lib/libfdt/fdt_ro.c

   1 /*
   2  * libfdt - Flat Device Tree manipulation
   3  * Copyright (C) 2006 David Gibson, IBM Corporation.
   4  * SPDX-License-Identifier:     GPL-2.0+ BSD-2-Clause
   5  */
   6 #include <libfdt_env.h>
   7
   8 #ifndef USE_HOSTCC
   9 #include <fdt.h>
  10 #include <libfdt.h>
  11 #else
  12 #include "fdt_host.h"
  13 #endif
  14
  15 #include "libfdt_internal.h"
  16
  17 static int _fdt_nodename_eq(const void *fdt, int offset,
  18                             const char *s, int len)
  19 {
  20         const char *p = fdt_offset_ptr(fdt, offset + FDT_TAGSIZE, len+1);
  21
  22         if (!p)
  23                 /* short match */
  24                 return 0;
  25
  26         if (memcmp(p, s, len) != 0)
  27                 return 0;
  28
  29         if (p[len] == '\0')
  30                 return 1;
  31         else if (!memchr(s, '@', len) && (p[len] == '@'))
  32                 return 1;
  33         else
  34                 return 0;
  35 }
  36
  37 const char *fdt_string(const void *fdt, int stroffset)
  38 {
  39         return (const char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
  40 }
  41
  42 static int _fdt_string_eq(const void *fdt, int stroffset,
  43                           const char *s, int len)
  44 {
  45         const char *p = fdt_string(fdt, stroffset);
  46
  47         return (strnlen(p, len + 1) == len) && (memcmp(p, s, len) == 0);
  48 }
  49
  50 uint32_t fdt_get_max_phandle(const void *fdt)
  51 {
  52         uint32_t max_phandle = 0;
  53         int offset;
  54
  55         for (offset = fdt_next_node(fdt, -1, NULL);;
  56              offset = fdt_next_node(fdt, offset, NULL)) {
  57                 uint32_t phandle;
  58
  59                 if (offset == -FDT_ERR_NOTFOUND)
  60                         return max_phandle;
  61
  62                 if (offset < 0)
  63                         return (uint32_t)-1;
  64
  65                 phandle = fdt_get_phandle(fdt, offset);
  66                 if (phandle == (uint32_t)-1)
  67                         continue;
  68
  69                 if (phandle > max_phandle)
  70                         max_phandle = phandle;
  71         }
  72
  73         return 0;
  74 }
  75
  76 int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
  77 {
  78         FDT_CHECK_HEADER(fdt);
  79         *address = fdt64_to_cpu(_fdt_mem_rsv(fdt, n)->address);
  80         *size = fdt64_to_cpu(_fdt_mem_rsv(fdt, n)->size);
  81         return 0;
  82 }
  83
  84 int fdt_num_mem_rsv(const void *fdt)
  85 {
  86         int i = 0;
  87
  88         while (fdt64_to_cpu(_fdt_mem_rsv(fdt, i)->size) != 0)
  89                 i++;
  90         return i;
  91 }
  92
  93 static int _nextprop(const void *fdt, int offset)
  94 {
  95         uint32_t tag;
  96         int nextoffset;
  97
  98         do {
  99                 tag = fdt_next_tag(fdt, offset, &nextoffset);
 100
 101                 switch (tag) {
 102                 case FDT_END:
 103                         if (nextoffset >= 0)
 104                                 return -FDT_ERR_BADSTRUCTURE;
 105                         else
 106                                 return nextoffset;
 107
 108                 case FDT_PROP:
 109                         return offset;
 110                 }
 111                 offset = nextoffset;
 112         } while (tag == FDT_NOP);
 113
 114         return -FDT_ERR_NOTFOUND;
 115 }
 116
 117 int fdt_subnode_offset_namelen(const void *fdt, int offset,
 118                                const char *name, int namelen)
 119 {
 120         int depth;
 121
 122         FDT_CHECK_HEADER(fdt);
 123
 124         for (depth = 0;
 125              (offset >= 0) && (depth >= 0);
 126              offset = fdt_next_node(fdt, offset, &depth))
 127                 if ((depth == 1)
 128                     && _fdt_nodename_eq(fdt, offset, name, namelen))
 129                         return offset;
 130
 131         if (depth < 0)
 132                 return -FDT_ERR_NOTFOUND;
 133         return offset; /* error */
 134 }
 135
 136 int fdt_subnode_offset(const void *fdt, int parentoffset,
 137                        const char *name)
 138 {
 139         return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
 140 }
 141
 142 /*
 143  * Find the next of path separator, note we need to search for both '/' and ':'
 144  * and then take the first one so that we do the right thing for e.g.
