1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Functions corresponding to enumeration type attributes under
4 * BIOS Enumeration GUID for use with hp-bioscfg driver.
5 *
6 * Copyright (c) 2022 HP Development Company, L.P.
7 */
8
9 #include "bioscfg.h"
10
11 GET_INSTANCE_ID(enumeration);
12
current_value_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)13 static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
14 {
15 int instance_id = get_enumeration_instance_id(kobj);
16
17 if (instance_id < 0)
18 return -EIO;
19
20 return sysfs_emit(buf, "%s\n",
21 bioscfg_drv.enumeration_data[instance_id].current_value);
22 }
23
24 /**
25 * validate_enumeration_input() -
26 * Validate input of current_value against possible values
27 *
28 * @instance_id: The instance on which input is validated
29 * @buf: Input value
30 */
validate_enumeration_input(int instance_id,const char * buf)31 static int validate_enumeration_input(int instance_id, const char *buf)
32 {
33 int i;
34 int found = 0;
35 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
36
37 /* Is it a read only attribute */
38 if (enum_data->common.is_readonly)
39 return -EIO;
40
41 for (i = 0; i < enum_data->possible_values_size && !found; i++)
42 if (!strcmp(enum_data->possible_values[i], buf))
43 found = 1;
44
45 if (!found)
46 return -EINVAL;
47
48 return 0;
49 }
50
update_enumeration_value(int instance_id,char * attr_value)51 static void update_enumeration_value(int instance_id, char *attr_value)
52 {
53 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
54
55 strscpy(enum_data->current_value, attr_value);
56 }
57
58 ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name, enumeration);
59 static struct kobj_attribute enumeration_display_name =
60 __ATTR_RO(display_name);
61
62 ATTRIBUTE_PROPERTY_STORE(current_value, enumeration);
63 static struct kobj_attribute enumeration_current_val =
64 __ATTR_RW(current_value);
65
66 ATTRIBUTE_VALUES_PROPERTY_SHOW(possible_values, enumeration, SEMICOLON_SEP);
67 static struct kobj_attribute enumeration_poss_val =
68 __ATTR_RO(possible_values);
69
type_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)70 static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
71 char *buf)
72 {
73 return sysfs_emit(buf, "enumeration\n");
74 }
75
76 static struct kobj_attribute enumeration_type =
77 __ATTR_RO(type);
78
79 static struct attribute *enumeration_attrs[] = {
80 &common_display_langcode.attr,
81 &enumeration_display_name.attr,
82 &enumeration_current_val.attr,
83 &enumeration_poss_val.attr,
84 &enumeration_type.attr,
85 NULL
86 };
87
88 static const struct attribute_group enumeration_attr_group = {
89 .attrs = enumeration_attrs,
90 };
91
hp_alloc_enumeration_data(void)92 int hp_alloc_enumeration_data(void)
93 {
94 bioscfg_drv.enumeration_instances_count =
95 hp_get_instance_count(HP_WMI_BIOS_ENUMERATION_GUID);
96
97 bioscfg_drv.enumeration_data = kcalloc(bioscfg_drv.enumeration_instances_count,
98 sizeof(*bioscfg_drv.enumeration_data), GFP_KERNEL);
99 if (!bioscfg_drv.enumeration_data) {
100 bioscfg_drv.enumeration_instances_count = 0;
101 return -ENOMEM;
102 }
103 return 0;
104 }
