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 const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
 208 {
 209         const struct fdt_node_header *nh = _fdt_offset_ptr(fdt, nodeoffset);
 210         int err;
 211
 212         if (((err = fdt_check_header(fdt)) != 0)
 213             || ((err = _fdt_check_node_offset(fdt, nodeoffset)) < 0))
 214                         goto fail;
 215
 216         if (len)
 217                 *len = strlen(nh->name);
 218
 219         return nh->name;
 220
 221  fail:
 222         if (len)
 223                 *len = err;
 224         return NULL;
 225 }
 226
 227 int fdt_first_property_offset(const void *fdt, int nodeoffset)
 228 {
 229         int offset;
 230
 231         if ((offset = _fdt_check_node_offset(fdt, nodeoffset)) < 0)
 232                 return offset;
 233
 234         return _nextprop(fdt, offset);
 235 }
 236
 237 int fdt_next_property_offset(const void *fdt, int offset)
 238 {
 239         if ((offset = _fdt_check_prop_offset(fdt, offset)) < 0)
 240                 return offset;
 241
 242         return _nextprop(fdt, offset);
 243 }
 244
 245 const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
 246                                                       int offset,
 247                                                       int *lenp)
 248 {
 249         int err;
 250         const struct fdt_property *prop;
 251
 252         if ((err = _fdt_check_prop_offset(fdt, offset)) < 0) {
 253                 if (lenp)
 254                         *lenp = err;
 255                 return NULL;
 256         }
 257
 258         prop = _fdt_offset_ptr(fdt, offset);
 259
 260         if (lenp)
 261                 *lenp = fdt32_to_cpu(prop->len);
 262
 263         return prop;
 264 }
 265
 266 const struct fdt_property *fdt_get_property_namelen(const void *fdt,
 267                                                     int offset,
 268                                                     const char *name,
 269                                                     int namelen, int *lenp)
 270 {
 271         for (offset = fdt_first_property_offset(fdt, offset);
 272              (offset >= 0);
 273              (offset = fdt_next_property_offset(fdt, offset))) {
 274                 const struct fdt_property *prop;
 275
 276                 if (!(prop = fdt_get_property_by_offset(fdt, offset, lenp))) {
 277                         offset = -FDT_ERR_INTERNAL;
 278                         break;
 279                 }
 280                 if (_fdt_string_eq(fdt, fdt32_to_cpu(prop->nameoff),
 281                                    name, namelen))
 282                         return prop;
 283         }
 284
 285         if (lenp)
 286                 *lenp = offset;
 287         return NULL;
 288 }
 289
 290 const struct fdt_property *fdt_get_property(const void *fdt,
 291                                             int nodeoffset,
 292                                             const char *name, int *lenp)
 293 {
 294         return fdt_get_property_namelen(fdt, nodeoffset, name,
 295                                         strlen(name), lenp);
 296 }
 297
 298 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
 299                                 const char *name, int namelen, int *lenp)
 300 {
 301         const struct fdt_property *prop;
 302
 303         prop = fdt_get_property_namelen(fdt, nodeoffset, name, namelen, lenp);
 304         if (!prop)
 305                 return NULL;
 306
 307         return prop->data;
 308 }
 309
 310 const void *fdt_getprop_by_offset(const void *fdt, int offset,
 311                                   const char **namep, int *lenp)
 312 {
 313         const struct fdt_property *prop;
 314
 315         prop = fdt_get_property_by_offset(fdt, offset, lenp);
 316         if (!prop)
 317                 return NULL;
 318         if (namep)
 319                 *namep = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
 320         return prop->data;
 321 }
 322
 323 const void *fdt_getprop(const void *fdt, int nodeoffset,
 324                         const char *name, int *lenp)
 325 {
 326         return fdt_getprop_namelen(fdt, nodeoffset, name, strlen(name), lenp);
 327 }
 328
 329 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
 330 {
 331         const fdt32_t *php;
 332         int len;
 333
 334         /* FIXME: This is a bit sub-optimal, since we potentially scan
 335          * over all the properties twice. */
 336         php = fdt_getprop(fdt, nodeoffset, "phandle", &len);
 337         if (!php || (len != sizeof(*php))) {
 338                 php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
 339                 if (!php || (len != sizeof(*php)))
 340                         return 0;
 341         }
 342
 343         return fdt32_to_cpu(*php);
 344 }
 345
 346 const char *fdt_get_alias_namelen(const void *fdt,
 347                                   const char *name, int namelen)
 348 {
 349         int aliasoffset;
 350
 351         aliasoffset = fdt_path_offset(fdt, "/aliases");
 352         if (aliasoffset < 0)
 353                 return NULL;
 354
 355         return fdt_getprop_namelen(fdt, aliasoffset, name, namelen, NULL);
 356 }
 357
