: Subsystem registration failed.\n"); |
680 | error = -ENOMEM; |
681 | 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 | */ |
715 | error = sysfs_create_bin_file(&vars_kset->kobj, |
716 | &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); |
720 | error = sysfs_create_bin_file(&vars_kset->kobj, |
721 | &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); |
725 | |
726 | /* Don't forget the systab entry */ |
727 | error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group); |
728 | if (error) |
729 | printk(KERN_ERR "efivars: Sysfs attribute export failed with error %d.\n", error); |
730 | else |
731 | goto out_free; |
732 | |
733 | kset_unregister(vars_kset); |
734 | |
735 | out_firmware_unregister: |
736 | kobject_put(efi_kobj); |
737 | |
738 | out_free: |
739 | kfree(variable_name); |
740 | |
741 | return error; |
742 | } |
743 | |
744 | static void __exit |
745 | efivars_exit(void) |
746 | { |
747 | struct efivar_entry *entry, *n; |
748 | |
749 | 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 | } |
755 | |
756 | kset_unregister(vars_kset); |
757 | kobject_put(efi_kobj); |
758 | } |
759 | |
760 | module_init(efivars_init); |
761 | module_exit(efivars_exit); |
762 | |
763 |
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