2 * Originally from efivars.c,
4 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
5 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
7 * This code takes all variables accessible from EFI runtime and
8 * exports them via sysfs
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.
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.
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
26 * 17 May 2004 - Matt Domsch <Matt_Domsch@dell.com>
27 * remove check for efi_enabled in exit
30 * 26 Apr 2004 - Matt Domsch <Matt_Domsch@dell.com>
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
38 * 10 Dec 2002 - Matt Domsch <Matt_Domsch@dell.com>
39 * fix locking per Peter Chubb's findings
41 * 25 Mar 2002 - Matt Domsch <Matt_Domsch@dell.com>
42 * move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_unparse()
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
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
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.
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
64 * 26 February 2001 - Matt Domsch <Matt_Domsch@dell.com>
65 * v0.01 release to linux-ia64@linuxia64.org
68 #include <linux/efi.h>
69 #include <linux/module.h>
70 #include <linux/ucs2_string.h>
72 #define EFIVARS_VERSION "0.08"
73 #define EFIVARS_DATE "2004-May-17"
75 MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
76 MODULE_DESCRIPTION("sysfs interface to EFI Variables");
77 MODULE_LICENSE("GPL");
78 MODULE_VERSION(EFIVARS_VERSION);
80 LIST_HEAD(efivar_sysfs_list);
81 EXPORT_SYMBOL_GPL(efivar_sysfs_list);
83 static struct kset *efivars_kset;
85 static struct bin_attribute *efivars_new_var;
86 static struct bin_attribute *efivars_del_var;
88 struct efivar_attribute {
89 struct attribute attr;
90 ssize_t (*show) (struct efivar_entry *entry, char *buf);
91 ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
94 #define EFIVAR_ATTR(_name, _mode, _show, _store) \
95 struct efivar_attribute efivar_attr_##_name = { \
96 .attr = {.name = __stringify(_name), .mode = _mode}, \
101 #define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
102 #define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
105 * Prototype for sysfs creation function
108 efivar_create_sysfs_entry(struct efivar_entry *new_var);
111 efivar_guid_read(struct efivar_entry *entry, char *buf)
113 struct efi_variable *var = &entry->var;
119 efi_guid_unparse(&var->VendorGuid, str);
121 str += sprintf(str, "\n");
127 efivar_attr_read(struct efivar_entry *entry, char *buf)
129 struct efi_variable *var = &entry->var;
135 var->DataSize = 1024;
136 if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data))
139 if (var->Attributes & EFI_VARIABLE_NON_VOLATILE)
140 str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
141 if (var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS)
142 str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
143 if (var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS)
144 str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
145 if (var->Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD)
146 str += sprintf(str, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n");
147 if (var->Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS)
149 "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n");
150 if (var->Attributes &
151 EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)
153 "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n");
154 if (var->Attributes & EFI_VARIABLE_APPEND_WRITE)
155 str += sprintf(str, "EFI_VARIABLE_APPEND_WRITE\n");
160 efivar_size_read(struct efivar_entry *entry, char *buf)
162 struct efi_variable *var = &entry->var;
168 var->DataSize = 1024;
169 if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data))
172 str += sprintf(str, "0x%lx\n", var->DataSize);
177 efivar_data_read(struct efivar_entry *entry, char *buf)
179 struct efi_variable *var = &entry->var;
184 var->DataSize = 1024;
185 if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data))
188 memcpy(buf, var->Data, var->DataSize);
189 return var->DataSize;
192 * We allow each variable to be edited via rewriting the
193 * entire efi variable structure.
