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Diffstat (limited to 'drivers/firmware/efivars.c')
-rw-r--r--drivers/firmware/efivars.c781
1 files changed, 781 insertions, 0 deletions
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
new file mode 100644
index 000000000000..0287ff65963b
--- /dev/null
+++ b/drivers/firmware/efivars.c
@@ -0,0 +1,781 @@
+/*
+ * EFI Variables - efivars.c
+ *
+ * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
+ * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
+ *
+ * This code takes all variables accessible from EFI runtime and
+ * exports them via sysfs
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Changelog:
+ *
+ * 17 May 2004 - Matt Domsch <Matt_Domsch@dell.com>
+ * remove check for efi_enabled in exit
+ * add MODULE_VERSION
+ *
+ * 26 Apr 2004 - Matt Domsch <Matt_Domsch@dell.com>
+ * minor bug fixes
+ *
+ * 21 Apr 2004 - Matt Tolentino <matthew.e.tolentino@intel.com)
+ * converted driver to export variable information via sysfs
+ * and moved to drivers/firmware directory
+ * bumped revision number to v0.07 to reflect conversion & move
+ *
+ * 10 Dec 2002 - Matt Domsch <Matt_Domsch@dell.com>
+ * fix locking per Peter Chubb's findings
+ *
+ * 25 Mar 2002 - Matt Domsch <Matt_Domsch@dell.com>
+ * move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_unparse()
+ *
+ * 12 Feb 2002 - Matt Domsch <Matt_Domsch@dell.com>
+ * use list_for_each_safe when deleting vars.
+ * remove ifdef CONFIG_SMP around include <linux/smp.h>
+ * v0.04 release to linux-ia64@linuxia64.org
+ *
+ * 20 April 2001 - Matt Domsch <Matt_Domsch@dell.com>
+ * Moved vars from /proc/efi to /proc/efi/vars, and made
+ * efi.c own the /proc/efi directory.
+ * v0.03 release to linux-ia64@linuxia64.org
+ *
+ * 26 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
+ * At the request of Stephane, moved ownership of /proc/efi
+ * to efi.c, and now efivars lives under /proc/efi/vars.
+ *
+ * 12 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
+ * Feedback received from Stephane Eranian incorporated.
+ * efivar_write() checks copy_from_user() return value.
+ * efivar_read/write() returns proper errno.
+ * v0.02 release to linux-ia64@linuxia64.org
+ *
+ * 26 February 2001 - Matt Domsch <Matt_Domsch@dell.com>
+ * v0.01 release to linux-ia64@linuxia64.org
+ */
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/sched.h> /* for capable() */
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/smp.h>
+#include <linux/efi.h>
+#include <linux/sysfs.h>
+#include <linux/kobject.h>
+#include <linux/device.h>
+
+#include <asm/uaccess.h>
+
+#define EFIVARS_VERSION "0.08"
+#define EFIVARS_DATE "2004-May-17"
+
+MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
+MODULE_DESCRIPTION("sysfs interface to EFI Variables");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(EFIVARS_VERSION);
+
+/*
+ * efivars_lock protects two things:
+ * 1) efivar_list - adds, removals, reads, writes
+ * 2) efi.[gs]et_variable() calls.
+ * It must not be held when creating sysfs entries or calling kmalloc.
+ * efi.get_next_variable() is only called from efivars_init(),
+ * which is protected by the BKL, so that path is safe.
+ */
+static DEFINE_SPINLOCK(efivars_lock);
+static LIST_HEAD(efivar_list);
+
+/*
+ * The maximum size of VariableName + Data = 1024
+ * Therefore, it's reasonable to save that much
+ * space in each part of the structure,
+ * and we use a page for reading/writing.
