enum-attributes.c

  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
 11GET_INSTANCE_ID(enumeration);
 12
 13static 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 */
 31static 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
 51static 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
 58ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name, enumeration);
 59static struct kobj_attribute enumeration_display_name =
 60		__ATTR_RO(display_name);
 61
 62ATTRIBUTE_PROPERTY_STORE(current_value, enumeration);
 63static struct kobj_attribute enumeration_current_val =
 64		__ATTR_RW(current_value);
 65
 66ATTRIBUTE_VALUES_PROPERTY_SHOW(possible_values, enumeration, SEMICOLON_SEP);
 67static struct kobj_attribute enumeration_poss_val =
 68		__ATTR_RO(possible_values);
 69
 70static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
 71			 char *buf)
 72{
 73	return sysfs_emit(buf, "enumeration\n");
 74}
 75
 76static struct kobj_attribute enumeration_type =
 77		__ATTR_RO(type);
 78
 79static 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
 88static const struct attribute_group enumeration_attr_group = {
 89	.attrs = enumeration_attrs,
 90};
 91
 92int 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 */
110static 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
126static 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_err("Error expected type %d for elem %d, but got type %d instead\n",
167			       expected_enum_types[eloc], elem, enum_obj[elem].type);
168			kfree(str_value);
169			return -EIO;
170		}
171
172		/* Assign appropriate element value to corresponding field */
173		switch (eloc) {
174		case NAME:
175		case VALUE:
176			break;
177		case PATH:
178			strscpy(enum_data->common.path, str_value);
179			break;
180		case IS_READONLY:
181			enum_data->common.is_readonly = int_value;
182			break;
183		case DISPLAY_IN_UI:
184			enum_data->common.display_in_ui = int_value;
185			break;
186		case REQUIRES_PHYSICAL_PRESENCE:
187			enum_data->common.requires_physical_presence = int_value;
188			break;
189		case SEQUENCE:
190			enum_data->common.sequence = int_value;
191			break;
192		case PREREQUISITES_SIZE:
193			if (int_value > MAX_PREREQUISITES_SIZE) {
194				pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
195				int_value = MAX_PREREQUISITES_SIZE;
196			}
197			enum_data->common.prerequisites_size = int_value;
198
199			/*
200			 * This step is needed to keep the expected
201			 * element list pointing to the right obj[elem].type
202			 * when the size is zero. PREREQUISITES
203			 * object is omitted by BIOS when the size is
204			 * zero.
205			 */
206			if (int_value == 0)
207				eloc++;
208			break;
209
210		case PREREQUISITES:
211			size = min_t(u32, enum_data->common.prerequisites_size, MAX_PREREQUISITES_SIZE);
212			for (reqs = 0; reqs < size; reqs++) {
213				if (elem + reqs >= enum_obj_count) {
214					pr_err("Error enum-objects package is too small\n");
215					return -EINVAL;
216				}
217
218				ret = hp_convert_hexstr_to_str(enum_obj[elem + reqs].string.pointer,
219							       enum_obj[elem + reqs].string.length,
220							       &str_value, &value_len);
221
222				if (ret)
223					return -EINVAL;
224
225				strscpy(enum_data->common.prerequisites[reqs], str_value);
226
227				kfree(str_value);
228				str_value = NULL;
229			}
230			break;
231
232		case SECURITY_LEVEL:
233			enum_data->common.security_level = int_value;
234			break;
235
236		case ENUM_CURRENT_VALUE:
237			strscpy(enum_data->current_value, str_value);
238			break;
239		case ENUM_SIZE:
240			if (int_value > MAX_VALUES_SIZE) {
241				pr_warn("Possible number values size value exceeded the maximum number of elements supported or data may be malformed\n");
242				int_value = MAX_VALUES_SIZE;
243			}
244			enum_data->possible_values_size = int_value;
245
246			/*
247			 * This step is needed to keep the expected
248			 * element list pointing to the right obj[elem].type
249			 * when the size is zero. POSSIBLE_VALUES
250			 * object is omitted by BIOS when the size is zero.