196 efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
198 struct efi_variable *new_var, *var = &entry->var;
201 if (count != sizeof(struct efi_variable))
204 new_var = (struct efi_variable *)buf;
206 * If only updating the variable data, then the name
207 * and guid should remain the same
209 if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
210 efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
211 printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
215 if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
216 printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
220 if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
221 efivar_validate(new_var, new_var->Data, new_var->DataSize) == false) {
222 printk(KERN_ERR "efivars: Malformed variable content\n");
226 memcpy(&entry->var, new_var, count);
228 err = efivar_entry_set(entry, new_var->Attributes,
229 new_var->DataSize, new_var->Data, false);
231 printk(KERN_WARNING "efivars: set_variable() failed: status=%d\n", err);
239 efivar_show_raw(struct efivar_entry *entry, char *buf)
241 struct efi_variable *var = &entry->var;
246 var->DataSize = 1024;
247 if (efivar_entry_get(entry, &entry->var.Attributes,
248 &entry->var.DataSize, entry->var.Data))
251 memcpy(buf, var, sizeof(*var));
257 * Generic read/write functions that call the specific functions of
260 static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
263 struct efivar_entry *var = to_efivar_entry(kobj);
264 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
267 if (!capable(CAP_SYS_ADMIN))
270 if (efivar_attr->show) {
271 ret = efivar_attr->show(var, buf);
276 static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
277 const char *buf, size_t count)
279 struct efivar_entry *var = to_efivar_entry(kobj);
280 struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
283 if (!capable(CAP_SYS_ADMIN))
286 if (efivar_attr->store)
287 ret = efivar_attr->store(var, buf, count);
292 static const struct sysfs_ops efivar_attr_ops = {
293 .show = efivar_attr_show,
294 .store = efivar_attr_store,
297 static void efivar_release(struct kobject *kobj)
299 struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
303 static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
304 static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
305 static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
306 static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
307 static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
309 static struct attribute *def_attrs[] = {
310 &efivar_attr_guid.attr,
311 &efivar_attr_size.attr,
312 &efivar_attr_attributes.attr,
313 &efivar_attr_data.attr,
314 &efivar_attr_raw_var.attr,
318 static struct kobj_type efivar_ktype = {
319 .release = efivar_release,
320 .sysfs_ops = &efivar_attr_ops,
321 .default_attrs = def_attrs,
324 static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
325 struct bin_attribute *bin_attr,
326 char *buf, loff_t pos, size_t count)
328 struct efi_variable *new_var = (struct efi_variable *)buf;
329 struct efivar_entry *new_entry;
332 if (!capable(CAP_SYS_ADMIN))
335 if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
336 efivar_validate(new_var, new_var->Data, new_var->DataSize) == false) {
337 printk(KERN_ERR "efivars: Malformed variable content\n");
341 new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL);
345 memcpy(&new_entry->var, new_var, sizeof(*new_var));
347 err = efivar_entry_set(new_entry, new_var->Attributes, new_var->DataSize,
348 new_var->Data, &efivar_sysfs_list);
355 if (efivar_create_sysfs_entry(new_entry)) {
356 printk(KERN_WARNING "efivars: failed to create sysfs entry.\n");
366 static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
367 struct bin_attribute *bin_attr,
368 char *buf, loff_t pos, size_t count)
370 struct efi_variable *del_var = (struct efi_variable *)buf;
371 struct efivar_entry *entry;
374 if (!capable(CAP_SYS_ADMIN))
377 efivar_entry_iter_begin();
378 entry = efivar_entry_find(del_var->VariableName, del_var->VendorGuid,
379 &efivar_sysfs_list, true);
382 else if (__efivar_entry_delete(entry))
385 efivar_entry_iter_end();
390 efivar_unregister(entry);
392 /* It's dead Jim.... */
397 * efivar_create_sysfs_entry - create a new entry in sysfs
398 * @new_var: efivar entry to create
400 * Returns 1 on failure, 0 on success
403 efivar_create_sysfs_entry(struct efivar_entry *new_var)