 145  * "foo/bar:option" and "bar:option/otheroption", both of which happen, so
 146  * first searching for either ':' or '/' does not work.
 147  */
 148 static const char *fdt_path_next_separator(const char *path, int len)
 149 {
 150         const void *sep1 = memchr(path, '/', len);
 151         const void *sep2 = memchr(path, ':', len);
 152
 153         if (sep1 && sep2)
 154                 return (sep1 < sep2) ? sep1 : sep2;
 155         else if (sep1)
 156                 return sep1;
 157         else
 158                 return sep2;
 159 }
 160
 161 int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen)
 162 {
 163         const char *end = path + namelen;
 164         const char *p = path;
 165         int offset = 0;
 166
 167         FDT_CHECK_HEADER(fdt);
 168
 169         /* see if we have an alias */
 170         if (*path != '/') {
 171                 const char *q = fdt_path_next_separator(path, namelen);
 172
 173                 if (!q)
 174                         q = end;
 175
 176                 p = fdt_get_alias_namelen(fdt, p, q - p);
 177                 if (!p)
 178                         return -FDT_ERR_BADPATH;
 179                 offset = fdt_path_offset(fdt, p);
 180
 181                 p = q;
 182         }
 183
 184         while (*p && (p < end)) {
 185                 const char *q;
 186
 187                 while (*p == '/')
 188                         p++;
 189
 190                 if (*p == '\0' || *p == ':')
 191                         return offset;
 192
 193                 q = fdt_path_next_separator(p, end - p);
 194                 if (!q)
 195                         q = end;
 196
 197                 offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
 198                 if (offset < 0)
 199                         return offset;
 200
 201                 p = q;
 202         }
 203
 204         return offset;
 205 }
 206
 207 int fdt_path_offset(const void *fdt, const char *path)
 208 {
 209         return fdt_path_offset_namelen(fdt, path, strlen(path));
 210 }
 211
 212 const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
 213 {
 214         const struct fdt_node_header *nh = _fdt_offset_ptr(fdt, nodeoffset);
 215         int err;
 216
 217         if (((err = fdt_check_header(fdt)) != 0)
 218             || ((err = _fdt_check_node_offset(fdt, nodeoffset)) < 0))
 219                         goto fail;
 220
 221         if (len)
 222                 *len = strlen(nh->name);
 223
 224         return nh->name;
 225
 226  fail:
 227         if (len)
 228                 *len = err;
 229         return NULL;
 230 }
 231
 232 int fdt_first_property_offset(const void *fdt, int nodeoffset)
 233 {
 234         int offset;
 235
 236         if ((offset = _fdt_check_node_offset(fdt, nodeoffset)) < 0)
 237                 return offset;
 238
 239         return _nextprop(fdt, offset);
 240 }
 241
 242 int fdt_next_property_offset(const void *fdt, int offset)
 243 {
 244         if ((offset = _fdt_check_prop_offset(fdt, offset)) < 0)
 245                 return offset;
 246
 247         return _nextprop(fdt, offset);
 248 }
 249
 250 const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
 251                                                       int offset,
 252                                                       int *lenp)
 253 {
 254         int err;
 255         const struct fdt_property *prop;
 256
 257         if ((err = _fdt_check_prop_offset(fdt, offset)) < 0) {
 258                 if (lenp)
 259                         *lenp = err;
 260                 return NULL;
 261         }
 262
 263         prop = _fdt_offset_ptr(fdt, offset);
 264
 265         if (lenp)
 266                 *lenp = fdt32_to_cpu(prop->len);
 267
 268         return prop;
 269 }
 270
 271 const struct fdt_property *fdt_get_property_namelen(const void *fdt,
 272                                                     int offset,
 273                                                     const char *name,
 274                                                     int namelen, int *lenp)
 275 {
 276         for (offset = fdt_first_property_offset(fdt, offset);
 277              (offset >= 0);
 278              (offset = fdt_next_property_offset(fdt, offset))) {
 279                 const struct fdt_property *prop;
 280
 281                 if (!(prop = fdt_get_property_by_offset(fdt, offset, lenp))) {
 282                         offset = -FDT_ERR_INTERNAL;
 283                         break;
 284                 }
 285                 if (_fdt_string_eq(fdt, fdt32_to_cpu(prop->nameoff),
 286                                    name, namelen))
