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				sizeof(integer_data->common.path));
197			break;
198		case IS_READONLY:
199			integer_data->common.is_readonly = int_value;
200			break;
201		case DISPLAY_IN_UI:
202			integer_data->common.display_in_ui = int_value;
203			break;
204		case REQUIRES_PHYSICAL_PRESENCE:
205			integer_data->common.requires_physical_presence = int_value;
206			break;
207		case SEQUENCE:
208			integer_data->common.sequence = int_value;
209			break;
210		case PREREQUISITES_SIZE:
211			if (int_value > MAX_PREREQUISITES_SIZE) {
212				pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
213				int_value = MAX_PREREQUISITES_SIZE;
214			}
215			integer_data->common.prerequisites_size = int_value;
216
217			/*
218			 * This step is needed to keep the expected
219			 * element list pointing to the right obj[elem].type
220			 * when the size is zero. PREREQUISITES
221			 * object is omitted by BIOS when the size is
222			 * zero.
223			 */
224			if (integer_data->common.prerequisites_size == 0)
225				eloc++;
226			break;
227		case PREREQUISITES:
228			size = min_t(u32, integer_data->common.prerequisites_size, MAX_PREREQUISITES_SIZE);
229
230			for (reqs = 0; reqs < size; reqs++) {
231				if (elem >= integer_obj_count) {
232					pr_err("Error elem-objects package is too small\n");
233					return -EINVAL;
234				}
235
236				ret = hp_convert_hexstr_to_str(integer_obj[elem + reqs].string.pointer,
237							       integer_obj[elem + reqs].string.length,
238							       &str_value, &value_len);
239
240				if (ret)
241					continue;
242
243				strscpy(integer_data->common.prerequisites[reqs],
244					str_value,
245					sizeof(integer_data->common.prerequisites[reqs]));
246				kfree(str_value);
247				str_value = NULL;
248			}
249			break;
250
251		case SECURITY_LEVEL:
252			integer_data->common.security_level = int_value;
253			break;
254		case INT_LOWER_BOUND:
255			integer_data->lower_bound = int_value;
256			break;
257		case INT_UPPER_BOUND:
258			integer_data->upper_bound = int_value;
259			break;
260		case INT_SCALAR_INCREMENT:
261			integer_data->scalar_increment = int_value;
262			break;
263		default:
264			pr_warn("Invalid element: %d found in Integer attribute or data may be malformed\n", elem);
265			break;
266		}
267
268		kfree(str_value);
269		str_value = NULL;
270	}
271exit_integer_package:
272	kfree(str_value);
273	return 0;
274}
275
276/**
277 * hp_populate_integer_package_data() -
278 * Populate all properties of an instance under integer attribute
279 *
280 * @integer_obj: ACPI object with integer data
281 * @instance_id: The instance to enumerate
282 * @attr_name_kobj: The parent kernel object
283 */
284int hp_populate_integer_package_data(union acpi_object *integer_obj,
285				     int instance_id,
286				     struct kobject *attr_name_kobj)
287{
288	struct integer_data *integer_data = &bioscfg_drv.integer_data[instance_id];
289
290	integer_data->attr_name_kobj = attr_name_kobj;
291	hp_populate_integer_elements_from_package(integer_obj,
292						  integer_obj->package.count,
293						  instance_id);
294	hp_update_attribute_permissions(integer_data->common.is_readonly,
295					&integer_current_val);
296	hp_friendly_user_name_update(integer_data->common.path,
297				     attr_name_kobj->name,
298				     integer_data->common.display_name,
299				     sizeof(integer_data->common.display_name));
300	return sysfs_create_group(attr_name_kobj, &integer_attr_group);
301}
302
303static int hp_populate_integer_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
304						    int instance_id)
305{
306	char *dst = NULL;
307	int dst_size = *buffer_size / sizeof(u16);
308	struct integer_data *integer_data = &bioscfg_drv.integer_data[instance_id];
309	int ret = 0;
310
311	dst = kcalloc(dst_size, sizeof(char), GFP_KERNEL);
312	if (!dst)
313		return -ENOMEM;
314
315	/*
316	 * Only data relevant to this driver and its functionality is
317	 * read. BIOS defines the order in which each * element is
318	 * read. Element 0 data is not relevant to this
319	 * driver hence it is ignored. For clarity, all element names
320	 * (DISPLAY_IN_UI) which defines the order in which is read
321	 * and the name matches the variable where the data is stored.