+ */
+
+struct efi_variable {
+ efi_char16_t VariableName[1024/sizeof(efi_char16_t)];
+ efi_guid_t VendorGuid;
+ unsigned long DataSize;
+ __u8 Data[1024];
+ efi_status_t Status;
+ __u32 Attributes;
+} __attribute__((packed));
+
+
+struct efivar_entry {
+ struct efi_variable var;
+ struct list_head list;
+ struct kobject kobj;
+};
+
+#define get_efivar_entry(n) list_entry(n, struct efivar_entry, list)
+
+struct efivar_attribute {
+ struct attribute attr;
+ ssize_t (*show) (struct efivar_entry *entry, char *buf);
+ ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
+};
+
+
+#define EFI_ATTR(_name, _mode, _show, _store) \
+struct subsys_attribute efi_attr_##_name = { \
+ .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \
+ .show = _show, \
+ .store = _store, \
+};
+
+#define EFIVAR_ATTR(_name, _mode, _show, _store) \
+struct efivar_attribute efivar_attr_##_name = { \
+ .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \
+ .show = _show, \
+ .store = _store, \
+};
+
+#define VAR_SUBSYS_ATTR(_name, _mode, _show, _store) \
+struct subsys_attribute var_subsys_attr_##_name = { \
+ .attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \
+ .show = _show, \
+ .store = _store, \
+};
+
+#define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
+#define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
+
+/*
+ * Prototype for sysfs creation function
+ */
+static int
+efivar_create_sysfs_entry(unsigned long variable_name_size,
+ efi_char16_t *variable_name,
+ efi_guid_t *vendor_guid);
+
+/* Return the number of unicode characters in data */
+static unsigned long
+utf8_strlen(efi_char16_t *data, unsigned long maxlength)
+{
+ unsigned long length = 0;
+
+ while (*data++ != 0 && length < maxlength)
+ length++;
+ return length;
+}
+
+/*
+ * Return the number of bytes is the length of this string
+ * Note: this is NOT the same as the number of unicode characters
+ */
+static inline unsigned long
+utf8_strsize(efi_char16_t *data, unsigned long maxlength)
+{
+ return utf8_strlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
+}
+
+static efi_status_t
+get_var_data(struct efi_variable *var)
+{
+ efi_status_t status;
+
+ spin_lock(&efivars_lock);
+ var->DataSize = 1024;
+ status = efi.get_variable(var->VariableName,
+ &var->VendorGuid,
+ &var->Attributes,
+ &var->DataSize,
+ var->Data);
+ spin_unlock(&efivars_lock);
+ if (status != EFI_SUCCESS) {
+ printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
+ status);
+ }
+ return status;
+}
+
+static ssize_t
+efivar_guid_read(struct efivar_entry *entry, char *buf)
+{
+ struct efi_variable *var = &entry->var;
+ char *str = buf;
+
+ if (!entry || !buf)
+ return 0;
+
+ efi_guid_unparse(&var->VendorGuid, str);
+ str += strlen(str);
+ str += sprintf(str, "\n");
+
+ return str - buf;
+}
+
+static ssize_t
+efivar_attr_read(struct efivar_entry *entry, char *buf)
+{
+ struct efi_variable *var = &entry->var;
+ char *str = buf;
+ efi_status_t status;
+
+ if (!entry || !buf)
+ return -EINVAL;
+
+ status = get_var_data(var);
+ if (status != EFI_SUCCESS)
+ return -EIO;
+
+ if (var->Attributes & 0x1)
+ str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
+ if (var->Attributes & 0x2)
+ str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
+ if (var->Attributes & 0x4)
+ str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
+ return str - buf;
+}
+
+static ssize_t
+efivar_size_read(struct efivar_entry *entry, char *buf)
+{
+ struct efi_variable *var = &entry->var;
+ char *str = buf;
+ efi_status_t status;
+
+ if (!entry || !buf)
+ return -EINVAL;
+
+ status = get_var_data(var);
+ if (status != EFI_SUCCESS)
+ return -EIO;
+
+ str += sprintf(str, "0x%lx\n", var->DataSize);
+ return str - buf;
+}
+
+static ssize_t
+efivar_data_read(struct efivar_entry *entry, char *buf)
+{
+ struct efi_variable *var = &entry->var;
+ efi_status_t status;
+
+ if (!entry || !buf)
+ return -EINVAL;
+
+ status = get_var_data(var);
+ if (status != EFI_SUCCESS)
+ return -EIO;
+
+ memcpy(buf, var->Data, var->DataSize);
+ return var->DataSize;
+}
+/*
+ * We allow each variable to be edited via rewriting the
+ * entire efi variable structure.
