diff options
Diffstat (limited to 'drivers/platform/x86/hp/hp-bioscfg/string-attributes.c')
| -rw-r--r-- | drivers/platform/x86/hp/hp-bioscfg/string-attributes.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c new file mode 100644 index 000000000000..f0c20070094d --- /dev/null +++ b/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c @@ -0,0 +1,395 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Functions corresponding to string type attributes under + * HP_WMI_BIOS_STRING_GUID for use with hp-bioscfg driver. + * + * Copyright (c) 2022 HP Development Company, L.P. + */ + +#include "bioscfg.h" + +#define WMI_STRING_TYPE "HPBIOS_BIOSString" + +GET_INSTANCE_ID(string); + +static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) +{ + int instance_id = get_string_instance_id(kobj); + + if (instance_id < 0) + return -EIO; + + return sysfs_emit(buf, "%s\n", + bioscfg_drv.string_data[instance_id].current_value); +} + +/** + * validate_string_input() - + * Validate input of current_value against min and max lengths + * + * @instance_id: The instance on which input is validated + * @buf: Input value + */ +static int validate_string_input(int instance_id, const char *buf) +{ + int in_len = strlen(buf); + struct string_data *string_data = &bioscfg_drv.string_data[instance_id]; + + /* BIOS treats it as a read only attribute */ + if (string_data->common.is_readonly) + return -EIO; + + if (in_len < string_data->min_length || in_len > string_data->max_length) + return -ERANGE; + + return 0; +} + +static void update_string_value(int instance_id, char *attr_value) +{ + struct string_data *string_data = &bioscfg_drv.string_data[instance_id]; + + /* Write settings to BIOS */ + strscpy(string_data->current_value, attr_value, sizeof(string_data->current_value)); +} + +/* + * ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name_language_code, string); + * static struct kobj_attribute string_display_langcode = + * __ATTR_RO(display_name_language_code); + */ + +ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name, string); +static struct kobj_attribute string_display_name = + __ATTR_RO(display_name); + +ATTRIBUTE_PROPERTY_STORE(current_value, string); +static struct kobj_attribute string_current_val = + __ATTR_RW_MODE(current_value, 0644); + +ATTRIBUTE_N_PROPERTY_SHOW(min_length, string); +static struct kobj_attribute string_min_length = + __ATTR_RO(min_length); + +ATTRIBUTE_N_PROPERTY_SHOW(max_length, string); +static struct kobj_attribute string_max_length = + __ATTR_RO(max_length); + +static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "string\n"); +} + +static struct kobj_attribute string_type = + __ATTR_RO(type); + +static struct attribute *string_attrs[] = { + &common_display_langcode.attr, + &string_display_name.attr, + &string_current_val.attr, + &string_min_length.attr, + &string_max_length.attr, + &string_type.attr, + NULL +}; + +static const struct attribute_group string_attr_group = { + .attrs = string_attrs, +}; + +int hp_alloc_string_data(void) +{ + bioscfg_drv.string_instances_count = hp_get_instance_count(HP_WMI_BIOS_STRING_GUID); + bioscfg_drv.string_data = kcalloc(bioscfg_drv.string_instances_count, + sizeof(*bioscfg_drv.string_data), GFP_KERNEL); + if (!bioscfg_drv.string_data) { + bioscfg_drv.string_instances_count = 0; + return -ENOMEM; + } + return 0; +} + +/* Expected Values types associated with each element */ +static const acpi_object_type expected_string_types[] = { + [NAME] = ACPI_TYPE_STRING, + [VALUE] = ACPI_TYPE_STRING, + [PATH] = ACPI_TYPE_STRING, + [IS_READONLY] = ACPI_TYPE_INTEGER, + [DISPLAY_IN_UI] = ACPI_TYPE_INTEGER, + [REQUIRES_PHYSICAL_PRESENCE] = ACPI_TYPE_INTEGER, + [SEQUENCE] = ACPI_TYPE_INTEGER, + [PREREQUISITES_SIZE] = ACPI_TYPE_INTEGER, + [PREREQUISITES] = ACPI_TYPE_STRING, + [SECURITY_LEVEL] = ACPI_TYPE_INTEGER, + [STR_MIN_LENGTH] = ACPI_TYPE_INTEGER, + [STR_MAX_LENGTH] = ACPI_TYPE_INTEGER, +}; + +static