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 if (!bioscfg_drv.enumeration_instances_count)
98 return -EINVAL;
99 bioscfg_drv.enumeration_data = kvcalloc(bioscfg_drv.enumeration_instances_count,
100 sizeof(*bioscfg_drv.enumeration_data), GFP_KERNEL);
101
102 if (!bioscfg_drv.enumeration_data) {
103 bioscfg_drv.enumeration_instances_count = 0;
104 return -ENOMEM;
105 }
106 return 0;
107 }
108
109 /* Expected Values types associated with each element */
110 static const acpi_object_type expected_enum_types[] = {
111 [NAME] = ACPI_TYPE_STRING,
112 [VALUE] = ACPI_TYPE_STRING,
113 [PATH] = ACPI_TYPE_STRING,
114 [IS_READONLY] = ACPI_TYPE_INTEGER,
115 [DISPLAY_IN_UI] = ACPI_TYPE_INTEGER,
116 [REQUIRES_PHYSICAL_PRESENCE] = ACPI_TYPE_INTEGER,
117 [SEQUENCE] = ACPI_TYPE_INTEGER,
118 [PREREQUISITES_SIZE] = ACPI_TYPE_INTEGER,
119 [PREREQUISITES] = ACPI_TYPE_STRING,
120 [SECURITY_LEVEL] = ACPI_TYPE_INTEGER,
121 [ENUM_CURRENT_VALUE] = ACPI_TYPE_STRING,
122 [ENUM_SIZE] = ACPI_TYPE_INTEGER,
123 [ENUM_POSSIBLE_VALUES] = ACPI_TYPE_STRING,
124 };
125
hp_populate_enumeration_elements_from_package(union acpi_object * enum_obj,int enum_obj_count,int instance_id)126 static int hp_populate_enumeration_elements_from_package(union acpi_object *enum_obj,
127 int enum_obj_count,
128 int instance_id)
129 {
130 char *str_value = NULL;
131 int value_len;
132 u32 size = 0;
133 u32 int_value = 0;
134 int elem = 0;
135 int reqs;
136 int pos_values;
137 int ret;
138 int eloc;
139 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
140
141 for (elem = 1, eloc = 1; elem < enum_obj_count; elem++, eloc++) {
142 /* ONLY look at the first ENUM_ELEM_CNT elements */
143 if (eloc == ENUM_ELEM_CNT)
144 goto exit_enumeration_package;
145
146 switch (enum_obj[elem].type) {
147 case ACPI_TYPE_STRING:
148 if (PREREQUISITES != elem && ENUM_POSSIBLE_VALUES != elem) {
149 ret = hp_convert_hexstr_to_str(enum_obj[elem].string.pointer,
150 enum_obj[elem].string.length,
151 &str_value, &value_len);
152 if (ret)
153 return -EINVAL;
154 }
155 break;
156 case ACPI_TYPE_INTEGER:
157 int_value = (u32)enum_obj[elem].integer.value;
158 break;
159 default:
160 pr_warn("Unsupported object type [%d]\n", enum_obj[elem].type);
161 continue;
162 }
163
164 /* Check that both expected and read object type match */
165 if (expected_enum_types[eloc] != enum_obj[elem].type) {
166 pr_warn("Unexpected element type at elem %d: expected %d, got %d, skipping\n",
167 elem, expected_enum_types[eloc], enum_obj[elem].type);
168 kfree(str_value);
169 str_value = NULL;
170 continue;
171 }
172
173 /* Assign appropriate element value to corresponding field */
174 switch (eloc) {
175 case NAME:
176 case VALUE:
177 break;
178 case PATH:
179 strscpy(enum_data->common.path, str_value);
180 break;
181 case IS_READONLY:
182 enum_data->common.is_readonly = int_value;
183 break;
184 case DISPLAY_IN_UI:
185 enum_data->common.display_in_ui = int_value;
186 break;
187 case REQUIRES_PHYSICAL_PRESENCE:
188 enum_data->common.requires_physical_presence = int_value;
189 break;
190 case SEQUENCE:
191 enum_data->common.sequence = int_value;
192 break;
193 case PREREQUISITES_SIZE:
194 if (int_value > MAX_PREREQUISITES_SIZE) {
195 pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
196 int_value = MAX_PREREQUISITES_SIZE;
197 }
198 enum_data->common.prerequisites_size = int_value;
199
200 /*
201 * This step is needed to keep the expected
202 * element list pointing to the right obj[elem].type
203 * when the size is zero. PREREQUISITES
204 * object is omitted by BIOS when the size is
205 * zero.