+ */
+static ssize_t
+efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
+{
+ struct efi_variable *new_var, *var = &entry->var;
+ efi_status_t status = EFI_NOT_FOUND;
+
+ if (count != sizeof(struct efi_variable))
+ return -EINVAL;
+
+ new_var = (struct efi_variable *)buf;
+ /*
+ * If only updating the variable data, then the name
+ * and guid should remain the same
+ */
+ if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
+ efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
+ printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
+ return -EINVAL;
+ }
+
+ if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
+ printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
+ return -EINVAL;
+ }
+
+ spin_lock(&efivars_lock);
+ status = efi.set_variable(new_var->VariableName,
+ &new_var->VendorGuid,
+ new_var->Attributes,
+ new_var->DataSize,
+ new_var->Data);
+
+ spin_unlock(&efivars_lock);
+
+ if (status != EFI_SUCCESS) {
+ printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
+ status);
+ return -EIO;
+ }
+
+ memcpy(&entry->var, new_var, count);
+ return count;
+}
+
+static ssize_t
+efivar_show_raw(struct efivar_entry *entry, char *buf)
+{
+ struct efi_variable *var = &entry->var;
+ efi_status_t status;
+
+ if (!entry || !buf)
+ return 0;
+
+ status = get_var_data(var);
+ if (status != EFI_SUCCESS)
+ return -EIO;
+
+ memcpy(buf, var, sizeof(*var));
+ return sizeof(*var);
+}
+
+/*
+ * Generic read/write functions that call the specific functions of
+ * the atttributes...
+ */
+static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
+ char *buf)
+{
+ struct efivar_entry *var = to_efivar_entry(kobj);
+ struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
+ ssize_t ret = 0;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ if (efivar_attr->show) {
+ ret = efivar_attr->show(var, buf);
+ }
+ return ret;
+}
+
+static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
+ const char *buf, size_t count)
+{
+ struct efivar_entry *var = to_efivar_entry(kobj);
+ struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
+ ssize_t ret = 0;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ if (efivar_attr->store)
+ ret = efivar_attr->store(var, buf, count);
+
+ return ret;
+}
+
+static struct sysfs_ops efivar_attr_ops = {
+ .show = efivar_attr_show,
+ .store = efivar_attr_store,
+};
+
+static void efivar_release(struct kobject *kobj)
+{
+ struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
+ spin_lock(&efivars_lock);
+ list_del(&var->list);
+ spin_unlock(&efivars_lock);
+ kfree(var);
+}
+
+static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
+static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
+static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
+static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
+static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
+
+static struct attribute *def_attrs[] = {
+ &efivar_attr_guid.attr,
+ &efivar_attr_size.attr,
+ &efivar_attr_attributes.attr,
+ &efivar_attr_data.attr,
+ &efivar_attr_raw_var.attr,
+ NULL,
+};
+
+static struct kobj_type ktype_efivar = {
+ .release = efivar_release,
+ .sysfs_ops = &efivar_attr_ops,
+ .default_attrs = def_attrs,
+};
+
+static ssize_t
+dummy(struct subsystem *sub, char *buf)
+{
+ return -ENODEV;
+}
+
+static inline void
+efivar_unregister(struct efivar_entry *var)
+{
+ kobject_unregister(&var->kobj);
+}
+
+
+static ssize_t
+efivar_create(struct subsystem *sub, const char *buf, size_t count)
+{
+ struct efi_variable *new_var = (struct efi_variable *)buf;
+ struct efivar_entry *search_efivar = NULL;
+ unsigned long strsize1, strsize2;
+ struct list_head *pos, *n;
+ efi_status_t status = EFI_NOT_FOUND;
+ int found = 0;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ spin_lock(&efivars_lock);
+
+ /*
+ * Does this variable already exist?
+ */
+ list_for_each_safe(pos, n, &efivar_list) {
+ search_efivar = get_efivar_entry(pos);
+ strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
+ strsize2 = utf8_strsize(new_var->VariableName, 1024);
+ if (strsize1 == strsize2 &&
+ !memcmp(&(search_efivar->var.VariableName),
+ new_var->VariableName, strsize1) &&
+ !efi_guidcmp(search_efivar->var.VendorGuid,
+ new_var->VendorGuid)) {
+ found = 1;
+ break;
+ }
+ }
+ if (found) {
+ spin_unlock(&efivars_lock);
+ return -EINVAL;
+ }
+
+ /* now *really* create the variable via EFI */
+ status = efi.set_variable(new_var->VariableName,
+ &new_var->VendorGuid,
+ new_var->Attributes,
+ new_var->DataSize,
+ new_var->Data);
+
+ if (status != EFI_SUCCESS) {
+ printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
+ status);
+ spin_unlock(&efivars_lock);
+ return -EIO;
+ }
+ spin_unlock(&efivars_lock);
+
+ /* Create the entry in sysfs. Locking is not required here */
+ status = efivar_create_sysfs_entry(utf8_strsize(new_var->VariableName,
+ 1024), new_var->VariableName, &new_var->VendorGuid);
+ if (status) {
+ printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
+ }
+ return count;
+}
+
+static ssize_t
+efivar_delete(struct subsystem *sub, const char *buf, size_t count)
+{
+ struct efi_variable *del_var = (struct efi_variable *)buf;
+ struct efivar_entry *search_efivar = NULL;
+ unsigned long strsize1, strsize2;
+ struct list_head *pos, *n;
+ efi_status_t status = EFI_NOT_FOUND;
+ int found = 0;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ spin_lock(&efivars_lock);
+
+ /*
+ * Does this variable already exist?
