summaryrefslogtreecommitdiff
path: root/drivers/thunderbolt/property.c
blob: b2f0d6386ceea26bfc738ff72d54f36cc6f7a505 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
// SPDX-License-Identifier: GPL-2.0
/*
 * Thunderbolt XDomain property support
 *
 * Copyright (C) 2017, Intel Corporation
 * Authors: Michael Jamet <michael.jamet@intel.com>
 *          Mika Westerberg <mika.westerberg@linux.intel.com>
 */

#include <linux/err.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/uuid.h>
#include <linux/thunderbolt.h>

struct tb_property_entry {
	u32 key_hi;
	u32 key_lo;
	u16 length;
	u8 reserved;
	u8 type;
	u32 value;
};

struct tb_property_rootdir_entry {
	u32 magic;
	u32 length;
	struct tb_property_entry entries[];
};

struct tb_property_dir_entry {
	u32 uuid[4];
	struct tb_property_entry entries[];
};

#define TB_PROPERTY_ROOTDIR_MAGIC	0x55584401

static struct tb_property_dir *__tb_property_parse_dir(const u32 *block,
	size_t block_len, unsigned int dir_offset, size_t dir_len,
	bool is_root);

static inline void parse_dwdata(void *dst, const void *src, size_t dwords)
{
	be32_to_cpu_array(dst, src, dwords);
}

static inline void format_dwdata(void *dst, const void *src, size_t dwords)
{
	cpu_to_be32_array(dst, src, dwords);
}

static bool tb_property_entry_valid(const struct tb_property_entry *entry,
				  size_t block_len)
{
	switch (entry->type) {
	case TB_PROPERTY_TYPE_DIRECTORY:
	case TB_PROPERTY_TYPE_DATA:
	case TB_PROPERTY_TYPE_TEXT:
		if (entry->length > block_len)
			return false;
		if (entry->value + entry->length > block_len)
			return false;
		break;

	case TB_PROPERTY_TYPE_VALUE:
		if (entry->length != 1)
			return false;
		break;
	}

	return true;
}

static bool tb_property_key_valid(const char *key)
{
	return key && strlen(key) <= TB_PROPERTY_KEY_SIZE;
}

static struct tb_property *
tb_property_alloc(const char *key, enum tb_property_type type)
{
	struct tb_property *property;

	property = kzalloc(sizeof(*property), GFP_KERNEL);
	if (!property)
		return NULL;

	strcpy(property->key, key);
	property->type = type;
	INIT_LIST_HEAD(&property->list);

	return property;
}

static struct tb_property *tb_property_parse(const u32 *block, size_t block_len,
					const struct tb_property_entry *entry)
{
	char key[TB_PROPERTY_KEY_SIZE + 1];
	struct tb_property *property;
	struct tb_property_dir *dir;

	if (!tb_property_entry_valid(entry, block_len))
		return NULL;

	parse_dwdata(key, entry, 2);
	key[TB_PROPERTY_KEY_SIZE] = '\0';

	property = tb_property_alloc(key, entry->type);
	if (!property)
		return NULL;

	property->length = entry->length;

	switch (property->type) {
	case TB_PROPERTY_TYPE_DIRECTORY:
		dir = __tb_property_parse_dir(block, block_len, entry->value,
					      entry->length, false);
		if (!dir) {
			kfree(property);
			return NULL;
		}
		property->value.dir = dir;
		break;

	case TB_PROPERTY_TYPE_DATA:
		property->value.data = kcalloc(property->length, sizeof(u32),
					       GFP_KERNEL);
		if (!property->value.data) {
			kfree(property);
			return NULL;
		}
		parse_dwdata(property->value.data, block + entry->value,
			     entry->length);
		break;

	case TB_PROPERTY_TYPE_TEXT:
		property->value.text = kcalloc(property->length, sizeof(u32),
					       GFP_KERNEL);
		if (!property->value.text) {
			kfree(property);
			return NULL;
		}
		parse_dwdata(property->value.text, block + entry->value,
			     entry->length);
		/* Force null termination */
		property->value.text[property->length * 4 - 1] = '\0';
		break;

	case TB_PROPERTY_TYPE_VALUE:
		property->value.immediate = entry->value;
		break;

	default:
		property->type = TB_PROPERTY_TYPE_UNKNOWN;
		break;
	}

	return property;
}

static struct tb_property_dir *__tb_property_parse_dir(const u32 *block,
	size_t block_len, unsigned int dir_offset, size_t dir_len, bool is_root)
{
	const struct tb_property_entry *entries;
	size_t i, content_len, nentries;
	unsigned int content_offset;
	struct tb_property_dir *dir;

	dir = kzalloc(sizeof(*dir), GFP_KERNEL);
	if (!dir)
		return NULL;

	if (is_root) {
		content_offset = dir_offset + 2;
		content_len = dir_len;
	} else {
		dir->uuid = kmemdup(&block[dir_offset], sizeof(*dir->uuid),
				    GFP_KERNEL);
		content_offset = dir_offset + 4;
		content_len = dir_len - 4; /* Length includes UUID */
	}

	entries = (const struct tb_property_entry *)&block[content_offset];
	nentries = content_len / (sizeof(*entries) / 4);

