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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Functions corresponding to integer type attributes under
4 * BIOS Enumeration GUID for use with hp-bioscfg driver.
5 *
6 * Copyright (c) 2022 Hewlett-Packard Inc.
7 */
8
9#include "bioscfg.h"
10
11GET_INSTANCE_ID(integer);
12
13static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
14{
15 int instance_id = get_integer_instance_id(kobj);
16
17 if (instance_id < 0)
18 return -EIO;
19
20 return sysfs_emit(buf, "%d\n",
21 bioscfg_drv.integer_data[instance_id].current_value);
22}
23
24/**
25 * validate_integer_input() -
26 * Validate input of current_value against lower and upper bound
27 *
28 * @instance_id: The instance on which input is validated
29 * @buf: Input value
30 */
31static int validate_integer_input(int instance_id, char *buf)
32{
33 int in_val;
34 int ret;
35 struct integer_data *integer_data = &bioscfg_drv.integer_data[instance_id];
36
37 /* BIOS treats it as a read only attribute */
38 if (integer_data->common.is_readonly)
39 return -EIO;
40
41 ret = kstrtoint(buf, 10, &in_val);
42 if (ret < 0)
43 return ret;
44
45 if (in_val < integer_data->lower_bound ||
46 in_val > integer_data->upper_bound)
47 return -ERANGE;
48
49 return 0;
50}
51
52static void update_integer_value(int instance_id, char *attr_value)
53{
54 int in_val;
55 int ret;
56 struct integer_data *integer_data = &bioscfg_drv.integer_data[instance_id];
57
58 ret = kstrtoint(attr_value, 10, &in_val);
59 if (ret == 0)
60 integer_data->current_value = in_val;
61 else
62 pr_warn("Invalid integer value found: %s\n", attr_value);
63}
64
65ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name, integer);
66static struct kobj_attribute integer_display_name =
67 __ATTR_RO(display_name);
68
69ATTRIBUTE_PROPERTY_STORE(current_value, integer);
70static struct kobj_attribute integer_current_val =
71 __ATTR_RW_MODE(current_value, 0644);
72
73ATTRIBUTE_N_PROPERTY_SHOW(lower_bound, integer);
74static struct kobj_attribute integer_lower_bound =
75 __ATTR_RO(lower_bound);
76
77ATTRIBUTE_N_PROPERTY_SHOW(upper_bound, integer);
78static struct kobj_attribute integer_upper_bound =
79 __ATTR_RO(upper_bound);
80
81ATTRIBUTE_N_PROPERTY_SHOW(scalar_increment, integer);
82static struct kobj_attribute integer_scalar_increment =
83 __ATTR_RO(scalar_increment);
84
85static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
86 char *buf)
87{
88 return sysfs_emit(buf, "integer\n");
89}
90
91static struct kobj_attribute integer_type =
92 __ATTR_RO(type);
93
94static struct attribute *integer_attrs[] = {
95 &common_display_langcode.attr,
96 &integer_display_name.attr,
97 &integer_current_val.attr,
98 &integer_lower_bound.attr,
99 &integer_upper_bound.attr,
100 &integer_scalar_increment.attr,
101 &integer_type.attr,
102 NULL
103};
104
105static const struct attribute_group integer_attr_group = {
106 .attrs = integer_attrs,
107};
108
109int hp_alloc_integer_data(void)
110{
111 bioscfg_drv.integer_instances_count = hp_get_instance_count(HP_WMI_BIOS_INTEGER_GUID);
112 bioscfg_drv.integer_data = kcalloc(bioscfg_drv.integer_instances_count,
113 sizeof(*bioscfg_drv.integer_data), GFP_KERNEL);
114
115 if (!bioscfg_drv.integer_data) {
116 bioscfg_drv.integer_instances_count = 0;
117 return -ENOMEM;
118 }
119 return 0;
120}
121
122/* Expected Values types associated with each element */
123static const acpi_object_type expected_integer_types[] = {
124 [NAME] = ACPI_TYPE_STRING,
125 [VALUE] = ACPI_TYPE_STRING,
126 [PATH] = ACPI_TYPE_STRING,
127 [IS_READONLY] = ACPI_TYPE_INTEGER,
128 [DISPLAY_IN_UI] = ACPI_TYPE_INTEGER,
129 [REQUIRES_PHYSICAL_PRESENCE] = ACPI_TYPE_INTEGER,
130 [SEQUENCE] = ACPI_TYPE_INTEGER,
131 [PREREQUISITES_SIZE] = ACPI_TYPE_INTEGER,
132 [PREREQUISITES] = ACPI_TYPE_STRING,
133 [SECURITY_LEVEL] = ACPI_TYPE_INTEGER,
134 [INT_LOWER_BOUND] = ACPI_TYPE_INTEGER,
135 [INT_UPPER_BOUND] = ACPI_TYPE_INTEGER,
136 [INT_SCALAR_INCREMENT] = ACPI_TYPE_INTEGER,
137};
138
139static int hp_populate_integer_elements_from_package(union acpi_object *integer_obj,
140 int integer_obj_count,
141 int instance_id)
142{
143 char *str_value = NULL;