+ */
+ list_for_each_safe(pos, n, &efivar_list) {
+ search_efivar = get_efivar_entry(pos);
+ strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
+ strsize2 = utf8_strsize(del_var->VariableName, 1024);
+ if (strsize1 == strsize2 &&
+ !memcmp(&(search_efivar->var.VariableName),
+ del_var->VariableName, strsize1) &&
+ !efi_guidcmp(search_efivar->var.VendorGuid,
+ del_var->VendorGuid)) {
+ found = 1;
+ break;
+ }
+ }
+ if (!found) {
+ spin_unlock(&efivars_lock);
+ return -EINVAL;
+ }
+ /* force the Attributes/DataSize to 0 to ensure deletion */
+ del_var->Attributes = 0;
+ del_var->DataSize = 0;
+
+ status = efi.set_variable(del_var->VariableName,
+ &del_var->VendorGuid,
+ del_var->Attributes,
+ del_var->DataSize,
+ del_var->Data);
+
+ if (status != EFI_SUCCESS) {
+ printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
+ status);
+ spin_unlock(&efivars_lock);
+ return -EIO;
+ }
+ /* We need to release this lock before unregistering. */
+ spin_unlock(&efivars_lock);
+
+ efivar_unregister(search_efivar);
+
+ /* It's dead Jim.... */
+ return count;
+}
+
+static VAR_SUBSYS_ATTR(new_var, 0200, dummy, efivar_create);
+static VAR_SUBSYS_ATTR(del_var, 0200, dummy, efivar_delete);
+
+static struct subsys_attribute *var_subsys_attrs[] = {
+ &var_subsys_attr_new_var,
+ &var_subsys_attr_del_var,
+ NULL,
+};
+
+/*
+ * Let's not leave out systab information that snuck into
+ * the efivars driver
+ */
+static ssize_t
+systab_read(struct subsystem *entry, char *buf)
+{
+ char *str = buf;
+
+ if (!entry || !buf)
+ return -EINVAL;
+
+ if (efi.mps)
+ str += sprintf(str, "MPS=0x%lx\n", __pa(efi.mps));
+ if (efi.acpi20)
+ str += sprintf(str, "ACPI20=0x%lx\n", __pa(efi.acpi20));
+ if (efi.acpi)
+ str += sprintf(str, "ACPI=0x%lx\n", __pa(efi.acpi));
+ if (efi.smbios)
+ str += sprintf(str, "SMBIOS=0x%lx\n", __pa(efi.smbios));
+ if (efi.hcdp)
+ str += sprintf(str, "HCDP=0x%lx\n", __pa(efi.hcdp));
+ if (efi.boot_info)
+ str += sprintf(str, "BOOTINFO=0x%lx\n", __pa(efi.boot_info));
+ if (efi.uga)
+ str += sprintf(str, "UGA=0x%lx\n", __pa(efi.uga));
+
+ return str - buf;
+}
+
+static EFI_ATTR(systab, 0400, systab_read, NULL);
+
+static struct subsys_attribute *efi_subsys_attrs[] = {
+ &efi_attr_systab,
+ NULL, /* maybe more in the future? */
+};
+
+static decl_subsys(vars, &ktype_efivar, NULL);
+static decl_subsys(efi, NULL, NULL);
+
+/*
+ * efivar_create_sysfs_entry()
+ * Requires:
+ * variable_name_size = number of bytes required to hold
+ * variable_name (not counting the NULL
+ * character at the end.
+ * efivars_lock is not held on entry or exit.