	INIT_LIST_HEAD(&dir->properties);

	for (i = 0; i < nentries; i++) {
		struct tb_property *property;

		property = tb_property_parse(block, block_len, &entries[i]);
		if (!property) {
			tb_property_free_dir(dir);
			return NULL;
		}

		list_add_tail(&property->list, &dir->properties);
	}

	return dir;
}

/**
 * tb_property_parse_dir() - Parses properties from given property block
 * @block: Property block to parse
 * @block_len: Number of dword elements in the property block
 *
 * This function parses the XDomain properties data block into format that
 * can be traversed using the helper functions provided by this module.
 * Upon success returns the parsed directory. In case of error returns
 * %NULL. The resulting &struct tb_property_dir needs to be released by
 * calling tb_property_free_dir() when not needed anymore.
 *
 * The @block is expected to be root directory.
 */
struct tb_property_dir *tb_property_parse_dir(const u32 *block,
					      size_t block_len)
{
	const struct tb_property_rootdir_entry *rootdir =
		(const struct tb_property_rootdir_entry *)block;

	if (rootdir->magic != TB_PROPERTY_ROOTDIR_MAGIC)
		return NULL;
	if (rootdir->length > block_len)
		return NULL;

	return __tb_property_parse_dir(block, block_len, 0, rootdir->length,
				       true);
}

/**
 * tb_property_create_dir() - Creates new property directory
 * @uuid: UUID used to identify the particular directory
 *
 * Creates new, empty property directory. If @uuid is %NULL then the
 * directory is assumed to be root directory.
 */
struct tb_property_dir *tb_property_create_dir(const uuid_t *uuid)
{
	struct tb_property_dir *dir;

	dir = kzalloc(sizeof(*dir), GFP_KERNEL);
	if (!dir)
		return NULL;

	INIT_LIST_HEAD(&dir->properties);
	if (uuid) {
		dir->uuid = kmemdup(uuid, sizeof(*dir->uuid), GFP_KERNEL);
		if (!dir->uuid) {
			kfree(dir);
			return NULL;
		}
	}

	return dir;
}
EXPORT_SYMBOL_GPL(tb_property_create_dir);

static void tb_property_free(struct tb_property *property)
{
	switch (property->type) {
	case TB_PROPERTY_TYPE_DIRECTORY:
		tb_property_free_dir(property->value.dir);
		break;

	case TB_PROPERTY_TYPE_DATA:
		kfree(property->value.data);
		break;

	case TB_PROPERTY_TYPE_TEXT:
		kfree(property->value.text);
		break;

	default:
		break;
	}

	kfree(property);
}

/**
 * tb_property_free_dir() - Release memory allocated for property directory
 * @dir: Directory to release
 *
 * This will release all the memory the directory occupies including all
 * descendants. It is OK to pass %NULL @dir, then the function does
 * nothing.
 */
void tb_property_free_dir(struct tb_property_dir *dir)
{
	struct tb_property *property, *tmp;

	if (!dir)
		return;

	list_for_each_entry_safe(property, tmp, &dir->properties, list) {
		list_del(&property->list);
		tb_property_free(property);
	}
	kfree(dir->uuid);
	kfree(dir);
}
EXPORT_SYMBOL_GPL(tb_property_free_dir);

static size_t tb_property_dir_length(const struct tb_property_dir *dir,
				     bool recurse, size_t *data_len)
{
	const struct tb_property *property;
	size_t len = 0;

	if (dir->uuid)
		len += sizeof(*dir->uuid) / 4;
	else
		len += sizeof(struct tb_property_rootdir_entry) / 4;

	list_for_each_entry(property, &dir->properties, list) {
		len += sizeof(struct tb_property_entry) / 4;

		switch (property->type) {
		case TB_PROPERTY_TYPE_DIRECTORY:
			if (recurse) {
				len += tb_property_dir_length(
					property->value.dir, recurse, data_len);
			}
			/* Reserve dword padding after each directory */
			if (data_len)
				*data_len += 1;
			break;

		case TB_PROPERTY_TYPE_DATA:
		case TB_PROPERTY_TYPE_TEXT:
			if (data_len)
				*data_len += property->length;
			break;

		default:
			break;
		}
	}

	return len;
}

static ssize_t __tb_property_format_dir(const struct tb_property_dir *dir,
	u32 *block, unsigned int start_offset, size_t block_len)
{
	unsigned int data_offset, dir_end;
	const struct tb_property *property;
	struct tb_property_entry *entry;
	size_t dir_len, data_len = 0;
	int ret;