 287                         return prop;
 288         }
 289
 290         if (lenp)
 291                 *lenp = offset;
 292         return NULL;
 293 }
 294
 295 const struct fdt_property *fdt_get_property(const void *fdt,
 296                                             int nodeoffset,
 297                                             const char *name, int *lenp)
 298 {
 299         return fdt_get_property_namelen(fdt, nodeoffset, name,
 300                                         strlen(name), lenp);
 301 }
 302
 303 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
 304                                 const char *name, int namelen, int *lenp)
 305 {
 306         const struct fdt_property *prop;
 307
 308         prop = fdt_get_property_namelen(fdt, nodeoffset, name, namelen, lenp);
 309         if (!prop)
 310                 return NULL;
 311
 312         return prop->data;
 313 }
 314
 315 const void *fdt_getprop_by_offset(const void *fdt, int offset,
 316                                   const char **namep, int *lenp)
 317 {
 318         const struct fdt_property *prop;
 319
 320         prop = fdt_get_property_by_offset(fdt, offset, lenp);
 321         if (!prop)
 322                 return NULL;
 323         if (namep)
 324                 *namep = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
 325         return prop->data;
 326 }
 327
 328 const void *fdt_getprop(const void *fdt, int nodeoffset,
 329                         const char *name, int *lenp)
 330 {
 331         return fdt_getprop_namelen(fdt, nodeoffset, name, strlen(name), lenp);
 332 }
 333
 334 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
 335 {
 336         const fdt32_t *php;
 337         int len;
 338
 339         /* FIXME: This is a bit sub-optimal, since we potentially scan
 340          * over all the properties twice. */
 341         php = fdt_getprop(fdt, nodeoffset, "phandle", &len);
 342         if (!php || (len != sizeof(*php))) {
 343                 php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
 344                 if (!php || (len != sizeof(*php)))
 345                         return 0;
 346         }
 347
 348         return fdt32_to_cpu(*php);
 349 }
 350
 351 const char *fdt_get_alias_namelen(const void *fdt,
 352                                   const char *name, int namelen)
 353 {
 354         int aliasoffset;
 355
 356         aliasoffset = fdt_path_offset(fdt, "/aliases");
 357         if (aliasoffset < 0)
 358                 return NULL;
 359
 360         return fdt_getprop_namelen(fdt, aliasoffset, name, namelen, NULL);
 361 }
 362
 363 const char *fdt_get_alias(const void *fdt, const char *name)
 364 {
 365         return fdt_get_alias_namelen(fdt, name, strlen(name));
 366 }
 367
 368 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
 369 {
 370         int pdepth = 0, p = 0;
 371         int offset, depth, namelen;
 372         const char *name;
 373
 374         FDT_CHECK_HEADER(fdt);
 375
 376         if (buflen < 2)
 377                 return -FDT_ERR_NOSPACE;
 378
 379         for (offset = 0, depth = 0;
 380              (offset >= 0) && (offset <= nodeoffset);
 381              offset = fdt_next_node(fdt, offset, &depth)) {
 382                 while (pdepth > depth) {
 383                         do {
 384                                 p--;
 385                         } while (buf[p-1] != '/');
 386                         pdepth--;
 387                 }
 388
 389                 if (pdepth >= depth) {
 390                         name = fdt_get_name(fdt, offset, &namelen);
 391                         if (!name)
 392                                 return namelen;
 393                         if ((p + namelen + 1) <= buflen) {
 394                                 memcpy(buf + p, name, namelen);
 395                                 p += namelen;
 396                                 buf[p++] = '/';
 397                                 pdepth++;
 398                         }
 399                 }
 400
 401                 if (offset == nodeoffset) {
 402                         if (pdepth < (depth + 1))
 403                                 return -FDT_ERR_NOSPACE;
 404
 405                         if (p > 1) /* special case so that root path is "/", not "" */
 406                                 p--;
 407                         buf[p] = '\0';
 408                         return 0;
 409                 }
 410         }
 411
 412         if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
 413                 return -FDT_ERR_BADOFFSET;
 414         else if (offset == -FDT_ERR_BADOFFSET)
 415                 return -FDT_ERR_BADSTRUCTURE;