251			 */
252			if (int_value == 0)
253				eloc++;
254			break;
255
256		case ENUM_POSSIBLE_VALUES:
257			size = enum_data->possible_values_size;
258
259			for (pos_values = 0; pos_values < size && pos_values < MAX_VALUES_SIZE;
260			     pos_values++) {
261				if (elem + pos_values >= enum_obj_count) {
262					pr_err("Error enum-objects package is too small\n");
263					return -EINVAL;
264				}
265
266				ret = hp_convert_hexstr_to_str(enum_obj[elem + pos_values].string.pointer,
267							       enum_obj[elem + pos_values].string.length,
268							       &str_value, &value_len);
269
270				if (ret)
271					return -EINVAL;
272
273				/*
274				 * ignore strings when possible values size
275				 * is greater than MAX_VALUES_SIZE
276				 */
277				if (size < MAX_VALUES_SIZE)
278					strscpy(enum_data->possible_values[pos_values], str_value);
279
280				kfree(str_value);
281				str_value = NULL;
282			}
283			break;
284		default:
285			pr_warn("Invalid element: %d found in Enumeration attribute or data may be malformed\n", elem);
286			break;
287		}
288
289		kfree(str_value);
290		str_value = NULL;
291	}
292
293exit_enumeration_package:
294	kfree(str_value);
295	return 0;
296}
297
298/**
299 * hp_populate_enumeration_package_data() -
300 * Populate all properties of an instance under enumeration attribute
301 *
302 * @enum_obj: ACPI object with enumeration data
303 * @instance_id: The instance to enumerate
304 * @attr_name_kobj: The parent kernel object
305 */
306int hp_populate_enumeration_package_data(union acpi_object *enum_obj,
307					 int instance_id,
308					 struct kobject *attr_name_kobj)
309{
310	struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
311
312	enum_data->attr_name_kobj = attr_name_kobj;
313
314	hp_populate_enumeration_elements_from_package(enum_obj,
315						      enum_obj->package.count,
316						      instance_id);
317	hp_update_attribute_permissions(enum_data->common.is_readonly,
318					&enumeration_current_val);
319	/*
320	 * Several attributes have names such "MONDAY". Friendly
321	 * user nane is generated to make the name more descriptive
322	 */
323	hp_friendly_user_name_update(enum_data->common.path,
324				     attr_name_kobj->name,
325				     enum_data->common.display_name,
326				     sizeof(enum_data->common.display_name));
327	return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
328}
329
330static int hp_populate_enumeration_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
331							int instance_id)
332{
333	int values;
334	struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
335	int ret = 0;
336
337	/*
338	 * Only data relevant to this driver and its functionality is
339	 * read. BIOS defines the order in which each * element is
340	 * read. Element 0 data is not relevant to this
341	 * driver hence it is ignored. For clarity, all element names
342	 * (DISPLAY_IN_UI) which defines the order in which is read
343	 * and the name matches the variable where the data is stored.
344	 *
345	 * In earlier implementation, reported errors were ignored
346	 * causing the data to remain uninitialized. It is not
347	 * possible to determine if data read from BIOS is valid or
348	 * not. It is for this reason functions may return a error
349	 * without validating the data itself.
350	 */
351
352	// VALUE:
353	ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size, enum_data->current_value,
354					sizeof(enum_data->current_value));
355	if (ret < 0)
356		goto buffer_exit;
357
358	// COMMON:
359	ret = hp_get_common_data_from_buffer(&buffer_ptr, buffer_size, &enum_data->common);
360	if (ret < 0)
361		goto buffer_exit;
362
363	// ENUM_CURRENT_VALUE:
364	ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
365					enum_data->current_value,
366					sizeof(enum_data->current_value));
367	if (ret < 0)
368		goto buffer_exit;
369
370	// ENUM_SIZE:
371	ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
372					 &enum_data->possible_values_size);
373
374	if (enum_data->possible_values_size > MAX_VALUES_SIZE) {
375		/* Report a message and limit possible values size to maximum value */
376		pr_warn("Enum Possible size value exceeded the maximum number of elements supported or data may be malformed\n");
377		enum_data->possible_values_size = MAX_VALUES_SIZE;
378	}
379
380	// ENUM_POSSIBLE_VALUES:
381	for (values = 0; values < enum_data->possible_values_size; values++) {
382		ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
383						enum_data->possible_values[values],
384						sizeof(enum_data->possible_values[values]));
385		if (ret < 0)
386			break;
387	}
388
389buffer_exit:
390	return ret;
391}
392
393/**
394 * hp_populate_enumeration_buffer_data() -
395 * Populate all properties of an instance under enumeration attribute
396 *
397 * @buffer_ptr: Buffer pointer
398 * @buffer_size: Buffer size
399 * @instance_id: The instance to enumerate
400 * @attr_name_kobj: The parent kernel object
401 */
402int hp_populate_enumeration_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
403					int instance_id,
404					struct kobject *attr_name_kobj)
405{
406	struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
407	int ret = 0;
408
409	enum_data->attr_name_kobj = attr_name_kobj;
410
411	/* Populate enumeration elements */
412	ret = hp_populate_enumeration_elements_from_buffer(buffer_ptr, buffer_size,
413							   instance_id);
414	if (ret < 0)
415		return ret;
416
417	hp_update_attribute_permissions(enum_data->common.is_readonly,
418					&enumeration_current_val);
419	/*
420	 * Several attributes have names such "MONDAY". A Friendlier
421	 * user nane is generated to make the name more descriptive
422	 */
423	hp_friendly_user_name_update(enum_data->common.path,
424				     attr_name_kobj->name,
425				     enum_data->common.display_name,
426				     sizeof(enum_data->common.display_name));
427
428	return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
429}
430
431/**
432 * hp_exit_enumeration_attributes() - Clear all attribute data
433 *
434 * Clears all data allocated for this group of attributes
435 */
436void hp_exit_enumeration_attributes(void)
437{
438	int instance_id;
439
440	for (instance_id = 0; instance_id < bioscfg_drv.enumeration_instances_count;
441	     instance_id++) {
442		struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
443		struct kobject *attr_name_kobj = enum_data->attr_name_kobj;
444
445		if (attr_name_kobj)
446			sysfs_remove_group(attr_name_kobj, &enumeration_attr_group);
447	}
448	bioscfg_drv.enumeration_instances_count = 0;
449
450	kvfree(bioscfg_drv.enumeration_data);
451	bioscfg_drv.enumeration_data = NULL;
452}