405 int i, short_name_size;
407 unsigned long variable_name_size;
408 efi_char16_t *variable_name;
410 variable_name = new_var->var.VariableName;
411 variable_name_size = ucs2_strlen(variable_name) * sizeof(efi_char16_t);
414 * Length of the variable bytes in ASCII, plus the '-' separator,
415 * plus the GUID, plus trailing NUL
417 short_name_size = variable_name_size / sizeof(efi_char16_t)
418 + 1 + EFI_VARIABLE_GUID_LEN + 1;
420 short_name = kzalloc(short_name_size, GFP_KERNEL);
427 /* Convert Unicode to normal chars (assume top bits are 0),
429 for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
430 short_name[i] = variable_name[i] & 0xFF;
432 /* This is ugly, but necessary to separate one vendor's
433 private variables from another's. */
435 *(short_name + strlen(short_name)) = '-';
436 efi_guid_unparse(&new_var->var.VendorGuid,
437 short_name + strlen(short_name));
439 new_var->kobj.kset = efivars_kset;
441 i = kobject_init_and_add(&new_var->kobj, &efivar_ktype,
442 NULL, "%s", short_name);
447 kobject_uevent(&new_var->kobj, KOBJ_ADD);
448 efivar_entry_add(new_var, &efivar_sysfs_list);
454 create_efivars_bin_attributes(void)
456 struct bin_attribute *attr;
460 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
464 attr->attr.name = "new_var";
465 attr->attr.mode = 0200;
466 attr->write = efivar_create;
467 efivars_new_var = attr;
470 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
475 attr->attr.name = "del_var";
476 attr->attr.mode = 0200;
477 attr->write = efivar_delete;
478 efivars_del_var = attr;
480 sysfs_bin_attr_init(efivars_new_var);
481 sysfs_bin_attr_init(efivars_del_var);
484 error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_new_var);
486 printk(KERN_ERR "efivars: unable to create new_var sysfs file"
487 " due to error %d\n", error);
491 error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_del_var);
493 printk(KERN_ERR "efivars: unable to create del_var sysfs file"
494 " due to error %d\n", error);
495 sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var);
501 kfree(efivars_del_var);
502 efivars_del_var = NULL;
503 kfree(efivars_new_var);
504 efivars_new_var = NULL;
508 static int efivar_update_sysfs_entry(efi_char16_t *name, efi_guid_t vendor,
509 unsigned long name_size, void *data)
511 struct efivar_entry *entry = data;
513 if (efivar_entry_find(name, vendor, &efivar_sysfs_list, false))
516 memcpy(entry->var.VariableName, name, name_size);
517 memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
522 static void efivar_update_sysfs_entries(struct work_struct *work)
524 struct efivar_entry *entry;
527 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
531 /* Add new sysfs entries */
533 memset(entry, 0, sizeof(*entry));
535 err = efivar_init(efivar_update_sysfs_entry, entry,
536 true, false, &efivar_sysfs_list);
540 efivar_create_sysfs_entry(entry);
546 static int efivars_sysfs_callback(efi_char16_t *name, efi_guid_t vendor,
547 unsigned long name_size, void *data)
549 struct efivar_entry *entry;
551 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
555 memcpy(entry->var.VariableName, name, name_size);
556 memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
558 efivar_create_sysfs_entry(entry);
563 static int efivar_sysfs_destroy(struct efivar_entry *entry, void *data)
565 efivar_entry_remove(entry);
566 efivar_unregister(entry);
570 void efivars_sysfs_exit(void)
572 /* Remove all entries and destroy */
573 __efivar_entry_iter(efivar_sysfs_destroy, &efivar_sysfs_list, NULL, NULL);
576 sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var);
578 sysfs_remove_bin_file(&efivars_kset->kobj, efivars_del_var);
579 kfree(efivars_new_var);
580 kfree(efivars_del_var);
581 kset_unregister(efivars_kset);
584 int efivars_sysfs_init(void)
586 struct kobject *parent_kobj = efivars_kobject();
589 /* No efivars has been registered yet */
593 printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
596 efivars_kset = kset_create_and_add("vars", NULL, parent_kobj);
598 printk(KERN_ERR "efivars: Subsystem registration failed.\n");
602 efivar_init(efivars_sysfs_callback, NULL, false,
603 true, &efivar_sysfs_list);
605 error = create_efivars_bin_attributes();
607 efivars_sysfs_exit();
611 INIT_WORK(&efivar_work, efivar_update_sysfs_entries);
615 EXPORT_SYMBOL_GPL(efivars_sysfs_init);
617 module_init(efivars_sysfs_init);
618 module_exit(efivars_sysfs_exit);