 358 const char *fdt_get_alias(const void *fdt, const char *name)
 359 {
 360         return fdt_get_alias_namelen(fdt, name, strlen(name));
 361 }
 362
 363 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
 364 {
 365         int pdepth = 0, p = 0;
 366         int offset, depth, namelen;
 367         const char *name;
 368
 369         FDT_CHECK_HEADER(fdt);
 370
 371         if (buflen < 2)
 372                 return -FDT_ERR_NOSPACE;
 373
 374         for (offset = 0, depth = 0;
 375              (offset >= 0) && (offset <= nodeoffset);
 376              offset = fdt_next_node(fdt, offset, &depth)) {
 377                 while (pdepth > depth) {
 378                         do {
 379                                 p--;
 380                         } while (buf[p-1] != '/');
 381                         pdepth--;
 382                 }
 383
 384                 if (pdepth >= depth) {
 385                         name = fdt_get_name(fdt, offset, &namelen);
 386                         if (!name)
 387                                 return namelen;
 388                         if ((p + namelen + 1) <= buflen) {
 389                                 memcpy(buf + p, name, namelen);
 390                                 p += namelen;
 391                                 buf[p++] = '/';
 392                                 pdepth++;
 393                         }
 394                 }
 395
 396                 if (offset == nodeoffset) {
 397                         if (pdepth < (depth + 1))
 398                                 return -FDT_ERR_NOSPACE;
 399
 400                         if (p > 1) /* special case so that root path is "/", not "" */
 401                                 p--;
 402                         buf[p] = '\0';
 403                         return 0;
 404                 }
 405         }
 406
 407         if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
 408                 return -FDT_ERR_BADOFFSET;
 409         else if (offset == -FDT_ERR_BADOFFSET)
 410                 return -FDT_ERR_BADSTRUCTURE;
 411
 412         return offset; /* error from fdt_next_node() */
 413 }
 414
 415 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
 416                                  int supernodedepth, int *nodedepth)
 417 {
 418         int offset, depth;
 419         int supernodeoffset = -FDT_ERR_INTERNAL;
 420
 421         FDT_CHECK_HEADER(fdt);
 422
 423         if (supernodedepth < 0)
 424                 return -FDT_ERR_NOTFOUND;
 425
 426         for (offset = 0, depth = 0;
 427              (offset >= 0) && (offset <= nodeoffset);
 428              offset = fdt_next_node(fdt, offset, &depth)) {
 429                 if (depth == supernodedepth)
 430                         supernodeoffset = offset;
 431
 432                 if (offset == nodeoffset) {
 433                         if (nodedepth)
 434                                 *nodedepth = depth;
 435
 436                         if (supernodedepth > depth)
 437                                 return -FDT_ERR_NOTFOUND;
 438                         else
 439                                 return supernodeoffset;
 440                 }
 441         }
 442
 443         if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
 444                 return -FDT_ERR_BADOFFSET;
 445         else if (offset == -FDT_ERR_BADOFFSET)
 446                 return -FDT_ERR_BADSTRUCTURE;
 447
 448         return offset; /* error from fdt_next_node() */
 449 }
 450
 451 int fdt_node_depth(const void *fdt, int nodeoffset)
 452 {
 453         int nodedepth;
 454         int err;
 455
 456         err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth);
 457         if (err)
 458                 return (err < 0) ? err : -FDT_ERR_INTERNAL;
 459         return nodedepth;
 460 }
 461
 462 int fdt_parent_offset(const void *fdt, int nodeoffset)
 463 {
 464         int nodedepth = fdt_node_depth(fdt, nodeoffset);
 465
 466         if (nodedepth < 0)
 467                 return nodedepth;
 468         return fdt_supernode_atdepth_offset(fdt, nodeoffset,
 469                                             nodedepth - 1, NULL);
 470 }
 471
 472 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
 473                                   const char *propname,
 474                                   const void *propval, int proplen)
 475 {
 476         int offset;
 477         const void *val;
 478         int len;
 479
 480         FDT_CHECK_HEADER(fdt);
 481
 482         /* FIXME: The algorithm here is pretty horrible: we scan each
 483          * property of a node in fdt_getprop(), then if that didn't
 484          * find what we want, we scan over them again making our way
 485          * to the next node.  Still it's the easiest to implement
 486          * approach; performance can come later. */
 487         for (offset = fdt_next_node(fdt, startoffset, NULL);
 488              offset >= 0;
 489              offset = fdt_next_node(fdt, offset, NULL)) {
 490                 val = fdt_getprop(fdt, offset, propname, &len);
 491                 if (val && (len == proplen)
 492                     && (memcmp(val, propval, len) == 0))
 493                         return offset;
 494         }
 495
 496         return offset; /* error from fdt_next_node() */