206 */
207 if (int_value == 0)
208 eloc++;
209 break;
210
211 case PREREQUISITES:
212 size = min_t(u32, enum_data->common.prerequisites_size, MAX_PREREQUISITES_SIZE);
213 for (reqs = 0; reqs < size; reqs++) {
214 if (elem + reqs >= enum_obj_count) {
215 pr_err("Error enum-objects package is too small\n");
216 return -EINVAL;
217 }
218
219 ret = hp_convert_hexstr_to_str(enum_obj[elem + reqs].string.pointer,
220 enum_obj[elem + reqs].string.length,
221 &str_value, &value_len);
222
223 if (ret)
224 return -EINVAL;
225
226 strscpy(enum_data->common.prerequisites[reqs], str_value);
227
228 kfree(str_value);
229 str_value = NULL;
230 }
231 if (size)
232 elem += size - 1;
233 break;
234
235 case SECURITY_LEVEL:
236 enum_data->common.security_level = int_value;
237 break;
238
239 case ENUM_CURRENT_VALUE:
240 strscpy(enum_data->current_value, str_value);
241 break;
242 case ENUM_SIZE:
243 if (int_value > MAX_VALUES_SIZE) {
244 pr_warn("Possible number values size value exceeded the maximum number of elements supported or data may be malformed\n");
245 int_value = MAX_VALUES_SIZE;
246 }
247 enum_data->possible_values_size = int_value;
248
249 /*
250 * This step is needed to keep the expected
251 * element list pointing to the right obj[elem].type
252 * when the size is zero. POSSIBLE_VALUES
253 * object is omitted by BIOS when the size is zero.
254 */
255 if (int_value == 0)
256 eloc++;
257 break;
258
259 case ENUM_POSSIBLE_VALUES:
260 size = enum_data->possible_values_size;
261
262 for (pos_values = 0; pos_values < size && pos_values < MAX_VALUES_SIZE;
263 pos_values++) {
264 if (elem + pos_values >= enum_obj_count) {
265 pr_err("Error enum-objects package is too small\n");
266 return -EINVAL;
267 }
268
269 ret = hp_convert_hexstr_to_str(enum_obj[elem + pos_values].string.pointer,
270 enum_obj[elem + pos_values].string.length,
271 &str_value, &value_len);
272
273 if (ret)
274 return -EINVAL;
275
276 /*
277 * ignore strings when possible values size
278 * is greater than MAX_VALUES_SIZE
279 */
280 if (size < MAX_VALUES_SIZE)
281 strscpy(enum_data->possible_values[pos_values], str_value);
282
283 kfree(str_value);
284 str_value = NULL;
285 }
286 if (size)
287 elem += (size < MAX_VALUES_SIZE ? size : MAX_VALUES_SIZE) - 1;
288 break;
289 default:
290 pr_warn("Invalid element: %d found in Enumeration attribute or data may be malformed\n", elem);
291 break;
292 }
293
294 kfree(str_value);
295 str_value = NULL;
296 }
297
298 exit_enumeration_package:
299 kfree(str_value);
300 return 0;
301 }
302
303 /**
304 * hp_populate_enumeration_package_data() -
305 * Populate all properties of an instance under enumeration attribute
306 *
307 * @enum_obj: ACPI object with enumeration data
308 * @enum_obj_count: Number of elements in @enum_obj
309 * @instance_id: The instance to enumerate
310 * @attr_name_kobj: The parent kernel object
311 */
hp_populate_enumeration_package_data(union acpi_object * enum_obj,int enum_obj_count,int instance_id,struct kobject * attr_name_kobj)312 int hp_populate_enumeration_package_data(union acpi_object *enum_obj,
313 int enum_obj_count,
314 int instance_id,
315 struct kobject *attr_name_kobj)
316 {
317 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
318
319 enum_data->attr_name_kobj = attr_name_kobj;
320
321 hp_populate_enumeration_elements_from_package(enum_obj,
322 enum_obj_count,
323 instance_id);
324 hp_update_attribute_permissions(enum_data->common.is_readonly,
325 &enumeration_current_val);
326 /*
327 * Several attributes have names such "MONDAY". Friendly
328 * user nane is generated to make the name more descriptive
329 */
330 hp_friendly_user_name_update(enum_data->common.path,
331 attr_name_kobj->name,
332 enum_data->common.display_name,
333 sizeof(enum_data->common.display_name));
334 return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
335 }
336
hp_populate_enumeration_elements_from_buffer(u8 * buffer_ptr,u32 * buffer_size,int instance_id)337 static int hp_populate_enumeration_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
338 int instance_id)
339 {
340 int values;
341 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
342 int ret = 0;
343
344 /*
345 * Only data relevant to this driver and its functionality is
346 * read. BIOS defines the order in which each * element is
347 * read. Element 0 data is not relevant to this
348 * driver hence it is ignored. For clarity, all element names
349 * (DISPLAY_IN_UI) which defines the order in which is read
350 * and the name matches the variable where the data is stored.
