drivers/thunderbolt/property.c

   1 /*
   2  * Thunderbolt XDomain property support
   3  *
   4  * Copyright (C) 2017, Intel Corporation
   5  * Authors: Michael Jamet <michael.jamet@intel.com>
   6  *          Mika Westerberg <mika.westerberg@linux.intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/err.h>
  14 #include <linux/slab.h>
  15 #include <linux/string.h>
  16 #include <linux/uuid.h>
  17 #include <linux/thunderbolt.h>
  18
  19 struct tb_property_entry {
  20         u32 key_hi;
  21         u32 key_lo;
  22         u16 length;
  23         u8 reserved;
  24         u8 type;
  25         u32 value;
  26 };
  27
  28 struct tb_property_rootdir_entry {
  29         u32 magic;
  30         u32 length;
  31         struct tb_property_entry entries[];
  32 };
  33
  34 struct tb_property_dir_entry {
  35         u32 uuid[4];
  36         struct tb_property_entry entries[];
  37 };
  38
  39 #define TB_PROPERTY_ROOTDIR_MAGIC       0x55584401
  40
  41 static struct tb_property_dir *__tb_property_parse_dir(const u32 *block,
  42         size_t block_len, unsigned int dir_offset, size_t dir_len,
  43         bool is_root);
  44
  45 static inline void parse_dwdata(void *dst, const void *src, size_t dwords)
  46 {
  47         be32_to_cpu_array(dst, src, dwords);
  48 }
  49
  50 static inline void format_dwdata(void *dst, const void *src, size_t dwords)
  51 {
  52         cpu_to_be32_array(dst, src, dwords);
  53 }
  54
  55 static bool tb_property_entry_valid(const struct tb_property_entry *entry,
  56                                   size_t block_len)
  57 {
  58         switch (entry->type) {
  59         case TB_PROPERTY_TYPE_DIRECTORY:
  60         case TB_PROPERTY_TYPE_DATA:
  61         case TB_PROPERTY_TYPE_TEXT:
  62                 if (entry->length > block_len)
  63                         return false;
  64                 if (entry->value + entry->length > block_len)
  65                         return false;
  66                 break;
  67
  68         case TB_PROPERTY_TYPE_VALUE:
  69                 if (entry->length != 1)
  70                         return false;
  71                 break;
  72         }
  73
  74         return true;
  75 }
  76
  77 static bool tb_property_key_valid(const char *key)
  78 {
  79         return key && strlen(key) <= TB_PROPERTY_KEY_SIZE;
  80 }
  81
  82 static struct tb_property *
  83 tb_property_alloc(const char *key, enum tb_property_type type)
  84 {
  85         struct tb_property *property;
  86
  87         property = kzalloc(sizeof(*property), GFP_KERNEL);
  88         if (!property)
  89                 return NULL;
  90
  91         strcpy(property->key, key);
  92         property->type = type;
  93         INIT_LIST_HEAD(&property->list);
  94
  95         return property;
  96 }
  97
  98 static struct tb_property *tb_property_parse(const u32 *block, size_t block_len,
  99                                         const struct tb_property_entry *entry)
 100 {
 101         char key[TB_PROPERTY_KEY_SIZE + 1];
 102         struct tb_property *property;
 103         struct tb_property_dir *dir;
 104
 105         if (!tb_property_entry_valid(entry, block_len))
 106                 return NULL;
 107
 108         parse_dwdata(key, entry, 2);
 109         key[TB_PROPERTY_KEY_SIZE] = '\0';
 110
 111         property = tb_property_alloc(key, entry->type);
 112         if (!property)
 113                 return NULL;
 114
 115         property->length = entry->length;
 116
 117         switch (property->type) {
 118         case TB_PROPERTY_TYPE_DIRECTORY:
 119                 dir = __tb_property_parse_dir(block, block_len, entry->value,
 120                                               entry->length, false);
 121                 if (!dir) {
 122                         kfree(property);
 123                         return NULL;
 124                 }
 125                 property->value.dir = dir;
 126                 break;
 127
 128         case TB_PROPERTY_TYPE_DATA:
 129                 property->value.data = kcalloc(property->length, sizeof(u32),
 130                                                GFP_KERNEL);
 131                 if (!property->value.data) {
 132                         kfree(property);