105
106 /* Expected Values types associated with each element */
107 static const acpi_object_type expected_enum_types[] = {
108 [NAME] = ACPI_TYPE_STRING,
109 [VALUE] = ACPI_TYPE_STRING,
110 [PATH] = ACPI_TYPE_STRING,
111 [IS_READONLY] = ACPI_TYPE_INTEGER,
112 [DISPLAY_IN_UI] = ACPI_TYPE_INTEGER,
113 [REQUIRES_PHYSICAL_PRESENCE] = ACPI_TYPE_INTEGER,
114 [SEQUENCE] = ACPI_TYPE_INTEGER,
115 [PREREQUISITES_SIZE] = ACPI_TYPE_INTEGER,
116 [PREREQUISITES] = ACPI_TYPE_STRING,
117 [SECURITY_LEVEL] = ACPI_TYPE_INTEGER,
118 [ENUM_CURRENT_VALUE] = ACPI_TYPE_STRING,
119 [ENUM_SIZE] = ACPI_TYPE_INTEGER,
120 [ENUM_POSSIBLE_VALUES] = ACPI_TYPE_STRING,
121 };
122
hp_populate_enumeration_elements_from_package(union acpi_object * enum_obj,int enum_obj_count,int instance_id)123 static int hp_populate_enumeration_elements_from_package(union acpi_object *enum_obj,
124 int enum_obj_count,
125 int instance_id)
126 {
127 char *str_value = NULL;
128 int value_len;
129 u32 size = 0;
130 u32 int_value = 0;
131 int elem = 0;
132 int reqs;
133 int pos_values;
134 int ret;
135 int eloc;
136 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
137
138 for (elem = 1, eloc = 1; elem < enum_obj_count; elem++, eloc++) {
139 /* ONLY look at the first ENUM_ELEM_CNT elements */
140 if (eloc == ENUM_ELEM_CNT)
141 goto exit_enumeration_package;
142
143 switch (enum_obj[elem].type) {
144 case ACPI_TYPE_STRING:
145 if (PREREQUISITES != elem && ENUM_POSSIBLE_VALUES != elem) {
146 ret = hp_convert_hexstr_to_str(enum_obj[elem].string.pointer,
147 enum_obj[elem].string.length,
148 &str_value, &value_len);
149 if (ret)
150 return -EINVAL;
151 }
152 break;
153 case ACPI_TYPE_INTEGER:
154 int_value = (u32)enum_obj[elem].integer.value;
155 break;
156 default:
157 pr_warn("Unsupported object type [%d]\n", enum_obj[elem].type);
158 continue;
159 }
160
161 /* Check that both expected and read object type match */
162 if (expected_enum_types[eloc] != enum_obj[elem].type) {
163 pr_err("Error expected type %d for elem %d, but got type %d instead\n",
164 expected_enum_types[eloc], elem, enum_obj[elem].type);
165 kfree(str_value);
166 return -EIO;
167 }
168
169 /* Assign appropriate element value to corresponding field */
170 switch (eloc) {
171 case NAME:
172 case VALUE:
173 break;
174 case PATH:
175 strscpy(enum_data->common.path, str_value);
176 break;
177 case IS_READONLY:
178 enum_data->common.is_readonly = int_value;
179 break;
180 case DISPLAY_IN_UI:
181 enum_data->common.display_in_ui = int_value;
182 break;
183 case REQUIRES_PHYSICAL_PRESENCE:
184 enum_data->common.requires_physical_presence = int_value;
185 break;
186 case SEQUENCE:
187 enum_data->common.sequence = int_value;
188 break;
189 case PREREQUISITES_SIZE:
190 if (int_value > MAX_PREREQUISITES_SIZE) {
191 pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
192 int_value = MAX_PREREQUISITES_SIZE;
193 }
194 enum_data->common.prerequisites_size = int_value;
195
196 /*
197 * This step is needed to keep the expected
198 * element list pointing to the right obj[elem].type
199 * when the size is zero. PREREQUISITES
200 * object is omitted by BIOS when the size is
201 * zero.
