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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 | ||
68 | #include <linux/config.h> | |
69 | #include <linux/types.h> | |
70 | #include <linux/errno.h> | |
71 | #include <linux/init.h> | |
72 | #include <linux/sched.h> /* for capable() */ | |
73 | #include <linux/mm.h> | |
74 | #include <linux/module.h> | |
75 | #include <linux/string.h> | |
76 | #include <linux/smp.h> | |
77 | #include <linux/efi.h> | |
78 | #include <linux/sysfs.h> | |
79 | #include <linux/kobject.h> | |
80 | #include <linux/device.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 | #define get_efivar_entry(n) list_entry(n, struct efivar_entry, list) | |
127 | ||
128 | struct efivar_attribute { | |
129 | struct attribute attr; | |
130 | ssize_t (*show) (struct efivar_entry *entry, char *buf); | |
131 | ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count); | |
132 | }; | |
133 | ||
134 | ||
135 | #define EFI_ATTR(_name, _mode, _show, _store) \ | |
136 | struct subsys_attribute efi_attr_##_name = { \ | |
137 | .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \ | |
138 | .show = _show, \ | |
139 | .store = _store, \ | |
140 | }; | |
141 | ||
142 | #define EFIVAR_ATTR(_name, _mode, _show, _store) \ | |
143 | struct efivar_attribute efivar_attr_##_name = { \ | |
144 | .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \ | |
145 | .show = _show, \ | |
146 | .store = _store, \ | |
147 | }; | |
148 | ||
149 | #define VAR_SUBSYS_ATTR(_name, _mode, _show, _store) \ | |
150 | struct subsys_attribute var_subsys_attr_##_name = { \ | |
151 | .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \ | |
152 | .show = _show, \ | |
153 | .store = _store, \ | |
154 | }; | |
155 | ||
156 | #define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr) | |
157 | #define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj) | |
158 | ||
159 | /* | |
160 | * Prototype for sysfs creation function | |
161 | */ | |
162 | static int | |
163 | efivar_create_sysfs_entry(unsigned long variable_name_size, | |
164 | efi_char16_t *variable_name, | |
165 | efi_guid_t *vendor_guid); | |
166 | ||
167 | /* Return the number of unicode characters in data */ | |
168 | static unsigned long | |
169 | utf8_strlen(efi_char16_t *data, unsigned long maxlength) | |
170 | { | |
171 | unsigned long length = 0; | |
172 | ||
173 | while (*data++ != 0 && length < maxlength) | |
174 | length++; | |
175 | return length; | |
176 | } | |
177 | ||
178 | /* | |
179 | * Return the number of bytes is the length of this string | |
180 | * Note: this is NOT the same as the number of unicode characters | |
181 | */ | |
182 | static inline unsigned long | |
183 | utf8_strsize(efi_char16_t *data, unsigned long maxlength) | |
184 | { | |
185 | return utf8_strlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t); | |
186 | } | |
187 | ||
188 | static efi_status_t | |
189 | get_var_data(struct efi_variable *var) | |
190 | { | |
191 | efi_status_t status; | |
192 | ||
193 | spin_lock(&efivars_lock); | |
194 | var->DataSize = 1024; | |
195 | status = efi.get_variable(var->VariableName, | |
196 | &var->VendorGuid, | |
197 | &var->Attributes, | |
198 | &var->DataSize, | |
199 | var->Data); | |
200 | spin_unlock(&efivars_lock); | |
201 | if (status != EFI_SUCCESS) { | |
202 | printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n", | |
203 | status); | |
204 | } | |
205 | return status; | |
206 | } | |
207 | ||
208 | static ssize_t | |
209 | efivar_guid_read(struct efivar_entry *entry, char *buf) | |
210 | { | |
211 | struct efi_variable *var = &entry->var; | |
212 | char *str = buf; | |
213 | ||
214 | if (!entry || !buf) | |
215 | return 0; | |
216 | ||