351 *
352 * In earlier implementation, reported errors were ignored
353 * causing the data to remain uninitialized. It is not
354 * possible to determine if data read from BIOS is valid or
355 * not. It is for this reason functions may return a error
356 * without validating the data itself.
357 */
358
359 // VALUE:
360 ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size, enum_data->current_value,
361 sizeof(enum_data->current_value));
362 if (ret < 0)
363 goto buffer_exit;
364
365 // COMMON:
366 ret = hp_get_common_data_from_buffer(&buffer_ptr, buffer_size, &enum_data->common);
367 if (ret < 0)
368 goto buffer_exit;
369
370 // ENUM_CURRENT_VALUE:
371 ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
372 enum_data->current_value,
373 sizeof(enum_data->current_value));
374 if (ret < 0)
375 goto buffer_exit;
376
377 // ENUM_SIZE:
378 ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
379 &enum_data->possible_values_size);
380
381 if (enum_data->possible_values_size > MAX_VALUES_SIZE) {
382 /* Report a message and limit possible values size to maximum value */
383 pr_warn("Enum Possible size value exceeded the maximum number of elements supported or data may be malformed\n");
384 enum_data->possible_values_size = MAX_VALUES_SIZE;
385 }
386
387 // ENUM_POSSIBLE_VALUES:
388 for (values = 0; values < enum_data->possible_values_size; values++) {
389 ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
390 enum_data->possible_values[values],
391 sizeof(enum_data->possible_values[values]));
392 if (ret < 0)
393 break;
394 }
395
396 buffer_exit:
397 return ret;
398 }
399
400 /**
401 * hp_populate_enumeration_buffer_data() -
402 * Populate all properties of an instance under enumeration attribute
403 *
404 * @buffer_ptr: Buffer pointer
405 * @buffer_size: Buffer size
406 * @instance_id: The instance to enumerate
407 * @attr_name_kobj: The parent kernel object
408 */
hp_populate_enumeration_buffer_data(u8 * buffer_ptr,u32 * buffer_size,int instance_id,struct kobject * attr_name_kobj)409 int hp_populate_enumeration_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
410 int instance_id,
411 struct kobject *attr_name_kobj)
412 {
413 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
414 int ret = 0;
415
416 enum_data->attr_name_kobj = attr_name_kobj;
417
418 /* Populate enumeration elements */
419 ret = hp_populate_enumeration_elements_from_buffer(buffer_ptr, buffer_size,
420 instance_id);
421 if (ret < 0)
422 return ret;
423
424 hp_update_attribute_permissions(enum_data->common.is_readonly,
425 &enumeration_current_val);
426 /*
427 * Several attributes have names such "MONDAY". A Friendlier
428 * user nane is generated to make the name more descriptive
429 */
430 hp_friendly_user_name_update(enum_data->common.path,
431 attr_name_kobj->name,
432 enum_data->common.display_name,
433 sizeof(enum_data->common.display_name));
434
435 return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
436 }
437
438 /**
439 * hp_exit_enumeration_attributes() - Clear all attribute data
440 *
441 * Clears all data allocated for this group of attributes
442 */
hp_exit_enumeration_attributes(void)443 void hp_exit_enumeration_attributes(void)
444 {
445 int instance_id;
446
447 for (instance_id = 0; instance_id < bioscfg_drv.enumeration_instances_count;
448 instance_id++) {
449 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
450 struct kobject *attr_name_kobj = enum_data->attr_name_kobj;
451
452 if (attr_name_kobj)
453 sysfs_remove_group(attr_name_kobj, &enumeration_attr_group);
454 }
455 bioscfg_drv.enumeration_instances_count = 0;
456
457 kvfree(bioscfg_drv.enumeration_data);
458 bioscfg_drv.enumeration_data = NULL;
459 }
460