 416
 417         return offset; /* error from fdt_next_node() */
 418 }
 419
 420 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
 421                                  int supernodedepth, int *nodedepth)
 422 {
 423         int offset, depth;
 424         int supernodeoffset = -FDT_ERR_INTERNAL;
 425
 426         FDT_CHECK_HEADER(fdt);
 427
 428         if (supernodedepth < 0)
 429                 return -FDT_ERR_NOTFOUND;
 430
 431         for (offset = 0, depth = 0;
 432              (offset >= 0) && (offset <= nodeoffset);
 433              offset = fdt_next_node(fdt, offset, &depth)) {
 434                 if (depth == supernodedepth)
 435                         supernodeoffset = offset;
 436
 437                 if (offset == nodeoffset) {
 438                         if (nodedepth)
 439                                 *nodedepth = depth;
 440
 441                         if (supernodedepth > depth)
 442                                 return -FDT_ERR_NOTFOUND;
 443                         else
 444                                 return supernodeoffset;
 445                 }
 446         }
 447
 448         if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
 449                 return -FDT_ERR_BADOFFSET;
 450         else if (offset == -FDT_ERR_BADOFFSET)
 451                 return -FDT_ERR_BADSTRUCTURE;
 452
 453         return offset; /* error from fdt_next_node() */
 454 }
 455
 456 int fdt_node_depth(const void *fdt, int nodeoffset)
 457 {
 458         int nodedepth;
 459         int err;
 460
 461         err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth);
 462         if (err)
 463                 return (err < 0) ? err : -FDT_ERR_INTERNAL;
 464         return nodedepth;
 465 }
 466
 467 int fdt_parent_offset(const void *fdt, int nodeoffset)
 468 {
 469         int nodedepth = fdt_node_depth(fdt, nodeoffset);
 470
 471         if (nodedepth < 0)
 472                 return nodedepth;
 473         return fdt_supernode_atdepth_offset(fdt, nodeoffset,
 474                                             nodedepth - 1, NULL);
 475 }
 476
 477 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
 478                                   const char *propname,
 479                                   const void *propval, int proplen)
 480 {
 481         int offset;
 482         const void *val;
 483         int len;
 484
 485         FDT_CHECK_HEADER(fdt);
 486
 487         /* FIXME: The algorithm here is pretty horrible: we scan each
 488          * property of a node in fdt_getprop(), then if that didn't
 489          * find what we want, we scan over them again making our way
 490          * to the next node.  Still it's the easiest to implement
 491          * approach; performance can come later. */
 492         for (offset = fdt_next_node(fdt, startoffset, NULL);
 493              offset >= 0;
 494              offset = fdt_next_node(fdt, offset, NULL)) {
 495                 val = fdt_getprop(fdt, offset, propname, &len);
 496                 if (val && (len == proplen)
 497                     && (memcmp(val, propval, len) == 0))
 498                         return offset;
 499         }
 500
 501         return offset; /* error from fdt_next_node() */
 502 }
 503
 504 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
 505 {
 506         int offset;
 507
 508         if ((phandle == 0) || (phandle == -1))
 509                 return -FDT_ERR_BADPHANDLE;
 510
 511         FDT_CHECK_HEADER(fdt);
 512
 513         /* FIXME: The algorithm here is pretty horrible: we
 514          * potentially scan each property of a node in
 515          * fdt_get_phandle(), then if that didn't find what
 516          * we want, we scan over them again making our way to the next
 517          * node.  Still it's the easiest to implement approach;
 518          * performance can come later. */
 519         for (offset = fdt_next_node(fdt, -1, NULL);
 520              offset >= 0;
 521              offset = fdt_next_node(fdt, offset, NULL)) {
 522                 if (fdt_get_phandle(fdt, offset) == phandle)
 523                         return offset;
 524         }
 525
 526         return offset; /* error from fdt_next_node() */
 527 }
 528
 529 int fdt_stringlist_contains(const char *strlist, int listlen, const char *str)
 530 {
 531         int len = strlen(str);
 532         const char *p;
 533
 534         while (listlen >= len) {
 535                 if (memcmp(str, strlist, len+1) == 0)
 536                         return 1;
 537                 p = memchr(strlist, '\0', listlen);
 538                 if (!p)
 539                         return 0; /* malformed strlist.. */
