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