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// SPDX-License-Identifier: GPL-2.0
/*
* Functions corresponding to SET methods under BIOS attributes interface GUID for use
* with dell-wmi-sysman
*
* Copyright (c) 2020 Dell Inc.
*/
#include <linux/wmi.h>
#include "dell-wmi-sysman.h"
#define SETDEFAULTVALUES_METHOD_ID 0x02
#define SETBIOSDEFAULTS_METHOD_ID 0x03
#define SETATTRIBUTE_METHOD_ID 0x04
static int call_biosattributes_interface(struct wmi_device *wdev, char *in_args, size_t size,
int method_id)
{
struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
struct acpi_buffer input;
union acpi_object *obj;
acpi_status status;
int ret = -EIO;
input.length = (acpi_size) size;
input.pointer = in_args;
status = wmidev_evaluate_method(wdev, 0, method_id, &input, &output);
if (ACPI_FAILURE(status))
return -EIO;
obj = (union acpi_object *)output.pointer;
if (obj->type == ACPI_TYPE_INTEGER)
ret = obj->integer.value;
if (wmi_priv.pending_changes == 0) {
wmi_priv.pending_changes = 1;
/* let userland know it may need to check reboot pending again */
kobject_uevent(&wmi_priv.class_dev->kobj, KOBJ_CHANGE);
}
kfree(output.pointer);
return map_wmi_error(ret);
}
/**
* set_attribute() - Update an attribute value
* @a_name: The attribute name
* @a_value: The attribute value
*
* Sets an attribute to new value
*/
int set_attribute(const char *a_name, const char *a_value)
{
size_t security_area_size, buffer_size;
size_t a_name_size, a_value_size;
char *buffer = NULL, *start;
int ret;
mutex_lock(&wmi_priv.mutex);
if (!wmi_priv.bios_attr_wdev) {
ret = -ENODEV;
goto out;
}
/* build/calculate buffer */
security_area_size = calculate_security_buffer(wmi_priv.current_admin_password);
a_name_size = calculate_string_buffer(a_name);
a_value_size = calculate_string_buffer(a_value);
buffer_size = security_area_size + a_name_size + a_value_size;
buffer = kzalloc(buffer_size, GFP_KERNEL);
if (!buffer) {
ret = -ENOMEM;
goto out;
}
/* build security area */
populate_security_buffer(buffer, wmi_priv.current_admin_password);
/* build variables to set */
start = buffer + security_area_size;
ret = populate_string_buffer(start, a_name_size, a_name);
if (ret < 0)
goto out;
start += ret;
ret = populate_string_buffer(start, a_value_size, a_value);
if (ret < 0)
goto out;
print_hex_dump_bytes("set attribute data: ", DUMP_PREFIX_NONE, buffer, buffer_size);
ret = call_biosattributes_interface(wmi_priv.bios_attr_wdev,
buffer, buffer_size,
SETATTRIBUTE_METHOD_ID);
if (ret == -EOPNOTSUPP)
dev_err(&wmi_priv.bios_attr_wdev->dev, "admin password must be configured\n");
else if (ret == -EACCES)
dev_err(&wmi_priv.bios_attr_wdev->dev, "invalid password\n");
out:
kfree(buffer);
mutex_unlock(&wmi_priv.mutex);
return ret;
}
/**
* set_bios_defaults() - Resets BIOS defaults
* @deftype: the type of BIOS value reset to issue.
*
* Resets BIOS defaults
*/
int set_bios_defaults(u8 deftype)
{
size_t security_area_size, buffer_size;
size_t integer_area_size = sizeof(u8);
char *buffer = NULL;
u8 *defaultType;
int ret;
mutex_lock(&wmi_priv.mutex);
if (!wmi_priv.bios_attr_wdev) {
ret = -ENODEV;
goto out;
}
security_area_size = calculate_security_buffer(wmi_priv.current_admin_password);
buffer_size = security_area_size + integer_area_size;
buffer = kzalloc(buffer_size, GFP_KERNEL);
if (!buffer) {
ret = -ENOMEM;
goto out;
}
/* build security area */
populate_security_buffer(buffer, wmi_priv.current_admin_password);
defaultType = buffer + security_area_size;
*defaultType = deftype;
ret = call_biosattributes_interface(wmi_priv.bios_attr_wdev, buffer, buffer_size,
SETBIOSDEFAULTS_METHOD_ID);
if (ret)
dev_err(&wmi_priv.bios_attr_wdev->dev, "reset BIOS defaults failed: %d\n", ret);
kfree(buffer);
out:
mutex_unlock(&wmi_priv.mutex);
return ret;
}
static int bios_attr_set_interface_probe(struct wmi_device *wdev, const void *context)
{
mutex_lock(&wmi_priv.mutex);
wmi_priv.bios_attr_wdev = wdev;
mutex_unlock(&wmi_priv.mutex);
return 0;
}
static void bios_attr_set_interface_remove(struct wmi_device *wdev)
{
mutex_lock(&wmi_priv.mutex);
wmi_priv.bios_attr_wdev = NULL;
mutex_unlock(&wmi_priv.mutex);
}
static const struct wmi_device_id bios_attr_set_interface_id_table[] = {
{ .guid_string = DELL_WMI_BIOS_ATTRIBUTES_INTERFACE_GUID },
{ },
};
static struct wmi_driver bios_attr_set_interface_driver = {
.driver = {
.name = DRIVER_NAME
},
.probe = bios_attr_set_interface_probe,
.remove = bios_attr_set_interface_remove,
.id_table = bios_attr_set_interface_id_table,
};
int init_bios_attr_set_interface(void)
{
return wmi_driver_register(&bios_attr_set_interface_driver);
}
void exit_bios_attr_set_interface(void)
{
wmi_driver_unregister(&bios_attr_set_interface_driver);
}
MODULE_DEVICE_TABLE(wmi, bios_attr_set_interface_id_table);
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