202 */
203 if (int_value == 0)
204 eloc++;
205 break;
206
207 case PREREQUISITES:
208 size = min_t(u32, enum_data->common.prerequisites_size, MAX_PREREQUISITES_SIZE);
209 for (reqs = 0; reqs < size; reqs++) {
210 if (elem >= enum_obj_count) {
211 pr_err("Error enum-objects package is too small\n");
212 return -EINVAL;
213 }
214
215 ret = hp_convert_hexstr_to_str(enum_obj[elem + reqs].string.pointer,
216 enum_obj[elem + reqs].string.length,
217 &str_value, &value_len);
218
219 if (ret)
220 return -EINVAL;
221
222 strscpy(enum_data->common.prerequisites[reqs], str_value);
223
224 kfree(str_value);
225 str_value = NULL;
226 }
227 break;
228
229 case SECURITY_LEVEL:
230 enum_data->common.security_level = int_value;
231 break;
232
233 case ENUM_CURRENT_VALUE:
234 strscpy(enum_data->current_value, str_value);
235 break;
236 case ENUM_SIZE:
237 if (int_value > MAX_VALUES_SIZE) {
238 pr_warn("Possible number values size value exceeded the maximum number of elements supported or data may be malformed\n");
239 int_value = MAX_VALUES_SIZE;
240 }
241 enum_data->possible_values_size = int_value;
242
243 /*
244 * This step is needed to keep the expected
245 * element list pointing to the right obj[elem].type
246 * when the size is zero. POSSIBLE_VALUES
247 * object is omitted by BIOS when the size is zero.
248 */
249 if (int_value == 0)
250 eloc++;
251 break;
252
253 case ENUM_POSSIBLE_VALUES:
254 size = enum_data->possible_values_size;
255
256 for (pos_values = 0; pos_values < size && pos_values < MAX_VALUES_SIZE;
257 pos_values++) {
258 if (elem >= enum_obj_count) {
259 pr_err("Error enum-objects package is too small\n");
260 return -EINVAL;
261 }
262
263 ret = hp_convert_hexstr_to_str(enum_obj[elem + pos_values].string.pointer,
264 enum_obj[elem + pos_values].string.length,
265 &str_value, &value_len);
266
267 if (ret)
268 return -EINVAL;
269
270 /*
271 * ignore strings when possible values size
272 * is greater than MAX_VALUES_SIZE
273 */
274 if (size < MAX_VALUES_SIZE)
275 strscpy(enum_data->possible_values[pos_values], str_value);
276
277 kfree(str_value);
278 str_value = NULL;
279 }
280 break;
281 default:
282 pr_warn("Invalid element: %d found in Enumeration attribute or data may be malformed\n", elem);
283 break;
284 }
285
286 kfree(str_value);
287 str_value = NULL;
288 }
289
290 exit_enumeration_package:
291 kfree(str_value);
292 return 0;
293 }
294
295 /**
296 * hp_populate_enumeration_package_data() -
297 * Populate all properties of an instance under enumeration attribute
298 *
299 * @enum_obj: ACPI object with enumeration data
300 * @instance_id: The instance to enumerate
301 * @attr_name_kobj: The parent kernel object
302 */
hp_populate_enumeration_package_data(union acpi_object * enum_obj,int instance_id,struct kobject * attr_name_kobj)303 int hp_populate_enumeration_package_data(union acpi_object *enum_obj,
304 int instance_id,
305 struct kobject *attr_name_kobj)
306 {
307 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
308
309 enum_data->attr_name_kobj = attr_name_kobj;
310
311 hp_populate_enumeration_elements_from_package(enum_obj,
312 enum_obj->package.count,
313 instance_id);
314 hp_update_attribute_permissions(enum_data->common.is_readonly,
315 &enumeration_current_val);
316 /*
317 * Several attributes have names such "MONDAY". Friendly
318 * user nane is generated to make the name more descriptive
319 */
320 hp_friendly_user_name_update(enum_data->common.path,
321 attr_name_kobj->name,
322 enum_data->common.display_name,
323 sizeof(enum_data->common.display_name));
324 return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
325 }
326
hp_populate_enumeration_elements_from_buffer(u8 * buffer_ptr,u32 * buffer_size,int instance_id)327 static int hp_populate_enumeration_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
328 int instance_id)
329 {
330 int values;
331 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
332 int ret = 0;
333
334 /*
335 * Only data relevant to this driver and its functionality is
336 * read. BIOS defines the order in which each * element is
337 * read. Element 0 data is not relevant to this
338 * driver hence it is ignored. For clarity, all element names
339 * (DISPLAY_IN_UI) which defines the order in which is read
340 * and the name matches the variable where the data is stored.