 133                         return NULL;
 134                 }
 135                 parse_dwdata(property->value.data, block + entry->value,
 136                              entry->length);
 137                 break;
 138
 139         case TB_PROPERTY_TYPE_TEXT:
 140                 property->value.text = kcalloc(property->length, sizeof(u32),
 141                                                GFP_KERNEL);
 142                 if (!property->value.text) {
 143                         kfree(property);
 144                         return NULL;
 145                 }
 146                 parse_dwdata(property->value.text, block + entry->value,
 147                              entry->length);
 148                 /* Force null termination */
 149                 property->value.text[property->length * 4 - 1] = '\0';
 150                 break;
 151
 152         case TB_PROPERTY_TYPE_VALUE:
 153                 property->value.immediate = entry->value;
 154                 break;
 155
 156         default:
 157                 property->type = TB_PROPERTY_TYPE_UNKNOWN;
 158                 break;
 159         }
 160
 161         return property;
 162 }
 163
 164 static struct tb_property_dir *__tb_property_parse_dir(const u32 *block,
 165         size_t block_len, unsigned int dir_offset, size_t dir_len, bool is_root)
 166 {
 167         const struct tb_property_entry *entries;
 168         size_t i, content_len, nentries;
 169         unsigned int content_offset;
 170         struct tb_property_dir *dir;
 171
 172         dir = kzalloc(sizeof(*dir), GFP_KERNEL);
 173         if (!dir)
 174                 return NULL;
 175
 176         if (is_root) {
 177                 content_offset = dir_offset + 2;
 178                 content_len = dir_len;
 179         } else {
 180                 dir->uuid = kmemdup(&block[dir_offset], sizeof(*dir->uuid),
 181                                     GFP_KERNEL);
 182                 content_offset = dir_offset + 4;
 183                 content_len = dir_len - 4; /* Length includes UUID */
 184         }
 185
 186         entries = (const struct tb_property_entry *)&block[content_offset];
 187         nentries = content_len / (sizeof(*entries) / 4);
 188
 189         INIT_LIST_HEAD(&dir->properties);
 190
 191         for (i = 0; i < nentries; i++) {
 192                 struct tb_property *property;
 193
 194                 property = tb_property_parse(block, block_len, &entries[i]);
 195                 if (!property) {
 196                         tb_property_free_dir(dir);
 197                         return NULL;
 198                 }
 199
 200                 list_add_tail(&property->list, &dir->properties);
 201         }
 202
 203         return dir;
 204 }
 205
 206 /**
 207  * tb_property_parse_dir() - Parses properties from given property block
 208  * @block: Property block to parse
 209  * @block_len: Number of dword elements in the property block
 210  *
 211  * This function parses the XDomain properties data block into format that
 212  * can be traversed using the helper functions provided by this module.
 213  * Upon success returns the parsed directory. In case of error returns
 214  * %NULL. The resulting &struct tb_property_dir needs to be released by
 215  * calling tb_property_free_dir() when not needed anymore.
 216  *
 217  * The @block is expected to be root directory.
 218  */
 219 struct tb_property_dir *tb_property_parse_dir(const u32 *block,
 220                                               size_t block_len)
 221 {
 222         const struct tb_property_rootdir_entry *rootdir =
 223                 (const struct tb_property_rootdir_entry *)block;
 224
 225         if (rootdir->magic != TB_PROPERTY_ROOTDIR_MAGIC)
 226                 return NULL;
 227         if (rootdir->length > block_len)
 228                 return NULL;
 229
 230         return __tb_property_parse_dir(block, block_len, 0, rootdir->length,
 231                                        true);
 232 }
 233
 234 /**
 235  * tb_property_create_dir() - Creates new property directory
 236  * @uuid: UUID used to identify the particular directory
 237  *
 238  * Creates new, empty property directory. If @uuid is %NULL then the
 239  * directory is assumed to be root directory.