322	 *
323	 * In earlier implementation, reported errors were ignored
324	 * causing the data to remain uninitialized. It is not
325	 * possible to determine if data read from BIOS is valid or
326	 * not. It is for this reason functions may return a error
327	 * without validating the data itself.
328	 */
329
330	// VALUE:
331	integer_data->current_value = 0;
332
333	hp_get_string_from_buffer(&buffer_ptr, buffer_size, dst, dst_size);
334	ret = kstrtoint(dst, 10, &integer_data->current_value);
335	if (ret)
336		pr_warn("Unable to convert string to integer: %s\n", dst);
337	kfree(dst);
338
339	// COMMON:
340	ret = hp_get_common_data_from_buffer(&buffer_ptr, buffer_size, &integer_data->common);
341	if (ret < 0)
342		goto buffer_exit;
343
344	// INT_LOWER_BOUND:
345	ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
346					 &integer_data->lower_bound);
347	if (ret < 0)
348		goto buffer_exit;
349
350	// INT_UPPER_BOUND:
351	ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
352					 &integer_data->upper_bound);
353	if (ret < 0)
354		goto buffer_exit;
355
356	// INT_SCALAR_INCREMENT:
357	ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
358					 &integer_data->scalar_increment);
359
360buffer_exit:
361	return ret;
362}
363
364/**
365 * hp_populate_integer_buffer_data() -
366 * Populate all properties of an instance under integer attribute
367 *
368 * @buffer_ptr: Buffer pointer
369 * @buffer_size: Buffer size
370 * @instance_id: The instance to enumerate
371 * @attr_name_kobj: The parent kernel object
372 */
373int hp_populate_integer_buffer_data(u8 *buffer_ptr, u32 *buffer_size, int instance_id,
374				    struct kobject *attr_name_kobj)
375{
376	struct integer_data *integer_data = &bioscfg_drv.integer_data[instance_id];
377	int ret = 0;
378
379	integer_data->attr_name_kobj = attr_name_kobj;
380
381	/* Populate integer elements */
382	ret = hp_populate_integer_elements_from_buffer(buffer_ptr, buffer_size,
383						       instance_id);
384	if (ret < 0)
385		return ret;
386
387	hp_update_attribute_permissions(integer_data->common.is_readonly,
388					&integer_current_val);
389	hp_friendly_user_name_update(integer_data->common.path,
390				     attr_name_kobj->name,
391				     integer_data->common.display_name,
392				     sizeof(integer_data->common.display_name));
393
394	return sysfs_create_group(attr_name_kobj, &integer_attr_group);
395}
396
397/**
398 * hp_exit_integer_attributes() - Clear all attribute data
399 *
400 * Clears all data allocated for this group of attributes
401 */
402void hp_exit_integer_attributes(void)
403{
404	int instance_id;
405
406	for (instance_id = 0; instance_id < bioscfg_drv.integer_instances_count;
407	     instance_id++) {
408		struct kobject *attr_name_kobj =
409			bioscfg_drv.integer_data[instance_id].attr_name_kobj;
410
411		if (attr_name_kobj)
412			sysfs_remove_group(attr_name_kobj, &integer_attr_group);
413	}
414	bioscfg_drv.integer_instances_count = 0;
415
416	kfree(bioscfg_drv.integer_data);
417	bioscfg_drv.integer_data = NULL;
418}
419