platform/x86: hp-bioscfg: biosattr-interface
Add WMI interface worker functions to hp-bioscfg. HP BIOS Configuration driver purpose is to provide a driver supporting the latest sysfs class firmware attributes framework allowing the user to change BIOS settings and security solutions on HP Inc.’s commercial notebooks. Signed-off-by: Jorge Lopez <jorge.lopez2@hp.com> Reviewed-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://lore.kernel.org/r/20230608163319.18934-5-jorge.lopez2@hp.com Signed-off-by: Hans de Goede <hdegoede@redhat.com>
This commit is contained in:
Jorge Lopez
Hans de Goede
parent
a34fc329b1
commit
69ea03e38f
312
drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c
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312
drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c
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@ -0,0 +1,312 @@
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Functions corresponding to methods under BIOS interface GUID
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* for use with hp-bioscfg driver.
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*
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* Copyright (c) 2022 Hewlett-Packard Inc.
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*/
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#include <linux/wmi.h>
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#include "bioscfg.h"
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/*
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* struct bios_args buffer is dynamically allocated. New WMI command types
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* were introduced that exceeds 128-byte data size. Changes to handle
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* the data size allocation scheme were kept in hp_wmi_perform_query function.
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*/
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struct bios_args {
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u32 signature;
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u32 command;
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u32 commandtype;
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u32 datasize;
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u8 data[];
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};
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/**
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* hp_set_attribute
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*
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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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* Returns zero on success
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* -ENODEV if device is not found
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* -EINVAL if the instance of 'Setup Admin' password is not found.
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* -ENOMEM unable to allocate memory
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*/
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int hp_set_attribute(const char *a_name, const char *a_value)
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{
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int security_area_size;
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int a_name_size, a_value_size;
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u16 *buffer = NULL;
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u16 *start;
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int buffer_size, instance, ret;
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char *auth_token_choice;
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mutex_lock(&bioscfg_drv.mutex);
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instance = hp_get_password_instance_for_type(SETUP_PASSWD);
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if (instance < 0) {
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ret = -EINVAL;
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goto out_set_attribute;
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}
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/* Select which auth token to use; password or [auth token] */
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if (bioscfg_drv.spm_data.auth_token)
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auth_token_choice = bioscfg_drv.spm_data.auth_token;
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else
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auth_token_choice = bioscfg_drv.password_data[instance].current_password;
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a_name_size = hp_calculate_string_buffer(a_name);
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a_value_size = hp_calculate_string_buffer(a_value);
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security_area_size = hp_calculate_security_buffer(auth_token_choice);
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buffer_size = a_name_size + a_value_size + security_area_size;
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buffer = kmalloc(buffer_size + 1, GFP_KERNEL);
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if (!buffer) {
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ret = -ENOMEM;
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goto out_set_attribute;
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}
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/* build variables to set */
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start = buffer;
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start = hp_ascii_to_utf16_unicode(start, a_name);
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if (!start) {
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ret = -EINVAL;
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goto out_set_attribute;
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}
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start = hp_ascii_to_utf16_unicode(start, a_value);
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if (!start) {
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ret = -EINVAL;
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goto out_set_attribute;
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}
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ret = hp_populate_security_buffer(start, auth_token_choice);
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if (ret < 0)
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goto out_set_attribute;
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ret = hp_wmi_set_bios_setting(buffer, buffer_size);
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out_set_attribute:
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kfree(buffer);
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mutex_unlock(&bioscfg_drv.mutex);
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return ret;
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}
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/**
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* hp_wmi_perform_query
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*
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* @query: The commandtype (enum hp_wmi_commandtype)
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* @command: The command (enum hp_wmi_command)
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* @buffer: Buffer used as input and/or output
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* @insize: Size of input buffer
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* @outsize: Size of output buffer
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*
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* returns zero on success
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* an HP WMI query specific error code (which is positive)
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* -EINVAL if the query was not successful at all
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* -EINVAL if the output buffer size exceeds buffersize
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*
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* Note: The buffersize must at least be the maximum of the input and output
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* size. E.g. Battery info query is defined to have 1 byte input
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* and 128 byte output. The caller would do:
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* buffer = kzalloc(128, GFP_KERNEL);
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* ret = hp_wmi_perform_query(HPWMI_BATTERY_QUERY, HPWMI_READ,
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* buffer, 1, 128)
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*/
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int hp_wmi_perform_query(int query, enum hp_wmi_command command, void *buffer,
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u32 insize, u32 outsize)
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{
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struct acpi_buffer input, output = { ACPI_ALLOCATE_BUFFER, NULL };
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struct bios_return *bios_return;
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union acpi_object *obj = NULL;
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struct bios_args *args = NULL;
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u32 mid, actual_outsize, ret;
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size_t bios_args_size;
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mid = hp_encode_outsize_for_pvsz(outsize);
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if (WARN_ON(mid < 0))
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return mid;
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bios_args_size = struct_size(args, data, insize);
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args = kmalloc(bios_args_size, GFP_KERNEL);
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if (!args)
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return -ENOMEM;
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input.length = bios_args_size;
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input.pointer = args;
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/* BIOS expects 'SECU' in hex as the signature value*/
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args->signature = 0x55434553;
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args->command = command;
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args->commandtype = query;
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args->datasize = insize;