 240  */
 241 struct tb_property_dir *tb_property_create_dir(const uuid_t *uuid)
 242 {
 243         struct tb_property_dir *dir;
 244
 245         dir = kzalloc(sizeof(*dir), GFP_KERNEL);
 246         if (!dir)
 247                 return NULL;
 248
 249         INIT_LIST_HEAD(&dir->properties);
 250         if (uuid) {
 251                 dir->uuid = kmemdup(uuid, sizeof(*dir->uuid), GFP_KERNEL);
 252                 if (!dir->uuid) {
 253                         kfree(dir);
 254                         return NULL;
 255                 }
 256         }
 257
 258         return dir;
 259 }
 260 EXPORT_SYMBOL_GPL(tb_property_create_dir);
 261
 262 static void tb_property_free(struct tb_property *property)
 263 {
 264         switch (property->type) {
 265         case TB_PROPERTY_TYPE_DIRECTORY:
 266                 tb_property_free_dir(property->value.dir);
 267                 break;
 268
 269         case TB_PROPERTY_TYPE_DATA:
 270                 kfree(property->value.data);
 271                 break;
 272
 273         case TB_PROPERTY_TYPE_TEXT:
 274                 kfree(property->value.text);
 275                 break;
 276
 277         default:
 278                 break;
 279         }
 280
 281         kfree(property);
 282 }
 283
 284 /**
 285  * tb_property_free_dir() - Release memory allocated for property directory
 286  * @dir: Directory to release
 287  *
 288  * This will release all the memory the directory occupies including all
 289  * descendants. It is OK to pass %NULL @dir, then the function does
 290  * nothing.
 291  */
 292 void tb_property_free_dir(struct tb_property_dir *dir)
 293 {
 294         struct tb_property *property, *tmp;
 295
 296         if (!dir)
 297                 return;
 298
 299         list_for_each_entry_safe(property, tmp, &dir->properties, list) {
 300                 list_del(&property->list);
 301                 tb_property_free(property);
 302         }
 303         kfree(dir->uuid);
 304         kfree(dir);
 305 }
 306 EXPORT_SYMBOL_GPL(tb_property_free_dir);
 307
 308 static size_t tb_property_dir_length(const struct tb_property_dir *dir,
 309                                      bool recurse, size_t *data_len)
 310 {
 311         const struct tb_property *property;
 312         size_t len = 0;
 313
 314         if (dir->uuid)
 315                 len += sizeof(*dir->uuid) / 4;
 316         else
 317                 len += sizeof(struct tb_property_rootdir_entry) / 4;
 318
 319         list_for_each_entry(property, &dir->properties, list) {
 320                 len += sizeof(struct tb_property_entry) / 4;
 321
 322                 switch (property->type) {
 323                 case TB_PROPERTY_TYPE_DIRECTORY:
 324                         if (recurse) {
 325                                 len += tb_property_dir_length(
 326                                         property->value.dir, recurse, data_len);
 327                         }
 328                         /* Reserve dword padding after each directory */
 329                         if (data_len)
 330                                 *data_len += 1;
 331                         break;
 332
 333                 case TB_PROPERTY_TYPE_DATA:
 334                 case TB_PROPERTY_TYPE_TEXT:
 335                         if (data_len)
 336                                 *data_len += property->length;
 337                         break;
 338
 339                 default:
 340                         break;
 341                 }
 342         }
 343
 344         return len;
 345 }
 346
 347 static ssize_t __tb_property_format_dir(const struct tb_property_dir *dir,
 348         u32 *block, unsigned int start_offset, size_t block_len)
 349 {
 350         unsigned int data_offset, dir_end;
 351         const struct tb_property *property;
 352         struct tb_property_entry *entry;
 353         size_t dir_len, data_len = 0;
 354         int ret;
 355
 356         /*
 357          * The structure of property block looks like following. Leaf
 358          * data/text is included right after the directory and each
 359          * directory follows each other (even nested ones).