int hp_populate_string_elements_from_package(union acpi_object *string_obj, + int string_obj_count, + int instance_id) +{ + char *str_value = NULL; + int value_len; + int ret = 0; + u32 int_value = 0; + int elem; + int reqs; + int eloc; + int size; + struct string_data *string_data = &bioscfg_drv.string_data[instance_id]; + + if (!string_obj) + return -EINVAL; + + for (elem = 1, eloc = 1; elem < string_obj_count; elem++, eloc++) { + /* ONLY look at the first STRING_ELEM_CNT elements */ + if (eloc == STR_ELEM_CNT) + goto exit_string_package; + + switch (string_obj[elem].type) { + case ACPI_TYPE_STRING: + if (elem != PREREQUISITES) { + ret = hp_convert_hexstr_to_str(string_obj[elem].string.pointer, + string_obj[elem].string.length, + &str_value, &value_len); + + if (ret) + continue; + } + break; + case ACPI_TYPE_INTEGER: + int_value = (u32)string_obj[elem].integer.value; + break; + default: + pr_warn("Unsupported object type [%d]\n", string_obj[elem].type); + continue; + } + + /* Check that both expected and read object type match */ + if (expected_string_types[eloc] != string_obj[elem].type) { + pr_err("Error expected type %d for elem %d, but got type %d instead\n", + expected_string_types[eloc], elem, string_obj[elem].type); + kfree(str_value); + return -EIO; + } + + /* Assign appropriate element value to corresponding field*/ + switch (eloc) { + case VALUE: + strscpy(string_data->current_value, + str_value, sizeof(string_data->current_value)); + break; + case PATH: + strscpy(string_data->common.path, str_value, + sizeof(string_data->common.path)); + break; + case IS_READONLY: + string_data->common.is_readonly = int_value; + break; + case DISPLAY_IN_UI: + string_data->common.display_in_ui = int_value; + break; + case REQUIRES_PHYSICAL_PRESENCE: + string_data->common.requires_physical_presence = int_value; + break; + case SEQUENCE: + string_data->common.sequence = int_value; + break; + case PREREQUISITES_SIZE: + if (int_value > MAX_PREREQUISITES_SIZE) { + pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n"); + int_value = MAX_PREREQUISITES_SIZE; + } + string_data->common.prerequisites_size = int_value; + + /* + * This step is needed to keep the expected + * element list pointing to the right obj[elem].type + * when the size is zero. PREREQUISITES + * object is omitted by BIOS when the size is + * zero. + */ + if (string_data->common.prerequisites_size == 0) + eloc++; + break; + case PREREQUISITES: + size = min_t(u32, string_data->common.prerequisites_size, + MAX_PREREQUISITES_SIZE); + + for (reqs = 0; reqs < size; reqs++) { + if (elem >= string_obj_count) { + pr_err("Error elem-objects package is too small\n"); + return -EINVAL; + } + + ret = hp_convert_hexstr_to_str(string_obj[elem + reqs].string.pointer, + string_obj[elem + reqs].string.length, + &str_value, &value_len); + + if (ret) + continue; + + strscpy(string_data->common.prerequisites[reqs], + str_value, + sizeof(string_data->common.prerequisites[reqs])); + kfree(str_value); + str_value = NULL; + } + break; + + case SECURITY_LEVEL: + string_data->common.security_level = int_value; + break; + case STR_MIN_LENGTH: + string_data->min_length = int_value; + break; + case STR_MAX_LENGTH: + string_data->max_length = int_value; + break; + default: + pr_warn("Invalid element: %d found in String attribute or data may be malformed\n", elem); + break; + } + + kfree(str_value); + str_value = NULL; + } + +exit_string_package: + kfree(str_value); + return 0; +} + +/** + * hp_populate_string_package_data() - + * Populate all properties of an instance under string attribute + * + * @string_obj: ACPI object with string data + * @instance_id: