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