144 int value_len;
145 int ret;
146 u32 int_value = 0;
147 int elem;
148 int reqs;
149 int eloc;
150 int size;
151 struct integer_data *integer_data = &bioscfg_drv.integer_data[instance_id];
152
153 if (!integer_obj)
154 return -EINVAL;
155
156 for (elem = 1, eloc = 1; elem < integer_obj_count; elem++, eloc++) {
157 /* ONLY look at the first INTEGER_ELEM_CNT elements */
158 if (eloc == INT_ELEM_CNT)
159 goto exit_integer_package;
160
161 switch (integer_obj[elem].type) {
162 case ACPI_TYPE_STRING:
163 if (elem != PREREQUISITES) {
164 ret = hp_convert_hexstr_to_str(integer_obj[elem].string.pointer,
165 integer_obj[elem].string.length,
166 &str_value, &value_len);
167 if (ret)
168 continue;
169 }
170 break;
171 case ACPI_TYPE_INTEGER:
172 int_value = (u32)integer_obj[elem].integer.value;
173 break;
174 default:
175 pr_warn("Unsupported object type [%d]\n", integer_obj[elem].type);
176 continue;
177 }
178 /* Check that both expected and read object type match */
179 if (expected_integer_types[eloc] != integer_obj[elem].type) {
180 pr_err("Error expected type %d for elem %d, but got type %d instead\n",
181 expected_integer_types[eloc], elem, integer_obj[elem].type);
182 kfree(str_value);
183 return -EIO;
184 }
185 /* Assign appropriate element value to corresponding field*/
186 switch (eloc) {
187 case VALUE:
188 ret = kstrtoint(str_value, 10, &int_value);
189 if (ret)
190 continue;
191
192 integer_data->current_value = int_value;
193 break;
194 case PATH:
195 strscpy(integer_data->common.path, str_value);
196 break;
197 case IS_READONLY:
198 integer_data->common.is_readonly = int_value;
199 break;
200 case DISPLAY_IN_UI:
201 integer_data->common.display_in_ui = int_value;
202 break;
203 case REQUIRES_PHYSICAL_PRESENCE:
204 integer_data->common.requires_physical_presence = int_value;
205 break;
206 case SEQUENCE:
207 integer_data->common.sequence = int_value;
208 break;
209 case PREREQUISITES_SIZE:
210 if (int_value > MAX_PREREQUISITES_SIZE) {
211 pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
212 int_value = MAX_PREREQUISITES_SIZE;
213 }
214 integer_data->common.prerequisites_size = int_value;
215
216 /*
217 * This step is needed to keep the expected
218 * element list pointing to the right obj[elem].type
219 * when the size is zero. PREREQUISITES
220 * object is omitted by BIOS when the size is
221 * zero.
222 */
223 if (integer_data->common.prerequisites_size == 0)
224 eloc++;
225 break;
226 case PREREQUISITES:
227 size = min_t(u32, integer_data->common.prerequisites_size, MAX_PREREQUISITES_SIZE);
228
229 for (reqs = 0; reqs < size; reqs++) {
230 if (elem >= integer_obj_count) {
231 pr_err("Error elem-objects package is too small\n");
232 return -EINVAL;
233 }
234
235 ret = hp_convert_hexstr_to_str(integer_obj[elem + reqs].string.pointer,
236 integer_obj[elem + reqs].string.length,
237 &str_value, &value_len);
238
239 if (ret)
240 continue;
241
242 strscpy(integer_data->common.prerequisites[reqs], str_value);
243 kfree(str_value);
244 str_value = NULL;
245 }
246 break;
247
248 case SECURITY_LEVEL:
249 integer_data->common.security_level = int_value;
250 break;
251 case INT_LOWER_BOUND:
252 integer_data->lower_bound = int_value;
253 break;
254 case INT_UPPER_BOUND:
255 integer_data->upper_bound = int_value;
256 break;
257 case INT_SCALAR_INCREMENT:
258 integer_data->scalar_increment = int_value;
259 break;
260 default:
261 pr_warn("Invalid element: %d found in Integer attribute or data may be malformed\n", elem);
262 break;
263 }
264
265 kfree(str_value);
266 str_value = NULL;
267 }
268exit_integer_package:
269 kfree(str_value);
270 return 0;
271}
272
273/**
274 * hp_populate_integer_package_data() -
275 * Populate all properties of an instance under integer attribute
276 *
277 * @integer_obj: ACPI object with integer data
278 * @instance_id: The instance to enumerate
279 * @attr_name_kobj: The parent kernel object
280 */
281int hp_populate_integer_package_data(union acpi_object *integer_obj,
282 int instance_id,
283 struct kobject *attr_name_kobj)
284{
285 struct integer_data *integer_data = &bioscfg_drv.integer_data[instance_id];
286
287 integer_data->attr_name_kobj = attr_name_kobj;