	/*
	 * The structure of property block looks like following. Leaf
	 * data/text is included right after the directory and each
	 * directory follows each other (even nested ones).
	 *
	 * +----------+ <-- start_offset
	 * |  header  | <-- root directory header
	 * +----------+ ---
	 * |  entry 0 | -^--------------------.
	 * +----------+  |                    |
	 * |  entry 1 | -|--------------------|--.
	 * +----------+  |                    |  |
	 * |  entry 2 | -|-----------------.  |  |
	 * +----------+  |                 |  |  |
	 * :          :  |  dir_len        |  |  |
	 * .          .  |                 |  |  |
	 * :          :  |                 |  |  |
	 * +----------+  |                 |  |  |
	 * |  entry n |  v                 |  |  |
	 * +----------+ <-- data_offset    |  |  |
	 * |  data 0  | <------------------|--'  |
	 * +----------+                    |     |
	 * |  data 1  | <------------------|-----'
	 * +----------+                    |
	 * | 00000000 | padding            |
	 * +----------+ <-- dir_end <------'
	 * |   UUID   | <-- directory UUID (child directory)
	 * +----------+
	 * |  entry 0 |
	 * +----------+
	 * |  entry 1 |
	 * +----------+
	 * :          :
	 * .          .
	 * :          :
	 * +----------+
	 * |  entry n |
	 * +----------+
	 * |  data 0  |
	 * +----------+
	 *
	 * We use dir_end to hold pointer to the end of the directory. It
	 * will increase as we add directories and each directory should be
	 * added starting from previous dir_end.
	 */
	dir_len = tb_property_dir_length(dir, false, &data_len);
	data_offset = start_offset + dir_len;
	dir_end = start_offset + data_len + dir_len;

	if (data_offset > dir_end)
		return -EINVAL;
	if (dir_end > block_len)
		return -EINVAL;

	/* Write headers first */
	if (dir->uuid) {
		struct tb_property_dir_entry *pe;

		pe = (struct tb_property_dir_entry *)&block[start_offset];
		memcpy(pe->uuid, dir->uuid, sizeof(pe->uuid));
		entry = pe->entries;
	} else {
		struct tb_property_rootdir_entry *re;

		re = (struct tb_property_rootdir_entry *)&block[start_offset];
		re->magic = TB_PROPERTY_ROOTDIR_MAGIC;
		re->length = dir_len - sizeof(*re) / 4;
		entry = re->entries;
	}

	list_for_each_entry(property, &dir->properties, list) {
		const struct tb_property_dir *child;

		format_dwdata(entry, property->key, 2);
		entry->type = property->type;

		switch (property->type) {
		case TB_PROPERTY_TYPE_DIRECTORY:
			child = property->value.dir;
			ret = __tb_property_format_dir(child, block, dir_end,
						       block_len);
			if (ret < 0)
				return ret;
			entry->length = tb_property_dir_length(child, false,
							       NULL);
			entry->value = dir_end;
			dir_end = ret;
			break;

		case TB_PROPERTY_TYPE_DATA:
			format_dwdata(&block[data_offset], property->value.data,
				      property->length);
			entry->length = property->length;
			entry->value = data_offset;
			data_offset += entry->length;
			break;

		case TB_PROPERTY_TYPE_TEXT:
			format_dwdata(&block[data_offset], property->value.text,
				      property->length);
			entry->length = property->length;
			entry->value = data_offset;
			data_offset += entry->length;
			break;

		case TB_PROPERTY_TYPE_VALUE:
			entry->length = property->length;
			entry->value = property->value.immediate;
			break;

		default:
			break;
		}

		entry++;
	}

	return dir_end;
}

/**
 * tb_property_format_dir() - Formats directory to the packed XDomain format
 * @dir: Directory to format
 * @block: Property block where the packed data is placed
 * @block_len: Length of the property block
 *
 * This function formats the directory to the packed format that can be
 * then send over the thunderbolt fabric to receiving host. Returns %0 in
 * case of success and negative errno on faulure. Passing %NULL in @block
 * returns number of entries the block takes.
 */
ssize_t tb_property_format_dir(const struct tb_property_dir *dir, u32 *block,
			       size_t block_len)
{
	ssize_t ret;

	if (!block) {
		size_t dir_len, data_len = 0;

		dir_len = tb_property_dir_length(dir, true, &data_len);
		return dir_len + data_len;
	}

	ret = __tb_property_format_dir(dir, block, 0, block_len);
	return ret < 0 ? ret : 0;
}