217 | efi_guid_unparse(&var->VendorGuid, str); | |
218 | str += strlen(str); | |
219 | str += sprintf(str, "\n"); | |
220 | ||
221 | return str - buf; | |
222 | } | |
223 | ||
224 | static ssize_t | |
225 | efivar_attr_read(struct efivar_entry *entry, char *buf) | |
226 | { | |
227 | struct efi_variable *var = &entry->var; | |
228 | char *str = buf; | |
229 | efi_status_t status; | |
230 | ||
231 | if (!entry || !buf) | |
232 | return -EINVAL; | |
233 | ||
234 | status = get_var_data(var); | |
235 | if (status != EFI_SUCCESS) | |
236 | return -EIO; | |
237 | ||
238 | if (var->Attributes & 0x1) | |
239 | str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n"); | |
240 | if (var->Attributes & 0x2) | |
241 | str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n"); | |
242 | if (var->Attributes & 0x4) | |
243 | str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n"); | |
244 | return str - buf; | |
245 | } | |
246 | ||
247 | static ssize_t | |
248 | efivar_size_read(struct efivar_entry *entry, char *buf) | |
249 | { | |
250 | struct efi_variable *var = &entry->var; | |
251 | char *str = buf; | |
252 | efi_status_t status; | |
253 | ||
254 | if (!entry || !buf) | |
255 | return -EINVAL; | |
256 | ||
257 | status = get_var_data(var); | |
258 | if (status != EFI_SUCCESS) | |
259 | return -EIO; | |
260 | ||
261 | str += sprintf(str, "0x%lx\n", var->DataSize); | |
262 | return str - buf; | |
263 | } | |
264 | ||
265 | static ssize_t | |
266 | efivar_data_read(struct efivar_entry *entry, char *buf) | |
267 | { | |
268 | struct efi_variable *var = &entry->var; | |
269 | efi_status_t status; | |
270 | ||
271 | if (!entry || !buf) | |
272 | return -EINVAL; | |
273 | ||
274 | status = get_var_data(var); | |
275 | if (status != EFI_SUCCESS) | |
276 | return -EIO; | |
277 | ||
278 | memcpy(buf, var->Data, var->DataSize); | |
279 | return var->DataSize; | |
280 | } | |
281 | /* | |
282 | * We allow each variable to be edited via rewriting the | |
283 | * entire efi variable structure. | |
284 | */ | |
285 | static ssize_t | |
286 | efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count) | |
287 | { | |
288 | struct efi_variable *new_var, *var = &entry->var; | |
289 | efi_status_t status = EFI_NOT_FOUND; | |
290 | ||
291 | if (count != sizeof(struct efi_variable)) | |
292 | return -EINVAL; | |
293 | ||
294 | new_var = (struct efi_variable *)buf; | |
295 | /* | |
296 | * If only updating the variable data, then the name | |
297 | * and guid should remain the same | |
298 | */ | |
299 | if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) || | |
300 | efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) { | |
301 | printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n"); | |
302 | return -EINVAL; | |
303 | } | |
304 | ||
305 | if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){ | |
306 | printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n"); | |
307 | return -EINVAL; | |
308 | } | |
309 | ||
310 | spin_lock(&efivars_lock); | |
311 | status = efi.set_variable(new_var->VariableName, | |
312 | &new_var->VendorGuid, | |
313 | new_var->Attributes, | |
314 | new_var->DataSize, | |
315 | new_var->Data); | |
316 | ||
317 | spin_unlock(&efivars_lock); | |
318 | ||
319 | if (status != EFI_SUCCESS) { | |
320 | printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n", | |
321 | status); | |
322 | return -EIO; | |
323 | } | |
324 | ||
325 | memcpy(&entry->var, new_var, count); | |
326 | return count; | |
327 | } | |
328 | ||
329 | static ssize_t | |
330 | efivar_show_raw(struct efivar_entry *entry, char *buf) | |
331 | { | |
332 | struct efi_variable *var = &entry->var; | |
333 | efi_status_t status; | |
334 | ||
335 | if (!entry || !buf) | |