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memcpy(args->data, buffer, flex_array_size(args, data, insize));
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ret = wmi_evaluate_method(HP_WMI_BIOS_GUID, 0, mid, &input, &output);
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if (ret)
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goto out_free;
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obj = output.pointer;
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if (!obj) {
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ret = -EINVAL;
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goto out_free;
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}
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if (obj->type != ACPI_TYPE_BUFFER ||
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obj->buffer.length < sizeof(*bios_return)) {
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pr_warn("query 0x%x returned wrong type or too small buffer\n", query);
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ret = -EINVAL;
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goto out_free;
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}
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bios_return = (struct bios_return *)obj->buffer.pointer;
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ret = bios_return->return_code;
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if (ret) {
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if (ret != INVALID_CMD_VALUE && ret != INVALID_CMD_TYPE)
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pr_warn("query 0x%x returned error 0x%x\n", query, ret);
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goto out_free;
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}
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/* Ignore output data of zero size */
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if (!outsize)
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goto out_free;
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actual_outsize = min_t(u32, outsize, obj->buffer.length - sizeof(*bios_return));
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memcpy_and_pad(buffer, outsize, obj->buffer.pointer + sizeof(*bios_return),
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actual_outsize, 0);
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out_free:
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ret = hp_wmi_error_and_message(ret);
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kfree(obj);
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kfree(args);
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return ret;
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}
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static void *utf16_empty_string(u16 *p)
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{
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*p++ = 2;
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*p++ = 0x00;
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return p;
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}
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/**
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* hp_ascii_to_utf16_unicode - Convert ascii string to UTF-16 unicode
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*
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* BIOS supports UTF-16 characters that are 2 bytes long. No variable
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* multi-byte language supported.
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*
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* @p: Unicode buffer address
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* @str: string to convert to unicode
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*
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* Returns a void pointer to the buffer string
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*/
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void *hp_ascii_to_utf16_unicode(u16 *p, const u8 *str)
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{
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int len = strlen(str);
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int ret;
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/*
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* Add null character when reading an empty string
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* "02 00 00 00"
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*/
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if (len == 0)
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return utf16_empty_string(p);
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/* Move pointer len * 2 number of bytes */
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*p++ = len * 2;
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ret = utf8s_to_utf16s(str, strlen(str), UTF16_HOST_ENDIAN, p, len);
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if (ret < 0) {
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dev_err(bioscfg_drv.class_dev, "UTF16 conversion failed\n");
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return NULL;
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}
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if (ret * sizeof(u16) > U16_MAX) {
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dev_err(bioscfg_drv.class_dev, "Error string too long\n");
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return NULL;
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}
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p += len;
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return p;
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}
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/**
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* hp_wmi_set_bios_setting - Set setting's value in BIOS
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*
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* @input_buffer: Input buffer address
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* @input_size: Input buffer size
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*
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* Returns: Count of unicode characters written to BIOS if successful, otherwise
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* -ENOMEM unable to allocate memory
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* -EINVAL buffer not allocated or too small
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*/
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int hp_wmi_set_bios_setting(u16 *input_buffer, u32 input_size)
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{
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union acpi_object *obj;
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struct acpi_buffer input = {input_size, input_buffer};
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struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
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int ret;
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ret = wmi_evaluate_method(HP_WMI_SET_BIOS_SETTING_GUID, 0, 1, &input, &output);
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obj = output.pointer;
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if (!obj)
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return -EINVAL;
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if (obj->type != ACPI_TYPE_INTEGER) {
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ret = -EINVAL;
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goto out_free;
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}
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ret = obj->integer.value;
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if (ret) {
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ret = hp_wmi_error_and_message(ret);
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goto out_free;
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}
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out_free:
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kfree(obj);
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return ret;
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}
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static int hp_attr_set_interface_probe(struct wmi_device *wdev, const void *context)
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{
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mutex_lock(&bioscfg_drv.mutex);
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mutex_unlock(&bioscfg_drv.mutex);
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return 0;
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}
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static void hp_attr_set_interface_remove(struct wmi_device *wdev)
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{
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mutex_lock(&bioscfg_drv.mutex);
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mutex_unlock(&bioscfg_drv.mutex);
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}
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static const struct wmi_device_id hp_attr_set_interface_id_table[] = {
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{ .guid_string = HP_WMI_BIOS_GUID},
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{ }
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};
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static struct wmi_driver hp_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 = hp_attr_set_interface_probe,
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.remove = hp_attr_set_interface_remove,
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.id_table = hp_attr_set_interface_id_table,
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};
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int hp_init_attr_set_interface(void)
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{
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return wmi_driver_register(&hp_attr_set_interface_driver);
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}
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void hp_exit_attr_set_interface(void)
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{
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wmi_driver_unregister(&hp_attr_set_interface_driver);
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}
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MODULE_DEVICE_TABLE(wmi, hp_attr_set_interface_id_table);
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