// SPDX-License-Identifier: GPL-2.0
/*
 * Functions corresponding to ordered list type attributes under
 * BIOS ORDERED LIST GUID for use with hp-bioscfg driver.
 *
 * Copyright (c) 2022 HP Development Company, L.P.
 */

#include "bioscfg.h"

GET_INSTANCE_ID(ordered_list);

static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
        int instance_id = get_ordered_list_instance_id(kobj);

        if (instance_id < 0)
                return -EIO;

        return sysfs_emit(buf, "%s\n",
                         bioscfg_drv.ordered_list_data[instance_id].current_value);
}

static int replace_char_str(u8 *buffer, char *repl_char, char *repl_with)
{
        char *src = buffer;
        int buflen = strlen(buffer);
        int item;

        if (buflen < 1)
                return -EINVAL;

        for (item = 0; item < buflen; item++)
                if (src[item] == *repl_char)
                        src[item] = *repl_with;

        return 0;
}

/**
 * validate_ordered_list_input() -
 * Validate input of current_value against possible values
 *
 * @instance: The instance on which input is validated
 * @buf: Input value
 */
static int validate_ordered_list_input(int instance, char *buf)
{
        /* validation is done by BIOS. This validation function will
         * convert semicolon to commas. BIOS uses commas as
         * separators when reporting ordered-list values.
         */
        return replace_char_str(buf, SEMICOLON_SEP, COMMA_SEP);
}

static void update_ordered_list_value(int instance, char *attr_value)
{
        struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance];

        strscpy(ordered_list_data->current_value, attr_value);
}

ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name, ordered_list);
static struct kobj_attribute ordered_list_display_name =
        __ATTR_RO(display_name);

ATTRIBUTE_PROPERTY_STORE(current_value, ordered_list);
static struct kobj_attribute ordered_list_current_val =
        __ATTR_RW_MODE(current_value, 0644);

ATTRIBUTE_VALUES_PROPERTY_SHOW(elements, ordered_list, SEMICOLON_SEP);
static struct kobj_attribute ordered_list_elements_val =
        __ATTR_RO(elements);

static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
                         char *buf)
{
        return sysfs_emit(buf, "ordered-list\n");
}

static struct kobj_attribute ordered_list_type =
        __ATTR_RO(type);

static struct attribute *ordered_list_attrs[] = {
        &common_display_langcode.attr,
        &ordered_list_display_name.attr,
        &ordered_list_current_val.attr,
        &ordered_list_elements_val.attr,
        &ordered_list_type.attr,
        NULL
};

static const struct attribute_group ordered_list_attr_group = {
        .attrs = ordered_list_attrs,
};

int hp_alloc_ordered_list_data(void)
{
        bioscfg_drv.ordered_list_instances_count =
                hp_get_instance_count(HP_WMI_BIOS_ORDERED_LIST_GUID);
        bioscfg_drv.ordered_list_data = kzalloc_objs(*bioscfg_drv.ordered_list_data,
                                                     bioscfg_drv.ordered_list_instances_count);
        if (!bioscfg_drv.ordered_list_data) {
                bioscfg_drv.ordered_list_instances_count = 0;
                return -ENOMEM;
        }
        return 0;
}

/* Expected Values types associated with each element */
static const acpi_object_type expected_order_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,
        [ORD_LIST_SIZE] = ACPI_TYPE_INTEGER,
        [ORD_LIST_ELEMENTS] = ACPI_TYPE_STRING,
};

static int hp_populate_ordered_list_elements_from_package(union acpi_object *order_obj,
                                                          int order_obj_count,
                                                          int instance_id)
{
        char *str_value = NULL;
        int value_len = 0;
        int ret;
        u32 size;
        u32 int_value = 0;
        int elem;
        int olist_elem;
        int reqs;
        int eloc;
        char *tmpstr = NULL;
        char *part_tmp = NULL;
        int tmp_len = 0;
        char *part = NULL;
        struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance_id];

        if (!order_obj)
                return -EINVAL;

        for (elem = 1, eloc = 1; eloc < ORD_ELEM_CNT; elem++, eloc++) {

                switch (order_obj[elem].type) {
                case ACPI_TYPE_STRING:
                        if (elem != PREREQUISITES && elem != ORD_LIST_ELEMENTS) {
                                ret = hp_convert_hexstr_to_str(order_obj[elem].string.pointer,
                                                               order_obj[elem].string.length,
                                                               &str_value, &value_len);
                                if (ret)
                                        continue;
                        }
                        break;
                case ACPI_TYPE_INTEGER:
                        int_value = (u32)order_obj[elem].integer.value;
                        break;
                default:
                        pr_warn("Unsupported object type [%d]\n", order_obj[elem].type);
                        continue;
                }