+ * Returns 1 on failure, 0 on success
+ */
+static int
+efivar_create_sysfs_entry(unsigned long variable_name_size,
+ efi_char16_t *variable_name,
+ efi_guid_t *vendor_guid)
+{
+ int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38;
+ char *short_name;
+ struct efivar_entry *new_efivar;
+
+ short_name = kmalloc(short_name_size + 1, GFP_KERNEL);
+ new_efivar = kmalloc(sizeof(struct efivar_entry), GFP_KERNEL);
+
+ if (!short_name || !new_efivar) {
+ if (short_name) kfree(short_name);
+ if (new_efivar) kfree(new_efivar);
+ return 1;
+ }
+ memset(short_name, 0, short_name_size+1);
+ memset(new_efivar, 0, sizeof(struct efivar_entry));
+
+ memcpy(new_efivar->var.VariableName, variable_name,
+ variable_name_size);
+ memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));
+
+ /* Convert Unicode to normal chars (assume top bits are 0),
+ ala UTF-8 */
+ for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
+ short_name[i] = variable_name[i] & 0xFF;
+ }
+ /* This is ugly, but necessary to separate one vendor's
+ private variables from another's. */
+
+ *(short_name + strlen(short_name)) = '-';
+ efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
+
+ kobject_set_name(&new_efivar->kobj, "%s", short_name);
+ kobj_set_kset_s(new_efivar, vars_subsys);
+ kobject_register(&new_efivar->kobj);
+
+ kfree(short_name); short_name = NULL;
+
+ spin_lock(&efivars_lock);
+ list_add(&new_efivar->list, &efivar_list);
+ spin_unlock(&efivars_lock);
+
+ return 0;
+}
+/*
+ * For now we register the efi subsystem with the firmware subsystem
+ * and the vars subsystem with the efi subsystem. In the future, it
+ * might make sense to split off the efi subsystem into its own
+ * driver, but for now only efivars will register with it, so just
+ * include it here.
+ */
+
+static int __init
+efivars_init(void)
+{
+ efi_status_t status = EFI_NOT_FOUND;
+ efi_guid_t vendor_guid;
+ efi_char16_t *variable_name;
+ struct subsys_attribute *attr;
+ unsigned long variable_name_size = 1024;
+ int i, error = 0;
+
+ if (!efi_enabled)
+ return -ENODEV;
+
+ variable_name = kmalloc(variable_name_size, GFP_KERNEL);
+ if (!variable_name) {
+ printk(KERN_ERR "efivars: Memory allocation failed.\n");
+ return -ENOMEM;
+ }
+
+ memset(variable_name, 0, variable_name_size);
+
+ printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
+ EFIVARS_DATE);
+
+ /*
+ * For now we'll register the efi subsys within this driver
+ */
+
+ error = firmware_register(&efi_subsys);
+
+ if (error) {
+ printk(KERN_ERR "efivars: Firmware registration failed with error %d.\n", error);
+ goto out_free;
+ }
+
+ kset_set_kset_s(&vars_subsys, efi_subsys);
+
+ error = subsystem_register(&vars_subsys);
+
+ if (error) {
+ printk(KERN_ERR "efivars: Subsystem registration failed with error %d.\n", error);
+ goto out_firmware_unregister;
+ }
+
+ /*
+ * Per EFI spec, the maximum storage allocated for both
+ * the variable name and variable data is 1024 bytes.
+ */
+
+ do {
+ variable_name_size = 1024;
+
+ status = efi.get_next_variable(&variable_name_size,
+ variable_name,
+ &vendor_guid);
+ switch (status) {
+ case EFI_SUCCESS:
+ efivar_create_sysfs_entry(variable_name_size,
+ variable_name,
+ &vendor_guid);
+ break;
+ case EFI_NOT_FOUND:
+ break;
+ default:
+ printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
+ status);
+ status = EFI_NOT_FOUND;
+ break;
+ }
+ } while (status != EFI_NOT_FOUND);
+
+ /*
+ * Now add attributes to allow creation of new vars
+ * and deletion of existing ones...
+ */
+
+ for (i = 0; (attr = var_subsys_attrs[i]) && !error; i++) {
+ if (attr->show && attr->store)
+ error = subsys_create_file(&vars_subsys, attr);
+ }
+
+ /* Don't forget the systab entry */
+
+ for (i = 0; (attr = efi_subsys_attrs[i]) && !error; i++) {
+ if (attr->show)
+ error = subsys_create_file(&efi_subsys, attr);
+ }
+
+ if (error)
+ printk(KERN_ERR "efivars: Sysfs attribute export failed with error %d.\n", error);
+ else
+ goto out_free;
+
+ subsystem_unregister(&vars_subsys);
+
+out_firmware_unregister:
+ firmware_unregister(&efi_subsys);
+
+out_free:
+ kfree(variable_name);
+
+ return error;
+}
+
+static void __exit
+efivars_exit(void)
+{
+ struct list_head *pos, *n;
+
+ list_for_each_safe(pos, n, &efivar_list)
+ efivar_unregister(get_efivar_entry(pos));
+
+ subsystem_unregister(&vars_subsys);
+ firmware_unregister(&efi_subsys);
+}
+
+module_init(efivars_init);
+module_exit(efivars_exit);
+
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-18 20:21:33 +0000