The instance to enumerate + * @attr_name_kobj: The parent kernel object + */ +int hp_populate_string_package_data(union acpi_object *string_obj, + int instance_id, + struct kobject *attr_name_kobj) +{ + struct string_data *string_data = &bioscfg_drv.string_data[instance_id]; + + string_data->attr_name_kobj = attr_name_kobj; + + hp_populate_string_elements_from_package(string_obj, + string_obj->package.count, + instance_id); + + hp_update_attribute_permissions(string_data->common.is_readonly, + &string_current_val); + hp_friendly_user_name_update(string_data->common.path, + attr_name_kobj->name, + string_data->common.display_name, + sizeof(string_data->common.display_name)); + return sysfs_create_group(attr_name_kobj, &string_attr_group); +} + +static int hp_populate_string_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size, + int instance_id) +{ + int ret = 0; + struct string_data *string_data = &bioscfg_drv.string_data[instance_id]; + + /* + * Only data relevant to this driver and its functionality is + * read. BIOS defines the order in which each * element is + * read. Element 0 data is not relevant to this + * driver hence it is ignored. For clarity, all element names + * (DISPLAY_IN_UI) which defines the order in which is read + * and the name matches the variable where the data is stored. + * + * In earlier implementation, reported errors were ignored + * causing the data to remain uninitialized. It is not + * possible to determine if data read from BIOS is valid or + * not. It is for this reason functions may return a error + * without validating the data itself. + */ + + // VALUE: + ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size, string_data->current_value, + sizeof(string_data->current_value)); + if (ret < 0) + goto buffer_exit; + + // COMMON: + ret = hp_get_common_data_from_buffer(&buffer_ptr, buffer_size, &string_data->common); + if (ret < 0) + goto buffer_exit; + + // STR_MIN_LENGTH: + ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size, + &string_data->min_length); + if (ret < 0) + goto buffer_exit; + + // STR_MAX_LENGTH: + ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size, + &string_data->max_length); + +buffer_exit: + + return ret; +} + +/** + * hp_populate_string_buffer_data() - + * Populate all properties of an instance under string attribute + * + * @buffer_ptr: Buffer pointer + * @buffer_size: Buffer size + * @instance_id: The instance to enumerate + * @attr_name_kobj: The parent kernel object + */ +int hp_populate_string_buffer_data(u8 *buffer_ptr, u32 *buffer_size, + int instance_id, + struct kobject *attr_name_kobj) +{ + struct string_data *string_data = &bioscfg_drv.string_data[instance_id]; + int ret = 0; + + string_data->attr_name_kobj = attr_name_kobj; + + ret = hp_populate_string_elements_from_buffer(buffer_ptr, buffer_size, + instance_id); + if (ret < 0) + return ret; + + hp_update_attribute_permissions(string_data->common.is_readonly, + &string_current_val); + hp_friendly_user_name_update(string_data->common.path, + attr_name_kobj->name, + string_data->common.display_name, + sizeof(string_data->common.display_name)); + + return sysfs_create_group(attr_name_kobj, &string_attr_group); +} + +/** + * hp_exit_string_attributes() - Clear all attribute data + * + * Clears all data allocated for this group of attributes + */ +void hp_exit_string_attributes(void) +{ + int instance_id; + + for (instance_id = 0; instance_id < bioscfg_drv.string_instances_count; + instance_id++) { + struct kobject *attr_name_kobj = + bioscfg_drv.string_data[instance_id].attr_name_kobj; + + if (attr_name_kobj) + sysfs_remove_group(attr_name_kobj, &string_attr_group); + } + bioscfg_drv.string_instances_count = 0; + + kfree(bioscfg_drv.string_data); + bioscfg_drv.string_data = NULL; +} |