336 | return 0; | |
337 | ||
338 | status = get_var_data(var); | |
339 | if (status != EFI_SUCCESS) | |
340 | return -EIO; | |
341 | ||
342 | memcpy(buf, var, sizeof(*var)); | |
343 | return sizeof(*var); | |
344 | } | |
345 | ||
346 | /* | |
347 | * Generic read/write functions that call the specific functions of | |
348 | * the atttributes... | |
349 | */ | |
350 | static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr, | |
351 | char *buf) | |
352 | { | |
353 | struct efivar_entry *var = to_efivar_entry(kobj); | |
354 | struct efivar_attribute *efivar_attr = to_efivar_attr(attr); | |
70f2817a | 355 | ssize_t ret = -EIO; |
1da177e4 LT |
356 | |
357 | if (!capable(CAP_SYS_ADMIN)) | |
358 | return -EACCES; | |
359 | ||
360 | if (efivar_attr->show) { | |
361 | ret = efivar_attr->show(var, buf); | |
362 | } | |
363 | return ret; | |
364 | } | |
365 | ||
366 | static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr, | |
367 | const char *buf, size_t count) | |
368 | { | |
369 | struct efivar_entry *var = to_efivar_entry(kobj); | |
370 | struct efivar_attribute *efivar_attr = to_efivar_attr(attr); | |
70f2817a | 371 | ssize_t ret = -EIO; |
1da177e4 LT |
372 | |
373 | if (!capable(CAP_SYS_ADMIN)) | |
374 | return -EACCES; | |
375 | ||
376 | if (efivar_attr->store) | |
377 | ret = efivar_attr->store(var, buf, count); | |
378 | ||
379 | return ret; | |
380 | } | |
381 | ||
382 | static struct sysfs_ops efivar_attr_ops = { | |
383 | .show = efivar_attr_show, | |
384 | .store = efivar_attr_store, | |
385 | }; | |
386 | ||
387 | static void efivar_release(struct kobject *kobj) | |
388 | { | |
389 | struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj); | |
390 | spin_lock(&efivars_lock); | |
391 | list_del(&var->list); | |
392 | spin_unlock(&efivars_lock); | |
393 | kfree(var); | |
394 | } | |
395 | ||
396 | static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL); | |
397 | static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL); | |
398 | static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL); | |
399 | static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL); | |
400 | static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw); | |
401 | ||
402 | static struct attribute *def_attrs[] = { | |
403 | &efivar_attr_guid.attr, | |
404 | &efivar_attr_size.attr, | |
405 | &efivar_attr_attributes.attr, | |
406 | &efivar_attr_data.attr, | |
407 | &efivar_attr_raw_var.attr, | |
408 | NULL, | |
409 | }; | |
410 | ||
411 | static struct kobj_type ktype_efivar = { | |
412 | .release = efivar_release, | |
413 | .sysfs_ops = &efivar_attr_ops, | |
414 | .default_attrs = def_attrs, | |
415 | }; | |
416 | ||
417 | static ssize_t | |
418 | dummy(struct subsystem *sub, char *buf) | |
419 | { | |
420 | return -ENODEV; | |
421 | } | |
422 | ||
423 | static inline void | |
424 | efivar_unregister(struct efivar_entry *var) | |
425 | { | |
426 | kobject_unregister(&var->kobj); | |
427 | } | |
428 | ||
429 | ||
430 | static ssize_t | |
431 | efivar_create(struct subsystem *sub, const char *buf, size_t count) | |
432 | { | |
433 | struct efi_variable *new_var = (struct efi_variable *)buf; | |
434 | struct efivar_entry *search_efivar = NULL; | |
435 | unsigned long strsize1, strsize2; | |
436 | struct list_head *pos, *n; | |
437 | efi_status_t status = EFI_NOT_FOUND; | |
438 | int found = 0; | |
439 | ||
440 | if (!capable(CAP_SYS_ADMIN)) | |
441 | return -EACCES; | |
442 | ||
443 | spin_lock(&efivars_lock); | |
444 | ||
445 | /* | |
446 | * Does this variable already exist? | |
447 | */ | |
448 | list_for_each_safe(pos, n, &efivar_list) { | |
449 | search_efivar = get_efivar_entry(pos); | |