 540                 listlen -= (p-strlist) + 1;
 541                 strlist = p + 1;
 542         }
 543         return 0;
 544 }
 545
 546 int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property)
 547 {
 548         const char *list, *end;
 549         int length, count = 0;
 550
 551         list = fdt_getprop(fdt, nodeoffset, property, &length);
 552         if (!list)
 553                 return length;
 554
 555         end = list + length;
 556
 557         while (list < end) {
 558                 length = strnlen(list, end - list) + 1;
 559
 560                 /* Abort if the last string isn't properly NUL-terminated. */
 561                 if (list + length > end)
 562                         return -FDT_ERR_BADVALUE;
 563
 564                 list += length;
 565                 count++;
 566         }
 567
 568         return count;
 569 }
 570
 571 int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
 572                           const char *string)
 573 {
 574         int length, len, idx = 0;
 575         const char *list, *end;
 576
 577         list = fdt_getprop(fdt, nodeoffset, property, &length);
 578         if (!list)
 579                 return length;
 580
 581         len = strlen(string) + 1;
 582         end = list + length;
 583
 584         while (list < end) {
 585                 length = strnlen(list, end - list) + 1;
 586
 587                 /* Abort if the last string isn't properly NUL-terminated. */
 588                 if (list + length > end)
 589                         return -FDT_ERR_BADVALUE;
 590
 591                 if (length == len && memcmp(list, string, length) == 0)
 592                         return idx;
 593
 594                 list += length;
 595                 idx++;
 596         }
 597
 598         return -FDT_ERR_NOTFOUND;
 599 }
 600
 601 const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
 602                                const char *property, int idx,
 603                                int *lenp)
 604 {
 605         const char *list, *end;
 606         int length;
 607
 608         list = fdt_getprop(fdt, nodeoffset, property, &length);
 609         if (!list) {
 610                 if (lenp)
 611                         *lenp = length;
 612
 613                 return NULL;
 614         }
 615
 616         end = list + length;
 617
 618         while (list < end) {
 619                 length = strnlen(list, end - list) + 1;
 620
 621                 /* Abort if the last string isn't properly NUL-terminated. */
 622                 if (list + length > end) {
 623                         if (lenp)
 624                                 *lenp = -FDT_ERR_BADVALUE;
 625
 626                         return NULL;
 627                 }
 628
 629                 if (idx == 0) {
 630                         if (lenp)
 631                                 *lenp = length - 1;
 632
 633                         return list;
 634                 }
 635
 636                 list += length;
 637                 idx--;
 638         }
 639
 640         if (lenp)
 641                 *lenp = -FDT_ERR_NOTFOUND;
 642
 643         return NULL;
 644 }
 645
 646 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
 647                               const char *compatible)
 648 {
 649         const void *prop;
 650         int len;
 651
 652         prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
 653         if (!prop)
 654                 return len;
 655
 656         return !fdt_stringlist_contains(prop, len, compatible);
 657 }
 658
 659 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
 660                                   const char *compatible)
 661 {
 662         int offset, err;
 663
 664         FDT_CHECK_HEADER(fdt);
 665
 666         /* FIXME: The algorithm here is pretty horrible: we scan each
 667          * property of a node in fdt_node_check_compatible(), then if
 668          * that didn't find what we want, we scan over them again
 669          * making our way to the next node.  Still it's the easiest to
 670          * implement approach; performance can come later. */
 671         for (offset = fdt_next_node(fdt, startoffset, NULL);
 672              offset >= 0;
 673              offset = fdt_next_node(fdt, offset, NULL)) {
 674                 err = fdt_node_check_compatible(fdt, offset, compatible);
 675                 if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
 676                         return err;
 677                 else if (err == 0)
 678                         return offset;
 679         }
 680
 681         return offset; /* error from fdt_next_node() */
 682 }