                /* Check that both expected and read object type match */
                if (expected_order_types[eloc] != order_obj[elem].type) {
                        pr_err("Error expected type %d for elem %d, but got type %d instead\n",
                               expected_order_types[eloc], elem, order_obj[elem].type);
                        kfree(str_value);
                        return -EIO;
                }

                /* Assign appropriate element value to corresponding field*/
                switch (eloc) {
                case VALUE:
                        strscpy(ordered_list_data->current_value, str_value);
                        replace_char_str(ordered_list_data->current_value, COMMA_SEP, SEMICOLON_SEP);
                        break;
                case PATH:
                        strscpy(ordered_list_data->common.path, str_value);
                        break;
                case IS_READONLY:
                        ordered_list_data->common.is_readonly = int_value;
                        break;
                case DISPLAY_IN_UI:
                        ordered_list_data->common.display_in_ui = int_value;
                        break;
                case REQUIRES_PHYSICAL_PRESENCE:
                        ordered_list_data->common.requires_physical_presence = int_value;
                        break;
                case SEQUENCE:
                        ordered_list_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;
                        }
                        ordered_list_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 (int_value == 0)
                                eloc++;
                        break;
                case PREREQUISITES:
                        size = min_t(u32, ordered_list_data->common.prerequisites_size,
                                     MAX_PREREQUISITES_SIZE);
                        for (reqs = 0; reqs < size; reqs++) {
                                if (elem + reqs >= order_obj_count) {
                                        pr_err("Error elem-objects package is too small\n");
                                        return -EINVAL;
                                }

                                ret = hp_convert_hexstr_to_str(order_obj[elem + reqs].string.pointer,
                                                               order_obj[elem + reqs].string.length,
                                                               &str_value, &value_len);

                                if (ret)
                                        continue;

                                strscpy(ordered_list_data->common.prerequisites[reqs], str_value);

                                kfree(str_value);
                                str_value = NULL;
                        }
                        break;

                case SECURITY_LEVEL:
                        ordered_list_data->common.security_level = int_value;
                        break;

                case ORD_LIST_SIZE:
                        if (int_value > MAX_ELEMENTS_SIZE) {
                                pr_warn("Order List size value exceeded the maximum number of elements supported or data may be malformed\n");
                                int_value = MAX_ELEMENTS_SIZE;
                        }
                        ordered_list_data->elements_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. ORD_LIST_ELEMENTS
                         * object is omitted by BIOS when the size is
                         * zero.
                         */
                        if (int_value == 0)
                                eloc++;
                        break;
                case ORD_LIST_ELEMENTS:

                        /*
                         * Ordered list data is stored in hex and comma separated format
                         * Convert the data and split it to show each element
                         */
                        ret = hp_convert_hexstr_to_str(str_value, value_len, &tmpstr, &tmp_len);
                        if (ret)
                                goto exit_list;

                        part_tmp = tmpstr;
                        part = strsep(&part_tmp, COMMA_SEP);

                        for (olist_elem = 0; olist_elem < MAX_ELEMENTS_SIZE && part; olist_elem++) {
                                strscpy(ordered_list_data->elements[olist_elem], part);
                                part = strsep(&part_tmp, COMMA_SEP);
                        }
                        ordered_list_data->elements_size = olist_elem;