/**
 * tb_property_add_immediate() - Add immediate property to directory
 * @parent: Directory to add the property
 * @key: Key for the property
 * @value: Immediate value to store with the property
 */
int tb_property_add_immediate(struct tb_property_dir *parent, const char *key,
			      u32 value)
{
	struct tb_property *property;

	if (!tb_property_key_valid(key))
		return -EINVAL;

	property = tb_property_alloc(key, TB_PROPERTY_TYPE_VALUE);
	if (!property)
		return -ENOMEM;

	property->length = 1;
	property->value.immediate = value;

	list_add_tail(&property->list, &parent->properties);
	return 0;
}
EXPORT_SYMBOL_GPL(tb_property_add_immediate);

/**
 * tb_property_add_data() - Adds arbitrary data property to directory
 * @parent: Directory to add the property
 * @key: Key for the property
 * @buf: Data buffer to add
 * @buflen: Number of bytes in the data buffer
 *
 * Function takes a copy of @buf and adds it to the directory.
 */
int tb_property_add_data(struct tb_property_dir *parent, const char *key,
			 const void *buf, size_t buflen)
{
	/* Need to pad to dword boundary */
	size_t size = round_up(buflen, 4);
	struct tb_property *property;

	if (!tb_property_key_valid(key))
		return -EINVAL;

	property = tb_property_alloc(key, TB_PROPERTY_TYPE_DATA);
	if (!property)
		return -ENOMEM;

	property->length = size / 4;
	property->value.data = kzalloc(size, GFP_KERNEL);
	memcpy(property->value.data, buf, buflen);

	list_add_tail(&property->list, &parent->properties);
	return 0;
}
EXPORT_SYMBOL_GPL(tb_property_add_data);

/**
 * tb_property_add_text() - Adds string property to directory
 * @parent: Directory to add the property
 * @key: Key for the property
 * @text: String to add
 *
 * Function takes a copy of @text and adds it to the directory.
 */
int tb_property_add_text(struct tb_property_dir *parent, const char *key,
			 const char *text)
{
	/* Need to pad to dword boundary */
	size_t size = round_up(strlen(text) + 1, 4);
	struct tb_property *property;

	if (!tb_property_key_valid(key))
		return -EINVAL;

	property = tb_property_alloc(key, TB_PROPERTY_TYPE_TEXT);
	if (!property)
		return -ENOMEM;

	property->length = size / 4;
	property->value.data = kzalloc(size, GFP_KERNEL);
	strcpy(property->value.text, text);

	list_add_tail(&property->list, &parent->properties);
	return 0;
}
EXPORT_SYMBOL_GPL(tb_property_add_text);

/**
 * tb_property_add_dir() - Adds a directory to the parent directory
 * @parent: Directory to add the property
 * @key: Key for the property
 * @dir: Directory to add
 */
int tb_property_add_dir(struct tb_property_dir *parent, const char *key,
			struct tb_property_dir *dir)
{
	struct tb_property *property;

	if (!tb_property_key_valid(key))
		return -EINVAL;

	property = tb_property_alloc(key, TB_PROPERTY_TYPE_DIRECTORY);
	if (!property)
		return -ENOMEM;

	property->value.dir = dir;

	list_add_tail(&property->list, &parent->properties);
	return 0;
}
EXPORT_SYMBOL_GPL(tb_property_add_dir);

/**
 * tb_property_remove() - Removes property from a parent directory
 * @property: Property to remove
 *
 * Note memory for @property is released as well so it is not allowed to
 * touch the object after call to this function.
 */
void tb_property_remove(struct tb_property *property)
{
	list_del(&property->list);
	kfree(property);
}
EXPORT_SYMBOL_GPL(tb_property_remove);

/**
 * tb_property_find() - Find a property from a directory
 * @dir: Directory where the property is searched
 * @key: Key to look for
 * @type: Type of the property
 *
 * Finds and returns property from the given directory. Does not recurse
 * into sub-directories. Returns %NULL if the property was not found.
 */
struct tb_property *tb_property_find(struct tb_property_dir *dir,
	const char *key, enum tb_property_type type)
{
	struct tb_property *property;

	list_for_each_entry(property, &dir->properties, list) {
		if (property->type == type && !strcmp(property->key, key))
			return property;
	}

	return NULL;
}
EXPORT_SYMBOL_GPL(tb_property_find);

/**
 * tb_property_get_next() - Get next property from directory
 * @dir: Directory holding properties
 * @prev: Previous property in the directory (%NULL returns the first)
 */
struct tb_property *tb_property_get_next(struct tb_property_dir *dir,
					 struct tb_property *prev)
{
	if (prev) {
		if (list_is_last(&prev->list, &dir->properties))
			return NULL;
		return list_next_entry(prev, list);
	}
	return list_first_entry_or_null(&dir->properties, struct tb_property,
					list);
}
EXPORT_SYMBOL_GPL(tb_property_get_next);