341 *
342 * In earlier implementation, reported errors were ignored
343 * causing the data to remain uninitialized. It is not
344 * possible to determine if data read from BIOS is valid or
345 * not. It is for this reason functions may return a error
346 * without validating the data itself.
347 */
348
349 // VALUE:
350 ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size, enum_data->current_value,
351 sizeof(enum_data->current_value));
352 if (ret < 0)
353 goto buffer_exit;
354
355 // COMMON:
356 ret = hp_get_common_data_from_buffer(&buffer_ptr, buffer_size, &enum_data->common);
357 if (ret < 0)
358 goto buffer_exit;
359
360 // ENUM_CURRENT_VALUE:
361 ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
362 enum_data->current_value,
363 sizeof(enum_data->current_value));
364 if (ret < 0)
365 goto buffer_exit;
366
367 // ENUM_SIZE:
368 ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
369 &enum_data->possible_values_size);
370
371 if (enum_data->possible_values_size > MAX_VALUES_SIZE) {
372 /* Report a message and limit possible values size to maximum value */
373 pr_warn("Enum Possible size value exceeded the maximum number of elements supported or data may be malformed\n");
374 enum_data->possible_values_size = MAX_VALUES_SIZE;
375 }
376
377 // ENUM_POSSIBLE_VALUES:
378 for (values = 0; values < enum_data->possible_values_size; values++) {
379 ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
380 enum_data->possible_values[values],
381 sizeof(enum_data->possible_values[values]));
382 if (ret < 0)
383 break;
384 }
385
386 buffer_exit:
387 return ret;
388 }
389
390 /**
391 * hp_populate_enumeration_buffer_data() -
392 * Populate all properties of an instance under enumeration attribute
393 *
394 * @buffer_ptr: Buffer pointer
395 * @buffer_size: Buffer size
396 * @instance_id: The instance to enumerate
397 * @attr_name_kobj: The parent kernel object
398 */
hp_populate_enumeration_buffer_data(u8 * buffer_ptr,u32 * buffer_size,int instance_id,struct kobject * attr_name_kobj)399 int hp_populate_enumeration_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
400 int instance_id,
401 struct kobject *attr_name_kobj)
402 {
403 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
404 int ret = 0;
405
406 enum_data->attr_name_kobj = attr_name_kobj;
407
408 /* Populate enumeration elements */
409 ret = hp_populate_enumeration_elements_from_buffer(buffer_ptr, buffer_size,
410 instance_id);
411 if (ret < 0)
412 return ret;
413
414 hp_update_attribute_permissions(enum_data->common.is_readonly,
415 &enumeration_current_val);
416 /*
417 * Several attributes have names such "MONDAY". A Friendlier
418 * user nane is generated to make the name more descriptive
419 */
420 hp_friendly_user_name_update(enum_data->common.path,
421 attr_name_kobj->name,
422 enum_data->common.display_name,
423 sizeof(enum_data->common.display_name));
424
425 return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
426 }
427
428 /**
429 * hp_exit_enumeration_attributes() - Clear all attribute data
430 *
431 * Clears all data allocated for this group of attributes
432 */
hp_exit_enumeration_attributes(void)433 void hp_exit_enumeration_attributes(void)
434 {
435 int instance_id;
436
437 for (instance_id = 0; instance_id < bioscfg_drv.enumeration_instances_count;
438 instance_id++) {
439 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
440 struct kobject *attr_name_kobj = enum_data->attr_name_kobj;
441
442 if (attr_name_kobj)
443 sysfs_remove_group(attr_name_kobj, &enumeration_attr_group);
444 }
445 bioscfg_drv.enumeration_instances_count = 0;
446
447 kfree(bioscfg_drv.enumeration_data);
448 bioscfg_drv.enumeration_data = NULL;
449 }
450