                        kfree(str_value);
                        str_value = NULL;
                        break;
                default:
                        pr_warn("Invalid element: %d found in Ordered_List attribute or data may be malformed\n", elem);
                        break;
                }
                kfree(tmpstr);
                tmpstr = NULL;
                kfree(str_value);
                str_value = NULL;
        }

exit_list:
        kfree(tmpstr);
        kfree(str_value);
        return 0;
}

/**
 * hp_populate_ordered_list_package_data() -
 * Populate all properties of an instance under ordered_list attribute
 *
 * @order_obj: ACPI object with ordered_list data
 * @instance_id: The instance to enumerate
 * @attr_name_kobj: The parent kernel object
 */
int hp_populate_ordered_list_package_data(union acpi_object *order_obj, int instance_id,
                                          struct kobject *attr_name_kobj)
{
        struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance_id];

        ordered_list_data->attr_name_kobj = attr_name_kobj;

        hp_populate_ordered_list_elements_from_package(order_obj,
                                                       order_obj->package.count,
                                                       instance_id);
        hp_update_attribute_permissions(ordered_list_data->common.is_readonly,
                                        &ordered_list_current_val);
        hp_friendly_user_name_update(ordered_list_data->common.path,
                                     attr_name_kobj->name,
                                     ordered_list_data->common.display_name,
                                     sizeof(ordered_list_data->common.display_name));
        return sysfs_create_group(attr_name_kobj, &ordered_list_attr_group);
}

static int hp_populate_ordered_list_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
                                                         int instance_id)
{
        int values;
        struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance_id];
        int ret = 0;

        /*
         * 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, ordered_list_data->current_value,
                                        sizeof(ordered_list_data->current_value));
        if (ret < 0)
                goto buffer_exit;

        replace_char_str(ordered_list_data->current_value, COMMA_SEP, SEMICOLON_SEP);

        // COMMON:
        ret = hp_get_common_data_from_buffer(&buffer_ptr, buffer_size,
                                             &ordered_list_data->common);
        if (ret < 0)
                goto buffer_exit;

        // ORD_LIST_SIZE:
        ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
                                         &ordered_list_data->elements_size);

        if (ordered_list_data->elements_size > MAX_ELEMENTS_SIZE) {
                /* Report a message and limit elements size to maximum value */
                pr_warn("Ordered List size value exceeded the maximum number of elements supported or data may be malformed\n");
                ordered_list_data->elements_size = MAX_ELEMENTS_SIZE;
        }

        // ORD_LIST_ELEMENTS:
        for (values = 0; values < ordered_list_data->elements_size; values++) {
                ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
                                                ordered_list_data->elements[values],
                                                sizeof(ordered_list_data->elements[values]));
                if (ret < 0)
                        break;
        }

buffer_exit:
        return ret;
}

/**
 * hp_populate_ordered_list_buffer_data() - Populate all properties of an
 * instance under ordered list 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_ordered_list_buffer_data(u8 *buffer_ptr, u32 *buffer_size, int instance_id,
                                         struct kobject *attr_name_kobj)
{
        struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance_id];
        int ret = 0;

        ordered_list_data->attr_name_kobj = attr_name_kobj;

        /* Populate ordered list elements */
        ret = hp_populate_ordered_list_elements_from_buffer(buffer_ptr, buffer_size,
                                                            instance_id);
        if (ret < 0)
                return ret;

        hp_update_attribute_permissions(ordered_list_data->common.is_readonly,
                                        &ordered_list_current_val);
        hp_friendly_user_name_update(ordered_list_data->common.path,
                                     attr_name_kobj->name,
                                     ordered_list_data->common.display_name,
                                     sizeof(ordered_list_data->common.display_name));

        return sysfs_create_group(attr_name_kobj, &ordered_list_attr_group);
}

/**
 * hp_exit_ordered_list_attributes() - Clear all attribute data
 *
 * Clears all data allocated for this group of attributes
 */
void hp_exit_ordered_list_attributes(void)
{
        int instance_id;

        for (instance_id = 0; instance_id < bioscfg_drv.ordered_list_instances_count;
             instance_id++) {
                struct kobject *attr_name_kobj =
                        bioscfg_drv.ordered_list_data[instance_id].attr_name_kobj;

                if (attr_name_kobj)
                        sysfs_remove_group(attr_name_kobj,
                                           &ordered_list_attr_group);
        }
        bioscfg_drv.ordered_list_instances_count = 0;

        kfree(bioscfg_drv.ordered_list_data);
        bioscfg_drv.ordered_list_data = NULL;
}