450 | strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024); | |
451 | strsize2 = utf8_strsize(new_var->VariableName, 1024); | |
452 | if (strsize1 == strsize2 && | |
453 | !memcmp(&(search_efivar->var.VariableName), | |
454 | new_var->VariableName, strsize1) && | |
455 | !efi_guidcmp(search_efivar->var.VendorGuid, | |
456 | new_var->VendorGuid)) { | |
457 | found = 1; | |
458 | break; | |
459 | } | |
460 | } | |
461 | if (found) { | |
462 | spin_unlock(&efivars_lock); | |
463 | return -EINVAL; | |
464 | } | |
465 | ||
466 | /* now *really* create the variable via EFI */ | |
467 | status = efi.set_variable(new_var->VariableName, | |
468 | &new_var->VendorGuid, | |
469 | new_var->Attributes, | |
470 | new_var->DataSize, | |
471 | new_var->Data); | |
472 | ||
473 | if (status != EFI_SUCCESS) { | |
474 | printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n", | |
475 | status); | |
476 | spin_unlock(&efivars_lock); | |
477 | return -EIO; | |
478 | } | |
479 | spin_unlock(&efivars_lock); | |
480 | ||
481 | /* Create the entry in sysfs. Locking is not required here */ | |
482 | status = efivar_create_sysfs_entry(utf8_strsize(new_var->VariableName, | |
483 | 1024), new_var->VariableName, &new_var->VendorGuid); | |
484 | if (status) { | |
485 | printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n"); | |
486 | } | |
487 | return count; | |
488 | } | |
489 | ||
490 | static ssize_t | |
491 | efivar_delete(struct subsystem *sub, const char *buf, size_t count) | |
492 | { | |
493 | struct efi_variable *del_var = (struct efi_variable *)buf; | |
494 | struct efivar_entry *search_efivar = NULL; | |
495 | unsigned long strsize1, strsize2; | |
496 | struct list_head *pos, *n; | |
497 | efi_status_t status = EFI_NOT_FOUND; | |
498 | int found = 0; | |
499 | ||
500 | if (!capable(CAP_SYS_ADMIN)) | |
501 | return -EACCES; | |
502 | ||
503 | spin_lock(&efivars_lock); | |
504 | ||
505 | /* | |
506 | * Does this variable already exist? | |
507 | */ | |
508 | list_for_each_safe(pos, n, &efivar_list) { | |
509 | search_efivar = get_efivar_entry(pos); | |
510 | strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024); | |
511 | strsize2 = utf8_strsize(del_var->VariableName, 1024); | |
512 | if (strsize1 == strsize2 && | |
513 | !memcmp(&(search_efivar->var.VariableName), | |
514 | del_var->VariableName, strsize1) && | |
515 | !efi_guidcmp(search_efivar->var.VendorGuid, | |
516 | del_var->VendorGuid)) { | |
517 | found = 1; | |
518 | break; | |
519 | } | |
520 | } | |
521 | if (!found) { | |
522 | spin_unlock(&efivars_lock); | |
523 | return -EINVAL; | |
524 | } | |
525 | /* force the Attributes/DataSize to 0 to ensure deletion */ | |
526 | del_var->Attributes = 0; | |
527 | del_var->DataSize = 0; | |
528 | ||
529 | status = efi.set_variable(del_var->VariableName, | |
530 | &del_var->VendorGuid, | |
531 | del_var->Attributes, | |
532 | del_var->DataSize, | |
533 | del_var->Data); | |
534 | ||
535 | if (status != EFI_SUCCESS) { | |
536 | printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n", | |
537 | status); | |
538 | spin_unlock(&efivars_lock); | |
539 | return -EIO; | |
540 | } | |
541 | /* We need to release this lock before unregistering. */ | |
542 | spin_unlock(&efivars_lock); | |
543 | ||
544 | efivar_unregister(search_efivar); | |
545 | ||
546 | /* It's dead Jim.... */ | |
547 | return count; | |
548 | } | |
549 | ||
550 | static VAR_SUBSYS_ATTR(new_var, 0200, dummy, efivar_create); | |
551 | static VAR_SUBSYS_ATTR(del_var, 0200, dummy, efivar_delete); | |
552 | ||
553 | static struct subsys_attribute *var_subsys_attrs[] = { | |
554 | &var_subsys_attr_new_var, | |
555 | &var_subsys_attr_del_var, | |
556 | NULL, | |
557 | }; | |
558 | ||
559 | /* | |