 360          *
 361          * +----------+ <-- start_offset
 362          * |  header  | <-- root directory header
 363          * +----------+ ---
 364          * |  entry 0 | -^--------------------.
 365          * +----------+  |                    |
 366          * |  entry 1 | -|--------------------|--.
 367          * +----------+  |                    |  |
 368          * |  entry 2 | -|-----------------.  |  |
 369          * +----------+  |                 |  |  |
 370          * :          :  |  dir_len        |  |  |
 371          * .          .  |                 |  |  |
 372          * :          :  |                 |  |  |
 373          * +----------+  |                 |  |  |
 374          * |  entry n |  v                 |  |  |
 375          * +----------+ <-- data_offset    |  |  |
 376          * |  data 0  | <------------------|--'  |
 377          * +----------+                    |     |
 378          * |  data 1  | <------------------|-----'
 379          * +----------+                    |
 380          * | 00000000 | padding            |
 381          * +----------+ <-- dir_end <------'
 382          * |   UUID   | <-- directory UUID (child directory)
 383          * +----------+
 384          * |  entry 0 |
 385          * +----------+
 386          * |  entry 1 |
 387          * +----------+
 388          * :          :
 389          * .          .
 390          * :          :
 391          * +----------+
 392          * |  entry n |
 393          * +----------+
 394          * |  data 0  |
 395          * +----------+
 396          *
 397          * We use dir_end to hold pointer to the end of the directory. It
 398          * will increase as we add directories and each directory should be
 399          * added starting from previous dir_end.
 400          */
 401         dir_len = tb_property_dir_length(dir, false, &data_len);
 402         data_offset = start_offset + dir_len;
 403         dir_end = start_offset + data_len + dir_len;
 404
 405         if (data_offset > dir_end)
 406                 return -EINVAL;
 407         if (dir_end > block_len)
 408                 return -EINVAL;
 409
 410         /* Write headers first */
 411         if (dir->uuid) {
 412                 struct tb_property_dir_entry *pe;
 413
 414                 pe = (struct tb_property_dir_entry *)&block[start_offset];
 415                 memcpy(pe->uuid, dir->uuid, sizeof(pe->uuid));
 416                 entry = pe->entries;
 417         } else {
 418                 struct tb_property_rootdir_entry *re;
 419
 420                 re = (struct tb_property_rootdir_entry *)&block[start_offset];
 421                 re->magic = TB_PROPERTY_ROOTDIR_MAGIC;
 422                 re->length = dir_len - sizeof(*re) / 4;
 423                 entry = re->entries;
 424         }
 425
 426         list_for_each_entry(property, &dir->properties, list) {
 427                 const struct tb_property_dir *child;
 428
 429                 format_dwdata(entry, property->key, 2);
 430                 entry->type = property->type;
 431
 432                 switch (property->type) {
 433                 case TB_PROPERTY_TYPE_DIRECTORY:
 434                         child = property->value.dir;
 435                         ret = __tb_property_format_dir(child, block, dir_end,
 436                                                        block_len);
 437                         if (ret < 0)
 438                                 return ret;
 439                         entry->length = tb_property_dir_length(child, false,
 440                                                                NULL);
 441                         entry->value = dir_end;
 442                         dir_end = ret;
 443                         break;
 444
 445                 case TB_PROPERTY_TYPE_DATA:
 446                         format_dwdata(&block[data_offset], property->value.data,
 447                                       property->length);
 448                         entry->length = property->length;
 449                         entry->value = data_offset;
 450                         data_offset += entry->length;
 451                         break;
 452
 453                 case TB_PROPERTY_TYPE_TEXT:
 454                         format_dwdata(&block[data_offset], property->value.text,
 455                                       property->length);
 456                         entry->length = property->length;
 457                         entry->value = data_offset;
 458                         data_offset += entry->length;
 459                         break;
 460
 461                 case TB_PROPERTY_TYPE_VALUE:
 462                         entry->length = property->length;
 463                         entry->value = property->value.immediate;
 464                         break;
 465
 466                 default:
 467                         break;
 468                 }
 469
 470                 entry++;
 471         }
 472
 473         return dir_end;
 474 }
 475
 476 /**
 477  * tb_property_format_dir() - Formats directory to the packed XDomain format
 478  * @dir: Directory to format
 479  * @block: Property block where the packed data is placed
 480  * @block_len: Length of the property block
 481  *
 482  * This function formats the directory to the packed format that can be
 483  * then send over the thunderbolt fabric to receiving host. Returns %0 in
 484  * case of success and negative errno on faulure. Passing %NULL in @block
 485  * returns number of entries the block takes.