288 hp_populate_integer_elements_from_package(integer_obj,
289 integer_obj->package.count,
290 instance_id);
291 hp_update_attribute_permissions(integer_data->common.is_readonly,
292 &integer_current_val);
293 hp_friendly_user_name_update(integer_data->common.path,
294 attr_name_kobj->name,
295 integer_data->common.display_name,
296 sizeof(integer_data->common.display_name));
297 return sysfs_create_group(attr_name_kobj, &integer_attr_group);
298}
299
300static int hp_populate_integer_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
301 int instance_id)
302{
303 char *dst = NULL;
304 int dst_size = *buffer_size / sizeof(u16);
305 struct integer_data *integer_data = &bioscfg_drv.integer_data[instance_id];
306 int ret = 0;
307
308 dst = kcalloc(dst_size, sizeof(char), GFP_KERNEL);
309 if (!dst)
310 return -ENOMEM;
311
312 /*
313 * Only data relevant to this driver and its functionality is
314 * read. BIOS defines the order in which each * element is
315 * read. Element 0 data is not relevant to this
316 * driver hence it is ignored. For clarity, all element names
317 * (DISPLAY_IN_UI) which defines the order in which is read
318 * and the name matches the variable where the data is stored.
319 *
320 * In earlier implementation, reported errors were ignored
321 * causing the data to remain uninitialized. It is not
322 * possible to determine if data read from BIOS is valid or
323 * not. It is for this reason functions may return a error
324 * without validating the data itself.
325 */
326
327 // VALUE:
328 integer_data->current_value = 0;
329
330 hp_get_string_from_buffer(&buffer_ptr, buffer_size, dst, dst_size);
331 ret = kstrtoint(dst, 10, &integer_data->current_value);
332 if (ret)
333 pr_warn("Unable to convert string to integer: %s\n", dst);
334 kfree(dst);
335
336 // COMMON:
337 ret = hp_get_common_data_from_buffer(&buffer_ptr, buffer_size, &integer_data->common);
338 if (ret < 0)
339 goto buffer_exit;
340
341 // INT_LOWER_BOUND:
342 ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
343 &integer_data->lower_bound);
344 if (ret < 0)
345 goto buffer_exit;
346
347 // INT_UPPER_BOUND:
348 ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
349 &integer_data->upper_bound);
350 if (ret < 0)
351 goto buffer_exit;
352
353 // INT_SCALAR_INCREMENT:
354 ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
355 &integer_data->scalar_increment);
356
357buffer_exit:
358 return ret;
359}
360
361/**
362 * hp_populate_integer_buffer_data() -
363 * Populate all properties of an instance under integer attribute
364 *
365 * @buffer_ptr: Buffer pointer
366 * @buffer_size: Buffer size
367 * @instance_id: The instance to enumerate
368 * @attr_name_kobj: The parent kernel object
369 */
370int hp_populate_integer_buffer_data(u8 *buffer_ptr, u32 *buffer_size, int instance_id,
371 struct kobject *attr_name_kobj)
372{
373 struct integer_data *integer_data = &bioscfg_drv.integer_data[instance_id];
374 int ret = 0;
375
376 integer_data->attr_name_kobj = attr_name_kobj;
377
378 /* Populate integer elements */
379 ret = hp_populate_integer_elements_from_buffer(buffer_ptr, buffer_size,
380 instance_id);
381 if (ret < 0)
382 return ret;
383
384 hp_update_attribute_permissions(integer_data->common.is_readonly,
385 &integer_current_val);
386 hp_friendly_user_name_update(integer_data->common.path,
387 attr_name_kobj->name,
388 integer_data->common.display_name,
389 sizeof(integer_data->common.display_name));
390
391 return sysfs_create_group(attr_name_kobj, &integer_attr_group);
392}
393
394/**
395 * hp_exit_integer_attributes() - Clear all attribute data
396 *
397 * Clears all data allocated for this group of attributes
398 */
399void hp_exit_integer_attributes(void)
400{
401 int instance_id;
402
403 for (instance_id = 0; instance_id < bioscfg_drv.integer_instances_count;
404 instance_id++) {
405 struct kobject *attr_name_kobj =
406 bioscfg_drv.integer_data[instance_id].attr_name_kobj;
407
408 if (attr_name_kobj)
409 sysfs_remove_group(attr_name_kobj, &integer_attr_group);
410 }
411 bioscfg_drv.integer_instances_count = 0;
412
413 kfree(bioscfg_drv.integer_data);
414 bioscfg_drv.integer_data = NULL;
415}