string-attributes.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Functions corresponding to string type attributes under BIOS String GUID for use with
  4 * dell-wmi-sysman
  5 *
  6 *  Copyright (c) 2020 Dell Inc.
  7 */
  8
  9#include "dell-wmi-sysman.h"
 10
 11enum string_properties {MIN_LEN = 6, MAX_LEN};
 12
 13get_instance_id(str);
 14
 15static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
 16{
 17	int instance_id = get_str_instance_id(kobj);
 18	union acpi_object *obj;
 19	ssize_t ret;
 20
 21	if (instance_id < 0)
 22		return -EIO;
 23
 24	/* need to use specific instance_id and guid combination to get right data */
 25	obj = get_wmiobj_pointer(instance_id, DELL_WMI_BIOS_STRING_ATTRIBUTE_GUID);
 26	if (!obj)
 27		return -EIO;
 28	if (obj->type != ACPI_TYPE_PACKAGE || obj->package.count < STR_MIN_ELEMENTS ||
 29	    obj->package.elements[CURRENT_VAL].type != ACPI_TYPE_STRING) {
 30		kfree(obj);
 31		return -EIO;
 32	}
 33	ret = snprintf(buf, PAGE_SIZE, "%s\n", obj->package.elements[CURRENT_VAL].string.pointer);
 34	kfree(obj);
 35	return ret;
 36}
 37
 38/**
 39 * validate_str_input() - Validate input of current_value against min and max lengths
 40 * @instance_id: The instance on which input is validated
 41 * @buf: Input value
 42 */
 43static int validate_str_input(int instance_id, const char *buf)
 44{
 45	int in_len = strlen(buf);
 46
 47	if ((in_len < wmi_priv.str_data[instance_id].min_length) ||
 48			(in_len > wmi_priv.str_data[instance_id].max_length))
 49		return -EINVAL;
 50
 51	return 0;
 52}
 53
 54attribute_s_property_show(display_name_language_code, str);
 55static struct kobj_attribute str_displ_langcode =
 56		__ATTR_RO(display_name_language_code);
 57
 58attribute_s_property_show(display_name, str);
 59static struct kobj_attribute str_displ_name =
 60		__ATTR_RO(display_name);
 61
 62attribute_s_property_show(default_value, str);
 63static struct kobj_attribute str_default_val =
 64		__ATTR_RO(default_value);
 65
 66attribute_property_store(current_value, str);
 67static struct kobj_attribute str_current_val =
 68		__ATTR_RW_MODE(current_value, 0600);
 69
 70attribute_s_property_show(dell_modifier, str);
 71static struct kobj_attribute str_modifier =
 72		__ATTR_RO(dell_modifier);
 73
 74attribute_n_property_show(min_length, str);
 75static struct kobj_attribute str_min_length =
 76		__ATTR_RO(min_length);
 77
 78attribute_n_property_show(max_length, str);
 79static struct kobj_attribute str_max_length =
 80		__ATTR_RO(max_length);
 81
 82static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
 83			 char *buf)
 84{
 85	return sprintf(buf, "string\n");
 86}
 87static struct kobj_attribute str_type =
 88	__ATTR_RO(type);
 89
 90static struct attribute *str_attrs[] = {
 91	&str_displ_langcode.attr,
 92	&str_displ_name.attr,
 93	&str_default_val.attr,
 94	&str_current_val.attr,
 95	&str_modifier.attr,
 96	&str_min_length.attr,
 97	&str_max_length.attr,
 98	&str_type.attr,
 99	NULL,
100};
101
102static const struct attribute_group str_attr_group = {
103	.attrs = str_attrs,
104};
105
106int alloc_str_data(void)
107{
108	int ret = 0;
109
110	wmi_priv.str_instances_count = get_instance_count(DELL_WMI_BIOS_STRING_ATTRIBUTE_GUID);
111	wmi_priv.str_data = kcalloc(wmi_priv.str_instances_count,
112					sizeof(struct str_data), GFP_KERNEL);
113	if (!wmi_priv.str_data) {
114		wmi_priv.str_instances_count = 0;
115		ret = -ENOMEM;
116	}
117	return ret;
118}
119
120/**
121 * populate_str_data() - Populate all properties of an instance under string attribute
122 * @str_obj: ACPI object with string data
123 * @instance_id: The instance to enumerate
124 * @attr_name_kobj: The parent kernel object
125 */
126int populate_str_data(union acpi_object *str_obj, int instance_id, struct kobject *attr_name_kobj)
127{
128	wmi_priv.str_data[instance_id].attr_name_kobj = attr_name_kobj;
129	if (check_property_type(str, ATTR_NAME, ACPI_TYPE_STRING))
130		return -EINVAL;
131	strlcpy_attr(wmi_priv.str_data[instance_id].attribute_name,
132		     str_obj[ATTR_NAME].string.pointer);
133	if (check_property_type(str, DISPL_NAME_LANG_CODE, ACPI_TYPE_STRING))
134		return -EINVAL;
135	strlcpy_attr(wmi_priv.str_data[instance_id].display_name_language_code,
136		     str_obj[DISPL_NAME_LANG_CODE].string.pointer);
137	if (check_property_type(str, DISPLAY_NAME, ACPI_TYPE_STRING))
138		return -EINVAL;
139	strlcpy_attr(wmi_priv.str_data[instance_id].display_name,
140		     str_obj[DISPLAY_NAME].string.pointer);
141	if (check_property_type(str, DEFAULT_VAL, ACPI_TYPE_STRING))
142		return -EINVAL;
143	strlcpy_attr(wmi_priv.str_data[instance_id].default_value,
144		     str_obj[DEFAULT_VAL].string.pointer);
145	if (check_property_type(str, MODIFIER, ACPI_TYPE_STRING))
146		return -EINVAL;
147	strlcpy_attr(wmi_priv.str_data[instance_id].dell_modifier,
148		     str_obj[MODIFIER].string.pointer);
149	if (check_property_type(str, MIN_LEN, ACPI_TYPE_INTEGER))
150		return -EINVAL;
151	wmi_priv.str_data[instance_id].min_length = (uintptr_t)str_obj[MIN_LEN].string.pointer;
152	if (check_property_type(str, MAX_LEN, ACPI_TYPE_INTEGER))
153		return -EINVAL;
154	wmi_priv.str_data[instance_id].max_length = (uintptr_t) str_obj[MAX_LEN].string.pointer;
155
156	return sysfs_create_group(attr_name_kobj, &str_attr_group);
157}
158
159/**
160 * exit_str_attributes() - Clear all attribute data
161 *
162 * Clears all data allocated for this group of attributes
163 */
164void exit_str_attributes(void)
165{
166	int instance_id;
167
168	for (instance_id = 0; instance_id < wmi_priv.str_instances_count; instance_id++) {
169		if (wmi_priv.str_data[instance_id].attr_name_kobj)
170			sysfs_remove_group(wmi_priv.str_data[instance_id].attr_name_kobj,
171								&str_attr_group);
172	}
173	wmi_priv.str_instances_count = 0;
174
175	kfree(wmi_priv.str_data);
176	wmi_priv.str_data = NULL;
177}