 486  */
 487 ssize_t tb_property_format_dir(const struct tb_property_dir *dir, u32 *block,
 488                                size_t block_len)
 489 {
 490         ssize_t ret;
 491
 492         if (!block) {
 493                 size_t dir_len, data_len = 0;
 494
 495                 dir_len = tb_property_dir_length(dir, true, &data_len);
 496                 return dir_len + data_len;
 497         }
 498
 499         ret = __tb_property_format_dir(dir, block, 0, block_len);
 500         return ret < 0 ? ret : 0;
 501 }
 502
 503 /**
 504  * tb_property_add_immediate() - Add immediate property to directory
 505  * @parent: Directory to add the property
 506  * @key: Key for the property
 507  * @value: Immediate value to store with the property
 508  */
 509 int tb_property_add_immediate(struct tb_property_dir *parent, const char *key,
 510                               u32 value)
 511 {
 512         struct tb_property *property;
 513
 514         if (!tb_property_key_valid(key))
 515                 return -EINVAL;
 516
 517         property = tb_property_alloc(key, TB_PROPERTY_TYPE_VALUE);
 518         if (!property)
 519                 return -ENOMEM;
 520
 521         property->length = 1;
 522         property->value.immediate = value;
 523
 524         list_add_tail(&property->list, &parent->properties);
 525         return 0;
 526 }
 527 EXPORT_SYMBOL_GPL(tb_property_add_immediate);
 528
 529 /**
 530  * tb_property_add_data() - Adds arbitrary data property to directory
 531  * @parent: Directory to add the property
 532  * @key: Key for the property
 533  * @buf: Data buffer to add
 534  * @buflen: Number of bytes in the data buffer
 535  *
 536  * Function takes a copy of @buf and adds it to the directory.
 537  */
 538 int tb_property_add_data(struct tb_property_dir *parent, const char *key,
 539                          const void *buf, size_t buflen)
 540 {
 541         /* Need to pad to dword boundary */
 542         size_t size = round_up(buflen, 4);
 543         struct tb_property *property;
 544
 545         if (!tb_property_key_valid(key))
 546                 return -EINVAL;
 547
 548         property = tb_property_alloc(key, TB_PROPERTY_TYPE_DATA);
 549         if (!property)
 550                 return -ENOMEM;
 551
 552         property->length = size / 4;
 553         property->value.data = kzalloc(size, GFP_KERNEL);
 554         if (!property->value.data) {
 555                 kfree(property);
 556                 return -ENOMEM;
 557         }
 558
 559         memcpy(property->value.data, buf, buflen);
 560
 561         list_add_tail(&property->list, &parent->properties);
 562         return 0;
 563 }
 564 EXPORT_SYMBOL_GPL(tb_property_add_data);
 565
 566 /**
 567  * tb_property_add_text() - Adds string property to directory
 568  * @parent: Directory to add the property
 569  * @key: Key for the property
 570  * @text: String to add
 571  *
 572  * Function takes a copy of @text and adds it to the directory.