560 | * Let's not leave out systab information that snuck into | |
561 | * the efivars driver | |
562 | */ | |
563 | static ssize_t | |
564 | systab_read(struct subsystem *entry, char *buf) | |
565 | { | |
566 | char *str = buf; | |
567 | ||
568 | if (!entry || !buf) | |
569 | return -EINVAL; | |
570 | ||
571 | if (efi.mps) | |
572 | str += sprintf(str, "MPS=0x%lx\n", __pa(efi.mps)); | |
573 | if (efi.acpi20) | |
574 | str += sprintf(str, "ACPI20=0x%lx\n", __pa(efi.acpi20)); | |
575 | if (efi.acpi) | |
576 | str += sprintf(str, "ACPI=0x%lx\n", __pa(efi.acpi)); | |
577 | if (efi.smbios) | |
578 | str += sprintf(str, "SMBIOS=0x%lx\n", __pa(efi.smbios)); | |
579 | if (efi.hcdp) | |
580 | str += sprintf(str, "HCDP=0x%lx\n", __pa(efi.hcdp)); | |
581 | if (efi.boot_info) | |
582 | str += sprintf(str, "BOOTINFO=0x%lx\n", __pa(efi.boot_info)); | |
583 | if (efi.uga) | |
584 | str += sprintf(str, "UGA=0x%lx\n", __pa(efi.uga)); | |
585 | ||
586 | return str - buf; | |
587 | } | |
588 | ||
589 | static EFI_ATTR(systab, 0400, systab_read, NULL); | |
590 | ||
591 | static struct subsys_attribute *efi_subsys_attrs[] = { | |
592 | &efi_attr_systab, | |
593 | NULL, /* maybe more in the future? */ | |
594 | }; | |
595 | ||
596 | static decl_subsys(vars, &ktype_efivar, NULL); | |
597 | static decl_subsys(efi, NULL, NULL); | |
598 | ||
599 | /* | |
600 | * efivar_create_sysfs_entry() | |
601 | * Requires: | |
602 | * variable_name_size = number of bytes required to hold | |
603 | * variable_name (not counting the NULL | |
604 | * character at the end. | |
605 | * efivars_lock is not held on entry or exit. | |
606 | * Returns 1 on failure, 0 on success | |
607 | */ | |
608 | static int | |
609 | efivar_create_sysfs_entry(unsigned long variable_name_size, | |
610 | efi_char16_t *variable_name, | |
611 | efi_guid_t *vendor_guid) | |
612 | { | |
613 | int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38; | |
614 | char *short_name; | |
615 | struct efivar_entry *new_efivar; | |
616 | ||
617 | short_name = kmalloc(short_name_size + 1, GFP_KERNEL); | |
618 | new_efivar = kmalloc(sizeof(struct efivar_entry), GFP_KERNEL); | |
619 | ||
620 | if (!short_name || !new_efivar) { | |
621 | if (short_name) kfree(short_name); | |
622 | if (new_efivar) kfree(new_efivar); | |
623 | return 1; | |
624 | } | |
625 | memset(short_name, 0, short_name_size+1); | |
626 | memset(new_efivar, 0, sizeof(struct efivar_entry)); | |
627 | ||
628 | memcpy(new_efivar->var.VariableName, variable_name, | |
629 | variable_name_size); | |
630 | memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t)); | |
631 | ||
632 | /* Convert Unicode to normal chars (assume top bits are 0), | |
633 | ala UTF-8 */ | |
634 | for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) { | |
635 | short_name[i] = variable_name[i] & 0xFF; | |
636 | } | |
637 | /* This is ugly, but necessary to separate one vendor's | |
638 | private variables from another's. */ | |
639 | ||
640 | *(short_name + strlen(short_name)) = '-'; | |
641 | efi_guid_unparse(vendor_guid, short_name + strlen(short_name)); | |
642 | ||
643 | kobject_set_name(&new_efivar->kobj, "%s", short_name); | |
644 | kobj_set_kset_s(new_efivar, vars_subsys); | |
645 | kobject_register(&new_efivar->kobj); | |
646 | ||
647 | kfree(short_name); short_name = NULL; | |
648 | ||
649 | spin_lock(&efivars_lock); | |
650 | list_add(&new_efivar->list, &efivar_list); | |
651 | spin_unlock(&efivars_lock); | |
652 | ||
653 | return 0; | |
654 | } | |
655 | /* | |
656 | * For now we register the efi subsystem with the firmware subsystem | |
657 | * and the vars subsystem with the efi subsystem. In the future, it | |
658 | * might make sense to split off the efi subsystem into its own | |
