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