 573  */
 574 int tb_property_add_text(struct tb_property_dir *parent, const char *key,
 575                          const char *text)
 576 {
 577         /* Need to pad to dword boundary */
 578         size_t size = round_up(strlen(text) + 1, 4);
 579         struct tb_property *property;
 580
 581         if (!tb_property_key_valid(key))
 582                 return -EINVAL;
 583
 584         property = tb_property_alloc(key, TB_PROPERTY_TYPE_TEXT);
 585         if (!property)
 586                 return -ENOMEM;
 587
 588         property->length = size / 4;
 589         property->value.text = kzalloc(size, GFP_KERNEL);
 590         if (!property->value.text) {
 591                 kfree(property);
 592                 return -ENOMEM;
 593         }
 594
 595         strcpy(property->value.text, text);
 596
 597         list_add_tail(&property->list, &parent->properties);
 598         return 0;
 599 }
 600 EXPORT_SYMBOL_GPL(tb_property_add_text);
 601
 602 /**
 603  * tb_property_add_dir() - Adds a directory to the parent directory
 604  * @parent: Directory to add the property
 605  * @key: Key for the property
 606  * @dir: Directory to add
 607  */
 608 int tb_property_add_dir(struct tb_property_dir *parent, const char *key,
 609                         struct tb_property_dir *dir)
 610 {
 611         struct tb_property *property;
 612
 613         if (!tb_property_key_valid(key))
 614                 return -EINVAL;
 615
 616         property = tb_property_alloc(key, TB_PROPERTY_TYPE_DIRECTORY);
 617         if (!property)
 618                 return -ENOMEM;
 619
 620         property->value.dir = dir;
 621
 622         list_add_tail(&property->list, &parent->properties);
 623         return 0;
 624 }
 625 EXPORT_SYMBOL_GPL(tb_property_add_dir);
 626
 627 /**
 628  * tb_property_remove() - Removes property from a parent directory
 629  * @property: Property to remove
 630  *
 631  * Note memory for @property is released as well so it is not allowed to
 632  * touch the object after call to this function.
 633  */
 634 void tb_property_remove(struct tb_property *property)
 635 {
 636         list_del(&property->list);
 637         kfree(property);
 638 }
 639 EXPORT_SYMBOL_GPL(tb_property_remove);
 640
 641 /**
 642  * tb_property_find() - Find a property from a directory
 643  * @dir: Directory where the property is searched
 644  * @key: Key to look for
 645  * @type: Type of the property
 646  *
 647  * Finds and returns property from the given directory. Does not recurse
 648  * into sub-directories. Returns %NULL if the property was not found.
 649  */
 650 struct tb_property *tb_property_find(struct tb_property_dir *dir,
 651         const char *key, enum tb_property_type type)
 652 {
 653         struct tb_property *property;
 654
 655         list_for_each_entry(property, &dir->properties, list) {
 656                 if (property->type == type && !strcmp(property->key, key))
 657                         return property;
 658         }
 659
 660         return NULL;
 661 }
 662 EXPORT_SYMBOL_GPL(tb_property_find);
 663
 664 /**
 665  * tb_property_get_next() - Get next property from directory
 666  * @dir: Directory holding properties
 667  * @prev: Previous property in the directory (%NULL returns the first)
 668  */
 669 struct tb_property *tb_property_get_next(struct tb_property_dir *dir,
 670                                          struct tb_property *prev)
 671 {
 672         if (prev) {
 673                 if (list_is_last(&prev->list, &dir->properties))
 674                         return NULL;
 675                 return list_next_entry(prev, list);
 676         }
 677         return list_first_entry_or_null(&dir->properties, struct tb_property,
 678                                         list);
 679 }
 680 EXPORT_SYMBOL_GPL(tb_property_get_next);