 497 }
 498
 499 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
 500 {
 501         int offset;
 502
 503         if ((phandle == 0) || (phandle == -1))
 504                 return -FDT_ERR_BADPHANDLE;
 505
 506         FDT_CHECK_HEADER(fdt);
 507
 508         /* FIXME: The algorithm here is pretty horrible: we
 509          * potentially scan each property of a node in
 510          * fdt_get_phandle(), then if that didn't find what
 511          * we want, we scan over them again making our way to the next
 512          * node.  Still it's the easiest to implement approach;
 513          * performance can come later. */
 514         for (offset = fdt_next_node(fdt, -1, NULL);
 515              offset >= 0;
 516              offset = fdt_next_node(fdt, offset, NULL)) {
 517                 if (fdt_get_phandle(fdt, offset) == phandle)
 518                         return offset;
 519         }
 520
 521         return offset; /* error from fdt_next_node() */
 522 }
 523
 524 int fdt_stringlist_contains(const char *strlist, int listlen, const char *str)
 525 {
 526         int len = strlen(str);
 527         const char *p;
 528
 529         while (listlen >= len) {
 530                 if (memcmp(str, strlist, len+1) == 0)
 531                         return 1;
 532                 p = memchr(strlist, '\0', listlen);
 533                 if (!p)
 534                         return 0; /* malformed strlist.. */
 535                 listlen -= (p-strlist) + 1;
 536                 strlist = p + 1;
 537         }
 538         return 0;
 539 }
 540
 541 int fdt_count_strings(const void *fdt, int node, const char *property)
 542 {
 543         int length, i, count = 0;
 544         const char *list;
 545
 546         list = fdt_getprop(fdt, node, property, &length);
 547         if (!list)
 548                 return length;
 549
 550         for (i = 0; i < length; i++) {
 551                 int len = strlen(list);
 552
 553                 list += len + 1;
 554                 i += len;
 555                 count++;
 556         }
 557
 558         return count;
 559 }
 560
 561 int fdt_find_string(const void *fdt, int node, const char *property,
 562                     const char *string)
 563 {
 564         const char *list, *end;
 565         int len, index = 0;
 566
 567         list = fdt_getprop(fdt, node, property, &len);
 568         if (!list)
 569                 return len;
 570
 571         end = list + len;
 572         len = strlen(string);
 573
 574         while (list < end) {
 575                 int l = strlen(list);
 576
 577                 if (l == len && memcmp(list, string, len) == 0)
 578                         return index;
 579
 580                 list += l + 1;
 581                 index++;
 582         }
 583
 584         return -FDT_ERR_NOTFOUND;
 585 }
 586
 587 int fdt_get_string_index(const void *fdt, int node, const char *property,
 588                          int index, const char **output)
 589 {
 590         const char *list;
 591         int length, i;
 592
 593         list = fdt_getprop(fdt, node, property, &length);
 594
 595         for (i = 0; i < length; i++) {
 596                 int len = strlen(list);
 597
 598                 if (index == 0) {
 599                         *output = list;
 600                         return 0;
 601                 }
 602
 603                 list += len + 1;
 604                 i += len;
 605                 index--;
 606         }
 607
 608         return -FDT_ERR_NOTFOUND;
 609 }
 610
 611 int fdt_get_string(const void *fdt, int node, const char *property,
 612                    const char **output)
 613 {
 614         return fdt_get_string_index(fdt, node, property, 0, output);
 615 }
 616
 617 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
 618                               const char *compatible)
 619 {
 620         const void *prop;
 621         int len;
 622
 623         prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
 624         if (!prop)
 625                 return len;
 626
 627         return !fdt_stringlist_contains(prop, len, compatible);
 628 }
 629
 630 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
 631                                   const char *compatible)
 632 {
 633         int offset, err;
 634
 635         FDT_CHECK_HEADER(fdt);
 636
 637         /* FIXME: The algorithm here is pretty horrible: we scan each
 638          * property of a node in fdt_node_check_compatible(), then if
 639          * that didn't find what we want, we scan over them again
 640          * making our way to the next node.  Still it's the easiest to
 641          * implement approach; performance can come later. */
 642         for (offset = fdt_next_node(fdt, startoffset, NULL);
 643              offset >= 0;
 644              offset = fdt_next_node(fdt, offset, NULL)) {
 645                 err = fdt_node_check_compatible(fdt, offset, compatible);
 646                 if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
 647                         return err;
 648                 else if (err == 0)
 649                         return offset;
 650         }
 651
 652         return offset; /* error from fdt_next_node() */
 653 }