659 | * driver, but for now only efivars will register with it, so just | |
660 | * include it here. | |
661 | */ | |
662 | ||
663 | static int __init | |
664 | efivars_init(void) | |
665 | { | |
666 | efi_status_t status = EFI_NOT_FOUND; | |
667 | efi_guid_t vendor_guid; | |
668 | efi_char16_t *variable_name; | |
669 | struct subsys_attribute *attr; | |
670 | unsigned long variable_name_size = 1024; | |
671 | int i, error = 0; | |
672 | ||
673 | if (!efi_enabled) | |
674 | return -ENODEV; | |
675 | ||
676 | variable_name = kmalloc(variable_name_size, GFP_KERNEL); | |
677 | if (!variable_name) { | |
678 | printk(KERN_ERR "efivars: Memory allocation failed.\n"); | |
679 | return -ENOMEM; | |
680 | } | |
681 | ||
682 | memset(variable_name, 0, variable_name_size); | |
683 | ||
684 | printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION, | |
685 | EFIVARS_DATE); | |
686 | ||
687 | /* | |
688 | * For now we'll register the efi subsys within this driver | |
689 | */ | |
690 | ||
691 | error = firmware_register(&efi_subsys); | |
692 | ||
693 | if (error) { | |
694 | printk(KERN_ERR "efivars: Firmware registration failed with error %d.\n", error); | |
695 | goto out_free; | |
696 | } | |
697 | ||
698 | kset_set_kset_s(&vars_subsys, efi_subsys); | |
699 | ||
700 | error = subsystem_register(&vars_subsys); | |
701 | ||
702 | if (error) { | |
703 | printk(KERN_ERR "efivars: Subsystem registration failed with error %d.\n", error); | |
704 | goto out_firmware_unregister; | |
705 | } | |
706 | ||
707 | /* | |
708 | * Per EFI spec, the maximum storage allocated for both | |
709 | * the variable name and variable data is 1024 bytes. | |
710 | */ | |
711 | ||
712 | do { | |
713 | variable_name_size = 1024; | |
714 | ||
715 | status = efi.get_next_variable(&variable_name_size, | |
716 | variable_name, | |
717 | &vendor_guid); | |
718 | switch (status) { | |
719 | case EFI_SUCCESS: | |
720 | efivar_create_sysfs_entry(variable_name_size, | |
721 | variable_name, | |
722 | &vendor_guid); | |
723 | break; | |
724 | case EFI_NOT_FOUND: | |
725 | break; | |
726 | default: | |
727 | printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n", | |
728 | status); | |
729 | status = EFI_NOT_FOUND; | |
730 | break; | |
731 | } | |
732 | } while (status != EFI_NOT_FOUND); | |
733 | ||
734 | /* | |
735 | * Now add attributes to allow creation of new vars | |
736 | * and deletion of existing ones... | |
737 | */ | |
738 | ||
739 | for (i = 0; (attr = var_subsys_attrs[i]) && !error; i++) { | |
740 | if (attr->show && attr->store) | |
741 | error = subsys_create_file(&vars_subsys, attr); | |
742 | } | |
743 | ||
744 | /* Don't forget the systab entry */ | |
745 | ||
746 | for (i = 0; (attr = efi_subsys_attrs[i]) && !error; i++) { | |
747 | if (attr->show) | |
748 | error = subsys_create_file(&efi_subsys, attr); | |
749 | } | |
750 | ||
751 | if (error) | |
752 | printk(KERN_ERR "efivars: Sysfs attribute export failed with error %d.\n", error); | |
753 | else | |
754 | goto out_free; | |
755 | ||
756 | subsystem_unregister(&vars_subsys); | |
757 | ||
758 | out_firmware_unregister: | |
759 | firmware_unregister(&efi_subsys); | |
760 | ||
761 | out_free: | |
762 | kfree(variable_name); | |
763 | ||
764 | return error; | |
765 | } | |
766 | ||
767 | static void __exit | |
768 | efivars_exit(void) | |
769 | { | |
770 | struct list_head *pos, *n; | |
771 | ||
772 | list_for_each_safe(pos, n, &efivar_list) | |
773 | efivar_unregister(get_efivar_entry(pos)); | |
774 | ||
775 | subsystem_unregister(&vars_subsys); | |
776 | firmware_unregister(&efi_subsys); | |
777 | } | |
778 | ||
779 | module_init(efivars_init); | |
780 | module_exit(efivars_exit); | |
781 |